[PATCH 01/12] USB: serial: xr: add support for XR21V1412 and XR21V1414

[Johan Hovold]

Add support for the two- and four-port variants of XR21V1410.

Use the interface number of each control interface (e.g. 0, 2, 4, 6) to
derive the zero-based channel index:

        XR21V1410       0
        XR21V1412       0, 1
        XR21V1414       0, 1, 2, 3

Note that the UART registers reside in separate blocks per channel,
while the UART Manager functionality is implemented using per-channel
registers.

Signed-off-by: Johan Hovold <jo...@kernel.org>
---
 drivers/usb/serial/xr_serial.c | 55 +++++++++++++++++++++++++++++++---
 1 file changed, 51 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/serial/xr_serial.c b/drivers/usb/serial/xr_serial.c
index 88c73f88cb26..64bc9d7b948b 100644
--- a/drivers/usb/serial/xr_serial.c
+++ b/drivers/usb/serial/xr_serial.c
@@ -109,6 +109,10 @@ struct xr_txrx_clk_mask {
 #define XR21V141X_REG_GPIO_CLR         0x1e
 #define XR21V141X_REG_GPIO_STATUS      0x1f
 
+struct xr_data {
+       u8 channel;             /* zero-based index */
+};
+
 static int xr_set_reg(struct usb_serial_port *port, u8 block, u8 reg, u8 val)
 {
        struct usb_serial *serial = port->serial;
@@ -160,16 +164,31 @@ static int xr_get_reg(struct usb_serial_port *port, u8 
block, u8 reg, u8 *val)
 
 static int xr_set_reg_uart(struct usb_serial_port *port, u8 reg, u8 val)
 {
-       return xr_set_reg(port, XR21V141X_UART_REG_BLOCK, reg, val);
+       struct xr_data *data = usb_get_serial_port_data(port);
+       u8 block;
+
+       block = XR21V141X_UART_REG_BLOCK + data->channel;
+
+       return xr_set_reg(port, block, reg, val);
 }
 
 static int xr_get_reg_uart(struct usb_serial_port *port, u8 reg, u8 *val)
 {
-       return xr_get_reg(port, XR21V141X_UART_REG_BLOCK, reg, val);
+       struct xr_data *data = usb_get_serial_port_data(port);
+       u8 block;
+
+       block = XR21V141X_UART_REG_BLOCK + data->channel;
+
+       return xr_get_reg(port, block, reg, val);
 }
 
-static int xr_set_reg_um(struct usb_serial_port *port, u8 reg, u8 val)
+static int xr_set_reg_um(struct usb_serial_port *port, u8 reg_base, u8 val)
 {
+       struct xr_data *data = usb_get_serial_port_data(port);
+       u8 reg;
+
+       reg = reg_base + data->channel;
+
        return xr_set_reg(port, XR21V141X_UM_REG_BLOCK, reg, val);
 }
 
@@ -577,8 +596,34 @@ static int xr_probe(struct usb_serial *serial, const 
struct usb_device_id *id)
        return 0;
 }
 
+static int xr_port_probe(struct usb_serial_port *port)
+{
+       struct usb_interface_descriptor *desc;
+       struct xr_data *data;
+
+       data = kzalloc(sizeof(*data), GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
+
+       desc = &port->serial->interface->cur_altsetting->desc;
+       data->channel = desc->bInterfaceNumber / 2;
+
+       usb_set_serial_port_data(port, data);
+
+       return 0;
+}
+
+static void xr_port_remove(struct usb_serial_port *port)
+{
+       struct xr_data *data = usb_get_serial_port_data(port);
+
+       kfree(data);
+}
+
 static const struct usb_device_id id_table[] = {
-       { USB_DEVICE_INTERFACE_CLASS(0x04e2, 0x1410, USB_CLASS_COMM) }, /* 
XR21V141X */
+       { USB_DEVICE_INTERFACE_CLASS(0x04e2, 0x1410, USB_CLASS_COMM) }, /* 
XR21V1410 */
+       { USB_DEVICE_INTERFACE_CLASS(0x04e2, 0x1412, USB_CLASS_COMM) }, /* 
XR21V1412 */
+       { USB_DEVICE_INTERFACE_CLASS(0x04e2, 0x1414, USB_CLASS_COMM) }, /* 
XR21V1414 */
        { }
 };
 MODULE_DEVICE_TABLE(usb, id_table);
@@ -591,6 +636,8 @@ static struct usb_serial_driver xr_device = {
        .id_table               = id_table,
        .num_ports              = 1,
        .probe                  = xr_probe,
+       .port_probe             = xr_port_probe,
+       .port_remove            = xr_port_remove,
        .open                   = xr_open,
        .close                  = xr_close,
        .break_ctl              = xr_break_ctl,
-- 
2.26.3