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;
  20enum gpiod_flags;
  21
  22#ifdef CONFIG_GPIOLIB
  23
  24#ifdef CONFIG_GPIOLIB_IRQCHIP
  25/**
  26 * struct gpio_irq_chip - GPIO interrupt controller
  27 */
  28struct gpio_irq_chip {
  29        /**
  30         * @chip:
  31         *
  32         * GPIO IRQ chip implementation, provided by GPIO driver.
  33         */
  34        struct irq_chip *chip;
  35
  36        /**
  37         * @domain:
  38         *
  39         * Interrupt translation domain; responsible for mapping between GPIO
  40         * hwirq number and Linux IRQ number.
  41         */
  42        struct irq_domain *domain;
  43
  44        /**
  45         * @domain_ops:
  46         *
  47         * Table of interrupt domain operations for this IRQ chip.
  48         */
  49        const struct irq_domain_ops *domain_ops;
  50
  51        /**
  52         * @handler:
  53         *
  54         * The IRQ handler to use (often a predefined IRQ core function) for
  55         * GPIO IRQs, provided by GPIO driver.
  56         */
  57        irq_flow_handler_t handler;
  58
  59        /**
  60         * @default_type:
  61         *
  62         * Default IRQ triggering type applied during GPIO driver
  63         * initialization, provided by GPIO driver.
  64         */
  65        unsigned int default_type;
  66
  67        /**
  68         * @lock_key:
  69         *
  70         * Per GPIO IRQ chip lockdep class for IRQ lock.
  71         */
  72        struct lock_class_key *lock_key;
  73
  74        /**
  75         * @request_key:
  76         *
  77         * Per GPIO IRQ chip lockdep class for IRQ request.
  78         */
  79        struct lock_class_key *request_key;
  80
  81        /**
  82         * @parent_handler:
  83         *
  84         * The interrupt handler for the GPIO chip's parent interrupts, may be
  85         * NULL if the parent interrupts are nested rather than cascaded.
  86         */
  87        irq_flow_handler_t parent_handler;
  88
  89        /**
  90         * @parent_handler_data:
  91         *
  92         * Data associated, and passed to, the handler for the parent
  93         * interrupt.
  94         */
  95        void *parent_handler_data;
  96
  97        /**
  98         * @num_parents:
  99         *
 100         * The number of interrupt parents of a GPIO chip.
 101         */
 102        unsigned int num_parents;
 103
 104        /**
 105         * @parent_irq:
 106         *
 107         * For use by gpiochip_set_cascaded_irqchip()
 108         */
 109        unsigned int parent_irq;
 110
 111        /**
 112         * @parents:
 113         *
 114         * A list of interrupt parents of a GPIO chip. This is owned by the
 115         * driver, so the core will only reference this list, not modify it.
 116         */
 117        unsigned int *parents;
 118
 119        /**
 120         * @map:
 121         *
 122         * A list of interrupt parents for each line of a GPIO chip.
 123         */
 124        unsigned int *map;
 125
 126        /**
 127         * @threaded:
 128         *
 129         * True if set the interrupt handling uses nested threads.
 130         */
 131        bool threaded;
 132
 133        /**
 134         * @need_valid_mask:
 135         *
 136         * If set core allocates @valid_mask with all bits set to one.
 137         */
 138        bool need_valid_mask;
 139
 140        /**
 141         * @valid_mask:
 142         *
 143         * If not %NULL holds bitmask of GPIOs which are valid to be included
 144         * in IRQ domain of the chip.
 145         */
 146        unsigned long *valid_mask;
 147
 148        /**
 149         * @first:
 150         *
 151         * Required for static IRQ allocation. If set, irq_domain_add_simple()
 152         * will allocate and map all IRQs during initialization.
 153         */
 154        unsigned int first;
 155
 156        /**
 157         * @irq_enable:
 158         *
 159         * Store old irq_chip irq_enable callback
 160         */
 161        void            (*irq_enable)(struct irq_data *data);
 162
 163        /**
 164         * @irq_disable:
 165         *
 166         * Store old irq_chip irq_disable callback
 167         */
 168        void            (*irq_disable)(struct irq_data *data);
 169};
 170#endif
 171
 172/**
 173 * struct gpio_chip - abstract a GPIO controller
 174 * @label: a functional name for the GPIO device, such as a part
 175 *      number or the name of the SoC IP-block implementing it.
 176 * @gpiodev: the internal state holder, opaque struct
 177 * @parent: optional parent device providing the GPIOs
 178 * @owner: helps prevent removal of modules exporting active GPIOs
 179 * @request: optional hook for chip-specific activation, such as
 180 *      enabling module power and clock; may sleep
 181 * @free: optional hook for chip-specific deactivation, such as
 182 *      disabling module power and clock; may sleep
 183 * @get_direction: returns direction for signal "offset", 0=out, 1=in,
 184 *      (same as GPIOF_DIR_XXX), or negative error.
 185 *      It is recommended to always implement this function, even on
 186 *      input-only or output-only gpio chips.
 187 * @direction_input: configures signal "offset" as input, or returns error
 188 *      This can be omitted on input-only or output-only gpio chips.
 189 * @direction_output: configures signal "offset" as output, or returns error
 190 *      This can be omitted on input-only or output-only gpio chips.
 191 * @get: returns value for signal "offset", 0=low, 1=high, or negative error
 192 * @get_multiple: reads values for multiple signals defined by "mask" and
 193 *      stores them in "bits", returns 0 on success or negative error
 194 * @set: assigns output value for signal "offset"
 195 * @set_multiple: assigns output values for multiple signals defined by "mask"
 196 * @set_config: optional hook for all kinds of settings. Uses the same
 197 *      packed config format as generic pinconf.
 198 * @to_irq: optional hook supporting non-static gpio_to_irq() mappings;
 199 *      implementation may not sleep
 200 * @dbg_show: optional routine to show contents in debugfs; default code
 201 *      will be used when this is omitted, but custom code can show extra
 202 *      state (such as pullup/pulldown configuration).
 203 * @base: identifies the first GPIO number handled by this chip;
 204 *      or, if negative during registration, requests dynamic ID allocation.
 205 *      DEPRECATION: providing anything non-negative and nailing the base
 206 *      offset of GPIO chips is deprecated. Please pass -1 as base to
 207 *      let gpiolib select the chip base in all possible cases. We want to
 208 *      get rid of the static GPIO number space in the long run.
 209 * @ngpio: the number of GPIOs handled by this controller; the last GPIO
 210 *      handled is (base + ngpio - 1).
 211 * @names: if set, must be an array of strings to use as alternative
 212 *      names for the GPIOs in this chip. Any entry in the array
 213 *      may be NULL if there is no alias for the GPIO, however the
 214 *      array must be @ngpio entries long.  A name can include a single printk
 215 *      format specifier for an unsigned int.  It is substituted by the actual
 216 *      number of the gpio.
 217 * @can_sleep: flag must be set iff get()/set() methods sleep, as they
 218 *      must while accessing GPIO expander chips over I2C or SPI. This
 219 *      implies that if the chip supports IRQs, these IRQs need to be threaded
 220 *      as the chip access may sleep when e.g. reading out the IRQ status
 221 *      registers.
 222 * @read_reg: reader function for generic GPIO
 223 * @write_reg: writer function for generic GPIO
 224 * @be_bits: if the generic GPIO has big endian bit order (bit 31 is representing
 225 *      line 0, bit 30 is line 1 ... bit 0 is line 31) this is set to true by the
 226 *      generic GPIO core. It is for internal housekeeping only.
 227 * @reg_dat: data (in) register for generic GPIO
 228 * @reg_set: output set register (out=high) for generic GPIO
 229 * @reg_clr: output clear register (out=low) for generic GPIO
 230 * @reg_dir: direction setting register for generic GPIO
 231 * @bgpio_dir_inverted: indicates that the direction register is inverted
 232 *      (gpiolib private state variable)
 233 * @bgpio_bits: number of register bits used for a generic GPIO i.e.
 234 *      <register width> * 8
 235 * @bgpio_lock: used to lock chip->bgpio_data. Also, this is needed to keep
 236 *      shadowed and real data registers writes together.
 237 * @bgpio_data: shadowed data register for generic GPIO to clear/set bits
 238 *      safely.
 239 * @bgpio_dir: shadowed direction register for generic GPIO to clear/set
 240 *      direction safely.
 241 *
 242 * A gpio_chip can help platforms abstract various sources of GPIOs so
 243 * they can all be accessed through a common programing interface.
 244 * Example sources would be SOC controllers, FPGAs, multifunction
 245 * chips, dedicated GPIO expanders, and so on.
 246 *
 247 * Each chip controls a number of signals, identified in method calls
 248 * by "offset" values in the range 0..(@ngpio - 1).  When those signals
 249 * are referenced through calls like gpio_get_value(gpio), the offset
 250 * is calculated by subtracting @base from the gpio number.
 251 */
 252struct gpio_chip {
 253        const char              *label;
 254        struct gpio_device      *gpiodev;
 255        struct device           *parent;
 256        struct module           *owner;
 257
 258        int                     (*request)(struct gpio_chip *chip,
 259                                                unsigned offset);
 260        void                    (*free)(struct gpio_chip *chip,
 261                                                unsigned offset);
 262        int                     (*get_direction)(struct gpio_chip *chip,
 263                                                unsigned offset);
 264        int                     (*direction_input)(struct gpio_chip *chip,
 265                                                unsigned offset);
 266        int                     (*direction_output)(struct gpio_chip *chip,
 267                                                unsigned offset, int value);
 268        int                     (*get)(struct gpio_chip *chip,
 269                                                unsigned offset);
 270        int                     (*get_multiple)(struct gpio_chip *chip,
 271                                                unsigned long *mask,
 272                                                unsigned long *bits);
 273        void                    (*set)(struct gpio_chip *chip,
 274                                                unsigned offset, int value);
 275        void                    (*set_multiple)(struct gpio_chip *chip,
 276                                                unsigned long *mask,
 277                                                unsigned long *bits);
 278        int                     (*set_config)(struct gpio_chip *chip,
 279                                              unsigned offset,
 280                                              unsigned long config);
 281        int                     (*to_irq)(struct gpio_chip *chip,
 282                                                unsigned offset);
 283
 284        void                    (*dbg_show)(struct seq_file *s,
 285                                                struct gpio_chip *chip);
 286
 287        int                     (*init_valid_mask)(struct gpio_chip *chip);
 288
 289        int                     base;
 290        u16                     ngpio;
 291        const char              *const *names;
 292        bool                    can_sleep;
 293
 294#if IS_ENABLED(CONFIG_GPIO_GENERIC)
 295        unsigned long (*read_reg)(void __iomem *reg);
 296        void (*write_reg)(void __iomem *reg, unsigned long data);
 297        bool be_bits;
 298        void __iomem *reg_dat;
 299        void __iomem *reg_set;
 300        void __iomem *reg_clr;
 301        void __iomem *reg_dir;
 302        bool bgpio_dir_inverted;
 303        int bgpio_bits;
 304        spinlock_t bgpio_lock;
 305        unsigned long bgpio_data;
 306        unsigned long bgpio_dir;
 307#endif
 308
 309#ifdef CONFIG_GPIOLIB_IRQCHIP
 310        /*
 311         * With CONFIG_GPIOLIB_IRQCHIP we get an irqchip inside the gpiolib
 312         * to handle IRQs for most practical cases.
 313         */
 314
 315        /**
 316         * @irq:
 317         *
 318         * Integrates interrupt chip functionality with the GPIO chip. Can be
 319         * used to handle IRQs for most practical cases.
 320         */
 321        struct gpio_irq_chip irq;
 322#endif
 323
 324        /**
 325         * @need_valid_mask:
 326         *
 327         * If set core allocates @valid_mask with all its values initialized
 328         * with init_valid_mask() or set to one if init_valid_mask() is not
 329         * defined
 330         */
 331        bool need_valid_mask;
 332
 333        /**
 334         * @valid_mask:
 335         *
 336         * If not %NULL holds bitmask of GPIOs which are valid to be used
 337         * from the chip.
 338         */
 339        unsigned long *valid_mask;
 340
 341#if defined(CONFIG_OF_GPIO)
 342        /*
 343         * If CONFIG_OF is enabled, then all GPIO controllers described in the
 344         * device tree automatically may have an OF translation
 345         */
 346
 347        /**
 348         * @of_node:
 349         *
 350         * Pointer to a device tree node representing this GPIO controller.
 351         */
 352        struct device_node *of_node;
 353
 354        /**
 355         * @of_gpio_n_cells:
 356         *
 357         * Number of cells used to form the GPIO specifier.
 358         */
 359        unsigned int of_gpio_n_cells;
 360
 361        /**
 362         * @of_xlate:
 363         *
 364         * Callback to translate a device tree GPIO specifier into a chip-
 365         * relative GPIO number and flags.
 366         */
 367        int (*of_xlate)(struct gpio_chip *gc,
 368                        const struct of_phandle_args *gpiospec, u32 *flags);
 369#endif
 370};
 371
 372extern const char *gpiochip_is_requested(struct gpio_chip *chip,
 373                        unsigned offset);
 374
 375/* add/remove chips */
 376extern int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
 377                                      struct lock_class_key *lock_key,
 378                                      struct lock_class_key *request_key);
 379
 380/**
 381 * gpiochip_add_data() - register a gpio_chip
 382 * @chip: the chip to register, with chip->base initialized
 383 * @data: driver-private data associated with this chip
 384 *
 385 * Context: potentially before irqs will work
 386 *
 387 * When gpiochip_add_data() is called very early during boot, so that GPIOs
 388 * can be freely used, the chip->parent device must be registered before
 389 * the gpio framework's arch_initcall().  Otherwise sysfs initialization
 390 * for GPIOs will fail rudely.
 391 *
 392 * gpiochip_add_data() must only be called after gpiolib initialization,
 393 * ie after core_initcall().
 394 *
 395 * If chip->base is negative, this requests dynamic assignment of
 396 * a range of valid GPIOs.
 397 *
 398 * Returns:
 399 * A negative errno if the chip can't be registered, such as because the
 400 * chip->base is invalid or already associated with a different chip.
 401 * Otherwise it returns zero as a success code.
 402 */
 403#ifdef CONFIG_LOCKDEP
 404#define gpiochip_add_data(chip, data) ({                \
 405                static struct lock_class_key lock_key;  \
 406                static struct lock_class_key request_key;         \
 407                gpiochip_add_data_with_key(chip, data, &lock_key, \
 408                                           &request_key);         \
 409        })
 410#else
 411#define gpiochip_add_data(chip, data) gpiochip_add_data_with_key(chip, data, NULL, NULL)
 412#endif
 413
 414static inline int gpiochip_add(struct gpio_chip *chip)
 415{
 416        return gpiochip_add_data(chip, NULL);
 417}
 418extern void gpiochip_remove(struct gpio_chip *chip);
 419extern int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
 420                                  void *data);
 421
 422extern struct gpio_chip *gpiochip_find(void *data,
 423                              int (*match)(struct gpio_chip *chip, void *data));
 424
 425/* lock/unlock as IRQ */
 426int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset);
 427void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset);
 428bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset);
 429int gpiochip_reqres_irq(struct gpio_chip *chip, unsigned int offset);
 430void gpiochip_relres_irq(struct gpio_chip *chip, unsigned int offset);
 431void gpiochip_disable_irq(struct gpio_chip *chip, unsigned int offset);
 432void gpiochip_enable_irq(struct gpio_chip *chip, unsigned int offset);
 433
 434/* Line status inquiry for drivers */
 435bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset);
 436bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset);
 437
 438/* Sleep persistence inquiry for drivers */
 439bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset);
 440bool gpiochip_line_is_valid(const struct gpio_chip *chip, unsigned int offset);
 441
 442/* get driver data */
 443void *gpiochip_get_data(struct gpio_chip *chip);
 444
 445struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);
 446
 447struct bgpio_pdata {
 448        const char *label;
 449        int base;
 450        int ngpio;
 451};
 452
 453#if IS_ENABLED(CONFIG_GPIO_GENERIC)
 454
 455int bgpio_init(struct gpio_chip *gc, struct device *dev,
 456               unsigned long sz, void __iomem *dat, void __iomem *set,
 457               void __iomem *clr, void __iomem *dirout, void __iomem *dirin,
 458               unsigned long flags);
 459
 460#define BGPIOF_BIG_ENDIAN               BIT(0)
 461#define BGPIOF_UNREADABLE_REG_SET       BIT(1) /* reg_set is unreadable */
 462#define BGPIOF_UNREADABLE_REG_DIR       BIT(2) /* reg_dir is unreadable */
 463#define BGPIOF_BIG_ENDIAN_BYTE_ORDER    BIT(3)
 464#define BGPIOF_READ_OUTPUT_REG_SET      BIT(4) /* reg_set stores output value */
 465#define BGPIOF_NO_OUTPUT                BIT(5) /* only input */
 466
 467#endif
 468
 469#ifdef CONFIG_GPIOLIB_IRQCHIP
 470
 471int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
 472                     irq_hw_number_t hwirq);
 473void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq);
 474
 475int gpiochip_irq_domain_activate(struct irq_domain *domain,
 476                                 struct irq_data *data, bool reserve);
 477void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
 478                                    struct irq_data *data);
 479
 480void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
 481                struct irq_chip *irqchip,
 482                unsigned int parent_irq,
 483                irq_flow_handler_t parent_handler);
 484
 485void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
 486                struct irq_chip *irqchip,
 487                unsigned int parent_irq);
 488
 489int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
 490                             struct irq_chip *irqchip,
 491                             unsigned int first_irq,
 492                             irq_flow_handler_t handler,
 493                             unsigned int type,
 494                             bool threaded,
 495                             struct lock_class_key *lock_key,
 496                             struct lock_class_key *request_key);
 497
 498bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
 499                                unsigned int offset);
 500
 501#ifdef CONFIG_LOCKDEP
 502
 503/*
 504 * Lockdep requires that each irqchip instance be created with a
 505 * unique key so as to avoid unnecessary warnings. This upfront
 506 * boilerplate static inlines provides such a key for each
 507 * unique instance.
 508 */
 509static inline int gpiochip_irqchip_add(struct gpio_chip *gpiochip,
 510                                       struct irq_chip *irqchip,
 511                                       unsigned int first_irq,
 512                                       irq_flow_handler_t handler,
 513                                       unsigned int type)
 514{
 515        static struct lock_class_key lock_key;
 516        static struct lock_class_key request_key;
 517
 518        return gpiochip_irqchip_add_key(gpiochip, irqchip, first_irq,
 519                                        handler, type, false,
 520                                        &lock_key, &request_key);
 521}
 522
 523static inline int gpiochip_irqchip_add_nested(struct gpio_chip *gpiochip,
 524                          struct irq_chip *irqchip,
 525                          unsigned int first_irq,
 526                          irq_flow_handler_t handler,
 527                          unsigned int type)
 528{
 529
 530        static struct lock_class_key lock_key;
 531        static struct lock_class_key request_key;
 532
 533        return gpiochip_irqchip_add_key(gpiochip, irqchip, first_irq,
 534                                        handler, type, true,
 535                                        &lock_key, &request_key);
 536}
 537#else
 538static inline int gpiochip_irqchip_add(struct gpio_chip *gpiochip,
 539                                       struct irq_chip *irqchip,
 540                                       unsigned int first_irq,
 541                                       irq_flow_handler_t handler,
 542                                       unsigned int type)
 543{
 544        return gpiochip_irqchip_add_key(gpiochip, irqchip, first_irq,
 545                                        handler, type, false, NULL, NULL);
 546}
 547
 548static inline int gpiochip_irqchip_add_nested(struct gpio_chip *gpiochip,
 549                          struct irq_chip *irqchip,
 550                          unsigned int first_irq,
 551                          irq_flow_handler_t handler,
 552                          unsigned int type)
 553{
 554        return gpiochip_irqchip_add_key(gpiochip, irqchip, first_irq,
 555                                        handler, type, true, NULL, NULL);
 556}
 557#endif /* CONFIG_LOCKDEP */
 558
 559#endif /* CONFIG_GPIOLIB_IRQCHIP */
 560
 561int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset);
 562void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset);
 563int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
 564                            unsigned long config);
 565
 566#ifdef CONFIG_PINCTRL
 567
 568/**
 569 * struct gpio_pin_range - pin range controlled by a gpio chip
 570 * @node: list for maintaining set of pin ranges, used internally
 571 * @pctldev: pinctrl device which handles corresponding pins
 572 * @range: actual range of pins controlled by a gpio controller
 573 */
 574struct gpio_pin_range {
 575        struct list_head node;
 576        struct pinctrl_dev *pctldev;
 577        struct pinctrl_gpio_range range;
 578};
 579
 580int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
 581                           unsigned int gpio_offset, unsigned int pin_offset,
 582                           unsigned int npins);
 583int gpiochip_add_pingroup_range(struct gpio_chip *chip,
 584                        struct pinctrl_dev *pctldev,
 585                        unsigned int gpio_offset, const char *pin_group);
 586void gpiochip_remove_pin_ranges(struct gpio_chip *chip);
 587
 588#else
 589
 590static inline int
 591gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
 592                       unsigned int gpio_offset, unsigned int pin_offset,
 593                       unsigned int npins)
 594{
 595        return 0;
 596}
 597static inline int
 598gpiochip_add_pingroup_range(struct gpio_chip *chip,
 599                        struct pinctrl_dev *pctldev,
 600                        unsigned int gpio_offset, const char *pin_group)
 601{
 602        return 0;
 603}
 604
 605static inline void
 606gpiochip_remove_pin_ranges(struct gpio_chip *chip)
 607{
 608}
 609
 610#endif /* CONFIG_PINCTRL */
 611
 612struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
 613                                            const char *label,
 614                                            enum gpiod_flags flags);
 615void gpiochip_free_own_desc(struct gpio_desc *desc);
 616
 617#else /* CONFIG_GPIOLIB */
 618
 619static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
 620{
 621        /* GPIO can never have been requested */
 622        WARN_ON(1);
 623        return ERR_PTR(-ENODEV);
 624}
 625
 626#endif /* CONFIG_GPIOLIB */
 627
 628#endif
 629