From d449991c4d1d0663b42db7648510a9911de21298 Mon Sep 17 00:00:00 2001 From: Thomas Petazzoni Date: Thu, 7 Feb 2019 17:28:58 +0100 Subject: gpio: add core support for pull-up/pull-down configuration This commit adds support for configuring the pull-up and pull-down resistors available in some GPIO controllers. While configuring pull-up/pull-down is already possible through the pinctrl subsystem, some GPIO controllers, especially simple ones such as GPIO expanders on I2C, don't have any pinmuxing capability and therefore do not use the pinctrl subsystem. This commit implements the GPIO_PULL_UP and GPIO_PULL_DOWN flags, which can be used from the Device Tree, to enable a pull-up or pull-down resistor on a given GPIO. The flag is simply propagated all the way to the core GPIO subsystem, where it is used to call the gpio_chip ->set_config callback with the appropriate existing PIN_CONFIG_BIAS_* values. Signed-off-by: Thomas Petazzoni Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib-of.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/gpio/gpiolib-of.c') diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index a6e1891217e2..9a8b78477f79 100644 --- a/drivers/gpio/gpiolib-of.c +++ b/drivers/gpio/gpiolib-of.c @@ -345,6 +345,11 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, if (of_flags & OF_GPIO_TRANSITORY) *flags |= GPIO_TRANSITORY; + if (of_flags & OF_GPIO_PULL_UP) + *flags |= GPIO_PULL_UP; + if (of_flags & OF_GPIO_PULL_DOWN) + *flags |= GPIO_PULL_DOWN; + return desc; } -- cgit v1.2.3 From 0e7d6f94016407fd7e1ae472e254d64d4454e9c8 Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Sat, 16 Feb 2019 14:46:27 +0100 Subject: 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 Cc: Geert Uytterhoeven Cc: Jan Kotas Cc: Linus Walleij Cc: Mark Brown Cc: Wolfram Sang Cc: linux-renesas-soc@vger.kernel.org To: linux-gpio@vger.kernel.org Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib-of.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/gpio/gpiolib-of.c') 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"))) { -- cgit v1.2.3 From 692ef26e72fcce0c1e73c41683fd3512f3719d55 Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Wed, 20 Feb 2019 11:52:14 +0100 Subject: gpio: of: Restrict enable-gpio quirk to regulator-gpio 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 Tested-by: Marek Vasut Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib-of.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/gpio/gpiolib-of.c') diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index 4547dba19956..950d3d6b2b7f 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 -- cgit v1.2.3 From 21b4ab8f9e7100286c380a13e0e46ca6bf35e692 Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Wed, 20 Feb 2019 12:24:30 +0100 Subject: gpio: of: Handle both enable-gpio{,s} Handle both enable-gpio and enable-gpios properties of the GPIO regulator in the quirk. The later is the preferred modern name of the property. Signed-off-by: Marek Vasut Cc: Geert Uytterhoeven Cc: Jan Kotas Cc: Linus Walleij Cc: Mark Brown Cc: Thierry Reding Cc: Wolfram Sang Cc: linux-renesas-soc@vger.kernel.org To: linux-gpio@vger.kernel.org Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib-of.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/gpio/gpiolib-of.c') diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index 950d3d6b2b7f..662c6f363ac2 100644 --- a/drivers/gpio/gpiolib-of.c +++ b/drivers/gpio/gpiolib-of.c @@ -87,7 +87,8 @@ static void of_gpio_flags_quirks(struct device_node *np, (of_device_is_compatible(np, "regulator-fixed") || of_device_is_compatible(np, "reg-fixed-voltage") || (of_device_is_compatible(np, "regulator-gpio") && - strcmp(propname, "enable-gpio") == 0))) { + !(strcmp(propname, "enable-gpio") && + strcmp(propname, "enable-gpios"))))) { /* * The regulator GPIO handles are specified such that the * presence or absence of "enable-active-high" solely controls -- cgit v1.2.3