From 1c8732bb0355b929b09173464cdca7df4d516f89 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Wed, 9 Apr 2014 13:34:39 +0200 Subject: gpio: support threaded interrupts in irqchip helpers Some off-chip GPIO expanders need to be communicated by I2C or SPI traffic, but may still support IRQs. By the sleeping nature of such buses, such IRQ handlers need to be threaded. Support such handlers in the gpiochip irqchip helpers by flagging IRQs as threaded if the .can_sleep property of the gpiochip is true. Helpfully deny registration of chained IRQ handlers if the .can_sleep property is set, as such chips will invariably need a nested handler rather than a chained handler. Cc: Thomas Gleixner Signed-off-by: Linus Walleij --- include/linux/gpio/driver.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include/linux/gpio') diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index 1827b43966d9..573e4f3243d0 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -51,7 +51,10 @@ struct seq_file; * format specifier for an unsigned int. It is substituted by the actual * number of the gpio. * @can_sleep: flag must be set iff get()/set() methods sleep, as they - * must while accessing GPIO expander chips over I2C or SPI + * must while accessing GPIO expander chips over I2C or SPI. This + * implies that if the chip supports IRQs, these IRQs need to be threaded + * as the chip access may sleep when e.g. reading out the IRQ status + * registers. * @exported: flags if the gpiochip is exported for use from sysfs. Private. * * A gpio_chip can help platforms abstract various sources of GPIOs so -- cgit From 29a1f2333e07bbbecb920cc78fd035fe8f53207a Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Fri, 25 Apr 2014 17:10:06 +0200 Subject: gpio: Add helpers for optional GPIOs Introduce gpiod_get_optional() and gpiod_get_index_optional() helpers that make it easier for drivers to handle optional GPIOs. Currently in order to handle optional GPIOs, a driver needs to special case error handling for -ENOENT, such as this: gpio = gpiod_get(dev, "foo"); if (IS_ERR(gpio)) { if (PTR_ERR(gpio) != -ENOENT) return PTR_ERR(gpio); gpio = NULL; } if (gpio) { /* set up GPIO */ } With these new helpers the above is reduced to: gpio = gpiod_get_optional(dev, "foo"); if (IS_ERR(gpio)) return PTR_ERR(gpio); if (gpio) { /* set up GPIO */ } While at it, device-managed variants of these functions are also provided. Signed-off-by: Thierry Reding Reviewed-by: Alexandre Courbot Signed-off-by: Linus Walleij --- Documentation/driver-model/devres.txt | 2 ++ drivers/gpio/devres.c | 43 +++++++++++++++++++++++++++++++++++ drivers/gpio/gpiolib.c | 43 +++++++++++++++++++++++++++++++++++ include/linux/gpio/consumer.h | 40 ++++++++++++++++++++++++++++++++ 4 files changed, 128 insertions(+) (limited to 'include/linux/gpio') diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt index 8ff1167cfedf..10b8c5d2c797 100644 --- a/Documentation/driver-model/devres.txt +++ b/Documentation/driver-model/devres.txt @@ -312,4 +312,6 @@ SPI GPIO devm_gpiod_get() devm_gpiod_get_index() + devm_gpiod_get_optional() + devm_gpiod_get_index_optional() devm_gpiod_put() diff --git a/drivers/gpio/devres.c b/drivers/gpio/devres.c index 307464fd015f..65978cf85f79 100644 --- a/drivers/gpio/devres.c +++ b/drivers/gpio/devres.c @@ -51,6 +51,22 @@ struct gpio_desc *__must_check devm_gpiod_get(struct device *dev, } EXPORT_SYMBOL(devm_gpiod_get); +/** + * devm_gpiod_get_optional - Resource-managed gpiod_get_optional() + * @dev: GPIO consumer + * @con_id: function within the GPIO consumer + * + * Managed gpiod_get_optional(). GPIO descriptors returned from this function + * are automatically disposed on driver detach. See gpiod_get_optional() for + * detailed information about behavior and return values. + */ +struct gpio_desc *__must_check devm_gpiod_get_optional(struct device *dev, + const char *con_id) +{ + return devm_gpiod_get_index_optional(dev, con_id, 0); +} +EXPORT_SYMBOL(devm_gpiod_get_optional); + /** * devm_gpiod_get_index - Resource-managed gpiod_get_index() * @dev: GPIO consumer @@ -86,6 +102,33 @@ struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev, } EXPORT_SYMBOL(devm_gpiod_get_index); +/** + * devm_gpiod_get_index_optional - Resource-managed gpiod_get_index_optional() + * @dev: GPIO consumer + * @con_id: function within the GPIO consumer + * @index: index of the GPIO to obtain in the consumer + * + * Managed gpiod_get_index_optional(). GPIO descriptors returned from this + * function are automatically disposed on driver detach. See + * gpiod_get_index_optional() for detailed information about behavior and + * return values. + */ +struct gpio_desc *__must_check devm_gpiod_get_index_optional(struct device *dev, + const char *con_id, + unsigned int index) +{ + struct gpio_desc *desc; + + desc = devm_gpiod_get_index(dev, con_id, index); + if (IS_ERR(desc)) { + if (PTR_ERR(desc) == -ENOENT) + return NULL; + } + + return desc; +} +EXPORT_SYMBOL(devm_gpiod_get_index_optional); + /** * devm_gpiod_put - Resource-managed gpiod_put() * @desc: GPIO descriptor to dispose of diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 4ad110e793c5..d9c9cb4665db 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2737,6 +2737,22 @@ struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id) } EXPORT_SYMBOL_GPL(gpiod_get); +/** + * 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 + * + * This is equivalent to 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 *__must_check gpiod_get_optional(struct device *dev, + const char *con_id) +{ + return gpiod_get_index_optional(dev, con_id, 0); +} +EXPORT_SYMBOL_GPL(gpiod_get_optional); + /** * gpiod_get_index - obtain a GPIO from a multi-index GPIO function * @dev: GPIO consumer, can be NULL for system-global GPIOs @@ -2799,6 +2815,33 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev, } EXPORT_SYMBOL_GPL(gpiod_get_index); +/** + * gpiod_get_index_optional - obtain an optional GPIO from a multi-index 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 + * + * This is equivalent to gpiod_get_index(), except that when no GPIO with the + * specified index was assigned to the requested function it will return NULL. + * This is convenient for drivers that need to handle optional GPIOs. + */ +struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev, + const char *con_id, + unsigned int index) +{ + struct gpio_desc *desc; + + desc = gpiod_get_index(dev, con_id, index); + if (IS_ERR(desc)) { + if (PTR_ERR(desc) == -ENOENT) + return NULL; + } + + return desc; +} +EXPORT_SYMBOL_GPL(gpiod_get_index_optional); + /** * gpiod_put - dispose of a GPIO descriptor * @desc: GPIO descriptor to dispose of diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h index bed128e8f4b1..6a37ef0dc59c 100644 --- a/include/linux/gpio/consumer.h +++ b/include/linux/gpio/consumer.h @@ -23,6 +23,12 @@ struct gpio_desc *__must_check gpiod_get(struct device *dev, struct gpio_desc *__must_check gpiod_get_index(struct device *dev, const char *con_id, unsigned int idx); +struct gpio_desc *__must_check gpiod_get_optional(struct device *dev, + const char *con_id); +struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev, + const char *con_id, + unsigned int index); + void gpiod_put(struct gpio_desc *desc); struct gpio_desc *__must_check devm_gpiod_get(struct device *dev, @@ -30,6 +36,12 @@ struct gpio_desc *__must_check devm_gpiod_get(struct device *dev, struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev, const char *con_id, unsigned int idx); +struct gpio_desc *__must_check devm_gpiod_get_optional(struct device *dev, + const char *con_id); +struct gpio_desc *__must_check +devm_gpiod_get_index_optional(struct device *dev, const char *con_id, + unsigned int index); + void devm_gpiod_put(struct device *dev, struct gpio_desc *desc); int gpiod_get_direction(const struct gpio_desc *desc); @@ -73,6 +85,20 @@ static inline struct gpio_desc *__must_check gpiod_get_index(struct device *dev, { return ERR_PTR(-ENOSYS); } + +static inline struct gpio_desc *__must_check +gpiod_get_optional(struct device *dev, const char *con_id) +{ + return ERR_PTR(-ENOSYS); +} + +static inline struct gpio_desc *__must_check +gpiod_get_index_optional(struct device *dev, const char *con_id, + unsigned int index) +{ + return ERR_PTR(-ENOSYS); +} + static inline void gpiod_put(struct gpio_desc *desc) { might_sleep(); @@ -93,6 +119,20 @@ struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev, { return ERR_PTR(-ENOSYS); } + +static inline struct gpio_desc *__must_check +devm_gpiod_get_optional(struct device *dev, const char *con_id) +{ + return ERR_PTR(-ENOSYS); +} + +static inline struct gpio_desc *__must_check +devm_gpiod_get_index_optional(struct device *dev, const char *con_id, + unsigned int index) +{ + return ERR_PTR(-ENOSYS); +} + static inline void devm_gpiod_put(struct device *dev, struct gpio_desc *desc) { might_sleep(); -- cgit From cdf86cd233207ed992a647f0b9d42c60735756e7 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 8 May 2014 15:42:25 +0200 Subject: gpio: include linux/bug.h in interface header Today's linux-next kernel started showing build errors for the use of WARN_ON in linux/gpio/consumer.h: In file included from drivers/video/backlight/pwm_bl.c:13:0: include/linux/gpio/consumer.h: In function 'gpiod_put': include/linux/gpio/consumer.h:81:2: error: implicit declaration of function 'WARN_ON' [-Werror=implicit-function-declaration] It's not clear why this never happened before, but this patch fixes it by including the header that contains the defintion of this macro. Signed-off-by: Arnd Bergmann Acked-by: Alexandre Courbot Signed-off-by: Linus Walleij --- include/linux/gpio/consumer.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/gpio') diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h index 6a37ef0dc59c..05e53ccb708b 100644 --- a/include/linux/gpio/consumer.h +++ b/include/linux/gpio/consumer.h @@ -1,6 +1,7 @@ #ifndef __LINUX_GPIO_CONSUMER_H #define __LINUX_GPIO_CONSUMER_H +#include #include #include -- cgit