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