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/device.h>
   5#include <linux/types.h>
   6#include <linux/module.h>
   7#include <linux/irq.h>
   8#include <linux/irqchip/chained_irq.h>
   9#include <linux/irqdomain.h>
  10#include <linux/lockdep.h>
  11#include <linux/pinctrl/pinctrl.h>
  12#include <linux/kconfig.h>
  13
  14struct gpio_desc;
  15struct of_phandle_args;
  16struct device_node;
  17struct seq_file;
  18struct gpio_device;
  19
  20#ifdef CONFIG_GPIOLIB
  21
  22/**
  23 * struct gpio_chip - abstract a GPIO controller
  24 * @label: a functional name for the GPIO device, such as a part
  25 *      number or the name of the SoC IP-block implementing it.
  26 * @gpiodev: the internal state holder, opaque struct
  27 * @parent: optional parent device providing the GPIOs
  28 * @owner: helps prevent removal of modules exporting active GPIOs
  29 * @request: optional hook for chip-specific activation, such as
  30 *      enabling module power and clock; may sleep
  31 * @free: optional hook for chip-specific deactivation, such as
  32 *      disabling module power and clock; may sleep
  33 * @get_direction: returns direction for signal "offset", 0=out, 1=in,
  34 *      (same as GPIOF_DIR_XXX), or negative error
  35 * @direction_input: configures signal "offset" as input, or returns error
  36 * @direction_output: configures signal "offset" as output, or returns error
  37 * @get: returns value for signal "offset", 0=low, 1=high, or negative error
  38 * @set: assigns output value for signal "offset"
  39 * @set_multiple: assigns output values for multiple signals defined by "mask"
  40 * @set_debounce: optional hook for setting debounce time for specified gpio in
  41 *      interrupt triggered gpio chips
  42 * @to_irq: optional hook supporting non-static gpio_to_irq() mappings;
  43 *      implementation may not sleep
  44 * @dbg_show: optional routine to show contents in debugfs; default code
  45 *      will be used when this is omitted, but custom code can show extra
  46 *      state (such as pullup/pulldown configuration).
  47 * @base: identifies the first GPIO number handled by this chip;
  48 *      or, if negative during registration, requests dynamic ID allocation.
  49 *      DEPRECATION: providing anything non-negative and nailing the base
  50 *      offset of GPIO chips is deprecated. Please pass -1 as base to
  51 *      let gpiolib select the chip base in all possible cases. We want to
  52 *      get rid of the static GPIO number space in the long run.
  53 * @ngpio: the number of GPIOs handled by this controller; the last GPIO
  54 *      handled is (base + ngpio - 1).
  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 * @read_reg: reader function for generic GPIO
  69 * @write_reg: writer function for generic GPIO
  70 * @pin2mask: some generic GPIO controllers work with the big-endian bits
  71 *      notation, e.g. in a 8-bits register, GPIO7 is the least significant
  72 *      bit. This callback assigns the right bit mask.
  73 * @reg_dat: data (in) register for generic GPIO
  74 * @reg_set: output set register (out=high) for generic GPIO
  75 * @reg_clk: output clear register (out=low) for generic GPIO
  76 * @reg_dir: direction setting register for generic GPIO
  77 * @bgpio_bits: number of register bits used for a generic GPIO i.e.
  78 *      <register width> * 8
  79 * @bgpio_lock: used to lock chip->bgpio_data. Also, this is needed to keep
  80 *      shadowed and real data registers writes together.
  81 * @bgpio_data: shadowed data register for generic GPIO to clear/set bits
  82 *      safely.
  83 * @bgpio_dir: shadowed direction register for generic GPIO to clear/set
  84 *      direction safely.
  85 * @irqchip: GPIO IRQ chip impl, provided by GPIO driver
  86 * @irqdomain: Interrupt translation domain; responsible for mapping
  87 *      between GPIO hwirq number and linux irq number
  88 * @irq_base: first linux IRQ number assigned to GPIO IRQ chip (deprecated)
  89 * @irq_handler: the irq handler to use (often a predefined irq core function)
  90 *      for GPIO IRQs, provided by GPIO driver
  91 * @irq_default_type: default IRQ triggering type applied during GPIO driver
  92 *      initialization, provided by GPIO driver
  93 * @irq_parent: GPIO IRQ chip parent/bank linux irq number,
  94 *      provided by GPIO driver
  95 * @lock_key: per GPIO IRQ chip lockdep class
  96 *
  97 * A gpio_chip can help platforms abstract various sources of GPIOs so
  98 * they can all be accessed through a common programing interface.
  99 * Example sources would be SOC controllers, FPGAs, multifunction
 100 * chips, dedicated GPIO expanders, and so on.
 101 *
 102 * Each chip controls a number of signals, identified in method calls
 103 * by "offset" values in the range 0..(@ngpio - 1).  When those signals
 104 * are referenced through calls like gpio_get_value(gpio), the offset
 105 * is calculated by subtracting @base from the gpio number.
 106 */
 107struct gpio_chip {
 108        const char              *label;
 109        struct gpio_device      *gpiodev;
 110        struct device           *parent;
 111        struct module           *owner;
 112
 113        int                     (*request)(struct gpio_chip *chip,
 114                                                unsigned offset);
 115        void                    (*free)(struct gpio_chip *chip,
 116                                                unsigned offset);
 117        int                     (*get_direction)(struct gpio_chip *chip,
 118                                                unsigned offset);
 119        int                     (*direction_input)(struct gpio_chip *chip,
 120                                                unsigned offset);
 121        int                     (*direction_output)(struct gpio_chip *chip,
 122                                                unsigned offset, int value);
 123        int                     (*get)(struct gpio_chip *chip,
 124                                                unsigned offset);
 125        void                    (*set)(struct gpio_chip *chip,
 126                                                unsigned offset, int value);
 127        void                    (*set_multiple)(struct gpio_chip *chip,
 128                                                unsigned long *mask,
 129                                                unsigned long *bits);
 130        int                     (*set_debounce)(struct gpio_chip *chip,
 131                                                unsigned offset,
 132                                                unsigned debounce);
 133
 134        int                     (*to_irq)(struct gpio_chip *chip,
 135                                                unsigned offset);
 136
 137        void                    (*dbg_show)(struct seq_file *s,
 138                                                struct gpio_chip *chip);
 139        int                     base;
 140        u16                     ngpio;
 141        const char              *const *names;
 142        bool                    can_sleep;
 143        bool                    irq_not_threaded;
 144
 145#if IS_ENABLED(CONFIG_GPIO_GENERIC)
 146        unsigned long (*read_reg)(void __iomem *reg);
 147        void (*write_reg)(void __iomem *reg, unsigned long data);
 148        unsigned long (*pin2mask)(struct gpio_chip *gc, unsigned int pin);
 149        void __iomem *reg_dat;
 150        void __iomem *reg_set;
 151        void __iomem *reg_clr;
 152        void __iomem *reg_dir;
 153        int bgpio_bits;
 154        spinlock_t bgpio_lock;
 155        unsigned long bgpio_data;
 156        unsigned long bgpio_dir;
 157#endif
 158
 159#ifdef CONFIG_GPIOLIB_IRQCHIP
 160        /*
 161         * With CONFIG_GPIOLIB_IRQCHIP we get an irqchip inside the gpiolib
 162         * to handle IRQs for most practical cases.
 163         */
 164        struct irq_chip         *irqchip;
 165        struct irq_domain       *irqdomain;
 166        unsigned int            irq_base;
 167        irq_flow_handler_t      irq_handler;
 168        unsigned int            irq_default_type;
 169        int                     irq_parent;
 170        struct lock_class_key   *lock_key;
 171#endif
 172
 173#if defined(CONFIG_OF_GPIO)
 174        /*
 175         * If CONFIG_OF is enabled, then all GPIO controllers described in the
 176         * device tree automatically may have an OF translation
 177         */
 178        struct device_node *of_node;
 179        int of_gpio_n_cells;
 180        int (*of_xlate)(struct gpio_chip *gc,
 181                        const struct of_phandle_args *gpiospec, u32 *flags);
 182#endif
 183};
 184
 185extern const char *gpiochip_is_requested(struct gpio_chip *chip,
 186                        unsigned offset);
 187
 188/* add/remove chips */
 189extern int gpiochip_add_data(struct gpio_chip *chip, void *data);
 190static inline int gpiochip_add(struct gpio_chip *chip)
 191{
 192        return gpiochip_add_data(chip, NULL);
 193}
 194extern void gpiochip_remove(struct gpio_chip *chip);
 195extern int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
 196                                  void *data);
 197extern void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip);
 198
 199extern struct gpio_chip *gpiochip_find(void *data,
 200                              int (*match)(struct gpio_chip *chip, void *data));
 201
 202/* lock/unlock as IRQ */
 203int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset);
 204void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset);
 205bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset);
 206
 207/* Line status inquiry for drivers */
 208bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset);
 209bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset);
 210
 211/* get driver data */
 212void *gpiochip_get_data(struct gpio_chip *chip);
 213
 214struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);
 215
 216struct bgpio_pdata {
 217        const char *label;
 218        int base;
 219        int ngpio;
 220};
 221
 222#if IS_ENABLED(CONFIG_GPIO_GENERIC)
 223
 224int bgpio_init(struct gpio_chip *gc, struct device *dev,
 225               unsigned long sz, void __iomem *dat, void __iomem *set,
 226               void __iomem *clr, void __iomem *dirout, void __iomem *dirin,
 227               unsigned long flags);
 228
 229#define BGPIOF_BIG_ENDIAN               BIT(0)
 230#define BGPIOF_UNREADABLE_REG_SET       BIT(1) /* reg_set is unreadable */
 231#define BGPIOF_UNREADABLE_REG_DIR       BIT(2) /* reg_dir is unreadable */
 232#define BGPIOF_BIG_ENDIAN_BYTE_ORDER    BIT(3)
 233#define BGPIOF_READ_OUTPUT_REG_SET      BIT(4) /* reg_set stores output value */
 234#define BGPIOF_NO_OUTPUT                BIT(5) /* only input */
 235
 236#endif
 237
 238#ifdef CONFIG_GPIOLIB_IRQCHIP
 239
 240void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
 241                struct irq_chip *irqchip,
 242                int parent_irq,
 243                irq_flow_handler_t parent_handler);
 244
 245int _gpiochip_irqchip_add(struct gpio_chip *gpiochip,
 246                          struct irq_chip *irqchip,
 247                          unsigned int first_irq,
 248                          irq_flow_handler_t handler,
 249                          unsigned int type,
 250                          struct lock_class_key *lock_key);
 251
 252#ifdef CONFIG_LOCKDEP
 253#define gpiochip_irqchip_add(...)                               \
 254(                                                               \
 255        ({                                                      \
 256                static struct lock_class_key _key;              \
 257                _gpiochip_irqchip_add(__VA_ARGS__, &_key);      \
 258        })                                                      \
 259)
 260#else
 261#define gpiochip_irqchip_add(...)                               \
 262        _gpiochip_irqchip_add(__VA_ARGS__, NULL)
 263#endif
 264
 265#endif /* CONFIG_GPIOLIB_IRQCHIP */
 266
 267int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset);
 268void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset);
 269
 270#ifdef CONFIG_PINCTRL
 271
 272/**
 273 * struct gpio_pin_range - pin range controlled by a gpio chip
 274 * @head: list for maintaining set of pin ranges, used internally
 275 * @pctldev: pinctrl device which handles corresponding pins
 276 * @range: actual range of pins controlled by a gpio controller
 277 */
 278
 279struct gpio_pin_range {
 280        struct list_head node;
 281        struct pinctrl_dev *pctldev;
 282        struct pinctrl_gpio_range range;
 283};
 284
 285int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
 286                           unsigned int gpio_offset, unsigned int pin_offset,
 287                           unsigned int npins);
 288int gpiochip_add_pingroup_range(struct gpio_chip *chip,
 289                        struct pinctrl_dev *pctldev,
 290                        unsigned int gpio_offset, const char *pin_group);
 291void gpiochip_remove_pin_ranges(struct gpio_chip *chip);
 292
 293#else
 294
 295static inline int
 296gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
 297                       unsigned int gpio_offset, unsigned int pin_offset,
 298                       unsigned int npins)
 299{
 300        return 0;
 301}
 302static inline int
 303gpiochip_add_pingroup_range(struct gpio_chip *chip,
 304                        struct pinctrl_dev *pctldev,
 305                        unsigned int gpio_offset, const char *pin_group)
 306{
 307        return 0;
 308}
 309
 310static inline void
 311gpiochip_remove_pin_ranges(struct gpio_chip *chip)
 312{
 313}
 314
 315#endif /* CONFIG_PINCTRL */
 316
 317struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
 318                                            const char *label);
 319void gpiochip_free_own_desc(struct gpio_desc *desc);
 320
 321#else /* CONFIG_GPIOLIB */
 322
 323static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
 324{
 325        /* GPIO can never have been requested */
 326        WARN_ON(1);
 327        return ERR_PTR(-ENODEV);
 328}
 329
 330#endif /* CONFIG_GPIOLIB */
 331
 332#endif
 333