diff options
Diffstat (limited to 'drivers/usb/serial/ch341.c')
| -rw-r--r-- | drivers/usb/serial/ch341.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c index f789b60ed..7eabb1bfa 100644 --- a/drivers/usb/serial/ch341.c +++ b/drivers/usb/serial/ch341.c @@ -96,6 +96,8 @@ struct ch341_private { u8 mcr; u8 msr; u8 lcr; + + u8 version; }; static void ch341_set_termios(struct tty_struct *tty, @@ -174,13 +176,20 @@ static int ch341_set_baudrate_lcr(struct usb_device *dev, /* * CH341A buffers data until a full endpoint-size packet (32 bytes) * has been received unless bit 7 is set. + * + * At least one device with version 0x27 appears to have this bit + * inverted. */ - a |= BIT(7); + if (priv->version > 0x27) + a |= BIT(7); r = ch341_control_out(dev, CH341_REQ_WRITE_REG, 0x1312, a); if (r) return r; + if (priv->version < 0x30) + return 0; + r = ch341_control_out(dev, CH341_REQ_WRITE_REG, 0x2518, lcr); if (r) return r; @@ -232,7 +241,9 @@ static int ch341_configure(struct usb_device *dev, struct ch341_private *priv) r = ch341_control_in(dev, CH341_REQ_READ_VERSION, 0, 0, buffer, size); if (r < 0) goto out; - dev_dbg(&dev->dev, "Chip version: 0x%02x\n", buffer[0]); + + priv->version = buffer[0]; + dev_dbg(&dev->dev, "Chip version: 0x%02x\n", priv->version); r = ch341_control_out(dev, CH341_REQ_SERIAL_INIT, 0, 0); if (r < 0) |