linux-kernel - [PATCH v2] pinctrl: baytrail: show output gpio state correctly on Intel Baytrail

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Date:	Tue, 14 Oct 2014 10:54:37 -0700
From:	David Cohen <david.a.cohen@...ux.intel.com>
To:	linus.walleij@...aro.org
Cc:	linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org,
	balbi@...com, David Cohen <david.a.cohen@...ux.intel.com>,
	<stable@...r.kernel.org>,
	Mathias Nyman <mathias.nyman@...ux.intel.com>
Subject: [PATCH v2] pinctrl: baytrail: show output gpio state correctly on Intel Baytrail

Even if a gpio pin is set to output, we still need to set INPUT_EN
functionality (by clearing INPUT_EN bit) to be able to read the pin's
level.

E.g. without this change, we'll always read low level state from sysfs.

Cc: <stable@...r.kernel.org> # v3.14+
Cc: Mathias Nyman <mathias.nyman@...ux.intel.com>
Signed-off-by: David Cohen <david.a.cohen@...ux.intel.com>
---

v1 to v2: improved patch's body description as requested by Felipe Balbi
---

 drivers/pinctrl/pinctrl-baytrail.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pinctrl/pinctrl-baytrail.c b/drivers/pinctrl/pinctrl-baytrail.c
index e12e5b07f6d7..c23d8ded936d 100644
--- a/drivers/pinctrl/pinctrl-baytrail.c
+++ b/drivers/pinctrl/pinctrl-baytrail.c
@@ -318,7 +318,7 @@ static int byt_gpio_direction_output(struct gpio_chip *chip,
 		"Potential Error: Setting GPIO with direct_irq_en to output");
 
 	reg_val = readl(reg) | BYT_DIR_MASK;
-	reg_val &= ~BYT_OUTPUT_EN;
+	reg_val &= ~(BYT_OUTPUT_EN | BYT_INPUT_EN);
 
 	if (value)
 		writel(reg_val | BYT_LEVEL, reg);
-- 
2.1.0

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