linux/include/linux/gpio/driver.h
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   1#ifndef __LINUX_GPIO_DRIVER_H
   2#define __LINUX_GPIO_DRIVER_H
   3
   4#include <linux/types.h>
   5#include <linux/module.h>
   6#include <linux/irq.h>
   7#include <linux/irqchip/chained_irq.h>
   8#include <linux/irqdomain.h>
   9#include <linux/lockdep.h>
  10#include <linux/pinctrl/pinctrl.h>
  11
  12struct device;
  13struct gpio_desc;
  14struct of_phandle_args;
  15struct device_node;
  16struct seq_file;
  17
  18#ifdef CONFIG_GPIOLIB
  19
  20/**
  21 * struct gpio_chip - abstract a GPIO controller
  22 * @label: for diagnostics
  23 * @dev: optional device providing the GPIOs
  24 * @cdev: class device used by sysfs interface (may be NULL)
  25 * @owner: helps prevent removal of modules exporting active GPIOs
  26 * @list: links gpio_chips together for traversal
  27 * @request: optional hook for chip-specific activation, such as
  28 *      enabling module power and clock; may sleep
  29 * @free: optional hook for chip-specific deactivation, such as
  30 *      disabling module power and clock; may sleep
  31 * @get_direction: returns direction for signal "offset", 0=out, 1=in,
  32 *      (same as GPIOF_DIR_XXX), or negative error
  33 * @direction_input: configures signal "offset" as input, or returns error
  34 * @direction_output: configures signal "offset" as output, or returns error
  35 * @get: returns value for signal "offset"; for output signals this
  36 *      returns either the value actually sensed, or zero
  37 * @set: assigns output value for signal "offset"
  38 * @set_multiple: assigns output values for multiple signals defined by "mask"
  39 * @set_debounce: optional hook for setting debounce time for specified gpio in
  40 *      interrupt triggered gpio chips
  41 * @to_irq: optional hook supporting non-static gpio_to_irq() mappings;
  42 *      implementation may not sleep
  43 * @dbg_show: optional routine to show contents in debugfs; default code
  44 *      will be used when this is omitted, but custom code can show extra
  45 *      state (such as pullup/pulldown configuration).
  46 * @base: identifies the first GPIO number handled by this chip;
  47 *      or, if negative during registration, requests dynamic ID allocation.
  48 *      DEPRECATION: providing anything non-negative and nailing the base
  49 *      offset of GPIO chips is deprecated. Please pass -1 as base to
  50 *      let gpiolib select the chip base in all possible cases. We want to
  51 *      get rid of the static GPIO number space in the long run.
  52 * @ngpio: the number of GPIOs handled by this controller; the last GPIO
  53 *      handled is (base + ngpio - 1).
  54 * @desc: array of ngpio descriptors. Private.
  55 * @names: if set, must be an array of strings to use as alternative
  56 *      names for the GPIOs in this chip. Any entry in the array
  57 *      may be NULL if there is no alias for the GPIO, however the
  58 *      array must be @ngpio entries long.  A name can include a single printk
  59 *      format specifier for an unsigned int.  It is substituted by the actual
  60 *      number of the gpio.
  61 * @can_sleep: flag must be set iff get()/set() methods sleep, as they
  62 *      must while accessing GPIO expander chips over I2C or SPI. This
  63 *      implies that if the chip supports IRQs, these IRQs need to be threaded
  64 *      as the chip access may sleep when e.g. reading out the IRQ status
  65 *      registers.
  66 * @irq_not_threaded: flag must be set if @can_sleep is set but the
  67 *      IRQs don't need to be threaded
  68 * @irqchip: GPIO IRQ chip impl, provided by GPIO driver
  69 * @irqdomain: Interrupt translation domain; responsible for mapping
  70 *      between GPIO hwirq number and linux irq number
  71 * @irq_base: first linux IRQ number assigned to GPIO IRQ chip (deprecated)
  72 * @irq_handler: the irq handler to use (often a predefined irq core function)
  73 *      for GPIO IRQs, provided by GPIO driver
  74 * @irq_default_type: default IRQ triggering type applied during GPIO driver
  75 *      initialization, provided by GPIO driver
  76 * @irq_parent: GPIO IRQ chip parent/bank linux irq number,
  77 *      provided by GPIO driver
  78 * @lock_key: per GPIO IRQ chip lockdep class
  79 *
  80 * A gpio_chip can help platforms abstract various sources of GPIOs so
  81 * they can all be accessed through a common programing interface.
  82 * Example sources would be SOC controllers, FPGAs, multifunction
  83 * chips, dedicated GPIO expanders, and so on.
  84 *
  85 * Each chip controls a number of signals, identified in method calls
  86 * by "offset" values in the range 0..(@ngpio - 1).  When those signals
  87 * are referenced through calls like gpio_get_value(gpio), the offset
  88 * is calculated by subtracting @base from the gpio number.
  89 */
  90struct gpio_chip {
  91        const char              *label;
  92        struct device           *dev;
  93        struct device           *cdev;
  94        struct module           *owner;
  95        struct list_head        list;
  96
  97        int                     (*request)(struct gpio_chip *chip,
  98                                                unsigned offset);
  99        void                    (*free)(struct gpio_chip *chip,
 100                                                unsigned offset);
 101        int                     (*get_direction)(struct gpio_chip *chip,
 102                                                unsigned offset);
 103        int                     (*direction_input)(struct gpio_chip *chip,
 104                                                unsigned offset);
 105        int                     (*direction_output)(struct gpio_chip *chip,
 106                                                unsigned offset, int value);
 107        int                     (*get)(struct gpio_chip *chip,
 108                                                unsigned offset);
 109        void                    (*set)(struct gpio_chip *chip,
 110                                                unsigned offset, int value);
 111        void                    (*set_multiple)(struct gpio_chip *chip,
 112                                                unsigned long *mask,
 113                                                unsigned long *bits);
 114        int                     (*set_debounce)(struct gpio_chip *chip,
 115                                                unsigned offset,
 116                                                unsigned debounce);
 117
 118        int                     (*to_irq)(struct gpio_chip *chip,
 119                                                unsigned offset);
 120
 121        void                    (*dbg_show)(struct seq_file *s,
 122                                                struct gpio_chip *chip);
 123        int                     base;
 124        u16                     ngpio;
 125        struct gpio_desc        *desc;
 126        const char              *const *names;
 127        bool                    can_sleep;
 128        bool                    irq_not_threaded;
 129
 130#ifdef CONFIG_GPIOLIB_IRQCHIP
 131        /*
 132         * With CONFIG_GPIOLIB_IRQCHIP we get an irqchip inside the gpiolib
 133         * to handle IRQs for most practical cases.
 134         */
 135        struct irq_chip         *irqchip;
 136        struct irq_domain       *irqdomain;
 137        unsigned int            irq_base;
 138        irq_flow_handler_t      irq_handler;
 139        unsigned int            irq_default_type;
 140        int                     irq_parent;
 141        struct lock_class_key   *lock_key;
 142#endif
 143
 144#if defined(CONFIG_OF_GPIO)
 145        /*
 146         * If CONFIG_OF is enabled, then all GPIO controllers described in the
 147         * device tree automatically may have an OF translation
 148         */
 149        struct device_node *of_node;
 150        int of_gpio_n_cells;
 151        int (*of_xlate)(struct gpio_chip *gc,
 152                        const struct of_phandle_args *gpiospec, u32 *flags);
 153#endif
 154#ifdef CONFIG_PINCTRL
 155        /*
 156         * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
 157         * describe the actual pin range which they serve in an SoC. This
 158         * information would be used by pinctrl subsystem to configure
 159         * corresponding pins for gpio usage.
 160         */
 161        struct list_head pin_ranges;
 162#endif
 163};
 164
 165extern const char *gpiochip_is_requested(struct gpio_chip *chip,
 166                        unsigned offset);
 167
 168/* add/remove chips */
 169extern int gpiochip_add(struct gpio_chip *chip);
 170extern void gpiochip_remove(struct gpio_chip *chip);
 171extern struct gpio_chip *gpiochip_find(void *data,
 172                              int (*match)(struct gpio_chip *chip, void *data));
 173
 174/* lock/unlock as IRQ */
 175int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset);
 176void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset);
 177
 178struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);
 179
 180#ifdef CONFIG_GPIOLIB_IRQCHIP
 181
 182void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
 183                struct irq_chip *irqchip,
 184                int parent_irq,
 185                irq_flow_handler_t parent_handler);
 186
 187int _gpiochip_irqchip_add(struct gpio_chip *gpiochip,
 188                          struct irq_chip *irqchip,
 189                          unsigned int first_irq,
 190                          irq_flow_handler_t handler,
 191                          unsigned int type,
 192                          struct lock_class_key *lock_key);
 193
 194#ifdef CONFIG_LOCKDEP
 195#define gpiochip_irqchip_add(...)                               \
 196(                                                               \
 197        ({                                                      \
 198                static struct lock_class_key _key;              \
 199                _gpiochip_irqchip_add(__VA_ARGS__, &_key);      \
 200        })                                                      \
 201)
 202#else
 203#define gpiochip_irqchip_add(...)                               \
 204        _gpiochip_irqchip_add(__VA_ARGS__, NULL)
 205#endif
 206
 207#endif /* CONFIG_GPIOLIB_IRQCHIP */
 208
 209#ifdef CONFIG_PINCTRL
 210
 211/**
 212 * struct gpio_pin_range - pin range controlled by a gpio chip
 213 * @head: list for maintaining set of pin ranges, used internally
 214 * @pctldev: pinctrl device which handles corresponding pins
 215 * @range: actual range of pins controlled by a gpio controller
 216 */
 217
 218struct gpio_pin_range {
 219        struct list_head node;
 220        struct pinctrl_dev *pctldev;
 221        struct pinctrl_gpio_range range;
 222};
 223
 224int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
 225                           unsigned int gpio_offset, unsigned int pin_offset,
 226                           unsigned int npins);
 227int gpiochip_add_pingroup_range(struct gpio_chip *chip,
 228                        struct pinctrl_dev *pctldev,
 229                        unsigned int gpio_offset, const char *pin_group);
 230void gpiochip_remove_pin_ranges(struct gpio_chip *chip);
 231
 232#else
 233
 234static inline int
 235gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
 236                       unsigned int gpio_offset, unsigned int pin_offset,
 237                       unsigned int npins)
 238{
 239        return 0;
 240}
 241static inline int
 242gpiochip_add_pingroup_range(struct gpio_chip *chip,
 243                        struct pinctrl_dev *pctldev,
 244                        unsigned int gpio_offset, const char *pin_group)
 245{
 246        return 0;
 247}
 248
 249static inline void
 250gpiochip_remove_pin_ranges(struct gpio_chip *chip)
 251{
 252}
 253
 254#endif /* CONFIG_PINCTRL */
 255
 256struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
 257                                            const char *label);
 258void gpiochip_free_own_desc(struct gpio_desc *desc);
 259
 260#else /* CONFIG_GPIOLIB */
 261
 262static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
 263{
 264        /* GPIO can never have been requested */
 265        WARN_ON(1);
 266        return ERR_PTR(-ENODEV);
 267}
 268
 269#endif /* CONFIG_GPIOLIB */
 270
 271#endif
 272