USB: serial: ch341: add support for parity, frame length, stop bits
With the new reinitialization method, configuring parity, different
frame lengths and different stop bit settings should work as expected
on both CH340G and CH341A. Tested on a loopback-connected CH340G
with a logic analyzer in a number of different configurations.
Based on a patch by Grigori Goronzy
Signed-off-by: Aidan Thornton <makosoft@gmail.com>
Reviewed-by: Grigori Goronzy <greg@chown.ath.cx>
Signed-off-by: Johan Hovold <johan@kernel.org>
diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
index 096bc07..af9edbe 100644
--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -356,8 +356,33 @@
baud_rate = tty_get_baud_rate(tty);
priv->baud_rate = baud_rate;
+ ctrl = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX;
- ctrl = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX | CH341_LCR_CS8;
+ switch (C_CSIZE(tty)) {
+ case CS5:
+ ctrl |= CH341_LCR_CS5;
+ break;
+ case CS6:
+ ctrl |= CH341_LCR_CS6;
+ break;
+ case CS7:
+ ctrl |= CH341_LCR_CS7;
+ break;
+ case CS8:
+ ctrl |= CH341_LCR_CS8;
+ break;
+ }
+
+ if (C_PARENB(tty)) {
+ ctrl |= CH341_LCR_ENABLE_PAR;
+ if (C_PARODD(tty) == 0)
+ ctrl |= CH341_LCR_PAR_EVEN;
+ if (C_CMSPAR(tty))
+ ctrl |= CH341_LCR_MARK_SPACE;
+ }
+
+ if (C_CSTOPB(tty))
+ ctrl |= CH341_LCR_STOP_BITS_2;
if (baud_rate) {
spin_lock_irqsave(&priv->lock, flags);
@@ -376,11 +401,6 @@
ch341_set_handshake(port->serial->dev, priv->line_control);
- /* Unimplemented:
- * (cflag & CSIZE) : data bits [5, 8]
- * (cflag & PARENB) : parity {NONE, EVEN, ODD}
- * (cflag & CSTOPB) : stop bits [1, 2]
- */
}
static void ch341_break_ctl(struct tty_struct *tty, int break_state)