linux-kernel - [PATCH] gpio: palmas: Fix misreported GPIO out value

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Date:	Fri, 26 Jul 2013 12:59:26 -0700
From:	Andrew Chew <achew@...dia.com>
To:	<linus.walleij@...aro.org>, <ldewangan@...dia.com>,
	<sameo@...ux.intel.com>
CC:	<achew@...dia.com>, <rklein@...dia.com>,
	<linux-gpio@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: [PATCH] gpio: palmas: Fix misreported GPIO out value

It seems that the value read back from the PALMAS_GPIO_DATA_IN register
isn't valid if the GPIO direction is out.  When that's the case, we can
read back the PALMAS_GPIO_DATA_OUT register to get the proper output value.

Change-Id: Iaf877e538cfdb37a6759c45ec3c6e4ee31078709
Signed-off-by: Andrew Chew <achew@...dia.com>
---
 drivers/gpio/gpio-palmas.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpio-palmas.c b/drivers/gpio/gpio-palmas.c
index e3a4e56..7606a85 100644
--- a/drivers/gpio/gpio-palmas.c
+++ b/drivers/gpio/gpio-palmas.c
@@ -43,9 +43,22 @@ static int palmas_gpio_get(struct gpio_chip *gc, unsigned offset)
 	unsigned int val;
 	int ret;
 
-	ret = palmas_read(palmas, PALMAS_GPIO_BASE, PALMAS_GPIO_DATA_IN, &val);
+	ret = palmas_read(palmas, PALMAS_GPIO_BASE, PALMAS_GPIO_DATA_DIR, &val);
 	if (ret < 0) {
-		dev_err(gc->dev, "GPIO_DATA_IN read failed, err = %d\n", ret);
+		dev_err(gc->dev, "GPIO_DATA_DIR read failed, err = %d\n", ret);
+		return ret;
+	}
+
+	if (test_bit(offset, &val)) {
+		ret = palmas_read(palmas, PALMAS_GPIO_BASE,
+				  PALMAS_GPIO_DATA_OUT, &val);
+	} else {
+		ret = palmas_read(palmas, PALMAS_GPIO_BASE,
+				  PALMAS_GPIO_DATA_IN, &val);
+	}
+	if (ret < 0) {
+		dev_err(gc->dev, "GPIO_DATA_IN/OUT read failed, err = %d\n",
+			ret);
 		return ret;
 	}
 	return !!(val & BIT(offset));
-- 
1.8.1.5

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