drivers/gpio/gpiolib.h

   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
  21 enum of_gpio_flags;
  22 enum gpiod_flags;
  23 struct 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  * @owner: helps prevent removal of modules exporting active GPIOs
  30  * @chip: pointer to the corresponding gpiochip, holding static
  31  * data for this device
  32  * @list: links gpio_device:s together for traversal
  33  *
  34  * This state container holds most of the runtime variable data
  35  * for a GPIO device and can hold references and live on after the
  36  * GPIO chip has been removed, if it is still being used from
  37  * userspace.
  38  */
  39 struct gpio_device {
  40         int                     id;
  41         struct device           dev;
  42         struct module           *owner;
  43         struct gpio_chip        *chip;
  44         struct list_head        list;
  45 };
  46
  47 /**
  48  * struct acpi_gpio_info - ACPI GPIO specific information
  49  * @gpioint: if %true this GPIO is of type GpioInt otherwise type is GpioIo
  50  * @active_low: in case of @gpioint, the pin is active low
  51  */
  52 struct acpi_gpio_info {
  53         bool gpioint;
  54         int polarity;
  55         int triggering;
  56 };
  57
  58 /* gpio suffixes used for ACPI and device tree lookup */
  59 static const char * const gpio_suffixes[] = { "gpios", "gpio" };
  60
  61 #ifdef CONFIG_ACPI
  62 void acpi_gpiochip_add(struct gpio_chip *chip);
  63 void acpi_gpiochip_remove(struct gpio_chip *chip);
  64
  65 void acpi_gpiochip_request_interrupts(struct gpio_chip *chip);
  66 void acpi_gpiochip_free_interrupts(struct gpio_chip *chip);
  67
  68 struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
  69                                           const char *propname, int index,
  70                                           struct acpi_gpio_info *info);
  71 struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode,
  72                                       const char *propname, int index,
  73                                       struct acpi_gpio_info *info);
  74
  75 int acpi_gpio_count(struct device *dev, const char *con_id);
  76
  77 bool acpi_can_fallback_to_crs(struct acpi_device *adev, const char *con_id);
  78 #else
  79 static inline void acpi_gpiochip_add(struct gpio_chip *chip) { }
  80 static inline void acpi_gpiochip_remove(struct gpio_chip *chip) { }
  81
  82 static inline void
  83 acpi_gpiochip_request_interrupts(struct gpio_chip *chip) { }
  84
  85 static inline void
  86 acpi_gpiochip_free_interrupts(struct gpio_chip *chip) { }
  87
  88 static inline struct gpio_desc *
  89 acpi_get_gpiod_by_index(struct acpi_device *adev, const char *propname,
  90                         int index, struct acpi_gpio_info *info)
  91 {
  92         return ERR_PTR(-ENOSYS);
  93 }
  94 static inline struct gpio_desc *
  95 acpi_node_get_gpiod(struct fwnode_handle *fwnode, const char *propname,
  96                     int index, struct acpi_gpio_info *info)
  97 {
  98         return ERR_PTR(-ENXIO);
  99 }
 100 static inline int acpi_gpio_count(struct device *dev, const char *con_id)
 101 {
 102         return -ENODEV;
 103 }
 104
 105 static inline bool acpi_can_fallback_to_crs(struct acpi_device *adev,
 106                                             const char *con_id)
 107 {
 108         return false;
 109 }
 110 #endif
 111
 112 struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
 113                    const char *list_name, int index, enum of_gpio_flags *flags);
 114
 115 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip, u16 hwnum);
 116
 117 extern struct spinlock gpio_lock;
 118 extern struct list_head gpio_devices;
 119
 120 struct gpio_desc {
 121         struct gpio_chip        *chip;
 122         unsigned long           flags;
 123 /* flag symbols are bit numbers */
 124 #define FLAG_REQUESTED  0
 125 #define FLAG_IS_OUT     1
 126 #define FLAG_EXPORT     2       /* protected by sysfs_lock */
 127 #define FLAG_SYSFS      3       /* exported via /sys/class/gpio/control */
 128 #define FLAG_ACTIVE_LOW 6       /* value has active low */
 129 #define FLAG_OPEN_DRAIN 7       /* Gpio is open drain type */
 130 #define FLAG_OPEN_SOURCE 8      /* Gpio is open source type */
 131 #define FLAG_USED_AS_IRQ 9      /* GPIO is connected to an IRQ */
 132 #define FLAG_IS_HOGGED  11      /* GPIO is hogged */
 133
 134         /* Connection label */
 135         const char              *label;
 136         /* Name of the GPIO */
 137         const char              *name;
 138 };
 139
 140 int gpiod_request(struct gpio_desc *desc, const char *label);
 141 void gpiod_free(struct gpio_desc *desc);
 142 int gpiod_hog(struct gpio_desc *desc, const char *name,
 143                 unsigned long lflags, enum gpiod_flags dflags);
 144
 145 /*
 146  * Return the GPIO number of the passed descriptor relative to its chip
 147  */
 148 static int __maybe_unused gpio_chip_hwgpio(const struct gpio_desc *desc)
 149 {
 150         return desc - &desc->chip->desc[0];
 151 }
 152
 153 /* With descriptor prefix */
 154
 155 #define gpiod_emerg(desc, fmt, ...)                                            \
 156         pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
 157                  ##__VA_ARGS__)
 158 #define gpiod_crit(desc, fmt, ...)                                             \
 159         pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
 160                  ##__VA_ARGS__)
 161 #define gpiod_err(desc, fmt, ...)                                              \
 162         pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",  \
 163                  ##__VA_ARGS__)
 164 #define gpiod_warn(desc, fmt, ...)                                             \
 165         pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
 166                  ##__VA_ARGS__)
 167 #define gpiod_info(desc, fmt, ...)                                             \
 168         pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
 169                  ##__VA_ARGS__)
 170 #define gpiod_dbg(desc, fmt, ...)                                              \
 171         pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
 172                  ##__VA_ARGS__)
 173
 174 /* With chip prefix */
 175
 176 #define chip_emerg(chip, fmt, ...)                                      \
 177         pr_emerg("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
 178 #define chip_crit(chip, fmt, ...)                                       \
 179         pr_crit("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
 180 #define chip_err(chip, fmt, ...)                                        \
 181         pr_err("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
 182 #define chip_warn(chip, fmt, ...)                                       \
 183         pr_warn("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
 184 #define chip_info(chip, fmt, ...)                                       \
 185         pr_info("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
 186 #define chip_dbg(chip, fmt, ...)                                        \
 187         pr_debug("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
 188
 189 #ifdef CONFIG_GPIO_SYSFS
 190
 191 int gpiochip_sysfs_register(struct gpio_chip *chip);
 192 void gpiochip_sysfs_unregister(struct gpio_chip *chip);
 193
 194 #else
 195
 196 static inline int gpiochip_sysfs_register(struct gpio_chip *chip)
 197 {
 198         return 0;
 199 }
 200
 201 static inline void gpiochip_sysfs_unregister(struct gpio_chip *chip)
 202 {
 203 }
 204
 205 #endif /* CONFIG_GPIO_SYSFS */
 206
 207 #endif /* GPIOLIB_H */