5.0-stable review patch. If anyone has any objections, please let me know.
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[ 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"))) {