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From:   Hugo Villeneuve <hugo@hugovil.com>
To:     gregkh@linuxfoundation.org, robh+dt@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org,
        jirislaby@kernel.org, jringle@gridpoint.com,
        l.perczak@camlintechnologies.com, tomasz.mon@camlingroup.com
Cc:     linux-serial@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, hugo@hugovil.com,
        linux-gpio@vger.kernel.org,
        Hugo Villeneuve <hvilleneuve@dimonoff.com>,
        stable@vger.kernel.org, Lech Perczak <lech.perczak@camlingroup.com>
Date:   Thu,  1 Jun 2023 12:31:06 -0400
Message-Id: <20230601163113.2785657-3-hugo@hugovil.com>
In-Reply-To: <20230601163113.2785657-1-hugo@hugovil.com>
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Subject: [PATCH v5 2/9] serial: sc16is7xx: mark IOCONTROL register as volatile
Precedence: bulk

From: Hugo Villeneuve <hvilleneuve@dimonoff.com>

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@vger.kernel.org> # 6.1.x
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Reviewed-by: Lech Perczak <lech.perczak@camlingroup.com>
Tested-by: Lech Perczak <lech.perczak@camlingroup.com>
---
 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 faa51a58671f..0c903d44429c 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