linux-kernel - [PATCH] gpio: of: Restrict enable-gpio quirk to regulator-gpio

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Message-Id: <20190220105214.26618-1-thierry.reding@gmail.com>
Date:   Wed, 20 Feb 2019 11:52:14 +0100
From:   Thierry Reding <thierry.reding@...il.com>
To:     Linus Walleij <linus.walleij@...aro.org>,
        Bartosz Golaszewski <bgolaszewski@...libre.com>
Cc:     Marek Vasut <marek.vasut@...il.com>, linux-gpio@...r.kernel.org,
        linux-tegra@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] gpio: of: Restrict enable-gpio quirk to regulator-gpio

From: Thierry Reding <treding@...dia.com>

Commit 0e7d6f940164 ("gpio: of: Apply regulator-gpio quirk only to
enable-gpios") breaks the device tree ABI specified in the device tree
bindings for fixed regulators (compatible "regulator-fixed"). According
to these bindings the polarity of the GPIO is exclusively controlled by
the presence or absence of the enable-active-high property. As such the
polarity quirk implemented in of_gpio_flags_quirks() must be applied to
the GPIO specified for fixed regulators.

However, commit 0e7d6f940164 ("gpio: of: Apply regulator-gpio quirk only
to enable-gpios") restricted the quirk to the enable-gpios property for
fixed regulators as well, whereas according to the commit message itself
it should only apply to "regulator-gpio" compatible device tree nodes.

Fix this by actually implementing what the offending commit intended,
which is to ensure that the quirk is applied to the GPIO specified by
the "enable-gpio" property for the "regulator-gpio" bindings only.

This fixes a regression on Jetson TX1 where the fixed regulator for the
HDMI +5V pin relies on the flags quirk for the proper polarity.

Fixes: 0e7d6f940164 ("gpio: of: Apply regulator-gpio quirk only to enable-gpios")
Signed-off-by: Thierry Reding <treding@...dia.com>
---
 drivers/gpio/gpiolib-of.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 1b4c741e0635..bddfc6102a50 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -84,10 +84,10 @@ static void of_gpio_flags_quirks(struct device_node *np,
 	 * Note that active low is the default.
 	 */
 	if (IS_ENABLED(CONFIG_REGULATOR) &&
-	    !strcmp(propname, "enable-gpio") &&
 	    (of_device_is_compatible(np, "regulator-fixed") ||
 	     of_device_is_compatible(np, "reg-fixed-voltage") ||
-	     of_device_is_compatible(np, "regulator-gpio"))) {
+	     (of_device_is_compatible(np, "regulator-gpio") &&
+	      strcmp(propname, "enable-gpio") == 0))) {
 		/*
 		 * The regulator GPIO handles are specified such that the
 		 * presence or absence of "enable-active-high" solely controls
-- 
2.20.1