]>
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 | |
e3274e91 | 251 | status = sprintf(buf, "%d\n", !!gpio_get_value_cansleep(gpio)); |
d8f388d8 DB |
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; | |
926b663c | 441 | char *ioname = NULL; |
d8f388d8 DB |
442 | |
443 | /* can't export until sysfs is available ... */ | |
444 | if (!gpio_class.p) { | |
445 | pr_debug("%s: called too early!\n", __func__); | |
446 | return -ENOENT; | |
447 | } | |
448 | ||
449 | if (!gpio_is_valid(gpio)) | |
450 | goto done; | |
451 | ||
452 | mutex_lock(&sysfs_lock); | |
453 | ||
454 | spin_lock_irqsave(&gpio_lock, flags); | |
455 | desc = &gpio_desc[gpio]; | |
456 | if (test_bit(FLAG_REQUESTED, &desc->flags) | |
457 | && !test_bit(FLAG_EXPORT, &desc->flags)) { | |
458 | status = 0; | |
459 | if (!desc->chip->direction_input | |
460 | || !desc->chip->direction_output) | |
461 | direction_may_change = false; | |
462 | } | |
463 | spin_unlock_irqrestore(&gpio_lock, flags); | |
464 | ||
926b663c DS |
465 | if (desc->chip->names && desc->chip->names[gpio - desc->chip->base]) |
466 | ioname = desc->chip->names[gpio - desc->chip->base]; | |
467 | ||
d8f388d8 DB |
468 | if (status == 0) { |
469 | struct device *dev; | |
470 | ||
471 | dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0), | |
926b663c | 472 | desc, ioname ? ioname : "gpio%d", gpio); |
d8f388d8 DB |
473 | if (dev) { |
474 | if (direction_may_change) | |
475 | status = sysfs_create_group(&dev->kobj, | |
476 | &gpio_attr_group); | |
477 | else | |
478 | status = device_create_file(dev, | |
479 | &dev_attr_value); | |
480 | if (status != 0) | |
481 | device_unregister(dev); | |
482 | } else | |
483 | status = -ENODEV; | |
484 | if (status == 0) | |
485 | set_bit(FLAG_EXPORT, &desc->flags); | |
486 | } | |
487 | ||
488 | mutex_unlock(&sysfs_lock); | |
489 | ||
490 | done: | |
491 | if (status) | |
492 | pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); | |
493 | ||
494 | return status; | |
495 | } | |
496 | EXPORT_SYMBOL_GPL(gpio_export); | |
497 | ||
498 | static int match_export(struct device *dev, void *data) | |
499 | { | |
500 | return dev_get_drvdata(dev) == data; | |
501 | } | |
502 | ||
503 | /** | |
504 | * gpio_unexport - reverse effect of gpio_export() | |
505 | * @gpio: gpio to make unavailable | |
506 | * | |
507 | * This is implicit on gpio_free(). | |
508 | */ | |
509 | void gpio_unexport(unsigned gpio) | |
510 | { | |
511 | struct gpio_desc *desc; | |
512 | int status = -EINVAL; | |
513 | ||
514 | if (!gpio_is_valid(gpio)) | |
515 | goto done; | |
516 | ||
517 | mutex_lock(&sysfs_lock); | |
518 | ||
519 | desc = &gpio_desc[gpio]; | |
926b663c | 520 | |
d8f388d8 DB |
521 | if (test_bit(FLAG_EXPORT, &desc->flags)) { |
522 | struct device *dev = NULL; | |
523 | ||
524 | dev = class_find_device(&gpio_class, NULL, desc, match_export); | |
525 | if (dev) { | |
526 | clear_bit(FLAG_EXPORT, &desc->flags); | |
527 | put_device(dev); | |
528 | device_unregister(dev); | |
529 | status = 0; | |
530 | } else | |
531 | status = -ENODEV; | |
532 | } | |
533 | ||
534 | mutex_unlock(&sysfs_lock); | |
535 | done: | |
536 | if (status) | |
537 | pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); | |
538 | } | |
539 | EXPORT_SYMBOL_GPL(gpio_unexport); | |
540 | ||
541 | static int gpiochip_export(struct gpio_chip *chip) | |
542 | { | |
543 | int status; | |
544 | struct device *dev; | |
545 | ||
546 | /* Many systems register gpio chips for SOC support very early, | |
547 | * before driver model support is available. In those cases we | |
548 | * export this later, in gpiolib_sysfs_init() ... here we just | |
549 | * verify that _some_ field of gpio_class got initialized. | |
550 | */ | |
551 | if (!gpio_class.p) | |
552 | return 0; | |
553 | ||
554 | /* use chip->base for the ID; it's already known to be unique */ | |
555 | mutex_lock(&sysfs_lock); | |
556 | dev = device_create(&gpio_class, chip->dev, MKDEV(0, 0), chip, | |
557 | "gpiochip%d", chip->base); | |
558 | if (dev) { | |
559 | status = sysfs_create_group(&dev->kobj, | |
560 | &gpiochip_attr_group); | |
561 | } else | |
562 | status = -ENODEV; | |
563 | chip->exported = (status == 0); | |
564 | mutex_unlock(&sysfs_lock); | |
565 | ||
566 | if (status) { | |
567 | unsigned long flags; | |
568 | unsigned gpio; | |
569 | ||
570 | spin_lock_irqsave(&gpio_lock, flags); | |
571 | gpio = chip->base; | |
572 | while (gpio_desc[gpio].chip == chip) | |
573 | gpio_desc[gpio++].chip = NULL; | |
574 | spin_unlock_irqrestore(&gpio_lock, flags); | |
575 | ||
576 | pr_debug("%s: chip %s status %d\n", __func__, | |
577 | chip->label, status); | |
578 | } | |
579 | ||
580 | return status; | |
581 | } | |
582 | ||
583 | static void gpiochip_unexport(struct gpio_chip *chip) | |
584 | { | |
585 | int status; | |
586 | struct device *dev; | |
587 | ||
588 | mutex_lock(&sysfs_lock); | |
589 | dev = class_find_device(&gpio_class, NULL, chip, match_export); | |
590 | if (dev) { | |
591 | put_device(dev); | |
592 | device_unregister(dev); | |
593 | chip->exported = 0; | |
594 | status = 0; | |
595 | } else | |
596 | status = -ENODEV; | |
597 | mutex_unlock(&sysfs_lock); | |
598 | ||
599 | if (status) | |
600 | pr_debug("%s: chip %s status %d\n", __func__, | |
601 | chip->label, status); | |
602 | } | |
603 | ||
604 | static int __init gpiolib_sysfs_init(void) | |
605 | { | |
606 | int status; | |
607 | unsigned long flags; | |
608 | unsigned gpio; | |
609 | ||
610 | status = class_register(&gpio_class); | |
611 | if (status < 0) | |
612 | return status; | |
613 | ||
614 | /* Scan and register the gpio_chips which registered very | |
615 | * early (e.g. before the class_register above was called). | |
616 | * | |
617 | * We run before arch_initcall() so chip->dev nodes can have | |
618 | * registered, and so arch_initcall() can always gpio_export(). | |
619 | */ | |
620 | spin_lock_irqsave(&gpio_lock, flags); | |
621 | for (gpio = 0; gpio < ARCH_NR_GPIOS; gpio++) { | |
622 | struct gpio_chip *chip; | |
623 | ||
624 | chip = gpio_desc[gpio].chip; | |
625 | if (!chip || chip->exported) | |
626 | continue; | |
627 | ||
628 | spin_unlock_irqrestore(&gpio_lock, flags); | |
629 | status = gpiochip_export(chip); | |
630 | spin_lock_irqsave(&gpio_lock, flags); | |
631 | } | |
632 | spin_unlock_irqrestore(&gpio_lock, flags); | |
633 | ||
634 | ||
635 | return status; | |
636 | } | |
637 | postcore_initcall(gpiolib_sysfs_init); | |
638 | ||
639 | #else | |
640 | static inline int gpiochip_export(struct gpio_chip *chip) | |
641 | { | |
642 | return 0; | |
643 | } | |
644 | ||
645 | static inline void gpiochip_unexport(struct gpio_chip *chip) | |
646 | { | |
647 | } | |
648 | ||
649 | #endif /* CONFIG_GPIO_SYSFS */ | |
650 | ||
d2876d08 DB |
651 | /** |
652 | * gpiochip_add() - register a gpio_chip | |
653 | * @chip: the chip to register, with chip->base initialized | |
654 | * Context: potentially before irqs or kmalloc will work | |
655 | * | |
656 | * Returns a negative errno if the chip can't be registered, such as | |
657 | * because the chip->base is invalid or already associated with a | |
658 | * different chip. Otherwise it returns zero as a success code. | |
8d0aab2f | 659 | * |
d8f388d8 DB |
660 | * When gpiochip_add() is called very early during boot, so that GPIOs |
661 | * can be freely used, the chip->dev device must be registered before | |
662 | * the gpio framework's arch_initcall(). Otherwise sysfs initialization | |
663 | * for GPIOs will fail rudely. | |
664 | * | |
8d0aab2f AV |
665 | * If chip->base is negative, this requests dynamic assignment of |
666 | * a range of valid GPIOs. | |
d2876d08 DB |
667 | */ |
668 | int gpiochip_add(struct gpio_chip *chip) | |
669 | { | |
670 | unsigned long flags; | |
671 | int status = 0; | |
672 | unsigned id; | |
8d0aab2f | 673 | int base = chip->base; |
d2876d08 | 674 | |
bff5fda9 | 675 | if ((!gpio_is_valid(base) || !gpio_is_valid(base + chip->ngpio - 1)) |
8d0aab2f | 676 | && base >= 0) { |
d2876d08 DB |
677 | status = -EINVAL; |
678 | goto fail; | |
679 | } | |
680 | ||
681 | spin_lock_irqsave(&gpio_lock, flags); | |
682 | ||
8d0aab2f AV |
683 | if (base < 0) { |
684 | base = gpiochip_find_base(chip->ngpio); | |
685 | if (base < 0) { | |
686 | status = base; | |
d8f388d8 | 687 | goto unlock; |
8d0aab2f AV |
688 | } |
689 | chip->base = base; | |
690 | } | |
691 | ||
d2876d08 | 692 | /* these GPIO numbers must not be managed by another gpio_chip */ |
8d0aab2f | 693 | for (id = base; id < base + chip->ngpio; id++) { |
d2876d08 DB |
694 | if (gpio_desc[id].chip != NULL) { |
695 | status = -EBUSY; | |
696 | break; | |
697 | } | |
698 | } | |
699 | if (status == 0) { | |
8d0aab2f | 700 | for (id = base; id < base + chip->ngpio; id++) { |
d2876d08 | 701 | gpio_desc[id].chip = chip; |
d8f388d8 DB |
702 | |
703 | /* REVISIT: most hardware initializes GPIOs as | |
704 | * inputs (often with pullups enabled) so power | |
705 | * usage is minimized. Linux code should set the | |
706 | * gpio direction first thing; but until it does, | |
707 | * we may expose the wrong direction in sysfs. | |
708 | */ | |
709 | gpio_desc[id].flags = !chip->direction_input | |
710 | ? (1 << FLAG_IS_OUT) | |
711 | : 0; | |
d2876d08 DB |
712 | } |
713 | } | |
714 | ||
d8f388d8 | 715 | unlock: |
d2876d08 | 716 | spin_unlock_irqrestore(&gpio_lock, flags); |
d8f388d8 DB |
717 | if (status == 0) |
718 | status = gpiochip_export(chip); | |
d2876d08 DB |
719 | fail: |
720 | /* failures here can mean systems won't boot... */ | |
721 | if (status) | |
722 | pr_err("gpiochip_add: gpios %d..%d (%s) not registered\n", | |
bff5fda9 | 723 | chip->base, chip->base + chip->ngpio - 1, |
d2876d08 DB |
724 | chip->label ? : "generic"); |
725 | return status; | |
726 | } | |
727 | EXPORT_SYMBOL_GPL(gpiochip_add); | |
728 | ||
729 | /** | |
730 | * gpiochip_remove() - unregister a gpio_chip | |
731 | * @chip: the chip to unregister | |
732 | * | |
733 | * A gpio_chip with any GPIOs still requested may not be removed. | |
734 | */ | |
735 | int gpiochip_remove(struct gpio_chip *chip) | |
736 | { | |
737 | unsigned long flags; | |
738 | int status = 0; | |
739 | unsigned id; | |
740 | ||
741 | spin_lock_irqsave(&gpio_lock, flags); | |
742 | ||
743 | for (id = chip->base; id < chip->base + chip->ngpio; id++) { | |
744 | if (test_bit(FLAG_REQUESTED, &gpio_desc[id].flags)) { | |
745 | status = -EBUSY; | |
746 | break; | |
747 | } | |
748 | } | |
749 | if (status == 0) { | |
750 | for (id = chip->base; id < chip->base + chip->ngpio; id++) | |
751 | gpio_desc[id].chip = NULL; | |
752 | } | |
753 | ||
754 | spin_unlock_irqrestore(&gpio_lock, flags); | |
d8f388d8 DB |
755 | |
756 | if (status == 0) | |
757 | gpiochip_unexport(chip); | |
758 | ||
d2876d08 DB |
759 | return status; |
760 | } | |
761 | EXPORT_SYMBOL_GPL(gpiochip_remove); | |
762 | ||
763 | ||
764 | /* These "optional" allocation calls help prevent drivers from stomping | |
765 | * on each other, and help provide better diagnostics in debugfs. | |
766 | * They're called even less than the "set direction" calls. | |
767 | */ | |
768 | int gpio_request(unsigned gpio, const char *label) | |
769 | { | |
770 | struct gpio_desc *desc; | |
35e8bb51 | 771 | struct gpio_chip *chip; |
d2876d08 DB |
772 | int status = -EINVAL; |
773 | unsigned long flags; | |
774 | ||
775 | spin_lock_irqsave(&gpio_lock, flags); | |
776 | ||
e6de1808 | 777 | if (!gpio_is_valid(gpio)) |
d2876d08 DB |
778 | goto done; |
779 | desc = &gpio_desc[gpio]; | |
35e8bb51 DB |
780 | chip = desc->chip; |
781 | if (chip == NULL) | |
d2876d08 DB |
782 | goto done; |
783 | ||
35e8bb51 | 784 | if (!try_module_get(chip->owner)) |
438d8908 GL |
785 | goto done; |
786 | ||
d2876d08 | 787 | /* NOTE: gpio_request() can be called in early boot, |
35e8bb51 | 788 | * before IRQs are enabled, for non-sleeping (SOC) GPIOs. |
d2876d08 DB |
789 | */ |
790 | ||
791 | if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) { | |
792 | desc_set_label(desc, label ? : "?"); | |
793 | status = 0; | |
438d8908 | 794 | } else { |
d2876d08 | 795 | status = -EBUSY; |
35e8bb51 | 796 | module_put(chip->owner); |
7460db56 | 797 | goto done; |
35e8bb51 DB |
798 | } |
799 | ||
800 | if (chip->request) { | |
801 | /* chip->request may sleep */ | |
802 | spin_unlock_irqrestore(&gpio_lock, flags); | |
803 | status = chip->request(chip, gpio - chip->base); | |
804 | spin_lock_irqsave(&gpio_lock, flags); | |
805 | ||
806 | if (status < 0) { | |
807 | desc_set_label(desc, NULL); | |
808 | module_put(chip->owner); | |
809 | clear_bit(FLAG_REQUESTED, &desc->flags); | |
810 | } | |
438d8908 | 811 | } |
d2876d08 DB |
812 | |
813 | done: | |
814 | if (status) | |
815 | pr_debug("gpio_request: gpio-%d (%s) status %d\n", | |
816 | gpio, label ? : "?", status); | |
817 | spin_unlock_irqrestore(&gpio_lock, flags); | |
818 | return status; | |
819 | } | |
820 | EXPORT_SYMBOL_GPL(gpio_request); | |
821 | ||
822 | void gpio_free(unsigned gpio) | |
823 | { | |
824 | unsigned long flags; | |
825 | struct gpio_desc *desc; | |
35e8bb51 | 826 | struct gpio_chip *chip; |
d2876d08 | 827 | |
3d599d1c UKK |
828 | might_sleep(); |
829 | ||
e6de1808 | 830 | if (!gpio_is_valid(gpio)) { |
d2876d08 DB |
831 | WARN_ON(extra_checks); |
832 | return; | |
833 | } | |
834 | ||
d8f388d8 DB |
835 | gpio_unexport(gpio); |
836 | ||
d2876d08 DB |
837 | spin_lock_irqsave(&gpio_lock, flags); |
838 | ||
839 | desc = &gpio_desc[gpio]; | |
35e8bb51 DB |
840 | chip = desc->chip; |
841 | if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) { | |
842 | if (chip->free) { | |
843 | spin_unlock_irqrestore(&gpio_lock, flags); | |
844 | might_sleep_if(extra_checks && chip->can_sleep); | |
845 | chip->free(chip, gpio - chip->base); | |
846 | spin_lock_irqsave(&gpio_lock, flags); | |
847 | } | |
d2876d08 | 848 | desc_set_label(desc, NULL); |
438d8908 | 849 | module_put(desc->chip->owner); |
35e8bb51 | 850 | clear_bit(FLAG_REQUESTED, &desc->flags); |
438d8908 | 851 | } else |
d2876d08 DB |
852 | WARN_ON(extra_checks); |
853 | ||
854 | spin_unlock_irqrestore(&gpio_lock, flags); | |
855 | } | |
856 | EXPORT_SYMBOL_GPL(gpio_free); | |
857 | ||
858 | ||
859 | /** | |
860 | * gpiochip_is_requested - return string iff signal was requested | |
861 | * @chip: controller managing the signal | |
862 | * @offset: of signal within controller's 0..(ngpio - 1) range | |
863 | * | |
864 | * Returns NULL if the GPIO is not currently requested, else a string. | |
865 | * If debugfs support is enabled, the string returned is the label passed | |
866 | * to gpio_request(); otherwise it is a meaningless constant. | |
867 | * | |
868 | * This function is for use by GPIO controller drivers. The label can | |
869 | * help with diagnostics, and knowing that the signal is used as a GPIO | |
870 | * can help avoid accidentally multiplexing it to another controller. | |
871 | */ | |
872 | const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset) | |
873 | { | |
874 | unsigned gpio = chip->base + offset; | |
875 | ||
e6de1808 | 876 | if (!gpio_is_valid(gpio) || gpio_desc[gpio].chip != chip) |
d2876d08 DB |
877 | return NULL; |
878 | if (test_bit(FLAG_REQUESTED, &gpio_desc[gpio].flags) == 0) | |
879 | return NULL; | |
880 | #ifdef CONFIG_DEBUG_FS | |
881 | return gpio_desc[gpio].label; | |
882 | #else | |
883 | return "?"; | |
884 | #endif | |
885 | } | |
886 | EXPORT_SYMBOL_GPL(gpiochip_is_requested); | |
887 | ||
888 | ||
889 | /* Drivers MUST set GPIO direction before making get/set calls. In | |
890 | * some cases this is done in early boot, before IRQs are enabled. | |
891 | * | |
892 | * As a rule these aren't called more than once (except for drivers | |
893 | * using the open-drain emulation idiom) so these are natural places | |
894 | * to accumulate extra debugging checks. Note that we can't (yet) | |
895 | * rely on gpio_request() having been called beforehand. | |
896 | */ | |
897 | ||
898 | int gpio_direction_input(unsigned gpio) | |
899 | { | |
900 | unsigned long flags; | |
901 | struct gpio_chip *chip; | |
902 | struct gpio_desc *desc = &gpio_desc[gpio]; | |
903 | int status = -EINVAL; | |
904 | ||
905 | spin_lock_irqsave(&gpio_lock, flags); | |
906 | ||
e6de1808 | 907 | if (!gpio_is_valid(gpio)) |
d2876d08 DB |
908 | goto fail; |
909 | chip = desc->chip; | |
910 | if (!chip || !chip->get || !chip->direction_input) | |
911 | goto fail; | |
912 | gpio -= chip->base; | |
913 | if (gpio >= chip->ngpio) | |
914 | goto fail; | |
35e8bb51 DB |
915 | status = gpio_ensure_requested(desc, gpio); |
916 | if (status < 0) | |
917 | goto fail; | |
d2876d08 DB |
918 | |
919 | /* now we know the gpio is valid and chip won't vanish */ | |
920 | ||
921 | spin_unlock_irqrestore(&gpio_lock, flags); | |
922 | ||
923 | might_sleep_if(extra_checks && chip->can_sleep); | |
924 | ||
35e8bb51 DB |
925 | if (status) { |
926 | status = chip->request(chip, gpio); | |
927 | if (status < 0) { | |
928 | pr_debug("GPIO-%d: chip request fail, %d\n", | |
929 | chip->base + gpio, status); | |
930 | /* and it's not available to anyone else ... | |
931 | * gpio_request() is the fully clean solution. | |
932 | */ | |
933 | goto lose; | |
934 | } | |
935 | } | |
936 | ||
d2876d08 DB |
937 | status = chip->direction_input(chip, gpio); |
938 | if (status == 0) | |
939 | clear_bit(FLAG_IS_OUT, &desc->flags); | |
35e8bb51 | 940 | lose: |
d2876d08 DB |
941 | return status; |
942 | fail: | |
943 | spin_unlock_irqrestore(&gpio_lock, flags); | |
944 | if (status) | |
945 | pr_debug("%s: gpio-%d status %d\n", | |
145980a0 | 946 | __func__, gpio, status); |
d2876d08 DB |
947 | return status; |
948 | } | |
949 | EXPORT_SYMBOL_GPL(gpio_direction_input); | |
950 | ||
951 | int gpio_direction_output(unsigned gpio, int value) | |
952 | { | |
953 | unsigned long flags; | |
954 | struct gpio_chip *chip; | |
955 | struct gpio_desc *desc = &gpio_desc[gpio]; | |
956 | int status = -EINVAL; | |
957 | ||
958 | spin_lock_irqsave(&gpio_lock, flags); | |
959 | ||
e6de1808 | 960 | if (!gpio_is_valid(gpio)) |
d2876d08 DB |
961 | goto fail; |
962 | chip = desc->chip; | |
963 | if (!chip || !chip->set || !chip->direction_output) | |
964 | goto fail; | |
965 | gpio -= chip->base; | |
966 | if (gpio >= chip->ngpio) | |
967 | goto fail; | |
35e8bb51 DB |
968 | status = gpio_ensure_requested(desc, gpio); |
969 | if (status < 0) | |
970 | goto fail; | |
d2876d08 DB |
971 | |
972 | /* now we know the gpio is valid and chip won't vanish */ | |
973 | ||
974 | spin_unlock_irqrestore(&gpio_lock, flags); | |
975 | ||
976 | might_sleep_if(extra_checks && chip->can_sleep); | |
977 | ||
35e8bb51 DB |
978 | if (status) { |
979 | status = chip->request(chip, gpio); | |
980 | if (status < 0) { | |
981 | pr_debug("GPIO-%d: chip request fail, %d\n", | |
982 | chip->base + gpio, status); | |
983 | /* and it's not available to anyone else ... | |
984 | * gpio_request() is the fully clean solution. | |
985 | */ | |
986 | goto lose; | |
987 | } | |
988 | } | |
989 | ||
d2876d08 DB |
990 | status = chip->direction_output(chip, gpio, value); |
991 | if (status == 0) | |
992 | set_bit(FLAG_IS_OUT, &desc->flags); | |
35e8bb51 | 993 | lose: |
d2876d08 DB |
994 | return status; |
995 | fail: | |
996 | spin_unlock_irqrestore(&gpio_lock, flags); | |
997 | if (status) | |
998 | pr_debug("%s: gpio-%d status %d\n", | |
145980a0 | 999 | __func__, gpio, status); |
d2876d08 DB |
1000 | return status; |
1001 | } | |
1002 | EXPORT_SYMBOL_GPL(gpio_direction_output); | |
1003 | ||
1004 | ||
1005 | /* I/O calls are only valid after configuration completed; the relevant | |
1006 | * "is this a valid GPIO" error checks should already have been done. | |
1007 | * | |
1008 | * "Get" operations are often inlinable as reading a pin value register, | |
1009 | * and masking the relevant bit in that register. | |
1010 | * | |
1011 | * When "set" operations are inlinable, they involve writing that mask to | |
1012 | * one register to set a low value, or a different register to set it high. | |
1013 | * Otherwise locking is needed, so there may be little value to inlining. | |
1014 | * | |
1015 | *------------------------------------------------------------------------ | |
1016 | * | |
1017 | * IMPORTANT!!! The hot paths -- get/set value -- assume that callers | |
1018 | * have requested the GPIO. That can include implicit requesting by | |
1019 | * a direction setting call. Marking a gpio as requested locks its chip | |
1020 | * in memory, guaranteeing that these table lookups need no more locking | |
1021 | * and that gpiochip_remove() will fail. | |
1022 | * | |
1023 | * REVISIT when debugging, consider adding some instrumentation to ensure | |
1024 | * that the GPIO was actually requested. | |
1025 | */ | |
1026 | ||
1027 | /** | |
1028 | * __gpio_get_value() - return a gpio's value | |
1029 | * @gpio: gpio whose value will be returned | |
1030 | * Context: any | |
1031 | * | |
1032 | * This is used directly or indirectly to implement gpio_get_value(). | |
1033 | * It returns the zero or nonzero value provided by the associated | |
1034 | * gpio_chip.get() method; or zero if no such method is provided. | |
1035 | */ | |
1036 | int __gpio_get_value(unsigned gpio) | |
1037 | { | |
1038 | struct gpio_chip *chip; | |
1039 | ||
1040 | chip = gpio_to_chip(gpio); | |
1041 | WARN_ON(extra_checks && chip->can_sleep); | |
1042 | return chip->get ? chip->get(chip, gpio - chip->base) : 0; | |
1043 | } | |
1044 | EXPORT_SYMBOL_GPL(__gpio_get_value); | |
1045 | ||
1046 | /** | |
1047 | * __gpio_set_value() - assign a gpio's value | |
1048 | * @gpio: gpio whose value will be assigned | |
1049 | * @value: value to assign | |
1050 | * Context: any | |
1051 | * | |
1052 | * This is used directly or indirectly to implement gpio_set_value(). | |
1053 | * It invokes the associated gpio_chip.set() method. | |
1054 | */ | |
1055 | void __gpio_set_value(unsigned gpio, int value) | |
1056 | { | |
1057 | struct gpio_chip *chip; | |
1058 | ||
1059 | chip = gpio_to_chip(gpio); | |
1060 | WARN_ON(extra_checks && chip->can_sleep); | |
1061 | chip->set(chip, gpio - chip->base, value); | |
1062 | } | |
1063 | EXPORT_SYMBOL_GPL(__gpio_set_value); | |
1064 | ||
1065 | /** | |
1066 | * __gpio_cansleep() - report whether gpio value access will sleep | |
1067 | * @gpio: gpio in question | |
1068 | * Context: any | |
1069 | * | |
1070 | * This is used directly or indirectly to implement gpio_cansleep(). It | |
1071 | * returns nonzero if access reading or writing the GPIO value can sleep. | |
1072 | */ | |
1073 | int __gpio_cansleep(unsigned gpio) | |
1074 | { | |
1075 | struct gpio_chip *chip; | |
1076 | ||
1077 | /* only call this on GPIOs that are valid! */ | |
1078 | chip = gpio_to_chip(gpio); | |
1079 | ||
1080 | return chip->can_sleep; | |
1081 | } | |
1082 | EXPORT_SYMBOL_GPL(__gpio_cansleep); | |
1083 | ||
0f6d504e DB |
1084 | /** |
1085 | * __gpio_to_irq() - return the IRQ corresponding to a GPIO | |
1086 | * @gpio: gpio whose IRQ will be returned (already requested) | |
1087 | * Context: any | |
1088 | * | |
1089 | * This is used directly or indirectly to implement gpio_to_irq(). | |
1090 | * It returns the number of the IRQ signaled by this (input) GPIO, | |
1091 | * or a negative errno. | |
1092 | */ | |
1093 | int __gpio_to_irq(unsigned gpio) | |
1094 | { | |
1095 | struct gpio_chip *chip; | |
1096 | ||
1097 | chip = gpio_to_chip(gpio); | |
1098 | return chip->to_irq ? chip->to_irq(chip, gpio - chip->base) : -ENXIO; | |
1099 | } | |
1100 | EXPORT_SYMBOL_GPL(__gpio_to_irq); | |
1101 | ||
d2876d08 DB |
1102 | |
1103 | ||
1104 | /* There's no value in making it easy to inline GPIO calls that may sleep. | |
1105 | * Common examples include ones connected to I2C or SPI chips. | |
1106 | */ | |
1107 | ||
1108 | int gpio_get_value_cansleep(unsigned gpio) | |
1109 | { | |
1110 | struct gpio_chip *chip; | |
1111 | ||
1112 | might_sleep_if(extra_checks); | |
1113 | chip = gpio_to_chip(gpio); | |
978ccaa8 | 1114 | return chip->get ? chip->get(chip, gpio - chip->base) : 0; |
d2876d08 DB |
1115 | } |
1116 | EXPORT_SYMBOL_GPL(gpio_get_value_cansleep); | |
1117 | ||
1118 | void gpio_set_value_cansleep(unsigned gpio, int value) | |
1119 | { | |
1120 | struct gpio_chip *chip; | |
1121 | ||
1122 | might_sleep_if(extra_checks); | |
1123 | chip = gpio_to_chip(gpio); | |
1124 | chip->set(chip, gpio - chip->base, value); | |
1125 | } | |
1126 | EXPORT_SYMBOL_GPL(gpio_set_value_cansleep); | |
1127 | ||
1128 | ||
1129 | #ifdef CONFIG_DEBUG_FS | |
1130 | ||
d2876d08 DB |
1131 | static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) |
1132 | { | |
1133 | unsigned i; | |
1134 | unsigned gpio = chip->base; | |
1135 | struct gpio_desc *gdesc = &gpio_desc[gpio]; | |
1136 | int is_out; | |
1137 | ||
1138 | for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) { | |
1139 | if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) | |
1140 | continue; | |
1141 | ||
1142 | is_out = test_bit(FLAG_IS_OUT, &gdesc->flags); | |
6e8ba729 | 1143 | seq_printf(s, " gpio-%-3d (%-20.20s) %s %s", |
d2876d08 DB |
1144 | gpio, gdesc->label, |
1145 | is_out ? "out" : "in ", | |
1146 | chip->get | |
1147 | ? (chip->get(chip, i) ? "hi" : "lo") | |
1148 | : "? "); | |
1149 | ||
1150 | if (!is_out) { | |
1151 | int irq = gpio_to_irq(gpio); | |
08678b08 | 1152 | struct irq_desc *desc = irq_to_desc(irq); |
d2876d08 DB |
1153 | |
1154 | /* This races with request_irq(), set_irq_type(), | |
1155 | * and set_irq_wake() ... but those are "rare". | |
1156 | * | |
1157 | * More significantly, trigger type flags aren't | |
1158 | * currently maintained by genirq. | |
1159 | */ | |
1160 | if (irq >= 0 && desc->action) { | |
1161 | char *trigger; | |
1162 | ||
1163 | switch (desc->status & IRQ_TYPE_SENSE_MASK) { | |
1164 | case IRQ_TYPE_NONE: | |
1165 | trigger = "(default)"; | |
1166 | break; | |
1167 | case IRQ_TYPE_EDGE_FALLING: | |
1168 | trigger = "edge-falling"; | |
1169 | break; | |
1170 | case IRQ_TYPE_EDGE_RISING: | |
1171 | trigger = "edge-rising"; | |
1172 | break; | |
1173 | case IRQ_TYPE_EDGE_BOTH: | |
1174 | trigger = "edge-both"; | |
1175 | break; | |
1176 | case IRQ_TYPE_LEVEL_HIGH: | |
1177 | trigger = "level-high"; | |
1178 | break; | |
1179 | case IRQ_TYPE_LEVEL_LOW: | |
1180 | trigger = "level-low"; | |
1181 | break; | |
1182 | default: | |
1183 | trigger = "?trigger?"; | |
1184 | break; | |
1185 | } | |
1186 | ||
1187 | seq_printf(s, " irq-%d %s%s", | |
1188 | irq, trigger, | |
1189 | (desc->status & IRQ_WAKEUP) | |
1190 | ? " wakeup" : ""); | |
1191 | } | |
1192 | } | |
1193 | ||
1194 | seq_printf(s, "\n"); | |
1195 | } | |
1196 | } | |
1197 | ||
1198 | static int gpiolib_show(struct seq_file *s, void *unused) | |
1199 | { | |
1200 | struct gpio_chip *chip = NULL; | |
1201 | unsigned gpio; | |
1202 | int started = 0; | |
1203 | ||
1204 | /* REVISIT this isn't locked against gpio_chip removal ... */ | |
1205 | ||
e6de1808 | 1206 | for (gpio = 0; gpio_is_valid(gpio); gpio++) { |
d8f388d8 DB |
1207 | struct device *dev; |
1208 | ||
d2876d08 DB |
1209 | if (chip == gpio_desc[gpio].chip) |
1210 | continue; | |
1211 | chip = gpio_desc[gpio].chip; | |
1212 | if (!chip) | |
1213 | continue; | |
1214 | ||
d8f388d8 | 1215 | seq_printf(s, "%sGPIOs %d-%d", |
d2876d08 | 1216 | started ? "\n" : "", |
d8f388d8 DB |
1217 | chip->base, chip->base + chip->ngpio - 1); |
1218 | dev = chip->dev; | |
1219 | if (dev) | |
1220 | seq_printf(s, ", %s/%s", | |
1221 | dev->bus ? dev->bus->name : "no-bus", | |
14ab309d | 1222 | dev_name(dev)); |
d8f388d8 DB |
1223 | if (chip->label) |
1224 | seq_printf(s, ", %s", chip->label); | |
1225 | if (chip->can_sleep) | |
1226 | seq_printf(s, ", can sleep"); | |
1227 | seq_printf(s, ":\n"); | |
1228 | ||
d2876d08 DB |
1229 | started = 1; |
1230 | if (chip->dbg_show) | |
1231 | chip->dbg_show(s, chip); | |
1232 | else | |
1233 | gpiolib_dbg_show(s, chip); | |
1234 | } | |
1235 | return 0; | |
1236 | } | |
1237 | ||
1238 | static int gpiolib_open(struct inode *inode, struct file *file) | |
1239 | { | |
1240 | return single_open(file, gpiolib_show, NULL); | |
1241 | } | |
1242 | ||
1243 | static struct file_operations gpiolib_operations = { | |
1244 | .open = gpiolib_open, | |
1245 | .read = seq_read, | |
1246 | .llseek = seq_lseek, | |
1247 | .release = single_release, | |
1248 | }; | |
1249 | ||
1250 | static int __init gpiolib_debugfs_init(void) | |
1251 | { | |
1252 | /* /sys/kernel/debug/gpio */ | |
1253 | (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO, | |
1254 | NULL, NULL, &gpiolib_operations); | |
1255 | return 0; | |
1256 | } | |
1257 | subsys_initcall(gpiolib_debugfs_init); | |
1258 | ||
1259 | #endif /* DEBUG_FS */ |