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> | |
d8f388d8 DB |
6 | #include <linux/device.h> |
7 | #include <linux/err.h> | |
8 | #include <linux/debugfs.h> | |
9 | #include <linux/seq_file.h> | |
10 | #include <linux/gpio.h> | |
391c970c | 11 | #include <linux/of_gpio.h> |
ff77c352 | 12 | #include <linux/idr.h> |
5a0e3ad6 | 13 | #include <linux/slab.h> |
d2876d08 | 14 | |
3f397c21 UKK |
15 | #define CREATE_TRACE_POINTS |
16 | #include <trace/events/gpio.h> | |
d2876d08 DB |
17 | |
18 | /* Optional implementation infrastructure for GPIO interfaces. | |
19 | * | |
20 | * Platforms may want to use this if they tend to use very many GPIOs | |
21 | * that aren't part of a System-On-Chip core; or across I2C/SPI/etc. | |
22 | * | |
23 | * When kernel footprint or instruction count is an issue, simpler | |
24 | * implementations may be preferred. The GPIO programming interface | |
25 | * allows for inlining speed-critical get/set operations for common | |
26 | * cases, so that access to SOC-integrated GPIOs can sometimes cost | |
27 | * only an instruction or two per bit. | |
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 | */ | |
47 | static DEFINE_SPINLOCK(gpio_lock); | |
48 | ||
49 | struct gpio_desc { | |
50 | struct gpio_chip *chip; | |
51 | unsigned long flags; | |
52 | /* flag symbols are bit numbers */ | |
53 | #define FLAG_REQUESTED 0 | |
54 | #define FLAG_IS_OUT 1 | |
169b6a7a | 55 | #define FLAG_RESERVED 2 |
d8f388d8 DB |
56 | #define FLAG_EXPORT 3 /* protected by sysfs_lock */ |
57 | #define FLAG_SYSFS 4 /* exported via /sys/class/gpio/control */ | |
ff77c352 DG |
58 | #define FLAG_TRIG_FALL 5 /* trigger on falling edge */ |
59 | #define FLAG_TRIG_RISE 6 /* trigger on rising edge */ | |
07697461 | 60 | #define FLAG_ACTIVE_LOW 7 /* sysfs value has active low */ |
aca5ce14 | 61 | #define FLAG_OPEN_DRAIN 8 /* Gpio is open drain type */ |
25553ff0 | 62 | #define FLAG_OPEN_SOURCE 9 /* Gpio is open source type */ |
ff77c352 | 63 | |
5ba1821d | 64 | #define ID_SHIFT 16 /* add new flags before this one */ |
ff77c352 | 65 | |
5ba1821d | 66 | #define GPIO_FLAGS_MASK ((1 << ID_SHIFT) - 1) |
ff77c352 | 67 | #define GPIO_TRIGGER_MASK (BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE)) |
d2876d08 DB |
68 | |
69 | #ifdef CONFIG_DEBUG_FS | |
70 | const char *label; | |
71 | #endif | |
72 | }; | |
73 | static struct gpio_desc gpio_desc[ARCH_NR_GPIOS]; | |
74 | ||
ff77c352 | 75 | #ifdef CONFIG_GPIO_SYSFS |
5ba1821d | 76 | static DEFINE_IDR(dirent_idr); |
ff77c352 DG |
77 | #endif |
78 | ||
d2876d08 DB |
79 | static inline void desc_set_label(struct gpio_desc *d, const char *label) |
80 | { | |
81 | #ifdef CONFIG_DEBUG_FS | |
82 | d->label = label; | |
83 | #endif | |
84 | } | |
85 | ||
86 | /* Warn when drivers omit gpio_request() calls -- legal but ill-advised | |
87 | * when setting direction, and otherwise illegal. Until board setup code | |
88 | * and drivers use explicit requests everywhere (which won't happen when | |
89 | * those calls have no teeth) we can't avoid autorequesting. This nag | |
35e8bb51 DB |
90 | * message should motivate switching to explicit requests... so should |
91 | * the weaker cleanup after faults, compared to gpio_request(). | |
8a0cecff DB |
92 | * |
93 | * NOTE: the autorequest mechanism is going away; at this point it's | |
94 | * only "legal" in the sense that (old) code using it won't break yet, | |
95 | * but instead only triggers a WARN() stack dump. | |
d2876d08 | 96 | */ |
35e8bb51 | 97 | static int gpio_ensure_requested(struct gpio_desc *desc, unsigned offset) |
d2876d08 | 98 | { |
8a0cecff DB |
99 | const struct gpio_chip *chip = desc->chip; |
100 | const int gpio = chip->base + offset; | |
35e8bb51 | 101 | |
8a0cecff DB |
102 | if (WARN(test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0, |
103 | "autorequest GPIO-%d\n", gpio)) { | |
35e8bb51 DB |
104 | if (!try_module_get(chip->owner)) { |
105 | pr_err("GPIO-%d: module can't be gotten \n", gpio); | |
106 | clear_bit(FLAG_REQUESTED, &desc->flags); | |
107 | /* lose */ | |
108 | return -EIO; | |
109 | } | |
d2876d08 | 110 | desc_set_label(desc, "[auto]"); |
35e8bb51 DB |
111 | /* caller must chip->request() w/o spinlock */ |
112 | if (chip->request) | |
113 | return 1; | |
d2876d08 | 114 | } |
35e8bb51 | 115 | return 0; |
d2876d08 DB |
116 | } |
117 | ||
118 | /* caller holds gpio_lock *OR* gpio is marked as requested */ | |
1a2d397a | 119 | struct gpio_chip *gpio_to_chip(unsigned gpio) |
d2876d08 DB |
120 | { |
121 | return gpio_desc[gpio].chip; | |
122 | } | |
123 | ||
8d0aab2f AV |
124 | /* dynamic allocation of GPIOs, e.g. on a hotplugged device */ |
125 | static int gpiochip_find_base(int ngpio) | |
126 | { | |
127 | int i; | |
128 | int spare = 0; | |
129 | int base = -ENOSPC; | |
130 | ||
131 | for (i = ARCH_NR_GPIOS - 1; i >= 0 ; i--) { | |
169b6a7a AV |
132 | struct gpio_desc *desc = &gpio_desc[i]; |
133 | struct gpio_chip *chip = desc->chip; | |
8d0aab2f | 134 | |
169b6a7a | 135 | if (!chip && !test_bit(FLAG_RESERVED, &desc->flags)) { |
8d0aab2f AV |
136 | spare++; |
137 | if (spare == ngpio) { | |
138 | base = i; | |
139 | break; | |
140 | } | |
141 | } else { | |
142 | spare = 0; | |
169b6a7a AV |
143 | if (chip) |
144 | i -= chip->ngpio - 1; | |
8d0aab2f AV |
145 | } |
146 | } | |
147 | ||
148 | if (gpio_is_valid(base)) | |
149 | pr_debug("%s: found new base at %d\n", __func__, base); | |
150 | return base; | |
151 | } | |
152 | ||
169b6a7a AV |
153 | /** |
154 | * gpiochip_reserve() - reserve range of gpios to use with platform code only | |
155 | * @start: starting gpio number | |
156 | * @ngpio: number of gpios to reserve | |
157 | * Context: platform init, potentially before irqs or kmalloc will work | |
158 | * | |
159 | * Returns a negative errno if any gpio within the range is already reserved | |
160 | * or registered, else returns zero as a success code. Use this function | |
161 | * to mark a range of gpios as unavailable for dynamic gpio number allocation, | |
162 | * for example because its driver support is not yet loaded. | |
163 | */ | |
164 | int __init gpiochip_reserve(int start, int ngpio) | |
165 | { | |
166 | int ret = 0; | |
167 | unsigned long flags; | |
168 | int i; | |
169 | ||
bff5fda9 | 170 | if (!gpio_is_valid(start) || !gpio_is_valid(start + ngpio - 1)) |
169b6a7a AV |
171 | return -EINVAL; |
172 | ||
173 | spin_lock_irqsave(&gpio_lock, flags); | |
174 | ||
175 | for (i = start; i < start + ngpio; i++) { | |
176 | struct gpio_desc *desc = &gpio_desc[i]; | |
177 | ||
178 | if (desc->chip || test_bit(FLAG_RESERVED, &desc->flags)) { | |
179 | ret = -EBUSY; | |
180 | goto err; | |
181 | } | |
182 | ||
183 | set_bit(FLAG_RESERVED, &desc->flags); | |
184 | } | |
185 | ||
186 | pr_debug("%s: reserved gpios from %d to %d\n", | |
187 | __func__, start, start + ngpio - 1); | |
188 | err: | |
189 | spin_unlock_irqrestore(&gpio_lock, flags); | |
190 | ||
191 | return ret; | |
192 | } | |
193 | ||
d8f388d8 DB |
194 | #ifdef CONFIG_GPIO_SYSFS |
195 | ||
196 | /* lock protects against unexport_gpio() being called while | |
197 | * sysfs files are active. | |
198 | */ | |
199 | static DEFINE_MUTEX(sysfs_lock); | |
200 | ||
201 | /* | |
202 | * /sys/class/gpio/gpioN... only for GPIOs that are exported | |
203 | * /direction | |
204 | * * MAY BE OMITTED if kernel won't allow direction changes | |
205 | * * is read/write as "in" or "out" | |
206 | * * may also be written as "high" or "low", initializing | |
207 | * output value as specified ("out" implies "low") | |
208 | * /value | |
209 | * * always readable, subject to hardware behavior | |
210 | * * may be writable, as zero/nonzero | |
ff77c352 DG |
211 | * /edge |
212 | * * configures behavior of poll(2) on /value | |
213 | * * available only if pin can generate IRQs on input | |
214 | * * is read/write as "none", "falling", "rising", or "both" | |
07697461 JN |
215 | * /active_low |
216 | * * configures polarity of /value | |
217 | * * is read/write as zero/nonzero | |
218 | * * also affects existing and subsequent "falling" and "rising" | |
219 | * /edge configuration | |
d8f388d8 DB |
220 | */ |
221 | ||
222 | static ssize_t gpio_direction_show(struct device *dev, | |
223 | struct device_attribute *attr, char *buf) | |
224 | { | |
225 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
226 | ssize_t status; | |
227 | ||
228 | mutex_lock(&sysfs_lock); | |
229 | ||
230 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
231 | status = -EIO; | |
232 | else | |
233 | status = sprintf(buf, "%s\n", | |
234 | test_bit(FLAG_IS_OUT, &desc->flags) | |
235 | ? "out" : "in"); | |
236 | ||
237 | mutex_unlock(&sysfs_lock); | |
238 | return status; | |
239 | } | |
240 | ||
241 | static ssize_t gpio_direction_store(struct device *dev, | |
242 | struct device_attribute *attr, const char *buf, size_t size) | |
243 | { | |
244 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
245 | unsigned gpio = desc - gpio_desc; | |
246 | ssize_t status; | |
247 | ||
248 | mutex_lock(&sysfs_lock); | |
249 | ||
250 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
251 | status = -EIO; | |
252 | else if (sysfs_streq(buf, "high")) | |
253 | status = gpio_direction_output(gpio, 1); | |
254 | else if (sysfs_streq(buf, "out") || sysfs_streq(buf, "low")) | |
255 | status = gpio_direction_output(gpio, 0); | |
256 | else if (sysfs_streq(buf, "in")) | |
257 | status = gpio_direction_input(gpio); | |
258 | else | |
259 | status = -EINVAL; | |
260 | ||
261 | mutex_unlock(&sysfs_lock); | |
262 | return status ? : size; | |
263 | } | |
264 | ||
07697461 | 265 | static /* const */ DEVICE_ATTR(direction, 0644, |
d8f388d8 DB |
266 | gpio_direction_show, gpio_direction_store); |
267 | ||
268 | static ssize_t gpio_value_show(struct device *dev, | |
269 | struct device_attribute *attr, char *buf) | |
270 | { | |
271 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
272 | unsigned gpio = desc - gpio_desc; | |
273 | ssize_t status; | |
274 | ||
275 | mutex_lock(&sysfs_lock); | |
276 | ||
07697461 | 277 | if (!test_bit(FLAG_EXPORT, &desc->flags)) { |
d8f388d8 | 278 | status = -EIO; |
07697461 JN |
279 | } else { |
280 | int value; | |
281 | ||
282 | value = !!gpio_get_value_cansleep(gpio); | |
283 | if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) | |
284 | value = !value; | |
285 | ||
286 | status = sprintf(buf, "%d\n", value); | |
287 | } | |
d8f388d8 DB |
288 | |
289 | mutex_unlock(&sysfs_lock); | |
290 | return status; | |
291 | } | |
292 | ||
293 | static ssize_t gpio_value_store(struct device *dev, | |
294 | struct device_attribute *attr, const char *buf, size_t size) | |
295 | { | |
296 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
297 | unsigned gpio = desc - gpio_desc; | |
298 | ssize_t status; | |
299 | ||
300 | mutex_lock(&sysfs_lock); | |
301 | ||
302 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
303 | status = -EIO; | |
304 | else if (!test_bit(FLAG_IS_OUT, &desc->flags)) | |
305 | status = -EPERM; | |
306 | else { | |
307 | long value; | |
308 | ||
309 | status = strict_strtol(buf, 0, &value); | |
310 | if (status == 0) { | |
07697461 JN |
311 | if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) |
312 | value = !value; | |
d8f388d8 DB |
313 | gpio_set_value_cansleep(gpio, value != 0); |
314 | status = size; | |
315 | } | |
316 | } | |
317 | ||
318 | mutex_unlock(&sysfs_lock); | |
319 | return status; | |
320 | } | |
321 | ||
07697461 | 322 | static const DEVICE_ATTR(value, 0644, |
d8f388d8 DB |
323 | gpio_value_show, gpio_value_store); |
324 | ||
ff77c352 DG |
325 | static irqreturn_t gpio_sysfs_irq(int irq, void *priv) |
326 | { | |
5ba1821d | 327 | struct sysfs_dirent *value_sd = priv; |
ff77c352 | 328 | |
5ba1821d | 329 | sysfs_notify_dirent(value_sd); |
ff77c352 DG |
330 | return IRQ_HANDLED; |
331 | } | |
332 | ||
ff77c352 DG |
333 | static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev, |
334 | unsigned long gpio_flags) | |
335 | { | |
5ba1821d | 336 | struct sysfs_dirent *value_sd; |
ff77c352 DG |
337 | unsigned long irq_flags; |
338 | int ret, irq, id; | |
339 | ||
340 | if ((desc->flags & GPIO_TRIGGER_MASK) == gpio_flags) | |
341 | return 0; | |
342 | ||
343 | irq = gpio_to_irq(desc - gpio_desc); | |
344 | if (irq < 0) | |
345 | return -EIO; | |
346 | ||
5ba1821d DG |
347 | id = desc->flags >> ID_SHIFT; |
348 | value_sd = idr_find(&dirent_idr, id); | |
349 | if (value_sd) | |
350 | free_irq(irq, value_sd); | |
ff77c352 DG |
351 | |
352 | desc->flags &= ~GPIO_TRIGGER_MASK; | |
353 | ||
354 | if (!gpio_flags) { | |
355 | ret = 0; | |
5ba1821d | 356 | goto free_id; |
ff77c352 DG |
357 | } |
358 | ||
359 | irq_flags = IRQF_SHARED; | |
360 | if (test_bit(FLAG_TRIG_FALL, &gpio_flags)) | |
07697461 JN |
361 | irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? |
362 | IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING; | |
ff77c352 | 363 | if (test_bit(FLAG_TRIG_RISE, &gpio_flags)) |
07697461 JN |
364 | irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? |
365 | IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; | |
ff77c352 | 366 | |
5ba1821d DG |
367 | if (!value_sd) { |
368 | value_sd = sysfs_get_dirent(dev->kobj.sd, NULL, "value"); | |
369 | if (!value_sd) { | |
370 | ret = -ENODEV; | |
ff77c352 DG |
371 | goto err_out; |
372 | } | |
373 | ||
374 | do { | |
375 | ret = -ENOMEM; | |
5ba1821d DG |
376 | if (idr_pre_get(&dirent_idr, GFP_KERNEL)) |
377 | ret = idr_get_new_above(&dirent_idr, value_sd, | |
378 | 1, &id); | |
ff77c352 DG |
379 | } while (ret == -EAGAIN); |
380 | ||
381 | if (ret) | |
5ba1821d | 382 | goto free_sd; |
ff77c352 DG |
383 | |
384 | desc->flags &= GPIO_FLAGS_MASK; | |
5ba1821d | 385 | desc->flags |= (unsigned long)id << ID_SHIFT; |
ff77c352 | 386 | |
5ba1821d | 387 | if (desc->flags >> ID_SHIFT != id) { |
ff77c352 DG |
388 | ret = -ERANGE; |
389 | goto free_id; | |
390 | } | |
ff77c352 DG |
391 | } |
392 | ||
364fadb3 | 393 | ret = request_any_context_irq(irq, gpio_sysfs_irq, irq_flags, |
5ba1821d | 394 | "gpiolib", value_sd); |
364fadb3 | 395 | if (ret < 0) |
5ba1821d | 396 | goto free_id; |
ff77c352 DG |
397 | |
398 | desc->flags |= gpio_flags; | |
399 | return 0; | |
400 | ||
ff77c352 | 401 | free_id: |
5ba1821d | 402 | idr_remove(&dirent_idr, id); |
ff77c352 | 403 | desc->flags &= GPIO_FLAGS_MASK; |
5ba1821d DG |
404 | free_sd: |
405 | if (value_sd) | |
406 | sysfs_put(value_sd); | |
ff77c352 DG |
407 | err_out: |
408 | return ret; | |
409 | } | |
410 | ||
411 | static const struct { | |
412 | const char *name; | |
413 | unsigned long flags; | |
414 | } trigger_types[] = { | |
415 | { "none", 0 }, | |
416 | { "falling", BIT(FLAG_TRIG_FALL) }, | |
417 | { "rising", BIT(FLAG_TRIG_RISE) }, | |
418 | { "both", BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE) }, | |
419 | }; | |
420 | ||
421 | static ssize_t gpio_edge_show(struct device *dev, | |
422 | struct device_attribute *attr, char *buf) | |
423 | { | |
424 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
425 | ssize_t status; | |
426 | ||
427 | mutex_lock(&sysfs_lock); | |
428 | ||
429 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
430 | status = -EIO; | |
431 | else { | |
432 | int i; | |
433 | ||
434 | status = 0; | |
435 | for (i = 0; i < ARRAY_SIZE(trigger_types); i++) | |
436 | if ((desc->flags & GPIO_TRIGGER_MASK) | |
437 | == trigger_types[i].flags) { | |
438 | status = sprintf(buf, "%s\n", | |
439 | trigger_types[i].name); | |
440 | break; | |
441 | } | |
442 | } | |
443 | ||
444 | mutex_unlock(&sysfs_lock); | |
445 | return status; | |
446 | } | |
447 | ||
448 | static ssize_t gpio_edge_store(struct device *dev, | |
449 | struct device_attribute *attr, const char *buf, size_t size) | |
450 | { | |
451 | struct gpio_desc *desc = dev_get_drvdata(dev); | |
452 | ssize_t status; | |
453 | int i; | |
454 | ||
455 | for (i = 0; i < ARRAY_SIZE(trigger_types); i++) | |
456 | if (sysfs_streq(trigger_types[i].name, buf)) | |
457 | goto found; | |
458 | return -EINVAL; | |
459 | ||
460 | found: | |
461 | mutex_lock(&sysfs_lock); | |
462 | ||
463 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
464 | status = -EIO; | |
465 | else { | |
466 | status = gpio_setup_irq(desc, dev, trigger_types[i].flags); | |
467 | if (!status) | |
468 | status = size; | |
469 | } | |
470 | ||
471 | mutex_unlock(&sysfs_lock); | |
472 | ||
473 | return status; | |
474 | } | |
475 | ||
476 | static DEVICE_ATTR(edge, 0644, gpio_edge_show, gpio_edge_store); | |
477 | ||
07697461 JN |
478 | static int sysfs_set_active_low(struct gpio_desc *desc, struct device *dev, |
479 | int value) | |
480 | { | |
481 | int status = 0; | |
482 | ||
483 | if (!!test_bit(FLAG_ACTIVE_LOW, &desc->flags) == !!value) | |
484 | return 0; | |
485 | ||
486 | if (value) | |
487 | set_bit(FLAG_ACTIVE_LOW, &desc->flags); | |
488 | else | |
489 | clear_bit(FLAG_ACTIVE_LOW, &desc->flags); | |
490 | ||
491 | /* reconfigure poll(2) support if enabled on one edge only */ | |
492 | if (dev != NULL && (!!test_bit(FLAG_TRIG_RISE, &desc->flags) ^ | |
493 | !!test_bit(FLAG_TRIG_FALL, &desc->flags))) { | |
494 | unsigned long trigger_flags = desc->flags & GPIO_TRIGGER_MASK; | |
495 | ||
496 | gpio_setup_irq(desc, dev, 0); | |
497 | status = gpio_setup_irq(desc, dev, trigger_flags); | |
498 | } | |
499 | ||
500 | return status; | |
501 | } | |
502 | ||
503 | static ssize_t gpio_active_low_show(struct device *dev, | |
504 | struct device_attribute *attr, char *buf) | |
505 | { | |
506 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
507 | ssize_t status; | |
508 | ||
509 | mutex_lock(&sysfs_lock); | |
510 | ||
511 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
512 | status = -EIO; | |
513 | else | |
514 | status = sprintf(buf, "%d\n", | |
515 | !!test_bit(FLAG_ACTIVE_LOW, &desc->flags)); | |
516 | ||
517 | mutex_unlock(&sysfs_lock); | |
518 | ||
519 | return status; | |
520 | } | |
521 | ||
522 | static ssize_t gpio_active_low_store(struct device *dev, | |
523 | struct device_attribute *attr, const char *buf, size_t size) | |
524 | { | |
525 | struct gpio_desc *desc = dev_get_drvdata(dev); | |
526 | ssize_t status; | |
527 | ||
528 | mutex_lock(&sysfs_lock); | |
529 | ||
530 | if (!test_bit(FLAG_EXPORT, &desc->flags)) { | |
531 | status = -EIO; | |
532 | } else { | |
533 | long value; | |
534 | ||
535 | status = strict_strtol(buf, 0, &value); | |
536 | if (status == 0) | |
537 | status = sysfs_set_active_low(desc, dev, value != 0); | |
538 | } | |
539 | ||
540 | mutex_unlock(&sysfs_lock); | |
541 | ||
542 | return status ? : size; | |
543 | } | |
544 | ||
545 | static const DEVICE_ATTR(active_low, 0644, | |
546 | gpio_active_low_show, gpio_active_low_store); | |
547 | ||
d8f388d8 | 548 | static const struct attribute *gpio_attrs[] = { |
d8f388d8 | 549 | &dev_attr_value.attr, |
07697461 | 550 | &dev_attr_active_low.attr, |
d8f388d8 DB |
551 | NULL, |
552 | }; | |
553 | ||
554 | static const struct attribute_group gpio_attr_group = { | |
555 | .attrs = (struct attribute **) gpio_attrs, | |
556 | }; | |
557 | ||
558 | /* | |
559 | * /sys/class/gpio/gpiochipN/ | |
560 | * /base ... matching gpio_chip.base (N) | |
561 | * /label ... matching gpio_chip.label | |
562 | * /ngpio ... matching gpio_chip.ngpio | |
563 | */ | |
564 | ||
565 | static ssize_t chip_base_show(struct device *dev, | |
566 | struct device_attribute *attr, char *buf) | |
567 | { | |
568 | const struct gpio_chip *chip = dev_get_drvdata(dev); | |
569 | ||
570 | return sprintf(buf, "%d\n", chip->base); | |
571 | } | |
572 | static DEVICE_ATTR(base, 0444, chip_base_show, NULL); | |
573 | ||
574 | static ssize_t chip_label_show(struct device *dev, | |
575 | struct device_attribute *attr, char *buf) | |
576 | { | |
577 | const struct gpio_chip *chip = dev_get_drvdata(dev); | |
578 | ||
579 | return sprintf(buf, "%s\n", chip->label ? : ""); | |
580 | } | |
581 | static DEVICE_ATTR(label, 0444, chip_label_show, NULL); | |
582 | ||
583 | static ssize_t chip_ngpio_show(struct device *dev, | |
584 | struct device_attribute *attr, char *buf) | |
585 | { | |
586 | const struct gpio_chip *chip = dev_get_drvdata(dev); | |
587 | ||
588 | return sprintf(buf, "%u\n", chip->ngpio); | |
589 | } | |
590 | static DEVICE_ATTR(ngpio, 0444, chip_ngpio_show, NULL); | |
591 | ||
592 | static const struct attribute *gpiochip_attrs[] = { | |
593 | &dev_attr_base.attr, | |
594 | &dev_attr_label.attr, | |
595 | &dev_attr_ngpio.attr, | |
596 | NULL, | |
597 | }; | |
598 | ||
599 | static const struct attribute_group gpiochip_attr_group = { | |
600 | .attrs = (struct attribute **) gpiochip_attrs, | |
601 | }; | |
602 | ||
603 | /* | |
604 | * /sys/class/gpio/export ... write-only | |
605 | * integer N ... number of GPIO to export (full access) | |
606 | * /sys/class/gpio/unexport ... write-only | |
607 | * integer N ... number of GPIO to unexport | |
608 | */ | |
28812fe1 AK |
609 | static ssize_t export_store(struct class *class, |
610 | struct class_attribute *attr, | |
611 | const char *buf, size_t len) | |
d8f388d8 DB |
612 | { |
613 | long gpio; | |
614 | int status; | |
615 | ||
616 | status = strict_strtol(buf, 0, &gpio); | |
617 | if (status < 0) | |
618 | goto done; | |
619 | ||
620 | /* No extra locking here; FLAG_SYSFS just signifies that the | |
621 | * request and export were done by on behalf of userspace, so | |
622 | * they may be undone on its behalf too. | |
623 | */ | |
624 | ||
625 | status = gpio_request(gpio, "sysfs"); | |
626 | if (status < 0) | |
627 | goto done; | |
628 | ||
629 | status = gpio_export(gpio, true); | |
630 | if (status < 0) | |
631 | gpio_free(gpio); | |
632 | else | |
633 | set_bit(FLAG_SYSFS, &gpio_desc[gpio].flags); | |
634 | ||
635 | done: | |
636 | if (status) | |
637 | pr_debug("%s: status %d\n", __func__, status); | |
638 | return status ? : len; | |
639 | } | |
640 | ||
28812fe1 AK |
641 | static ssize_t unexport_store(struct class *class, |
642 | struct class_attribute *attr, | |
643 | const char *buf, size_t len) | |
d8f388d8 DB |
644 | { |
645 | long gpio; | |
646 | int status; | |
647 | ||
648 | status = strict_strtol(buf, 0, &gpio); | |
649 | if (status < 0) | |
650 | goto done; | |
651 | ||
652 | status = -EINVAL; | |
653 | ||
654 | /* reject bogus commands (gpio_unexport ignores them) */ | |
655 | if (!gpio_is_valid(gpio)) | |
656 | goto done; | |
657 | ||
658 | /* No extra locking here; FLAG_SYSFS just signifies that the | |
659 | * request and export were done by on behalf of userspace, so | |
660 | * they may be undone on its behalf too. | |
661 | */ | |
662 | if (test_and_clear_bit(FLAG_SYSFS, &gpio_desc[gpio].flags)) { | |
663 | status = 0; | |
664 | gpio_free(gpio); | |
665 | } | |
666 | done: | |
667 | if (status) | |
668 | pr_debug("%s: status %d\n", __func__, status); | |
669 | return status ? : len; | |
670 | } | |
671 | ||
672 | static struct class_attribute gpio_class_attrs[] = { | |
673 | __ATTR(export, 0200, NULL, export_store), | |
674 | __ATTR(unexport, 0200, NULL, unexport_store), | |
675 | __ATTR_NULL, | |
676 | }; | |
677 | ||
678 | static struct class gpio_class = { | |
679 | .name = "gpio", | |
680 | .owner = THIS_MODULE, | |
681 | ||
682 | .class_attrs = gpio_class_attrs, | |
683 | }; | |
684 | ||
685 | ||
686 | /** | |
687 | * gpio_export - export a GPIO through sysfs | |
688 | * @gpio: gpio to make available, already requested | |
689 | * @direction_may_change: true if userspace may change gpio direction | |
690 | * Context: arch_initcall or later | |
691 | * | |
692 | * When drivers want to make a GPIO accessible to userspace after they | |
693 | * have requested it -- perhaps while debugging, or as part of their | |
694 | * public interface -- they may use this routine. If the GPIO can | |
695 | * change direction (some can't) and the caller allows it, userspace | |
696 | * will see "direction" sysfs attribute which may be used to change | |
697 | * the gpio's direction. A "value" attribute will always be provided. | |
698 | * | |
699 | * Returns zero on success, else an error. | |
700 | */ | |
701 | int gpio_export(unsigned gpio, bool direction_may_change) | |
702 | { | |
703 | unsigned long flags; | |
704 | struct gpio_desc *desc; | |
705 | int status = -EINVAL; | |
62154991 | 706 | const char *ioname = NULL; |
d8f388d8 DB |
707 | |
708 | /* can't export until sysfs is available ... */ | |
709 | if (!gpio_class.p) { | |
710 | pr_debug("%s: called too early!\n", __func__); | |
711 | return -ENOENT; | |
712 | } | |
713 | ||
714 | if (!gpio_is_valid(gpio)) | |
715 | goto done; | |
716 | ||
717 | mutex_lock(&sysfs_lock); | |
718 | ||
719 | spin_lock_irqsave(&gpio_lock, flags); | |
720 | desc = &gpio_desc[gpio]; | |
721 | if (test_bit(FLAG_REQUESTED, &desc->flags) | |
722 | && !test_bit(FLAG_EXPORT, &desc->flags)) { | |
723 | status = 0; | |
724 | if (!desc->chip->direction_input | |
725 | || !desc->chip->direction_output) | |
726 | direction_may_change = false; | |
727 | } | |
728 | spin_unlock_irqrestore(&gpio_lock, flags); | |
729 | ||
926b663c DS |
730 | if (desc->chip->names && desc->chip->names[gpio - desc->chip->base]) |
731 | ioname = desc->chip->names[gpio - desc->chip->base]; | |
732 | ||
d8f388d8 DB |
733 | if (status == 0) { |
734 | struct device *dev; | |
735 | ||
736 | dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0), | |
7cfe1395 | 737 | desc, ioname ? ioname : "gpio%u", gpio); |
d62668e1 | 738 | if (!IS_ERR(dev)) { |
07697461 | 739 | status = sysfs_create_group(&dev->kobj, |
d8f388d8 | 740 | &gpio_attr_group); |
07697461 JN |
741 | |
742 | if (!status && direction_may_change) | |
d8f388d8 | 743 | status = device_create_file(dev, |
07697461 | 744 | &dev_attr_direction); |
ff77c352 DG |
745 | |
746 | if (!status && gpio_to_irq(gpio) >= 0 | |
747 | && (direction_may_change | |
748 | || !test_bit(FLAG_IS_OUT, | |
749 | &desc->flags))) | |
750 | status = device_create_file(dev, | |
751 | &dev_attr_edge); | |
752 | ||
d8f388d8 DB |
753 | if (status != 0) |
754 | device_unregister(dev); | |
755 | } else | |
d62668e1 | 756 | status = PTR_ERR(dev); |
d8f388d8 DB |
757 | if (status == 0) |
758 | set_bit(FLAG_EXPORT, &desc->flags); | |
759 | } | |
760 | ||
761 | mutex_unlock(&sysfs_lock); | |
762 | ||
763 | done: | |
764 | if (status) | |
765 | pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); | |
766 | ||
767 | return status; | |
768 | } | |
769 | EXPORT_SYMBOL_GPL(gpio_export); | |
770 | ||
771 | static int match_export(struct device *dev, void *data) | |
772 | { | |
773 | return dev_get_drvdata(dev) == data; | |
774 | } | |
775 | ||
a4177ee7 JN |
776 | /** |
777 | * gpio_export_link - create a sysfs link to an exported GPIO node | |
778 | * @dev: device under which to create symlink | |
779 | * @name: name of the symlink | |
780 | * @gpio: gpio to create symlink to, already exported | |
781 | * | |
782 | * Set up a symlink from /sys/.../dev/name to /sys/class/gpio/gpioN | |
783 | * node. Caller is responsible for unlinking. | |
784 | * | |
785 | * Returns zero on success, else an error. | |
786 | */ | |
787 | int gpio_export_link(struct device *dev, const char *name, unsigned gpio) | |
788 | { | |
789 | struct gpio_desc *desc; | |
790 | int status = -EINVAL; | |
791 | ||
792 | if (!gpio_is_valid(gpio)) | |
793 | goto done; | |
794 | ||
795 | mutex_lock(&sysfs_lock); | |
796 | ||
797 | desc = &gpio_desc[gpio]; | |
798 | ||
799 | if (test_bit(FLAG_EXPORT, &desc->flags)) { | |
800 | struct device *tdev; | |
801 | ||
802 | tdev = class_find_device(&gpio_class, NULL, desc, match_export); | |
803 | if (tdev != NULL) { | |
804 | status = sysfs_create_link(&dev->kobj, &tdev->kobj, | |
805 | name); | |
806 | } else { | |
807 | status = -ENODEV; | |
808 | } | |
809 | } | |
810 | ||
811 | mutex_unlock(&sysfs_lock); | |
812 | ||
813 | done: | |
814 | if (status) | |
815 | pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); | |
816 | ||
817 | return status; | |
818 | } | |
819 | EXPORT_SYMBOL_GPL(gpio_export_link); | |
820 | ||
07697461 JN |
821 | |
822 | /** | |
823 | * gpio_sysfs_set_active_low - set the polarity of gpio sysfs value | |
824 | * @gpio: gpio to change | |
825 | * @value: non-zero to use active low, i.e. inverted values | |
826 | * | |
827 | * Set the polarity of /sys/class/gpio/gpioN/value sysfs attribute. | |
828 | * The GPIO does not have to be exported yet. If poll(2) support has | |
829 | * been enabled for either rising or falling edge, it will be | |
830 | * reconfigured to follow the new polarity. | |
831 | * | |
832 | * Returns zero on success, else an error. | |
833 | */ | |
834 | int gpio_sysfs_set_active_low(unsigned gpio, int value) | |
835 | { | |
836 | struct gpio_desc *desc; | |
837 | struct device *dev = NULL; | |
838 | int status = -EINVAL; | |
839 | ||
840 | if (!gpio_is_valid(gpio)) | |
841 | goto done; | |
842 | ||
843 | mutex_lock(&sysfs_lock); | |
844 | ||
845 | desc = &gpio_desc[gpio]; | |
846 | ||
847 | if (test_bit(FLAG_EXPORT, &desc->flags)) { | |
07697461 JN |
848 | dev = class_find_device(&gpio_class, NULL, desc, match_export); |
849 | if (dev == NULL) { | |
850 | status = -ENODEV; | |
851 | goto unlock; | |
852 | } | |
853 | } | |
854 | ||
855 | status = sysfs_set_active_low(desc, dev, value); | |
856 | ||
857 | unlock: | |
858 | mutex_unlock(&sysfs_lock); | |
859 | ||
860 | done: | |
861 | if (status) | |
862 | pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); | |
863 | ||
864 | return status; | |
865 | } | |
866 | EXPORT_SYMBOL_GPL(gpio_sysfs_set_active_low); | |
867 | ||
d8f388d8 DB |
868 | /** |
869 | * gpio_unexport - reverse effect of gpio_export() | |
870 | * @gpio: gpio to make unavailable | |
871 | * | |
872 | * This is implicit on gpio_free(). | |
873 | */ | |
874 | void gpio_unexport(unsigned gpio) | |
875 | { | |
876 | struct gpio_desc *desc; | |
6a99ad4a | 877 | int status = 0; |
864533ce | 878 | struct device *dev = NULL; |
d8f388d8 | 879 | |
6a99ad4a JP |
880 | if (!gpio_is_valid(gpio)) { |
881 | status = -EINVAL; | |
d8f388d8 | 882 | goto done; |
6a99ad4a | 883 | } |
d8f388d8 DB |
884 | |
885 | mutex_lock(&sysfs_lock); | |
886 | ||
887 | desc = &gpio_desc[gpio]; | |
926b663c | 888 | |
d8f388d8 | 889 | if (test_bit(FLAG_EXPORT, &desc->flags)) { |
d8f388d8 DB |
890 | |
891 | dev = class_find_device(&gpio_class, NULL, desc, match_export); | |
892 | if (dev) { | |
ff77c352 | 893 | gpio_setup_irq(desc, dev, 0); |
d8f388d8 | 894 | clear_bit(FLAG_EXPORT, &desc->flags); |
d8f388d8 DB |
895 | } else |
896 | status = -ENODEV; | |
897 | } | |
898 | ||
899 | mutex_unlock(&sysfs_lock); | |
864533ce ML |
900 | if (dev) { |
901 | device_unregister(dev); | |
902 | put_device(dev); | |
903 | } | |
d8f388d8 DB |
904 | done: |
905 | if (status) | |
906 | pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); | |
907 | } | |
908 | EXPORT_SYMBOL_GPL(gpio_unexport); | |
909 | ||
910 | static int gpiochip_export(struct gpio_chip *chip) | |
911 | { | |
912 | int status; | |
913 | struct device *dev; | |
914 | ||
915 | /* Many systems register gpio chips for SOC support very early, | |
916 | * before driver model support is available. In those cases we | |
917 | * export this later, in gpiolib_sysfs_init() ... here we just | |
918 | * verify that _some_ field of gpio_class got initialized. | |
919 | */ | |
920 | if (!gpio_class.p) | |
921 | return 0; | |
922 | ||
923 | /* use chip->base for the ID; it's already known to be unique */ | |
924 | mutex_lock(&sysfs_lock); | |
925 | dev = device_create(&gpio_class, chip->dev, MKDEV(0, 0), chip, | |
926 | "gpiochip%d", chip->base); | |
d62668e1 | 927 | if (!IS_ERR(dev)) { |
d8f388d8 DB |
928 | status = sysfs_create_group(&dev->kobj, |
929 | &gpiochip_attr_group); | |
930 | } else | |
d62668e1 | 931 | status = PTR_ERR(dev); |
d8f388d8 DB |
932 | chip->exported = (status == 0); |
933 | mutex_unlock(&sysfs_lock); | |
934 | ||
935 | if (status) { | |
936 | unsigned long flags; | |
937 | unsigned gpio; | |
938 | ||
939 | spin_lock_irqsave(&gpio_lock, flags); | |
940 | gpio = chip->base; | |
941 | while (gpio_desc[gpio].chip == chip) | |
942 | gpio_desc[gpio++].chip = NULL; | |
943 | spin_unlock_irqrestore(&gpio_lock, flags); | |
944 | ||
945 | pr_debug("%s: chip %s status %d\n", __func__, | |
946 | chip->label, status); | |
947 | } | |
948 | ||
949 | return status; | |
950 | } | |
951 | ||
952 | static void gpiochip_unexport(struct gpio_chip *chip) | |
953 | { | |
954 | int status; | |
955 | struct device *dev; | |
956 | ||
957 | mutex_lock(&sysfs_lock); | |
958 | dev = class_find_device(&gpio_class, NULL, chip, match_export); | |
959 | if (dev) { | |
960 | put_device(dev); | |
961 | device_unregister(dev); | |
962 | chip->exported = 0; | |
963 | status = 0; | |
964 | } else | |
965 | status = -ENODEV; | |
966 | mutex_unlock(&sysfs_lock); | |
967 | ||
968 | if (status) | |
969 | pr_debug("%s: chip %s status %d\n", __func__, | |
970 | chip->label, status); | |
971 | } | |
972 | ||
973 | static int __init gpiolib_sysfs_init(void) | |
974 | { | |
975 | int status; | |
976 | unsigned long flags; | |
977 | unsigned gpio; | |
978 | ||
979 | status = class_register(&gpio_class); | |
980 | if (status < 0) | |
981 | return status; | |
982 | ||
983 | /* Scan and register the gpio_chips which registered very | |
984 | * early (e.g. before the class_register above was called). | |
985 | * | |
986 | * We run before arch_initcall() so chip->dev nodes can have | |
987 | * registered, and so arch_initcall() can always gpio_export(). | |
988 | */ | |
989 | spin_lock_irqsave(&gpio_lock, flags); | |
990 | for (gpio = 0; gpio < ARCH_NR_GPIOS; gpio++) { | |
991 | struct gpio_chip *chip; | |
992 | ||
993 | chip = gpio_desc[gpio].chip; | |
994 | if (!chip || chip->exported) | |
995 | continue; | |
996 | ||
997 | spin_unlock_irqrestore(&gpio_lock, flags); | |
998 | status = gpiochip_export(chip); | |
999 | spin_lock_irqsave(&gpio_lock, flags); | |
1000 | } | |
1001 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1002 | ||
1003 | ||
1004 | return status; | |
1005 | } | |
1006 | postcore_initcall(gpiolib_sysfs_init); | |
1007 | ||
1008 | #else | |
1009 | static inline int gpiochip_export(struct gpio_chip *chip) | |
1010 | { | |
1011 | return 0; | |
1012 | } | |
1013 | ||
1014 | static inline void gpiochip_unexport(struct gpio_chip *chip) | |
1015 | { | |
1016 | } | |
1017 | ||
1018 | #endif /* CONFIG_GPIO_SYSFS */ | |
1019 | ||
d2876d08 DB |
1020 | /** |
1021 | * gpiochip_add() - register a gpio_chip | |
1022 | * @chip: the chip to register, with chip->base initialized | |
1023 | * Context: potentially before irqs or kmalloc will work | |
1024 | * | |
1025 | * Returns a negative errno if the chip can't be registered, such as | |
1026 | * because the chip->base is invalid or already associated with a | |
1027 | * different chip. Otherwise it returns zero as a success code. | |
8d0aab2f | 1028 | * |
d8f388d8 DB |
1029 | * When gpiochip_add() is called very early during boot, so that GPIOs |
1030 | * can be freely used, the chip->dev device must be registered before | |
1031 | * the gpio framework's arch_initcall(). Otherwise sysfs initialization | |
1032 | * for GPIOs will fail rudely. | |
1033 | * | |
8d0aab2f AV |
1034 | * If chip->base is negative, this requests dynamic assignment of |
1035 | * a range of valid GPIOs. | |
d2876d08 DB |
1036 | */ |
1037 | int gpiochip_add(struct gpio_chip *chip) | |
1038 | { | |
1039 | unsigned long flags; | |
1040 | int status = 0; | |
1041 | unsigned id; | |
8d0aab2f | 1042 | int base = chip->base; |
d2876d08 | 1043 | |
bff5fda9 | 1044 | if ((!gpio_is_valid(base) || !gpio_is_valid(base + chip->ngpio - 1)) |
8d0aab2f | 1045 | && base >= 0) { |
d2876d08 DB |
1046 | status = -EINVAL; |
1047 | goto fail; | |
1048 | } | |
1049 | ||
1050 | spin_lock_irqsave(&gpio_lock, flags); | |
1051 | ||
8d0aab2f AV |
1052 | if (base < 0) { |
1053 | base = gpiochip_find_base(chip->ngpio); | |
1054 | if (base < 0) { | |
1055 | status = base; | |
d8f388d8 | 1056 | goto unlock; |
8d0aab2f AV |
1057 | } |
1058 | chip->base = base; | |
1059 | } | |
1060 | ||
d2876d08 | 1061 | /* these GPIO numbers must not be managed by another gpio_chip */ |
8d0aab2f | 1062 | for (id = base; id < base + chip->ngpio; id++) { |
d2876d08 DB |
1063 | if (gpio_desc[id].chip != NULL) { |
1064 | status = -EBUSY; | |
1065 | break; | |
1066 | } | |
1067 | } | |
1068 | if (status == 0) { | |
8d0aab2f | 1069 | for (id = base; id < base + chip->ngpio; id++) { |
d2876d08 | 1070 | gpio_desc[id].chip = chip; |
d8f388d8 DB |
1071 | |
1072 | /* REVISIT: most hardware initializes GPIOs as | |
1073 | * inputs (often with pullups enabled) so power | |
1074 | * usage is minimized. Linux code should set the | |
1075 | * gpio direction first thing; but until it does, | |
1076 | * we may expose the wrong direction in sysfs. | |
1077 | */ | |
1078 | gpio_desc[id].flags = !chip->direction_input | |
1079 | ? (1 << FLAG_IS_OUT) | |
1080 | : 0; | |
d2876d08 DB |
1081 | } |
1082 | } | |
1083 | ||
391c970c AV |
1084 | of_gpiochip_add(chip); |
1085 | ||
d8f388d8 | 1086 | unlock: |
d2876d08 | 1087 | spin_unlock_irqrestore(&gpio_lock, flags); |
cedb1881 AV |
1088 | |
1089 | if (status) | |
1090 | goto fail; | |
1091 | ||
1092 | status = gpiochip_export(chip); | |
1093 | if (status) | |
1094 | goto fail; | |
1095 | ||
64842aad GL |
1096 | pr_info("gpiochip_add: registered GPIOs %d to %d on device: %s\n", |
1097 | chip->base, chip->base + chip->ngpio - 1, | |
1098 | chip->label ? : "generic"); | |
1099 | ||
cedb1881 | 1100 | return 0; |
d2876d08 DB |
1101 | fail: |
1102 | /* failures here can mean systems won't boot... */ | |
cedb1881 AV |
1103 | pr_err("gpiochip_add: gpios %d..%d (%s) failed to register\n", |
1104 | chip->base, chip->base + chip->ngpio - 1, | |
1105 | chip->label ? : "generic"); | |
d2876d08 DB |
1106 | return status; |
1107 | } | |
1108 | EXPORT_SYMBOL_GPL(gpiochip_add); | |
1109 | ||
1110 | /** | |
1111 | * gpiochip_remove() - unregister a gpio_chip | |
1112 | * @chip: the chip to unregister | |
1113 | * | |
1114 | * A gpio_chip with any GPIOs still requested may not be removed. | |
1115 | */ | |
1116 | int gpiochip_remove(struct gpio_chip *chip) | |
1117 | { | |
1118 | unsigned long flags; | |
1119 | int status = 0; | |
1120 | unsigned id; | |
1121 | ||
1122 | spin_lock_irqsave(&gpio_lock, flags); | |
1123 | ||
391c970c AV |
1124 | of_gpiochip_remove(chip); |
1125 | ||
d2876d08 DB |
1126 | for (id = chip->base; id < chip->base + chip->ngpio; id++) { |
1127 | if (test_bit(FLAG_REQUESTED, &gpio_desc[id].flags)) { | |
1128 | status = -EBUSY; | |
1129 | break; | |
1130 | } | |
1131 | } | |
1132 | if (status == 0) { | |
1133 | for (id = chip->base; id < chip->base + chip->ngpio; id++) | |
1134 | gpio_desc[id].chip = NULL; | |
1135 | } | |
1136 | ||
1137 | spin_unlock_irqrestore(&gpio_lock, flags); | |
d8f388d8 DB |
1138 | |
1139 | if (status == 0) | |
1140 | gpiochip_unexport(chip); | |
1141 | ||
d2876d08 DB |
1142 | return status; |
1143 | } | |
1144 | EXPORT_SYMBOL_GPL(gpiochip_remove); | |
1145 | ||
594fa265 GL |
1146 | /** |
1147 | * gpiochip_find() - iterator for locating a specific gpio_chip | |
1148 | * @data: data to pass to match function | |
1149 | * @callback: Callback function to check gpio_chip | |
1150 | * | |
1151 | * Similar to bus_find_device. It returns a reference to a gpio_chip as | |
1152 | * determined by a user supplied @match callback. The callback should return | |
1153 | * 0 if the device doesn't match and non-zero if it does. If the callback is | |
1154 | * non-zero, this function will return to the caller and not iterate over any | |
1155 | * more gpio_chips. | |
1156 | */ | |
6e2cf651 GL |
1157 | struct gpio_chip *gpiochip_find(const void *data, |
1158 | int (*match)(struct gpio_chip *chip, | |
1159 | const void *data)) | |
594fa265 GL |
1160 | { |
1161 | struct gpio_chip *chip = NULL; | |
1162 | unsigned long flags; | |
1163 | int i; | |
1164 | ||
1165 | spin_lock_irqsave(&gpio_lock, flags); | |
1166 | for (i = 0; i < ARCH_NR_GPIOS; i++) { | |
1167 | if (!gpio_desc[i].chip) | |
1168 | continue; | |
1169 | ||
1170 | if (match(gpio_desc[i].chip, data)) { | |
1171 | chip = gpio_desc[i].chip; | |
1172 | break; | |
1173 | } | |
1174 | } | |
1175 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1176 | ||
1177 | return chip; | |
1178 | } | |
8fa0c9bf | 1179 | EXPORT_SYMBOL_GPL(gpiochip_find); |
d2876d08 DB |
1180 | |
1181 | /* These "optional" allocation calls help prevent drivers from stomping | |
1182 | * on each other, and help provide better diagnostics in debugfs. | |
1183 | * They're called even less than the "set direction" calls. | |
1184 | */ | |
1185 | int gpio_request(unsigned gpio, const char *label) | |
1186 | { | |
1187 | struct gpio_desc *desc; | |
35e8bb51 | 1188 | struct gpio_chip *chip; |
d2876d08 DB |
1189 | int status = -EINVAL; |
1190 | unsigned long flags; | |
1191 | ||
1192 | spin_lock_irqsave(&gpio_lock, flags); | |
1193 | ||
e6de1808 | 1194 | if (!gpio_is_valid(gpio)) |
d2876d08 DB |
1195 | goto done; |
1196 | desc = &gpio_desc[gpio]; | |
35e8bb51 DB |
1197 | chip = desc->chip; |
1198 | if (chip == NULL) | |
d2876d08 DB |
1199 | goto done; |
1200 | ||
35e8bb51 | 1201 | if (!try_module_get(chip->owner)) |
438d8908 GL |
1202 | goto done; |
1203 | ||
d2876d08 | 1204 | /* NOTE: gpio_request() can be called in early boot, |
35e8bb51 | 1205 | * before IRQs are enabled, for non-sleeping (SOC) GPIOs. |
d2876d08 DB |
1206 | */ |
1207 | ||
1208 | if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) { | |
1209 | desc_set_label(desc, label ? : "?"); | |
1210 | status = 0; | |
438d8908 | 1211 | } else { |
d2876d08 | 1212 | status = -EBUSY; |
35e8bb51 | 1213 | module_put(chip->owner); |
7460db56 | 1214 | goto done; |
35e8bb51 DB |
1215 | } |
1216 | ||
1217 | if (chip->request) { | |
1218 | /* chip->request may sleep */ | |
1219 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1220 | status = chip->request(chip, gpio - chip->base); | |
1221 | spin_lock_irqsave(&gpio_lock, flags); | |
1222 | ||
1223 | if (status < 0) { | |
1224 | desc_set_label(desc, NULL); | |
1225 | module_put(chip->owner); | |
1226 | clear_bit(FLAG_REQUESTED, &desc->flags); | |
1227 | } | |
438d8908 | 1228 | } |
d2876d08 DB |
1229 | |
1230 | done: | |
1231 | if (status) | |
1232 | pr_debug("gpio_request: gpio-%d (%s) status %d\n", | |
1233 | gpio, label ? : "?", status); | |
1234 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1235 | return status; | |
1236 | } | |
1237 | EXPORT_SYMBOL_GPL(gpio_request); | |
1238 | ||
1239 | void gpio_free(unsigned gpio) | |
1240 | { | |
1241 | unsigned long flags; | |
1242 | struct gpio_desc *desc; | |
35e8bb51 | 1243 | struct gpio_chip *chip; |
d2876d08 | 1244 | |
3d599d1c UKK |
1245 | might_sleep(); |
1246 | ||
e6de1808 | 1247 | if (!gpio_is_valid(gpio)) { |
d2876d08 DB |
1248 | WARN_ON(extra_checks); |
1249 | return; | |
1250 | } | |
1251 | ||
d8f388d8 DB |
1252 | gpio_unexport(gpio); |
1253 | ||
d2876d08 DB |
1254 | spin_lock_irqsave(&gpio_lock, flags); |
1255 | ||
1256 | desc = &gpio_desc[gpio]; | |
35e8bb51 DB |
1257 | chip = desc->chip; |
1258 | if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) { | |
1259 | if (chip->free) { | |
1260 | spin_unlock_irqrestore(&gpio_lock, flags); | |
9c4ba946 | 1261 | might_sleep_if(chip->can_sleep); |
35e8bb51 DB |
1262 | chip->free(chip, gpio - chip->base); |
1263 | spin_lock_irqsave(&gpio_lock, flags); | |
1264 | } | |
d2876d08 | 1265 | desc_set_label(desc, NULL); |
438d8908 | 1266 | module_put(desc->chip->owner); |
07697461 | 1267 | clear_bit(FLAG_ACTIVE_LOW, &desc->flags); |
35e8bb51 | 1268 | clear_bit(FLAG_REQUESTED, &desc->flags); |
aca5ce14 | 1269 | clear_bit(FLAG_OPEN_DRAIN, &desc->flags); |
25553ff0 | 1270 | clear_bit(FLAG_OPEN_SOURCE, &desc->flags); |
438d8908 | 1271 | } else |
d2876d08 DB |
1272 | WARN_ON(extra_checks); |
1273 | ||
1274 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1275 | } | |
1276 | EXPORT_SYMBOL_GPL(gpio_free); | |
1277 | ||
3e45f1d1 EM |
1278 | /** |
1279 | * gpio_request_one - request a single GPIO with initial configuration | |
1280 | * @gpio: the GPIO number | |
1281 | * @flags: GPIO configuration as specified by GPIOF_* | |
1282 | * @label: a literal description string of this GPIO | |
1283 | */ | |
1284 | int gpio_request_one(unsigned gpio, unsigned long flags, const char *label) | |
1285 | { | |
1286 | int err; | |
1287 | ||
1288 | err = gpio_request(gpio, label); | |
1289 | if (err) | |
1290 | return err; | |
1291 | ||
aca5ce14 LD |
1292 | if (flags & GPIOF_OPEN_DRAIN) |
1293 | set_bit(FLAG_OPEN_DRAIN, &gpio_desc[gpio].flags); | |
1294 | ||
25553ff0 LD |
1295 | if (flags & GPIOF_OPEN_SOURCE) |
1296 | set_bit(FLAG_OPEN_SOURCE, &gpio_desc[gpio].flags); | |
1297 | ||
3e45f1d1 EM |
1298 | if (flags & GPIOF_DIR_IN) |
1299 | err = gpio_direction_input(gpio); | |
1300 | else | |
1301 | err = gpio_direction_output(gpio, | |
1302 | (flags & GPIOF_INIT_HIGH) ? 1 : 0); | |
1303 | ||
e254811c AK |
1304 | if (err) |
1305 | gpio_free(gpio); | |
1306 | ||
3e45f1d1 EM |
1307 | return err; |
1308 | } | |
1309 | EXPORT_SYMBOL_GPL(gpio_request_one); | |
1310 | ||
1311 | /** | |
1312 | * gpio_request_array - request multiple GPIOs in a single call | |
1313 | * @array: array of the 'struct gpio' | |
1314 | * @num: how many GPIOs in the array | |
1315 | */ | |
7c295975 | 1316 | int gpio_request_array(const struct gpio *array, size_t num) |
3e45f1d1 EM |
1317 | { |
1318 | int i, err; | |
1319 | ||
1320 | for (i = 0; i < num; i++, array++) { | |
1321 | err = gpio_request_one(array->gpio, array->flags, array->label); | |
1322 | if (err) | |
1323 | goto err_free; | |
1324 | } | |
1325 | return 0; | |
1326 | ||
1327 | err_free: | |
1328 | while (i--) | |
1329 | gpio_free((--array)->gpio); | |
1330 | return err; | |
1331 | } | |
1332 | EXPORT_SYMBOL_GPL(gpio_request_array); | |
1333 | ||
1334 | /** | |
1335 | * gpio_free_array - release multiple GPIOs in a single call | |
1336 | * @array: array of the 'struct gpio' | |
1337 | * @num: how many GPIOs in the array | |
1338 | */ | |
7c295975 | 1339 | void gpio_free_array(const struct gpio *array, size_t num) |
3e45f1d1 EM |
1340 | { |
1341 | while (num--) | |
1342 | gpio_free((array++)->gpio); | |
1343 | } | |
1344 | EXPORT_SYMBOL_GPL(gpio_free_array); | |
d2876d08 DB |
1345 | |
1346 | /** | |
1347 | * gpiochip_is_requested - return string iff signal was requested | |
1348 | * @chip: controller managing the signal | |
1349 | * @offset: of signal within controller's 0..(ngpio - 1) range | |
1350 | * | |
1351 | * Returns NULL if the GPIO is not currently requested, else a string. | |
1352 | * If debugfs support is enabled, the string returned is the label passed | |
1353 | * to gpio_request(); otherwise it is a meaningless constant. | |
1354 | * | |
1355 | * This function is for use by GPIO controller drivers. The label can | |
1356 | * help with diagnostics, and knowing that the signal is used as a GPIO | |
1357 | * can help avoid accidentally multiplexing it to another controller. | |
1358 | */ | |
1359 | const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset) | |
1360 | { | |
1361 | unsigned gpio = chip->base + offset; | |
1362 | ||
e6de1808 | 1363 | if (!gpio_is_valid(gpio) || gpio_desc[gpio].chip != chip) |
d2876d08 DB |
1364 | return NULL; |
1365 | if (test_bit(FLAG_REQUESTED, &gpio_desc[gpio].flags) == 0) | |
1366 | return NULL; | |
1367 | #ifdef CONFIG_DEBUG_FS | |
1368 | return gpio_desc[gpio].label; | |
1369 | #else | |
1370 | return "?"; | |
1371 | #endif | |
1372 | } | |
1373 | EXPORT_SYMBOL_GPL(gpiochip_is_requested); | |
1374 | ||
1375 | ||
1376 | /* Drivers MUST set GPIO direction before making get/set calls. In | |
1377 | * some cases this is done in early boot, before IRQs are enabled. | |
1378 | * | |
1379 | * As a rule these aren't called more than once (except for drivers | |
1380 | * using the open-drain emulation idiom) so these are natural places | |
1381 | * to accumulate extra debugging checks. Note that we can't (yet) | |
1382 | * rely on gpio_request() having been called beforehand. | |
1383 | */ | |
1384 | ||
1385 | int gpio_direction_input(unsigned gpio) | |
1386 | { | |
1387 | unsigned long flags; | |
1388 | struct gpio_chip *chip; | |
1389 | struct gpio_desc *desc = &gpio_desc[gpio]; | |
1390 | int status = -EINVAL; | |
1391 | ||
1392 | spin_lock_irqsave(&gpio_lock, flags); | |
1393 | ||
e6de1808 | 1394 | if (!gpio_is_valid(gpio)) |
d2876d08 DB |
1395 | goto fail; |
1396 | chip = desc->chip; | |
1397 | if (!chip || !chip->get || !chip->direction_input) | |
1398 | goto fail; | |
1399 | gpio -= chip->base; | |
1400 | if (gpio >= chip->ngpio) | |
1401 | goto fail; | |
35e8bb51 DB |
1402 | status = gpio_ensure_requested(desc, gpio); |
1403 | if (status < 0) | |
1404 | goto fail; | |
d2876d08 DB |
1405 | |
1406 | /* now we know the gpio is valid and chip won't vanish */ | |
1407 | ||
1408 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1409 | ||
9c4ba946 | 1410 | might_sleep_if(chip->can_sleep); |
d2876d08 | 1411 | |
35e8bb51 DB |
1412 | if (status) { |
1413 | status = chip->request(chip, gpio); | |
1414 | if (status < 0) { | |
1415 | pr_debug("GPIO-%d: chip request fail, %d\n", | |
1416 | chip->base + gpio, status); | |
1417 | /* and it's not available to anyone else ... | |
1418 | * gpio_request() is the fully clean solution. | |
1419 | */ | |
1420 | goto lose; | |
1421 | } | |
1422 | } | |
1423 | ||
d2876d08 DB |
1424 | status = chip->direction_input(chip, gpio); |
1425 | if (status == 0) | |
1426 | clear_bit(FLAG_IS_OUT, &desc->flags); | |
3f397c21 UKK |
1427 | |
1428 | trace_gpio_direction(chip->base + gpio, 1, status); | |
35e8bb51 | 1429 | lose: |
d2876d08 DB |
1430 | return status; |
1431 | fail: | |
1432 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1433 | if (status) | |
1434 | pr_debug("%s: gpio-%d status %d\n", | |
145980a0 | 1435 | __func__, gpio, status); |
d2876d08 DB |
1436 | return status; |
1437 | } | |
1438 | EXPORT_SYMBOL_GPL(gpio_direction_input); | |
1439 | ||
1440 | int gpio_direction_output(unsigned gpio, int value) | |
1441 | { | |
1442 | unsigned long flags; | |
1443 | struct gpio_chip *chip; | |
1444 | struct gpio_desc *desc = &gpio_desc[gpio]; | |
1445 | int status = -EINVAL; | |
1446 | ||
aca5ce14 LD |
1447 | /* Open drain pin should not be driven to 1 */ |
1448 | if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags)) | |
1449 | return gpio_direction_input(gpio); | |
1450 | ||
25553ff0 LD |
1451 | /* Open source pin should not be driven to 0 */ |
1452 | if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags)) | |
1453 | return gpio_direction_input(gpio); | |
1454 | ||
d2876d08 DB |
1455 | spin_lock_irqsave(&gpio_lock, flags); |
1456 | ||
e6de1808 | 1457 | if (!gpio_is_valid(gpio)) |
d2876d08 DB |
1458 | goto fail; |
1459 | chip = desc->chip; | |
1460 | if (!chip || !chip->set || !chip->direction_output) | |
1461 | goto fail; | |
1462 | gpio -= chip->base; | |
1463 | if (gpio >= chip->ngpio) | |
1464 | goto fail; | |
35e8bb51 DB |
1465 | status = gpio_ensure_requested(desc, gpio); |
1466 | if (status < 0) | |
1467 | goto fail; | |
d2876d08 DB |
1468 | |
1469 | /* now we know the gpio is valid and chip won't vanish */ | |
1470 | ||
1471 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1472 | ||
9c4ba946 | 1473 | might_sleep_if(chip->can_sleep); |
d2876d08 | 1474 | |
35e8bb51 DB |
1475 | if (status) { |
1476 | status = chip->request(chip, gpio); | |
1477 | if (status < 0) { | |
1478 | pr_debug("GPIO-%d: chip request fail, %d\n", | |
1479 | chip->base + gpio, status); | |
1480 | /* and it's not available to anyone else ... | |
1481 | * gpio_request() is the fully clean solution. | |
1482 | */ | |
1483 | goto lose; | |
1484 | } | |
1485 | } | |
1486 | ||
d2876d08 DB |
1487 | status = chip->direction_output(chip, gpio, value); |
1488 | if (status == 0) | |
1489 | set_bit(FLAG_IS_OUT, &desc->flags); | |
3f397c21 UKK |
1490 | trace_gpio_value(chip->base + gpio, 0, value); |
1491 | trace_gpio_direction(chip->base + gpio, 0, status); | |
35e8bb51 | 1492 | lose: |
d2876d08 DB |
1493 | return status; |
1494 | fail: | |
1495 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1496 | if (status) | |
1497 | pr_debug("%s: gpio-%d status %d\n", | |
145980a0 | 1498 | __func__, gpio, status); |
d2876d08 DB |
1499 | return status; |
1500 | } | |
1501 | EXPORT_SYMBOL_GPL(gpio_direction_output); | |
1502 | ||
c4b5be98 FB |
1503 | /** |
1504 | * gpio_set_debounce - sets @debounce time for a @gpio | |
1505 | * @gpio: the gpio to set debounce time | |
1506 | * @debounce: debounce time is microseconds | |
1507 | */ | |
1508 | int gpio_set_debounce(unsigned gpio, unsigned debounce) | |
1509 | { | |
1510 | unsigned long flags; | |
1511 | struct gpio_chip *chip; | |
1512 | struct gpio_desc *desc = &gpio_desc[gpio]; | |
1513 | int status = -EINVAL; | |
1514 | ||
1515 | spin_lock_irqsave(&gpio_lock, flags); | |
1516 | ||
1517 | if (!gpio_is_valid(gpio)) | |
1518 | goto fail; | |
1519 | chip = desc->chip; | |
1520 | if (!chip || !chip->set || !chip->set_debounce) | |
1521 | goto fail; | |
1522 | gpio -= chip->base; | |
1523 | if (gpio >= chip->ngpio) | |
1524 | goto fail; | |
1525 | status = gpio_ensure_requested(desc, gpio); | |
1526 | if (status < 0) | |
1527 | goto fail; | |
1528 | ||
1529 | /* now we know the gpio is valid and chip won't vanish */ | |
1530 | ||
1531 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1532 | ||
9c4ba946 | 1533 | might_sleep_if(chip->can_sleep); |
c4b5be98 FB |
1534 | |
1535 | return chip->set_debounce(chip, gpio, debounce); | |
1536 | ||
1537 | fail: | |
1538 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1539 | if (status) | |
1540 | pr_debug("%s: gpio-%d status %d\n", | |
1541 | __func__, gpio, status); | |
1542 | ||
1543 | return status; | |
1544 | } | |
1545 | EXPORT_SYMBOL_GPL(gpio_set_debounce); | |
d2876d08 DB |
1546 | |
1547 | /* I/O calls are only valid after configuration completed; the relevant | |
1548 | * "is this a valid GPIO" error checks should already have been done. | |
1549 | * | |
1550 | * "Get" operations are often inlinable as reading a pin value register, | |
1551 | * and masking the relevant bit in that register. | |
1552 | * | |
1553 | * When "set" operations are inlinable, they involve writing that mask to | |
1554 | * one register to set a low value, or a different register to set it high. | |
1555 | * Otherwise locking is needed, so there may be little value to inlining. | |
1556 | * | |
1557 | *------------------------------------------------------------------------ | |
1558 | * | |
1559 | * IMPORTANT!!! The hot paths -- get/set value -- assume that callers | |
1560 | * have requested the GPIO. That can include implicit requesting by | |
1561 | * a direction setting call. Marking a gpio as requested locks its chip | |
1562 | * in memory, guaranteeing that these table lookups need no more locking | |
1563 | * and that gpiochip_remove() will fail. | |
1564 | * | |
1565 | * REVISIT when debugging, consider adding some instrumentation to ensure | |
1566 | * that the GPIO was actually requested. | |
1567 | */ | |
1568 | ||
1569 | /** | |
1570 | * __gpio_get_value() - return a gpio's value | |
1571 | * @gpio: gpio whose value will be returned | |
1572 | * Context: any | |
1573 | * | |
1574 | * This is used directly or indirectly to implement gpio_get_value(). | |
1575 | * It returns the zero or nonzero value provided by the associated | |
1576 | * gpio_chip.get() method; or zero if no such method is provided. | |
1577 | */ | |
1578 | int __gpio_get_value(unsigned gpio) | |
1579 | { | |
1580 | struct gpio_chip *chip; | |
3f397c21 | 1581 | int value; |
d2876d08 DB |
1582 | |
1583 | chip = gpio_to_chip(gpio); | |
e4e449e8 | 1584 | /* Should be using gpio_get_value_cansleep() */ |
9c4ba946 | 1585 | WARN_ON(chip->can_sleep); |
3f397c21 UKK |
1586 | value = chip->get ? chip->get(chip, gpio - chip->base) : 0; |
1587 | trace_gpio_value(gpio, 1, value); | |
1588 | return value; | |
d2876d08 DB |
1589 | } |
1590 | EXPORT_SYMBOL_GPL(__gpio_get_value); | |
1591 | ||
aca5ce14 LD |
1592 | /* |
1593 | * _gpio_set_open_drain_value() - Set the open drain gpio's value. | |
1594 | * @gpio: Gpio whose state need to be set. | |
1595 | * @chip: Gpio chip. | |
1596 | * @value: Non-zero for setting it HIGH otherise it will set to LOW. | |
1597 | */ | |
1598 | static void _gpio_set_open_drain_value(unsigned gpio, | |
1599 | struct gpio_chip *chip, int value) | |
1600 | { | |
1601 | int err = 0; | |
1602 | if (value) { | |
1603 | err = chip->direction_input(chip, gpio - chip->base); | |
1604 | if (!err) | |
1605 | clear_bit(FLAG_IS_OUT, &gpio_desc[gpio].flags); | |
1606 | } else { | |
1607 | err = chip->direction_output(chip, gpio - chip->base, 0); | |
1608 | if (!err) | |
1609 | set_bit(FLAG_IS_OUT, &gpio_desc[gpio].flags); | |
1610 | } | |
1611 | trace_gpio_direction(gpio, value, err); | |
1612 | if (err < 0) | |
1613 | pr_err("%s: Error in set_value for open drain gpio%d err %d\n", | |
1614 | __func__, gpio, err); | |
1615 | } | |
1616 | ||
25553ff0 LD |
1617 | /* |
1618 | * _gpio_set_open_source() - Set the open source gpio's value. | |
1619 | * @gpio: Gpio whose state need to be set. | |
1620 | * @chip: Gpio chip. | |
1621 | * @value: Non-zero for setting it HIGH otherise it will set to LOW. | |
1622 | */ | |
1623 | static void _gpio_set_open_source_value(unsigned gpio, | |
1624 | struct gpio_chip *chip, int value) | |
1625 | { | |
1626 | int err = 0; | |
1627 | if (value) { | |
1628 | err = chip->direction_output(chip, gpio - chip->base, 1); | |
1629 | if (!err) | |
1630 | set_bit(FLAG_IS_OUT, &gpio_desc[gpio].flags); | |
1631 | } else { | |
1632 | err = chip->direction_input(chip, gpio - chip->base); | |
1633 | if (!err) | |
1634 | clear_bit(FLAG_IS_OUT, &gpio_desc[gpio].flags); | |
1635 | } | |
1636 | trace_gpio_direction(gpio, !value, err); | |
1637 | if (err < 0) | |
1638 | pr_err("%s: Error in set_value for open source gpio%d err %d\n", | |
1639 | __func__, gpio, err); | |
1640 | } | |
1641 | ||
1642 | ||
d2876d08 DB |
1643 | /** |
1644 | * __gpio_set_value() - assign a gpio's value | |
1645 | * @gpio: gpio whose value will be assigned | |
1646 | * @value: value to assign | |
1647 | * Context: any | |
1648 | * | |
1649 | * This is used directly or indirectly to implement gpio_set_value(). | |
1650 | * It invokes the associated gpio_chip.set() method. | |
1651 | */ | |
1652 | void __gpio_set_value(unsigned gpio, int value) | |
1653 | { | |
1654 | struct gpio_chip *chip; | |
1655 | ||
1656 | chip = gpio_to_chip(gpio); | |
e4e449e8 | 1657 | /* Should be using gpio_set_value_cansleep() */ |
9c4ba946 | 1658 | WARN_ON(chip->can_sleep); |
3f397c21 | 1659 | trace_gpio_value(gpio, 0, value); |
aca5ce14 LD |
1660 | if (test_bit(FLAG_OPEN_DRAIN, &gpio_desc[gpio].flags)) |
1661 | _gpio_set_open_drain_value(gpio, chip, value); | |
25553ff0 LD |
1662 | else if (test_bit(FLAG_OPEN_SOURCE, &gpio_desc[gpio].flags)) |
1663 | _gpio_set_open_source_value(gpio, chip, value); | |
aca5ce14 LD |
1664 | else |
1665 | chip->set(chip, gpio - chip->base, value); | |
d2876d08 DB |
1666 | } |
1667 | EXPORT_SYMBOL_GPL(__gpio_set_value); | |
1668 | ||
1669 | /** | |
1670 | * __gpio_cansleep() - report whether gpio value access will sleep | |
1671 | * @gpio: gpio in question | |
1672 | * Context: any | |
1673 | * | |
1674 | * This is used directly or indirectly to implement gpio_cansleep(). It | |
1675 | * returns nonzero if access reading or writing the GPIO value can sleep. | |
1676 | */ | |
1677 | int __gpio_cansleep(unsigned gpio) | |
1678 | { | |
1679 | struct gpio_chip *chip; | |
1680 | ||
1681 | /* only call this on GPIOs that are valid! */ | |
1682 | chip = gpio_to_chip(gpio); | |
1683 | ||
1684 | return chip->can_sleep; | |
1685 | } | |
1686 | EXPORT_SYMBOL_GPL(__gpio_cansleep); | |
1687 | ||
0f6d504e DB |
1688 | /** |
1689 | * __gpio_to_irq() - return the IRQ corresponding to a GPIO | |
1690 | * @gpio: gpio whose IRQ will be returned (already requested) | |
1691 | * Context: any | |
1692 | * | |
1693 | * This is used directly or indirectly to implement gpio_to_irq(). | |
1694 | * It returns the number of the IRQ signaled by this (input) GPIO, | |
1695 | * or a negative errno. | |
1696 | */ | |
1697 | int __gpio_to_irq(unsigned gpio) | |
1698 | { | |
1699 | struct gpio_chip *chip; | |
1700 | ||
1701 | chip = gpio_to_chip(gpio); | |
1702 | return chip->to_irq ? chip->to_irq(chip, gpio - chip->base) : -ENXIO; | |
1703 | } | |
1704 | EXPORT_SYMBOL_GPL(__gpio_to_irq); | |
1705 | ||
d2876d08 DB |
1706 | |
1707 | ||
1708 | /* There's no value in making it easy to inline GPIO calls that may sleep. | |
1709 | * Common examples include ones connected to I2C or SPI chips. | |
1710 | */ | |
1711 | ||
1712 | int gpio_get_value_cansleep(unsigned gpio) | |
1713 | { | |
1714 | struct gpio_chip *chip; | |
3f397c21 | 1715 | int value; |
d2876d08 DB |
1716 | |
1717 | might_sleep_if(extra_checks); | |
1718 | chip = gpio_to_chip(gpio); | |
3f397c21 UKK |
1719 | value = chip->get ? chip->get(chip, gpio - chip->base) : 0; |
1720 | trace_gpio_value(gpio, 1, value); | |
1721 | return value; | |
d2876d08 DB |
1722 | } |
1723 | EXPORT_SYMBOL_GPL(gpio_get_value_cansleep); | |
1724 | ||
1725 | void gpio_set_value_cansleep(unsigned gpio, int value) | |
1726 | { | |
1727 | struct gpio_chip *chip; | |
1728 | ||
1729 | might_sleep_if(extra_checks); | |
1730 | chip = gpio_to_chip(gpio); | |
3f397c21 | 1731 | trace_gpio_value(gpio, 0, value); |
aca5ce14 LD |
1732 | if (test_bit(FLAG_OPEN_DRAIN, &gpio_desc[gpio].flags)) |
1733 | _gpio_set_open_drain_value(gpio, chip, value); | |
25553ff0 LD |
1734 | else if (test_bit(FLAG_OPEN_SOURCE, &gpio_desc[gpio].flags)) |
1735 | _gpio_set_open_source_value(gpio, chip, value); | |
aca5ce14 LD |
1736 | else |
1737 | chip->set(chip, gpio - chip->base, value); | |
d2876d08 DB |
1738 | } |
1739 | EXPORT_SYMBOL_GPL(gpio_set_value_cansleep); | |
1740 | ||
1741 | ||
1742 | #ifdef CONFIG_DEBUG_FS | |
1743 | ||
d2876d08 DB |
1744 | static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) |
1745 | { | |
1746 | unsigned i; | |
1747 | unsigned gpio = chip->base; | |
1748 | struct gpio_desc *gdesc = &gpio_desc[gpio]; | |
1749 | int is_out; | |
1750 | ||
1751 | for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) { | |
1752 | if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) | |
1753 | continue; | |
1754 | ||
1755 | is_out = test_bit(FLAG_IS_OUT, &gdesc->flags); | |
6e8ba729 | 1756 | seq_printf(s, " gpio-%-3d (%-20.20s) %s %s", |
d2876d08 DB |
1757 | gpio, gdesc->label, |
1758 | is_out ? "out" : "in ", | |
1759 | chip->get | |
1760 | ? (chip->get(chip, i) ? "hi" : "lo") | |
1761 | : "? "); | |
d2876d08 DB |
1762 | seq_printf(s, "\n"); |
1763 | } | |
1764 | } | |
1765 | ||
1766 | static int gpiolib_show(struct seq_file *s, void *unused) | |
1767 | { | |
1768 | struct gpio_chip *chip = NULL; | |
1769 | unsigned gpio; | |
1770 | int started = 0; | |
1771 | ||
1772 | /* REVISIT this isn't locked against gpio_chip removal ... */ | |
1773 | ||
e6de1808 | 1774 | for (gpio = 0; gpio_is_valid(gpio); gpio++) { |
d8f388d8 DB |
1775 | struct device *dev; |
1776 | ||
d2876d08 DB |
1777 | if (chip == gpio_desc[gpio].chip) |
1778 | continue; | |
1779 | chip = gpio_desc[gpio].chip; | |
1780 | if (!chip) | |
1781 | continue; | |
1782 | ||
d8f388d8 | 1783 | seq_printf(s, "%sGPIOs %d-%d", |
d2876d08 | 1784 | started ? "\n" : "", |
d8f388d8 DB |
1785 | chip->base, chip->base + chip->ngpio - 1); |
1786 | dev = chip->dev; | |
1787 | if (dev) | |
1788 | seq_printf(s, ", %s/%s", | |
1789 | dev->bus ? dev->bus->name : "no-bus", | |
14ab309d | 1790 | dev_name(dev)); |
d8f388d8 DB |
1791 | if (chip->label) |
1792 | seq_printf(s, ", %s", chip->label); | |
1793 | if (chip->can_sleep) | |
1794 | seq_printf(s, ", can sleep"); | |
1795 | seq_printf(s, ":\n"); | |
1796 | ||
d2876d08 DB |
1797 | started = 1; |
1798 | if (chip->dbg_show) | |
1799 | chip->dbg_show(s, chip); | |
1800 | else | |
1801 | gpiolib_dbg_show(s, chip); | |
1802 | } | |
1803 | return 0; | |
1804 | } | |
1805 | ||
1806 | static int gpiolib_open(struct inode *inode, struct file *file) | |
1807 | { | |
1808 | return single_open(file, gpiolib_show, NULL); | |
1809 | } | |
1810 | ||
828c0950 | 1811 | static const struct file_operations gpiolib_operations = { |
d2876d08 DB |
1812 | .open = gpiolib_open, |
1813 | .read = seq_read, | |
1814 | .llseek = seq_lseek, | |
1815 | .release = single_release, | |
1816 | }; | |
1817 | ||
1818 | static int __init gpiolib_debugfs_init(void) | |
1819 | { | |
1820 | /* /sys/kernel/debug/gpio */ | |
1821 | (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO, | |
1822 | NULL, NULL, &gpiolib_operations); | |
1823 | return 0; | |
1824 | } | |
1825 | subsys_initcall(gpiolib_debugfs_init); | |
1826 | ||
1827 | #endif /* DEBUG_FS */ |