From: Roger Quadros <rogerq@ti.com>
Date: Thu, 5 Dec 2013 09:23:35 +0000 (+0200)
Subject: gpio: twl4030: Fix regression for twl gpio LED output
X-Git-Tag: firefly_0821_release~3679^2~3170
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=d459f7e344ccdbdcba68192710642f90297de5b4;p=firefly-linux-kernel-4.4.55.git

gpio: twl4030: Fix regression for twl gpio LED output

commit f5837ec11f8cfa6d53ebc5806582771b2c9988c6 upstream.

Commit 0b2aa8be introduced a regression that causes failure
in setting LED GPO direction to OUT.

This causes USB host probe failures for Beagleboard C4.

platform usb_phy_gen_xceiv.2: Driver usb_phy_gen_xceiv requests probe deferral
hsusb2_vcc: Failed to request enable GPIO510: -22
reg-fixed-voltage reg-fixed-voltage.0.auto: Failed to register regulator: -22
reg-fixed-voltage: probe of reg-fixed-voltage.0.auto failed with error -22

direction_out/direction_in must return 0 if the operation succeeded.

Also, don't update direction flag and output data if twl4030_set_gpio_direction()
failed inside twl_direction_out();

Signed-off-by: Roger Quadros <rogerq@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/gpio/gpio-twl4030.c b/drivers/gpio/gpio-twl4030.c
index ed1d10ae1999..28d987661146 100644
--- a/drivers/gpio/gpio-twl4030.c
+++ b/drivers/gpio/gpio-twl4030.c
@@ -300,7 +300,7 @@ static int twl_direction_in(struct gpio_chip *chip, unsigned offset)
 	if (offset < TWL4030_GPIO_MAX)
 		ret = twl4030_set_gpio_direction(offset, 1);
 	else
-		ret = -EINVAL;
+		ret = -EINVAL;	/* LED outputs can't be set as input */
 
 	if (!ret)
 		priv->direction &= ~BIT(offset);
@@ -354,11 +354,20 @@ static void twl_set(struct gpio_chip *chip, unsigned offset, int value)
 static int twl_direction_out(struct gpio_chip *chip, unsigned offset, int value)
 {
 	struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip);
-	int ret = -EINVAL;
+	int ret = 0;
 
 	mutex_lock(&priv->mutex);
-	if (offset < TWL4030_GPIO_MAX)
+	if (offset < TWL4030_GPIO_MAX) {
 		ret = twl4030_set_gpio_direction(offset, 0);
+		if (ret) {
+			mutex_unlock(&priv->mutex);
+			return ret;
+		}
+	}
+
+	/*
+	 *  LED gpios i.e. offset >= TWL4030_GPIO_MAX are always output
+	 */
 
 	priv->direction |= BIT(offset);
 	mutex_unlock(&priv->mutex);