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/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#include <linux/pinctrl/pinconf-generic.h>
  12
  13struct gpio_desc;
  14struct of_phandle_args;
  15struct device_node;
  16struct seq_file;
  17struct gpio_device;
  18struct module;
  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_config: optional hook for all kinds of settings. Uses the same
  41 *      packed config format as generic pinconf.
  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 * @read_reg: reader function for generic GPIO
  67 * @write_reg: writer function for generic GPIO
  68 * @pin2mask: some generic GPIO controllers work with the big-endian bits
  69 *      notation, e.g. in a 8-bits register, GPIO7 is the least significant
  70 *      bit. This callback assigns the right bit mask.
  71 * @reg_dat: data (in) register for generic GPIO
  72 * @reg_set: output set register (out=high) for generic GPIO
  73 * @reg_clr: output clear register (out=low) for generic GPIO
  74 * @reg_dir: direction setting register for generic GPIO
  75 * @bgpio_bits: number of register bits used for a generic GPIO i.e.
  76 *      <register width> * 8
  77 * @bgpio_lock: used to lock chip->bgpio_data. Also, this is needed to keep
  78 *      shadowed and real data registers writes together.
  79 * @bgpio_data: shadowed data register for generic GPIO to clear/set bits
  80 *      safely.
  81 * @bgpio_dir: shadowed direction register for generic GPIO to clear/set
  82 *      direction safely.
  83 * @irqchip: GPIO IRQ chip impl, provided by GPIO driver
  84 * @irqdomain: Interrupt translation domain; responsible for mapping
  85 *      between GPIO hwirq number and linux irq number
  86 * @irq_base: first linux IRQ number assigned to GPIO IRQ chip (deprecated)
  87 * @irq_handler: the irq handler to use (often a predefined irq core function)
  88 *      for GPIO IRQs, provided by GPIO driver
  89 * @irq_default_type: default IRQ triggering type applied during GPIO driver
  90 *      initialization, provided by GPIO driver
  91 * @irq_chained_parent: GPIO IRQ chip parent/bank linux irq number,
  92 *      provided by GPIO driver for chained interrupt (not for nested
  93 *      interrupts).
  94 * @irq_nested: True if set the interrupt handling is nested.
  95 * @irq_need_valid_mask: If set core allocates @irq_valid_mask with all
  96 *      bits set to one
  97 * @irq_valid_mask: If not %NULL holds bitmask of GPIOs which are valid to
  98 *      be included in IRQ domain of the chip
  99 * @lock_key: per GPIO IRQ chip lockdep class
 100 *
 101 * A gpio_chip can help platforms abstract various sources of GPIOs so
 102 * they can all be accessed through a common programing interface.
 103 * Example sources would be SOC controllers, FPGAs, multifunction
 104 * chips, dedicated GPIO expanders, and so on.
 105 *
 106 * Each chip controls a number of signals, identified in method calls
 107 * by "offset" values in the range 0..(@ngpio - 1).  When those signals
 108 * are referenced through calls like gpio_get_value(gpio), the offset
 109 * is calculated by subtracting @base from the gpio number.
 110 */
 111struct gpio_chip {
 112        const char              *label;
 113        struct gpio_device      *gpiodev;
 114        struct device           *parent;
 115        struct module           *owner;
 116
 117        int                     (*request)(struct gpio_chip *chip,
 118                                                unsigned offset);
 119        void                    (*free)(struct gpio_chip *chip,
 120                                                unsigned offset);
 121        int                     (*get_direction)(struct gpio_chip *chip,
 122                                                unsigned offset);
 123        int                     (*direction_input)(struct gpio_chip *chip,
 124                                                unsigned offset);
 125        int                     (*direction_output)(struct gpio_chip *chip,
 126                                                unsigned offset, int value);
 127        int                     (*get)(struct gpio_chip *chip,
 128                                                unsigned offset);
 129        void                    (*set)(struct gpio_chip *chip,
 130                                                unsigned offset, int value);
 131        void                    (*set_multiple)(struct gpio_chip *chip,
 132                                                unsigned long *mask,
 133                                                unsigned long *bits);
 134        int                     (*set_config)(struct gpio_chip *chip,
 135                                              unsigned offset,
 136                                              unsigned long config);
 137        int                     (*to_irq)(struct gpio_chip *chip,
 138                                                unsigned offset);
 139
 140        void                    (*dbg_show)(struct seq_file *s,
 141                                                struct gpio_chip *chip);
 142        int                     base;
 143        u16                     ngpio;
 144        const char              *const *names;
 145        bool                    can_sleep;
 146
 147#if IS_ENABLED(CONFIG_GPIO_GENERIC)
 148        unsigned long (*read_reg)(void __iomem *reg);
 149        void (*write_reg)(void __iomem *reg, unsigned long data);
 150        unsigned long (*pin2mask)(struct gpio_chip *gc, unsigned int pin);
 151        void __iomem *reg_dat;
 152        void __iomem *reg_set;
 153        void __iomem *reg_clr;
 154        void __iomem *reg_dir;
 155        int bgpio_bits;
 156        spinlock_t bgpio_lock;
 157        unsigned long bgpio_data;
 158        unsigned long bgpio_dir;
 159#endif
 160
 161#ifdef CONFIG_GPIOLIB_IRQCHIP
 162        /*
 163         * With CONFIG_GPIOLIB_IRQCHIP we get an irqchip inside the gpiolib
 164         * to handle IRQs for most practical cases.
 165         */
 166        struct irq_chip         *irqchip;
 167        struct irq_domain       *irqdomain;
 168        unsigned int            irq_base;
 169        irq_flow_handler_t      irq_handler;
 170        unsigned int            irq_default_type;
 171        int                     irq_chained_parent;
 172        bool                    irq_nested;
 173        bool                    irq_need_valid_mask;
 174        unsigned long           *irq_valid_mask;
 175        struct lock_class_key   *lock_key;
 176#endif
 177
 178#if defined(CONFIG_OF_GPIO)
 179        /*
 180         * If CONFIG_OF is enabled, then all GPIO controllers described in the
 181         * device tree automatically may have an OF translation
 182         */
 183        struct device_node *of_node;
 184        int of_gpio_n_cells;
 185        int (*of_xlate)(struct gpio_chip *gc,
 186                        const struct of_phandle_args *gpiospec, u32 *flags);
 187#endif
 188};
 189
 190extern const char *gpiochip_is_requested(struct gpio_chip *chip,
 191                        unsigned offset);
 192
 193/* add/remove chips */
 194extern int gpiochip_add_data(struct gpio_chip *chip, void *data);
 195static inline int gpiochip_add(struct gpio_chip *chip)
 196{
 197        return gpiochip_add_data(chip, NULL);
 198}
 199extern void gpiochip_remove(struct gpio_chip *chip);
 200extern int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
 201                                  void *data);
 202extern void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip);
 203
 204extern struct gpio_chip *gpiochip_find(void *data,
 205                              int (*match)(struct gpio_chip *chip, void *data));
 206
 207/* lock/unlock as IRQ */
 208int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset);
 209void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset);
 210bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset);
 211
 212/* Line status inquiry for drivers */
 213bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset);
 214bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset);
 215
 216/* get driver data */
 217void *gpiochip_get_data(struct gpio_chip *chip);
 218
 219struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);
 220
 221struct bgpio_pdata {
 222        const char *label;
 223        int base;
 224        int ngpio;
 225};
 226
 227#if IS_ENABLED(CONFIG_GPIO_GENERIC)
 228
 229int bgpio_init(struct gpio_chip *gc, struct device *dev,
 230               unsigned long sz, void __iomem *dat, void __iomem *set,
 231               void __iomem *clr, void __iomem *dirout, void __iomem *dirin,
 232               unsigned long flags);
 233
 234#define BGPIOF_BIG_ENDIAN               BIT(0)
 235#define BGPIOF_UNREADABLE_REG_SET       BIT(1) /* reg_set is unreadable */
 236#define BGPIOF_UNREADABLE_REG_DIR       BIT(2) /* reg_dir is unreadable */
 237#define BGPIOF_BIG_ENDIAN_BYTE_ORDER    BIT(3)
 238#define BGPIOF_READ_OUTPUT_REG_SET      BIT(4) /* reg_set stores output value */
 239#define BGPIOF_NO_OUTPUT                BIT(5) /* only input */
 240
 241#endif
 242
 243#ifdef CONFIG_GPIOLIB_IRQCHIP
 244
 245void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
 246                struct irq_chip *irqchip,
 247                int parent_irq,
 248                irq_flow_handler_t parent_handler);
 249
 250void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
 251                struct irq_chip *irqchip,
 252                int parent_irq);
 253
 254int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
 255                             struct irq_chip *irqchip,
 256                             unsigned int first_irq,
 257                             irq_flow_handler_t handler,
 258                             unsigned int type,
 259                             bool nested,
 260                             struct lock_class_key *lock_key);
 261
 262#ifdef CONFIG_LOCKDEP
 263
 264/*
 265 * Lockdep requires that each irqchip instance be created with a
 266 * unique key so as to avoid unnecessary warnings. This upfront
 267 * boilerplate static inlines provides such a key for each
 268 * unique instance.
 269 */
 270static inline int gpiochip_irqchip_add(struct gpio_chip *gpiochip,
 271                                       struct irq_chip *irqchip,
 272                                       unsigned int first_irq,
 273                                       irq_flow_handler_t handler,
 274                                       unsigned int type)
 275{
 276        static struct lock_class_key key;
 277
 278        return gpiochip_irqchip_add_key(gpiochip, irqchip, first_irq,
 279                                        handler, type, false, &key);
 280}
 281
 282static inline int gpiochip_irqchip_add_nested(struct gpio_chip *gpiochip,
 283                          struct irq_chip *irqchip,
 284                          unsigned int first_irq,
 285                          irq_flow_handler_t handler,
 286                          unsigned int type)
 287{
 288
 289        static struct lock_class_key key;
 290
 291        return gpiochip_irqchip_add_key(gpiochip, irqchip, first_irq,
 292                                        handler, type, true, &key);
 293}
 294#else
 295static inline int gpiochip_irqchip_add(struct gpio_chip *gpiochip,
 296                                       struct irq_chip *irqchip,
 297                                       unsigned int first_irq,
 298                                       irq_flow_handler_t handler,
 299                                       unsigned int type)
 300{
 301        return gpiochip_irqchip_add_key(gpiochip, irqchip, first_irq,
 302                                        handler, type, false, NULL);
 303}
 304
 305static inline int gpiochip_irqchip_add_nested(struct gpio_chip *gpiochip,
 306                          struct irq_chip *irqchip,
 307                          unsigned int first_irq,
 308                          irq_flow_handler_t handler,
 309                          unsigned int type)
 310{
 311        return gpiochip_irqchip_add_key(gpiochip, irqchip, first_irq,
 312                                        handler, type, true, NULL);
 313}
 314#endif /* CONFIG_LOCKDEP */
 315
 316#endif /* CONFIG_GPIOLIB_IRQCHIP */
 317
 318int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset);
 319void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset);
 320int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
 321                            unsigned long config);
 322
 323#ifdef CONFIG_PINCTRL
 324
 325/**
 326 * struct gpio_pin_range - pin range controlled by a gpio chip
 327 * @head: list for maintaining set of pin ranges, used internally
 328 * @pctldev: pinctrl device which handles corresponding pins
 329 * @range: actual range of pins controlled by a gpio controller
 330 */
 331
 332struct gpio_pin_range {
 333        struct list_head node;
 334        struct pinctrl_dev *pctldev;
 335        struct pinctrl_gpio_range range;
 336};
 337
 338int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
 339                           unsigned int gpio_offset, unsigned int pin_offset,
 340                           unsigned int npins);
 341int gpiochip_add_pingroup_range(struct gpio_chip *chip,
 342                        struct pinctrl_dev *pctldev,
 343                        unsigned int gpio_offset, const char *pin_group);
 344void gpiochip_remove_pin_ranges(struct gpio_chip *chip);
 345
 346#else
 347
 348static inline int
 349gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
 350                       unsigned int gpio_offset, unsigned int pin_offset,
 351                       unsigned int npins)
 352{
 353        return 0;
 354}
 355static inline int
 356gpiochip_add_pingroup_range(struct gpio_chip *chip,
 357                        struct pinctrl_dev *pctldev,
 358                        unsigned int gpio_offset, const char *pin_group)
 359{
 360        return 0;
 361}
 362
 363static inline void
 364gpiochip_remove_pin_ranges(struct gpio_chip *chip)
 365{
 366}
 367
 368#endif /* CONFIG_PINCTRL */
 369
 370struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
 371                                            const char *label);
 372void gpiochip_free_own_desc(struct gpio_desc *desc);
 373
 374#else /* CONFIG_GPIOLIB */
 375
 376static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
 377{
 378        /* GPIO can never have been requested */
 379        WARN_ON(1);
 380        return ERR_PTR(-ENODEV);
 381}
 382
 383#endif /* CONFIG_GPIOLIB */
 384
 385#endif
 386