diff mbox series

[v4,1/3] serial: sc16is7xx: announce support of SER_RS485_RTS_ON_SEND

Message ID 20240419124506.1531035-2-rilian.la.te@ya.ru
State Superseded
Headers show
Series add support for EXAR XR20M1172 UART | expand

Commit Message

Konstantin Pugin April 19, 2024, 12:45 p.m. UTC 
From: Konstantin Pugin <ria.freelander@gmail.com>

The hardware supports both RTS_ON_SEND and RTS_AFTER_SEND modes, but
after the commit 4afeced55baa ("serial: core: fix sanitizing check for
RTS settings") we always end up with SER_RS485_RTS_AFTER_SEND set and
always write to the register field SC16IS7XX_EFCR_RTS_INVERT_BIT, which
breaks some hardware using these chips.

Fixes: 267913ecf737 ("serial: sc16is7xx: Fill in rs485_supported")
Signed-off-by: Konstantin Pugin <ria.freelander@gmail.com>
---
 drivers/tty/serial/sc16is7xx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Hugo Villeneuve April 19, 2024, 1:29 p.m. UTC | #1 
On Fri, 19 Apr 2024 15:45:01 +0300
Konstantin Pugin <rilian.la.te@ya.ru> wrote:

> From: Konstantin Pugin <ria.freelander@gmail.com>
> 
> The hardware supports both RTS_ON_SEND and RTS_AFTER_SEND modes, but
> after the commit 4afeced55baa ("serial: core: fix sanitizing check for
> RTS settings") we always end up with SER_RS485_RTS_AFTER_SEND set and
> always write to the register field SC16IS7XX_EFCR_RTS_INVERT_BIT, which
> breaks some hardware using these chips.

Hi Konstantin,
I am using RS-485 mode, and currently I may need SC16IS7XX_EFCR_RTS_INVERT_BIT to be set for my setup to work (not sure, must check this). Does it mean that with this patch it will be cleared? I am not sure by reading your commit message...

I need to look at this in more details, and test it on my hardware, which I will be able to do only next week. I will keep you posted.

Hugo.



> 
> Fixes: 267913ecf737 ("serial: sc16is7xx: Fill in rs485_supported")
> Signed-off-by: Konstantin Pugin <ria.freelander@gmail.com>
> ---
>  drivers/tty/serial/sc16is7xx.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
> index 03cf30e20b75..dfcc804f558f 100644
> --- a/drivers/tty/serial/sc16is7xx.c
> +++ b/drivers/tty/serial/sc16is7xx.c
> @@ -1449,7 +1449,7 @@ static int sc16is7xx_setup_mctrl_ports(struct sc16is7xx_port *s,
>  }
>  
>  static const struct serial_rs485 sc16is7xx_rs485_supported = {
> -	.flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
> +	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND,
>  	.delay_rts_before_send = 1,
>  	.delay_rts_after_send = 1,	/* Not supported but keep returning -EINVAL */
>  };
> -- 
> 2.34.1
> 
> 
>
diff mbox series

Patch

diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 03cf30e20b75..dfcc804f558f 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -1449,7 +1449,7 @@  static int sc16is7xx_setup_mctrl_ports(struct sc16is7xx_port *s,
 }
 
 static const struct serial_rs485 sc16is7xx_rs485_supported = {
-	.flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
+	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND,
 	.delay_rts_before_send = 1,
 	.delay_rts_after_send = 1,	/* Not supported but keep returning -EINVAL */
 };