diff options
Diffstat (limited to 'drivers/usb/serial/ch341.c')
| -rw-r--r-- | drivers/usb/serial/ch341.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c index 2798fca71261..af01a462cc43 100644 --- a/drivers/usb/serial/ch341.c +++ b/drivers/usb/serial/ch341.c @@ -97,7 +97,10 @@ struct ch341_private { u8 mcr; u8 msr; u8 lcr; + unsigned long quirks; + u8 version; + unsigned long break_end; }; @@ -250,8 +253,12 @@ 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. */ - val |= BIT(7); + if (priv->version > 0x27) + val |= BIT(7); r = ch341_control_out(dev, CH341_REQ_WRITE_REG, CH341_REG_DIVISOR << 8 | CH341_REG_PRESCALER, @@ -265,6 +272,9 @@ static int ch341_set_baudrate_lcr(struct usb_device *dev, * (stop bits, parity and word length). Version 0x30 and above use * CH341_REG_LCR only and CH341_REG_LCR2 is always set to zero. */ + if (priv->version < 0x30) + return 0; + r = ch341_control_out(dev, CH341_REQ_WRITE_REG, CH341_REG_LCR2 << 8 | CH341_REG_LCR, lcr); if (r) @@ -308,7 +318,9 @@ 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) return r; - 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) |