[RESEND PATCH v8 02/10] serial: sc16is7xx: mark IOCONTROL register as volatile

From: Hugo Villeneuve
Date: Fri Jul 21 2023 - 12:20:33 EST


From: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>

Bit SRESET (3) is cleared when a reset operation is completed. Having
the IOCONTROL register as non-volatile will always read SRESET as 1,
which is incorrect.

Also, if IOCONTROL register is not a volatile register, the upcoming
patch "serial: sc16is7xx: fix regression with GPIO configuration"
doesn't work when setting some shared GPIO lines as modem control
lines.

Therefore mark IOCONTROL register as a volatile register.

Cc: <stable@xxxxxxxxxxxxxxx> # 6.1.x
Signed-off-by: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
Reviewed-by: Lech Perczak <lech.perczak@xxxxxxxxxxxxxxx>
Tested-by: Lech Perczak <lech.perczak@xxxxxxxxxxxxxxx>
---
drivers/tty/serial/sc16is7xx.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 8ae2afc76a9b..306ae512b38a 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -488,6 +488,7 @@ static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg)
case SC16IS7XX_TXLVL_REG:
case SC16IS7XX_RXLVL_REG:
case SC16IS7XX_IOSTATE_REG:
+ case SC16IS7XX_IOCONTROL_REG:
return true;
default:
break;
--
2.30.2