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> |
81f59e9d | 13 | #include <linux/acpi_gpio.h> |
ff77c352 | 14 | #include <linux/idr.h> |
5a0e3ad6 | 15 | #include <linux/slab.h> |
d2876d08 | 16 | |
3f397c21 UKK |
17 | #define CREATE_TRACE_POINTS |
18 | #include <trace/events/gpio.h> | |
d2876d08 | 19 | |
79a9becd | 20 | /* Implementation infrastructure for GPIO interfaces. |
d2876d08 | 21 | * |
79a9becd AC |
22 | * The GPIO programming interface allows for inlining speed-critical |
23 | * get/set operations for common cases, so that access to SOC-integrated | |
24 | * GPIOs can sometimes cost only an instruction or two per bit. | |
d2876d08 DB |
25 | */ |
26 | ||
27 | ||
28 | /* When debugging, extend minimal trust to callers and platform code. | |
29 | * Also emit diagnostic messages that may help initial bringup, when | |
30 | * board setup or driver bugs are most common. | |
31 | * | |
32 | * Otherwise, minimize overhead in what may be bitbanging codepaths. | |
33 | */ | |
34 | #ifdef DEBUG | |
35 | #define extra_checks 1 | |
36 | #else | |
37 | #define extra_checks 0 | |
38 | #endif | |
39 | ||
40 | /* gpio_lock prevents conflicts during gpio_desc[] table updates. | |
41 | * While any GPIO is requested, its gpio_chip is not removable; | |
42 | * each GPIO's "requested" flag serves as a lock and refcount. | |
43 | */ | |
44 | static DEFINE_SPINLOCK(gpio_lock); | |
45 | ||
46 | struct gpio_desc { | |
47 | struct gpio_chip *chip; | |
48 | unsigned long flags; | |
49 | /* flag symbols are bit numbers */ | |
50 | #define FLAG_REQUESTED 0 | |
51 | #define FLAG_IS_OUT 1 | |
710b40ea AC |
52 | #define FLAG_EXPORT 2 /* protected by sysfs_lock */ |
53 | #define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */ | |
54 | #define FLAG_TRIG_FALL 4 /* trigger on falling edge */ | |
55 | #define FLAG_TRIG_RISE 5 /* trigger on rising edge */ | |
79a9becd | 56 | #define FLAG_ACTIVE_LOW 6 /* value has active low */ |
710b40ea AC |
57 | #define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */ |
58 | #define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */ | |
d468bf9e | 59 | #define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */ |
ff77c352 | 60 | |
5ba1821d | 61 | #define ID_SHIFT 16 /* add new flags before this one */ |
ff77c352 | 62 | |
5ba1821d | 63 | #define GPIO_FLAGS_MASK ((1 << ID_SHIFT) - 1) |
ff77c352 | 64 | #define GPIO_TRIGGER_MASK (BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE)) |
d2876d08 DB |
65 | |
66 | #ifdef CONFIG_DEBUG_FS | |
67 | const char *label; | |
68 | #endif | |
69 | }; | |
70 | static struct gpio_desc gpio_desc[ARCH_NR_GPIOS]; | |
71 | ||
6c0b4e6c AC |
72 | #define GPIO_OFFSET_VALID(chip, offset) (offset >= 0 && offset < chip->ngpio) |
73 | ||
bae48da2 AC |
74 | static DEFINE_MUTEX(gpio_lookup_lock); |
75 | static LIST_HEAD(gpio_lookup_list); | |
1a989d0f AC |
76 | static LIST_HEAD(gpio_chips); |
77 | ||
ff77c352 | 78 | #ifdef CONFIG_GPIO_SYSFS |
5ba1821d | 79 | static DEFINE_IDR(dirent_idr); |
ff77c352 DG |
80 | #endif |
81 | ||
372e722e AC |
82 | static int gpiod_request(struct gpio_desc *desc, const char *label); |
83 | static void gpiod_free(struct gpio_desc *desc); | |
372e722e | 84 | |
7b17b59f MB |
85 | #ifdef CONFIG_DEBUG_FS |
86 | #define gpiod_emerg(desc, fmt, ...) \ | |
87 | pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \ | |
88 | ##__VA_ARGS__) | |
89 | #define gpiod_crit(desc, fmt, ...) \ | |
90 | pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \ | |
91 | ##__VA_ARGS__) | |
92 | #define gpiod_err(desc, fmt, ...) \ | |
93 | pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \ | |
94 | ##__VA_ARGS__) | |
95 | #define gpiod_warn(desc, fmt, ...) \ | |
96 | pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \ | |
97 | ##__VA_ARGS__) | |
98 | #define gpiod_info(desc, fmt, ...) \ | |
99 | pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \ | |
100 | ##__VA_ARGS__) | |
101 | #define gpiod_dbg(desc, fmt, ...) \ | |
102 | pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \ | |
103 | ##__VA_ARGS__) | |
104 | #else | |
6424de5a MB |
105 | #define gpiod_emerg(desc, fmt, ...) \ |
106 | pr_emerg("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__) | |
107 | #define gpiod_crit(desc, fmt, ...) \ | |
108 | pr_crit("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__) | |
109 | #define gpiod_err(desc, fmt, ...) \ | |
110 | pr_err("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__) | |
111 | #define gpiod_warn(desc, fmt, ...) \ | |
112 | pr_warn("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__) | |
113 | #define gpiod_info(desc, fmt, ...) \ | |
114 | pr_info("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__) | |
115 | #define gpiod_dbg(desc, fmt, ...) \ | |
116 | pr_debug("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__) | |
7b17b59f | 117 | #endif |
372e722e | 118 | |
d2876d08 DB |
119 | static inline void desc_set_label(struct gpio_desc *d, const char *label) |
120 | { | |
121 | #ifdef CONFIG_DEBUG_FS | |
122 | d->label = label; | |
123 | #endif | |
124 | } | |
125 | ||
372e722e AC |
126 | /* |
127 | * Return the GPIO number of the passed descriptor relative to its chip | |
128 | */ | |
129 | static int gpio_chip_hwgpio(const struct gpio_desc *desc) | |
130 | { | |
6c0b4e6c | 131 | return desc - &desc->chip->desc[0]; |
372e722e AC |
132 | } |
133 | ||
134 | /** | |
135 | * Convert a GPIO number to its descriptor | |
136 | */ | |
79a9becd | 137 | struct gpio_desc *gpio_to_desc(unsigned gpio) |
372e722e AC |
138 | { |
139 | if (WARN(!gpio_is_valid(gpio), "invalid GPIO %d\n", gpio)) | |
140 | return NULL; | |
141 | else | |
142 | return &gpio_desc[gpio]; | |
143 | } | |
79a9becd | 144 | EXPORT_SYMBOL_GPL(gpio_to_desc); |
372e722e | 145 | |
d468bf9e LW |
146 | /** |
147 | * Convert an offset on a certain chip to a corresponding descriptor | |
148 | */ | |
149 | static struct gpio_desc *gpiochip_offset_to_desc(struct gpio_chip *chip, | |
150 | unsigned int offset) | |
151 | { | |
152 | unsigned int gpio = chip->base + offset; | |
153 | ||
154 | return gpio_to_desc(gpio); | |
155 | } | |
156 | ||
372e722e AC |
157 | /** |
158 | * Convert a GPIO descriptor to the integer namespace. | |
159 | * This should disappear in the future but is needed since we still | |
160 | * use GPIO numbers for error messages and sysfs nodes | |
161 | */ | |
79a9becd | 162 | int desc_to_gpio(const struct gpio_desc *desc) |
372e722e | 163 | { |
8c0fca81 | 164 | return desc - &gpio_desc[0]; |
372e722e | 165 | } |
79a9becd | 166 | EXPORT_SYMBOL_GPL(desc_to_gpio); |
372e722e AC |
167 | |
168 | ||
d2876d08 DB |
169 | /* Warn when drivers omit gpio_request() calls -- legal but ill-advised |
170 | * when setting direction, and otherwise illegal. Until board setup code | |
171 | * and drivers use explicit requests everywhere (which won't happen when | |
172 | * those calls have no teeth) we can't avoid autorequesting. This nag | |
35e8bb51 DB |
173 | * message should motivate switching to explicit requests... so should |
174 | * the weaker cleanup after faults, compared to gpio_request(). | |
8a0cecff DB |
175 | * |
176 | * NOTE: the autorequest mechanism is going away; at this point it's | |
177 | * only "legal" in the sense that (old) code using it won't break yet, | |
178 | * but instead only triggers a WARN() stack dump. | |
d2876d08 | 179 | */ |
372e722e | 180 | static int gpio_ensure_requested(struct gpio_desc *desc) |
d2876d08 | 181 | { |
8a0cecff | 182 | const struct gpio_chip *chip = desc->chip; |
372e722e | 183 | const int gpio = desc_to_gpio(desc); |
35e8bb51 | 184 | |
8a0cecff DB |
185 | if (WARN(test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0, |
186 | "autorequest GPIO-%d\n", gpio)) { | |
35e8bb51 DB |
187 | if (!try_module_get(chip->owner)) { |
188 | pr_err("GPIO-%d: module can't be gotten \n", gpio); | |
189 | clear_bit(FLAG_REQUESTED, &desc->flags); | |
190 | /* lose */ | |
191 | return -EIO; | |
192 | } | |
d2876d08 | 193 | desc_set_label(desc, "[auto]"); |
35e8bb51 DB |
194 | /* caller must chip->request() w/o spinlock */ |
195 | if (chip->request) | |
196 | return 1; | |
d2876d08 | 197 | } |
35e8bb51 | 198 | return 0; |
d2876d08 DB |
199 | } |
200 | ||
79a9becd AC |
201 | /** |
202 | * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs | |
203 | * @desc: descriptor to return the chip of | |
204 | */ | |
205 | struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc) | |
372e722e | 206 | { |
bcabdef1 | 207 | return desc ? desc->chip : NULL; |
372e722e | 208 | } |
79a9becd | 209 | EXPORT_SYMBOL_GPL(gpiod_to_chip); |
d2876d08 | 210 | |
8d0aab2f AV |
211 | /* dynamic allocation of GPIOs, e.g. on a hotplugged device */ |
212 | static int gpiochip_find_base(int ngpio) | |
213 | { | |
83cabe33 AC |
214 | struct gpio_chip *chip; |
215 | int base = ARCH_NR_GPIOS - ngpio; | |
8d0aab2f | 216 | |
83cabe33 AC |
217 | list_for_each_entry_reverse(chip, &gpio_chips, list) { |
218 | /* found a free space? */ | |
219 | if (chip->base + chip->ngpio <= base) | |
220 | break; | |
221 | else | |
222 | /* nope, check the space right before the chip */ | |
223 | base = chip->base - ngpio; | |
8d0aab2f AV |
224 | } |
225 | ||
83cabe33 | 226 | if (gpio_is_valid(base)) { |
8d0aab2f | 227 | pr_debug("%s: found new base at %d\n", __func__, base); |
83cabe33 AC |
228 | return base; |
229 | } else { | |
230 | pr_err("%s: cannot find free range\n", __func__); | |
231 | return -ENOSPC; | |
169b6a7a | 232 | } |
169b6a7a AV |
233 | } |
234 | ||
79a9becd AC |
235 | /** |
236 | * gpiod_get_direction - return the current direction of a GPIO | |
237 | * @desc: GPIO to get the direction of | |
238 | * | |
239 | * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error. | |
240 | * | |
241 | * This function may sleep if gpiod_cansleep() is true. | |
242 | */ | |
243 | int gpiod_get_direction(const struct gpio_desc *desc) | |
80b0a602 MN |
244 | { |
245 | struct gpio_chip *chip; | |
372e722e | 246 | unsigned offset; |
80b0a602 MN |
247 | int status = -EINVAL; |
248 | ||
372e722e AC |
249 | chip = gpiod_to_chip(desc); |
250 | offset = gpio_chip_hwgpio(desc); | |
80b0a602 MN |
251 | |
252 | if (!chip->get_direction) | |
253 | return status; | |
254 | ||
372e722e | 255 | status = chip->get_direction(chip, offset); |
80b0a602 MN |
256 | if (status > 0) { |
257 | /* GPIOF_DIR_IN, or other positive */ | |
258 | status = 1; | |
def63433 AC |
259 | /* FLAG_IS_OUT is just a cache of the result of get_direction(), |
260 | * so it does not affect constness per se */ | |
261 | clear_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags); | |
80b0a602 MN |
262 | } |
263 | if (status == 0) { | |
264 | /* GPIOF_DIR_OUT */ | |
def63433 | 265 | set_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags); |
80b0a602 MN |
266 | } |
267 | return status; | |
268 | } | |
79a9becd | 269 | EXPORT_SYMBOL_GPL(gpiod_get_direction); |
80b0a602 | 270 | |
d8f388d8 DB |
271 | #ifdef CONFIG_GPIO_SYSFS |
272 | ||
273 | /* lock protects against unexport_gpio() being called while | |
274 | * sysfs files are active. | |
275 | */ | |
276 | static DEFINE_MUTEX(sysfs_lock); | |
277 | ||
278 | /* | |
279 | * /sys/class/gpio/gpioN... only for GPIOs that are exported | |
280 | * /direction | |
281 | * * MAY BE OMITTED if kernel won't allow direction changes | |
282 | * * is read/write as "in" or "out" | |
283 | * * may also be written as "high" or "low", initializing | |
284 | * output value as specified ("out" implies "low") | |
285 | * /value | |
286 | * * always readable, subject to hardware behavior | |
287 | * * may be writable, as zero/nonzero | |
ff77c352 DG |
288 | * /edge |
289 | * * configures behavior of poll(2) on /value | |
290 | * * available only if pin can generate IRQs on input | |
291 | * * is read/write as "none", "falling", "rising", or "both" | |
07697461 JN |
292 | * /active_low |
293 | * * configures polarity of /value | |
294 | * * is read/write as zero/nonzero | |
295 | * * also affects existing and subsequent "falling" and "rising" | |
296 | * /edge configuration | |
d8f388d8 DB |
297 | */ |
298 | ||
299 | static ssize_t gpio_direction_show(struct device *dev, | |
300 | struct device_attribute *attr, char *buf) | |
301 | { | |
def63433 | 302 | const struct gpio_desc *desc = dev_get_drvdata(dev); |
d8f388d8 DB |
303 | ssize_t status; |
304 | ||
305 | mutex_lock(&sysfs_lock); | |
306 | ||
476171ce | 307 | if (!test_bit(FLAG_EXPORT, &desc->flags)) { |
d8f388d8 | 308 | status = -EIO; |
476171ce | 309 | } else { |
372e722e | 310 | gpiod_get_direction(desc); |
d8f388d8 DB |
311 | status = sprintf(buf, "%s\n", |
312 | test_bit(FLAG_IS_OUT, &desc->flags) | |
313 | ? "out" : "in"); | |
476171ce | 314 | } |
d8f388d8 DB |
315 | |
316 | mutex_unlock(&sysfs_lock); | |
317 | return status; | |
318 | } | |
319 | ||
320 | static ssize_t gpio_direction_store(struct device *dev, | |
321 | struct device_attribute *attr, const char *buf, size_t size) | |
322 | { | |
372e722e | 323 | struct gpio_desc *desc = dev_get_drvdata(dev); |
d8f388d8 DB |
324 | ssize_t status; |
325 | ||
326 | mutex_lock(&sysfs_lock); | |
327 | ||
328 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
329 | status = -EIO; | |
330 | else if (sysfs_streq(buf, "high")) | |
372e722e | 331 | status = gpiod_direction_output(desc, 1); |
d8f388d8 | 332 | else if (sysfs_streq(buf, "out") || sysfs_streq(buf, "low")) |
372e722e | 333 | status = gpiod_direction_output(desc, 0); |
d8f388d8 | 334 | else if (sysfs_streq(buf, "in")) |
372e722e | 335 | status = gpiod_direction_input(desc); |
d8f388d8 DB |
336 | else |
337 | status = -EINVAL; | |
338 | ||
339 | mutex_unlock(&sysfs_lock); | |
340 | return status ? : size; | |
341 | } | |
342 | ||
07697461 | 343 | static /* const */ DEVICE_ATTR(direction, 0644, |
d8f388d8 DB |
344 | gpio_direction_show, gpio_direction_store); |
345 | ||
346 | static ssize_t gpio_value_show(struct device *dev, | |
347 | struct device_attribute *attr, char *buf) | |
348 | { | |
372e722e | 349 | struct gpio_desc *desc = dev_get_drvdata(dev); |
d8f388d8 DB |
350 | ssize_t status; |
351 | ||
352 | mutex_lock(&sysfs_lock); | |
353 | ||
79a9becd | 354 | if (!test_bit(FLAG_EXPORT, &desc->flags)) |
d8f388d8 | 355 | status = -EIO; |
79a9becd AC |
356 | else |
357 | status = sprintf(buf, "%d\n", gpiod_get_value_cansleep(desc)); | |
d8f388d8 DB |
358 | |
359 | mutex_unlock(&sysfs_lock); | |
360 | return status; | |
361 | } | |
362 | ||
363 | static ssize_t gpio_value_store(struct device *dev, | |
364 | struct device_attribute *attr, const char *buf, size_t size) | |
365 | { | |
372e722e | 366 | struct gpio_desc *desc = dev_get_drvdata(dev); |
d8f388d8 DB |
367 | ssize_t status; |
368 | ||
369 | mutex_lock(&sysfs_lock); | |
370 | ||
371 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
372 | status = -EIO; | |
373 | else if (!test_bit(FLAG_IS_OUT, &desc->flags)) | |
374 | status = -EPERM; | |
375 | else { | |
376 | long value; | |
377 | ||
a3d88c92 | 378 | status = kstrtol(buf, 0, &value); |
d8f388d8 | 379 | if (status == 0) { |
79a9becd | 380 | gpiod_set_value_cansleep(desc, value); |
d8f388d8 DB |
381 | status = size; |
382 | } | |
383 | } | |
384 | ||
385 | mutex_unlock(&sysfs_lock); | |
386 | return status; | |
387 | } | |
388 | ||
07697461 | 389 | static const DEVICE_ATTR(value, 0644, |
d8f388d8 DB |
390 | gpio_value_show, gpio_value_store); |
391 | ||
ff77c352 DG |
392 | static irqreturn_t gpio_sysfs_irq(int irq, void *priv) |
393 | { | |
5ba1821d | 394 | struct sysfs_dirent *value_sd = priv; |
ff77c352 | 395 | |
5ba1821d | 396 | sysfs_notify_dirent(value_sd); |
ff77c352 DG |
397 | return IRQ_HANDLED; |
398 | } | |
399 | ||
ff77c352 DG |
400 | static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev, |
401 | unsigned long gpio_flags) | |
402 | { | |
5ba1821d | 403 | struct sysfs_dirent *value_sd; |
ff77c352 DG |
404 | unsigned long irq_flags; |
405 | int ret, irq, id; | |
406 | ||
407 | if ((desc->flags & GPIO_TRIGGER_MASK) == gpio_flags) | |
408 | return 0; | |
409 | ||
372e722e | 410 | irq = gpiod_to_irq(desc); |
ff77c352 DG |
411 | if (irq < 0) |
412 | return -EIO; | |
413 | ||
5ba1821d DG |
414 | id = desc->flags >> ID_SHIFT; |
415 | value_sd = idr_find(&dirent_idr, id); | |
416 | if (value_sd) | |
417 | free_irq(irq, value_sd); | |
ff77c352 DG |
418 | |
419 | desc->flags &= ~GPIO_TRIGGER_MASK; | |
420 | ||
421 | if (!gpio_flags) { | |
d468bf9e | 422 | gpiod_unlock_as_irq(desc); |
ff77c352 | 423 | ret = 0; |
5ba1821d | 424 | goto free_id; |
ff77c352 DG |
425 | } |
426 | ||
427 | irq_flags = IRQF_SHARED; | |
428 | if (test_bit(FLAG_TRIG_FALL, &gpio_flags)) | |
07697461 JN |
429 | irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? |
430 | IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING; | |
ff77c352 | 431 | if (test_bit(FLAG_TRIG_RISE, &gpio_flags)) |
07697461 JN |
432 | irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? |
433 | IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; | |
ff77c352 | 434 | |
5ba1821d DG |
435 | if (!value_sd) { |
436 | value_sd = sysfs_get_dirent(dev->kobj.sd, NULL, "value"); | |
437 | if (!value_sd) { | |
438 | ret = -ENODEV; | |
ff77c352 DG |
439 | goto err_out; |
440 | } | |
441 | ||
62f516b8 TH |
442 | ret = idr_alloc(&dirent_idr, value_sd, 1, 0, GFP_KERNEL); |
443 | if (ret < 0) | |
5ba1821d | 444 | goto free_sd; |
62f516b8 | 445 | id = ret; |
ff77c352 DG |
446 | |
447 | desc->flags &= GPIO_FLAGS_MASK; | |
5ba1821d | 448 | desc->flags |= (unsigned long)id << ID_SHIFT; |
ff77c352 | 449 | |
5ba1821d | 450 | if (desc->flags >> ID_SHIFT != id) { |
ff77c352 DG |
451 | ret = -ERANGE; |
452 | goto free_id; | |
453 | } | |
ff77c352 DG |
454 | } |
455 | ||
364fadb3 | 456 | ret = request_any_context_irq(irq, gpio_sysfs_irq, irq_flags, |
5ba1821d | 457 | "gpiolib", value_sd); |
364fadb3 | 458 | if (ret < 0) |
5ba1821d | 459 | goto free_id; |
ff77c352 | 460 | |
d468bf9e LW |
461 | ret = gpiod_lock_as_irq(desc); |
462 | if (ret < 0) { | |
463 | gpiod_warn(desc, "failed to flag the GPIO for IRQ\n"); | |
464 | goto free_id; | |
465 | } | |
466 | ||
ff77c352 DG |
467 | desc->flags |= gpio_flags; |
468 | return 0; | |
469 | ||
ff77c352 | 470 | free_id: |
5ba1821d | 471 | idr_remove(&dirent_idr, id); |
ff77c352 | 472 | desc->flags &= GPIO_FLAGS_MASK; |
5ba1821d DG |
473 | free_sd: |
474 | if (value_sd) | |
475 | sysfs_put(value_sd); | |
ff77c352 DG |
476 | err_out: |
477 | return ret; | |
478 | } | |
479 | ||
480 | static const struct { | |
481 | const char *name; | |
482 | unsigned long flags; | |
483 | } trigger_types[] = { | |
484 | { "none", 0 }, | |
485 | { "falling", BIT(FLAG_TRIG_FALL) }, | |
486 | { "rising", BIT(FLAG_TRIG_RISE) }, | |
487 | { "both", BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE) }, | |
488 | }; | |
489 | ||
490 | static ssize_t gpio_edge_show(struct device *dev, | |
491 | struct device_attribute *attr, char *buf) | |
492 | { | |
493 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
494 | ssize_t status; | |
495 | ||
496 | mutex_lock(&sysfs_lock); | |
497 | ||
498 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
499 | status = -EIO; | |
500 | else { | |
501 | int i; | |
502 | ||
503 | status = 0; | |
504 | for (i = 0; i < ARRAY_SIZE(trigger_types); i++) | |
505 | if ((desc->flags & GPIO_TRIGGER_MASK) | |
506 | == trigger_types[i].flags) { | |
507 | status = sprintf(buf, "%s\n", | |
508 | trigger_types[i].name); | |
509 | break; | |
510 | } | |
511 | } | |
512 | ||
513 | mutex_unlock(&sysfs_lock); | |
514 | return status; | |
515 | } | |
516 | ||
517 | static ssize_t gpio_edge_store(struct device *dev, | |
518 | struct device_attribute *attr, const char *buf, size_t size) | |
519 | { | |
520 | struct gpio_desc *desc = dev_get_drvdata(dev); | |
521 | ssize_t status; | |
522 | int i; | |
523 | ||
524 | for (i = 0; i < ARRAY_SIZE(trigger_types); i++) | |
525 | if (sysfs_streq(trigger_types[i].name, buf)) | |
526 | goto found; | |
527 | return -EINVAL; | |
528 | ||
529 | found: | |
530 | mutex_lock(&sysfs_lock); | |
531 | ||
532 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
533 | status = -EIO; | |
534 | else { | |
535 | status = gpio_setup_irq(desc, dev, trigger_types[i].flags); | |
536 | if (!status) | |
537 | status = size; | |
538 | } | |
539 | ||
540 | mutex_unlock(&sysfs_lock); | |
541 | ||
542 | return status; | |
543 | } | |
544 | ||
545 | static DEVICE_ATTR(edge, 0644, gpio_edge_show, gpio_edge_store); | |
546 | ||
07697461 JN |
547 | static int sysfs_set_active_low(struct gpio_desc *desc, struct device *dev, |
548 | int value) | |
549 | { | |
550 | int status = 0; | |
551 | ||
552 | if (!!test_bit(FLAG_ACTIVE_LOW, &desc->flags) == !!value) | |
553 | return 0; | |
554 | ||
555 | if (value) | |
556 | set_bit(FLAG_ACTIVE_LOW, &desc->flags); | |
557 | else | |
558 | clear_bit(FLAG_ACTIVE_LOW, &desc->flags); | |
559 | ||
560 | /* reconfigure poll(2) support if enabled on one edge only */ | |
561 | if (dev != NULL && (!!test_bit(FLAG_TRIG_RISE, &desc->flags) ^ | |
562 | !!test_bit(FLAG_TRIG_FALL, &desc->flags))) { | |
563 | unsigned long trigger_flags = desc->flags & GPIO_TRIGGER_MASK; | |
564 | ||
565 | gpio_setup_irq(desc, dev, 0); | |
566 | status = gpio_setup_irq(desc, dev, trigger_flags); | |
567 | } | |
568 | ||
569 | return status; | |
570 | } | |
571 | ||
572 | static ssize_t gpio_active_low_show(struct device *dev, | |
573 | struct device_attribute *attr, char *buf) | |
574 | { | |
575 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
576 | ssize_t status; | |
577 | ||
578 | mutex_lock(&sysfs_lock); | |
579 | ||
580 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
581 | status = -EIO; | |
582 | else | |
583 | status = sprintf(buf, "%d\n", | |
584 | !!test_bit(FLAG_ACTIVE_LOW, &desc->flags)); | |
585 | ||
586 | mutex_unlock(&sysfs_lock); | |
587 | ||
588 | return status; | |
589 | } | |
590 | ||
591 | static ssize_t gpio_active_low_store(struct device *dev, | |
592 | struct device_attribute *attr, const char *buf, size_t size) | |
593 | { | |
594 | struct gpio_desc *desc = dev_get_drvdata(dev); | |
595 | ssize_t status; | |
596 | ||
597 | mutex_lock(&sysfs_lock); | |
598 | ||
599 | if (!test_bit(FLAG_EXPORT, &desc->flags)) { | |
600 | status = -EIO; | |
601 | } else { | |
602 | long value; | |
603 | ||
a3d88c92 | 604 | status = kstrtol(buf, 0, &value); |
07697461 JN |
605 | if (status == 0) |
606 | status = sysfs_set_active_low(desc, dev, value != 0); | |
607 | } | |
608 | ||
609 | mutex_unlock(&sysfs_lock); | |
610 | ||
611 | return status ? : size; | |
612 | } | |
613 | ||
614 | static const DEVICE_ATTR(active_low, 0644, | |
615 | gpio_active_low_show, gpio_active_low_store); | |
616 | ||
d8f388d8 | 617 | static const struct attribute *gpio_attrs[] = { |
d8f388d8 | 618 | &dev_attr_value.attr, |
07697461 | 619 | &dev_attr_active_low.attr, |
d8f388d8 DB |
620 | NULL, |
621 | }; | |
622 | ||
623 | static const struct attribute_group gpio_attr_group = { | |
624 | .attrs = (struct attribute **) gpio_attrs, | |
625 | }; | |
626 | ||
627 | /* | |
628 | * /sys/class/gpio/gpiochipN/ | |
629 | * /base ... matching gpio_chip.base (N) | |
630 | * /label ... matching gpio_chip.label | |
631 | * /ngpio ... matching gpio_chip.ngpio | |
632 | */ | |
633 | ||
634 | static ssize_t chip_base_show(struct device *dev, | |
635 | struct device_attribute *attr, char *buf) | |
636 | { | |
637 | const struct gpio_chip *chip = dev_get_drvdata(dev); | |
638 | ||
639 | return sprintf(buf, "%d\n", chip->base); | |
640 | } | |
641 | static DEVICE_ATTR(base, 0444, chip_base_show, NULL); | |
642 | ||
643 | static ssize_t chip_label_show(struct device *dev, | |
644 | struct device_attribute *attr, char *buf) | |
645 | { | |
646 | const struct gpio_chip *chip = dev_get_drvdata(dev); | |
647 | ||
648 | return sprintf(buf, "%s\n", chip->label ? : ""); | |
649 | } | |
650 | static DEVICE_ATTR(label, 0444, chip_label_show, NULL); | |
651 | ||
652 | static ssize_t chip_ngpio_show(struct device *dev, | |
653 | struct device_attribute *attr, char *buf) | |
654 | { | |
655 | const struct gpio_chip *chip = dev_get_drvdata(dev); | |
656 | ||
657 | return sprintf(buf, "%u\n", chip->ngpio); | |
658 | } | |
659 | static DEVICE_ATTR(ngpio, 0444, chip_ngpio_show, NULL); | |
660 | ||
661 | static const struct attribute *gpiochip_attrs[] = { | |
662 | &dev_attr_base.attr, | |
663 | &dev_attr_label.attr, | |
664 | &dev_attr_ngpio.attr, | |
665 | NULL, | |
666 | }; | |
667 | ||
668 | static const struct attribute_group gpiochip_attr_group = { | |
669 | .attrs = (struct attribute **) gpiochip_attrs, | |
670 | }; | |
671 | ||
672 | /* | |
673 | * /sys/class/gpio/export ... write-only | |
674 | * integer N ... number of GPIO to export (full access) | |
675 | * /sys/class/gpio/unexport ... write-only | |
676 | * integer N ... number of GPIO to unexport | |
677 | */ | |
28812fe1 AK |
678 | static ssize_t export_store(struct class *class, |
679 | struct class_attribute *attr, | |
680 | const char *buf, size_t len) | |
d8f388d8 | 681 | { |
372e722e AC |
682 | long gpio; |
683 | struct gpio_desc *desc; | |
684 | int status; | |
d8f388d8 | 685 | |
a3d88c92 | 686 | status = kstrtol(buf, 0, &gpio); |
d8f388d8 DB |
687 | if (status < 0) |
688 | goto done; | |
689 | ||
372e722e | 690 | desc = gpio_to_desc(gpio); |
bcabdef1 AC |
691 | /* reject invalid GPIOs */ |
692 | if (!desc) { | |
693 | pr_warn("%s: invalid GPIO %ld\n", __func__, gpio); | |
694 | return -EINVAL; | |
695 | } | |
372e722e | 696 | |
d8f388d8 DB |
697 | /* No extra locking here; FLAG_SYSFS just signifies that the |
698 | * request and export were done by on behalf of userspace, so | |
699 | * they may be undone on its behalf too. | |
700 | */ | |
701 | ||
372e722e | 702 | status = gpiod_request(desc, "sysfs"); |
ad2fab36 MN |
703 | if (status < 0) { |
704 | if (status == -EPROBE_DEFER) | |
705 | status = -ENODEV; | |
d8f388d8 | 706 | goto done; |
ad2fab36 | 707 | } |
372e722e | 708 | status = gpiod_export(desc, true); |
d8f388d8 | 709 | if (status < 0) |
372e722e | 710 | gpiod_free(desc); |
d8f388d8 | 711 | else |
372e722e | 712 | set_bit(FLAG_SYSFS, &desc->flags); |
d8f388d8 DB |
713 | |
714 | done: | |
715 | if (status) | |
716 | pr_debug("%s: status %d\n", __func__, status); | |
717 | return status ? : len; | |
718 | } | |
719 | ||
28812fe1 AK |
720 | static ssize_t unexport_store(struct class *class, |
721 | struct class_attribute *attr, | |
722 | const char *buf, size_t len) | |
d8f388d8 | 723 | { |
372e722e AC |
724 | long gpio; |
725 | struct gpio_desc *desc; | |
726 | int status; | |
d8f388d8 | 727 | |
a3d88c92 | 728 | status = kstrtol(buf, 0, &gpio); |
d8f388d8 DB |
729 | if (status < 0) |
730 | goto done; | |
731 | ||
372e722e | 732 | desc = gpio_to_desc(gpio); |
d8f388d8 | 733 | /* reject bogus commands (gpio_unexport ignores them) */ |
bcabdef1 AC |
734 | if (!desc) { |
735 | pr_warn("%s: invalid GPIO %ld\n", __func__, gpio); | |
736 | return -EINVAL; | |
737 | } | |
738 | ||
739 | status = -EINVAL; | |
d8f388d8 DB |
740 | |
741 | /* No extra locking here; FLAG_SYSFS just signifies that the | |
742 | * request and export were done by on behalf of userspace, so | |
743 | * they may be undone on its behalf too. | |
744 | */ | |
372e722e | 745 | if (test_and_clear_bit(FLAG_SYSFS, &desc->flags)) { |
d8f388d8 | 746 | status = 0; |
372e722e | 747 | gpiod_free(desc); |
d8f388d8 DB |
748 | } |
749 | done: | |
750 | if (status) | |
751 | pr_debug("%s: status %d\n", __func__, status); | |
752 | return status ? : len; | |
753 | } | |
754 | ||
755 | static struct class_attribute gpio_class_attrs[] = { | |
756 | __ATTR(export, 0200, NULL, export_store), | |
757 | __ATTR(unexport, 0200, NULL, unexport_store), | |
758 | __ATTR_NULL, | |
759 | }; | |
760 | ||
761 | static struct class gpio_class = { | |
762 | .name = "gpio", | |
763 | .owner = THIS_MODULE, | |
764 | ||
765 | .class_attrs = gpio_class_attrs, | |
766 | }; | |
767 | ||
768 | ||
769 | /** | |
79a9becd | 770 | * gpiod_export - export a GPIO through sysfs |
d8f388d8 DB |
771 | * @gpio: gpio to make available, already requested |
772 | * @direction_may_change: true if userspace may change gpio direction | |
773 | * Context: arch_initcall or later | |
774 | * | |
775 | * When drivers want to make a GPIO accessible to userspace after they | |
776 | * have requested it -- perhaps while debugging, or as part of their | |
777 | * public interface -- they may use this routine. If the GPIO can | |
778 | * change direction (some can't) and the caller allows it, userspace | |
779 | * will see "direction" sysfs attribute which may be used to change | |
780 | * the gpio's direction. A "value" attribute will always be provided. | |
781 | * | |
782 | * Returns zero on success, else an error. | |
783 | */ | |
79a9becd | 784 | int gpiod_export(struct gpio_desc *desc, bool direction_may_change) |
d8f388d8 DB |
785 | { |
786 | unsigned long flags; | |
fc4e2514 | 787 | int status; |
62154991 | 788 | const char *ioname = NULL; |
fc4e2514 | 789 | struct device *dev; |
372e722e | 790 | int offset; |
d8f388d8 DB |
791 | |
792 | /* can't export until sysfs is available ... */ | |
793 | if (!gpio_class.p) { | |
794 | pr_debug("%s: called too early!\n", __func__); | |
795 | return -ENOENT; | |
796 | } | |
797 | ||
372e722e AC |
798 | if (!desc) { |
799 | pr_debug("%s: invalid gpio descriptor\n", __func__); | |
fc4e2514 RM |
800 | return -EINVAL; |
801 | } | |
d8f388d8 DB |
802 | |
803 | mutex_lock(&sysfs_lock); | |
804 | ||
805 | spin_lock_irqsave(&gpio_lock, flags); | |
fc4e2514 RM |
806 | if (!test_bit(FLAG_REQUESTED, &desc->flags) || |
807 | test_bit(FLAG_EXPORT, &desc->flags)) { | |
808 | spin_unlock_irqrestore(&gpio_lock, flags); | |
809 | pr_debug("%s: gpio %d unavailable (requested=%d, exported=%d)\n", | |
372e722e | 810 | __func__, desc_to_gpio(desc), |
fc4e2514 RM |
811 | test_bit(FLAG_REQUESTED, &desc->flags), |
812 | test_bit(FLAG_EXPORT, &desc->flags)); | |
529f2ad5 DC |
813 | status = -EPERM; |
814 | goto fail_unlock; | |
d8f388d8 | 815 | } |
fc4e2514 RM |
816 | |
817 | if (!desc->chip->direction_input || !desc->chip->direction_output) | |
818 | direction_may_change = false; | |
d8f388d8 DB |
819 | spin_unlock_irqrestore(&gpio_lock, flags); |
820 | ||
372e722e AC |
821 | offset = gpio_chip_hwgpio(desc); |
822 | if (desc->chip->names && desc->chip->names[offset]) | |
823 | ioname = desc->chip->names[offset]; | |
926b663c | 824 | |
fc4e2514 | 825 | dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0), |
372e722e AC |
826 | desc, ioname ? ioname : "gpio%u", |
827 | desc_to_gpio(desc)); | |
fc4e2514 RM |
828 | if (IS_ERR(dev)) { |
829 | status = PTR_ERR(dev); | |
830 | goto fail_unlock; | |
d8f388d8 DB |
831 | } |
832 | ||
fc4e2514 | 833 | status = sysfs_create_group(&dev->kobj, &gpio_attr_group); |
d8f388d8 | 834 | if (status) |
fc4e2514 | 835 | goto fail_unregister_device; |
d8f388d8 | 836 | |
fc4e2514 RM |
837 | if (direction_may_change) { |
838 | status = device_create_file(dev, &dev_attr_direction); | |
839 | if (status) | |
840 | goto fail_unregister_device; | |
841 | } | |
842 | ||
372e722e | 843 | if (gpiod_to_irq(desc) >= 0 && (direction_may_change || |
fc4e2514 RM |
844 | !test_bit(FLAG_IS_OUT, &desc->flags))) { |
845 | status = device_create_file(dev, &dev_attr_edge); | |
846 | if (status) | |
847 | goto fail_unregister_device; | |
848 | } | |
d8f388d8 | 849 | |
fc4e2514 RM |
850 | set_bit(FLAG_EXPORT, &desc->flags); |
851 | mutex_unlock(&sysfs_lock); | |
852 | return 0; | |
853 | ||
854 | fail_unregister_device: | |
855 | device_unregister(dev); | |
856 | fail_unlock: | |
857 | mutex_unlock(&sysfs_lock); | |
372e722e AC |
858 | pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc), |
859 | status); | |
d8f388d8 DB |
860 | return status; |
861 | } | |
79a9becd | 862 | EXPORT_SYMBOL_GPL(gpiod_export); |
d8f388d8 | 863 | |
9f3b795a | 864 | static int match_export(struct device *dev, const void *data) |
d8f388d8 DB |
865 | { |
866 | return dev_get_drvdata(dev) == data; | |
867 | } | |
868 | ||
a4177ee7 | 869 | /** |
79a9becd | 870 | * gpiod_export_link - create a sysfs link to an exported GPIO node |
a4177ee7 JN |
871 | * @dev: device under which to create symlink |
872 | * @name: name of the symlink | |
873 | * @gpio: gpio to create symlink to, already exported | |
874 | * | |
875 | * Set up a symlink from /sys/.../dev/name to /sys/class/gpio/gpioN | |
876 | * node. Caller is responsible for unlinking. | |
877 | * | |
878 | * Returns zero on success, else an error. | |
879 | */ | |
79a9becd AC |
880 | int gpiod_export_link(struct device *dev, const char *name, |
881 | struct gpio_desc *desc) | |
a4177ee7 | 882 | { |
a4177ee7 JN |
883 | int status = -EINVAL; |
884 | ||
bcabdef1 AC |
885 | if (!desc) { |
886 | pr_warn("%s: invalid GPIO\n", __func__); | |
887 | return -EINVAL; | |
888 | } | |
a4177ee7 JN |
889 | |
890 | mutex_lock(&sysfs_lock); | |
891 | ||
a4177ee7 JN |
892 | if (test_bit(FLAG_EXPORT, &desc->flags)) { |
893 | struct device *tdev; | |
894 | ||
895 | tdev = class_find_device(&gpio_class, NULL, desc, match_export); | |
896 | if (tdev != NULL) { | |
897 | status = sysfs_create_link(&dev->kobj, &tdev->kobj, | |
898 | name); | |
899 | } else { | |
900 | status = -ENODEV; | |
901 | } | |
902 | } | |
903 | ||
904 | mutex_unlock(&sysfs_lock); | |
905 | ||
a4177ee7 | 906 | if (status) |
372e722e AC |
907 | pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc), |
908 | status); | |
a4177ee7 JN |
909 | |
910 | return status; | |
911 | } | |
79a9becd | 912 | EXPORT_SYMBOL_GPL(gpiod_export_link); |
07697461 JN |
913 | |
914 | /** | |
79a9becd | 915 | * gpiod_sysfs_set_active_low - set the polarity of gpio sysfs value |
07697461 JN |
916 | * @gpio: gpio to change |
917 | * @value: non-zero to use active low, i.e. inverted values | |
918 | * | |
919 | * Set the polarity of /sys/class/gpio/gpioN/value sysfs attribute. | |
920 | * The GPIO does not have to be exported yet. If poll(2) support has | |
921 | * been enabled for either rising or falling edge, it will be | |
922 | * reconfigured to follow the new polarity. | |
923 | * | |
924 | * Returns zero on success, else an error. | |
925 | */ | |
79a9becd | 926 | int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value) |
07697461 | 927 | { |
07697461 JN |
928 | struct device *dev = NULL; |
929 | int status = -EINVAL; | |
930 | ||
bcabdef1 AC |
931 | if (!desc) { |
932 | pr_warn("%s: invalid GPIO\n", __func__); | |
933 | return -EINVAL; | |
934 | } | |
07697461 JN |
935 | |
936 | mutex_lock(&sysfs_lock); | |
937 | ||
07697461 | 938 | if (test_bit(FLAG_EXPORT, &desc->flags)) { |
07697461 JN |
939 | dev = class_find_device(&gpio_class, NULL, desc, match_export); |
940 | if (dev == NULL) { | |
941 | status = -ENODEV; | |
942 | goto unlock; | |
943 | } | |
944 | } | |
945 | ||
946 | status = sysfs_set_active_low(desc, dev, value); | |
947 | ||
948 | unlock: | |
949 | mutex_unlock(&sysfs_lock); | |
950 | ||
07697461 | 951 | if (status) |
372e722e AC |
952 | pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc), |
953 | status); | |
07697461 JN |
954 | |
955 | return status; | |
956 | } | |
79a9becd | 957 | EXPORT_SYMBOL_GPL(gpiod_sysfs_set_active_low); |
07697461 | 958 | |
d8f388d8 | 959 | /** |
79a9becd | 960 | * gpiod_unexport - reverse effect of gpio_export() |
d8f388d8 DB |
961 | * @gpio: gpio to make unavailable |
962 | * | |
963 | * This is implicit on gpio_free(). | |
964 | */ | |
79a9becd | 965 | void gpiod_unexport(struct gpio_desc *desc) |
d8f388d8 | 966 | { |
6a99ad4a | 967 | int status = 0; |
864533ce | 968 | struct device *dev = NULL; |
d8f388d8 | 969 | |
372e722e | 970 | if (!desc) { |
bcabdef1 AC |
971 | pr_warn("%s: invalid GPIO\n", __func__); |
972 | return; | |
6a99ad4a | 973 | } |
d8f388d8 DB |
974 | |
975 | mutex_lock(&sysfs_lock); | |
976 | ||
d8f388d8 | 977 | if (test_bit(FLAG_EXPORT, &desc->flags)) { |
d8f388d8 DB |
978 | |
979 | dev = class_find_device(&gpio_class, NULL, desc, match_export); | |
980 | if (dev) { | |
ff77c352 | 981 | gpio_setup_irq(desc, dev, 0); |
d8f388d8 | 982 | clear_bit(FLAG_EXPORT, &desc->flags); |
d8f388d8 DB |
983 | } else |
984 | status = -ENODEV; | |
985 | } | |
986 | ||
987 | mutex_unlock(&sysfs_lock); | |
372e722e | 988 | |
864533ce ML |
989 | if (dev) { |
990 | device_unregister(dev); | |
991 | put_device(dev); | |
992 | } | |
bcabdef1 | 993 | |
d8f388d8 | 994 | if (status) |
372e722e AC |
995 | pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc), |
996 | status); | |
997 | } | |
79a9becd | 998 | EXPORT_SYMBOL_GPL(gpiod_unexport); |
d8f388d8 DB |
999 | |
1000 | static int gpiochip_export(struct gpio_chip *chip) | |
1001 | { | |
1002 | int status; | |
1003 | struct device *dev; | |
1004 | ||
1005 | /* Many systems register gpio chips for SOC support very early, | |
1006 | * before driver model support is available. In those cases we | |
1007 | * export this later, in gpiolib_sysfs_init() ... here we just | |
1008 | * verify that _some_ field of gpio_class got initialized. | |
1009 | */ | |
1010 | if (!gpio_class.p) | |
1011 | return 0; | |
1012 | ||
1013 | /* use chip->base for the ID; it's already known to be unique */ | |
1014 | mutex_lock(&sysfs_lock); | |
1015 | dev = device_create(&gpio_class, chip->dev, MKDEV(0, 0), chip, | |
1016 | "gpiochip%d", chip->base); | |
d62668e1 | 1017 | if (!IS_ERR(dev)) { |
d8f388d8 DB |
1018 | status = sysfs_create_group(&dev->kobj, |
1019 | &gpiochip_attr_group); | |
1020 | } else | |
d62668e1 | 1021 | status = PTR_ERR(dev); |
d8f388d8 DB |
1022 | chip->exported = (status == 0); |
1023 | mutex_unlock(&sysfs_lock); | |
1024 | ||
1025 | if (status) { | |
1026 | unsigned long flags; | |
1027 | unsigned gpio; | |
1028 | ||
1029 | spin_lock_irqsave(&gpio_lock, flags); | |
6c0b4e6c AC |
1030 | gpio = 0; |
1031 | while (gpio < chip->ngpio) | |
1032 | chip->desc[gpio++].chip = NULL; | |
d8f388d8 DB |
1033 | spin_unlock_irqrestore(&gpio_lock, flags); |
1034 | ||
1035 | pr_debug("%s: chip %s status %d\n", __func__, | |
1036 | chip->label, status); | |
1037 | } | |
1038 | ||
1039 | return status; | |
1040 | } | |
1041 | ||
1042 | static void gpiochip_unexport(struct gpio_chip *chip) | |
1043 | { | |
1044 | int status; | |
1045 | struct device *dev; | |
1046 | ||
1047 | mutex_lock(&sysfs_lock); | |
1048 | dev = class_find_device(&gpio_class, NULL, chip, match_export); | |
1049 | if (dev) { | |
1050 | put_device(dev); | |
1051 | device_unregister(dev); | |
1052 | chip->exported = 0; | |
1053 | status = 0; | |
1054 | } else | |
1055 | status = -ENODEV; | |
1056 | mutex_unlock(&sysfs_lock); | |
1057 | ||
1058 | if (status) | |
1059 | pr_debug("%s: chip %s status %d\n", __func__, | |
1060 | chip->label, status); | |
1061 | } | |
1062 | ||
1063 | static int __init gpiolib_sysfs_init(void) | |
1064 | { | |
1065 | int status; | |
1066 | unsigned long flags; | |
65493e3a | 1067 | struct gpio_chip *chip; |
d8f388d8 DB |
1068 | |
1069 | status = class_register(&gpio_class); | |
1070 | if (status < 0) | |
1071 | return status; | |
1072 | ||
1073 | /* Scan and register the gpio_chips which registered very | |
1074 | * early (e.g. before the class_register above was called). | |
1075 | * | |
1076 | * We run before arch_initcall() so chip->dev nodes can have | |
1077 | * registered, and so arch_initcall() can always gpio_export(). | |
1078 | */ | |
1079 | spin_lock_irqsave(&gpio_lock, flags); | |
65493e3a | 1080 | list_for_each_entry(chip, &gpio_chips, list) { |
d8f388d8 DB |
1081 | if (!chip || chip->exported) |
1082 | continue; | |
1083 | ||
1084 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1085 | status = gpiochip_export(chip); | |
1086 | spin_lock_irqsave(&gpio_lock, flags); | |
1087 | } | |
1088 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1089 | ||
1090 | ||
1091 | return status; | |
1092 | } | |
1093 | postcore_initcall(gpiolib_sysfs_init); | |
1094 | ||
1095 | #else | |
1096 | static inline int gpiochip_export(struct gpio_chip *chip) | |
1097 | { | |
1098 | return 0; | |
1099 | } | |
1100 | ||
1101 | static inline void gpiochip_unexport(struct gpio_chip *chip) | |
1102 | { | |
1103 | } | |
1104 | ||
1105 | #endif /* CONFIG_GPIO_SYSFS */ | |
1106 | ||
1a989d0f AC |
1107 | /* |
1108 | * Add a new chip to the global chips list, keeping the list of chips sorted | |
1109 | * by base order. | |
1110 | * | |
1111 | * Return -EBUSY if the new chip overlaps with some other chip's integer | |
1112 | * space. | |
1113 | */ | |
1114 | static int gpiochip_add_to_list(struct gpio_chip *chip) | |
1115 | { | |
1116 | struct list_head *pos = &gpio_chips; | |
1117 | struct gpio_chip *_chip; | |
1118 | int err = 0; | |
1119 | ||
1120 | /* find where to insert our chip */ | |
1121 | list_for_each(pos, &gpio_chips) { | |
1122 | _chip = list_entry(pos, struct gpio_chip, list); | |
1123 | /* shall we insert before _chip? */ | |
1124 | if (_chip->base >= chip->base + chip->ngpio) | |
1125 | break; | |
1126 | } | |
1127 | ||
1128 | /* are we stepping on the chip right before? */ | |
1129 | if (pos != &gpio_chips && pos->prev != &gpio_chips) { | |
1130 | _chip = list_entry(pos->prev, struct gpio_chip, list); | |
1131 | if (_chip->base + _chip->ngpio > chip->base) { | |
1132 | dev_err(chip->dev, | |
1133 | "GPIO integer space overlap, cannot add chip\n"); | |
1134 | err = -EBUSY; | |
1135 | } | |
1136 | } | |
1137 | ||
1138 | if (!err) | |
1139 | list_add_tail(&chip->list, pos); | |
1140 | ||
1141 | return err; | |
1142 | } | |
1143 | ||
d2876d08 DB |
1144 | /** |
1145 | * gpiochip_add() - register a gpio_chip | |
1146 | * @chip: the chip to register, with chip->base initialized | |
1147 | * Context: potentially before irqs or kmalloc will work | |
1148 | * | |
1149 | * Returns a negative errno if the chip can't be registered, such as | |
1150 | * because the chip->base is invalid or already associated with a | |
1151 | * different chip. Otherwise it returns zero as a success code. | |
8d0aab2f | 1152 | * |
d8f388d8 DB |
1153 | * When gpiochip_add() is called very early during boot, so that GPIOs |
1154 | * can be freely used, the chip->dev device must be registered before | |
1155 | * the gpio framework's arch_initcall(). Otherwise sysfs initialization | |
1156 | * for GPIOs will fail rudely. | |
1157 | * | |
8d0aab2f AV |
1158 | * If chip->base is negative, this requests dynamic assignment of |
1159 | * a range of valid GPIOs. | |
d2876d08 DB |
1160 | */ |
1161 | int gpiochip_add(struct gpio_chip *chip) | |
1162 | { | |
1163 | unsigned long flags; | |
1164 | int status = 0; | |
1165 | unsigned id; | |
8d0aab2f | 1166 | int base = chip->base; |
d2876d08 | 1167 | |
bff5fda9 | 1168 | if ((!gpio_is_valid(base) || !gpio_is_valid(base + chip->ngpio - 1)) |
8d0aab2f | 1169 | && base >= 0) { |
d2876d08 DB |
1170 | status = -EINVAL; |
1171 | goto fail; | |
1172 | } | |
1173 | ||
1174 | spin_lock_irqsave(&gpio_lock, flags); | |
1175 | ||
8d0aab2f AV |
1176 | if (base < 0) { |
1177 | base = gpiochip_find_base(chip->ngpio); | |
1178 | if (base < 0) { | |
1179 | status = base; | |
d8f388d8 | 1180 | goto unlock; |
8d0aab2f AV |
1181 | } |
1182 | chip->base = base; | |
1183 | } | |
1184 | ||
1a989d0f AC |
1185 | status = gpiochip_add_to_list(chip); |
1186 | ||
d2876d08 | 1187 | if (status == 0) { |
6c0b4e6c AC |
1188 | chip->desc = &gpio_desc[chip->base]; |
1189 | ||
1190 | for (id = 0; id < chip->ngpio; id++) { | |
1191 | struct gpio_desc *desc = &chip->desc[id]; | |
1192 | desc->chip = chip; | |
d8f388d8 DB |
1193 | |
1194 | /* REVISIT: most hardware initializes GPIOs as | |
1195 | * inputs (often with pullups enabled) so power | |
1196 | * usage is minimized. Linux code should set the | |
1197 | * gpio direction first thing; but until it does, | |
80b0a602 | 1198 | * and in case chip->get_direction is not set, |
d8f388d8 DB |
1199 | * we may expose the wrong direction in sysfs. |
1200 | */ | |
6c0b4e6c | 1201 | desc->flags = !chip->direction_input |
d8f388d8 DB |
1202 | ? (1 << FLAG_IS_OUT) |
1203 | : 0; | |
d2876d08 DB |
1204 | } |
1205 | } | |
1206 | ||
3bae4811 ZG |
1207 | spin_unlock_irqrestore(&gpio_lock, flags); |
1208 | ||
f23f1516 SH |
1209 | #ifdef CONFIG_PINCTRL |
1210 | INIT_LIST_HEAD(&chip->pin_ranges); | |
1211 | #endif | |
1212 | ||
391c970c AV |
1213 | of_gpiochip_add(chip); |
1214 | ||
cedb1881 AV |
1215 | if (status) |
1216 | goto fail; | |
1217 | ||
1218 | status = gpiochip_export(chip); | |
1219 | if (status) | |
1220 | goto fail; | |
1221 | ||
ee1c1e7d | 1222 | pr_debug("gpiochip_add: registered GPIOs %d to %d on device: %s\n", |
64842aad GL |
1223 | chip->base, chip->base + chip->ngpio - 1, |
1224 | chip->label ? : "generic"); | |
1225 | ||
cedb1881 | 1226 | return 0; |
3bae4811 ZG |
1227 | |
1228 | unlock: | |
1229 | spin_unlock_irqrestore(&gpio_lock, flags); | |
d2876d08 DB |
1230 | fail: |
1231 | /* failures here can mean systems won't boot... */ | |
cedb1881 AV |
1232 | pr_err("gpiochip_add: gpios %d..%d (%s) failed to register\n", |
1233 | chip->base, chip->base + chip->ngpio - 1, | |
1234 | chip->label ? : "generic"); | |
d2876d08 DB |
1235 | return status; |
1236 | } | |
1237 | EXPORT_SYMBOL_GPL(gpiochip_add); | |
1238 | ||
1239 | /** | |
1240 | * gpiochip_remove() - unregister a gpio_chip | |
1241 | * @chip: the chip to unregister | |
1242 | * | |
1243 | * A gpio_chip with any GPIOs still requested may not be removed. | |
1244 | */ | |
1245 | int gpiochip_remove(struct gpio_chip *chip) | |
1246 | { | |
1247 | unsigned long flags; | |
1248 | int status = 0; | |
1249 | unsigned id; | |
1250 | ||
1251 | spin_lock_irqsave(&gpio_lock, flags); | |
1252 | ||
9ef0d6f7 | 1253 | gpiochip_remove_pin_ranges(chip); |
391c970c AV |
1254 | of_gpiochip_remove(chip); |
1255 | ||
6c0b4e6c AC |
1256 | for (id = 0; id < chip->ngpio; id++) { |
1257 | if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) { | |
d2876d08 DB |
1258 | status = -EBUSY; |
1259 | break; | |
1260 | } | |
1261 | } | |
1262 | if (status == 0) { | |
6c0b4e6c AC |
1263 | for (id = 0; id < chip->ngpio; id++) |
1264 | chip->desc[id].chip = NULL; | |
1a989d0f AC |
1265 | |
1266 | list_del(&chip->list); | |
d2876d08 DB |
1267 | } |
1268 | ||
1269 | spin_unlock_irqrestore(&gpio_lock, flags); | |
d8f388d8 DB |
1270 | |
1271 | if (status == 0) | |
1272 | gpiochip_unexport(chip); | |
1273 | ||
d2876d08 DB |
1274 | return status; |
1275 | } | |
1276 | EXPORT_SYMBOL_GPL(gpiochip_remove); | |
1277 | ||
594fa265 GL |
1278 | /** |
1279 | * gpiochip_find() - iterator for locating a specific gpio_chip | |
1280 | * @data: data to pass to match function | |
1281 | * @callback: Callback function to check gpio_chip | |
1282 | * | |
1283 | * Similar to bus_find_device. It returns a reference to a gpio_chip as | |
1284 | * determined by a user supplied @match callback. The callback should return | |
1285 | * 0 if the device doesn't match and non-zero if it does. If the callback is | |
1286 | * non-zero, this function will return to the caller and not iterate over any | |
1287 | * more gpio_chips. | |
1288 | */ | |
07ce8ec7 | 1289 | struct gpio_chip *gpiochip_find(void *data, |
6e2cf651 | 1290 | int (*match)(struct gpio_chip *chip, |
3d0f7cf0 | 1291 | void *data)) |
594fa265 | 1292 | { |
125eef96 | 1293 | struct gpio_chip *chip; |
594fa265 | 1294 | unsigned long flags; |
594fa265 GL |
1295 | |
1296 | spin_lock_irqsave(&gpio_lock, flags); | |
125eef96 AC |
1297 | list_for_each_entry(chip, &gpio_chips, list) |
1298 | if (match(chip, data)) | |
594fa265 | 1299 | break; |
125eef96 AC |
1300 | |
1301 | /* No match? */ | |
1302 | if (&chip->list == &gpio_chips) | |
1303 | chip = NULL; | |
594fa265 GL |
1304 | spin_unlock_irqrestore(&gpio_lock, flags); |
1305 | ||
1306 | return chip; | |
1307 | } | |
8fa0c9bf | 1308 | EXPORT_SYMBOL_GPL(gpiochip_find); |
d2876d08 | 1309 | |
f23f1516 | 1310 | #ifdef CONFIG_PINCTRL |
165adc9c | 1311 | |
3f0f8670 LW |
1312 | /** |
1313 | * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping | |
1314 | * @chip: the gpiochip to add the range for | |
1315 | * @pinctrl_name: the dev_name() of the pin controller to map to | |
316511c0 LW |
1316 | * @gpio_offset: the start offset in the current gpio_chip number space |
1317 | * @pin_offset: the start offset in the pin controller number space | |
3f0f8670 LW |
1318 | * @npins: the number of pins from the offset of each pin space (GPIO and |
1319 | * pin controller) to accumulate in this range | |
1320 | */ | |
1e63d7b9 | 1321 | int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name, |
316511c0 | 1322 | unsigned int gpio_offset, unsigned int pin_offset, |
3f0f8670 | 1323 | unsigned int npins) |
f23f1516 SH |
1324 | { |
1325 | struct gpio_pin_range *pin_range; | |
b4d4b1f0 | 1326 | int ret; |
f23f1516 | 1327 | |
3f0f8670 | 1328 | pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL); |
f23f1516 SH |
1329 | if (!pin_range) { |
1330 | pr_err("%s: GPIO chip: failed to allocate pin ranges\n", | |
1331 | chip->label); | |
1e63d7b9 | 1332 | return -ENOMEM; |
f23f1516 SH |
1333 | } |
1334 | ||
3f0f8670 | 1335 | /* Use local offset as range ID */ |
316511c0 | 1336 | pin_range->range.id = gpio_offset; |
3f0f8670 | 1337 | pin_range->range.gc = chip; |
f23f1516 | 1338 | pin_range->range.name = chip->label; |
316511c0 LW |
1339 | pin_range->range.base = chip->base + gpio_offset; |
1340 | pin_range->range.pin_base = pin_offset; | |
f23f1516 | 1341 | pin_range->range.npins = npins; |
192c369c | 1342 | pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name, |
f23f1516 | 1343 | &pin_range->range); |
8f23ca1a | 1344 | if (IS_ERR(pin_range->pctldev)) { |
b4d4b1f0 | 1345 | ret = PTR_ERR(pin_range->pctldev); |
3f0f8670 LW |
1346 | pr_err("%s: GPIO chip: could not create pin range\n", |
1347 | chip->label); | |
1348 | kfree(pin_range); | |
b4d4b1f0 | 1349 | return ret; |
3f0f8670 | 1350 | } |
316511c0 LW |
1351 | pr_debug("GPIO chip %s: created GPIO range %d->%d ==> %s PIN %d->%d\n", |
1352 | chip->label, gpio_offset, gpio_offset + npins - 1, | |
1353 | pinctl_name, | |
1354 | pin_offset, pin_offset + npins - 1); | |
f23f1516 SH |
1355 | |
1356 | list_add_tail(&pin_range->node, &chip->pin_ranges); | |
1e63d7b9 LW |
1357 | |
1358 | return 0; | |
f23f1516 | 1359 | } |
165adc9c | 1360 | EXPORT_SYMBOL_GPL(gpiochip_add_pin_range); |
f23f1516 | 1361 | |
3f0f8670 LW |
1362 | /** |
1363 | * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings | |
1364 | * @chip: the chip to remove all the mappings for | |
1365 | */ | |
f23f1516 SH |
1366 | void gpiochip_remove_pin_ranges(struct gpio_chip *chip) |
1367 | { | |
1368 | struct gpio_pin_range *pin_range, *tmp; | |
1369 | ||
1370 | list_for_each_entry_safe(pin_range, tmp, &chip->pin_ranges, node) { | |
1371 | list_del(&pin_range->node); | |
1372 | pinctrl_remove_gpio_range(pin_range->pctldev, | |
1373 | &pin_range->range); | |
3f0f8670 | 1374 | kfree(pin_range); |
f23f1516 SH |
1375 | } |
1376 | } | |
165adc9c LW |
1377 | EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges); |
1378 | ||
1379 | #endif /* CONFIG_PINCTRL */ | |
f23f1516 | 1380 | |
d2876d08 DB |
1381 | /* These "optional" allocation calls help prevent drivers from stomping |
1382 | * on each other, and help provide better diagnostics in debugfs. | |
1383 | * They're called even less than the "set direction" calls. | |
1384 | */ | |
372e722e | 1385 | static int gpiod_request(struct gpio_desc *desc, const char *label) |
d2876d08 | 1386 | { |
35e8bb51 | 1387 | struct gpio_chip *chip; |
e9354576 | 1388 | int status = -EPROBE_DEFER; |
d2876d08 DB |
1389 | unsigned long flags; |
1390 | ||
0204df47 | 1391 | if (!desc) { |
bcabdef1 AC |
1392 | pr_warn("%s: invalid GPIO\n", __func__); |
1393 | return -EINVAL; | |
ad2fab36 | 1394 | } |
bcabdef1 AC |
1395 | |
1396 | spin_lock_irqsave(&gpio_lock, flags); | |
1397 | ||
35e8bb51 | 1398 | chip = desc->chip; |
0204df47 AC |
1399 | if (chip == NULL) |
1400 | goto done; | |
d2876d08 | 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 | 1439 | pr_debug("_gpio_request: gpio-%d (%s) status %d\n", |
bcabdef1 | 1440 | desc_to_gpio(desc), label ? : "?", status); |
d2876d08 DB |
1441 | spin_unlock_irqrestore(&gpio_lock, flags); |
1442 | return status; | |
1443 | } | |
372e722e AC |
1444 | |
1445 | int gpio_request(unsigned gpio, const char *label) | |
1446 | { | |
1447 | return gpiod_request(gpio_to_desc(gpio), label); | |
1448 | } | |
d2876d08 DB |
1449 | EXPORT_SYMBOL_GPL(gpio_request); |
1450 | ||
372e722e | 1451 | static void gpiod_free(struct gpio_desc *desc) |
d2876d08 DB |
1452 | { |
1453 | unsigned long flags; | |
35e8bb51 | 1454 | struct gpio_chip *chip; |
d2876d08 | 1455 | |
3d599d1c UKK |
1456 | might_sleep(); |
1457 | ||
372e722e | 1458 | if (!desc) { |
d2876d08 DB |
1459 | WARN_ON(extra_checks); |
1460 | return; | |
1461 | } | |
1462 | ||
372e722e | 1463 | gpiod_unexport(desc); |
d8f388d8 | 1464 | |
d2876d08 DB |
1465 | spin_lock_irqsave(&gpio_lock, flags); |
1466 | ||
35e8bb51 DB |
1467 | chip = desc->chip; |
1468 | if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) { | |
1469 | if (chip->free) { | |
1470 | spin_unlock_irqrestore(&gpio_lock, flags); | |
9c4ba946 | 1471 | might_sleep_if(chip->can_sleep); |
372e722e | 1472 | chip->free(chip, gpio_chip_hwgpio(desc)); |
35e8bb51 DB |
1473 | spin_lock_irqsave(&gpio_lock, flags); |
1474 | } | |
d2876d08 | 1475 | desc_set_label(desc, NULL); |
438d8908 | 1476 | module_put(desc->chip->owner); |
07697461 | 1477 | clear_bit(FLAG_ACTIVE_LOW, &desc->flags); |
35e8bb51 | 1478 | clear_bit(FLAG_REQUESTED, &desc->flags); |
aca5ce14 | 1479 | clear_bit(FLAG_OPEN_DRAIN, &desc->flags); |
25553ff0 | 1480 | clear_bit(FLAG_OPEN_SOURCE, &desc->flags); |
438d8908 | 1481 | } else |
d2876d08 DB |
1482 | WARN_ON(extra_checks); |
1483 | ||
1484 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1485 | } | |
372e722e AC |
1486 | |
1487 | void gpio_free(unsigned gpio) | |
1488 | { | |
1489 | gpiod_free(gpio_to_desc(gpio)); | |
1490 | } | |
d2876d08 DB |
1491 | EXPORT_SYMBOL_GPL(gpio_free); |
1492 | ||
3e45f1d1 EM |
1493 | /** |
1494 | * gpio_request_one - request a single GPIO with initial configuration | |
1495 | * @gpio: the GPIO number | |
1496 | * @flags: GPIO configuration as specified by GPIOF_* | |
1497 | * @label: a literal description string of this GPIO | |
1498 | */ | |
1499 | int gpio_request_one(unsigned gpio, unsigned long flags, const char *label) | |
1500 | { | |
372e722e | 1501 | struct gpio_desc *desc; |
3e45f1d1 EM |
1502 | int err; |
1503 | ||
372e722e AC |
1504 | desc = gpio_to_desc(gpio); |
1505 | ||
1506 | err = gpiod_request(desc, label); | |
3e45f1d1 EM |
1507 | if (err) |
1508 | return err; | |
1509 | ||
aca5ce14 | 1510 | if (flags & GPIOF_OPEN_DRAIN) |
372e722e | 1511 | set_bit(FLAG_OPEN_DRAIN, &desc->flags); |
aca5ce14 | 1512 | |
25553ff0 | 1513 | if (flags & GPIOF_OPEN_SOURCE) |
372e722e | 1514 | set_bit(FLAG_OPEN_SOURCE, &desc->flags); |
25553ff0 | 1515 | |
3e45f1d1 | 1516 | if (flags & GPIOF_DIR_IN) |
372e722e | 1517 | err = gpiod_direction_input(desc); |
3e45f1d1 | 1518 | else |
372e722e | 1519 | err = gpiod_direction_output(desc, |
3e45f1d1 EM |
1520 | (flags & GPIOF_INIT_HIGH) ? 1 : 0); |
1521 | ||
e254811c | 1522 | if (err) |
fc3a1f04 WS |
1523 | goto free_gpio; |
1524 | ||
1525 | if (flags & GPIOF_EXPORT) { | |
372e722e | 1526 | err = gpiod_export(desc, flags & GPIOF_EXPORT_CHANGEABLE); |
fc3a1f04 WS |
1527 | if (err) |
1528 | goto free_gpio; | |
1529 | } | |
1530 | ||
1531 | return 0; | |
e254811c | 1532 | |
fc3a1f04 | 1533 | free_gpio: |
372e722e | 1534 | gpiod_free(desc); |
3e45f1d1 EM |
1535 | return err; |
1536 | } | |
1537 | EXPORT_SYMBOL_GPL(gpio_request_one); | |
1538 | ||
1539 | /** | |
1540 | * gpio_request_array - request multiple GPIOs in a single call | |
1541 | * @array: array of the 'struct gpio' | |
1542 | * @num: how many GPIOs in the array | |
1543 | */ | |
7c295975 | 1544 | int gpio_request_array(const struct gpio *array, size_t num) |
3e45f1d1 EM |
1545 | { |
1546 | int i, err; | |
1547 | ||
1548 | for (i = 0; i < num; i++, array++) { | |
1549 | err = gpio_request_one(array->gpio, array->flags, array->label); | |
1550 | if (err) | |
1551 | goto err_free; | |
1552 | } | |
1553 | return 0; | |
1554 | ||
1555 | err_free: | |
1556 | while (i--) | |
1557 | gpio_free((--array)->gpio); | |
1558 | return err; | |
1559 | } | |
1560 | EXPORT_SYMBOL_GPL(gpio_request_array); | |
1561 | ||
1562 | /** | |
1563 | * gpio_free_array - release multiple GPIOs in a single call | |
1564 | * @array: array of the 'struct gpio' | |
1565 | * @num: how many GPIOs in the array | |
1566 | */ | |
7c295975 | 1567 | void gpio_free_array(const struct gpio *array, size_t num) |
3e45f1d1 EM |
1568 | { |
1569 | while (num--) | |
1570 | gpio_free((array++)->gpio); | |
1571 | } | |
1572 | EXPORT_SYMBOL_GPL(gpio_free_array); | |
d2876d08 DB |
1573 | |
1574 | /** | |
1575 | * gpiochip_is_requested - return string iff signal was requested | |
1576 | * @chip: controller managing the signal | |
1577 | * @offset: of signal within controller's 0..(ngpio - 1) range | |
1578 | * | |
1579 | * Returns NULL if the GPIO is not currently requested, else a string. | |
1580 | * If debugfs support is enabled, the string returned is the label passed | |
1581 | * to gpio_request(); otherwise it is a meaningless constant. | |
1582 | * | |
1583 | * This function is for use by GPIO controller drivers. The label can | |
1584 | * help with diagnostics, and knowing that the signal is used as a GPIO | |
1585 | * can help avoid accidentally multiplexing it to another controller. | |
1586 | */ | |
1587 | const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset) | |
1588 | { | |
6c0b4e6c | 1589 | struct gpio_desc *desc; |
d2876d08 | 1590 | |
6c0b4e6c | 1591 | if (!GPIO_OFFSET_VALID(chip, offset)) |
d2876d08 | 1592 | return NULL; |
6c0b4e6c AC |
1593 | |
1594 | desc = &chip->desc[offset]; | |
1595 | ||
372e722e | 1596 | if (test_bit(FLAG_REQUESTED, &desc->flags) == 0) |
d2876d08 DB |
1597 | return NULL; |
1598 | #ifdef CONFIG_DEBUG_FS | |
372e722e | 1599 | return desc->label; |
d2876d08 DB |
1600 | #else |
1601 | return "?"; | |
1602 | #endif | |
1603 | } | |
1604 | EXPORT_SYMBOL_GPL(gpiochip_is_requested); | |
1605 | ||
1606 | ||
1607 | /* Drivers MUST set GPIO direction before making get/set calls. In | |
1608 | * some cases this is done in early boot, before IRQs are enabled. | |
1609 | * | |
1610 | * As a rule these aren't called more than once (except for drivers | |
1611 | * using the open-drain emulation idiom) so these are natural places | |
1612 | * to accumulate extra debugging checks. Note that we can't (yet) | |
1613 | * rely on gpio_request() having been called beforehand. | |
1614 | */ | |
1615 | ||
79a9becd AC |
1616 | /** |
1617 | * gpiod_direction_input - set the GPIO direction to input | |
1618 | * @desc: GPIO to set to input | |
1619 | * | |
1620 | * Set the direction of the passed GPIO to input, such as gpiod_get_value() can | |
1621 | * be called safely on it. | |
1622 | * | |
1623 | * Return 0 in case of success, else an error code. | |
1624 | */ | |
1625 | int gpiod_direction_input(struct gpio_desc *desc) | |
d2876d08 DB |
1626 | { |
1627 | unsigned long flags; | |
1628 | struct gpio_chip *chip; | |
d2876d08 | 1629 | int status = -EINVAL; |
372e722e | 1630 | int offset; |
d2876d08 | 1631 | |
be1a4b13 | 1632 | if (!desc || !desc->chip) { |
bcabdef1 AC |
1633 | pr_warn("%s: invalid GPIO\n", __func__); |
1634 | return -EINVAL; | |
1635 | } | |
1636 | ||
be1a4b13 LW |
1637 | chip = desc->chip; |
1638 | if (!chip->get || !chip->direction_input) { | |
6424de5a MB |
1639 | gpiod_warn(desc, |
1640 | "%s: missing get() or direction_input() operations\n", | |
1641 | __func__); | |
be1a4b13 LW |
1642 | return -EIO; |
1643 | } | |
1644 | ||
d2876d08 DB |
1645 | spin_lock_irqsave(&gpio_lock, flags); |
1646 | ||
372e722e | 1647 | status = gpio_ensure_requested(desc); |
35e8bb51 DB |
1648 | if (status < 0) |
1649 | goto fail; | |
d2876d08 DB |
1650 | |
1651 | /* now we know the gpio is valid and chip won't vanish */ | |
1652 | ||
1653 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1654 | ||
9c4ba946 | 1655 | might_sleep_if(chip->can_sleep); |
d2876d08 | 1656 | |
372e722e | 1657 | offset = gpio_chip_hwgpio(desc); |
35e8bb51 | 1658 | if (status) { |
372e722e | 1659 | status = chip->request(chip, offset); |
35e8bb51 | 1660 | if (status < 0) { |
6424de5a | 1661 | gpiod_dbg(desc, "chip request fail, %d\n", status); |
35e8bb51 DB |
1662 | /* and it's not available to anyone else ... |
1663 | * gpio_request() is the fully clean solution. | |
1664 | */ | |
1665 | goto lose; | |
1666 | } | |
1667 | } | |
1668 | ||
372e722e | 1669 | status = chip->direction_input(chip, offset); |
d2876d08 DB |
1670 | if (status == 0) |
1671 | clear_bit(FLAG_IS_OUT, &desc->flags); | |
3f397c21 | 1672 | |
372e722e | 1673 | trace_gpio_direction(desc_to_gpio(desc), 1, status); |
35e8bb51 | 1674 | lose: |
d2876d08 DB |
1675 | return status; |
1676 | fail: | |
1677 | spin_unlock_irqrestore(&gpio_lock, flags); | |
bcabdef1 | 1678 | if (status) |
6424de5a | 1679 | gpiod_dbg(desc, "%s status %d\n", __func__, status); |
d2876d08 DB |
1680 | return status; |
1681 | } | |
79a9becd | 1682 | EXPORT_SYMBOL_GPL(gpiod_direction_input); |
372e722e | 1683 | |
79a9becd AC |
1684 | /** |
1685 | * gpiod_direction_output - set the GPIO direction to input | |
1686 | * @desc: GPIO to set to output | |
1687 | * @value: initial output value of the GPIO | |
1688 | * | |
1689 | * Set the direction of the passed GPIO to output, such as gpiod_set_value() can | |
1690 | * be called safely on it. The initial value of the output must be specified. | |
1691 | * | |
1692 | * Return 0 in case of success, else an error code. | |
1693 | */ | |
1694 | int gpiod_direction_output(struct gpio_desc *desc, int value) | |
d2876d08 DB |
1695 | { |
1696 | unsigned long flags; | |
1697 | struct gpio_chip *chip; | |
d2876d08 | 1698 | int status = -EINVAL; |
372e722e | 1699 | int offset; |
d2876d08 | 1700 | |
be1a4b13 | 1701 | if (!desc || !desc->chip) { |
bcabdef1 AC |
1702 | pr_warn("%s: invalid GPIO\n", __func__); |
1703 | return -EINVAL; | |
1704 | } | |
1705 | ||
d468bf9e LW |
1706 | /* GPIOs used for IRQs shall not be set as output */ |
1707 | if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) { | |
1708 | gpiod_err(desc, | |
1709 | "%s: tried to set a GPIO tied to an IRQ as output\n", | |
1710 | __func__); | |
1711 | return -EIO; | |
1712 | } | |
1713 | ||
aca5ce14 LD |
1714 | /* Open drain pin should not be driven to 1 */ |
1715 | if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags)) | |
372e722e | 1716 | return gpiod_direction_input(desc); |
aca5ce14 | 1717 | |
25553ff0 LD |
1718 | /* Open source pin should not be driven to 0 */ |
1719 | if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags)) | |
372e722e | 1720 | return gpiod_direction_input(desc); |
25553ff0 | 1721 | |
be1a4b13 LW |
1722 | chip = desc->chip; |
1723 | if (!chip->set || !chip->direction_output) { | |
6424de5a MB |
1724 | gpiod_warn(desc, |
1725 | "%s: missing set() or direction_output() operations\n", | |
1726 | __func__); | |
be1a4b13 LW |
1727 | return -EIO; |
1728 | } | |
1729 | ||
d2876d08 DB |
1730 | spin_lock_irqsave(&gpio_lock, flags); |
1731 | ||
372e722e | 1732 | status = gpio_ensure_requested(desc); |
35e8bb51 DB |
1733 | if (status < 0) |
1734 | goto fail; | |
d2876d08 DB |
1735 | |
1736 | /* now we know the gpio is valid and chip won't vanish */ | |
1737 | ||
1738 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1739 | ||
9c4ba946 | 1740 | might_sleep_if(chip->can_sleep); |
d2876d08 | 1741 | |
372e722e | 1742 | offset = gpio_chip_hwgpio(desc); |
35e8bb51 | 1743 | if (status) { |
372e722e | 1744 | status = chip->request(chip, offset); |
35e8bb51 | 1745 | if (status < 0) { |
6424de5a | 1746 | gpiod_dbg(desc, "chip request fail, %d\n", status); |
35e8bb51 DB |
1747 | /* and it's not available to anyone else ... |
1748 | * gpio_request() is the fully clean solution. | |
1749 | */ | |
1750 | goto lose; | |
1751 | } | |
1752 | } | |
1753 | ||
372e722e | 1754 | status = chip->direction_output(chip, offset, value); |
d2876d08 DB |
1755 | if (status == 0) |
1756 | set_bit(FLAG_IS_OUT, &desc->flags); | |
372e722e AC |
1757 | trace_gpio_value(desc_to_gpio(desc), 0, value); |
1758 | trace_gpio_direction(desc_to_gpio(desc), 0, status); | |
35e8bb51 | 1759 | lose: |
d2876d08 DB |
1760 | return status; |
1761 | fail: | |
1762 | spin_unlock_irqrestore(&gpio_lock, flags); | |
bcabdef1 | 1763 | if (status) |
6424de5a | 1764 | gpiod_dbg(desc, "%s: gpio status %d\n", __func__, status); |
d2876d08 DB |
1765 | return status; |
1766 | } | |
79a9becd | 1767 | EXPORT_SYMBOL_GPL(gpiod_direction_output); |
d2876d08 | 1768 | |
c4b5be98 | 1769 | /** |
79a9becd | 1770 | * gpiod_set_debounce - sets @debounce time for a @gpio |
c4b5be98 FB |
1771 | * @gpio: the gpio to set debounce time |
1772 | * @debounce: debounce time is microseconds | |
65d87656 LW |
1773 | * |
1774 | * returns -ENOTSUPP if the controller does not support setting | |
1775 | * debounce. | |
c4b5be98 | 1776 | */ |
79a9becd | 1777 | int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) |
c4b5be98 FB |
1778 | { |
1779 | unsigned long flags; | |
1780 | struct gpio_chip *chip; | |
c4b5be98 | 1781 | int status = -EINVAL; |
372e722e | 1782 | int offset; |
c4b5be98 | 1783 | |
be1a4b13 | 1784 | if (!desc || !desc->chip) { |
bcabdef1 AC |
1785 | pr_warn("%s: invalid GPIO\n", __func__); |
1786 | return -EINVAL; | |
1787 | } | |
1788 | ||
c4b5be98 | 1789 | chip = desc->chip; |
be1a4b13 | 1790 | if (!chip->set || !chip->set_debounce) { |
6424de5a MB |
1791 | gpiod_dbg(desc, |
1792 | "%s: missing set() or set_debounce() operations\n", | |
1793 | __func__); | |
65d87656 | 1794 | return -ENOTSUPP; |
be1a4b13 LW |
1795 | } |
1796 | ||
1797 | spin_lock_irqsave(&gpio_lock, flags); | |
372e722e AC |
1798 | |
1799 | status = gpio_ensure_requested(desc); | |
c4b5be98 FB |
1800 | if (status < 0) |
1801 | goto fail; | |
1802 | ||
1803 | /* now we know the gpio is valid and chip won't vanish */ | |
1804 | ||
1805 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1806 | ||
9c4ba946 | 1807 | might_sleep_if(chip->can_sleep); |
c4b5be98 | 1808 | |
372e722e AC |
1809 | offset = gpio_chip_hwgpio(desc); |
1810 | return chip->set_debounce(chip, offset, debounce); | |
c4b5be98 FB |
1811 | |
1812 | fail: | |
1813 | spin_unlock_irqrestore(&gpio_lock, flags); | |
bcabdef1 | 1814 | if (status) |
6424de5a | 1815 | gpiod_dbg(desc, "%s: status %d\n", __func__, status); |
c4b5be98 FB |
1816 | |
1817 | return status; | |
1818 | } | |
79a9becd | 1819 | EXPORT_SYMBOL_GPL(gpiod_set_debounce); |
372e722e | 1820 | |
79a9becd AC |
1821 | /** |
1822 | * gpiod_is_active_low - test whether a GPIO is active-low or not | |
1823 | * @desc: the gpio descriptor to test | |
1824 | * | |
1825 | * Returns 1 if the GPIO is active-low, 0 otherwise. | |
1826 | */ | |
1827 | int gpiod_is_active_low(const struct gpio_desc *desc) | |
372e722e | 1828 | { |
79a9becd | 1829 | return test_bit(FLAG_ACTIVE_LOW, &desc->flags); |
372e722e | 1830 | } |
79a9becd | 1831 | EXPORT_SYMBOL_GPL(gpiod_is_active_low); |
d2876d08 DB |
1832 | |
1833 | /* I/O calls are only valid after configuration completed; the relevant | |
1834 | * "is this a valid GPIO" error checks should already have been done. | |
1835 | * | |
1836 | * "Get" operations are often inlinable as reading a pin value register, | |
1837 | * and masking the relevant bit in that register. | |
1838 | * | |
1839 | * When "set" operations are inlinable, they involve writing that mask to | |
1840 | * one register to set a low value, or a different register to set it high. | |
1841 | * Otherwise locking is needed, so there may be little value to inlining. | |
1842 | * | |
1843 | *------------------------------------------------------------------------ | |
1844 | * | |
1845 | * IMPORTANT!!! The hot paths -- get/set value -- assume that callers | |
1846 | * have requested the GPIO. That can include implicit requesting by | |
1847 | * a direction setting call. Marking a gpio as requested locks its chip | |
1848 | * in memory, guaranteeing that these table lookups need no more locking | |
1849 | * and that gpiochip_remove() will fail. | |
1850 | * | |
1851 | * REVISIT when debugging, consider adding some instrumentation to ensure | |
1852 | * that the GPIO was actually requested. | |
1853 | */ | |
1854 | ||
79a9becd | 1855 | static int _gpiod_get_raw_value(const struct gpio_desc *desc) |
d8e0ac08 AC |
1856 | { |
1857 | struct gpio_chip *chip; | |
1858 | int value; | |
1859 | int offset; | |
1860 | ||
1861 | chip = desc->chip; | |
1862 | offset = gpio_chip_hwgpio(desc); | |
1863 | value = chip->get ? chip->get(chip, offset) : 0; | |
1864 | trace_gpio_value(desc_to_gpio(desc), 1, value); | |
1865 | return value; | |
1866 | } | |
1867 | ||
d2876d08 | 1868 | /** |
79a9becd AC |
1869 | * gpiod_get_raw_value() - return a gpio's raw value |
1870 | * @desc: gpio whose value will be returned | |
d2876d08 | 1871 | * |
79a9becd AC |
1872 | * Return the GPIO's raw value, i.e. the value of the physical line disregarding |
1873 | * its ACTIVE_LOW status. | |
1874 | * | |
1875 | * This function should be called from contexts where we cannot sleep, and will | |
1876 | * complain if the GPIO chip functions potentially sleep. | |
d2876d08 | 1877 | */ |
79a9becd | 1878 | int gpiod_get_raw_value(const struct gpio_desc *desc) |
d2876d08 | 1879 | { |
bcabdef1 AC |
1880 | if (!desc) |
1881 | return 0; | |
e4e449e8 | 1882 | /* Should be using gpio_get_value_cansleep() */ |
d8e0ac08 | 1883 | WARN_ON(desc->chip->can_sleep); |
79a9becd | 1884 | return _gpiod_get_raw_value(desc); |
d2876d08 | 1885 | } |
79a9becd | 1886 | EXPORT_SYMBOL_GPL(gpiod_get_raw_value); |
372e722e | 1887 | |
79a9becd AC |
1888 | /** |
1889 | * gpiod_get_value() - return a gpio's value | |
1890 | * @desc: gpio whose value will be returned | |
1891 | * | |
1892 | * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into | |
1893 | * account. | |
1894 | * | |
1895 | * This function should be called from contexts where we cannot sleep, and will | |
1896 | * complain if the GPIO chip functions potentially sleep. | |
1897 | */ | |
1898 | int gpiod_get_value(const struct gpio_desc *desc) | |
372e722e | 1899 | { |
79a9becd AC |
1900 | int value; |
1901 | if (!desc) | |
1902 | return 0; | |
1903 | /* Should be using gpio_get_value_cansleep() */ | |
1904 | WARN_ON(desc->chip->can_sleep); | |
1905 | ||
1906 | value = _gpiod_get_raw_value(desc); | |
1907 | if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) | |
1908 | value = !value; | |
1909 | ||
1910 | return value; | |
372e722e | 1911 | } |
79a9becd | 1912 | EXPORT_SYMBOL_GPL(gpiod_get_value); |
d2876d08 | 1913 | |
aca5ce14 LD |
1914 | /* |
1915 | * _gpio_set_open_drain_value() - Set the open drain gpio's value. | |
79a9becd | 1916 | * @desc: gpio descriptor whose state need to be set. |
aca5ce14 LD |
1917 | * @value: Non-zero for setting it HIGH otherise it will set to LOW. |
1918 | */ | |
372e722e | 1919 | static void _gpio_set_open_drain_value(struct gpio_desc *desc, int value) |
aca5ce14 LD |
1920 | { |
1921 | int err = 0; | |
372e722e AC |
1922 | struct gpio_chip *chip = desc->chip; |
1923 | int offset = gpio_chip_hwgpio(desc); | |
1924 | ||
aca5ce14 | 1925 | if (value) { |
372e722e | 1926 | err = chip->direction_input(chip, offset); |
aca5ce14 | 1927 | if (!err) |
372e722e | 1928 | clear_bit(FLAG_IS_OUT, &desc->flags); |
aca5ce14 | 1929 | } else { |
372e722e | 1930 | err = chip->direction_output(chip, offset, 0); |
aca5ce14 | 1931 | if (!err) |
372e722e | 1932 | set_bit(FLAG_IS_OUT, &desc->flags); |
aca5ce14 | 1933 | } |
372e722e | 1934 | trace_gpio_direction(desc_to_gpio(desc), value, err); |
aca5ce14 | 1935 | if (err < 0) |
6424de5a MB |
1936 | gpiod_err(desc, |
1937 | "%s: Error in set_value for open drain err %d\n", | |
1938 | __func__, err); | |
aca5ce14 LD |
1939 | } |
1940 | ||
25553ff0 | 1941 | /* |
79a9becd AC |
1942 | * _gpio_set_open_source_value() - Set the open source gpio's value. |
1943 | * @desc: gpio descriptor whose state need to be set. | |
25553ff0 LD |
1944 | * @value: Non-zero for setting it HIGH otherise it will set to LOW. |
1945 | */ | |
372e722e | 1946 | static void _gpio_set_open_source_value(struct gpio_desc *desc, int value) |
25553ff0 LD |
1947 | { |
1948 | int err = 0; | |
372e722e AC |
1949 | struct gpio_chip *chip = desc->chip; |
1950 | int offset = gpio_chip_hwgpio(desc); | |
1951 | ||
25553ff0 | 1952 | if (value) { |
372e722e | 1953 | err = chip->direction_output(chip, offset, 1); |
25553ff0 | 1954 | if (!err) |
372e722e | 1955 | set_bit(FLAG_IS_OUT, &desc->flags); |
25553ff0 | 1956 | } else { |
372e722e | 1957 | err = chip->direction_input(chip, offset); |
25553ff0 | 1958 | if (!err) |
372e722e | 1959 | clear_bit(FLAG_IS_OUT, &desc->flags); |
25553ff0 | 1960 | } |
372e722e | 1961 | trace_gpio_direction(desc_to_gpio(desc), !value, err); |
25553ff0 | 1962 | if (err < 0) |
6424de5a MB |
1963 | gpiod_err(desc, |
1964 | "%s: Error in set_value for open source err %d\n", | |
1965 | __func__, err); | |
25553ff0 LD |
1966 | } |
1967 | ||
79a9becd | 1968 | static void _gpiod_set_raw_value(struct gpio_desc *desc, int value) |
d8e0ac08 AC |
1969 | { |
1970 | struct gpio_chip *chip; | |
1971 | ||
1972 | chip = desc->chip; | |
1973 | trace_gpio_value(desc_to_gpio(desc), 0, value); | |
1974 | if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) | |
1975 | _gpio_set_open_drain_value(desc, value); | |
1976 | else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) | |
1977 | _gpio_set_open_source_value(desc, value); | |
1978 | else | |
1979 | chip->set(chip, gpio_chip_hwgpio(desc), value); | |
1980 | } | |
1981 | ||
d2876d08 | 1982 | /** |
79a9becd AC |
1983 | * gpiod_set_raw_value() - assign a gpio's raw value |
1984 | * @desc: gpio whose value will be assigned | |
d2876d08 | 1985 | * @value: value to assign |
d2876d08 | 1986 | * |
79a9becd AC |
1987 | * Set the raw value of the GPIO, i.e. the value of its physical line without |
1988 | * regard for its ACTIVE_LOW status. | |
1989 | * | |
1990 | * This function should be called from contexts where we cannot sleep, and will | |
1991 | * complain if the GPIO chip functions potentially sleep. | |
d2876d08 | 1992 | */ |
79a9becd | 1993 | void gpiod_set_raw_value(struct gpio_desc *desc, int value) |
d2876d08 | 1994 | { |
bcabdef1 AC |
1995 | if (!desc) |
1996 | return; | |
e4e449e8 | 1997 | /* Should be using gpio_set_value_cansleep() */ |
d8e0ac08 | 1998 | WARN_ON(desc->chip->can_sleep); |
79a9becd | 1999 | _gpiod_set_raw_value(desc, value); |
372e722e | 2000 | } |
79a9becd | 2001 | EXPORT_SYMBOL_GPL(gpiod_set_raw_value); |
372e722e | 2002 | |
79a9becd AC |
2003 | /** |
2004 | * gpiod_set_value() - assign a gpio's value | |
2005 | * @desc: gpio whose value will be assigned | |
2006 | * @value: value to assign | |
2007 | * | |
2008 | * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into | |
2009 | * account | |
2010 | * | |
2011 | * This function should be called from contexts where we cannot sleep, and will | |
2012 | * complain if the GPIO chip functions potentially sleep. | |
2013 | */ | |
2014 | void gpiod_set_value(struct gpio_desc *desc, int value) | |
372e722e | 2015 | { |
79a9becd AC |
2016 | if (!desc) |
2017 | return; | |
2018 | /* Should be using gpio_set_value_cansleep() */ | |
2019 | WARN_ON(desc->chip->can_sleep); | |
2020 | if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) | |
2021 | value = !value; | |
2022 | _gpiod_set_raw_value(desc, value); | |
d2876d08 | 2023 | } |
79a9becd | 2024 | EXPORT_SYMBOL_GPL(gpiod_set_value); |
d2876d08 DB |
2025 | |
2026 | /** | |
79a9becd AC |
2027 | * gpiod_cansleep() - report whether gpio value access may sleep |
2028 | * @desc: gpio to check | |
d2876d08 | 2029 | * |
d2876d08 | 2030 | */ |
79a9becd | 2031 | int gpiod_cansleep(const struct gpio_desc *desc) |
d2876d08 | 2032 | { |
bcabdef1 AC |
2033 | if (!desc) |
2034 | return 0; | |
372e722e AC |
2035 | return desc->chip->can_sleep; |
2036 | } | |
79a9becd | 2037 | EXPORT_SYMBOL_GPL(gpiod_cansleep); |
d2876d08 | 2038 | |
0f6d504e | 2039 | /** |
79a9becd AC |
2040 | * gpiod_to_irq() - return the IRQ corresponding to a GPIO |
2041 | * @desc: gpio whose IRQ will be returned (already requested) | |
0f6d504e | 2042 | * |
79a9becd AC |
2043 | * Return the IRQ corresponding to the passed GPIO, or an error code in case of |
2044 | * error. | |
0f6d504e | 2045 | */ |
79a9becd | 2046 | int gpiod_to_irq(const struct gpio_desc *desc) |
0f6d504e DB |
2047 | { |
2048 | struct gpio_chip *chip; | |
372e722e | 2049 | int offset; |
0f6d504e | 2050 | |
bcabdef1 AC |
2051 | if (!desc) |
2052 | return -EINVAL; | |
372e722e AC |
2053 | chip = desc->chip; |
2054 | offset = gpio_chip_hwgpio(desc); | |
2055 | return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO; | |
0f6d504e | 2056 | } |
79a9becd | 2057 | EXPORT_SYMBOL_GPL(gpiod_to_irq); |
d2876d08 | 2058 | |
d468bf9e LW |
2059 | /** |
2060 | * gpiod_lock_as_irq() - lock a GPIO to be used as IRQ | |
2061 | * @gpio: the GPIO line to lock as used for IRQ | |
2062 | * | |
2063 | * This is used directly by GPIO drivers that want to lock down | |
2064 | * a certain GPIO line to be used as IRQs, for example in the | |
2065 | * .to_irq() callback of their gpio_chip, or in the .irq_enable() | |
2066 | * of its irq_chip implementation if the GPIO is known from that | |
2067 | * code. | |
2068 | */ | |
79a9becd | 2069 | int gpiod_lock_as_irq(struct gpio_desc *desc) |
d468bf9e LW |
2070 | { |
2071 | if (!desc) | |
2072 | return -EINVAL; | |
2073 | ||
2074 | if (test_bit(FLAG_IS_OUT, &desc->flags)) { | |
2075 | gpiod_err(desc, | |
2076 | "%s: tried to flag a GPIO set as output for IRQ\n", | |
2077 | __func__); | |
2078 | return -EIO; | |
2079 | } | |
2080 | ||
2081 | set_bit(FLAG_USED_AS_IRQ, &desc->flags); | |
2082 | return 0; | |
2083 | } | |
79a9becd | 2084 | EXPORT_SYMBOL_GPL(gpiod_lock_as_irq); |
d468bf9e LW |
2085 | |
2086 | int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset) | |
2087 | { | |
2088 | return gpiod_lock_as_irq(gpiochip_offset_to_desc(chip, offset)); | |
2089 | } | |
2090 | EXPORT_SYMBOL_GPL(gpio_lock_as_irq); | |
2091 | ||
2092 | /** | |
2093 | * gpiod_unlock_as_irq() - unlock a GPIO used as IRQ | |
2094 | * @gpio: the GPIO line to unlock from IRQ usage | |
2095 | * | |
2096 | * This is used directly by GPIO drivers that want to indicate | |
2097 | * that a certain GPIO is no longer used exclusively for IRQ. | |
2098 | */ | |
79a9becd | 2099 | void gpiod_unlock_as_irq(struct gpio_desc *desc) |
d468bf9e LW |
2100 | { |
2101 | if (!desc) | |
2102 | return; | |
2103 | ||
2104 | clear_bit(FLAG_USED_AS_IRQ, &desc->flags); | |
2105 | } | |
79a9becd | 2106 | EXPORT_SYMBOL_GPL(gpiod_unlock_as_irq); |
d468bf9e LW |
2107 | |
2108 | void gpio_unlock_as_irq(struct gpio_chip *chip, unsigned int offset) | |
2109 | { | |
2110 | return gpiod_unlock_as_irq(gpiochip_offset_to_desc(chip, offset)); | |
2111 | } | |
2112 | EXPORT_SYMBOL_GPL(gpio_unlock_as_irq); | |
d2876d08 | 2113 | |
79a9becd AC |
2114 | /** |
2115 | * gpiod_get_raw_value_cansleep() - return a gpio's raw value | |
2116 | * @desc: gpio whose value will be returned | |
2117 | * | |
2118 | * Return the GPIO's raw value, i.e. the value of the physical line disregarding | |
2119 | * its ACTIVE_LOW status. | |
2120 | * | |
2121 | * This function is to be called from contexts that can sleep. | |
d2876d08 | 2122 | */ |
79a9becd | 2123 | int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc) |
d2876d08 | 2124 | { |
d2876d08 | 2125 | might_sleep_if(extra_checks); |
bcabdef1 AC |
2126 | if (!desc) |
2127 | return 0; | |
79a9becd | 2128 | return _gpiod_get_raw_value(desc); |
d2876d08 | 2129 | } |
79a9becd | 2130 | EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep); |
372e722e | 2131 | |
79a9becd AC |
2132 | /** |
2133 | * gpiod_get_value_cansleep() - return a gpio's value | |
2134 | * @desc: gpio whose value will be returned | |
2135 | * | |
2136 | * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into | |
2137 | * account. | |
2138 | * | |
2139 | * This function is to be called from contexts that can sleep. | |
2140 | */ | |
2141 | int gpiod_get_value_cansleep(const struct gpio_desc *desc) | |
372e722e | 2142 | { |
79a9becd AC |
2143 | int value; |
2144 | ||
2145 | might_sleep_if(extra_checks); | |
2146 | if (!desc) | |
2147 | return 0; | |
2148 | ||
2149 | value = _gpiod_get_raw_value(desc); | |
2150 | if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) | |
2151 | value = !value; | |
2152 | ||
2153 | return value; | |
372e722e | 2154 | } |
79a9becd | 2155 | EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep); |
d2876d08 | 2156 | |
79a9becd AC |
2157 | /** |
2158 | * gpiod_set_raw_value_cansleep() - assign a gpio's raw value | |
2159 | * @desc: gpio whose value will be assigned | |
2160 | * @value: value to assign | |
2161 | * | |
2162 | * Set the raw value of the GPIO, i.e. the value of its physical line without | |
2163 | * regard for its ACTIVE_LOW status. | |
2164 | * | |
2165 | * This function is to be called from contexts that can sleep. | |
2166 | */ | |
2167 | void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value) | |
d2876d08 | 2168 | { |
d2876d08 | 2169 | might_sleep_if(extra_checks); |
bcabdef1 AC |
2170 | if (!desc) |
2171 | return; | |
79a9becd | 2172 | _gpiod_set_raw_value(desc, value); |
d2876d08 | 2173 | } |
79a9becd | 2174 | EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep); |
d2876d08 | 2175 | |
79a9becd AC |
2176 | /** |
2177 | * gpiod_set_value_cansleep() - assign a gpio's value | |
2178 | * @desc: gpio whose value will be assigned | |
2179 | * @value: value to assign | |
2180 | * | |
2181 | * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into | |
2182 | * account | |
2183 | * | |
2184 | * This function is to be called from contexts that can sleep. | |
2185 | */ | |
2186 | void gpiod_set_value_cansleep(struct gpio_desc *desc, int value) | |
372e722e | 2187 | { |
79a9becd AC |
2188 | might_sleep_if(extra_checks); |
2189 | if (!desc) | |
2190 | return; | |
2191 | ||
2192 | if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) | |
2193 | value = !value; | |
2194 | _gpiod_set_raw_value(desc, value); | |
372e722e | 2195 | } |
79a9becd | 2196 | EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep); |
d2876d08 | 2197 | |
bae48da2 AC |
2198 | /** |
2199 | * gpiod_add_table() - register GPIO device consumers | |
2200 | * @table: array of consumers to register | |
2201 | * @num: number of consumers in table | |
2202 | */ | |
2203 | void gpiod_add_table(struct gpiod_lookup *table, size_t size) | |
2204 | { | |
2205 | mutex_lock(&gpio_lookup_lock); | |
2206 | ||
2207 | while (size--) { | |
2208 | list_add_tail(&table->list, &gpio_lookup_list); | |
2209 | table++; | |
2210 | } | |
2211 | ||
2212 | mutex_unlock(&gpio_lookup_lock); | |
2213 | } | |
2214 | ||
2215 | /* | |
2216 | * Caller must have a acquired gpio_lookup_lock | |
2217 | */ | |
2218 | static struct gpio_chip *find_chip_by_name(const char *name) | |
2219 | { | |
2220 | struct gpio_chip *chip = NULL; | |
2221 | ||
2222 | list_for_each_entry(chip, &gpio_lookup_list, list) { | |
2223 | if (chip->label == NULL) | |
2224 | continue; | |
2225 | if (!strcmp(chip->label, name)) | |
2226 | break; | |
2227 | } | |
2228 | ||
2229 | return chip; | |
2230 | } | |
2231 | ||
2232 | #ifdef CONFIG_OF | |
2233 | static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, | |
2234 | unsigned int idx, unsigned long *flags) | |
2235 | { | |
2236 | char prop_name[32]; /* 32 is max size of property name */ | |
2237 | enum of_gpio_flags of_flags; | |
2238 | struct gpio_desc *desc; | |
2239 | ||
2240 | if (con_id) | |
2241 | snprintf(prop_name, 32, "%s-gpios", con_id); | |
2242 | else | |
2243 | snprintf(prop_name, 32, "gpios"); | |
2244 | ||
2245 | desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx, | |
2246 | &of_flags); | |
2247 | ||
2248 | if (IS_ERR(desc)) | |
2249 | return desc; | |
2250 | ||
2251 | if (of_flags & OF_GPIO_ACTIVE_LOW) | |
2252 | *flags |= GPIOF_ACTIVE_LOW; | |
2253 | ||
2254 | return desc; | |
2255 | } | |
2256 | #else | |
2257 | static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, | |
2258 | unsigned int idx, unsigned long *flags) | |
2259 | { | |
2260 | return ERR_PTR(-ENODEV); | |
2261 | } | |
2262 | #endif | |
2263 | ||
81f59e9d MW |
2264 | static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id, |
2265 | unsigned int idx, unsigned long *flags) | |
2266 | { | |
2267 | return acpi_get_gpiod_by_index(dev, idx, NULL); | |
2268 | } | |
2269 | ||
bae48da2 AC |
2270 | static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id, |
2271 | unsigned int idx, unsigned long *flags) | |
2272 | { | |
2273 | const char *dev_id = dev ? dev_name(dev) : NULL; | |
2274 | struct gpio_desc *desc = ERR_PTR(-ENODEV); | |
2275 | unsigned int match, best = 0; | |
2276 | struct gpiod_lookup *p; | |
2277 | ||
2278 | mutex_lock(&gpio_lookup_lock); | |
2279 | ||
2280 | list_for_each_entry(p, &gpio_lookup_list, list) { | |
2281 | match = 0; | |
2282 | ||
2283 | if (p->dev_id) { | |
2284 | if (!dev_id || strcmp(p->dev_id, dev_id)) | |
2285 | continue; | |
2286 | ||
2287 | match += 2; | |
2288 | } | |
2289 | ||
2290 | if (p->con_id) { | |
2291 | if (!con_id || strcmp(p->con_id, con_id)) | |
2292 | continue; | |
2293 | ||
2294 | match += 1; | |
2295 | } | |
2296 | ||
2297 | if (p->idx != idx) | |
2298 | continue; | |
2299 | ||
2300 | if (match > best) { | |
2301 | struct gpio_chip *chip; | |
2302 | ||
2303 | chip = find_chip_by_name(p->chip_label); | |
2304 | ||
2305 | if (!chip) { | |
2306 | dev_warn(dev, "cannot find GPIO chip %s\n", | |
2307 | p->chip_label); | |
2308 | continue; | |
2309 | } | |
2310 | ||
2311 | if (chip->ngpio >= p->chip_hwnum) { | |
2312 | dev_warn(dev, "GPIO chip %s has %d GPIOs\n", | |
2313 | chip->label, chip->ngpio); | |
2314 | continue; | |
2315 | } | |
2316 | ||
2317 | desc = gpio_to_desc(chip->base + p->chip_hwnum); | |
2318 | *flags = p->flags; | |
2319 | ||
2320 | if (match != 3) | |
2321 | best = match; | |
2322 | else | |
2323 | break; | |
2324 | } | |
2325 | } | |
2326 | ||
2327 | mutex_unlock(&gpio_lookup_lock); | |
2328 | ||
2329 | return desc; | |
2330 | } | |
2331 | ||
2332 | /** | |
2333 | * gpio_get - obtain a GPIO for a given GPIO function | |
2334 | * @dev: GPIO consumer | |
2335 | * @con_id: function within the GPIO consumer | |
2336 | * | |
2337 | * Return the GPIO descriptor corresponding to the function con_id of device | |
2338 | * dev, or an IS_ERR() condition if an error occured. | |
2339 | */ | |
2340 | struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id) | |
2341 | { | |
2342 | return gpiod_get_index(dev, con_id, 0); | |
2343 | } | |
2344 | EXPORT_SYMBOL_GPL(gpiod_get); | |
2345 | ||
2346 | /** | |
2347 | * gpiod_get_index - obtain a GPIO from a multi-index GPIO function | |
2348 | * @dev: GPIO consumer | |
2349 | * @con_id: function within the GPIO consumer | |
2350 | * @idx: index of the GPIO to obtain in the consumer | |
2351 | * | |
2352 | * This variant of gpiod_get() allows to access GPIOs other than the first | |
2353 | * defined one for functions that define several GPIOs. | |
2354 | * | |
2355 | * Return a valid GPIO descriptor, or an IS_ERR() condition in case of error. | |
2356 | */ | |
2357 | struct gpio_desc *__must_check gpiod_get_index(struct device *dev, | |
2358 | const char *con_id, | |
2359 | unsigned int idx) | |
2360 | { | |
2361 | struct gpio_desc *desc; | |
2362 | int status; | |
2363 | unsigned long flags = 0; | |
2364 | ||
2365 | dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id); | |
2366 | ||
2367 | /* Using device tree? */ | |
2368 | if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) { | |
2369 | dev_dbg(dev, "using device tree for GPIO lookup\n"); | |
2370 | desc = of_find_gpio(dev, con_id, idx, &flags); | |
81f59e9d MW |
2371 | } else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev)) { |
2372 | dev_dbg(dev, "using ACPI for GPIO lookup\n"); | |
2373 | desc = acpi_find_gpio(dev, con_id, idx, &flags); | |
bae48da2 AC |
2374 | } else { |
2375 | dev_dbg(dev, "using lookup tables for GPIO lookup"); | |
2376 | desc = gpiod_find(dev, con_id, idx, &flags); | |
2377 | } | |
2378 | ||
2379 | if (IS_ERR(desc)) { | |
2380 | dev_warn(dev, "lookup for GPIO %s failed\n", con_id); | |
2381 | return desc; | |
2382 | } | |
2383 | ||
2384 | status = gpiod_request(desc, con_id); | |
2385 | ||
2386 | if (status < 0) | |
2387 | return ERR_PTR(status); | |
2388 | ||
2389 | if (flags & GPIOF_ACTIVE_LOW) | |
2390 | set_bit(FLAG_ACTIVE_LOW, &desc->flags); | |
2391 | ||
2392 | return desc; | |
2393 | } | |
2394 | EXPORT_SYMBOL_GPL(gpiod_get_index); | |
2395 | ||
2396 | /** | |
2397 | * gpiod_put - dispose of a GPIO descriptor | |
2398 | * @desc: GPIO descriptor to dispose of | |
2399 | * | |
2400 | * No descriptor can be used after gpiod_put() has been called on it. | |
2401 | */ | |
2402 | void gpiod_put(struct gpio_desc *desc) | |
2403 | { | |
2404 | gpiod_free(desc); | |
2405 | } | |
2406 | EXPORT_SYMBOL_GPL(gpiod_put); | |
2407 | ||
d2876d08 DB |
2408 | #ifdef CONFIG_DEBUG_FS |
2409 | ||
d2876d08 DB |
2410 | static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) |
2411 | { | |
2412 | unsigned i; | |
2413 | unsigned gpio = chip->base; | |
6c0b4e6c | 2414 | struct gpio_desc *gdesc = &chip->desc[0]; |
d2876d08 | 2415 | int is_out; |
d468bf9e | 2416 | int is_irq; |
d2876d08 DB |
2417 | |
2418 | for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) { | |
2419 | if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) | |
2420 | continue; | |
2421 | ||
372e722e | 2422 | gpiod_get_direction(gdesc); |
d2876d08 | 2423 | is_out = test_bit(FLAG_IS_OUT, &gdesc->flags); |
d468bf9e LW |
2424 | is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags); |
2425 | seq_printf(s, " gpio-%-3d (%-20.20s) %s %s %s", | |
d2876d08 DB |
2426 | gpio, gdesc->label, |
2427 | is_out ? "out" : "in ", | |
2428 | chip->get | |
2429 | ? (chip->get(chip, i) ? "hi" : "lo") | |
d468bf9e LW |
2430 | : "? ", |
2431 | is_irq ? "IRQ" : " "); | |
d2876d08 DB |
2432 | seq_printf(s, "\n"); |
2433 | } | |
2434 | } | |
2435 | ||
f9c4a31f | 2436 | static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos) |
d2876d08 | 2437 | { |
362432ae | 2438 | unsigned long flags; |
f9c4a31f | 2439 | struct gpio_chip *chip = NULL; |
cb1650d4 | 2440 | loff_t index = *pos; |
d2876d08 | 2441 | |
f9c4a31f | 2442 | s->private = ""; |
d2876d08 | 2443 | |
362432ae | 2444 | spin_lock_irqsave(&gpio_lock, flags); |
cb1650d4 | 2445 | list_for_each_entry(chip, &gpio_chips, list) |
362432ae GL |
2446 | if (index-- == 0) { |
2447 | spin_unlock_irqrestore(&gpio_lock, flags); | |
cb1650d4 | 2448 | return chip; |
f9c4a31f | 2449 | } |
362432ae | 2450 | spin_unlock_irqrestore(&gpio_lock, flags); |
f9c4a31f | 2451 | |
cb1650d4 | 2452 | return NULL; |
f9c4a31f TR |
2453 | } |
2454 | ||
2455 | static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
2456 | { | |
362432ae | 2457 | unsigned long flags; |
f9c4a31f | 2458 | struct gpio_chip *chip = v; |
f9c4a31f TR |
2459 | void *ret = NULL; |
2460 | ||
362432ae | 2461 | spin_lock_irqsave(&gpio_lock, flags); |
cb1650d4 AC |
2462 | if (list_is_last(&chip->list, &gpio_chips)) |
2463 | ret = NULL; | |
2464 | else | |
2465 | ret = list_entry(chip->list.next, struct gpio_chip, list); | |
362432ae | 2466 | spin_unlock_irqrestore(&gpio_lock, flags); |
f9c4a31f TR |
2467 | |
2468 | s->private = "\n"; | |
2469 | ++*pos; | |
2470 | ||
2471 | return ret; | |
2472 | } | |
2473 | ||
2474 | static void gpiolib_seq_stop(struct seq_file *s, void *v) | |
2475 | { | |
2476 | } | |
2477 | ||
2478 | static int gpiolib_seq_show(struct seq_file *s, void *v) | |
2479 | { | |
2480 | struct gpio_chip *chip = v; | |
2481 | struct device *dev; | |
2482 | ||
2483 | seq_printf(s, "%sGPIOs %d-%d", (char *)s->private, | |
2484 | chip->base, chip->base + chip->ngpio - 1); | |
2485 | dev = chip->dev; | |
2486 | if (dev) | |
2487 | seq_printf(s, ", %s/%s", dev->bus ? dev->bus->name : "no-bus", | |
2488 | dev_name(dev)); | |
2489 | if (chip->label) | |
2490 | seq_printf(s, ", %s", chip->label); | |
2491 | if (chip->can_sleep) | |
2492 | seq_printf(s, ", can sleep"); | |
2493 | seq_printf(s, ":\n"); | |
2494 | ||
2495 | if (chip->dbg_show) | |
2496 | chip->dbg_show(s, chip); | |
2497 | else | |
2498 | gpiolib_dbg_show(s, chip); | |
2499 | ||
d2876d08 DB |
2500 | return 0; |
2501 | } | |
2502 | ||
f9c4a31f TR |
2503 | static const struct seq_operations gpiolib_seq_ops = { |
2504 | .start = gpiolib_seq_start, | |
2505 | .next = gpiolib_seq_next, | |
2506 | .stop = gpiolib_seq_stop, | |
2507 | .show = gpiolib_seq_show, | |
2508 | }; | |
2509 | ||
d2876d08 DB |
2510 | static int gpiolib_open(struct inode *inode, struct file *file) |
2511 | { | |
f9c4a31f | 2512 | return seq_open(file, &gpiolib_seq_ops); |
d2876d08 DB |
2513 | } |
2514 | ||
828c0950 | 2515 | static const struct file_operations gpiolib_operations = { |
f9c4a31f | 2516 | .owner = THIS_MODULE, |
d2876d08 DB |
2517 | .open = gpiolib_open, |
2518 | .read = seq_read, | |
2519 | .llseek = seq_lseek, | |
f9c4a31f | 2520 | .release = seq_release, |
d2876d08 DB |
2521 | }; |
2522 | ||
2523 | static int __init gpiolib_debugfs_init(void) | |
2524 | { | |
2525 | /* /sys/kernel/debug/gpio */ | |
2526 | (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO, | |
2527 | NULL, NULL, &gpiolib_operations); | |
2528 | return 0; | |
2529 | } | |
2530 | subsys_initcall(gpiolib_debugfs_init); | |
2531 | ||
2532 | #endif /* DEBUG_FS */ |