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    Subject[PATCH AUTOSEL 5.0 129/262] gpio: of: Apply regulator-gpio quirk only to enable-gpios
    Date
    From: Marek Vasut <marek.vasut+renesas@gmail.com>

    [ Upstream commit 0e7d6f94016407fd7e1ae472e254d64d4454e9c8 ]

    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>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    drivers/gpio/gpiolib-of.c | 1 +
    1 file changed, 1 insertion(+)

    diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
    index a6e1891217e2..30542a10014f 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"))) {
    --
    2.19.1
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