Commit | Line | Data |
---|---|---|
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> | |
1a989d0f | 6 | #include <linux/list.h> |
d8f388d8 DB |
7 | #include <linux/device.h> |
8 | #include <linux/err.h> | |
9 | #include <linux/debugfs.h> | |
10 | #include <linux/seq_file.h> | |
11 | #include <linux/gpio.h> | |
391c970c | 12 | #include <linux/of_gpio.h> |
ff77c352 | 13 | #include <linux/idr.h> |
5a0e3ad6 | 14 | #include <linux/slab.h> |
d2876d08 | 15 | |
3f397c21 UKK |
16 | #define CREATE_TRACE_POINTS |
17 | #include <trace/events/gpio.h> | |
d2876d08 DB |
18 | |
19 | /* Optional implementation infrastructure for GPIO interfaces. | |
20 | * | |
21 | * Platforms may want to use this if they tend to use very many GPIOs | |
22 | * that aren't part of a System-On-Chip core; or across I2C/SPI/etc. | |
23 | * | |
24 | * When kernel footprint or instruction count is an issue, simpler | |
25 | * implementations may be preferred. The GPIO programming interface | |
26 | * allows for inlining speed-critical get/set operations for common | |
27 | * cases, so that access to SOC-integrated GPIOs can sometimes cost | |
28 | * only an instruction or two per bit. | |
29 | */ | |
30 | ||
31 | ||
32 | /* When debugging, extend minimal trust to callers and platform code. | |
33 | * Also emit diagnostic messages that may help initial bringup, when | |
34 | * board setup or driver bugs are most common. | |
35 | * | |
36 | * Otherwise, minimize overhead in what may be bitbanging codepaths. | |
37 | */ | |
38 | #ifdef DEBUG | |
39 | #define extra_checks 1 | |
40 | #else | |
41 | #define extra_checks 0 | |
42 | #endif | |
43 | ||
44 | /* gpio_lock prevents conflicts during gpio_desc[] table updates. | |
45 | * While any GPIO is requested, its gpio_chip is not removable; | |
46 | * each GPIO's "requested" flag serves as a lock and refcount. | |
47 | */ | |
48 | static DEFINE_SPINLOCK(gpio_lock); | |
49 | ||
50 | struct gpio_desc { | |
51 | struct gpio_chip *chip; | |
52 | unsigned long flags; | |
53 | /* flag symbols are bit numbers */ | |
54 | #define FLAG_REQUESTED 0 | |
55 | #define FLAG_IS_OUT 1 | |
710b40ea AC |
56 | #define FLAG_EXPORT 2 /* protected by sysfs_lock */ |
57 | #define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */ | |
58 | #define FLAG_TRIG_FALL 4 /* trigger on falling edge */ | |
59 | #define FLAG_TRIG_RISE 5 /* trigger on rising edge */ | |
60 | #define FLAG_ACTIVE_LOW 6 /* sysfs value has active low */ | |
61 | #define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */ | |
62 | #define FLAG_OPEN_SOURCE 8 /* 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 | ||
6c0b4e6c AC |
75 | #define GPIO_OFFSET_VALID(chip, offset) (offset >= 0 && offset < chip->ngpio) |
76 | ||
1a989d0f AC |
77 | static LIST_HEAD(gpio_chips); |
78 | ||
ff77c352 | 79 | #ifdef CONFIG_GPIO_SYSFS |
5ba1821d | 80 | static DEFINE_IDR(dirent_idr); |
ff77c352 DG |
81 | #endif |
82 | ||
372e722e AC |
83 | /* |
84 | * Internal gpiod_* API using descriptors instead of the integer namespace. | |
85 | * Most of this should eventually go public. | |
86 | */ | |
87 | static int gpiod_request(struct gpio_desc *desc, const char *label); | |
88 | static void gpiod_free(struct gpio_desc *desc); | |
89 | static int gpiod_direction_input(struct gpio_desc *desc); | |
90 | static int gpiod_direction_output(struct gpio_desc *desc, int value); | |
91 | static int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce); | |
92 | static int gpiod_get_value_cansleep(struct gpio_desc *desc); | |
93 | static void gpiod_set_value_cansleep(struct gpio_desc *desc, int value); | |
94 | static int gpiod_get_value(struct gpio_desc *desc); | |
95 | static void gpiod_set_value(struct gpio_desc *desc, int value); | |
96 | static int gpiod_cansleep(struct gpio_desc *desc); | |
97 | static int gpiod_to_irq(struct gpio_desc *desc); | |
98 | static int gpiod_export(struct gpio_desc *desc, bool direction_may_change); | |
99 | static int gpiod_export_link(struct device *dev, const char *name, | |
100 | struct gpio_desc *desc); | |
101 | static int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value); | |
102 | static void gpiod_unexport(struct gpio_desc *desc); | |
103 | ||
104 | ||
d2876d08 DB |
105 | static inline void desc_set_label(struct gpio_desc *d, const char *label) |
106 | { | |
107 | #ifdef CONFIG_DEBUG_FS | |
108 | d->label = label; | |
109 | #endif | |
110 | } | |
111 | ||
372e722e AC |
112 | /* |
113 | * Return the GPIO number of the passed descriptor relative to its chip | |
114 | */ | |
115 | static int gpio_chip_hwgpio(const struct gpio_desc *desc) | |
116 | { | |
6c0b4e6c | 117 | return desc - &desc->chip->desc[0]; |
372e722e AC |
118 | } |
119 | ||
120 | /** | |
121 | * Convert a GPIO number to its descriptor | |
122 | */ | |
123 | static struct gpio_desc *gpio_to_desc(unsigned gpio) | |
124 | { | |
125 | if (WARN(!gpio_is_valid(gpio), "invalid GPIO %d\n", gpio)) | |
126 | return NULL; | |
127 | else | |
128 | return &gpio_desc[gpio]; | |
129 | } | |
130 | ||
131 | /** | |
132 | * Convert a GPIO descriptor to the integer namespace. | |
133 | * This should disappear in the future but is needed since we still | |
134 | * use GPIO numbers for error messages and sysfs nodes | |
135 | */ | |
136 | static int desc_to_gpio(const struct gpio_desc *desc) | |
137 | { | |
6c0b4e6c | 138 | return desc->chip->base + gpio_chip_hwgpio(desc); |
372e722e AC |
139 | } |
140 | ||
141 | ||
d2876d08 DB |
142 | /* Warn when drivers omit gpio_request() calls -- legal but ill-advised |
143 | * when setting direction, and otherwise illegal. Until board setup code | |
144 | * and drivers use explicit requests everywhere (which won't happen when | |
145 | * those calls have no teeth) we can't avoid autorequesting. This nag | |
35e8bb51 DB |
146 | * message should motivate switching to explicit requests... so should |
147 | * the weaker cleanup after faults, compared to gpio_request(). | |
8a0cecff DB |
148 | * |
149 | * NOTE: the autorequest mechanism is going away; at this point it's | |
150 | * only "legal" in the sense that (old) code using it won't break yet, | |
151 | * but instead only triggers a WARN() stack dump. | |
d2876d08 | 152 | */ |
372e722e | 153 | static int gpio_ensure_requested(struct gpio_desc *desc) |
d2876d08 | 154 | { |
8a0cecff | 155 | const struct gpio_chip *chip = desc->chip; |
372e722e | 156 | const int gpio = desc_to_gpio(desc); |
35e8bb51 | 157 | |
8a0cecff DB |
158 | if (WARN(test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0, |
159 | "autorequest GPIO-%d\n", gpio)) { | |
35e8bb51 DB |
160 | if (!try_module_get(chip->owner)) { |
161 | pr_err("GPIO-%d: module can't be gotten \n", gpio); | |
162 | clear_bit(FLAG_REQUESTED, &desc->flags); | |
163 | /* lose */ | |
164 | return -EIO; | |
165 | } | |
d2876d08 | 166 | desc_set_label(desc, "[auto]"); |
35e8bb51 DB |
167 | /* caller must chip->request() w/o spinlock */ |
168 | if (chip->request) | |
169 | return 1; | |
d2876d08 | 170 | } |
35e8bb51 | 171 | return 0; |
d2876d08 DB |
172 | } |
173 | ||
174 | /* caller holds gpio_lock *OR* gpio is marked as requested */ | |
372e722e AC |
175 | static struct gpio_chip *gpiod_to_chip(struct gpio_desc *desc) |
176 | { | |
177 | return desc->chip; | |
178 | } | |
179 | ||
1a2d397a | 180 | struct gpio_chip *gpio_to_chip(unsigned gpio) |
d2876d08 | 181 | { |
372e722e | 182 | return gpiod_to_chip(gpio_to_desc(gpio)); |
d2876d08 DB |
183 | } |
184 | ||
8d0aab2f AV |
185 | /* dynamic allocation of GPIOs, e.g. on a hotplugged device */ |
186 | static int gpiochip_find_base(int ngpio) | |
187 | { | |
83cabe33 AC |
188 | struct gpio_chip *chip; |
189 | int base = ARCH_NR_GPIOS - ngpio; | |
8d0aab2f | 190 | |
83cabe33 AC |
191 | list_for_each_entry_reverse(chip, &gpio_chips, list) { |
192 | /* found a free space? */ | |
193 | if (chip->base + chip->ngpio <= base) | |
194 | break; | |
195 | else | |
196 | /* nope, check the space right before the chip */ | |
197 | base = chip->base - ngpio; | |
8d0aab2f AV |
198 | } |
199 | ||
83cabe33 | 200 | if (gpio_is_valid(base)) { |
8d0aab2f | 201 | pr_debug("%s: found new base at %d\n", __func__, base); |
83cabe33 AC |
202 | return base; |
203 | } else { | |
204 | pr_err("%s: cannot find free range\n", __func__); | |
205 | return -ENOSPC; | |
169b6a7a | 206 | } |
169b6a7a AV |
207 | } |
208 | ||
80b0a602 | 209 | /* caller ensures gpio is valid and requested, chip->get_direction may sleep */ |
372e722e | 210 | static int gpiod_get_direction(struct gpio_desc *desc) |
80b0a602 MN |
211 | { |
212 | struct gpio_chip *chip; | |
372e722e | 213 | unsigned offset; |
80b0a602 MN |
214 | int status = -EINVAL; |
215 | ||
372e722e AC |
216 | chip = gpiod_to_chip(desc); |
217 | offset = gpio_chip_hwgpio(desc); | |
80b0a602 MN |
218 | |
219 | if (!chip->get_direction) | |
220 | return status; | |
221 | ||
372e722e | 222 | status = chip->get_direction(chip, offset); |
80b0a602 MN |
223 | if (status > 0) { |
224 | /* GPIOF_DIR_IN, or other positive */ | |
225 | status = 1; | |
226 | clear_bit(FLAG_IS_OUT, &desc->flags); | |
227 | } | |
228 | if (status == 0) { | |
229 | /* GPIOF_DIR_OUT */ | |
230 | set_bit(FLAG_IS_OUT, &desc->flags); | |
231 | } | |
232 | return status; | |
233 | } | |
234 | ||
d8f388d8 DB |
235 | #ifdef CONFIG_GPIO_SYSFS |
236 | ||
237 | /* lock protects against unexport_gpio() being called while | |
238 | * sysfs files are active. | |
239 | */ | |
240 | static DEFINE_MUTEX(sysfs_lock); | |
241 | ||
242 | /* | |
243 | * /sys/class/gpio/gpioN... only for GPIOs that are exported | |
244 | * /direction | |
245 | * * MAY BE OMITTED if kernel won't allow direction changes | |
246 | * * is read/write as "in" or "out" | |
247 | * * may also be written as "high" or "low", initializing | |
248 | * output value as specified ("out" implies "low") | |
249 | * /value | |
250 | * * always readable, subject to hardware behavior | |
251 | * * may be writable, as zero/nonzero | |
ff77c352 DG |
252 | * /edge |
253 | * * configures behavior of poll(2) on /value | |
254 | * * available only if pin can generate IRQs on input | |
255 | * * is read/write as "none", "falling", "rising", or "both" | |
07697461 JN |
256 | * /active_low |
257 | * * configures polarity of /value | |
258 | * * is read/write as zero/nonzero | |
259 | * * also affects existing and subsequent "falling" and "rising" | |
260 | * /edge configuration | |
d8f388d8 DB |
261 | */ |
262 | ||
263 | static ssize_t gpio_direction_show(struct device *dev, | |
264 | struct device_attribute *attr, char *buf) | |
265 | { | |
372e722e | 266 | struct gpio_desc *desc = dev_get_drvdata(dev); |
d8f388d8 DB |
267 | ssize_t status; |
268 | ||
269 | mutex_lock(&sysfs_lock); | |
270 | ||
476171ce | 271 | if (!test_bit(FLAG_EXPORT, &desc->flags)) { |
d8f388d8 | 272 | status = -EIO; |
476171ce | 273 | } else { |
372e722e | 274 | gpiod_get_direction(desc); |
d8f388d8 DB |
275 | status = sprintf(buf, "%s\n", |
276 | test_bit(FLAG_IS_OUT, &desc->flags) | |
277 | ? "out" : "in"); | |
476171ce | 278 | } |
d8f388d8 DB |
279 | |
280 | mutex_unlock(&sysfs_lock); | |
281 | return status; | |
282 | } | |
283 | ||
284 | static ssize_t gpio_direction_store(struct device *dev, | |
285 | struct device_attribute *attr, const char *buf, size_t size) | |
286 | { | |
372e722e | 287 | struct gpio_desc *desc = dev_get_drvdata(dev); |
d8f388d8 DB |
288 | ssize_t status; |
289 | ||
290 | mutex_lock(&sysfs_lock); | |
291 | ||
292 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
293 | status = -EIO; | |
294 | else if (sysfs_streq(buf, "high")) | |
372e722e | 295 | status = gpiod_direction_output(desc, 1); |
d8f388d8 | 296 | else if (sysfs_streq(buf, "out") || sysfs_streq(buf, "low")) |
372e722e | 297 | status = gpiod_direction_output(desc, 0); |
d8f388d8 | 298 | else if (sysfs_streq(buf, "in")) |
372e722e | 299 | status = gpiod_direction_input(desc); |
d8f388d8 DB |
300 | else |
301 | status = -EINVAL; | |
302 | ||
303 | mutex_unlock(&sysfs_lock); | |
304 | return status ? : size; | |
305 | } | |
306 | ||
07697461 | 307 | static /* const */ DEVICE_ATTR(direction, 0644, |
d8f388d8 DB |
308 | gpio_direction_show, gpio_direction_store); |
309 | ||
310 | static ssize_t gpio_value_show(struct device *dev, | |
311 | struct device_attribute *attr, char *buf) | |
312 | { | |
372e722e | 313 | struct gpio_desc *desc = dev_get_drvdata(dev); |
d8f388d8 DB |
314 | ssize_t status; |
315 | ||
316 | mutex_lock(&sysfs_lock); | |
317 | ||
07697461 | 318 | if (!test_bit(FLAG_EXPORT, &desc->flags)) { |
d8f388d8 | 319 | status = -EIO; |
07697461 JN |
320 | } else { |
321 | int value; | |
322 | ||
372e722e | 323 | value = !!gpiod_get_value_cansleep(desc); |
07697461 JN |
324 | if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) |
325 | value = !value; | |
326 | ||
327 | status = sprintf(buf, "%d\n", value); | |
328 | } | |
d8f388d8 DB |
329 | |
330 | mutex_unlock(&sysfs_lock); | |
331 | return status; | |
332 | } | |
333 | ||
334 | static ssize_t gpio_value_store(struct device *dev, | |
335 | struct device_attribute *attr, const char *buf, size_t size) | |
336 | { | |
372e722e | 337 | struct gpio_desc *desc = dev_get_drvdata(dev); |
d8f388d8 DB |
338 | ssize_t status; |
339 | ||
340 | mutex_lock(&sysfs_lock); | |
341 | ||
342 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
343 | status = -EIO; | |
344 | else if (!test_bit(FLAG_IS_OUT, &desc->flags)) | |
345 | status = -EPERM; | |
346 | else { | |
347 | long value; | |
348 | ||
349 | status = strict_strtol(buf, 0, &value); | |
350 | if (status == 0) { | |
07697461 JN |
351 | if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) |
352 | value = !value; | |
372e722e | 353 | gpiod_set_value_cansleep(desc, value != 0); |
d8f388d8 DB |
354 | status = size; |
355 | } | |
356 | } | |
357 | ||
358 | mutex_unlock(&sysfs_lock); | |
359 | return status; | |
360 | } | |
361 | ||
07697461 | 362 | static const DEVICE_ATTR(value, 0644, |
d8f388d8 DB |
363 | gpio_value_show, gpio_value_store); |
364 | ||
ff77c352 DG |
365 | static irqreturn_t gpio_sysfs_irq(int irq, void *priv) |
366 | { | |
5ba1821d | 367 | struct sysfs_dirent *value_sd = priv; |
ff77c352 | 368 | |
5ba1821d | 369 | sysfs_notify_dirent(value_sd); |
ff77c352 DG |
370 | return IRQ_HANDLED; |
371 | } | |
372 | ||
ff77c352 DG |
373 | static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev, |
374 | unsigned long gpio_flags) | |
375 | { | |
5ba1821d | 376 | struct sysfs_dirent *value_sd; |
ff77c352 DG |
377 | unsigned long irq_flags; |
378 | int ret, irq, id; | |
379 | ||
380 | if ((desc->flags & GPIO_TRIGGER_MASK) == gpio_flags) | |
381 | return 0; | |
382 | ||
372e722e | 383 | irq = gpiod_to_irq(desc); |
ff77c352 DG |
384 | if (irq < 0) |
385 | return -EIO; | |
386 | ||
5ba1821d DG |
387 | id = desc->flags >> ID_SHIFT; |
388 | value_sd = idr_find(&dirent_idr, id); | |
389 | if (value_sd) | |
390 | free_irq(irq, value_sd); | |
ff77c352 DG |
391 | |
392 | desc->flags &= ~GPIO_TRIGGER_MASK; | |
393 | ||
394 | if (!gpio_flags) { | |
395 | ret = 0; | |
5ba1821d | 396 | goto free_id; |
ff77c352 DG |
397 | } |
398 | ||
399 | irq_flags = IRQF_SHARED; | |
400 | if (test_bit(FLAG_TRIG_FALL, &gpio_flags)) | |
07697461 JN |
401 | irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? |
402 | IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING; | |
ff77c352 | 403 | if (test_bit(FLAG_TRIG_RISE, &gpio_flags)) |
07697461 JN |
404 | irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? |
405 | IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; | |
ff77c352 | 406 | |
5ba1821d DG |
407 | if (!value_sd) { |
408 | value_sd = sysfs_get_dirent(dev->kobj.sd, NULL, "value"); | |
409 | if (!value_sd) { | |
410 | ret = -ENODEV; | |
ff77c352 DG |
411 | goto err_out; |
412 | } | |
413 | ||
414 | do { | |
415 | ret = -ENOMEM; | |
5ba1821d DG |
416 | if (idr_pre_get(&dirent_idr, GFP_KERNEL)) |
417 | ret = idr_get_new_above(&dirent_idr, value_sd, | |
418 | 1, &id); | |
ff77c352 DG |
419 | } while (ret == -EAGAIN); |
420 | ||
421 | if (ret) | |
5ba1821d | 422 | goto free_sd; |
ff77c352 DG |
423 | |
424 | desc->flags &= GPIO_FLAGS_MASK; | |
5ba1821d | 425 | desc->flags |= (unsigned long)id << ID_SHIFT; |
ff77c352 | 426 | |
5ba1821d | 427 | if (desc->flags >> ID_SHIFT != id) { |
ff77c352 DG |
428 | ret = -ERANGE; |
429 | goto free_id; | |
430 | } | |
ff77c352 DG |
431 | } |
432 | ||
364fadb3 | 433 | ret = request_any_context_irq(irq, gpio_sysfs_irq, irq_flags, |
5ba1821d | 434 | "gpiolib", value_sd); |
364fadb3 | 435 | if (ret < 0) |
5ba1821d | 436 | goto free_id; |
ff77c352 DG |
437 | |
438 | desc->flags |= gpio_flags; | |
439 | return 0; | |
440 | ||
ff77c352 | 441 | free_id: |
5ba1821d | 442 | idr_remove(&dirent_idr, id); |
ff77c352 | 443 | desc->flags &= GPIO_FLAGS_MASK; |
5ba1821d DG |
444 | free_sd: |
445 | if (value_sd) | |
446 | sysfs_put(value_sd); | |
ff77c352 DG |
447 | err_out: |
448 | return ret; | |
449 | } | |
450 | ||
451 | static const struct { | |
452 | const char *name; | |
453 | unsigned long flags; | |
454 | } trigger_types[] = { | |
455 | { "none", 0 }, | |
456 | { "falling", BIT(FLAG_TRIG_FALL) }, | |
457 | { "rising", BIT(FLAG_TRIG_RISE) }, | |
458 | { "both", BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE) }, | |
459 | }; | |
460 | ||
461 | static ssize_t gpio_edge_show(struct device *dev, | |
462 | struct device_attribute *attr, char *buf) | |
463 | { | |
464 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
465 | ssize_t status; | |
466 | ||
467 | mutex_lock(&sysfs_lock); | |
468 | ||
469 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
470 | status = -EIO; | |
471 | else { | |
472 | int i; | |
473 | ||
474 | status = 0; | |
475 | for (i = 0; i < ARRAY_SIZE(trigger_types); i++) | |
476 | if ((desc->flags & GPIO_TRIGGER_MASK) | |
477 | == trigger_types[i].flags) { | |
478 | status = sprintf(buf, "%s\n", | |
479 | trigger_types[i].name); | |
480 | break; | |
481 | } | |
482 | } | |
483 | ||
484 | mutex_unlock(&sysfs_lock); | |
485 | return status; | |
486 | } | |
487 | ||
488 | static ssize_t gpio_edge_store(struct device *dev, | |
489 | struct device_attribute *attr, const char *buf, size_t size) | |
490 | { | |
491 | struct gpio_desc *desc = dev_get_drvdata(dev); | |
492 | ssize_t status; | |
493 | int i; | |
494 | ||
495 | for (i = 0; i < ARRAY_SIZE(trigger_types); i++) | |
496 | if (sysfs_streq(trigger_types[i].name, buf)) | |
497 | goto found; | |
498 | return -EINVAL; | |
499 | ||
500 | found: | |
501 | mutex_lock(&sysfs_lock); | |
502 | ||
503 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
504 | status = -EIO; | |
505 | else { | |
506 | status = gpio_setup_irq(desc, dev, trigger_types[i].flags); | |
507 | if (!status) | |
508 | status = size; | |
509 | } | |
510 | ||
511 | mutex_unlock(&sysfs_lock); | |
512 | ||
513 | return status; | |
514 | } | |
515 | ||
516 | static DEVICE_ATTR(edge, 0644, gpio_edge_show, gpio_edge_store); | |
517 | ||
07697461 JN |
518 | static int sysfs_set_active_low(struct gpio_desc *desc, struct device *dev, |
519 | int value) | |
520 | { | |
521 | int status = 0; | |
522 | ||
523 | if (!!test_bit(FLAG_ACTIVE_LOW, &desc->flags) == !!value) | |
524 | return 0; | |
525 | ||
526 | if (value) | |
527 | set_bit(FLAG_ACTIVE_LOW, &desc->flags); | |
528 | else | |
529 | clear_bit(FLAG_ACTIVE_LOW, &desc->flags); | |
530 | ||
531 | /* reconfigure poll(2) support if enabled on one edge only */ | |
532 | if (dev != NULL && (!!test_bit(FLAG_TRIG_RISE, &desc->flags) ^ | |
533 | !!test_bit(FLAG_TRIG_FALL, &desc->flags))) { | |
534 | unsigned long trigger_flags = desc->flags & GPIO_TRIGGER_MASK; | |
535 | ||
536 | gpio_setup_irq(desc, dev, 0); | |
537 | status = gpio_setup_irq(desc, dev, trigger_flags); | |
538 | } | |
539 | ||
540 | return status; | |
541 | } | |
542 | ||
543 | static ssize_t gpio_active_low_show(struct device *dev, | |
544 | struct device_attribute *attr, char *buf) | |
545 | { | |
546 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
547 | ssize_t status; | |
548 | ||
549 | mutex_lock(&sysfs_lock); | |
550 | ||
551 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
552 | status = -EIO; | |
553 | else | |
554 | status = sprintf(buf, "%d\n", | |
555 | !!test_bit(FLAG_ACTIVE_LOW, &desc->flags)); | |
556 | ||
557 | mutex_unlock(&sysfs_lock); | |
558 | ||
559 | return status; | |
560 | } | |
561 | ||
562 | static ssize_t gpio_active_low_store(struct device *dev, | |
563 | struct device_attribute *attr, const char *buf, size_t size) | |
564 | { | |
565 | struct gpio_desc *desc = dev_get_drvdata(dev); | |
566 | ssize_t status; | |
567 | ||
568 | mutex_lock(&sysfs_lock); | |
569 | ||
570 | if (!test_bit(FLAG_EXPORT, &desc->flags)) { | |
571 | status = -EIO; | |
572 | } else { | |
573 | long value; | |
574 | ||
575 | status = strict_strtol(buf, 0, &value); | |
576 | if (status == 0) | |
577 | status = sysfs_set_active_low(desc, dev, value != 0); | |
578 | } | |
579 | ||
580 | mutex_unlock(&sysfs_lock); | |
581 | ||
582 | return status ? : size; | |
583 | } | |
584 | ||
585 | static const DEVICE_ATTR(active_low, 0644, | |
586 | gpio_active_low_show, gpio_active_low_store); | |
587 | ||
d8f388d8 | 588 | static const struct attribute *gpio_attrs[] = { |
d8f388d8 | 589 | &dev_attr_value.attr, |
07697461 | 590 | &dev_attr_active_low.attr, |
d8f388d8 DB |
591 | NULL, |
592 | }; | |
593 | ||
594 | static const struct attribute_group gpio_attr_group = { | |
595 | .attrs = (struct attribute **) gpio_attrs, | |
596 | }; | |
597 | ||
598 | /* | |
599 | * /sys/class/gpio/gpiochipN/ | |
600 | * /base ... matching gpio_chip.base (N) | |
601 | * /label ... matching gpio_chip.label | |
602 | * /ngpio ... matching gpio_chip.ngpio | |
603 | */ | |
604 | ||
605 | static ssize_t chip_base_show(struct device *dev, | |
606 | struct device_attribute *attr, char *buf) | |
607 | { | |
608 | const struct gpio_chip *chip = dev_get_drvdata(dev); | |
609 | ||
610 | return sprintf(buf, "%d\n", chip->base); | |
611 | } | |
612 | static DEVICE_ATTR(base, 0444, chip_base_show, NULL); | |
613 | ||
614 | static ssize_t chip_label_show(struct device *dev, | |
615 | struct device_attribute *attr, char *buf) | |
616 | { | |
617 | const struct gpio_chip *chip = dev_get_drvdata(dev); | |
618 | ||
619 | return sprintf(buf, "%s\n", chip->label ? : ""); | |
620 | } | |
621 | static DEVICE_ATTR(label, 0444, chip_label_show, NULL); | |
622 | ||
623 | static ssize_t chip_ngpio_show(struct device *dev, | |
624 | struct device_attribute *attr, char *buf) | |
625 | { | |
626 | const struct gpio_chip *chip = dev_get_drvdata(dev); | |
627 | ||
628 | return sprintf(buf, "%u\n", chip->ngpio); | |
629 | } | |
630 | static DEVICE_ATTR(ngpio, 0444, chip_ngpio_show, NULL); | |
631 | ||
632 | static const struct attribute *gpiochip_attrs[] = { | |
633 | &dev_attr_base.attr, | |
634 | &dev_attr_label.attr, | |
635 | &dev_attr_ngpio.attr, | |
636 | NULL, | |
637 | }; | |
638 | ||
639 | static const struct attribute_group gpiochip_attr_group = { | |
640 | .attrs = (struct attribute **) gpiochip_attrs, | |
641 | }; | |
642 | ||
643 | /* | |
644 | * /sys/class/gpio/export ... write-only | |
645 | * integer N ... number of GPIO to export (full access) | |
646 | * /sys/class/gpio/unexport ... write-only | |
647 | * integer N ... number of GPIO to unexport | |
648 | */ | |
28812fe1 AK |
649 | static ssize_t export_store(struct class *class, |
650 | struct class_attribute *attr, | |
651 | const char *buf, size_t len) | |
d8f388d8 | 652 | { |
372e722e AC |
653 | long gpio; |
654 | struct gpio_desc *desc; | |
655 | int status; | |
d8f388d8 DB |
656 | |
657 | status = strict_strtol(buf, 0, &gpio); | |
658 | if (status < 0) | |
659 | goto done; | |
660 | ||
372e722e AC |
661 | desc = gpio_to_desc(gpio); |
662 | ||
d8f388d8 DB |
663 | /* No extra locking here; FLAG_SYSFS just signifies that the |
664 | * request and export were done by on behalf of userspace, so | |
665 | * they may be undone on its behalf too. | |
666 | */ | |
667 | ||
372e722e | 668 | status = gpiod_request(desc, "sysfs"); |
ad2fab36 MN |
669 | if (status < 0) { |
670 | if (status == -EPROBE_DEFER) | |
671 | status = -ENODEV; | |
d8f388d8 | 672 | goto done; |
ad2fab36 | 673 | } |
372e722e | 674 | status = gpiod_export(desc, true); |
d8f388d8 | 675 | if (status < 0) |
372e722e | 676 | gpiod_free(desc); |
d8f388d8 | 677 | else |
372e722e | 678 | set_bit(FLAG_SYSFS, &desc->flags); |
d8f388d8 DB |
679 | |
680 | done: | |
681 | if (status) | |
682 | pr_debug("%s: status %d\n", __func__, status); | |
683 | return status ? : len; | |
684 | } | |
685 | ||
28812fe1 AK |
686 | static ssize_t unexport_store(struct class *class, |
687 | struct class_attribute *attr, | |
688 | const char *buf, size_t len) | |
d8f388d8 | 689 | { |
372e722e AC |
690 | long gpio; |
691 | struct gpio_desc *desc; | |
692 | int status; | |
d8f388d8 DB |
693 | |
694 | status = strict_strtol(buf, 0, &gpio); | |
695 | if (status < 0) | |
696 | goto done; | |
697 | ||
698 | status = -EINVAL; | |
699 | ||
372e722e | 700 | desc = gpio_to_desc(gpio); |
d8f388d8 | 701 | /* reject bogus commands (gpio_unexport ignores them) */ |
372e722e | 702 | if (!desc) |
d8f388d8 DB |
703 | goto done; |
704 | ||
705 | /* No extra locking here; FLAG_SYSFS just signifies that the | |
706 | * request and export were done by on behalf of userspace, so | |
707 | * they may be undone on its behalf too. | |
708 | */ | |
372e722e | 709 | if (test_and_clear_bit(FLAG_SYSFS, &desc->flags)) { |
d8f388d8 | 710 | status = 0; |
372e722e | 711 | gpiod_free(desc); |
d8f388d8 DB |
712 | } |
713 | done: | |
714 | if (status) | |
715 | pr_debug("%s: status %d\n", __func__, status); | |
716 | return status ? : len; | |
717 | } | |
718 | ||
719 | static struct class_attribute gpio_class_attrs[] = { | |
720 | __ATTR(export, 0200, NULL, export_store), | |
721 | __ATTR(unexport, 0200, NULL, unexport_store), | |
722 | __ATTR_NULL, | |
723 | }; | |
724 | ||
725 | static struct class gpio_class = { | |
726 | .name = "gpio", | |
727 | .owner = THIS_MODULE, | |
728 | ||
729 | .class_attrs = gpio_class_attrs, | |
730 | }; | |
731 | ||
732 | ||
733 | /** | |
734 | * gpio_export - export a GPIO through sysfs | |
735 | * @gpio: gpio to make available, already requested | |
736 | * @direction_may_change: true if userspace may change gpio direction | |
737 | * Context: arch_initcall or later | |
738 | * | |
739 | * When drivers want to make a GPIO accessible to userspace after they | |
740 | * have requested it -- perhaps while debugging, or as part of their | |
741 | * public interface -- they may use this routine. If the GPIO can | |
742 | * change direction (some can't) and the caller allows it, userspace | |
743 | * will see "direction" sysfs attribute which may be used to change | |
744 | * the gpio's direction. A "value" attribute will always be provided. | |
745 | * | |
746 | * Returns zero on success, else an error. | |
747 | */ | |
372e722e | 748 | static int gpiod_export(struct gpio_desc *desc, bool direction_may_change) |
d8f388d8 DB |
749 | { |
750 | unsigned long flags; | |
fc4e2514 | 751 | int status; |
62154991 | 752 | const char *ioname = NULL; |
fc4e2514 | 753 | struct device *dev; |
372e722e | 754 | int offset; |
d8f388d8 DB |
755 | |
756 | /* can't export until sysfs is available ... */ | |
757 | if (!gpio_class.p) { | |
758 | pr_debug("%s: called too early!\n", __func__); | |
759 | return -ENOENT; | |
760 | } | |
761 | ||
372e722e AC |
762 | if (!desc) { |
763 | pr_debug("%s: invalid gpio descriptor\n", __func__); | |
fc4e2514 RM |
764 | return -EINVAL; |
765 | } | |
d8f388d8 DB |
766 | |
767 | mutex_lock(&sysfs_lock); | |
768 | ||
769 | spin_lock_irqsave(&gpio_lock, flags); | |
fc4e2514 RM |
770 | if (!test_bit(FLAG_REQUESTED, &desc->flags) || |
771 | test_bit(FLAG_EXPORT, &desc->flags)) { | |
772 | spin_unlock_irqrestore(&gpio_lock, flags); | |
773 | pr_debug("%s: gpio %d unavailable (requested=%d, exported=%d)\n", | |
372e722e | 774 | __func__, desc_to_gpio(desc), |
fc4e2514 RM |
775 | test_bit(FLAG_REQUESTED, &desc->flags), |
776 | test_bit(FLAG_EXPORT, &desc->flags)); | |
529f2ad5 DC |
777 | status = -EPERM; |
778 | goto fail_unlock; | |
d8f388d8 | 779 | } |
fc4e2514 RM |
780 | |
781 | if (!desc->chip->direction_input || !desc->chip->direction_output) | |
782 | direction_may_change = false; | |
d8f388d8 DB |
783 | spin_unlock_irqrestore(&gpio_lock, flags); |
784 | ||
372e722e AC |
785 | offset = gpio_chip_hwgpio(desc); |
786 | if (desc->chip->names && desc->chip->names[offset]) | |
787 | ioname = desc->chip->names[offset]; | |
926b663c | 788 | |
fc4e2514 | 789 | dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0), |
372e722e AC |
790 | desc, ioname ? ioname : "gpio%u", |
791 | desc_to_gpio(desc)); | |
fc4e2514 RM |
792 | if (IS_ERR(dev)) { |
793 | status = PTR_ERR(dev); | |
794 | goto fail_unlock; | |
d8f388d8 DB |
795 | } |
796 | ||
fc4e2514 | 797 | status = sysfs_create_group(&dev->kobj, &gpio_attr_group); |
d8f388d8 | 798 | if (status) |
fc4e2514 | 799 | goto fail_unregister_device; |
d8f388d8 | 800 | |
fc4e2514 RM |
801 | if (direction_may_change) { |
802 | status = device_create_file(dev, &dev_attr_direction); | |
803 | if (status) | |
804 | goto fail_unregister_device; | |
805 | } | |
806 | ||
372e722e | 807 | if (gpiod_to_irq(desc) >= 0 && (direction_may_change || |
fc4e2514 RM |
808 | !test_bit(FLAG_IS_OUT, &desc->flags))) { |
809 | status = device_create_file(dev, &dev_attr_edge); | |
810 | if (status) | |
811 | goto fail_unregister_device; | |
812 | } | |
d8f388d8 | 813 | |
fc4e2514 RM |
814 | set_bit(FLAG_EXPORT, &desc->flags); |
815 | mutex_unlock(&sysfs_lock); | |
816 | return 0; | |
817 | ||
818 | fail_unregister_device: | |
819 | device_unregister(dev); | |
820 | fail_unlock: | |
821 | mutex_unlock(&sysfs_lock); | |
372e722e AC |
822 | pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc), |
823 | status); | |
d8f388d8 DB |
824 | return status; |
825 | } | |
372e722e AC |
826 | |
827 | int gpio_export(unsigned gpio, bool direction_may_change) | |
828 | { | |
829 | return gpiod_export(gpio_to_desc(gpio), direction_may_change); | |
830 | } | |
d8f388d8 DB |
831 | EXPORT_SYMBOL_GPL(gpio_export); |
832 | ||
9f3b795a | 833 | static int match_export(struct device *dev, const void *data) |
d8f388d8 DB |
834 | { |
835 | return dev_get_drvdata(dev) == data; | |
836 | } | |
837 | ||
a4177ee7 JN |
838 | /** |
839 | * gpio_export_link - create a sysfs link to an exported GPIO node | |
840 | * @dev: device under which to create symlink | |
841 | * @name: name of the symlink | |
842 | * @gpio: gpio to create symlink to, already exported | |
843 | * | |
844 | * Set up a symlink from /sys/.../dev/name to /sys/class/gpio/gpioN | |
845 | * node. Caller is responsible for unlinking. | |
846 | * | |
847 | * Returns zero on success, else an error. | |
848 | */ | |
372e722e AC |
849 | static int gpiod_export_link(struct device *dev, const char *name, |
850 | struct gpio_desc *desc) | |
a4177ee7 | 851 | { |
a4177ee7 JN |
852 | int status = -EINVAL; |
853 | ||
372e722e | 854 | if (!desc) |
a4177ee7 JN |
855 | goto done; |
856 | ||
857 | mutex_lock(&sysfs_lock); | |
858 | ||
a4177ee7 JN |
859 | if (test_bit(FLAG_EXPORT, &desc->flags)) { |
860 | struct device *tdev; | |
861 | ||
862 | tdev = class_find_device(&gpio_class, NULL, desc, match_export); | |
863 | if (tdev != NULL) { | |
864 | status = sysfs_create_link(&dev->kobj, &tdev->kobj, | |
865 | name); | |
866 | } else { | |
867 | status = -ENODEV; | |
868 | } | |
869 | } | |
870 | ||
871 | mutex_unlock(&sysfs_lock); | |
872 | ||
873 | done: | |
874 | if (status) | |
372e722e AC |
875 | pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc), |
876 | status); | |
a4177ee7 JN |
877 | |
878 | return status; | |
879 | } | |
a4177ee7 | 880 | |
372e722e AC |
881 | int gpio_export_link(struct device *dev, const char *name, unsigned gpio) |
882 | { | |
883 | return gpiod_export_link(dev, name, gpio_to_desc(gpio)); | |
884 | } | |
885 | EXPORT_SYMBOL_GPL(gpio_export_link); | |
07697461 JN |
886 | |
887 | /** | |
888 | * gpio_sysfs_set_active_low - set the polarity of gpio sysfs value | |
889 | * @gpio: gpio to change | |
890 | * @value: non-zero to use active low, i.e. inverted values | |
891 | * | |
892 | * Set the polarity of /sys/class/gpio/gpioN/value sysfs attribute. | |
893 | * The GPIO does not have to be exported yet. If poll(2) support has | |
894 | * been enabled for either rising or falling edge, it will be | |
895 | * reconfigured to follow the new polarity. | |
896 | * | |
897 | * Returns zero on success, else an error. | |
898 | */ | |
372e722e | 899 | static int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value) |
07697461 | 900 | { |
07697461 JN |
901 | struct device *dev = NULL; |
902 | int status = -EINVAL; | |
903 | ||
372e722e | 904 | if (!desc) |
07697461 JN |
905 | goto done; |
906 | ||
907 | mutex_lock(&sysfs_lock); | |
908 | ||
07697461 | 909 | if (test_bit(FLAG_EXPORT, &desc->flags)) { |
07697461 JN |
910 | dev = class_find_device(&gpio_class, NULL, desc, match_export); |
911 | if (dev == NULL) { | |
912 | status = -ENODEV; | |
913 | goto unlock; | |
914 | } | |
915 | } | |
916 | ||
917 | status = sysfs_set_active_low(desc, dev, value); | |
918 | ||
919 | unlock: | |
920 | mutex_unlock(&sysfs_lock); | |
921 | ||
922 | done: | |
923 | if (status) | |
372e722e AC |
924 | pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc), |
925 | status); | |
07697461 JN |
926 | |
927 | return status; | |
928 | } | |
372e722e AC |
929 | |
930 | int gpio_sysfs_set_active_low(unsigned gpio, int value) | |
931 | { | |
932 | return gpiod_sysfs_set_active_low(gpio_to_desc(gpio), value); | |
933 | } | |
07697461 JN |
934 | EXPORT_SYMBOL_GPL(gpio_sysfs_set_active_low); |
935 | ||
d8f388d8 DB |
936 | /** |
937 | * gpio_unexport - reverse effect of gpio_export() | |
938 | * @gpio: gpio to make unavailable | |
939 | * | |
940 | * This is implicit on gpio_free(). | |
941 | */ | |
372e722e | 942 | static void gpiod_unexport(struct gpio_desc *desc) |
d8f388d8 | 943 | { |
6a99ad4a | 944 | int status = 0; |
864533ce | 945 | struct device *dev = NULL; |
d8f388d8 | 946 | |
372e722e | 947 | if (!desc) { |
6a99ad4a | 948 | status = -EINVAL; |
d8f388d8 | 949 | goto done; |
6a99ad4a | 950 | } |
d8f388d8 DB |
951 | |
952 | mutex_lock(&sysfs_lock); | |
953 | ||
d8f388d8 | 954 | if (test_bit(FLAG_EXPORT, &desc->flags)) { |
d8f388d8 DB |
955 | |
956 | dev = class_find_device(&gpio_class, NULL, desc, match_export); | |
957 | if (dev) { | |
ff77c352 | 958 | gpio_setup_irq(desc, dev, 0); |
d8f388d8 | 959 | clear_bit(FLAG_EXPORT, &desc->flags); |
d8f388d8 DB |
960 | } else |
961 | status = -ENODEV; | |
962 | } | |
963 | ||
964 | mutex_unlock(&sysfs_lock); | |
372e722e | 965 | |
864533ce ML |
966 | if (dev) { |
967 | device_unregister(dev); | |
968 | put_device(dev); | |
969 | } | |
d8f388d8 DB |
970 | done: |
971 | if (status) | |
372e722e AC |
972 | pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc), |
973 | status); | |
974 | } | |
975 | ||
976 | void gpio_unexport(unsigned gpio) | |
977 | { | |
978 | gpiod_unexport(gpio_to_desc(gpio)); | |
d8f388d8 DB |
979 | } |
980 | EXPORT_SYMBOL_GPL(gpio_unexport); | |
981 | ||
982 | static int gpiochip_export(struct gpio_chip *chip) | |
983 | { | |
984 | int status; | |
985 | struct device *dev; | |
986 | ||
987 | /* Many systems register gpio chips for SOC support very early, | |
988 | * before driver model support is available. In those cases we | |
989 | * export this later, in gpiolib_sysfs_init() ... here we just | |
990 | * verify that _some_ field of gpio_class got initialized. | |
991 | */ | |
992 | if (!gpio_class.p) | |
993 | return 0; | |
994 | ||
995 | /* use chip->base for the ID; it's already known to be unique */ | |
996 | mutex_lock(&sysfs_lock); | |
997 | dev = device_create(&gpio_class, chip->dev, MKDEV(0, 0), chip, | |
998 | "gpiochip%d", chip->base); | |
d62668e1 | 999 | if (!IS_ERR(dev)) { |
d8f388d8 DB |
1000 | status = sysfs_create_group(&dev->kobj, |
1001 | &gpiochip_attr_group); | |
1002 | } else | |
d62668e1 | 1003 | status = PTR_ERR(dev); |
d8f388d8 DB |
1004 | chip->exported = (status == 0); |
1005 | mutex_unlock(&sysfs_lock); | |
1006 | ||
1007 | if (status) { | |
1008 | unsigned long flags; | |
1009 | unsigned gpio; | |
1010 | ||
1011 | spin_lock_irqsave(&gpio_lock, flags); | |
6c0b4e6c AC |
1012 | gpio = 0; |
1013 | while (gpio < chip->ngpio) | |
1014 | chip->desc[gpio++].chip = NULL; | |
d8f388d8 DB |
1015 | spin_unlock_irqrestore(&gpio_lock, flags); |
1016 | ||
1017 | pr_debug("%s: chip %s status %d\n", __func__, | |
1018 | chip->label, status); | |
1019 | } | |
1020 | ||
1021 | return status; | |
1022 | } | |
1023 | ||
1024 | static void gpiochip_unexport(struct gpio_chip *chip) | |
1025 | { | |
1026 | int status; | |
1027 | struct device *dev; | |
1028 | ||
1029 | mutex_lock(&sysfs_lock); | |
1030 | dev = class_find_device(&gpio_class, NULL, chip, match_export); | |
1031 | if (dev) { | |
1032 | put_device(dev); | |
1033 | device_unregister(dev); | |
1034 | chip->exported = 0; | |
1035 | status = 0; | |
1036 | } else | |
1037 | status = -ENODEV; | |
1038 | mutex_unlock(&sysfs_lock); | |
1039 | ||
1040 | if (status) | |
1041 | pr_debug("%s: chip %s status %d\n", __func__, | |
1042 | chip->label, status); | |
1043 | } | |
1044 | ||
1045 | static int __init gpiolib_sysfs_init(void) | |
1046 | { | |
1047 | int status; | |
1048 | unsigned long flags; | |
65493e3a | 1049 | struct gpio_chip *chip; |
d8f388d8 DB |
1050 | |
1051 | status = class_register(&gpio_class); | |
1052 | if (status < 0) | |
1053 | return status; | |
1054 | ||
1055 | /* Scan and register the gpio_chips which registered very | |
1056 | * early (e.g. before the class_register above was called). | |
1057 | * | |
1058 | * We run before arch_initcall() so chip->dev nodes can have | |
1059 | * registered, and so arch_initcall() can always gpio_export(). | |
1060 | */ | |
1061 | spin_lock_irqsave(&gpio_lock, flags); | |
65493e3a | 1062 | list_for_each_entry(chip, &gpio_chips, list) { |
d8f388d8 DB |
1063 | if (!chip || chip->exported) |
1064 | continue; | |
1065 | ||
1066 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1067 | status = gpiochip_export(chip); | |
1068 | spin_lock_irqsave(&gpio_lock, flags); | |
1069 | } | |
1070 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1071 | ||
1072 | ||
1073 | return status; | |
1074 | } | |
1075 | postcore_initcall(gpiolib_sysfs_init); | |
1076 | ||
1077 | #else | |
1078 | static inline int gpiochip_export(struct gpio_chip *chip) | |
1079 | { | |
1080 | return 0; | |
1081 | } | |
1082 | ||
1083 | static inline void gpiochip_unexport(struct gpio_chip *chip) | |
1084 | { | |
1085 | } | |
1086 | ||
372e722e AC |
1087 | static inline int gpiod_export(struct gpio_desc *desc, |
1088 | bool direction_may_change) | |
1089 | { | |
1090 | return -ENOSYS; | |
1091 | } | |
1092 | ||
1093 | static inline int gpiod_export_link(struct device *dev, const char *name, | |
1094 | struct gpio_desc *desc) | |
1095 | { | |
1096 | return -ENOSYS; | |
1097 | } | |
1098 | ||
1099 | static inline int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value) | |
1100 | { | |
1101 | return -ENOSYS; | |
1102 | } | |
1103 | ||
1104 | static inline void gpiod_unexport(struct gpio_desc *desc) | |
1105 | { | |
1106 | } | |
1107 | ||
d8f388d8 DB |
1108 | #endif /* CONFIG_GPIO_SYSFS */ |
1109 | ||
1a989d0f AC |
1110 | /* |
1111 | * Add a new chip to the global chips list, keeping the list of chips sorted | |
1112 | * by base order. | |
1113 | * | |
1114 | * Return -EBUSY if the new chip overlaps with some other chip's integer | |
1115 | * space. | |
1116 | */ | |
1117 | static int gpiochip_add_to_list(struct gpio_chip *chip) | |
1118 | { | |
1119 | struct list_head *pos = &gpio_chips; | |
1120 | struct gpio_chip *_chip; | |
1121 | int err = 0; | |
1122 | ||
1123 | /* find where to insert our chip */ | |
1124 | list_for_each(pos, &gpio_chips) { | |
1125 | _chip = list_entry(pos, struct gpio_chip, list); | |
1126 | /* shall we insert before _chip? */ | |
1127 | if (_chip->base >= chip->base + chip->ngpio) | |
1128 | break; | |
1129 | } | |
1130 | ||
1131 | /* are we stepping on the chip right before? */ | |
1132 | if (pos != &gpio_chips && pos->prev != &gpio_chips) { | |
1133 | _chip = list_entry(pos->prev, struct gpio_chip, list); | |
1134 | if (_chip->base + _chip->ngpio > chip->base) { | |
1135 | dev_err(chip->dev, | |
1136 | "GPIO integer space overlap, cannot add chip\n"); | |
1137 | err = -EBUSY; | |
1138 | } | |
1139 | } | |
1140 | ||
1141 | if (!err) | |
1142 | list_add_tail(&chip->list, pos); | |
1143 | ||
1144 | return err; | |
1145 | } | |
1146 | ||
d2876d08 DB |
1147 | /** |
1148 | * gpiochip_add() - register a gpio_chip | |
1149 | * @chip: the chip to register, with chip->base initialized | |
1150 | * Context: potentially before irqs or kmalloc will work | |
1151 | * | |
1152 | * Returns a negative errno if the chip can't be registered, such as | |
1153 | * because the chip->base is invalid or already associated with a | |
1154 | * different chip. Otherwise it returns zero as a success code. | |
8d0aab2f | 1155 | * |
d8f388d8 DB |
1156 | * When gpiochip_add() is called very early during boot, so that GPIOs |
1157 | * can be freely used, the chip->dev device must be registered before | |
1158 | * the gpio framework's arch_initcall(). Otherwise sysfs initialization | |
1159 | * for GPIOs will fail rudely. | |
1160 | * | |
8d0aab2f AV |
1161 | * If chip->base is negative, this requests dynamic assignment of |
1162 | * a range of valid GPIOs. | |
d2876d08 DB |
1163 | */ |
1164 | int gpiochip_add(struct gpio_chip *chip) | |
1165 | { | |
1166 | unsigned long flags; | |
1167 | int status = 0; | |
1168 | unsigned id; | |
8d0aab2f | 1169 | int base = chip->base; |
d2876d08 | 1170 | |
bff5fda9 | 1171 | if ((!gpio_is_valid(base) || !gpio_is_valid(base + chip->ngpio - 1)) |
8d0aab2f | 1172 | && base >= 0) { |
d2876d08 DB |
1173 | status = -EINVAL; |
1174 | goto fail; | |
1175 | } | |
1176 | ||
1177 | spin_lock_irqsave(&gpio_lock, flags); | |
1178 | ||
8d0aab2f AV |
1179 | if (base < 0) { |
1180 | base = gpiochip_find_base(chip->ngpio); | |
1181 | if (base < 0) { | |
1182 | status = base; | |
d8f388d8 | 1183 | goto unlock; |
8d0aab2f AV |
1184 | } |
1185 | chip->base = base; | |
1186 | } | |
1187 | ||
1a989d0f AC |
1188 | status = gpiochip_add_to_list(chip); |
1189 | ||
d2876d08 | 1190 | if (status == 0) { |
6c0b4e6c AC |
1191 | chip->desc = &gpio_desc[chip->base]; |
1192 | ||
1193 | for (id = 0; id < chip->ngpio; id++) { | |
1194 | struct gpio_desc *desc = &chip->desc[id]; | |
1195 | desc->chip = chip; | |
d8f388d8 DB |
1196 | |
1197 | /* REVISIT: most hardware initializes GPIOs as | |
1198 | * inputs (often with pullups enabled) so power | |
1199 | * usage is minimized. Linux code should set the | |
1200 | * gpio direction first thing; but until it does, | |
80b0a602 | 1201 | * and in case chip->get_direction is not set, |
d8f388d8 DB |
1202 | * we may expose the wrong direction in sysfs. |
1203 | */ | |
6c0b4e6c | 1204 | desc->flags = !chip->direction_input |
d8f388d8 DB |
1205 | ? (1 << FLAG_IS_OUT) |
1206 | : 0; | |
d2876d08 DB |
1207 | } |
1208 | } | |
1209 | ||
f23f1516 SH |
1210 | #ifdef CONFIG_PINCTRL |
1211 | INIT_LIST_HEAD(&chip->pin_ranges); | |
1212 | #endif | |
1213 | ||
391c970c AV |
1214 | of_gpiochip_add(chip); |
1215 | ||
d8f388d8 | 1216 | unlock: |
d2876d08 | 1217 | spin_unlock_irqrestore(&gpio_lock, flags); |
cedb1881 AV |
1218 | |
1219 | if (status) | |
1220 | goto fail; | |
1221 | ||
1222 | status = gpiochip_export(chip); | |
1223 | if (status) | |
1224 | goto fail; | |
1225 | ||
ee1c1e7d | 1226 | pr_debug("gpiochip_add: registered GPIOs %d to %d on device: %s\n", |
64842aad GL |
1227 | chip->base, chip->base + chip->ngpio - 1, |
1228 | chip->label ? : "generic"); | |
1229 | ||
cedb1881 | 1230 | return 0; |
d2876d08 DB |
1231 | fail: |
1232 | /* failures here can mean systems won't boot... */ | |
cedb1881 AV |
1233 | pr_err("gpiochip_add: gpios %d..%d (%s) failed to register\n", |
1234 | chip->base, chip->base + chip->ngpio - 1, | |
1235 | chip->label ? : "generic"); | |
d2876d08 DB |
1236 | return status; |
1237 | } | |
1238 | EXPORT_SYMBOL_GPL(gpiochip_add); | |
1239 | ||
1240 | /** | |
1241 | * gpiochip_remove() - unregister a gpio_chip | |
1242 | * @chip: the chip to unregister | |
1243 | * | |
1244 | * A gpio_chip with any GPIOs still requested may not be removed. | |
1245 | */ | |
1246 | int gpiochip_remove(struct gpio_chip *chip) | |
1247 | { | |
1248 | unsigned long flags; | |
1249 | int status = 0; | |
1250 | unsigned id; | |
1251 | ||
1252 | spin_lock_irqsave(&gpio_lock, flags); | |
1253 | ||
9ef0d6f7 | 1254 | gpiochip_remove_pin_ranges(chip); |
391c970c AV |
1255 | of_gpiochip_remove(chip); |
1256 | ||
6c0b4e6c AC |
1257 | for (id = 0; id < chip->ngpio; id++) { |
1258 | if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) { | |
d2876d08 DB |
1259 | status = -EBUSY; |
1260 | break; | |
1261 | } | |
1262 | } | |
1263 | if (status == 0) { | |
6c0b4e6c AC |
1264 | for (id = 0; id < chip->ngpio; id++) |
1265 | chip->desc[id].chip = NULL; | |
1a989d0f AC |
1266 | |
1267 | list_del(&chip->list); | |
d2876d08 DB |
1268 | } |
1269 | ||
1270 | spin_unlock_irqrestore(&gpio_lock, flags); | |
d8f388d8 DB |
1271 | |
1272 | if (status == 0) | |
1273 | gpiochip_unexport(chip); | |
1274 | ||
d2876d08 DB |
1275 | return status; |
1276 | } | |
1277 | EXPORT_SYMBOL_GPL(gpiochip_remove); | |
1278 | ||
594fa265 GL |
1279 | /** |
1280 | * gpiochip_find() - iterator for locating a specific gpio_chip | |
1281 | * @data: data to pass to match function | |
1282 | * @callback: Callback function to check gpio_chip | |
1283 | * | |
1284 | * Similar to bus_find_device. It returns a reference to a gpio_chip as | |
1285 | * determined by a user supplied @match callback. The callback should return | |
1286 | * 0 if the device doesn't match and non-zero if it does. If the callback is | |
1287 | * non-zero, this function will return to the caller and not iterate over any | |
1288 | * more gpio_chips. | |
1289 | */ | |
07ce8ec7 | 1290 | struct gpio_chip *gpiochip_find(void *data, |
6e2cf651 | 1291 | int (*match)(struct gpio_chip *chip, |
3d0f7cf0 | 1292 | void *data)) |
594fa265 | 1293 | { |
125eef96 | 1294 | struct gpio_chip *chip; |
594fa265 | 1295 | unsigned long flags; |
594fa265 GL |
1296 | |
1297 | spin_lock_irqsave(&gpio_lock, flags); | |
125eef96 AC |
1298 | list_for_each_entry(chip, &gpio_chips, list) |
1299 | if (match(chip, data)) | |
594fa265 | 1300 | break; |
125eef96 AC |
1301 | |
1302 | /* No match? */ | |
1303 | if (&chip->list == &gpio_chips) | |
1304 | chip = NULL; | |
594fa265 GL |
1305 | spin_unlock_irqrestore(&gpio_lock, flags); |
1306 | ||
1307 | return chip; | |
1308 | } | |
8fa0c9bf | 1309 | EXPORT_SYMBOL_GPL(gpiochip_find); |
d2876d08 | 1310 | |
f23f1516 | 1311 | #ifdef CONFIG_PINCTRL |
165adc9c | 1312 | |
3f0f8670 LW |
1313 | /** |
1314 | * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping | |
1315 | * @chip: the gpiochip to add the range for | |
1316 | * @pinctrl_name: the dev_name() of the pin controller to map to | |
316511c0 LW |
1317 | * @gpio_offset: the start offset in the current gpio_chip number space |
1318 | * @pin_offset: the start offset in the pin controller number space | |
3f0f8670 LW |
1319 | * @npins: the number of pins from the offset of each pin space (GPIO and |
1320 | * pin controller) to accumulate in this range | |
1321 | */ | |
1e63d7b9 | 1322 | int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name, |
316511c0 | 1323 | unsigned int gpio_offset, unsigned int pin_offset, |
3f0f8670 | 1324 | unsigned int npins) |
f23f1516 SH |
1325 | { |
1326 | struct gpio_pin_range *pin_range; | |
b4d4b1f0 | 1327 | int ret; |
f23f1516 | 1328 | |
3f0f8670 | 1329 | pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL); |
f23f1516 SH |
1330 | if (!pin_range) { |
1331 | pr_err("%s: GPIO chip: failed to allocate pin ranges\n", | |
1332 | chip->label); | |
1e63d7b9 | 1333 | return -ENOMEM; |
f23f1516 SH |
1334 | } |
1335 | ||
3f0f8670 | 1336 | /* Use local offset as range ID */ |
316511c0 | 1337 | pin_range->range.id = gpio_offset; |
3f0f8670 | 1338 | pin_range->range.gc = chip; |
f23f1516 | 1339 | pin_range->range.name = chip->label; |
316511c0 LW |
1340 | pin_range->range.base = chip->base + gpio_offset; |
1341 | pin_range->range.pin_base = pin_offset; | |
f23f1516 | 1342 | pin_range->range.npins = npins; |
192c369c | 1343 | pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name, |
f23f1516 | 1344 | &pin_range->range); |
8f23ca1a | 1345 | if (IS_ERR(pin_range->pctldev)) { |
b4d4b1f0 | 1346 | ret = PTR_ERR(pin_range->pctldev); |
3f0f8670 LW |
1347 | pr_err("%s: GPIO chip: could not create pin range\n", |
1348 | chip->label); | |
1349 | kfree(pin_range); | |
b4d4b1f0 | 1350 | return ret; |
3f0f8670 | 1351 | } |
316511c0 LW |
1352 | pr_debug("GPIO chip %s: created GPIO range %d->%d ==> %s PIN %d->%d\n", |
1353 | chip->label, gpio_offset, gpio_offset + npins - 1, | |
1354 | pinctl_name, | |
1355 | pin_offset, pin_offset + npins - 1); | |
f23f1516 SH |
1356 | |
1357 | list_add_tail(&pin_range->node, &chip->pin_ranges); | |
1e63d7b9 LW |
1358 | |
1359 | return 0; | |
f23f1516 | 1360 | } |
165adc9c | 1361 | EXPORT_SYMBOL_GPL(gpiochip_add_pin_range); |
f23f1516 | 1362 | |
3f0f8670 LW |
1363 | /** |
1364 | * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings | |
1365 | * @chip: the chip to remove all the mappings for | |
1366 | */ | |
f23f1516 SH |
1367 | void gpiochip_remove_pin_ranges(struct gpio_chip *chip) |
1368 | { | |
1369 | struct gpio_pin_range *pin_range, *tmp; | |
1370 | ||
1371 | list_for_each_entry_safe(pin_range, tmp, &chip->pin_ranges, node) { | |
1372 | list_del(&pin_range->node); | |
1373 | pinctrl_remove_gpio_range(pin_range->pctldev, | |
1374 | &pin_range->range); | |
3f0f8670 | 1375 | kfree(pin_range); |
f23f1516 SH |
1376 | } |
1377 | } | |
165adc9c LW |
1378 | EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges); |
1379 | ||
1380 | #endif /* CONFIG_PINCTRL */ | |
f23f1516 | 1381 | |
d2876d08 DB |
1382 | /* These "optional" allocation calls help prevent drivers from stomping |
1383 | * on each other, and help provide better diagnostics in debugfs. | |
1384 | * They're called even less than the "set direction" calls. | |
1385 | */ | |
372e722e | 1386 | static int gpiod_request(struct gpio_desc *desc, const char *label) |
d2876d08 | 1387 | { |
35e8bb51 | 1388 | struct gpio_chip *chip; |
e9354576 | 1389 | int status = -EPROBE_DEFER; |
d2876d08 DB |
1390 | unsigned long flags; |
1391 | ||
1392 | spin_lock_irqsave(&gpio_lock, flags); | |
1393 | ||
372e722e | 1394 | if (!desc) { |
ad2fab36 | 1395 | status = -EINVAL; |
d2876d08 | 1396 | goto done; |
ad2fab36 | 1397 | } |
35e8bb51 DB |
1398 | chip = desc->chip; |
1399 | if (chip == NULL) | |
d2876d08 DB |
1400 | goto done; |
1401 | ||
35e8bb51 | 1402 | if (!try_module_get(chip->owner)) |
438d8908 GL |
1403 | goto done; |
1404 | ||
d2876d08 | 1405 | /* NOTE: gpio_request() can be called in early boot, |
35e8bb51 | 1406 | * before IRQs are enabled, for non-sleeping (SOC) GPIOs. |
d2876d08 DB |
1407 | */ |
1408 | ||
1409 | if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) { | |
1410 | desc_set_label(desc, label ? : "?"); | |
1411 | status = 0; | |
438d8908 | 1412 | } else { |
d2876d08 | 1413 | status = -EBUSY; |
35e8bb51 | 1414 | module_put(chip->owner); |
7460db56 | 1415 | goto done; |
35e8bb51 DB |
1416 | } |
1417 | ||
1418 | if (chip->request) { | |
1419 | /* chip->request may sleep */ | |
1420 | spin_unlock_irqrestore(&gpio_lock, flags); | |
372e722e | 1421 | status = chip->request(chip, gpio_chip_hwgpio(desc)); |
35e8bb51 DB |
1422 | spin_lock_irqsave(&gpio_lock, flags); |
1423 | ||
1424 | if (status < 0) { | |
1425 | desc_set_label(desc, NULL); | |
1426 | module_put(chip->owner); | |
1427 | clear_bit(FLAG_REQUESTED, &desc->flags); | |
80b0a602 | 1428 | goto done; |
35e8bb51 | 1429 | } |
438d8908 | 1430 | } |
80b0a602 MN |
1431 | if (chip->get_direction) { |
1432 | /* chip->get_direction may sleep */ | |
1433 | spin_unlock_irqrestore(&gpio_lock, flags); | |
372e722e | 1434 | gpiod_get_direction(desc); |
80b0a602 MN |
1435 | spin_lock_irqsave(&gpio_lock, flags); |
1436 | } | |
d2876d08 DB |
1437 | done: |
1438 | if (status) | |
372e722e AC |
1439 | pr_debug("_gpio_request: gpio-%d (%s) status %d\n", |
1440 | desc ? desc_to_gpio(desc) : -1, | |
1441 | label ? : "?", status); | |
d2876d08 DB |
1442 | spin_unlock_irqrestore(&gpio_lock, flags); |
1443 | return status; | |
1444 | } | |
372e722e AC |
1445 | |
1446 | int gpio_request(unsigned gpio, const char *label) | |
1447 | { | |
1448 | return gpiod_request(gpio_to_desc(gpio), label); | |
1449 | } | |
d2876d08 DB |
1450 | EXPORT_SYMBOL_GPL(gpio_request); |
1451 | ||
372e722e | 1452 | static void gpiod_free(struct gpio_desc *desc) |
d2876d08 DB |
1453 | { |
1454 | unsigned long flags; | |
35e8bb51 | 1455 | struct gpio_chip *chip; |
d2876d08 | 1456 | |
3d599d1c UKK |
1457 | might_sleep(); |
1458 | ||
372e722e | 1459 | if (!desc) { |
d2876d08 DB |
1460 | WARN_ON(extra_checks); |
1461 | return; | |
1462 | } | |
1463 | ||
372e722e | 1464 | gpiod_unexport(desc); |
d8f388d8 | 1465 | |
d2876d08 DB |
1466 | spin_lock_irqsave(&gpio_lock, flags); |
1467 | ||
35e8bb51 DB |
1468 | chip = desc->chip; |
1469 | if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) { | |
1470 | if (chip->free) { | |
1471 | spin_unlock_irqrestore(&gpio_lock, flags); | |
9c4ba946 | 1472 | might_sleep_if(chip->can_sleep); |
372e722e | 1473 | chip->free(chip, gpio_chip_hwgpio(desc)); |
35e8bb51 DB |
1474 | spin_lock_irqsave(&gpio_lock, flags); |
1475 | } | |
d2876d08 | 1476 | desc_set_label(desc, NULL); |
438d8908 | 1477 | module_put(desc->chip->owner); |
07697461 | 1478 | clear_bit(FLAG_ACTIVE_LOW, &desc->flags); |
35e8bb51 | 1479 | clear_bit(FLAG_REQUESTED, &desc->flags); |
aca5ce14 | 1480 | clear_bit(FLAG_OPEN_DRAIN, &desc->flags); |
25553ff0 | 1481 | clear_bit(FLAG_OPEN_SOURCE, &desc->flags); |
438d8908 | 1482 | } else |
d2876d08 DB |
1483 | WARN_ON(extra_checks); |
1484 | ||
1485 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1486 | } | |
372e722e AC |
1487 | |
1488 | void gpio_free(unsigned gpio) | |
1489 | { | |
1490 | gpiod_free(gpio_to_desc(gpio)); | |
1491 | } | |
d2876d08 DB |
1492 | EXPORT_SYMBOL_GPL(gpio_free); |
1493 | ||
3e45f1d1 EM |
1494 | /** |
1495 | * gpio_request_one - request a single GPIO with initial configuration | |
1496 | * @gpio: the GPIO number | |
1497 | * @flags: GPIO configuration as specified by GPIOF_* | |
1498 | * @label: a literal description string of this GPIO | |
1499 | */ | |
1500 | int gpio_request_one(unsigned gpio, unsigned long flags, const char *label) | |
1501 | { | |
372e722e | 1502 | struct gpio_desc *desc; |
3e45f1d1 EM |
1503 | int err; |
1504 | ||
372e722e AC |
1505 | desc = gpio_to_desc(gpio); |
1506 | ||
1507 | err = gpiod_request(desc, label); | |
3e45f1d1 EM |
1508 | if (err) |
1509 | return err; | |
1510 | ||
aca5ce14 | 1511 | if (flags & GPIOF_OPEN_DRAIN) |
372e722e | 1512 | set_bit(FLAG_OPEN_DRAIN, &desc->flags); |
aca5ce14 | 1513 | |
25553ff0 | 1514 | if (flags & GPIOF_OPEN_SOURCE) |
372e722e | 1515 | set_bit(FLAG_OPEN_SOURCE, &desc->flags); |
25553ff0 | 1516 | |
3e45f1d1 | 1517 | if (flags & GPIOF_DIR_IN) |
372e722e | 1518 | err = gpiod_direction_input(desc); |
3e45f1d1 | 1519 | else |
372e722e | 1520 | err = gpiod_direction_output(desc, |
3e45f1d1 EM |
1521 | (flags & GPIOF_INIT_HIGH) ? 1 : 0); |
1522 | ||
e254811c | 1523 | if (err) |
fc3a1f04 WS |
1524 | goto free_gpio; |
1525 | ||
1526 | if (flags & GPIOF_EXPORT) { | |
372e722e | 1527 | err = gpiod_export(desc, flags & GPIOF_EXPORT_CHANGEABLE); |
fc3a1f04 WS |
1528 | if (err) |
1529 | goto free_gpio; | |
1530 | } | |
1531 | ||
1532 | return 0; | |
e254811c | 1533 | |
fc3a1f04 | 1534 | free_gpio: |
372e722e | 1535 | gpiod_free(desc); |
3e45f1d1 EM |
1536 | return err; |
1537 | } | |
1538 | EXPORT_SYMBOL_GPL(gpio_request_one); | |
1539 | ||
1540 | /** | |
1541 | * gpio_request_array - request multiple GPIOs in a single call | |
1542 | * @array: array of the 'struct gpio' | |
1543 | * @num: how many GPIOs in the array | |
1544 | */ | |
7c295975 | 1545 | int gpio_request_array(const struct gpio *array, size_t num) |
3e45f1d1 EM |
1546 | { |
1547 | int i, err; | |
1548 | ||
1549 | for (i = 0; i < num; i++, array++) { | |
1550 | err = gpio_request_one(array->gpio, array->flags, array->label); | |
1551 | if (err) | |
1552 | goto err_free; | |
1553 | } | |
1554 | return 0; | |
1555 | ||
1556 | err_free: | |
1557 | while (i--) | |
1558 | gpio_free((--array)->gpio); | |
1559 | return err; | |
1560 | } | |
1561 | EXPORT_SYMBOL_GPL(gpio_request_array); | |
1562 | ||
1563 | /** | |
1564 | * gpio_free_array - release multiple GPIOs in a single call | |
1565 | * @array: array of the 'struct gpio' | |
1566 | * @num: how many GPIOs in the array | |
1567 | */ | |
7c295975 | 1568 | void gpio_free_array(const struct gpio *array, size_t num) |
3e45f1d1 EM |
1569 | { |
1570 | while (num--) | |
1571 | gpio_free((array++)->gpio); | |
1572 | } | |
1573 | EXPORT_SYMBOL_GPL(gpio_free_array); | |
d2876d08 DB |
1574 | |
1575 | /** | |
1576 | * gpiochip_is_requested - return string iff signal was requested | |
1577 | * @chip: controller managing the signal | |
1578 | * @offset: of signal within controller's 0..(ngpio - 1) range | |
1579 | * | |
1580 | * Returns NULL if the GPIO is not currently requested, else a string. | |
1581 | * If debugfs support is enabled, the string returned is the label passed | |
1582 | * to gpio_request(); otherwise it is a meaningless constant. | |
1583 | * | |
1584 | * This function is for use by GPIO controller drivers. The label can | |
1585 | * help with diagnostics, and knowing that the signal is used as a GPIO | |
1586 | * can help avoid accidentally multiplexing it to another controller. | |
1587 | */ | |
1588 | const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset) | |
1589 | { | |
6c0b4e6c | 1590 | struct gpio_desc *desc; |
d2876d08 | 1591 | |
6c0b4e6c | 1592 | if (!GPIO_OFFSET_VALID(chip, offset)) |
d2876d08 | 1593 | return NULL; |
6c0b4e6c AC |
1594 | |
1595 | desc = &chip->desc[offset]; | |
1596 | ||
372e722e | 1597 | if (test_bit(FLAG_REQUESTED, &desc->flags) == 0) |
d2876d08 DB |
1598 | return NULL; |
1599 | #ifdef CONFIG_DEBUG_FS | |
372e722e | 1600 | return desc->label; |
d2876d08 DB |
1601 | #else |
1602 | return "?"; | |
1603 | #endif | |
1604 | } | |
1605 | EXPORT_SYMBOL_GPL(gpiochip_is_requested); | |
1606 | ||
1607 | ||
1608 | /* Drivers MUST set GPIO direction before making get/set calls. In | |
1609 | * some cases this is done in early boot, before IRQs are enabled. | |
1610 | * | |
1611 | * As a rule these aren't called more than once (except for drivers | |
1612 | * using the open-drain emulation idiom) so these are natural places | |
1613 | * to accumulate extra debugging checks. Note that we can't (yet) | |
1614 | * rely on gpio_request() having been called beforehand. | |
1615 | */ | |
1616 | ||
372e722e | 1617 | static int gpiod_direction_input(struct gpio_desc *desc) |
d2876d08 DB |
1618 | { |
1619 | unsigned long flags; | |
1620 | struct gpio_chip *chip; | |
d2876d08 | 1621 | int status = -EINVAL; |
372e722e | 1622 | int offset; |
d2876d08 DB |
1623 | |
1624 | spin_lock_irqsave(&gpio_lock, flags); | |
1625 | ||
372e722e | 1626 | if (!desc) |
d2876d08 DB |
1627 | goto fail; |
1628 | chip = desc->chip; | |
1629 | if (!chip || !chip->get || !chip->direction_input) | |
1630 | goto fail; | |
372e722e | 1631 | status = gpio_ensure_requested(desc); |
35e8bb51 DB |
1632 | if (status < 0) |
1633 | goto fail; | |
d2876d08 DB |
1634 | |
1635 | /* now we know the gpio is valid and chip won't vanish */ | |
1636 | ||
1637 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1638 | ||
9c4ba946 | 1639 | might_sleep_if(chip->can_sleep); |
d2876d08 | 1640 | |
372e722e | 1641 | offset = gpio_chip_hwgpio(desc); |
35e8bb51 | 1642 | if (status) { |
372e722e | 1643 | status = chip->request(chip, offset); |
35e8bb51 DB |
1644 | if (status < 0) { |
1645 | pr_debug("GPIO-%d: chip request fail, %d\n", | |
372e722e | 1646 | desc_to_gpio(desc), status); |
35e8bb51 DB |
1647 | /* and it's not available to anyone else ... |
1648 | * gpio_request() is the fully clean solution. | |
1649 | */ | |
1650 | goto lose; | |
1651 | } | |
1652 | } | |
1653 | ||
372e722e | 1654 | status = chip->direction_input(chip, offset); |
d2876d08 DB |
1655 | if (status == 0) |
1656 | clear_bit(FLAG_IS_OUT, &desc->flags); | |
3f397c21 | 1657 | |
372e722e | 1658 | trace_gpio_direction(desc_to_gpio(desc), 1, status); |
35e8bb51 | 1659 | lose: |
d2876d08 DB |
1660 | return status; |
1661 | fail: | |
1662 | spin_unlock_irqrestore(&gpio_lock, flags); | |
372e722e AC |
1663 | if (status) { |
1664 | int gpio = -1; | |
1665 | if (desc) | |
1666 | gpio = desc_to_gpio(desc); | |
d2876d08 | 1667 | pr_debug("%s: gpio-%d status %d\n", |
145980a0 | 1668 | __func__, gpio, status); |
372e722e | 1669 | } |
d2876d08 DB |
1670 | return status; |
1671 | } | |
372e722e AC |
1672 | |
1673 | int gpio_direction_input(unsigned gpio) | |
1674 | { | |
1675 | return gpiod_direction_input(gpio_to_desc(gpio)); | |
1676 | } | |
d2876d08 DB |
1677 | EXPORT_SYMBOL_GPL(gpio_direction_input); |
1678 | ||
372e722e | 1679 | static int gpiod_direction_output(struct gpio_desc *desc, int value) |
d2876d08 DB |
1680 | { |
1681 | unsigned long flags; | |
1682 | struct gpio_chip *chip; | |
d2876d08 | 1683 | int status = -EINVAL; |
372e722e | 1684 | int offset; |
d2876d08 | 1685 | |
aca5ce14 LD |
1686 | /* Open drain pin should not be driven to 1 */ |
1687 | if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags)) | |
372e722e | 1688 | return gpiod_direction_input(desc); |
aca5ce14 | 1689 | |
25553ff0 LD |
1690 | /* Open source pin should not be driven to 0 */ |
1691 | if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags)) | |
372e722e | 1692 | return gpiod_direction_input(desc); |
25553ff0 | 1693 | |
d2876d08 DB |
1694 | spin_lock_irqsave(&gpio_lock, flags); |
1695 | ||
372e722e | 1696 | if (!desc) |
d2876d08 DB |
1697 | goto fail; |
1698 | chip = desc->chip; | |
1699 | if (!chip || !chip->set || !chip->direction_output) | |
1700 | goto fail; | |
372e722e | 1701 | status = gpio_ensure_requested(desc); |
35e8bb51 DB |
1702 | if (status < 0) |
1703 | goto fail; | |
d2876d08 DB |
1704 | |
1705 | /* now we know the gpio is valid and chip won't vanish */ | |
1706 | ||
1707 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1708 | ||
9c4ba946 | 1709 | might_sleep_if(chip->can_sleep); |
d2876d08 | 1710 | |
372e722e | 1711 | offset = gpio_chip_hwgpio(desc); |
35e8bb51 | 1712 | if (status) { |
372e722e | 1713 | status = chip->request(chip, offset); |
35e8bb51 DB |
1714 | if (status < 0) { |
1715 | pr_debug("GPIO-%d: chip request fail, %d\n", | |
372e722e | 1716 | desc_to_gpio(desc), status); |
35e8bb51 DB |
1717 | /* and it's not available to anyone else ... |
1718 | * gpio_request() is the fully clean solution. | |
1719 | */ | |
1720 | goto lose; | |
1721 | } | |
1722 | } | |
1723 | ||
372e722e | 1724 | status = chip->direction_output(chip, offset, value); |
d2876d08 DB |
1725 | if (status == 0) |
1726 | set_bit(FLAG_IS_OUT, &desc->flags); | |
372e722e AC |
1727 | trace_gpio_value(desc_to_gpio(desc), 0, value); |
1728 | trace_gpio_direction(desc_to_gpio(desc), 0, status); | |
35e8bb51 | 1729 | lose: |
d2876d08 DB |
1730 | return status; |
1731 | fail: | |
1732 | spin_unlock_irqrestore(&gpio_lock, flags); | |
372e722e AC |
1733 | if (status) { |
1734 | int gpio = -1; | |
1735 | if (desc) | |
1736 | gpio = desc_to_gpio(desc); | |
d2876d08 | 1737 | pr_debug("%s: gpio-%d status %d\n", |
145980a0 | 1738 | __func__, gpio, status); |
372e722e | 1739 | } |
d2876d08 DB |
1740 | return status; |
1741 | } | |
372e722e AC |
1742 | |
1743 | int gpio_direction_output(unsigned gpio, int value) | |
1744 | { | |
1745 | return gpiod_direction_output(gpio_to_desc(gpio), value); | |
1746 | } | |
d2876d08 DB |
1747 | EXPORT_SYMBOL_GPL(gpio_direction_output); |
1748 | ||
c4b5be98 FB |
1749 | /** |
1750 | * gpio_set_debounce - sets @debounce time for a @gpio | |
1751 | * @gpio: the gpio to set debounce time | |
1752 | * @debounce: debounce time is microseconds | |
1753 | */ | |
372e722e | 1754 | static int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) |
c4b5be98 FB |
1755 | { |
1756 | unsigned long flags; | |
1757 | struct gpio_chip *chip; | |
c4b5be98 | 1758 | int status = -EINVAL; |
372e722e | 1759 | int offset; |
c4b5be98 FB |
1760 | |
1761 | spin_lock_irqsave(&gpio_lock, flags); | |
1762 | ||
372e722e | 1763 | if (!desc) |
c4b5be98 FB |
1764 | goto fail; |
1765 | chip = desc->chip; | |
1766 | if (!chip || !chip->set || !chip->set_debounce) | |
1767 | goto fail; | |
372e722e AC |
1768 | |
1769 | status = gpio_ensure_requested(desc); | |
c4b5be98 FB |
1770 | if (status < 0) |
1771 | goto fail; | |
1772 | ||
1773 | /* now we know the gpio is valid and chip won't vanish */ | |
1774 | ||
1775 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1776 | ||
9c4ba946 | 1777 | might_sleep_if(chip->can_sleep); |
c4b5be98 | 1778 | |
372e722e AC |
1779 | offset = gpio_chip_hwgpio(desc); |
1780 | return chip->set_debounce(chip, offset, debounce); | |
c4b5be98 FB |
1781 | |
1782 | fail: | |
1783 | spin_unlock_irqrestore(&gpio_lock, flags); | |
372e722e AC |
1784 | if (status) { |
1785 | int gpio = -1; | |
1786 | if (desc) | |
1787 | gpio = desc_to_gpio(desc); | |
c4b5be98 FB |
1788 | pr_debug("%s: gpio-%d status %d\n", |
1789 | __func__, gpio, status); | |
372e722e | 1790 | } |
c4b5be98 FB |
1791 | |
1792 | return status; | |
1793 | } | |
372e722e AC |
1794 | |
1795 | int gpio_set_debounce(unsigned gpio, unsigned debounce) | |
1796 | { | |
1797 | return gpiod_set_debounce(gpio_to_desc(gpio), debounce); | |
1798 | } | |
c4b5be98 | 1799 | EXPORT_SYMBOL_GPL(gpio_set_debounce); |
d2876d08 DB |
1800 | |
1801 | /* I/O calls are only valid after configuration completed; the relevant | |
1802 | * "is this a valid GPIO" error checks should already have been done. | |
1803 | * | |
1804 | * "Get" operations are often inlinable as reading a pin value register, | |
1805 | * and masking the relevant bit in that register. | |
1806 | * | |
1807 | * When "set" operations are inlinable, they involve writing that mask to | |
1808 | * one register to set a low value, or a different register to set it high. | |
1809 | * Otherwise locking is needed, so there may be little value to inlining. | |
1810 | * | |
1811 | *------------------------------------------------------------------------ | |
1812 | * | |
1813 | * IMPORTANT!!! The hot paths -- get/set value -- assume that callers | |
1814 | * have requested the GPIO. That can include implicit requesting by | |
1815 | * a direction setting call. Marking a gpio as requested locks its chip | |
1816 | * in memory, guaranteeing that these table lookups need no more locking | |
1817 | * and that gpiochip_remove() will fail. | |
1818 | * | |
1819 | * REVISIT when debugging, consider adding some instrumentation to ensure | |
1820 | * that the GPIO was actually requested. | |
1821 | */ | |
1822 | ||
1823 | /** | |
1824 | * __gpio_get_value() - return a gpio's value | |
1825 | * @gpio: gpio whose value will be returned | |
1826 | * Context: any | |
1827 | * | |
1828 | * This is used directly or indirectly to implement gpio_get_value(). | |
1829 | * It returns the zero or nonzero value provided by the associated | |
1830 | * gpio_chip.get() method; or zero if no such method is provided. | |
1831 | */ | |
372e722e | 1832 | static int gpiod_get_value(struct gpio_desc *desc) |
d2876d08 DB |
1833 | { |
1834 | struct gpio_chip *chip; | |
3f397c21 | 1835 | int value; |
372e722e | 1836 | int offset; |
d2876d08 | 1837 | |
372e722e AC |
1838 | chip = desc->chip; |
1839 | offset = gpio_chip_hwgpio(desc); | |
e4e449e8 | 1840 | /* Should be using gpio_get_value_cansleep() */ |
9c4ba946 | 1841 | WARN_ON(chip->can_sleep); |
372e722e AC |
1842 | value = chip->get ? chip->get(chip, offset) : 0; |
1843 | trace_gpio_value(desc_to_gpio(desc), 1, value); | |
3f397c21 | 1844 | return value; |
d2876d08 | 1845 | } |
372e722e AC |
1846 | |
1847 | int __gpio_get_value(unsigned gpio) | |
1848 | { | |
1849 | return gpiod_get_value(gpio_to_desc(gpio)); | |
1850 | } | |
d2876d08 DB |
1851 | EXPORT_SYMBOL_GPL(__gpio_get_value); |
1852 | ||
aca5ce14 LD |
1853 | /* |
1854 | * _gpio_set_open_drain_value() - Set the open drain gpio's value. | |
1855 | * @gpio: Gpio whose state need to be set. | |
1856 | * @chip: Gpio chip. | |
1857 | * @value: Non-zero for setting it HIGH otherise it will set to LOW. | |
1858 | */ | |
372e722e | 1859 | static void _gpio_set_open_drain_value(struct gpio_desc *desc, int value) |
aca5ce14 LD |
1860 | { |
1861 | int err = 0; | |
372e722e AC |
1862 | struct gpio_chip *chip = desc->chip; |
1863 | int offset = gpio_chip_hwgpio(desc); | |
1864 | ||
aca5ce14 | 1865 | if (value) { |
372e722e | 1866 | err = chip->direction_input(chip, offset); |
aca5ce14 | 1867 | if (!err) |
372e722e | 1868 | clear_bit(FLAG_IS_OUT, &desc->flags); |
aca5ce14 | 1869 | } else { |
372e722e | 1870 | err = chip->direction_output(chip, offset, 0); |
aca5ce14 | 1871 | if (!err) |
372e722e | 1872 | set_bit(FLAG_IS_OUT, &desc->flags); |
aca5ce14 | 1873 | } |
372e722e | 1874 | trace_gpio_direction(desc_to_gpio(desc), value, err); |
aca5ce14 LD |
1875 | if (err < 0) |
1876 | pr_err("%s: Error in set_value for open drain gpio%d err %d\n", | |
372e722e | 1877 | __func__, desc_to_gpio(desc), err); |
aca5ce14 LD |
1878 | } |
1879 | ||
25553ff0 LD |
1880 | /* |
1881 | * _gpio_set_open_source() - Set the open source gpio's value. | |
1882 | * @gpio: Gpio whose state need to be set. | |
1883 | * @chip: Gpio chip. | |
1884 | * @value: Non-zero for setting it HIGH otherise it will set to LOW. | |
1885 | */ | |
372e722e | 1886 | static void _gpio_set_open_source_value(struct gpio_desc *desc, int value) |
25553ff0 LD |
1887 | { |
1888 | int err = 0; | |
372e722e AC |
1889 | struct gpio_chip *chip = desc->chip; |
1890 | int offset = gpio_chip_hwgpio(desc); | |
1891 | ||
25553ff0 | 1892 | if (value) { |
372e722e | 1893 | err = chip->direction_output(chip, offset, 1); |
25553ff0 | 1894 | if (!err) |
372e722e | 1895 | set_bit(FLAG_IS_OUT, &desc->flags); |
25553ff0 | 1896 | } else { |
372e722e | 1897 | err = chip->direction_input(chip, offset); |
25553ff0 | 1898 | if (!err) |
372e722e | 1899 | clear_bit(FLAG_IS_OUT, &desc->flags); |
25553ff0 | 1900 | } |
372e722e | 1901 | trace_gpio_direction(desc_to_gpio(desc), !value, err); |
25553ff0 LD |
1902 | if (err < 0) |
1903 | pr_err("%s: Error in set_value for open source gpio%d err %d\n", | |
372e722e | 1904 | __func__, desc_to_gpio(desc), err); |
25553ff0 LD |
1905 | } |
1906 | ||
d2876d08 DB |
1907 | /** |
1908 | * __gpio_set_value() - assign a gpio's value | |
1909 | * @gpio: gpio whose value will be assigned | |
1910 | * @value: value to assign | |
1911 | * Context: any | |
1912 | * | |
1913 | * This is used directly or indirectly to implement gpio_set_value(). | |
1914 | * It invokes the associated gpio_chip.set() method. | |
1915 | */ | |
372e722e | 1916 | static void gpiod_set_value(struct gpio_desc *desc, int value) |
d2876d08 DB |
1917 | { |
1918 | struct gpio_chip *chip; | |
1919 | ||
372e722e | 1920 | chip = desc->chip; |
e4e449e8 | 1921 | /* Should be using gpio_set_value_cansleep() */ |
9c4ba946 | 1922 | WARN_ON(chip->can_sleep); |
372e722e AC |
1923 | trace_gpio_value(desc_to_gpio(desc), 0, value); |
1924 | if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) | |
1925 | _gpio_set_open_drain_value(desc, value); | |
1926 | else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) | |
1927 | _gpio_set_open_source_value(desc, value); | |
aca5ce14 | 1928 | else |
372e722e AC |
1929 | chip->set(chip, gpio_chip_hwgpio(desc), value); |
1930 | } | |
1931 | ||
1932 | void __gpio_set_value(unsigned gpio, int value) | |
1933 | { | |
1934 | return gpiod_set_value(gpio_to_desc(gpio), value); | |
d2876d08 DB |
1935 | } |
1936 | EXPORT_SYMBOL_GPL(__gpio_set_value); | |
1937 | ||
1938 | /** | |
1939 | * __gpio_cansleep() - report whether gpio value access will sleep | |
1940 | * @gpio: gpio in question | |
1941 | * Context: any | |
1942 | * | |
1943 | * This is used directly or indirectly to implement gpio_cansleep(). It | |
1944 | * returns nonzero if access reading or writing the GPIO value can sleep. | |
1945 | */ | |
372e722e | 1946 | static int gpiod_cansleep(struct gpio_desc *desc) |
d2876d08 | 1947 | { |
d2876d08 | 1948 | /* only call this on GPIOs that are valid! */ |
372e722e AC |
1949 | return desc->chip->can_sleep; |
1950 | } | |
d2876d08 | 1951 | |
372e722e AC |
1952 | int __gpio_cansleep(unsigned gpio) |
1953 | { | |
1954 | return gpiod_cansleep(gpio_to_desc(gpio)); | |
d2876d08 DB |
1955 | } |
1956 | EXPORT_SYMBOL_GPL(__gpio_cansleep); | |
1957 | ||
0f6d504e DB |
1958 | /** |
1959 | * __gpio_to_irq() - return the IRQ corresponding to a GPIO | |
1960 | * @gpio: gpio whose IRQ will be returned (already requested) | |
1961 | * Context: any | |
1962 | * | |
1963 | * This is used directly or indirectly to implement gpio_to_irq(). | |
1964 | * It returns the number of the IRQ signaled by this (input) GPIO, | |
1965 | * or a negative errno. | |
1966 | */ | |
372e722e | 1967 | static int gpiod_to_irq(struct gpio_desc *desc) |
0f6d504e DB |
1968 | { |
1969 | struct gpio_chip *chip; | |
372e722e | 1970 | int offset; |
0f6d504e | 1971 | |
372e722e AC |
1972 | chip = desc->chip; |
1973 | offset = gpio_chip_hwgpio(desc); | |
1974 | return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO; | |
0f6d504e | 1975 | } |
0f6d504e | 1976 | |
372e722e AC |
1977 | int __gpio_to_irq(unsigned gpio) |
1978 | { | |
1979 | return gpiod_to_irq(gpio_to_desc(gpio)); | |
1980 | } | |
1981 | EXPORT_SYMBOL_GPL(__gpio_to_irq); | |
d2876d08 DB |
1982 | |
1983 | ||
1984 | /* There's no value in making it easy to inline GPIO calls that may sleep. | |
1985 | * Common examples include ones connected to I2C or SPI chips. | |
1986 | */ | |
1987 | ||
372e722e | 1988 | static int gpiod_get_value_cansleep(struct gpio_desc *desc) |
d2876d08 DB |
1989 | { |
1990 | struct gpio_chip *chip; | |
3f397c21 | 1991 | int value; |
372e722e | 1992 | int offset; |
d2876d08 DB |
1993 | |
1994 | might_sleep_if(extra_checks); | |
372e722e AC |
1995 | chip = desc->chip; |
1996 | offset = gpio_chip_hwgpio(desc); | |
1997 | value = chip->get ? chip->get(chip, offset) : 0; | |
1998 | trace_gpio_value(desc_to_gpio(desc), 1, value); | |
3f397c21 | 1999 | return value; |
d2876d08 | 2000 | } |
372e722e AC |
2001 | |
2002 | int gpio_get_value_cansleep(unsigned gpio) | |
2003 | { | |
2004 | return gpiod_get_value_cansleep(gpio_to_desc(gpio)); | |
2005 | } | |
d2876d08 DB |
2006 | EXPORT_SYMBOL_GPL(gpio_get_value_cansleep); |
2007 | ||
372e722e | 2008 | static void gpiod_set_value_cansleep(struct gpio_desc *desc, int value) |
d2876d08 DB |
2009 | { |
2010 | struct gpio_chip *chip; | |
2011 | ||
2012 | might_sleep_if(extra_checks); | |
372e722e AC |
2013 | chip = desc->chip; |
2014 | trace_gpio_value(desc_to_gpio(desc), 0, value); | |
2015 | if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) | |
2016 | _gpio_set_open_drain_value(desc, value); | |
2017 | else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) | |
2018 | _gpio_set_open_source_value(desc, value); | |
aca5ce14 | 2019 | else |
372e722e | 2020 | chip->set(chip, gpio_chip_hwgpio(desc), value); |
d2876d08 | 2021 | } |
d2876d08 | 2022 | |
372e722e AC |
2023 | void gpio_set_value_cansleep(unsigned gpio, int value) |
2024 | { | |
2025 | return gpiod_set_value_cansleep(gpio_to_desc(gpio), value); | |
2026 | } | |
2027 | EXPORT_SYMBOL_GPL(gpio_set_value_cansleep); | |
d2876d08 DB |
2028 | |
2029 | #ifdef CONFIG_DEBUG_FS | |
2030 | ||
d2876d08 DB |
2031 | static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) |
2032 | { | |
2033 | unsigned i; | |
2034 | unsigned gpio = chip->base; | |
6c0b4e6c | 2035 | struct gpio_desc *gdesc = &chip->desc[0]; |
d2876d08 DB |
2036 | int is_out; |
2037 | ||
2038 | for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) { | |
2039 | if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) | |
2040 | continue; | |
2041 | ||
372e722e | 2042 | gpiod_get_direction(gdesc); |
d2876d08 | 2043 | is_out = test_bit(FLAG_IS_OUT, &gdesc->flags); |
6e8ba729 | 2044 | seq_printf(s, " gpio-%-3d (%-20.20s) %s %s", |
d2876d08 DB |
2045 | gpio, gdesc->label, |
2046 | is_out ? "out" : "in ", | |
2047 | chip->get | |
2048 | ? (chip->get(chip, i) ? "hi" : "lo") | |
2049 | : "? "); | |
d2876d08 DB |
2050 | seq_printf(s, "\n"); |
2051 | } | |
2052 | } | |
2053 | ||
f9c4a31f | 2054 | static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos) |
d2876d08 | 2055 | { |
362432ae | 2056 | unsigned long flags; |
f9c4a31f | 2057 | struct gpio_chip *chip = NULL; |
cb1650d4 | 2058 | loff_t index = *pos; |
d2876d08 | 2059 | |
f9c4a31f | 2060 | s->private = ""; |
d2876d08 | 2061 | |
362432ae | 2062 | spin_lock_irqsave(&gpio_lock, flags); |
cb1650d4 | 2063 | list_for_each_entry(chip, &gpio_chips, list) |
362432ae GL |
2064 | if (index-- == 0) { |
2065 | spin_unlock_irqrestore(&gpio_lock, flags); | |
cb1650d4 | 2066 | return chip; |
f9c4a31f | 2067 | } |
362432ae | 2068 | spin_unlock_irqrestore(&gpio_lock, flags); |
f9c4a31f | 2069 | |
cb1650d4 | 2070 | return NULL; |
f9c4a31f TR |
2071 | } |
2072 | ||
2073 | static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
2074 | { | |
362432ae | 2075 | unsigned long flags; |
f9c4a31f | 2076 | struct gpio_chip *chip = v; |
f9c4a31f TR |
2077 | void *ret = NULL; |
2078 | ||
362432ae | 2079 | spin_lock_irqsave(&gpio_lock, flags); |
cb1650d4 AC |
2080 | if (list_is_last(&chip->list, &gpio_chips)) |
2081 | ret = NULL; | |
2082 | else | |
2083 | ret = list_entry(chip->list.next, struct gpio_chip, list); | |
362432ae | 2084 | spin_unlock_irqrestore(&gpio_lock, flags); |
f9c4a31f TR |
2085 | |
2086 | s->private = "\n"; | |
2087 | ++*pos; | |
2088 | ||
2089 | return ret; | |
2090 | } | |
2091 | ||
2092 | static void gpiolib_seq_stop(struct seq_file *s, void *v) | |
2093 | { | |
2094 | } | |
2095 | ||
2096 | static int gpiolib_seq_show(struct seq_file *s, void *v) | |
2097 | { | |
2098 | struct gpio_chip *chip = v; | |
2099 | struct device *dev; | |
2100 | ||
2101 | seq_printf(s, "%sGPIOs %d-%d", (char *)s->private, | |
2102 | chip->base, chip->base + chip->ngpio - 1); | |
2103 | dev = chip->dev; | |
2104 | if (dev) | |
2105 | seq_printf(s, ", %s/%s", dev->bus ? dev->bus->name : "no-bus", | |
2106 | dev_name(dev)); | |
2107 | if (chip->label) | |
2108 | seq_printf(s, ", %s", chip->label); | |
2109 | if (chip->can_sleep) | |
2110 | seq_printf(s, ", can sleep"); | |
2111 | seq_printf(s, ":\n"); | |
2112 | ||
2113 | if (chip->dbg_show) | |
2114 | chip->dbg_show(s, chip); | |
2115 | else | |
2116 | gpiolib_dbg_show(s, chip); | |
2117 | ||
d2876d08 DB |
2118 | return 0; |
2119 | } | |
2120 | ||
f9c4a31f TR |
2121 | static const struct seq_operations gpiolib_seq_ops = { |
2122 | .start = gpiolib_seq_start, | |
2123 | .next = gpiolib_seq_next, | |
2124 | .stop = gpiolib_seq_stop, | |
2125 | .show = gpiolib_seq_show, | |
2126 | }; | |
2127 | ||
d2876d08 DB |
2128 | static int gpiolib_open(struct inode *inode, struct file *file) |
2129 | { | |
f9c4a31f | 2130 | return seq_open(file, &gpiolib_seq_ops); |
d2876d08 DB |
2131 | } |
2132 | ||
828c0950 | 2133 | static const struct file_operations gpiolib_operations = { |
f9c4a31f | 2134 | .owner = THIS_MODULE, |
d2876d08 DB |
2135 | .open = gpiolib_open, |
2136 | .read = seq_read, | |
2137 | .llseek = seq_lseek, | |
f9c4a31f | 2138 | .release = seq_release, |
d2876d08 DB |
2139 | }; |
2140 | ||
2141 | static int __init gpiolib_debugfs_init(void) | |
2142 | { | |
2143 | /* /sys/kernel/debug/gpio */ | |
2144 | (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO, | |
2145 | NULL, NULL, &gpiolib_operations); | |
2146 | return 0; | |
2147 | } | |
2148 | subsys_initcall(gpiolib_debugfs_init); | |
2149 | ||
2150 | #endif /* DEBUG_FS */ |