Commit | Line | Data |
---|---|---|
d2876d08 DB |
1 | #include <linux/kernel.h> |
2 | #include <linux/module.h> | |
3 | #include <linux/irq.h> | |
4 | #include <linux/spinlock.h> | |
d8f388d8 DB |
5 | #include <linux/device.h> |
6 | #include <linux/err.h> | |
7 | #include <linux/debugfs.h> | |
8 | #include <linux/seq_file.h> | |
9 | #include <linux/gpio.h> | |
d2876d08 DB |
10 | |
11 | ||
12 | /* Optional implementation infrastructure for GPIO interfaces. | |
13 | * | |
14 | * Platforms may want to use this if they tend to use very many GPIOs | |
15 | * that aren't part of a System-On-Chip core; or across I2C/SPI/etc. | |
16 | * | |
17 | * When kernel footprint or instruction count is an issue, simpler | |
18 | * implementations may be preferred. The GPIO programming interface | |
19 | * allows for inlining speed-critical get/set operations for common | |
20 | * cases, so that access to SOC-integrated GPIOs can sometimes cost | |
21 | * only an instruction or two per bit. | |
22 | */ | |
23 | ||
24 | ||
25 | /* When debugging, extend minimal trust to callers and platform code. | |
26 | * Also emit diagnostic messages that may help initial bringup, when | |
27 | * board setup or driver bugs are most common. | |
28 | * | |
29 | * Otherwise, minimize overhead in what may be bitbanging codepaths. | |
30 | */ | |
31 | #ifdef DEBUG | |
32 | #define extra_checks 1 | |
33 | #else | |
34 | #define extra_checks 0 | |
35 | #endif | |
36 | ||
37 | /* gpio_lock prevents conflicts during gpio_desc[] table updates. | |
38 | * While any GPIO is requested, its gpio_chip is not removable; | |
39 | * each GPIO's "requested" flag serves as a lock and refcount. | |
40 | */ | |
41 | static DEFINE_SPINLOCK(gpio_lock); | |
42 | ||
43 | struct gpio_desc { | |
44 | struct gpio_chip *chip; | |
45 | unsigned long flags; | |
46 | /* flag symbols are bit numbers */ | |
47 | #define FLAG_REQUESTED 0 | |
48 | #define FLAG_IS_OUT 1 | |
169b6a7a | 49 | #define FLAG_RESERVED 2 |
d8f388d8 DB |
50 | #define FLAG_EXPORT 3 /* protected by sysfs_lock */ |
51 | #define FLAG_SYSFS 4 /* exported via /sys/class/gpio/control */ | |
d2876d08 DB |
52 | |
53 | #ifdef CONFIG_DEBUG_FS | |
54 | const char *label; | |
55 | #endif | |
56 | }; | |
57 | static struct gpio_desc gpio_desc[ARCH_NR_GPIOS]; | |
58 | ||
59 | static inline void desc_set_label(struct gpio_desc *d, const char *label) | |
60 | { | |
61 | #ifdef CONFIG_DEBUG_FS | |
62 | d->label = label; | |
63 | #endif | |
64 | } | |
65 | ||
66 | /* Warn when drivers omit gpio_request() calls -- legal but ill-advised | |
67 | * when setting direction, and otherwise illegal. Until board setup code | |
68 | * and drivers use explicit requests everywhere (which won't happen when | |
69 | * those calls have no teeth) we can't avoid autorequesting. This nag | |
35e8bb51 DB |
70 | * message should motivate switching to explicit requests... so should |
71 | * the weaker cleanup after faults, compared to gpio_request(). | |
d2876d08 | 72 | */ |
35e8bb51 | 73 | static int gpio_ensure_requested(struct gpio_desc *desc, unsigned offset) |
d2876d08 DB |
74 | { |
75 | if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) { | |
35e8bb51 DB |
76 | struct gpio_chip *chip = desc->chip; |
77 | int gpio = chip->base + offset; | |
78 | ||
79 | if (!try_module_get(chip->owner)) { | |
80 | pr_err("GPIO-%d: module can't be gotten \n", gpio); | |
81 | clear_bit(FLAG_REQUESTED, &desc->flags); | |
82 | /* lose */ | |
83 | return -EIO; | |
84 | } | |
85 | pr_warning("GPIO-%d autorequested\n", gpio); | |
d2876d08 | 86 | desc_set_label(desc, "[auto]"); |
35e8bb51 DB |
87 | /* caller must chip->request() w/o spinlock */ |
88 | if (chip->request) | |
89 | return 1; | |
d2876d08 | 90 | } |
35e8bb51 | 91 | return 0; |
d2876d08 DB |
92 | } |
93 | ||
94 | /* caller holds gpio_lock *OR* gpio is marked as requested */ | |
95 | static inline struct gpio_chip *gpio_to_chip(unsigned gpio) | |
96 | { | |
97 | return gpio_desc[gpio].chip; | |
98 | } | |
99 | ||
8d0aab2f AV |
100 | /* dynamic allocation of GPIOs, e.g. on a hotplugged device */ |
101 | static int gpiochip_find_base(int ngpio) | |
102 | { | |
103 | int i; | |
104 | int spare = 0; | |
105 | int base = -ENOSPC; | |
106 | ||
107 | for (i = ARCH_NR_GPIOS - 1; i >= 0 ; i--) { | |
169b6a7a AV |
108 | struct gpio_desc *desc = &gpio_desc[i]; |
109 | struct gpio_chip *chip = desc->chip; | |
8d0aab2f | 110 | |
169b6a7a | 111 | if (!chip && !test_bit(FLAG_RESERVED, &desc->flags)) { |
8d0aab2f AV |
112 | spare++; |
113 | if (spare == ngpio) { | |
114 | base = i; | |
115 | break; | |
116 | } | |
117 | } else { | |
118 | spare = 0; | |
169b6a7a AV |
119 | if (chip) |
120 | i -= chip->ngpio - 1; | |
8d0aab2f AV |
121 | } |
122 | } | |
123 | ||
124 | if (gpio_is_valid(base)) | |
125 | pr_debug("%s: found new base at %d\n", __func__, base); | |
126 | return base; | |
127 | } | |
128 | ||
169b6a7a AV |
129 | /** |
130 | * gpiochip_reserve() - reserve range of gpios to use with platform code only | |
131 | * @start: starting gpio number | |
132 | * @ngpio: number of gpios to reserve | |
133 | * Context: platform init, potentially before irqs or kmalloc will work | |
134 | * | |
135 | * Returns a negative errno if any gpio within the range is already reserved | |
136 | * or registered, else returns zero as a success code. Use this function | |
137 | * to mark a range of gpios as unavailable for dynamic gpio number allocation, | |
138 | * for example because its driver support is not yet loaded. | |
139 | */ | |
140 | int __init gpiochip_reserve(int start, int ngpio) | |
141 | { | |
142 | int ret = 0; | |
143 | unsigned long flags; | |
144 | int i; | |
145 | ||
bff5fda9 | 146 | if (!gpio_is_valid(start) || !gpio_is_valid(start + ngpio - 1)) |
169b6a7a AV |
147 | return -EINVAL; |
148 | ||
149 | spin_lock_irqsave(&gpio_lock, flags); | |
150 | ||
151 | for (i = start; i < start + ngpio; i++) { | |
152 | struct gpio_desc *desc = &gpio_desc[i]; | |
153 | ||
154 | if (desc->chip || test_bit(FLAG_RESERVED, &desc->flags)) { | |
155 | ret = -EBUSY; | |
156 | goto err; | |
157 | } | |
158 | ||
159 | set_bit(FLAG_RESERVED, &desc->flags); | |
160 | } | |
161 | ||
162 | pr_debug("%s: reserved gpios from %d to %d\n", | |
163 | __func__, start, start + ngpio - 1); | |
164 | err: | |
165 | spin_unlock_irqrestore(&gpio_lock, flags); | |
166 | ||
167 | return ret; | |
168 | } | |
169 | ||
d8f388d8 DB |
170 | #ifdef CONFIG_GPIO_SYSFS |
171 | ||
172 | /* lock protects against unexport_gpio() being called while | |
173 | * sysfs files are active. | |
174 | */ | |
175 | static DEFINE_MUTEX(sysfs_lock); | |
176 | ||
177 | /* | |
178 | * /sys/class/gpio/gpioN... only for GPIOs that are exported | |
179 | * /direction | |
180 | * * MAY BE OMITTED if kernel won't allow direction changes | |
181 | * * is read/write as "in" or "out" | |
182 | * * may also be written as "high" or "low", initializing | |
183 | * output value as specified ("out" implies "low") | |
184 | * /value | |
185 | * * always readable, subject to hardware behavior | |
186 | * * may be writable, as zero/nonzero | |
187 | * | |
188 | * REVISIT there will likely be an attribute for configuring async | |
189 | * notifications, e.g. to specify polling interval or IRQ trigger type | |
190 | * that would for example trigger a poll() on the "value". | |
191 | */ | |
192 | ||
193 | static ssize_t gpio_direction_show(struct device *dev, | |
194 | struct device_attribute *attr, char *buf) | |
195 | { | |
196 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
197 | ssize_t status; | |
198 | ||
199 | mutex_lock(&sysfs_lock); | |
200 | ||
201 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
202 | status = -EIO; | |
203 | else | |
204 | status = sprintf(buf, "%s\n", | |
205 | test_bit(FLAG_IS_OUT, &desc->flags) | |
206 | ? "out" : "in"); | |
207 | ||
208 | mutex_unlock(&sysfs_lock); | |
209 | return status; | |
210 | } | |
211 | ||
212 | static ssize_t gpio_direction_store(struct device *dev, | |
213 | struct device_attribute *attr, const char *buf, size_t size) | |
214 | { | |
215 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
216 | unsigned gpio = desc - gpio_desc; | |
217 | ssize_t status; | |
218 | ||
219 | mutex_lock(&sysfs_lock); | |
220 | ||
221 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
222 | status = -EIO; | |
223 | else if (sysfs_streq(buf, "high")) | |
224 | status = gpio_direction_output(gpio, 1); | |
225 | else if (sysfs_streq(buf, "out") || sysfs_streq(buf, "low")) | |
226 | status = gpio_direction_output(gpio, 0); | |
227 | else if (sysfs_streq(buf, "in")) | |
228 | status = gpio_direction_input(gpio); | |
229 | else | |
230 | status = -EINVAL; | |
231 | ||
232 | mutex_unlock(&sysfs_lock); | |
233 | return status ? : size; | |
234 | } | |
235 | ||
236 | static const DEVICE_ATTR(direction, 0644, | |
237 | gpio_direction_show, gpio_direction_store); | |
238 | ||
239 | static ssize_t gpio_value_show(struct device *dev, | |
240 | struct device_attribute *attr, char *buf) | |
241 | { | |
242 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
243 | unsigned gpio = desc - gpio_desc; | |
244 | ssize_t status; | |
245 | ||
246 | mutex_lock(&sysfs_lock); | |
247 | ||
248 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
249 | status = -EIO; | |
250 | else | |
251 | status = sprintf(buf, "%d\n", gpio_get_value_cansleep(gpio)); | |
252 | ||
253 | mutex_unlock(&sysfs_lock); | |
254 | return status; | |
255 | } | |
256 | ||
257 | static ssize_t gpio_value_store(struct device *dev, | |
258 | struct device_attribute *attr, const char *buf, size_t size) | |
259 | { | |
260 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
261 | unsigned gpio = desc - gpio_desc; | |
262 | ssize_t status; | |
263 | ||
264 | mutex_lock(&sysfs_lock); | |
265 | ||
266 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
267 | status = -EIO; | |
268 | else if (!test_bit(FLAG_IS_OUT, &desc->flags)) | |
269 | status = -EPERM; | |
270 | else { | |
271 | long value; | |
272 | ||
273 | status = strict_strtol(buf, 0, &value); | |
274 | if (status == 0) { | |
275 | gpio_set_value_cansleep(gpio, value != 0); | |
276 | status = size; | |
277 | } | |
278 | } | |
279 | ||
280 | mutex_unlock(&sysfs_lock); | |
281 | return status; | |
282 | } | |
283 | ||
284 | static /*const*/ DEVICE_ATTR(value, 0644, | |
285 | gpio_value_show, gpio_value_store); | |
286 | ||
287 | static const struct attribute *gpio_attrs[] = { | |
288 | &dev_attr_direction.attr, | |
289 | &dev_attr_value.attr, | |
290 | NULL, | |
291 | }; | |
292 | ||
293 | static const struct attribute_group gpio_attr_group = { | |
294 | .attrs = (struct attribute **) gpio_attrs, | |
295 | }; | |
296 | ||
297 | /* | |
298 | * /sys/class/gpio/gpiochipN/ | |
299 | * /base ... matching gpio_chip.base (N) | |
300 | * /label ... matching gpio_chip.label | |
301 | * /ngpio ... matching gpio_chip.ngpio | |
302 | */ | |
303 | ||
304 | static ssize_t chip_base_show(struct device *dev, | |
305 | struct device_attribute *attr, char *buf) | |
306 | { | |
307 | const struct gpio_chip *chip = dev_get_drvdata(dev); | |
308 | ||
309 | return sprintf(buf, "%d\n", chip->base); | |
310 | } | |
311 | static DEVICE_ATTR(base, 0444, chip_base_show, NULL); | |
312 | ||
313 | static ssize_t chip_label_show(struct device *dev, | |
314 | struct device_attribute *attr, char *buf) | |
315 | { | |
316 | const struct gpio_chip *chip = dev_get_drvdata(dev); | |
317 | ||
318 | return sprintf(buf, "%s\n", chip->label ? : ""); | |
319 | } | |
320 | static DEVICE_ATTR(label, 0444, chip_label_show, NULL); | |
321 | ||
322 | static ssize_t chip_ngpio_show(struct device *dev, | |
323 | struct device_attribute *attr, char *buf) | |
324 | { | |
325 | const struct gpio_chip *chip = dev_get_drvdata(dev); | |
326 | ||
327 | return sprintf(buf, "%u\n", chip->ngpio); | |
328 | } | |
329 | static DEVICE_ATTR(ngpio, 0444, chip_ngpio_show, NULL); | |
330 | ||
331 | static const struct attribute *gpiochip_attrs[] = { | |
332 | &dev_attr_base.attr, | |
333 | &dev_attr_label.attr, | |
334 | &dev_attr_ngpio.attr, | |
335 | NULL, | |
336 | }; | |
337 | ||
338 | static const struct attribute_group gpiochip_attr_group = { | |
339 | .attrs = (struct attribute **) gpiochip_attrs, | |
340 | }; | |
341 | ||
342 | /* | |
343 | * /sys/class/gpio/export ... write-only | |
344 | * integer N ... number of GPIO to export (full access) | |
345 | * /sys/class/gpio/unexport ... write-only | |
346 | * integer N ... number of GPIO to unexport | |
347 | */ | |
348 | static ssize_t export_store(struct class *class, const char *buf, size_t len) | |
349 | { | |
350 | long gpio; | |
351 | int status; | |
352 | ||
353 | status = strict_strtol(buf, 0, &gpio); | |
354 | if (status < 0) | |
355 | goto done; | |
356 | ||
357 | /* No extra locking here; FLAG_SYSFS just signifies that the | |
358 | * request and export were done by on behalf of userspace, so | |
359 | * they may be undone on its behalf too. | |
360 | */ | |
361 | ||
362 | status = gpio_request(gpio, "sysfs"); | |
363 | if (status < 0) | |
364 | goto done; | |
365 | ||
366 | status = gpio_export(gpio, true); | |
367 | if (status < 0) | |
368 | gpio_free(gpio); | |
369 | else | |
370 | set_bit(FLAG_SYSFS, &gpio_desc[gpio].flags); | |
371 | ||
372 | done: | |
373 | if (status) | |
374 | pr_debug("%s: status %d\n", __func__, status); | |
375 | return status ? : len; | |
376 | } | |
377 | ||
378 | static ssize_t unexport_store(struct class *class, const char *buf, size_t len) | |
379 | { | |
380 | long gpio; | |
381 | int status; | |
382 | ||
383 | status = strict_strtol(buf, 0, &gpio); | |
384 | if (status < 0) | |
385 | goto done; | |
386 | ||
387 | status = -EINVAL; | |
388 | ||
389 | /* reject bogus commands (gpio_unexport ignores them) */ | |
390 | if (!gpio_is_valid(gpio)) | |
391 | goto done; | |
392 | ||
393 | /* No extra locking here; FLAG_SYSFS just signifies that the | |
394 | * request and export were done by on behalf of userspace, so | |
395 | * they may be undone on its behalf too. | |
396 | */ | |
397 | if (test_and_clear_bit(FLAG_SYSFS, &gpio_desc[gpio].flags)) { | |
398 | status = 0; | |
399 | gpio_free(gpio); | |
400 | } | |
401 | done: | |
402 | if (status) | |
403 | pr_debug("%s: status %d\n", __func__, status); | |
404 | return status ? : len; | |
405 | } | |
406 | ||
407 | static struct class_attribute gpio_class_attrs[] = { | |
408 | __ATTR(export, 0200, NULL, export_store), | |
409 | __ATTR(unexport, 0200, NULL, unexport_store), | |
410 | __ATTR_NULL, | |
411 | }; | |
412 | ||
413 | static struct class gpio_class = { | |
414 | .name = "gpio", | |
415 | .owner = THIS_MODULE, | |
416 | ||
417 | .class_attrs = gpio_class_attrs, | |
418 | }; | |
419 | ||
420 | ||
421 | /** | |
422 | * gpio_export - export a GPIO through sysfs | |
423 | * @gpio: gpio to make available, already requested | |
424 | * @direction_may_change: true if userspace may change gpio direction | |
425 | * Context: arch_initcall or later | |
426 | * | |
427 | * When drivers want to make a GPIO accessible to userspace after they | |
428 | * have requested it -- perhaps while debugging, or as part of their | |
429 | * public interface -- they may use this routine. If the GPIO can | |
430 | * change direction (some can't) and the caller allows it, userspace | |
431 | * will see "direction" sysfs attribute which may be used to change | |
432 | * the gpio's direction. A "value" attribute will always be provided. | |
433 | * | |
434 | * Returns zero on success, else an error. | |
435 | */ | |
436 | int gpio_export(unsigned gpio, bool direction_may_change) | |
437 | { | |
438 | unsigned long flags; | |
439 | struct gpio_desc *desc; | |
440 | int status = -EINVAL; | |
441 | ||
442 | /* can't export until sysfs is available ... */ | |
443 | if (!gpio_class.p) { | |
444 | pr_debug("%s: called too early!\n", __func__); | |
445 | return -ENOENT; | |
446 | } | |
447 | ||
448 | if (!gpio_is_valid(gpio)) | |
449 | goto done; | |
450 | ||
451 | mutex_lock(&sysfs_lock); | |
452 | ||
453 | spin_lock_irqsave(&gpio_lock, flags); | |
454 | desc = &gpio_desc[gpio]; | |
455 | if (test_bit(FLAG_REQUESTED, &desc->flags) | |
456 | && !test_bit(FLAG_EXPORT, &desc->flags)) { | |
457 | status = 0; | |
458 | if (!desc->chip->direction_input | |
459 | || !desc->chip->direction_output) | |
460 | direction_may_change = false; | |
461 | } | |
462 | spin_unlock_irqrestore(&gpio_lock, flags); | |
463 | ||
464 | if (status == 0) { | |
465 | struct device *dev; | |
466 | ||
467 | dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0), | |
468 | desc, "gpio%d", gpio); | |
469 | if (dev) { | |
470 | if (direction_may_change) | |
471 | status = sysfs_create_group(&dev->kobj, | |
472 | &gpio_attr_group); | |
473 | else | |
474 | status = device_create_file(dev, | |
475 | &dev_attr_value); | |
476 | if (status != 0) | |
477 | device_unregister(dev); | |
478 | } else | |
479 | status = -ENODEV; | |
480 | if (status == 0) | |
481 | set_bit(FLAG_EXPORT, &desc->flags); | |
482 | } | |
483 | ||
484 | mutex_unlock(&sysfs_lock); | |
485 | ||
486 | done: | |
487 | if (status) | |
488 | pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); | |
489 | ||
490 | return status; | |
491 | } | |
492 | EXPORT_SYMBOL_GPL(gpio_export); | |
493 | ||
494 | static int match_export(struct device *dev, void *data) | |
495 | { | |
496 | return dev_get_drvdata(dev) == data; | |
497 | } | |
498 | ||
499 | /** | |
500 | * gpio_unexport - reverse effect of gpio_export() | |
501 | * @gpio: gpio to make unavailable | |
502 | * | |
503 | * This is implicit on gpio_free(). | |
504 | */ | |
505 | void gpio_unexport(unsigned gpio) | |
506 | { | |
507 | struct gpio_desc *desc; | |
508 | int status = -EINVAL; | |
509 | ||
510 | if (!gpio_is_valid(gpio)) | |
511 | goto done; | |
512 | ||
513 | mutex_lock(&sysfs_lock); | |
514 | ||
515 | desc = &gpio_desc[gpio]; | |
516 | if (test_bit(FLAG_EXPORT, &desc->flags)) { | |
517 | struct device *dev = NULL; | |
518 | ||
519 | dev = class_find_device(&gpio_class, NULL, desc, match_export); | |
520 | if (dev) { | |
521 | clear_bit(FLAG_EXPORT, &desc->flags); | |
522 | put_device(dev); | |
523 | device_unregister(dev); | |
524 | status = 0; | |
525 | } else | |
526 | status = -ENODEV; | |
527 | } | |
528 | ||
529 | mutex_unlock(&sysfs_lock); | |
530 | done: | |
531 | if (status) | |
532 | pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); | |
533 | } | |
534 | EXPORT_SYMBOL_GPL(gpio_unexport); | |
535 | ||
536 | static int gpiochip_export(struct gpio_chip *chip) | |
537 | { | |
538 | int status; | |
539 | struct device *dev; | |
540 | ||
541 | /* Many systems register gpio chips for SOC support very early, | |
542 | * before driver model support is available. In those cases we | |
543 | * export this later, in gpiolib_sysfs_init() ... here we just | |
544 | * verify that _some_ field of gpio_class got initialized. | |
545 | */ | |
546 | if (!gpio_class.p) | |
547 | return 0; | |
548 | ||
549 | /* use chip->base for the ID; it's already known to be unique */ | |
550 | mutex_lock(&sysfs_lock); | |
551 | dev = device_create(&gpio_class, chip->dev, MKDEV(0, 0), chip, | |
552 | "gpiochip%d", chip->base); | |
553 | if (dev) { | |
554 | status = sysfs_create_group(&dev->kobj, | |
555 | &gpiochip_attr_group); | |
556 | } else | |
557 | status = -ENODEV; | |
558 | chip->exported = (status == 0); | |
559 | mutex_unlock(&sysfs_lock); | |
560 | ||
561 | if (status) { | |
562 | unsigned long flags; | |
563 | unsigned gpio; | |
564 | ||
565 | spin_lock_irqsave(&gpio_lock, flags); | |
566 | gpio = chip->base; | |
567 | while (gpio_desc[gpio].chip == chip) | |
568 | gpio_desc[gpio++].chip = NULL; | |
569 | spin_unlock_irqrestore(&gpio_lock, flags); | |
570 | ||
571 | pr_debug("%s: chip %s status %d\n", __func__, | |
572 | chip->label, status); | |
573 | } | |
574 | ||
575 | return status; | |
576 | } | |
577 | ||
578 | static void gpiochip_unexport(struct gpio_chip *chip) | |
579 | { | |
580 | int status; | |
581 | struct device *dev; | |
582 | ||
583 | mutex_lock(&sysfs_lock); | |
584 | dev = class_find_device(&gpio_class, NULL, chip, match_export); | |
585 | if (dev) { | |
586 | put_device(dev); | |
587 | device_unregister(dev); | |
588 | chip->exported = 0; | |
589 | status = 0; | |
590 | } else | |
591 | status = -ENODEV; | |
592 | mutex_unlock(&sysfs_lock); | |
593 | ||
594 | if (status) | |
595 | pr_debug("%s: chip %s status %d\n", __func__, | |
596 | chip->label, status); | |
597 | } | |
598 | ||
599 | static int __init gpiolib_sysfs_init(void) | |
600 | { | |
601 | int status; | |
602 | unsigned long flags; | |
603 | unsigned gpio; | |
604 | ||
605 | status = class_register(&gpio_class); | |
606 | if (status < 0) | |
607 | return status; | |
608 | ||
609 | /* Scan and register the gpio_chips which registered very | |
610 | * early (e.g. before the class_register above was called). | |
611 | * | |
612 | * We run before arch_initcall() so chip->dev nodes can have | |
613 | * registered, and so arch_initcall() can always gpio_export(). | |
614 | */ | |
615 | spin_lock_irqsave(&gpio_lock, flags); | |
616 | for (gpio = 0; gpio < ARCH_NR_GPIOS; gpio++) { | |
617 | struct gpio_chip *chip; | |
618 | ||
619 | chip = gpio_desc[gpio].chip; | |
620 | if (!chip || chip->exported) | |
621 | continue; | |
622 | ||
623 | spin_unlock_irqrestore(&gpio_lock, flags); | |
624 | status = gpiochip_export(chip); | |
625 | spin_lock_irqsave(&gpio_lock, flags); | |
626 | } | |
627 | spin_unlock_irqrestore(&gpio_lock, flags); | |
628 | ||
629 | ||
630 | return status; | |
631 | } | |
632 | postcore_initcall(gpiolib_sysfs_init); | |
633 | ||
634 | #else | |
635 | static inline int gpiochip_export(struct gpio_chip *chip) | |
636 | { | |
637 | return 0; | |
638 | } | |
639 | ||
640 | static inline void gpiochip_unexport(struct gpio_chip *chip) | |
641 | { | |
642 | } | |
643 | ||
644 | #endif /* CONFIG_GPIO_SYSFS */ | |
645 | ||
d2876d08 DB |
646 | /** |
647 | * gpiochip_add() - register a gpio_chip | |
648 | * @chip: the chip to register, with chip->base initialized | |
649 | * Context: potentially before irqs or kmalloc will work | |
650 | * | |
651 | * Returns a negative errno if the chip can't be registered, such as | |
652 | * because the chip->base is invalid or already associated with a | |
653 | * different chip. Otherwise it returns zero as a success code. | |
8d0aab2f | 654 | * |
d8f388d8 DB |
655 | * When gpiochip_add() is called very early during boot, so that GPIOs |
656 | * can be freely used, the chip->dev device must be registered before | |
657 | * the gpio framework's arch_initcall(). Otherwise sysfs initialization | |
658 | * for GPIOs will fail rudely. | |
659 | * | |
8d0aab2f AV |
660 | * If chip->base is negative, this requests dynamic assignment of |
661 | * a range of valid GPIOs. | |
d2876d08 DB |
662 | */ |
663 | int gpiochip_add(struct gpio_chip *chip) | |
664 | { | |
665 | unsigned long flags; | |
666 | int status = 0; | |
667 | unsigned id; | |
8d0aab2f | 668 | int base = chip->base; |
d2876d08 | 669 | |
bff5fda9 | 670 | if ((!gpio_is_valid(base) || !gpio_is_valid(base + chip->ngpio - 1)) |
8d0aab2f | 671 | && base >= 0) { |
d2876d08 DB |
672 | status = -EINVAL; |
673 | goto fail; | |
674 | } | |
675 | ||
676 | spin_lock_irqsave(&gpio_lock, flags); | |
677 | ||
8d0aab2f AV |
678 | if (base < 0) { |
679 | base = gpiochip_find_base(chip->ngpio); | |
680 | if (base < 0) { | |
681 | status = base; | |
d8f388d8 | 682 | goto unlock; |
8d0aab2f AV |
683 | } |
684 | chip->base = base; | |
685 | } | |
686 | ||
d2876d08 | 687 | /* these GPIO numbers must not be managed by another gpio_chip */ |
8d0aab2f | 688 | for (id = base; id < base + chip->ngpio; id++) { |
d2876d08 DB |
689 | if (gpio_desc[id].chip != NULL) { |
690 | status = -EBUSY; | |
691 | break; | |
692 | } | |
693 | } | |
694 | if (status == 0) { | |
8d0aab2f | 695 | for (id = base; id < base + chip->ngpio; id++) { |
d2876d08 | 696 | gpio_desc[id].chip = chip; |
d8f388d8 DB |
697 | |
698 | /* REVISIT: most hardware initializes GPIOs as | |
699 | * inputs (often with pullups enabled) so power | |
700 | * usage is minimized. Linux code should set the | |
701 | * gpio direction first thing; but until it does, | |
702 | * we may expose the wrong direction in sysfs. | |
703 | */ | |
704 | gpio_desc[id].flags = !chip->direction_input | |
705 | ? (1 << FLAG_IS_OUT) | |
706 | : 0; | |
d2876d08 DB |
707 | } |
708 | } | |
709 | ||
d8f388d8 | 710 | unlock: |
d2876d08 | 711 | spin_unlock_irqrestore(&gpio_lock, flags); |
d8f388d8 DB |
712 | if (status == 0) |
713 | status = gpiochip_export(chip); | |
d2876d08 DB |
714 | fail: |
715 | /* failures here can mean systems won't boot... */ | |
716 | if (status) | |
717 | pr_err("gpiochip_add: gpios %d..%d (%s) not registered\n", | |
bff5fda9 | 718 | chip->base, chip->base + chip->ngpio - 1, |
d2876d08 DB |
719 | chip->label ? : "generic"); |
720 | return status; | |
721 | } | |
722 | EXPORT_SYMBOL_GPL(gpiochip_add); | |
723 | ||
724 | /** | |
725 | * gpiochip_remove() - unregister a gpio_chip | |
726 | * @chip: the chip to unregister | |
727 | * | |
728 | * A gpio_chip with any GPIOs still requested may not be removed. | |
729 | */ | |
730 | int gpiochip_remove(struct gpio_chip *chip) | |
731 | { | |
732 | unsigned long flags; | |
733 | int status = 0; | |
734 | unsigned id; | |
735 | ||
736 | spin_lock_irqsave(&gpio_lock, flags); | |
737 | ||
738 | for (id = chip->base; id < chip->base + chip->ngpio; id++) { | |
739 | if (test_bit(FLAG_REQUESTED, &gpio_desc[id].flags)) { | |
740 | status = -EBUSY; | |
741 | break; | |
742 | } | |
743 | } | |
744 | if (status == 0) { | |
745 | for (id = chip->base; id < chip->base + chip->ngpio; id++) | |
746 | gpio_desc[id].chip = NULL; | |
747 | } | |
748 | ||
749 | spin_unlock_irqrestore(&gpio_lock, flags); | |
d8f388d8 DB |
750 | |
751 | if (status == 0) | |
752 | gpiochip_unexport(chip); | |
753 | ||
d2876d08 DB |
754 | return status; |
755 | } | |
756 | EXPORT_SYMBOL_GPL(gpiochip_remove); | |
757 | ||
758 | ||
759 | /* These "optional" allocation calls help prevent drivers from stomping | |
760 | * on each other, and help provide better diagnostics in debugfs. | |
761 | * They're called even less than the "set direction" calls. | |
762 | */ | |
763 | int gpio_request(unsigned gpio, const char *label) | |
764 | { | |
765 | struct gpio_desc *desc; | |
35e8bb51 | 766 | struct gpio_chip *chip; |
d2876d08 DB |
767 | int status = -EINVAL; |
768 | unsigned long flags; | |
769 | ||
770 | spin_lock_irqsave(&gpio_lock, flags); | |
771 | ||
e6de1808 | 772 | if (!gpio_is_valid(gpio)) |
d2876d08 DB |
773 | goto done; |
774 | desc = &gpio_desc[gpio]; | |
35e8bb51 DB |
775 | chip = desc->chip; |
776 | if (chip == NULL) | |
d2876d08 DB |
777 | goto done; |
778 | ||
35e8bb51 | 779 | if (!try_module_get(chip->owner)) |
438d8908 GL |
780 | goto done; |
781 | ||
d2876d08 | 782 | /* NOTE: gpio_request() can be called in early boot, |
35e8bb51 | 783 | * before IRQs are enabled, for non-sleeping (SOC) GPIOs. |
d2876d08 DB |
784 | */ |
785 | ||
786 | if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) { | |
787 | desc_set_label(desc, label ? : "?"); | |
788 | status = 0; | |
438d8908 | 789 | } else { |
d2876d08 | 790 | status = -EBUSY; |
35e8bb51 DB |
791 | module_put(chip->owner); |
792 | } | |
793 | ||
794 | if (chip->request) { | |
795 | /* chip->request may sleep */ | |
796 | spin_unlock_irqrestore(&gpio_lock, flags); | |
797 | status = chip->request(chip, gpio - chip->base); | |
798 | spin_lock_irqsave(&gpio_lock, flags); | |
799 | ||
800 | if (status < 0) { | |
801 | desc_set_label(desc, NULL); | |
802 | module_put(chip->owner); | |
803 | clear_bit(FLAG_REQUESTED, &desc->flags); | |
804 | } | |
438d8908 | 805 | } |
d2876d08 DB |
806 | |
807 | done: | |
808 | if (status) | |
809 | pr_debug("gpio_request: gpio-%d (%s) status %d\n", | |
810 | gpio, label ? : "?", status); | |
811 | spin_unlock_irqrestore(&gpio_lock, flags); | |
812 | return status; | |
813 | } | |
814 | EXPORT_SYMBOL_GPL(gpio_request); | |
815 | ||
816 | void gpio_free(unsigned gpio) | |
817 | { | |
818 | unsigned long flags; | |
819 | struct gpio_desc *desc; | |
35e8bb51 | 820 | struct gpio_chip *chip; |
d2876d08 | 821 | |
3d599d1c UKK |
822 | might_sleep(); |
823 | ||
e6de1808 | 824 | if (!gpio_is_valid(gpio)) { |
d2876d08 DB |
825 | WARN_ON(extra_checks); |
826 | return; | |
827 | } | |
828 | ||
d8f388d8 DB |
829 | gpio_unexport(gpio); |
830 | ||
d2876d08 DB |
831 | spin_lock_irqsave(&gpio_lock, flags); |
832 | ||
833 | desc = &gpio_desc[gpio]; | |
35e8bb51 DB |
834 | chip = desc->chip; |
835 | if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) { | |
836 | if (chip->free) { | |
837 | spin_unlock_irqrestore(&gpio_lock, flags); | |
838 | might_sleep_if(extra_checks && chip->can_sleep); | |
839 | chip->free(chip, gpio - chip->base); | |
840 | spin_lock_irqsave(&gpio_lock, flags); | |
841 | } | |
d2876d08 | 842 | desc_set_label(desc, NULL); |
438d8908 | 843 | module_put(desc->chip->owner); |
35e8bb51 | 844 | clear_bit(FLAG_REQUESTED, &desc->flags); |
438d8908 | 845 | } else |
d2876d08 DB |
846 | WARN_ON(extra_checks); |
847 | ||
848 | spin_unlock_irqrestore(&gpio_lock, flags); | |
849 | } | |
850 | EXPORT_SYMBOL_GPL(gpio_free); | |
851 | ||
852 | ||
853 | /** | |
854 | * gpiochip_is_requested - return string iff signal was requested | |
855 | * @chip: controller managing the signal | |
856 | * @offset: of signal within controller's 0..(ngpio - 1) range | |
857 | * | |
858 | * Returns NULL if the GPIO is not currently requested, else a string. | |
859 | * If debugfs support is enabled, the string returned is the label passed | |
860 | * to gpio_request(); otherwise it is a meaningless constant. | |
861 | * | |
862 | * This function is for use by GPIO controller drivers. The label can | |
863 | * help with diagnostics, and knowing that the signal is used as a GPIO | |
864 | * can help avoid accidentally multiplexing it to another controller. | |
865 | */ | |
866 | const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset) | |
867 | { | |
868 | unsigned gpio = chip->base + offset; | |
869 | ||
e6de1808 | 870 | if (!gpio_is_valid(gpio) || gpio_desc[gpio].chip != chip) |
d2876d08 DB |
871 | return NULL; |
872 | if (test_bit(FLAG_REQUESTED, &gpio_desc[gpio].flags) == 0) | |
873 | return NULL; | |
874 | #ifdef CONFIG_DEBUG_FS | |
875 | return gpio_desc[gpio].label; | |
876 | #else | |
877 | return "?"; | |
878 | #endif | |
879 | } | |
880 | EXPORT_SYMBOL_GPL(gpiochip_is_requested); | |
881 | ||
882 | ||
883 | /* Drivers MUST set GPIO direction before making get/set calls. In | |
884 | * some cases this is done in early boot, before IRQs are enabled. | |
885 | * | |
886 | * As a rule these aren't called more than once (except for drivers | |
887 | * using the open-drain emulation idiom) so these are natural places | |
888 | * to accumulate extra debugging checks. Note that we can't (yet) | |
889 | * rely on gpio_request() having been called beforehand. | |
890 | */ | |
891 | ||
892 | int gpio_direction_input(unsigned gpio) | |
893 | { | |
894 | unsigned long flags; | |
895 | struct gpio_chip *chip; | |
896 | struct gpio_desc *desc = &gpio_desc[gpio]; | |
897 | int status = -EINVAL; | |
898 | ||
899 | spin_lock_irqsave(&gpio_lock, flags); | |
900 | ||
e6de1808 | 901 | if (!gpio_is_valid(gpio)) |
d2876d08 DB |
902 | goto fail; |
903 | chip = desc->chip; | |
904 | if (!chip || !chip->get || !chip->direction_input) | |
905 | goto fail; | |
906 | gpio -= chip->base; | |
907 | if (gpio >= chip->ngpio) | |
908 | goto fail; | |
35e8bb51 DB |
909 | status = gpio_ensure_requested(desc, gpio); |
910 | if (status < 0) | |
911 | goto fail; | |
d2876d08 DB |
912 | |
913 | /* now we know the gpio is valid and chip won't vanish */ | |
914 | ||
915 | spin_unlock_irqrestore(&gpio_lock, flags); | |
916 | ||
917 | might_sleep_if(extra_checks && chip->can_sleep); | |
918 | ||
35e8bb51 DB |
919 | if (status) { |
920 | status = chip->request(chip, gpio); | |
921 | if (status < 0) { | |
922 | pr_debug("GPIO-%d: chip request fail, %d\n", | |
923 | chip->base + gpio, status); | |
924 | /* and it's not available to anyone else ... | |
925 | * gpio_request() is the fully clean solution. | |
926 | */ | |
927 | goto lose; | |
928 | } | |
929 | } | |
930 | ||
d2876d08 DB |
931 | status = chip->direction_input(chip, gpio); |
932 | if (status == 0) | |
933 | clear_bit(FLAG_IS_OUT, &desc->flags); | |
35e8bb51 | 934 | lose: |
d2876d08 DB |
935 | return status; |
936 | fail: | |
937 | spin_unlock_irqrestore(&gpio_lock, flags); | |
938 | if (status) | |
939 | pr_debug("%s: gpio-%d status %d\n", | |
145980a0 | 940 | __func__, gpio, status); |
d2876d08 DB |
941 | return status; |
942 | } | |
943 | EXPORT_SYMBOL_GPL(gpio_direction_input); | |
944 | ||
945 | int gpio_direction_output(unsigned gpio, int value) | |
946 | { | |
947 | unsigned long flags; | |
948 | struct gpio_chip *chip; | |
949 | struct gpio_desc *desc = &gpio_desc[gpio]; | |
950 | int status = -EINVAL; | |
951 | ||
952 | spin_lock_irqsave(&gpio_lock, flags); | |
953 | ||
e6de1808 | 954 | if (!gpio_is_valid(gpio)) |
d2876d08 DB |
955 | goto fail; |
956 | chip = desc->chip; | |
957 | if (!chip || !chip->set || !chip->direction_output) | |
958 | goto fail; | |
959 | gpio -= chip->base; | |
960 | if (gpio >= chip->ngpio) | |
961 | goto fail; | |
35e8bb51 DB |
962 | status = gpio_ensure_requested(desc, gpio); |
963 | if (status < 0) | |
964 | goto fail; | |
d2876d08 DB |
965 | |
966 | /* now we know the gpio is valid and chip won't vanish */ | |
967 | ||
968 | spin_unlock_irqrestore(&gpio_lock, flags); | |
969 | ||
970 | might_sleep_if(extra_checks && chip->can_sleep); | |
971 | ||
35e8bb51 DB |
972 | if (status) { |
973 | status = chip->request(chip, gpio); | |
974 | if (status < 0) { | |
975 | pr_debug("GPIO-%d: chip request fail, %d\n", | |
976 | chip->base + gpio, status); | |
977 | /* and it's not available to anyone else ... | |
978 | * gpio_request() is the fully clean solution. | |
979 | */ | |
980 | goto lose; | |
981 | } | |
982 | } | |
983 | ||
d2876d08 DB |
984 | status = chip->direction_output(chip, gpio, value); |
985 | if (status == 0) | |
986 | set_bit(FLAG_IS_OUT, &desc->flags); | |
35e8bb51 | 987 | lose: |
d2876d08 DB |
988 | return status; |
989 | fail: | |
990 | spin_unlock_irqrestore(&gpio_lock, flags); | |
991 | if (status) | |
992 | pr_debug("%s: gpio-%d status %d\n", | |
145980a0 | 993 | __func__, gpio, status); |
d2876d08 DB |
994 | return status; |
995 | } | |
996 | EXPORT_SYMBOL_GPL(gpio_direction_output); | |
997 | ||
998 | ||
999 | /* I/O calls are only valid after configuration completed; the relevant | |
1000 | * "is this a valid GPIO" error checks should already have been done. | |
1001 | * | |
1002 | * "Get" operations are often inlinable as reading a pin value register, | |
1003 | * and masking the relevant bit in that register. | |
1004 | * | |
1005 | * When "set" operations are inlinable, they involve writing that mask to | |
1006 | * one register to set a low value, or a different register to set it high. | |
1007 | * Otherwise locking is needed, so there may be little value to inlining. | |
1008 | * | |
1009 | *------------------------------------------------------------------------ | |
1010 | * | |
1011 | * IMPORTANT!!! The hot paths -- get/set value -- assume that callers | |
1012 | * have requested the GPIO. That can include implicit requesting by | |
1013 | * a direction setting call. Marking a gpio as requested locks its chip | |
1014 | * in memory, guaranteeing that these table lookups need no more locking | |
1015 | * and that gpiochip_remove() will fail. | |
1016 | * | |
1017 | * REVISIT when debugging, consider adding some instrumentation to ensure | |
1018 | * that the GPIO was actually requested. | |
1019 | */ | |
1020 | ||
1021 | /** | |
1022 | * __gpio_get_value() - return a gpio's value | |
1023 | * @gpio: gpio whose value will be returned | |
1024 | * Context: any | |
1025 | * | |
1026 | * This is used directly or indirectly to implement gpio_get_value(). | |
1027 | * It returns the zero or nonzero value provided by the associated | |
1028 | * gpio_chip.get() method; or zero if no such method is provided. | |
1029 | */ | |
1030 | int __gpio_get_value(unsigned gpio) | |
1031 | { | |
1032 | struct gpio_chip *chip; | |
1033 | ||
1034 | chip = gpio_to_chip(gpio); | |
1035 | WARN_ON(extra_checks && chip->can_sleep); | |
1036 | return chip->get ? chip->get(chip, gpio - chip->base) : 0; | |
1037 | } | |
1038 | EXPORT_SYMBOL_GPL(__gpio_get_value); | |
1039 | ||
1040 | /** | |
1041 | * __gpio_set_value() - assign a gpio's value | |
1042 | * @gpio: gpio whose value will be assigned | |
1043 | * @value: value to assign | |
1044 | * Context: any | |
1045 | * | |
1046 | * This is used directly or indirectly to implement gpio_set_value(). | |
1047 | * It invokes the associated gpio_chip.set() method. | |
1048 | */ | |
1049 | void __gpio_set_value(unsigned gpio, int value) | |
1050 | { | |
1051 | struct gpio_chip *chip; | |
1052 | ||
1053 | chip = gpio_to_chip(gpio); | |
1054 | WARN_ON(extra_checks && chip->can_sleep); | |
1055 | chip->set(chip, gpio - chip->base, value); | |
1056 | } | |
1057 | EXPORT_SYMBOL_GPL(__gpio_set_value); | |
1058 | ||
1059 | /** | |
1060 | * __gpio_cansleep() - report whether gpio value access will sleep | |
1061 | * @gpio: gpio in question | |
1062 | * Context: any | |
1063 | * | |
1064 | * This is used directly or indirectly to implement gpio_cansleep(). It | |
1065 | * returns nonzero if access reading or writing the GPIO value can sleep. | |
1066 | */ | |
1067 | int __gpio_cansleep(unsigned gpio) | |
1068 | { | |
1069 | struct gpio_chip *chip; | |
1070 | ||
1071 | /* only call this on GPIOs that are valid! */ | |
1072 | chip = gpio_to_chip(gpio); | |
1073 | ||
1074 | return chip->can_sleep; | |
1075 | } | |
1076 | EXPORT_SYMBOL_GPL(__gpio_cansleep); | |
1077 | ||
0f6d504e DB |
1078 | /** |
1079 | * __gpio_to_irq() - return the IRQ corresponding to a GPIO | |
1080 | * @gpio: gpio whose IRQ will be returned (already requested) | |
1081 | * Context: any | |
1082 | * | |
1083 | * This is used directly or indirectly to implement gpio_to_irq(). | |
1084 | * It returns the number of the IRQ signaled by this (input) GPIO, | |
1085 | * or a negative errno. | |
1086 | */ | |
1087 | int __gpio_to_irq(unsigned gpio) | |
1088 | { | |
1089 | struct gpio_chip *chip; | |
1090 | ||
1091 | chip = gpio_to_chip(gpio); | |
1092 | return chip->to_irq ? chip->to_irq(chip, gpio - chip->base) : -ENXIO; | |
1093 | } | |
1094 | EXPORT_SYMBOL_GPL(__gpio_to_irq); | |
1095 | ||
d2876d08 DB |
1096 | |
1097 | ||
1098 | /* There's no value in making it easy to inline GPIO calls that may sleep. | |
1099 | * Common examples include ones connected to I2C or SPI chips. | |
1100 | */ | |
1101 | ||
1102 | int gpio_get_value_cansleep(unsigned gpio) | |
1103 | { | |
1104 | struct gpio_chip *chip; | |
1105 | ||
1106 | might_sleep_if(extra_checks); | |
1107 | chip = gpio_to_chip(gpio); | |
1108 | return chip->get(chip, gpio - chip->base); | |
1109 | } | |
1110 | EXPORT_SYMBOL_GPL(gpio_get_value_cansleep); | |
1111 | ||
1112 | void gpio_set_value_cansleep(unsigned gpio, int value) | |
1113 | { | |
1114 | struct gpio_chip *chip; | |
1115 | ||
1116 | might_sleep_if(extra_checks); | |
1117 | chip = gpio_to_chip(gpio); | |
1118 | chip->set(chip, gpio - chip->base, value); | |
1119 | } | |
1120 | EXPORT_SYMBOL_GPL(gpio_set_value_cansleep); | |
1121 | ||
1122 | ||
1123 | #ifdef CONFIG_DEBUG_FS | |
1124 | ||
d2876d08 DB |
1125 | static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) |
1126 | { | |
1127 | unsigned i; | |
1128 | unsigned gpio = chip->base; | |
1129 | struct gpio_desc *gdesc = &gpio_desc[gpio]; | |
1130 | int is_out; | |
1131 | ||
1132 | for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) { | |
1133 | if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) | |
1134 | continue; | |
1135 | ||
1136 | is_out = test_bit(FLAG_IS_OUT, &gdesc->flags); | |
1137 | seq_printf(s, " gpio-%-3d (%-12s) %s %s", | |
1138 | gpio, gdesc->label, | |
1139 | is_out ? "out" : "in ", | |
1140 | chip->get | |
1141 | ? (chip->get(chip, i) ? "hi" : "lo") | |
1142 | : "? "); | |
1143 | ||
1144 | if (!is_out) { | |
1145 | int irq = gpio_to_irq(gpio); | |
1146 | struct irq_desc *desc = irq_desc + irq; | |
1147 | ||
1148 | /* This races with request_irq(), set_irq_type(), | |
1149 | * and set_irq_wake() ... but those are "rare". | |
1150 | * | |
1151 | * More significantly, trigger type flags aren't | |
1152 | * currently maintained by genirq. | |
1153 | */ | |
1154 | if (irq >= 0 && desc->action) { | |
1155 | char *trigger; | |
1156 | ||
1157 | switch (desc->status & IRQ_TYPE_SENSE_MASK) { | |
1158 | case IRQ_TYPE_NONE: | |
1159 | trigger = "(default)"; | |
1160 | break; | |
1161 | case IRQ_TYPE_EDGE_FALLING: | |
1162 | trigger = "edge-falling"; | |
1163 | break; | |
1164 | case IRQ_TYPE_EDGE_RISING: | |
1165 | trigger = "edge-rising"; | |
1166 | break; | |
1167 | case IRQ_TYPE_EDGE_BOTH: | |
1168 | trigger = "edge-both"; | |
1169 | break; | |
1170 | case IRQ_TYPE_LEVEL_HIGH: | |
1171 | trigger = "level-high"; | |
1172 | break; | |
1173 | case IRQ_TYPE_LEVEL_LOW: | |
1174 | trigger = "level-low"; | |
1175 | break; | |
1176 | default: | |
1177 | trigger = "?trigger?"; | |
1178 | break; | |
1179 | } | |
1180 | ||
1181 | seq_printf(s, " irq-%d %s%s", | |
1182 | irq, trigger, | |
1183 | (desc->status & IRQ_WAKEUP) | |
1184 | ? " wakeup" : ""); | |
1185 | } | |
1186 | } | |
1187 | ||
1188 | seq_printf(s, "\n"); | |
1189 | } | |
1190 | } | |
1191 | ||
1192 | static int gpiolib_show(struct seq_file *s, void *unused) | |
1193 | { | |
1194 | struct gpio_chip *chip = NULL; | |
1195 | unsigned gpio; | |
1196 | int started = 0; | |
1197 | ||
1198 | /* REVISIT this isn't locked against gpio_chip removal ... */ | |
1199 | ||
e6de1808 | 1200 | for (gpio = 0; gpio_is_valid(gpio); gpio++) { |
d8f388d8 DB |
1201 | struct device *dev; |
1202 | ||
d2876d08 DB |
1203 | if (chip == gpio_desc[gpio].chip) |
1204 | continue; | |
1205 | chip = gpio_desc[gpio].chip; | |
1206 | if (!chip) | |
1207 | continue; | |
1208 | ||
d8f388d8 | 1209 | seq_printf(s, "%sGPIOs %d-%d", |
d2876d08 | 1210 | started ? "\n" : "", |
d8f388d8 DB |
1211 | chip->base, chip->base + chip->ngpio - 1); |
1212 | dev = chip->dev; | |
1213 | if (dev) | |
1214 | seq_printf(s, ", %s/%s", | |
1215 | dev->bus ? dev->bus->name : "no-bus", | |
1216 | dev->bus_id); | |
1217 | if (chip->label) | |
1218 | seq_printf(s, ", %s", chip->label); | |
1219 | if (chip->can_sleep) | |
1220 | seq_printf(s, ", can sleep"); | |
1221 | seq_printf(s, ":\n"); | |
1222 | ||
d2876d08 DB |
1223 | started = 1; |
1224 | if (chip->dbg_show) | |
1225 | chip->dbg_show(s, chip); | |
1226 | else | |
1227 | gpiolib_dbg_show(s, chip); | |
1228 | } | |
1229 | return 0; | |
1230 | } | |
1231 | ||
1232 | static int gpiolib_open(struct inode *inode, struct file *file) | |
1233 | { | |
1234 | return single_open(file, gpiolib_show, NULL); | |
1235 | } | |
1236 | ||
1237 | static struct file_operations gpiolib_operations = { | |
1238 | .open = gpiolib_open, | |
1239 | .read = seq_read, | |
1240 | .llseek = seq_lseek, | |
1241 | .release = single_release, | |
1242 | }; | |
1243 | ||
1244 | static int __init gpiolib_debugfs_init(void) | |
1245 | { | |
1246 | /* /sys/kernel/debug/gpio */ | |
1247 | (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO, | |
1248 | NULL, NULL, &gpiolib_operations); | |
1249 | return 0; | |
1250 | } | |
1251 | subsys_initcall(gpiolib_debugfs_init); | |
1252 | ||
1253 | #endif /* DEBUG_FS */ |