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 DB |
14 | |
15 | ||
16 | /* Optional implementation infrastructure for GPIO interfaces. | |
17 | * | |
18 | * Platforms may want to use this if they tend to use very many GPIOs | |
19 | * that aren't part of a System-On-Chip core; or across I2C/SPI/etc. | |
20 | * | |
21 | * When kernel footprint or instruction count is an issue, simpler | |
22 | * implementations may be preferred. The GPIO programming interface | |
23 | * allows for inlining speed-critical get/set operations for common | |
24 | * cases, so that access to SOC-integrated GPIOs can sometimes cost | |
25 | * only an instruction or two per bit. | |
26 | */ | |
27 | ||
28 | ||
29 | /* When debugging, extend minimal trust to callers and platform code. | |
30 | * Also emit diagnostic messages that may help initial bringup, when | |
31 | * board setup or driver bugs are most common. | |
32 | * | |
33 | * Otherwise, minimize overhead in what may be bitbanging codepaths. | |
34 | */ | |
35 | #ifdef DEBUG | |
36 | #define extra_checks 1 | |
37 | #else | |
38 | #define extra_checks 0 | |
39 | #endif | |
40 | ||
41 | /* gpio_lock prevents conflicts during gpio_desc[] table updates. | |
42 | * While any GPIO is requested, its gpio_chip is not removable; | |
43 | * each GPIO's "requested" flag serves as a lock and refcount. | |
44 | */ | |
45 | static DEFINE_SPINLOCK(gpio_lock); | |
46 | ||
47 | struct gpio_desc { | |
48 | struct gpio_chip *chip; | |
49 | unsigned long flags; | |
50 | /* flag symbols are bit numbers */ | |
51 | #define FLAG_REQUESTED 0 | |
52 | #define FLAG_IS_OUT 1 | |
169b6a7a | 53 | #define FLAG_RESERVED 2 |
d8f388d8 DB |
54 | #define FLAG_EXPORT 3 /* protected by sysfs_lock */ |
55 | #define FLAG_SYSFS 4 /* exported via /sys/class/gpio/control */ | |
ff77c352 DG |
56 | #define FLAG_TRIG_FALL 5 /* trigger on falling edge */ |
57 | #define FLAG_TRIG_RISE 6 /* trigger on rising edge */ | |
07697461 | 58 | #define FLAG_ACTIVE_LOW 7 /* sysfs value has active low */ |
ff77c352 DG |
59 | |
60 | #define PDESC_ID_SHIFT 16 /* add new flags before this one */ | |
61 | ||
62 | #define GPIO_FLAGS_MASK ((1 << PDESC_ID_SHIFT) - 1) | |
63 | #define GPIO_TRIGGER_MASK (BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE)) | |
d2876d08 DB |
64 | |
65 | #ifdef CONFIG_DEBUG_FS | |
66 | const char *label; | |
67 | #endif | |
68 | }; | |
69 | static struct gpio_desc gpio_desc[ARCH_NR_GPIOS]; | |
70 | ||
ff77c352 DG |
71 | #ifdef CONFIG_GPIO_SYSFS |
72 | struct poll_desc { | |
73 | struct work_struct work; | |
74 | struct sysfs_dirent *value_sd; | |
75 | }; | |
76 | ||
77 | static struct idr pdesc_idr; | |
78 | #endif | |
79 | ||
d2876d08 DB |
80 | static inline void desc_set_label(struct gpio_desc *d, const char *label) |
81 | { | |
82 | #ifdef CONFIG_DEBUG_FS | |
83 | d->label = label; | |
84 | #endif | |
85 | } | |
86 | ||
87 | /* Warn when drivers omit gpio_request() calls -- legal but ill-advised | |
88 | * when setting direction, and otherwise illegal. Until board setup code | |
89 | * and drivers use explicit requests everywhere (which won't happen when | |
90 | * those calls have no teeth) we can't avoid autorequesting. This nag | |
35e8bb51 DB |
91 | * message should motivate switching to explicit requests... so should |
92 | * the weaker cleanup after faults, compared to gpio_request(). | |
8a0cecff DB |
93 | * |
94 | * NOTE: the autorequest mechanism is going away; at this point it's | |
95 | * only "legal" in the sense that (old) code using it won't break yet, | |
96 | * but instead only triggers a WARN() stack dump. | |
d2876d08 | 97 | */ |
35e8bb51 | 98 | static int gpio_ensure_requested(struct gpio_desc *desc, unsigned offset) |
d2876d08 | 99 | { |
8a0cecff DB |
100 | const struct gpio_chip *chip = desc->chip; |
101 | const int gpio = chip->base + offset; | |
35e8bb51 | 102 | |
8a0cecff DB |
103 | if (WARN(test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0, |
104 | "autorequest GPIO-%d\n", gpio)) { | |
35e8bb51 DB |
105 | if (!try_module_get(chip->owner)) { |
106 | pr_err("GPIO-%d: module can't be gotten \n", gpio); | |
107 | clear_bit(FLAG_REQUESTED, &desc->flags); | |
108 | /* lose */ | |
109 | return -EIO; | |
110 | } | |
d2876d08 | 111 | desc_set_label(desc, "[auto]"); |
35e8bb51 DB |
112 | /* caller must chip->request() w/o spinlock */ |
113 | if (chip->request) | |
114 | return 1; | |
d2876d08 | 115 | } |
35e8bb51 | 116 | return 0; |
d2876d08 DB |
117 | } |
118 | ||
119 | /* caller holds gpio_lock *OR* gpio is marked as requested */ | |
120 | static inline struct gpio_chip *gpio_to_chip(unsigned gpio) | |
121 | { | |
122 | return gpio_desc[gpio].chip; | |
123 | } | |
124 | ||
8d0aab2f AV |
125 | /* dynamic allocation of GPIOs, e.g. on a hotplugged device */ |
126 | static int gpiochip_find_base(int ngpio) | |
127 | { | |
128 | int i; | |
129 | int spare = 0; | |
130 | int base = -ENOSPC; | |
131 | ||
132 | for (i = ARCH_NR_GPIOS - 1; i >= 0 ; i--) { | |
169b6a7a AV |
133 | struct gpio_desc *desc = &gpio_desc[i]; |
134 | struct gpio_chip *chip = desc->chip; | |
8d0aab2f | 135 | |
169b6a7a | 136 | if (!chip && !test_bit(FLAG_RESERVED, &desc->flags)) { |
8d0aab2f AV |
137 | spare++; |
138 | if (spare == ngpio) { | |
139 | base = i; | |
140 | break; | |
141 | } | |
142 | } else { | |
143 | spare = 0; | |
169b6a7a AV |
144 | if (chip) |
145 | i -= chip->ngpio - 1; | |
8d0aab2f AV |
146 | } |
147 | } | |
148 | ||
149 | if (gpio_is_valid(base)) | |
150 | pr_debug("%s: found new base at %d\n", __func__, base); | |
151 | return base; | |
152 | } | |
153 | ||
169b6a7a AV |
154 | /** |
155 | * gpiochip_reserve() - reserve range of gpios to use with platform code only | |
156 | * @start: starting gpio number | |
157 | * @ngpio: number of gpios to reserve | |
158 | * Context: platform init, potentially before irqs or kmalloc will work | |
159 | * | |
160 | * Returns a negative errno if any gpio within the range is already reserved | |
161 | * or registered, else returns zero as a success code. Use this function | |
162 | * to mark a range of gpios as unavailable for dynamic gpio number allocation, | |
163 | * for example because its driver support is not yet loaded. | |
164 | */ | |
165 | int __init gpiochip_reserve(int start, int ngpio) | |
166 | { | |
167 | int ret = 0; | |
168 | unsigned long flags; | |
169 | int i; | |
170 | ||
bff5fda9 | 171 | if (!gpio_is_valid(start) || !gpio_is_valid(start + ngpio - 1)) |
169b6a7a AV |
172 | return -EINVAL; |
173 | ||
174 | spin_lock_irqsave(&gpio_lock, flags); | |
175 | ||
176 | for (i = start; i < start + ngpio; i++) { | |
177 | struct gpio_desc *desc = &gpio_desc[i]; | |
178 | ||
179 | if (desc->chip || test_bit(FLAG_RESERVED, &desc->flags)) { | |
180 | ret = -EBUSY; | |
181 | goto err; | |
182 | } | |
183 | ||
184 | set_bit(FLAG_RESERVED, &desc->flags); | |
185 | } | |
186 | ||
187 | pr_debug("%s: reserved gpios from %d to %d\n", | |
188 | __func__, start, start + ngpio - 1); | |
189 | err: | |
190 | spin_unlock_irqrestore(&gpio_lock, flags); | |
191 | ||
192 | return ret; | |
193 | } | |
194 | ||
d8f388d8 DB |
195 | #ifdef CONFIG_GPIO_SYSFS |
196 | ||
197 | /* lock protects against unexport_gpio() being called while | |
198 | * sysfs files are active. | |
199 | */ | |
200 | static DEFINE_MUTEX(sysfs_lock); | |
201 | ||
202 | /* | |
203 | * /sys/class/gpio/gpioN... only for GPIOs that are exported | |
204 | * /direction | |
205 | * * MAY BE OMITTED if kernel won't allow direction changes | |
206 | * * is read/write as "in" or "out" | |
207 | * * may also be written as "high" or "low", initializing | |
208 | * output value as specified ("out" implies "low") | |
209 | * /value | |
210 | * * always readable, subject to hardware behavior | |
211 | * * may be writable, as zero/nonzero | |
ff77c352 DG |
212 | * /edge |
213 | * * configures behavior of poll(2) on /value | |
214 | * * available only if pin can generate IRQs on input | |
215 | * * is read/write as "none", "falling", "rising", or "both" | |
07697461 JN |
216 | * /active_low |
217 | * * configures polarity of /value | |
218 | * * is read/write as zero/nonzero | |
219 | * * also affects existing and subsequent "falling" and "rising" | |
220 | * /edge configuration | |
d8f388d8 DB |
221 | */ |
222 | ||
223 | static ssize_t gpio_direction_show(struct device *dev, | |
224 | struct device_attribute *attr, char *buf) | |
225 | { | |
226 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
227 | ssize_t status; | |
228 | ||
229 | mutex_lock(&sysfs_lock); | |
230 | ||
231 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
232 | status = -EIO; | |
233 | else | |
234 | status = sprintf(buf, "%s\n", | |
235 | test_bit(FLAG_IS_OUT, &desc->flags) | |
236 | ? "out" : "in"); | |
237 | ||
238 | mutex_unlock(&sysfs_lock); | |
239 | return status; | |
240 | } | |
241 | ||
242 | static ssize_t gpio_direction_store(struct device *dev, | |
243 | struct device_attribute *attr, const char *buf, size_t size) | |
244 | { | |
245 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
246 | unsigned gpio = desc - gpio_desc; | |
247 | ssize_t status; | |
248 | ||
249 | mutex_lock(&sysfs_lock); | |
250 | ||
251 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
252 | status = -EIO; | |
253 | else if (sysfs_streq(buf, "high")) | |
254 | status = gpio_direction_output(gpio, 1); | |
255 | else if (sysfs_streq(buf, "out") || sysfs_streq(buf, "low")) | |
256 | status = gpio_direction_output(gpio, 0); | |
257 | else if (sysfs_streq(buf, "in")) | |
258 | status = gpio_direction_input(gpio); | |
259 | else | |
260 | status = -EINVAL; | |
261 | ||
262 | mutex_unlock(&sysfs_lock); | |
263 | return status ? : size; | |
264 | } | |
265 | ||
07697461 | 266 | static /* const */ DEVICE_ATTR(direction, 0644, |
d8f388d8 DB |
267 | gpio_direction_show, gpio_direction_store); |
268 | ||
269 | static ssize_t gpio_value_show(struct device *dev, | |
270 | struct device_attribute *attr, char *buf) | |
271 | { | |
272 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
273 | unsigned gpio = desc - gpio_desc; | |
274 | ssize_t status; | |
275 | ||
276 | mutex_lock(&sysfs_lock); | |
277 | ||
07697461 | 278 | if (!test_bit(FLAG_EXPORT, &desc->flags)) { |
d8f388d8 | 279 | status = -EIO; |
07697461 JN |
280 | } else { |
281 | int value; | |
282 | ||
283 | value = !!gpio_get_value_cansleep(gpio); | |
284 | if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) | |
285 | value = !value; | |
286 | ||
287 | status = sprintf(buf, "%d\n", value); | |
288 | } | |
d8f388d8 DB |
289 | |
290 | mutex_unlock(&sysfs_lock); | |
291 | return status; | |
292 | } | |
293 | ||
294 | static ssize_t gpio_value_store(struct device *dev, | |
295 | struct device_attribute *attr, const char *buf, size_t size) | |
296 | { | |
297 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
298 | unsigned gpio = desc - gpio_desc; | |
299 | ssize_t status; | |
300 | ||
301 | mutex_lock(&sysfs_lock); | |
302 | ||
303 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
304 | status = -EIO; | |
305 | else if (!test_bit(FLAG_IS_OUT, &desc->flags)) | |
306 | status = -EPERM; | |
307 | else { | |
308 | long value; | |
309 | ||
310 | status = strict_strtol(buf, 0, &value); | |
311 | if (status == 0) { | |
07697461 JN |
312 | if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) |
313 | value = !value; | |
d8f388d8 DB |
314 | gpio_set_value_cansleep(gpio, value != 0); |
315 | status = size; | |
316 | } | |
317 | } | |
318 | ||
319 | mutex_unlock(&sysfs_lock); | |
320 | return status; | |
321 | } | |
322 | ||
07697461 | 323 | static const DEVICE_ATTR(value, 0644, |
d8f388d8 DB |
324 | gpio_value_show, gpio_value_store); |
325 | ||
ff77c352 DG |
326 | static irqreturn_t gpio_sysfs_irq(int irq, void *priv) |
327 | { | |
328 | struct work_struct *work = priv; | |
329 | ||
330 | schedule_work(work); | |
331 | return IRQ_HANDLED; | |
332 | } | |
333 | ||
334 | static void gpio_notify_sysfs(struct work_struct *work) | |
335 | { | |
336 | struct poll_desc *pdesc; | |
337 | ||
338 | pdesc = container_of(work, struct poll_desc, work); | |
339 | sysfs_notify_dirent(pdesc->value_sd); | |
340 | } | |
341 | ||
342 | static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev, | |
343 | unsigned long gpio_flags) | |
344 | { | |
345 | struct poll_desc *pdesc; | |
346 | unsigned long irq_flags; | |
347 | int ret, irq, id; | |
348 | ||
349 | if ((desc->flags & GPIO_TRIGGER_MASK) == gpio_flags) | |
350 | return 0; | |
351 | ||
352 | irq = gpio_to_irq(desc - gpio_desc); | |
353 | if (irq < 0) | |
354 | return -EIO; | |
355 | ||
356 | id = desc->flags >> PDESC_ID_SHIFT; | |
357 | pdesc = idr_find(&pdesc_idr, id); | |
358 | if (pdesc) { | |
359 | free_irq(irq, &pdesc->work); | |
360 | cancel_work_sync(&pdesc->work); | |
361 | } | |
362 | ||
363 | desc->flags &= ~GPIO_TRIGGER_MASK; | |
364 | ||
365 | if (!gpio_flags) { | |
366 | ret = 0; | |
367 | goto free_sd; | |
368 | } | |
369 | ||
370 | irq_flags = IRQF_SHARED; | |
371 | if (test_bit(FLAG_TRIG_FALL, &gpio_flags)) | |
07697461 JN |
372 | irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? |
373 | IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING; | |
ff77c352 | 374 | if (test_bit(FLAG_TRIG_RISE, &gpio_flags)) |
07697461 JN |
375 | irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? |
376 | IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; | |
ff77c352 DG |
377 | |
378 | if (!pdesc) { | |
379 | pdesc = kmalloc(sizeof(*pdesc), GFP_KERNEL); | |
380 | if (!pdesc) { | |
381 | ret = -ENOMEM; | |
382 | goto err_out; | |
383 | } | |
384 | ||
385 | do { | |
386 | ret = -ENOMEM; | |
387 | if (idr_pre_get(&pdesc_idr, GFP_KERNEL)) | |
388 | ret = idr_get_new_above(&pdesc_idr, | |
389 | pdesc, 1, &id); | |
390 | } while (ret == -EAGAIN); | |
391 | ||
392 | if (ret) | |
393 | goto free_mem; | |
394 | ||
395 | desc->flags &= GPIO_FLAGS_MASK; | |
396 | desc->flags |= (unsigned long)id << PDESC_ID_SHIFT; | |
397 | ||
398 | if (desc->flags >> PDESC_ID_SHIFT != id) { | |
399 | ret = -ERANGE; | |
400 | goto free_id; | |
401 | } | |
402 | ||
3ff195b0 | 403 | pdesc->value_sd = sysfs_get_dirent(dev->kobj.sd, NULL, "value"); |
ff77c352 DG |
404 | if (!pdesc->value_sd) { |
405 | ret = -ENODEV; | |
406 | goto free_id; | |
407 | } | |
408 | INIT_WORK(&pdesc->work, gpio_notify_sysfs); | |
409 | } | |
410 | ||
411 | ret = request_irq(irq, gpio_sysfs_irq, irq_flags, | |
412 | "gpiolib", &pdesc->work); | |
413 | if (ret) | |
414 | goto free_sd; | |
415 | ||
416 | desc->flags |= gpio_flags; | |
417 | return 0; | |
418 | ||
419 | free_sd: | |
3913fd5e DC |
420 | if (pdesc) |
421 | sysfs_put(pdesc->value_sd); | |
ff77c352 DG |
422 | free_id: |
423 | idr_remove(&pdesc_idr, id); | |
424 | desc->flags &= GPIO_FLAGS_MASK; | |
425 | free_mem: | |
426 | kfree(pdesc); | |
427 | err_out: | |
428 | return ret; | |
429 | } | |
430 | ||
431 | static const struct { | |
432 | const char *name; | |
433 | unsigned long flags; | |
434 | } trigger_types[] = { | |
435 | { "none", 0 }, | |
436 | { "falling", BIT(FLAG_TRIG_FALL) }, | |
437 | { "rising", BIT(FLAG_TRIG_RISE) }, | |
438 | { "both", BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE) }, | |
439 | }; | |
440 | ||
441 | static ssize_t gpio_edge_show(struct device *dev, | |
442 | struct device_attribute *attr, char *buf) | |
443 | { | |
444 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
445 | ssize_t status; | |
446 | ||
447 | mutex_lock(&sysfs_lock); | |
448 | ||
449 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
450 | status = -EIO; | |
451 | else { | |
452 | int i; | |
453 | ||
454 | status = 0; | |
455 | for (i = 0; i < ARRAY_SIZE(trigger_types); i++) | |
456 | if ((desc->flags & GPIO_TRIGGER_MASK) | |
457 | == trigger_types[i].flags) { | |
458 | status = sprintf(buf, "%s\n", | |
459 | trigger_types[i].name); | |
460 | break; | |
461 | } | |
462 | } | |
463 | ||
464 | mutex_unlock(&sysfs_lock); | |
465 | return status; | |
466 | } | |
467 | ||
468 | static ssize_t gpio_edge_store(struct device *dev, | |
469 | struct device_attribute *attr, const char *buf, size_t size) | |
470 | { | |
471 | struct gpio_desc *desc = dev_get_drvdata(dev); | |
472 | ssize_t status; | |
473 | int i; | |
474 | ||
475 | for (i = 0; i < ARRAY_SIZE(trigger_types); i++) | |
476 | if (sysfs_streq(trigger_types[i].name, buf)) | |
477 | goto found; | |
478 | return -EINVAL; | |
479 | ||
480 | found: | |
481 | mutex_lock(&sysfs_lock); | |
482 | ||
483 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
484 | status = -EIO; | |
485 | else { | |
486 | status = gpio_setup_irq(desc, dev, trigger_types[i].flags); | |
487 | if (!status) | |
488 | status = size; | |
489 | } | |
490 | ||
491 | mutex_unlock(&sysfs_lock); | |
492 | ||
493 | return status; | |
494 | } | |
495 | ||
496 | static DEVICE_ATTR(edge, 0644, gpio_edge_show, gpio_edge_store); | |
497 | ||
07697461 JN |
498 | static int sysfs_set_active_low(struct gpio_desc *desc, struct device *dev, |
499 | int value) | |
500 | { | |
501 | int status = 0; | |
502 | ||
503 | if (!!test_bit(FLAG_ACTIVE_LOW, &desc->flags) == !!value) | |
504 | return 0; | |
505 | ||
506 | if (value) | |
507 | set_bit(FLAG_ACTIVE_LOW, &desc->flags); | |
508 | else | |
509 | clear_bit(FLAG_ACTIVE_LOW, &desc->flags); | |
510 | ||
511 | /* reconfigure poll(2) support if enabled on one edge only */ | |
512 | if (dev != NULL && (!!test_bit(FLAG_TRIG_RISE, &desc->flags) ^ | |
513 | !!test_bit(FLAG_TRIG_FALL, &desc->flags))) { | |
514 | unsigned long trigger_flags = desc->flags & GPIO_TRIGGER_MASK; | |
515 | ||
516 | gpio_setup_irq(desc, dev, 0); | |
517 | status = gpio_setup_irq(desc, dev, trigger_flags); | |
518 | } | |
519 | ||
520 | return status; | |
521 | } | |
522 | ||
523 | static ssize_t gpio_active_low_show(struct device *dev, | |
524 | struct device_attribute *attr, char *buf) | |
525 | { | |
526 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
527 | ssize_t status; | |
528 | ||
529 | mutex_lock(&sysfs_lock); | |
530 | ||
531 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
532 | status = -EIO; | |
533 | else | |
534 | status = sprintf(buf, "%d\n", | |
535 | !!test_bit(FLAG_ACTIVE_LOW, &desc->flags)); | |
536 | ||
537 | mutex_unlock(&sysfs_lock); | |
538 | ||
539 | return status; | |
540 | } | |
541 | ||
542 | static ssize_t gpio_active_low_store(struct device *dev, | |
543 | struct device_attribute *attr, const char *buf, size_t size) | |
544 | { | |
545 | struct gpio_desc *desc = dev_get_drvdata(dev); | |
546 | ssize_t status; | |
547 | ||
548 | mutex_lock(&sysfs_lock); | |
549 | ||
550 | if (!test_bit(FLAG_EXPORT, &desc->flags)) { | |
551 | status = -EIO; | |
552 | } else { | |
553 | long value; | |
554 | ||
555 | status = strict_strtol(buf, 0, &value); | |
556 | if (status == 0) | |
557 | status = sysfs_set_active_low(desc, dev, value != 0); | |
558 | } | |
559 | ||
560 | mutex_unlock(&sysfs_lock); | |
561 | ||
562 | return status ? : size; | |
563 | } | |
564 | ||
565 | static const DEVICE_ATTR(active_low, 0644, | |
566 | gpio_active_low_show, gpio_active_low_store); | |
567 | ||
d8f388d8 | 568 | static const struct attribute *gpio_attrs[] = { |
d8f388d8 | 569 | &dev_attr_value.attr, |
07697461 | 570 | &dev_attr_active_low.attr, |
d8f388d8 DB |
571 | NULL, |
572 | }; | |
573 | ||
574 | static const struct attribute_group gpio_attr_group = { | |
575 | .attrs = (struct attribute **) gpio_attrs, | |
576 | }; | |
577 | ||
578 | /* | |
579 | * /sys/class/gpio/gpiochipN/ | |
580 | * /base ... matching gpio_chip.base (N) | |
581 | * /label ... matching gpio_chip.label | |
582 | * /ngpio ... matching gpio_chip.ngpio | |
583 | */ | |
584 | ||
585 | static ssize_t chip_base_show(struct device *dev, | |
586 | struct device_attribute *attr, char *buf) | |
587 | { | |
588 | const struct gpio_chip *chip = dev_get_drvdata(dev); | |
589 | ||
590 | return sprintf(buf, "%d\n", chip->base); | |
591 | } | |
592 | static DEVICE_ATTR(base, 0444, chip_base_show, NULL); | |
593 | ||
594 | static ssize_t chip_label_show(struct device *dev, | |
595 | struct device_attribute *attr, char *buf) | |
596 | { | |
597 | const struct gpio_chip *chip = dev_get_drvdata(dev); | |
598 | ||
599 | return sprintf(buf, "%s\n", chip->label ? : ""); | |
600 | } | |
601 | static DEVICE_ATTR(label, 0444, chip_label_show, NULL); | |
602 | ||
603 | static ssize_t chip_ngpio_show(struct device *dev, | |
604 | struct device_attribute *attr, char *buf) | |
605 | { | |
606 | const struct gpio_chip *chip = dev_get_drvdata(dev); | |
607 | ||
608 | return sprintf(buf, "%u\n", chip->ngpio); | |
609 | } | |
610 | static DEVICE_ATTR(ngpio, 0444, chip_ngpio_show, NULL); | |
611 | ||
612 | static const struct attribute *gpiochip_attrs[] = { | |
613 | &dev_attr_base.attr, | |
614 | &dev_attr_label.attr, | |
615 | &dev_attr_ngpio.attr, | |
616 | NULL, | |
617 | }; | |
618 | ||
619 | static const struct attribute_group gpiochip_attr_group = { | |
620 | .attrs = (struct attribute **) gpiochip_attrs, | |
621 | }; | |
622 | ||
623 | /* | |
624 | * /sys/class/gpio/export ... write-only | |
625 | * integer N ... number of GPIO to export (full access) | |
626 | * /sys/class/gpio/unexport ... write-only | |
627 | * integer N ... number of GPIO to unexport | |
628 | */ | |
28812fe1 AK |
629 | static ssize_t export_store(struct class *class, |
630 | struct class_attribute *attr, | |
631 | const char *buf, size_t len) | |
d8f388d8 DB |
632 | { |
633 | long gpio; | |
634 | int status; | |
635 | ||
636 | status = strict_strtol(buf, 0, &gpio); | |
637 | if (status < 0) | |
638 | goto done; | |
639 | ||
640 | /* No extra locking here; FLAG_SYSFS just signifies that the | |
641 | * request and export were done by on behalf of userspace, so | |
642 | * they may be undone on its behalf too. | |
643 | */ | |
644 | ||
645 | status = gpio_request(gpio, "sysfs"); | |
646 | if (status < 0) | |
647 | goto done; | |
648 | ||
649 | status = gpio_export(gpio, true); | |
650 | if (status < 0) | |
651 | gpio_free(gpio); | |
652 | else | |
653 | set_bit(FLAG_SYSFS, &gpio_desc[gpio].flags); | |
654 | ||
655 | done: | |
656 | if (status) | |
657 | pr_debug("%s: status %d\n", __func__, status); | |
658 | return status ? : len; | |
659 | } | |
660 | ||
28812fe1 AK |
661 | static ssize_t unexport_store(struct class *class, |
662 | struct class_attribute *attr, | |
663 | const char *buf, size_t len) | |
d8f388d8 DB |
664 | { |
665 | long gpio; | |
666 | int status; | |
667 | ||
668 | status = strict_strtol(buf, 0, &gpio); | |
669 | if (status < 0) | |
670 | goto done; | |
671 | ||
672 | status = -EINVAL; | |
673 | ||
674 | /* reject bogus commands (gpio_unexport ignores them) */ | |
675 | if (!gpio_is_valid(gpio)) | |
676 | goto done; | |
677 | ||
678 | /* No extra locking here; FLAG_SYSFS just signifies that the | |
679 | * request and export were done by on behalf of userspace, so | |
680 | * they may be undone on its behalf too. | |
681 | */ | |
682 | if (test_and_clear_bit(FLAG_SYSFS, &gpio_desc[gpio].flags)) { | |
683 | status = 0; | |
684 | gpio_free(gpio); | |
685 | } | |
686 | done: | |
687 | if (status) | |
688 | pr_debug("%s: status %d\n", __func__, status); | |
689 | return status ? : len; | |
690 | } | |
691 | ||
692 | static struct class_attribute gpio_class_attrs[] = { | |
693 | __ATTR(export, 0200, NULL, export_store), | |
694 | __ATTR(unexport, 0200, NULL, unexport_store), | |
695 | __ATTR_NULL, | |
696 | }; | |
697 | ||
698 | static struct class gpio_class = { | |
699 | .name = "gpio", | |
700 | .owner = THIS_MODULE, | |
701 | ||
702 | .class_attrs = gpio_class_attrs, | |
703 | }; | |
704 | ||
705 | ||
706 | /** | |
707 | * gpio_export - export a GPIO through sysfs | |
708 | * @gpio: gpio to make available, already requested | |
709 | * @direction_may_change: true if userspace may change gpio direction | |
710 | * Context: arch_initcall or later | |
711 | * | |
712 | * When drivers want to make a GPIO accessible to userspace after they | |
713 | * have requested it -- perhaps while debugging, or as part of their | |
714 | * public interface -- they may use this routine. If the GPIO can | |
715 | * change direction (some can't) and the caller allows it, userspace | |
716 | * will see "direction" sysfs attribute which may be used to change | |
717 | * the gpio's direction. A "value" attribute will always be provided. | |
718 | * | |
719 | * Returns zero on success, else an error. | |
720 | */ | |
721 | int gpio_export(unsigned gpio, bool direction_may_change) | |
722 | { | |
723 | unsigned long flags; | |
724 | struct gpio_desc *desc; | |
725 | int status = -EINVAL; | |
62154991 | 726 | const char *ioname = NULL; |
d8f388d8 DB |
727 | |
728 | /* can't export until sysfs is available ... */ | |
729 | if (!gpio_class.p) { | |
730 | pr_debug("%s: called too early!\n", __func__); | |
731 | return -ENOENT; | |
732 | } | |
733 | ||
734 | if (!gpio_is_valid(gpio)) | |
735 | goto done; | |
736 | ||
737 | mutex_lock(&sysfs_lock); | |
738 | ||
739 | spin_lock_irqsave(&gpio_lock, flags); | |
740 | desc = &gpio_desc[gpio]; | |
741 | if (test_bit(FLAG_REQUESTED, &desc->flags) | |
742 | && !test_bit(FLAG_EXPORT, &desc->flags)) { | |
743 | status = 0; | |
744 | if (!desc->chip->direction_input | |
745 | || !desc->chip->direction_output) | |
746 | direction_may_change = false; | |
747 | } | |
748 | spin_unlock_irqrestore(&gpio_lock, flags); | |
749 | ||
926b663c DS |
750 | if (desc->chip->names && desc->chip->names[gpio - desc->chip->base]) |
751 | ioname = desc->chip->names[gpio - desc->chip->base]; | |
752 | ||
d8f388d8 DB |
753 | if (status == 0) { |
754 | struct device *dev; | |
755 | ||
756 | dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0), | |
7cfe1395 | 757 | desc, ioname ? ioname : "gpio%u", gpio); |
d62668e1 | 758 | if (!IS_ERR(dev)) { |
07697461 | 759 | status = sysfs_create_group(&dev->kobj, |
d8f388d8 | 760 | &gpio_attr_group); |
07697461 JN |
761 | |
762 | if (!status && direction_may_change) | |
d8f388d8 | 763 | status = device_create_file(dev, |
07697461 | 764 | &dev_attr_direction); |
ff77c352 DG |
765 | |
766 | if (!status && gpio_to_irq(gpio) >= 0 | |
767 | && (direction_may_change | |
768 | || !test_bit(FLAG_IS_OUT, | |
769 | &desc->flags))) | |
770 | status = device_create_file(dev, | |
771 | &dev_attr_edge); | |
772 | ||
d8f388d8 DB |
773 | if (status != 0) |
774 | device_unregister(dev); | |
775 | } else | |
d62668e1 | 776 | status = PTR_ERR(dev); |
d8f388d8 DB |
777 | if (status == 0) |
778 | set_bit(FLAG_EXPORT, &desc->flags); | |
779 | } | |
780 | ||
781 | mutex_unlock(&sysfs_lock); | |
782 | ||
783 | done: | |
784 | if (status) | |
785 | pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); | |
786 | ||
787 | return status; | |
788 | } | |
789 | EXPORT_SYMBOL_GPL(gpio_export); | |
790 | ||
791 | static int match_export(struct device *dev, void *data) | |
792 | { | |
793 | return dev_get_drvdata(dev) == data; | |
794 | } | |
795 | ||
a4177ee7 JN |
796 | /** |
797 | * gpio_export_link - create a sysfs link to an exported GPIO node | |
798 | * @dev: device under which to create symlink | |
799 | * @name: name of the symlink | |
800 | * @gpio: gpio to create symlink to, already exported | |
801 | * | |
802 | * Set up a symlink from /sys/.../dev/name to /sys/class/gpio/gpioN | |
803 | * node. Caller is responsible for unlinking. | |
804 | * | |
805 | * Returns zero on success, else an error. | |
806 | */ | |
807 | int gpio_export_link(struct device *dev, const char *name, unsigned gpio) | |
808 | { | |
809 | struct gpio_desc *desc; | |
810 | int status = -EINVAL; | |
811 | ||
812 | if (!gpio_is_valid(gpio)) | |
813 | goto done; | |
814 | ||
815 | mutex_lock(&sysfs_lock); | |
816 | ||
817 | desc = &gpio_desc[gpio]; | |
818 | ||
819 | if (test_bit(FLAG_EXPORT, &desc->flags)) { | |
820 | struct device *tdev; | |
821 | ||
822 | tdev = class_find_device(&gpio_class, NULL, desc, match_export); | |
823 | if (tdev != NULL) { | |
824 | status = sysfs_create_link(&dev->kobj, &tdev->kobj, | |
825 | name); | |
826 | } else { | |
827 | status = -ENODEV; | |
828 | } | |
829 | } | |
830 | ||
831 | mutex_unlock(&sysfs_lock); | |
832 | ||
833 | done: | |
834 | if (status) | |
835 | pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); | |
836 | ||
837 | return status; | |
838 | } | |
839 | EXPORT_SYMBOL_GPL(gpio_export_link); | |
840 | ||
07697461 JN |
841 | |
842 | /** | |
843 | * gpio_sysfs_set_active_low - set the polarity of gpio sysfs value | |
844 | * @gpio: gpio to change | |
845 | * @value: non-zero to use active low, i.e. inverted values | |
846 | * | |
847 | * Set the polarity of /sys/class/gpio/gpioN/value sysfs attribute. | |
848 | * The GPIO does not have to be exported yet. If poll(2) support has | |
849 | * been enabled for either rising or falling edge, it will be | |
850 | * reconfigured to follow the new polarity. | |
851 | * | |
852 | * Returns zero on success, else an error. | |
853 | */ | |
854 | int gpio_sysfs_set_active_low(unsigned gpio, int value) | |
855 | { | |
856 | struct gpio_desc *desc; | |
857 | struct device *dev = NULL; | |
858 | int status = -EINVAL; | |
859 | ||
860 | if (!gpio_is_valid(gpio)) | |
861 | goto done; | |
862 | ||
863 | mutex_lock(&sysfs_lock); | |
864 | ||
865 | desc = &gpio_desc[gpio]; | |
866 | ||
867 | if (test_bit(FLAG_EXPORT, &desc->flags)) { | |
07697461 JN |
868 | dev = class_find_device(&gpio_class, NULL, desc, match_export); |
869 | if (dev == NULL) { | |
870 | status = -ENODEV; | |
871 | goto unlock; | |
872 | } | |
873 | } | |
874 | ||
875 | status = sysfs_set_active_low(desc, dev, value); | |
876 | ||
877 | unlock: | |
878 | mutex_unlock(&sysfs_lock); | |
879 | ||
880 | done: | |
881 | if (status) | |
882 | pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); | |
883 | ||
884 | return status; | |
885 | } | |
886 | EXPORT_SYMBOL_GPL(gpio_sysfs_set_active_low); | |
887 | ||
d8f388d8 DB |
888 | /** |
889 | * gpio_unexport - reverse effect of gpio_export() | |
890 | * @gpio: gpio to make unavailable | |
891 | * | |
892 | * This is implicit on gpio_free(). | |
893 | */ | |
894 | void gpio_unexport(unsigned gpio) | |
895 | { | |
896 | struct gpio_desc *desc; | |
6a99ad4a | 897 | int status = 0; |
d8f388d8 | 898 | |
6a99ad4a JP |
899 | if (!gpio_is_valid(gpio)) { |
900 | status = -EINVAL; | |
d8f388d8 | 901 | goto done; |
6a99ad4a | 902 | } |
d8f388d8 DB |
903 | |
904 | mutex_lock(&sysfs_lock); | |
905 | ||
906 | desc = &gpio_desc[gpio]; | |
926b663c | 907 | |
d8f388d8 DB |
908 | if (test_bit(FLAG_EXPORT, &desc->flags)) { |
909 | struct device *dev = NULL; | |
910 | ||
911 | dev = class_find_device(&gpio_class, NULL, desc, match_export); | |
912 | if (dev) { | |
ff77c352 | 913 | gpio_setup_irq(desc, dev, 0); |
d8f388d8 DB |
914 | clear_bit(FLAG_EXPORT, &desc->flags); |
915 | put_device(dev); | |
916 | device_unregister(dev); | |
d8f388d8 DB |
917 | } else |
918 | status = -ENODEV; | |
919 | } | |
920 | ||
921 | mutex_unlock(&sysfs_lock); | |
922 | done: | |
923 | if (status) | |
924 | pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); | |
925 | } | |
926 | EXPORT_SYMBOL_GPL(gpio_unexport); | |
927 | ||
928 | static int gpiochip_export(struct gpio_chip *chip) | |
929 | { | |
930 | int status; | |
931 | struct device *dev; | |
932 | ||
933 | /* Many systems register gpio chips for SOC support very early, | |
934 | * before driver model support is available. In those cases we | |
935 | * export this later, in gpiolib_sysfs_init() ... here we just | |
936 | * verify that _some_ field of gpio_class got initialized. | |
937 | */ | |
938 | if (!gpio_class.p) | |
939 | return 0; | |
940 | ||
941 | /* use chip->base for the ID; it's already known to be unique */ | |
942 | mutex_lock(&sysfs_lock); | |
943 | dev = device_create(&gpio_class, chip->dev, MKDEV(0, 0), chip, | |
944 | "gpiochip%d", chip->base); | |
d62668e1 | 945 | if (!IS_ERR(dev)) { |
d8f388d8 DB |
946 | status = sysfs_create_group(&dev->kobj, |
947 | &gpiochip_attr_group); | |
948 | } else | |
d62668e1 | 949 | status = PTR_ERR(dev); |
d8f388d8 DB |
950 | chip->exported = (status == 0); |
951 | mutex_unlock(&sysfs_lock); | |
952 | ||
953 | if (status) { | |
954 | unsigned long flags; | |
955 | unsigned gpio; | |
956 | ||
957 | spin_lock_irqsave(&gpio_lock, flags); | |
958 | gpio = chip->base; | |
959 | while (gpio_desc[gpio].chip == chip) | |
960 | gpio_desc[gpio++].chip = NULL; | |
961 | spin_unlock_irqrestore(&gpio_lock, flags); | |
962 | ||
963 | pr_debug("%s: chip %s status %d\n", __func__, | |
964 | chip->label, status); | |
965 | } | |
966 | ||
967 | return status; | |
968 | } | |
969 | ||
970 | static void gpiochip_unexport(struct gpio_chip *chip) | |
971 | { | |
972 | int status; | |
973 | struct device *dev; | |
974 | ||
975 | mutex_lock(&sysfs_lock); | |
976 | dev = class_find_device(&gpio_class, NULL, chip, match_export); | |
977 | if (dev) { | |
978 | put_device(dev); | |
979 | device_unregister(dev); | |
980 | chip->exported = 0; | |
981 | status = 0; | |
982 | } else | |
983 | status = -ENODEV; | |
984 | mutex_unlock(&sysfs_lock); | |
985 | ||
986 | if (status) | |
987 | pr_debug("%s: chip %s status %d\n", __func__, | |
988 | chip->label, status); | |
989 | } | |
990 | ||
991 | static int __init gpiolib_sysfs_init(void) | |
992 | { | |
993 | int status; | |
994 | unsigned long flags; | |
995 | unsigned gpio; | |
996 | ||
ff77c352 DG |
997 | idr_init(&pdesc_idr); |
998 | ||
d8f388d8 DB |
999 | status = class_register(&gpio_class); |
1000 | if (status < 0) | |
1001 | return status; | |
1002 | ||
1003 | /* Scan and register the gpio_chips which registered very | |
1004 | * early (e.g. before the class_register above was called). | |
1005 | * | |
1006 | * We run before arch_initcall() so chip->dev nodes can have | |
1007 | * registered, and so arch_initcall() can always gpio_export(). | |
1008 | */ | |
1009 | spin_lock_irqsave(&gpio_lock, flags); | |
1010 | for (gpio = 0; gpio < ARCH_NR_GPIOS; gpio++) { | |
1011 | struct gpio_chip *chip; | |
1012 | ||
1013 | chip = gpio_desc[gpio].chip; | |
1014 | if (!chip || chip->exported) | |
1015 | continue; | |
1016 | ||
1017 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1018 | status = gpiochip_export(chip); | |
1019 | spin_lock_irqsave(&gpio_lock, flags); | |
1020 | } | |
1021 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1022 | ||
1023 | ||
1024 | return status; | |
1025 | } | |
1026 | postcore_initcall(gpiolib_sysfs_init); | |
1027 | ||
1028 | #else | |
1029 | static inline int gpiochip_export(struct gpio_chip *chip) | |
1030 | { | |
1031 | return 0; | |
1032 | } | |
1033 | ||
1034 | static inline void gpiochip_unexport(struct gpio_chip *chip) | |
1035 | { | |
1036 | } | |
1037 | ||
1038 | #endif /* CONFIG_GPIO_SYSFS */ | |
1039 | ||
d2876d08 DB |
1040 | /** |
1041 | * gpiochip_add() - register a gpio_chip | |
1042 | * @chip: the chip to register, with chip->base initialized | |
1043 | * Context: potentially before irqs or kmalloc will work | |
1044 | * | |
1045 | * Returns a negative errno if the chip can't be registered, such as | |
1046 | * because the chip->base is invalid or already associated with a | |
1047 | * different chip. Otherwise it returns zero as a success code. | |
8d0aab2f | 1048 | * |
d8f388d8 DB |
1049 | * When gpiochip_add() is called very early during boot, so that GPIOs |
1050 | * can be freely used, the chip->dev device must be registered before | |
1051 | * the gpio framework's arch_initcall(). Otherwise sysfs initialization | |
1052 | * for GPIOs will fail rudely. | |
1053 | * | |
8d0aab2f AV |
1054 | * If chip->base is negative, this requests dynamic assignment of |
1055 | * a range of valid GPIOs. | |
d2876d08 DB |
1056 | */ |
1057 | int gpiochip_add(struct gpio_chip *chip) | |
1058 | { | |
1059 | unsigned long flags; | |
1060 | int status = 0; | |
1061 | unsigned id; | |
8d0aab2f | 1062 | int base = chip->base; |
d2876d08 | 1063 | |
bff5fda9 | 1064 | if ((!gpio_is_valid(base) || !gpio_is_valid(base + chip->ngpio - 1)) |
8d0aab2f | 1065 | && base >= 0) { |
d2876d08 DB |
1066 | status = -EINVAL; |
1067 | goto fail; | |
1068 | } | |
1069 | ||
1070 | spin_lock_irqsave(&gpio_lock, flags); | |
1071 | ||
8d0aab2f AV |
1072 | if (base < 0) { |
1073 | base = gpiochip_find_base(chip->ngpio); | |
1074 | if (base < 0) { | |
1075 | status = base; | |
d8f388d8 | 1076 | goto unlock; |
8d0aab2f AV |
1077 | } |
1078 | chip->base = base; | |
1079 | } | |
1080 | ||
d2876d08 | 1081 | /* these GPIO numbers must not be managed by another gpio_chip */ |
8d0aab2f | 1082 | for (id = base; id < base + chip->ngpio; id++) { |
d2876d08 DB |
1083 | if (gpio_desc[id].chip != NULL) { |
1084 | status = -EBUSY; | |
1085 | break; | |
1086 | } | |
1087 | } | |
1088 | if (status == 0) { | |
8d0aab2f | 1089 | for (id = base; id < base + chip->ngpio; id++) { |
d2876d08 | 1090 | gpio_desc[id].chip = chip; |
d8f388d8 DB |
1091 | |
1092 | /* REVISIT: most hardware initializes GPIOs as | |
1093 | * inputs (often with pullups enabled) so power | |
1094 | * usage is minimized. Linux code should set the | |
1095 | * gpio direction first thing; but until it does, | |
1096 | * we may expose the wrong direction in sysfs. | |
1097 | */ | |
1098 | gpio_desc[id].flags = !chip->direction_input | |
1099 | ? (1 << FLAG_IS_OUT) | |
1100 | : 0; | |
d2876d08 DB |
1101 | } |
1102 | } | |
1103 | ||
391c970c AV |
1104 | of_gpiochip_add(chip); |
1105 | ||
d8f388d8 | 1106 | unlock: |
d2876d08 | 1107 | spin_unlock_irqrestore(&gpio_lock, flags); |
cedb1881 AV |
1108 | |
1109 | if (status) | |
1110 | goto fail; | |
1111 | ||
1112 | status = gpiochip_export(chip); | |
1113 | if (status) | |
1114 | goto fail; | |
1115 | ||
1116 | return 0; | |
d2876d08 DB |
1117 | fail: |
1118 | /* failures here can mean systems won't boot... */ | |
cedb1881 AV |
1119 | pr_err("gpiochip_add: gpios %d..%d (%s) failed to register\n", |
1120 | chip->base, chip->base + chip->ngpio - 1, | |
1121 | chip->label ? : "generic"); | |
d2876d08 DB |
1122 | return status; |
1123 | } | |
1124 | EXPORT_SYMBOL_GPL(gpiochip_add); | |
1125 | ||
1126 | /** | |
1127 | * gpiochip_remove() - unregister a gpio_chip | |
1128 | * @chip: the chip to unregister | |
1129 | * | |
1130 | * A gpio_chip with any GPIOs still requested may not be removed. | |
1131 | */ | |
1132 | int gpiochip_remove(struct gpio_chip *chip) | |
1133 | { | |
1134 | unsigned long flags; | |
1135 | int status = 0; | |
1136 | unsigned id; | |
1137 | ||
1138 | spin_lock_irqsave(&gpio_lock, flags); | |
1139 | ||
391c970c AV |
1140 | of_gpiochip_remove(chip); |
1141 | ||
d2876d08 DB |
1142 | for (id = chip->base; id < chip->base + chip->ngpio; id++) { |
1143 | if (test_bit(FLAG_REQUESTED, &gpio_desc[id].flags)) { | |
1144 | status = -EBUSY; | |
1145 | break; | |
1146 | } | |
1147 | } | |
1148 | if (status == 0) { | |
1149 | for (id = chip->base; id < chip->base + chip->ngpio; id++) | |
1150 | gpio_desc[id].chip = NULL; | |
1151 | } | |
1152 | ||
1153 | spin_unlock_irqrestore(&gpio_lock, flags); | |
d8f388d8 DB |
1154 | |
1155 | if (status == 0) | |
1156 | gpiochip_unexport(chip); | |
1157 | ||
d2876d08 DB |
1158 | return status; |
1159 | } | |
1160 | EXPORT_SYMBOL_GPL(gpiochip_remove); | |
1161 | ||
594fa265 GL |
1162 | /** |
1163 | * gpiochip_find() - iterator for locating a specific gpio_chip | |
1164 | * @data: data to pass to match function | |
1165 | * @callback: Callback function to check gpio_chip | |
1166 | * | |
1167 | * Similar to bus_find_device. It returns a reference to a gpio_chip as | |
1168 | * determined by a user supplied @match callback. The callback should return | |
1169 | * 0 if the device doesn't match and non-zero if it does. If the callback is | |
1170 | * non-zero, this function will return to the caller and not iterate over any | |
1171 | * more gpio_chips. | |
1172 | */ | |
1173 | struct gpio_chip *gpiochip_find(void *data, | |
1174 | int (*match)(struct gpio_chip *chip, void *data)) | |
1175 | { | |
1176 | struct gpio_chip *chip = NULL; | |
1177 | unsigned long flags; | |
1178 | int i; | |
1179 | ||
1180 | spin_lock_irqsave(&gpio_lock, flags); | |
1181 | for (i = 0; i < ARCH_NR_GPIOS; i++) { | |
1182 | if (!gpio_desc[i].chip) | |
1183 | continue; | |
1184 | ||
1185 | if (match(gpio_desc[i].chip, data)) { | |
1186 | chip = gpio_desc[i].chip; | |
1187 | break; | |
1188 | } | |
1189 | } | |
1190 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1191 | ||
1192 | return chip; | |
1193 | } | |
d2876d08 DB |
1194 | |
1195 | /* These "optional" allocation calls help prevent drivers from stomping | |
1196 | * on each other, and help provide better diagnostics in debugfs. | |
1197 | * They're called even less than the "set direction" calls. | |
1198 | */ | |
1199 | int gpio_request(unsigned gpio, const char *label) | |
1200 | { | |
1201 | struct gpio_desc *desc; | |
35e8bb51 | 1202 | struct gpio_chip *chip; |
d2876d08 DB |
1203 | int status = -EINVAL; |
1204 | unsigned long flags; | |
1205 | ||
1206 | spin_lock_irqsave(&gpio_lock, flags); | |
1207 | ||
e6de1808 | 1208 | if (!gpio_is_valid(gpio)) |
d2876d08 DB |
1209 | goto done; |
1210 | desc = &gpio_desc[gpio]; | |
35e8bb51 DB |
1211 | chip = desc->chip; |
1212 | if (chip == NULL) | |
d2876d08 DB |
1213 | goto done; |
1214 | ||
35e8bb51 | 1215 | if (!try_module_get(chip->owner)) |
438d8908 GL |
1216 | goto done; |
1217 | ||
d2876d08 | 1218 | /* NOTE: gpio_request() can be called in early boot, |
35e8bb51 | 1219 | * before IRQs are enabled, for non-sleeping (SOC) GPIOs. |
d2876d08 DB |
1220 | */ |
1221 | ||
1222 | if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) { | |
1223 | desc_set_label(desc, label ? : "?"); | |
1224 | status = 0; | |
438d8908 | 1225 | } else { |
d2876d08 | 1226 | status = -EBUSY; |
35e8bb51 | 1227 | module_put(chip->owner); |
7460db56 | 1228 | goto done; |
35e8bb51 DB |
1229 | } |
1230 | ||
1231 | if (chip->request) { | |
1232 | /* chip->request may sleep */ | |
1233 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1234 | status = chip->request(chip, gpio - chip->base); | |
1235 | spin_lock_irqsave(&gpio_lock, flags); | |
1236 | ||
1237 | if (status < 0) { | |
1238 | desc_set_label(desc, NULL); | |
1239 | module_put(chip->owner); | |
1240 | clear_bit(FLAG_REQUESTED, &desc->flags); | |
1241 | } | |
438d8908 | 1242 | } |
d2876d08 DB |
1243 | |
1244 | done: | |
1245 | if (status) | |
1246 | pr_debug("gpio_request: gpio-%d (%s) status %d\n", | |
1247 | gpio, label ? : "?", status); | |
1248 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1249 | return status; | |
1250 | } | |
1251 | EXPORT_SYMBOL_GPL(gpio_request); | |
1252 | ||
1253 | void gpio_free(unsigned gpio) | |
1254 | { | |
1255 | unsigned long flags; | |
1256 | struct gpio_desc *desc; | |
35e8bb51 | 1257 | struct gpio_chip *chip; |
d2876d08 | 1258 | |
3d599d1c UKK |
1259 | might_sleep(); |
1260 | ||
e6de1808 | 1261 | if (!gpio_is_valid(gpio)) { |
d2876d08 DB |
1262 | WARN_ON(extra_checks); |
1263 | return; | |
1264 | } | |
1265 | ||
d8f388d8 DB |
1266 | gpio_unexport(gpio); |
1267 | ||
d2876d08 DB |
1268 | spin_lock_irqsave(&gpio_lock, flags); |
1269 | ||
1270 | desc = &gpio_desc[gpio]; | |
35e8bb51 DB |
1271 | chip = desc->chip; |
1272 | if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) { | |
1273 | if (chip->free) { | |
1274 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1275 | might_sleep_if(extra_checks && chip->can_sleep); | |
1276 | chip->free(chip, gpio - chip->base); | |
1277 | spin_lock_irqsave(&gpio_lock, flags); | |
1278 | } | |
d2876d08 | 1279 | desc_set_label(desc, NULL); |
438d8908 | 1280 | module_put(desc->chip->owner); |
07697461 | 1281 | clear_bit(FLAG_ACTIVE_LOW, &desc->flags); |
35e8bb51 | 1282 | clear_bit(FLAG_REQUESTED, &desc->flags); |
438d8908 | 1283 | } else |
d2876d08 DB |
1284 | WARN_ON(extra_checks); |
1285 | ||
1286 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1287 | } | |
1288 | EXPORT_SYMBOL_GPL(gpio_free); | |
1289 | ||
3e45f1d1 EM |
1290 | /** |
1291 | * gpio_request_one - request a single GPIO with initial configuration | |
1292 | * @gpio: the GPIO number | |
1293 | * @flags: GPIO configuration as specified by GPIOF_* | |
1294 | * @label: a literal description string of this GPIO | |
1295 | */ | |
1296 | int gpio_request_one(unsigned gpio, unsigned long flags, const char *label) | |
1297 | { | |
1298 | int err; | |
1299 | ||
1300 | err = gpio_request(gpio, label); | |
1301 | if (err) | |
1302 | return err; | |
1303 | ||
1304 | if (flags & GPIOF_DIR_IN) | |
1305 | err = gpio_direction_input(gpio); | |
1306 | else | |
1307 | err = gpio_direction_output(gpio, | |
1308 | (flags & GPIOF_INIT_HIGH) ? 1 : 0); | |
1309 | ||
1310 | return err; | |
1311 | } | |
1312 | EXPORT_SYMBOL_GPL(gpio_request_one); | |
1313 | ||
1314 | /** | |
1315 | * gpio_request_array - request multiple GPIOs in a single call | |
1316 | * @array: array of the 'struct gpio' | |
1317 | * @num: how many GPIOs in the array | |
1318 | */ | |
1319 | int gpio_request_array(struct gpio *array, size_t num) | |
1320 | { | |
1321 | int i, err; | |
1322 | ||
1323 | for (i = 0; i < num; i++, array++) { | |
1324 | err = gpio_request_one(array->gpio, array->flags, array->label); | |
1325 | if (err) | |
1326 | goto err_free; | |
1327 | } | |
1328 | return 0; | |
1329 | ||
1330 | err_free: | |
1331 | while (i--) | |
1332 | gpio_free((--array)->gpio); | |
1333 | return err; | |
1334 | } | |
1335 | EXPORT_SYMBOL_GPL(gpio_request_array); | |
1336 | ||
1337 | /** | |
1338 | * gpio_free_array - release multiple GPIOs in a single call | |
1339 | * @array: array of the 'struct gpio' | |
1340 | * @num: how many GPIOs in the array | |
1341 | */ | |
1342 | void gpio_free_array(struct gpio *array, size_t num) | |
1343 | { | |
1344 | while (num--) | |
1345 | gpio_free((array++)->gpio); | |
1346 | } | |
1347 | EXPORT_SYMBOL_GPL(gpio_free_array); | |
d2876d08 DB |
1348 | |
1349 | /** | |
1350 | * gpiochip_is_requested - return string iff signal was requested | |
1351 | * @chip: controller managing the signal | |
1352 | * @offset: of signal within controller's 0..(ngpio - 1) range | |
1353 | * | |
1354 | * Returns NULL if the GPIO is not currently requested, else a string. | |
1355 | * If debugfs support is enabled, the string returned is the label passed | |
1356 | * to gpio_request(); otherwise it is a meaningless constant. | |
1357 | * | |
1358 | * This function is for use by GPIO controller drivers. The label can | |
1359 | * help with diagnostics, and knowing that the signal is used as a GPIO | |
1360 | * can help avoid accidentally multiplexing it to another controller. | |
1361 | */ | |
1362 | const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset) | |
1363 | { | |
1364 | unsigned gpio = chip->base + offset; | |
1365 | ||
e6de1808 | 1366 | if (!gpio_is_valid(gpio) || gpio_desc[gpio].chip != chip) |
d2876d08 DB |
1367 | return NULL; |
1368 | if (test_bit(FLAG_REQUESTED, &gpio_desc[gpio].flags) == 0) | |
1369 | return NULL; | |
1370 | #ifdef CONFIG_DEBUG_FS | |
1371 | return gpio_desc[gpio].label; | |
1372 | #else | |
1373 | return "?"; | |
1374 | #endif | |
1375 | } | |
1376 | EXPORT_SYMBOL_GPL(gpiochip_is_requested); | |
1377 | ||
1378 | ||
1379 | /* Drivers MUST set GPIO direction before making get/set calls. In | |
1380 | * some cases this is done in early boot, before IRQs are enabled. | |
1381 | * | |
1382 | * As a rule these aren't called more than once (except for drivers | |
1383 | * using the open-drain emulation idiom) so these are natural places | |
1384 | * to accumulate extra debugging checks. Note that we can't (yet) | |
1385 | * rely on gpio_request() having been called beforehand. | |
1386 | */ | |
1387 | ||
1388 | int gpio_direction_input(unsigned gpio) | |
1389 | { | |
1390 | unsigned long flags; | |
1391 | struct gpio_chip *chip; | |
1392 | struct gpio_desc *desc = &gpio_desc[gpio]; | |
1393 | int status = -EINVAL; | |
1394 | ||
1395 | spin_lock_irqsave(&gpio_lock, flags); | |
1396 | ||
e6de1808 | 1397 | if (!gpio_is_valid(gpio)) |
d2876d08 DB |
1398 | goto fail; |
1399 | chip = desc->chip; | |
1400 | if (!chip || !chip->get || !chip->direction_input) | |
1401 | goto fail; | |
1402 | gpio -= chip->base; | |
1403 | if (gpio >= chip->ngpio) | |
1404 | goto fail; | |
35e8bb51 DB |
1405 | status = gpio_ensure_requested(desc, gpio); |
1406 | if (status < 0) | |
1407 | goto fail; | |
d2876d08 DB |
1408 | |
1409 | /* now we know the gpio is valid and chip won't vanish */ | |
1410 | ||
1411 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1412 | ||
1413 | might_sleep_if(extra_checks && chip->can_sleep); | |
1414 | ||
35e8bb51 DB |
1415 | if (status) { |
1416 | status = chip->request(chip, gpio); | |
1417 | if (status < 0) { | |
1418 | pr_debug("GPIO-%d: chip request fail, %d\n", | |
1419 | chip->base + gpio, status); | |
1420 | /* and it's not available to anyone else ... | |
1421 | * gpio_request() is the fully clean solution. | |
1422 | */ | |
1423 | goto lose; | |
1424 | } | |
1425 | } | |
1426 | ||
d2876d08 DB |
1427 | status = chip->direction_input(chip, gpio); |
1428 | if (status == 0) | |
1429 | clear_bit(FLAG_IS_OUT, &desc->flags); | |
35e8bb51 | 1430 | lose: |
d2876d08 DB |
1431 | return status; |
1432 | fail: | |
1433 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1434 | if (status) | |
1435 | pr_debug("%s: gpio-%d status %d\n", | |
145980a0 | 1436 | __func__, gpio, status); |
d2876d08 DB |
1437 | return status; |
1438 | } | |
1439 | EXPORT_SYMBOL_GPL(gpio_direction_input); | |
1440 | ||
1441 | int gpio_direction_output(unsigned gpio, int value) | |
1442 | { | |
1443 | unsigned long flags; | |
1444 | struct gpio_chip *chip; | |
1445 | struct gpio_desc *desc = &gpio_desc[gpio]; | |
1446 | int status = -EINVAL; | |
1447 | ||
1448 | spin_lock_irqsave(&gpio_lock, flags); | |
1449 | ||
e6de1808 | 1450 | if (!gpio_is_valid(gpio)) |
d2876d08 DB |
1451 | goto fail; |
1452 | chip = desc->chip; | |
1453 | if (!chip || !chip->set || !chip->direction_output) | |
1454 | goto fail; | |
1455 | gpio -= chip->base; | |
1456 | if (gpio >= chip->ngpio) | |
1457 | goto fail; | |
35e8bb51 DB |
1458 | status = gpio_ensure_requested(desc, gpio); |
1459 | if (status < 0) | |
1460 | goto fail; | |
d2876d08 DB |
1461 | |
1462 | /* now we know the gpio is valid and chip won't vanish */ | |
1463 | ||
1464 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1465 | ||
1466 | might_sleep_if(extra_checks && chip->can_sleep); | |
1467 | ||
35e8bb51 DB |
1468 | if (status) { |
1469 | status = chip->request(chip, gpio); | |
1470 | if (status < 0) { | |
1471 | pr_debug("GPIO-%d: chip request fail, %d\n", | |
1472 | chip->base + gpio, status); | |
1473 | /* and it's not available to anyone else ... | |
1474 | * gpio_request() is the fully clean solution. | |
1475 | */ | |
1476 | goto lose; | |
1477 | } | |
1478 | } | |
1479 | ||
d2876d08 DB |
1480 | status = chip->direction_output(chip, gpio, value); |
1481 | if (status == 0) | |
1482 | set_bit(FLAG_IS_OUT, &desc->flags); | |
35e8bb51 | 1483 | lose: |
d2876d08 DB |
1484 | return status; |
1485 | fail: | |
1486 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1487 | if (status) | |
1488 | pr_debug("%s: gpio-%d status %d\n", | |
145980a0 | 1489 | __func__, gpio, status); |
d2876d08 DB |
1490 | return status; |
1491 | } | |
1492 | EXPORT_SYMBOL_GPL(gpio_direction_output); | |
1493 | ||
c4b5be98 FB |
1494 | /** |
1495 | * gpio_set_debounce - sets @debounce time for a @gpio | |
1496 | * @gpio: the gpio to set debounce time | |
1497 | * @debounce: debounce time is microseconds | |
1498 | */ | |
1499 | int gpio_set_debounce(unsigned gpio, unsigned debounce) | |
1500 | { | |
1501 | unsigned long flags; | |
1502 | struct gpio_chip *chip; | |
1503 | struct gpio_desc *desc = &gpio_desc[gpio]; | |
1504 | int status = -EINVAL; | |
1505 | ||
1506 | spin_lock_irqsave(&gpio_lock, flags); | |
1507 | ||
1508 | if (!gpio_is_valid(gpio)) | |
1509 | goto fail; | |
1510 | chip = desc->chip; | |
1511 | if (!chip || !chip->set || !chip->set_debounce) | |
1512 | goto fail; | |
1513 | gpio -= chip->base; | |
1514 | if (gpio >= chip->ngpio) | |
1515 | goto fail; | |
1516 | status = gpio_ensure_requested(desc, gpio); | |
1517 | if (status < 0) | |
1518 | goto fail; | |
1519 | ||
1520 | /* now we know the gpio is valid and chip won't vanish */ | |
1521 | ||
1522 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1523 | ||
1524 | might_sleep_if(extra_checks && chip->can_sleep); | |
1525 | ||
1526 | return chip->set_debounce(chip, gpio, debounce); | |
1527 | ||
1528 | fail: | |
1529 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1530 | if (status) | |
1531 | pr_debug("%s: gpio-%d status %d\n", | |
1532 | __func__, gpio, status); | |
1533 | ||
1534 | return status; | |
1535 | } | |
1536 | EXPORT_SYMBOL_GPL(gpio_set_debounce); | |
d2876d08 DB |
1537 | |
1538 | /* I/O calls are only valid after configuration completed; the relevant | |
1539 | * "is this a valid GPIO" error checks should already have been done. | |
1540 | * | |
1541 | * "Get" operations are often inlinable as reading a pin value register, | |
1542 | * and masking the relevant bit in that register. | |
1543 | * | |
1544 | * When "set" operations are inlinable, they involve writing that mask to | |
1545 | * one register to set a low value, or a different register to set it high. | |
1546 | * Otherwise locking is needed, so there may be little value to inlining. | |
1547 | * | |
1548 | *------------------------------------------------------------------------ | |
1549 | * | |
1550 | * IMPORTANT!!! The hot paths -- get/set value -- assume that callers | |
1551 | * have requested the GPIO. That can include implicit requesting by | |
1552 | * a direction setting call. Marking a gpio as requested locks its chip | |
1553 | * in memory, guaranteeing that these table lookups need no more locking | |
1554 | * and that gpiochip_remove() will fail. | |
1555 | * | |
1556 | * REVISIT when debugging, consider adding some instrumentation to ensure | |
1557 | * that the GPIO was actually requested. | |
1558 | */ | |
1559 | ||
1560 | /** | |
1561 | * __gpio_get_value() - return a gpio's value | |
1562 | * @gpio: gpio whose value will be returned | |
1563 | * Context: any | |
1564 | * | |
1565 | * This is used directly or indirectly to implement gpio_get_value(). | |
1566 | * It returns the zero or nonzero value provided by the associated | |
1567 | * gpio_chip.get() method; or zero if no such method is provided. | |
1568 | */ | |
1569 | int __gpio_get_value(unsigned gpio) | |
1570 | { | |
1571 | struct gpio_chip *chip; | |
1572 | ||
1573 | chip = gpio_to_chip(gpio); | |
1574 | WARN_ON(extra_checks && chip->can_sleep); | |
1575 | return chip->get ? chip->get(chip, gpio - chip->base) : 0; | |
1576 | } | |
1577 | EXPORT_SYMBOL_GPL(__gpio_get_value); | |
1578 | ||
1579 | /** | |
1580 | * __gpio_set_value() - assign a gpio's value | |
1581 | * @gpio: gpio whose value will be assigned | |
1582 | * @value: value to assign | |
1583 | * Context: any | |
1584 | * | |
1585 | * This is used directly or indirectly to implement gpio_set_value(). | |
1586 | * It invokes the associated gpio_chip.set() method. | |
1587 | */ | |
1588 | void __gpio_set_value(unsigned gpio, int value) | |
1589 | { | |
1590 | struct gpio_chip *chip; | |
1591 | ||
1592 | chip = gpio_to_chip(gpio); | |
1593 | WARN_ON(extra_checks && chip->can_sleep); | |
1594 | chip->set(chip, gpio - chip->base, value); | |
1595 | } | |
1596 | EXPORT_SYMBOL_GPL(__gpio_set_value); | |
1597 | ||
1598 | /** | |
1599 | * __gpio_cansleep() - report whether gpio value access will sleep | |
1600 | * @gpio: gpio in question | |
1601 | * Context: any | |
1602 | * | |
1603 | * This is used directly or indirectly to implement gpio_cansleep(). It | |
1604 | * returns nonzero if access reading or writing the GPIO value can sleep. | |
1605 | */ | |
1606 | int __gpio_cansleep(unsigned gpio) | |
1607 | { | |
1608 | struct gpio_chip *chip; | |
1609 | ||
1610 | /* only call this on GPIOs that are valid! */ | |
1611 | chip = gpio_to_chip(gpio); | |
1612 | ||
1613 | return chip->can_sleep; | |
1614 | } | |
1615 | EXPORT_SYMBOL_GPL(__gpio_cansleep); | |
1616 | ||
0f6d504e DB |
1617 | /** |
1618 | * __gpio_to_irq() - return the IRQ corresponding to a GPIO | |
1619 | * @gpio: gpio whose IRQ will be returned (already requested) | |
1620 | * Context: any | |
1621 | * | |
1622 | * This is used directly or indirectly to implement gpio_to_irq(). | |
1623 | * It returns the number of the IRQ signaled by this (input) GPIO, | |
1624 | * or a negative errno. | |
1625 | */ | |
1626 | int __gpio_to_irq(unsigned gpio) | |
1627 | { | |
1628 | struct gpio_chip *chip; | |
1629 | ||
1630 | chip = gpio_to_chip(gpio); | |
1631 | return chip->to_irq ? chip->to_irq(chip, gpio - chip->base) : -ENXIO; | |
1632 | } | |
1633 | EXPORT_SYMBOL_GPL(__gpio_to_irq); | |
1634 | ||
d2876d08 DB |
1635 | |
1636 | ||
1637 | /* There's no value in making it easy to inline GPIO calls that may sleep. | |
1638 | * Common examples include ones connected to I2C or SPI chips. | |
1639 | */ | |
1640 | ||
1641 | int gpio_get_value_cansleep(unsigned gpio) | |
1642 | { | |
1643 | struct gpio_chip *chip; | |
1644 | ||
1645 | might_sleep_if(extra_checks); | |
1646 | chip = gpio_to_chip(gpio); | |
978ccaa8 | 1647 | return chip->get ? chip->get(chip, gpio - chip->base) : 0; |
d2876d08 DB |
1648 | } |
1649 | EXPORT_SYMBOL_GPL(gpio_get_value_cansleep); | |
1650 | ||
1651 | void gpio_set_value_cansleep(unsigned gpio, int value) | |
1652 | { | |
1653 | struct gpio_chip *chip; | |
1654 | ||
1655 | might_sleep_if(extra_checks); | |
1656 | chip = gpio_to_chip(gpio); | |
1657 | chip->set(chip, gpio - chip->base, value); | |
1658 | } | |
1659 | EXPORT_SYMBOL_GPL(gpio_set_value_cansleep); | |
1660 | ||
1661 | ||
1662 | #ifdef CONFIG_DEBUG_FS | |
1663 | ||
d2876d08 DB |
1664 | static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) |
1665 | { | |
1666 | unsigned i; | |
1667 | unsigned gpio = chip->base; | |
1668 | struct gpio_desc *gdesc = &gpio_desc[gpio]; | |
1669 | int is_out; | |
1670 | ||
1671 | for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) { | |
1672 | if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) | |
1673 | continue; | |
1674 | ||
1675 | is_out = test_bit(FLAG_IS_OUT, &gdesc->flags); | |
6e8ba729 | 1676 | seq_printf(s, " gpio-%-3d (%-20.20s) %s %s", |
d2876d08 DB |
1677 | gpio, gdesc->label, |
1678 | is_out ? "out" : "in ", | |
1679 | chip->get | |
1680 | ? (chip->get(chip, i) ? "hi" : "lo") | |
1681 | : "? "); | |
1682 | ||
1683 | if (!is_out) { | |
1684 | int irq = gpio_to_irq(gpio); | |
08678b08 | 1685 | struct irq_desc *desc = irq_to_desc(irq); |
d2876d08 DB |
1686 | |
1687 | /* This races with request_irq(), set_irq_type(), | |
1688 | * and set_irq_wake() ... but those are "rare". | |
1689 | * | |
1690 | * More significantly, trigger type flags aren't | |
1691 | * currently maintained by genirq. | |
1692 | */ | |
1693 | if (irq >= 0 && desc->action) { | |
1694 | char *trigger; | |
1695 | ||
1696 | switch (desc->status & IRQ_TYPE_SENSE_MASK) { | |
1697 | case IRQ_TYPE_NONE: | |
1698 | trigger = "(default)"; | |
1699 | break; | |
1700 | case IRQ_TYPE_EDGE_FALLING: | |
1701 | trigger = "edge-falling"; | |
1702 | break; | |
1703 | case IRQ_TYPE_EDGE_RISING: | |
1704 | trigger = "edge-rising"; | |
1705 | break; | |
1706 | case IRQ_TYPE_EDGE_BOTH: | |
1707 | trigger = "edge-both"; | |
1708 | break; | |
1709 | case IRQ_TYPE_LEVEL_HIGH: | |
1710 | trigger = "level-high"; | |
1711 | break; | |
1712 | case IRQ_TYPE_LEVEL_LOW: | |
1713 | trigger = "level-low"; | |
1714 | break; | |
1715 | default: | |
1716 | trigger = "?trigger?"; | |
1717 | break; | |
1718 | } | |
1719 | ||
1720 | seq_printf(s, " irq-%d %s%s", | |
1721 | irq, trigger, | |
1722 | (desc->status & IRQ_WAKEUP) | |
1723 | ? " wakeup" : ""); | |
1724 | } | |
1725 | } | |
1726 | ||
1727 | seq_printf(s, "\n"); | |
1728 | } | |
1729 | } | |
1730 | ||
1731 | static int gpiolib_show(struct seq_file *s, void *unused) | |
1732 | { | |
1733 | struct gpio_chip *chip = NULL; | |
1734 | unsigned gpio; | |
1735 | int started = 0; | |
1736 | ||
1737 | /* REVISIT this isn't locked against gpio_chip removal ... */ | |
1738 | ||
e6de1808 | 1739 | for (gpio = 0; gpio_is_valid(gpio); gpio++) { |
d8f388d8 DB |
1740 | struct device *dev; |
1741 | ||
d2876d08 DB |
1742 | if (chip == gpio_desc[gpio].chip) |
1743 | continue; | |
1744 | chip = gpio_desc[gpio].chip; | |
1745 | if (!chip) | |
1746 | continue; | |
1747 | ||
d8f388d8 | 1748 | seq_printf(s, "%sGPIOs %d-%d", |
d2876d08 | 1749 | started ? "\n" : "", |
d8f388d8 DB |
1750 | chip->base, chip->base + chip->ngpio - 1); |
1751 | dev = chip->dev; | |
1752 | if (dev) | |
1753 | seq_printf(s, ", %s/%s", | |
1754 | dev->bus ? dev->bus->name : "no-bus", | |
14ab309d | 1755 | dev_name(dev)); |
d8f388d8 DB |
1756 | if (chip->label) |
1757 | seq_printf(s, ", %s", chip->label); | |
1758 | if (chip->can_sleep) | |
1759 | seq_printf(s, ", can sleep"); | |
1760 | seq_printf(s, ":\n"); | |
1761 | ||
d2876d08 DB |
1762 | started = 1; |
1763 | if (chip->dbg_show) | |
1764 | chip->dbg_show(s, chip); | |
1765 | else | |
1766 | gpiolib_dbg_show(s, chip); | |
1767 | } | |
1768 | return 0; | |
1769 | } | |
1770 | ||
1771 | static int gpiolib_open(struct inode *inode, struct file *file) | |
1772 | { | |
1773 | return single_open(file, gpiolib_show, NULL); | |
1774 | } | |
1775 | ||
828c0950 | 1776 | static const struct file_operations gpiolib_operations = { |
d2876d08 DB |
1777 | .open = gpiolib_open, |
1778 | .read = seq_read, | |
1779 | .llseek = seq_lseek, | |
1780 | .release = single_release, | |
1781 | }; | |
1782 | ||
1783 | static int __init gpiolib_debugfs_init(void) | |
1784 | { | |
1785 | /* /sys/kernel/debug/gpio */ | |
1786 | (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO, | |
1787 | NULL, NULL, &gpiolib_operations); | |
1788 | return 0; | |
1789 | } | |
1790 | subsys_initcall(gpiolib_debugfs_init); | |
1791 | ||
1792 | #endif /* DEBUG_FS */ |