diff options
author | Alexandre Courbot <acourbot@nvidia.com> | 2013-10-17 10:21:36 -0700 |
---|---|---|
committer | Linus Walleij <linus.walleij@linaro.org> | 2013-10-19 23:24:45 +0200 |
commit | 79a9becda8940deb2274b5aa4577c86d52ee7ecb (patch) | |
tree | 2e10b344abcf76446ff97855d280fe9b7fb34ef0 /include/asm-generic | |
parent | b41fb43911b4cb864812adec88d028cc6219f23e (diff) | |
download | linux-79a9becda8940deb2274b5aa4577c86d52ee7ecb.tar.gz linux-79a9becda8940deb2274b5aa4577c86d52ee7ecb.tar.bz2 linux-79a9becda8940deb2274b5aa4577c86d52ee7ecb.zip |
gpiolib: export descriptor-based GPIO interface
This patch exports the gpiod_* family of API functions, a safer
alternative to the legacy GPIO interface. Differences between the gpiod
and legacy gpio APIs are:
- gpio works with integers, whereas gpiod operates on opaque handlers
which cannot be forged or used before proper acquisition
- gpiod get/set functions are aware of the active low state of a GPIO
- gpio consumers should now include <linux/gpio/consumer.h> to access
the new interface, whereas chips drivers will use
<linux/gpio/driver.h>
The legacy gpio API is now built as inline functions on top of gpiod.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'include/asm-generic')
-rw-r--r-- | include/asm-generic/gpio.h | 222 |
1 files changed, 62 insertions, 160 deletions
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index b309a5c0019e..00f8f0a9edcd 100644 --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -10,6 +10,8 @@ #ifdef CONFIG_GPIOLIB #include <linux/compiler.h> +#include <linux/gpio/driver.h> +#include <linux/gpio/consumer.h> /* Platforms may implement their GPIO interface with library code, * at a small performance cost for non-inlined operations and some @@ -49,122 +51,11 @@ struct module; struct device_node; struct gpio_desc; -/** - * struct gpio_chip - abstract a GPIO controller - * @label: for diagnostics - * @dev: optional device providing the GPIOs - * @owner: helps prevent removal of modules exporting active GPIOs - * @list: links gpio_chips together for traversal - * @request: optional hook for chip-specific activation, such as - * enabling module power and clock; may sleep - * @free: optional hook for chip-specific deactivation, such as - * disabling module power and clock; may sleep - * @get_direction: returns direction for signal "offset", 0=out, 1=in, - * (same as GPIOF_DIR_XXX), or negative error - * @direction_input: configures signal "offset" as input, or returns error - * @get: returns value for signal "offset"; for output signals this - * returns either the value actually sensed, or zero - * @direction_output: configures signal "offset" as output, or returns error - * @set_debounce: optional hook for setting debounce time for specified gpio in - * interrupt triggered gpio chips - * @set: assigns output value for signal "offset" - * @to_irq: optional hook supporting non-static gpio_to_irq() mappings; - * implementation may not sleep - * @dbg_show: optional routine to show contents in debugfs; default code - * will be used when this is omitted, but custom code can show extra - * state (such as pullup/pulldown configuration). - * @base: identifies the first GPIO number handled by this chip; or, if - * negative during registration, requests dynamic ID allocation. - * @ngpio: the number of GPIOs handled by this controller; the last GPIO - * handled is (base + ngpio - 1). - * @desc: array of ngpio descriptors. Private. - * @can_sleep: flag must be set iff get()/set() methods sleep, as they - * must while accessing GPIO expander chips over I2C or SPI - * @names: if set, must be an array of strings to use as alternative - * names for the GPIOs in this chip. Any entry in the array - * may be NULL if there is no alias for the GPIO, however the - * array must be @ngpio entries long. A name can include a single printk - * format specifier for an unsigned int. It is substituted by the actual - * number of the gpio. - * - * A gpio_chip can help platforms abstract various sources of GPIOs so - * they can all be accessed through a common programing interface. - * Example sources would be SOC controllers, FPGAs, multifunction - * chips, dedicated GPIO expanders, and so on. - * - * Each chip controls a number of signals, identified in method calls - * by "offset" values in the range 0..(@ngpio - 1). When those signals - * are referenced through calls like gpio_get_value(gpio), the offset - * is calculated by subtracting @base from the gpio number. - */ -struct gpio_chip { - const char *label; - struct device *dev; - struct module *owner; - struct list_head list; - - int (*request)(struct gpio_chip *chip, - unsigned offset); - void (*free)(struct gpio_chip *chip, - unsigned offset); - int (*get_direction)(struct gpio_chip *chip, - unsigned offset); - int (*direction_input)(struct gpio_chip *chip, - unsigned offset); - int (*get)(struct gpio_chip *chip, - unsigned offset); - int (*direction_output)(struct gpio_chip *chip, - unsigned offset, int value); - int (*set_debounce)(struct gpio_chip *chip, - unsigned offset, unsigned debounce); - - void (*set)(struct gpio_chip *chip, - unsigned offset, int value); - - int (*to_irq)(struct gpio_chip *chip, - unsigned offset); - - void (*dbg_show)(struct seq_file *s, - struct gpio_chip *chip); - int base; - u16 ngpio; - struct gpio_desc *desc; - const char *const *names; - unsigned can_sleep:1; - unsigned exported:1; - -#if defined(CONFIG_OF_GPIO) - /* - * If CONFIG_OF is enabled, then all GPIO controllers described in the - * device tree automatically may have an OF translation - */ - struct device_node *of_node; - int of_gpio_n_cells; - int (*of_xlate)(struct gpio_chip *gc, - const struct of_phandle_args *gpiospec, u32 *flags); -#endif -#ifdef CONFIG_PINCTRL - /* - * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally - * describe the actual pin range which they serve in an SoC. This - * information would be used by pinctrl subsystem to configure - * corresponding pins for gpio usage. - */ - struct list_head pin_ranges; -#endif -}; - -extern const char *gpiochip_is_requested(struct gpio_chip *chip, - unsigned offset); -extern struct gpio_chip *gpio_to_chip(unsigned gpio); - -/* add/remove chips */ -extern int gpiochip_add(struct gpio_chip *chip); -extern int __must_check gpiochip_remove(struct gpio_chip *chip); -extern struct gpio_chip *gpiochip_find(void *data, - int (*match)(struct gpio_chip *chip, - void *data)); - +/* caller holds gpio_lock *OR* gpio is marked as requested */ +static inline struct gpio_chip *gpio_to_chip(unsigned gpio) +{ + return gpiod_to_chip(gpio_to_desc(gpio)); +} /* Always use the library code for GPIO management calls, * or when sleeping may be involved. @@ -172,25 +63,52 @@ extern struct gpio_chip *gpiochip_find(void *data, extern int gpio_request(unsigned gpio, const char *label); extern void gpio_free(unsigned gpio); -extern int gpio_direction_input(unsigned gpio); -extern int gpio_direction_output(unsigned gpio, int value); +static inline int gpio_direction_input(unsigned gpio) +{ + return gpiod_direction_input(gpio_to_desc(gpio)); +} +static inline int gpio_direction_output(unsigned gpio, int value) +{ + return gpiod_direction_output(gpio_to_desc(gpio), value); +} -extern int gpio_set_debounce(unsigned gpio, unsigned debounce); +static inline int gpio_set_debounce(unsigned gpio, unsigned debounce) +{ + return gpiod_set_debounce(gpio_to_desc(gpio), debounce); +} -extern int gpio_get_value_cansleep(unsigned gpio); -extern void gpio_set_value_cansleep(unsigned gpio, int value); +static inline int gpio_get_value_cansleep(unsigned gpio) +{ + return gpiod_get_raw_value_cansleep(gpio_to_desc(gpio)); +} +static inline void gpio_set_value_cansleep(unsigned gpio, int value) +{ + return gpiod_set_raw_value_cansleep(gpio_to_desc(gpio), value); +} /* A platform's <asm/gpio.h> code may want to inline the I/O calls when * the GPIO is constant and refers to some always-present controller, * giving direct access to chip registers and tight bitbanging loops. */ -extern int __gpio_get_value(unsigned gpio); -extern void __gpio_set_value(unsigned gpio, int value); +static inline int __gpio_get_value(unsigned gpio) +{ + return gpiod_get_raw_value(gpio_to_desc(gpio)); +} +static inline void __gpio_set_value(unsigned gpio, int value) +{ + return gpiod_set_raw_value(gpio_to_desc(gpio), value); +} -extern int __gpio_cansleep(unsigned gpio); +static inline int __gpio_cansleep(unsigned gpio) +{ + return gpiod_cansleep(gpio_to_desc(gpio)); +} -extern int __gpio_to_irq(unsigned gpio); +static inline int __gpio_to_irq(unsigned gpio) +{ + return gpiod_to_irq(gpio_to_desc(gpio)); +} extern int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset); extern void gpio_unlock_as_irq(struct gpio_chip *chip, unsigned int offset); @@ -199,19 +117,30 @@ extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *labe extern int gpio_request_array(const struct gpio *array, size_t num); extern void gpio_free_array(const struct gpio *array, size_t num); -#ifdef CONFIG_GPIO_SYSFS - /* * A sysfs interface can be exported by individual drivers if they want, * but more typically is configured entirely from userspace. */ -extern int gpio_export(unsigned gpio, bool direction_may_change); -extern int gpio_export_link(struct device *dev, const char *name, - unsigned gpio); -extern int gpio_sysfs_set_active_low(unsigned gpio, int value); -extern void gpio_unexport(unsigned gpio); +static inline int gpio_export(unsigned gpio, bool direction_may_change) +{ + return gpiod_export(gpio_to_desc(gpio), direction_may_change); +} -#endif /* CONFIG_GPIO_SYSFS */ +static inline int gpio_export_link(struct device *dev, const char *name, + unsigned gpio) +{ + return gpiod_export_link(dev, name, gpio_to_desc(gpio)); +} + +static inline int gpio_sysfs_set_active_low(unsigned gpio, int value) +{ + return gpiod_sysfs_set_active_low(gpio_to_desc(gpio), value); +} + +static inline void gpio_unexport(unsigned gpio) +{ + gpiod_unexport(gpio_to_desc(gpio)); +} #ifdef CONFIG_PINCTRL @@ -281,31 +210,4 @@ static inline void gpio_set_value_cansleep(unsigned gpio, int value) #endif /* !CONFIG_GPIOLIB */ -#ifndef CONFIG_GPIO_SYSFS - -struct device; - -/* sysfs support is only available with gpiolib, where it's optional */ - -static inline int gpio_export(unsigned gpio, bool direction_may_change) -{ - return -ENOSYS; -} - -static inline int gpio_export_link(struct device *dev, const char *name, - unsigned gpio) -{ - return -ENOSYS; -} - -static inline int gpio_sysfs_set_active_low(unsigned gpio, int value) -{ - return -ENOSYS; -} - -static inline void gpio_unexport(unsigned gpio) -{ -} -#endif /* CONFIG_GPIO_SYSFS */ - #endif /* _ASM_GENERIC_GPIO_H */ |