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Commit | Line | Data |
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d2876d08 DB |
1 | #include <linux/kernel.h> |
2 | #include <linux/module.h> | |
ff77c352 | 3 | #include <linux/interrupt.h> |
d2876d08 DB |
4 | #include <linux/irq.h> |
5 | #include <linux/spinlock.h> | |
d8f388d8 DB |
6 | #include <linux/device.h> |
7 | #include <linux/err.h> | |
8 | #include <linux/debugfs.h> | |
9 | #include <linux/seq_file.h> | |
10 | #include <linux/gpio.h> | |
391c970c | 11 | #include <linux/of_gpio.h> |
ff77c352 | 12 | #include <linux/idr.h> |
5a0e3ad6 | 13 | #include <linux/slab.h> |
d2876d08 | 14 | |
3f397c21 UKK |
15 | #define CREATE_TRACE_POINTS |
16 | #include <trace/events/gpio.h> | |
d2876d08 DB |
17 | |
18 | /* Optional implementation infrastructure for GPIO interfaces. | |
19 | * | |
20 | * Platforms may want to use this if they tend to use very many GPIOs | |
21 | * that aren't part of a System-On-Chip core; or across I2C/SPI/etc. | |
22 | * | |
23 | * When kernel footprint or instruction count is an issue, simpler | |
24 | * implementations may be preferred. The GPIO programming interface | |
25 | * allows for inlining speed-critical get/set operations for common | |
26 | * cases, so that access to SOC-integrated GPIOs can sometimes cost | |
27 | * only an instruction or two per bit. | |
28 | */ | |
29 | ||
30 | ||
31 | /* When debugging, extend minimal trust to callers and platform code. | |
32 | * Also emit diagnostic messages that may help initial bringup, when | |
33 | * board setup or driver bugs are most common. | |
34 | * | |
35 | * Otherwise, minimize overhead in what may be bitbanging codepaths. | |
36 | */ | |
37 | #ifdef DEBUG | |
38 | #define extra_checks 1 | |
39 | #else | |
40 | #define extra_checks 0 | |
41 | #endif | |
42 | ||
43 | /* gpio_lock prevents conflicts during gpio_desc[] table updates. | |
44 | * While any GPIO is requested, its gpio_chip is not removable; | |
45 | * each GPIO's "requested" flag serves as a lock and refcount. | |
46 | */ | |
47 | static DEFINE_SPINLOCK(gpio_lock); | |
48 | ||
49 | struct gpio_desc { | |
50 | struct gpio_chip *chip; | |
51 | unsigned long flags; | |
52 | /* flag symbols are bit numbers */ | |
53 | #define FLAG_REQUESTED 0 | |
54 | #define FLAG_IS_OUT 1 | |
169b6a7a | 55 | #define FLAG_RESERVED 2 |
d8f388d8 DB |
56 | #define FLAG_EXPORT 3 /* protected by sysfs_lock */ |
57 | #define FLAG_SYSFS 4 /* exported via /sys/class/gpio/control */ | |
ff77c352 DG |
58 | #define FLAG_TRIG_FALL 5 /* trigger on falling edge */ |
59 | #define FLAG_TRIG_RISE 6 /* trigger on rising edge */ | |
07697461 | 60 | #define FLAG_ACTIVE_LOW 7 /* sysfs value has active low */ |
aca5ce14 | 61 | #define FLAG_OPEN_DRAIN 8 /* Gpio is open drain type */ |
25553ff0 | 62 | #define FLAG_OPEN_SOURCE 9 /* Gpio is open source type */ |
ff77c352 | 63 | |
5ba1821d | 64 | #define ID_SHIFT 16 /* add new flags before this one */ |
ff77c352 | 65 | |
5ba1821d | 66 | #define GPIO_FLAGS_MASK ((1 << ID_SHIFT) - 1) |
ff77c352 | 67 | #define GPIO_TRIGGER_MASK (BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE)) |
d2876d08 DB |
68 | |
69 | #ifdef CONFIG_DEBUG_FS | |
70 | const char *label; | |
71 | #endif | |
72 | }; | |
73 | static struct gpio_desc gpio_desc[ARCH_NR_GPIOS]; | |
74 | ||
ff77c352 | 75 | #ifdef CONFIG_GPIO_SYSFS |
5ba1821d | 76 | static DEFINE_IDR(dirent_idr); |
ff77c352 DG |
77 | #endif |
78 | ||
d2876d08 DB |
79 | static inline void desc_set_label(struct gpio_desc *d, const char *label) |
80 | { | |
81 | #ifdef CONFIG_DEBUG_FS | |
82 | d->label = label; | |
83 | #endif | |
84 | } | |
85 | ||
86 | /* Warn when drivers omit gpio_request() calls -- legal but ill-advised | |
87 | * when setting direction, and otherwise illegal. Until board setup code | |
88 | * and drivers use explicit requests everywhere (which won't happen when | |
89 | * those calls have no teeth) we can't avoid autorequesting. This nag | |
35e8bb51 DB |
90 | * message should motivate switching to explicit requests... so should |
91 | * the weaker cleanup after faults, compared to gpio_request(). | |
8a0cecff DB |
92 | * |
93 | * NOTE: the autorequest mechanism is going away; at this point it's | |
94 | * only "legal" in the sense that (old) code using it won't break yet, | |
95 | * but instead only triggers a WARN() stack dump. | |
d2876d08 | 96 | */ |
35e8bb51 | 97 | static int gpio_ensure_requested(struct gpio_desc *desc, unsigned offset) |
d2876d08 | 98 | { |
8a0cecff DB |
99 | const struct gpio_chip *chip = desc->chip; |
100 | const int gpio = chip->base + offset; | |
35e8bb51 | 101 | |
8a0cecff DB |
102 | if (WARN(test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0, |
103 | "autorequest GPIO-%d\n", gpio)) { | |
35e8bb51 DB |
104 | if (!try_module_get(chip->owner)) { |
105 | pr_err("GPIO-%d: module can't be gotten \n", gpio); | |
106 | clear_bit(FLAG_REQUESTED, &desc->flags); | |
107 | /* lose */ | |
108 | return -EIO; | |
109 | } | |
d2876d08 | 110 | desc_set_label(desc, "[auto]"); |
35e8bb51 DB |
111 | /* caller must chip->request() w/o spinlock */ |
112 | if (chip->request) | |
113 | return 1; | |
d2876d08 | 114 | } |
35e8bb51 | 115 | return 0; |
d2876d08 DB |
116 | } |
117 | ||
118 | /* caller holds gpio_lock *OR* gpio is marked as requested */ | |
1a2d397a | 119 | struct gpio_chip *gpio_to_chip(unsigned gpio) |
d2876d08 DB |
120 | { |
121 | return gpio_desc[gpio].chip; | |
122 | } | |
123 | ||
8d0aab2f AV |
124 | /* dynamic allocation of GPIOs, e.g. on a hotplugged device */ |
125 | static int gpiochip_find_base(int ngpio) | |
126 | { | |
127 | int i; | |
128 | int spare = 0; | |
129 | int base = -ENOSPC; | |
130 | ||
131 | for (i = ARCH_NR_GPIOS - 1; i >= 0 ; i--) { | |
169b6a7a AV |
132 | struct gpio_desc *desc = &gpio_desc[i]; |
133 | struct gpio_chip *chip = desc->chip; | |
8d0aab2f | 134 | |
169b6a7a | 135 | if (!chip && !test_bit(FLAG_RESERVED, &desc->flags)) { |
8d0aab2f AV |
136 | spare++; |
137 | if (spare == ngpio) { | |
138 | base = i; | |
139 | break; | |
140 | } | |
141 | } else { | |
142 | spare = 0; | |
169b6a7a AV |
143 | if (chip) |
144 | i -= chip->ngpio - 1; | |
8d0aab2f AV |
145 | } |
146 | } | |
147 | ||
148 | if (gpio_is_valid(base)) | |
149 | pr_debug("%s: found new base at %d\n", __func__, base); | |
150 | return base; | |
151 | } | |
152 | ||
169b6a7a AV |
153 | /** |
154 | * gpiochip_reserve() - reserve range of gpios to use with platform code only | |
155 | * @start: starting gpio number | |
156 | * @ngpio: number of gpios to reserve | |
157 | * Context: platform init, potentially before irqs or kmalloc will work | |
158 | * | |
159 | * Returns a negative errno if any gpio within the range is already reserved | |
160 | * or registered, else returns zero as a success code. Use this function | |
161 | * to mark a range of gpios as unavailable for dynamic gpio number allocation, | |
162 | * for example because its driver support is not yet loaded. | |
163 | */ | |
164 | int __init gpiochip_reserve(int start, int ngpio) | |
165 | { | |
166 | int ret = 0; | |
167 | unsigned long flags; | |
168 | int i; | |
169 | ||
bff5fda9 | 170 | if (!gpio_is_valid(start) || !gpio_is_valid(start + ngpio - 1)) |
169b6a7a AV |
171 | return -EINVAL; |
172 | ||
173 | spin_lock_irqsave(&gpio_lock, flags); | |
174 | ||
175 | for (i = start; i < start + ngpio; i++) { | |
176 | struct gpio_desc *desc = &gpio_desc[i]; | |
177 | ||
178 | if (desc->chip || test_bit(FLAG_RESERVED, &desc->flags)) { | |
179 | ret = -EBUSY; | |
180 | goto err; | |
181 | } | |
182 | ||
183 | set_bit(FLAG_RESERVED, &desc->flags); | |
184 | } | |
185 | ||
186 | pr_debug("%s: reserved gpios from %d to %d\n", | |
187 | __func__, start, start + ngpio - 1); | |
188 | err: | |
189 | spin_unlock_irqrestore(&gpio_lock, flags); | |
190 | ||
191 | return ret; | |
192 | } | |
193 | ||
80b0a602 MN |
194 | /* caller ensures gpio is valid and requested, chip->get_direction may sleep */ |
195 | static int gpio_get_direction(unsigned gpio) | |
196 | { | |
197 | struct gpio_chip *chip; | |
198 | struct gpio_desc *desc = &gpio_desc[gpio]; | |
199 | int status = -EINVAL; | |
200 | ||
201 | chip = gpio_to_chip(gpio); | |
202 | gpio -= chip->base; | |
203 | ||
204 | if (!chip->get_direction) | |
205 | return status; | |
206 | ||
207 | status = chip->get_direction(chip, gpio); | |
208 | if (status > 0) { | |
209 | /* GPIOF_DIR_IN, or other positive */ | |
210 | status = 1; | |
211 | clear_bit(FLAG_IS_OUT, &desc->flags); | |
212 | } | |
213 | if (status == 0) { | |
214 | /* GPIOF_DIR_OUT */ | |
215 | set_bit(FLAG_IS_OUT, &desc->flags); | |
216 | } | |
217 | return status; | |
218 | } | |
219 | ||
d8f388d8 DB |
220 | #ifdef CONFIG_GPIO_SYSFS |
221 | ||
222 | /* lock protects against unexport_gpio() being called while | |
223 | * sysfs files are active. | |
224 | */ | |
225 | static DEFINE_MUTEX(sysfs_lock); | |
226 | ||
227 | /* | |
228 | * /sys/class/gpio/gpioN... only for GPIOs that are exported | |
229 | * /direction | |
230 | * * MAY BE OMITTED if kernel won't allow direction changes | |
231 | * * is read/write as "in" or "out" | |
232 | * * may also be written as "high" or "low", initializing | |
233 | * output value as specified ("out" implies "low") | |
234 | * /value | |
235 | * * always readable, subject to hardware behavior | |
236 | * * may be writable, as zero/nonzero | |
ff77c352 DG |
237 | * /edge |
238 | * * configures behavior of poll(2) on /value | |
239 | * * available only if pin can generate IRQs on input | |
240 | * * is read/write as "none", "falling", "rising", or "both" | |
07697461 JN |
241 | * /active_low |
242 | * * configures polarity of /value | |
243 | * * is read/write as zero/nonzero | |
244 | * * also affects existing and subsequent "falling" and "rising" | |
245 | * /edge configuration | |
d8f388d8 DB |
246 | */ |
247 | ||
248 | static ssize_t gpio_direction_show(struct device *dev, | |
249 | struct device_attribute *attr, char *buf) | |
250 | { | |
251 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
80b0a602 | 252 | unsigned gpio = desc - gpio_desc; |
d8f388d8 DB |
253 | ssize_t status; |
254 | ||
255 | mutex_lock(&sysfs_lock); | |
256 | ||
257 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
258 | status = -EIO; | |
259 | else | |
80b0a602 | 260 | gpio_get_direction(gpio); |
d8f388d8 DB |
261 | status = sprintf(buf, "%s\n", |
262 | test_bit(FLAG_IS_OUT, &desc->flags) | |
263 | ? "out" : "in"); | |
264 | ||
265 | mutex_unlock(&sysfs_lock); | |
266 | return status; | |
267 | } | |
268 | ||
269 | static ssize_t gpio_direction_store(struct device *dev, | |
270 | struct device_attribute *attr, const char *buf, size_t size) | |
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 | ||
278 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
279 | status = -EIO; | |
280 | else if (sysfs_streq(buf, "high")) | |
281 | status = gpio_direction_output(gpio, 1); | |
282 | else if (sysfs_streq(buf, "out") || sysfs_streq(buf, "low")) | |
283 | status = gpio_direction_output(gpio, 0); | |
284 | else if (sysfs_streq(buf, "in")) | |
285 | status = gpio_direction_input(gpio); | |
286 | else | |
287 | status = -EINVAL; | |
288 | ||
289 | mutex_unlock(&sysfs_lock); | |
290 | return status ? : size; | |
291 | } | |
292 | ||
07697461 | 293 | static /* const */ DEVICE_ATTR(direction, 0644, |
d8f388d8 DB |
294 | gpio_direction_show, gpio_direction_store); |
295 | ||
296 | static ssize_t gpio_value_show(struct device *dev, | |
297 | struct device_attribute *attr, char *buf) | |
298 | { | |
299 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
300 | unsigned gpio = desc - gpio_desc; | |
301 | ssize_t status; | |
302 | ||
303 | mutex_lock(&sysfs_lock); | |
304 | ||
07697461 | 305 | if (!test_bit(FLAG_EXPORT, &desc->flags)) { |
d8f388d8 | 306 | status = -EIO; |
07697461 JN |
307 | } else { |
308 | int value; | |
309 | ||
310 | value = !!gpio_get_value_cansleep(gpio); | |
311 | if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) | |
312 | value = !value; | |
313 | ||
314 | status = sprintf(buf, "%d\n", value); | |
315 | } | |
d8f388d8 DB |
316 | |
317 | mutex_unlock(&sysfs_lock); | |
318 | return status; | |
319 | } | |
320 | ||
321 | static ssize_t gpio_value_store(struct device *dev, | |
322 | struct device_attribute *attr, const char *buf, size_t size) | |
323 | { | |
324 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
325 | unsigned gpio = desc - gpio_desc; | |
326 | ssize_t status; | |
327 | ||
328 | mutex_lock(&sysfs_lock); | |
329 | ||
330 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
331 | status = -EIO; | |
332 | else if (!test_bit(FLAG_IS_OUT, &desc->flags)) | |
333 | status = -EPERM; | |
334 | else { | |
335 | long value; | |
336 | ||
337 | status = strict_strtol(buf, 0, &value); | |
338 | if (status == 0) { | |
07697461 JN |
339 | if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) |
340 | value = !value; | |
d8f388d8 DB |
341 | gpio_set_value_cansleep(gpio, value != 0); |
342 | status = size; | |
343 | } | |
344 | } | |
345 | ||
346 | mutex_unlock(&sysfs_lock); | |
347 | return status; | |
348 | } | |
349 | ||
07697461 | 350 | static const DEVICE_ATTR(value, 0644, |
d8f388d8 DB |
351 | gpio_value_show, gpio_value_store); |
352 | ||
ff77c352 DG |
353 | static irqreturn_t gpio_sysfs_irq(int irq, void *priv) |
354 | { | |
5ba1821d | 355 | struct sysfs_dirent *value_sd = priv; |
ff77c352 | 356 | |
5ba1821d | 357 | sysfs_notify_dirent(value_sd); |
ff77c352 DG |
358 | return IRQ_HANDLED; |
359 | } | |
360 | ||
ff77c352 DG |
361 | static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev, |
362 | unsigned long gpio_flags) | |
363 | { | |
5ba1821d | 364 | struct sysfs_dirent *value_sd; |
ff77c352 DG |
365 | unsigned long irq_flags; |
366 | int ret, irq, id; | |
367 | ||
368 | if ((desc->flags & GPIO_TRIGGER_MASK) == gpio_flags) | |
369 | return 0; | |
370 | ||
371 | irq = gpio_to_irq(desc - gpio_desc); | |
372 | if (irq < 0) | |
373 | return -EIO; | |
374 | ||
5ba1821d DG |
375 | id = desc->flags >> ID_SHIFT; |
376 | value_sd = idr_find(&dirent_idr, id); | |
377 | if (value_sd) | |
378 | free_irq(irq, value_sd); | |
ff77c352 DG |
379 | |
380 | desc->flags &= ~GPIO_TRIGGER_MASK; | |
381 | ||
382 | if (!gpio_flags) { | |
383 | ret = 0; | |
5ba1821d | 384 | goto free_id; |
ff77c352 DG |
385 | } |
386 | ||
387 | irq_flags = IRQF_SHARED; | |
388 | if (test_bit(FLAG_TRIG_FALL, &gpio_flags)) | |
07697461 JN |
389 | irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? |
390 | IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING; | |
ff77c352 | 391 | if (test_bit(FLAG_TRIG_RISE, &gpio_flags)) |
07697461 JN |
392 | irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? |
393 | IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; | |
ff77c352 | 394 | |
5ba1821d DG |
395 | if (!value_sd) { |
396 | value_sd = sysfs_get_dirent(dev->kobj.sd, NULL, "value"); | |
397 | if (!value_sd) { | |
398 | ret = -ENODEV; | |
ff77c352 DG |
399 | goto err_out; |
400 | } | |
401 | ||
402 | do { | |
403 | ret = -ENOMEM; | |
5ba1821d DG |
404 | if (idr_pre_get(&dirent_idr, GFP_KERNEL)) |
405 | ret = idr_get_new_above(&dirent_idr, value_sd, | |
406 | 1, &id); | |
ff77c352 DG |
407 | } while (ret == -EAGAIN); |
408 | ||
409 | if (ret) | |
5ba1821d | 410 | goto free_sd; |
ff77c352 DG |
411 | |
412 | desc->flags &= GPIO_FLAGS_MASK; | |
5ba1821d | 413 | desc->flags |= (unsigned long)id << ID_SHIFT; |
ff77c352 | 414 | |
5ba1821d | 415 | if (desc->flags >> ID_SHIFT != id) { |
ff77c352 DG |
416 | ret = -ERANGE; |
417 | goto free_id; | |
418 | } | |
ff77c352 DG |
419 | } |
420 | ||
364fadb3 | 421 | ret = request_any_context_irq(irq, gpio_sysfs_irq, irq_flags, |
5ba1821d | 422 | "gpiolib", value_sd); |
364fadb3 | 423 | if (ret < 0) |
5ba1821d | 424 | goto free_id; |
ff77c352 DG |
425 | |
426 | desc->flags |= gpio_flags; | |
427 | return 0; | |
428 | ||
ff77c352 | 429 | free_id: |
5ba1821d | 430 | idr_remove(&dirent_idr, id); |
ff77c352 | 431 | desc->flags &= GPIO_FLAGS_MASK; |
5ba1821d DG |
432 | free_sd: |
433 | if (value_sd) | |
434 | sysfs_put(value_sd); | |
ff77c352 DG |
435 | err_out: |
436 | return ret; | |
437 | } | |
438 | ||
439 | static const struct { | |
440 | const char *name; | |
441 | unsigned long flags; | |
442 | } trigger_types[] = { | |
443 | { "none", 0 }, | |
444 | { "falling", BIT(FLAG_TRIG_FALL) }, | |
445 | { "rising", BIT(FLAG_TRIG_RISE) }, | |
446 | { "both", BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE) }, | |
447 | }; | |
448 | ||
449 | static ssize_t gpio_edge_show(struct device *dev, | |
450 | struct device_attribute *attr, char *buf) | |
451 | { | |
452 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
453 | ssize_t status; | |
454 | ||
455 | mutex_lock(&sysfs_lock); | |
456 | ||
457 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
458 | status = -EIO; | |
459 | else { | |
460 | int i; | |
461 | ||
462 | status = 0; | |
463 | for (i = 0; i < ARRAY_SIZE(trigger_types); i++) | |
464 | if ((desc->flags & GPIO_TRIGGER_MASK) | |
465 | == trigger_types[i].flags) { | |
466 | status = sprintf(buf, "%s\n", | |
467 | trigger_types[i].name); | |
468 | break; | |
469 | } | |
470 | } | |
471 | ||
472 | mutex_unlock(&sysfs_lock); | |
473 | return status; | |
474 | } | |
475 | ||
476 | static ssize_t gpio_edge_store(struct device *dev, | |
477 | struct device_attribute *attr, const char *buf, size_t size) | |
478 | { | |
479 | struct gpio_desc *desc = dev_get_drvdata(dev); | |
480 | ssize_t status; | |
481 | int i; | |
482 | ||
483 | for (i = 0; i < ARRAY_SIZE(trigger_types); i++) | |
484 | if (sysfs_streq(trigger_types[i].name, buf)) | |
485 | goto found; | |
486 | return -EINVAL; | |
487 | ||
488 | found: | |
489 | mutex_lock(&sysfs_lock); | |
490 | ||
491 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
492 | status = -EIO; | |
493 | else { | |
494 | status = gpio_setup_irq(desc, dev, trigger_types[i].flags); | |
495 | if (!status) | |
496 | status = size; | |
497 | } | |
498 | ||
499 | mutex_unlock(&sysfs_lock); | |
500 | ||
501 | return status; | |
502 | } | |
503 | ||
504 | static DEVICE_ATTR(edge, 0644, gpio_edge_show, gpio_edge_store); | |
505 | ||
07697461 JN |
506 | static int sysfs_set_active_low(struct gpio_desc *desc, struct device *dev, |
507 | int value) | |
508 | { | |
509 | int status = 0; | |
510 | ||
511 | if (!!test_bit(FLAG_ACTIVE_LOW, &desc->flags) == !!value) | |
512 | return 0; | |
513 | ||
514 | if (value) | |
515 | set_bit(FLAG_ACTIVE_LOW, &desc->flags); | |
516 | else | |
517 | clear_bit(FLAG_ACTIVE_LOW, &desc->flags); | |
518 | ||
519 | /* reconfigure poll(2) support if enabled on one edge only */ | |
520 | if (dev != NULL && (!!test_bit(FLAG_TRIG_RISE, &desc->flags) ^ | |
521 | !!test_bit(FLAG_TRIG_FALL, &desc->flags))) { | |
522 | unsigned long trigger_flags = desc->flags & GPIO_TRIGGER_MASK; | |
523 | ||
524 | gpio_setup_irq(desc, dev, 0); | |
525 | status = gpio_setup_irq(desc, dev, trigger_flags); | |
526 | } | |
527 | ||
528 | return status; | |
529 | } | |
530 | ||
531 | static ssize_t gpio_active_low_show(struct device *dev, | |
532 | struct device_attribute *attr, char *buf) | |
533 | { | |
534 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
535 | ssize_t status; | |
536 | ||
537 | mutex_lock(&sysfs_lock); | |
538 | ||
539 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
540 | status = -EIO; | |
541 | else | |
542 | status = sprintf(buf, "%d\n", | |
543 | !!test_bit(FLAG_ACTIVE_LOW, &desc->flags)); | |
544 | ||
545 | mutex_unlock(&sysfs_lock); | |
546 | ||
547 | return status; | |
548 | } | |
549 | ||
550 | static ssize_t gpio_active_low_store(struct device *dev, | |
551 | struct device_attribute *attr, const char *buf, size_t size) | |
552 | { | |
553 | struct gpio_desc *desc = dev_get_drvdata(dev); | |
554 | ssize_t status; | |
555 | ||
556 | mutex_lock(&sysfs_lock); | |
557 | ||
558 | if (!test_bit(FLAG_EXPORT, &desc->flags)) { | |
559 | status = -EIO; | |
560 | } else { | |
561 | long value; | |
562 | ||
563 | status = strict_strtol(buf, 0, &value); | |
564 | if (status == 0) | |
565 | status = sysfs_set_active_low(desc, dev, value != 0); | |
566 | } | |
567 | ||
568 | mutex_unlock(&sysfs_lock); | |
569 | ||
570 | return status ? : size; | |
571 | } | |
572 | ||
573 | static const DEVICE_ATTR(active_low, 0644, | |
574 | gpio_active_low_show, gpio_active_low_store); | |
575 | ||
d8f388d8 | 576 | static const struct attribute *gpio_attrs[] = { |
d8f388d8 | 577 | &dev_attr_value.attr, |
07697461 | 578 | &dev_attr_active_low.attr, |
d8f388d8 DB |
579 | NULL, |
580 | }; | |
581 | ||
582 | static const struct attribute_group gpio_attr_group = { | |
583 | .attrs = (struct attribute **) gpio_attrs, | |
584 | }; | |
585 | ||
586 | /* | |
587 | * /sys/class/gpio/gpiochipN/ | |
588 | * /base ... matching gpio_chip.base (N) | |
589 | * /label ... matching gpio_chip.label | |
590 | * /ngpio ... matching gpio_chip.ngpio | |
591 | */ | |
592 | ||
593 | static ssize_t chip_base_show(struct device *dev, | |
594 | struct device_attribute *attr, char *buf) | |
595 | { | |
596 | const struct gpio_chip *chip = dev_get_drvdata(dev); | |
597 | ||
598 | return sprintf(buf, "%d\n", chip->base); | |
599 | } | |
600 | static DEVICE_ATTR(base, 0444, chip_base_show, NULL); | |
601 | ||
602 | static ssize_t chip_label_show(struct device *dev, | |
603 | struct device_attribute *attr, char *buf) | |
604 | { | |
605 | const struct gpio_chip *chip = dev_get_drvdata(dev); | |
606 | ||
607 | return sprintf(buf, "%s\n", chip->label ? : ""); | |
608 | } | |
609 | static DEVICE_ATTR(label, 0444, chip_label_show, NULL); | |
610 | ||
611 | static ssize_t chip_ngpio_show(struct device *dev, | |
612 | struct device_attribute *attr, char *buf) | |
613 | { | |
614 | const struct gpio_chip *chip = dev_get_drvdata(dev); | |
615 | ||
616 | return sprintf(buf, "%u\n", chip->ngpio); | |
617 | } | |
618 | static DEVICE_ATTR(ngpio, 0444, chip_ngpio_show, NULL); | |
619 | ||
620 | static const struct attribute *gpiochip_attrs[] = { | |
621 | &dev_attr_base.attr, | |
622 | &dev_attr_label.attr, | |
623 | &dev_attr_ngpio.attr, | |
624 | NULL, | |
625 | }; | |
626 | ||
627 | static const struct attribute_group gpiochip_attr_group = { | |
628 | .attrs = (struct attribute **) gpiochip_attrs, | |
629 | }; | |
630 | ||
631 | /* | |
632 | * /sys/class/gpio/export ... write-only | |
633 | * integer N ... number of GPIO to export (full access) | |
634 | * /sys/class/gpio/unexport ... write-only | |
635 | * integer N ... number of GPIO to unexport | |
636 | */ | |
28812fe1 AK |
637 | static ssize_t export_store(struct class *class, |
638 | struct class_attribute *attr, | |
639 | const char *buf, size_t len) | |
d8f388d8 DB |
640 | { |
641 | long gpio; | |
642 | int status; | |
643 | ||
644 | status = strict_strtol(buf, 0, &gpio); | |
645 | if (status < 0) | |
646 | goto done; | |
647 | ||
648 | /* No extra locking here; FLAG_SYSFS just signifies that the | |
649 | * request and export were done by on behalf of userspace, so | |
650 | * they may be undone on its behalf too. | |
651 | */ | |
652 | ||
653 | status = gpio_request(gpio, "sysfs"); | |
ad2fab36 MN |
654 | if (status < 0) { |
655 | if (status == -EPROBE_DEFER) | |
656 | status = -ENODEV; | |
d8f388d8 | 657 | goto done; |
ad2fab36 | 658 | } |
d8f388d8 DB |
659 | status = gpio_export(gpio, true); |
660 | if (status < 0) | |
661 | gpio_free(gpio); | |
662 | else | |
663 | set_bit(FLAG_SYSFS, &gpio_desc[gpio].flags); | |
664 | ||
665 | done: | |
666 | if (status) | |
667 | pr_debug("%s: status %d\n", __func__, status); | |
668 | return status ? : len; | |
669 | } | |
670 | ||
28812fe1 AK |
671 | static ssize_t unexport_store(struct class *class, |
672 | struct class_attribute *attr, | |
673 | const char *buf, size_t len) | |
d8f388d8 DB |
674 | { |
675 | long gpio; | |
676 | int status; | |
677 | ||
678 | status = strict_strtol(buf, 0, &gpio); | |
679 | if (status < 0) | |
680 | goto done; | |
681 | ||
682 | status = -EINVAL; | |
683 | ||
684 | /* reject bogus commands (gpio_unexport ignores them) */ | |
685 | if (!gpio_is_valid(gpio)) | |
686 | goto done; | |
687 | ||
688 | /* No extra locking here; FLAG_SYSFS just signifies that the | |
689 | * request and export were done by on behalf of userspace, so | |
690 | * they may be undone on its behalf too. | |
691 | */ | |
692 | if (test_and_clear_bit(FLAG_SYSFS, &gpio_desc[gpio].flags)) { | |
693 | status = 0; | |
694 | gpio_free(gpio); | |
695 | } | |
696 | done: | |
697 | if (status) | |
698 | pr_debug("%s: status %d\n", __func__, status); | |
699 | return status ? : len; | |
700 | } | |
701 | ||
702 | static struct class_attribute gpio_class_attrs[] = { | |
703 | __ATTR(export, 0200, NULL, export_store), | |
704 | __ATTR(unexport, 0200, NULL, unexport_store), | |
705 | __ATTR_NULL, | |
706 | }; | |
707 | ||
708 | static struct class gpio_class = { | |
709 | .name = "gpio", | |
710 | .owner = THIS_MODULE, | |
711 | ||
712 | .class_attrs = gpio_class_attrs, | |
713 | }; | |
714 | ||
715 | ||
716 | /** | |
717 | * gpio_export - export a GPIO through sysfs | |
718 | * @gpio: gpio to make available, already requested | |
719 | * @direction_may_change: true if userspace may change gpio direction | |
720 | * Context: arch_initcall or later | |
721 | * | |
722 | * When drivers want to make a GPIO accessible to userspace after they | |
723 | * have requested it -- perhaps while debugging, or as part of their | |
724 | * public interface -- they may use this routine. If the GPIO can | |
725 | * change direction (some can't) and the caller allows it, userspace | |
726 | * will see "direction" sysfs attribute which may be used to change | |
727 | * the gpio's direction. A "value" attribute will always be provided. | |
728 | * | |
729 | * Returns zero on success, else an error. | |
730 | */ | |
731 | int gpio_export(unsigned gpio, bool direction_may_change) | |
732 | { | |
733 | unsigned long flags; | |
734 | struct gpio_desc *desc; | |
fc4e2514 | 735 | int status; |
62154991 | 736 | const char *ioname = NULL; |
fc4e2514 | 737 | struct device *dev; |
d8f388d8 DB |
738 | |
739 | /* can't export until sysfs is available ... */ | |
740 | if (!gpio_class.p) { | |
741 | pr_debug("%s: called too early!\n", __func__); | |
742 | return -ENOENT; | |
743 | } | |
744 | ||
fc4e2514 RM |
745 | if (!gpio_is_valid(gpio)) { |
746 | pr_debug("%s: gpio %d is not valid\n", __func__, gpio); | |
747 | return -EINVAL; | |
748 | } | |
d8f388d8 DB |
749 | |
750 | mutex_lock(&sysfs_lock); | |
751 | ||
752 | spin_lock_irqsave(&gpio_lock, flags); | |
753 | desc = &gpio_desc[gpio]; | |
fc4e2514 RM |
754 | if (!test_bit(FLAG_REQUESTED, &desc->flags) || |
755 | test_bit(FLAG_EXPORT, &desc->flags)) { | |
756 | spin_unlock_irqrestore(&gpio_lock, flags); | |
757 | pr_debug("%s: gpio %d unavailable (requested=%d, exported=%d)\n", | |
758 | __func__, gpio, | |
759 | test_bit(FLAG_REQUESTED, &desc->flags), | |
760 | test_bit(FLAG_EXPORT, &desc->flags)); | |
529f2ad5 DC |
761 | status = -EPERM; |
762 | goto fail_unlock; | |
d8f388d8 | 763 | } |
fc4e2514 RM |
764 | |
765 | if (!desc->chip->direction_input || !desc->chip->direction_output) | |
766 | direction_may_change = false; | |
d8f388d8 DB |
767 | spin_unlock_irqrestore(&gpio_lock, flags); |
768 | ||
926b663c DS |
769 | if (desc->chip->names && desc->chip->names[gpio - desc->chip->base]) |
770 | ioname = desc->chip->names[gpio - desc->chip->base]; | |
771 | ||
fc4e2514 RM |
772 | dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0), |
773 | desc, ioname ? ioname : "gpio%u", gpio); | |
774 | if (IS_ERR(dev)) { | |
775 | status = PTR_ERR(dev); | |
776 | goto fail_unlock; | |
d8f388d8 DB |
777 | } |
778 | ||
fc4e2514 | 779 | status = sysfs_create_group(&dev->kobj, &gpio_attr_group); |
d8f388d8 | 780 | if (status) |
fc4e2514 | 781 | goto fail_unregister_device; |
d8f388d8 | 782 | |
fc4e2514 RM |
783 | if (direction_may_change) { |
784 | status = device_create_file(dev, &dev_attr_direction); | |
785 | if (status) | |
786 | goto fail_unregister_device; | |
787 | } | |
788 | ||
789 | if (gpio_to_irq(gpio) >= 0 && (direction_may_change || | |
790 | !test_bit(FLAG_IS_OUT, &desc->flags))) { | |
791 | status = device_create_file(dev, &dev_attr_edge); | |
792 | if (status) | |
793 | goto fail_unregister_device; | |
794 | } | |
d8f388d8 | 795 | |
fc4e2514 RM |
796 | set_bit(FLAG_EXPORT, &desc->flags); |
797 | mutex_unlock(&sysfs_lock); | |
798 | return 0; | |
799 | ||
800 | fail_unregister_device: | |
801 | device_unregister(dev); | |
802 | fail_unlock: | |
803 | mutex_unlock(&sysfs_lock); | |
804 | pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); | |
d8f388d8 DB |
805 | return status; |
806 | } | |
807 | EXPORT_SYMBOL_GPL(gpio_export); | |
808 | ||
809 | static int match_export(struct device *dev, void *data) | |
810 | { | |
811 | return dev_get_drvdata(dev) == data; | |
812 | } | |
813 | ||
a4177ee7 JN |
814 | /** |
815 | * gpio_export_link - create a sysfs link to an exported GPIO node | |
816 | * @dev: device under which to create symlink | |
817 | * @name: name of the symlink | |
818 | * @gpio: gpio to create symlink to, already exported | |
819 | * | |
820 | * Set up a symlink from /sys/.../dev/name to /sys/class/gpio/gpioN | |
821 | * node. Caller is responsible for unlinking. | |
822 | * | |
823 | * Returns zero on success, else an error. | |
824 | */ | |
825 | int gpio_export_link(struct device *dev, const char *name, unsigned gpio) | |
826 | { | |
827 | struct gpio_desc *desc; | |
828 | int status = -EINVAL; | |
829 | ||
830 | if (!gpio_is_valid(gpio)) | |
831 | goto done; | |
832 | ||
833 | mutex_lock(&sysfs_lock); | |
834 | ||
835 | desc = &gpio_desc[gpio]; | |
836 | ||
837 | if (test_bit(FLAG_EXPORT, &desc->flags)) { | |
838 | struct device *tdev; | |
839 | ||
840 | tdev = class_find_device(&gpio_class, NULL, desc, match_export); | |
841 | if (tdev != NULL) { | |
842 | status = sysfs_create_link(&dev->kobj, &tdev->kobj, | |
843 | name); | |
844 | } else { | |
845 | status = -ENODEV; | |
846 | } | |
847 | } | |
848 | ||
849 | mutex_unlock(&sysfs_lock); | |
850 | ||
851 | done: | |
852 | if (status) | |
853 | pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); | |
854 | ||
855 | return status; | |
856 | } | |
857 | EXPORT_SYMBOL_GPL(gpio_export_link); | |
858 | ||
07697461 JN |
859 | |
860 | /** | |
861 | * gpio_sysfs_set_active_low - set the polarity of gpio sysfs value | |
862 | * @gpio: gpio to change | |
863 | * @value: non-zero to use active low, i.e. inverted values | |
864 | * | |
865 | * Set the polarity of /sys/class/gpio/gpioN/value sysfs attribute. | |
866 | * The GPIO does not have to be exported yet. If poll(2) support has | |
867 | * been enabled for either rising or falling edge, it will be | |
868 | * reconfigured to follow the new polarity. | |
869 | * | |
870 | * Returns zero on success, else an error. | |
871 | */ | |
872 | int gpio_sysfs_set_active_low(unsigned gpio, int value) | |
873 | { | |
874 | struct gpio_desc *desc; | |
875 | struct device *dev = NULL; | |
876 | int status = -EINVAL; | |
877 | ||
878 | if (!gpio_is_valid(gpio)) | |
879 | goto done; | |
880 | ||
881 | mutex_lock(&sysfs_lock); | |
882 | ||
883 | desc = &gpio_desc[gpio]; | |
884 | ||
885 | if (test_bit(FLAG_EXPORT, &desc->flags)) { | |
07697461 JN |
886 | dev = class_find_device(&gpio_class, NULL, desc, match_export); |
887 | if (dev == NULL) { | |
888 | status = -ENODEV; | |
889 | goto unlock; | |
890 | } | |
891 | } | |
892 | ||
893 | status = sysfs_set_active_low(desc, dev, value); | |
894 | ||
895 | unlock: | |
896 | mutex_unlock(&sysfs_lock); | |
897 | ||
898 | done: | |
899 | if (status) | |
900 | pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); | |
901 | ||
902 | return status; | |
903 | } | |
904 | EXPORT_SYMBOL_GPL(gpio_sysfs_set_active_low); | |
905 | ||
d8f388d8 DB |
906 | /** |
907 | * gpio_unexport - reverse effect of gpio_export() | |
908 | * @gpio: gpio to make unavailable | |
909 | * | |
910 | * This is implicit on gpio_free(). | |
911 | */ | |
912 | void gpio_unexport(unsigned gpio) | |
913 | { | |
914 | struct gpio_desc *desc; | |
6a99ad4a | 915 | int status = 0; |
864533ce | 916 | struct device *dev = NULL; |
d8f388d8 | 917 | |
6a99ad4a JP |
918 | if (!gpio_is_valid(gpio)) { |
919 | status = -EINVAL; | |
d8f388d8 | 920 | goto done; |
6a99ad4a | 921 | } |
d8f388d8 DB |
922 | |
923 | mutex_lock(&sysfs_lock); | |
924 | ||
925 | desc = &gpio_desc[gpio]; | |
926b663c | 926 | |
d8f388d8 | 927 | if (test_bit(FLAG_EXPORT, &desc->flags)) { |
d8f388d8 DB |
928 | |
929 | dev = class_find_device(&gpio_class, NULL, desc, match_export); | |
930 | if (dev) { | |
ff77c352 | 931 | gpio_setup_irq(desc, dev, 0); |
d8f388d8 | 932 | clear_bit(FLAG_EXPORT, &desc->flags); |
d8f388d8 DB |
933 | } else |
934 | status = -ENODEV; | |
935 | } | |
936 | ||
937 | mutex_unlock(&sysfs_lock); | |
864533ce ML |
938 | if (dev) { |
939 | device_unregister(dev); | |
940 | put_device(dev); | |
941 | } | |
d8f388d8 DB |
942 | done: |
943 | if (status) | |
944 | pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); | |
945 | } | |
946 | EXPORT_SYMBOL_GPL(gpio_unexport); | |
947 | ||
948 | static int gpiochip_export(struct gpio_chip *chip) | |
949 | { | |
950 | int status; | |
951 | struct device *dev; | |
952 | ||
953 | /* Many systems register gpio chips for SOC support very early, | |
954 | * before driver model support is available. In those cases we | |
955 | * export this later, in gpiolib_sysfs_init() ... here we just | |
956 | * verify that _some_ field of gpio_class got initialized. | |
957 | */ | |
958 | if (!gpio_class.p) | |
959 | return 0; | |
960 | ||
961 | /* use chip->base for the ID; it's already known to be unique */ | |
962 | mutex_lock(&sysfs_lock); | |
963 | dev = device_create(&gpio_class, chip->dev, MKDEV(0, 0), chip, | |
964 | "gpiochip%d", chip->base); | |
d62668e1 | 965 | if (!IS_ERR(dev)) { |
d8f388d8 DB |
966 | status = sysfs_create_group(&dev->kobj, |
967 | &gpiochip_attr_group); | |
968 | } else | |
d62668e1 | 969 | status = PTR_ERR(dev); |
d8f388d8 DB |
970 | chip->exported = (status == 0); |
971 | mutex_unlock(&sysfs_lock); | |
972 | ||
973 | if (status) { | |
974 | unsigned long flags; | |
975 | unsigned gpio; | |
976 | ||
977 | spin_lock_irqsave(&gpio_lock, flags); | |
978 | gpio = chip->base; | |
979 | while (gpio_desc[gpio].chip == chip) | |
980 | gpio_desc[gpio++].chip = NULL; | |
981 | spin_unlock_irqrestore(&gpio_lock, flags); | |
982 | ||
983 | pr_debug("%s: chip %s status %d\n", __func__, | |
984 | chip->label, status); | |
985 | } | |
986 | ||
987 | return status; | |
988 | } | |
989 | ||
990 | static void gpiochip_unexport(struct gpio_chip *chip) | |
991 | { | |
992 | int status; | |
993 | struct device *dev; | |
994 | ||
995 | mutex_lock(&sysfs_lock); | |
996 | dev = class_find_device(&gpio_class, NULL, chip, match_export); | |
997 | if (dev) { | |
998 | put_device(dev); | |
999 | device_unregister(dev); | |
1000 | chip->exported = 0; | |
1001 | status = 0; | |
1002 | } else | |
1003 | status = -ENODEV; | |
1004 | mutex_unlock(&sysfs_lock); | |
1005 | ||
1006 | if (status) | |
1007 | pr_debug("%s: chip %s status %d\n", __func__, | |
1008 | chip->label, status); | |
1009 | } | |
1010 | ||
1011 | static int __init gpiolib_sysfs_init(void) | |
1012 | { | |
1013 | int status; | |
1014 | unsigned long flags; | |
1015 | unsigned gpio; | |
1016 | ||
1017 | status = class_register(&gpio_class); | |
1018 | if (status < 0) | |
1019 | return status; | |
1020 | ||
1021 | /* Scan and register the gpio_chips which registered very | |
1022 | * early (e.g. before the class_register above was called). | |
1023 | * | |
1024 | * We run before arch_initcall() so chip->dev nodes can have | |
1025 | * registered, and so arch_initcall() can always gpio_export(). | |
1026 | */ | |
1027 | spin_lock_irqsave(&gpio_lock, flags); | |
1028 | for (gpio = 0; gpio < ARCH_NR_GPIOS; gpio++) { | |
1029 | struct gpio_chip *chip; | |
1030 | ||
1031 | chip = gpio_desc[gpio].chip; | |
1032 | if (!chip || chip->exported) | |
1033 | continue; | |
1034 | ||
1035 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1036 | status = gpiochip_export(chip); | |
1037 | spin_lock_irqsave(&gpio_lock, flags); | |
1038 | } | |
1039 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1040 | ||
1041 | ||
1042 | return status; | |
1043 | } | |
1044 | postcore_initcall(gpiolib_sysfs_init); | |
1045 | ||
1046 | #else | |
1047 | static inline int gpiochip_export(struct gpio_chip *chip) | |
1048 | { | |
1049 | return 0; | |
1050 | } | |
1051 | ||
1052 | static inline void gpiochip_unexport(struct gpio_chip *chip) | |
1053 | { | |
1054 | } | |
1055 | ||
1056 | #endif /* CONFIG_GPIO_SYSFS */ | |
1057 | ||
d2876d08 DB |
1058 | /** |
1059 | * gpiochip_add() - register a gpio_chip | |
1060 | * @chip: the chip to register, with chip->base initialized | |
1061 | * Context: potentially before irqs or kmalloc will work | |
1062 | * | |
1063 | * Returns a negative errno if the chip can't be registered, such as | |
1064 | * because the chip->base is invalid or already associated with a | |
1065 | * different chip. Otherwise it returns zero as a success code. | |
8d0aab2f | 1066 | * |
d8f388d8 DB |
1067 | * When gpiochip_add() is called very early during boot, so that GPIOs |
1068 | * can be freely used, the chip->dev device must be registered before | |
1069 | * the gpio framework's arch_initcall(). Otherwise sysfs initialization | |
1070 | * for GPIOs will fail rudely. | |
1071 | * | |
8d0aab2f AV |
1072 | * If chip->base is negative, this requests dynamic assignment of |
1073 | * a range of valid GPIOs. | |
d2876d08 DB |
1074 | */ |
1075 | int gpiochip_add(struct gpio_chip *chip) | |
1076 | { | |
1077 | unsigned long flags; | |
1078 | int status = 0; | |
1079 | unsigned id; | |
8d0aab2f | 1080 | int base = chip->base; |
d2876d08 | 1081 | |
bff5fda9 | 1082 | if ((!gpio_is_valid(base) || !gpio_is_valid(base + chip->ngpio - 1)) |
8d0aab2f | 1083 | && base >= 0) { |
d2876d08 DB |
1084 | status = -EINVAL; |
1085 | goto fail; | |
1086 | } | |
1087 | ||
1088 | spin_lock_irqsave(&gpio_lock, flags); | |
1089 | ||
8d0aab2f AV |
1090 | if (base < 0) { |
1091 | base = gpiochip_find_base(chip->ngpio); | |
1092 | if (base < 0) { | |
1093 | status = base; | |
d8f388d8 | 1094 | goto unlock; |
8d0aab2f AV |
1095 | } |
1096 | chip->base = base; | |
1097 | } | |
1098 | ||
d2876d08 | 1099 | /* these GPIO numbers must not be managed by another gpio_chip */ |
8d0aab2f | 1100 | for (id = base; id < base + chip->ngpio; id++) { |
d2876d08 DB |
1101 | if (gpio_desc[id].chip != NULL) { |
1102 | status = -EBUSY; | |
1103 | break; | |
1104 | } | |
1105 | } | |
1106 | if (status == 0) { | |
8d0aab2f | 1107 | for (id = base; id < base + chip->ngpio; id++) { |
d2876d08 | 1108 | gpio_desc[id].chip = chip; |
d8f388d8 DB |
1109 | |
1110 | /* REVISIT: most hardware initializes GPIOs as | |
1111 | * inputs (often with pullups enabled) so power | |
1112 | * usage is minimized. Linux code should set the | |
1113 | * gpio direction first thing; but until it does, | |
80b0a602 | 1114 | * and in case chip->get_direction is not set, |
d8f388d8 DB |
1115 | * we may expose the wrong direction in sysfs. |
1116 | */ | |
1117 | gpio_desc[id].flags = !chip->direction_input | |
1118 | ? (1 << FLAG_IS_OUT) | |
1119 | : 0; | |
d2876d08 DB |
1120 | } |
1121 | } | |
1122 | ||
f23f1516 SH |
1123 | #ifdef CONFIG_PINCTRL |
1124 | INIT_LIST_HEAD(&chip->pin_ranges); | |
1125 | #endif | |
1126 | ||
391c970c AV |
1127 | of_gpiochip_add(chip); |
1128 | ||
d8f388d8 | 1129 | unlock: |
d2876d08 | 1130 | spin_unlock_irqrestore(&gpio_lock, flags); |
cedb1881 AV |
1131 | |
1132 | if (status) | |
1133 | goto fail; | |
1134 | ||
1135 | status = gpiochip_export(chip); | |
1136 | if (status) | |
1137 | goto fail; | |
1138 | ||
ee1c1e7d | 1139 | pr_debug("gpiochip_add: registered GPIOs %d to %d on device: %s\n", |
64842aad GL |
1140 | chip->base, chip->base + chip->ngpio - 1, |
1141 | chip->label ? : "generic"); | |
1142 | ||
cedb1881 | 1143 | return 0; |
d2876d08 DB |
1144 | fail: |
1145 | /* failures here can mean systems won't boot... */ | |
cedb1881 AV |
1146 | pr_err("gpiochip_add: gpios %d..%d (%s) failed to register\n", |
1147 | chip->base, chip->base + chip->ngpio - 1, | |
1148 | chip->label ? : "generic"); | |
d2876d08 DB |
1149 | return status; |
1150 | } | |
1151 | EXPORT_SYMBOL_GPL(gpiochip_add); | |
1152 | ||
1153 | /** | |
1154 | * gpiochip_remove() - unregister a gpio_chip | |
1155 | * @chip: the chip to unregister | |
1156 | * | |
1157 | * A gpio_chip with any GPIOs still requested may not be removed. | |
1158 | */ | |
1159 | int gpiochip_remove(struct gpio_chip *chip) | |
1160 | { | |
1161 | unsigned long flags; | |
1162 | int status = 0; | |
1163 | unsigned id; | |
1164 | ||
1165 | spin_lock_irqsave(&gpio_lock, flags); | |
1166 | ||
9ef0d6f7 | 1167 | gpiochip_remove_pin_ranges(chip); |
391c970c AV |
1168 | of_gpiochip_remove(chip); |
1169 | ||
d2876d08 DB |
1170 | for (id = chip->base; id < chip->base + chip->ngpio; id++) { |
1171 | if (test_bit(FLAG_REQUESTED, &gpio_desc[id].flags)) { | |
1172 | status = -EBUSY; | |
1173 | break; | |
1174 | } | |
1175 | } | |
1176 | if (status == 0) { | |
1177 | for (id = chip->base; id < chip->base + chip->ngpio; id++) | |
1178 | gpio_desc[id].chip = NULL; | |
1179 | } | |
1180 | ||
1181 | spin_unlock_irqrestore(&gpio_lock, flags); | |
d8f388d8 DB |
1182 | |
1183 | if (status == 0) | |
1184 | gpiochip_unexport(chip); | |
1185 | ||
d2876d08 DB |
1186 | return status; |
1187 | } | |
1188 | EXPORT_SYMBOL_GPL(gpiochip_remove); | |
1189 | ||
594fa265 GL |
1190 | /** |
1191 | * gpiochip_find() - iterator for locating a specific gpio_chip | |
1192 | * @data: data to pass to match function | |
1193 | * @callback: Callback function to check gpio_chip | |
1194 | * | |
1195 | * Similar to bus_find_device. It returns a reference to a gpio_chip as | |
1196 | * determined by a user supplied @match callback. The callback should return | |
1197 | * 0 if the device doesn't match and non-zero if it does. If the callback is | |
1198 | * non-zero, this function will return to the caller and not iterate over any | |
1199 | * more gpio_chips. | |
1200 | */ | |
07ce8ec7 | 1201 | struct gpio_chip *gpiochip_find(void *data, |
6e2cf651 | 1202 | int (*match)(struct gpio_chip *chip, |
3d0f7cf0 | 1203 | void *data)) |
594fa265 GL |
1204 | { |
1205 | struct gpio_chip *chip = NULL; | |
1206 | unsigned long flags; | |
1207 | int i; | |
1208 | ||
1209 | spin_lock_irqsave(&gpio_lock, flags); | |
1210 | for (i = 0; i < ARCH_NR_GPIOS; i++) { | |
1211 | if (!gpio_desc[i].chip) | |
1212 | continue; | |
1213 | ||
1214 | if (match(gpio_desc[i].chip, data)) { | |
1215 | chip = gpio_desc[i].chip; | |
1216 | break; | |
1217 | } | |
1218 | } | |
1219 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1220 | ||
1221 | return chip; | |
1222 | } | |
8fa0c9bf | 1223 | EXPORT_SYMBOL_GPL(gpiochip_find); |
d2876d08 | 1224 | |
f23f1516 | 1225 | #ifdef CONFIG_PINCTRL |
165adc9c | 1226 | |
3f0f8670 LW |
1227 | /** |
1228 | * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping | |
1229 | * @chip: the gpiochip to add the range for | |
1230 | * @pinctrl_name: the dev_name() of the pin controller to map to | |
316511c0 LW |
1231 | * @gpio_offset: the start offset in the current gpio_chip number space |
1232 | * @pin_offset: the start offset in the pin controller number space | |
3f0f8670 LW |
1233 | * @npins: the number of pins from the offset of each pin space (GPIO and |
1234 | * pin controller) to accumulate in this range | |
1235 | */ | |
1e63d7b9 | 1236 | int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name, |
316511c0 | 1237 | unsigned int gpio_offset, unsigned int pin_offset, |
3f0f8670 | 1238 | unsigned int npins) |
f23f1516 SH |
1239 | { |
1240 | struct gpio_pin_range *pin_range; | |
b4d4b1f0 | 1241 | int ret; |
f23f1516 | 1242 | |
3f0f8670 | 1243 | pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL); |
f23f1516 SH |
1244 | if (!pin_range) { |
1245 | pr_err("%s: GPIO chip: failed to allocate pin ranges\n", | |
1246 | chip->label); | |
1e63d7b9 | 1247 | return -ENOMEM; |
f23f1516 SH |
1248 | } |
1249 | ||
3f0f8670 | 1250 | /* Use local offset as range ID */ |
316511c0 | 1251 | pin_range->range.id = gpio_offset; |
3f0f8670 | 1252 | pin_range->range.gc = chip; |
f23f1516 | 1253 | pin_range->range.name = chip->label; |
316511c0 LW |
1254 | pin_range->range.base = chip->base + gpio_offset; |
1255 | pin_range->range.pin_base = pin_offset; | |
f23f1516 | 1256 | pin_range->range.npins = npins; |
192c369c | 1257 | pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name, |
f23f1516 | 1258 | &pin_range->range); |
8f23ca1a | 1259 | if (IS_ERR(pin_range->pctldev)) { |
b4d4b1f0 | 1260 | ret = PTR_ERR(pin_range->pctldev); |
3f0f8670 LW |
1261 | pr_err("%s: GPIO chip: could not create pin range\n", |
1262 | chip->label); | |
1263 | kfree(pin_range); | |
b4d4b1f0 | 1264 | return ret; |
3f0f8670 | 1265 | } |
316511c0 LW |
1266 | pr_debug("GPIO chip %s: created GPIO range %d->%d ==> %s PIN %d->%d\n", |
1267 | chip->label, gpio_offset, gpio_offset + npins - 1, | |
1268 | pinctl_name, | |
1269 | pin_offset, pin_offset + npins - 1); | |
f23f1516 SH |
1270 | |
1271 | list_add_tail(&pin_range->node, &chip->pin_ranges); | |
1e63d7b9 LW |
1272 | |
1273 | return 0; | |
f23f1516 | 1274 | } |
165adc9c | 1275 | EXPORT_SYMBOL_GPL(gpiochip_add_pin_range); |
f23f1516 | 1276 | |
3f0f8670 LW |
1277 | /** |
1278 | * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings | |
1279 | * @chip: the chip to remove all the mappings for | |
1280 | */ | |
f23f1516 SH |
1281 | void gpiochip_remove_pin_ranges(struct gpio_chip *chip) |
1282 | { | |
1283 | struct gpio_pin_range *pin_range, *tmp; | |
1284 | ||
1285 | list_for_each_entry_safe(pin_range, tmp, &chip->pin_ranges, node) { | |
1286 | list_del(&pin_range->node); | |
1287 | pinctrl_remove_gpio_range(pin_range->pctldev, | |
1288 | &pin_range->range); | |
3f0f8670 | 1289 | kfree(pin_range); |
f23f1516 SH |
1290 | } |
1291 | } | |
165adc9c LW |
1292 | EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges); |
1293 | ||
1294 | #endif /* CONFIG_PINCTRL */ | |
f23f1516 | 1295 | |
d2876d08 DB |
1296 | /* These "optional" allocation calls help prevent drivers from stomping |
1297 | * on each other, and help provide better diagnostics in debugfs. | |
1298 | * They're called even less than the "set direction" calls. | |
1299 | */ | |
1300 | int gpio_request(unsigned gpio, const char *label) | |
1301 | { | |
1302 | struct gpio_desc *desc; | |
35e8bb51 | 1303 | struct gpio_chip *chip; |
e9354576 | 1304 | int status = -EPROBE_DEFER; |
d2876d08 DB |
1305 | unsigned long flags; |
1306 | ||
1307 | spin_lock_irqsave(&gpio_lock, flags); | |
1308 | ||
ad2fab36 MN |
1309 | if (!gpio_is_valid(gpio)) { |
1310 | status = -EINVAL; | |
d2876d08 | 1311 | goto done; |
ad2fab36 | 1312 | } |
d2876d08 | 1313 | desc = &gpio_desc[gpio]; |
35e8bb51 DB |
1314 | chip = desc->chip; |
1315 | if (chip == NULL) | |
d2876d08 DB |
1316 | goto done; |
1317 | ||
35e8bb51 | 1318 | if (!try_module_get(chip->owner)) |
438d8908 GL |
1319 | goto done; |
1320 | ||
d2876d08 | 1321 | /* NOTE: gpio_request() can be called in early boot, |
35e8bb51 | 1322 | * before IRQs are enabled, for non-sleeping (SOC) GPIOs. |
d2876d08 DB |
1323 | */ |
1324 | ||
1325 | if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) { | |
1326 | desc_set_label(desc, label ? : "?"); | |
1327 | status = 0; | |
438d8908 | 1328 | } else { |
d2876d08 | 1329 | status = -EBUSY; |
35e8bb51 | 1330 | module_put(chip->owner); |
7460db56 | 1331 | goto done; |
35e8bb51 DB |
1332 | } |
1333 | ||
1334 | if (chip->request) { | |
1335 | /* chip->request may sleep */ | |
1336 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1337 | status = chip->request(chip, gpio - chip->base); | |
1338 | spin_lock_irqsave(&gpio_lock, flags); | |
1339 | ||
1340 | if (status < 0) { | |
1341 | desc_set_label(desc, NULL); | |
1342 | module_put(chip->owner); | |
1343 | clear_bit(FLAG_REQUESTED, &desc->flags); | |
80b0a602 | 1344 | goto done; |
35e8bb51 | 1345 | } |
438d8908 | 1346 | } |
80b0a602 MN |
1347 | if (chip->get_direction) { |
1348 | /* chip->get_direction may sleep */ | |
1349 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1350 | gpio_get_direction(gpio); | |
1351 | spin_lock_irqsave(&gpio_lock, flags); | |
1352 | } | |
d2876d08 DB |
1353 | done: |
1354 | if (status) | |
1355 | pr_debug("gpio_request: gpio-%d (%s) status %d\n", | |
1356 | gpio, label ? : "?", status); | |
1357 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1358 | return status; | |
1359 | } | |
1360 | EXPORT_SYMBOL_GPL(gpio_request); | |
1361 | ||
1362 | void gpio_free(unsigned gpio) | |
1363 | { | |
1364 | unsigned long flags; | |
1365 | struct gpio_desc *desc; | |
35e8bb51 | 1366 | struct gpio_chip *chip; |
d2876d08 | 1367 | |
3d599d1c UKK |
1368 | might_sleep(); |
1369 | ||
e6de1808 | 1370 | if (!gpio_is_valid(gpio)) { |
d2876d08 DB |
1371 | WARN_ON(extra_checks); |
1372 | return; | |
1373 | } | |
1374 | ||
d8f388d8 DB |
1375 | gpio_unexport(gpio); |
1376 | ||
d2876d08 DB |
1377 | spin_lock_irqsave(&gpio_lock, flags); |
1378 | ||
1379 | desc = &gpio_desc[gpio]; | |
35e8bb51 DB |
1380 | chip = desc->chip; |
1381 | if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) { | |
1382 | if (chip->free) { | |
1383 | spin_unlock_irqrestore(&gpio_lock, flags); | |
9c4ba946 | 1384 | might_sleep_if(chip->can_sleep); |
35e8bb51 DB |
1385 | chip->free(chip, gpio - chip->base); |
1386 | spin_lock_irqsave(&gpio_lock, flags); | |
1387 | } | |
d2876d08 | 1388 | desc_set_label(desc, NULL); |
438d8908 | 1389 | module_put(desc->chip->owner); |
07697461 | 1390 | clear_bit(FLAG_ACTIVE_LOW, &desc->flags); |
35e8bb51 | 1391 | clear_bit(FLAG_REQUESTED, &desc->flags); |
aca5ce14 | 1392 | clear_bit(FLAG_OPEN_DRAIN, &desc->flags); |
25553ff0 | 1393 | clear_bit(FLAG_OPEN_SOURCE, &desc->flags); |
438d8908 | 1394 | } else |
d2876d08 DB |
1395 | WARN_ON(extra_checks); |
1396 | ||
1397 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1398 | } | |
1399 | EXPORT_SYMBOL_GPL(gpio_free); | |
1400 | ||
3e45f1d1 EM |
1401 | /** |
1402 | * gpio_request_one - request a single GPIO with initial configuration | |
1403 | * @gpio: the GPIO number | |
1404 | * @flags: GPIO configuration as specified by GPIOF_* | |
1405 | * @label: a literal description string of this GPIO | |
1406 | */ | |
1407 | int gpio_request_one(unsigned gpio, unsigned long flags, const char *label) | |
1408 | { | |
1409 | int err; | |
1410 | ||
1411 | err = gpio_request(gpio, label); | |
1412 | if (err) | |
1413 | return err; | |
1414 | ||
aca5ce14 LD |
1415 | if (flags & GPIOF_OPEN_DRAIN) |
1416 | set_bit(FLAG_OPEN_DRAIN, &gpio_desc[gpio].flags); | |
1417 | ||
25553ff0 LD |
1418 | if (flags & GPIOF_OPEN_SOURCE) |
1419 | set_bit(FLAG_OPEN_SOURCE, &gpio_desc[gpio].flags); | |
1420 | ||
3e45f1d1 EM |
1421 | if (flags & GPIOF_DIR_IN) |
1422 | err = gpio_direction_input(gpio); | |
1423 | else | |
1424 | err = gpio_direction_output(gpio, | |
1425 | (flags & GPIOF_INIT_HIGH) ? 1 : 0); | |
1426 | ||
e254811c | 1427 | if (err) |
fc3a1f04 WS |
1428 | goto free_gpio; |
1429 | ||
1430 | if (flags & GPIOF_EXPORT) { | |
1431 | err = gpio_export(gpio, flags & GPIOF_EXPORT_CHANGEABLE); | |
1432 | if (err) | |
1433 | goto free_gpio; | |
1434 | } | |
1435 | ||
1436 | return 0; | |
e254811c | 1437 | |
fc3a1f04 WS |
1438 | free_gpio: |
1439 | gpio_free(gpio); | |
3e45f1d1 EM |
1440 | return err; |
1441 | } | |
1442 | EXPORT_SYMBOL_GPL(gpio_request_one); | |
1443 | ||
1444 | /** | |
1445 | * gpio_request_array - request multiple GPIOs in a single call | |
1446 | * @array: array of the 'struct gpio' | |
1447 | * @num: how many GPIOs in the array | |
1448 | */ | |
7c295975 | 1449 | int gpio_request_array(const struct gpio *array, size_t num) |
3e45f1d1 EM |
1450 | { |
1451 | int i, err; | |
1452 | ||
1453 | for (i = 0; i < num; i++, array++) { | |
1454 | err = gpio_request_one(array->gpio, array->flags, array->label); | |
1455 | if (err) | |
1456 | goto err_free; | |
1457 | } | |
1458 | return 0; | |
1459 | ||
1460 | err_free: | |
1461 | while (i--) | |
1462 | gpio_free((--array)->gpio); | |
1463 | return err; | |
1464 | } | |
1465 | EXPORT_SYMBOL_GPL(gpio_request_array); | |
1466 | ||
1467 | /** | |
1468 | * gpio_free_array - release multiple GPIOs in a single call | |
1469 | * @array: array of the 'struct gpio' | |
1470 | * @num: how many GPIOs in the array | |
1471 | */ | |
7c295975 | 1472 | void gpio_free_array(const struct gpio *array, size_t num) |
3e45f1d1 EM |
1473 | { |
1474 | while (num--) | |
1475 | gpio_free((array++)->gpio); | |
1476 | } | |
1477 | EXPORT_SYMBOL_GPL(gpio_free_array); | |
d2876d08 DB |
1478 | |
1479 | /** | |
1480 | * gpiochip_is_requested - return string iff signal was requested | |
1481 | * @chip: controller managing the signal | |
1482 | * @offset: of signal within controller's 0..(ngpio - 1) range | |
1483 | * | |
1484 | * Returns NULL if the GPIO is not currently requested, else a string. | |
1485 | * If debugfs support is enabled, the string returned is the label passed | |
1486 | * to gpio_request(); otherwise it is a meaningless constant. | |
1487 | * | |
1488 | * This function is for use by GPIO controller drivers. The label can | |
1489 | * help with diagnostics, and knowing that the signal is used as a GPIO | |
1490 | * can help avoid accidentally multiplexing it to another controller. | |
1491 | */ | |
1492 | const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset) | |
1493 | { | |
1494 | unsigned gpio = chip->base + offset; | |
1495 | ||
e6de1808 | 1496 | if (!gpio_is_valid(gpio) || gpio_desc[gpio].chip != chip) |
d2876d08 DB |
1497 | return NULL; |
1498 | if (test_bit(FLAG_REQUESTED, &gpio_desc[gpio].flags) == 0) | |
1499 | return NULL; | |
1500 | #ifdef CONFIG_DEBUG_FS | |
1501 | return gpio_desc[gpio].label; | |
1502 | #else | |
1503 | return "?"; | |
1504 | #endif | |
1505 | } | |
1506 | EXPORT_SYMBOL_GPL(gpiochip_is_requested); | |
1507 | ||
1508 | ||
1509 | /* Drivers MUST set GPIO direction before making get/set calls. In | |
1510 | * some cases this is done in early boot, before IRQs are enabled. | |
1511 | * | |
1512 | * As a rule these aren't called more than once (except for drivers | |
1513 | * using the open-drain emulation idiom) so these are natural places | |
1514 | * to accumulate extra debugging checks. Note that we can't (yet) | |
1515 | * rely on gpio_request() having been called beforehand. | |
1516 | */ | |
1517 | ||
1518 | int gpio_direction_input(unsigned gpio) | |
1519 | { | |
1520 | unsigned long flags; | |
1521 | struct gpio_chip *chip; | |
1522 | struct gpio_desc *desc = &gpio_desc[gpio]; | |
1523 | int status = -EINVAL; | |
1524 | ||
1525 | spin_lock_irqsave(&gpio_lock, flags); | |
1526 | ||
e6de1808 | 1527 | if (!gpio_is_valid(gpio)) |
d2876d08 DB |
1528 | goto fail; |
1529 | chip = desc->chip; | |
1530 | if (!chip || !chip->get || !chip->direction_input) | |
1531 | goto fail; | |
1532 | gpio -= chip->base; | |
1533 | if (gpio >= chip->ngpio) | |
1534 | goto fail; | |
35e8bb51 DB |
1535 | status = gpio_ensure_requested(desc, gpio); |
1536 | if (status < 0) | |
1537 | goto fail; | |
d2876d08 DB |
1538 | |
1539 | /* now we know the gpio is valid and chip won't vanish */ | |
1540 | ||
1541 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1542 | ||
9c4ba946 | 1543 | might_sleep_if(chip->can_sleep); |
d2876d08 | 1544 | |
35e8bb51 DB |
1545 | if (status) { |
1546 | status = chip->request(chip, gpio); | |
1547 | if (status < 0) { | |
1548 | pr_debug("GPIO-%d: chip request fail, %d\n", | |
1549 | chip->base + gpio, status); | |
1550 | /* and it's not available to anyone else ... | |
1551 | * gpio_request() is the fully clean solution. | |
1552 | */ | |
1553 | goto lose; | |
1554 | } | |
1555 | } | |
1556 | ||
d2876d08 DB |
1557 | status = chip->direction_input(chip, gpio); |
1558 | if (status == 0) | |
1559 | clear_bit(FLAG_IS_OUT, &desc->flags); | |
3f397c21 UKK |
1560 | |
1561 | trace_gpio_direction(chip->base + gpio, 1, status); | |
35e8bb51 | 1562 | lose: |
d2876d08 DB |
1563 | return status; |
1564 | fail: | |
1565 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1566 | if (status) | |
1567 | pr_debug("%s: gpio-%d status %d\n", | |
145980a0 | 1568 | __func__, gpio, status); |
d2876d08 DB |
1569 | return status; |
1570 | } | |
1571 | EXPORT_SYMBOL_GPL(gpio_direction_input); | |
1572 | ||
1573 | int gpio_direction_output(unsigned gpio, int value) | |
1574 | { | |
1575 | unsigned long flags; | |
1576 | struct gpio_chip *chip; | |
1577 | struct gpio_desc *desc = &gpio_desc[gpio]; | |
1578 | int status = -EINVAL; | |
1579 | ||
aca5ce14 LD |
1580 | /* Open drain pin should not be driven to 1 */ |
1581 | if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags)) | |
1582 | return gpio_direction_input(gpio); | |
1583 | ||
25553ff0 LD |
1584 | /* Open source pin should not be driven to 0 */ |
1585 | if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags)) | |
1586 | return gpio_direction_input(gpio); | |
1587 | ||
d2876d08 DB |
1588 | spin_lock_irqsave(&gpio_lock, flags); |
1589 | ||
e6de1808 | 1590 | if (!gpio_is_valid(gpio)) |
d2876d08 DB |
1591 | goto fail; |
1592 | chip = desc->chip; | |
1593 | if (!chip || !chip->set || !chip->direction_output) | |
1594 | goto fail; | |
1595 | gpio -= chip->base; | |
1596 | if (gpio >= chip->ngpio) | |
1597 | goto fail; | |
35e8bb51 DB |
1598 | status = gpio_ensure_requested(desc, gpio); |
1599 | if (status < 0) | |
1600 | goto fail; | |
d2876d08 DB |
1601 | |
1602 | /* now we know the gpio is valid and chip won't vanish */ | |
1603 | ||
1604 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1605 | ||
9c4ba946 | 1606 | might_sleep_if(chip->can_sleep); |
d2876d08 | 1607 | |
35e8bb51 DB |
1608 | if (status) { |
1609 | status = chip->request(chip, gpio); | |
1610 | if (status < 0) { | |
1611 | pr_debug("GPIO-%d: chip request fail, %d\n", | |
1612 | chip->base + gpio, status); | |
1613 | /* and it's not available to anyone else ... | |
1614 | * gpio_request() is the fully clean solution. | |
1615 | */ | |
1616 | goto lose; | |
1617 | } | |
1618 | } | |
1619 | ||
d2876d08 DB |
1620 | status = chip->direction_output(chip, gpio, value); |
1621 | if (status == 0) | |
1622 | set_bit(FLAG_IS_OUT, &desc->flags); | |
3f397c21 UKK |
1623 | trace_gpio_value(chip->base + gpio, 0, value); |
1624 | trace_gpio_direction(chip->base + gpio, 0, status); | |
35e8bb51 | 1625 | lose: |
d2876d08 DB |
1626 | return status; |
1627 | fail: | |
1628 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1629 | if (status) | |
1630 | pr_debug("%s: gpio-%d status %d\n", | |
145980a0 | 1631 | __func__, gpio, status); |
d2876d08 DB |
1632 | return status; |
1633 | } | |
1634 | EXPORT_SYMBOL_GPL(gpio_direction_output); | |
1635 | ||
c4b5be98 FB |
1636 | /** |
1637 | * gpio_set_debounce - sets @debounce time for a @gpio | |
1638 | * @gpio: the gpio to set debounce time | |
1639 | * @debounce: debounce time is microseconds | |
1640 | */ | |
1641 | int gpio_set_debounce(unsigned gpio, unsigned debounce) | |
1642 | { | |
1643 | unsigned long flags; | |
1644 | struct gpio_chip *chip; | |
1645 | struct gpio_desc *desc = &gpio_desc[gpio]; | |
1646 | int status = -EINVAL; | |
1647 | ||
1648 | spin_lock_irqsave(&gpio_lock, flags); | |
1649 | ||
1650 | if (!gpio_is_valid(gpio)) | |
1651 | goto fail; | |
1652 | chip = desc->chip; | |
1653 | if (!chip || !chip->set || !chip->set_debounce) | |
1654 | goto fail; | |
1655 | gpio -= chip->base; | |
1656 | if (gpio >= chip->ngpio) | |
1657 | goto fail; | |
1658 | status = gpio_ensure_requested(desc, gpio); | |
1659 | if (status < 0) | |
1660 | goto fail; | |
1661 | ||
1662 | /* now we know the gpio is valid and chip won't vanish */ | |
1663 | ||
1664 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1665 | ||
9c4ba946 | 1666 | might_sleep_if(chip->can_sleep); |
c4b5be98 FB |
1667 | |
1668 | return chip->set_debounce(chip, gpio, debounce); | |
1669 | ||
1670 | fail: | |
1671 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1672 | if (status) | |
1673 | pr_debug("%s: gpio-%d status %d\n", | |
1674 | __func__, gpio, status); | |
1675 | ||
1676 | return status; | |
1677 | } | |
1678 | EXPORT_SYMBOL_GPL(gpio_set_debounce); | |
d2876d08 DB |
1679 | |
1680 | /* I/O calls are only valid after configuration completed; the relevant | |
1681 | * "is this a valid GPIO" error checks should already have been done. | |
1682 | * | |
1683 | * "Get" operations are often inlinable as reading a pin value register, | |
1684 | * and masking the relevant bit in that register. | |
1685 | * | |
1686 | * When "set" operations are inlinable, they involve writing that mask to | |
1687 | * one register to set a low value, or a different register to set it high. | |
1688 | * Otherwise locking is needed, so there may be little value to inlining. | |
1689 | * | |
1690 | *------------------------------------------------------------------------ | |
1691 | * | |
1692 | * IMPORTANT!!! The hot paths -- get/set value -- assume that callers | |
1693 | * have requested the GPIO. That can include implicit requesting by | |
1694 | * a direction setting call. Marking a gpio as requested locks its chip | |
1695 | * in memory, guaranteeing that these table lookups need no more locking | |
1696 | * and that gpiochip_remove() will fail. | |
1697 | * | |
1698 | * REVISIT when debugging, consider adding some instrumentation to ensure | |
1699 | * that the GPIO was actually requested. | |
1700 | */ | |
1701 | ||
1702 | /** | |
1703 | * __gpio_get_value() - return a gpio's value | |
1704 | * @gpio: gpio whose value will be returned | |
1705 | * Context: any | |
1706 | * | |
1707 | * This is used directly or indirectly to implement gpio_get_value(). | |
1708 | * It returns the zero or nonzero value provided by the associated | |
1709 | * gpio_chip.get() method; or zero if no such method is provided. | |
1710 | */ | |
1711 | int __gpio_get_value(unsigned gpio) | |
1712 | { | |
1713 | struct gpio_chip *chip; | |
3f397c21 | 1714 | int value; |
d2876d08 DB |
1715 | |
1716 | chip = gpio_to_chip(gpio); | |
e4e449e8 | 1717 | /* Should be using gpio_get_value_cansleep() */ |
9c4ba946 | 1718 | WARN_ON(chip->can_sleep); |
3f397c21 UKK |
1719 | value = chip->get ? chip->get(chip, gpio - chip->base) : 0; |
1720 | trace_gpio_value(gpio, 1, value); | |
1721 | return value; | |
d2876d08 DB |
1722 | } |
1723 | EXPORT_SYMBOL_GPL(__gpio_get_value); | |
1724 | ||
aca5ce14 LD |
1725 | /* |
1726 | * _gpio_set_open_drain_value() - Set the open drain gpio's value. | |
1727 | * @gpio: Gpio whose state need to be set. | |
1728 | * @chip: Gpio chip. | |
1729 | * @value: Non-zero for setting it HIGH otherise it will set to LOW. | |
1730 | */ | |
1731 | static void _gpio_set_open_drain_value(unsigned gpio, | |
1732 | struct gpio_chip *chip, int value) | |
1733 | { | |
1734 | int err = 0; | |
1735 | if (value) { | |
1736 | err = chip->direction_input(chip, gpio - chip->base); | |
1737 | if (!err) | |
1738 | clear_bit(FLAG_IS_OUT, &gpio_desc[gpio].flags); | |
1739 | } else { | |
1740 | err = chip->direction_output(chip, gpio - chip->base, 0); | |
1741 | if (!err) | |
1742 | set_bit(FLAG_IS_OUT, &gpio_desc[gpio].flags); | |
1743 | } | |
1744 | trace_gpio_direction(gpio, value, err); | |
1745 | if (err < 0) | |
1746 | pr_err("%s: Error in set_value for open drain gpio%d err %d\n", | |
1747 | __func__, gpio, err); | |
1748 | } | |
1749 | ||
25553ff0 LD |
1750 | /* |
1751 | * _gpio_set_open_source() - Set the open source gpio's value. | |
1752 | * @gpio: Gpio whose state need to be set. | |
1753 | * @chip: Gpio chip. | |
1754 | * @value: Non-zero for setting it HIGH otherise it will set to LOW. | |
1755 | */ | |
1756 | static void _gpio_set_open_source_value(unsigned gpio, | |
1757 | struct gpio_chip *chip, int value) | |
1758 | { | |
1759 | int err = 0; | |
1760 | if (value) { | |
1761 | err = chip->direction_output(chip, gpio - chip->base, 1); | |
1762 | if (!err) | |
1763 | set_bit(FLAG_IS_OUT, &gpio_desc[gpio].flags); | |
1764 | } else { | |
1765 | err = chip->direction_input(chip, gpio - chip->base); | |
1766 | if (!err) | |
1767 | clear_bit(FLAG_IS_OUT, &gpio_desc[gpio].flags); | |
1768 | } | |
1769 | trace_gpio_direction(gpio, !value, err); | |
1770 | if (err < 0) | |
1771 | pr_err("%s: Error in set_value for open source gpio%d err %d\n", | |
1772 | __func__, gpio, err); | |
1773 | } | |
1774 | ||
1775 | ||
d2876d08 DB |
1776 | /** |
1777 | * __gpio_set_value() - assign a gpio's value | |
1778 | * @gpio: gpio whose value will be assigned | |
1779 | * @value: value to assign | |
1780 | * Context: any | |
1781 | * | |
1782 | * This is used directly or indirectly to implement gpio_set_value(). | |
1783 | * It invokes the associated gpio_chip.set() method. | |
1784 | */ | |
1785 | void __gpio_set_value(unsigned gpio, int value) | |
1786 | { | |
1787 | struct gpio_chip *chip; | |
1788 | ||
1789 | chip = gpio_to_chip(gpio); | |
e4e449e8 | 1790 | /* Should be using gpio_set_value_cansleep() */ |
9c4ba946 | 1791 | WARN_ON(chip->can_sleep); |
3f397c21 | 1792 | trace_gpio_value(gpio, 0, value); |
aca5ce14 LD |
1793 | if (test_bit(FLAG_OPEN_DRAIN, &gpio_desc[gpio].flags)) |
1794 | _gpio_set_open_drain_value(gpio, chip, value); | |
25553ff0 LD |
1795 | else if (test_bit(FLAG_OPEN_SOURCE, &gpio_desc[gpio].flags)) |
1796 | _gpio_set_open_source_value(gpio, chip, value); | |
aca5ce14 LD |
1797 | else |
1798 | chip->set(chip, gpio - chip->base, value); | |
d2876d08 DB |
1799 | } |
1800 | EXPORT_SYMBOL_GPL(__gpio_set_value); | |
1801 | ||
1802 | /** | |
1803 | * __gpio_cansleep() - report whether gpio value access will sleep | |
1804 | * @gpio: gpio in question | |
1805 | * Context: any | |
1806 | * | |
1807 | * This is used directly or indirectly to implement gpio_cansleep(). It | |
1808 | * returns nonzero if access reading or writing the GPIO value can sleep. | |
1809 | */ | |
1810 | int __gpio_cansleep(unsigned gpio) | |
1811 | { | |
1812 | struct gpio_chip *chip; | |
1813 | ||
1814 | /* only call this on GPIOs that are valid! */ | |
1815 | chip = gpio_to_chip(gpio); | |
1816 | ||
1817 | return chip->can_sleep; | |
1818 | } | |
1819 | EXPORT_SYMBOL_GPL(__gpio_cansleep); | |
1820 | ||
0f6d504e DB |
1821 | /** |
1822 | * __gpio_to_irq() - return the IRQ corresponding to a GPIO | |
1823 | * @gpio: gpio whose IRQ will be returned (already requested) | |
1824 | * Context: any | |
1825 | * | |
1826 | * This is used directly or indirectly to implement gpio_to_irq(). | |
1827 | * It returns the number of the IRQ signaled by this (input) GPIO, | |
1828 | * or a negative errno. | |
1829 | */ | |
1830 | int __gpio_to_irq(unsigned gpio) | |
1831 | { | |
1832 | struct gpio_chip *chip; | |
1833 | ||
1834 | chip = gpio_to_chip(gpio); | |
1835 | return chip->to_irq ? chip->to_irq(chip, gpio - chip->base) : -ENXIO; | |
1836 | } | |
1837 | EXPORT_SYMBOL_GPL(__gpio_to_irq); | |
1838 | ||
d2876d08 DB |
1839 | |
1840 | ||
1841 | /* There's no value in making it easy to inline GPIO calls that may sleep. | |
1842 | * Common examples include ones connected to I2C or SPI chips. | |
1843 | */ | |
1844 | ||
1845 | int gpio_get_value_cansleep(unsigned gpio) | |
1846 | { | |
1847 | struct gpio_chip *chip; | |
3f397c21 | 1848 | int value; |
d2876d08 DB |
1849 | |
1850 | might_sleep_if(extra_checks); | |
1851 | chip = gpio_to_chip(gpio); | |
3f397c21 UKK |
1852 | value = chip->get ? chip->get(chip, gpio - chip->base) : 0; |
1853 | trace_gpio_value(gpio, 1, value); | |
1854 | return value; | |
d2876d08 DB |
1855 | } |
1856 | EXPORT_SYMBOL_GPL(gpio_get_value_cansleep); | |
1857 | ||
1858 | void gpio_set_value_cansleep(unsigned gpio, int value) | |
1859 | { | |
1860 | struct gpio_chip *chip; | |
1861 | ||
1862 | might_sleep_if(extra_checks); | |
1863 | chip = gpio_to_chip(gpio); | |
3f397c21 | 1864 | trace_gpio_value(gpio, 0, value); |
aca5ce14 LD |
1865 | if (test_bit(FLAG_OPEN_DRAIN, &gpio_desc[gpio].flags)) |
1866 | _gpio_set_open_drain_value(gpio, chip, value); | |
25553ff0 LD |
1867 | else if (test_bit(FLAG_OPEN_SOURCE, &gpio_desc[gpio].flags)) |
1868 | _gpio_set_open_source_value(gpio, chip, value); | |
aca5ce14 LD |
1869 | else |
1870 | chip->set(chip, gpio - chip->base, value); | |
d2876d08 DB |
1871 | } |
1872 | EXPORT_SYMBOL_GPL(gpio_set_value_cansleep); | |
1873 | ||
1874 | ||
1875 | #ifdef CONFIG_DEBUG_FS | |
1876 | ||
d2876d08 DB |
1877 | static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) |
1878 | { | |
1879 | unsigned i; | |
1880 | unsigned gpio = chip->base; | |
1881 | struct gpio_desc *gdesc = &gpio_desc[gpio]; | |
1882 | int is_out; | |
1883 | ||
1884 | for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) { | |
1885 | if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) | |
1886 | continue; | |
1887 | ||
80b0a602 | 1888 | gpio_get_direction(gpio); |
d2876d08 | 1889 | is_out = test_bit(FLAG_IS_OUT, &gdesc->flags); |
6e8ba729 | 1890 | seq_printf(s, " gpio-%-3d (%-20.20s) %s %s", |
d2876d08 DB |
1891 | gpio, gdesc->label, |
1892 | is_out ? "out" : "in ", | |
1893 | chip->get | |
1894 | ? (chip->get(chip, i) ? "hi" : "lo") | |
1895 | : "? "); | |
d2876d08 DB |
1896 | seq_printf(s, "\n"); |
1897 | } | |
1898 | } | |
1899 | ||
f9c4a31f | 1900 | static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos) |
d2876d08 | 1901 | { |
f9c4a31f TR |
1902 | struct gpio_chip *chip = NULL; |
1903 | unsigned int gpio; | |
1904 | void *ret = NULL; | |
1905 | loff_t index = 0; | |
d2876d08 DB |
1906 | |
1907 | /* REVISIT this isn't locked against gpio_chip removal ... */ | |
1908 | ||
e6de1808 | 1909 | for (gpio = 0; gpio_is_valid(gpio); gpio++) { |
f9c4a31f | 1910 | if (gpio_desc[gpio].chip == chip) |
d2876d08 | 1911 | continue; |
f9c4a31f | 1912 | |
d2876d08 DB |
1913 | chip = gpio_desc[gpio].chip; |
1914 | if (!chip) | |
1915 | continue; | |
1916 | ||
f9c4a31f TR |
1917 | if (index++ >= *pos) { |
1918 | ret = chip; | |
1919 | break; | |
1920 | } | |
d2876d08 | 1921 | } |
f9c4a31f TR |
1922 | |
1923 | s->private = ""; | |
1924 | ||
1925 | return ret; | |
1926 | } | |
1927 | ||
1928 | static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
1929 | { | |
1930 | struct gpio_chip *chip = v; | |
1931 | unsigned int gpio; | |
1932 | void *ret = NULL; | |
1933 | ||
1934 | /* skip GPIOs provided by the current chip */ | |
1935 | for (gpio = chip->base + chip->ngpio; gpio_is_valid(gpio); gpio++) { | |
1936 | chip = gpio_desc[gpio].chip; | |
1937 | if (chip) { | |
1938 | ret = chip; | |
1939 | break; | |
1940 | } | |
1941 | } | |
1942 | ||
1943 | s->private = "\n"; | |
1944 | ++*pos; | |
1945 | ||
1946 | return ret; | |
1947 | } | |
1948 | ||
1949 | static void gpiolib_seq_stop(struct seq_file *s, void *v) | |
1950 | { | |
1951 | } | |
1952 | ||
1953 | static int gpiolib_seq_show(struct seq_file *s, void *v) | |
1954 | { | |
1955 | struct gpio_chip *chip = v; | |
1956 | struct device *dev; | |
1957 | ||
1958 | seq_printf(s, "%sGPIOs %d-%d", (char *)s->private, | |
1959 | chip->base, chip->base + chip->ngpio - 1); | |
1960 | dev = chip->dev; | |
1961 | if (dev) | |
1962 | seq_printf(s, ", %s/%s", dev->bus ? dev->bus->name : "no-bus", | |
1963 | dev_name(dev)); | |
1964 | if (chip->label) | |
1965 | seq_printf(s, ", %s", chip->label); | |
1966 | if (chip->can_sleep) | |
1967 | seq_printf(s, ", can sleep"); | |
1968 | seq_printf(s, ":\n"); | |
1969 | ||
1970 | if (chip->dbg_show) | |
1971 | chip->dbg_show(s, chip); | |
1972 | else | |
1973 | gpiolib_dbg_show(s, chip); | |
1974 | ||
d2876d08 DB |
1975 | return 0; |
1976 | } | |
1977 | ||
f9c4a31f TR |
1978 | static const struct seq_operations gpiolib_seq_ops = { |
1979 | .start = gpiolib_seq_start, | |
1980 | .next = gpiolib_seq_next, | |
1981 | .stop = gpiolib_seq_stop, | |
1982 | .show = gpiolib_seq_show, | |
1983 | }; | |
1984 | ||
d2876d08 DB |
1985 | static int gpiolib_open(struct inode *inode, struct file *file) |
1986 | { | |
f9c4a31f | 1987 | return seq_open(file, &gpiolib_seq_ops); |
d2876d08 DB |
1988 | } |
1989 | ||
828c0950 | 1990 | static const struct file_operations gpiolib_operations = { |
f9c4a31f | 1991 | .owner = THIS_MODULE, |
d2876d08 DB |
1992 | .open = gpiolib_open, |
1993 | .read = seq_read, | |
1994 | .llseek = seq_lseek, | |
f9c4a31f | 1995 | .release = seq_release, |
d2876d08 DB |
1996 | }; |
1997 | ||
1998 | static int __init gpiolib_debugfs_init(void) | |
1999 | { | |
2000 | /* /sys/kernel/debug/gpio */ | |
2001 | (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO, | |
2002 | NULL, NULL, &gpiolib_operations); | |
2003 | return 0; | |
2004 | } | |
2005 | subsys_initcall(gpiolib_debugfs_init); | |
2006 | ||
2007 | #endif /* DEBUG_FS */ |