linux-kernel - [PATCH] pinctrl: bcm: pinctrl-iproc-gpio: Fix setting GPIO as output

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Message-Id: <20201116215842.29488-1-mark.tomlinson@alliedtelesis.co.nz>
Date:   Tue, 17 Nov 2020 10:58:42 +1300
From:   Mark Tomlinson <mark.tomlinson@...iedtelesis.co.nz>
To:     rjui@...adcom.com, sbranden@...adcom.com
Cc:     linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org,
        Mark Tomlinson <mark.tomlinson@...iedtelesis.co.nz>
Subject: [PATCH] pinctrl: bcm: pinctrl-iproc-gpio: Fix setting GPIO as output

When setting a GPIO pin to an output, it is important to set the value
correctly before enabling the output so that a glitch is not seen on the
pin. This glitch may be very short, but can be important if this is a
reset signal.

Fixes: b64333ce769c ("pinctrl: cygnus: add gpio/pinconf driver")
Signed-off-by: Mark Tomlinson <mark.tomlinson@...iedtelesis.co.nz>
---
 drivers/pinctrl/bcm/pinctrl-iproc-gpio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pinctrl/bcm/pinctrl-iproc-gpio.c b/drivers/pinctrl/bcm/pinctrl-iproc-gpio.c
index e2bd2dce6bb4..cadcf5eb0466 100644
--- a/drivers/pinctrl/bcm/pinctrl-iproc-gpio.c
+++ b/drivers/pinctrl/bcm/pinctrl-iproc-gpio.c
@@ -348,8 +348,8 @@ static int iproc_gpio_direction_output(struct gpio_chip *gc, unsigned gpio,
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&chip->lock, flags);
-	iproc_set_bit(chip, IPROC_GPIO_OUT_EN_OFFSET, gpio, true);
 	iproc_set_bit(chip, IPROC_GPIO_DATA_OUT_OFFSET, gpio, !!(val));
+	iproc_set_bit(chip, IPROC_GPIO_OUT_EN_OFFSET, gpio, true);
 	raw_spin_unlock_irqrestore(&chip->lock, flags);
 
 	dev_dbg(chip->dev, "gpio:%u set output, value:%d\n", gpio, val);
-- 
2.29.2