linux/drivers/gpio/gpiolib.h
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   1/*
   2 * Internal GPIO functions.
   3 *
   4 * Copyright (C) 2013, Intel Corporation
   5 * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License version 2 as
   9 * published by the Free Software Foundation.
  10 */
  11
  12#ifndef GPIOLIB_H
  13#define GPIOLIB_H
  14
  15#include <linux/gpio/driver.h>
  16#include <linux/err.h>
  17#include <linux/device.h>
  18#include <linux/module.h>
  19#include <linux/cdev.h>
  20
  21enum of_gpio_flags;
  22enum gpiod_flags;
  23struct acpi_device;
  24
  25/**
  26 * struct gpio_device - internal state container for GPIO devices
  27 * @id: numerical ID number for the GPIO chip
  28 * @dev: the GPIO device struct
  29 * @chrdev: character device for the GPIO device
  30 * @mockdev: class device used by the deprecated sysfs interface (may be
  31 * NULL)
  32 * @owner: helps prevent removal of modules exporting active GPIOs
  33 * @chip: pointer to the corresponding gpiochip, holding static
  34 * data for this device
  35 * @descs: array of ngpio descriptors.
  36 * @ngpio: the number of GPIO lines on this GPIO device, equal to the size
  37 * of the @descs array.
  38 * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned
  39 * at device creation time.
  40 * @label: a descriptive name for the GPIO device, such as the part number
  41 * or name of the IP component in a System on Chip.
  42 * @data: per-instance data assigned by the driver
  43 * @list: links gpio_device:s together for traversal
  44 *
  45 * This state container holds most of the runtime variable data
  46 * for a GPIO device and can hold references and live on after the
  47 * GPIO chip has been removed, if it is still being used from
  48 * userspace.
  49 */
  50struct gpio_device {
  51        int                     id;
  52        struct device           dev;
  53        struct cdev             chrdev;
  54        struct device           *mockdev;
  55        struct module           *owner;
  56        struct gpio_chip        *chip;
  57        struct gpio_desc        *descs;
  58        int                     base;
  59        u16                     ngpio;
  60        char                    *label;
  61        void                    *data;
  62        struct list_head        list;
  63
  64#ifdef CONFIG_PINCTRL
  65        /*
  66         * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
  67         * describe the actual pin range which they serve in an SoC. This
  68         * information would be used by pinctrl subsystem to configure
  69         * corresponding pins for gpio usage.
  70         */
  71        struct list_head pin_ranges;
  72#endif
  73};
  74
  75/**
  76 * struct acpi_gpio_info - ACPI GPIO specific information
  77 * @gpioint: if %true this GPIO is of type GpioInt otherwise type is GpioIo
  78 * @active_low: in case of @gpioint, the pin is active low
  79 */
  80struct acpi_gpio_info {
  81        bool gpioint;
  82        int polarity;
  83        int triggering;
  84};
  85
  86/* gpio suffixes used for ACPI and device tree lookup */
  87static const char * const gpio_suffixes[] = { "gpios", "gpio" };
  88
  89#ifdef CONFIG_ACPI
  90void acpi_gpiochip_add(struct gpio_chip *chip);
  91void acpi_gpiochip_remove(struct gpio_chip *chip);
  92
  93void acpi_gpiochip_request_interrupts(struct gpio_chip *chip);
  94void acpi_gpiochip_free_interrupts(struct gpio_chip *chip);
  95
  96struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
  97                                          const char *propname, int index,
  98                                          struct acpi_gpio_info *info);
  99struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode,
 100                                      const char *propname, int index,
 101                                      struct acpi_gpio_info *info);
 102
 103int acpi_gpio_count(struct device *dev, const char *con_id);
 104
 105bool acpi_can_fallback_to_crs(struct acpi_device *adev, const char *con_id);
 106#else
 107static inline void acpi_gpiochip_add(struct gpio_chip *chip) { }
 108static inline void acpi_gpiochip_remove(struct gpio_chip *chip) { }
 109
 110static inline void
 111acpi_gpiochip_request_interrupts(struct gpio_chip *chip) { }
 112
 113static inline void
 114acpi_gpiochip_free_interrupts(struct gpio_chip *chip) { }
 115
 116static inline struct gpio_desc *
 117acpi_get_gpiod_by_index(struct acpi_device *adev, const char *propname,
 118                        int index, struct acpi_gpio_info *info)
 119{
 120        return ERR_PTR(-ENOSYS);
 121}
 122static inline struct gpio_desc *
 123acpi_node_get_gpiod(struct fwnode_handle *fwnode, const char *propname,
 124                    int index, struct acpi_gpio_info *info)
 125{
 126        return ERR_PTR(-ENXIO);
 127}
 128static inline int acpi_gpio_count(struct device *dev, const char *con_id)
 129{
 130        return -ENODEV;
 131}
 132
 133static inline bool acpi_can_fallback_to_crs(struct acpi_device *adev,
 134                                            const char *con_id)
 135{
 136        return false;
 137}
 138#endif
 139
 140struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
 141                   const char *list_name, int index, enum of_gpio_flags *flags);
 142
 143struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip, u16 hwnum);
 144void gpiod_set_array_value_complex(bool raw, bool can_sleep,
 145                                   unsigned int array_size,
 146                                   struct gpio_desc **desc_array,
 147                                   int *value_array);
 148
 149extern struct spinlock gpio_lock;
 150extern struct list_head gpio_devices;
 151
 152struct gpio_desc {
 153        struct gpio_device      *gdev;
 154        unsigned long           flags;
 155/* flag symbols are bit numbers */
 156#define FLAG_REQUESTED  0
 157#define FLAG_IS_OUT     1
 158#define FLAG_EXPORT     2       /* protected by sysfs_lock */
 159#define FLAG_SYSFS      3       /* exported via /sys/class/gpio/control */
 160#define FLAG_ACTIVE_LOW 6       /* value has active low */
 161#define FLAG_OPEN_DRAIN 7       /* Gpio is open drain type */
 162#define FLAG_OPEN_SOURCE 8      /* Gpio is open source type */
 163#define FLAG_USED_AS_IRQ 9      /* GPIO is connected to an IRQ */
 164#define FLAG_IS_HOGGED  11      /* GPIO is hogged */
 165
 166        /* Connection label */
 167        const char              *label;
 168        /* Name of the GPIO */
 169        const char              *name;
 170};
 171
 172int gpiod_request(struct gpio_desc *desc, const char *label);
 173void gpiod_free(struct gpio_desc *desc);
 174int gpiod_hog(struct gpio_desc *desc, const char *name,
 175                unsigned long lflags, enum gpiod_flags dflags);
 176
 177/*
 178 * Return the GPIO number of the passed descriptor relative to its chip
 179 */
 180static int __maybe_unused gpio_chip_hwgpio(const struct gpio_desc *desc)
 181{
 182        return desc - &desc->gdev->descs[0];
 183}
 184
 185/* With descriptor prefix */
 186
 187#define gpiod_emerg(desc, fmt, ...)                                            \
 188        pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
 189                 ##__VA_ARGS__)
 190#define gpiod_crit(desc, fmt, ...)                                             \
 191        pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
 192                 ##__VA_ARGS__)
 193#define gpiod_err(desc, fmt, ...)                                              \
 194        pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",  \
 195                 ##__VA_ARGS__)
 196#define gpiod_warn(desc, fmt, ...)                                             \
 197        pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
 198                 ##__VA_ARGS__)
 199#define gpiod_info(desc, fmt, ...)                                             \
 200        pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
 201                 ##__VA_ARGS__)
 202#define gpiod_dbg(desc, fmt, ...)                                              \
 203        pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
 204                 ##__VA_ARGS__)
 205
 206/* With chip prefix */
 207
 208#define chip_emerg(chip, fmt, ...)                                      \
 209        dev_emerg(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
 210#define chip_crit(chip, fmt, ...)                                       \
 211        dev_crit(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
 212#define chip_err(chip, fmt, ...)                                        \
 213        dev_err(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
 214#define chip_warn(chip, fmt, ...)                                       \
 215        dev_warn(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
 216#define chip_info(chip, fmt, ...)                                       \
 217        dev_info(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
 218#define chip_dbg(chip, fmt, ...)                                        \
 219        dev_dbg(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
 220
 221#ifdef CONFIG_GPIO_SYSFS
 222
 223int gpiochip_sysfs_register(struct gpio_device *gdev);
 224void gpiochip_sysfs_unregister(struct gpio_device *gdev);
 225
 226#else
 227
 228static inline int gpiochip_sysfs_register(struct gpio_device *gdev)
 229{
 230        return 0;
 231}
 232
 233static inline void gpiochip_sysfs_unregister(struct gpio_device *gdev)
 234{
 235}
 236
 237#endif /* CONFIG_GPIO_SYSFS */
 238
 239#endif /* GPIOLIB_H */
 240