diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2025-04-10 06:58:06 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2025-04-10 06:58:06 -0700 |
commit | 8f43640c9109bd82bcf37def6adfe1b8b09e7b61 (patch) | |
tree | e1e786bc787327d17bd4f9a9b79e2b51f761c23e | |
parent | b4991c01ad07c1b3954a95e49bfae80c726b4b48 (diff) | |
parent | b8c7a1ac884cc267d1031f8de07f1a689a69fbab (diff) |
Merge tag 'gpio-fixes-for-v6.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux
Pull gpio fixes from Bartosz Golaszewski:
- fix resource handling in gpio-tegra186
- fix wakeup source leaks in gpio-mpc8xxx and gpio-zynq
- fix minor issues with some GPIO OF quirks
- deprecate GPIOD_FLAGS_BIT_NONEXCLUSIVE and devm_gpiod_unhinge()
symbols and add a TODO task to track replacing them with a better
solution
* tag 'gpio-fixes-for-v6.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
gpiolib: of: Move Atmel HSMCI quirk up out of the regulator comment
gpiolib: of: Fix the choice for Ingenic NAND quirk
gpio: zynq: Fix wakeup source leaks on device unbind
gpio: mpc8xxx: Fix wakeup source leaks on device unbind
gpio: TODO: track the removal of regulator-related workarounds
MAINTAINERS: add more keywords for the GPIO subsystem entry
gpio: deprecate devm_gpiod_unhinge()
gpio: deprecate the GPIOD_FLAGS_BIT_NONEXCLUSIVE flag
gpio: tegra186: fix resource handling in ACPI probe path
-rw-r--r-- | MAINTAINERS | 2 | ||||
-rw-r--r-- | drivers/gpio/TODO | 34 | ||||
-rw-r--r-- | drivers/gpio/gpio-mpc8xxx.c | 4 | ||||
-rw-r--r-- | drivers/gpio/gpio-tegra186.c | 27 | ||||
-rw-r--r-- | drivers/gpio/gpio-zynq.c | 1 | ||||
-rw-r--r-- | drivers/gpio/gpiolib-devres.c | 6 | ||||
-rw-r--r-- | drivers/gpio/gpiolib-of.c | 8 | ||||
-rw-r--r-- | include/linux/gpio/consumer.h | 1 |
8 files changed, 65 insertions, 18 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index 96b827049501..c59316109e3f 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -10151,6 +10151,8 @@ F: include/linux/gpio.h F: include/linux/gpio/ F: include/linux/of_gpio.h K: (devm_)?gpio_(request|free|direction|get|set) +K: GPIOD_FLAGS_BIT_NONEXCLUSIVE +K: devm_gpiod_unhinge GPIO UAPI M: Bartosz Golaszewski <brgl@bgdev.pl> diff --git a/drivers/gpio/TODO b/drivers/gpio/TODO index b5f0a7a2e1bf..4b70cbaa1caa 100644 --- a/drivers/gpio/TODO +++ b/drivers/gpio/TODO @@ -186,3 +186,37 @@ their hardware offsets within the chip. Encourage users to switch to using them and eventually remove the existing global export/unexport attribues. + +------------------------------------------------------------------------------- + +Remove GPIOD_FLAGS_BIT_NONEXCLUSIVE + +GPIOs in the linux kernel are meant to be an exclusive resource. This means +that the GPIO descriptors (the software representation of the hardware concept) +are not reference counted and - in general - only one user at a time can +request a GPIO line and control its settings. The consumer API is designed +around full control of the line's state as evidenced by the fact that, for +instance, gpiod_set_value() does indeed drive the line as requested, instead +of bumping an enable counter of some sort. + +A problematic use-case for GPIOs is when two consumers want to use the same +descriptor independently. An example of such a user is the regulator subsystem +which may instantiate several struct regulator_dev instances containing +a struct device but using the same enable GPIO line. + +A workaround was introduced in the form of the GPIOD_FLAGS_BIT_NONEXCLUSIVE +flag but its implementation is problematic: it does not provide any +synchronization of usage nor did it introduce any enable count meaning the +non-exclusive users of the same descriptor will in fact "fight" for the +control over it. This flag should be removed and replaced with a better +solution, possibly based on the new power sequencing subsystem. + +------------------------------------------------------------------------------- + +Remove devm_gpiod_unhinge() + +devm_gpiod_unhinge() is provided as a way to transfer the ownership of managed +enable GPIOs to the regulator core. Rather than doing that however, we should +make it possible for the regulator subsystem to deal with GPIO resources the +lifetime of which it doesn't control as logically, a GPIO obtained by a caller +should also be freed by it. diff --git a/drivers/gpio/gpio-mpc8xxx.c b/drivers/gpio/gpio-mpc8xxx.c index 0cd4c36ae8aa..541517536489 100644 --- a/drivers/gpio/gpio-mpc8xxx.c +++ b/drivers/gpio/gpio-mpc8xxx.c @@ -410,7 +410,9 @@ static int mpc8xxx_probe(struct platform_device *pdev) goto err; } - device_init_wakeup(dev, true); + ret = devm_device_init_wakeup(dev); + if (ret) + return dev_err_probe(dev, ret, "Failed to init wakeup\n"); return 0; err: diff --git a/drivers/gpio/gpio-tegra186.c b/drivers/gpio/gpio-tegra186.c index 6895b65c86af..d27bfac6c9f5 100644 --- a/drivers/gpio/gpio-tegra186.c +++ b/drivers/gpio/gpio-tegra186.c @@ -823,6 +823,7 @@ static int tegra186_gpio_probe(struct platform_device *pdev) struct gpio_irq_chip *irq; struct tegra_gpio *gpio; struct device_node *np; + struct resource *res; char **names; int err; @@ -842,19 +843,19 @@ static int tegra186_gpio_probe(struct platform_device *pdev) gpio->num_banks++; /* get register apertures */ - gpio->secure = devm_platform_ioremap_resource_byname(pdev, "security"); - if (IS_ERR(gpio->secure)) { - gpio->secure = devm_platform_ioremap_resource(pdev, 0); - if (IS_ERR(gpio->secure)) - return PTR_ERR(gpio->secure); - } - - gpio->base = devm_platform_ioremap_resource_byname(pdev, "gpio"); - if (IS_ERR(gpio->base)) { - gpio->base = devm_platform_ioremap_resource(pdev, 1); - if (IS_ERR(gpio->base)) - return PTR_ERR(gpio->base); - } + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "security"); + if (!res) + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + gpio->secure = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(gpio->secure)) + return PTR_ERR(gpio->secure); + + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "gpio"); + if (!res) + res = platform_get_resource(pdev, IORESOURCE_MEM, 1); + gpio->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(gpio->base)) + return PTR_ERR(gpio->base); err = platform_irq_count(pdev); if (err < 0) diff --git a/drivers/gpio/gpio-zynq.c b/drivers/gpio/gpio-zynq.c index be81fa2b17ab..3dae63f3ea21 100644 --- a/drivers/gpio/gpio-zynq.c +++ b/drivers/gpio/gpio-zynq.c @@ -1011,6 +1011,7 @@ static void zynq_gpio_remove(struct platform_device *pdev) ret = pm_runtime_get_sync(&pdev->dev); if (ret < 0) dev_warn(&pdev->dev, "pm_runtime_get_sync() Failed\n"); + device_init_wakeup(&pdev->dev, 0); gpiochip_remove(&gpio->chip); device_set_wakeup_capable(&pdev->dev, 0); pm_runtime_disable(&pdev->dev); diff --git a/drivers/gpio/gpiolib-devres.c b/drivers/gpio/gpiolib-devres.c index 08205f355ceb..120d1ec5af3b 100644 --- a/drivers/gpio/gpiolib-devres.c +++ b/drivers/gpio/gpiolib-devres.c @@ -317,11 +317,15 @@ EXPORT_SYMBOL_GPL(devm_gpiod_put); * @dev: GPIO consumer * @desc: GPIO descriptor to remove resource management from * + * *DEPRECATED* + * This function should not be used. It's been provided as a workaround for + * resource ownership issues in the regulator framework and should be replaced + * with a better solution. + * * Remove resource management from a GPIO descriptor. This is needed when * you want to hand over lifecycle management of a descriptor to another * mechanism. */ - void devm_gpiod_unhinge(struct device *dev, struct gpio_desc *desc) { int ret; diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index eb667f8f1ead..65f6a7177b78 100644 --- a/drivers/gpio/gpiolib-of.c +++ b/drivers/gpio/gpiolib-of.c @@ -193,6 +193,8 @@ static void of_gpio_try_fixup_polarity(const struct device_node *np, */ { "himax,hx8357", "gpios-reset", false }, { "himax,hx8369", "gpios-reset", false }, +#endif +#if IS_ENABLED(CONFIG_MTD_NAND_JZ4780) /* * The rb-gpios semantics was undocumented and qi,lb60 (along with * the ingenic driver) got it wrong. The active state encodes the @@ -266,6 +268,9 @@ static void of_gpio_set_polarity_by_property(const struct device_node *np, { "fsl,imx8qm-fec", "phy-reset-gpios", "phy-reset-active-high" }, { "fsl,s32v234-fec", "phy-reset-gpios", "phy-reset-active-high" }, #endif +#if IS_ENABLED(CONFIG_MMC_ATMELMCI) + { "atmel,hsmci", "cd-gpios", "cd-inverted" }, +#endif #if IS_ENABLED(CONFIG_PCI_IMX6) { "fsl,imx6q-pcie", "reset-gpio", "reset-gpio-active-high" }, { "fsl,imx6sx-pcie", "reset-gpio", "reset-gpio-active-high" }, @@ -292,9 +297,6 @@ static void of_gpio_set_polarity_by_property(const struct device_node *np, { "regulator-gpio", "enable-gpio", "enable-active-high" }, { "regulator-gpio", "enable-gpios", "enable-active-high" }, #endif -#if IS_ENABLED(CONFIG_MMC_ATMELMCI) - { "atmel,hsmci", "cd-gpios", "cd-inverted" }, -#endif }; unsigned int i; bool active_high; diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h index 45b651c05b9c..8adc8e9cb4a7 100644 --- a/include/linux/gpio/consumer.h +++ b/include/linux/gpio/consumer.h @@ -31,6 +31,7 @@ struct gpio_descs { #define GPIOD_FLAGS_BIT_DIR_OUT BIT(1) #define GPIOD_FLAGS_BIT_DIR_VAL BIT(2) #define GPIOD_FLAGS_BIT_OPEN_DRAIN BIT(3) +/* GPIOD_FLAGS_BIT_NONEXCLUSIVE is DEPRECATED, don't use in new code. */ #define GPIOD_FLAGS_BIT_NONEXCLUSIVE BIT(4) /** |