On 27/12/2024 at 18:57, Ming Yu wrote:
> This driver supports Socket CANfd functionality for NCT6694 MFD
> device based on USB interface.
>
> Signed-off-by: Ming Yu <a0282524688@xxxxxxxxx>
> ---
> MAINTAINERS | 1 +
> drivers/net/can/Kconfig | 10 +
> drivers/net/can/Makefile | 1 +
> drivers/net/can/nct6694_canfd.c | 826 ++++++++++++++++++++++++++++++++
> 4 files changed, 838 insertions(+)
> create mode 100644 drivers/net/can/nct6694_canfd.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 5d63542233c4..b961c4827648 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -16729,6 +16729,7 @@ S: Supported
> F: drivers/gpio/gpio-nct6694.c
> F: drivers/i2c/busses/i2c-nct6694.c
> F: drivers/mfd/nct6694.c
> +F: drivers/net/can/nct6694_canfd.c
> F: include/linux/mfd/nct6694.h
>
> NVIDIA (rivafb and nvidiafb) FRAMEBUFFER DRIVER
> diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig
> index cf989bea9aa3..130e98ec28a5 100644
> --- a/drivers/net/can/Kconfig
> +++ b/drivers/net/can/Kconfig
> @@ -200,6 +200,16 @@ config CAN_SUN4I
> To compile this driver as a module, choose M here: the module will
> be called sun4i_can.
>
> +config CAN_NCT6694
> + tristate "Nuvoton NCT6694 Socket CANfd support"
> + depends on MFD_NCT6694
> + help
> + If you say yes to this option, support will be included for Nuvoton
> + NCT6694, a USB device to socket CANfd controller.
> +
> + This driver can also be built as a module. If so, the module will
> + be called nct6694_canfd.
> +
> config CAN_TI_HECC
> depends on ARM
> tristate "TI High End CAN Controller"
> diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile
> index a71db2cfe990..4a6b5b9d6c2b 100644
> --- a/drivers/net/can/Makefile
> +++ b/drivers/net/can/Makefile
> @@ -28,6 +28,7 @@ obj-$(CONFIG_CAN_JANZ_ICAN3) += janz-ican3.o
> obj-$(CONFIG_CAN_KVASER_PCIEFD) += kvaser_pciefd.o
> obj-$(CONFIG_CAN_MSCAN) += mscan/
> obj-$(CONFIG_CAN_M_CAN) += m_can/
> +obj-$(CONFIG_CAN_NCT6694) += nct6694_canfd.o
> obj-$(CONFIG_CAN_PEAK_PCIEFD) += peak_canfd/
> obj-$(CONFIG_CAN_SJA1000) += sja1000/
> obj-$(CONFIG_CAN_SUN4I) += sun4i_can.o
> diff --git a/drivers/net/can/nct6694_canfd.c b/drivers/net/can/nct6694_canfd.c
> new file mode 100644
> index 000000000000..94cfff288c14
> --- /dev/null
> +++ b/drivers/net/can/nct6694_canfd.c
> @@ -0,0 +1,826 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Nuvoton NCT6694 Socket CANfd driver based on USB interface.
> + *
> + * Copyright (C) 2024 Nuvoton Technology Corp.
> + */
> +
> +#include <linux/can/dev.h>
> +#include <linux/can/rx-offload.h>
> +#include <linux/ethtool.h>
> +#include <linux/irqdomain.h>
> +#include <linux/kernel.h>
> +#include <linux/mfd/core.h>
> +#include <linux/mfd/nct6694.h>
> +#include <linux/module.h>
> +#include <linux/netdevice.h>
> +#include <linux/platform_device.h>
> +
> +#define DRVNAME "nct6694-can"
> +
> +/*
> + * USB command module type for NCT6694 CANfd controller.
> + * This defines the module type used for communication with the NCT6694
> + * CANfd controller over the USB interface.
> + */
> +#define NCT6694_CAN_MOD 0x05
> +
> +/* Command 00h - CAN Setting and Initialization */
> +#define NCT6694_CAN_SETTING(idx) (idx ? 0x0100 : 0x0000) /* CMD|SEL */
> +#define NCT6694_CAN_SETTING_CTRL1_MON BIT(0)
> +#define NCT6694_CAN_SETTING_CTRL1_NISO BIT(1)
> +#define NCT6694_CAN_SETTING_CTRL1_LBCK BIT(2)
> +
> +/* Command 01h - CAN Information */
> +#define NCT6694_CAN_INFORMATION 0x0001 /* CMD|SEL */
> +
> +/* Command 02h - CAN Event */
> +#define NCT6694_CAN_EVENT(idx, mask) \
> + ((((idx ? 0x80 : 0x00) | \
> + ((mask) & 0xFF)) << 8) | 0x02) /* CMD|SEL */
> +#define NCT6694_CAN_EVENT_ERR BIT(0)
> +#define NCT6694_CAN_EVENT_STATUS BIT(1)
> +#define NCT6694_CAN_EVENT_TX_EVT BIT(2)
> +#define NCT6694_CAN_EVENT_RX_EVT BIT(3)
> +#define NCT6694_CAN_EVENT_REC BIT(4)
> +#define NCT6694_CAN_EVENT_TEC BIT(5)
> +#define NCT6694_CAN_EVENT_MASK GENMASK(3, 0)
> +#define NCT6694_CAN_EVT_TX_FIFO_EMPTY BIT(7) /* Read-clear */
> +#define NCT6694_CAN_EVT_RX_DATA_LOST BIT(5) /* Read-clear */
> +#define NCT6694_CAN_EVT_RX_HALF_FULL BIT(6) /* Read-clear */
> +#define NCT6694_CAN_EVT_RX_DATA_IN BIT(7) /* Read-clear*/
> +
> +/* Command 10h - CAN Deliver */
> +#define NCT6694_CAN_DELIVER(buf_cnt) \
> + ((((buf_cnt) & 0xFF) << 8) | 0x10) /* CMD|SEL */
> +
> +/* Command 11h - CAN Receive */
> +#define NCT6694_CAN_RECEIVE(idx, buf_cnt) \
> + ((((idx ? 0x80 : 0x00) | \
> + ((buf_cnt) & 0xFF)) << 8) | 0x11) /* CMD|SEL */
> +
> +#define NCT6694_CAN_FRAME_TAG_CAN0 0xC0
> +#define NCT6694_CAN_FRAME_TAG_CAN1 0xC1
> +#define NCT6694_CAN_FRAME_FLAG_EFF BIT(0)
> +#define NCT6694_CAN_FRAME_FLAG_RTR BIT(1)
> +#define NCT6694_CAN_FRAME_FLAG_FD BIT(2)
> +#define NCT6694_CAN_FRAME_FLAG_BRS BIT(3)
> +#define NCT6694_CAN_FRAME_FLAG_ERR BIT(4)
> +
> +#define NCT6694_NAPI_WEIGHT 32
> +
> +enum nct6694_event_err {
> + NCT6694_CAN_EVT_ERR_NO_ERROR,
> + NCT6694_CAN_EVT_ERR_CRC_ERROR,
> + NCT6694_CAN_EVT_ERR_STUFF_ERROR,
> + NCT6694_CAN_EVT_ERR_ACK_ERROR,
> + NCT6694_CAN_EVT_ERR_FORM_ERROR,
> + NCT6694_CAN_EVT_ERR_BIT_ERROR,
> + NCT6694_CAN_EVT_ERR_TIMEOUT_ERROR,
> + NCT6694_CAN_EVT_ERR_UNKNOWN_ERROR,
> +};
> +
> +enum nct6694_event_status {
> + NCT6694_CAN_EVT_STS_ERROR_ACTIVE,
> + NCT6694_CAN_EVT_STS_ERROR_PASSIVE,
> + NCT6694_CAN_EVT_STS_BUS_OFF,
> + NCT6694_CAN_EVT_STS_WARNING,
> +};
> +
> +struct __packed nct6694_can_setting {
> + __le32 nbr;
> + __le32 dbr;
> + u8 active;
> + u8 reserved[3];
> + __le16 ctrl1;
> + __le16 ctrl2;
> + __le32 nbtp;
> + __le32 dbtp;
> +};
> +
> +struct __packed nct6694_can_information {
> + u8 tx_fifo_cnt;
> + u8 rx_fifo_cnt;
> + u8 reserved[2];
> + __le32 can_clk;
> +};
> +
> +struct __packed nct6694_can_event_channel {
> + u8 err;
> + u8 status;
> + u8 tx_evt;
> + u8 rx_evt;
> + u8 rec;
> + u8 tec;
> + u8 reserved[2];
> +};
> +
> +struct __packed nct6694_can_event {
> + struct nct6694_can_event_channel evt_ch[2];
> +};
Remove this intermediate struct...
> +struct __packed nct6694_can_frame {
> + u8 tag;
> + u8 flag;
> + u8 reserved;
> + u8 length;
> + __le32 id;
> + u8 data[64];
> +};
> +
> +union nct6694_can_tx {
> + struct nct6694_can_frame frame;
> + struct nct6694_can_setting setting;
> +};
> +
> +union nct6694_can_rx {
> + struct nct6694_can_event event;
... and instead, dircectly declare the array here:
struct nct6694_can_event event[2];
> + struct nct6694_can_frame frame;
> + struct nct6694_can_information info;
> +};
> +
> +struct nct6694_can_priv {
> + struct can_priv can; /* must be the first member */
> + struct can_rx_offload offload;
> + struct net_device *ndev;
> + struct nct6694 *nct6694;
> + struct mutex lock;
> + struct sk_buff *tx_skb;
> + struct workqueue_struct *wq;
> + struct work_struct tx_work;
> + union nct6694_can_tx *tx;
> + union nct6694_can_rx *rx;
> + unsigned char can_idx;
> + bool tx_busy;
tx_busy is only set when the network queue is stopped, right? Isn't it
possible to use netif_tx_queue_stopped() instead of tx_busy?
> +};
> +
> +static inline struct nct6694_can_priv *rx_offload_to_priv(struct can_rx_offload *offload)
> +{
> + return container_of(offload, struct nct6694_can_priv, offload);
> +}
> +
> +static const struct can_bittiming_const nct6694_can_bittiming_nominal_const = {
> + .name = DRVNAME,
> + .tseg1_min = 2,
> + .tseg1_max = 256,
> + .tseg2_min = 2,
> + .tseg2_max = 128,
> + .sjw_max = 128,
> + .brp_min = 1,
> + .brp_max = 511,
> + .brp_inc = 1,
> +};
> +
> +static const struct can_bittiming_const nct6694_can_bittiming_data_const = {
> + .name = DRVNAME,
> + .tseg1_min = 1,
> + .tseg1_max = 32,
> + .tseg2_min = 1,
> + .tseg2_max = 16,
> + .sjw_max = 16,
> + .brp_min = 1,
> + .brp_max = 31,
> + .brp_inc = 1,
> +};
> +
> +static void nct6694_can_rx_offload(struct can_rx_offload *offload,
> + struct sk_buff *skb)
> +{
> + struct nct6694_can_priv *priv = rx_offload_to_priv(offload);
> + int ret;
> +
> + ret = can_rx_offload_queue_tail(offload, skb);
> + if (ret)
> + priv->ndev->stats.rx_fifo_errors++;
> +}
> +
> +static void nct6694_can_handle_lost_msg(struct net_device *ndev)
> +{
> + struct nct6694_can_priv *priv = netdev_priv(ndev);
> + struct net_device_stats *stats = &ndev->stats;
> + struct can_frame *cf;
> + struct sk_buff *skb;
> +
> + netdev_err(ndev, "RX FIFO overflow, message(s) lost.\n");
> +
> + stats->rx_errors++;
> + stats->rx_over_errors++;
> +
> + skb = alloc_can_err_skb(ndev, &cf);
> + if (!skb)
> + return;
> +
> + cf->can_id |= CAN_ERR_CRTL;
> + cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
> +
> + nct6694_can_rx_offload(&priv->offload, skb);
> +}
> +
> +static void nct6694_can_rx(struct net_device *ndev, u8 rx_evt)
> +{
> + struct nct6694_can_priv *priv = netdev_priv(ndev);
> + struct nct6694_can_frame *frame = &priv->rx->frame;
> + struct canfd_frame *cfd;
> + struct can_frame *cf;
> + struct sk_buff *skb;
> + int ret;
> +
> + ret = nct6694_read_msg(priv->nct6694, NCT6694_CAN_MOD,
> + NCT6694_CAN_RECEIVE(priv->can_idx, 1),
> + sizeof(*frame), frame);
> + if (ret)
> + return;
> +
> + if (frame->flag & NCT6694_CAN_FRAME_FLAG_FD) {
> + skb = alloc_canfd_skb(priv->ndev, &cfd);
> + if (!skb)
> + return;
> +
> + cfd->can_id = le32_to_cpu(frame->id);
> + cfd->len = frame->length;
> + if (frame->flag & NCT6694_CAN_FRAME_FLAG_EFF)
> + cfd->can_id |= CAN_EFF_FLAG;
> + if (frame->flag & NCT6694_CAN_FRAME_FLAG_BRS)
> + cfd->flags |= CANFD_BRS;
> + if (frame->flag & NCT6694_CAN_FRAME_FLAG_ERR)
> + cfd->flags |= CANFD_ESI;
> +
> + memcpy(cfd->data, frame->data, cfd->len);
> + } else {
> + skb = alloc_can_skb(priv->ndev, &cf);
> + if (!skb)
> + return;
> +
> + cf->can_id = le32_to_cpu(frame->id);
> + cf->len = frame->length;
> + if (frame->flag & NCT6694_CAN_FRAME_FLAG_EFF)
> + cf->can_id |= CAN_EFF_FLAG;
> + if (frame->flag & NCT6694_CAN_FRAME_FLAG_RTR)
> + cf->can_id |= CAN_RTR_FLAG;
> +
> + memcpy(cf->data, frame->data, cf->len);
> + }
> +
> + nct6694_can_rx_offload(&priv->offload, skb);
> +}
> +
> +static void nct6694_can_clean(struct net_device *ndev)
> +{
> + struct nct6694_can_priv *priv = netdev_priv(ndev);
> +
> + if (priv->tx_skb || priv->tx_busy)
> + ndev->stats.tx_errors++;
> + dev_kfree_skb(priv->tx_skb);
> + if (priv->tx_busy)
> + can_free_echo_skb(priv->ndev, 0, NULL);
> + priv->tx_skb = NULL;
> + priv->tx_busy = false;
> +}
> +
> +static int nct6694_can_get_berr_counter(const struct net_device *ndev,
> + struct can_berr_counter *bec)
> +{
> + struct nct6694_can_priv *priv = netdev_priv(ndev);
> + struct nct6694_can_event *evt = &priv->rx->event;
> + u8 mask = NCT6694_CAN_EVENT_REC | NCT6694_CAN_EVENT_TEC;
> + int ret;
> +
> + guard(mutex)(&priv->lock);
> +
> + ret = nct6694_read_msg(priv->nct6694, NCT6694_CAN_MOD,
> + NCT6694_CAN_EVENT(priv->can_idx, mask),
> + sizeof(*evt),
> + evt);
> + if (ret < 0)
> + return ret;
> +
> + bec->rxerr = evt->evt_ch[priv->can_idx].rec;
> + bec->txerr = evt->evt_ch[priv->can_idx].tec;
> +
> + return 0;
> +}
> +
> +static void nct6694_can_handle_state_change(struct net_device *ndev,
> + u8 status)
> +{
> + struct nct6694_can_priv *priv = netdev_priv(ndev);
> + enum can_state new_state = priv->can.state;
> + enum can_state rx_state, tx_state;
> + struct can_berr_counter bec;
> + struct can_frame *cf;
> + struct sk_buff *skb;
> +
> + nct6694_can_get_berr_counter(ndev, &bec);
> + can_state_get_by_berr_counter(ndev, &bec, &tx_state, &rx_state);
> +
> + if (status & NCT6694_CAN_EVT_STS_BUS_OFF)
> + new_state = CAN_STATE_BUS_OFF;
> + else if (status & NCT6694_CAN_EVT_STS_ERROR_PASSIVE)
> + new_state = CAN_STATE_ERROR_PASSIVE;
> + else if (status & NCT6694_CAN_EVT_STS_WARNING)
> + new_state = CAN_STATE_ERROR_WARNING;
> +
> + /* state hasn't changed */
> + if (new_state == priv->can.state)
> + return;
> +
> + skb = alloc_can_err_skb(ndev, &cf);
> +
> + tx_state = bec.txerr >= bec.rxerr ? new_state : 0;
> + rx_state = bec.txerr <= bec.rxerr ? new_state : 0;
> + can_change_state(ndev, cf, tx_state, rx_state);
> +
> + if (new_state == CAN_STATE_BUS_OFF) {
> + can_bus_off(ndev);
> + } else if (skb) {
> + cf->can_id |= CAN_ERR_CNT;
> + cf->data[6] = bec.txerr;
> + cf->data[7] = bec.rxerr;
> + }
> +
> + nct6694_can_rx_offload(&priv->offload, skb);
> +}
> +
> +static void nct6694_handle_bus_err(struct net_device *ndev, u8 bus_err)
> +{
> + struct nct6694_can_priv *priv = netdev_priv(ndev);
> + struct can_frame *cf;
> + struct sk_buff *skb;
> +
> + if (bus_err == NCT6694_CAN_EVT_ERR_NO_ERROR)
> + return;
> +
> + priv->can.can_stats.bus_error++;
> +
> + skb = alloc_can_err_skb(ndev, &cf);
> + if (skb)
> + cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
> +
> + switch (bus_err) {
> + case NCT6694_CAN_EVT_ERR_CRC_ERROR:
> + netdev_dbg(ndev, "CRC error\n");
> + ndev->stats.rx_errors++;
> + if (skb)
> + cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
> + break;
> +
> + case NCT6694_CAN_EVT_ERR_STUFF_ERROR:
> + netdev_dbg(ndev, "Stuff error\n");
> + ndev->stats.rx_errors++;
> + if (skb)
> + cf->data[2] |= CAN_ERR_PROT_STUFF;
> + break;
> +
> + case NCT6694_CAN_EVT_ERR_ACK_ERROR:
> + netdev_dbg(ndev, "Ack error\n");
> + ndev->stats.tx_errors++;
> + if (skb) {
> + cf->can_id |= CAN_ERR_ACK;
> + cf->data[2] |= CAN_ERR_PROT_TX;
> + }
> + break;
> +
> + case NCT6694_CAN_EVT_ERR_FORM_ERROR:
> + netdev_dbg(ndev, "Form error\n");
> + ndev->stats.rx_errors++;
> + if (skb)
> + cf->data[2] |= CAN_ERR_PROT_FORM;
> + break;
> +
> + case NCT6694_CAN_EVT_ERR_BIT_ERROR:
> + netdev_dbg(ndev, "Bit error\n");
> + ndev->stats.tx_errors++;
> + if (skb)
> + cf->data[2] |= CAN_ERR_PROT_TX | CAN_ERR_PROT_BIT;
> + break;
> +
> + default:
> + break;
> + }
Aren't you missing something here? You are populating a can frame but
you are returning without using it.
> +}
> +
> +static void nct6694_can_tx_irq(struct net_device *ndev)
> +{
> + struct nct6694_can_priv *priv = netdev_priv(ndev);
> + struct net_device_stats *stats = &ndev->stats;
> +
> + guard(mutex)(&priv->lock);
> + stats->tx_bytes += can_get_echo_skb(ndev, 0, NULL);
> + stats->tx_packets++;
> + priv->tx_busy = false;
> + netif_wake_queue(ndev);
> +}
> +
> +static irqreturn_t nct6694_can_irq(int irq, void *data)
> +{
> + struct net_device *ndev = data;
> + struct nct6694_can_priv *priv = netdev_priv(ndev);
> + struct nct6694_can_event *evt = &priv->rx->event;
> + u8 tx_evt, rx_evt, bus_err, can_status;
> + u8 mask_sts = NCT6694_CAN_EVENT_MASK;
> + irqreturn_t handled = IRQ_NONE;
> + int can_idx = priv->can_idx;
> + int ret;
> +
> + scoped_guard(mutex, &priv->lock) {
> + ret = nct6694_read_msg(priv->nct6694, NCT6694_CAN_MOD,
> + NCT6694_CAN_EVENT(can_idx, mask_sts),
> + sizeof(*evt), evt);
> + if (ret < 0)
> + return handled;
> +
> + tx_evt = evt->evt_ch[can_idx].tx_evt;
> + rx_evt = evt->evt_ch[can_idx].rx_evt;
> + bus_err = evt->evt_ch[can_idx].err;
> + can_status = evt->evt_ch[can_idx].status;
> + }
> +
> + if (rx_evt & NCT6694_CAN_EVT_RX_DATA_IN) {
> + nct6694_can_rx(ndev, rx_evt);
> + handled = IRQ_HANDLED;
> + }
> +
> + if (rx_evt & NCT6694_CAN_EVT_RX_DATA_LOST) {
> + nct6694_can_handle_lost_msg(ndev);
> + handled = IRQ_HANDLED;
> + }
> +
> + if (can_status) {
> + nct6694_can_handle_state_change(ndev, can_status);
> + handled = IRQ_HANDLED;
> + }
> +
> + if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) {
> + nct6694_handle_bus_err(ndev, bus_err);
> + handled = IRQ_HANDLED;
> + }
> +
> + if (handled)
> + can_rx_offload_threaded_irq_finish(&priv->offload);
> +
> + if (tx_evt & NCT6694_CAN_EVT_TX_FIFO_EMPTY)
> + nct6694_can_tx_irq(ndev);
> +
> + return handled;
> +}
> +
> +static void nct6694_can_tx(struct net_device *ndev)
> +{
> + struct nct6694_can_priv *priv = netdev_priv(ndev);
> + struct nct6694_can_frame *frame = &priv->tx->frame;
> + struct net_device_stats *stats = &ndev->stats;
> + struct sk_buff *skb = priv->tx_skb;
> + struct canfd_frame *cfd;
> + struct can_frame *cf;
> + u32 txid;
> + int err;
> +
> + memset(frame, 0, sizeof(*frame));
> +
> + if (priv->can_idx == 0)
> + frame->tag = NCT6694_CAN_FRAME_TAG_CAN0;
> + else
> + frame->tag = NCT6694_CAN_FRAME_TAG_CAN1;
> +
> + if (can_is_canfd_skb(skb)) {
> + cfd = (struct canfd_frame *)priv->tx_skb->data;
> +
> + if (cfd->flags & CANFD_BRS)
> + frame->flag |= NCT6694_CAN_FRAME_FLAG_BRS;
> +
> + if (cfd->can_id & CAN_EFF_FLAG) {
> + txid = cfd->can_id & CAN_EFF_MASK;
> + frame->flag |= NCT6694_CAN_FRAME_FLAG_EFF;
> + } else {
> + txid = cfd->can_id & CAN_SFF_MASK;
> + }
> + frame->flag |= NCT6694_CAN_FRAME_FLAG_FD;
> + frame->id = cpu_to_le32(txid);
> + frame->length = cfd->len;
> +
> + memcpy(frame->data, cfd->data, cfd->len);
> + } else {
> + cf = (struct can_frame *)priv->tx_skb->data;
> +
> + if (cf->can_id & CAN_RTR_FLAG)
> + frame->flag |= NCT6694_CAN_FRAME_FLAG_RTR;
> +
> + if (cf->can_id & CAN_EFF_FLAG) {
> + txid = cf->can_id & CAN_EFF_MASK;
> + frame->flag |= NCT6694_CAN_FRAME_FLAG_EFF;
> + } else {
> + txid = cf->can_id & CAN_SFF_MASK;
> + }
> + frame->id = cpu_to_le32(txid);
> + frame->length = cf->len;
> +
> + memcpy(frame->data, cf->data, cf->len);
Don't copy the payload if the frame is a remote frame.
> + }
^^^^^^^^
Bad indentation. Did you run script/checkpatch.pl before sending?
> + err = nct6694_write_msg(priv->nct6694, NCT6694_CAN_MOD,
> + NCT6694_CAN_DELIVER(1),
> + sizeof(*frame),
> + frame);
> + if (err) {
> + netdev_err(ndev, "%s: Tx FIFO full!\n", __func__);
> + can_free_echo_skb(ndev, 0, NULL);
> + stats->tx_dropped++;
> + stats->tx_errors++;
> + netif_wake_queue(ndev);
> + }
> +}
> +
> +static void nct6694_can_tx_work(struct work_struct *work)
> +{
> + struct nct6694_can_priv *priv = container_of(work,
> + struct nct6694_can_priv,
> + tx_work);
> + struct net_device *ndev = priv->ndev;
> +
> + guard(mutex)(&priv->lock);
> +
> + if (priv->tx_skb) {
> + if (priv->can.state == CAN_STATE_BUS_OFF) {
> + nct6694_can_clean(ndev);
> + } else {
> + nct6694_can_tx(ndev);
> + can_put_echo_skb(priv->tx_skb, ndev, 0, 0);
> + priv->tx_busy = true;
> + priv->tx_skb = NULL;
> + }
> + }
> +}
> +
> +static netdev_tx_t nct6694_can_start_xmit(struct sk_buff *skb,
> + struct net_device *ndev)
> +{
> + struct nct6694_can_priv *priv = netdev_priv(ndev);
> +
> + if (can_dev_dropped_skb(ndev, skb))
> + return NETDEV_TX_OK;
> +
> + if (priv->tx_skb || priv->tx_busy) {
> + netdev_err(ndev, "hard_xmit called while tx busy\n");
> + return NETDEV_TX_BUSY;
> + }
> +
> + netif_stop_queue(ndev);
> + priv->tx_skb = skb;
> + queue_work(priv->wq, &priv->tx_work);
> +
> + return NETDEV_TX_OK;
> +}
> +
> +static int nct6694_can_start(struct net_device *ndev)
> +{
> + struct nct6694_can_priv *priv = netdev_priv(ndev);
> + struct nct6694_can_setting *setting = &priv->tx->setting;
> + const struct can_bittiming *n_bt = &priv->can.bittiming;
> + const struct can_bittiming *d_bt = &priv->can.data_bittiming;
> + int ret;
> +
> + guard(mutex)(&priv->lock);
> +
> + memset(setting, 0, sizeof(*setting));
> + setting->nbr = cpu_to_le32(n_bt->bitrate);
> + setting->dbr = cpu_to_le32(d_bt->bitrate);
> +
> + if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
> + setting->ctrl1 |= cpu_to_le16(NCT6694_CAN_SETTING_CTRL1_MON);
> +
> + if ((priv->can.ctrlmode & CAN_CTRLMODE_FD) &&
> + priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO)
> + setting->ctrl1 |= cpu_to_le16(NCT6694_CAN_SETTING_CTRL1_NISO);
> +
> + if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
> + setting->ctrl1 |= cpu_to_le16(NCT6694_CAN_SETTING_CTRL1_LBCK);
> +
> + ret = nct6694_write_msg(priv->nct6694, NCT6694_CAN_MOD,
> + NCT6694_CAN_SETTING(priv->can_idx),
> + sizeof(*setting), setting);
> + if (ret)
> + return ret;
> +
> + priv->can.state = CAN_STATE_ERROR_ACTIVE;
> +
> + return ret;
> +}
> +
> +static int nct6694_can_stop(struct net_device *ndev)
> +{
> + struct nct6694_can_priv *priv = netdev_priv(ndev);
> +
> + netif_stop_queue(ndev);
> + free_irq(ndev->irq, ndev);
> + destroy_workqueue(priv->wq);
> + priv->wq = NULL;
> + nct6694_can_clean(ndev);
> + priv->can.state = CAN_STATE_STOPPED;
> + can_rx_offload_disable(&priv->offload);
> + close_candev(ndev);
> +
> + return 0;
> +}
> +
> +static int nct6694_can_set_mode(struct net_device *ndev, enum can_mode mode)
> +{
> + switch (mode) {
> + case CAN_MODE_START:
> + nct6694_can_clean(ndev);
> + nct6694_can_start(ndev);
> + netif_wake_queue(ndev);
> + break;
Nitpick: here, directly return 0...
> + default:
> + return -EOPNOTSUPP;
> + }
> +
> + return 0;
... and then remove that line.
> +}
> +
> +static int nct6694_can_open(struct net_device *ndev)
> +{
> + struct nct6694_can_priv *priv = netdev_priv(ndev);
> + int ret;
> +
> + ret = open_candev(ndev);
> + if (ret)
> + return ret;
> +
> + can_rx_offload_enable(&priv->offload);
> +
> + ret = request_threaded_irq(ndev->irq, NULL,
> + nct6694_can_irq, IRQF_ONESHOT,
> + "nct6694_can", ndev);
> + if (ret) {
> + netdev_err(ndev, "Failed to request IRQ\n");
> + goto close_candev;
> + }
> +
> + priv->wq = alloc_ordered_workqueue("%s-nct6694_wq",
> + WQ_FREEZABLE | WQ_MEM_RECLAIM,
> + ndev->name);
> + if (!priv->wq) {
> + ret = -ENOMEM;
> + goto free_irq;
> + }
> +
> + priv->tx_skb = NULL;
> + priv->tx_busy = false;
> +
> + ret = nct6694_can_start(ndev);
> + if (ret)
> + goto destroy_wq;
> +
> + netif_start_queue(ndev);
> +
> + return 0;
> +
> +destroy_wq:
> + destroy_workqueue(priv->wq);
> +free_irq:
> + free_irq(ndev->irq, ndev);
> +close_candev:
> + can_rx_offload_disable(&priv->offload);
> + close_candev(ndev);
> + return ret;
> +}
> +
> +static const struct net_device_ops nct6694_can_netdev_ops = {
> + .ndo_open = nct6694_can_open,
> + .ndo_stop = nct6694_can_stop,
> + .ndo_start_xmit = nct6694_can_start_xmit,
> + .ndo_change_mtu = can_change_mtu,
> +};
> +
> +static const struct ethtool_ops nct6694_can_ethtool_ops = {
> + .get_ts_info = ethtool_op_get_ts_info,
> +};
> +
> +static int nct6694_can_get_clock(struct nct6694_can_priv *priv)
> +{
> + struct nct6694_can_information *info = &priv->rx->info;
> + int ret;
> +
> + ret = nct6694_read_msg(priv->nct6694, NCT6694_CAN_MOD,
> + NCT6694_CAN_INFORMATION,
> + sizeof(*info),
> + info);
> + if (ret)
> + return ret;
> +
> + return le32_to_cpu(info->can_clk);
> +}
> +
> +static int nct6694_can_probe(struct platform_device *pdev)
> +{
> + const struct mfd_cell *cell = mfd_get_cell(pdev);
> + struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent);
> + struct nct6694_can_priv *priv;
> + struct net_device *ndev;
> + int ret, irq, can_clk;
> +
> + irq = irq_create_mapping(nct6694->domain,
> + NCT6694_IRQ_CAN1 + cell->id);
> + if (!irq)
> + return irq;
> +
> + ndev = alloc_candev(sizeof(struct nct6694_can_priv), 1);
> + if (!ndev)
> + return -ENOMEM;
> +
> + ndev->irq = irq;
> + ndev->flags |= IFF_ECHO;
> + ndev->netdev_ops = &nct6694_can_netdev_ops;
> + ndev->ethtool_ops = &nct6694_can_ethtool_ops;
> +
> + priv = netdev_priv(ndev);
> + priv->nct6694 = nct6694;
> + priv->ndev = ndev;
> +
> + priv->tx = devm_kzalloc(&pdev->dev, sizeof(union nct6694_can_tx),
> + GFP_KERNEL);
> + if (!priv->tx) {
> + ret = -ENOMEM;
> + goto free_candev;
> + }
> +
> + priv->rx = devm_kzalloc(&pdev->dev, sizeof(union nct6694_can_rx),
> + GFP_KERNEL);
> + if (!priv->rx) {
> + ret = -ENOMEM;
> + goto free_candev;
> + }
> +
> + can_clk = nct6694_can_get_clock(priv);
> + if (can_clk < 0) {
> + ret = dev_err_probe(&pdev->dev, can_clk,
> + "Failed to get clock\n");
> + goto free_candev;
> + }
> +
> + devm_mutex_init(&pdev->dev, &priv->lock);
> + INIT_WORK(&priv->tx_work, nct6694_can_tx_work);
> +
> + priv->can_idx = cell->id;
> + priv->can.state = CAN_STATE_STOPPED;
> + priv->can.clock.freq = can_clk;
> + priv->can.bittiming_const = &nct6694_can_bittiming_nominal_const;
> + priv->can.data_bittiming_const = &nct6694_can_bittiming_data_const;
> + priv->can.do_set_mode = nct6694_can_set_mode;
> + priv->can.do_get_berr_counter = nct6694_can_get_berr_counter;
> +
> + priv->can.ctrlmode = CAN_CTRLMODE_FD;
> +
> + priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
> + CAN_CTRLMODE_LISTENONLY |
> + CAN_CTRLMODE_FD |
> + CAN_CTRLMODE_FD_NON_ISO |
> + CAN_CTRLMODE_BERR_REPORTING;
> +
> + ret = can_rx_offload_add_manual(ndev, &priv->offload,
> + NCT6694_NAPI_WEIGHT);
> + if (ret) {
> + dev_err_probe(&pdev->dev, ret, "Failed to add rx_offload\n");
> + goto free_candev;
> + }
> +
> + platform_set_drvdata(pdev, priv);
> + SET_NETDEV_DEV(priv->ndev, &pdev->dev);
> +
> + ret = register_candev(priv->ndev);
> + if (ret)
> + goto del_rx_offload;
> +
> + return 0;
> +
> +del_rx_offload:
> + can_rx_offload_del(&priv->offload);
> +free_candev:
> + free_candev(ndev);
> + return ret;
> +}
> +
> +static void nct6694_can_remove(struct platform_device *pdev)
> +{
> + struct nct6694_can_priv *priv = platform_get_drvdata(pdev);
> +
> + cancel_work_sync(&priv->tx_work);
> + unregister_candev(priv->ndev);
> + can_rx_offload_del(&priv->offload);
> + free_candev(priv->ndev);
> +}
> +
> +static struct platform_driver nct6694_can_driver = {
> + .driver = {
> + .name = DRVNAME,
> + },
> + .probe = nct6694_can_probe,
> + .remove = nct6694_can_remove,
> +};
> +
> +module_platform_driver(nct6694_can_driver);
> +
> +MODULE_DESCRIPTION("USB-CAN FD driver for NCT6694");
> +MODULE_AUTHOR("Ming Yu <tmyu0@xxxxxxxxxxx>");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:nct6694-can");
Yours sincerely,
Vincent Mailhol
