linux/include/linux/gpio/driver.h
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef __LINUX_GPIO_DRIVER_H
   3#define __LINUX_GPIO_DRIVER_H
   4
   5#include <linux/device.h>
   6#include <linux/types.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/pinctrl/pinconf-generic.h>
  13
  14struct gpio_desc;
  15struct of_phandle_args;
  16struct device_node;
  17struct seq_file;
  18struct gpio_device;
  19struct module;
  20
  21#ifdef CONFIG_GPIOLIB
  22
  23#ifdef CONFIG_GPIOLIB_IRQCHIP
  24/**
  25 * struct gpio_irq_chip - GPIO interrupt controller
  26 */
  27struct gpio_irq_chip {
  28        /**
  29         * @chip:
  30         *
  31         * GPIO IRQ chip implementation, provided by GPIO driver.
  32         */
  33        struct irq_chip *chip;
  34
  35        /**
  36         * @domain:
  37         *
  38         * Interrupt translation domain; responsible for mapping between GPIO
  39         * hwirq number and Linux IRQ number.
  40         */
  41        struct irq_domain *domain;
  42
  43        /**
  44         * @domain_ops:
  45         *
  46         * Table of interrupt domain operations for this IRQ chip.
  47         */
  48        const struct irq_domain_ops *domain_ops;
  49
  50        /**
  51         * @handler:
  52         *
  53         * The IRQ handler to use (often a predefined IRQ core function) for
  54         * GPIO IRQs, provided by GPIO driver.
  55         */
  56        irq_flow_handler_t handler;
  57
  58        /**
  59         * @default_type:
  60         *
  61         * Default IRQ triggering type applied during GPIO driver
  62         * initialization, provided by GPIO driver.
  63         */
  64        unsigned int default_type;
  65
  66        /**
  67         * @lock_key:
  68         *
  69         * Per GPIO IRQ chip lockdep classes.
  70         */
  71        struct lock_class_key *lock_key;
  72        struct lock_class_key *request_key;
  73
  74        /**
  75         * @parent_handler:
  76         *
  77         * The interrupt handler for the GPIO chip's parent interrupts, may be
  78         * NULL if the parent interrupts are nested rather than cascaded.
  79         */
  80        irq_flow_handler_t parent_handler;
  81
  82        /**
  83         * @parent_handler_data:
  84         *
  85         * Data associated, and passed to, the handler for the parent
  86         * interrupt.
  87         */
  88        void *parent_handler_data;
  89
  90        /**
  91         * @num_parents:
  92         *
  93         * The number of interrupt parents of a GPIO chip.
  94         */
  95        unsigned int num_parents;
  96
  97        /**
  98         * @parents:
  99         *
 100         * A list of interrupt parents of a GPIO chip. This is owned by the
 101         * driver, so the core will only reference this list, not modify it.
 102         */
 103        unsigned int *parents;
 104
 105        /**
 106         * @map:
 107         *
 108         * A list of interrupt parents for each line of a GPIO chip.
 109         */
 110        unsigned int *map;
 111
 112        /**
 113         * @threaded:
 114         *
 115         * True if set the interrupt handling uses nested threads.
 116         */
 117        bool threaded;
 118
 119        /**
 120         * @need_valid_mask:
 121         *
 122         * If set core allocates @valid_mask with all bits set to one.
 123         */
 124        bool need_valid_mask;
 125
 126        /**
 127         * @valid_mask:
 128         *
 129         * If not %NULL holds bitmask of GPIOs which are valid to be included
 130         * in IRQ domain of the chip.
 131         */
 132        unsigned long *valid_mask;
 133
 134        /**
 135         * @first:
 136         *
 137         * Required for static IRQ allocation. If set, irq_domain_add_simple()
 138         * will allocate and map all IRQs during initialization.
 139         */
 140        unsigned int first;
 141};
 142
 143static inline struct gpio_irq_chip *to_gpio_irq_chip(struct irq_chip *chip)
 144{
 145        return container_of(chip, struct gpio_irq_chip, chip);
 146}
 147#endif
 148
 149/**
 150 * struct gpio_chip - abstract a GPIO controller
 151 * @label: a functional name for the GPIO device, such as a part
 152 *      number or the name of the SoC IP-block implementing it.
 153 * @gpiodev: the internal state holder, opaque struct
 154 * @parent: optional parent device providing the GPIOs
 155 * @owner: helps prevent removal of modules exporting active GPIOs
 156 * @request: optional hook for chip-specific activation, such as
 157 *      enabling module power and clock; may sleep
 158 * @free: optional hook for chip-specific deactivation, such as
 159 *      disabling module power and clock; may sleep
 160 * @get_direction: returns direction for signal "offset", 0=out, 1=in,
 161 *      (same as GPIOF_DIR_XXX), or negative error
 162 * @direction_input: configures signal "offset" as input, or returns error
 163 * @direction_output: configures signal "offset" as output, or returns error
 164 * @get: returns value for signal "offset", 0=low, 1=high, or negative error
 165 * @get_multiple: reads values for multiple signals defined by "mask" and
 166 *      stores them in "bits", returns 0 on success or negative error
 167 * @set: assigns output value for signal "offset"
 168 * @set_multiple: assigns output values for multiple signals defined by "mask"
 169 * @set_config: optional hook for all kinds of settings. Uses the same
 170 *      packed config format as generic pinconf.
 171 * @to_irq: optional hook supporting non-static gpio_to_irq() mappings;
 172 *      implementation may not sleep
 173 * @dbg_show: optional routine to show contents in debugfs; default code
 174 *      will be used when this is omitted, but custom code can show extra
 175 *      state (such as pullup/pulldown configuration).
 176 * @base: identifies the first GPIO number handled by this chip;
 177 *      or, if negative during registration, requests dynamic ID allocation.
 178 *      DEPRECATION: providing anything non-negative and nailing the base
 179 *      offset of GPIO chips is deprecated. Please pass -1 as base to
 180 *      let gpiolib select the chip base in all possible cases. We want to
 181 *      get rid of the static GPIO number space in the long run.
 182 * @ngpio: the number of GPIOs handled by this controller; the last GPIO
 183 *      handled is (base + ngpio - 1).
 184 * @names: if set, must be an array of strings to use as alternative
 185 *      names for the GPIOs in this chip. Any entry in the array
 186 *      may be NULL if there is no alias for the GPIO, however the
 187 *      array must be @ngpio entries long.  A name can include a single printk
 188 *      format specifier for an unsigned int.  It is substituted by the actual
 189 *      number of the gpio.
 190 * @can_sleep: flag must be set iff get()/set() methods sleep, as they
 191 *      must while accessing GPIO expander chips over I2C or SPI. This
 192 *      implies that if the chip supports IRQs, these IRQs need to be threaded
 193 *      as the chip access may sleep when e.g. reading out the IRQ status
 194 *      registers.
 195 * @read_reg: reader function for generic GPIO
 196 * @write_reg: writer function for generic GPIO
 197 * @be_bits: if the generic GPIO has big endian bit order (bit 31 is representing
 198 *      line 0, bit 30 is line 1 ... bit 0 is line 31) this is set to true by the
 199 *      generic GPIO core. It is for internal housekeeping only.
 200 * @reg_dat: data (in) register for generic GPIO
 201 * @reg_set: output set register (out=high) for generic GPIO
 202 * @reg_clr: output clear register (out=low) for generic GPIO
 203 * @reg_dir: direction setting register for generic GPIO
 204 * @bgpio_bits: number of register bits used for a generic GPIO i.e.
 205 *      <register width> * 8
 206 * @bgpio_lock: used to lock chip->bgpio_data. Also, this is needed to keep
 207 *      shadowed and real data registers writes together.
 208 * @bgpio_data: shadowed data register for generic GPIO to clear/set bits
 209 *      safely.
 210 * @bgpio_dir: shadowed direction register for generic GPIO to clear/set
 211 *      direction safely.
 212 *
 213 * A gpio_chip can help platforms abstract various sources of GPIOs so
 214 * they can all be accessed through a common programing interface.
 215 * Example sources would be SOC controllers, FPGAs, multifunction
 216 * chips, dedicated GPIO expanders, and so on.
 217 *
 218 * Each chip controls a number of signals, identified in method calls
 219 * by "offset" values in the range 0..(@ngpio - 1).  When those signals
 220 * are referenced through calls like gpio_get_value(gpio), the offset
 221 * is calculated by subtracting @base from the gpio number.
 222 */
 223struct gpio_chip {
 224        const char              *label;
 225        struct gpio_device      *gpiodev;
 226        struct device           *parent;
 227        struct module           *owner;
 228
 229        int                     (*request)(struct gpio_chip *chip,
 230                                                unsigned offset);
 231        void                    (*free)(struct gpio_chip *chip,
 232                                                unsigned offset);
 233        int                     (*get_direction)(struct gpio_chip *chip,
 234                                                unsigned offset);
 235        int                     (*direction_input)(struct gpio_chip *chip,
 236                                                unsigned offset);
 237        int                     (*direction_output)(struct gpio_chip *chip,
 238                                                unsigned offset, int value);
 239        int                     (*get)(struct gpio_chip *chip,
 240                                                unsigned offset);
 241        int                     (*get_multiple)(struct gpio_chip *chip,
 242                                                unsigned long *mask,
 243                                                unsigned long *bits);
 244        void                    (*set)(struct gpio_chip *chip,
 245                                                unsigned offset, int value);
 246        void                    (*set_multiple)(struct gpio_chip *chip,
 247                                                unsigned long *mask,
 248                                                unsigned long *bits);
 249        int                     (*set_config)(struct gpio_chip *chip,
 250                                              unsigned offset,
 251                                              unsigned long config);
 252        int                     (*to_irq)(struct gpio_chip *chip,
 253                                                unsigned offset);
 254
 255        void                    (*dbg_show)(struct seq_file *s,
 256                                                struct gpio_chip *chip);
 257        int                     base;
 258        u16                     ngpio;
 259        const char              *const *names;
 260        bool                    can_sleep;
 261
 262#if IS_ENABLED(CONFIG_GPIO_GENERIC)
 263        unsigned long (*read_reg)(void __iomem *reg);
 264        void (*write_reg)(void __iomem *reg, unsigned long data);
 265        bool be_bits;
 266        void __iomem *reg_dat;
 267        void __iomem *reg_set;
 268        void __iomem *reg_clr;
 269        void __iomem *reg_dir;
 270        int bgpio_bits;
 271        spinlock_t bgpio_lock;
 272        unsigned long bgpio_data;
 273        unsigned long bgpio_dir;
 274#endif
 275
 276#ifdef CONFIG_GPIOLIB_IRQCHIP
 277        /*
 278         * With CONFIG_GPIOLIB_IRQCHIP we get an irqchip inside the gpiolib
 279         * to handle IRQs for most practical cases.
 280         */
 281
 282        /**
 283         * @irq:
 284         *
 285         * Integrates interrupt chip functionality with the GPIO chip. Can be
 286         * used to handle IRQs for most practical cases.
 287         */
 288        struct gpio_irq_chip irq;
 289#endif
 290
 291        /**
 292         * @need_valid_mask:
 293         *
 294         * If set core allocates @valid_mask with all bits set to one.
 295         */
 296        bool need_valid_mask;
 297
 298        /**
 299         * @valid_mask:
 300         *
 301         * If not %NULL holds bitmask of GPIOs which are valid to be used
 302         * from the chip.
 303         */
 304        unsigned long *valid_mask;
 305
 306#if defined(CONFIG_OF_GPIO)
 307        /*
 308         * If CONFIG_OF is enabled, then all GPIO controllers described in the
 309         * device tree automatically may have an OF translation
 310         */
 311
 312        /**
 313         * @of_node:
 314         *
 315         * Pointer to a device tree node representing this GPIO controller.
 316         */
 317        struct device_node *of_node;
 318
 319        /**
 320         * @of_gpio_n_cells:
 321         *
 322         * Number of cells used to form the GPIO specifier.
 323         */
 324        unsigned int of_gpio_n_cells;
 325
 326        /**
 327         * @of_xlate:
 328         *
 329         * Callback to translate a device tree GPIO specifier into a chip-
 330         * relative GPIO number and flags.
 331         */
 332        int (*of_xlate)(struct gpio_chip *gc,
 333                        const struct of_phandle_args *gpiospec, u32 *flags);
 334#endif
 335};
 336
 337extern const char *gpiochip_is_requested(struct gpio_chip *chip,
 338                        unsigned offset);
 339
 340/* add/remove chips */
 341extern int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
 342                                      struct lock_class_key *lock_key,
 343                                      struct lock_class_key *request_key);
 344
 345/**
 346 * gpiochip_add_data() - register a gpio_chip
 347 * @chip: the chip to register, with chip->base initialized
 348 * @data: driver-private data associated with this chip
 349 *
 350 * Context: potentially before irqs will work
 351 *
 352 * When gpiochip_add_data() is called very early during boot, so that GPIOs
 353 * can be freely used, the chip->parent device must be registered before
 354 * the gpio framework's arch_initcall().  Otherwise sysfs initialization
 355 * for GPIOs will fail rudely.
 356 *
 357 * gpiochip_add_data() must only be called after gpiolib initialization,
 358 * ie after core_initcall().
 359 *
 360 * If chip->base is negative, this requests dynamic assignment of
 361 * a range of valid GPIOs.
 362 *
 363 * Returns:
 364 * A negative errno if the chip can't be registered, such as because the
 365 * chip->base is invalid or already associated with a different chip.
 366 * Otherwise it returns zero as a success code.
 367 */
 368#ifdef CONFIG_LOCKDEP
 369#define gpiochip_add_data(chip, data) ({                \
 370                static struct lock_class_key lock_key;  \
 371                static struct lock_class_key request_key;         \
 372                gpiochip_add_data_with_key(chip, data, &lock_key, \
 373                                           &request_key);         \
 374        })
 375#else
 376#define gpiochip_add_data(chip, data) gpiochip_add_data_with_key(chip, data, NULL, NULL)
 377#endif
 378
 379static inline int gpiochip_add(struct gpio_chip *chip)
 380{
 381        return gpiochip_add_data(chip, NULL);
 382}
 383extern void gpiochip_remove(struct gpio_chip *chip);
 384extern int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
 385                                  void *data);
 386extern void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip);
 387
 388extern struct gpio_chip *gpiochip_find(void *data,
 389                              int (*match)(struct gpio_chip *chip, void *data));
 390
 391/* lock/unlock as IRQ */
 392int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset);
 393void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset);
 394bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset);
 395
 396/* Line status inquiry for drivers */
 397bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset);
 398bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset);
 399
 400/* Sleep persistence inquiry for drivers */
 401bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset);
 402bool gpiochip_line_is_valid(const struct gpio_chip *chip, unsigned int offset);
 403
 404/* get driver data */
 405void *gpiochip_get_data(struct gpio_chip *chip);
 406
 407struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);
 408
 409struct bgpio_pdata {
 410        const char *label;
 411        int base;
 412        int ngpio;
 413};
 414
 415#if IS_ENABLED(CONFIG_GPIO_GENERIC)
 416
 417int bgpio_init(struct gpio_chip *gc, struct device *dev,
 418               unsigned long sz, void __iomem *dat, void __iomem *set,
 419               void __iomem *clr, void __iomem *dirout, void __iomem *dirin,
 420               unsigned long flags);
 421
 422#define BGPIOF_BIG_ENDIAN               BIT(0)
 423#define BGPIOF_UNREADABLE_REG_SET       BIT(1) /* reg_set is unreadable */
 424#define BGPIOF_UNREADABLE_REG_DIR       BIT(2) /* reg_dir is unreadable */
 425#define BGPIOF_BIG_ENDIAN_BYTE_ORDER    BIT(3)
 426#define BGPIOF_READ_OUTPUT_REG_SET      BIT(4) /* reg_set stores output value */
 427#define BGPIOF_NO_OUTPUT                BIT(5) /* only input */
 428
 429#endif
 430
 431#ifdef CONFIG_GPIOLIB_IRQCHIP
 432
 433int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
 434                     irq_hw_number_t hwirq);
 435void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq);
 436
 437void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
 438                struct irq_chip *irqchip,
 439                unsigned int parent_irq,
 440                irq_flow_handler_t parent_handler);
 441
 442void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
 443                struct irq_chip *irqchip,
 444                unsigned int parent_irq);
 445
 446int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
 447                             struct irq_chip *irqchip,
 448                             unsigned int first_irq,
 449                             irq_flow_handler_t handler,
 450                             unsigned int type,
 451                             bool threaded,
 452                             struct lock_class_key *lock_key,
 453                             struct lock_class_key *request_key);
 454
 455bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
 456                                unsigned int offset);
 457
 458#ifdef CONFIG_LOCKDEP
 459
 460/*
 461 * Lockdep requires that each irqchip instance be created with a
 462 * unique key so as to avoid unnecessary warnings. This upfront
 463 * boilerplate static inlines provides such a key for each
 464 * unique instance.
 465 */
 466static inline int gpiochip_irqchip_add(struct gpio_chip *gpiochip,
 467                                       struct irq_chip *irqchip,
 468                                       unsigned int first_irq,
 469                                       irq_flow_handler_t handler,
 470                                       unsigned int type)
 471{
 472        static struct lock_class_key lock_key;
 473        static struct lock_class_key request_key;
 474
 475        return gpiochip_irqchip_add_key(gpiochip, irqchip, first_irq,
 476                                        handler, type, false,
 477                                        &lock_key, &request_key);
 478}
 479
 480static inline int gpiochip_irqchip_add_nested(struct gpio_chip *gpiochip,
 481                          struct irq_chip *irqchip,
 482                          unsigned int first_irq,
 483                          irq_flow_handler_t handler,
 484                          unsigned int type)
 485{
 486
 487        static struct lock_class_key lock_key;
 488        static struct lock_class_key request_key;
 489
 490        return gpiochip_irqchip_add_key(gpiochip, irqchip, first_irq,
 491                                        handler, type, true,
 492                                        &lock_key, &request_key);
 493}
 494#else
 495static inline int gpiochip_irqchip_add(struct gpio_chip *gpiochip,
 496                                       struct irq_chip *irqchip,
 497                                       unsigned int first_irq,
 498                                       irq_flow_handler_t handler,
 499                                       unsigned int type)
 500{
 501        return gpiochip_irqchip_add_key(gpiochip, irqchip, first_irq,
 502                                        handler, type, false, NULL, NULL);
 503}
 504
 505static inline int gpiochip_irqchip_add_nested(struct gpio_chip *gpiochip,
 506                          struct irq_chip *irqchip,
 507                          unsigned int first_irq,
 508                          irq_flow_handler_t handler,
 509                          unsigned int type)
 510{
 511        return gpiochip_irqchip_add_key(gpiochip, irqchip, first_irq,
 512                                        handler, type, true, NULL, NULL);
 513}
 514#endif /* CONFIG_LOCKDEP */
 515
 516#endif /* CONFIG_GPIOLIB_IRQCHIP */
 517
 518int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset);
 519void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset);
 520int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
 521                            unsigned long config);
 522
 523#ifdef CONFIG_PINCTRL
 524
 525/**
 526 * struct gpio_pin_range - pin range controlled by a gpio chip
 527 * @node: list for maintaining set of pin ranges, used internally
 528 * @pctldev: pinctrl device which handles corresponding pins
 529 * @range: actual range of pins controlled by a gpio controller
 530 */
 531struct gpio_pin_range {
 532        struct list_head node;
 533        struct pinctrl_dev *pctldev;
 534        struct pinctrl_gpio_range range;
 535};
 536
 537int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
 538                           unsigned int gpio_offset, unsigned int pin_offset,
 539                           unsigned int npins);
 540int gpiochip_add_pingroup_range(struct gpio_chip *chip,
 541                        struct pinctrl_dev *pctldev,
 542                        unsigned int gpio_offset, const char *pin_group);
 543void gpiochip_remove_pin_ranges(struct gpio_chip *chip);
 544
 545#else
 546
 547static inline int
 548gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
 549                       unsigned int gpio_offset, unsigned int pin_offset,
 550                       unsigned int npins)
 551{
 552        return 0;
 553}
 554static inline int
 555gpiochip_add_pingroup_range(struct gpio_chip *chip,
 556                        struct pinctrl_dev *pctldev,
 557                        unsigned int gpio_offset, const char *pin_group)
 558{
 559        return 0;
 560}
 561
 562static inline void
 563gpiochip_remove_pin_ranges(struct gpio_chip *chip)
 564{
 565}
 566
 567#endif /* CONFIG_PINCTRL */
 568
 569struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
 570                                            const char *label);
 571void gpiochip_free_own_desc(struct gpio_desc *desc);
 572
 573#else /* CONFIG_GPIOLIB */
 574
 575static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
 576{
 577        /* GPIO can never have been requested */
 578        WARN_ON(1);
 579        return ERR_PTR(-ENODEV);
 580}
 581
 582#endif /* CONFIG_GPIOLIB */
 583
 584#endif
 585