Re: [PATCH 1/2] staging: gdm7240: adding LTE USB driver

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On Mon, Jul 22, 2013 at 03:56:31PM +0900, Won Kang wrote:
> GCT Semiconductor GDM7240 is 4G LTE chip.
> This driver supports GCT reference platform as a USB device.
> 

Really I don't think this driver needs to go through staging.  I
reviewed it a bit and there is plenty to comment on, but it's not
that far off in terms of style.  The networking people will have a
lot more comments on this.

By the end, I really hated the custom endian macros and the funny
jumbled function endings and the bad placement of the curly braces
on list_for_each() loops.  Also all the ifdefs.  I hated the ifdefs.
I didn't totally finish because I figured it would be easier to
review once the obvious small things were fixed.  But in the end
this driver is not bad.  I say fix the things I mentioned and then
see what the people on netdev@xxxxxxxxxxxxxxx have to say.  That's
going to be the stricter review.

When I reviewed it, I only commented on the first example of a
mistake.  Go through and fix all similar places.

regards,
dan carpenter

> @@ -0,0 +1,9 @@
> +#
> +# GCT GDM724x LTE driver configuration
> +#
> +
> +config LTE_GDM724X
> +	tristate "GCT GDM724x LTE support"
> +	depends on NET && USB
> +	help
> +	  Support for the GCT GDM724x LTE chip

Not very descriptive.

> diff --git a/drivers/staging/gdm724x/Makefile b/drivers/staging/gdm724x/Makefile
> new file mode 100644
> index 0000000..4ee5426
> --- /dev/null
> +++ b/drivers/staging/gdm724x/Makefile
> @@ -0,0 +1,9 @@
> +obj-$(CONFIG_LTE_GDM724X) := gdmulte.o
> +gdmulte-y += gdm_lte.o netlink_k.o
> +gdmulte-y += gdm_usb.o gdm_endian.o
> +
> +obj-$(CONFIG_LTE_GDM724X) += gdmtty.o
> +gdmtty-y := gdm_tty.o gdm_mux.o
> +
> +EXTRA_CFLAGS += -DLTE_USB_PM

Just delete this and the related ifdefs.

> --- /dev/null
> +++ b/drivers/staging/gdm724x/gdm_endian.c

The endian stuff should not test for host endian and the functions
need to be renamed.

> +u16 H2D(struct gdm_endian *ed, u16 x)
> +{
> +	if (ed->dev_ed == ed->host_ed)
> +		return x;
> +
> +	return Endian16_Swap(x);
> +}

This should be:
u16 gdm_dev16_to_cpu(struct gdm_endian *ed, u16 val)
{
	if (ed->dev_ed == BIG_ENDIAN)
		return be16_to_cpu((__be16)val);
	else
		return le16_to_cpu((__be16)val);
}

etc.

> +#define gdm_dev_endian(n) (\
> +	n->phy_dev->get_endian(n->phy_dev->priv_dev))
> +
> +#define gdm_lte_hci_send(n, d, l) (\
> +	n->phy_dev->send_hci_func(n->phy_dev->priv_dev, d, l, NULL, NULL))
> +
> +#define gdm_lte_sdu_send(n, d, l, c, b, i, t) (\
> +	n->phy_dev->send_sdu_func(n->phy_dev->priv_dev, d, l, n->pdn_table.dft_eps_id, 0, c, b, i, t))
> +
> +#define gdm_lte_rcv_with_cb(n, c, b, e) (\
> +	n->rcv_func(n->priv_dev, c, b, e))
> +

These macros are nasty and only used once.  Delete them.

> +static void tx_complete(void *arg)
> +{
> +	struct nic *nic = arg;
> +
> +	if (nic == NULL) {

This can't happen.  Don't test for stuff that can't happen.

> +		printk(KERN_ERR "glte: tx complete - invalid nic\n");
> +		return;
> +	}
> +
> +	if (netif_queue_stopped(nic->netdev))
> +		netif_wake_queue(nic->netdev);
> +}
> +
> +static int gdm_lte_rx(struct sk_buff *skb, struct nic *nic, int nic_type)
> +{
> +	int ret;
> +
> +	if (nic == NULL) {
> +		printk(KERN_ERR "glte: rx - invalid nic\n");
> +		return -1;

1) Don't test for things which can't happen.
2) Use pr_err()
3) Don't return -1 ever (almost).  You just use the english error
   codes.  In this case -1 is -EPERM.

> +	}
> +
> +	ret = netif_rx_ni(skb);
> +	if (ret == NET_RX_DROP) {
> +		printk(KERN_ERR "glte: rx - dropped\n");

Don't print KERN_ERR for dropped packets.

> +		nic->stats.rx_dropped++;
> +	} else {
> +		nic->stats.rx_packets++;
> +		nic->stats.rx_bytes += skb->len + ETH_HLEN;
> +	}
> +
> +	return 0;
> +}
> +
> +#ifdef EMULATE_ARP

This is always defined.  Delete the #ifdef check.

> +int gdm_lte_emulate_arp(struct sk_buff *skb_in, u32 nic_type)
> +{
> +	struct nic *nic = netdev_priv(skb_in->dev);
> +	struct sk_buff *skb_out;
> +	struct ethhdr eth;
> +	struct vlan_ethhdr vlan_eth;
> +	struct arphdr *arp_in;
> +	struct arphdr *arp_out;
> +	struct arpdata {
> +		u8 ar_sha[ETH_ALEN];
> +		u8 ar_sip[4];
> +		u8 ar_tha[ETH_ALEN];
> +		u8 ar_tip[4];
> +	};
> +	struct arpdata *arp_data_in;
> +	struct arpdata *arp_data_out;
> +	u8 arp_temp[60];
> +	void *mac_header_data;
> +	u32 mac_header_len;
> +
> +	/* Format the mac header so that it can be put to skb */
> +	if (ntohs(((struct ethhdr *)skb_in->data)->h_proto) == ETH_P_8021Q) {
> +		memcpy(&vlan_eth, skb_in->data, sizeof(struct vlan_ethhdr));
> +		mac_header_data = &vlan_eth;
> +		mac_header_len = VLAN_ETH_HLEN;
> +	} else {
> +		memcpy(&eth, skb_in->data, sizeof(struct ethhdr));
> +		mac_header_data = ð
> +		mac_header_len = ETH_HLEN;
> +	}

I'm not a networking person but if feels like we should check that
skb->len is large enough.  Otherwise we read past the end which is
a potential info leak and we might not reserve enough memory for the
reply which is memory corruption.

> +
> +	/* Get the pointer of the original request */
> +	arp_in = (struct arphdr *)(skb_in->data + mac_header_len);
> +	arp_data_in = (struct arpdata *)(skb_in->data + mac_header_len + sizeof(struct arphdr));
> +
> +	/* Get the pointer of the outgoing response */
> +	arp_out = (struct arphdr *)arp_temp;
> +	arp_data_out = (struct arpdata *)(arp_temp + sizeof(struct arphdr));
> +
> +	/* Copy the arp header */
> +	memcpy(arp_out, arp_in, sizeof(struct arphdr));
> +	arp_out->ar_op = htons(ARPOP_REPLY);
> +
> +	/* Copy the arp payload: based on 2 bytes of mac and fill the IP */
> +	arp_data_out->ar_sha[0] = arp_data_in->ar_sha[0];
> +	arp_data_out->ar_sha[1] = arp_data_in->ar_sha[1];
> +	memcpy(&arp_data_out->ar_sha[2], &arp_data_in->ar_tip[0], 4);
> +	memcpy(&arp_data_out->ar_sip[0], &arp_data_in->ar_tip[0], 4);
> +	memcpy(&arp_data_out->ar_tha[0], &arp_data_in->ar_sha[0], 6);
> +	memcpy(&arp_data_out->ar_tip[0], &arp_data_in->ar_sip[0], 4);
> +
> +	/* Fill the destination mac with source mac of the received packet */
> +	memcpy(mac_header_data, mac_header_data + ETH_ALEN, ETH_ALEN);
> +	/* Fill the source mac with nic's source mac */
> +	memcpy(mac_header_data + ETH_ALEN, nic->src_mac_addr, ETH_ALEN);
> +
> +	/* Alloc skb and reserve align */
> +	skb_out = dev_alloc_skb(skb_in->len);
> +	if (!skb_out)
> +		return -1;
> +	skb_reserve(skb_out, NET_IP_ALIGN);
> +
> +	memcpy(skb_put(skb_out, mac_header_len), mac_header_data, mac_header_len);
> +	memcpy(skb_put(skb_out, sizeof(struct arphdr)), arp_out, sizeof(struct arphdr));
> +	memcpy(skb_put(skb_out, sizeof(struct arpdata)), arp_data_out, sizeof(struct arpdata));
> +
> +	skb_out->protocol = ((struct ethhdr *)mac_header_data)->h_proto;
> +	skb_out->dev = skb_in->dev;
> +	skb_reset_mac_header(skb_out);
> +	skb_pull(skb_out, ETH_HLEN);
> +
> +	gdm_lte_rx(skb_out, nic, nic_type);
> +
> +	return 0;
> +}
> +#endif
> +
> +#ifdef EMULATE_NDP
> +int icmp6_checksum(struct ipv6hdr *ipv6, u16 *ptr, int len)
> +{
> +	unsigned short *w = ptr;
> +	int sum = 0;
> +	int i;
> +
> +	#pragma pack(1)
> +	union {
> +		struct {
> +			u8 ph_src[16];
> +			u8 ph_dst[16];
> +			u32 ph_len;
> +			u8 ph_zero[3];
> +			u8 ph_nxt;
> +		} ph;
> +		u16 pa[20];
> +	} pseudo_header;
> +	#pragma pack()

Use the __packed macro.

	union {
		struct {
			u8 ph_src[16];
			u8 ph_dst[16];
			u32 ph_len;
			u8 ph_zero[3];
			u8 ph_nxt;
		} ph;
		u16 pa[20];
	} pseudo_header __packed;



> +
> +	memset(&pseudo_header, 0, sizeof(pseudo_header));
> +	memcpy(&pseudo_header.ph.ph_src, &ipv6->saddr.in6_u.u6_addr8, 16);
> +	memcpy(&pseudo_header.ph.ph_dst, &ipv6->daddr.in6_u.u6_addr8, 16);
> +	pseudo_header.ph.ph_len = ipv6->payload_len;
> +	pseudo_header.ph.ph_nxt = ipv6->nexthdr;
> +
> +	w = (u16 *)&pseudo_header;
> +	for (i = 0; i < sizeof(pseudo_header.pa) / sizeof(pseudo_header.pa[0]); i++)
> +		sum += pseudo_header.pa[i];
> +
> +	w = ptr;
> +	while (len > 1) {
> +		sum += *w++;
> +		len -= 2;
> +	}
> +
> +	sum = (sum >> 16) + (sum & 0xFFFF);
> +	sum += (sum >> 16);
> +	sum = ~sum & 0xffff;
> +
> +	return sum;
> +}
> +
> +int gdm_lte_emulate_ndp(struct sk_buff *skb_in, u32 nic_type)
> +{
> +	struct nic *nic = netdev_priv(skb_in->dev);
> +	struct sk_buff *skb_out;
> +	struct ethhdr eth;
> +	struct vlan_ethhdr vlan_eth;
> +	struct neighbour_advertisement {
> +		u8 target_address[16];
> +		u8 type;
> +		u8 length;
> +		u8 link_layer_address[6];
> +	};
> +	struct neighbour_advertisement na;
> +	struct neighbour_solicitation {
> +		u8 target_address[16];
> +	};
> +	struct neighbour_solicitation *ns;
> +	struct ipv6hdr *ipv6_in;
> +	struct ipv6hdr ipv6_out;
> +	struct icmp6hdr *icmp6_in;
> +	struct icmp6hdr icmp6_out;
> +
> +	void *mac_header_data;
> +	u32 mac_header_len;
> +
> +	/* Format the mac header so that it can be put to skb */
> +	if (ntohs(((struct ethhdr *)skb_in->data)->h_proto) == ETH_P_8021Q) {
> +		memcpy(&vlan_eth, skb_in->data, sizeof(struct vlan_ethhdr));
> +		if (ntohs(vlan_eth.h_vlan_encapsulated_proto) != ETH_P_IPV6)
> +			return -1;
> +		mac_header_data = &vlan_eth;
> +		mac_header_len = VLAN_ETH_HLEN;
> +	} else {
> +		memcpy(&eth, skb_in->data, sizeof(struct ethhdr));
> +		if (ntohs(eth.h_proto) != ETH_P_IPV6)
> +			return -1;
> +		mac_header_data = &eth;
> +		mac_header_len = ETH_HLEN;
> +	}
> +
> +
> +	/* Check if this is IPv6 ICMP packet */
> +	ipv6_in = (struct ipv6hdr *)(skb_in->data + mac_header_len);
> +	if (ipv6_in->version != 6 || ipv6_in->nexthdr != IPPROTO_ICMPV6)
> +		return -1;
> +
> +	/* Check if this is NDP packet */
> +	icmp6_in = (struct icmp6hdr *)(skb_in->data + mac_header_len + sizeof(struct ipv6hdr));
> +	if (icmp6_in->icmp6_type == NDISC_ROUTER_SOLICITATION) { /* Check RS */
> +		return -1;
> +	} else if (icmp6_in->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION) { /* Check NS */
> +		u8 icmp_na[sizeof(struct icmp6hdr) + sizeof(struct neighbour_advertisement)];
> +		u8 zero_addr8[16] = {0,};
> +
> +		if (memcmp(ipv6_in->saddr.in6_u.u6_addr8, zero_addr8, 16) == 0)
> +			/* Duplicate Address Detection: Source IP is all zero */
> +			return 0;
> +
> +		icmp6_out.icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT;
> +		icmp6_out.icmp6_code = 0;
> +		icmp6_out.icmp6_cksum = 0;
> +		icmp6_out.icmp6_dataun.un_data32[0] = htonl(0x60000000); /* R=0, S=1, O=1 */
> +
> +		ns = (struct neighbour_solicitation *)(skb_in->data + mac_header_len + sizeof(struct ipv6hdr) + sizeof(struct icmp6hdr));
> +		memcpy(&na.target_address, ns->target_address, 16);
> +		na.type = 0x02;
> +		na.length = 1;
> +		na.link_layer_address[0] = 0x00;
> +		na.link_layer_address[1] = 0x0a;
> +		na.link_layer_address[2] = 0x3b;
> +		na.link_layer_address[3] = 0xaf;
> +		na.link_layer_address[4] = 0x63;
> +		na.link_layer_address[5] = 0xc7;
> +
> +		memcpy(&ipv6_out, ipv6_in, sizeof(struct ipv6hdr));
> +		memcpy(ipv6_out.saddr.in6_u.u6_addr8, &na.target_address, 16);
> +		memcpy(ipv6_out.daddr.in6_u.u6_addr8, ipv6_in->saddr.in6_u.u6_addr8, 16);
> +		ipv6_out.payload_len = htons(sizeof(struct icmp6hdr) + sizeof(struct neighbour_advertisement));
> +
> +		memcpy(icmp_na, &icmp6_out, sizeof(struct icmp6hdr));
> +		memcpy(icmp_na + sizeof(struct icmp6hdr), &na, sizeof(struct neighbour_advertisement));
> +
> +		icmp6_out.icmp6_cksum = icmp6_checksum(&ipv6_out, (u16 *)icmp_na, sizeof(icmp_na));
> +	} else {
> +		return -1;
> +	}
> +
> +	/* Fill the destination mac with source mac of the received packet */
> +	memcpy(mac_header_data, mac_header_data + ETH_ALEN, ETH_ALEN);
> +	/* Fill the source mac with nic's source mac */
> +	memcpy(mac_header_data + ETH_ALEN, nic->src_mac_addr, ETH_ALEN);
> +
> +	/* Alloc skb and reserve align */
> +	skb_out = dev_alloc_skb(skb_in->len);
> +	if (!skb_out)
> +		return -1;
> +	skb_reserve(skb_out, NET_IP_ALIGN);
> +
> +	memcpy(skb_put(skb_out, mac_header_len), mac_header_data, mac_header_len);
> +	memcpy(skb_put(skb_out, sizeof(struct ipv6hdr)), &ipv6_out, sizeof(struct ipv6hdr));
> +	memcpy(skb_put(skb_out, sizeof(struct icmp6hdr)), &icmp6_out, sizeof(struct icmp6hdr));
> +	memcpy(skb_put(skb_out, sizeof(struct neighbour_advertisement)), &na, sizeof(struct neighbour_advertisement));
> +
> +	skb_out->protocol = ((struct ethhdr *)mac_header_data)->h_proto;
> +	skb_out->dev = skb_in->dev;
> +	skb_reset_mac_header(skb_out);
> +	skb_pull(skb_out, ETH_HLEN);
> +
> +	gdm_lte_rx(skb_out, nic, nic_type);
> +
> +	return 0;
> +}
> +#endif
> +
> +static s32 gdm_lte_tx_nic_type(struct net_device *dev, struct sk_buff *skb)
> +{
> +	struct nic *nic = netdev_priv(dev);
> +	struct ethhdr *eth;
> +	struct vlan_ethhdr *vlan_eth;
> +	struct iphdr *ip;
> +	struct ipv6hdr *ipv6;
> +	int mac_proto;
> +	void *network_data;
> +	u32 nic_type = 0;
> +
> +	if (nic == NULL)
> +		return -1;
> +
> +	if (nic->nic_id >= MAX_NIC_TYPE)
> +		return -1;
> +
> +	/* NIC TYPE is based on the nic_id of this net_device */
> +	nic_type = 0x00000010 | nic->nic_id;
> +
> +	/* Get ethernet protocol */
> +	eth = (struct ethhdr *)skb->data;
> +	if (ntohs(eth->h_proto) == ETH_P_8021Q) {
> +		vlan_eth = (struct vlan_ethhdr *)skb->data;
> +		mac_proto = ntohs(vlan_eth->h_vlan_encapsulated_proto);
> +		network_data = skb->data + VLAN_ETH_HLEN;
> +		nic_type |= NIC_TYPE_F_VLAN;
> +	} else {
> +		mac_proto = ntohs(eth->h_proto);
> +		network_data = skb->data + ETH_HLEN;
> +	}
> +
> +	/* Process packet for nic type */
> +	switch (mac_proto) {
> +	case ETH_P_ARP:
> +		nic_type |= NIC_TYPE_ARP;
> +		break;
> +	case ETH_P_IP:
> +		nic_type |= NIC_TYPE_F_IPV4;
> +		ip = (struct iphdr *)network_data;
> +
> +		/* Check DHCPv4 */
> +		if (ip->protocol == IPPROTO_UDP) {
> +			struct udphdr *udp = (struct udphdr *)(network_data + sizeof(struct iphdr));
> +			if (ntohs(udp->dest) == 67 || ntohs(udp->dest) == 68)
> +				nic_type |= NIC_TYPE_F_DHCP;
> +		}
> +		break;
> +	case ETH_P_IPV6:
> +		nic_type |= NIC_TYPE_F_IPV6;
> +		ipv6 = (struct ipv6hdr *)network_data;
> +
> +		if (ipv6->nexthdr == IPPROTO_ICMPV6) /* Check NDP request */ {
> +			struct icmp6hdr *icmp6 = (struct icmp6hdr *)(network_data + sizeof(struct ipv6hdr));
> +			if (/*icmp6->icmp6_type == NDISC_ROUTER_SOLICITATION || */
> +				icmp6->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION)
> +				nic_type |= NIC_TYPE_ICMPV6;
> +		} else if (ipv6->nexthdr == IPPROTO_UDP) /* Check DHCPv6 */ {
> +			struct udphdr *udp = (struct udphdr *)(network_data + sizeof(struct ipv6hdr));
> +			if (ntohs(udp->dest) == 546 || ntohs(udp->dest) == 547)
> +				nic_type |= NIC_TYPE_F_DHCP;
> +		}
> +		break;
> +	default:
> +		return -1;
> +		break;
> +	}
> +
> +	return nic_type;
> +}
> +
> +static int gdm_lte_tx(struct sk_buff *skb, struct net_device *dev)
> +{
> +	struct nic *nic = netdev_priv(dev);
> +	u32 nic_type;
> +	void *data_buf;
> +	int data_len;
> +	int idx;
> +	int ret = 0;
> +
> +	nic_type = gdm_lte_tx_nic_type(dev, skb);
> +	if (nic_type == 0) {
> +		printk(KERN_ERR "glte: tx - invalid nic_type\n");
> +		return -1;
> +	}
> +
> +#ifdef EMULATE_ARP
> +	if (nic_type & NIC_TYPE_ARP) {
> +		if (gdm_lte_emulate_arp(skb, nic_type) == 0) {
> +			dev_kfree_skb(skb);
> +			return 0;
> +		}
> +	}
> +#endif
> +
> +#ifdef EMULATE_NDP
> +	if (nic_type & NIC_TYPE_ICMPV6) {
> +		if (gdm_lte_emulate_ndp(skb, nic_type) == 0) {
> +			dev_kfree_skb(skb);
> +			return 0;
> +		}
> +	}
> +#endif
> +
> +	/*
> +	Need byte shift (that is, remove VLAN tag) if there is one
> +	For the case of ARP, this breaks the offset as vlan_ethhdr+4 is treated as ethhdr
> +	However, it shouldn't be a problem as the reponse starts from arp_hdr and ethhdr
> +	is created by this driver based on the NIC mac
> +	*/
> +	if (nic_type & NIC_TYPE_F_VLAN) {
> +		struct vlan_ethhdr *vlan_eth = (struct vlan_ethhdr *)skb->data;
> +		nic->vlan_id = ntohs(vlan_eth->h_vlan_TCI) & VLAN_VID_MASK;
> +		data_buf = skb->data + (VLAN_ETH_HLEN - ETH_HLEN);
> +		data_len = skb->len - (VLAN_ETH_HLEN - ETH_HLEN);
> +	} else {
> +		nic->vlan_id = 0;
> +		data_buf = skb->data;
> +		data_len = skb->len;
> +	}
> +
> +	/* If it is a ICMPV6 packet, clear all the other bits : for backward compatibilty with the firmware */
> +	if (nic_type & NIC_TYPE_ICMPV6)
> +		nic_type = NIC_TYPE_ICMPV6;
> +
> +	/* If it is not a dhcp packet, clear all the flag bits : original NIC, otherwise the special flag (IPVX | DHCP) */
> +	if (!(nic_type & NIC_TYPE_F_DHCP))
> +		nic_type &= NIC_TYPE_MASK;
> +
> +	sscanf(dev->name, "lte%d", &idx);
> +
> +	ret = gdm_lte_sdu_send(nic,
> +			       data_buf,
> +			       data_len,
> +			       tx_complete,
> +			       nic,
> +			       idx,
> +			       nic_type);
> +
> +	if (ret == TX_NO_BUFFER || ret == TX_NO_SPC) {
> +		netif_stop_queue(dev);
> +		if (ret == TX_NO_BUFFER)
> +			ret = 0;
> +		else
> +			ret = -ENOSPC;
> +	} else if (ret == TX_NO_DEV) {
> +		ret = -ENODEV;
> +	}
> +
> +	/* Updates tx stats */
> +	if (ret) {
> +		printk(KERN_ERR "glte: tx - sending sdu failed\n");

Don't DoS the system by filling /var/log/messages with noise.

> +		nic->stats.tx_dropped++;
> +	} else {
> +		nic->stats.tx_packets++;
> +		nic->stats.tx_bytes += data_len;
> +	}
> +	dev_kfree_skb(skb);
> +
> +	return 0;
> +}
> +
> +static struct net_device_stats *gdm_lte_stats(struct net_device *dev)
> +{
> +	struct nic *nic = netdev_priv(dev);
> +	return &nic->stats;
> +}
> +
> +static void get_network_statics(struct data_t *data, struct net_device *dev)
> +{
> +	struct nic *nic = netdev_priv(dev);
> +	struct phy_dev *pdev = nic->phy_dev;
> +	unsigned char *buf;
> +	struct net_info_t *net_stats;
> +	struct net_info_t *net_stats_requested = (struct net_info_t *)data->buf;
> +	int i;
> +	unsigned long ret;
> +
> +	buf = kmalloc(sizeof(*net_stats), GFP_KERNEL);
> +	if (!buf)
> +		return;
> +
> +	memset(buf, 0, sizeof(*net_stats));
> +
> +	net_stats = (struct net_info_t *)buf;

Don't use "buf", and use kzalloc() instead of kmalloc().  This
function should return a negative value on error.

	struct net_info_t *net_stats;

	net_stats = kzalloc(sizeof(*net_stats), GFP_KERNEL);
	if (!net_stats)
		return -ENOMEM;

	net_stats->nic_index = net_stats_requested->nic_index;

Actually this whole function is part of a custom ioctl and it should
be replaced with normal networking stats function.  Look it up.
Don't make Ben Hutchings have to be the only one who knows how
mii-tool works.  :P

> +	net_stats->nic_index = net_stats_requested->nic_index;
> +
> +	if (net_stats->nic_index > MAX_NIC_TYPE) {
> +		printk(KERN_INFO "glte: stats - invalid nic_index\n");
> +		kfree(buf);
> +		return;
> +	}
> +
> +	if (net_stats->nic_index == MAX_NIC_TYPE) {
> +		for (i = 0; i < MAX_NIC_TYPE; i++) {
> +			nic = netdev_priv(pdev->dev[i]);
> +			net_stats->stats.tx_packets += nic->stats.tx_packets;
> +			net_stats->stats.tx_bytes += nic->stats.tx_bytes;
> +			net_stats->stats.tx_dropped += nic->stats.tx_dropped;
> +			net_stats->stats.rx_packets += nic->stats.rx_packets;
> +			net_stats->stats.rx_bytes += nic->stats.rx_bytes;
> +			net_stats->stats.rx_dropped += nic->stats.rx_dropped;
> +		}
> +	} else {
> +		nic = netdev_priv(pdev->dev[net_stats->nic_index]);
> +		net_stats->stats.tx_packets = nic->stats.tx_packets;
> +		net_stats->stats.tx_bytes = nic->stats.tx_bytes;
> +		net_stats->stats.tx_dropped = nic->stats.tx_dropped;
> +		net_stats->stats.rx_packets = nic->stats.rx_packets;
> +		net_stats->stats.rx_bytes = nic->stats.rx_bytes;
> +		net_stats->stats.rx_dropped = nic->stats.rx_dropped;
> +	}
> +
> +	ret = copy_to_user(data->buf, buf, sizeof(*net_stats));
> +	if (ret)
> +		printk(KERN_INFO "glte: state - failed to copy\n");
> +	kfree(buf);
> +}
> +
> +static int get_ver(u8 *src, u8 *dst)

Use MODULE_VERSION() and delete this part of the ioctl.  Basically
we hate every custom ioctl.  Delete it all.


> +{
> +	u8 tmp_buf[4] = {0,};
> +	int i = 0;
> +
> +	while (1) {
> +		if (dst[i] < '0' || dst[i] > '9')
> +			break;
> +
> +		tmp_buf[i] = dst[i] % 0x30;
> +		i++;
> +	}
> +
> +	if (i == 1)
> +		*src = tmp_buf[0];
> +	else if (i == 2)
> +		*src = (tmp_buf[0] * 10) + tmp_buf[1];
> +	else if (i == 3)
> +		*src = (tmp_buf[0] * 100) + (tmp_buf[1] * 10) + tmp_buf[3];
> +
> +	return i;
> +}
> +
> +static void get_driver_version(struct data_t *data, struct net_device *dev)
> +{
> +	u8 ver[16] = {0,};
> +	u8 drv_ver[4] = {0,};
> +	int i = 0;
> +	int j = 0;
> +	unsigned long ret;
> +
> +	memcpy(ver, DRIVER_VERSION, sizeof(DRIVER_VERSION));
> +
> +	while (i < sizeof(DRIVER_VERSION)) {
> +		if (ver[i] != '.') {
> +			i += get_ver(&drv_ver[j], &ver[i]);
> +			j++;
> +		} else {
> +			i++;
> +		}
> +
> +		if (j == 4)
> +			break;
> +	}
> +
> +	ret = copy_to_user(data->buf, drv_ver, sizeof(drv_ver));
> +	if (ret)
> +		printk(KERN_INFO "glte: state - failed to copy\n");

The error handling here sucks but we're going to delete this anyway.


> +}
> +
> +static void get_dev_endian(struct data_t *data, struct net_device *dev)
> +{
> +	struct nic *nic = netdev_priv(dev);
> +	unsigned long ret;
> +	
> +	ret = copy_to_user(data->buf, gdm_dev_endian(nic), sizeof(struct dev_endian_t));
> +	if (ret)
> +		printk(KERN_INFO "glte: state - failed to copy\n");
> +}
> +
> +static int gdm_lte_ioctl_get_data(struct wm_req_t *req, struct net_device *dev)
> +{
> +	u16 id = req->data_id;
> +
> +	switch (id) {
> +	case GET_NETWORK_STATICS:
> +		get_network_statics(&req->data, dev);
> +		break;
> +	case GET_DRV_VER:
> +		get_driver_version(&req->data, dev);
> +		break;
> +	case GET_ENDIAN_INFO:
> +		get_dev_endian(&req->data, dev);
> +		break;
> +	default:
> +		printk(KERN_ERR "glte: ioctl - unknown type %d\n", id);
> +		break;
> +	}
> +	return 0;
> +}
> +
> +static int gdm_lte_ioctl_set_data(struct wm_req_t *req, struct net_device *dev)
> +{
> +	u16 id = req->data_id;
> +
> +	switch (id) {
> +	case LINK_ON:
> +		netif_carrier_on(dev);
> +		break;
> +	case LINK_OFF:
> +		netif_carrier_off(dev);
> +		break;
> +	}
> +
> +	return 0;
> +}
> +
> +static int gdm_lte_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
> +{
> +	struct wm_req_t *req = (struct wm_req_t *)ifr;
> +
> +	if (cmd != SIOCLTEIOCTL)
> +		return -EOPNOTSUPP;
> +
> +	switch (req->cmd) {
> +	case SIOCG_DATA:
> +	case SIOCS_DATA:
> +		if (req->data_id >= 100)
> +			return -EOPNOTSUPP;
> +		if (req->cmd == SIOCG_DATA)
> +			gdm_lte_ioctl_get_data(req, dev);
> +		else if (req->cmd == SIOCS_DATA)
> +			gdm_lte_ioctl_set_data(req, dev);
> +		break;
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +
> +	return 0;
> +}
> +
> +static int gdm_lte_event_send(struct net_device *dev, char *buf, int len)
> +{
> +	struct nic *nic = netdev_priv(dev);
> +	struct hci_packet *hci = (struct hci_packet *)buf;
> +	int idx;
> +
> +#ifdef DEBUG
> +	printk(KERN_DEBUG "glte: D=>H: 0x%04x(%d) len %d\n",
> +	       D2H(gdm_dev_endian(nic), hci->cmd_evt),
> +	       D2H(gdm_dev_endian(nic), hci->len),
> +	       len);
> +#endif

Delete this.

> +
> +	sscanf(dev->name, "lte%d", &idx);
> +
> +	return netlink_send(lte_event.sock, idx, 0, buf,
> +			    D2H(gdm_dev_endian(nic), hci->len) + HCI_HEADER_SIZE);
> +}
> +
> +static void gdm_lte_event_rcv(struct net_device *dev, u16 type, void *msg, int len)
> +{
> +	struct nic *nic = netdev_priv(dev);
> +
> +#ifdef DEBUG
> +	struct hci_packet *hci = (struct hci_packet *)msg;
> +	printk(KERN_DEBUG, "glte: H=>D: 0x%04x(%d) len %d\n",
> +	       D2H(gdm_dev_endian(nic), hci->cmd_evt),
> +	       D2H(gdm_dev_endian(nic), hci->len),
> +	       len);
> +#endif

Delete.

> +
> +	gdm_lte_hci_send(nic, msg, len);
> +}
> +
> +int gdm_lte_event_init(void)
> +{
> +	if (lte_event.ref_cnt == 0)
> +		lte_event.sock = netlink_init(NETLINK_LTE, gdm_lte_event_rcv);
> +
> +	if (lte_event.sock) {
> +		lte_event.ref_cnt++;
> +		return 0;
> +	}
> +
> +	printk(KERN_ERR "glte: event init failed\n");
> +	return -1;
> +}
> +
> +void gdm_lte_event_exit(void)
> +{
> +	if (lte_event.sock && --lte_event.ref_cnt == 0) {
> +		netlink_exit(lte_event.sock);
> +		lte_event.sock = NULL;
> +	}
> +}
> +
> +static int find_dev_index(u32 nic_type)
> +{
> +	int index;
> +
> +	index = nic_type & 0x0000000f;
> +	if (index > MAX_NIC_TYPE || index < 0)

It can never be negative because we masked away the signed bit.
Also the error handling on this function confuses me a lot.
It feels like it should be "index >= MAX_NIC_TYPE".  Some of the
callers for check that.

> +		index = 0;
> +
> +	return index;
> +}
> +
> +static void gdm_lte_netif_rx(struct net_device *dev, char *buf, int len, int flagged_nic_type)
> +{
> +	u32 nic_type;
> +	struct nic *nic;
> +	struct sk_buff *skb;
> +	struct ethhdr eth;
> +	struct vlan_ethhdr vlan_eth;
> +	void *mac_header_data;
> +	u32 mac_header_len;
> +	char ip_version = 0;
> +
> +	nic_type = flagged_nic_type & NIC_TYPE_MASK;
> +	nic = netdev_priv(dev);
> +	if (nic == NULL) {
> +		printk(KERN_ERR "glte: rx, invalid nic\n");
> +		return;
> +	}

netdev_priv() will never return a NULL here.  Delete this unneeded
noise.


> +	if (flagged_nic_type & NIC_TYPE_F_DHCP) {
> +		/* Change the destination mac address with the one requested the IP */
> +		if (flagged_nic_type & NIC_TYPE_F_IPV4) {
> +			struct dhcp_packet {
> +				u8 op;      /* BOOTREQUEST or BOOTREPLY */
> +				u8 htype;   /* hardware address type. 1 = 10mb ethernet */
> +				u8 hlen;    /* hardware address length */
> +				u8 hops;    /* used by relay agents only */
> +				u32 xid;    /* unique id */
> +				u16 secs;   /* elapsed since client began acquisition/renewal */
> +				u16 flags;  /* only one flag so far: */
> +				#define BROADCAST_FLAG 0x8000 /* "I need broadcast replies" */
> +				u32 ciaddr; /* client IP (if client is in BOUND, RENEW or REBINDING state) */
> +				u32 yiaddr; /* 'your' (client) IP address */
> +				/* IP address of next server to use in bootstrap, returned in DHCPOFFER, DHCPACK by server */
> +				u32 siaddr_nip;
> +				u32 gateway_nip; /* relay agent IP address */
> +				u8 chaddr[16];   /* link-layer client hardware address (MAC) */
> +				u8 sname[64];    /* server host name (ASCIZ) */
> +				u8 file[128];    /* boot file name (ASCIZ) */
> +				u32 cookie;      /* fixed first four option bytes (99,130,83,99 dec) */
> +			} __packed;
> +
> +			#define DHCP_V4_HW_ADDR_OFFSET	(\
> +				sizeof(struct iphdr) + \
> +				sizeof(struct udphdr) + \
> +				offsetof(struct dhcp_packet, chaddr))
> +			#define DHCP_V4_IP_ADDR_OFFSET (\
> +				sizeof(struct iphdr) + \
> +				sizeof(struct udphdr) + \
> +				offsetof(struct dhcp_packet, yiaddr))

These defines are ugly.  The second one isn't even used.  Just say:

	void *addr;

	addr = buf + sizeof(struct iphdr) + sizeof(struct udphdr) +
		offsetof(struct dhcp_packet, chaddr);

	memcpy(nic->dest_mac_addr, addr, ETH_ALEN);


> +
> +			memcpy(nic->dest_mac_addr, buf + DHCP_V4_HW_ADDR_OFFSET, 6);
> +		} else if (flagged_nic_type & NIC_TYPE_F_IPV6) {
> +			printk(KERN_INFO "glte: DHCPv6 not supported yet\n");
> +		}
> +	}
> +
> +	if (nic->vlan_id > 0) {
> +		mac_header_data = (void *)&vlan_eth;
> +		mac_header_len = VLAN_ETH_HLEN;
> +	} else {
> +		mac_header_data = (void *)&eth;
> +		mac_header_len = ETH_HLEN;
> +	}
> +
> +	/* Format the data so that it can be put to skb */
> +	memcpy(mac_header_data, nic->dest_mac_addr, ETH_ALEN);
> +	memcpy(mac_header_data + ETH_ALEN, nic->src_mac_addr, ETH_ALEN);
> +
> +	vlan_eth.h_vlan_TCI = htons(nic->vlan_id);
> +	vlan_eth.h_vlan_proto = htons(ETH_P_8021Q);
> +
> +	if (nic_type == NIC_TYPE_ARP) {
> +		/* Should be response: Only happens because there was a request from the host */
> +		eth.h_proto = htons(ETH_P_ARP);
> +		vlan_eth.h_vlan_encapsulated_proto = htons(ETH_P_ARP);
> +	} else {
> +		ip_version = buf[0] >> 4;
> +		if (ip_version == IP_VERSION_4) {
> +			eth.h_proto = htons(ETH_P_IP);
> +			vlan_eth.h_vlan_encapsulated_proto = htons(ETH_P_IP);
> +		} else if (ip_version == IP_VERSION_6) {
> +			eth.h_proto = htons(ETH_P_IPV6);
> +			vlan_eth.h_vlan_encapsulated_proto = htons(ETH_P_IPV6);
> +		} else {
> +			printk(KERN_ERR "glte: Unknown IP version %d\n", ip_version);
> +			return;
> +		}
> +	}
> +
> +	/* Alloc skb and reserve align */
> +	skb = dev_alloc_skb(len + mac_header_len + NET_IP_ALIGN);
> +	if (!skb)
> +		return;
> +	skb_reserve(skb, NET_IP_ALIGN);
> +
> +	memcpy(skb_put(skb, mac_header_len), mac_header_data, mac_header_len);
> +	memcpy(skb_put(skb, len), buf, len);
> +
> +	skb->protocol = ((struct ethhdr *)mac_header_data)->h_proto;
> +	skb->dev = dev;
> +	skb_reset_mac_header(skb);
> +	skb_pull(skb, ETH_HLEN);
> +
> +	gdm_lte_rx(skb, nic, nic_type);
> +}
> +
> +static void gdm_lte_multi_sdu_pkt(struct phy_dev *phy_dev, char *buf, int len)
> +{
> +	struct net_device *dev;
> +	struct multi_sdu *multi_sdu = (struct multi_sdu *)buf;
> +	struct sdu *sdu = NULL;
> +	u8 *data = (u8 *)multi_sdu->data;
> +	u16 i = 0;
> +	u16 num_packet;
> +	u16 hci_len;
> +	u16 cmd_evt;
> +	u32 nic_type;
> +	int index;
> +
> +	hci_len = D2H(phy_dev->get_endian(phy_dev->priv_dev), multi_sdu->len);
> +	num_packet = D2H(phy_dev->get_endian(phy_dev->priv_dev), multi_sdu->num_packet);
> +
> +#ifdef DEBUG
> +	printk(KERN_DEBUG "glte: rx sdu len %d, num_packet %d\n",
> +	       multi_sdu->len, multi_sdu->num_packet);
> +#endif
> +
> +	for (i = 0; i < num_packet; i++) {
> +		sdu = (struct sdu *)data;
> +
> +		cmd_evt = D2H(phy_dev->get_endian(phy_dev->priv_dev), sdu->cmd_evt);
> +		hci_len = D2H(phy_dev->get_endian(phy_dev->priv_dev), sdu->len);
> +		nic_type = D4H(phy_dev->get_endian(phy_dev->priv_dev), sdu->nic_type);
> +
> +		if (cmd_evt != LTE_RX_SDU) {
> +			printk(KERN_ERR "glte: rx sdu wrong hci %04x\n", cmd_evt);
> +			return;
> +		}
> +		if (hci_len < 12) {
> +			printk(KERN_ERR "glte: rx sdu invalid len %d\n", hci_len);
> +			return;
> +		}
> +
> +		index = find_dev_index(nic_type);
> +		if (index >= 0 && index < MAX_NIC_TYPE) {
> +			dev = phy_dev->dev[index];
> +			gdm_lte_netif_rx(dev, (char *)sdu->data, (int)(hci_len-12), nic_type);
> +		} else {
> +			printk(KERN_ERR "glte: rx sdu invalid nic_type : %x\n", nic_type);
> +		}
> +
> +		data += ((hci_len+3) & 0xfffc) + HCI_HEADER_SIZE;
> +	}
> +}
> +
> +static void gdm_lte_pdn_table(struct net_device *dev, char *buf, int len)
> +{
> +	struct nic *nic = netdev_priv(dev);
> +	struct hci_pdn_table_ind *pdn_table = (struct hci_pdn_table_ind *)buf;
> +
> +	if (pdn_table->activate) {
> +		nic->pdn_table.activate = pdn_table->activate;
> +		nic->pdn_table.dft_eps_id = D4H(gdm_dev_endian(nic), pdn_table->dft_eps_id);
> +		nic->pdn_table.nic_type = D4H(gdm_dev_endian(nic), pdn_table->nic_type);
> +
> +		printk(KERN_INFO "glte: pdn %s activated, nic_type=0x%x\n",
> +		       dev->name, nic->pdn_table.nic_type);
> +	} else {
> +		memset(&nic->pdn_table, 0x00, sizeof(struct pdn_table));
> +		printk(KERN_INFO "glte: pdn %s deactivated\n",
> +		       dev->name);
> +	}
> +}
> +
> +static int gdm_lte_receive_pkt(struct phy_dev *phy_dev, char *buf, int len)
> +{
> +	struct hci_packet *hci = (struct hci_packet *)buf;
> +	struct hci_pdn_table_ind *pdn_table = (struct hci_pdn_table_ind *)buf;
> +	struct sdu *sdu;
> +	struct net_device *dev;
> +	int ret = 0;
> +	u16 cmd_evt;
> +	u32 nic_type;
> +	int index;
> +
> +	if (!len)
> +		return ret;
> +
> +	cmd_evt = D2H(phy_dev->get_endian(phy_dev->priv_dev), hci->cmd_evt);
> +
> +	dev = phy_dev->dev[0];
> +	if (dev == NULL)
> +		return 0;
> +
> +	switch (cmd_evt) {
> +	case LTE_RX_SDU:
> +		sdu = (struct sdu *)hci->data;
> +		nic_type = D4H(phy_dev->get_endian(phy_dev->priv_dev), sdu->nic_type);
> +		index = find_dev_index(nic_type);
> +		if (index >= 0) {
> +			dev = phy_dev->dev[index];
> +			gdm_lte_netif_rx(dev, hci->data, len, nic_type);
> +		}
> +		break;
> +	case LTE_RX_MULTI_SDU:
> +		gdm_lte_multi_sdu_pkt(phy_dev, buf, len);
> +		break;
> +	case LTE_LINK_ON_OFF_INDICATION:
> +		{
> +			struct hci_connect_ind *connect_ind = (struct hci_connect_ind *)buf;
> +			printk(KERN_INFO "glte: link %s\n",
> +			       connect_ind->connect ? "on" : "off");
> +		}
> +		break;
> +	case LTE_PDN_TABLE_IND:
> +		pdn_table = (struct hci_pdn_table_ind *)buf;
> +		nic_type = D4H(phy_dev->get_endian(phy_dev->priv_dev), pdn_table->nic_type);
> +		index = find_dev_index(nic_type);
> +		if (index >= 0) {
> +			dev = phy_dev->dev[index];
> +			gdm_lte_pdn_table(dev, buf, len);
> +		}
> +		/* Fall through */
> +	default:
> +		ret = gdm_lte_event_send(dev, buf, len);
> +		break;
> +	}
> +
> +	return ret;
> +}
> +
> +static int rx_complete(void *arg, void *data, int len, int context)
> +{
> +	struct phy_dev *phy_dev = (struct phy_dev *)arg;
> +
> +	return gdm_lte_receive_pkt(phy_dev, (char *)data, len);
> +}
> +
> +void start_rx_proc(struct phy_dev *phy_dev)
> +{
> +	int i;
> +
> +	for (i = 0; i < MAX_RX_SUBMIT_COUNT; i++)
> +		gdm_lte_rcv_with_cb(phy_dev, rx_complete, phy_dev, USB_COMPLETE);
> +}
> +
> +static struct net_device_ops gdm_netdev_ops = {
> +	.ndo_open			= gdm_lte_open,
> +	.ndo_stop			= gdm_lte_close,
> +	.ndo_set_config			= gdm_lte_set_config,
> +	.ndo_start_xmit			= gdm_lte_tx,
> +	.ndo_get_stats			= gdm_lte_stats,
> +	.ndo_do_ioctl			= gdm_lte_ioctl,
> +};
> +
> +static u8 gdm_lte_macaddr[6] = {0x00, 0x0a, 0x3b, 0x00, 0x00, 0x00};
> +
> +static void form_mac_address(u8 *dev_addr, u8 *nic_src, u8 *nic_dest, u8 *mac_address, u8 index)
> +{
> +	/* Form the dev_addr */
> +	if (!mac_address)
> +		memcpy(dev_addr, gdm_lte_macaddr, 6);
> +	else
> +		memcpy(dev_addr, mac_address, 6);

Use ETH_ALEN.


> +
> +	/* The last byte of the mac address should be less than or equal to 0xFC */
> +	dev_addr[5] = (u8) (dev_addr[5] + index);

No need to cast.

> +
> +	/* Create random nic src and copy the first 3 bytes to be the same as dev_addr */
> +	random_ether_addr(nic_src);
> +	memcpy(nic_src, dev_addr, 3);
> +
> +	/* Copy the nic_dest from dev_addr*/
> +	memcpy(nic_dest,  dev_addr, 6);
> +}
> +
> +static void mac_validation(u8 *mac_address)
> +{
> +	u8 invalid_mac = 0;
> +
> +	/* the mac address is not 00-00-00-00-00-00 */
> +	if (
> +		(mac_address[0] == 0x00) &&
> +		(mac_address[1] == 0x00) &&
> +		(mac_address[2] == 0x00) &&
> +		(mac_address[3] == 0x00) &&
> +		(mac_address[4] == 0x00) &&
> +		(mac_address[5] == 0x00))
> +		invalid_mac = 1;

Use is_zero_ether_addr().


> +	/* check for multicast bit */
> +	else if ((mac_address[0] & 0x01) == 0x01)
> +		invalid_mac = 1;
> +
> +	if (invalid_mac) {
> +		/* Restore the default value */
> +		printk(KERN_ERR "glte: MAC invalid, restoring default\n");
> +		memcpy(mac_address, gdm_lte_macaddr, 6);
> +	} else {
> +		printk(KERN_INFO "glte: MAC validated\n");

I feel like this driver is too spammy.

> +	}
> +}
> +
> +int register_lte_device(struct phy_dev *phy_dev, struct device *dev, u8 *mac_address)
> +{
> +	struct nic *nic;
> +	struct net_device *net;
> +	char pdn_dev_name[16];
> +	int ret = 0;
> +	u8 index;
> +
> +	mac_validation(mac_address);
> +
> +	for (index = 0; index < MAX_NIC_TYPE; index++) {
> +		/* Create device name lteXpdnX */
> +		sprintf(pdn_dev_name, "lte%%dpdn%d", index);
> +
> +		/* Allocate netdev */
> +		net =  alloc_netdev(sizeof(struct nic), pdn_dev_name, ether_setup);
                      ^
Extra space.

> +		if (net == NULL) {
> +			printk(KERN_ERR "glte: alloc_netdev failed\n");
> +			ret = -1;

-ENOMEM;

> +			break;
> +		}
> +
> +		/* Configure device */

Obvious comment is not useful.  Delete.

> +
> +		net->netdev_ops = &gdm_netdev_ops;
> +		net->flags &= ~IFF_MULTICAST;
> +		net->mtu = DEFAULT_MTU_SIZE;
> +
> +		/* Configure nic */
> +		nic = netdev_priv(net);
> +		memset(nic, 0, sizeof(struct nic));
> +		nic->netdev = net;
> +		nic->phy_dev = phy_dev;
> +		nic->nic_id = index;
> +
> +		form_mac_address(
> +				net->dev_addr,
> +				nic->src_mac_addr,
> +				nic->dest_mac_addr,
> +				mac_address,
> +				index);
> +
> +		SET_NETDEV_DEV(net, dev);
> +		SET_NETDEV_DEVTYPE(net, &wwan_type);
> +
> +		ret = register_netdev(net);
> +		if (ret) {
> +			printk(KERN_ERR "glte: register %s failed\n", net->name);
> +			free_netdev(net);

We should free all the previously allocated devices in a loop.  We
should return an error code instead of zero.

> +			break;
> +		}
> +
> +		netif_carrier_on(net);
> +
> +		phy_dev->dev[index] = net;
> +
> +		printk(KERN_INFO "glte: register %s\n", net->name);
> +	}
> +
> +	return 0;
> +}
> +
> +void unregister_lte_device(struct phy_dev *phy_dev)
> +{
> +	struct net_device *net;
> +	int index;
> +
> +	for (index = MAX_NIC_TYPE-1; index >= 0; index--) {
> +		net = phy_dev->dev[index];
> +		if (net == NULL)
> +			continue;
> +
> +		printk(KERN_INFO "glte: unregister %s\n", net->name);
> +
> +		unregister_netdev(net);
> +		free_netdev(net);
> +	}
> +}
> diff --git a/drivers/staging/gdm724x/gdm_lte.h b/drivers/staging/gdm724x/gdm_lte.h
> new file mode 100644
> index 0000000..61f62d6
> --- /dev/null
> +++ b/drivers/staging/gdm724x/gdm_lte.h
> @@ -0,0 +1,93 @@
> +/*
> + * Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved.
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#ifndef _GDM_LTE_H_
> +#define _GDM_LTE_H_
> +
> +#include <linux/netdevice.h>
> +#include <linux/version.h>
> +#include <linux/types.h>
> +
> +#include "gdm_endian.h"
> +
> +#ifndef __packed
> +#define __packed __attribute__((packed))
> +#endif

Delete.

> +
> +#define SPBC_PATH		"GCT_LTE_MBL.bin"
> +#define SIMG_PATH		"signed_app.bin"
> +
> +#define MAX_NIC_TYPE		4
> +#define MAX_RX_SUBMIT_COUNT	3
> +#define MAX_FILE_PATH		260
> +#define DRIVER_VERSION		"3.7.17.0"
> +
> +#define H2L(x)		__cpu_to_le16(x)
> +#define L2H(x)		__le16_to_cpu(x)
> +#define H4L(x)		__cpu_to_le32(x)
> +#define L4H(x)		__le32_to_cpu(x)

Delete these.

> +
> +enum TX_ERROR_CODE {
> +	TX_NO_ERROR = 0,
> +	TX_NO_DEV,
> +	TX_NO_SPC,
> +	TX_NO_BUFFER,
> +};
> +
> +enum CALLBACK_CONTEXT {
> +	KERNEL_THREAD = 0,
> +	USB_COMPLETE,
> +};
> +
> +struct pdn_table {
> +	u8 activate;
> +	u32 dft_eps_id;
> +	u32 nic_type;
> +} __packed;
> +
> +struct nic;
> +
> +struct phy_dev {
> +	void	*priv_dev;
> +	struct net_device *dev[MAX_NIC_TYPE];
> +	int	(*send_hci_func)(void *priv_dev, void *data, int len,
> +			void (*cb)(void *cb_data), void *cb_data);
> +	int	(*send_sdu_func)(void *priv_dev, void *data, int len,
> +			unsigned int dftEpsId, unsigned int epsId,
> +			void (*cb)(void *cb_data), void *cb_data,
> +			int dev_idx, int nic_type);
> +	int	(*rcv_func)(void *priv_dev,
> +			int (*cb)(void *cb_data, void *data, int len, int context),
> +			void *cb_data, int context);
> +	struct gdm_endian *(*get_endian)(void *priv_dev);
> +};
> +
> +struct nic {
> +	struct net_device *netdev;
> +	struct phy_dev *phy_dev;
> +	struct net_device_stats stats;
> +	struct pdn_table pdn_table;
> +	u8 dest_mac_addr[6];
> +	u8 src_mac_addr[6];

ETH_ALEN.

> +	u32 nic_id;
> +	u16 vlan_id;
> +};
> +
> +int gdm_lte_event_init(void);
> +void gdm_lte_event_exit(void);
> +
> +void start_rx_proc(struct phy_dev *phy_dev);
> +int register_lte_device(struct phy_dev *phy_dev, struct device *dev, u8 *mac_address);
> +void unregister_lte_device(struct phy_dev *phy_dev);
> +
> +#endif /* _GDM_LTE_H_ */
> diff --git a/drivers/staging/gdm724x/gdm_mux.c b/drivers/staging/gdm724x/gdm_mux.c
> new file mode 100644
> index 0000000..7908fb7
> --- /dev/null
> +++ b/drivers/staging/gdm724x/gdm_mux.c
> @@ -0,0 +1,789 @@
> +/*
> + * Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved.
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/version.h>
> +#include <linux/kernel.h>
> +#include <linux/usb.h>
> +#include <linux/errno.h>
> +#include <linux/init.h>
> +#include <linux/tty.h>
> +#include <linux/tty_driver.h>
> +#include <linux/tty_flip.h>
> +#include <linux/slab.h>
> +#include <linux/usb/cdc.h>
> +
> +#include "gdm_mux.h"
> +#include "gdm_tty.h"
> +
> +#ifdef LTE_USB_PM
> +#define PM_NORMAL 0
> +#define PM_SUSPEND 1
> +#endif /* LTE_USB_PM */
> +
> +#define USB_RT_ACM          (USB_TYPE_CLASS | USB_RECIP_INTERFACE)
> +
> +#define START_FLAG 0xA512485A
> +#define MUX_HEADER_SIZE 14
> +#define MUX_RX_MAX_SIZE (1024*30)

This seems like a lot of data for kmalloc to allocate.

> +#define AT_PKT_TYPE 0xF011
> +#define DM_PKT_TYPE 0xF010
> +
> +#define RETRY_TIMER 30 /* msec */
> +
> +struct workqueue_struct *mux_rx_wq;
> +
> +

Only one blank line needed.

> +static u16 PACKET_TYPE[TTY_MAX_COUNT] = {0xF011, 0xF010};
> +
> +#define USB_DEVICE_CDC_DATA(vid, pid) \
> +	.match_flags = \
> +		USB_DEVICE_ID_MATCH_DEVICE |\
> +		USB_DEVICE_ID_MATCH_INT_CLASS |\
> +		USB_DEVICE_ID_MATCH_INT_SUBCLASS,\
> +	.idVendor = vid,\
> +	.idProduct = pid,\
> +	.bInterfaceClass = USB_CLASS_COMM,\
> +	.bInterfaceSubClass = USB_CDC_SUBCLASS_ACM
> +
> +static const struct usb_device_id id_table[] = {
> +	{ USB_DEVICE_CDC_DATA(0x1076, 0x8000) }, /* GCT GDM7240 */
> +	{ USB_DEVICE_CDC_DATA(0x1076, 0x8f00) }, /* GCT GDM7243 */
> +	{ USB_DEVICE_CDC_DATA(0x1076, 0x9000) }, /* GCT GDM7243 */
> +	{ USB_DEVICE_CDC_DATA(0x1d74, 0x2300) }, /* LGIT Phoenix */
> +	{}
> +};
> +
> +
> +MODULE_DEVICE_TABLE(usb, id_table);
> +
> +int PacketTypeToIndex(u16 packetType)

CamelCase function.

> +{
> +	int i;
> +
> +	for (i = 0; i < TTY_MAX_COUNT; i++) {
> +		if (PACKET_TYPE[i] == packetType)
> +			return i;
> +	}
> +
> +	printk(KERN_ERR "glte: invalid packet type:%d\n", packetType);

Noise.

> +
> +	return -1;
> +}
> +
> +static struct mux_tx *alloc_mux_tx(int len)
> +{
> +	struct mux_tx *t = NULL;
> +	int ret = 0;
> +
> +

Extra blank.


> +	t = kmalloc(sizeof(struct mux_tx), GFP_ATOMIC);
> +	if (!t) {
> +		ret = -ENOMEM;
> +		goto out;

Return NULL directly.  There is no error handling in this case.

> +	}
> +	memset(t, 0, sizeof(struct mux_tx));


Use kzalloc.

> +
> +	t->urb = usb_alloc_urb(0, GFP_ATOMIC);
> +	t->buf = kmalloc(1024*10, GFP_ATOMIC);
> +	if (!t->urb || !t->buf) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +

	return t;


> +out:
> +
> +	if (ret < 0) {

Now it's only errors here.  Remove the check.  Pull it in one
indent.

> +		if (t) {

"t" is always non-null now.  Remove this check.  Pull it in one
indent level.  Update the label.

err_free_t:
	usb_free_urb(t->urb);
	kfree(t->buf);
	kfree(t);

	return NULL;
}

PLEASE PLEASE fix these.  They are horrible to look at.  It should
be:

	ret = soemthing();
	if (ret)
		goto release_resource_b;

	return success;

release_resource_b:
	release(b);
free_a;
	free(a);

	return ret;
}

This way has no nested if statements and multiple indents.

> +			usb_free_urb(t->urb);
> +			kfree(t->buf);
> +			kfree(t);
> +		}
> +
> +		return NULL;
> +	}
> +
> +	return t;
> +}
> +
> +static void free_mux_tx(struct mux_tx *t)
> +{
> +	if (t) {
> +		usb_free_urb(t->urb);
> +		kfree(t->buf);
> +		kfree(t);
> +	}
> +}
> +
> +static struct mux_rx *alloc_mux_rx(void)
> +{
> +	struct mux_rx *r = NULL;
> +	int ret = 0;
> +
> +
> +	r = kmalloc(sizeof(struct mux_rx), GFP_ATOMIC);
> +	if (!r) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +
> +	r->urb = usb_alloc_urb(0, GFP_ATOMIC);
> +	r->buf = kmalloc(MUX_RX_MAX_SIZE, GFP_ATOMIC);
> +	if (!r->urb || !r->buf) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}

Same thing.  No need for spaghetti code at the end of the function.

> +out:
> +
> +	if (ret < 0) {
> +		if (r) {
> +			usb_free_urb(r->urb);
> +			kfree(r->buf);
> +			kfree(r);
> +		}
> +
> +		return NULL;
> +	}
> +
> +	return r;
> +}
> +
> +static void free_mux_rx(struct mux_rx *r)
> +{
> +	if (r) {
> +		usb_free_urb(r->urb);
> +		kfree(r->buf);
> +		kfree(r);
> +	}
> +}
> +
> +static struct mux_rx *get_rx_struct(struct rx_cxt *rx)
> +{
> +	struct mux_rx *r;
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&rx->free_list_lock, flags);
> +
> +	if (list_empty(&rx->rx_free_list)) {
> +		spin_unlock_irqrestore(&rx->free_list_lock, flags);
> +		return NULL;
> +	}
> +
> +	r = list_entry(rx->rx_free_list.prev, struct mux_rx, free_list);
> +	list_del(&r->free_list);
> +
> +	spin_unlock_irqrestore(&rx->free_list_lock, flags);
> +
> +	return r;
> +}
> +
> +static void put_rx_struct(struct rx_cxt *rx, struct mux_rx *r)
> +{
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&rx->free_list_lock, flags);
> +	list_add_tail(&r->free_list, &rx->rx_free_list);
> +	spin_unlock_irqrestore(&rx->free_list_lock, flags);
> +}
> +
> +
> +static int up_to_host(struct mux_rx *r)
> +{
> +	struct mux_dev *mux_dev = (struct mux_dev *)r->mux_dev;
> +	struct mux_pkt_header *mux_header = NULL;

Unneeded initialization.  These just suppress GCC's natural error
finding abilities.  Remove all unneeded initialization.

> +	unsigned int start_flag;
> +	unsigned int payload_size;
> +	unsigned short packet_type;
> +	int remain;
> +	int dummy_cnt;
> +	u32 packet_size_sum = r->offset;
> +	u8 *buf;
> +	int index;
> +	int ret = 0;
> +	int len = r->len;
> +
> +	while (1) {
> +		mux_header =
> +			(struct mux_pkt_header *)(r->buf + packet_size_sum);
> +		start_flag = L4H(mux_header->start_flag);
> +		payload_size = L4H(mux_header->payload_size);
> +		packet_type = L2H(mux_header->packet_type);
> +
> +		if (start_flag != START_FLAG) {
> +			printk(KERN_ERR "glte: invalid START_FLAG %x\n",
> +				start_flag);
> +			break;
> +		}
> +
> +		remain = (MUX_HEADER_SIZE + payload_size) % 4;
> +		dummy_cnt = remain ? (4-remain) : 0;

Use the ALIGN() macro?

> +
> +		if (len - packet_size_sum <
> +			MUX_HEADER_SIZE + payload_size + dummy_cnt) {
> +			printk(KERN_ERR "glte: invalid payload : %d %d %04x\n",
> +			       payload_size, len,
> +			       packet_type
> +			       );
> +			break;
> +		}
> +
> +		index = PacketTypeToIndex(packet_type);
> +		if (index < 0) {
> +			printk(KERN_ERR "glte: invalid index %d\n", index);

Returning success but printing an error message.

> +			break;
> +		}
> +
> +		buf = (u8 *)(mux_header);
> +		ret = r->callback((void *)&buf[MUX_HEADER_SIZE],

r->callback() doesn't care about the type.  No need for a cast.

The pointer math here is confusing.  MUX_HEADER_SIZE is just
sizeof(struct mux_pkt_header).  It might be nicer to do something
like:

struct mux_pkt {
	unsigned int start_flag;
	unsigned int seq_num;
	unsigned int payload_size;
	unsigned short packet_type;
	unsigned char data[0];
};

That way you could just say:

		ret = r->callback(mux_pkt->data,

Which is more clear.

> +				payload_size,
> +				index,
> +				mux_dev->minor[index],
> +				RECV_PACKET_PROCESS_CONTINUE
> +				);
> +		if (ret == TO_HOST_BUFFER_REQUEST_FAIL) {
> +			r->offset += packet_size_sum;
> +			break;
> +		}
> +
> +		packet_size_sum += MUX_HEADER_SIZE + payload_size + dummy_cnt;
> +
> +		if (len - packet_size_sum <= MUX_HEADER_SIZE + 2) {
> +			ret = r->callback((void *)NULL,
> +					0,
> +					index,
> +					mux_dev->minor[index],
> +					RECV_PACKET_PROCESS_COMPLETE
> +					);
> +			break;
> +		}
> +	}
> +
> +	return ret;
> +}
> +
> +static void do_rx(struct work_struct *work)
> +{
> +	struct mux_dev *mux_dev =
> +		container_of(work, struct mux_dev , work_rx.work);
> +	struct mux_rx *r;
> +	struct rx_cxt *rx = (struct rx_cxt *)&mux_dev->rx;
> +	unsigned long flags;
> +	int ret = 0;
> +
> +	while (1) {
> +		spin_lock_irqsave(&rx->to_host_lock, flags);
> +		if (list_empty(&rx->to_host_list)) {
> +			spin_unlock_irqrestore(&rx->to_host_lock, flags);
> +			break;
> +		}
> +		r = list_entry(rx->to_host_list.next, struct mux_rx, to_host_list);
> +		list_del(&r->to_host_list);
> +		spin_unlock_irqrestore(&rx->to_host_lock, flags);
> +
> +		ret = up_to_host(r);
> +		if (ret == TO_HOST_BUFFER_REQUEST_FAIL)
> +			printk(KERN_ERR "glte: failed to send mux data to host\n");
> +		else
> +			put_rx_struct(rx, r);
> +	}
> +}
> +
> +static void remove_rx_submit_list(struct mux_rx *r, struct rx_cxt *rx)
> +{
> +	unsigned long flags;
> +	struct mux_rx	*r_remove, *r_remove_next;
> +
> +	spin_lock_irqsave(&rx->submit_list_lock, flags);
> +	list_for_each_entry_safe(r_remove, r_remove_next, &rx->rx_submit_list, rx_submit_list)
> +	{

Checkpatch error.  Put the braces on the line before.

> +		if (r == r_remove)
> +			list_del(&r->rx_submit_list);
> +	}
> +	spin_unlock_irqrestore(&rx->submit_list_lock, flags);
> +}
> +
> +static void gdm_mux_rcv_complete(struct urb *urb)
> +{
> +	struct mux_rx *r = urb->context;
> +	struct mux_dev *mux_dev = (struct mux_dev *)r->mux_dev;
> +	struct rx_cxt *rx = &mux_dev->rx;
> +	unsigned long flags;
> +
> +	remove_rx_submit_list(r, rx);
> +
> +	if (urb->status) {
> +#ifdef LTE_USB_PM
> +		if (mux_dev->usb_state == PM_NORMAL)
> +			printk(KERN_ERR "glte: gdm_mux_rcv_complete urb status error %d\n", urb->status);
> +#else
> +		printk(KERN_ERR "glte: gdm_mux_rcv_complete urb status error %d\n", urb->status);
> +#endif /* LTE_USB_PM */
> +
> +		put_rx_struct(rx, r);
> +	} else {
> +		r->len = r->urb->actual_length;
> +
> +		spin_lock_irqsave(&rx->to_host_lock, flags);
> +		list_add_tail(&r->to_host_list, &rx->to_host_list);
> +		queue_work(mux_rx_wq, &mux_dev->work_rx.work);
> +		spin_unlock_irqrestore(&rx->to_host_lock, flags);
> +	}
> +}
> +
> +static int gdm_mux_recv(void *priv_dev,
> +			int (*cb)(void *data, int len, int tty_index, int minor, int complete)
> +			)
> +{
> +	struct mux_dev *mux_dev = priv_dev;
> +	struct usb_device *usbdev = mux_dev->usbdev;
> +	struct mux_rx *r;
> +	struct rx_cxt *rx = &mux_dev->rx;
> +	unsigned long flags;
> +	int ret;
> +
> +	if (!usbdev) {
> +		printk(KERN_ERR "glte: Device is Disconnect\n");
> +		return -ENODEV;
> +	}
> +
> +	r = get_rx_struct(rx);
> +	if (!r) {
> +		printk(KERN_ERR "glte: alloc_rx_struct fail\n");

Error message out of date.  It's get_rx_struct().

> +		return -ENOMEM;
> +	}
> +
> +	r->offset = 0;
> +	r->mux_dev = (void *)mux_dev;
> +	r->callback = cb;
> +#ifdef LTE_USB_PM
> +	mux_dev->rx_cb = cb;
> +#endif /* LTE_USB_PM */
> +
> +	usb_fill_bulk_urb(r->urb,
> +			  usbdev,
> +			  usb_rcvbulkpipe(usbdev, 0x86),
> +			  r->buf,
> +			  MUX_RX_MAX_SIZE,
> +			  gdm_mux_rcv_complete,
> +			  r);
> +
> +	spin_lock_irqsave(&rx->submit_list_lock, flags);
> +	list_add_tail(&r->rx_submit_list, &rx->rx_submit_list);
> +	spin_unlock_irqrestore(&rx->submit_list_lock, flags);
> +
> +	ret = usb_submit_urb(r->urb, GFP_KERNEL);
> +
> +	if (ret) {
> +		spin_lock_irqsave(&rx->submit_list_lock, flags);
> +		list_del(&r->rx_submit_list);
> +		spin_unlock_irqrestore(&rx->submit_list_lock, flags);
> +
> +		put_rx_struct(rx, r);
> +
> +		printk(KERN_ERR "glte: usb_submit_urb ret=%d\n", ret);
> +	}
> +
> +#ifdef LTE_USB_PM
> +	usb_mark_last_busy(usbdev);
> +#endif /* LTE_USB_PM */
> +
> +	return ret;
> +}
> +
> +static void gdm_mux_send_complete(struct urb *urb)
> +{
> +	struct mux_tx *t = urb->context;
> +
> +	if (urb->status == -ECONNRESET) {
> +		printk(KERN_INFO "glte: CONNRESET\n");
> +		free_mux_tx(t);
> +		return;
> +	}
> +
> +	if (t->callback)
> +		t->callback(t->cb_data);
> +
> +	free_mux_tx(t);
> +}
> +
> +static int gdm_mux_send(void *priv_dev, void *data, int len, int tty_index,
> +			void (*cb)(void *data), void *cb_data)

It could be better to declare *data as const.

> +{
> +	struct mux_dev *mux_dev = priv_dev;
> +	struct usb_device *usbdev = mux_dev->usbdev;
> +	struct mux_pkt_header *mux_header;
> +	struct mux_tx *t = NULL;
> +	static u32 seq_num = 1;
> +	int remain;
> +	int dummy_cnt;
> +	int total_len;
> +	int ret;
> +	unsigned long flags;
> +
> +#ifdef LTE_USB_PM
> +	if (mux_dev->usb_state == PM_SUSPEND) {
> +		ret = usb_autopm_get_interface(mux_dev->intf);
> +		if (!ret)
> +			usb_autopm_put_interface(mux_dev->intf);
> +	}
> +#endif /* LTE_USB_PM */
> +
> +	spin_lock_irqsave(&mux_dev->write_lock, flags);
> +
> +	remain = (MUX_HEADER_SIZE + len) % 4;
> +	dummy_cnt = remain ? (4 - remain) : 0;

ALIGN()


> +
> +	total_len = len + MUX_HEADER_SIZE + dummy_cnt;
> +
> +	t = alloc_mux_tx(total_len);
> +	if (!t) {
> +		printk(KERN_ERR "glte: alloc_mux_tx fail\n");
> +		spin_unlock_irqrestore(&mux_dev->write_lock, flags);
> +		return -ENOMEM;
> +	}
> +
> +	mux_header = (struct mux_pkt_header *)t->buf;
> +	mux_header->start_flag = H4L(START_FLAG);
> +	mux_header->seq_num = H4L(seq_num++);
> +	mux_header->payload_size = H4L((u32)len);
> +	mux_header->packet_type = H2L(PACKET_TYPE[tty_index]);
> +
> +	memcpy(t->buf+MUX_HEADER_SIZE, data, len);
> +	memset(t->buf+MUX_HEADER_SIZE+len, 0, dummy_cnt);
> +
> +	t->len = total_len;
> +	t->callback = cb;
> +	t->cb_data = cb_data;
> +
> +	usb_fill_bulk_urb(t->urb,
> +			  usbdev,
> +			  usb_sndbulkpipe(usbdev, 5),
> +			  t->buf,
> +			  total_len,
> +			  gdm_mux_send_complete,
> +			  t);
> +
> +	ret = usb_submit_urb(t->urb, GFP_KERNEL);
> +
> +	spin_unlock_irqrestore(&mux_dev->write_lock, flags);
> +
> +	if (ret)
> +		printk(KERN_ERR "glte: usb_submit_urb Error : %d\n", ret);
> +
> +#ifdef LTE_USB_PM
> +	usb_mark_last_busy(usbdev);
> +#endif /* LTE_USB_PM */
> +
> +	return ret;
> +}
> +
> +static int gdm_mux_send_control(void *priv_dev, int request, int value, void *buf, int len)
> +{
> +	struct mux_dev *mux_dev = priv_dev;
> +	struct usb_device *usbdev = mux_dev->usbdev;
> +	int ret;
> +
> +	ret = usb_control_msg(usbdev,
> +			      usb_sndctrlpipe(usbdev, 0),
> +			      request,
> +			      USB_RT_ACM,
> +			      value,
> +			      2,
> +			      buf,
> +			      len,
> +			      5000
> +			     );
> +
> +	if (ret < 0)
> +		printk(KERN_ERR "glte: usb_control_msg error : %d\n", ret);
> +
> +	return ret < 0 ? ret : 0;
> +}
> +
> +static void release_usb(struct mux_dev *mux_dev)
> +{
> +	struct rx_cxt		*rx = &mux_dev->rx;
> +	struct mux_rx		*r, *r_next;
> +	unsigned long		flags;
> +
> +	cancel_delayed_work(&mux_dev->work_rx);
> +
> +	spin_lock_irqsave(&rx->submit_list_lock, flags);
> +	list_for_each_entry_safe(r, r_next, &rx->rx_submit_list, rx_submit_list)
> +	{

Put the { on the line before.  (It's not a function).


> +		spin_unlock_irqrestore(&rx->submit_list_lock, flags);
> +		usb_kill_urb(r->urb);
> +		spin_lock_irqsave(&rx->submit_list_lock, flags);
> +	}
> +	spin_unlock_irqrestore(&rx->submit_list_lock, flags);
> +
> +	spin_lock_irqsave(&rx->free_list_lock, flags);
> +	list_for_each_entry_safe(r, r_next, &rx->rx_free_list, free_list)
> +	{
> +		list_del(&r->free_list);
> +		free_mux_rx(r);
> +	}
> +	spin_unlock_irqrestore(&rx->free_list_lock, flags);
> +
> +	spin_lock_irqsave(&rx->to_host_lock, flags);
> +	list_for_each_entry_safe(r, r_next, &rx->to_host_list, to_host_list)
> +	{
> +		if (r->mux_dev == (void *)mux_dev) {
> +			list_del(&r->to_host_list);
> +			free_mux_rx(r);
> +		}
> +	}
> +	spin_unlock_irqrestore(&rx->to_host_lock, flags);
> +}
> +
> +
> +static int init_usb(struct mux_dev *mux_dev)
> +{
> +	struct mux_rx *r;
> +	struct rx_cxt *rx = &mux_dev->rx;
> +	int ret = 0;
> +	int i;
> +	unsigned long flags;
> +
> +	spin_lock_init(&mux_dev->write_lock);
> +	INIT_LIST_HEAD(&rx->to_host_list);
> +	INIT_LIST_HEAD(&rx->rx_submit_list);
> +	INIT_LIST_HEAD(&rx->rx_free_list);
> +	spin_lock_init(&rx->to_host_lock);
> +	spin_lock_init(&rx->submit_list_lock);
> +	spin_lock_init(&rx->free_list_lock);
> +
> +	for (i = 0; i < MAX_ISSUE_NUM*2; i++) {

Space around math operators.

                    i < MAX_ISSUE_NUM * 2;

> +		r = alloc_mux_rx();
> +		if (r == NULL) {
> +			ret = -ENOMEM;
> +			break;

The error handling here is not correct.  It needs to unwind.  We
don't want to INIT_DELAYED_WORK().

> +		}
> +
> +		spin_lock_irqsave(&rx->free_list_lock, flags);
> +		list_add(&r->free_list, &rx->rx_free_list);
> +		spin_unlock_irqrestore(&rx->free_list_lock, flags);
> +	}
> +
> +	INIT_DELAYED_WORK(&mux_dev->work_rx, do_rx);
> +
> +	return ret;
> +}
> +
> +static int gdm_mux_probe(struct usb_interface *intf, const struct usb_device_id *id)
> +{
> +	struct mux_dev *mux_dev = NULL;
> +	struct tty_dev *tty_dev = NULL;
> +	u16 idVendor, idProduct;
> +	int bInterfaceNumber;
> +	int ret = 0;
> +	int i;
> +	struct usb_device *usbdev = interface_to_usbdev(intf);
> +	bInterfaceNumber = intf->cur_altsetting->desc.bInterfaceNumber;
> +
> +	idVendor = L2H(usbdev->descriptor.idVendor);
> +	idProduct = L2H(usbdev->descriptor.idProduct);
> +
> +	printk(KERN_INFO "glte: mux vid = 0x%04x pid = 0x%04x\n",
> +	       idVendor, idProduct);
> +
> +	if (bInterfaceNumber != 2) {
> +		ret = -1;

-1.

> +		goto out;
> +	}
> +
> +	mux_dev = kmalloc(sizeof(struct mux_dev), GFP_KERNEL);
> +	if (!mux_dev) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +
> +	tty_dev = kmalloc(sizeof(struct tty_dev), GFP_KERNEL);
> +	if (!tty_dev) {
> +		kfree(mux_dev);
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +
> +	memset(mux_dev, 0, sizeof(struct mux_dev));
> +	memset(tty_dev, 0, sizeof(struct tty_dev));


Use kzalloc().

> +
> +	mux_dev->usbdev = usbdev;
> +	mux_dev->control_intf = intf;
> +
> +	ret = init_usb(mux_dev);
> +	if (ret < 0)
> +		goto out;
> +
> +	tty_dev->priv_dev = (void *)mux_dev;
> +	tty_dev->send_func = gdm_mux_send;
> +	tty_dev->recv_func = gdm_mux_recv;
> +	tty_dev->send_control = gdm_mux_send_control;
> +
> +	if (register_lte_tty_device(tty_dev, &intf->dev) < 0) {
> +		unregister_lte_tty_device(tty_dev);
> +		mux_dev = tty_dev->priv_dev;
> +
> +		ret = -1;
> +		goto out;
> +	}
> +	for (i = 0; i < TTY_MAX_COUNT; i++)
> +		mux_dev->minor[i] = tty_dev->minor[i];
> +
> +out:
> +
> +	if (ret >= 0) {


These end of function splotches of spaghetti are super annoying.
Why are we even testing for greater than zero when it can never be
greater?  Anyway, I've already explained about error handling.

> +#ifdef LTE_USB_PM
> +		mux_dev->intf = intf;
> +		mux_dev->usb_state = PM_NORMAL;
> +#endif /* LTE_USB_PM */
> +	} else {
> +		kfree(tty_dev);
> +
> +		if (mux_dev) {
> +			release_usb(mux_dev);
> +			kfree(mux_dev);
> +		}
> +	}
> +
> +	usb_get_dev(usbdev);
> +	usb_set_intfdata(intf, tty_dev);
> +
> +	return ret;
> +}
> +
> +static void gdm_mux_disconnect(struct usb_interface *intf)
> +{
> +	struct tty_dev *tty_dev;
> +	struct mux_dev *mux_dev;
> +	struct usb_device *usbdev = interface_to_usbdev(intf);
> +
> +	tty_dev = usb_get_intfdata(intf);
> +
> +	mux_dev = tty_dev->priv_dev;
> +
> +	release_usb(mux_dev);
> +	unregister_lte_tty_device(tty_dev);
> +
> +	kfree(mux_dev);
> +	mux_dev = NULL;

Delete this no-op line.  The compiler already does.

> +
> +	kfree(tty_dev);
> +	tty_dev = NULL;

And this.

> +
> +	usb_put_dev(usbdev);
> +}
> +
> +#ifdef LTE_USB_PM
> +static int gdm_mux_suspend(struct usb_interface *intf, pm_message_t pm_msg)
> +{
> +	struct tty_dev *tty_dev;
> +	struct mux_dev *mux_dev;
> +	struct rx_cxt *rx;
> +	struct mux_rx *r, *r_next;
> +	unsigned long flags;
> +
> +	/* printk(KERN_INFO "gdm_mux_suspend\n"); */
> +
> +	tty_dev = usb_get_intfdata(intf);
> +	mux_dev = tty_dev->priv_dev;
> +	rx = &mux_dev->rx;
> +
> +	if (mux_dev->usb_state != PM_NORMAL) {
> +		printk(KERN_ERR "glte: usb suspend - invalid state\n");
> +		return -1;
> +	}
> +
> +	mux_dev->usb_state = PM_SUSPEND;
> +
> +
> +	spin_lock_irqsave(&rx->submit_list_lock, flags);
> +	list_for_each_entry_safe(r, r_next, &rx->rx_submit_list, rx_submit_list) {
> +		spin_unlock_irqrestore(&rx->submit_list_lock, flags);
> +		usb_kill_urb(r->urb);
> +		spin_lock_irqsave(&rx->submit_list_lock, flags);
> +	}
> +	spin_unlock_irqrestore(&rx->submit_list_lock, flags);
> +
> +	return 0;
> +}
> +
> +static int gdm_mux_resume(struct usb_interface *intf)
> +{
> +	struct tty_dev *tty_dev;
> +	struct mux_dev *mux_dev;
> +	u8 i;
> +
> +	/* printk(KERN_INFO "gdm_mux_resume\n"); */

Delete commented out code.

> +
> +	tty_dev = usb_get_intfdata(intf);
> +	mux_dev = tty_dev->priv_dev;
> +
> +	if (mux_dev->usb_state != PM_SUSPEND) {
> +		printk(KERN_ERR "glte: usb resume - invalid state\n");
> +		return -1;
> +	}
> +
> +	mux_dev->usb_state = PM_NORMAL;
> +
> +	for (i = 0;  i < MAX_ISSUE_NUM; i++)
> +		gdm_mux_recv((void *)mux_dev, mux_dev->rx_cb);

No need for the cast.

> +
> +	return 0;
> +}
> +#endif /* LTE_USB_PM */
> +
> +static struct usb_driver gdm_mux_driver = {
> +	.name = "gdm_mux",
> +	.probe = gdm_mux_probe,
> +	.disconnect = gdm_mux_disconnect,
> +	.id_table = id_table,
> +#ifdef LTE_USB_PM
> +	.supports_autosuspend = 1,
> +	.suspend = gdm_mux_suspend,
> +	.resume = gdm_mux_resume,
> +	.reset_resume = gdm_mux_resume,
> +#endif /* LTE_USB_PM */
> +};
> +
> +static int __init gdm_usb_mux_init(void)
> +{
> +
> +	mux_rx_wq = create_workqueue("mux_rx_wq");
> +	if (mux_rx_wq == NULL) {
> +		printk(KERN_ERR "glte: work queue create fail");
> +		return -1;
> +	}
> +
> +	register_lte_tty_driver();
> +
> +	return usb_register(&gdm_mux_driver);
> +}
> +
> +static void __exit gdm_usb_mux_exit(void)
> +{
> +	unregister_lte_tty_driver();
> +
> +	if (mux_rx_wq) {
> +		flush_workqueue(mux_rx_wq);
> +		destroy_workqueue(mux_rx_wq);
> +	}
> +
> +	usb_deregister(&gdm_mux_driver);
> +}
> +
> +module_init(gdm_usb_mux_init);
> +module_exit(gdm_usb_mux_exit);
> +
> +MODULE_DESCRIPTION("GCT LTE TTY Device Driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/staging/gdm724x/gdm_mux.h b/drivers/staging/gdm724x/gdm_mux.h
> new file mode 100644
> index 0000000..8b5ebee
> --- /dev/null
> +++ b/drivers/staging/gdm724x/gdm_mux.h
> @@ -0,0 +1,77 @@
> +/*
> + * Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved.
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#ifndef _GDM_MUX_H_
> +#define _GDM_MUX_H_
> +
> +#include <linux/types.h>
> +#include <linux/usb.h>
> +#include <linux/list.h>
> +
> +#define H2L(x)		__cpu_to_le16(x)
> +#define L2H(x)		__le16_to_cpu(x)
> +#define H4L(x)		__cpu_to_le32(x)
> +#define L4H(x)		__le32_to_cpu(x)
> +
> +struct mux_pkt_header {
> +	unsigned int start_flag;
> +	unsigned int seq_num;
> +	unsigned int payload_size;
> +	unsigned short packet_type;
> +};
> +
> +struct mux_tx {
> +	struct urb *urb;
> +	u8 *buf;
> +	int  len;
> +	void (*callback)(void *cb_data);
> +	void *cb_data;
> +};
> +
> +struct mux_rx {
> +	struct list_head free_list;
> +	struct list_head rx_submit_list;
> +	struct list_head to_host_list;
> +	struct urb *urb;
> +	u8 *buf;
> +	void *mux_dev;
> +	u32 offset;
> +	u32 len;
> +	int (*callback)(void *data, int len, int tty_index, int minor, int complete);
> +};
> +
> +struct rx_cxt {
> +	struct list_head to_host_list;
> +	struct list_head rx_submit_list;
> +	struct list_head rx_free_list;
> +	spinlock_t to_host_lock;
> +	spinlock_t submit_list_lock;
> +	spinlock_t free_list_lock;
> +};
> +
> +struct mux_dev {
> +	struct usb_device *usbdev;
> +	struct usb_interface *control_intf;
> +	struct usb_interface *data_intf;
> +	struct rx_cxt	rx;
> +	struct delayed_work work_rx;
> +#ifdef LTE_USB_PM
> +	struct usb_interface *intf;
> +	int usb_state;
> +	int (*rx_cb)(void *data, int len, int tty_index, int minor, int complete);
> +#endif /* LTE_USB_PM */
> +	spinlock_t write_lock;
> +	u8 minor[2];
> +};
> +
> +#endif /* _GDM_MUX_H_ */
> diff --git a/drivers/staging/gdm724x/gdm_tty.c b/drivers/staging/gdm724x/gdm_tty.c
> new file mode 100644
> index 0000000..130fce7
> --- /dev/null
> +++ b/drivers/staging/gdm724x/gdm_tty.c
> @@ -0,0 +1,382 @@
> +/*
> + * Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved.
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/version.h>
> +#include <linux/kernel.h>
> +#include <linux/errno.h>
> +#include <linux/init.h>
> +#include <linux/tty.h>
> +#include <linux/tty_driver.h>
> +#include <linux/tty_flip.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/usb/cdc.h>
> +#include <linux/serial.h>
> +#include "gdm_tty.h"
> +
> +#define GDM_TTY_MAJOR 0
> +#define GDM_TTY_MINOR 32
> +
> +#define ACM_CTRL_DTR 0x01
> +#define ACM_CTRL_RTS 0x02
> +#define ACM_CTRL_DSR 0x02
> +#define ACM_CTRL_RI  0x08
> +#define ACM_CTRL_DCD 0x01
> +
> +#define WRITE_SIZE 2048
> +
> +#define MUX_TX_MAX_SIZE 2048
> +
> +#define gdm_tty_send(n, d, l, i, c, b) (\
> +	n->tty_dev->send_func(n->tty_dev->priv_dev, d, l, i, c, b))
> +#define gdm_tty_recv(n, c) (\
> +	n->tty_dev->recv_func(n->tty_dev->priv_dev, c))
> +#define gdm_tty_send_control(n, r, v, d, l) (\
> +	n->tty_dev->send_control(n->tty_dev->priv_dev, r, v, d, l))
> +
> +#define acm_set_comm_feature(n, v)	\
> +	gdm_tty_send_control(n, 0x02, v, NULL, 0)
> +
> +#define GDM_TTY_READY(tty_str) (tty_str && tty_str->tty_dev && tty_str->port.count)
> +
> +struct tty_driver *g_tty_drv[TTY_MAX_COUNT] = {NULL, };
> +struct tty_str *g_tty_str[TTY_MAX_COUNT][GDM_TTY_MINOR] = {{NULL, }, };
> +
> +static char *DRIVER_STRING[TTY_MAX_COUNT] = {"GCTATC", "GCTDM"};
> +static char *DEVICE_STRING[TTY_MAX_COUNT] = {"GCT-ATC", "GCT-DM"};
> +
> +static DEFINE_MUTEX(open_mutex);
> +
> +static struct tty_port_operations gdm_tty_port_ops = {
> +};
> +
> +static int gdm_tty_open(struct tty_struct *tty, struct file *filp)
> +{
> +	struct tty_str *tty_str = NULL;
> +	int i;
> +	int ret = 0;
> +
> +	mutex_lock(&open_mutex);
> +
> +	for (i = 0; i < TTY_MAX_COUNT; i++) {
> +		if (!strcmp(tty->driver->driver_name, DRIVER_STRING[i])) {
> +			tty_str = g_tty_str[i][tty->index];
> +			break;
> +		}
> +	}
> +
> +	if (!tty_str) {
> +		printk(KERN_INFO "glte: no tty device\n");
> +		mutex_unlock(&open_mutex);
> +		return -ENODEV;
> +	}
> +
> +	set_bit(TTY_NO_WRITE_SPLIT, &tty->flags);
> +
> +	tty->driver_data = tty_str;
> +	tty_port_tty_set(&tty_str->port, tty);
> +	tty_str->port.count++;
> +	set_bit(ASYNCB_INITIALIZED, &tty_str->port.flags);
> +	ret = tty_port_block_til_ready(&tty_str->port, tty, filp);
> +
> +	mutex_unlock(&open_mutex);
> +
> +	return ret;
> +}
> +
> +static void gdm_tty_close(struct tty_struct *tty, struct file *filp)
> +{
> +	struct tty_str *tty_str = tty->driver_data;
> +	int i;
> +
> +	if (!tty_str) {
> +		printk(KERN_INFO "glte: tty device already close\n");
> +		return;
> +	}
> +
> +	if (tty_str->port.count != 0) {
> +		tty_port_close_start(&tty_str->port, tty, filp);
> +		tty_port_close_end(&tty_str->port, tty);
> +
> +		if (tty_str->port.count == 0)
> +			tty_port_tty_set(&tty_str->port, NULL);
> +			tty_str->port.tty = NULL;
> +	}
> +
> +	if (!tty_str->tty_dev) {
> +		for (i = 0; i < TTY_MAX_COUNT; i++) {
> +			if (!strcmp(tty->driver->driver_name, DRIVER_STRING[i]))
> +				break;
> +		}
> +
> +		if (i < TTY_MAX_COUNT) {
> +			tty_unregister_device(g_tty_drv[i], tty->index);
> +			g_tty_str[i][tty->index] = NULL;
> +			tty_port_tty_set(&tty_str->port, NULL);
> +			kfree(tty_str);
> +			printk(KERN_INFO "glte: unregister %s\n", DEVICE_STRING[i]);
> +		}
> +	}
> +
> +	tty->driver_data = NULL;
> +}
> +
> +static int gdm_tty_recv_complete(void *data, int len, int index, int minor, int complete)
> +{
> +	struct tty_str *tty_str = g_tty_str[index][minor];
> +	struct tty_struct *tty;
> +
> +	if (!GDM_TTY_READY(tty_str)) {
> +		if (complete == RECV_PACKET_PROCESS_COMPLETE)
> +			gdm_tty_recv(tty_str, gdm_tty_recv_complete);
> +		return TO_HOST_PORT_CLOSE;
> +	}
> +
> +	if (!data || !len)
> +		goto complete_routine;
> +
> +	tty = tty_port_tty_get(&tty_str->port);
> +
> +	if (tty_buffer_request_room(tty, len) == len) {
> +		tty_insert_flip_string(tty, data, len);
> +		tty_flip_buffer_push(tty);
> +	} else {
> +		tty_kref_put(tty);
> +		return TO_HOST_BUFFER_REQUEST_FAIL;
> +	}
> +
> +	tty_kref_put(tty);
> +complete_routine:
> +	if (complete == RECV_PACKET_PROCESS_COMPLETE)
> +		gdm_tty_recv(tty_str, gdm_tty_recv_complete);
> +
> +	return TO_HOST_SUCCESS;
> +}
> +
> +static void gdm_tty_send_complete(void *arg)
> +{
> +	struct tty_str *tty_str = (struct tty_str *)arg;
> +	struct tty_struct *tty;
> +
> +	return;
> +

What's the story here?  It probably needs a comment or something for
this stubbed out function.

> +	if (!GDM_TTY_READY(tty_str))
> +		return;
> +
> +	tty = tty_port_tty_get(&tty_str->port);
> +	tty_wakeup(tty);
> +	tty_kref_put(tty);
> +}
> +
> +static int gdm_tty_write(struct tty_struct *tty, const unsigned char *buf, int len)
> +{
> +	struct tty_str *tty_str = tty->driver_data;
> +	int remain = len;
> +	int sent_len = 0;
> +	int sending_len = 0;
> +
> +	if (!GDM_TTY_READY(tty_str))
> +		return -ENODEV;
> +
> +	if (!len)
> +		return 0;
> +
> +	while (1) {
> +		sending_len = remain > MUX_TX_MAX_SIZE ? MUX_TX_MAX_SIZE : remain;
> +		gdm_tty_send(tty_str,
> +			     (void *)(buf+sent_len),
> +			     sending_len,
> +			     tty_str->tty_drv_index,
> +			     gdm_tty_send_complete,
> +			     tty_str
> +			    );
> +		sent_len += sending_len;
> +		remain -= sending_len;
> +		if (remain <= 0)
> +			break;
> +	}
> +
> +	return len;
> +}
> +
> +static int gdm_tty_write_room(struct tty_struct *tty)
> +{
> +	struct tty_str *tty_str = tty->driver_data;
> +
> +	if (!GDM_TTY_READY(tty_str))
> +		return -ENODEV;
> +
> +	return WRITE_SIZE;
> +}
> +
> +static int gdm_tty_tiocmget(struct tty_struct *tty)
> +{
> +	struct tty_str *tty_str = tty->driver_data;
> +
> +	if (!GDM_TTY_READY(tty_str))
> +		return -ENODEV;
> +
> +	return (0 & ACM_CTRL_DTR ? TIOCM_DTR : 0) |
> +	       (0 & ACM_CTRL_RTS ? TIOCM_RTS : 0) |
> +	       (0 & ACM_CTRL_DSR ? TIOCM_DSR : 0) |
> +	       (0 & ACM_CTRL_RI  ? TIOCM_RI  : 0) |
> +	       (0 & ACM_CTRL_DCD ? TIOCM_CD  : 0) |

I never understand why people do (0 & ...  I assume you are planning
to add that feature and are stubbing it out for now.  Put a big
comment why we have these no-ops here.

> +	       TIOCM_CTS;
> +}
> +
> +static int gdm_tty_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
> +{
> +	struct tty_str *tty_str = tty->driver_data;
> +
> +	if (!GDM_TTY_READY(tty_str))
> +		return -ENODEV;
> +
> +	return 1;
> +}
> +
> +int register_lte_tty_device(struct tty_dev *tty_dev, struct device *dev)
> +{
> +	struct tty_str *tty_str;
> +	u8 i, j;

	int i, j;

> +
> +	for (i = 0; i < TTY_MAX_COUNT; i++) {
> +		for (j = 0; j < GDM_TTY_MINOR; j++) {
> +			if (!g_tty_str[i][j])
> +				break;
> +		}
> +
> +		if (j == GDM_TTY_MINOR) {
> +			tty_dev->minor[i] = j;
> +			return -1;


Don't return -1

> +		}
> +
> +		tty_str = kmalloc(sizeof(struct tty_str), GFP_KERNEL);
> +		if (!tty_str)
> +			return -ENOMEM;
> +
> +		g_tty_str[i][j] = tty_str;
> +
> +		tty_str->tty_dev = tty_dev;
> +		tty_str->tty_drv_index = i;
> +		tty_dev->minor[i] = j;
> +		tty_port_init(&tty_str->port);
> +		tty_str->port.ops = &gdm_tty_port_ops;
> +
> +		if (strcmp(DEVICE_STRING[i], "GCT-ATC") != 0)
> +			dev = NULL;
> +		tty_register_device(g_tty_drv[i], j, dev);
> +
> +		printk(KERN_INFO "glte: register %s\n", DEVICE_STRING[i]);
> +	}
> +
> +	acm_set_comm_feature(tty_str, 1);
> +
> +	for (i = 0; i < MAX_ISSUE_NUM; i++)
> +		gdm_tty_recv(tty_str, gdm_tty_recv_complete);
> +
> +	return 0;
> +}
> +
> +void unregister_lte_tty_device(struct tty_dev *tty_dev)
> +{
> +	struct tty_str *tty_str;
> +	struct tty_struct *tty;
> +	int i;
> +
> +	for (i = 0; i < TTY_MAX_COUNT; i++) {
> +		if (tty_dev->minor[i] >= GDM_TTY_MINOR)
> +			continue;
> +
> +		tty_str = g_tty_str[i][tty_dev->minor[i]];
> +		if (!tty_str)
> +			continue;
> +
> +		tty_str->tty_dev = NULL;
> +
> +		if (!tty_str->port.count) {
> +			tty_unregister_device(g_tty_drv[i], tty_dev->minor[i]);
> +			tty_port_tty_set(&tty_str->port, NULL);
> +			kfree(tty_str);
> +			g_tty_str[i][tty_dev->minor[i]] = NULL;
> +			printk(KERN_INFO "glte: unregister %s\n", DEVICE_STRING[i]);
> +		} else {
> +			tty = tty_port_tty_get(&tty_str->port);
> +			if (tty) {
> +				tty_hangup(tty);
> +				tty_kref_put(tty);
> +			}
> +		}
> +	}
> +}
> +
> +static void gdm_tty_set_termios(struct tty_struct *tty, struct ktermios *termios_old)
> +{
> +	return;
> +}
> +
> +static const struct tty_operations gdm_tty_ops = {
> +	.open = gdm_tty_open,
> +	.close = gdm_tty_close,
> +	.write = gdm_tty_write,
> +	.write_room = gdm_tty_write_room,
> +	.tiocmget = gdm_tty_tiocmget,
> +	.tiocmset = gdm_tty_tiocmset,
> +	.set_termios = gdm_tty_set_termios,
> +};
> +
> +int register_lte_tty_driver(void)
> +{
> +	struct tty_driver *tty_driver = NULL;
> +	int i;
> +	int ret;
> +
> +	for (i = 0; i < TTY_MAX_COUNT; i++) {
> +		tty_driver = alloc_tty_driver(GDM_TTY_MINOR);
> +		if (!tty_driver) {
> +			printk(KERN_ERR "glte: alloc_tty_driver fail\n");
> +			return -ENOMEM;
> +		}
> +
> +		tty_driver->owner = THIS_MODULE;
> +		tty_driver->driver_name = DRIVER_STRING[i];
> +		tty_driver->name = DEVICE_STRING[i];
> +		tty_driver->major = GDM_TTY_MAJOR;
> +		tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
> +		tty_driver->subtype = SERIAL_TYPE_NORMAL;
> +		tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
> +		tty_driver->init_termios = tty_std_termios;
> +		tty_driver->init_termios.c_cflag = B9600 | CS8 | HUPCL | CLOCAL;
> +		tty_driver->init_termios.c_lflag = ISIG | ICANON | IEXTEN;
> +		tty_set_operations(tty_driver, &gdm_tty_ops);
> +
> +		ret = tty_register_driver(tty_driver);
> +
> +		g_tty_drv[i] = tty_driver;
> +	}
> +
> +	return ret;
> +}
> +
> +void unregister_lte_tty_driver(void)
> +{
> +	struct tty_driver *tty_driver;
> +	int i;
> +
> +	for (i = 0; i < TTY_MAX_COUNT; i++) {
> +		tty_driver = g_tty_drv[i];
> +		if (tty_driver) {
> +			tty_unregister_driver(tty_driver);
> +			put_tty_driver(tty_driver);
> +		}
> +	}
> +}
> diff --git a/drivers/staging/gdm724x/gdm_tty.h b/drivers/staging/gdm724x/gdm_tty.h
> new file mode 100644
> index 0000000..0277175
> --- /dev/null
> +++ b/drivers/staging/gdm724x/gdm_tty.h
> @@ -0,0 +1,63 @@
> +/*
> + * Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved.
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#ifndef _GDM_TTY_H_
> +#define _GDM_TTY_H_
> +
> +#include <linux/version.h>
> +#include <linux/types.h>
> +#include <linux/tty.h>
> +
> +#define ttydev_priv(tty)	((tty)->driver_data)
> +#define TTY_MAX_COUNT		2
> +
> +#define H2L(x)		__cpu_to_le16(x)
> +#define L2H(x)		__le16_to_cpu(x)
> +#define H4L(x)		__cpu_to_le32(x)
> +#define L4H(x)		__le32_to_cpu(x)

These defines are redefined over and over and over.  They were so
horrible the first time but by the third time I'm about to go nuts.
Hopefully I'm coming to the end of this patch?

> +
> +#define MAX_ISSUE_NUM 3
> +
> +enum TO_HOST_RESULT {
> +	TO_HOST_SUCCESS = 0,
> +	TO_HOST_BUFFER_REQUEST_FAIL = 1,
> +	TO_HOST_PORT_CLOSE = 2,
> +};
> +
> +enum RECV_PACKET_PROCESS {
> +	RECV_PACKET_PROCESS_COMPLETE = 0,
> +	RECV_PACKET_PROCESS_CONTINUE = 1,
> +};
> +
> +struct tty_dev {
> +	void *priv_dev;
> +	int (*send_func)(void *priv_dev, void *data, int len, int tty_index,
> +			void (*cb)(void *cb_data), void *cb_data);
> +	int (*recv_func)(void *priv_dev, int (*cb)(void *data, int len, int tty_index, int minor, int complete));
> +	int (*send_control)(void *priv_dev, int request, int value, void *data, int len);
> +	u8 minor[2];
> +};
> +
> +struct tty_str {
> +	struct tty_dev *tty_dev;
> +	int tty_drv_index;
> +	struct tty_port port;
> +};
> +
> +int register_lte_tty_driver(void);
> +void unregister_lte_tty_driver(void);
> +int register_lte_tty_device(struct tty_dev *tty_dev, struct device *dev);
> +void unregister_lte_tty_device(struct tty_dev *tty_dev);
> +
> +#endif /* _GDM_USB_H_ */
> +
> diff --git a/drivers/staging/gdm724x/gdm_usb.c b/drivers/staging/gdm724x/gdm_usb.c
> new file mode 100644
> index 0000000..4e8d519
> --- /dev/null
> +++ b/drivers/staging/gdm724x/gdm_usb.c
> @@ -0,0 +1,1105 @@
> +/*
> + * Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved.
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/version.h>
> +#include <linux/kernel.h>
> +#include <linux/usb.h>
> +#include <linux/sched.h>
> +#include <linux/kthread.h>
> +#include <linux/usb/cdc.h>
> +#include <linux/wait.h>
> +#include <linux/if_ether.h>
> +#include <linux/pm_runtime.h>
> +
> +#include "gdm_usb.h"
> +#include "gdm_lte.h"
> +#include "hci.h"
> +#include "hci_packet.h"
> +#include "gdm_endian.h"
> +
> +#ifdef LTE_USB_PM
> +#define PM_NORMAL 0
> +#define PM_SUSPEND 1
> +#define AUTO_SUSPEND_TIMER 5000 /* ms */
> +#endif /* LTE_USB_PM */
> +
> +#define RX_BUF_SIZE		(1024*32)
> +#define TX_BUF_SIZE		(1024*32)
> +#define SDU_BUF_SIZE	2048
> +#define MAX_SDU_SIZE	(1024*30)
> +
> +
> +#define VID_GCT			0x1076
> +#define PID_GDM7240		0x8000
> +#define PID_GDM7243		0x9000
> +
> +#define NETWORK_INTERFACE 1
> +#define USB_SC_SCSI 0x06
> +#define USB_PR_BULK 0x50
> +
> +#define USB_DEVICE_CDC_DATA(vid, pid) \
> +	.match_flags = USB_DEVICE_ID_MATCH_DEVICE | USB_DEVICE_ID_MATCH_INT_CLASS | USB_DEVICE_ID_MATCH_INT_SUBCLASS,\
> +	.idVendor = vid,\
> +	.idProduct = pid,\
> +	.bInterfaceClass = USB_CLASS_COMM,\
> +	.bInterfaceSubClass = USB_CDC_SUBCLASS_ETHERNET
> +
> +#define USB_DEVICE_MASS_DATA(vid, pid) \
> +	.match_flags = USB_DEVICE_ID_MATCH_DEVICE | USB_DEVICE_ID_MATCH_INT_INFO,\
> +	.idVendor = vid,\
> +	.idProduct = pid,\
> +	.bInterfaceSubClass = USB_SC_SCSI, \
> +	.bInterfaceClass = USB_CLASS_MASS_STORAGE,\
> +	.bInterfaceProtocol = USB_PR_BULK
> +
> +static const struct usb_device_id id_table[] = {
> +	{ USB_DEVICE_CDC_DATA(VID_GCT, PID_GDM7240) }, /* GCT GDM7240 */
> +	{ USB_DEVICE_CDC_DATA(VID_GCT, PID_GDM7243) }, /* GCT GDM7243 */
> +	{ }
> +};
> +
> +MODULE_DEVICE_TABLE(usb, id_table);
> +
> +static struct workqueue_struct *usb_tx_wq;
> +static struct workqueue_struct *usb_rx_wq;
> +
> +static void do_tx(struct work_struct *work);
> +static void do_rx(struct work_struct *work);
> +
> +static int gdm_usb_recv(void *priv_dev,
> +			int (*cb)(void *cb_data, void *data, int len, int context),
> +			void *cb_data,
> +			int context);
> +
> +static int request_mac_address(struct lte_udev *udev)
> +{
> +	u8 buf[16] = {0,};

This looks like a DMA transfer buffer.  It has to be allocated with
kmalloc().

> +	struct hci_packet *hci = (struct hci_packet *)buf;
> +	struct usb_device *usbdev = udev->usbdev;
> +	int actual;
> +	int ret = -1;
> +
> +	hci->cmd_evt = H2D(&udev->gdm_ed, LTE_GET_INFORMATION);
> +	hci->len = H2D(&udev->gdm_ed, 1);
> +	hci->data[0] = MAC_ADDRESS;
> +
> +	ret = usb_bulk_msg(usbdev, usb_sndbulkpipe(usbdev, 2), buf, 5,
> +		     &actual, 1000);
> +
> +	udev->request_mac_addr = 1;
> +
> +	return ret;
> +}
> +
> +static struct usb_tx *alloc_tx_struct(int len)
> +{
> +	struct usb_tx *t = NULL;
> +	int ret = 0;
> +
> +	t = kmalloc(sizeof(struct usb_tx), GFP_ATOMIC);
> +	if (!t) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +	memset(t, 0, sizeof(struct usb_tx));
> +
> +	t->urb = usb_alloc_urb(0, GFP_ATOMIC);
> +	if (!(len % 512))
> +		len++;

Why are we not allowed multiples of 512?

> +
> +	t->buf = kmalloc(len, GFP_ATOMIC);
> +	if (!t->urb || !t->buf) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +
> +out:
> +	if (ret < 0) {
> +		if (t) {
> +			usb_free_urb(t->urb);
> +			kfree(t->buf);
> +			kfree(t);
> +		}
> +		return NULL;
> +	}
> +
> +	return t;
> +}
> +
> +static struct usb_tx_sdu *alloc_tx_sdu_struct(void)
> +{
> +	struct usb_tx_sdu *t_sdu = NULL;
> +	int ret = 0;
> +
> +
> +	t_sdu = kmalloc(sizeof(struct usb_tx_sdu), GFP_ATOMIC);
> +	if (!t_sdu) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +	memset(t_sdu, 0, sizeof(struct usb_tx_sdu));
> +
> +	t_sdu->buf = kmalloc(SDU_BUF_SIZE, GFP_ATOMIC);
> +	if (!t_sdu->buf) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +out:
> +
> +	if (ret < 0) {
> +		if (t_sdu) {
> +			kfree(t_sdu->buf);
> +			kfree(t_sdu);
> +		}
> +		return NULL;
> +	}
> +
> +	return t_sdu;
> +}
> +
> +static void free_tx_struct(struct usb_tx *t)
> +{
> +	if (t) {
> +		usb_free_urb(t->urb);
> +		kfree(t->buf);
> +		kfree(t);
> +	}
> +}
> +
> +static void free_tx_sdu_struct(struct usb_tx_sdu *t_sdu)
> +{
> +	if (t_sdu) {
> +		kfree(t_sdu->buf);
> +		kfree(t_sdu);
> +	}
> +}
> +
> +static struct usb_tx_sdu *get_tx_sdu_struct(struct tx_cxt *tx, int *no_spc)
> +{
> +	struct usb_tx_sdu *t_sdu;
> +
> +	if (list_empty(&tx->free_list))
> +		return NULL;
> +
> +	t_sdu = list_entry(tx->free_list.next, struct usb_tx_sdu, list);
> +	list_del(&t_sdu->list);
> +
> +	tx->avail_count--;
> +
> +	*no_spc = list_empty(&tx->free_list) ? 1 : 0;
> +
> +	return t_sdu;
> +}
> +
> +static void put_tx_struct(struct tx_cxt *tx, struct usb_tx_sdu *t_sdu)
> +{
> +	list_add_tail(&t_sdu->list, &tx->free_list);
> +	tx->avail_count++;
> +}
> +
> +static struct usb_rx *alloc_rx_struct(void)
> +{
> +	struct usb_rx *r = NULL;
> +	int ret = 0;
> +
> +	r = kmalloc(sizeof(struct usb_rx), GFP_ATOMIC);
> +	if (!r) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +
> +	r->urb = usb_alloc_urb(0, GFP_ATOMIC);
> +	r->buf = kmalloc(RX_BUF_SIZE, GFP_ATOMIC);

We're allocating huge chunks of memory here.  I don't think it needs
to be atomic also.

> +	if (!r->urb || !r->buf) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +out:
> +
> +	if (ret < 0) {
> +		if (r) {
> +			usb_free_urb(r->urb);
> +			kfree(r->buf);
> +			kfree(r);
> +		}
> +		return NULL;
> +	}
> +
> +	return r;
> +}
> +
> +static void free_rx_struct(struct usb_rx *r)
> +{
> +	if (r) {
> +		usb_free_urb(r->urb);
> +		kfree(r->buf);
> +		kfree(r);
> +	}
> +}
> +
> +static struct usb_rx *get_rx_struct(struct rx_cxt *rx, int *no_spc)
> +{
> +	struct usb_rx *r;
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&rx->rx_lock, flags);
> +
> +	if (list_empty(&rx->free_list)) {
> +		spin_unlock_irqrestore(&rx->rx_lock, flags);
> +		return NULL;
> +	}
> +
> +	r = list_entry(rx->free_list.next, struct usb_rx, free_list);
> +	list_del(&r->free_list);
> +
> +	rx->avail_count--;
> +
> +	*no_spc = list_empty(&rx->free_list) ? 1 : 0;
> +
> +	spin_unlock_irqrestore(&rx->rx_lock, flags);
> +
> +	return r;
> +}
> +
> +static void put_rx_struct(struct rx_cxt *rx, struct usb_rx *r)
> +{
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&rx->rx_lock, flags);
> +
> +	list_add_tail(&r->free_list, &rx->free_list);
> +	rx->avail_count++;
> +
> +	spin_unlock_irqrestore(&rx->rx_lock, flags);
> +}
> +
> +static void release_usb(struct lte_udev *udev)
> +{
> +	struct rx_cxt	*rx = &udev->rx;
> +	struct tx_cxt	*tx = &udev->tx;
> +	struct usb_tx	*t, *t_next;
> +	struct usb_rx	*r, *r_next;
> +	struct usb_tx_sdu	*t_sdu, *t_sdu_next;
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&tx->lock, flags);
> +	list_for_each_entry_safe(t_sdu, t_sdu_next, &tx->sdu_list, list)
> +	{
> +		list_del(&t_sdu->list);
> +		free_tx_sdu_struct(t_sdu);
> +	}
> +
> +	list_for_each_entry_safe(t, t_next, &tx->hci_list, list)
> +	{
> +		list_del(&t->list);
> +		free_tx_struct(t);
> +	}
> +
> +	list_for_each_entry_safe(t_sdu, t_sdu_next, &tx->free_list, list)
> +	{
> +		list_del(&t_sdu->list);
> +		free_tx_sdu_struct(t_sdu);
> +	}
> +	spin_unlock_irqrestore(&tx->lock, flags);
> +
> +	spin_lock_irqsave(&rx->submit_lock, flags);
> +	list_for_each_entry_safe(r, r_next, &rx->rx_submit_list, rx_submit_list)
> +	{
> +		spin_unlock_irqrestore(&rx->submit_lock, flags);
> +		usb_kill_urb(r->urb);
> +		spin_lock_irqsave(&rx->submit_lock, flags);
> +	}
> +	spin_unlock_irqrestore(&rx->submit_lock, flags);
> +
> +	spin_lock_irqsave(&rx->rx_lock, flags);
> +	list_for_each_entry_safe(r, r_next, &rx->free_list, free_list)
> +	{
> +		list_del(&r->free_list);
> +		free_rx_struct(r);
> +	}
> +	spin_unlock_irqrestore(&rx->rx_lock, flags);
> +
> +	spin_lock_irqsave(&rx->to_host_lock, flags);
> +	list_for_each_entry_safe(r, r_next, &rx->to_host_list, to_host_list)
> +	{
> +		if (r->index == (void *)udev) {
> +			list_del(&r->to_host_list);
> +			free_rx_struct(r);
> +		}
> +	}
> +	spin_unlock_irqrestore(&rx->to_host_lock, flags);
> +}
> +
> +static int init_usb(struct lte_udev *udev)
> +{
> +#define MAX_NUM_SDU_BUF	64

Put these things in a header file.

> +	int ret = 0;
> +	int i;
> +	struct tx_cxt *tx = &udev->tx;
> +	struct rx_cxt *rx = &udev->rx;
> +	struct usb_tx_sdu *t_sdu = NULL;
> +	struct usb_rx *r = NULL;
> +	unsigned long flags;
> +
> +	udev->send_complete = 1;
> +	udev->tx_stop = 0;
> +	udev->request_mac_addr = 0;
> +
> +#ifdef LTE_USB_PM
> +	udev->usb_state = PM_NORMAL;
> +#endif /* LTE_USB_PM */
> +
> +
> +	INIT_LIST_HEAD(&tx->sdu_list);
> +	INIT_LIST_HEAD(&tx->hci_list);
> +	INIT_LIST_HEAD(&tx->free_list);
> +	INIT_LIST_HEAD(&rx->rx_submit_list);
> +	INIT_LIST_HEAD(&rx->free_list);
> +	INIT_LIST_HEAD(&rx->to_host_list);
> +	spin_lock_init(&tx->lock);
> +	spin_lock_init(&rx->rx_lock);
> +	spin_lock_init(&rx->submit_lock);
> +	spin_lock_init(&rx->to_host_lock);
> +
> +	tx->avail_count = 0;
> +	rx->avail_count = 0;
> +
> +#ifdef LTE_USB_PM
> +	udev->rx_cb = NULL;
> +#endif /* LTE_USB_PM */
> +
> +	for (i = 0; i < MAX_NUM_SDU_BUF; i++) {
> +		t_sdu = alloc_tx_sdu_struct();
> +		if (t_sdu == NULL) {
> +			ret = -ENOMEM;
> +			goto fail;
> +		}
> +
> +		spin_lock_irqsave(&tx->lock, flags);

Do we need this locking in the init() fuction?  What are we racing
against?

> +		list_add(&t_sdu->list, &tx->free_list);
> +		tx->avail_count++;
> +		spin_unlock_irqrestore(&tx->lock, flags);
> +	}
> +
> +	for (i = 0; i < MAX_RX_SUBMIT_COUNT*2; i++) {
> +		r = alloc_rx_struct();
> +		if (r == NULL) {
> +			ret = -ENOMEM;
> +			goto fail;
> +		}
> +
> +		spin_lock_irqsave(&rx->rx_lock, flags);
> +		list_add(&r->free_list, &rx->free_list);
> +		rx->avail_count++;
> +		spin_unlock_irqrestore(&rx->rx_lock, flags);
> +	}
> +	INIT_DELAYED_WORK(&udev->work_tx, do_tx);
> +	INIT_DELAYED_WORK(&udev->work_rx, do_rx);
> +	return 0;
> +fail:
> +	return ret;
> +}
> +
> +static int set_mac_address(u8 *data, void *arg)
> +{
> +	struct phy_dev *phy_dev = (struct phy_dev *)arg;
> +	struct lte_udev *udev = phy_dev->priv_dev;
> +	struct tlv *tlv = (struct tlv *)data;
> +	u8 mac_address[6] = {0, };

ETH_ALEN

> +
> +	if (tlv->type == MAC_ADDRESS && udev->request_mac_addr) {
> +		memcpy(mac_address, tlv->data, tlv->len);
> +
> +		if (register_lte_device(phy_dev, &udev->intf->dev, mac_address) < 0)
> +			printk(KERN_ERR "glte: register lte device failed\n");
> +
> +		udev->request_mac_addr = 0;
> +
> +		return 1;
> +	}
> +
> +	return 0;
> +}
> +
> +static void do_rx(struct work_struct *work)
> +{
> +	struct lte_udev *udev = container_of(work, struct lte_udev, work_rx.work);
> +	struct rx_cxt *rx = &udev->rx;
> +	struct usb_rx *r;
> +	struct hci_packet *hci;
> +	struct phy_dev *phy_dev;
> +	u16 cmd_evt;
> +	int ret;
> +	unsigned long flags;
> +
> +	while (1) {
> +		spin_lock_irqsave(&rx->to_host_lock, flags);
> +		if (list_empty(&rx->to_host_list)) {
> +			spin_unlock_irqrestore(&rx->to_host_lock, flags);
> +			break;
> +		}
> +		r = list_entry(rx->to_host_list.next, struct usb_rx, to_host_list);
> +		list_del(&r->to_host_list);
> +		spin_unlock_irqrestore(&rx->to_host_lock, flags);
> +
> +		phy_dev = (struct phy_dev *)r->cb_data;
> +		udev = (struct lte_udev *)phy_dev->priv_dev;
> +		hci = (struct hci_packet *)r->buf;
> +		cmd_evt = D2H(&udev->gdm_ed, hci->cmd_evt);
> +
> +		switch (cmd_evt) {
> +		case LTE_GET_INFORMATION_RESULT:
> +			if (set_mac_address(hci->data, r->cb_data) == 0) {
> +				ret = r->callback(r->cb_data,
> +						  r->buf,
> +						  r->urb->actual_length,
> +						  KERNEL_THREAD);
> +			}
> +			break;
> +
> +		default:
> +			if (r->callback) {
> +				ret = r->callback(r->cb_data,
> +						  r->buf,
> +						  r->urb->actual_length,
> +						  KERNEL_THREAD);
> +
> +				if (ret == -EAGAIN)
> +					printk(KERN_ERR "glte: failed to send received data\n");
> +			}
> +			break;
> +		}
> +
> +		put_rx_struct(rx, r);
> +
> +		gdm_usb_recv(udev,
> +			     r->callback,
> +			     r->cb_data,
> +			     USB_COMPLETE);
> +	}
> +}
> +
> +static void remove_rx_submit_list(struct usb_rx *r, struct rx_cxt *rx)
> +{
> +	unsigned long flags;
> +	struct usb_rx	*r_remove, *r_remove_next;
> +
> +	spin_lock_irqsave(&rx->submit_lock, flags);
> +	list_for_each_entry_safe(r_remove, r_remove_next, &rx->rx_submit_list, rx_submit_list)
> +	{
> +		if (r == r_remove) {
> +			list_del(&r->rx_submit_list);
> +			break;
> +		}
> +	}
> +	spin_unlock_irqrestore(&rx->submit_lock, flags);
> +}
> +
> +static void gdm_usb_rcv_complete(struct urb *urb)
> +{
> +	struct usb_rx *r = urb->context;
> +	struct rx_cxt *rx = r->rx;
> +	unsigned long flags;
> +	struct lte_udev *udev = container_of(r->rx, struct lte_udev, rx);
> +#ifdef LTE_USB_PM
> +	struct usb_device *usbdev = udev->usbdev;
> +#endif /* LTE_USB_PM */
> +
> +	remove_rx_submit_list(r, rx);
> +
> +	if (!urb->status && r->callback) {
> +		spin_lock_irqsave(&rx->to_host_lock, flags);
> +		list_add_tail(&r->to_host_list, &rx->to_host_list);
> +		queue_work(usb_rx_wq, &udev->work_rx.work);
> +		spin_unlock_irqrestore(&rx->to_host_lock, flags);
> +	} else {
> +#ifdef LTE_USB_PM
> +		if (urb->status && udev->usb_state == PM_NORMAL)
> +#else
> +		if (urb->status)
> +#endif /* LTE_USB_PM */
> +			printk(KERN_ERR "glte: gdm_usb_rcv_complete urb status error %d\n", urb->status);
> +
> +		put_rx_struct(rx, r);
> +	}
> +
> +#ifdef LTE_USB_PM
> +	usb_mark_last_busy(usbdev);
> +#endif /* LTE_USB_PM */
> +
> +}
> +
> +static int gdm_usb_recv(void *priv_dev,
> +			int (*cb)(void *cb_data, void *data, int len, int context),
> +			void *cb_data,
> +			int context)
> +{
> +	struct lte_udev *udev = priv_dev;
> +	struct usb_device *usbdev = udev->usbdev;
> +	struct rx_cxt *rx = &udev->rx;
> +	struct usb_rx *r;
> +	int no_spc;
> +	int ret;
> +	unsigned long flags;
> +
> +	if (!udev->usbdev) {
> +		printk(KERN_ERR "glte: invalid device\n");
> +		return -ENODEV;
> +	}
> +
> +	r = get_rx_struct(rx, &no_spc);
> +	if (!r) {
> +		printk(KERN_ERR "glte: Out of Memory\n");
> +		return -ENOMEM;
> +	}
> +
> +#ifdef LTE_USB_PM
> +	udev->rx_cb = cb;
> +#endif /* LTE_USB_PM */
> +	r->callback = cb;
> +	r->cb_data = cb_data;
> +	r->index = (void *)udev;
> +	r->rx = rx;
> +
> +	usb_fill_bulk_urb(r->urb,
> +			  usbdev,
> +			  usb_rcvbulkpipe(usbdev, 0x83),
> +			  r->buf,
> +			  RX_BUF_SIZE,
> +			  gdm_usb_rcv_complete,
> +			  r);
> +
> +	spin_lock_irqsave(&rx->submit_lock, flags);
> +	list_add_tail(&r->rx_submit_list, &rx->rx_submit_list);
> +	spin_unlock_irqrestore(&rx->submit_lock, flags);
> +
> +	if (context == KERNEL_THREAD)
> +		ret = usb_submit_urb(r->urb, GFP_KERNEL);
> +	else
> +		ret = usb_submit_urb(r->urb, GFP_ATOMIC);
> +
> +	if (ret) {
> +		spin_lock_irqsave(&rx->submit_lock, flags);
> +		list_del(&r->rx_submit_list);
> +		spin_unlock_irqrestore(&rx->submit_lock, flags);
> +
> +		printk(KERN_ERR "glte: usb_submit_urb fail (%p)\n", r);
> +		put_rx_struct(rx, r);
> +	}
> +
> +	return ret;
> +}
> +
> +static void gdm_usb_send_complete(struct urb *urb)
> +{
> +	struct usb_tx *t = urb->context;
> +	struct tx_cxt *tx = t->tx;
> +	struct lte_udev *udev = container_of(tx, struct lte_udev, tx);
> +	unsigned long flags;
> +
> +	if (urb->status == -ECONNRESET) {
> +		printk(KERN_INFO "glte: CONNRESET\n");
> +		return;
> +	}
> +
> +	if (t->callback)
> +		t->callback(t->cb_data);
> +
> +	free_tx_struct(t);
> +
> +	spin_lock_irqsave(&tx->lock, flags);
> +	udev->send_complete = 1;
> +	queue_work(usb_tx_wq, &udev->work_tx.work);
> +	spin_unlock_irqrestore(&tx->lock, flags);
> +}
> +
> +static int send_tx_packet(struct usb_device *usbdev, struct usb_tx *t, u32 len)
> +{
> +	int ret = 0;
> +
> +	if (!(len%512))
> +		len++;

What does this do?  We have it other places as well.

> +
> +	usb_fill_bulk_urb(t->urb,
> +			  usbdev,
> +			  usb_sndbulkpipe(usbdev, 2),
> +			  t->buf,
> +			  len,
> +			  gdm_usb_send_complete,
> +			  t);
> +
> +	ret = usb_submit_urb(t->urb, GFP_ATOMIC);
> +
> +	if (ret)
> +		printk(KERN_ERR "glte: usb_submit_urb fail %d\n", ret);
> +
> +#ifdef LTE_USB_PM
> +	usb_mark_last_busy(usbdev);
> +#endif /* LTE_USB_PM */
> +
> +	return ret;
> +}
> +
> +static u32 packet_aggregation(struct lte_udev *udev, u8 *send_buf)
> +{
> +	struct tx_cxt *tx = &udev->tx;
> +	struct usb_tx_sdu *t_sdu = NULL;
> +	struct multi_sdu *multi_sdu = (struct multi_sdu *)send_buf;
> +	u16 send_len = 0;
> +	u16 num_packet = 0;
> +	unsigned long flags;
> +
> +	multi_sdu->cmd_evt = H2D(&udev->gdm_ed, LTE_TX_MULTI_SDU);
> +
> +	while (1) {

	while (num_packet < 256) {

or better yet:

	while (num_packet < SOMETHING_MAX_PACKET) {


> +		spin_lock_irqsave(&tx->lock, flags);
> +		if (list_empty(&tx->sdu_list)) {
> +			spin_unlock_irqrestore(&tx->lock, flags);
> +			break;
> +		}
> +		t_sdu = list_entry(tx->sdu_list.next, struct usb_tx_sdu, list);	
> +		if (send_len + t_sdu->len > MAX_SDU_SIZE) {
> +			spin_unlock_irqrestore(&tx->lock, flags);
> +			break;
> +		}
> +
> +		list_del(&t_sdu->list);
> +		spin_unlock_irqrestore(&tx->lock, flags);
> +
> +		memcpy(multi_sdu->data + send_len, t_sdu->buf, t_sdu->len);
> +
> +		send_len += (t_sdu->len + 3) & 0xfffc;
> +		num_packet++;
> +
> +		if (tx->avail_count > 10)
> +			t_sdu->callback(t_sdu->cb_data);
> +
> +		spin_lock_irqsave(&tx->lock, flags);
> +		put_tx_struct(tx, t_sdu);
> +		spin_unlock_irqrestore(&tx->lock, flags);
> +
> +		if (num_packet >= 256)
> +			break;
> +	}
> +
> +	multi_sdu->len = H2D(&udev->gdm_ed, send_len);
> +	multi_sdu->num_packet = H2D(&udev->gdm_ed, num_packet);
> +
> +	return send_len + offsetof(struct multi_sdu, data);
> +}
> +
> +static void do_tx(struct work_struct *work)
> +{
> +	struct lte_udev *udev = container_of(work, struct lte_udev, work_tx.work);
> +	struct usb_device *usbdev = udev->usbdev;
> +	struct tx_cxt *tx = &udev->tx;
> +	struct usb_tx *t = NULL;
> +	int is_send = 0;
> +	u32 len = 0;
> +	unsigned long flags;

Put a blank line between declarations and code.

> +#ifdef LTE_USB_PM
> +	if (!usb_autopm_get_interface(udev->intf))
> +		usb_autopm_put_interface(udev->intf);
> +
> +	if (udev->usb_state == PM_SUSPEND)
> +		return;
> +#endif /* LTE_USB_PM */
> +
> +	spin_lock_irqsave(&tx->lock, flags);
> +	if (!udev->send_complete) {
> +		spin_unlock_irqrestore(&tx->lock, flags);
> +		return;
> +	} else {
> +		udev->send_complete = 0;
> +	}
> +
> +	if (!list_empty(&tx->hci_list)) {
> +		t = list_entry(tx->hci_list.next, struct usb_tx, list);
> +		list_del(&t->list);
> +		len = t->len;
> +		t->is_sdu = 0;
> +		is_send = 1;
> +	} else if (!list_empty(&tx->sdu_list)) {
> +		if (udev->tx_stop) {
> +			udev->send_complete = 1;
> +			spin_unlock_irqrestore(&tx->lock, flags);
> +			return;
> +		}
> +
> +		t = alloc_tx_struct(TX_BUF_SIZE);

No error checking here.

> +		t->callback = NULL;
> +		t->tx = tx;
> +		t->is_sdu = 1;
> +		is_send = 1;
> +	}
> +
> +	if (!is_send) {
> +		udev->send_complete = 1;
> +		spin_unlock_irqrestore(&tx->lock, flags);
> +		return;
> +	}
> +	spin_unlock_irqrestore(&tx->lock, flags);
> +
> +	if (t->is_sdu)
> +		len = packet_aggregation(udev, t->buf);
> +
> +	if (send_tx_packet(usbdev, t, len)) {
> +		printk(KERN_ERR "glte: send_tx_packet fail\n");
> +		t->callback = NULL;
> +		gdm_usb_send_complete(t->urb);
> +	}
> +}
> +
> +#define SDU_PARAM_LEN 12
> +static int gdm_usb_sdu_send(void *priv_dev, void *data, int len,
> +				unsigned int dftEpsId, unsigned int epsId,
> +				void (*cb)(void *data), void *cb_data,
> +			    int dev_idx, int nic_type)
> +{
> +	struct lte_udev *udev = priv_dev;
> +	struct tx_cxt *tx = &udev->tx;
> +	struct usb_tx_sdu *t_sdu;
> +	struct sdu *sdu = NULL;
> +	unsigned long flags;
> +	int no_spc = 0;
> +	u16 send_len;
> +
> +	if (!udev->usbdev) {
> +		printk(KERN_ERR "glte: sdu send - invalid device\n");
> +		return TX_NO_DEV;
> +	}
> +
> +	spin_lock_irqsave(&tx->lock, flags);
> +	t_sdu = get_tx_sdu_struct(tx, &no_spc);
> +	spin_unlock_irqrestore(&tx->lock, flags);
> +
> +	if (t_sdu == NULL) {
> +		printk(KERN_ERR "glte: sdu send - free list empty\n");
> +		return TX_NO_SPC;
> +	}
> +
> +	sdu = (struct sdu *)t_sdu->buf;
> +	sdu->cmd_evt = H2D(&udev->gdm_ed, LTE_TX_SDU);
> +	if (nic_type == NIC_TYPE_ARP) {
> +		send_len = len + SDU_PARAM_LEN;
> +	    memcpy(sdu->data, data, len);
> +	} else {
> +	    send_len = len - ETH_HLEN;
> +	    send_len += SDU_PARAM_LEN;
> +	    memcpy(sdu->data, data+ETH_HLEN, len-ETH_HLEN);
> +	}
> +
> +	sdu->len = H2D(&udev->gdm_ed, send_len);
> +	sdu->dftEpsId = H4D(&udev->gdm_ed, dftEpsId);
> +	sdu->bearer_ID = H4D(&udev->gdm_ed, epsId);
> +	sdu->nic_type = H4D(&udev->gdm_ed, nic_type);
> +
> +	t_sdu->len = send_len + HCI_HEADER_SIZE;
> +	t_sdu->callback = cb;
> +	t_sdu->cb_data = cb_data;
> +
> +	spin_lock_irqsave(&tx->lock, flags);
> +	list_add_tail(&t_sdu->list, &tx->sdu_list);
> +	queue_work(usb_tx_wq, &udev->work_tx.work);
> +	spin_unlock_irqrestore(&tx->lock, flags);
> +
> +	if (no_spc)
> +		return TX_NO_BUFFER;
> +
> +	return 0;
> +}
> +
> +static int gdm_usb_hci_send(void *priv_dev, void *data, int len,
> +			void (*cb)(void *data), void *cb_data)
> +{
> +	struct lte_udev *udev = priv_dev;
> +	struct tx_cxt *tx = &udev->tx;
> +	struct usb_tx *t;
> +	unsigned long flags;
> +
> +	if (!udev->usbdev) {
> +		printk(KERN_ERR "glte: hci send - invalid device\n");
> +		return -ENODEV;
> +	}
> +
> +	t = alloc_tx_struct(len);
> +	if (t == NULL) {
> +		printk(KERN_ERR "glte: hci_send - out of memory\n");

kmalloc() already has much better error messages than this.  Just
return -ENOMEM directly.

> +		return -ENOMEM;
> +	}
> +
> +	memcpy(t->buf, data, len);
> +	t->callback = cb;
> +	t->cb_data = cb_data;
> +	t->len = len;
> +	t->tx = tx;
> +	t->is_sdu = 0;
> +
> +	spin_lock_irqsave(&tx->lock, flags);
> +	list_add_tail(&t->list, &tx->hci_list);
> +	queue_work(usb_tx_wq, &udev->work_tx.work);
> +	spin_unlock_irqrestore(&tx->lock, flags);
> +
> +	return 0;
> +}
> +
> +static struct gdm_endian *gdm_usb_get_endian(void *priv_dev)
> +{
> +	struct lte_udev *udev = priv_dev;
> +
> +	return &udev->gdm_ed;
> +}
> +
> +static int gdm_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
> +{
> +	int ret = 0;
> +	struct phy_dev *phy_dev = NULL;
> +	struct lte_udev *udev = NULL;
> +	u16 idVendor, idProduct;
> +	int bInterfaceNumber;
> +	struct usb_device *usbdev = interface_to_usbdev(intf);
> +
> +	bInterfaceNumber = intf->cur_altsetting->desc.bInterfaceNumber;
> +	idVendor = L2H(usbdev->descriptor.idVendor);
> +	idProduct = L2H(usbdev->descriptor.idProduct);
> +
> +	printk(KERN_INFO "glte: net vid = 0x%04x pid = 0x%04x\n", idVendor, idProduct);
> +
> +	if (bInterfaceNumber > NETWORK_INTERFACE) {
> +		printk(KERN_INFO "glte: not a network device");
> +		return -1;
> +	}
> +
> +	phy_dev = kmalloc(sizeof(struct phy_dev), GFP_ATOMIC);

Surely the prope() can use GFP_KERNEL.

> +	if (!phy_dev) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +
> +	udev = kmalloc(sizeof(struct lte_udev), GFP_ATOMIC);
> +	if (!udev) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +
> +	memset(phy_dev, 0, sizeof(struct phy_dev));
> +	memset(udev, 0, sizeof(struct lte_udev));
> +
> +	phy_dev->priv_dev = (void *)udev;
> +	phy_dev->send_hci_func = gdm_usb_hci_send;
> +	phy_dev->send_sdu_func = gdm_usb_sdu_send;
> +	phy_dev->rcv_func = gdm_usb_recv;
> +	phy_dev->get_endian = gdm_usb_get_endian;
> +
> +	udev->usbdev = usbdev;
> +	ret = init_usb(udev);
> +	if (ret < 0) {
> +		printk(KERN_ERR "glte: init_usb func fail\n");
> +		goto out;
> +	}
> +	udev->intf = intf;
> +
> +#ifdef LTE_USB_PM
> +	intf->needs_remote_wakeup = 1;
> +	usb_enable_autosuspend(usbdev);
> +	pm_runtime_set_autosuspend_delay(&usbdev->dev, AUTO_SUSPEND_TIMER);
> +#endif /* LTE_USB_PM */
> +
> +	/* List up hosts with big endians, otherwise, defaults to little endian */
> +	if (idProduct == PID_GDM7243)
> +		set_endian(&udev->gdm_ed, ENDIANNESS_BIG);
> +	else
> +		set_endian(&udev->gdm_ed, ENDIANNESS_LITTLE);
> +
> +	ret = request_mac_address(udev);
> +	if (ret < 0) {
> +		printk(KERN_ERR "glte: request Mac address failed\n");
> +		goto out;
> +	}
> +
> +	start_rx_proc(phy_dev);
> +out:
> +
> +	if (ret < 0) {
> +		kfree(phy_dev);
> +		if (udev) {
> +			release_usb(udev);
> +			kfree(udev);
> +		}
> +	}
> +
> +	usb_get_dev(usbdev);
> +	usb_set_intfdata(intf, phy_dev);
> +
> +	return ret;
> +}
> +
> +static void gdm_usb_disconnect(struct usb_interface *intf)
> +{
> +	struct phy_dev *phy_dev;
> +	struct lte_udev *udev;
> +	u16 idVendor, idProduct;
> +	struct usb_device *usbdev;
> +	usbdev = interface_to_usbdev(intf);
> +
> +	idVendor = L2H(usbdev->descriptor.idVendor);
> +	idProduct = L2H(usbdev->descriptor.idProduct);
> +
> +	phy_dev = usb_get_intfdata(intf);
> +
> +	udev = phy_dev->priv_dev;
> +	unregister_lte_device(phy_dev);
> +
> +	release_usb(udev);
> +
> +	kfree(udev);
> +	udev = NULL;
> +
> +	kfree(phy_dev);
> +	phy_dev = NULL;
> +
> +	usb_put_dev(usbdev);
> +}
> +
> +#ifdef LTE_USB_PM
> +static int gdm_usb_suspend(struct usb_interface *intf, pm_message_t pm_msg)
> +{
> +	struct phy_dev *phy_dev;
> +	struct lte_udev *udev;
> +	struct rx_cxt *rx;
> +	struct usb_rx *r;
> +	struct usb_rx *r_next;
> +	unsigned long flags;
> +
> +	printk(KERN_INFO "gdm_usb_suspend\n");
> +
> +	phy_dev = usb_get_intfdata(intf);
> +	udev = phy_dev->priv_dev;
> +	rx = &udev->rx;
> +	if (udev->usb_state != PM_NORMAL) {
> +		printk(KERN_ERR "glte: usb suspend - invalid state");
> +		return -1;
> +	}
> +
> +	udev->usb_state = PM_SUSPEND;
> +
> +	spin_lock_irqsave(&rx->submit_lock, flags);
> +	list_for_each_entry_safe(r, r_next, &rx->rx_submit_list, rx_submit_list)
> +	{
> +		spin_unlock_irqrestore(&rx->submit_lock, flags);
> +		usb_kill_urb(r->urb);
> +		spin_lock_irqsave(&rx->submit_lock, flags);
> +	}
> +	spin_unlock_irqrestore(&rx->submit_lock, flags);
> +
> +	return 0;
> +}
> +
> +static int gdm_usb_resume(struct usb_interface *intf)
> +{
> +	struct phy_dev *phy_dev;
> +	struct lte_udev *udev;
> +	struct tx_cxt *tx;
> +	struct rx_cxt *rx;
> +	unsigned long flags;
> +	int issue_count;
> +	int i;
> +
> +	printk(KERN_INFO "gdm_usb_resume\n");
> +
> +	phy_dev = usb_get_intfdata(intf);
> +	udev = phy_dev->priv_dev;
> +	rx = &udev->rx;
> +
> +	if (udev->usb_state != PM_SUSPEND) {
> +		printk(KERN_ERR "glte: usb resume - invalid state");
> +		return -1;
> +	}
> +	udev->usb_state = PM_NORMAL;
> +
> +	spin_lock_irqsave(&rx->rx_lock, flags);
> +	issue_count = rx->avail_count - MAX_RX_SUBMIT_COUNT;
> +	spin_unlock_irqrestore(&rx->rx_lock, flags);
> +
> +	if (issue_count >= 0) {
> +		for (i = 0; i < issue_count; i++)
> +			gdm_usb_recv(phy_dev->priv_dev,
> +				     udev->rx_cb,
> +				     phy_dev,
> +				     USB_COMPLETE);
> +	}
> +
> +	tx = &udev->tx;
> +	spin_lock_irqsave(&tx->lock, flags);
> +	queue_work(usb_tx_wq, &udev->work_tx.work);
> +	spin_unlock_irqrestore(&tx->lock, flags);
> +
> +	return 0;
> +}
> +#endif /* LTE_USB_PM */
> +
> +static struct usb_driver gdm_usb_lte_driver = {
> +	.name = "gdm_lte",
> +	.probe = gdm_usb_probe,
> +	.disconnect = gdm_usb_disconnect,
> +	.id_table = id_table,
> +#ifdef LTE_USB_PM
> +	.supports_autosuspend = 1,
> +	.suspend = gdm_usb_suspend,
> +	.resume = gdm_usb_resume,
> +	.reset_resume = gdm_usb_resume,
> +#endif /* LTE_USB_PM */
> +};
> +
> +static int __init gdm_usb_lte_init(void)
> +{
> +	if (gdm_lte_event_init() < 0) {
> +		printk(KERN_ERR "glte: error creating event\n");
> +		return -1;
> +	}
> +
> +	usb_tx_wq = create_workqueue("usb_tx_wq");
> +	if (usb_tx_wq == NULL)
> +		return -1;
> +
> +	usb_rx_wq = create_workqueue("usb_rx_wq");
> +	if (usb_rx_wq == NULL)
> +		return -1;
> +
> +	return usb_register(&gdm_usb_lte_driver);
> +}
> +
> +static void __exit gdm_usb_lte_exit(void)
> +{
> +	gdm_lte_event_exit();
> +
> +	usb_deregister(&gdm_usb_lte_driver);
> +
> +	if (usb_tx_wq) {
> +		flush_workqueue(usb_tx_wq);
> +		destroy_workqueue(usb_tx_wq);
> +	}
> +
> +	if (usb_rx_wq) {
> +		flush_workqueue(usb_rx_wq);
> +		destroy_workqueue(usb_rx_wq);
> +	}
> +}
> +
> +module_init(gdm_usb_lte_init);
> +module_exit(gdm_usb_lte_exit);
> +
> +MODULE_VERSION(DRIVER_VERSION);
> +MODULE_DESCRIPTION("GCT LTE USB Device Driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/staging/gdm724x/gdm_usb.h b/drivers/staging/gdm724x/gdm_usb.h
> new file mode 100644
> index 0000000..c6118fc
> --- /dev/null
> +++ b/drivers/staging/gdm724x/gdm_usb.h
> @@ -0,0 +1,92 @@
> +/*
> + * Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved.
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#ifndef _GDM_USB_H_
> +#define _GDM_USB_H_
> +
> +#include <linux/version.h>
> +#include <linux/types.h>
> +#include <linux/usb.h>
> +#include <linux/list.h>
> +#include <linux/time.h>
> +
> +#include "gdm_endian.h"
> +#include "hci_packet.h"
> +
> +struct usb_tx {
> +	struct list_head list;
> +	struct urb *urb;
> +	u8 *buf;
> +	u32 len;
> +	void (*callback)(void *cb_data);
> +	void *cb_data;
> +	struct tx_cxt *tx;
> +	u8 is_sdu;
> +};
> +
> +struct usb_tx_sdu {
> +	struct list_head list;
> +	u8 *buf;
> +	u32 len;
> +	void (*callback)(void *cb_data);
> +	void *cb_data;
> +};
> +
> +struct usb_rx {
> +	struct list_head to_host_list;
> +	struct list_head free_list;
> +	struct list_head rx_submit_list;
> +	struct rx_cxt	*rx;
> +	struct urb *urb;
> +	u8 *buf;
> +	int (*callback)(void *cb_data, void *data, int len, int context);
> +	void *cb_data;
> +	void *index;
> +};
> +
> +struct tx_cxt {
> +	struct list_head sdu_list;
> +	struct list_head hci_list;
> +	struct list_head free_list;
> +	u32 avail_count;
> +	spinlock_t lock;
> +};
> +
> +struct rx_cxt {
> +	struct list_head to_host_list;
> +	struct list_head rx_submit_list;
> +	struct list_head free_list;
> +	u32	avail_count;
> +	spinlock_t to_host_lock;
> +	spinlock_t rx_lock;
> +	spinlock_t submit_lock;
> +};
> +
> +struct lte_udev {
> +	struct usb_device *usbdev;
> +	struct gdm_endian gdm_ed;
> +	struct tx_cxt tx;
> +	struct rx_cxt rx;
> +	struct delayed_work work_tx;
> +	struct delayed_work work_rx;
> +	u8 send_complete;
> +	u8 tx_stop;
> +	struct usb_interface *intf;
> +#ifdef LTE_USB_PM
> +	int (*rx_cb)(void *cb_data, void *data, int len, int context);
> +	int usb_state;
> +#endif /* LTE_USB_PM */
> +	u8 request_mac_addr;
> +};
> +
> +#endif /* _GDM_USB_H_ */
> diff --git a/drivers/staging/gdm724x/hci.h b/drivers/staging/gdm724x/hci.h
> new file mode 100644
> index 0000000..9a591b0
> --- /dev/null
> +++ b/drivers/staging/gdm724x/hci.h
> @@ -0,0 +1,55 @@
> +/*
> + * Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved.
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#ifndef _HCI_H_
> +#define _HCI_H_
> +
> +#define LTE_GET_INFORMATION		0x3002
> +#define LTE_GET_INFORMATION_RESULT	0xB003
> +	#define MAC_ADDRESS		0xA2
> +
> +#define LTE_LINK_ON_OFF_INDICATION	0xB133
> +#define LTE_PDN_TABLE_IND		0xB143
> +
> +#define LTE_TX_SDU			0x3200
> +#define LTE_RX_SDU			0xB201
> +#define LTE_TX_MULTI_SDU		0x3202
> +#define LTE_RX_MULTI_SDU		0xB203
> +
> +#define LTE_DL_SDU_FLOW_CONTROL		0x3305
> +#define LTE_UL_SDU_FLOW_CONTROL		0xB306
> +
> +#define LTE_AT_CMD_TO_DEVICE		0x3307
> +#define LTE_AT_CMD_FROM_DEVICE		0xB308
> +
> +#define LTE_SDIO_DM_SEND_PKT		0x3312
> +#define LTE_SDIO_DM_RECV_PKT		0xB313
> +
> +#define LTE_NV_RESTORE_REQUEST		0xB30C
> +#define LTE_NV_RESTORE_RESPONSE		0x330D
> +#define LTE_NV_SAVE_REQUEST		0xB30E
> +	#define NV_TYPE_LTE_INFO	0x00
> +	#define NV_TYPE_BOARD_CONFIG	0x01
> +	#define NV_TYPE_RF_CAL		0x02
> +	#define NV_TYPE_TEMP		0x03
> +	#define NV_TYPE_NET_INFO	0x04
> +	#define NV_TYPE_SAFETY_INFO	0x05
> +	#define NV_TYPE_CDMA_CAL	0x06
> +	#define NV_TYPE_VENDOR		0x07
> +	#define NV_TYPE_ALL		0xff
> +#define LTE_NV_SAVE_RESPONSE		0x330F
> +
> +#define LTE_AT_CMD_TO_DEVICE_EXT	0x3323
> +#define LTE_AT_CMD_FROM_DEVICE_EXT	0xB324
> +
> +#endif /* _HCI_H_ */
> diff --git a/drivers/staging/gdm724x/hci_packet.h b/drivers/staging/gdm724x/hci_packet.h
> new file mode 100644
> index 0000000..cef381f
> --- /dev/null
> +++ b/drivers/staging/gdm724x/hci_packet.h
> @@ -0,0 +1,97 @@
> +/*
> + * Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved.
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#ifndef _HCI_PACKET_H_
> +#define _HCI_PACKET_H_
> +
> +#define HCI_HEADER_SIZE 4
> +
> +/*
> + * The NIC type definition:
> + * For backward compatibility, lower 16 bits used as they were.
> + * Lower 16 bit: NIC_TYPE values
> + * Uppoer 16 bit: NIC_TYPE Flags
> + */
> +#define NIC_TYPE_NIC0		0x00000010
> +#define NIC_TYPE_NIC1		0x00000011
> +#define NIC_TYPE_NIC2		0x00000012
> +#define NIC_TYPE_NIC3		0x00000013
> +#define NIC_TYPE_ARP		0x00000100
> +#define NIC_TYPE_ICMPV6		0x00000200
> +#define NIC_TYPE_MASK		0x0000FFFF
> +#define NIC_TYPE_F_IPV4		0x00010000
> +#define NIC_TYPE_F_IPV6		0x00020000
> +#define NIC_TYPE_F_DHCP		0x00040000
> +#define NIC_TYPE_F_NDP		0x00080000
> +#define NIC_TYPE_F_VLAN		0x00100000
> +
> +#ifndef __packed
> +#define __packed __attribute__((packed))
> +#endif
> +
> +struct hci_packet {
> +	u16 cmd_evt;
> +	u16 len;
> +	u8 data[0];
> +} __packed;
> +
> +struct tlv {
> +	u8 type;
> +	u8 len;
> +	u8 *data[1];
> +} __packed;
> +
> +struct sdu_header {
> +	u16 cmd_evt;
> +	u16 len;
> +	u32 dftEpsId;
> +	u32 bearer_ID;
> +	u32 nic_type;
> +} __packed;
> +
> +struct sdu {
> +	u16 cmd_evt;
> +	u16 len;
> +	u32 dftEpsId;
> +	u32 bearer_ID;
> +	u32 nic_type;
> +	u8 data[0];
> +} __packed;
> +
> +struct multi_sdu {
> +	u16 cmd_evt;
> +	u16 len;
> +	u16 num_packet;
> +	u16 reserved;
> +	u8 data[0];
> +} __packed;
> +
> +struct hci_pdn_table_ind {
> +	u16 cmd_evt;
> +	u16 len;
> +	u8 activate;
> +	u32 dft_eps_id;
> +	u32 nic_type;
> +	u8 pdn_type;
> +	u8 ipv4_addr[4];
> +	u8 ipv6_intf_id[8];
> +} __packed;
> +
> +struct hci_connect_ind {
> +	u16 cmd_evt;
> +	u16 len;
> +	u32 connect;
> +} __packed;
> +
> +
> +#endif /* _HCI_PACKET_H_ */
> diff --git a/drivers/staging/gdm724x/lte_ioctl.h b/drivers/staging/gdm724x/lte_ioctl.h
> new file mode 100644
> index 0000000..8941ebf7
> --- /dev/null
> +++ b/drivers/staging/gdm724x/lte_ioctl.h
> @@ -0,0 +1,73 @@
> +/*
> + * Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved.
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#ifndef _LTE_IOCTL_H_
> +#define _LTE_IOCTL_H_
> +
> +#define SIOCLTEIOCTL	SIOCDEVPRIVATE
> +#define SIOCG_DATA	0x8D10
> +#define SIOCS_DATA	0x8D11
> +
> +#ifndef __packed
> +#define __packed __attribute__((packed))
> +#endif
> +
> +enum {
> +	LINK_ON,
> +	LINK_OFF,
> +	GET_NETWORK_STATICS,
> +	RX_STOP,
> +	RX_RESUME,
> +	GET_DRV_VER,
> +	GET_SDIO_DEVICE_STATUS,
> +	GET_ENDIAN_INFO,
> +};
> +
> +struct dev_endian_t {
> +	unsigned char dev_endian;
> +	unsigned char host_endian;
> +} __packed;
> +
> +struct net_stat_t {
> +	unsigned long tx_packets;
> +	unsigned long rx_packets;
> +	unsigned long tx_bytes;
> +	unsigned long rx_bytes;
> +	unsigned long tx_dropped;
> +	unsigned long rx_dropped;
> +} __packed;
> +
> +struct net_info_t {
> +	unsigned int nic_index;
> +	struct net_stat_t stats;
> +} __packed;
> +
> +struct data_t {
> +	long len;
> +	void *buf;
> +} __packed;
> +
> +struct wm_req_t {
> +	union {
> +		char ifrn_name[IFNAMSIZ];
> +	} ifr_ifrn;
> +	unsigned short cmd;
> +	unsigned short data_id;
> +	struct data_t data;
> +} __packed;
> +
> +#ifndef ifr_name
> +#define ifr_name	(ifr_ifrn.ifrm_name)
> +#endif
> +
> +#endif /* _LTE_IOCTL_H_ */
> diff --git a/drivers/staging/gdm724x/netlink_k.c b/drivers/staging/gdm724x/netlink_k.c
> new file mode 100644
> index 0000000..d5170f6
> --- /dev/null
> +++ b/drivers/staging/gdm724x/netlink_k.c
> @@ -0,0 +1,161 @@
> +/*
> + * Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved.
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/version.h>
> +#include <linux/export.h>
> +#include <linux/etherdevice.h>
> +#include <linux/netlink.h>
> +#include <asm/byteorder.h>
> +#include <net/sock.h>
> +
> +#include "netlink_k.h"
> +
> +#if defined(DEFINE_MUTEX)
> +static DEFINE_MUTEX(netlink_mutex);
> +#else
> +static struct semaphore netlink_mutex;
> +#define mutex_lock(x)		down(x)
> +#define mutex_unlock(x)		up(x)
> +#endif
> +
> +#define ND_MAX_GROUP		30
> +#define ND_IFINDEX_LEN		sizeof(int)
> +#define ND_NLMSG_SPACE(len)	(NLMSG_SPACE(len) + ND_IFINDEX_LEN)
> +#define ND_NLMSG_DATA(nlh)	((void *)((char *)NLMSG_DATA(nlh) + ND_IFINDEX_LEN))
> +#define ND_NLMSG_S_LEN(len)	(len+ND_IFINDEX_LEN)
> +#define ND_NLMSG_R_LEN(nlh)	(nlh->nlmsg_len-ND_IFINDEX_LEN)
> +#define ND_NLMSG_IFIDX(nlh)	NLMSG_DATA(nlh)
> +#define ND_MAX_MSG_LEN		(1024 * 32)
> +
> +static void (*rcv_cb)(struct net_device *dev, u16 type, void *msg, int len);
> +
> +static void netlink_rcv_cb(struct sk_buff *skb)
> +{
> +	struct nlmsghdr	*nlh;
> +	struct net_device *dev;
> +	u32 mlen;
> +	void *msg;
> +	int ifindex;
> +
> +	if (!rcv_cb) {
> +		printk(KERN_ERR "glte: nl cb - unregistered\n");
> +		return;
> +	}
> +
> +	if (skb->len < NLMSG_SPACE(0)) {
> +		printk(KERN_ERR "glte: nl cb - invalid skb length\n");
> +		return;
> +	}
> +
> +	nlh = (struct nlmsghdr *)skb->data;
> +
> +	if (skb->len < nlh->nlmsg_len || nlh->nlmsg_len > ND_MAX_MSG_LEN) {
> +		printk(KERN_ERR "glte: nl cb - invalid length (%d,%d)\n",
> +		       skb->len, nlh->nlmsg_len);
> +		return;
> +	}
> +
> +	memcpy(&ifindex, ND_NLMSG_IFIDX(nlh), ND_IFINDEX_LEN);
> +	msg = ND_NLMSG_DATA(nlh);
> +	mlen = ND_NLMSG_R_LEN(nlh);
> +
> +	dev = dev_get_by_index(&init_net, ifindex);
> +	if (dev) {
> +		rcv_cb(dev, nlh->nlmsg_type, msg, mlen);
> +		dev_put(dev);
> +	} else {
> +		printk(KERN_ERR "glte: nl cb - dev (%d) not found\n", ifindex);
> +	}
> +
> +}
> +
> +static void netlink_rcv(struct sk_buff *skb)
> +{
> +	mutex_lock(&netlink_mutex);
> +	netlink_rcv_cb(skb);
> +	mutex_unlock(&netlink_mutex);
> +}
> +
> +struct sock *netlink_init(int unit,
> +	void (*cb)(struct net_device *dev, u16 type, void *msg, int len))
> +{
> +	struct sock *sock;
> +#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 6, 0)
> +	struct netlink_kernel_cfg cfg = {
> +		.input  = netlink_rcv,
> +	};
> +#endif
> +
> +#if !defined(DEFINE_MUTEX)
> +	init_MUTEX(&netlink_mutex);
> +#endif
> +
> +#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 6, 0)
> +	sock = netlink_kernel_create(&init_net, unit, 0, netlink_rcv, NULL,
> +		THIS_MODULE);
> +#elif LINUX_VERSION_CODE < KERNEL_VERSION(3, 7, 0)
> +	sock = netlink_kernel_create(&init_net, unit, THIS_MODULE, &cfg);
> +#else
> +	sock = netlink_kernel_create(&init_net, unit, &cfg);
> +#endif
> +
> +	if (sock)
> +		rcv_cb = cb;
> +	return sock;
> +}
> +
> +void netlink_exit(struct sock *sock)
> +{
> +	sock_release(sock->sk_socket);
> +}
> +
> +int netlink_send(struct sock *sock, int group, u16 type, void *msg, int len)
> +{
> +	static u32 seq;
> +	struct sk_buff *skb = NULL;
> +	struct nlmsghdr *nlh;
> +	int ret = 0;
> +
> +	if (group > ND_MAX_GROUP)
> +		return -EINVAL;
> +
> +	if (!netlink_has_listeners(sock, group+1))
> +		return -ESRCH;
> +
> +	skb = alloc_skb(NLMSG_SPACE(len), GFP_ATOMIC);
> +	if (!skb)
> +		return -ENOMEM;
> +
> +	seq++;
> +
> +	nlh = nlmsg_put(skb, 0, seq, type, len, 0);
> +	memcpy(NLMSG_DATA(nlh), msg, len);
> +#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 7, 0)
> +	NETLINK_CB(skb).pid = 0;
> +#else
> +	NETLINK_CB(skb).portid = 0;
> +#endif
> +	NETLINK_CB(skb).dst_group = 0;
> +
> +	ret = netlink_broadcast(sock, skb, 0, group+1, GFP_ATOMIC);
> +	if (!ret)
> +		return len;
> +
> +	if (ret != -ESRCH)
> +		printk(KERN_ERR "glte: nl broadcast g=%d, t=%d, l=%d, r=%d\n",
> +		       group, type, len, ret);
> +	else if (netlink_has_listeners(sock, group+1))
> +		return -EAGAIN;
> +
> +	return ret;
> +}
> diff --git a/drivers/staging/gdm724x/netlink_k.h b/drivers/staging/gdm724x/netlink_k.h
> new file mode 100644
> index 0000000..589486d
> --- /dev/null
> +++ b/drivers/staging/gdm724x/netlink_k.h
> @@ -0,0 +1,25 @@
> +/*
> + * Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved.
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#ifndef _NETLINK_K_H
> +#define _NETLINK_K_H
> +
> +#include <linux/netdevice.h>
> +#include <net/sock.h>
> +
> +struct sock *netlink_init(int unit,
> +	void (*cb)(struct net_device *dev, u16 type, void *msg, int len));
> +void netlink_exit(struct sock *sock);
> +int netlink_send(struct sock *sock, int group, u16 type, void *msg, int len);
> +
> +#endif /* _NETLINK_K_H_ */
> -- 
> 1.7.10.4
> 
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