diff options
Diffstat (limited to 'drivers/gpio/gpiolib.h')
| -rw-r--r-- | drivers/gpio/gpiolib.h | 141 |
1 files changed, 103 insertions, 38 deletions
diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h index a4a2520b5f31..c129a03e2040 100644 --- a/drivers/gpio/gpiolib.h +++ b/drivers/gpio/gpiolib.h @@ -16,7 +16,9 @@ #include <linux/gpio/driver.h> #include <linux/module.h> #include <linux/notifier.h> -#include <linux/rwsem.h> +#include <linux/spinlock.h> +#include <linux/srcu.h> +#include <linux/workqueue.h> #define GPIOCHIP_NAME "gpiochip" @@ -31,8 +33,11 @@ * @chip: pointer to the corresponding gpiochip, holding static * data for this device * @descs: array of ngpio descriptors. + * @desc_srcu: ensures consistent state of GPIO descriptors exposed to users * @ngpio: the number of GPIO lines on this GPIO device, equal to the size * of the @descs array. + * @can_sleep: indicate whether the GPIO chip driver's callbacks can sleep + * implying that they cannot be used from atomic context * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned * at device creation time. * @label: a descriptive name for the GPIO device, such as the part number @@ -41,11 +46,12 @@ * @list: links gpio_device:s together for traversal * @line_state_notifier: used to notify subscribers about lines being * requested, released or reconfigured + * @line_state_lock: RW-spinlock protecting the line state notifier + * @line_state_wq: used to emit line state events from a separate thread in + * process context * @device_notifier: used to notify character device wait queues about the GPIO * device being unregistered - * @sem: protects the structure from a NULL-pointer dereference of @chip by - * user-space operations when the device gets unregistered during - * a hot-unplug event + * @srcu: protects the pointer to the underlying GPIO chip * @pin_ranges: range of pins served by the GPIO driver * * This state container holds most of the runtime variable data @@ -59,16 +65,20 @@ struct gpio_device { int id; struct device *mockdev; struct module *owner; - struct gpio_chip *chip; + struct gpio_chip __rcu *chip; struct gpio_desc *descs; - int base; + struct srcu_struct desc_srcu; + unsigned int base; u16 ngpio; + bool can_sleep; const char *label; void *data; struct list_head list; - struct blocking_notifier_head line_state_notifier; + struct raw_notifier_head line_state_notifier; + rwlock_t line_state_lock; + struct workqueue_struct *line_state_wq; struct blocking_notifier_head device_notifier; - struct rw_semaphore sem; + struct srcu_struct srcu; #ifdef CONFIG_PINCTRL /* @@ -86,15 +96,28 @@ static inline struct gpio_device *to_gpio_device(struct device *dev) return container_of(dev, struct gpio_device, dev); } -/* gpio suffixes used for ACPI and device tree lookup */ -static __maybe_unused const char * const gpio_suffixes[] = { "gpios", "gpio" }; +/* GPIO suffixes used for ACPI and device tree lookup */ +extern const char *const gpio_suffixes[]; + +#define for_each_gpio_property_name(propname, con_id) \ + for (const char * const *__suffixes = gpio_suffixes; \ + *__suffixes && ({ \ + const char *__gs = *__suffixes; \ + \ + if (con_id) \ + snprintf(propname, sizeof(propname), "%s-%s", con_id, __gs); \ + else \ + snprintf(propname, sizeof(propname), "%s", __gs); \ + 1; \ + }); \ + __suffixes++) /** * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes * * @desc: Array of pointers to the GPIO descriptors * @size: Number of elements in desc - * @chip: Parent GPIO chip + * @gdev: Parent GPIO device * @get_mask: Get mask used in fastpath * @set_mask: Set mask used in fastpath * @invert_mask: Invert mask used in fastpath @@ -106,7 +129,7 @@ static __maybe_unused const char * const gpio_suffixes[] = { "gpios", "gpio" }; struct gpio_array { struct gpio_desc **desc; unsigned int size; - struct gpio_chip *chip; + struct gpio_device *gdev; unsigned long *get_mask; unsigned long *set_mask; unsigned long invert_mask[]; @@ -134,10 +157,14 @@ int gpiod_set_array_value_complex(bool raw, bool can_sleep, int gpiod_set_transitory(struct gpio_desc *desc, bool transitory); -extern spinlock_t gpio_lock; -extern struct list_head gpio_devices; - void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action); +int gpiod_direction_output_nonotify(struct gpio_desc *desc, int value); +int gpiod_direction_input_nonotify(struct gpio_desc *desc); + +struct gpio_desc_label { + struct rcu_head rh; + char str[]; +}; /** * struct gpio_desc - Opaque descriptor for a GPIO @@ -147,6 +174,7 @@ void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action); * @label: Name of the consumer * @name: Line name * @hog: Pointer to the device node that hogs this line (if any) + * @debounce_period_us: Debounce period in microseconds * * These are obtained using gpiod_get() and are preferable to the old * integer-based handles. @@ -178,16 +206,41 @@ struct gpio_desc { #define FLAG_EVENT_CLOCK_HTE 19 /* GPIO CDEV reports hardware timestamps in events */ /* Connection label */ - const char *label; + struct gpio_desc_label __rcu *label; /* Name of the GPIO */ const char *name; #ifdef CONFIG_OF_DYNAMIC struct device_node *hog; #endif +#ifdef CONFIG_GPIO_CDEV + /* debounce period in microseconds */ + unsigned int debounce_period_us; +#endif }; #define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT) +struct gpio_chip_guard { + struct gpio_device *gdev; + struct gpio_chip *gc; + int idx; +}; + +DEFINE_CLASS(gpio_chip_guard, + struct gpio_chip_guard, + srcu_read_unlock(&_T.gdev->srcu, _T.idx), + ({ + struct gpio_chip_guard _guard; + + _guard.gdev = desc->gdev; + _guard.idx = srcu_read_lock(&_guard.gdev->srcu); + _guard.gc = srcu_dereference(_guard.gdev->chip, + &_guard.gdev->srcu); + + _guard; + }), + struct gpio_desc *desc) + int gpiod_request(struct gpio_desc *desc, const char *label); void gpiod_free(struct gpio_desc *desc); @@ -202,12 +255,23 @@ static inline int gpiod_request_user(struct gpio_desc *desc, const char *label) return ret; } +struct gpio_desc *gpiod_find_and_request(struct device *consumer, + struct fwnode_handle *fwnode, + const char *con_id, + unsigned int idx, + enum gpiod_flags flags, + const char *label, + bool platform_lookup_allowed); + +int gpio_do_set_config(struct gpio_desc *desc, unsigned long config); int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id, unsigned long lflags, enum gpiod_flags dflags); int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce); int gpiod_hog(struct gpio_desc *desc, const char *name, unsigned long lflags, enum gpiod_flags dflags); int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev); +struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum); +const char *gpiod_get_label(struct gpio_desc *desc); /* * Return the GPIO number of the passed descriptor relative to its chip @@ -219,31 +283,32 @@ static inline int gpio_chip_hwgpio(const struct gpio_desc *desc) /* With descriptor prefix */ -#define gpiod_emerg(desc, fmt, ...) \ - pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\ - ##__VA_ARGS__) -#define gpiod_crit(desc, fmt, ...) \ - pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \ - ##__VA_ARGS__) -#define gpiod_err(desc, fmt, ...) \ - pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \ - ##__VA_ARGS__) -#define gpiod_warn(desc, fmt, ...) \ - pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \ - ##__VA_ARGS__) -#define gpiod_info(desc, fmt, ...) \ - pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \ - ##__VA_ARGS__) -#define gpiod_dbg(desc, fmt, ...) \ - pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\ - ##__VA_ARGS__) +#define gpiod_err(desc, fmt, ...) \ +do { \ + scoped_guard(srcu, &desc->gdev->desc_srcu) { \ + pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), \ + gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \ + } \ +} while (0) + +#define gpiod_warn(desc, fmt, ...) \ +do { \ + scoped_guard(srcu, &desc->gdev->desc_srcu) { \ + pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), \ + gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \ + } \ +} while (0) + +#define gpiod_dbg(desc, fmt, ...) \ +do { \ + scoped_guard(srcu, &desc->gdev->desc_srcu) { \ + pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), \ + gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \ + } \ +} while (0) /* With chip prefix */ -#define chip_emerg(gc, fmt, ...) \ - dev_emerg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) -#define chip_crit(gc, fmt, ...) \ - dev_crit(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) #define chip_err(gc, fmt, ...) \ dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) #define chip_warn(gc, fmt, ...) \ |