On Mon, Nov 14, 2022 at 07:37:35AM +0000, Corentin Labbe wrote:
> The CH348 is an USB octo port serial adapter.
Please add some more details on the endpoints are used etc. Perhaps
mention some of the magic you've incorporated from the vendor driver
(with a link?).
> This patch adds support for it.
No need for this bit.
> Signed-off-by: Corentin Labbe <clabbe@xxxxxxxxxxxx>
> ---
> drivers/usb/serial/Kconfig | 9 +
> drivers/usb/serial/Makefile | 1 +
> drivers/usb/serial/ch348.c | 739 ++++++++++++++++++++++++++++++++++++
> 3 files changed, 749 insertions(+)
> create mode 100644 drivers/usb/serial/ch348.c
>
> diff --git a/drivers/usb/serial/Kconfig b/drivers/usb/serial/Kconfig
> index ef8d1c73c754..1e1842656b54 100644
> --- a/drivers/usb/serial/Kconfig
> +++ b/drivers/usb/serial/Kconfig
> @@ -112,6 +112,15 @@ config USB_SERIAL_CH341
> To compile this driver as a module, choose M here: the
> module will be called ch341.
>
> +config USB_SERIAL_CH348
> + tristate "USB Winchiphead CH348 Octo Port Serial Driver"
> + help
> + Say Y here if you want to use a Winchiphead CH348 octo port
> + USB to serial adapter.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called ch348.
> +
> config USB_SERIAL_WHITEHEAT
> tristate "USB ConnectTech WhiteHEAT Serial Driver"
> select USB_EZUSB_FX2
> diff --git a/drivers/usb/serial/Makefile b/drivers/usb/serial/Makefile
> index c7bb1a88173e..d16ff59fde68 100644
> --- a/drivers/usb/serial/Makefile
> +++ b/drivers/usb/serial/Makefile
> @@ -15,6 +15,7 @@ obj-$(CONFIG_USB_SERIAL_AIRCABLE) += aircable.o
> obj-$(CONFIG_USB_SERIAL_ARK3116) += ark3116.o
> obj-$(CONFIG_USB_SERIAL_BELKIN) += belkin_sa.o
> obj-$(CONFIG_USB_SERIAL_CH341) += ch341.o
> +obj-$(CONFIG_USB_SERIAL_CH348) += ch348.o
> obj-$(CONFIG_USB_SERIAL_CP210X) += cp210x.o
> obj-$(CONFIG_USB_SERIAL_CYBERJACK) += cyberjack.o
> obj-$(CONFIG_USB_SERIAL_CYPRESS_M8) += cypress_m8.o
> diff --git a/drivers/usb/serial/ch348.c b/drivers/usb/serial/ch348.c
> new file mode 100644
> index 000000000000..eb3d7d62f799
> --- /dev/null
> +++ b/drivers/usb/serial/ch348.c
> @@ -0,0 +1,739 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * USB serial driver for USB to Octal UARTs chip ch348.
> + *
> + * Copyright (C) 2022 Corentin Labbe <clabbe@xxxxxxxxxxxx>
> + * With the help of Neil Armstrong <neil.armstrong@xxxxxxxxxx>
> + */
> +
> +#include <linux/errno.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/serial.h>
> +#include <linux/slab.h>
> +#include <linux/tty.h>
> +#include <linux/tty_driver.h>
> +#include <linux/tty_flip.h>
> +#include <linux/usb.h>
> +#include <linux/usb/serial.h>
> +
> +#define DEFAULT_BAUD_RATE 9600
> +#define DEFAULT_TIMEOUT 2000
> +
> +#define CH348_CTO_D 0x01
> +#define CH348_CTO_R 0x02
> +
> +#define CH348_CTI_C 0x10
> +#define CH348_CTI_DSR 0x20
> +#define CH348_CTI_R 0x40
> +#define CH348_CTI_DCD 0x80
> +
> +#define CH348_LO 0x02
> +#define CH348_LP 0x04
> +#define CH348_LF 0x08
> +#define CH348_LB 0x10
> +
> +#define CMD_W_R 0xC0
> +#define CMD_W_BR 0x80
> +
> +#define CMD_WB_E 0x90
> +#define CMD_RB_E 0xC0
> +
> +#define M_NOR 0x00
> +#define M_HF 0x03
> +
> +#define R_MOD 0x97
> +#define R_IO_D 0x98
> +#define R_IO_O 0x99
> +#define R_IO_I 0x9b
> +#define R_TM_O 0x9c
> +#define R_INIT 0xa1
> +
> +#define R_C1 0x01
> +#define R_C2 0x02
> +#define R_C4 0x04
> +#define R_C5 0x06
> +
> +#define R_II_B1 0x06
> +#define R_II_B2 0x02
> +#define R_II_B3 0x00
> +
> +#define CH348_RX_PORT_CHUNK_LENGTH 32
> +#define CH348_RX_PORT_MAX_LENGTH 30
> +
> +struct ch348_rxbuf {
> + u8 port;
> + u8 length;
> + u8 data[CH348_RX_PORT_MAX_LENGTH];
> +} __packed;
> +
> +struct ch348_txbuf {
> + u8 port;
> + __le16 length;
> + u8 data[];
> +} __packed;
> +
> +#define CH348_TX_HDRSIZE offsetof(struct ch348_txbuf, data)
> +
> +struct ch348_initbuf {
> + u8 cmd;
> + u8 reg;
> + u8 port;
> + __be32 dwDTERate;
> + u8 bCharFormat;
> + u8 bParityType;
> + u8 bDataBits;
> + u8 rate;
> + u8 unk;
> +} __packed;
> +
> +#define CH348_MAXPORT 8
> +
> +/*
> + * The CH348 multiplexes rx & tx into a pair of Bulk USB endpoints for
> + * the 8 serial ports, and another pair of Bulk USB endpoints to
> + * set port settings and receive port status events.
> + *
> + * The USB serial cores ties every Bulk endpoints pairs to each ports,
> + * but in our case it will set port 0 with the rx/tx endpoints
> + * and port 1 with the setup/status endpoints.
> + *
> + * To still take advantage of the generic code, we (re-)initialize
> + * the USB serial port structure with the correct USB endpoint
> + * for read and write, and write proper process_read_urb()
> + * and prepare_write_buffer() to correctly (de-)multiplex data.
> + */
Take a look at how this was implemented for mx_uport.c which uses a
similar setup, including commit d69f138747b9 ("USB: serial: mxuport:
clean up port bulk-out setup") which allows to use core to allocate the
resources needed. Each port gets a write fifo and write URBs, while only
the read and status URBs are shared via ports 0 and 1.
mx_uport submits the shared URBs at attach, but this is preferable done
at first open.
> +
> +/* struct ch348_ttyport - per-port information
> + * @uartmode UART port current mode
> + * @port: USB Serial Port structure
> + * @io_status: last reported I/O state
> + * @modem_status: last reported modem signals state
> + */
Kernel doc starts with /** and you need a newline after the opening
marker (throughout).
> +struct ch348_ttyport {
> + u8 uartmode;
> + struct usb_serial_port *port;
> + unsigned int io_status;
> + unsigned int modem_status;
> +};
> +
> +/* struct ch348 - main container for all this driver information
> + * @udev: pointer to the CH348 usb device
> + * @ttyport: List of per-port information
> + * @rx_endpoint: endpoint number for read operations
> + * @statusrx_endpoint: endpoint number for status operations
> + * @cmdtx_endpoint: endpoint number for configure operations
> + * @status_read_urb: URB for status
> + * @status_read_buffer: buffer used by status_read_urb
> + * @status_lock: control access of io_status/modem_status
> + * @readsize: packet size for bulk_in
> + * @writesize: packet size for bulk_out
> + */
> +struct ch348 {
> + struct usb_device *udev;
> + struct ch348_ttyport ttyport[CH348_MAXPORT];
This should not be needed. You have pointers to the usb-serial ports in
struct usb_serial.
> +
> + int rx_endpoint;
> + int tx_endpoint;
> + int statusrx_endpoint;
> + int cmdtx_endpoint;
> +
> + struct urb *status_read_urb;
> + u8 *status_read_buffer;
> +
> + spinlock_t status_lock;
> + int readsize;
> + int writesize;
> +};
> +
> +struct ch348_magic {
> + u8 action;
> + u8 reg;
> + u8 control;
> +} __packed;
> +
> +/* Some values came from vendor tree, and we have no meaning for them, this
> + * function simply use them.
> + */
> +static int ch348_do_magic(struct ch348 *ch348, int portnum, u8 action, u8 reg, u8 control)
> +{
> + int ret = 0, len;
> + struct ch348_magic *buffer;
> +
> + buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
> + if (!buffer)
> + return -ENOMEM;
> +
> + if (portnum < 4)
> + reg += 0x10 * portnum;
> + else
> + reg += 0x10 * (portnum - 4) + 0x08;
> +
> + buffer->action = action;
> + buffer->reg = reg;
> + buffer->control = control;
> +
> + ret = usb_bulk_msg(ch348->udev, ch348->cmdtx_endpoint, buffer, 3, &len,
> + DEFAULT_TIMEOUT);
> + if (ret)
> + dev_err(&ch348->udev->dev, "%s usb_bulk_msg err=%d\n", __func__, ret);
> +
> + kfree(buffer);
> + return ret;
> +}
> +
> +static int ch348_configure(struct ch348 *ch348, int portnum)
> +{
> + int ret;
> +
> + ret = ch348_do_magic(ch348, portnum, CMD_W_R, R_C2, 0x87);
> + if (ret)
> + return ret;
> + ret = ch348_do_magic(ch348, portnum, CMD_W_R, R_C4, 0x08);
> + return ret;
Here I'd use an explicit error path for symmetry and return 0 on the
success path.
> +}
> +
> +static void ch348_process_read_urb(struct urb *urb)
> +{
> + struct usb_serial_port *port = urb->context;
> + struct ch348 *ch348 = usb_get_serial_data(port->serial);
> + u8 *buffer = urb->transfer_buffer, *end;
> + unsigned int portnum, usblen;
> + struct ch348_rxbuf *rxb;
> +
> + if (urb->actual_length < 2) {
> + dev_warn(&port->dev, "%s:%d empty rx buffer\n", __func__, __LINE__);
Drop the __func__ and __LINE__ from all error messages. But here you
should just return as there's no point in spamming in the logs for
malfunctioning hardware.
> + return;
> + }
> +
> + end = buffer + urb->actual_length;
> +
> + for (; buffer < end; buffer += CH348_RX_PORT_CHUNK_LENGTH) {
> + rxb = (struct ch348_rxbuf *)buffer;
> + portnum = rxb->port;
> + if (portnum >= CH348_MAXPORT) {
> + dev_warn(&port->dev, "%s:%d invalid port %d\n",
> + __func__, __LINE__, portnum);
> + break;
> + }
> +
> + usblen = rxb->length;
> + if (usblen > CH348_RX_PORT_MAX_LENGTH) {
> + dev_warn(&port->dev, "%s:%d invalid length %d for port %d\n",
> + __func__, __LINE__, usblen, portnum);
> + break;
> + }
> +
> + port = ch348->ttyport[portnum].port;
> + tty_insert_flip_string(&port->port, rxb->data, usblen);
> + tty_flip_buffer_push(&port->port);
> + port->icount.rx += usblen;
> + usb_serial_debug_data(&port->dev, __func__, usblen, rxb->data);
> + }
> +}
> +
> +static int ch348_prepare_write_buffer(struct usb_serial_port *port, void *dest, size_t size)
> +{
> + struct ch348_txbuf *rxt = dest;
> + int count;
> +
> + count = kfifo_out_locked(&port->write_fifo, rxt->data,
> + size - CH348_TX_HDRSIZE, &port->lock);
> +
> + rxt->port = port->port_number;
> + rxt->length = cpu_to_le16(count);
> +
> + return count + CH348_TX_HDRSIZE;
> +}
> +
> +static int ch348_set_uartmode(struct ch348 *ch348, int portnum, u8 index, u8 mode)
> +{
> + int ret = 0;
No need to initialise.
> +
> + if (ch348->ttyport[portnum].uartmode == M_NOR && mode == M_HF) {
> + ret = ch348_do_magic(ch348, portnum, CMD_W_BR, R_C4, 0x51);
> + if (ret)
> + return ret;
> + ch348->ttyport[portnum].uartmode = M_HF;
> + }
> +
> + if (ch348->ttyport[portnum].uartmode == M_HF && mode == M_NOR) {
> + ret = ch348_do_magic(ch348, portnum, CMD_W_BR, R_C4, 0x50);
> + if (ret)
> + return ret;
> + ch348->ttyport[portnum].uartmode = M_NOR;
> + }
> + return 0;
> +}
> +
> +static void ch348_set_termios(struct tty_struct *tty, struct usb_serial_port *port,
> + const struct ktermios *termios_old)
> +{
> + struct ch348 *ch348 = usb_get_serial_data(port->serial);
> + int portnum = port->port_number;
> + struct ktermios *termios = &tty->termios;
> + int ret, sent;
> + speed_t dwDTERate;
> + u8 bCharFormat;
Drop indentation of identifier.
Perhaps drop the camel case and just call these rate and format, it's
clear below how they are used. Ok, maybe not rate that's used for a
different purpose.
> + struct ch348_initbuf *buffer;
> +
> + if (termios_old && !tty_termios_hw_change(&tty->termios, termios_old))
> + return;
> +
> + buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
> + if (!buffer) {
> + if (termios_old)
> + tty->termios = *termios_old;
> + return;
> + }
> +
> + dwDTERate = tty_get_baud_rate(tty);
> + /* test show no success on low baud and datasheet said it is not supported */
> + if (dwDTERate < 1200)
> + dwDTERate = DEFAULT_BAUD_RATE;
> + /* datasheet said it is not supported */
> + if (dwDTERate > 6000000)
> + dwDTERate = 6000000;
> +
> + bCharFormat = termios->c_cflag & CSTOPB ? 2 : 1;
> +
> + buffer->bParityType = termios->c_cflag & PARENB ?
> + (termios->c_cflag & PARODD ? 1 : 2) +
> + (termios->c_cflag & CMSPAR ? 2 : 0) : 0;
I know we have this elsewhere, but please just spell it out using nested
conditionals (not ternary ?:) so that is it obvious what is going on.
> +
> + switch (termios->c_cflag & CSIZE) {
Use C_CSIZE(tty) and friends.
> + case CS5:
> + buffer->bDataBits = 5;
> + break;
> + case CS6:
> + buffer->bDataBits = 6;
> + break;
> + case CS7:
> + buffer->bDataBits = 7;
> + break;
> + case CS8:
> + default:
> + buffer->bDataBits = 8;
> + break;
> + }
> + buffer->cmd = CMD_WB_E | (portnum & 0x0F);
> + buffer->reg = R_INIT;
> + buffer->port = portnum;
> + buffer->dwDTERate = cpu_to_be32(dwDTERate);
> + if (bCharFormat == 2)
> + buffer->bCharFormat = 0x02;
> + else if (bCharFormat == 1)
> + buffer->bCharFormat = 0x00;
> + buffer->rate = max_t(speed_t, 5, DIV_ROUND_CLOSEST(10000 * 15, dwDTERate));
Some newlines (e.g. here) should improve readability.
> + ret = usb_bulk_msg(ch348->udev, ch348->cmdtx_endpoint, buffer,
> + sizeof(*buffer), &sent, DEFAULT_TIMEOUT);
> + if (ret < 0) {
> + dev_err(&ch348->udev->dev, "%s usb_bulk_msg err=%d\n",
> + __func__, ret);
Use a message like
"failed to change line settings: %d\n"
> + goto out;
> + }
> +
> + ret = ch348_do_magic(ch348, portnum, CMD_W_R, R_C1, 0x0F);
> + if (ret < 0)
> + goto out;
> +
> + if (C_CRTSCTS(tty))
> + ret = ch348_set_uartmode(ch348, portnum, portnum, M_HF);
> + else
> + ret = ch348_set_uartmode(ch348, portnum, portnum, M_NOR);
> +
> +out:
> + kfree(buffer);
> +}
> +
> +static int ch348_open(struct tty_struct *tty, struct usb_serial_port *port)
> +{
> + struct ch348 *ch348 = usb_get_serial_data(port->serial);
> + int rv;
Use 'ret' consistently.
> +
> + if (tty)
> + ch348_set_termios(tty, port, NULL);
> +
> + rv = ch348_configure(ch348, port->port_number);
> + if (rv)
> + pr_err("%s configure err\n", __func__);
> +
> + rv = usb_serial_generic_open(tty, port);
> +
> + return rv;
Either add an explicit error path or
return usb_serial_generic_open(tty, port);
> +}
[...]
> +static void ch348_update_status(struct ch348 *ch348, u8 *data, unsigned int len)
> +{
> + u8 *end = data + len;
> + unsigned int portnum, reg;
> +
> + for (; data < end; ) {
> + portnum = data[0] & 0xf;
> + reg = data[1];
This looks broken, what if len is 1? Similar below.
> +
> + if (reg == R_INIT) {
> + data += sizeof(struct ch348_initbuf);
> + continue;
> + }
> +
> + if (reg >= R_MOD && reg <= R_IO_I) {
> + /* This signal is used by vendor driver to handle GPIO Interrupts */
> + dev_dbg(&ch348->udev->dev, "port%d: unhandled status %02x%02x\n",
> + portnum, data[2], data[3]);
> + data += 4;
> + continue;
> + }
> +
> + if ((reg & 0xf) == R_II_B1) {
> + dev_dbg(&ch348->udev->dev, "port%d: uart io state %02x\n",
> + portnum, data[2]);
> + ch348_update_io_status(ch348, portnum, data[2]);
> + data += 3;
> + continue;
> + }
> +
> + if ((reg & 0xf) == R_II_B2) {
> + /* This signal is used by vendor driver to aggregate multiple port TX */
> + dev_dbg(&ch348->udev->dev,
> + "port%d: unhandled Write Empty status\n", portnum);
> + data += 3;
> + continue;
> + }
> +
> + if ((reg & 0xf) == R_II_B3) {
> + dev_dbg(&ch348->udev->dev, "port%d: modem status %02x\n", portnum, data[2]);
> + ch348_update_modem_status(ch348, portnum, data[2]);
> + data += 3;
> + continue;
> + }
> +
> + dev_dbg(&ch348->udev->dev, "port%d: unknown status %02x\n", portnum, reg);
> + data += 3;
> + }
> +}
> +
> +static void ch348_status_read_bulk_callback(struct urb *urb)
> +{
> + struct ch348 *ch348 = urb->context;
> + u8 *data = urb->transfer_buffer;
> + unsigned int len = urb->actual_length;
> + int ret;
> +
> + switch (urb->status) {
> + case 0:
> + /* success */
> + break;
> + case -ECONNRESET:
> + case -ENOENT:
> + case -ESHUTDOWN:
> + /* this urb is terminated, clean up */
> + dev_dbg(&ch348->udev->dev, "%s - urb shutting down: %d\n",
> + __func__, urb->status);
> + return;
> + default:
> + dev_dbg(&ch348->udev->dev, "%s - nonzero urb status: %d\n",
> + __func__, urb->status);
> + goto exit;
> + }
> +
> + usb_serial_debug_data(&ch348->udev->dev, __func__, len, data);
> + ch348_update_status(ch348, data, len);
> +
> +exit:
> + ret = usb_submit_urb(urb, GFP_ATOMIC);
> + if (ret) {
> + dev_err(&ch348->udev->dev, "%s - usb_submit_urb failed: %d\n",
Spell out "failed to submit status urb: %d\n" (and similar elsewhere).
> + __func__, ret);
> + }
> +}
> +
> +static int ch348_allocate_status_read(struct ch348 *ch348, struct usb_endpoint_descriptor *epd)
> +{
> + int buffer_size = usb_endpoint_maxp(epd);
> +
> + ch348->status_read_urb = usb_alloc_urb(0, GFP_KERNEL);
> + if (!ch348->status_read_urb)
> + return -ENOMEM;
> + ch348->status_read_buffer = kmalloc(buffer_size, GFP_KERNEL);
This buffer is not freed anywhere.
> + if (!ch348->status_read_buffer) {
> + usb_free_urb(ch348->status_read_urb);
> + return -ENOMEM;
> + }
> +
> + usb_fill_bulk_urb(ch348->status_read_urb, ch348->udev,
> + ch348->statusrx_endpoint, ch348->status_read_buffer,
> + buffer_size, ch348_status_read_bulk_callback, ch348);
> +
> + return 0;
> +}
> +
> +static void ch348_release(struct usb_serial *serial)
> +{
> + struct ch348 *ch348 = usb_get_serial_data(serial);
> +
> + usb_kill_urb(ch348->status_read_urb);
> + usb_free_urb(ch348->status_read_urb);
> +}
> +
> +static int ch348_probe(struct usb_serial *serial, const struct usb_device_id *id)
> +{
> + struct usb_interface *intf;
> + struct usb_endpoint_descriptor *epcmdwrite = NULL;
> + struct usb_endpoint_descriptor *epstatusread = NULL;
> + struct usb_endpoint_descriptor *epread = NULL;
> + struct usb_endpoint_descriptor *epwrite = NULL;
> + struct usb_device *usb_dev = serial->dev;
> + struct ch348 *ch348;
> + int ret;
> +
> + intf = usb_ifnum_to_if(usb_dev, 0);
> +
> + ret = usb_find_common_endpoints(intf->cur_altsetting, &epread, &epwrite,
> + NULL, NULL);
> + if (ret) {
> + dev_err(&serial->dev->dev, "ERROR: failed to find basic endpoints ret=%d\n", ret);
> + return ret;
> + }
> + epstatusread = &intf->cur_altsetting->endpoint[2].desc;
> + epcmdwrite = &intf->cur_altsetting->endpoint[3].desc;
> +
> + if (!usb_endpoint_is_bulk_in(epstatusread)) {
> + dev_err(&serial->dev->dev, "ERROR: missing second bulk in\n");
> + return -EINVAL;
> + }
> + if (!usb_endpoint_is_bulk_out(epcmdwrite)) {
> + dev_err(&serial->dev->dev, "ERROR: missing second bulk out\n");
> + return -EINVAL;
> + }
The above should not be needed (cf. mx_uport).
> +
> + ch348 = devm_kzalloc(&serial->dev->dev, sizeof(*ch348), GFP_KERNEL);
> + if (!ch348)
> + return -ENOMEM;
> +
> + usb_set_serial_data(serial, ch348);
> +
> + ch348->readsize = usb_endpoint_maxp(epread);
> + ch348->writesize = usb_endpoint_maxp(epwrite);
> + ch348->udev = serial->dev;
> +
> + spin_lock_init(&ch348->status_lock);
> +
> + ch348->rx_endpoint = usb_rcvbulkpipe(usb_dev, epread->bEndpointAddress);
> + ch348->tx_endpoint = usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress);
> + ch348->cmdtx_endpoint = usb_sndbulkpipe(usb_dev, epcmdwrite->bEndpointAddress);
> + ch348->statusrx_endpoint = usb_rcvbulkpipe(usb_dev, epstatusread->bEndpointAddress);
> +
> + ret = ch348_allocate_status_read(ch348, epstatusread);
> + if (ret)
> + return ret;
Neither should this.
> + return 0;
> +}
> +
> +static int ch348_port_probe(struct usb_serial_port *port)
> +{
> + struct ch348 *ch348 = usb_get_serial_data(port->serial);
> +
> + ch348->ttyport[port->port_number].port = port;
Or this.
> +
> + return 0;
> +}
Johan
