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Commit | Line | Data |
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d2876d08 DB |
1 | #include <linux/kernel.h> |
2 | #include <linux/module.h> | |
ff77c352 | 3 | #include <linux/interrupt.h> |
d2876d08 DB |
4 | #include <linux/irq.h> |
5 | #include <linux/spinlock.h> | |
1a989d0f | 6 | #include <linux/list.h> |
d8f388d8 DB |
7 | #include <linux/device.h> |
8 | #include <linux/err.h> | |
9 | #include <linux/debugfs.h> | |
10 | #include <linux/seq_file.h> | |
11 | #include <linux/gpio.h> | |
391c970c | 12 | #include <linux/of_gpio.h> |
ff77c352 | 13 | #include <linux/idr.h> |
5a0e3ad6 | 14 | #include <linux/slab.h> |
7b199811 | 15 | #include <linux/acpi.h> |
53e7cac3 | 16 | #include <linux/gpio/driver.h> |
d2876d08 | 17 | |
664e3e5a MW |
18 | #include "gpiolib.h" |
19 | ||
3f397c21 UKK |
20 | #define CREATE_TRACE_POINTS |
21 | #include <trace/events/gpio.h> | |
d2876d08 | 22 | |
79a9becd | 23 | /* Implementation infrastructure for GPIO interfaces. |
d2876d08 | 24 | * |
79a9becd AC |
25 | * The GPIO programming interface allows for inlining speed-critical |
26 | * get/set operations for common cases, so that access to SOC-integrated | |
27 | * GPIOs can sometimes cost only an instruction or two per bit. | |
d2876d08 DB |
28 | */ |
29 | ||
30 | ||
31 | /* When debugging, extend minimal trust to callers and platform code. | |
32 | * Also emit diagnostic messages that may help initial bringup, when | |
33 | * board setup or driver bugs are most common. | |
34 | * | |
35 | * Otherwise, minimize overhead in what may be bitbanging codepaths. | |
36 | */ | |
37 | #ifdef DEBUG | |
38 | #define extra_checks 1 | |
39 | #else | |
40 | #define extra_checks 0 | |
41 | #endif | |
42 | ||
43 | /* gpio_lock prevents conflicts during gpio_desc[] table updates. | |
44 | * While any GPIO is requested, its gpio_chip is not removable; | |
45 | * each GPIO's "requested" flag serves as a lock and refcount. | |
46 | */ | |
0eb4c6c2 | 47 | DEFINE_SPINLOCK(gpio_lock); |
d2876d08 | 48 | |
d2876d08 DB |
49 | static struct gpio_desc gpio_desc[ARCH_NR_GPIOS]; |
50 | ||
6c0b4e6c AC |
51 | #define GPIO_OFFSET_VALID(chip, offset) (offset >= 0 && offset < chip->ngpio) |
52 | ||
bae48da2 AC |
53 | static DEFINE_MUTEX(gpio_lookup_lock); |
54 | static LIST_HEAD(gpio_lookup_list); | |
0eb4c6c2 | 55 | LIST_HEAD(gpio_chips); |
1a2a99c6 | 56 | |
d2876d08 DB |
57 | static inline void desc_set_label(struct gpio_desc *d, const char *label) |
58 | { | |
d2876d08 | 59 | d->label = label; |
d2876d08 DB |
60 | } |
61 | ||
372e722e AC |
62 | /** |
63 | * Convert a GPIO number to its descriptor | |
64 | */ | |
79a9becd | 65 | struct gpio_desc *gpio_to_desc(unsigned gpio) |
372e722e AC |
66 | { |
67 | if (WARN(!gpio_is_valid(gpio), "invalid GPIO %d\n", gpio)) | |
68 | return NULL; | |
69 | else | |
70 | return &gpio_desc[gpio]; | |
71 | } | |
79a9becd | 72 | EXPORT_SYMBOL_GPL(gpio_to_desc); |
372e722e | 73 | |
d468bf9e | 74 | /** |
bb1e88cc | 75 | * Get the GPIO descriptor corresponding to the given hw number for this chip. |
d468bf9e | 76 | */ |
bb1e88cc AC |
77 | struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip, |
78 | u16 hwnum) | |
d468bf9e | 79 | { |
bb1e88cc | 80 | if (hwnum >= chip->ngpio) |
b7d0a28a | 81 | return ERR_PTR(-EINVAL); |
d468bf9e | 82 | |
bb1e88cc | 83 | return &chip->desc[hwnum]; |
d468bf9e | 84 | } |
372e722e AC |
85 | |
86 | /** | |
87 | * Convert a GPIO descriptor to the integer namespace. | |
88 | * This should disappear in the future but is needed since we still | |
89 | * use GPIO numbers for error messages and sysfs nodes | |
90 | */ | |
79a9becd | 91 | int desc_to_gpio(const struct gpio_desc *desc) |
372e722e | 92 | { |
8c0fca81 | 93 | return desc - &gpio_desc[0]; |
372e722e | 94 | } |
79a9becd | 95 | EXPORT_SYMBOL_GPL(desc_to_gpio); |
372e722e AC |
96 | |
97 | ||
d2876d08 DB |
98 | /* Warn when drivers omit gpio_request() calls -- legal but ill-advised |
99 | * when setting direction, and otherwise illegal. Until board setup code | |
100 | * and drivers use explicit requests everywhere (which won't happen when | |
101 | * those calls have no teeth) we can't avoid autorequesting. This nag | |
35e8bb51 DB |
102 | * message should motivate switching to explicit requests... so should |
103 | * the weaker cleanup after faults, compared to gpio_request(). | |
8a0cecff DB |
104 | * |
105 | * NOTE: the autorequest mechanism is going away; at this point it's | |
106 | * only "legal" in the sense that (old) code using it won't break yet, | |
107 | * but instead only triggers a WARN() stack dump. | |
d2876d08 | 108 | */ |
372e722e | 109 | static int gpio_ensure_requested(struct gpio_desc *desc) |
d2876d08 | 110 | { |
8a0cecff | 111 | const struct gpio_chip *chip = desc->chip; |
372e722e | 112 | const int gpio = desc_to_gpio(desc); |
35e8bb51 | 113 | |
8a0cecff DB |
114 | if (WARN(test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0, |
115 | "autorequest GPIO-%d\n", gpio)) { | |
35e8bb51 | 116 | if (!try_module_get(chip->owner)) { |
7589e59f AS |
117 | gpiod_err(desc, "%s: module can't be gotten\n", |
118 | __func__); | |
35e8bb51 DB |
119 | clear_bit(FLAG_REQUESTED, &desc->flags); |
120 | /* lose */ | |
121 | return -EIO; | |
122 | } | |
d2876d08 | 123 | desc_set_label(desc, "[auto]"); |
35e8bb51 DB |
124 | /* caller must chip->request() w/o spinlock */ |
125 | if (chip->request) | |
126 | return 1; | |
d2876d08 | 127 | } |
35e8bb51 | 128 | return 0; |
d2876d08 DB |
129 | } |
130 | ||
79a9becd AC |
131 | /** |
132 | * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs | |
133 | * @desc: descriptor to return the chip of | |
134 | */ | |
135 | struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc) | |
372e722e | 136 | { |
bcabdef1 | 137 | return desc ? desc->chip : NULL; |
372e722e | 138 | } |
79a9becd | 139 | EXPORT_SYMBOL_GPL(gpiod_to_chip); |
d2876d08 | 140 | |
8d0aab2f AV |
141 | /* dynamic allocation of GPIOs, e.g. on a hotplugged device */ |
142 | static int gpiochip_find_base(int ngpio) | |
143 | { | |
83cabe33 AC |
144 | struct gpio_chip *chip; |
145 | int base = ARCH_NR_GPIOS - ngpio; | |
8d0aab2f | 146 | |
83cabe33 AC |
147 | list_for_each_entry_reverse(chip, &gpio_chips, list) { |
148 | /* found a free space? */ | |
149 | if (chip->base + chip->ngpio <= base) | |
150 | break; | |
151 | else | |
152 | /* nope, check the space right before the chip */ | |
153 | base = chip->base - ngpio; | |
8d0aab2f AV |
154 | } |
155 | ||
83cabe33 | 156 | if (gpio_is_valid(base)) { |
8d0aab2f | 157 | pr_debug("%s: found new base at %d\n", __func__, base); |
83cabe33 AC |
158 | return base; |
159 | } else { | |
160 | pr_err("%s: cannot find free range\n", __func__); | |
161 | return -ENOSPC; | |
169b6a7a | 162 | } |
169b6a7a AV |
163 | } |
164 | ||
79a9becd AC |
165 | /** |
166 | * gpiod_get_direction - return the current direction of a GPIO | |
167 | * @desc: GPIO to get the direction of | |
168 | * | |
169 | * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error. | |
170 | * | |
171 | * This function may sleep if gpiod_cansleep() is true. | |
172 | */ | |
173 | int gpiod_get_direction(const struct gpio_desc *desc) | |
80b0a602 MN |
174 | { |
175 | struct gpio_chip *chip; | |
372e722e | 176 | unsigned offset; |
80b0a602 MN |
177 | int status = -EINVAL; |
178 | ||
372e722e AC |
179 | chip = gpiod_to_chip(desc); |
180 | offset = gpio_chip_hwgpio(desc); | |
80b0a602 MN |
181 | |
182 | if (!chip->get_direction) | |
183 | return status; | |
184 | ||
372e722e | 185 | status = chip->get_direction(chip, offset); |
80b0a602 MN |
186 | if (status > 0) { |
187 | /* GPIOF_DIR_IN, or other positive */ | |
188 | status = 1; | |
def63433 AC |
189 | /* FLAG_IS_OUT is just a cache of the result of get_direction(), |
190 | * so it does not affect constness per se */ | |
191 | clear_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags); | |
80b0a602 MN |
192 | } |
193 | if (status == 0) { | |
194 | /* GPIOF_DIR_OUT */ | |
def63433 | 195 | set_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags); |
80b0a602 MN |
196 | } |
197 | return status; | |
198 | } | |
79a9becd | 199 | EXPORT_SYMBOL_GPL(gpiod_get_direction); |
80b0a602 | 200 | |
1a989d0f AC |
201 | /* |
202 | * Add a new chip to the global chips list, keeping the list of chips sorted | |
203 | * by base order. | |
204 | * | |
205 | * Return -EBUSY if the new chip overlaps with some other chip's integer | |
206 | * space. | |
207 | */ | |
208 | static int gpiochip_add_to_list(struct gpio_chip *chip) | |
209 | { | |
210 | struct list_head *pos = &gpio_chips; | |
211 | struct gpio_chip *_chip; | |
212 | int err = 0; | |
213 | ||
214 | /* find where to insert our chip */ | |
215 | list_for_each(pos, &gpio_chips) { | |
216 | _chip = list_entry(pos, struct gpio_chip, list); | |
217 | /* shall we insert before _chip? */ | |
218 | if (_chip->base >= chip->base + chip->ngpio) | |
219 | break; | |
220 | } | |
221 | ||
222 | /* are we stepping on the chip right before? */ | |
223 | if (pos != &gpio_chips && pos->prev != &gpio_chips) { | |
224 | _chip = list_entry(pos->prev, struct gpio_chip, list); | |
225 | if (_chip->base + _chip->ngpio > chip->base) { | |
226 | dev_err(chip->dev, | |
227 | "GPIO integer space overlap, cannot add chip\n"); | |
228 | err = -EBUSY; | |
229 | } | |
230 | } | |
231 | ||
232 | if (!err) | |
233 | list_add_tail(&chip->list, pos); | |
234 | ||
235 | return err; | |
236 | } | |
237 | ||
d2876d08 DB |
238 | /** |
239 | * gpiochip_add() - register a gpio_chip | |
240 | * @chip: the chip to register, with chip->base initialized | |
241 | * Context: potentially before irqs or kmalloc will work | |
242 | * | |
243 | * Returns a negative errno if the chip can't be registered, such as | |
244 | * because the chip->base is invalid or already associated with a | |
245 | * different chip. Otherwise it returns zero as a success code. | |
8d0aab2f | 246 | * |
d8f388d8 DB |
247 | * When gpiochip_add() is called very early during boot, so that GPIOs |
248 | * can be freely used, the chip->dev device must be registered before | |
249 | * the gpio framework's arch_initcall(). Otherwise sysfs initialization | |
250 | * for GPIOs will fail rudely. | |
251 | * | |
8d0aab2f AV |
252 | * If chip->base is negative, this requests dynamic assignment of |
253 | * a range of valid GPIOs. | |
d2876d08 DB |
254 | */ |
255 | int gpiochip_add(struct gpio_chip *chip) | |
256 | { | |
257 | unsigned long flags; | |
258 | int status = 0; | |
259 | unsigned id; | |
8d0aab2f | 260 | int base = chip->base; |
d2876d08 | 261 | |
bff5fda9 | 262 | if ((!gpio_is_valid(base) || !gpio_is_valid(base + chip->ngpio - 1)) |
8d0aab2f | 263 | && base >= 0) { |
d2876d08 DB |
264 | status = -EINVAL; |
265 | goto fail; | |
266 | } | |
267 | ||
268 | spin_lock_irqsave(&gpio_lock, flags); | |
269 | ||
8d0aab2f AV |
270 | if (base < 0) { |
271 | base = gpiochip_find_base(chip->ngpio); | |
272 | if (base < 0) { | |
273 | status = base; | |
d8f388d8 | 274 | goto unlock; |
8d0aab2f AV |
275 | } |
276 | chip->base = base; | |
277 | } | |
278 | ||
1a989d0f AC |
279 | status = gpiochip_add_to_list(chip); |
280 | ||
d2876d08 | 281 | if (status == 0) { |
6c0b4e6c AC |
282 | chip->desc = &gpio_desc[chip->base]; |
283 | ||
284 | for (id = 0; id < chip->ngpio; id++) { | |
285 | struct gpio_desc *desc = &chip->desc[id]; | |
286 | desc->chip = chip; | |
d8f388d8 DB |
287 | |
288 | /* REVISIT: most hardware initializes GPIOs as | |
289 | * inputs (often with pullups enabled) so power | |
290 | * usage is minimized. Linux code should set the | |
291 | * gpio direction first thing; but until it does, | |
80b0a602 | 292 | * and in case chip->get_direction is not set, |
d8f388d8 DB |
293 | * we may expose the wrong direction in sysfs. |
294 | */ | |
6c0b4e6c | 295 | desc->flags = !chip->direction_input |
d8f388d8 DB |
296 | ? (1 << FLAG_IS_OUT) |
297 | : 0; | |
d2876d08 DB |
298 | } |
299 | } | |
300 | ||
3bae4811 ZG |
301 | spin_unlock_irqrestore(&gpio_lock, flags); |
302 | ||
f23f1516 SH |
303 | #ifdef CONFIG_PINCTRL |
304 | INIT_LIST_HEAD(&chip->pin_ranges); | |
305 | #endif | |
306 | ||
391c970c | 307 | of_gpiochip_add(chip); |
664e3e5a | 308 | acpi_gpiochip_add(chip); |
391c970c | 309 | |
cedb1881 AV |
310 | if (status) |
311 | goto fail; | |
312 | ||
313 | status = gpiochip_export(chip); | |
314 | if (status) | |
315 | goto fail; | |
316 | ||
7589e59f | 317 | pr_debug("%s: registered GPIOs %d to %d on device: %s\n", __func__, |
64842aad GL |
318 | chip->base, chip->base + chip->ngpio - 1, |
319 | chip->label ? : "generic"); | |
320 | ||
cedb1881 | 321 | return 0; |
3bae4811 ZG |
322 | |
323 | unlock: | |
324 | spin_unlock_irqrestore(&gpio_lock, flags); | |
d2876d08 DB |
325 | fail: |
326 | /* failures here can mean systems won't boot... */ | |
7589e59f | 327 | pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__, |
cedb1881 AV |
328 | chip->base, chip->base + chip->ngpio - 1, |
329 | chip->label ? : "generic"); | |
d2876d08 DB |
330 | return status; |
331 | } | |
332 | EXPORT_SYMBOL_GPL(gpiochip_add); | |
333 | ||
14250520 LW |
334 | /* Forward-declaration */ |
335 | static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip); | |
336 | ||
d2876d08 DB |
337 | /** |
338 | * gpiochip_remove() - unregister a gpio_chip | |
339 | * @chip: the chip to unregister | |
340 | * | |
341 | * A gpio_chip with any GPIOs still requested may not be removed. | |
342 | */ | |
343 | int gpiochip_remove(struct gpio_chip *chip) | |
344 | { | |
345 | unsigned long flags; | |
346 | int status = 0; | |
347 | unsigned id; | |
348 | ||
6072b9dc MW |
349 | acpi_gpiochip_remove(chip); |
350 | ||
d2876d08 DB |
351 | spin_lock_irqsave(&gpio_lock, flags); |
352 | ||
14250520 | 353 | gpiochip_irqchip_remove(chip); |
9ef0d6f7 | 354 | gpiochip_remove_pin_ranges(chip); |
391c970c AV |
355 | of_gpiochip_remove(chip); |
356 | ||
6c0b4e6c AC |
357 | for (id = 0; id < chip->ngpio; id++) { |
358 | if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) { | |
d2876d08 DB |
359 | status = -EBUSY; |
360 | break; | |
361 | } | |
362 | } | |
363 | if (status == 0) { | |
6c0b4e6c AC |
364 | for (id = 0; id < chip->ngpio; id++) |
365 | chip->desc[id].chip = NULL; | |
1a989d0f AC |
366 | |
367 | list_del(&chip->list); | |
d2876d08 DB |
368 | } |
369 | ||
370 | spin_unlock_irqrestore(&gpio_lock, flags); | |
d8f388d8 DB |
371 | |
372 | if (status == 0) | |
373 | gpiochip_unexport(chip); | |
374 | ||
d2876d08 DB |
375 | return status; |
376 | } | |
377 | EXPORT_SYMBOL_GPL(gpiochip_remove); | |
378 | ||
594fa265 GL |
379 | /** |
380 | * gpiochip_find() - iterator for locating a specific gpio_chip | |
381 | * @data: data to pass to match function | |
382 | * @callback: Callback function to check gpio_chip | |
383 | * | |
384 | * Similar to bus_find_device. It returns a reference to a gpio_chip as | |
385 | * determined by a user supplied @match callback. The callback should return | |
386 | * 0 if the device doesn't match and non-zero if it does. If the callback is | |
387 | * non-zero, this function will return to the caller and not iterate over any | |
388 | * more gpio_chips. | |
389 | */ | |
07ce8ec7 | 390 | struct gpio_chip *gpiochip_find(void *data, |
6e2cf651 | 391 | int (*match)(struct gpio_chip *chip, |
3d0f7cf0 | 392 | void *data)) |
594fa265 | 393 | { |
125eef96 | 394 | struct gpio_chip *chip; |
594fa265 | 395 | unsigned long flags; |
594fa265 GL |
396 | |
397 | spin_lock_irqsave(&gpio_lock, flags); | |
125eef96 AC |
398 | list_for_each_entry(chip, &gpio_chips, list) |
399 | if (match(chip, data)) | |
594fa265 | 400 | break; |
125eef96 AC |
401 | |
402 | /* No match? */ | |
403 | if (&chip->list == &gpio_chips) | |
404 | chip = NULL; | |
594fa265 GL |
405 | spin_unlock_irqrestore(&gpio_lock, flags); |
406 | ||
407 | return chip; | |
408 | } | |
8fa0c9bf | 409 | EXPORT_SYMBOL_GPL(gpiochip_find); |
d2876d08 | 410 | |
79697ef9 AC |
411 | static int gpiochip_match_name(struct gpio_chip *chip, void *data) |
412 | { | |
413 | const char *name = data; | |
414 | ||
415 | return !strcmp(chip->label, name); | |
416 | } | |
417 | ||
418 | static struct gpio_chip *find_chip_by_name(const char *name) | |
419 | { | |
420 | return gpiochip_find((void *)name, gpiochip_match_name); | |
421 | } | |
422 | ||
14250520 LW |
423 | #ifdef CONFIG_GPIOLIB_IRQCHIP |
424 | ||
425 | /* | |
426 | * The following is irqchip helper code for gpiochips. | |
427 | */ | |
428 | ||
429 | /** | |
430 | * gpiochip_add_chained_irqchip() - adds a chained irqchip to a gpiochip | |
431 | * @gpiochip: the gpiochip to add the irqchip to | |
432 | * @irqchip: the irqchip to add to the gpiochip | |
433 | * @parent_irq: the irq number corresponding to the parent IRQ for this | |
434 | * chained irqchip | |
435 | * @parent_handler: the parent interrupt handler for the accumulated IRQ | |
436 | * coming out of the gpiochip | |
437 | */ | |
438 | void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip, | |
439 | struct irq_chip *irqchip, | |
440 | int parent_irq, | |
441 | irq_flow_handler_t parent_handler) | |
442 | { | |
1c8732bb LW |
443 | if (gpiochip->can_sleep) { |
444 | chip_err(gpiochip, "you cannot have chained interrupts on a chip that may sleep\n"); | |
445 | return; | |
446 | } | |
447 | ||
14250520 LW |
448 | irq_set_chained_handler(parent_irq, parent_handler); |
449 | /* | |
450 | * The parent irqchip is already using the chip_data for this | |
451 | * irqchip, so our callbacks simply use the handler_data. | |
452 | */ | |
453 | irq_set_handler_data(parent_irq, gpiochip); | |
454 | } | |
455 | EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip); | |
456 | ||
e45d1c80 LW |
457 | /* |
458 | * This lock class tells lockdep that GPIO irqs are in a different | |
459 | * category than their parents, so it won't report false recursion. | |
460 | */ | |
461 | static struct lock_class_key gpiochip_irq_lock_class; | |
462 | ||
14250520 LW |
463 | /** |
464 | * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip | |
465 | * @d: the irqdomain used by this irqchip | |
466 | * @irq: the global irq number used by this GPIO irqchip irq | |
467 | * @hwirq: the local IRQ/GPIO line offset on this gpiochip | |
468 | * | |
469 | * This function will set up the mapping for a certain IRQ line on a | |
470 | * gpiochip by assigning the gpiochip as chip data, and using the irqchip | |
471 | * stored inside the gpiochip. | |
472 | */ | |
473 | static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq, | |
474 | irq_hw_number_t hwirq) | |
475 | { | |
476 | struct gpio_chip *chip = d->host_data; | |
477 | ||
14250520 | 478 | irq_set_chip_data(irq, chip); |
e45d1c80 | 479 | irq_set_lockdep_class(irq, &gpiochip_irq_lock_class); |
7633fb95 | 480 | irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler); |
1c8732bb LW |
481 | /* Chips that can sleep need nested thread handlers */ |
482 | if (chip->can_sleep) | |
483 | irq_set_nested_thread(irq, 1); | |
14250520 LW |
484 | #ifdef CONFIG_ARM |
485 | set_irq_flags(irq, IRQF_VALID); | |
486 | #else | |
487 | irq_set_noprobe(irq); | |
488 | #endif | |
1333b90f LW |
489 | /* |
490 | * No set-up of the hardware will happen if IRQ_TYPE_NONE | |
491 | * is passed as default type. | |
492 | */ | |
493 | if (chip->irq_default_type != IRQ_TYPE_NONE) | |
494 | irq_set_irq_type(irq, chip->irq_default_type); | |
14250520 LW |
495 | |
496 | return 0; | |
497 | } | |
498 | ||
c3626fde LW |
499 | static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq) |
500 | { | |
1c8732bb LW |
501 | struct gpio_chip *chip = d->host_data; |
502 | ||
c3626fde LW |
503 | #ifdef CONFIG_ARM |
504 | set_irq_flags(irq, 0); | |
505 | #endif | |
1c8732bb LW |
506 | if (chip->can_sleep) |
507 | irq_set_nested_thread(irq, 0); | |
c3626fde LW |
508 | irq_set_chip_and_handler(irq, NULL, NULL); |
509 | irq_set_chip_data(irq, NULL); | |
510 | } | |
511 | ||
14250520 LW |
512 | static const struct irq_domain_ops gpiochip_domain_ops = { |
513 | .map = gpiochip_irq_map, | |
c3626fde | 514 | .unmap = gpiochip_irq_unmap, |
14250520 LW |
515 | /* Virtually all GPIO irqchips are twocell:ed */ |
516 | .xlate = irq_domain_xlate_twocell, | |
517 | }; | |
518 | ||
519 | static int gpiochip_irq_reqres(struct irq_data *d) | |
520 | { | |
521 | struct gpio_chip *chip = irq_data_get_irq_chip_data(d); | |
522 | ||
523 | if (gpio_lock_as_irq(chip, d->hwirq)) { | |
524 | chip_err(chip, | |
525 | "unable to lock HW IRQ %lu for IRQ\n", | |
526 | d->hwirq); | |
527 | return -EINVAL; | |
528 | } | |
529 | return 0; | |
530 | } | |
531 | ||
532 | static void gpiochip_irq_relres(struct irq_data *d) | |
533 | { | |
534 | struct gpio_chip *chip = irq_data_get_irq_chip_data(d); | |
535 | ||
536 | gpio_unlock_as_irq(chip, d->hwirq); | |
537 | } | |
538 | ||
539 | static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset) | |
540 | { | |
541 | return irq_find_mapping(chip->irqdomain, offset); | |
542 | } | |
543 | ||
544 | /** | |
545 | * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip | |
546 | * @gpiochip: the gpiochip to remove the irqchip from | |
547 | * | |
548 | * This is called only from gpiochip_remove() | |
549 | */ | |
550 | static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) | |
551 | { | |
c3626fde LW |
552 | unsigned int offset; |
553 | ||
554 | /* Remove all IRQ mappings and delete the domain */ | |
555 | if (gpiochip->irqdomain) { | |
556 | for (offset = 0; offset < gpiochip->ngpio; offset++) | |
557 | irq_dispose_mapping(gpiochip->irq_base + offset); | |
14250520 | 558 | irq_domain_remove(gpiochip->irqdomain); |
c3626fde | 559 | } |
14250520 LW |
560 | |
561 | if (gpiochip->irqchip) { | |
562 | gpiochip->irqchip->irq_request_resources = NULL; | |
563 | gpiochip->irqchip->irq_release_resources = NULL; | |
564 | gpiochip->irqchip = NULL; | |
565 | } | |
566 | } | |
567 | ||
568 | /** | |
569 | * gpiochip_irqchip_add() - adds an irqchip to a gpiochip | |
570 | * @gpiochip: the gpiochip to add the irqchip to | |
571 | * @irqchip: the irqchip to add to the gpiochip | |
572 | * @first_irq: if not dynamically assigned, the base (first) IRQ to | |
573 | * allocate gpiochip irqs from | |
574 | * @handler: the irq handler to use (often a predefined irq core function) | |
1333b90f LW |
575 | * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE |
576 | * to have the core avoid setting up any default type in the hardware. | |
14250520 LW |
577 | * |
578 | * This function closely associates a certain irqchip with a certain | |
579 | * gpiochip, providing an irq domain to translate the local IRQs to | |
580 | * global irqs in the gpiolib core, and making sure that the gpiochip | |
581 | * is passed as chip data to all related functions. Driver callbacks | |
582 | * need to use container_of() to get their local state containers back | |
583 | * from the gpiochip passed as chip data. An irqdomain will be stored | |
584 | * in the gpiochip that shall be used by the driver to handle IRQ number | |
585 | * translation. The gpiochip will need to be initialized and registered | |
586 | * before calling this function. | |
587 | * | |
c3626fde LW |
588 | * This function will handle two cell:ed simple IRQs and assumes all |
589 | * the pins on the gpiochip can generate a unique IRQ. Everything else | |
14250520 LW |
590 | * need to be open coded. |
591 | */ | |
592 | int gpiochip_irqchip_add(struct gpio_chip *gpiochip, | |
593 | struct irq_chip *irqchip, | |
594 | unsigned int first_irq, | |
595 | irq_flow_handler_t handler, | |
596 | unsigned int type) | |
597 | { | |
598 | struct device_node *of_node; | |
599 | unsigned int offset; | |
c3626fde | 600 | unsigned irq_base = 0; |
14250520 LW |
601 | |
602 | if (!gpiochip || !irqchip) | |
603 | return -EINVAL; | |
604 | ||
605 | if (!gpiochip->dev) { | |
606 | pr_err("missing gpiochip .dev parent pointer\n"); | |
607 | return -EINVAL; | |
608 | } | |
609 | of_node = gpiochip->dev->of_node; | |
610 | #ifdef CONFIG_OF_GPIO | |
611 | /* | |
612 | * If the gpiochip has an assigned OF node this takes precendence | |
613 | * FIXME: get rid of this and use gpiochip->dev->of_node everywhere | |
614 | */ | |
615 | if (gpiochip->of_node) | |
616 | of_node = gpiochip->of_node; | |
617 | #endif | |
618 | gpiochip->irqchip = irqchip; | |
619 | gpiochip->irq_handler = handler; | |
620 | gpiochip->irq_default_type = type; | |
621 | gpiochip->to_irq = gpiochip_to_irq; | |
622 | gpiochip->irqdomain = irq_domain_add_simple(of_node, | |
623 | gpiochip->ngpio, first_irq, | |
624 | &gpiochip_domain_ops, gpiochip); | |
625 | if (!gpiochip->irqdomain) { | |
626 | gpiochip->irqchip = NULL; | |
627 | return -EINVAL; | |
628 | } | |
629 | irqchip->irq_request_resources = gpiochip_irq_reqres; | |
630 | irqchip->irq_release_resources = gpiochip_irq_relres; | |
631 | ||
632 | /* | |
633 | * Prepare the mapping since the irqchip shall be orthogonal to | |
634 | * any gpiochip calls. If the first_irq was zero, this is | |
635 | * necessary to allocate descriptors for all IRQs. | |
636 | */ | |
c3626fde LW |
637 | for (offset = 0; offset < gpiochip->ngpio; offset++) { |
638 | irq_base = irq_create_mapping(gpiochip->irqdomain, offset); | |
639 | if (offset == 0) | |
640 | /* | |
641 | * Store the base into the gpiochip to be used when | |
642 | * unmapping the irqs. | |
643 | */ | |
644 | gpiochip->irq_base = irq_base; | |
645 | } | |
14250520 LW |
646 | |
647 | return 0; | |
648 | } | |
649 | EXPORT_SYMBOL_GPL(gpiochip_irqchip_add); | |
650 | ||
651 | #else /* CONFIG_GPIOLIB_IRQCHIP */ | |
652 | ||
653 | static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {} | |
654 | ||
655 | #endif /* CONFIG_GPIOLIB_IRQCHIP */ | |
656 | ||
f23f1516 | 657 | #ifdef CONFIG_PINCTRL |
165adc9c | 658 | |
586a87e6 CR |
659 | /** |
660 | * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping | |
661 | * @chip: the gpiochip to add the range for | |
662 | * @pinctrl: the dev_name() of the pin controller to map to | |
663 | * @gpio_offset: the start offset in the current gpio_chip number space | |
664 | * @pin_group: name of the pin group inside the pin controller | |
665 | */ | |
666 | int gpiochip_add_pingroup_range(struct gpio_chip *chip, | |
667 | struct pinctrl_dev *pctldev, | |
668 | unsigned int gpio_offset, const char *pin_group) | |
669 | { | |
670 | struct gpio_pin_range *pin_range; | |
671 | int ret; | |
672 | ||
673 | pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL); | |
674 | if (!pin_range) { | |
1a2a99c6 | 675 | chip_err(chip, "failed to allocate pin ranges\n"); |
586a87e6 CR |
676 | return -ENOMEM; |
677 | } | |
678 | ||
679 | /* Use local offset as range ID */ | |
680 | pin_range->range.id = gpio_offset; | |
681 | pin_range->range.gc = chip; | |
682 | pin_range->range.name = chip->label; | |
683 | pin_range->range.base = chip->base + gpio_offset; | |
684 | pin_range->pctldev = pctldev; | |
685 | ||
686 | ret = pinctrl_get_group_pins(pctldev, pin_group, | |
687 | &pin_range->range.pins, | |
688 | &pin_range->range.npins); | |
61c6375d MN |
689 | if (ret < 0) { |
690 | kfree(pin_range); | |
586a87e6 | 691 | return ret; |
61c6375d | 692 | } |
586a87e6 CR |
693 | |
694 | pinctrl_add_gpio_range(pctldev, &pin_range->range); | |
695 | ||
1a2a99c6 AS |
696 | chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n", |
697 | gpio_offset, gpio_offset + pin_range->range.npins - 1, | |
586a87e6 CR |
698 | pinctrl_dev_get_devname(pctldev), pin_group); |
699 | ||
700 | list_add_tail(&pin_range->node, &chip->pin_ranges); | |
701 | ||
702 | return 0; | |
703 | } | |
704 | EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range); | |
705 | ||
3f0f8670 LW |
706 | /** |
707 | * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping | |
708 | * @chip: the gpiochip to add the range for | |
709 | * @pinctrl_name: the dev_name() of the pin controller to map to | |
316511c0 LW |
710 | * @gpio_offset: the start offset in the current gpio_chip number space |
711 | * @pin_offset: the start offset in the pin controller number space | |
3f0f8670 LW |
712 | * @npins: the number of pins from the offset of each pin space (GPIO and |
713 | * pin controller) to accumulate in this range | |
714 | */ | |
1e63d7b9 | 715 | int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name, |
316511c0 | 716 | unsigned int gpio_offset, unsigned int pin_offset, |
3f0f8670 | 717 | unsigned int npins) |
f23f1516 SH |
718 | { |
719 | struct gpio_pin_range *pin_range; | |
b4d4b1f0 | 720 | int ret; |
f23f1516 | 721 | |
3f0f8670 | 722 | pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL); |
f23f1516 | 723 | if (!pin_range) { |
1a2a99c6 | 724 | chip_err(chip, "failed to allocate pin ranges\n"); |
1e63d7b9 | 725 | return -ENOMEM; |
f23f1516 SH |
726 | } |
727 | ||
3f0f8670 | 728 | /* Use local offset as range ID */ |
316511c0 | 729 | pin_range->range.id = gpio_offset; |
3f0f8670 | 730 | pin_range->range.gc = chip; |
f23f1516 | 731 | pin_range->range.name = chip->label; |
316511c0 LW |
732 | pin_range->range.base = chip->base + gpio_offset; |
733 | pin_range->range.pin_base = pin_offset; | |
f23f1516 | 734 | pin_range->range.npins = npins; |
192c369c | 735 | pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name, |
f23f1516 | 736 | &pin_range->range); |
8f23ca1a | 737 | if (IS_ERR(pin_range->pctldev)) { |
b4d4b1f0 | 738 | ret = PTR_ERR(pin_range->pctldev); |
1a2a99c6 | 739 | chip_err(chip, "could not create pin range\n"); |
3f0f8670 | 740 | kfree(pin_range); |
b4d4b1f0 | 741 | return ret; |
3f0f8670 | 742 | } |
1a2a99c6 AS |
743 | chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n", |
744 | gpio_offset, gpio_offset + npins - 1, | |
316511c0 LW |
745 | pinctl_name, |
746 | pin_offset, pin_offset + npins - 1); | |
f23f1516 SH |
747 | |
748 | list_add_tail(&pin_range->node, &chip->pin_ranges); | |
1e63d7b9 LW |
749 | |
750 | return 0; | |
f23f1516 | 751 | } |
165adc9c | 752 | EXPORT_SYMBOL_GPL(gpiochip_add_pin_range); |
f23f1516 | 753 | |
3f0f8670 LW |
754 | /** |
755 | * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings | |
756 | * @chip: the chip to remove all the mappings for | |
757 | */ | |
f23f1516 SH |
758 | void gpiochip_remove_pin_ranges(struct gpio_chip *chip) |
759 | { | |
760 | struct gpio_pin_range *pin_range, *tmp; | |
761 | ||
762 | list_for_each_entry_safe(pin_range, tmp, &chip->pin_ranges, node) { | |
763 | list_del(&pin_range->node); | |
764 | pinctrl_remove_gpio_range(pin_range->pctldev, | |
765 | &pin_range->range); | |
3f0f8670 | 766 | kfree(pin_range); |
f23f1516 SH |
767 | } |
768 | } | |
165adc9c LW |
769 | EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges); |
770 | ||
771 | #endif /* CONFIG_PINCTRL */ | |
f23f1516 | 772 | |
d2876d08 DB |
773 | /* These "optional" allocation calls help prevent drivers from stomping |
774 | * on each other, and help provide better diagnostics in debugfs. | |
775 | * They're called even less than the "set direction" calls. | |
776 | */ | |
77c2d792 | 777 | static int __gpiod_request(struct gpio_desc *desc, const char *label) |
d2876d08 | 778 | { |
77c2d792 MW |
779 | struct gpio_chip *chip = desc->chip; |
780 | int status; | |
d2876d08 DB |
781 | unsigned long flags; |
782 | ||
bcabdef1 AC |
783 | spin_lock_irqsave(&gpio_lock, flags); |
784 | ||
d2876d08 | 785 | /* NOTE: gpio_request() can be called in early boot, |
35e8bb51 | 786 | * before IRQs are enabled, for non-sleeping (SOC) GPIOs. |
d2876d08 DB |
787 | */ |
788 | ||
789 | if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) { | |
790 | desc_set_label(desc, label ? : "?"); | |
791 | status = 0; | |
438d8908 | 792 | } else { |
d2876d08 | 793 | status = -EBUSY; |
7460db56 | 794 | goto done; |
35e8bb51 DB |
795 | } |
796 | ||
797 | if (chip->request) { | |
798 | /* chip->request may sleep */ | |
799 | spin_unlock_irqrestore(&gpio_lock, flags); | |
372e722e | 800 | status = chip->request(chip, gpio_chip_hwgpio(desc)); |
35e8bb51 DB |
801 | spin_lock_irqsave(&gpio_lock, flags); |
802 | ||
803 | if (status < 0) { | |
804 | desc_set_label(desc, NULL); | |
35e8bb51 | 805 | clear_bit(FLAG_REQUESTED, &desc->flags); |
80b0a602 | 806 | goto done; |
35e8bb51 | 807 | } |
438d8908 | 808 | } |
80b0a602 MN |
809 | if (chip->get_direction) { |
810 | /* chip->get_direction may sleep */ | |
811 | spin_unlock_irqrestore(&gpio_lock, flags); | |
372e722e | 812 | gpiod_get_direction(desc); |
80b0a602 MN |
813 | spin_lock_irqsave(&gpio_lock, flags); |
814 | } | |
77c2d792 MW |
815 | done: |
816 | spin_unlock_irqrestore(&gpio_lock, flags); | |
817 | return status; | |
818 | } | |
819 | ||
0eb4c6c2 | 820 | int gpiod_request(struct gpio_desc *desc, const char *label) |
77c2d792 MW |
821 | { |
822 | int status = -EPROBE_DEFER; | |
823 | struct gpio_chip *chip; | |
824 | ||
825 | if (!desc) { | |
826 | pr_warn("%s: invalid GPIO\n", __func__); | |
827 | return -EINVAL; | |
828 | } | |
829 | ||
830 | chip = desc->chip; | |
831 | if (!chip) | |
832 | goto done; | |
833 | ||
834 | if (try_module_get(chip->owner)) { | |
835 | status = __gpiod_request(desc, label); | |
836 | if (status < 0) | |
837 | module_put(chip->owner); | |
838 | } | |
839 | ||
d2876d08 DB |
840 | done: |
841 | if (status) | |
7589e59f | 842 | gpiod_dbg(desc, "%s: status %d\n", __func__, status); |
77c2d792 | 843 | |
d2876d08 DB |
844 | return status; |
845 | } | |
372e722e | 846 | |
77c2d792 | 847 | static bool __gpiod_free(struct gpio_desc *desc) |
d2876d08 | 848 | { |
77c2d792 | 849 | bool ret = false; |
d2876d08 | 850 | unsigned long flags; |
35e8bb51 | 851 | struct gpio_chip *chip; |
d2876d08 | 852 | |
3d599d1c UKK |
853 | might_sleep(); |
854 | ||
372e722e | 855 | gpiod_unexport(desc); |
d8f388d8 | 856 | |
d2876d08 DB |
857 | spin_lock_irqsave(&gpio_lock, flags); |
858 | ||
35e8bb51 DB |
859 | chip = desc->chip; |
860 | if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) { | |
861 | if (chip->free) { | |
862 | spin_unlock_irqrestore(&gpio_lock, flags); | |
9c4ba946 | 863 | might_sleep_if(chip->can_sleep); |
372e722e | 864 | chip->free(chip, gpio_chip_hwgpio(desc)); |
35e8bb51 DB |
865 | spin_lock_irqsave(&gpio_lock, flags); |
866 | } | |
d2876d08 | 867 | desc_set_label(desc, NULL); |
07697461 | 868 | clear_bit(FLAG_ACTIVE_LOW, &desc->flags); |
35e8bb51 | 869 | clear_bit(FLAG_REQUESTED, &desc->flags); |
aca5ce14 | 870 | clear_bit(FLAG_OPEN_DRAIN, &desc->flags); |
25553ff0 | 871 | clear_bit(FLAG_OPEN_SOURCE, &desc->flags); |
77c2d792 MW |
872 | ret = true; |
873 | } | |
d2876d08 DB |
874 | |
875 | spin_unlock_irqrestore(&gpio_lock, flags); | |
77c2d792 MW |
876 | return ret; |
877 | } | |
878 | ||
0eb4c6c2 | 879 | void gpiod_free(struct gpio_desc *desc) |
77c2d792 MW |
880 | { |
881 | if (desc && __gpiod_free(desc)) | |
882 | module_put(desc->chip->owner); | |
883 | else | |
884 | WARN_ON(extra_checks); | |
d2876d08 | 885 | } |
372e722e | 886 | |
d2876d08 DB |
887 | /** |
888 | * gpiochip_is_requested - return string iff signal was requested | |
889 | * @chip: controller managing the signal | |
890 | * @offset: of signal within controller's 0..(ngpio - 1) range | |
891 | * | |
892 | * Returns NULL if the GPIO is not currently requested, else a string. | |
9c8318ff AC |
893 | * The string returned is the label passed to gpio_request(); if none has been |
894 | * passed it is a meaningless, non-NULL constant. | |
d2876d08 DB |
895 | * |
896 | * This function is for use by GPIO controller drivers. The label can | |
897 | * help with diagnostics, and knowing that the signal is used as a GPIO | |
898 | * can help avoid accidentally multiplexing it to another controller. | |
899 | */ | |
900 | const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset) | |
901 | { | |
6c0b4e6c | 902 | struct gpio_desc *desc; |
d2876d08 | 903 | |
6c0b4e6c | 904 | if (!GPIO_OFFSET_VALID(chip, offset)) |
d2876d08 | 905 | return NULL; |
6c0b4e6c AC |
906 | |
907 | desc = &chip->desc[offset]; | |
908 | ||
372e722e | 909 | if (test_bit(FLAG_REQUESTED, &desc->flags) == 0) |
d2876d08 | 910 | return NULL; |
372e722e | 911 | return desc->label; |
d2876d08 DB |
912 | } |
913 | EXPORT_SYMBOL_GPL(gpiochip_is_requested); | |
914 | ||
77c2d792 MW |
915 | /** |
916 | * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor | |
917 | * @desc: GPIO descriptor to request | |
918 | * @label: label for the GPIO | |
919 | * | |
920 | * Function allows GPIO chip drivers to request and use their own GPIO | |
921 | * descriptors via gpiolib API. Difference to gpiod_request() is that this | |
922 | * function will not increase reference count of the GPIO chip module. This | |
923 | * allows the GPIO chip module to be unloaded as needed (we assume that the | |
924 | * GPIO chip driver handles freeing the GPIOs it has requested). | |
925 | */ | |
926 | int gpiochip_request_own_desc(struct gpio_desc *desc, const char *label) | |
927 | { | |
928 | if (!desc || !desc->chip) | |
929 | return -EINVAL; | |
930 | ||
931 | return __gpiod_request(desc, label); | |
932 | } | |
933 | ||
934 | /** | |
935 | * gpiochip_free_own_desc - Free GPIO requested by the chip driver | |
936 | * @desc: GPIO descriptor to free | |
937 | * | |
938 | * Function frees the given GPIO requested previously with | |
939 | * gpiochip_request_own_desc(). | |
940 | */ | |
941 | void gpiochip_free_own_desc(struct gpio_desc *desc) | |
942 | { | |
943 | if (desc) | |
944 | __gpiod_free(desc); | |
945 | } | |
d2876d08 DB |
946 | |
947 | /* Drivers MUST set GPIO direction before making get/set calls. In | |
948 | * some cases this is done in early boot, before IRQs are enabled. | |
949 | * | |
950 | * As a rule these aren't called more than once (except for drivers | |
951 | * using the open-drain emulation idiom) so these are natural places | |
952 | * to accumulate extra debugging checks. Note that we can't (yet) | |
953 | * rely on gpio_request() having been called beforehand. | |
954 | */ | |
955 | ||
79a9becd AC |
956 | /** |
957 | * gpiod_direction_input - set the GPIO direction to input | |
958 | * @desc: GPIO to set to input | |
959 | * | |
960 | * Set the direction of the passed GPIO to input, such as gpiod_get_value() can | |
961 | * be called safely on it. | |
962 | * | |
963 | * Return 0 in case of success, else an error code. | |
964 | */ | |
965 | int gpiod_direction_input(struct gpio_desc *desc) | |
d2876d08 DB |
966 | { |
967 | unsigned long flags; | |
968 | struct gpio_chip *chip; | |
d2876d08 | 969 | int status = -EINVAL; |
372e722e | 970 | int offset; |
d2876d08 | 971 | |
be1a4b13 | 972 | if (!desc || !desc->chip) { |
bcabdef1 AC |
973 | pr_warn("%s: invalid GPIO\n", __func__); |
974 | return -EINVAL; | |
975 | } | |
976 | ||
be1a4b13 LW |
977 | chip = desc->chip; |
978 | if (!chip->get || !chip->direction_input) { | |
6424de5a MB |
979 | gpiod_warn(desc, |
980 | "%s: missing get() or direction_input() operations\n", | |
7589e59f | 981 | __func__); |
be1a4b13 LW |
982 | return -EIO; |
983 | } | |
984 | ||
d2876d08 DB |
985 | spin_lock_irqsave(&gpio_lock, flags); |
986 | ||
372e722e | 987 | status = gpio_ensure_requested(desc); |
35e8bb51 DB |
988 | if (status < 0) |
989 | goto fail; | |
d2876d08 DB |
990 | |
991 | /* now we know the gpio is valid and chip won't vanish */ | |
992 | ||
993 | spin_unlock_irqrestore(&gpio_lock, flags); | |
994 | ||
9c4ba946 | 995 | might_sleep_if(chip->can_sleep); |
d2876d08 | 996 | |
372e722e | 997 | offset = gpio_chip_hwgpio(desc); |
35e8bb51 | 998 | if (status) { |
372e722e | 999 | status = chip->request(chip, offset); |
35e8bb51 | 1000 | if (status < 0) { |
7589e59f AS |
1001 | gpiod_dbg(desc, "%s: chip request fail, %d\n", |
1002 | __func__, status); | |
35e8bb51 DB |
1003 | /* and it's not available to anyone else ... |
1004 | * gpio_request() is the fully clean solution. | |
1005 | */ | |
1006 | goto lose; | |
1007 | } | |
1008 | } | |
1009 | ||
372e722e | 1010 | status = chip->direction_input(chip, offset); |
d2876d08 DB |
1011 | if (status == 0) |
1012 | clear_bit(FLAG_IS_OUT, &desc->flags); | |
3f397c21 | 1013 | |
372e722e | 1014 | trace_gpio_direction(desc_to_gpio(desc), 1, status); |
35e8bb51 | 1015 | lose: |
d2876d08 DB |
1016 | return status; |
1017 | fail: | |
1018 | spin_unlock_irqrestore(&gpio_lock, flags); | |
bcabdef1 | 1019 | if (status) |
7589e59f | 1020 | gpiod_dbg(desc, "%s: status %d\n", __func__, status); |
d2876d08 DB |
1021 | return status; |
1022 | } | |
79a9becd | 1023 | EXPORT_SYMBOL_GPL(gpiod_direction_input); |
372e722e | 1024 | |
ef70bbe1 | 1025 | static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value) |
d2876d08 DB |
1026 | { |
1027 | unsigned long flags; | |
1028 | struct gpio_chip *chip; | |
d2876d08 | 1029 | int status = -EINVAL; |
372e722e | 1030 | int offset; |
d2876d08 | 1031 | |
d468bf9e LW |
1032 | /* GPIOs used for IRQs shall not be set as output */ |
1033 | if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) { | |
1034 | gpiod_err(desc, | |
1035 | "%s: tried to set a GPIO tied to an IRQ as output\n", | |
1036 | __func__); | |
1037 | return -EIO; | |
1038 | } | |
1039 | ||
aca5ce14 LD |
1040 | /* Open drain pin should not be driven to 1 */ |
1041 | if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags)) | |
372e722e | 1042 | return gpiod_direction_input(desc); |
aca5ce14 | 1043 | |
25553ff0 LD |
1044 | /* Open source pin should not be driven to 0 */ |
1045 | if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags)) | |
372e722e | 1046 | return gpiod_direction_input(desc); |
25553ff0 | 1047 | |
be1a4b13 LW |
1048 | chip = desc->chip; |
1049 | if (!chip->set || !chip->direction_output) { | |
6424de5a MB |
1050 | gpiod_warn(desc, |
1051 | "%s: missing set() or direction_output() operations\n", | |
1052 | __func__); | |
be1a4b13 LW |
1053 | return -EIO; |
1054 | } | |
1055 | ||
d2876d08 DB |
1056 | spin_lock_irqsave(&gpio_lock, flags); |
1057 | ||
372e722e | 1058 | status = gpio_ensure_requested(desc); |
35e8bb51 DB |
1059 | if (status < 0) |
1060 | goto fail; | |
d2876d08 DB |
1061 | |
1062 | /* now we know the gpio is valid and chip won't vanish */ | |
1063 | ||
1064 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1065 | ||
9c4ba946 | 1066 | might_sleep_if(chip->can_sleep); |
d2876d08 | 1067 | |
372e722e | 1068 | offset = gpio_chip_hwgpio(desc); |
35e8bb51 | 1069 | if (status) { |
372e722e | 1070 | status = chip->request(chip, offset); |
35e8bb51 | 1071 | if (status < 0) { |
7589e59f AS |
1072 | gpiod_dbg(desc, "%s: chip request fail, %d\n", |
1073 | __func__, status); | |
35e8bb51 DB |
1074 | /* and it's not available to anyone else ... |
1075 | * gpio_request() is the fully clean solution. | |
1076 | */ | |
1077 | goto lose; | |
1078 | } | |
1079 | } | |
1080 | ||
372e722e | 1081 | status = chip->direction_output(chip, offset, value); |
d2876d08 DB |
1082 | if (status == 0) |
1083 | set_bit(FLAG_IS_OUT, &desc->flags); | |
372e722e AC |
1084 | trace_gpio_value(desc_to_gpio(desc), 0, value); |
1085 | trace_gpio_direction(desc_to_gpio(desc), 0, status); | |
35e8bb51 | 1086 | lose: |
d2876d08 DB |
1087 | return status; |
1088 | fail: | |
1089 | spin_unlock_irqrestore(&gpio_lock, flags); | |
bcabdef1 | 1090 | if (status) |
6424de5a | 1091 | gpiod_dbg(desc, "%s: gpio status %d\n", __func__, status); |
d2876d08 DB |
1092 | return status; |
1093 | } | |
ef70bbe1 PZ |
1094 | |
1095 | /** | |
1096 | * gpiod_direction_output_raw - set the GPIO direction to output | |
1097 | * @desc: GPIO to set to output | |
1098 | * @value: initial output value of the GPIO | |
1099 | * | |
1100 | * Set the direction of the passed GPIO to output, such as gpiod_set_value() can | |
1101 | * be called safely on it. The initial value of the output must be specified | |
1102 | * as raw value on the physical line without regard for the ACTIVE_LOW status. | |
1103 | * | |
1104 | * Return 0 in case of success, else an error code. | |
1105 | */ | |
1106 | int gpiod_direction_output_raw(struct gpio_desc *desc, int value) | |
1107 | { | |
1108 | if (!desc || !desc->chip) { | |
1109 | pr_warn("%s: invalid GPIO\n", __func__); | |
1110 | return -EINVAL; | |
1111 | } | |
1112 | return _gpiod_direction_output_raw(desc, value); | |
1113 | } | |
1114 | EXPORT_SYMBOL_GPL(gpiod_direction_output_raw); | |
1115 | ||
1116 | /** | |
90df4fe0 | 1117 | * gpiod_direction_output - set the GPIO direction to output |
ef70bbe1 PZ |
1118 | * @desc: GPIO to set to output |
1119 | * @value: initial output value of the GPIO | |
1120 | * | |
1121 | * Set the direction of the passed GPIO to output, such as gpiod_set_value() can | |
1122 | * be called safely on it. The initial value of the output must be specified | |
1123 | * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into | |
1124 | * account. | |
1125 | * | |
1126 | * Return 0 in case of success, else an error code. | |
1127 | */ | |
1128 | int gpiod_direction_output(struct gpio_desc *desc, int value) | |
1129 | { | |
1130 | if (!desc || !desc->chip) { | |
1131 | pr_warn("%s: invalid GPIO\n", __func__); | |
1132 | return -EINVAL; | |
1133 | } | |
1134 | if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) | |
1135 | value = !value; | |
1136 | return _gpiod_direction_output_raw(desc, value); | |
1137 | } | |
79a9becd | 1138 | EXPORT_SYMBOL_GPL(gpiod_direction_output); |
d2876d08 | 1139 | |
c4b5be98 | 1140 | /** |
79a9becd | 1141 | * gpiod_set_debounce - sets @debounce time for a @gpio |
c4b5be98 FB |
1142 | * @gpio: the gpio to set debounce time |
1143 | * @debounce: debounce time is microseconds | |
65d87656 LW |
1144 | * |
1145 | * returns -ENOTSUPP if the controller does not support setting | |
1146 | * debounce. | |
c4b5be98 | 1147 | */ |
79a9becd | 1148 | int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) |
c4b5be98 FB |
1149 | { |
1150 | unsigned long flags; | |
1151 | struct gpio_chip *chip; | |
c4b5be98 | 1152 | int status = -EINVAL; |
372e722e | 1153 | int offset; |
c4b5be98 | 1154 | |
be1a4b13 | 1155 | if (!desc || !desc->chip) { |
bcabdef1 AC |
1156 | pr_warn("%s: invalid GPIO\n", __func__); |
1157 | return -EINVAL; | |
1158 | } | |
1159 | ||
c4b5be98 | 1160 | chip = desc->chip; |
be1a4b13 | 1161 | if (!chip->set || !chip->set_debounce) { |
6424de5a MB |
1162 | gpiod_dbg(desc, |
1163 | "%s: missing set() or set_debounce() operations\n", | |
1164 | __func__); | |
65d87656 | 1165 | return -ENOTSUPP; |
be1a4b13 LW |
1166 | } |
1167 | ||
1168 | spin_lock_irqsave(&gpio_lock, flags); | |
372e722e AC |
1169 | |
1170 | status = gpio_ensure_requested(desc); | |
c4b5be98 FB |
1171 | if (status < 0) |
1172 | goto fail; | |
1173 | ||
1174 | /* now we know the gpio is valid and chip won't vanish */ | |
1175 | ||
1176 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1177 | ||
9c4ba946 | 1178 | might_sleep_if(chip->can_sleep); |
c4b5be98 | 1179 | |
372e722e AC |
1180 | offset = gpio_chip_hwgpio(desc); |
1181 | return chip->set_debounce(chip, offset, debounce); | |
c4b5be98 FB |
1182 | |
1183 | fail: | |
1184 | spin_unlock_irqrestore(&gpio_lock, flags); | |
bcabdef1 | 1185 | if (status) |
6424de5a | 1186 | gpiod_dbg(desc, "%s: status %d\n", __func__, status); |
c4b5be98 FB |
1187 | |
1188 | return status; | |
1189 | } | |
79a9becd | 1190 | EXPORT_SYMBOL_GPL(gpiod_set_debounce); |
372e722e | 1191 | |
79a9becd AC |
1192 | /** |
1193 | * gpiod_is_active_low - test whether a GPIO is active-low or not | |
1194 | * @desc: the gpio descriptor to test | |
1195 | * | |
1196 | * Returns 1 if the GPIO is active-low, 0 otherwise. | |
1197 | */ | |
1198 | int gpiod_is_active_low(const struct gpio_desc *desc) | |
372e722e | 1199 | { |
79a9becd | 1200 | return test_bit(FLAG_ACTIVE_LOW, &desc->flags); |
372e722e | 1201 | } |
79a9becd | 1202 | EXPORT_SYMBOL_GPL(gpiod_is_active_low); |
d2876d08 DB |
1203 | |
1204 | /* I/O calls are only valid after configuration completed; the relevant | |
1205 | * "is this a valid GPIO" error checks should already have been done. | |
1206 | * | |
1207 | * "Get" operations are often inlinable as reading a pin value register, | |
1208 | * and masking the relevant bit in that register. | |
1209 | * | |
1210 | * When "set" operations are inlinable, they involve writing that mask to | |
1211 | * one register to set a low value, or a different register to set it high. | |
1212 | * Otherwise locking is needed, so there may be little value to inlining. | |
1213 | * | |
1214 | *------------------------------------------------------------------------ | |
1215 | * | |
1216 | * IMPORTANT!!! The hot paths -- get/set value -- assume that callers | |
1217 | * have requested the GPIO. That can include implicit requesting by | |
1218 | * a direction setting call. Marking a gpio as requested locks its chip | |
1219 | * in memory, guaranteeing that these table lookups need no more locking | |
1220 | * and that gpiochip_remove() will fail. | |
1221 | * | |
1222 | * REVISIT when debugging, consider adding some instrumentation to ensure | |
1223 | * that the GPIO was actually requested. | |
1224 | */ | |
1225 | ||
23600969 | 1226 | static bool _gpiod_get_raw_value(const struct gpio_desc *desc) |
d2876d08 DB |
1227 | { |
1228 | struct gpio_chip *chip; | |
23600969 | 1229 | bool value; |
372e722e | 1230 | int offset; |
d2876d08 | 1231 | |
372e722e AC |
1232 | chip = desc->chip; |
1233 | offset = gpio_chip_hwgpio(desc); | |
23600969 | 1234 | value = chip->get ? chip->get(chip, offset) : false; |
372e722e | 1235 | trace_gpio_value(desc_to_gpio(desc), 1, value); |
3f397c21 | 1236 | return value; |
d2876d08 | 1237 | } |
372e722e | 1238 | |
d2876d08 | 1239 | /** |
79a9becd AC |
1240 | * gpiod_get_raw_value() - return a gpio's raw value |
1241 | * @desc: gpio whose value will be returned | |
d2876d08 | 1242 | * |
79a9becd AC |
1243 | * Return the GPIO's raw value, i.e. the value of the physical line disregarding |
1244 | * its ACTIVE_LOW status. | |
1245 | * | |
1246 | * This function should be called from contexts where we cannot sleep, and will | |
1247 | * complain if the GPIO chip functions potentially sleep. | |
d2876d08 | 1248 | */ |
79a9becd | 1249 | int gpiod_get_raw_value(const struct gpio_desc *desc) |
d2876d08 | 1250 | { |
bcabdef1 AC |
1251 | if (!desc) |
1252 | return 0; | |
e4e449e8 | 1253 | /* Should be using gpio_get_value_cansleep() */ |
d8e0ac08 | 1254 | WARN_ON(desc->chip->can_sleep); |
79a9becd | 1255 | return _gpiod_get_raw_value(desc); |
d2876d08 | 1256 | } |
79a9becd | 1257 | EXPORT_SYMBOL_GPL(gpiod_get_raw_value); |
372e722e | 1258 | |
79a9becd AC |
1259 | /** |
1260 | * gpiod_get_value() - return a gpio's value | |
1261 | * @desc: gpio whose value will be returned | |
1262 | * | |
1263 | * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into | |
1264 | * account. | |
1265 | * | |
1266 | * This function should be called from contexts where we cannot sleep, and will | |
1267 | * complain if the GPIO chip functions potentially sleep. | |
1268 | */ | |
1269 | int gpiod_get_value(const struct gpio_desc *desc) | |
372e722e | 1270 | { |
79a9becd AC |
1271 | int value; |
1272 | if (!desc) | |
1273 | return 0; | |
1274 | /* Should be using gpio_get_value_cansleep() */ | |
1275 | WARN_ON(desc->chip->can_sleep); | |
1276 | ||
1277 | value = _gpiod_get_raw_value(desc); | |
1278 | if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) | |
1279 | value = !value; | |
1280 | ||
1281 | return value; | |
372e722e | 1282 | } |
79a9becd | 1283 | EXPORT_SYMBOL_GPL(gpiod_get_value); |
d2876d08 | 1284 | |
aca5ce14 LD |
1285 | /* |
1286 | * _gpio_set_open_drain_value() - Set the open drain gpio's value. | |
79a9becd | 1287 | * @desc: gpio descriptor whose state need to be set. |
aca5ce14 LD |
1288 | * @value: Non-zero for setting it HIGH otherise it will set to LOW. |
1289 | */ | |
23600969 | 1290 | static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value) |
aca5ce14 LD |
1291 | { |
1292 | int err = 0; | |
372e722e AC |
1293 | struct gpio_chip *chip = desc->chip; |
1294 | int offset = gpio_chip_hwgpio(desc); | |
1295 | ||
aca5ce14 | 1296 | if (value) { |
372e722e | 1297 | err = chip->direction_input(chip, offset); |
aca5ce14 | 1298 | if (!err) |
372e722e | 1299 | clear_bit(FLAG_IS_OUT, &desc->flags); |
aca5ce14 | 1300 | } else { |
372e722e | 1301 | err = chip->direction_output(chip, offset, 0); |
aca5ce14 | 1302 | if (!err) |
372e722e | 1303 | set_bit(FLAG_IS_OUT, &desc->flags); |
aca5ce14 | 1304 | } |
372e722e | 1305 | trace_gpio_direction(desc_to_gpio(desc), value, err); |
aca5ce14 | 1306 | if (err < 0) |
6424de5a MB |
1307 | gpiod_err(desc, |
1308 | "%s: Error in set_value for open drain err %d\n", | |
1309 | __func__, err); | |
aca5ce14 LD |
1310 | } |
1311 | ||
25553ff0 | 1312 | /* |
79a9becd AC |
1313 | * _gpio_set_open_source_value() - Set the open source gpio's value. |
1314 | * @desc: gpio descriptor whose state need to be set. | |
25553ff0 LD |
1315 | * @value: Non-zero for setting it HIGH otherise it will set to LOW. |
1316 | */ | |
23600969 | 1317 | static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value) |
25553ff0 LD |
1318 | { |
1319 | int err = 0; | |
372e722e AC |
1320 | struct gpio_chip *chip = desc->chip; |
1321 | int offset = gpio_chip_hwgpio(desc); | |
1322 | ||
25553ff0 | 1323 | if (value) { |
372e722e | 1324 | err = chip->direction_output(chip, offset, 1); |
25553ff0 | 1325 | if (!err) |
372e722e | 1326 | set_bit(FLAG_IS_OUT, &desc->flags); |
25553ff0 | 1327 | } else { |
372e722e | 1328 | err = chip->direction_input(chip, offset); |
25553ff0 | 1329 | if (!err) |
372e722e | 1330 | clear_bit(FLAG_IS_OUT, &desc->flags); |
25553ff0 | 1331 | } |
372e722e | 1332 | trace_gpio_direction(desc_to_gpio(desc), !value, err); |
25553ff0 | 1333 | if (err < 0) |
6424de5a MB |
1334 | gpiod_err(desc, |
1335 | "%s: Error in set_value for open source err %d\n", | |
1336 | __func__, err); | |
25553ff0 LD |
1337 | } |
1338 | ||
23600969 | 1339 | static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value) |
d2876d08 DB |
1340 | { |
1341 | struct gpio_chip *chip; | |
1342 | ||
372e722e | 1343 | chip = desc->chip; |
372e722e AC |
1344 | trace_gpio_value(desc_to_gpio(desc), 0, value); |
1345 | if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) | |
1346 | _gpio_set_open_drain_value(desc, value); | |
1347 | else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) | |
1348 | _gpio_set_open_source_value(desc, value); | |
aca5ce14 | 1349 | else |
372e722e AC |
1350 | chip->set(chip, gpio_chip_hwgpio(desc), value); |
1351 | } | |
1352 | ||
d2876d08 | 1353 | /** |
79a9becd AC |
1354 | * gpiod_set_raw_value() - assign a gpio's raw value |
1355 | * @desc: gpio whose value will be assigned | |
d2876d08 | 1356 | * @value: value to assign |
d2876d08 | 1357 | * |
79a9becd AC |
1358 | * Set the raw value of the GPIO, i.e. the value of its physical line without |
1359 | * regard for its ACTIVE_LOW status. | |
1360 | * | |
1361 | * This function should be called from contexts where we cannot sleep, and will | |
1362 | * complain if the GPIO chip functions potentially sleep. | |
d2876d08 | 1363 | */ |
79a9becd | 1364 | void gpiod_set_raw_value(struct gpio_desc *desc, int value) |
372e722e | 1365 | { |
bcabdef1 AC |
1366 | if (!desc) |
1367 | return; | |
e4e449e8 | 1368 | /* Should be using gpio_set_value_cansleep() */ |
d8e0ac08 | 1369 | WARN_ON(desc->chip->can_sleep); |
79a9becd | 1370 | _gpiod_set_raw_value(desc, value); |
d2876d08 | 1371 | } |
79a9becd | 1372 | EXPORT_SYMBOL_GPL(gpiod_set_raw_value); |
d2876d08 DB |
1373 | |
1374 | /** | |
79a9becd AC |
1375 | * gpiod_set_value() - assign a gpio's value |
1376 | * @desc: gpio whose value will be assigned | |
1377 | * @value: value to assign | |
1378 | * | |
1379 | * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into | |
1380 | * account | |
d2876d08 | 1381 | * |
79a9becd AC |
1382 | * This function should be called from contexts where we cannot sleep, and will |
1383 | * complain if the GPIO chip functions potentially sleep. | |
d2876d08 | 1384 | */ |
79a9becd | 1385 | void gpiod_set_value(struct gpio_desc *desc, int value) |
d2876d08 | 1386 | { |
bcabdef1 | 1387 | if (!desc) |
79a9becd AC |
1388 | return; |
1389 | /* Should be using gpio_set_value_cansleep() */ | |
1390 | WARN_ON(desc->chip->can_sleep); | |
1391 | if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) | |
1392 | value = !value; | |
1393 | _gpiod_set_raw_value(desc, value); | |
372e722e | 1394 | } |
79a9becd | 1395 | EXPORT_SYMBOL_GPL(gpiod_set_value); |
d2876d08 | 1396 | |
d2876d08 | 1397 | /** |
79a9becd AC |
1398 | * gpiod_cansleep() - report whether gpio value access may sleep |
1399 | * @desc: gpio to check | |
d2876d08 | 1400 | * |
d2876d08 | 1401 | */ |
79a9becd | 1402 | int gpiod_cansleep(const struct gpio_desc *desc) |
372e722e | 1403 | { |
bcabdef1 AC |
1404 | if (!desc) |
1405 | return 0; | |
372e722e | 1406 | return desc->chip->can_sleep; |
d2876d08 | 1407 | } |
79a9becd | 1408 | EXPORT_SYMBOL_GPL(gpiod_cansleep); |
d2876d08 | 1409 | |
0f6d504e | 1410 | /** |
79a9becd AC |
1411 | * gpiod_to_irq() - return the IRQ corresponding to a GPIO |
1412 | * @desc: gpio whose IRQ will be returned (already requested) | |
0f6d504e | 1413 | * |
79a9becd AC |
1414 | * Return the IRQ corresponding to the passed GPIO, or an error code in case of |
1415 | * error. | |
0f6d504e | 1416 | */ |
79a9becd | 1417 | int gpiod_to_irq(const struct gpio_desc *desc) |
0f6d504e DB |
1418 | { |
1419 | struct gpio_chip *chip; | |
372e722e | 1420 | int offset; |
0f6d504e | 1421 | |
bcabdef1 AC |
1422 | if (!desc) |
1423 | return -EINVAL; | |
372e722e AC |
1424 | chip = desc->chip; |
1425 | offset = gpio_chip_hwgpio(desc); | |
1426 | return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO; | |
0f6d504e | 1427 | } |
79a9becd | 1428 | EXPORT_SYMBOL_GPL(gpiod_to_irq); |
0f6d504e | 1429 | |
d468bf9e LW |
1430 | /** |
1431 | * gpiod_lock_as_irq() - lock a GPIO to be used as IRQ | |
1432 | * @gpio: the GPIO line to lock as used for IRQ | |
1433 | * | |
1434 | * This is used directly by GPIO drivers that want to lock down | |
f438acdf | 1435 | * a certain GPIO line to be used for IRQs. |
d468bf9e | 1436 | */ |
79a9becd | 1437 | int gpiod_lock_as_irq(struct gpio_desc *desc) |
372e722e | 1438 | { |
d468bf9e LW |
1439 | if (!desc) |
1440 | return -EINVAL; | |
1441 | ||
1442 | if (test_bit(FLAG_IS_OUT, &desc->flags)) { | |
1443 | gpiod_err(desc, | |
1444 | "%s: tried to flag a GPIO set as output for IRQ\n", | |
1445 | __func__); | |
1446 | return -EIO; | |
1447 | } | |
1448 | ||
1449 | set_bit(FLAG_USED_AS_IRQ, &desc->flags); | |
1450 | return 0; | |
372e722e | 1451 | } |
79a9becd | 1452 | EXPORT_SYMBOL_GPL(gpiod_lock_as_irq); |
d2876d08 | 1453 | |
d468bf9e LW |
1454 | /** |
1455 | * gpiod_unlock_as_irq() - unlock a GPIO used as IRQ | |
1456 | * @gpio: the GPIO line to unlock from IRQ usage | |
1457 | * | |
1458 | * This is used directly by GPIO drivers that want to indicate | |
1459 | * that a certain GPIO is no longer used exclusively for IRQ. | |
d2876d08 | 1460 | */ |
79a9becd | 1461 | void gpiod_unlock_as_irq(struct gpio_desc *desc) |
d468bf9e LW |
1462 | { |
1463 | if (!desc) | |
1464 | return; | |
d2876d08 | 1465 | |
d468bf9e LW |
1466 | clear_bit(FLAG_USED_AS_IRQ, &desc->flags); |
1467 | } | |
79a9becd | 1468 | EXPORT_SYMBOL_GPL(gpiod_unlock_as_irq); |
d468bf9e | 1469 | |
79a9becd AC |
1470 | /** |
1471 | * gpiod_get_raw_value_cansleep() - return a gpio's raw value | |
1472 | * @desc: gpio whose value will be returned | |
1473 | * | |
1474 | * Return the GPIO's raw value, i.e. the value of the physical line disregarding | |
1475 | * its ACTIVE_LOW status. | |
1476 | * | |
1477 | * This function is to be called from contexts that can sleep. | |
d2876d08 | 1478 | */ |
79a9becd | 1479 | int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc) |
d2876d08 | 1480 | { |
d2876d08 | 1481 | might_sleep_if(extra_checks); |
bcabdef1 AC |
1482 | if (!desc) |
1483 | return 0; | |
79a9becd | 1484 | return _gpiod_get_raw_value(desc); |
d2876d08 | 1485 | } |
79a9becd | 1486 | EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep); |
372e722e | 1487 | |
79a9becd AC |
1488 | /** |
1489 | * gpiod_get_value_cansleep() - return a gpio's value | |
1490 | * @desc: gpio whose value will be returned | |
1491 | * | |
1492 | * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into | |
1493 | * account. | |
1494 | * | |
1495 | * This function is to be called from contexts that can sleep. | |
1496 | */ | |
1497 | int gpiod_get_value_cansleep(const struct gpio_desc *desc) | |
d2876d08 | 1498 | { |
3f397c21 | 1499 | int value; |
d2876d08 DB |
1500 | |
1501 | might_sleep_if(extra_checks); | |
bcabdef1 AC |
1502 | if (!desc) |
1503 | return 0; | |
79a9becd AC |
1504 | |
1505 | value = _gpiod_get_raw_value(desc); | |
1506 | if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) | |
1507 | value = !value; | |
1508 | ||
3f397c21 | 1509 | return value; |
d2876d08 | 1510 | } |
79a9becd | 1511 | EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep); |
372e722e | 1512 | |
79a9becd AC |
1513 | /** |
1514 | * gpiod_set_raw_value_cansleep() - assign a gpio's raw value | |
1515 | * @desc: gpio whose value will be assigned | |
1516 | * @value: value to assign | |
1517 | * | |
1518 | * Set the raw value of the GPIO, i.e. the value of its physical line without | |
1519 | * regard for its ACTIVE_LOW status. | |
1520 | * | |
1521 | * This function is to be called from contexts that can sleep. | |
1522 | */ | |
1523 | void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value) | |
372e722e | 1524 | { |
d2876d08 | 1525 | might_sleep_if(extra_checks); |
bcabdef1 AC |
1526 | if (!desc) |
1527 | return; | |
79a9becd | 1528 | _gpiod_set_raw_value(desc, value); |
372e722e | 1529 | } |
79a9becd | 1530 | EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep); |
d2876d08 | 1531 | |
79a9becd AC |
1532 | /** |
1533 | * gpiod_set_value_cansleep() - assign a gpio's value | |
1534 | * @desc: gpio whose value will be assigned | |
1535 | * @value: value to assign | |
1536 | * | |
1537 | * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into | |
1538 | * account | |
1539 | * | |
1540 | * This function is to be called from contexts that can sleep. | |
1541 | */ | |
1542 | void gpiod_set_value_cansleep(struct gpio_desc *desc, int value) | |
d2876d08 | 1543 | { |
d2876d08 | 1544 | might_sleep_if(extra_checks); |
bcabdef1 AC |
1545 | if (!desc) |
1546 | return; | |
79a9becd AC |
1547 | |
1548 | if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) | |
1549 | value = !value; | |
1550 | _gpiod_set_raw_value(desc, value); | |
372e722e | 1551 | } |
79a9becd | 1552 | EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep); |
d2876d08 | 1553 | |
bae48da2 | 1554 | /** |
ad824783 AC |
1555 | * gpiod_add_lookup_table() - register GPIO device consumers |
1556 | * @table: table of consumers to register | |
bae48da2 | 1557 | */ |
ad824783 | 1558 | void gpiod_add_lookup_table(struct gpiod_lookup_table *table) |
bae48da2 AC |
1559 | { |
1560 | mutex_lock(&gpio_lookup_lock); | |
1561 | ||
ad824783 | 1562 | list_add_tail(&table->list, &gpio_lookup_list); |
bae48da2 AC |
1563 | |
1564 | mutex_unlock(&gpio_lookup_lock); | |
1565 | } | |
1566 | ||
bae48da2 | 1567 | static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, |
53e7cac3 AC |
1568 | unsigned int idx, |
1569 | enum gpio_lookup_flags *flags) | |
bae48da2 | 1570 | { |
dd34c37a | 1571 | static const char *suffixes[] = { "gpios", "gpio" }; |
bae48da2 AC |
1572 | char prop_name[32]; /* 32 is max size of property name */ |
1573 | enum of_gpio_flags of_flags; | |
1574 | struct gpio_desc *desc; | |
dd34c37a | 1575 | unsigned int i; |
bae48da2 | 1576 | |
dd34c37a TR |
1577 | for (i = 0; i < ARRAY_SIZE(suffixes); i++) { |
1578 | if (con_id) | |
1579 | snprintf(prop_name, 32, "%s-%s", con_id, suffixes[i]); | |
1580 | else | |
1581 | snprintf(prop_name, 32, "%s", suffixes[i]); | |
bae48da2 | 1582 | |
dd34c37a TR |
1583 | desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx, |
1584 | &of_flags); | |
06fc3b70 | 1585 | if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER)) |
dd34c37a TR |
1586 | break; |
1587 | } | |
bae48da2 AC |
1588 | |
1589 | if (IS_ERR(desc)) | |
1590 | return desc; | |
1591 | ||
1592 | if (of_flags & OF_GPIO_ACTIVE_LOW) | |
53e7cac3 | 1593 | *flags |= GPIO_ACTIVE_LOW; |
bae48da2 AC |
1594 | |
1595 | return desc; | |
1596 | } | |
d2876d08 | 1597 | |
81f59e9d | 1598 | static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id, |
53e7cac3 AC |
1599 | unsigned int idx, |
1600 | enum gpio_lookup_flags *flags) | |
372e722e | 1601 | { |
e01f440a MW |
1602 | struct acpi_gpio_info info; |
1603 | struct gpio_desc *desc; | |
1604 | ||
1605 | desc = acpi_get_gpiod_by_index(dev, idx, &info); | |
1606 | if (IS_ERR(desc)) | |
1607 | return desc; | |
1608 | ||
1609 | if (info.gpioint && info.active_low) | |
53e7cac3 | 1610 | *flags |= GPIO_ACTIVE_LOW; |
e01f440a MW |
1611 | |
1612 | return desc; | |
81f59e9d MW |
1613 | } |
1614 | ||
ad824783 | 1615 | static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev) |
bae48da2 AC |
1616 | { |
1617 | const char *dev_id = dev ? dev_name(dev) : NULL; | |
ad824783 | 1618 | struct gpiod_lookup_table *table; |
bae48da2 AC |
1619 | |
1620 | mutex_lock(&gpio_lookup_lock); | |
1621 | ||
ad824783 AC |
1622 | list_for_each_entry(table, &gpio_lookup_list, list) { |
1623 | if (table->dev_id && dev_id) { | |
1624 | /* | |
1625 | * Valid strings on both ends, must be identical to have | |
1626 | * a match | |
1627 | */ | |
1628 | if (!strcmp(table->dev_id, dev_id)) | |
1629 | goto found; | |
1630 | } else { | |
1631 | /* | |
1632 | * One of the pointers is NULL, so both must be to have | |
1633 | * a match | |
1634 | */ | |
1635 | if (dev_id == table->dev_id) | |
1636 | goto found; | |
1637 | } | |
1638 | } | |
1639 | table = NULL; | |
bae48da2 | 1640 | |
ad824783 AC |
1641 | found: |
1642 | mutex_unlock(&gpio_lookup_lock); | |
1643 | return table; | |
1644 | } | |
bae48da2 | 1645 | |
ad824783 AC |
1646 | static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id, |
1647 | unsigned int idx, | |
1648 | enum gpio_lookup_flags *flags) | |
1649 | { | |
2a3cf6a3 | 1650 | struct gpio_desc *desc = ERR_PTR(-ENOENT); |
ad824783 AC |
1651 | struct gpiod_lookup_table *table; |
1652 | struct gpiod_lookup *p; | |
bae48da2 | 1653 | |
ad824783 AC |
1654 | table = gpiod_find_lookup_table(dev); |
1655 | if (!table) | |
1656 | return desc; | |
bae48da2 | 1657 | |
ad824783 AC |
1658 | for (p = &table->table[0]; p->chip_label; p++) { |
1659 | struct gpio_chip *chip; | |
bae48da2 | 1660 | |
ad824783 | 1661 | /* idx must always match exactly */ |
bae48da2 AC |
1662 | if (p->idx != idx) |
1663 | continue; | |
1664 | ||
ad824783 AC |
1665 | /* If the lookup entry has a con_id, require exact match */ |
1666 | if (p->con_id && (!con_id || strcmp(p->con_id, con_id))) | |
1667 | continue; | |
bae48da2 | 1668 | |
ad824783 | 1669 | chip = find_chip_by_name(p->chip_label); |
bae48da2 | 1670 | |
ad824783 | 1671 | if (!chip) { |
2a3cf6a3 AC |
1672 | dev_err(dev, "cannot find GPIO chip %s\n", |
1673 | p->chip_label); | |
1674 | return ERR_PTR(-ENODEV); | |
ad824783 | 1675 | } |
bae48da2 | 1676 | |
ad824783 | 1677 | if (chip->ngpio <= p->chip_hwnum) { |
2a3cf6a3 AC |
1678 | dev_err(dev, |
1679 | "requested GPIO %d is out of range [0..%d] for chip %s\n", | |
1680 | idx, chip->ngpio, chip->label); | |
1681 | return ERR_PTR(-EINVAL); | |
bae48da2 | 1682 | } |
bae48da2 | 1683 | |
bb1e88cc | 1684 | desc = gpiochip_get_desc(chip, p->chip_hwnum); |
ad824783 | 1685 | *flags = p->flags; |
bae48da2 | 1686 | |
2a3cf6a3 | 1687 | return desc; |
bae48da2 AC |
1688 | } |
1689 | ||
bae48da2 AC |
1690 | return desc; |
1691 | } | |
1692 | ||
1693 | /** | |
0879162f | 1694 | * gpiod_get - obtain a GPIO for a given GPIO function |
ad824783 | 1695 | * @dev: GPIO consumer, can be NULL for system-global GPIOs |
bae48da2 AC |
1696 | * @con_id: function within the GPIO consumer |
1697 | * | |
1698 | * Return the GPIO descriptor corresponding to the function con_id of device | |
2a3cf6a3 AC |
1699 | * dev, -ENOENT if no GPIO has been assigned to the requested function, or |
1700 | * another IS_ERR() code if an error occured while trying to acquire the GPIO. | |
bae48da2 AC |
1701 | */ |
1702 | struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id) | |
1703 | { | |
1704 | return gpiod_get_index(dev, con_id, 0); | |
1705 | } | |
1706 | EXPORT_SYMBOL_GPL(gpiod_get); | |
1707 | ||
29a1f233 TR |
1708 | /** |
1709 | * gpiod_get_optional - obtain an optional GPIO for a given GPIO function | |
1710 | * @dev: GPIO consumer, can be NULL for system-global GPIOs | |
1711 | * @con_id: function within the GPIO consumer | |
1712 | * | |
1713 | * This is equivalent to gpiod_get(), except that when no GPIO was assigned to | |
1714 | * the requested function it will return NULL. This is convenient for drivers | |
1715 | * that need to handle optional GPIOs. | |
1716 | */ | |
1717 | struct gpio_desc *__must_check gpiod_get_optional(struct device *dev, | |
1718 | const char *con_id) | |
1719 | { | |
1720 | return gpiod_get_index_optional(dev, con_id, 0); | |
1721 | } | |
1722 | EXPORT_SYMBOL_GPL(gpiod_get_optional); | |
1723 | ||
bae48da2 AC |
1724 | /** |
1725 | * gpiod_get_index - obtain a GPIO from a multi-index GPIO function | |
fdd6a5fe | 1726 | * @dev: GPIO consumer, can be NULL for system-global GPIOs |
bae48da2 AC |
1727 | * @con_id: function within the GPIO consumer |
1728 | * @idx: index of the GPIO to obtain in the consumer | |
1729 | * | |
1730 | * This variant of gpiod_get() allows to access GPIOs other than the first | |
1731 | * defined one for functions that define several GPIOs. | |
1732 | * | |
2a3cf6a3 AC |
1733 | * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the |
1734 | * requested function and/or index, or another IS_ERR() code if an error | |
1735 | * occured while trying to acquire the GPIO. | |
bae48da2 AC |
1736 | */ |
1737 | struct gpio_desc *__must_check gpiod_get_index(struct device *dev, | |
1738 | const char *con_id, | |
1739 | unsigned int idx) | |
1740 | { | |
35c5d7fd | 1741 | struct gpio_desc *desc = NULL; |
bae48da2 | 1742 | int status; |
53e7cac3 | 1743 | enum gpio_lookup_flags flags = 0; |
bae48da2 AC |
1744 | |
1745 | dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id); | |
1746 | ||
1747 | /* Using device tree? */ | |
1748 | if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) { | |
1749 | dev_dbg(dev, "using device tree for GPIO lookup\n"); | |
1750 | desc = of_find_gpio(dev, con_id, idx, &flags); | |
81f59e9d MW |
1751 | } else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev)) { |
1752 | dev_dbg(dev, "using ACPI for GPIO lookup\n"); | |
1753 | desc = acpi_find_gpio(dev, con_id, idx, &flags); | |
35c5d7fd AC |
1754 | } |
1755 | ||
1756 | /* | |
1757 | * Either we are not using DT or ACPI, or their lookup did not return | |
1758 | * a result. In that case, use platform lookup as a fallback. | |
1759 | */ | |
2a3cf6a3 | 1760 | if (!desc || desc == ERR_PTR(-ENOENT)) { |
bae48da2 | 1761 | dev_dbg(dev, "using lookup tables for GPIO lookup"); |
2a3cf6a3 | 1762 | desc = gpiod_find(dev, con_id, idx, &flags); |
bae48da2 AC |
1763 | } |
1764 | ||
1765 | if (IS_ERR(desc)) { | |
351cfe0f | 1766 | dev_dbg(dev, "lookup for GPIO %s failed\n", con_id); |
bae48da2 AC |
1767 | return desc; |
1768 | } | |
1769 | ||
1770 | status = gpiod_request(desc, con_id); | |
1771 | ||
1772 | if (status < 0) | |
1773 | return ERR_PTR(status); | |
1774 | ||
53e7cac3 | 1775 | if (flags & GPIO_ACTIVE_LOW) |
bae48da2 | 1776 | set_bit(FLAG_ACTIVE_LOW, &desc->flags); |
53e7cac3 AC |
1777 | if (flags & GPIO_OPEN_DRAIN) |
1778 | set_bit(FLAG_OPEN_DRAIN, &desc->flags); | |
1779 | if (flags & GPIO_OPEN_SOURCE) | |
1780 | set_bit(FLAG_OPEN_SOURCE, &desc->flags); | |
bae48da2 AC |
1781 | |
1782 | return desc; | |
1783 | } | |
1784 | EXPORT_SYMBOL_GPL(gpiod_get_index); | |
1785 | ||
29a1f233 TR |
1786 | /** |
1787 | * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO | |
1788 | * function | |
1789 | * @dev: GPIO consumer, can be NULL for system-global GPIOs | |
1790 | * @con_id: function within the GPIO consumer | |
1791 | * @index: index of the GPIO to obtain in the consumer | |
1792 | * | |
1793 | * This is equivalent to gpiod_get_index(), except that when no GPIO with the | |
1794 | * specified index was assigned to the requested function it will return NULL. | |
1795 | * This is convenient for drivers that need to handle optional GPIOs. | |
1796 | */ | |
1797 | struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev, | |
1798 | const char *con_id, | |
1799 | unsigned int index) | |
1800 | { | |
1801 | struct gpio_desc *desc; | |
1802 | ||
1803 | desc = gpiod_get_index(dev, con_id, index); | |
1804 | if (IS_ERR(desc)) { | |
1805 | if (PTR_ERR(desc) == -ENOENT) | |
1806 | return NULL; | |
1807 | } | |
1808 | ||
1809 | return desc; | |
1810 | } | |
1811 | EXPORT_SYMBOL_GPL(gpiod_get_index_optional); | |
1812 | ||
bae48da2 AC |
1813 | /** |
1814 | * gpiod_put - dispose of a GPIO descriptor | |
1815 | * @desc: GPIO descriptor to dispose of | |
1816 | * | |
1817 | * No descriptor can be used after gpiod_put() has been called on it. | |
1818 | */ | |
1819 | void gpiod_put(struct gpio_desc *desc) | |
1820 | { | |
1821 | gpiod_free(desc); | |
372e722e | 1822 | } |
bae48da2 | 1823 | EXPORT_SYMBOL_GPL(gpiod_put); |
d2876d08 DB |
1824 | |
1825 | #ifdef CONFIG_DEBUG_FS | |
1826 | ||
d2876d08 DB |
1827 | static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) |
1828 | { | |
1829 | unsigned i; | |
1830 | unsigned gpio = chip->base; | |
6c0b4e6c | 1831 | struct gpio_desc *gdesc = &chip->desc[0]; |
d2876d08 | 1832 | int is_out; |
d468bf9e | 1833 | int is_irq; |
d2876d08 DB |
1834 | |
1835 | for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) { | |
1836 | if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) | |
1837 | continue; | |
1838 | ||
372e722e | 1839 | gpiod_get_direction(gdesc); |
d2876d08 | 1840 | is_out = test_bit(FLAG_IS_OUT, &gdesc->flags); |
d468bf9e LW |
1841 | is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags); |
1842 | seq_printf(s, " gpio-%-3d (%-20.20s) %s %s %s", | |
d2876d08 DB |
1843 | gpio, gdesc->label, |
1844 | is_out ? "out" : "in ", | |
1845 | chip->get | |
1846 | ? (chip->get(chip, i) ? "hi" : "lo") | |
d468bf9e LW |
1847 | : "? ", |
1848 | is_irq ? "IRQ" : " "); | |
d2876d08 DB |
1849 | seq_printf(s, "\n"); |
1850 | } | |
1851 | } | |
1852 | ||
f9c4a31f | 1853 | static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos) |
d2876d08 | 1854 | { |
362432ae | 1855 | unsigned long flags; |
f9c4a31f | 1856 | struct gpio_chip *chip = NULL; |
cb1650d4 | 1857 | loff_t index = *pos; |
d2876d08 | 1858 | |
f9c4a31f | 1859 | s->private = ""; |
d2876d08 | 1860 | |
362432ae | 1861 | spin_lock_irqsave(&gpio_lock, flags); |
cb1650d4 | 1862 | list_for_each_entry(chip, &gpio_chips, list) |
362432ae GL |
1863 | if (index-- == 0) { |
1864 | spin_unlock_irqrestore(&gpio_lock, flags); | |
cb1650d4 | 1865 | return chip; |
f9c4a31f | 1866 | } |
362432ae | 1867 | spin_unlock_irqrestore(&gpio_lock, flags); |
f9c4a31f | 1868 | |
cb1650d4 | 1869 | return NULL; |
f9c4a31f TR |
1870 | } |
1871 | ||
1872 | static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
1873 | { | |
362432ae | 1874 | unsigned long flags; |
f9c4a31f | 1875 | struct gpio_chip *chip = v; |
f9c4a31f TR |
1876 | void *ret = NULL; |
1877 | ||
362432ae | 1878 | spin_lock_irqsave(&gpio_lock, flags); |
cb1650d4 AC |
1879 | if (list_is_last(&chip->list, &gpio_chips)) |
1880 | ret = NULL; | |
1881 | else | |
1882 | ret = list_entry(chip->list.next, struct gpio_chip, list); | |
362432ae | 1883 | spin_unlock_irqrestore(&gpio_lock, flags); |
f9c4a31f TR |
1884 | |
1885 | s->private = "\n"; | |
1886 | ++*pos; | |
1887 | ||
1888 | return ret; | |
1889 | } | |
1890 | ||
1891 | static void gpiolib_seq_stop(struct seq_file *s, void *v) | |
1892 | { | |
1893 | } | |
1894 | ||
1895 | static int gpiolib_seq_show(struct seq_file *s, void *v) | |
1896 | { | |
1897 | struct gpio_chip *chip = v; | |
1898 | struct device *dev; | |
1899 | ||
1900 | seq_printf(s, "%sGPIOs %d-%d", (char *)s->private, | |
1901 | chip->base, chip->base + chip->ngpio - 1); | |
1902 | dev = chip->dev; | |
1903 | if (dev) | |
1904 | seq_printf(s, ", %s/%s", dev->bus ? dev->bus->name : "no-bus", | |
1905 | dev_name(dev)); | |
1906 | if (chip->label) | |
1907 | seq_printf(s, ", %s", chip->label); | |
1908 | if (chip->can_sleep) | |
1909 | seq_printf(s, ", can sleep"); | |
1910 | seq_printf(s, ":\n"); | |
1911 | ||
1912 | if (chip->dbg_show) | |
1913 | chip->dbg_show(s, chip); | |
1914 | else | |
1915 | gpiolib_dbg_show(s, chip); | |
1916 | ||
d2876d08 DB |
1917 | return 0; |
1918 | } | |
1919 | ||
f9c4a31f TR |
1920 | static const struct seq_operations gpiolib_seq_ops = { |
1921 | .start = gpiolib_seq_start, | |
1922 | .next = gpiolib_seq_next, | |
1923 | .stop = gpiolib_seq_stop, | |
1924 | .show = gpiolib_seq_show, | |
1925 | }; | |
1926 | ||
d2876d08 DB |
1927 | static int gpiolib_open(struct inode *inode, struct file *file) |
1928 | { | |
f9c4a31f | 1929 | return seq_open(file, &gpiolib_seq_ops); |
d2876d08 DB |
1930 | } |
1931 | ||
828c0950 | 1932 | static const struct file_operations gpiolib_operations = { |
f9c4a31f | 1933 | .owner = THIS_MODULE, |
d2876d08 DB |
1934 | .open = gpiolib_open, |
1935 | .read = seq_read, | |
1936 | .llseek = seq_lseek, | |
f9c4a31f | 1937 | .release = seq_release, |
d2876d08 DB |
1938 | }; |
1939 | ||
1940 | static int __init gpiolib_debugfs_init(void) | |
1941 | { | |
1942 | /* /sys/kernel/debug/gpio */ | |
1943 | (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO, | |
1944 | NULL, NULL, &gpiolib_operations); | |
1945 | return 0; | |
1946 | } | |
1947 | subsys_initcall(gpiolib_debugfs_init); | |
1948 | ||
1949 | #endif /* DEBUG_FS */ |