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

From: Konstantin Pugin
Date: Fri Apr 19 2024 - 08:45:32 EST


From: Konstantin Pugin <ria.freelander@xxxxxxxxx>

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@xxxxxxxxx>
---
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