diff options
| author | Marek Vasut <marek.vasut+renesas@gmail.com> | 2019-02-16 14:46:27 +0100 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2019-02-17 22:20:11 +0100 |
| commit | 0e7d6f94016407fd7e1ae472e254d64d4454e9c8 (patch) | |
| tree | 3b06a5b7b205d1c0934e2528b05f8f35bdd44f2e /drivers/gpio | |
| parent | 0248baca03b8f188eccbb991bda2caec4c330975 (diff) | |
gpio: of: Apply regulator-gpio quirk only to enable-gpios
Since commit d6cd33ad7102 ("regulator: gpio: Convert to use descriptors")
the GPIO regulator had inverted the polarity of the control GPIO. This
problem manifested itself on systems with DT containing the following
description (snippet from salvator-common.dtsi):
gpios = <&gpio5 1 GPIO_ACTIVE_HIGH>;
gpios-states = <1>;
states = <3300000 1
1800000 0>;
Prior to the aforementioned commit, the gpio-regulator code used
gpio_request_array() to claim the GPIO(s) specified in the "gpios"
DT node, while the commit changed that to devm_gpiod_get_index().
The legacy gpio_request_array() calls gpio_request_one() and then
gpiod_request(), which parses the DT flags of the "gpios" node and
populates the GPIO descriptor flags field accordingly.
The new devm_gpiod_get_index() calls gpiod_get_index(), then
of_find_gpio(), of_get_named_gpiod_flags() with flags != NULL,
and then of_gpio_flags_quirks(). Since commit a603a2b8d86e
("gpio: of: Add special quirk to parse regulator flags"),
of_gpio_flags_quirks() contains a quirk for regulator-gpio
which was never triggered by the legacy gpio_request_array()
code path, but is triggered by devm_gpiod_get_index() code
path.
This quirk checks whether a GPIO is associated with a fixed
or gpio-regulator and if so, checks two additional conditions.
First, whether such GPIO is active-low, and if so, ignores the
active-low flag. Second, whether the regulator DT node does
have an "enable-active-high" property and if the property is
NOT present, sets the GPIO flags as active-low.
The second check triggers a problem, since it is applied to all
GPIOs associated with a gpio-regulator, rather than only on the
"enable" GPIOs, as the old code did. This changes the way the
gpio-regulator interprets the DT description of the control
GPIOs.
The old code using gpio_request_array() explicitly parsed the
"enable-active-high" DT property and only applied it to the
GPIOs described in the "enable-gpios" DT node, and only if
those were present.
This patch fixes the quirk code by only applying the quirk
to "enable-gpios", thus restoring the old behavior.
Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Jan Kotas <jank@cadence.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: linux-renesas-soc@vger.kernel.org
To: linux-gpio@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio')
| -rw-r--r-- | drivers/gpio/gpiolib-of.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index 9a8b78477f79..4547dba19956 100644 --- a/drivers/gpio/gpiolib-of.c +++ b/drivers/gpio/gpiolib-of.c @@ -84,6 +84,7 @@ 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"))) { |