Commit ba781bdf authored by Aidan Thornton's avatar Aidan Thornton Committed by Johan Hovold
Browse files

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: default avatarAidan Thornton <makosoft@gmail.com>
Reviewed-by: default avatarGrigori Goronzy <greg@chown.ath.cx>
Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
parent 4e46c410

drivers/usb/serial/ch341.c

+26 −6
Original line number Diff line number Diff line
@@ -356,8 +356,33 @@ static void ch341_set_termios(struct tty_struct *tty, 
	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 @@ static void ch341_set_termios(struct tty_struct *tty, 


	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)

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