driver.h 17 KB

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