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Commit | Line | Data |
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d2876d08 DB |
1 | #include <linux/kernel.h> |
2 | #include <linux/module.h> | |
ff77c352 | 3 | #include <linux/interrupt.h> |
d2876d08 DB |
4 | #include <linux/irq.h> |
5 | #include <linux/spinlock.h> | |
1a989d0f | 6 | #include <linux/list.h> |
d8f388d8 DB |
7 | #include <linux/device.h> |
8 | #include <linux/err.h> | |
9 | #include <linux/debugfs.h> | |
10 | #include <linux/seq_file.h> | |
11 | #include <linux/gpio.h> | |
391c970c | 12 | #include <linux/of_gpio.h> |
ff77c352 | 13 | #include <linux/idr.h> |
5a0e3ad6 | 14 | #include <linux/slab.h> |
d2876d08 | 15 | |
3f397c21 UKK |
16 | #define CREATE_TRACE_POINTS |
17 | #include <trace/events/gpio.h> | |
d2876d08 DB |
18 | |
19 | /* Optional implementation infrastructure for GPIO interfaces. | |
20 | * | |
21 | * Platforms may want to use this if they tend to use very many GPIOs | |
22 | * that aren't part of a System-On-Chip core; or across I2C/SPI/etc. | |
23 | * | |
24 | * When kernel footprint or instruction count is an issue, simpler | |
25 | * implementations may be preferred. The GPIO programming interface | |
26 | * allows for inlining speed-critical get/set operations for common | |
27 | * cases, so that access to SOC-integrated GPIOs can sometimes cost | |
28 | * only an instruction or two per bit. | |
29 | */ | |
30 | ||
31 | ||
32 | /* When debugging, extend minimal trust to callers and platform code. | |
33 | * Also emit diagnostic messages that may help initial bringup, when | |
34 | * board setup or driver bugs are most common. | |
35 | * | |
36 | * Otherwise, minimize overhead in what may be bitbanging codepaths. | |
37 | */ | |
38 | #ifdef DEBUG | |
39 | #define extra_checks 1 | |
40 | #else | |
41 | #define extra_checks 0 | |
42 | #endif | |
43 | ||
44 | /* gpio_lock prevents conflicts during gpio_desc[] table updates. | |
45 | * While any GPIO is requested, its gpio_chip is not removable; | |
46 | * each GPIO's "requested" flag serves as a lock and refcount. | |
47 | */ | |
48 | static DEFINE_SPINLOCK(gpio_lock); | |
49 | ||
50 | struct gpio_desc { | |
51 | struct gpio_chip *chip; | |
52 | unsigned long flags; | |
53 | /* flag symbols are bit numbers */ | |
54 | #define FLAG_REQUESTED 0 | |
55 | #define FLAG_IS_OUT 1 | |
710b40ea AC |
56 | #define FLAG_EXPORT 2 /* protected by sysfs_lock */ |
57 | #define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */ | |
58 | #define FLAG_TRIG_FALL 4 /* trigger on falling edge */ | |
59 | #define FLAG_TRIG_RISE 5 /* trigger on rising edge */ | |
60 | #define FLAG_ACTIVE_LOW 6 /* sysfs value has active low */ | |
61 | #define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */ | |
62 | #define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */ | |
ff77c352 | 63 | |
5ba1821d | 64 | #define ID_SHIFT 16 /* add new flags before this one */ |
ff77c352 | 65 | |
5ba1821d | 66 | #define GPIO_FLAGS_MASK ((1 << ID_SHIFT) - 1) |
ff77c352 | 67 | #define GPIO_TRIGGER_MASK (BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE)) |
d2876d08 DB |
68 | |
69 | #ifdef CONFIG_DEBUG_FS | |
70 | const char *label; | |
71 | #endif | |
72 | }; | |
73 | static struct gpio_desc gpio_desc[ARCH_NR_GPIOS]; | |
74 | ||
6c0b4e6c AC |
75 | #define GPIO_OFFSET_VALID(chip, offset) (offset >= 0 && offset < chip->ngpio) |
76 | ||
1a989d0f AC |
77 | static LIST_HEAD(gpio_chips); |
78 | ||
ff77c352 | 79 | #ifdef CONFIG_GPIO_SYSFS |
5ba1821d | 80 | static DEFINE_IDR(dirent_idr); |
ff77c352 DG |
81 | #endif |
82 | ||
372e722e AC |
83 | /* |
84 | * Internal gpiod_* API using descriptors instead of the integer namespace. | |
85 | * Most of this should eventually go public. | |
86 | */ | |
87 | static int gpiod_request(struct gpio_desc *desc, const char *label); | |
88 | static void gpiod_free(struct gpio_desc *desc); | |
89 | static int gpiod_direction_input(struct gpio_desc *desc); | |
90 | static int gpiod_direction_output(struct gpio_desc *desc, int value); | |
def63433 | 91 | static int gpiod_get_direction(const struct gpio_desc *desc); |
372e722e | 92 | static int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce); |
def63433 | 93 | static int gpiod_get_value_cansleep(const struct gpio_desc *desc); |
372e722e | 94 | static void gpiod_set_value_cansleep(struct gpio_desc *desc, int value); |
def63433 | 95 | static int gpiod_get_value(const struct gpio_desc *desc); |
372e722e | 96 | static void gpiod_set_value(struct gpio_desc *desc, int value); |
def63433 AC |
97 | static int gpiod_cansleep(const struct gpio_desc *desc); |
98 | static int gpiod_to_irq(const struct gpio_desc *desc); | |
372e722e AC |
99 | static int gpiod_export(struct gpio_desc *desc, bool direction_may_change); |
100 | static int gpiod_export_link(struct device *dev, const char *name, | |
101 | struct gpio_desc *desc); | |
102 | static int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value); | |
103 | static void gpiod_unexport(struct gpio_desc *desc); | |
104 | ||
7b17b59f MB |
105 | #ifdef CONFIG_DEBUG_FS |
106 | #define gpiod_emerg(desc, fmt, ...) \ | |
107 | pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \ | |
108 | ##__VA_ARGS__) | |
109 | #define gpiod_crit(desc, fmt, ...) \ | |
110 | pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \ | |
111 | ##__VA_ARGS__) | |
112 | #define gpiod_err(desc, fmt, ...) \ | |
113 | pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \ | |
114 | ##__VA_ARGS__) | |
115 | #define gpiod_warn(desc, fmt, ...) \ | |
116 | pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \ | |
117 | ##__VA_ARGS__) | |
118 | #define gpiod_info(desc, fmt, ...) \ | |
119 | pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \ | |
120 | ##__VA_ARGS__) | |
121 | #define gpiod_dbg(desc, fmt, ...) \ | |
122 | pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \ | |
123 | ##__VA_ARGS__) | |
124 | #else | |
6424de5a MB |
125 | #define gpiod_emerg(desc, fmt, ...) \ |
126 | pr_emerg("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__) | |
127 | #define gpiod_crit(desc, fmt, ...) \ | |
128 | pr_crit("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__) | |
129 | #define gpiod_err(desc, fmt, ...) \ | |
130 | pr_err("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__) | |
131 | #define gpiod_warn(desc, fmt, ...) \ | |
132 | pr_warn("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__) | |
133 | #define gpiod_info(desc, fmt, ...) \ | |
134 | pr_info("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__) | |
135 | #define gpiod_dbg(desc, fmt, ...) \ | |
136 | pr_debug("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__) | |
7b17b59f | 137 | #endif |
372e722e | 138 | |
d2876d08 DB |
139 | static inline void desc_set_label(struct gpio_desc *d, const char *label) |
140 | { | |
141 | #ifdef CONFIG_DEBUG_FS | |
142 | d->label = label; | |
143 | #endif | |
144 | } | |
145 | ||
372e722e AC |
146 | /* |
147 | * Return the GPIO number of the passed descriptor relative to its chip | |
148 | */ | |
149 | static int gpio_chip_hwgpio(const struct gpio_desc *desc) | |
150 | { | |
6c0b4e6c | 151 | return desc - &desc->chip->desc[0]; |
372e722e AC |
152 | } |
153 | ||
154 | /** | |
155 | * Convert a GPIO number to its descriptor | |
156 | */ | |
157 | static struct gpio_desc *gpio_to_desc(unsigned gpio) | |
158 | { | |
159 | if (WARN(!gpio_is_valid(gpio), "invalid GPIO %d\n", gpio)) | |
160 | return NULL; | |
161 | else | |
162 | return &gpio_desc[gpio]; | |
163 | } | |
164 | ||
165 | /** | |
166 | * Convert a GPIO descriptor to the integer namespace. | |
167 | * This should disappear in the future but is needed since we still | |
168 | * use GPIO numbers for error messages and sysfs nodes | |
169 | */ | |
170 | static int desc_to_gpio(const struct gpio_desc *desc) | |
171 | { | |
6c0b4e6c | 172 | return desc->chip->base + gpio_chip_hwgpio(desc); |
372e722e AC |
173 | } |
174 | ||
175 | ||
d2876d08 DB |
176 | /* Warn when drivers omit gpio_request() calls -- legal but ill-advised |
177 | * when setting direction, and otherwise illegal. Until board setup code | |
178 | * and drivers use explicit requests everywhere (which won't happen when | |
179 | * those calls have no teeth) we can't avoid autorequesting. This nag | |
35e8bb51 DB |
180 | * message should motivate switching to explicit requests... so should |
181 | * the weaker cleanup after faults, compared to gpio_request(). | |
8a0cecff DB |
182 | * |
183 | * NOTE: the autorequest mechanism is going away; at this point it's | |
184 | * only "legal" in the sense that (old) code using it won't break yet, | |
185 | * but instead only triggers a WARN() stack dump. | |
d2876d08 | 186 | */ |
372e722e | 187 | static int gpio_ensure_requested(struct gpio_desc *desc) |
d2876d08 | 188 | { |
8a0cecff | 189 | const struct gpio_chip *chip = desc->chip; |
372e722e | 190 | const int gpio = desc_to_gpio(desc); |
35e8bb51 | 191 | |
8a0cecff DB |
192 | if (WARN(test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0, |
193 | "autorequest GPIO-%d\n", gpio)) { | |
35e8bb51 DB |
194 | if (!try_module_get(chip->owner)) { |
195 | pr_err("GPIO-%d: module can't be gotten \n", gpio); | |
196 | clear_bit(FLAG_REQUESTED, &desc->flags); | |
197 | /* lose */ | |
198 | return -EIO; | |
199 | } | |
d2876d08 | 200 | desc_set_label(desc, "[auto]"); |
35e8bb51 DB |
201 | /* caller must chip->request() w/o spinlock */ |
202 | if (chip->request) | |
203 | return 1; | |
d2876d08 | 204 | } |
35e8bb51 | 205 | return 0; |
d2876d08 DB |
206 | } |
207 | ||
def63433 | 208 | static struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc) |
372e722e | 209 | { |
bcabdef1 | 210 | return desc ? desc->chip : NULL; |
372e722e AC |
211 | } |
212 | ||
24d7628f | 213 | /* caller holds gpio_lock *OR* gpio is marked as requested */ |
1a2d397a | 214 | struct gpio_chip *gpio_to_chip(unsigned gpio) |
d2876d08 | 215 | { |
372e722e | 216 | return gpiod_to_chip(gpio_to_desc(gpio)); |
d2876d08 DB |
217 | } |
218 | ||
8d0aab2f AV |
219 | /* dynamic allocation of GPIOs, e.g. on a hotplugged device */ |
220 | static int gpiochip_find_base(int ngpio) | |
221 | { | |
83cabe33 AC |
222 | struct gpio_chip *chip; |
223 | int base = ARCH_NR_GPIOS - ngpio; | |
8d0aab2f | 224 | |
83cabe33 AC |
225 | list_for_each_entry_reverse(chip, &gpio_chips, list) { |
226 | /* found a free space? */ | |
227 | if (chip->base + chip->ngpio <= base) | |
228 | break; | |
229 | else | |
230 | /* nope, check the space right before the chip */ | |
231 | base = chip->base - ngpio; | |
8d0aab2f AV |
232 | } |
233 | ||
83cabe33 | 234 | if (gpio_is_valid(base)) { |
8d0aab2f | 235 | pr_debug("%s: found new base at %d\n", __func__, base); |
83cabe33 AC |
236 | return base; |
237 | } else { | |
238 | pr_err("%s: cannot find free range\n", __func__); | |
239 | return -ENOSPC; | |
169b6a7a | 240 | } |
169b6a7a AV |
241 | } |
242 | ||
80b0a602 | 243 | /* caller ensures gpio is valid and requested, chip->get_direction may sleep */ |
def63433 | 244 | static int gpiod_get_direction(const struct gpio_desc *desc) |
80b0a602 MN |
245 | { |
246 | struct gpio_chip *chip; | |
372e722e | 247 | unsigned offset; |
80b0a602 MN |
248 | int status = -EINVAL; |
249 | ||
372e722e AC |
250 | chip = gpiod_to_chip(desc); |
251 | offset = gpio_chip_hwgpio(desc); | |
80b0a602 MN |
252 | |
253 | if (!chip->get_direction) | |
254 | return status; | |
255 | ||
372e722e | 256 | status = chip->get_direction(chip, offset); |
80b0a602 MN |
257 | if (status > 0) { |
258 | /* GPIOF_DIR_IN, or other positive */ | |
259 | status = 1; | |
def63433 AC |
260 | /* FLAG_IS_OUT is just a cache of the result of get_direction(), |
261 | * so it does not affect constness per se */ | |
262 | clear_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags); | |
80b0a602 MN |
263 | } |
264 | if (status == 0) { | |
265 | /* GPIOF_DIR_OUT */ | |
def63433 | 266 | set_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags); |
80b0a602 MN |
267 | } |
268 | return status; | |
269 | } | |
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 | ||
07697461 | 354 | if (!test_bit(FLAG_EXPORT, &desc->flags)) { |
d8f388d8 | 355 | status = -EIO; |
07697461 JN |
356 | } else { |
357 | int value; | |
358 | ||
372e722e | 359 | value = !!gpiod_get_value_cansleep(desc); |
07697461 JN |
360 | if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) |
361 | value = !value; | |
362 | ||
363 | status = sprintf(buf, "%d\n", value); | |
364 | } | |
d8f388d8 DB |
365 | |
366 | mutex_unlock(&sysfs_lock); | |
367 | return status; | |
368 | } | |
369 | ||
370 | static ssize_t gpio_value_store(struct device *dev, | |
371 | struct device_attribute *attr, const char *buf, size_t size) | |
372 | { | |
372e722e | 373 | struct gpio_desc *desc = dev_get_drvdata(dev); |
d8f388d8 DB |
374 | ssize_t status; |
375 | ||
376 | mutex_lock(&sysfs_lock); | |
377 | ||
378 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
379 | status = -EIO; | |
380 | else if (!test_bit(FLAG_IS_OUT, &desc->flags)) | |
381 | status = -EPERM; | |
382 | else { | |
383 | long value; | |
384 | ||
a3d88c92 | 385 | status = kstrtol(buf, 0, &value); |
d8f388d8 | 386 | if (status == 0) { |
07697461 JN |
387 | if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) |
388 | value = !value; | |
372e722e | 389 | gpiod_set_value_cansleep(desc, value != 0); |
d8f388d8 DB |
390 | status = size; |
391 | } | |
392 | } | |
393 | ||
394 | mutex_unlock(&sysfs_lock); | |
395 | return status; | |
396 | } | |
397 | ||
07697461 | 398 | static const DEVICE_ATTR(value, 0644, |
d8f388d8 DB |
399 | gpio_value_show, gpio_value_store); |
400 | ||
ff77c352 DG |
401 | static irqreturn_t gpio_sysfs_irq(int irq, void *priv) |
402 | { | |
5ba1821d | 403 | struct sysfs_dirent *value_sd = priv; |
ff77c352 | 404 | |
5ba1821d | 405 | sysfs_notify_dirent(value_sd); |
ff77c352 DG |
406 | return IRQ_HANDLED; |
407 | } | |
408 | ||
ff77c352 DG |
409 | static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev, |
410 | unsigned long gpio_flags) | |
411 | { | |
5ba1821d | 412 | struct sysfs_dirent *value_sd; |
ff77c352 DG |
413 | unsigned long irq_flags; |
414 | int ret, irq, id; | |
415 | ||
416 | if ((desc->flags & GPIO_TRIGGER_MASK) == gpio_flags) | |
417 | return 0; | |
418 | ||
372e722e | 419 | irq = gpiod_to_irq(desc); |
ff77c352 DG |
420 | if (irq < 0) |
421 | return -EIO; | |
422 | ||
5ba1821d DG |
423 | id = desc->flags >> ID_SHIFT; |
424 | value_sd = idr_find(&dirent_idr, id); | |
425 | if (value_sd) | |
426 | free_irq(irq, value_sd); | |
ff77c352 DG |
427 | |
428 | desc->flags &= ~GPIO_TRIGGER_MASK; | |
429 | ||
430 | if (!gpio_flags) { | |
431 | ret = 0; | |
5ba1821d | 432 | goto free_id; |
ff77c352 DG |
433 | } |
434 | ||
435 | irq_flags = IRQF_SHARED; | |
436 | if (test_bit(FLAG_TRIG_FALL, &gpio_flags)) | |
07697461 JN |
437 | irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? |
438 | IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING; | |
ff77c352 | 439 | if (test_bit(FLAG_TRIG_RISE, &gpio_flags)) |
07697461 JN |
440 | irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? |
441 | IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; | |
ff77c352 | 442 | |
5ba1821d DG |
443 | if (!value_sd) { |
444 | value_sd = sysfs_get_dirent(dev->kobj.sd, NULL, "value"); | |
445 | if (!value_sd) { | |
446 | ret = -ENODEV; | |
ff77c352 DG |
447 | goto err_out; |
448 | } | |
449 | ||
62f516b8 TH |
450 | ret = idr_alloc(&dirent_idr, value_sd, 1, 0, GFP_KERNEL); |
451 | if (ret < 0) | |
5ba1821d | 452 | goto free_sd; |
62f516b8 | 453 | id = ret; |
ff77c352 DG |
454 | |
455 | desc->flags &= GPIO_FLAGS_MASK; | |
5ba1821d | 456 | desc->flags |= (unsigned long)id << ID_SHIFT; |
ff77c352 | 457 | |
5ba1821d | 458 | if (desc->flags >> ID_SHIFT != id) { |
ff77c352 DG |
459 | ret = -ERANGE; |
460 | goto free_id; | |
461 | } | |
ff77c352 DG |
462 | } |
463 | ||
364fadb3 | 464 | ret = request_any_context_irq(irq, gpio_sysfs_irq, irq_flags, |
5ba1821d | 465 | "gpiolib", value_sd); |
364fadb3 | 466 | if (ret < 0) |
5ba1821d | 467 | goto free_id; |
ff77c352 DG |
468 | |
469 | desc->flags |= gpio_flags; | |
470 | return 0; | |
471 | ||
ff77c352 | 472 | free_id: |
5ba1821d | 473 | idr_remove(&dirent_idr, id); |
ff77c352 | 474 | desc->flags &= GPIO_FLAGS_MASK; |
5ba1821d DG |
475 | free_sd: |
476 | if (value_sd) | |
477 | sysfs_put(value_sd); | |
ff77c352 DG |
478 | err_out: |
479 | return ret; | |
480 | } | |
481 | ||
482 | static const struct { | |
483 | const char *name; | |
484 | unsigned long flags; | |
485 | } trigger_types[] = { | |
486 | { "none", 0 }, | |
487 | { "falling", BIT(FLAG_TRIG_FALL) }, | |
488 | { "rising", BIT(FLAG_TRIG_RISE) }, | |
489 | { "both", BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE) }, | |
490 | }; | |
491 | ||
492 | static ssize_t gpio_edge_show(struct device *dev, | |
493 | struct device_attribute *attr, char *buf) | |
494 | { | |
495 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
496 | ssize_t status; | |
497 | ||
498 | mutex_lock(&sysfs_lock); | |
499 | ||
500 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
501 | status = -EIO; | |
502 | else { | |
503 | int i; | |
504 | ||
505 | status = 0; | |
506 | for (i = 0; i < ARRAY_SIZE(trigger_types); i++) | |
507 | if ((desc->flags & GPIO_TRIGGER_MASK) | |
508 | == trigger_types[i].flags) { | |
509 | status = sprintf(buf, "%s\n", | |
510 | trigger_types[i].name); | |
511 | break; | |
512 | } | |
513 | } | |
514 | ||
515 | mutex_unlock(&sysfs_lock); | |
516 | return status; | |
517 | } | |
518 | ||
519 | static ssize_t gpio_edge_store(struct device *dev, | |
520 | struct device_attribute *attr, const char *buf, size_t size) | |
521 | { | |
522 | struct gpio_desc *desc = dev_get_drvdata(dev); | |
523 | ssize_t status; | |
524 | int i; | |
525 | ||
526 | for (i = 0; i < ARRAY_SIZE(trigger_types); i++) | |
527 | if (sysfs_streq(trigger_types[i].name, buf)) | |
528 | goto found; | |
529 | return -EINVAL; | |
530 | ||
531 | found: | |
532 | mutex_lock(&sysfs_lock); | |
533 | ||
534 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
535 | status = -EIO; | |
536 | else { | |
537 | status = gpio_setup_irq(desc, dev, trigger_types[i].flags); | |
538 | if (!status) | |
539 | status = size; | |
540 | } | |
541 | ||
542 | mutex_unlock(&sysfs_lock); | |
543 | ||
544 | return status; | |
545 | } | |
546 | ||
547 | static DEVICE_ATTR(edge, 0644, gpio_edge_show, gpio_edge_store); | |
548 | ||
07697461 JN |
549 | static int sysfs_set_active_low(struct gpio_desc *desc, struct device *dev, |
550 | int value) | |
551 | { | |
552 | int status = 0; | |
553 | ||
554 | if (!!test_bit(FLAG_ACTIVE_LOW, &desc->flags) == !!value) | |
555 | return 0; | |
556 | ||
557 | if (value) | |
558 | set_bit(FLAG_ACTIVE_LOW, &desc->flags); | |
559 | else | |
560 | clear_bit(FLAG_ACTIVE_LOW, &desc->flags); | |
561 | ||
562 | /* reconfigure poll(2) support if enabled on one edge only */ | |
563 | if (dev != NULL && (!!test_bit(FLAG_TRIG_RISE, &desc->flags) ^ | |
564 | !!test_bit(FLAG_TRIG_FALL, &desc->flags))) { | |
565 | unsigned long trigger_flags = desc->flags & GPIO_TRIGGER_MASK; | |
566 | ||
567 | gpio_setup_irq(desc, dev, 0); | |
568 | status = gpio_setup_irq(desc, dev, trigger_flags); | |
569 | } | |
570 | ||
571 | return status; | |
572 | } | |
573 | ||
574 | static ssize_t gpio_active_low_show(struct device *dev, | |
575 | struct device_attribute *attr, char *buf) | |
576 | { | |
577 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
578 | ssize_t status; | |
579 | ||
580 | mutex_lock(&sysfs_lock); | |
581 | ||
582 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
583 | status = -EIO; | |
584 | else | |
585 | status = sprintf(buf, "%d\n", | |
586 | !!test_bit(FLAG_ACTIVE_LOW, &desc->flags)); | |
587 | ||
588 | mutex_unlock(&sysfs_lock); | |
589 | ||
590 | return status; | |
591 | } | |
592 | ||
593 | static ssize_t gpio_active_low_store(struct device *dev, | |
594 | struct device_attribute *attr, const char *buf, size_t size) | |
595 | { | |
596 | struct gpio_desc *desc = dev_get_drvdata(dev); | |
597 | ssize_t status; | |
598 | ||
599 | mutex_lock(&sysfs_lock); | |
600 | ||
601 | if (!test_bit(FLAG_EXPORT, &desc->flags)) { | |
602 | status = -EIO; | |
603 | } else { | |
604 | long value; | |
605 | ||
a3d88c92 | 606 | status = kstrtol(buf, 0, &value); |
07697461 JN |
607 | if (status == 0) |
608 | status = sysfs_set_active_low(desc, dev, value != 0); | |
609 | } | |
610 | ||
611 | mutex_unlock(&sysfs_lock); | |
612 | ||
613 | return status ? : size; | |
614 | } | |
615 | ||
616 | static const DEVICE_ATTR(active_low, 0644, | |
617 | gpio_active_low_show, gpio_active_low_store); | |
618 | ||
d8f388d8 | 619 | static const struct attribute *gpio_attrs[] = { |
d8f388d8 | 620 | &dev_attr_value.attr, |
07697461 | 621 | &dev_attr_active_low.attr, |
d8f388d8 DB |
622 | NULL, |
623 | }; | |
624 | ||
625 | static const struct attribute_group gpio_attr_group = { | |
626 | .attrs = (struct attribute **) gpio_attrs, | |
627 | }; | |
628 | ||
629 | /* | |
630 | * /sys/class/gpio/gpiochipN/ | |
631 | * /base ... matching gpio_chip.base (N) | |
632 | * /label ... matching gpio_chip.label | |
633 | * /ngpio ... matching gpio_chip.ngpio | |
634 | */ | |
635 | ||
636 | static ssize_t chip_base_show(struct device *dev, | |
637 | struct device_attribute *attr, char *buf) | |
638 | { | |
639 | const struct gpio_chip *chip = dev_get_drvdata(dev); | |
640 | ||
641 | return sprintf(buf, "%d\n", chip->base); | |
642 | } | |
643 | static DEVICE_ATTR(base, 0444, chip_base_show, NULL); | |
644 | ||
645 | static ssize_t chip_label_show(struct device *dev, | |
646 | struct device_attribute *attr, char *buf) | |
647 | { | |
648 | const struct gpio_chip *chip = dev_get_drvdata(dev); | |
649 | ||
650 | return sprintf(buf, "%s\n", chip->label ? : ""); | |
651 | } | |
652 | static DEVICE_ATTR(label, 0444, chip_label_show, NULL); | |
653 | ||
654 | static ssize_t chip_ngpio_show(struct device *dev, | |
655 | struct device_attribute *attr, char *buf) | |
656 | { | |
657 | const struct gpio_chip *chip = dev_get_drvdata(dev); | |
658 | ||
659 | return sprintf(buf, "%u\n", chip->ngpio); | |
660 | } | |
661 | static DEVICE_ATTR(ngpio, 0444, chip_ngpio_show, NULL); | |
662 | ||
663 | static const struct attribute *gpiochip_attrs[] = { | |
664 | &dev_attr_base.attr, | |
665 | &dev_attr_label.attr, | |
666 | &dev_attr_ngpio.attr, | |
667 | NULL, | |
668 | }; | |
669 | ||
670 | static const struct attribute_group gpiochip_attr_group = { | |
671 | .attrs = (struct attribute **) gpiochip_attrs, | |
672 | }; | |
673 | ||
674 | /* | |
675 | * /sys/class/gpio/export ... write-only | |
676 | * integer N ... number of GPIO to export (full access) | |
677 | * /sys/class/gpio/unexport ... write-only | |
678 | * integer N ... number of GPIO to unexport | |
679 | */ | |
28812fe1 AK |
680 | static ssize_t export_store(struct class *class, |
681 | struct class_attribute *attr, | |
682 | const char *buf, size_t len) | |
d8f388d8 | 683 | { |
372e722e AC |
684 | long gpio; |
685 | struct gpio_desc *desc; | |
686 | int status; | |
d8f388d8 | 687 | |
a3d88c92 | 688 | status = kstrtol(buf, 0, &gpio); |
d8f388d8 DB |
689 | if (status < 0) |
690 | goto done; | |
691 | ||
372e722e | 692 | desc = gpio_to_desc(gpio); |
bcabdef1 AC |
693 | /* reject invalid GPIOs */ |
694 | if (!desc) { | |
695 | pr_warn("%s: invalid GPIO %ld\n", __func__, gpio); | |
696 | return -EINVAL; | |
697 | } | |
372e722e | 698 | |
d8f388d8 DB |
699 | /* No extra locking here; FLAG_SYSFS just signifies that the |
700 | * request and export were done by on behalf of userspace, so | |
701 | * they may be undone on its behalf too. | |
702 | */ | |
703 | ||
372e722e | 704 | status = gpiod_request(desc, "sysfs"); |
ad2fab36 MN |
705 | if (status < 0) { |
706 | if (status == -EPROBE_DEFER) | |
707 | status = -ENODEV; | |
d8f388d8 | 708 | goto done; |
ad2fab36 | 709 | } |
372e722e | 710 | status = gpiod_export(desc, true); |
d8f388d8 | 711 | if (status < 0) |
372e722e | 712 | gpiod_free(desc); |
d8f388d8 | 713 | else |
372e722e | 714 | set_bit(FLAG_SYSFS, &desc->flags); |
d8f388d8 DB |
715 | |
716 | done: | |
717 | if (status) | |
718 | pr_debug("%s: status %d\n", __func__, status); | |
719 | return status ? : len; | |
720 | } | |
721 | ||
28812fe1 AK |
722 | static ssize_t unexport_store(struct class *class, |
723 | struct class_attribute *attr, | |
724 | const char *buf, size_t len) | |
d8f388d8 | 725 | { |
372e722e AC |
726 | long gpio; |
727 | struct gpio_desc *desc; | |
728 | int status; | |
d8f388d8 | 729 | |
a3d88c92 | 730 | status = kstrtol(buf, 0, &gpio); |
d8f388d8 DB |
731 | if (status < 0) |
732 | goto done; | |
733 | ||
372e722e | 734 | desc = gpio_to_desc(gpio); |
d8f388d8 | 735 | /* reject bogus commands (gpio_unexport ignores them) */ |
bcabdef1 AC |
736 | if (!desc) { |
737 | pr_warn("%s: invalid GPIO %ld\n", __func__, gpio); | |
738 | return -EINVAL; | |
739 | } | |
740 | ||
741 | status = -EINVAL; | |
d8f388d8 DB |
742 | |
743 | /* No extra locking here; FLAG_SYSFS just signifies that the | |
744 | * request and export were done by on behalf of userspace, so | |
745 | * they may be undone on its behalf too. | |
746 | */ | |
372e722e | 747 | if (test_and_clear_bit(FLAG_SYSFS, &desc->flags)) { |
d8f388d8 | 748 | status = 0; |
372e722e | 749 | gpiod_free(desc); |
d8f388d8 DB |
750 | } |
751 | done: | |
752 | if (status) | |
753 | pr_debug("%s: status %d\n", __func__, status); | |
754 | return status ? : len; | |
755 | } | |
756 | ||
757 | static struct class_attribute gpio_class_attrs[] = { | |
758 | __ATTR(export, 0200, NULL, export_store), | |
759 | __ATTR(unexport, 0200, NULL, unexport_store), | |
760 | __ATTR_NULL, | |
761 | }; | |
762 | ||
763 | static struct class gpio_class = { | |
764 | .name = "gpio", | |
765 | .owner = THIS_MODULE, | |
766 | ||
767 | .class_attrs = gpio_class_attrs, | |
768 | }; | |
769 | ||
770 | ||
771 | /** | |
772 | * gpio_export - export a GPIO through sysfs | |
773 | * @gpio: gpio to make available, already requested | |
774 | * @direction_may_change: true if userspace may change gpio direction | |
775 | * Context: arch_initcall or later | |
776 | * | |
777 | * When drivers want to make a GPIO accessible to userspace after they | |
778 | * have requested it -- perhaps while debugging, or as part of their | |
779 | * public interface -- they may use this routine. If the GPIO can | |
780 | * change direction (some can't) and the caller allows it, userspace | |
781 | * will see "direction" sysfs attribute which may be used to change | |
782 | * the gpio's direction. A "value" attribute will always be provided. | |
783 | * | |
784 | * Returns zero on success, else an error. | |
785 | */ | |
372e722e | 786 | static int gpiod_export(struct gpio_desc *desc, bool direction_may_change) |
d8f388d8 DB |
787 | { |
788 | unsigned long flags; | |
fc4e2514 | 789 | int status; |
62154991 | 790 | const char *ioname = NULL; |
fc4e2514 | 791 | struct device *dev; |
372e722e | 792 | int offset; |
d8f388d8 DB |
793 | |
794 | /* can't export until sysfs is available ... */ | |
795 | if (!gpio_class.p) { | |
796 | pr_debug("%s: called too early!\n", __func__); | |
797 | return -ENOENT; | |
798 | } | |
799 | ||
372e722e AC |
800 | if (!desc) { |
801 | pr_debug("%s: invalid gpio descriptor\n", __func__); | |
fc4e2514 RM |
802 | return -EINVAL; |
803 | } | |
d8f388d8 DB |
804 | |
805 | mutex_lock(&sysfs_lock); | |
806 | ||
807 | spin_lock_irqsave(&gpio_lock, flags); | |
fc4e2514 RM |
808 | if (!test_bit(FLAG_REQUESTED, &desc->flags) || |
809 | test_bit(FLAG_EXPORT, &desc->flags)) { | |
810 | spin_unlock_irqrestore(&gpio_lock, flags); | |
811 | pr_debug("%s: gpio %d unavailable (requested=%d, exported=%d)\n", | |
372e722e | 812 | __func__, desc_to_gpio(desc), |
fc4e2514 RM |
813 | test_bit(FLAG_REQUESTED, &desc->flags), |
814 | test_bit(FLAG_EXPORT, &desc->flags)); | |
529f2ad5 DC |
815 | status = -EPERM; |
816 | goto fail_unlock; | |
d8f388d8 | 817 | } |
fc4e2514 RM |
818 | |
819 | if (!desc->chip->direction_input || !desc->chip->direction_output) | |
820 | direction_may_change = false; | |
d8f388d8 DB |
821 | spin_unlock_irqrestore(&gpio_lock, flags); |
822 | ||
372e722e AC |
823 | offset = gpio_chip_hwgpio(desc); |
824 | if (desc->chip->names && desc->chip->names[offset]) | |
825 | ioname = desc->chip->names[offset]; | |
926b663c | 826 | |
fc4e2514 | 827 | dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0), |
372e722e AC |
828 | desc, ioname ? ioname : "gpio%u", |
829 | desc_to_gpio(desc)); | |
fc4e2514 RM |
830 | if (IS_ERR(dev)) { |
831 | status = PTR_ERR(dev); | |
832 | goto fail_unlock; | |
d8f388d8 DB |
833 | } |
834 | ||
fc4e2514 | 835 | status = sysfs_create_group(&dev->kobj, &gpio_attr_group); |
d8f388d8 | 836 | if (status) |
fc4e2514 | 837 | goto fail_unregister_device; |
d8f388d8 | 838 | |
fc4e2514 RM |
839 | if (direction_may_change) { |
840 | status = device_create_file(dev, &dev_attr_direction); | |
841 | if (status) | |
842 | goto fail_unregister_device; | |
843 | } | |
844 | ||
372e722e | 845 | if (gpiod_to_irq(desc) >= 0 && (direction_may_change || |
fc4e2514 RM |
846 | !test_bit(FLAG_IS_OUT, &desc->flags))) { |
847 | status = device_create_file(dev, &dev_attr_edge); | |
848 | if (status) | |
849 | goto fail_unregister_device; | |
850 | } | |
d8f388d8 | 851 | |
fc4e2514 RM |
852 | set_bit(FLAG_EXPORT, &desc->flags); |
853 | mutex_unlock(&sysfs_lock); | |
854 | return 0; | |
855 | ||
856 | fail_unregister_device: | |
857 | device_unregister(dev); | |
858 | fail_unlock: | |
859 | mutex_unlock(&sysfs_lock); | |
372e722e AC |
860 | pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc), |
861 | status); | |
d8f388d8 DB |
862 | return status; |
863 | } | |
372e722e AC |
864 | |
865 | int gpio_export(unsigned gpio, bool direction_may_change) | |
866 | { | |
867 | return gpiod_export(gpio_to_desc(gpio), direction_may_change); | |
868 | } | |
d8f388d8 DB |
869 | EXPORT_SYMBOL_GPL(gpio_export); |
870 | ||
9f3b795a | 871 | static int match_export(struct device *dev, const void *data) |
d8f388d8 DB |
872 | { |
873 | return dev_get_drvdata(dev) == data; | |
874 | } | |
875 | ||
a4177ee7 JN |
876 | /** |
877 | * gpio_export_link - create a sysfs link to an exported GPIO node | |
878 | * @dev: device under which to create symlink | |
879 | * @name: name of the symlink | |
880 | * @gpio: gpio to create symlink to, already exported | |
881 | * | |
882 | * Set up a symlink from /sys/.../dev/name to /sys/class/gpio/gpioN | |
883 | * node. Caller is responsible for unlinking. | |
884 | * | |
885 | * Returns zero on success, else an error. | |
886 | */ | |
372e722e AC |
887 | static int gpiod_export_link(struct device *dev, const char *name, |
888 | struct gpio_desc *desc) | |
a4177ee7 | 889 | { |
a4177ee7 JN |
890 | int status = -EINVAL; |
891 | ||
bcabdef1 AC |
892 | if (!desc) { |
893 | pr_warn("%s: invalid GPIO\n", __func__); | |
894 | return -EINVAL; | |
895 | } | |
a4177ee7 JN |
896 | |
897 | mutex_lock(&sysfs_lock); | |
898 | ||
a4177ee7 JN |
899 | if (test_bit(FLAG_EXPORT, &desc->flags)) { |
900 | struct device *tdev; | |
901 | ||
902 | tdev = class_find_device(&gpio_class, NULL, desc, match_export); | |
903 | if (tdev != NULL) { | |
904 | status = sysfs_create_link(&dev->kobj, &tdev->kobj, | |
905 | name); | |
906 | } else { | |
907 | status = -ENODEV; | |
908 | } | |
909 | } | |
910 | ||
911 | mutex_unlock(&sysfs_lock); | |
912 | ||
a4177ee7 | 913 | if (status) |
372e722e AC |
914 | pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc), |
915 | status); | |
a4177ee7 JN |
916 | |
917 | return status; | |
918 | } | |
a4177ee7 | 919 | |
372e722e AC |
920 | int gpio_export_link(struct device *dev, const char *name, unsigned gpio) |
921 | { | |
922 | return gpiod_export_link(dev, name, gpio_to_desc(gpio)); | |
923 | } | |
924 | EXPORT_SYMBOL_GPL(gpio_export_link); | |
07697461 JN |
925 | |
926 | /** | |
927 | * gpio_sysfs_set_active_low - set the polarity of gpio sysfs value | |
928 | * @gpio: gpio to change | |
929 | * @value: non-zero to use active low, i.e. inverted values | |
930 | * | |
931 | * Set the polarity of /sys/class/gpio/gpioN/value sysfs attribute. | |
932 | * The GPIO does not have to be exported yet. If poll(2) support has | |
933 | * been enabled for either rising or falling edge, it will be | |
934 | * reconfigured to follow the new polarity. | |
935 | * | |
936 | * Returns zero on success, else an error. | |
937 | */ | |
372e722e | 938 | static int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value) |
07697461 | 939 | { |
07697461 JN |
940 | struct device *dev = NULL; |
941 | int status = -EINVAL; | |
942 | ||
bcabdef1 AC |
943 | if (!desc) { |
944 | pr_warn("%s: invalid GPIO\n", __func__); | |
945 | return -EINVAL; | |
946 | } | |
07697461 JN |
947 | |
948 | mutex_lock(&sysfs_lock); | |
949 | ||
07697461 | 950 | if (test_bit(FLAG_EXPORT, &desc->flags)) { |
07697461 JN |
951 | dev = class_find_device(&gpio_class, NULL, desc, match_export); |
952 | if (dev == NULL) { | |
953 | status = -ENODEV; | |
954 | goto unlock; | |
955 | } | |
956 | } | |
957 | ||
958 | status = sysfs_set_active_low(desc, dev, value); | |
959 | ||
960 | unlock: | |
961 | mutex_unlock(&sysfs_lock); | |
962 | ||
07697461 | 963 | if (status) |
372e722e AC |
964 | pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc), |
965 | status); | |
07697461 JN |
966 | |
967 | return status; | |
968 | } | |
372e722e AC |
969 | |
970 | int gpio_sysfs_set_active_low(unsigned gpio, int value) | |
971 | { | |
972 | return gpiod_sysfs_set_active_low(gpio_to_desc(gpio), value); | |
973 | } | |
07697461 JN |
974 | EXPORT_SYMBOL_GPL(gpio_sysfs_set_active_low); |
975 | ||
d8f388d8 DB |
976 | /** |
977 | * gpio_unexport - reverse effect of gpio_export() | |
978 | * @gpio: gpio to make unavailable | |
979 | * | |
980 | * This is implicit on gpio_free(). | |
981 | */ | |
372e722e | 982 | static void gpiod_unexport(struct gpio_desc *desc) |
d8f388d8 | 983 | { |
6a99ad4a | 984 | int status = 0; |
864533ce | 985 | struct device *dev = NULL; |
d8f388d8 | 986 | |
372e722e | 987 | if (!desc) { |
bcabdef1 AC |
988 | pr_warn("%s: invalid GPIO\n", __func__); |
989 | return; | |
6a99ad4a | 990 | } |
d8f388d8 DB |
991 | |
992 | mutex_lock(&sysfs_lock); | |
993 | ||
d8f388d8 | 994 | if (test_bit(FLAG_EXPORT, &desc->flags)) { |
d8f388d8 DB |
995 | |
996 | dev = class_find_device(&gpio_class, NULL, desc, match_export); | |
997 | if (dev) { | |
ff77c352 | 998 | gpio_setup_irq(desc, dev, 0); |
d8f388d8 | 999 | clear_bit(FLAG_EXPORT, &desc->flags); |
d8f388d8 DB |
1000 | } else |
1001 | status = -ENODEV; | |
1002 | } | |
1003 | ||
1004 | mutex_unlock(&sysfs_lock); | |
372e722e | 1005 | |
864533ce ML |
1006 | if (dev) { |
1007 | device_unregister(dev); | |
1008 | put_device(dev); | |
1009 | } | |
bcabdef1 | 1010 | |
d8f388d8 | 1011 | if (status) |
372e722e AC |
1012 | pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc), |
1013 | status); | |
1014 | } | |
1015 | ||
1016 | void gpio_unexport(unsigned gpio) | |
1017 | { | |
1018 | gpiod_unexport(gpio_to_desc(gpio)); | |
d8f388d8 DB |
1019 | } |
1020 | EXPORT_SYMBOL_GPL(gpio_unexport); | |
1021 | ||
1022 | static int gpiochip_export(struct gpio_chip *chip) | |
1023 | { | |
1024 | int status; | |
1025 | struct device *dev; | |
1026 | ||
1027 | /* Many systems register gpio chips for SOC support very early, | |
1028 | * before driver model support is available. In those cases we | |
1029 | * export this later, in gpiolib_sysfs_init() ... here we just | |
1030 | * verify that _some_ field of gpio_class got initialized. | |
1031 | */ | |
1032 | if (!gpio_class.p) | |
1033 | return 0; | |
1034 | ||
1035 | /* use chip->base for the ID; it's already known to be unique */ | |
1036 | mutex_lock(&sysfs_lock); | |
1037 | dev = device_create(&gpio_class, chip->dev, MKDEV(0, 0), chip, | |
1038 | "gpiochip%d", chip->base); | |
d62668e1 | 1039 | if (!IS_ERR(dev)) { |
d8f388d8 DB |
1040 | status = sysfs_create_group(&dev->kobj, |
1041 | &gpiochip_attr_group); | |
1042 | } else | |
d62668e1 | 1043 | status = PTR_ERR(dev); |
d8f388d8 DB |
1044 | chip->exported = (status == 0); |
1045 | mutex_unlock(&sysfs_lock); | |
1046 | ||
1047 | if (status) { | |
1048 | unsigned long flags; | |
1049 | unsigned gpio; | |
1050 | ||
1051 | spin_lock_irqsave(&gpio_lock, flags); | |
6c0b4e6c AC |
1052 | gpio = 0; |
1053 | while (gpio < chip->ngpio) | |
1054 | chip->desc[gpio++].chip = NULL; | |
d8f388d8 DB |
1055 | spin_unlock_irqrestore(&gpio_lock, flags); |
1056 | ||
1057 | pr_debug("%s: chip %s status %d\n", __func__, | |
1058 | chip->label, status); | |
1059 | } | |
1060 | ||
1061 | return status; | |
1062 | } | |
1063 | ||
1064 | static void gpiochip_unexport(struct gpio_chip *chip) | |
1065 | { | |
1066 | int status; | |
1067 | struct device *dev; | |
1068 | ||
1069 | mutex_lock(&sysfs_lock); | |
1070 | dev = class_find_device(&gpio_class, NULL, chip, match_export); | |
1071 | if (dev) { | |
1072 | put_device(dev); | |
1073 | device_unregister(dev); | |
1074 | chip->exported = 0; | |
1075 | status = 0; | |
1076 | } else | |
1077 | status = -ENODEV; | |
1078 | mutex_unlock(&sysfs_lock); | |
1079 | ||
1080 | if (status) | |
1081 | pr_debug("%s: chip %s status %d\n", __func__, | |
1082 | chip->label, status); | |
1083 | } | |
1084 | ||
1085 | static int __init gpiolib_sysfs_init(void) | |
1086 | { | |
1087 | int status; | |
1088 | unsigned long flags; | |
65493e3a | 1089 | struct gpio_chip *chip; |
d8f388d8 DB |
1090 | |
1091 | status = class_register(&gpio_class); | |
1092 | if (status < 0) | |
1093 | return status; | |
1094 | ||
1095 | /* Scan and register the gpio_chips which registered very | |
1096 | * early (e.g. before the class_register above was called). | |
1097 | * | |
1098 | * We run before arch_initcall() so chip->dev nodes can have | |
1099 | * registered, and so arch_initcall() can always gpio_export(). | |
1100 | */ | |
1101 | spin_lock_irqsave(&gpio_lock, flags); | |
65493e3a | 1102 | list_for_each_entry(chip, &gpio_chips, list) { |
d8f388d8 DB |
1103 | if (!chip || chip->exported) |
1104 | continue; | |
1105 | ||
1106 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1107 | status = gpiochip_export(chip); | |
1108 | spin_lock_irqsave(&gpio_lock, flags); | |
1109 | } | |
1110 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1111 | ||
1112 | ||
1113 | return status; | |
1114 | } | |
1115 | postcore_initcall(gpiolib_sysfs_init); | |
1116 | ||
1117 | #else | |
1118 | static inline int gpiochip_export(struct gpio_chip *chip) | |
1119 | { | |
1120 | return 0; | |
1121 | } | |
1122 | ||
1123 | static inline void gpiochip_unexport(struct gpio_chip *chip) | |
1124 | { | |
1125 | } | |
1126 | ||
372e722e AC |
1127 | static inline int gpiod_export(struct gpio_desc *desc, |
1128 | bool direction_may_change) | |
1129 | { | |
1130 | return -ENOSYS; | |
1131 | } | |
1132 | ||
1133 | static inline int gpiod_export_link(struct device *dev, const char *name, | |
1134 | struct gpio_desc *desc) | |
1135 | { | |
1136 | return -ENOSYS; | |
1137 | } | |
1138 | ||
1139 | static inline int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value) | |
1140 | { | |
1141 | return -ENOSYS; | |
1142 | } | |
1143 | ||
1144 | static inline void gpiod_unexport(struct gpio_desc *desc) | |
1145 | { | |
1146 | } | |
1147 | ||
d8f388d8 DB |
1148 | #endif /* CONFIG_GPIO_SYSFS */ |
1149 | ||
1a989d0f AC |
1150 | /* |
1151 | * Add a new chip to the global chips list, keeping the list of chips sorted | |
1152 | * by base order. | |
1153 | * | |
1154 | * Return -EBUSY if the new chip overlaps with some other chip's integer | |
1155 | * space. | |
1156 | */ | |
1157 | static int gpiochip_add_to_list(struct gpio_chip *chip) | |
1158 | { | |
1159 | struct list_head *pos = &gpio_chips; | |
1160 | struct gpio_chip *_chip; | |
1161 | int err = 0; | |
1162 | ||
1163 | /* find where to insert our chip */ | |
1164 | list_for_each(pos, &gpio_chips) { | |
1165 | _chip = list_entry(pos, struct gpio_chip, list); | |
1166 | /* shall we insert before _chip? */ | |
1167 | if (_chip->base >= chip->base + chip->ngpio) | |
1168 | break; | |
1169 | } | |
1170 | ||
1171 | /* are we stepping on the chip right before? */ | |
1172 | if (pos != &gpio_chips && pos->prev != &gpio_chips) { | |
1173 | _chip = list_entry(pos->prev, struct gpio_chip, list); | |
1174 | if (_chip->base + _chip->ngpio > chip->base) { | |
1175 | dev_err(chip->dev, | |
1176 | "GPIO integer space overlap, cannot add chip\n"); | |
1177 | err = -EBUSY; | |
1178 | } | |
1179 | } | |
1180 | ||
1181 | if (!err) | |
1182 | list_add_tail(&chip->list, pos); | |
1183 | ||
1184 | return err; | |
1185 | } | |
1186 | ||
d2876d08 DB |
1187 | /** |
1188 | * gpiochip_add() - register a gpio_chip | |
1189 | * @chip: the chip to register, with chip->base initialized | |
1190 | * Context: potentially before irqs or kmalloc will work | |
1191 | * | |
1192 | * Returns a negative errno if the chip can't be registered, such as | |
1193 | * because the chip->base is invalid or already associated with a | |
1194 | * different chip. Otherwise it returns zero as a success code. | |
8d0aab2f | 1195 | * |
d8f388d8 DB |
1196 | * When gpiochip_add() is called very early during boot, so that GPIOs |
1197 | * can be freely used, the chip->dev device must be registered before | |
1198 | * the gpio framework's arch_initcall(). Otherwise sysfs initialization | |
1199 | * for GPIOs will fail rudely. | |
1200 | * | |
8d0aab2f AV |
1201 | * If chip->base is negative, this requests dynamic assignment of |
1202 | * a range of valid GPIOs. | |
d2876d08 DB |
1203 | */ |
1204 | int gpiochip_add(struct gpio_chip *chip) | |
1205 | { | |
1206 | unsigned long flags; | |
1207 | int status = 0; | |
1208 | unsigned id; | |
8d0aab2f | 1209 | int base = chip->base; |
d2876d08 | 1210 | |
bff5fda9 | 1211 | if ((!gpio_is_valid(base) || !gpio_is_valid(base + chip->ngpio - 1)) |
8d0aab2f | 1212 | && base >= 0) { |
d2876d08 DB |
1213 | status = -EINVAL; |
1214 | goto fail; | |
1215 | } | |
1216 | ||
1217 | spin_lock_irqsave(&gpio_lock, flags); | |
1218 | ||
8d0aab2f AV |
1219 | if (base < 0) { |
1220 | base = gpiochip_find_base(chip->ngpio); | |
1221 | if (base < 0) { | |
1222 | status = base; | |
d8f388d8 | 1223 | goto unlock; |
8d0aab2f AV |
1224 | } |
1225 | chip->base = base; | |
1226 | } | |
1227 | ||
1a989d0f AC |
1228 | status = gpiochip_add_to_list(chip); |
1229 | ||
d2876d08 | 1230 | if (status == 0) { |
6c0b4e6c AC |
1231 | chip->desc = &gpio_desc[chip->base]; |
1232 | ||
1233 | for (id = 0; id < chip->ngpio; id++) { | |
1234 | struct gpio_desc *desc = &chip->desc[id]; | |
1235 | desc->chip = chip; | |
d8f388d8 DB |
1236 | |
1237 | /* REVISIT: most hardware initializes GPIOs as | |
1238 | * inputs (often with pullups enabled) so power | |
1239 | * usage is minimized. Linux code should set the | |
1240 | * gpio direction first thing; but until it does, | |
80b0a602 | 1241 | * and in case chip->get_direction is not set, |
d8f388d8 DB |
1242 | * we may expose the wrong direction in sysfs. |
1243 | */ | |
6c0b4e6c | 1244 | desc->flags = !chip->direction_input |
d8f388d8 DB |
1245 | ? (1 << FLAG_IS_OUT) |
1246 | : 0; | |
d2876d08 DB |
1247 | } |
1248 | } | |
1249 | ||
3bae4811 ZG |
1250 | spin_unlock_irqrestore(&gpio_lock, flags); |
1251 | ||
f23f1516 SH |
1252 | #ifdef CONFIG_PINCTRL |
1253 | INIT_LIST_HEAD(&chip->pin_ranges); | |
1254 | #endif | |
1255 | ||
391c970c AV |
1256 | of_gpiochip_add(chip); |
1257 | ||
cedb1881 AV |
1258 | if (status) |
1259 | goto fail; | |
1260 | ||
1261 | status = gpiochip_export(chip); | |
1262 | if (status) | |
1263 | goto fail; | |
1264 | ||
ee1c1e7d | 1265 | pr_debug("gpiochip_add: registered GPIOs %d to %d on device: %s\n", |
64842aad GL |
1266 | chip->base, chip->base + chip->ngpio - 1, |
1267 | chip->label ? : "generic"); | |
1268 | ||
cedb1881 | 1269 | return 0; |
3bae4811 ZG |
1270 | |
1271 | unlock: | |
1272 | spin_unlock_irqrestore(&gpio_lock, flags); | |
d2876d08 DB |
1273 | fail: |
1274 | /* failures here can mean systems won't boot... */ | |
cedb1881 AV |
1275 | pr_err("gpiochip_add: gpios %d..%d (%s) failed to register\n", |
1276 | chip->base, chip->base + chip->ngpio - 1, | |
1277 | chip->label ? : "generic"); | |
d2876d08 DB |
1278 | return status; |
1279 | } | |
1280 | EXPORT_SYMBOL_GPL(gpiochip_add); | |
1281 | ||
1282 | /** | |
1283 | * gpiochip_remove() - unregister a gpio_chip | |
1284 | * @chip: the chip to unregister | |
1285 | * | |
1286 | * A gpio_chip with any GPIOs still requested may not be removed. | |
1287 | */ | |
1288 | int gpiochip_remove(struct gpio_chip *chip) | |
1289 | { | |
1290 | unsigned long flags; | |
1291 | int status = 0; | |
1292 | unsigned id; | |
1293 | ||
1294 | spin_lock_irqsave(&gpio_lock, flags); | |
1295 | ||
9ef0d6f7 | 1296 | gpiochip_remove_pin_ranges(chip); |
391c970c AV |
1297 | of_gpiochip_remove(chip); |
1298 | ||
6c0b4e6c AC |
1299 | for (id = 0; id < chip->ngpio; id++) { |
1300 | if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) { | |
d2876d08 DB |
1301 | status = -EBUSY; |
1302 | break; | |
1303 | } | |
1304 | } | |
1305 | if (status == 0) { | |
6c0b4e6c AC |
1306 | for (id = 0; id < chip->ngpio; id++) |
1307 | chip->desc[id].chip = NULL; | |
1a989d0f AC |
1308 | |
1309 | list_del(&chip->list); | |
d2876d08 DB |
1310 | } |
1311 | ||
1312 | spin_unlock_irqrestore(&gpio_lock, flags); | |
d8f388d8 DB |
1313 | |
1314 | if (status == 0) | |
1315 | gpiochip_unexport(chip); | |
1316 | ||
d2876d08 DB |
1317 | return status; |
1318 | } | |
1319 | EXPORT_SYMBOL_GPL(gpiochip_remove); | |
1320 | ||
594fa265 GL |
1321 | /** |
1322 | * gpiochip_find() - iterator for locating a specific gpio_chip | |
1323 | * @data: data to pass to match function | |
1324 | * @callback: Callback function to check gpio_chip | |
1325 | * | |
1326 | * Similar to bus_find_device. It returns a reference to a gpio_chip as | |
1327 | * determined by a user supplied @match callback. The callback should return | |
1328 | * 0 if the device doesn't match and non-zero if it does. If the callback is | |
1329 | * non-zero, this function will return to the caller and not iterate over any | |
1330 | * more gpio_chips. | |
1331 | */ | |
07ce8ec7 | 1332 | struct gpio_chip *gpiochip_find(void *data, |
6e2cf651 | 1333 | int (*match)(struct gpio_chip *chip, |
3d0f7cf0 | 1334 | void *data)) |
594fa265 | 1335 | { |
125eef96 | 1336 | struct gpio_chip *chip; |
594fa265 | 1337 | unsigned long flags; |
594fa265 GL |
1338 | |
1339 | spin_lock_irqsave(&gpio_lock, flags); | |
125eef96 AC |
1340 | list_for_each_entry(chip, &gpio_chips, list) |
1341 | if (match(chip, data)) | |
594fa265 | 1342 | break; |
125eef96 AC |
1343 | |
1344 | /* No match? */ | |
1345 | if (&chip->list == &gpio_chips) | |
1346 | chip = NULL; | |
594fa265 GL |
1347 | spin_unlock_irqrestore(&gpio_lock, flags); |
1348 | ||
1349 | return chip; | |
1350 | } | |
8fa0c9bf | 1351 | EXPORT_SYMBOL_GPL(gpiochip_find); |
d2876d08 | 1352 | |
f23f1516 | 1353 | #ifdef CONFIG_PINCTRL |
165adc9c | 1354 | |
3f0f8670 LW |
1355 | /** |
1356 | * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping | |
1357 | * @chip: the gpiochip to add the range for | |
1358 | * @pinctrl_name: the dev_name() of the pin controller to map to | |
316511c0 LW |
1359 | * @gpio_offset: the start offset in the current gpio_chip number space |
1360 | * @pin_offset: the start offset in the pin controller number space | |
3f0f8670 LW |
1361 | * @npins: the number of pins from the offset of each pin space (GPIO and |
1362 | * pin controller) to accumulate in this range | |
1363 | */ | |
1e63d7b9 | 1364 | int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name, |
316511c0 | 1365 | unsigned int gpio_offset, unsigned int pin_offset, |
3f0f8670 | 1366 | unsigned int npins) |
f23f1516 SH |
1367 | { |
1368 | struct gpio_pin_range *pin_range; | |
b4d4b1f0 | 1369 | int ret; |
f23f1516 | 1370 | |
3f0f8670 | 1371 | pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL); |
f23f1516 SH |
1372 | if (!pin_range) { |
1373 | pr_err("%s: GPIO chip: failed to allocate pin ranges\n", | |
1374 | chip->label); | |
1e63d7b9 | 1375 | return -ENOMEM; |
f23f1516 SH |
1376 | } |
1377 | ||
3f0f8670 | 1378 | /* Use local offset as range ID */ |
316511c0 | 1379 | pin_range->range.id = gpio_offset; |
3f0f8670 | 1380 | pin_range->range.gc = chip; |
f23f1516 | 1381 | pin_range->range.name = chip->label; |
316511c0 LW |
1382 | pin_range->range.base = chip->base + gpio_offset; |
1383 | pin_range->range.pin_base = pin_offset; | |
f23f1516 | 1384 | pin_range->range.npins = npins; |
192c369c | 1385 | pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name, |
f23f1516 | 1386 | &pin_range->range); |
8f23ca1a | 1387 | if (IS_ERR(pin_range->pctldev)) { |
b4d4b1f0 | 1388 | ret = PTR_ERR(pin_range->pctldev); |
3f0f8670 LW |
1389 | pr_err("%s: GPIO chip: could not create pin range\n", |
1390 | chip->label); | |
1391 | kfree(pin_range); | |
b4d4b1f0 | 1392 | return ret; |
3f0f8670 | 1393 | } |
316511c0 LW |
1394 | pr_debug("GPIO chip %s: created GPIO range %d->%d ==> %s PIN %d->%d\n", |
1395 | chip->label, gpio_offset, gpio_offset + npins - 1, | |
1396 | pinctl_name, | |
1397 | pin_offset, pin_offset + npins - 1); | |
f23f1516 SH |
1398 | |
1399 | list_add_tail(&pin_range->node, &chip->pin_ranges); | |
1e63d7b9 LW |
1400 | |
1401 | return 0; | |
f23f1516 | 1402 | } |
165adc9c | 1403 | EXPORT_SYMBOL_GPL(gpiochip_add_pin_range); |
f23f1516 | 1404 | |
3f0f8670 LW |
1405 | /** |
1406 | * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings | |
1407 | * @chip: the chip to remove all the mappings for | |
1408 | */ | |
f23f1516 SH |
1409 | void gpiochip_remove_pin_ranges(struct gpio_chip *chip) |
1410 | { | |
1411 | struct gpio_pin_range *pin_range, *tmp; | |
1412 | ||
1413 | list_for_each_entry_safe(pin_range, tmp, &chip->pin_ranges, node) { | |
1414 | list_del(&pin_range->node); | |
1415 | pinctrl_remove_gpio_range(pin_range->pctldev, | |
1416 | &pin_range->range); | |
3f0f8670 | 1417 | kfree(pin_range); |
f23f1516 SH |
1418 | } |
1419 | } | |
165adc9c LW |
1420 | EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges); |
1421 | ||
1422 | #endif /* CONFIG_PINCTRL */ | |
f23f1516 | 1423 | |
d2876d08 DB |
1424 | /* These "optional" allocation calls help prevent drivers from stomping |
1425 | * on each other, and help provide better diagnostics in debugfs. | |
1426 | * They're called even less than the "set direction" calls. | |
1427 | */ | |
372e722e | 1428 | static int gpiod_request(struct gpio_desc *desc, const char *label) |
d2876d08 | 1429 | { |
35e8bb51 | 1430 | struct gpio_chip *chip; |
e9354576 | 1431 | int status = -EPROBE_DEFER; |
d2876d08 DB |
1432 | unsigned long flags; |
1433 | ||
be1a4b13 | 1434 | if (!desc || !desc->chip) { |
bcabdef1 AC |
1435 | pr_warn("%s: invalid GPIO\n", __func__); |
1436 | return -EINVAL; | |
ad2fab36 | 1437 | } |
bcabdef1 AC |
1438 | |
1439 | spin_lock_irqsave(&gpio_lock, flags); | |
1440 | ||
35e8bb51 | 1441 | chip = desc->chip; |
d2876d08 | 1442 | |
35e8bb51 | 1443 | if (!try_module_get(chip->owner)) |
438d8908 GL |
1444 | goto done; |
1445 | ||
d2876d08 | 1446 | /* NOTE: gpio_request() can be called in early boot, |
35e8bb51 | 1447 | * before IRQs are enabled, for non-sleeping (SOC) GPIOs. |
d2876d08 DB |
1448 | */ |
1449 | ||
1450 | if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) { | |
1451 | desc_set_label(desc, label ? : "?"); | |
1452 | status = 0; | |
438d8908 | 1453 | } else { |
d2876d08 | 1454 | status = -EBUSY; |
35e8bb51 | 1455 | module_put(chip->owner); |
7460db56 | 1456 | goto done; |
35e8bb51 DB |
1457 | } |
1458 | ||
1459 | if (chip->request) { | |
1460 | /* chip->request may sleep */ | |
1461 | spin_unlock_irqrestore(&gpio_lock, flags); | |
372e722e | 1462 | status = chip->request(chip, gpio_chip_hwgpio(desc)); |
35e8bb51 DB |
1463 | spin_lock_irqsave(&gpio_lock, flags); |
1464 | ||
1465 | if (status < 0) { | |
1466 | desc_set_label(desc, NULL); | |
1467 | module_put(chip->owner); | |
1468 | clear_bit(FLAG_REQUESTED, &desc->flags); | |
80b0a602 | 1469 | goto done; |
35e8bb51 | 1470 | } |
438d8908 | 1471 | } |
80b0a602 MN |
1472 | if (chip->get_direction) { |
1473 | /* chip->get_direction may sleep */ | |
1474 | spin_unlock_irqrestore(&gpio_lock, flags); | |
372e722e | 1475 | gpiod_get_direction(desc); |
80b0a602 MN |
1476 | spin_lock_irqsave(&gpio_lock, flags); |
1477 | } | |
d2876d08 DB |
1478 | done: |
1479 | if (status) | |
372e722e | 1480 | pr_debug("_gpio_request: gpio-%d (%s) status %d\n", |
bcabdef1 | 1481 | desc_to_gpio(desc), label ? : "?", status); |
d2876d08 DB |
1482 | spin_unlock_irqrestore(&gpio_lock, flags); |
1483 | return status; | |
1484 | } | |
372e722e AC |
1485 | |
1486 | int gpio_request(unsigned gpio, const char *label) | |
1487 | { | |
1488 | return gpiod_request(gpio_to_desc(gpio), label); | |
1489 | } | |
d2876d08 DB |
1490 | EXPORT_SYMBOL_GPL(gpio_request); |
1491 | ||
372e722e | 1492 | static void gpiod_free(struct gpio_desc *desc) |
d2876d08 DB |
1493 | { |
1494 | unsigned long flags; | |
35e8bb51 | 1495 | struct gpio_chip *chip; |
d2876d08 | 1496 | |
3d599d1c UKK |
1497 | might_sleep(); |
1498 | ||
372e722e | 1499 | if (!desc) { |
d2876d08 DB |
1500 | WARN_ON(extra_checks); |
1501 | return; | |
1502 | } | |
1503 | ||
372e722e | 1504 | gpiod_unexport(desc); |
d8f388d8 | 1505 | |
d2876d08 DB |
1506 | spin_lock_irqsave(&gpio_lock, flags); |
1507 | ||
35e8bb51 DB |
1508 | chip = desc->chip; |
1509 | if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) { | |
1510 | if (chip->free) { | |
1511 | spin_unlock_irqrestore(&gpio_lock, flags); | |
9c4ba946 | 1512 | might_sleep_if(chip->can_sleep); |
372e722e | 1513 | chip->free(chip, gpio_chip_hwgpio(desc)); |
35e8bb51 DB |
1514 | spin_lock_irqsave(&gpio_lock, flags); |
1515 | } | |
d2876d08 | 1516 | desc_set_label(desc, NULL); |
438d8908 | 1517 | module_put(desc->chip->owner); |
07697461 | 1518 | clear_bit(FLAG_ACTIVE_LOW, &desc->flags); |
35e8bb51 | 1519 | clear_bit(FLAG_REQUESTED, &desc->flags); |
aca5ce14 | 1520 | clear_bit(FLAG_OPEN_DRAIN, &desc->flags); |
25553ff0 | 1521 | clear_bit(FLAG_OPEN_SOURCE, &desc->flags); |
438d8908 | 1522 | } else |
d2876d08 DB |
1523 | WARN_ON(extra_checks); |
1524 | ||
1525 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1526 | } | |
372e722e AC |
1527 | |
1528 | void gpio_free(unsigned gpio) | |
1529 | { | |
1530 | gpiod_free(gpio_to_desc(gpio)); | |
1531 | } | |
d2876d08 DB |
1532 | EXPORT_SYMBOL_GPL(gpio_free); |
1533 | ||
3e45f1d1 EM |
1534 | /** |
1535 | * gpio_request_one - request a single GPIO with initial configuration | |
1536 | * @gpio: the GPIO number | |
1537 | * @flags: GPIO configuration as specified by GPIOF_* | |
1538 | * @label: a literal description string of this GPIO | |
1539 | */ | |
1540 | int gpio_request_one(unsigned gpio, unsigned long flags, const char *label) | |
1541 | { | |
372e722e | 1542 | struct gpio_desc *desc; |
3e45f1d1 EM |
1543 | int err; |
1544 | ||
372e722e AC |
1545 | desc = gpio_to_desc(gpio); |
1546 | ||
1547 | err = gpiod_request(desc, label); | |
3e45f1d1 EM |
1548 | if (err) |
1549 | return err; | |
1550 | ||
aca5ce14 | 1551 | if (flags & GPIOF_OPEN_DRAIN) |
372e722e | 1552 | set_bit(FLAG_OPEN_DRAIN, &desc->flags); |
aca5ce14 | 1553 | |
25553ff0 | 1554 | if (flags & GPIOF_OPEN_SOURCE) |
372e722e | 1555 | set_bit(FLAG_OPEN_SOURCE, &desc->flags); |
25553ff0 | 1556 | |
3e45f1d1 | 1557 | if (flags & GPIOF_DIR_IN) |
372e722e | 1558 | err = gpiod_direction_input(desc); |
3e45f1d1 | 1559 | else |
372e722e | 1560 | err = gpiod_direction_output(desc, |
3e45f1d1 EM |
1561 | (flags & GPIOF_INIT_HIGH) ? 1 : 0); |
1562 | ||
e254811c | 1563 | if (err) |
fc3a1f04 WS |
1564 | goto free_gpio; |
1565 | ||
1566 | if (flags & GPIOF_EXPORT) { | |
372e722e | 1567 | err = gpiod_export(desc, flags & GPIOF_EXPORT_CHANGEABLE); |
fc3a1f04 WS |
1568 | if (err) |
1569 | goto free_gpio; | |
1570 | } | |
1571 | ||
1572 | return 0; | |
e254811c | 1573 | |
fc3a1f04 | 1574 | free_gpio: |
372e722e | 1575 | gpiod_free(desc); |
3e45f1d1 EM |
1576 | return err; |
1577 | } | |
1578 | EXPORT_SYMBOL_GPL(gpio_request_one); | |
1579 | ||
1580 | /** | |
1581 | * gpio_request_array - request multiple GPIOs in a single call | |
1582 | * @array: array of the 'struct gpio' | |
1583 | * @num: how many GPIOs in the array | |
1584 | */ | |
7c295975 | 1585 | int gpio_request_array(const struct gpio *array, size_t num) |
3e45f1d1 EM |
1586 | { |
1587 | int i, err; | |
1588 | ||
1589 | for (i = 0; i < num; i++, array++) { | |
1590 | err = gpio_request_one(array->gpio, array->flags, array->label); | |
1591 | if (err) | |
1592 | goto err_free; | |
1593 | } | |
1594 | return 0; | |
1595 | ||
1596 | err_free: | |
1597 | while (i--) | |
1598 | gpio_free((--array)->gpio); | |
1599 | return err; | |
1600 | } | |
1601 | EXPORT_SYMBOL_GPL(gpio_request_array); | |
1602 | ||
1603 | /** | |
1604 | * gpio_free_array - release multiple GPIOs in a single call | |
1605 | * @array: array of the 'struct gpio' | |
1606 | * @num: how many GPIOs in the array | |
1607 | */ | |
7c295975 | 1608 | void gpio_free_array(const struct gpio *array, size_t num) |
3e45f1d1 EM |
1609 | { |
1610 | while (num--) | |
1611 | gpio_free((array++)->gpio); | |
1612 | } | |
1613 | EXPORT_SYMBOL_GPL(gpio_free_array); | |
d2876d08 DB |
1614 | |
1615 | /** | |
1616 | * gpiochip_is_requested - return string iff signal was requested | |
1617 | * @chip: controller managing the signal | |
1618 | * @offset: of signal within controller's 0..(ngpio - 1) range | |
1619 | * | |
1620 | * Returns NULL if the GPIO is not currently requested, else a string. | |
1621 | * If debugfs support is enabled, the string returned is the label passed | |
1622 | * to gpio_request(); otherwise it is a meaningless constant. | |
1623 | * | |
1624 | * This function is for use by GPIO controller drivers. The label can | |
1625 | * help with diagnostics, and knowing that the signal is used as a GPIO | |
1626 | * can help avoid accidentally multiplexing it to another controller. | |
1627 | */ | |
1628 | const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset) | |
1629 | { | |
6c0b4e6c | 1630 | struct gpio_desc *desc; |
d2876d08 | 1631 | |
6c0b4e6c | 1632 | if (!GPIO_OFFSET_VALID(chip, offset)) |
d2876d08 | 1633 | return NULL; |
6c0b4e6c AC |
1634 | |
1635 | desc = &chip->desc[offset]; | |
1636 | ||
372e722e | 1637 | if (test_bit(FLAG_REQUESTED, &desc->flags) == 0) |
d2876d08 DB |
1638 | return NULL; |
1639 | #ifdef CONFIG_DEBUG_FS | |
372e722e | 1640 | return desc->label; |
d2876d08 DB |
1641 | #else |
1642 | return "?"; | |
1643 | #endif | |
1644 | } | |
1645 | EXPORT_SYMBOL_GPL(gpiochip_is_requested); | |
1646 | ||
1647 | ||
1648 | /* Drivers MUST set GPIO direction before making get/set calls. In | |
1649 | * some cases this is done in early boot, before IRQs are enabled. | |
1650 | * | |
1651 | * As a rule these aren't called more than once (except for drivers | |
1652 | * using the open-drain emulation idiom) so these are natural places | |
1653 | * to accumulate extra debugging checks. Note that we can't (yet) | |
1654 | * rely on gpio_request() having been called beforehand. | |
1655 | */ | |
1656 | ||
372e722e | 1657 | static int gpiod_direction_input(struct gpio_desc *desc) |
d2876d08 DB |
1658 | { |
1659 | unsigned long flags; | |
1660 | struct gpio_chip *chip; | |
d2876d08 | 1661 | int status = -EINVAL; |
372e722e | 1662 | int offset; |
d2876d08 | 1663 | |
be1a4b13 | 1664 | if (!desc || !desc->chip) { |
bcabdef1 AC |
1665 | pr_warn("%s: invalid GPIO\n", __func__); |
1666 | return -EINVAL; | |
1667 | } | |
1668 | ||
be1a4b13 LW |
1669 | chip = desc->chip; |
1670 | if (!chip->get || !chip->direction_input) { | |
6424de5a MB |
1671 | gpiod_warn(desc, |
1672 | "%s: missing get() or direction_input() operations\n", | |
1673 | __func__); | |
be1a4b13 LW |
1674 | return -EIO; |
1675 | } | |
1676 | ||
d2876d08 DB |
1677 | spin_lock_irqsave(&gpio_lock, flags); |
1678 | ||
372e722e | 1679 | status = gpio_ensure_requested(desc); |
35e8bb51 DB |
1680 | if (status < 0) |
1681 | goto fail; | |
d2876d08 DB |
1682 | |
1683 | /* now we know the gpio is valid and chip won't vanish */ | |
1684 | ||
1685 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1686 | ||
9c4ba946 | 1687 | might_sleep_if(chip->can_sleep); |
d2876d08 | 1688 | |
372e722e | 1689 | offset = gpio_chip_hwgpio(desc); |
35e8bb51 | 1690 | if (status) { |
372e722e | 1691 | status = chip->request(chip, offset); |
35e8bb51 | 1692 | if (status < 0) { |
6424de5a | 1693 | gpiod_dbg(desc, "chip request fail, %d\n", status); |
35e8bb51 DB |
1694 | /* and it's not available to anyone else ... |
1695 | * gpio_request() is the fully clean solution. | |
1696 | */ | |
1697 | goto lose; | |
1698 | } | |
1699 | } | |
1700 | ||
372e722e | 1701 | status = chip->direction_input(chip, offset); |
d2876d08 DB |
1702 | if (status == 0) |
1703 | clear_bit(FLAG_IS_OUT, &desc->flags); | |
3f397c21 | 1704 | |
372e722e | 1705 | trace_gpio_direction(desc_to_gpio(desc), 1, status); |
35e8bb51 | 1706 | lose: |
d2876d08 DB |
1707 | return status; |
1708 | fail: | |
1709 | spin_unlock_irqrestore(&gpio_lock, flags); | |
bcabdef1 | 1710 | if (status) |
6424de5a | 1711 | gpiod_dbg(desc, "%s status %d\n", __func__, status); |
d2876d08 DB |
1712 | return status; |
1713 | } | |
372e722e AC |
1714 | |
1715 | int gpio_direction_input(unsigned gpio) | |
1716 | { | |
1717 | return gpiod_direction_input(gpio_to_desc(gpio)); | |
1718 | } | |
d2876d08 DB |
1719 | EXPORT_SYMBOL_GPL(gpio_direction_input); |
1720 | ||
372e722e | 1721 | static int gpiod_direction_output(struct gpio_desc *desc, int value) |
d2876d08 DB |
1722 | { |
1723 | unsigned long flags; | |
1724 | struct gpio_chip *chip; | |
d2876d08 | 1725 | int status = -EINVAL; |
372e722e | 1726 | int offset; |
d2876d08 | 1727 | |
be1a4b13 | 1728 | if (!desc || !desc->chip) { |
bcabdef1 AC |
1729 | pr_warn("%s: invalid GPIO\n", __func__); |
1730 | return -EINVAL; | |
1731 | } | |
1732 | ||
aca5ce14 LD |
1733 | /* Open drain pin should not be driven to 1 */ |
1734 | if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags)) | |
372e722e | 1735 | return gpiod_direction_input(desc); |
aca5ce14 | 1736 | |
25553ff0 LD |
1737 | /* Open source pin should not be driven to 0 */ |
1738 | if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags)) | |
372e722e | 1739 | return gpiod_direction_input(desc); |
25553ff0 | 1740 | |
be1a4b13 LW |
1741 | chip = desc->chip; |
1742 | if (!chip->set || !chip->direction_output) { | |
6424de5a MB |
1743 | gpiod_warn(desc, |
1744 | "%s: missing set() or direction_output() operations\n", | |
1745 | __func__); | |
be1a4b13 LW |
1746 | return -EIO; |
1747 | } | |
1748 | ||
d2876d08 DB |
1749 | spin_lock_irqsave(&gpio_lock, flags); |
1750 | ||
372e722e | 1751 | status = gpio_ensure_requested(desc); |
35e8bb51 DB |
1752 | if (status < 0) |
1753 | goto fail; | |
d2876d08 DB |
1754 | |
1755 | /* now we know the gpio is valid and chip won't vanish */ | |
1756 | ||
1757 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1758 | ||
9c4ba946 | 1759 | might_sleep_if(chip->can_sleep); |
d2876d08 | 1760 | |
372e722e | 1761 | offset = gpio_chip_hwgpio(desc); |
35e8bb51 | 1762 | if (status) { |
372e722e | 1763 | status = chip->request(chip, offset); |
35e8bb51 | 1764 | if (status < 0) { |
6424de5a | 1765 | gpiod_dbg(desc, "chip request fail, %d\n", status); |
35e8bb51 DB |
1766 | /* and it's not available to anyone else ... |
1767 | * gpio_request() is the fully clean solution. | |
1768 | */ | |
1769 | goto lose; | |
1770 | } | |
1771 | } | |
1772 | ||
372e722e | 1773 | status = chip->direction_output(chip, offset, value); |
d2876d08 DB |
1774 | if (status == 0) |
1775 | set_bit(FLAG_IS_OUT, &desc->flags); | |
372e722e AC |
1776 | trace_gpio_value(desc_to_gpio(desc), 0, value); |
1777 | trace_gpio_direction(desc_to_gpio(desc), 0, status); | |
35e8bb51 | 1778 | lose: |
d2876d08 DB |
1779 | return status; |
1780 | fail: | |
1781 | spin_unlock_irqrestore(&gpio_lock, flags); | |
bcabdef1 | 1782 | if (status) |
6424de5a | 1783 | gpiod_dbg(desc, "%s: gpio status %d\n", __func__, status); |
d2876d08 DB |
1784 | return status; |
1785 | } | |
372e722e AC |
1786 | |
1787 | int gpio_direction_output(unsigned gpio, int value) | |
1788 | { | |
1789 | return gpiod_direction_output(gpio_to_desc(gpio), value); | |
1790 | } | |
d2876d08 DB |
1791 | EXPORT_SYMBOL_GPL(gpio_direction_output); |
1792 | ||
c4b5be98 FB |
1793 | /** |
1794 | * gpio_set_debounce - sets @debounce time for a @gpio | |
1795 | * @gpio: the gpio to set debounce time | |
1796 | * @debounce: debounce time is microseconds | |
65d87656 LW |
1797 | * |
1798 | * returns -ENOTSUPP if the controller does not support setting | |
1799 | * debounce. | |
c4b5be98 | 1800 | */ |
372e722e | 1801 | static int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) |
c4b5be98 FB |
1802 | { |
1803 | unsigned long flags; | |
1804 | struct gpio_chip *chip; | |
c4b5be98 | 1805 | int status = -EINVAL; |
372e722e | 1806 | int offset; |
c4b5be98 | 1807 | |
be1a4b13 | 1808 | if (!desc || !desc->chip) { |
bcabdef1 AC |
1809 | pr_warn("%s: invalid GPIO\n", __func__); |
1810 | return -EINVAL; | |
1811 | } | |
1812 | ||
c4b5be98 | 1813 | chip = desc->chip; |
be1a4b13 | 1814 | if (!chip->set || !chip->set_debounce) { |
6424de5a MB |
1815 | gpiod_dbg(desc, |
1816 | "%s: missing set() or set_debounce() operations\n", | |
1817 | __func__); | |
65d87656 | 1818 | return -ENOTSUPP; |
be1a4b13 LW |
1819 | } |
1820 | ||
1821 | spin_lock_irqsave(&gpio_lock, flags); | |
372e722e AC |
1822 | |
1823 | status = gpio_ensure_requested(desc); | |
c4b5be98 FB |
1824 | if (status < 0) |
1825 | goto fail; | |
1826 | ||
1827 | /* now we know the gpio is valid and chip won't vanish */ | |
1828 | ||
1829 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1830 | ||
9c4ba946 | 1831 | might_sleep_if(chip->can_sleep); |
c4b5be98 | 1832 | |
372e722e AC |
1833 | offset = gpio_chip_hwgpio(desc); |
1834 | return chip->set_debounce(chip, offset, debounce); | |
c4b5be98 FB |
1835 | |
1836 | fail: | |
1837 | spin_unlock_irqrestore(&gpio_lock, flags); | |
bcabdef1 | 1838 | if (status) |
6424de5a | 1839 | gpiod_dbg(desc, "%s: status %d\n", __func__, status); |
c4b5be98 FB |
1840 | |
1841 | return status; | |
1842 | } | |
372e722e AC |
1843 | |
1844 | int gpio_set_debounce(unsigned gpio, unsigned debounce) | |
1845 | { | |
1846 | return gpiod_set_debounce(gpio_to_desc(gpio), debounce); | |
1847 | } | |
c4b5be98 | 1848 | EXPORT_SYMBOL_GPL(gpio_set_debounce); |
d2876d08 DB |
1849 | |
1850 | /* I/O calls are only valid after configuration completed; the relevant | |
1851 | * "is this a valid GPIO" error checks should already have been done. | |
1852 | * | |
1853 | * "Get" operations are often inlinable as reading a pin value register, | |
1854 | * and masking the relevant bit in that register. | |
1855 | * | |
1856 | * When "set" operations are inlinable, they involve writing that mask to | |
1857 | * one register to set a low value, or a different register to set it high. | |
1858 | * Otherwise locking is needed, so there may be little value to inlining. | |
1859 | * | |
1860 | *------------------------------------------------------------------------ | |
1861 | * | |
1862 | * IMPORTANT!!! The hot paths -- get/set value -- assume that callers | |
1863 | * have requested the GPIO. That can include implicit requesting by | |
1864 | * a direction setting call. Marking a gpio as requested locks its chip | |
1865 | * in memory, guaranteeing that these table lookups need no more locking | |
1866 | * and that gpiochip_remove() will fail. | |
1867 | * | |
1868 | * REVISIT when debugging, consider adding some instrumentation to ensure | |
1869 | * that the GPIO was actually requested. | |
1870 | */ | |
1871 | ||
d8e0ac08 AC |
1872 | static int _gpiod_get_value(const struct gpio_desc *desc) |
1873 | { | |
1874 | struct gpio_chip *chip; | |
1875 | int value; | |
1876 | int offset; | |
1877 | ||
1878 | chip = desc->chip; | |
1879 | offset = gpio_chip_hwgpio(desc); | |
1880 | value = chip->get ? chip->get(chip, offset) : 0; | |
1881 | trace_gpio_value(desc_to_gpio(desc), 1, value); | |
1882 | return value; | |
1883 | } | |
1884 | ||
d2876d08 DB |
1885 | /** |
1886 | * __gpio_get_value() - return a gpio's value | |
1887 | * @gpio: gpio whose value will be returned | |
1888 | * Context: any | |
1889 | * | |
1890 | * This is used directly or indirectly to implement gpio_get_value(). | |
1891 | * It returns the zero or nonzero value provided by the associated | |
1892 | * gpio_chip.get() method; or zero if no such method is provided. | |
1893 | */ | |
def63433 | 1894 | static int gpiod_get_value(const struct gpio_desc *desc) |
d2876d08 | 1895 | { |
bcabdef1 AC |
1896 | if (!desc) |
1897 | return 0; | |
e4e449e8 | 1898 | /* Should be using gpio_get_value_cansleep() */ |
d8e0ac08 AC |
1899 | WARN_ON(desc->chip->can_sleep); |
1900 | return _gpiod_get_value(desc); | |
d2876d08 | 1901 | } |
372e722e AC |
1902 | |
1903 | int __gpio_get_value(unsigned gpio) | |
1904 | { | |
1905 | return gpiod_get_value(gpio_to_desc(gpio)); | |
1906 | } | |
d2876d08 DB |
1907 | EXPORT_SYMBOL_GPL(__gpio_get_value); |
1908 | ||
aca5ce14 LD |
1909 | /* |
1910 | * _gpio_set_open_drain_value() - Set the open drain gpio's value. | |
1911 | * @gpio: Gpio whose state need to be set. | |
1912 | * @chip: Gpio chip. | |
1913 | * @value: Non-zero for setting it HIGH otherise it will set to LOW. | |
1914 | */ | |
372e722e | 1915 | static void _gpio_set_open_drain_value(struct gpio_desc *desc, int value) |
aca5ce14 LD |
1916 | { |
1917 | int err = 0; | |
372e722e AC |
1918 | struct gpio_chip *chip = desc->chip; |
1919 | int offset = gpio_chip_hwgpio(desc); | |
1920 | ||
aca5ce14 | 1921 | if (value) { |
372e722e | 1922 | err = chip->direction_input(chip, offset); |
aca5ce14 | 1923 | if (!err) |
372e722e | 1924 | clear_bit(FLAG_IS_OUT, &desc->flags); |
aca5ce14 | 1925 | } else { |
372e722e | 1926 | err = chip->direction_output(chip, offset, 0); |
aca5ce14 | 1927 | if (!err) |
372e722e | 1928 | set_bit(FLAG_IS_OUT, &desc->flags); |
aca5ce14 | 1929 | } |
372e722e | 1930 | trace_gpio_direction(desc_to_gpio(desc), value, err); |
aca5ce14 | 1931 | if (err < 0) |
6424de5a MB |
1932 | gpiod_err(desc, |
1933 | "%s: Error in set_value for open drain err %d\n", | |
1934 | __func__, err); | |
aca5ce14 LD |
1935 | } |
1936 | ||
25553ff0 LD |
1937 | /* |
1938 | * _gpio_set_open_source() - Set the open source gpio's value. | |
1939 | * @gpio: Gpio whose state need to be set. | |
1940 | * @chip: Gpio chip. | |
1941 | * @value: Non-zero for setting it HIGH otherise it will set to LOW. | |
1942 | */ | |
372e722e | 1943 | static void _gpio_set_open_source_value(struct gpio_desc *desc, int value) |
25553ff0 LD |
1944 | { |
1945 | int err = 0; | |
372e722e AC |
1946 | struct gpio_chip *chip = desc->chip; |
1947 | int offset = gpio_chip_hwgpio(desc); | |
1948 | ||
25553ff0 | 1949 | if (value) { |
372e722e | 1950 | err = chip->direction_output(chip, offset, 1); |
25553ff0 | 1951 | if (!err) |
372e722e | 1952 | set_bit(FLAG_IS_OUT, &desc->flags); |
25553ff0 | 1953 | } else { |
372e722e | 1954 | err = chip->direction_input(chip, offset); |
25553ff0 | 1955 | if (!err) |
372e722e | 1956 | clear_bit(FLAG_IS_OUT, &desc->flags); |
25553ff0 | 1957 | } |
372e722e | 1958 | trace_gpio_direction(desc_to_gpio(desc), !value, err); |
25553ff0 | 1959 | if (err < 0) |
6424de5a MB |
1960 | gpiod_err(desc, |
1961 | "%s: Error in set_value for open source err %d\n", | |
1962 | __func__, err); | |
25553ff0 LD |
1963 | } |
1964 | ||
d8e0ac08 AC |
1965 | static void _gpiod_set_value(struct gpio_desc *desc, int value) |
1966 | { | |
1967 | struct gpio_chip *chip; | |
1968 | ||
1969 | chip = desc->chip; | |
1970 | trace_gpio_value(desc_to_gpio(desc), 0, value); | |
1971 | if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) | |
1972 | _gpio_set_open_drain_value(desc, value); | |
1973 | else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) | |
1974 | _gpio_set_open_source_value(desc, value); | |
1975 | else | |
1976 | chip->set(chip, gpio_chip_hwgpio(desc), value); | |
1977 | } | |
1978 | ||
d2876d08 DB |
1979 | /** |
1980 | * __gpio_set_value() - assign a gpio's value | |
1981 | * @gpio: gpio whose value will be assigned | |
1982 | * @value: value to assign | |
1983 | * Context: any | |
1984 | * | |
1985 | * This is used directly or indirectly to implement gpio_set_value(). | |
1986 | * It invokes the associated gpio_chip.set() method. | |
1987 | */ | |
372e722e | 1988 | static void gpiod_set_value(struct gpio_desc *desc, int value) |
d2876d08 | 1989 | { |
d2876d08 | 1990 | |
bcabdef1 AC |
1991 | if (!desc) |
1992 | return; | |
e4e449e8 | 1993 | /* Should be using gpio_set_value_cansleep() */ |
d8e0ac08 AC |
1994 | WARN_ON(desc->chip->can_sleep); |
1995 | _gpiod_set_value(desc, value); | |
372e722e AC |
1996 | } |
1997 | ||
1998 | void __gpio_set_value(unsigned gpio, int value) | |
1999 | { | |
2000 | return gpiod_set_value(gpio_to_desc(gpio), value); | |
d2876d08 DB |
2001 | } |
2002 | EXPORT_SYMBOL_GPL(__gpio_set_value); | |
2003 | ||
2004 | /** | |
2005 | * __gpio_cansleep() - report whether gpio value access will sleep | |
2006 | * @gpio: gpio in question | |
2007 | * Context: any | |
2008 | * | |
2009 | * This is used directly or indirectly to implement gpio_cansleep(). It | |
2010 | * returns nonzero if access reading or writing the GPIO value can sleep. | |
2011 | */ | |
def63433 | 2012 | static int gpiod_cansleep(const struct gpio_desc *desc) |
d2876d08 | 2013 | { |
bcabdef1 AC |
2014 | if (!desc) |
2015 | return 0; | |
d2876d08 | 2016 | /* only call this on GPIOs that are valid! */ |
372e722e AC |
2017 | return desc->chip->can_sleep; |
2018 | } | |
d2876d08 | 2019 | |
372e722e AC |
2020 | int __gpio_cansleep(unsigned gpio) |
2021 | { | |
2022 | return gpiod_cansleep(gpio_to_desc(gpio)); | |
d2876d08 DB |
2023 | } |
2024 | EXPORT_SYMBOL_GPL(__gpio_cansleep); | |
2025 | ||
0f6d504e DB |
2026 | /** |
2027 | * __gpio_to_irq() - return the IRQ corresponding to a GPIO | |
2028 | * @gpio: gpio whose IRQ will be returned (already requested) | |
2029 | * Context: any | |
2030 | * | |
2031 | * This is used directly or indirectly to implement gpio_to_irq(). | |
2032 | * It returns the number of the IRQ signaled by this (input) GPIO, | |
2033 | * or a negative errno. | |
2034 | */ | |
def63433 | 2035 | static int gpiod_to_irq(const struct gpio_desc *desc) |
0f6d504e DB |
2036 | { |
2037 | struct gpio_chip *chip; | |
372e722e | 2038 | int offset; |
0f6d504e | 2039 | |
bcabdef1 AC |
2040 | if (!desc) |
2041 | return -EINVAL; | |
372e722e AC |
2042 | chip = desc->chip; |
2043 | offset = gpio_chip_hwgpio(desc); | |
2044 | return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO; | |
0f6d504e | 2045 | } |
0f6d504e | 2046 | |
372e722e AC |
2047 | int __gpio_to_irq(unsigned gpio) |
2048 | { | |
2049 | return gpiod_to_irq(gpio_to_desc(gpio)); | |
2050 | } | |
2051 | EXPORT_SYMBOL_GPL(__gpio_to_irq); | |
d2876d08 DB |
2052 | |
2053 | ||
2054 | /* There's no value in making it easy to inline GPIO calls that may sleep. | |
2055 | * Common examples include ones connected to I2C or SPI chips. | |
2056 | */ | |
2057 | ||
def63433 | 2058 | static int gpiod_get_value_cansleep(const struct gpio_desc *desc) |
d2876d08 | 2059 | { |
d2876d08 | 2060 | might_sleep_if(extra_checks); |
bcabdef1 AC |
2061 | if (!desc) |
2062 | return 0; | |
d8e0ac08 | 2063 | return _gpiod_get_value(desc); |
d2876d08 | 2064 | } |
372e722e AC |
2065 | |
2066 | int gpio_get_value_cansleep(unsigned gpio) | |
2067 | { | |
2068 | return gpiod_get_value_cansleep(gpio_to_desc(gpio)); | |
2069 | } | |
d2876d08 DB |
2070 | EXPORT_SYMBOL_GPL(gpio_get_value_cansleep); |
2071 | ||
372e722e | 2072 | static void gpiod_set_value_cansleep(struct gpio_desc *desc, int value) |
d2876d08 | 2073 | { |
d2876d08 | 2074 | might_sleep_if(extra_checks); |
bcabdef1 AC |
2075 | if (!desc) |
2076 | return; | |
d8e0ac08 | 2077 | _gpiod_set_value(desc, value); |
d2876d08 | 2078 | } |
d2876d08 | 2079 | |
372e722e AC |
2080 | void gpio_set_value_cansleep(unsigned gpio, int value) |
2081 | { | |
2082 | return gpiod_set_value_cansleep(gpio_to_desc(gpio), value); | |
2083 | } | |
2084 | EXPORT_SYMBOL_GPL(gpio_set_value_cansleep); | |
d2876d08 DB |
2085 | |
2086 | #ifdef CONFIG_DEBUG_FS | |
2087 | ||
d2876d08 DB |
2088 | static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) |
2089 | { | |
2090 | unsigned i; | |
2091 | unsigned gpio = chip->base; | |
6c0b4e6c | 2092 | struct gpio_desc *gdesc = &chip->desc[0]; |
d2876d08 DB |
2093 | int is_out; |
2094 | ||
2095 | for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) { | |
2096 | if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) | |
2097 | continue; | |
2098 | ||
372e722e | 2099 | gpiod_get_direction(gdesc); |
d2876d08 | 2100 | is_out = test_bit(FLAG_IS_OUT, &gdesc->flags); |
6e8ba729 | 2101 | seq_printf(s, " gpio-%-3d (%-20.20s) %s %s", |
d2876d08 DB |
2102 | gpio, gdesc->label, |
2103 | is_out ? "out" : "in ", | |
2104 | chip->get | |
2105 | ? (chip->get(chip, i) ? "hi" : "lo") | |
2106 | : "? "); | |
d2876d08 DB |
2107 | seq_printf(s, "\n"); |
2108 | } | |
2109 | } | |
2110 | ||
f9c4a31f | 2111 | static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos) |
d2876d08 | 2112 | { |
362432ae | 2113 | unsigned long flags; |
f9c4a31f | 2114 | struct gpio_chip *chip = NULL; |
cb1650d4 | 2115 | loff_t index = *pos; |
d2876d08 | 2116 | |
f9c4a31f | 2117 | s->private = ""; |
d2876d08 | 2118 | |
362432ae | 2119 | spin_lock_irqsave(&gpio_lock, flags); |
cb1650d4 | 2120 | list_for_each_entry(chip, &gpio_chips, list) |
362432ae GL |
2121 | if (index-- == 0) { |
2122 | spin_unlock_irqrestore(&gpio_lock, flags); | |
cb1650d4 | 2123 | return chip; |
f9c4a31f | 2124 | } |
362432ae | 2125 | spin_unlock_irqrestore(&gpio_lock, flags); |
f9c4a31f | 2126 | |
cb1650d4 | 2127 | return NULL; |
f9c4a31f TR |
2128 | } |
2129 | ||
2130 | static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
2131 | { | |
362432ae | 2132 | unsigned long flags; |
f9c4a31f | 2133 | struct gpio_chip *chip = v; |
f9c4a31f TR |
2134 | void *ret = NULL; |
2135 | ||
362432ae | 2136 | spin_lock_irqsave(&gpio_lock, flags); |
cb1650d4 AC |
2137 | if (list_is_last(&chip->list, &gpio_chips)) |
2138 | ret = NULL; | |
2139 | else | |
2140 | ret = list_entry(chip->list.next, struct gpio_chip, list); | |
362432ae | 2141 | spin_unlock_irqrestore(&gpio_lock, flags); |
f9c4a31f TR |
2142 | |
2143 | s->private = "\n"; | |
2144 | ++*pos; | |
2145 | ||
2146 | return ret; | |
2147 | } | |
2148 | ||
2149 | static void gpiolib_seq_stop(struct seq_file *s, void *v) | |
2150 | { | |
2151 | } | |
2152 | ||
2153 | static int gpiolib_seq_show(struct seq_file *s, void *v) | |
2154 | { | |
2155 | struct gpio_chip *chip = v; | |
2156 | struct device *dev; | |
2157 | ||
2158 | seq_printf(s, "%sGPIOs %d-%d", (char *)s->private, | |
2159 | chip->base, chip->base + chip->ngpio - 1); | |
2160 | dev = chip->dev; | |
2161 | if (dev) | |
2162 | seq_printf(s, ", %s/%s", dev->bus ? dev->bus->name : "no-bus", | |
2163 | dev_name(dev)); | |
2164 | if (chip->label) | |
2165 | seq_printf(s, ", %s", chip->label); | |
2166 | if (chip->can_sleep) | |
2167 | seq_printf(s, ", can sleep"); | |
2168 | seq_printf(s, ":\n"); | |
2169 | ||
2170 | if (chip->dbg_show) | |
2171 | chip->dbg_show(s, chip); | |
2172 | else | |
2173 | gpiolib_dbg_show(s, chip); | |
2174 | ||
d2876d08 DB |
2175 | return 0; |
2176 | } | |
2177 | ||
f9c4a31f TR |
2178 | static const struct seq_operations gpiolib_seq_ops = { |
2179 | .start = gpiolib_seq_start, | |
2180 | .next = gpiolib_seq_next, | |
2181 | .stop = gpiolib_seq_stop, | |
2182 | .show = gpiolib_seq_show, | |
2183 | }; | |
2184 | ||
d2876d08 DB |
2185 | static int gpiolib_open(struct inode *inode, struct file *file) |
2186 | { | |
f9c4a31f | 2187 | return seq_open(file, &gpiolib_seq_ops); |
d2876d08 DB |
2188 | } |
2189 | ||
828c0950 | 2190 | static const struct file_operations gpiolib_operations = { |
f9c4a31f | 2191 | .owner = THIS_MODULE, |
d2876d08 DB |
2192 | .open = gpiolib_open, |
2193 | .read = seq_read, | |
2194 | .llseek = seq_lseek, | |
f9c4a31f | 2195 | .release = seq_release, |
d2876d08 DB |
2196 | }; |
2197 | ||
2198 | static int __init gpiolib_debugfs_init(void) | |
2199 | { | |
2200 | /* /sys/kernel/debug/gpio */ | |
2201 | (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO, | |
2202 | NULL, NULL, &gpiolib_operations); | |
2203 | return 0; | |
2204 | } | |
2205 | subsys_initcall(gpiolib_debugfs_init); | |
2206 | ||
2207 | #endif /* DEBUG_FS */ |