From patchwork Fri May 29 21:38:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pratyush Yadav X-Patchwork-Id: 246850 List-Id: U-Boot discussion From: p.yadav at ti.com (Pratyush Yadav) Date: Sat, 30 May 2020 03:08:07 +0530 Subject: [PATCH v2 1/2] drivers: gpio: Add a managed API to get a GPIO from the device-tree In-Reply-To: <20200529213808.2815-1-p.yadav@ti.com> References: <20200529213808.2815-1-p.yadav@ti.com> Message-ID: <20200529213808.2815-2-p.yadav@ti.com> From: Jean-Jacques Hiblot Add managed functions to get a gpio from the devce-tree, based on a property name (minus the '-gpios' suffix) and optionally an index. When the device is unbound, the GPIO is automatically released and the data structure is freed. Signed-off-by: Jean-Jacques Hiblot --- drivers/gpio/gpio-uclass.c | 70 ++++++++++++++++++++++++++++++++++++++ include/asm-generic/gpio.h | 47 +++++++++++++++++++++++++ 2 files changed, 117 insertions(+) diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c index 9eeab22eef..fd868608fc 100644 --- a/drivers/gpio/gpio-uclass.c +++ b/drivers/gpio/gpio-uclass.c @@ -6,6 +6,8 @@ #include #include #include +#include +#include #include #include #include @@ -1141,6 +1143,74 @@ int gpio_dev_request_index(struct udevice *dev, const char *nodename, flags, 0, dev); } +static void devm_gpiod_release(struct udevice *dev, void *res) +{ + dm_gpio_free(dev, res); +} + +static int devm_gpiod_match(struct udevice *dev, void *res, void *data) +{ + return res == data; +} + +struct gpio_desc *devm_gpiod_get_index(struct udevice *dev, const char *id, + unsigned int index, int flags) +{ + int rc; + struct gpio_desc *desc; + char *propname; + static const char suffix[] = "-gpios"; + + propname = malloc(strlen(id) + sizeof(suffix)); + if (!propname) { + rc = -ENOMEM; + goto end; + } + + strcpy(propname, id); + strcat(propname, suffix); + + desc = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc), + __GFP_ZERO); + if (unlikely(!desc)) { + rc = -ENOMEM; + goto end; + } + + rc = gpio_request_by_name(dev, propname, index, desc, flags); + +end: + if (propname) + free(propname); + + if (rc) + return ERR_PTR(rc); + + devres_add(dev, desc); + return desc; +} + +struct gpio_desc *devm_gpiod_get_index_optional(struct udevice *dev, + const char *id, + unsigned int index, + int flags) +{ + struct gpio_desc *desc = devm_gpiod_get_index(dev, id, index, flags); + + if (IS_ERR(desc)) + return NULL; + + return desc; +} + +void devm_gpiod_put(struct udevice *dev, struct gpio_desc *desc) +{ + int rc; + + rc = devres_release(dev, devm_gpiod_release, devm_gpiod_match, desc); + WARN_ON(rc); +} + static int gpio_post_bind(struct udevice *dev) { struct udevice *child; diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index e16c2f31d9..76e0e902c4 100644 --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -674,4 +674,51 @@ int dm_gpio_get_dir_flags(struct gpio_desc *desc, ulong *flags); */ int gpio_get_number(const struct gpio_desc *desc); +/** + * devm_gpiod_get_index - Resource-managed gpiod_get() + * @dev: GPIO consumer + * @con_id: function within the GPIO consumer + * @index: index of the GPIO to obtain in the consumer + * @flags: optional GPIO initialization flags + * + * Managed gpiod_get(). GPIO descriptors returned from this function are + * automatically disposed on driver detach. + * Return the GPIO descriptor corresponding to the function con_id of device + * dev, -ENOENT if no GPIO has been assigned to the requested function, or + * another IS_ERR() code if an error occurred while trying to acquire the GPIO. + */ +struct gpio_desc *devm_gpiod_get_index(struct udevice *dev, const char *id, + unsigned int index, int flags); + +#define devm_gpiod_get(dev, id, flags) devm_gpiod_get_index(dev, id, 0, flags) +/** + * gpiod_get_optional - obtain an optional GPIO for a given GPIO function + * @dev: GPIO consumer, can be NULL for system-global GPIOs + * @con_id: function within the GPIO consumer + * @index: index of the GPIO to obtain in the consumer + * @flags: optional GPIO initialization flags + * + * This is equivalent to devm_gpiod_get(), except that when no GPIO was + * assigned to the requested function it will return NULL. This is convenient + * for drivers that need to handle optional GPIOs. + */ +struct gpio_desc *devm_gpiod_get_index_optional(struct udevice *dev, + const char *id, + unsigned int index, + int flags); + +#define devm_gpiod_get_optional(dev, id, flags) \ + devm_gpiod_get_index_optional(dev, id, 0, flags) + +/** + * devm_gpiod_put - Resource-managed gpiod_put() + * @dev: GPIO consumer + * @desc: GPIO descriptor to dispose of + * + * Dispose of a GPIO descriptor obtained with devm_gpiod_get() or + * devm_gpiod_get_index(). Normally this function will not be called as the GPIO + * will be disposed of by the resource management code. + */ +void devm_gpiod_put(struct udevice *dev, struct gpio_desc *desc); + #endif /* _ASM_GENERIC_GPIO_H_ */