Commit 72a43046 authored by Chanho Park's avatar Chanho Park Committed by Greg Kroah-Hartman
Browse files

tty: serial: samsung_tty: loopback mode support 



Internal loopback mode can be supported by setting
UCON register's Loopback Mode bit. The mode & bit can be supported
since s3c2410 and later SoCs. The prefix of LOOPBACK / BIT(5) naming
should be also changed to S3C2410_ in order to avoid confusion.

Reviewed-by: default avatarKrzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: default avatarChanho Park <chanho61.park@samsung.com>
Link: https://lore.kernel.org/r/20220629004141.51484-1-chanho61.park@samsung.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 9636047f

drivers/tty/serial/samsung_tty.c

+8 −0
Original line number Diff line number Diff line
@@ -1018,6 +1018,7 @@ static unsigned int s3c24xx_serial_get_mctrl(struct uart_port *port) 
static void s3c24xx_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)

{

	unsigned int umcon = rd_regl(port, S3C2410_UMCON);

	unsigned int ucon = rd_reg(port, S3C2410_UCON);



	if (mctrl & TIOCM_RTS)

		umcon |= S3C2410_UMCOM_RTS_LOW;
@@ -1025,6 +1026,13 @@ static void s3c24xx_serial_set_mctrl(struct uart_port *port, unsigned int mctrl) 
		umcon &= ~S3C2410_UMCOM_RTS_LOW;



	wr_regl(port, S3C2410_UMCON, umcon);



	if (mctrl & TIOCM_LOOP)

		ucon |= S3C2410_UCON_LOOPBACK;

	else

		ucon &= ~S3C2410_UCON_LOOPBACK;



	wr_regl(port, S3C2410_UCON, ucon);

}



static void s3c24xx_serial_break_ctl(struct uart_port *port, int break_state)

include/linux/serial_s3c.h

+1 −1
Original line number Diff line number Diff line
@@ -83,7 +83,7 @@ 
#define S3C2410_UCON_RXIRQMODE	  (1<<0)

#define S3C2410_UCON_RXFIFO_TOI	  (1<<7)

#define S3C2443_UCON_RXERR_IRQEN  (1<<6)

#define S3C2443_UCON_LOOPBACK	  (1<<5)

#define S3C2410_UCON_LOOPBACK	  (1<<5)



#define S3C2410_UCON_DEFAULT	  (S3C2410_UCON_TXILEVEL  | \

				   S3C2410_UCON_RXILEVEL  | \