diff options
Diffstat (limited to 'drivers/gpio/gpiolib.h')
| -rw-r--r-- | drivers/gpio/gpiolib.h | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h new file mode 100644 index 000000000..9ad68a0ad --- /dev/null +++ b/drivers/gpio/gpiolib.h @@ -0,0 +1,250 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Internal GPIO functions. + * + * Copyright (C) 2013, Intel Corporation + * Author: Mika Westerberg <mika.westerberg@linux.intel.com> + */ + +#ifndef GPIOLIB_H +#define GPIOLIB_H + +#include <linux/gpio/driver.h> +#include <linux/gpio/consumer.h> /* for enum gpiod_flags */ +#include <linux/err.h> +#include <linux/device.h> +#include <linux/module.h> +#include <linux/cdev.h> +#include <linux/rwsem.h> + +#define GPIOCHIP_NAME "gpiochip" + +/** + * struct gpio_device - internal state container for GPIO devices + * @id: numerical ID number for the GPIO chip + * @dev: the GPIO device struct + * @chrdev: character device for the GPIO device + * @mockdev: class device used by the deprecated sysfs interface (may be + * NULL) + * @owner: helps prevent removal of modules exporting active GPIOs + * @chip: pointer to the corresponding gpiochip, holding static + * data for this device + * @descs: array of ngpio descriptors. + * @ngpio: the number of GPIO lines on this GPIO device, equal to the size + * of the @descs array. + * @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 + * or name of the IP component in a System on Chip. + * @data: per-instance data assigned by the driver + * @list: links gpio_device:s together for traversal + * @notifier: used to notify subscribers about lines being requested, released + * or reconfigured + * @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 + * @pin_ranges: range of pins served by the GPIO driver + * + * This state container holds most of the runtime variable data + * for a GPIO device and can hold references and live on after the + * GPIO chip has been removed, if it is still being used from + * userspace. + */ +struct gpio_device { + int id; + struct device dev; + struct cdev chrdev; + struct device *mockdev; + struct module *owner; + struct gpio_chip *chip; + struct gpio_desc *descs; + int base; + u16 ngpio; + const char *label; + void *data; + struct list_head list; + struct blocking_notifier_head notifier; + struct rw_semaphore sem; + +#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 +}; + +/* gpio suffixes used for ACPI and device tree lookup */ +static __maybe_unused const char * const gpio_suffixes[] = { "gpios", "gpio" }; + +/** + * 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 + * @get_mask: Get mask used in fastpath + * @set_mask: Set mask used in fastpath + * @invert_mask: Invert mask used in fastpath + * + * This structure is attached to struct gpiod_descs obtained from + * gpiod_get_array() and can be passed back to get/set array functions in order + * to activate fast processing path if applicable. + */ +struct gpio_array { + struct gpio_desc **desc; + unsigned int size; + struct gpio_chip *chip; + unsigned long *get_mask; + unsigned long *set_mask; + unsigned long invert_mask[]; +}; + +struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum); + +#define for_each_gpio_desc(gc, desc) \ + for (unsigned int __i = 0; \ + __i < gc->ngpio && (desc = gpiochip_get_desc(gc, __i)); \ + __i++) \ + +#define for_each_gpio_desc_with_flag(gc, desc, flag) \ + for_each_gpio_desc(gc, desc) \ + if (!test_bit(flag, &desc->flags)) {} else + +int gpiod_get_array_value_complex(bool raw, bool can_sleep, + unsigned int array_size, + struct gpio_desc **desc_array, + struct gpio_array *array_info, + unsigned long *value_bitmap); +int gpiod_set_array_value_complex(bool raw, bool can_sleep, + unsigned int array_size, + struct gpio_desc **desc_array, + struct gpio_array *array_info, + unsigned long *value_bitmap); + +extern spinlock_t gpio_lock; +extern struct list_head gpio_devices; + + +/** + * struct gpio_desc - Opaque descriptor for a GPIO + * + * @gdev: Pointer to the parent GPIO device + * @flags: Binary descriptor flags + * @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. + * + * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be + * valid until the GPIO is released. + */ +struct gpio_desc { + struct gpio_device *gdev; + unsigned long flags; +/* flag symbols are bit numbers */ +#define FLAG_REQUESTED 0 +#define FLAG_IS_OUT 1 +#define FLAG_EXPORT 2 /* protected by sysfs_lock */ +#define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */ +#define FLAG_ACTIVE_LOW 6 /* value has active low */ +#define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */ +#define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */ +#define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */ +#define FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */ +#define FLAG_IS_HOGGED 11 /* GPIO is hogged */ +#define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */ +#define FLAG_PULL_UP 13 /* GPIO has pull up enabled */ +#define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */ +#define FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */ +#define FLAG_EDGE_RISING 16 /* GPIO CDEV detects rising edge events */ +#define FLAG_EDGE_FALLING 17 /* GPIO CDEV detects falling edge events */ +#define FLAG_EVENT_CLOCK_REALTIME 18 /* GPIO CDEV reports REALTIME timestamps in events */ +#define FLAG_EVENT_CLOCK_HTE 19 /* GPIO CDEV reports hardware timestamps in events */ + + /* Connection label */ + const char *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) + +int gpiod_request(struct gpio_desc *desc, const char *label); +void gpiod_free(struct gpio_desc *desc); + +static inline int gpiod_request_user(struct gpio_desc *desc, const char *label) +{ + int ret; + + ret = gpiod_request(desc, label); + if (ret == -EPROBE_DEFER) + ret = -ENODEV; + + return ret; +} + +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); + +/* + * Return the GPIO number of the passed descriptor relative to its chip + */ +static inline int gpio_chip_hwgpio(const struct gpio_desc *desc) +{ + return desc - &desc->gdev->descs[0]; +} + +/* 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__) + +/* 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, ...) \ + dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) +#define chip_info(gc, fmt, ...) \ + dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) +#define chip_dbg(gc, fmt, ...) \ + dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) + +#endif /* GPIOLIB_H */ |