The CH348 is an USB octo port serial adapter.
The device multiplexes all 8 ports in the same pair of Bulk endpoints.
Since there is no public datasheet, unfortunately it remains some magic values
Signed-off-by: Corentin Labbe <clabbe@xxxxxxxxxxxx>
---
drivers/usb/serial/Kconfig | 9 +
drivers/usb/serial/Makefile | 1 +
drivers/usb/serial/ch348.c | 491 ++++++++++++++++++++++++++++++++++++
3 files changed, 501 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..f89ef554954f
--- /dev/null
+++ b/drivers/usb/serial/ch348.c
@@ -0,0 +1,491 @@
+// 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 CH348_CMD_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 baudrate;
+ u8 format;
+ u8 paritytype;
+ u8 databits;
+ u8 rate;
+ u8 unknown;
+} __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.
+ */
+
+/*
+ * struct ch348_port - per-port information
+ * @uartmode: UART port current mode
+ */
+struct ch348_port {
+ u8 uartmode;
+};
+
+/*
+ * struct ch348 - main container for all this driver information
+ * @udev: pointer to the CH348 USB device
+ * @ports: List of per-port information
+ * @serial: pointer to the serial structure
+ * @status_ep: endpoint number for status operations
+ * @cmd_ep: endpoint number for configure operations
+ * @status_urb: URB for status
+ * @status_buffer: buffer used by status_urb
+ */
+struct ch348 {
+ struct usb_device *udev;
+ struct ch348_port ports[CH348_MAXPORT];
+ struct usb_serial *serial;
+
+ int status_ep;
+ int cmd_ep;
+
+ struct urb *status_urb;
+ u8 *status_buffer;
+};
+
+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)
+{
+ struct ch348_magic *buffer;
+ int ret, len;
+
+ 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->cmd_ep, buffer, 3, &len,
+ CH348_CMD_TIMEOUT);
+ if (ret)
+ dev_err(&ch348->udev->dev, "Failed to write magic err=%d\n", 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;
+
+ return ch348_do_magic(ch348, portnum, CMD_W_R, R_C4, 0x08);
+}
+
+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);
+ unsigned int portnum, usblen;
+ struct ch348_rxbuf *rxb;
+ u8 *buffer, *end;
+
+ buffer = urb->transfer_buffer;
+
+ if (urb->actual_length < 2) {
+ dev_dbg(&port->dev, "Empty rx buffer\n");
+ 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_dbg(&port->dev, "Invalid port %d\n", portnum);
+ break;
+ }
+
+ port = ch348->serial->port[portnum];
+
+ usblen = rxb->length;
+ if (usblen > CH348_RX_PORT_MAX_LENGTH) {
+ dev_dbg(&port->dev, "Invalid length %d for port %d\n",
+ usblen, portnum);
+ break;
+ }
+
+ 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;
+
+ if (ch348->ports[portnum].uartmode == M_NOR && mode == M_HF) {
+ ret = ch348_do_magic(ch348, portnum, CMD_W_BR, R_C4, 0x51);
+ if (ret)
+ return ret;
+ ch348->ports[portnum].uartmode = M_HF;
+ }
+
+ if (ch348->ports[portnum].uartmode == M_HF && mode == M_NOR) {
+ ret = ch348_do_magic(ch348, portnum, CMD_W_BR, R_C4, 0x50);
+ if (ret)
+ return ret;
+ ch348->ports[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 baudrate;
+ u8 format;
+ 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;
+ }
+
+ baudrate = tty_get_baud_rate(tty);
+ /* test show no success on low baud and datasheet said it is not supported */
+ if (baudrate < 1200)
+ baudrate = DEFAULT_BAUD_RATE;
+ /* datasheet said it is not supported */
+ if (baudrate > 6000000)
+ baudrate = 6000000;
+
+ format = termios->c_cflag & CSTOPB ? 2 : 1;
+
+ buffer->paritytype = 0;
+ if (termios->c_cflag & PARENB) {
+ if (termios->c_cflag & PARODD)
+ buffer->paritytype += 1;
+ else
+ buffer->paritytype += 2;
+ if (termios->c_cflag & CMSPAR)
+ buffer->paritytype += 2;
+ }
+
+ switch (C_CSIZE(tty)) {
+ case CS5:
+ buffer->databits = 5;
+ break;
+ case CS6:
+ buffer->databits = 6;
+ break;
+ case CS7:
+ buffer->databits = 7;
+ break;
+ case CS8:
+ default:
+ buffer->databits = 8;
+ break;
+ }
+ buffer->cmd = CMD_WB_E | (portnum & 0x0F);
+ buffer->reg = R_INIT;
+ buffer->port = portnum;
+ buffer->baudrate = cpu_to_be32(baudrate);
+
+ if (format == 2)
+ buffer->format = 0x02;
+ else if (format == 1)
+ buffer->format = 0x00;
+
+ buffer->rate = max_t(speed_t, 5, DIV_ROUND_CLOSEST(10000 * 15, baudrate));
+
+ ret = usb_bulk_msg(ch348->udev, ch348->cmd_ep, buffer,
+ sizeof(*buffer), &sent, CH348_CMD_TIMEOUT);
+ if (ret < 0) {
+ dev_err(&ch348->udev->dev, "Failed to change line settings: err=%d\n",
+ ret);
+ 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 ret;
+
+ if (tty)
+ ch348_set_termios(tty, port, NULL);
+
+ ret = ch348_configure(ch348, port->port_number);
+ if (ret) {
+ dev_err(&ch348->udev->dev, "Fail to configure err=%d\n", ret);
+ return ret;
+ }
+
+ return usb_serial_generic_open(tty, port);
+}
+
+static void ch348_disconnect(struct usb_serial *serial)
+{
+ struct ch348 *ch348 = usb_get_serial_data(serial);
+
+ usb_kill_urb(ch348->status_urb);
+}
+
+static int ch348_attach(struct usb_serial *serial)
+{
+ struct usb_serial_port *port0 = serial->port[1];
+ struct usb_device *usb_dev = serial->dev;
+ struct usb_endpoint_descriptor *epcmd;
+ struct usb_interface *intf;
+ struct ch348 *ch348;
+ int ret;
+
+ ch348 = kzalloc(sizeof(*ch348), GFP_KERNEL);
+ if (!ch348)
+ return -ENOMEM;
+
+ usb_set_serial_data(serial, ch348);
+
+ ch348->udev = serial->dev;
+ ch348->serial = serial;
+
+ intf = usb_ifnum_to_if(usb_dev, 0);
+ epcmd = &intf->cur_altsetting->endpoint[3].desc;
+ ret = usb_serial_generic_submit_read_urbs(port0, GFP_KERNEL);
+ if (ret)
+ return ret;
+
+ ch348->cmd_ep = usb_sndbulkpipe(usb_dev, epcmd->bEndpointAddress);
+
+ return 0;
+}
+
+static void ch348_release(struct usb_serial *serial)
+{
+ struct ch348 *ch348 = usb_get_serial_data(serial);
+ struct usb_serial_port *port0 = serial->port[1];
+
+ usb_serial_generic_close(port0);
+
+ kfree(ch348);
+}
+
+static int ch348_probe(struct usb_serial *serial, const struct usb_device_id *id)
+{
+ struct usb_device *usb_dev = serial->dev;
+ struct usb_endpoint_descriptor *epcmd;
+ struct usb_endpoint_descriptor *epread;
+ struct usb_endpoint_descriptor *epwrite;
+ struct usb_interface *intf;
+ 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, "Failed to find basic endpoints ret=%d\n", ret);
+ return ret;
+ }
+ epcmd = &intf->cur_altsetting->endpoint[3].desc;
+
+ if (!usb_endpoint_is_bulk_out(epcmd)) {
+ dev_err(&serial->dev->dev, "Missing second bulk out\n");
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+static int ch348_calc_num_ports(struct usb_serial *serial,
+ struct usb_serial_endpoints *epds)
+{
+ int i;
+
+ for (i = 1; i < CH348_MAXPORT; ++i) {
+ epds->bulk_out[i] = epds->bulk_out[0];
+ epds->bulk_in[i] = epds->bulk_in[0];
+ }
+ epds->num_bulk_out = CH348_MAXPORT;
+ epds->num_bulk_in = CH348_MAXPORT;
+
+ return CH348_MAXPORT;
+}
+
+static const struct usb_device_id ch348_ids[] = {
+ { USB_DEVICE(0x1a86, 0x55d9), },
+ { }
+};
+
+MODULE_DEVICE_TABLE(usb, ch348_ids);
+
+static struct usb_serial_driver ch348_device = {
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "ch348",
+ },
+ .id_table = ch348_ids,
+ .num_ports = CH348_MAXPORT,
+ .num_bulk_in = 1,
+ .num_bulk_out = 2,
+ .open = ch348_open,
+ .set_termios = ch348_set_termios,
+ .process_read_urb = ch348_process_read_urb,
+ .prepare_write_buffer = ch348_prepare_write_buffer,
+ .probe = ch348_probe,
+ .calc_num_ports = ch348_calc_num_ports,
+ .attach = ch348_attach,
+ .release = ch348_release,
+ .disconnect = ch348_disconnect,
+};
+
+static struct usb_serial_driver * const serial_drivers[] = {
+ &ch348_device, NULL
+};
+
+module_usb_serial_driver(serial_drivers, ch348_ids);
+
+MODULE_AUTHOR("Corentin Labbe <clabbe@xxxxxxxxxxxx>");
+MODULE_DESCRIPTION("USB CH348 Octo port serial converter driver");
+MODULE_LICENSE("GPL");
--
2.39.3
