UbiquitousOS
/
OpenCloudOS-Kernel
mirror of https://gitee.com/OpenCloudOS/OpenCloudOS-Kernel.git
11
0
Fork 0
Code Issues Projects Releases Wiki Activity

USB: serial: xr: fix pin configuration 

Make sure that the modem pins are set up correctly when opening the
port to avoid leaving, for example, DTR and RTS configured as inputs,
which is the device default.

This is specifically needed to be able to control DTR and RTS when
hardware flow control is disabled.

Fixes: c2d405aa86 ("USB: serial: add MaxLinear/Exar USB to Serial driver")
Signed-off-by: Johan Hovold <johan@kernel.org>
This commit is contained in:
Johan Hovold 2021-01-21 11:29:21 +01:00
parent 465d3b3a0d
commit 0d05d7d913
1 changed files with 8 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
drivers/usb/serial/xr_serial.c
View File

@ -502,6 +502,7 @@ static void xr_set_termios(struct tty_struct *tty,
static int xr_open(struct tty_struct *tty, struct usb_serial_port *port)
{
u8 gpio_dir;
int ret;
ret = xr_uart_enable(port);
@ -510,6 +511,13 @@ static int xr_open(struct tty_struct *tty, struct usb_serial_port *port)
return ret;
}
/*
* Configure DTR and RTS as outputs and RI, CD, DSR and CTS as
* inputs.
*/
gpio_dir = XR21V141X_UART_MODE_DTR | XR21V141X_UART_MODE_RTS;
xr_set_reg_uart(port, XR21V141X_REG_GPIO_DIR, gpio_dir);
/* Setup termios */
if (tty)
xr_set_termios(tty, port, NULL);