USB: serial: ftdi_sio: clean up baudrate request

Multi-channel devices need to encode the channel selector in their
control requests and newer single-channel chip types use the same
request format.

Set the channel index also for these single-channel types so that the
index can be used to determine the baudrate request format instead of
listing types explicitly.

Note that FT232H and FTX accept either 0 or 1 as selector for their
single channel, presumably for backward compatibility reasons.

Signed-off-by: Johan Hovold <johan@kernel.org>

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 05c635e..af0ed7f 100644 (file)
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1406,13 +1406,8 @@ static int change_speed(struct tty_struct *tty, struct usb_serial_port *port)
        index_value = get_ftdi_divisor(tty, port);
        value = (u16)index_value;
        index = (u16)(index_value >> 16);
-       if (priv->chip_type == FT2232C || priv->chip_type == FT2232H ||
-                       priv->chip_type == FT4232H || priv->chip_type == FT232H ||
-                       priv->chip_type == FTX) {
-               /* Probably the BM type needs the MSB of the encoded fractional
-                * divider also moved like for the chips above. Any infos? */
+       if (priv->channel)
                index = (u16)((index << 8) | priv->channel);
-       }
 
        rv = usb_control_msg(port->serial->dev,
                            usb_sndctrlpipe(port->serial->dev, 0),
@@ -1595,10 +1590,12 @@ static int ftdi_determine_type(struct usb_serial_port *port)
                break;
        case 0x900:
                priv->chip_type = FT232H;
+               priv->channel = CHANNEL_A + ifnum;
                priv->baud_base = 120000000 / 2;
                break;
        case 0x1000:
                priv->chip_type = FTX;
+               priv->channel = CHANNEL_A + ifnum;
                break;
        default:
                if (version < 0x200) {