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  * @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  */
  50 struct 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  */
  80 struct acpi_gpio_info {
  81         bool gpioint;
  82         int polarity;
  83         int triggering;
  84 };
  85
  86 /* gpio suffixes used for ACPI and device tree lookup */
  87 static const char * const gpio_suffixes[] = { "gpios", "gpio" };
  88
  89 #ifdef CONFIG_ACPI
  90 void acpi_gpiochip_add(struct gpio_chip *chip);
  91 void acpi_gpiochip_remove(struct gpio_chip *chip);
  92
  93 void acpi_gpiochip_request_interrupts(struct gpio_chip *chip);
  94 void acpi_gpiochip_free_interrupts(struct gpio_chip *chip);
  95
  96 struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
  97                                           const char *propname, int index,
  98                                           struct acpi_gpio_info *info);
  99 struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode,
 100                                       const char *propname, int index,
 101                                       struct acpi_gpio_info *info);
 102
 103 int acpi_gpio_count(struct device *dev, const char *con_id);
 104
 105 bool acpi_can_fallback_to_crs(struct acpi_device *adev, const char *con_id);
 106 #else
 107 static inline void acpi_gpiochip_add(struct gpio_chip *chip) { }
 108 static inline void acpi_gpiochip_remove(struct gpio_chip *chip) { }
 109
 110 static inline void
 111 acpi_gpiochip_request_interrupts(struct gpio_chip *chip) { }
 112
 113 static inline void
 114 acpi_gpiochip_free_interrupts(struct gpio_chip *chip) { }
 115
 116 static inline struct gpio_desc *
 117 acpi_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 }
 122 static inline struct gpio_desc *
 123 acpi_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 }
 128 static inline int acpi_gpio_count(struct device *dev, const char *con_id)
 129 {
 130         return -ENODEV;
 131 }
 132
 133 static inline bool acpi_can_fallback_to_crs(struct acpi_device *adev,
 134                                             const char *con_id)
 135 {
 136         return false;
 137 }
 138 #endif
 139
 140 struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
 141                    const char *list_name, int index, enum of_gpio_flags *flags);
 142
 143 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip, u16 hwnum);
 144
 145 extern struct spinlock gpio_lock;
 146 extern struct list_head gpio_devices;
 147
 148 struct gpio_desc {
 149         struct gpio_device      *gdev;
 150         unsigned long           flags;
 151 /* flag symbols are bit numbers */
 152 #define FLAG_REQUESTED  0
 153 #define FLAG_IS_OUT     1
 154 #define FLAG_EXPORT     2       /* protected by sysfs_lock */
 155 #define FLAG_SYSFS      3       /* exported via /sys/class/gpio/control */
 156 #define FLAG_ACTIVE_LOW 6       /* value has active low */
 157 #define FLAG_OPEN_DRAIN 7       /* Gpio is open drain type */
 158 #define FLAG_OPEN_SOURCE 8      /* Gpio is open source type */
 159 #define FLAG_USED_AS_IRQ 9      /* GPIO is connected to an IRQ */
 160 #define FLAG_IS_HOGGED  11      /* GPIO is hogged */
 161
 162         /* Connection label */
 163         const char              *label;
 164         /* Name of the GPIO */
 165         const char              *name;
 166 };
 167
 168 int gpiod_request(struct gpio_desc *desc, const char *label);
 169 void gpiod_free(struct gpio_desc *desc);
 170 int gpiod_hog(struct gpio_desc *desc, const char *name,
 171                 unsigned long lflags, enum gpiod_flags dflags);
 172
 173 /*
 174  * Return the GPIO number of the passed descriptor relative to its chip
 175  */
 176 static int __maybe_unused gpio_chip_hwgpio(const struct gpio_desc *desc)
 177 {
 178         return desc - &desc->gdev->descs[0];
 179 }
 180
 181 /* With descriptor prefix */
 182
 183 #define gpiod_emerg(desc, fmt, ...)                                            \
 184         pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
 185                  ##__VA_ARGS__)
 186 #define gpiod_crit(desc, fmt, ...)                                             \
 187         pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
 188                  ##__VA_ARGS__)
 189 #define gpiod_err(desc, fmt, ...)                                              \
 190         pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",  \
 191                  ##__VA_ARGS__)
 192 #define gpiod_warn(desc, fmt, ...)                                             \
 193         pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
 194                  ##__VA_ARGS__)
 195 #define gpiod_info(desc, fmt, ...)                                             \
 196         pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
 197                  ##__VA_ARGS__)
 198 #define gpiod_dbg(desc, fmt, ...)                                              \
 199         pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
 200                  ##__VA_ARGS__)
 201
 202 /* With chip prefix */
 203
 204 #define chip_emerg(chip, fmt, ...)                                      \
 205         dev_emerg(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
 206 #define chip_crit(chip, fmt, ...)                                       \
 207         dev_crit(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
 208 #define chip_err(chip, fmt, ...)                                        \
 209         dev_err(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
 210 #define chip_warn(chip, fmt, ...)                                       \
 211         dev_warn(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
 212 #define chip_info(chip, fmt, ...)                                       \
 213         dev_info(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
 214 #define chip_dbg(chip, fmt, ...)                                        \
 215         dev_dbg(&chip->gpiodev->dev, "(%s): " fmt, chip->label, ##__VA_ARGS__)
 216
 217 #ifdef CONFIG_GPIO_SYSFS
 218
 219 int gpiochip_sysfs_register(struct gpio_device *gdev);
 220 void gpiochip_sysfs_unregister(struct gpio_device *gdev);
 221
 222 #else
 223
 224 static inline int gpiochip_sysfs_register(struct gpio_device *gdev)
 225 {
 226         return 0;
 227 }
 228
 229 static inline void gpiochip_sysfs_unregister(struct gpio_device *gdev)
 230 {
 231 }
 232
 233 #endif /* CONFIG_GPIO_SYSFS */
 234
 235 #endif /* GPIOLIB_H */