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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> |
81f59e9d | 13 | #include <linux/acpi_gpio.h> |
ff77c352 | 14 | #include <linux/idr.h> |
5a0e3ad6 | 15 | #include <linux/slab.h> |
7b199811 | 16 | #include <linux/acpi.h> |
d2876d08 | 17 | |
3f397c21 UKK |
18 | #define CREATE_TRACE_POINTS |
19 | #include <trace/events/gpio.h> | |
d2876d08 | 20 | |
79a9becd | 21 | /* Implementation infrastructure for GPIO interfaces. |
d2876d08 | 22 | * |
79a9becd AC |
23 | * The GPIO programming interface allows for inlining speed-critical |
24 | * get/set operations for common cases, so that access to SOC-integrated | |
25 | * GPIOs can sometimes cost only an instruction or two per bit. | |
d2876d08 DB |
26 | */ |
27 | ||
28 | ||
29 | /* When debugging, extend minimal trust to callers and platform code. | |
30 | * Also emit diagnostic messages that may help initial bringup, when | |
31 | * board setup or driver bugs are most common. | |
32 | * | |
33 | * Otherwise, minimize overhead in what may be bitbanging codepaths. | |
34 | */ | |
35 | #ifdef DEBUG | |
36 | #define extra_checks 1 | |
37 | #else | |
38 | #define extra_checks 0 | |
39 | #endif | |
40 | ||
41 | /* gpio_lock prevents conflicts during gpio_desc[] table updates. | |
42 | * While any GPIO is requested, its gpio_chip is not removable; | |
43 | * each GPIO's "requested" flag serves as a lock and refcount. | |
44 | */ | |
45 | static DEFINE_SPINLOCK(gpio_lock); | |
46 | ||
47 | struct gpio_desc { | |
48 | struct gpio_chip *chip; | |
49 | unsigned long flags; | |
50 | /* flag symbols are bit numbers */ | |
51 | #define FLAG_REQUESTED 0 | |
52 | #define FLAG_IS_OUT 1 | |
710b40ea AC |
53 | #define FLAG_EXPORT 2 /* protected by sysfs_lock */ |
54 | #define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */ | |
55 | #define FLAG_TRIG_FALL 4 /* trigger on falling edge */ | |
56 | #define FLAG_TRIG_RISE 5 /* trigger on rising edge */ | |
79a9becd | 57 | #define FLAG_ACTIVE_LOW 6 /* value has active low */ |
710b40ea AC |
58 | #define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */ |
59 | #define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */ | |
d468bf9e | 60 | #define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */ |
ff77c352 | 61 | |
5ba1821d | 62 | #define ID_SHIFT 16 /* add new flags before this one */ |
ff77c352 | 63 | |
5ba1821d | 64 | #define GPIO_FLAGS_MASK ((1 << ID_SHIFT) - 1) |
ff77c352 | 65 | #define GPIO_TRIGGER_MASK (BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE)) |
d2876d08 DB |
66 | |
67 | #ifdef CONFIG_DEBUG_FS | |
68 | const char *label; | |
69 | #endif | |
70 | }; | |
71 | static struct gpio_desc gpio_desc[ARCH_NR_GPIOS]; | |
72 | ||
6c0b4e6c AC |
73 | #define GPIO_OFFSET_VALID(chip, offset) (offset >= 0 && offset < chip->ngpio) |
74 | ||
bae48da2 AC |
75 | static DEFINE_MUTEX(gpio_lookup_lock); |
76 | static LIST_HEAD(gpio_lookup_list); | |
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 | static int gpiod_request(struct gpio_desc *desc, const char *label); |
84 | static void gpiod_free(struct gpio_desc *desc); | |
372e722e | 85 | |
7b17b59f MB |
86 | #ifdef CONFIG_DEBUG_FS |
87 | #define gpiod_emerg(desc, fmt, ...) \ | |
88 | pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \ | |
89 | ##__VA_ARGS__) | |
90 | #define gpiod_crit(desc, fmt, ...) \ | |
91 | pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \ | |
92 | ##__VA_ARGS__) | |
93 | #define gpiod_err(desc, fmt, ...) \ | |
94 | pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \ | |
95 | ##__VA_ARGS__) | |
96 | #define gpiod_warn(desc, fmt, ...) \ | |
97 | pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \ | |
98 | ##__VA_ARGS__) | |
99 | #define gpiod_info(desc, fmt, ...) \ | |
100 | pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \ | |
101 | ##__VA_ARGS__) | |
102 | #define gpiod_dbg(desc, fmt, ...) \ | |
103 | pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \ | |
104 | ##__VA_ARGS__) | |
105 | #else | |
6424de5a MB |
106 | #define gpiod_emerg(desc, fmt, ...) \ |
107 | pr_emerg("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__) | |
108 | #define gpiod_crit(desc, fmt, ...) \ | |
109 | pr_crit("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__) | |
110 | #define gpiod_err(desc, fmt, ...) \ | |
111 | pr_err("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__) | |
112 | #define gpiod_warn(desc, fmt, ...) \ | |
113 | pr_warn("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__) | |
114 | #define gpiod_info(desc, fmt, ...) \ | |
115 | pr_info("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__) | |
116 | #define gpiod_dbg(desc, fmt, ...) \ | |
117 | pr_debug("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__) | |
7b17b59f | 118 | #endif |
372e722e | 119 | |
d2876d08 DB |
120 | static inline void desc_set_label(struct gpio_desc *d, const char *label) |
121 | { | |
122 | #ifdef CONFIG_DEBUG_FS | |
123 | d->label = label; | |
124 | #endif | |
125 | } | |
126 | ||
372e722e AC |
127 | /* |
128 | * Return the GPIO number of the passed descriptor relative to its chip | |
129 | */ | |
130 | static int gpio_chip_hwgpio(const struct gpio_desc *desc) | |
131 | { | |
6c0b4e6c | 132 | return desc - &desc->chip->desc[0]; |
372e722e AC |
133 | } |
134 | ||
135 | /** | |
136 | * Convert a GPIO number to its descriptor | |
137 | */ | |
79a9becd | 138 | struct gpio_desc *gpio_to_desc(unsigned gpio) |
372e722e AC |
139 | { |
140 | if (WARN(!gpio_is_valid(gpio), "invalid GPIO %d\n", gpio)) | |
141 | return NULL; | |
142 | else | |
143 | return &gpio_desc[gpio]; | |
144 | } | |
79a9becd | 145 | EXPORT_SYMBOL_GPL(gpio_to_desc); |
372e722e | 146 | |
d468bf9e LW |
147 | /** |
148 | * Convert an offset on a certain chip to a corresponding descriptor | |
149 | */ | |
150 | static struct gpio_desc *gpiochip_offset_to_desc(struct gpio_chip *chip, | |
151 | unsigned int offset) | |
152 | { | |
153 | unsigned int gpio = chip->base + offset; | |
154 | ||
155 | return gpio_to_desc(gpio); | |
156 | } | |
372e722e AC |
157 | |
158 | /** | |
159 | * Convert a GPIO descriptor to the integer namespace. | |
160 | * This should disappear in the future but is needed since we still | |
161 | * use GPIO numbers for error messages and sysfs nodes | |
162 | */ | |
79a9becd | 163 | int desc_to_gpio(const struct gpio_desc *desc) |
372e722e | 164 | { |
8c0fca81 | 165 | return desc - &gpio_desc[0]; |
372e722e | 166 | } |
79a9becd | 167 | EXPORT_SYMBOL_GPL(desc_to_gpio); |
372e722e AC |
168 | |
169 | ||
d2876d08 DB |
170 | /* Warn when drivers omit gpio_request() calls -- legal but ill-advised |
171 | * when setting direction, and otherwise illegal. Until board setup code | |
172 | * and drivers use explicit requests everywhere (which won't happen when | |
173 | * those calls have no teeth) we can't avoid autorequesting. This nag | |
35e8bb51 DB |
174 | * message should motivate switching to explicit requests... so should |
175 | * the weaker cleanup after faults, compared to gpio_request(). | |
8a0cecff DB |
176 | * |
177 | * NOTE: the autorequest mechanism is going away; at this point it's | |
178 | * only "legal" in the sense that (old) code using it won't break yet, | |
179 | * but instead only triggers a WARN() stack dump. | |
d2876d08 | 180 | */ |
372e722e | 181 | static int gpio_ensure_requested(struct gpio_desc *desc) |
d2876d08 | 182 | { |
8a0cecff | 183 | const struct gpio_chip *chip = desc->chip; |
372e722e | 184 | const int gpio = desc_to_gpio(desc); |
35e8bb51 | 185 | |
8a0cecff DB |
186 | if (WARN(test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0, |
187 | "autorequest GPIO-%d\n", gpio)) { | |
35e8bb51 DB |
188 | if (!try_module_get(chip->owner)) { |
189 | pr_err("GPIO-%d: module can't be gotten \n", gpio); | |
190 | clear_bit(FLAG_REQUESTED, &desc->flags); | |
191 | /* lose */ | |
192 | return -EIO; | |
193 | } | |
d2876d08 | 194 | desc_set_label(desc, "[auto]"); |
35e8bb51 DB |
195 | /* caller must chip->request() w/o spinlock */ |
196 | if (chip->request) | |
197 | return 1; | |
d2876d08 | 198 | } |
35e8bb51 | 199 | return 0; |
d2876d08 DB |
200 | } |
201 | ||
79a9becd AC |
202 | /** |
203 | * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs | |
204 | * @desc: descriptor to return the chip of | |
205 | */ | |
206 | struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc) | |
372e722e | 207 | { |
bcabdef1 | 208 | return desc ? desc->chip : NULL; |
372e722e | 209 | } |
79a9becd | 210 | EXPORT_SYMBOL_GPL(gpiod_to_chip); |
d2876d08 | 211 | |
8d0aab2f AV |
212 | /* dynamic allocation of GPIOs, e.g. on a hotplugged device */ |
213 | static int gpiochip_find_base(int ngpio) | |
214 | { | |
83cabe33 AC |
215 | struct gpio_chip *chip; |
216 | int base = ARCH_NR_GPIOS - ngpio; | |
8d0aab2f | 217 | |
83cabe33 AC |
218 | list_for_each_entry_reverse(chip, &gpio_chips, list) { |
219 | /* found a free space? */ | |
220 | if (chip->base + chip->ngpio <= base) | |
221 | break; | |
222 | else | |
223 | /* nope, check the space right before the chip */ | |
224 | base = chip->base - ngpio; | |
8d0aab2f AV |
225 | } |
226 | ||
83cabe33 | 227 | if (gpio_is_valid(base)) { |
8d0aab2f | 228 | pr_debug("%s: found new base at %d\n", __func__, base); |
83cabe33 AC |
229 | return base; |
230 | } else { | |
231 | pr_err("%s: cannot find free range\n", __func__); | |
232 | return -ENOSPC; | |
169b6a7a | 233 | } |
169b6a7a AV |
234 | } |
235 | ||
79a9becd AC |
236 | /** |
237 | * gpiod_get_direction - return the current direction of a GPIO | |
238 | * @desc: GPIO to get the direction of | |
239 | * | |
240 | * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error. | |
241 | * | |
242 | * This function may sleep if gpiod_cansleep() is true. | |
243 | */ | |
244 | 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 | } | |
79a9becd | 270 | EXPORT_SYMBOL_GPL(gpiod_get_direction); |
80b0a602 | 271 | |
d8f388d8 DB |
272 | #ifdef CONFIG_GPIO_SYSFS |
273 | ||
274 | /* lock protects against unexport_gpio() being called while | |
275 | * sysfs files are active. | |
276 | */ | |
277 | static DEFINE_MUTEX(sysfs_lock); | |
278 | ||
279 | /* | |
280 | * /sys/class/gpio/gpioN... only for GPIOs that are exported | |
281 | * /direction | |
282 | * * MAY BE OMITTED if kernel won't allow direction changes | |
283 | * * is read/write as "in" or "out" | |
284 | * * may also be written as "high" or "low", initializing | |
285 | * output value as specified ("out" implies "low") | |
286 | * /value | |
287 | * * always readable, subject to hardware behavior | |
288 | * * may be writable, as zero/nonzero | |
ff77c352 DG |
289 | * /edge |
290 | * * configures behavior of poll(2) on /value | |
291 | * * available only if pin can generate IRQs on input | |
292 | * * is read/write as "none", "falling", "rising", or "both" | |
07697461 JN |
293 | * /active_low |
294 | * * configures polarity of /value | |
295 | * * is read/write as zero/nonzero | |
296 | * * also affects existing and subsequent "falling" and "rising" | |
297 | * /edge configuration | |
d8f388d8 DB |
298 | */ |
299 | ||
300 | static ssize_t gpio_direction_show(struct device *dev, | |
301 | struct device_attribute *attr, char *buf) | |
302 | { | |
def63433 | 303 | const struct gpio_desc *desc = dev_get_drvdata(dev); |
d8f388d8 DB |
304 | ssize_t status; |
305 | ||
306 | mutex_lock(&sysfs_lock); | |
307 | ||
476171ce | 308 | if (!test_bit(FLAG_EXPORT, &desc->flags)) { |
d8f388d8 | 309 | status = -EIO; |
476171ce | 310 | } else { |
372e722e | 311 | gpiod_get_direction(desc); |
d8f388d8 DB |
312 | status = sprintf(buf, "%s\n", |
313 | test_bit(FLAG_IS_OUT, &desc->flags) | |
314 | ? "out" : "in"); | |
476171ce | 315 | } |
d8f388d8 DB |
316 | |
317 | mutex_unlock(&sysfs_lock); | |
318 | return status; | |
319 | } | |
320 | ||
321 | static ssize_t gpio_direction_store(struct device *dev, | |
322 | struct device_attribute *attr, const char *buf, size_t size) | |
323 | { | |
372e722e | 324 | struct gpio_desc *desc = dev_get_drvdata(dev); |
d8f388d8 DB |
325 | ssize_t status; |
326 | ||
327 | mutex_lock(&sysfs_lock); | |
328 | ||
329 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
330 | status = -EIO; | |
331 | else if (sysfs_streq(buf, "high")) | |
372e722e | 332 | status = gpiod_direction_output(desc, 1); |
d8f388d8 | 333 | else if (sysfs_streq(buf, "out") || sysfs_streq(buf, "low")) |
372e722e | 334 | status = gpiod_direction_output(desc, 0); |
d8f388d8 | 335 | else if (sysfs_streq(buf, "in")) |
372e722e | 336 | status = gpiod_direction_input(desc); |
d8f388d8 DB |
337 | else |
338 | status = -EINVAL; | |
339 | ||
340 | mutex_unlock(&sysfs_lock); | |
341 | return status ? : size; | |
342 | } | |
343 | ||
07697461 | 344 | static /* const */ DEVICE_ATTR(direction, 0644, |
d8f388d8 DB |
345 | gpio_direction_show, gpio_direction_store); |
346 | ||
347 | static ssize_t gpio_value_show(struct device *dev, | |
348 | struct device_attribute *attr, char *buf) | |
349 | { | |
372e722e | 350 | struct gpio_desc *desc = dev_get_drvdata(dev); |
d8f388d8 DB |
351 | ssize_t status; |
352 | ||
353 | mutex_lock(&sysfs_lock); | |
354 | ||
79a9becd | 355 | if (!test_bit(FLAG_EXPORT, &desc->flags)) |
d8f388d8 | 356 | status = -EIO; |
79a9becd AC |
357 | else |
358 | status = sprintf(buf, "%d\n", gpiod_get_value_cansleep(desc)); | |
d8f388d8 DB |
359 | |
360 | mutex_unlock(&sysfs_lock); | |
361 | return status; | |
362 | } | |
363 | ||
364 | static ssize_t gpio_value_store(struct device *dev, | |
365 | struct device_attribute *attr, const char *buf, size_t size) | |
366 | { | |
372e722e | 367 | struct gpio_desc *desc = dev_get_drvdata(dev); |
d8f388d8 DB |
368 | ssize_t status; |
369 | ||
370 | mutex_lock(&sysfs_lock); | |
371 | ||
372 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
373 | status = -EIO; | |
374 | else if (!test_bit(FLAG_IS_OUT, &desc->flags)) | |
375 | status = -EPERM; | |
376 | else { | |
377 | long value; | |
378 | ||
a3d88c92 | 379 | status = kstrtol(buf, 0, &value); |
d8f388d8 | 380 | if (status == 0) { |
79a9becd | 381 | gpiod_set_value_cansleep(desc, value); |
d8f388d8 DB |
382 | status = size; |
383 | } | |
384 | } | |
385 | ||
386 | mutex_unlock(&sysfs_lock); | |
387 | return status; | |
388 | } | |
389 | ||
07697461 | 390 | static const DEVICE_ATTR(value, 0644, |
d8f388d8 DB |
391 | gpio_value_show, gpio_value_store); |
392 | ||
ff77c352 DG |
393 | static irqreturn_t gpio_sysfs_irq(int irq, void *priv) |
394 | { | |
5ba1821d | 395 | struct sysfs_dirent *value_sd = priv; |
ff77c352 | 396 | |
5ba1821d | 397 | sysfs_notify_dirent(value_sd); |
ff77c352 DG |
398 | return IRQ_HANDLED; |
399 | } | |
400 | ||
ff77c352 DG |
401 | static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev, |
402 | unsigned long gpio_flags) | |
403 | { | |
5ba1821d | 404 | struct sysfs_dirent *value_sd; |
ff77c352 DG |
405 | unsigned long irq_flags; |
406 | int ret, irq, id; | |
407 | ||
408 | if ((desc->flags & GPIO_TRIGGER_MASK) == gpio_flags) | |
409 | return 0; | |
410 | ||
372e722e | 411 | irq = gpiod_to_irq(desc); |
ff77c352 DG |
412 | if (irq < 0) |
413 | return -EIO; | |
414 | ||
5ba1821d DG |
415 | id = desc->flags >> ID_SHIFT; |
416 | value_sd = idr_find(&dirent_idr, id); | |
417 | if (value_sd) | |
418 | free_irq(irq, value_sd); | |
ff77c352 DG |
419 | |
420 | desc->flags &= ~GPIO_TRIGGER_MASK; | |
421 | ||
422 | if (!gpio_flags) { | |
d468bf9e | 423 | gpiod_unlock_as_irq(desc); |
ff77c352 | 424 | ret = 0; |
5ba1821d | 425 | goto free_id; |
ff77c352 DG |
426 | } |
427 | ||
428 | irq_flags = IRQF_SHARED; | |
429 | if (test_bit(FLAG_TRIG_FALL, &gpio_flags)) | |
07697461 JN |
430 | irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? |
431 | IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING; | |
ff77c352 | 432 | if (test_bit(FLAG_TRIG_RISE, &gpio_flags)) |
07697461 JN |
433 | irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? |
434 | IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; | |
ff77c352 | 435 | |
5ba1821d | 436 | if (!value_sd) { |
388975cc | 437 | value_sd = sysfs_get_dirent(dev->kobj.sd, "value"); |
5ba1821d DG |
438 | if (!value_sd) { |
439 | ret = -ENODEV; | |
ff77c352 DG |
440 | goto err_out; |
441 | } | |
442 | ||
62f516b8 TH |
443 | ret = idr_alloc(&dirent_idr, value_sd, 1, 0, GFP_KERNEL); |
444 | if (ret < 0) | |
5ba1821d | 445 | goto free_sd; |
62f516b8 | 446 | id = ret; |
ff77c352 DG |
447 | |
448 | desc->flags &= GPIO_FLAGS_MASK; | |
5ba1821d | 449 | desc->flags |= (unsigned long)id << ID_SHIFT; |
ff77c352 | 450 | |
5ba1821d | 451 | if (desc->flags >> ID_SHIFT != id) { |
ff77c352 DG |
452 | ret = -ERANGE; |
453 | goto free_id; | |
454 | } | |
ff77c352 DG |
455 | } |
456 | ||
364fadb3 | 457 | ret = request_any_context_irq(irq, gpio_sysfs_irq, irq_flags, |
5ba1821d | 458 | "gpiolib", value_sd); |
364fadb3 | 459 | if (ret < 0) |
5ba1821d | 460 | goto free_id; |
ff77c352 | 461 | |
d468bf9e LW |
462 | ret = gpiod_lock_as_irq(desc); |
463 | if (ret < 0) { | |
464 | gpiod_warn(desc, "failed to flag the GPIO for IRQ\n"); | |
465 | goto free_id; | |
466 | } | |
467 | ||
ff77c352 DG |
468 | desc->flags |= gpio_flags; |
469 | return 0; | |
470 | ||
ff77c352 | 471 | free_id: |
5ba1821d | 472 | idr_remove(&dirent_idr, id); |
ff77c352 | 473 | desc->flags &= GPIO_FLAGS_MASK; |
5ba1821d DG |
474 | free_sd: |
475 | if (value_sd) | |
476 | sysfs_put(value_sd); | |
ff77c352 DG |
477 | err_out: |
478 | return ret; | |
479 | } | |
480 | ||
481 | static const struct { | |
482 | const char *name; | |
483 | unsigned long flags; | |
484 | } trigger_types[] = { | |
485 | { "none", 0 }, | |
486 | { "falling", BIT(FLAG_TRIG_FALL) }, | |
487 | { "rising", BIT(FLAG_TRIG_RISE) }, | |
488 | { "both", BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE) }, | |
489 | }; | |
490 | ||
491 | static ssize_t gpio_edge_show(struct device *dev, | |
492 | struct device_attribute *attr, char *buf) | |
493 | { | |
494 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
495 | ssize_t status; | |
496 | ||
497 | mutex_lock(&sysfs_lock); | |
498 | ||
499 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
500 | status = -EIO; | |
501 | else { | |
502 | int i; | |
503 | ||
504 | status = 0; | |
505 | for (i = 0; i < ARRAY_SIZE(trigger_types); i++) | |
506 | if ((desc->flags & GPIO_TRIGGER_MASK) | |
507 | == trigger_types[i].flags) { | |
508 | status = sprintf(buf, "%s\n", | |
509 | trigger_types[i].name); | |
510 | break; | |
511 | } | |
512 | } | |
513 | ||
514 | mutex_unlock(&sysfs_lock); | |
515 | return status; | |
516 | } | |
517 | ||
518 | static ssize_t gpio_edge_store(struct device *dev, | |
519 | struct device_attribute *attr, const char *buf, size_t size) | |
520 | { | |
521 | struct gpio_desc *desc = dev_get_drvdata(dev); | |
522 | ssize_t status; | |
523 | int i; | |
524 | ||
525 | for (i = 0; i < ARRAY_SIZE(trigger_types); i++) | |
526 | if (sysfs_streq(trigger_types[i].name, buf)) | |
527 | goto found; | |
528 | return -EINVAL; | |
529 | ||
530 | found: | |
531 | mutex_lock(&sysfs_lock); | |
532 | ||
533 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
534 | status = -EIO; | |
535 | else { | |
536 | status = gpio_setup_irq(desc, dev, trigger_types[i].flags); | |
537 | if (!status) | |
538 | status = size; | |
539 | } | |
540 | ||
541 | mutex_unlock(&sysfs_lock); | |
542 | ||
543 | return status; | |
544 | } | |
545 | ||
546 | static DEVICE_ATTR(edge, 0644, gpio_edge_show, gpio_edge_store); | |
547 | ||
07697461 JN |
548 | static int sysfs_set_active_low(struct gpio_desc *desc, struct device *dev, |
549 | int value) | |
550 | { | |
551 | int status = 0; | |
552 | ||
553 | if (!!test_bit(FLAG_ACTIVE_LOW, &desc->flags) == !!value) | |
554 | return 0; | |
555 | ||
556 | if (value) | |
557 | set_bit(FLAG_ACTIVE_LOW, &desc->flags); | |
558 | else | |
559 | clear_bit(FLAG_ACTIVE_LOW, &desc->flags); | |
560 | ||
561 | /* reconfigure poll(2) support if enabled on one edge only */ | |
562 | if (dev != NULL && (!!test_bit(FLAG_TRIG_RISE, &desc->flags) ^ | |
563 | !!test_bit(FLAG_TRIG_FALL, &desc->flags))) { | |
564 | unsigned long trigger_flags = desc->flags & GPIO_TRIGGER_MASK; | |
565 | ||
566 | gpio_setup_irq(desc, dev, 0); | |
567 | status = gpio_setup_irq(desc, dev, trigger_flags); | |
568 | } | |
569 | ||
570 | return status; | |
571 | } | |
572 | ||
573 | static ssize_t gpio_active_low_show(struct device *dev, | |
574 | struct device_attribute *attr, char *buf) | |
575 | { | |
576 | const struct gpio_desc *desc = dev_get_drvdata(dev); | |
577 | ssize_t status; | |
578 | ||
579 | mutex_lock(&sysfs_lock); | |
580 | ||
581 | if (!test_bit(FLAG_EXPORT, &desc->flags)) | |
582 | status = -EIO; | |
583 | else | |
584 | status = sprintf(buf, "%d\n", | |
585 | !!test_bit(FLAG_ACTIVE_LOW, &desc->flags)); | |
586 | ||
587 | mutex_unlock(&sysfs_lock); | |
588 | ||
589 | return status; | |
590 | } | |
591 | ||
592 | static ssize_t gpio_active_low_store(struct device *dev, | |
593 | struct device_attribute *attr, const char *buf, size_t size) | |
594 | { | |
595 | struct gpio_desc *desc = dev_get_drvdata(dev); | |
596 | ssize_t status; | |
597 | ||
598 | mutex_lock(&sysfs_lock); | |
599 | ||
600 | if (!test_bit(FLAG_EXPORT, &desc->flags)) { | |
601 | status = -EIO; | |
602 | } else { | |
603 | long value; | |
604 | ||
a3d88c92 | 605 | status = kstrtol(buf, 0, &value); |
07697461 JN |
606 | if (status == 0) |
607 | status = sysfs_set_active_low(desc, dev, value != 0); | |
608 | } | |
609 | ||
610 | mutex_unlock(&sysfs_lock); | |
611 | ||
612 | return status ? : size; | |
613 | } | |
614 | ||
615 | static const DEVICE_ATTR(active_low, 0644, | |
616 | gpio_active_low_show, gpio_active_low_store); | |
617 | ||
d8f388d8 | 618 | static const struct attribute *gpio_attrs[] = { |
d8f388d8 | 619 | &dev_attr_value.attr, |
07697461 | 620 | &dev_attr_active_low.attr, |
d8f388d8 DB |
621 | NULL, |
622 | }; | |
623 | ||
624 | static const struct attribute_group gpio_attr_group = { | |
625 | .attrs = (struct attribute **) gpio_attrs, | |
626 | }; | |
627 | ||
628 | /* | |
629 | * /sys/class/gpio/gpiochipN/ | |
630 | * /base ... matching gpio_chip.base (N) | |
631 | * /label ... matching gpio_chip.label | |
632 | * /ngpio ... matching gpio_chip.ngpio | |
633 | */ | |
634 | ||
635 | static ssize_t chip_base_show(struct device *dev, | |
636 | struct device_attribute *attr, char *buf) | |
637 | { | |
638 | const struct gpio_chip *chip = dev_get_drvdata(dev); | |
639 | ||
640 | return sprintf(buf, "%d\n", chip->base); | |
641 | } | |
642 | static DEVICE_ATTR(base, 0444, chip_base_show, NULL); | |
643 | ||
644 | static ssize_t chip_label_show(struct device *dev, | |
645 | struct device_attribute *attr, char *buf) | |
646 | { | |
647 | const struct gpio_chip *chip = dev_get_drvdata(dev); | |
648 | ||
649 | return sprintf(buf, "%s\n", chip->label ? : ""); | |
650 | } | |
651 | static DEVICE_ATTR(label, 0444, chip_label_show, NULL); | |
652 | ||
653 | static ssize_t chip_ngpio_show(struct device *dev, | |
654 | struct device_attribute *attr, char *buf) | |
655 | { | |
656 | const struct gpio_chip *chip = dev_get_drvdata(dev); | |
657 | ||
658 | return sprintf(buf, "%u\n", chip->ngpio); | |
659 | } | |
660 | static DEVICE_ATTR(ngpio, 0444, chip_ngpio_show, NULL); | |
661 | ||
662 | static const struct attribute *gpiochip_attrs[] = { | |
663 | &dev_attr_base.attr, | |
664 | &dev_attr_label.attr, | |
665 | &dev_attr_ngpio.attr, | |
666 | NULL, | |
667 | }; | |
668 | ||
669 | static const struct attribute_group gpiochip_attr_group = { | |
670 | .attrs = (struct attribute **) gpiochip_attrs, | |
671 | }; | |
672 | ||
673 | /* | |
674 | * /sys/class/gpio/export ... write-only | |
675 | * integer N ... number of GPIO to export (full access) | |
676 | * /sys/class/gpio/unexport ... write-only | |
677 | * integer N ... number of GPIO to unexport | |
678 | */ | |
28812fe1 AK |
679 | static ssize_t export_store(struct class *class, |
680 | struct class_attribute *attr, | |
681 | const char *buf, size_t len) | |
d8f388d8 | 682 | { |
372e722e AC |
683 | long gpio; |
684 | struct gpio_desc *desc; | |
685 | int status; | |
d8f388d8 | 686 | |
a3d88c92 | 687 | status = kstrtol(buf, 0, &gpio); |
d8f388d8 DB |
688 | if (status < 0) |
689 | goto done; | |
690 | ||
372e722e | 691 | desc = gpio_to_desc(gpio); |
bcabdef1 AC |
692 | /* reject invalid GPIOs */ |
693 | if (!desc) { | |
694 | pr_warn("%s: invalid GPIO %ld\n", __func__, gpio); | |
695 | return -EINVAL; | |
696 | } | |
372e722e | 697 | |
d8f388d8 DB |
698 | /* No extra locking here; FLAG_SYSFS just signifies that the |
699 | * request and export were done by on behalf of userspace, so | |
700 | * they may be undone on its behalf too. | |
701 | */ | |
702 | ||
372e722e | 703 | status = gpiod_request(desc, "sysfs"); |
ad2fab36 MN |
704 | if (status < 0) { |
705 | if (status == -EPROBE_DEFER) | |
706 | status = -ENODEV; | |
d8f388d8 | 707 | goto done; |
ad2fab36 | 708 | } |
372e722e | 709 | status = gpiod_export(desc, true); |
d8f388d8 | 710 | if (status < 0) |
372e722e | 711 | gpiod_free(desc); |
d8f388d8 | 712 | else |
372e722e | 713 | set_bit(FLAG_SYSFS, &desc->flags); |
d8f388d8 DB |
714 | |
715 | done: | |
716 | if (status) | |
717 | pr_debug("%s: status %d\n", __func__, status); | |
718 | return status ? : len; | |
719 | } | |
720 | ||
28812fe1 AK |
721 | static ssize_t unexport_store(struct class *class, |
722 | struct class_attribute *attr, | |
723 | const char *buf, size_t len) | |
d8f388d8 | 724 | { |
372e722e AC |
725 | long gpio; |
726 | struct gpio_desc *desc; | |
727 | int status; | |
d8f388d8 | 728 | |
a3d88c92 | 729 | status = kstrtol(buf, 0, &gpio); |
d8f388d8 DB |
730 | if (status < 0) |
731 | goto done; | |
732 | ||
372e722e | 733 | desc = gpio_to_desc(gpio); |
d8f388d8 | 734 | /* reject bogus commands (gpio_unexport ignores them) */ |
bcabdef1 AC |
735 | if (!desc) { |
736 | pr_warn("%s: invalid GPIO %ld\n", __func__, gpio); | |
737 | return -EINVAL; | |
738 | } | |
739 | ||
740 | status = -EINVAL; | |
d8f388d8 DB |
741 | |
742 | /* No extra locking here; FLAG_SYSFS just signifies that the | |
743 | * request and export were done by on behalf of userspace, so | |
744 | * they may be undone on its behalf too. | |
745 | */ | |
372e722e | 746 | if (test_and_clear_bit(FLAG_SYSFS, &desc->flags)) { |
d8f388d8 | 747 | status = 0; |
372e722e | 748 | gpiod_free(desc); |
d8f388d8 DB |
749 | } |
750 | done: | |
751 | if (status) | |
752 | pr_debug("%s: status %d\n", __func__, status); | |
753 | return status ? : len; | |
754 | } | |
755 | ||
756 | static struct class_attribute gpio_class_attrs[] = { | |
757 | __ATTR(export, 0200, NULL, export_store), | |
758 | __ATTR(unexport, 0200, NULL, unexport_store), | |
759 | __ATTR_NULL, | |
760 | }; | |
761 | ||
762 | static struct class gpio_class = { | |
763 | .name = "gpio", | |
764 | .owner = THIS_MODULE, | |
765 | ||
766 | .class_attrs = gpio_class_attrs, | |
767 | }; | |
768 | ||
769 | ||
770 | /** | |
79a9becd | 771 | * gpiod_export - export a GPIO through sysfs |
d8f388d8 DB |
772 | * @gpio: gpio to make available, already requested |
773 | * @direction_may_change: true if userspace may change gpio direction | |
774 | * Context: arch_initcall or later | |
775 | * | |
776 | * When drivers want to make a GPIO accessible to userspace after they | |
777 | * have requested it -- perhaps while debugging, or as part of their | |
778 | * public interface -- they may use this routine. If the GPIO can | |
779 | * change direction (some can't) and the caller allows it, userspace | |
780 | * will see "direction" sysfs attribute which may be used to change | |
781 | * the gpio's direction. A "value" attribute will always be provided. | |
782 | * | |
783 | * Returns zero on success, else an error. | |
784 | */ | |
79a9becd | 785 | int gpiod_export(struct gpio_desc *desc, bool direction_may_change) |
d8f388d8 DB |
786 | { |
787 | unsigned long flags; | |
fc4e2514 | 788 | int status; |
62154991 | 789 | const char *ioname = NULL; |
fc4e2514 | 790 | struct device *dev; |
372e722e | 791 | int offset; |
d8f388d8 DB |
792 | |
793 | /* can't export until sysfs is available ... */ | |
794 | if (!gpio_class.p) { | |
795 | pr_debug("%s: called too early!\n", __func__); | |
796 | return -ENOENT; | |
797 | } | |
798 | ||
372e722e AC |
799 | if (!desc) { |
800 | pr_debug("%s: invalid gpio descriptor\n", __func__); | |
fc4e2514 RM |
801 | return -EINVAL; |
802 | } | |
d8f388d8 DB |
803 | |
804 | mutex_lock(&sysfs_lock); | |
805 | ||
806 | spin_lock_irqsave(&gpio_lock, flags); | |
fc4e2514 RM |
807 | if (!test_bit(FLAG_REQUESTED, &desc->flags) || |
808 | test_bit(FLAG_EXPORT, &desc->flags)) { | |
809 | spin_unlock_irqrestore(&gpio_lock, flags); | |
810 | pr_debug("%s: gpio %d unavailable (requested=%d, exported=%d)\n", | |
372e722e | 811 | __func__, desc_to_gpio(desc), |
fc4e2514 RM |
812 | test_bit(FLAG_REQUESTED, &desc->flags), |
813 | test_bit(FLAG_EXPORT, &desc->flags)); | |
529f2ad5 DC |
814 | status = -EPERM; |
815 | goto fail_unlock; | |
d8f388d8 | 816 | } |
fc4e2514 RM |
817 | |
818 | if (!desc->chip->direction_input || !desc->chip->direction_output) | |
819 | direction_may_change = false; | |
d8f388d8 DB |
820 | spin_unlock_irqrestore(&gpio_lock, flags); |
821 | ||
372e722e AC |
822 | offset = gpio_chip_hwgpio(desc); |
823 | if (desc->chip->names && desc->chip->names[offset]) | |
824 | ioname = desc->chip->names[offset]; | |
926b663c | 825 | |
fc4e2514 | 826 | dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0), |
372e722e AC |
827 | desc, ioname ? ioname : "gpio%u", |
828 | desc_to_gpio(desc)); | |
fc4e2514 RM |
829 | if (IS_ERR(dev)) { |
830 | status = PTR_ERR(dev); | |
831 | goto fail_unlock; | |
d8f388d8 DB |
832 | } |
833 | ||
fc4e2514 | 834 | status = sysfs_create_group(&dev->kobj, &gpio_attr_group); |
d8f388d8 | 835 | if (status) |
fc4e2514 | 836 | goto fail_unregister_device; |
d8f388d8 | 837 | |
fc4e2514 RM |
838 | if (direction_may_change) { |
839 | status = device_create_file(dev, &dev_attr_direction); | |
840 | if (status) | |
841 | goto fail_unregister_device; | |
842 | } | |
843 | ||
372e722e | 844 | if (gpiod_to_irq(desc) >= 0 && (direction_may_change || |
fc4e2514 RM |
845 | !test_bit(FLAG_IS_OUT, &desc->flags))) { |
846 | status = device_create_file(dev, &dev_attr_edge); | |
847 | if (status) | |
848 | goto fail_unregister_device; | |
849 | } | |
d8f388d8 | 850 | |
fc4e2514 RM |
851 | set_bit(FLAG_EXPORT, &desc->flags); |
852 | mutex_unlock(&sysfs_lock); | |
853 | return 0; | |
854 | ||
855 | fail_unregister_device: | |
856 | device_unregister(dev); | |
857 | fail_unlock: | |
858 | mutex_unlock(&sysfs_lock); | |
372e722e AC |
859 | pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc), |
860 | status); | |
d8f388d8 DB |
861 | return status; |
862 | } | |
79a9becd | 863 | EXPORT_SYMBOL_GPL(gpiod_export); |
d8f388d8 | 864 | |
9f3b795a | 865 | static int match_export(struct device *dev, const void *data) |
d8f388d8 DB |
866 | { |
867 | return dev_get_drvdata(dev) == data; | |
868 | } | |
869 | ||
a4177ee7 | 870 | /** |
79a9becd | 871 | * gpiod_export_link - create a sysfs link to an exported GPIO node |
a4177ee7 JN |
872 | * @dev: device under which to create symlink |
873 | * @name: name of the symlink | |
874 | * @gpio: gpio to create symlink to, already exported | |
875 | * | |
876 | * Set up a symlink from /sys/.../dev/name to /sys/class/gpio/gpioN | |
877 | * node. Caller is responsible for unlinking. | |
878 | * | |
879 | * Returns zero on success, else an error. | |
880 | */ | |
79a9becd AC |
881 | int gpiod_export_link(struct device *dev, const char *name, |
882 | struct gpio_desc *desc) | |
a4177ee7 | 883 | { |
a4177ee7 JN |
884 | int status = -EINVAL; |
885 | ||
bcabdef1 AC |
886 | if (!desc) { |
887 | pr_warn("%s: invalid GPIO\n", __func__); | |
888 | return -EINVAL; | |
889 | } | |
a4177ee7 JN |
890 | |
891 | mutex_lock(&sysfs_lock); | |
892 | ||
a4177ee7 JN |
893 | if (test_bit(FLAG_EXPORT, &desc->flags)) { |
894 | struct device *tdev; | |
895 | ||
896 | tdev = class_find_device(&gpio_class, NULL, desc, match_export); | |
897 | if (tdev != NULL) { | |
898 | status = sysfs_create_link(&dev->kobj, &tdev->kobj, | |
899 | name); | |
900 | } else { | |
901 | status = -ENODEV; | |
902 | } | |
903 | } | |
904 | ||
905 | mutex_unlock(&sysfs_lock); | |
906 | ||
a4177ee7 | 907 | if (status) |
372e722e AC |
908 | pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc), |
909 | status); | |
a4177ee7 JN |
910 | |
911 | return status; | |
912 | } | |
79a9becd | 913 | EXPORT_SYMBOL_GPL(gpiod_export_link); |
07697461 JN |
914 | |
915 | /** | |
79a9becd | 916 | * gpiod_sysfs_set_active_low - set the polarity of gpio sysfs value |
07697461 JN |
917 | * @gpio: gpio to change |
918 | * @value: non-zero to use active low, i.e. inverted values | |
919 | * | |
920 | * Set the polarity of /sys/class/gpio/gpioN/value sysfs attribute. | |
921 | * The GPIO does not have to be exported yet. If poll(2) support has | |
922 | * been enabled for either rising or falling edge, it will be | |
923 | * reconfigured to follow the new polarity. | |
924 | * | |
925 | * Returns zero on success, else an error. | |
926 | */ | |
79a9becd | 927 | int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value) |
07697461 | 928 | { |
07697461 JN |
929 | struct device *dev = NULL; |
930 | int status = -EINVAL; | |
931 | ||
bcabdef1 AC |
932 | if (!desc) { |
933 | pr_warn("%s: invalid GPIO\n", __func__); | |
934 | return -EINVAL; | |
935 | } | |
07697461 JN |
936 | |
937 | mutex_lock(&sysfs_lock); | |
938 | ||
07697461 | 939 | if (test_bit(FLAG_EXPORT, &desc->flags)) { |
07697461 JN |
940 | dev = class_find_device(&gpio_class, NULL, desc, match_export); |
941 | if (dev == NULL) { | |
942 | status = -ENODEV; | |
943 | goto unlock; | |
944 | } | |
945 | } | |
946 | ||
947 | status = sysfs_set_active_low(desc, dev, value); | |
948 | ||
949 | unlock: | |
950 | mutex_unlock(&sysfs_lock); | |
951 | ||
07697461 | 952 | if (status) |
372e722e AC |
953 | pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc), |
954 | status); | |
07697461 JN |
955 | |
956 | return status; | |
957 | } | |
79a9becd | 958 | EXPORT_SYMBOL_GPL(gpiod_sysfs_set_active_low); |
07697461 | 959 | |
d8f388d8 | 960 | /** |
79a9becd | 961 | * gpiod_unexport - reverse effect of gpio_export() |
d8f388d8 DB |
962 | * @gpio: gpio to make unavailable |
963 | * | |
964 | * This is implicit on gpio_free(). | |
965 | */ | |
79a9becd | 966 | void gpiod_unexport(struct gpio_desc *desc) |
d8f388d8 | 967 | { |
6a99ad4a | 968 | int status = 0; |
864533ce | 969 | struct device *dev = NULL; |
d8f388d8 | 970 | |
372e722e | 971 | if (!desc) { |
bcabdef1 AC |
972 | pr_warn("%s: invalid GPIO\n", __func__); |
973 | return; | |
6a99ad4a | 974 | } |
d8f388d8 DB |
975 | |
976 | mutex_lock(&sysfs_lock); | |
977 | ||
d8f388d8 | 978 | if (test_bit(FLAG_EXPORT, &desc->flags)) { |
d8f388d8 DB |
979 | |
980 | dev = class_find_device(&gpio_class, NULL, desc, match_export); | |
981 | if (dev) { | |
ff77c352 | 982 | gpio_setup_irq(desc, dev, 0); |
d8f388d8 | 983 | clear_bit(FLAG_EXPORT, &desc->flags); |
d8f388d8 DB |
984 | } else |
985 | status = -ENODEV; | |
986 | } | |
987 | ||
988 | mutex_unlock(&sysfs_lock); | |
372e722e | 989 | |
864533ce ML |
990 | if (dev) { |
991 | device_unregister(dev); | |
992 | put_device(dev); | |
993 | } | |
bcabdef1 | 994 | |
d8f388d8 | 995 | if (status) |
372e722e AC |
996 | pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc), |
997 | status); | |
998 | } | |
79a9becd | 999 | EXPORT_SYMBOL_GPL(gpiod_unexport); |
d8f388d8 DB |
1000 | |
1001 | static int gpiochip_export(struct gpio_chip *chip) | |
1002 | { | |
1003 | int status; | |
1004 | struct device *dev; | |
1005 | ||
1006 | /* Many systems register gpio chips for SOC support very early, | |
1007 | * before driver model support is available. In those cases we | |
1008 | * export this later, in gpiolib_sysfs_init() ... here we just | |
1009 | * verify that _some_ field of gpio_class got initialized. | |
1010 | */ | |
1011 | if (!gpio_class.p) | |
1012 | return 0; | |
1013 | ||
1014 | /* use chip->base for the ID; it's already known to be unique */ | |
1015 | mutex_lock(&sysfs_lock); | |
1016 | dev = device_create(&gpio_class, chip->dev, MKDEV(0, 0), chip, | |
1017 | "gpiochip%d", chip->base); | |
d62668e1 | 1018 | if (!IS_ERR(dev)) { |
d8f388d8 DB |
1019 | status = sysfs_create_group(&dev->kobj, |
1020 | &gpiochip_attr_group); | |
1021 | } else | |
d62668e1 | 1022 | status = PTR_ERR(dev); |
d8f388d8 DB |
1023 | chip->exported = (status == 0); |
1024 | mutex_unlock(&sysfs_lock); | |
1025 | ||
1026 | if (status) { | |
1027 | unsigned long flags; | |
1028 | unsigned gpio; | |
1029 | ||
1030 | spin_lock_irqsave(&gpio_lock, flags); | |
6c0b4e6c AC |
1031 | gpio = 0; |
1032 | while (gpio < chip->ngpio) | |
1033 | chip->desc[gpio++].chip = NULL; | |
d8f388d8 DB |
1034 | spin_unlock_irqrestore(&gpio_lock, flags); |
1035 | ||
1036 | pr_debug("%s: chip %s status %d\n", __func__, | |
1037 | chip->label, status); | |
1038 | } | |
1039 | ||
1040 | return status; | |
1041 | } | |
1042 | ||
1043 | static void gpiochip_unexport(struct gpio_chip *chip) | |
1044 | { | |
1045 | int status; | |
1046 | struct device *dev; | |
1047 | ||
1048 | mutex_lock(&sysfs_lock); | |
1049 | dev = class_find_device(&gpio_class, NULL, chip, match_export); | |
1050 | if (dev) { | |
1051 | put_device(dev); | |
1052 | device_unregister(dev); | |
1053 | chip->exported = 0; | |
1054 | status = 0; | |
1055 | } else | |
1056 | status = -ENODEV; | |
1057 | mutex_unlock(&sysfs_lock); | |
1058 | ||
1059 | if (status) | |
1060 | pr_debug("%s: chip %s status %d\n", __func__, | |
1061 | chip->label, status); | |
1062 | } | |
1063 | ||
1064 | static int __init gpiolib_sysfs_init(void) | |
1065 | { | |
1066 | int status; | |
1067 | unsigned long flags; | |
65493e3a | 1068 | struct gpio_chip *chip; |
d8f388d8 DB |
1069 | |
1070 | status = class_register(&gpio_class); | |
1071 | if (status < 0) | |
1072 | return status; | |
1073 | ||
1074 | /* Scan and register the gpio_chips which registered very | |
1075 | * early (e.g. before the class_register above was called). | |
1076 | * | |
1077 | * We run before arch_initcall() so chip->dev nodes can have | |
1078 | * registered, and so arch_initcall() can always gpio_export(). | |
1079 | */ | |
1080 | spin_lock_irqsave(&gpio_lock, flags); | |
65493e3a | 1081 | list_for_each_entry(chip, &gpio_chips, list) { |
d8f388d8 DB |
1082 | if (!chip || chip->exported) |
1083 | continue; | |
1084 | ||
1085 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1086 | status = gpiochip_export(chip); | |
1087 | spin_lock_irqsave(&gpio_lock, flags); | |
1088 | } | |
1089 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1090 | ||
1091 | ||
1092 | return status; | |
1093 | } | |
1094 | postcore_initcall(gpiolib_sysfs_init); | |
1095 | ||
1096 | #else | |
1097 | static inline int gpiochip_export(struct gpio_chip *chip) | |
1098 | { | |
1099 | return 0; | |
1100 | } | |
1101 | ||
1102 | static inline void gpiochip_unexport(struct gpio_chip *chip) | |
1103 | { | |
1104 | } | |
1105 | ||
1106 | #endif /* CONFIG_GPIO_SYSFS */ | |
1107 | ||
1a989d0f AC |
1108 | /* |
1109 | * Add a new chip to the global chips list, keeping the list of chips sorted | |
1110 | * by base order. | |
1111 | * | |
1112 | * Return -EBUSY if the new chip overlaps with some other chip's integer | |
1113 | * space. | |
1114 | */ | |
1115 | static int gpiochip_add_to_list(struct gpio_chip *chip) | |
1116 | { | |
1117 | struct list_head *pos = &gpio_chips; | |
1118 | struct gpio_chip *_chip; | |
1119 | int err = 0; | |
1120 | ||
1121 | /* find where to insert our chip */ | |
1122 | list_for_each(pos, &gpio_chips) { | |
1123 | _chip = list_entry(pos, struct gpio_chip, list); | |
1124 | /* shall we insert before _chip? */ | |
1125 | if (_chip->base >= chip->base + chip->ngpio) | |
1126 | break; | |
1127 | } | |
1128 | ||
1129 | /* are we stepping on the chip right before? */ | |
1130 | if (pos != &gpio_chips && pos->prev != &gpio_chips) { | |
1131 | _chip = list_entry(pos->prev, struct gpio_chip, list); | |
1132 | if (_chip->base + _chip->ngpio > chip->base) { | |
1133 | dev_err(chip->dev, | |
1134 | "GPIO integer space overlap, cannot add chip\n"); | |
1135 | err = -EBUSY; | |
1136 | } | |
1137 | } | |
1138 | ||
1139 | if (!err) | |
1140 | list_add_tail(&chip->list, pos); | |
1141 | ||
1142 | return err; | |
1143 | } | |
1144 | ||
d2876d08 DB |
1145 | /** |
1146 | * gpiochip_add() - register a gpio_chip | |
1147 | * @chip: the chip to register, with chip->base initialized | |
1148 | * Context: potentially before irqs or kmalloc will work | |
1149 | * | |
1150 | * Returns a negative errno if the chip can't be registered, such as | |
1151 | * because the chip->base is invalid or already associated with a | |
1152 | * different chip. Otherwise it returns zero as a success code. | |
8d0aab2f | 1153 | * |
d8f388d8 DB |
1154 | * When gpiochip_add() is called very early during boot, so that GPIOs |
1155 | * can be freely used, the chip->dev device must be registered before | |
1156 | * the gpio framework's arch_initcall(). Otherwise sysfs initialization | |
1157 | * for GPIOs will fail rudely. | |
1158 | * | |
8d0aab2f AV |
1159 | * If chip->base is negative, this requests dynamic assignment of |
1160 | * a range of valid GPIOs. | |
d2876d08 DB |
1161 | */ |
1162 | int gpiochip_add(struct gpio_chip *chip) | |
1163 | { | |
1164 | unsigned long flags; | |
1165 | int status = 0; | |
1166 | unsigned id; | |
8d0aab2f | 1167 | int base = chip->base; |
d2876d08 | 1168 | |
bff5fda9 | 1169 | if ((!gpio_is_valid(base) || !gpio_is_valid(base + chip->ngpio - 1)) |
8d0aab2f | 1170 | && base >= 0) { |
d2876d08 DB |
1171 | status = -EINVAL; |
1172 | goto fail; | |
1173 | } | |
1174 | ||
1175 | spin_lock_irqsave(&gpio_lock, flags); | |
1176 | ||
8d0aab2f AV |
1177 | if (base < 0) { |
1178 | base = gpiochip_find_base(chip->ngpio); | |
1179 | if (base < 0) { | |
1180 | status = base; | |
d8f388d8 | 1181 | goto unlock; |
8d0aab2f AV |
1182 | } |
1183 | chip->base = base; | |
1184 | } | |
1185 | ||
1a989d0f AC |
1186 | status = gpiochip_add_to_list(chip); |
1187 | ||
d2876d08 | 1188 | if (status == 0) { |
6c0b4e6c AC |
1189 | chip->desc = &gpio_desc[chip->base]; |
1190 | ||
1191 | for (id = 0; id < chip->ngpio; id++) { | |
1192 | struct gpio_desc *desc = &chip->desc[id]; | |
1193 | desc->chip = chip; | |
d8f388d8 DB |
1194 | |
1195 | /* REVISIT: most hardware initializes GPIOs as | |
1196 | * inputs (often with pullups enabled) so power | |
1197 | * usage is minimized. Linux code should set the | |
1198 | * gpio direction first thing; but until it does, | |
80b0a602 | 1199 | * and in case chip->get_direction is not set, |
d8f388d8 DB |
1200 | * we may expose the wrong direction in sysfs. |
1201 | */ | |
6c0b4e6c | 1202 | desc->flags = !chip->direction_input |
d8f388d8 DB |
1203 | ? (1 << FLAG_IS_OUT) |
1204 | : 0; | |
d2876d08 DB |
1205 | } |
1206 | } | |
1207 | ||
3bae4811 ZG |
1208 | spin_unlock_irqrestore(&gpio_lock, flags); |
1209 | ||
f23f1516 SH |
1210 | #ifdef CONFIG_PINCTRL |
1211 | INIT_LIST_HEAD(&chip->pin_ranges); | |
1212 | #endif | |
1213 | ||
391c970c AV |
1214 | of_gpiochip_add(chip); |
1215 | ||
cedb1881 AV |
1216 | if (status) |
1217 | goto fail; | |
1218 | ||
1219 | status = gpiochip_export(chip); | |
1220 | if (status) | |
1221 | goto fail; | |
1222 | ||
ee1c1e7d | 1223 | pr_debug("gpiochip_add: registered GPIOs %d to %d on device: %s\n", |
64842aad GL |
1224 | chip->base, chip->base + chip->ngpio - 1, |
1225 | chip->label ? : "generic"); | |
1226 | ||
cedb1881 | 1227 | return 0; |
3bae4811 ZG |
1228 | |
1229 | unlock: | |
1230 | spin_unlock_irqrestore(&gpio_lock, flags); | |
d2876d08 DB |
1231 | fail: |
1232 | /* failures here can mean systems won't boot... */ | |
cedb1881 AV |
1233 | pr_err("gpiochip_add: gpios %d..%d (%s) failed to register\n", |
1234 | chip->base, chip->base + chip->ngpio - 1, | |
1235 | chip->label ? : "generic"); | |
d2876d08 DB |
1236 | return status; |
1237 | } | |
1238 | EXPORT_SYMBOL_GPL(gpiochip_add); | |
1239 | ||
1240 | /** | |
1241 | * gpiochip_remove() - unregister a gpio_chip | |
1242 | * @chip: the chip to unregister | |
1243 | * | |
1244 | * A gpio_chip with any GPIOs still requested may not be removed. | |
1245 | */ | |
1246 | int gpiochip_remove(struct gpio_chip *chip) | |
1247 | { | |
1248 | unsigned long flags; | |
1249 | int status = 0; | |
1250 | unsigned id; | |
1251 | ||
1252 | spin_lock_irqsave(&gpio_lock, flags); | |
1253 | ||
9ef0d6f7 | 1254 | gpiochip_remove_pin_ranges(chip); |
391c970c AV |
1255 | of_gpiochip_remove(chip); |
1256 | ||
6c0b4e6c AC |
1257 | for (id = 0; id < chip->ngpio; id++) { |
1258 | if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) { | |
d2876d08 DB |
1259 | status = -EBUSY; |
1260 | break; | |
1261 | } | |
1262 | } | |
1263 | if (status == 0) { | |
6c0b4e6c AC |
1264 | for (id = 0; id < chip->ngpio; id++) |
1265 | chip->desc[id].chip = NULL; | |
1a989d0f AC |
1266 | |
1267 | list_del(&chip->list); | |
d2876d08 DB |
1268 | } |
1269 | ||
1270 | spin_unlock_irqrestore(&gpio_lock, flags); | |
d8f388d8 DB |
1271 | |
1272 | if (status == 0) | |
1273 | gpiochip_unexport(chip); | |
1274 | ||
d2876d08 DB |
1275 | return status; |
1276 | } | |
1277 | EXPORT_SYMBOL_GPL(gpiochip_remove); | |
1278 | ||
594fa265 GL |
1279 | /** |
1280 | * gpiochip_find() - iterator for locating a specific gpio_chip | |
1281 | * @data: data to pass to match function | |
1282 | * @callback: Callback function to check gpio_chip | |
1283 | * | |
1284 | * Similar to bus_find_device. It returns a reference to a gpio_chip as | |
1285 | * determined by a user supplied @match callback. The callback should return | |
1286 | * 0 if the device doesn't match and non-zero if it does. If the callback is | |
1287 | * non-zero, this function will return to the caller and not iterate over any | |
1288 | * more gpio_chips. | |
1289 | */ | |
07ce8ec7 | 1290 | struct gpio_chip *gpiochip_find(void *data, |
6e2cf651 | 1291 | int (*match)(struct gpio_chip *chip, |
3d0f7cf0 | 1292 | void *data)) |
594fa265 | 1293 | { |
125eef96 | 1294 | struct gpio_chip *chip; |
594fa265 | 1295 | unsigned long flags; |
594fa265 GL |
1296 | |
1297 | spin_lock_irqsave(&gpio_lock, flags); | |
125eef96 AC |
1298 | list_for_each_entry(chip, &gpio_chips, list) |
1299 | if (match(chip, data)) | |
594fa265 | 1300 | break; |
125eef96 AC |
1301 | |
1302 | /* No match? */ | |
1303 | if (&chip->list == &gpio_chips) | |
1304 | chip = NULL; | |
594fa265 GL |
1305 | spin_unlock_irqrestore(&gpio_lock, flags); |
1306 | ||
1307 | return chip; | |
1308 | } | |
8fa0c9bf | 1309 | EXPORT_SYMBOL_GPL(gpiochip_find); |
d2876d08 | 1310 | |
79697ef9 AC |
1311 | static int gpiochip_match_name(struct gpio_chip *chip, void *data) |
1312 | { | |
1313 | const char *name = data; | |
1314 | ||
1315 | return !strcmp(chip->label, name); | |
1316 | } | |
1317 | ||
1318 | static struct gpio_chip *find_chip_by_name(const char *name) | |
1319 | { | |
1320 | return gpiochip_find((void *)name, gpiochip_match_name); | |
1321 | } | |
1322 | ||
f23f1516 | 1323 | #ifdef CONFIG_PINCTRL |
165adc9c | 1324 | |
586a87e6 CR |
1325 | /** |
1326 | * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping | |
1327 | * @chip: the gpiochip to add the range for | |
1328 | * @pinctrl: the dev_name() of the pin controller to map to | |
1329 | * @gpio_offset: the start offset in the current gpio_chip number space | |
1330 | * @pin_group: name of the pin group inside the pin controller | |
1331 | */ | |
1332 | int gpiochip_add_pingroup_range(struct gpio_chip *chip, | |
1333 | struct pinctrl_dev *pctldev, | |
1334 | unsigned int gpio_offset, const char *pin_group) | |
1335 | { | |
1336 | struct gpio_pin_range *pin_range; | |
1337 | int ret; | |
1338 | ||
1339 | pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL); | |
1340 | if (!pin_range) { | |
1341 | pr_err("%s: GPIO chip: failed to allocate pin ranges\n", | |
1342 | chip->label); | |
1343 | return -ENOMEM; | |
1344 | } | |
1345 | ||
1346 | /* Use local offset as range ID */ | |
1347 | pin_range->range.id = gpio_offset; | |
1348 | pin_range->range.gc = chip; | |
1349 | pin_range->range.name = chip->label; | |
1350 | pin_range->range.base = chip->base + gpio_offset; | |
1351 | pin_range->pctldev = pctldev; | |
1352 | ||
1353 | ret = pinctrl_get_group_pins(pctldev, pin_group, | |
1354 | &pin_range->range.pins, | |
1355 | &pin_range->range.npins); | |
1356 | if (ret < 0) | |
1357 | return ret; | |
1358 | ||
1359 | pinctrl_add_gpio_range(pctldev, &pin_range->range); | |
1360 | ||
1361 | pr_debug("GPIO chip %s: created GPIO range %d->%d ==> %s PINGRP %s\n", | |
1362 | chip->label, gpio_offset, | |
1363 | gpio_offset + pin_range->range.npins - 1, | |
1364 | pinctrl_dev_get_devname(pctldev), pin_group); | |
1365 | ||
1366 | list_add_tail(&pin_range->node, &chip->pin_ranges); | |
1367 | ||
1368 | return 0; | |
1369 | } | |
1370 | EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range); | |
1371 | ||
3f0f8670 LW |
1372 | /** |
1373 | * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping | |
1374 | * @chip: the gpiochip to add the range for | |
1375 | * @pinctrl_name: the dev_name() of the pin controller to map to | |
316511c0 LW |
1376 | * @gpio_offset: the start offset in the current gpio_chip number space |
1377 | * @pin_offset: the start offset in the pin controller number space | |
3f0f8670 LW |
1378 | * @npins: the number of pins from the offset of each pin space (GPIO and |
1379 | * pin controller) to accumulate in this range | |
1380 | */ | |
1e63d7b9 | 1381 | int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name, |
316511c0 | 1382 | unsigned int gpio_offset, unsigned int pin_offset, |
3f0f8670 | 1383 | unsigned int npins) |
f23f1516 SH |
1384 | { |
1385 | struct gpio_pin_range *pin_range; | |
b4d4b1f0 | 1386 | int ret; |
f23f1516 | 1387 | |
3f0f8670 | 1388 | pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL); |
f23f1516 SH |
1389 | if (!pin_range) { |
1390 | pr_err("%s: GPIO chip: failed to allocate pin ranges\n", | |
1391 | chip->label); | |
1e63d7b9 | 1392 | return -ENOMEM; |
f23f1516 SH |
1393 | } |
1394 | ||
3f0f8670 | 1395 | /* Use local offset as range ID */ |
316511c0 | 1396 | pin_range->range.id = gpio_offset; |
3f0f8670 | 1397 | pin_range->range.gc = chip; |
f23f1516 | 1398 | pin_range->range.name = chip->label; |
316511c0 LW |
1399 | pin_range->range.base = chip->base + gpio_offset; |
1400 | pin_range->range.pin_base = pin_offset; | |
f23f1516 | 1401 | pin_range->range.npins = npins; |
192c369c | 1402 | pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name, |
f23f1516 | 1403 | &pin_range->range); |
8f23ca1a | 1404 | if (IS_ERR(pin_range->pctldev)) { |
b4d4b1f0 | 1405 | ret = PTR_ERR(pin_range->pctldev); |
3f0f8670 LW |
1406 | pr_err("%s: GPIO chip: could not create pin range\n", |
1407 | chip->label); | |
1408 | kfree(pin_range); | |
b4d4b1f0 | 1409 | return ret; |
3f0f8670 | 1410 | } |
316511c0 LW |
1411 | pr_debug("GPIO chip %s: created GPIO range %d->%d ==> %s PIN %d->%d\n", |
1412 | chip->label, gpio_offset, gpio_offset + npins - 1, | |
1413 | pinctl_name, | |
1414 | pin_offset, pin_offset + npins - 1); | |
f23f1516 SH |
1415 | |
1416 | list_add_tail(&pin_range->node, &chip->pin_ranges); | |
1e63d7b9 LW |
1417 | |
1418 | return 0; | |
f23f1516 | 1419 | } |
165adc9c | 1420 | EXPORT_SYMBOL_GPL(gpiochip_add_pin_range); |
f23f1516 | 1421 | |
3f0f8670 LW |
1422 | /** |
1423 | * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings | |
1424 | * @chip: the chip to remove all the mappings for | |
1425 | */ | |
f23f1516 SH |
1426 | void gpiochip_remove_pin_ranges(struct gpio_chip *chip) |
1427 | { | |
1428 | struct gpio_pin_range *pin_range, *tmp; | |
1429 | ||
1430 | list_for_each_entry_safe(pin_range, tmp, &chip->pin_ranges, node) { | |
1431 | list_del(&pin_range->node); | |
1432 | pinctrl_remove_gpio_range(pin_range->pctldev, | |
1433 | &pin_range->range); | |
3f0f8670 | 1434 | kfree(pin_range); |
f23f1516 SH |
1435 | } |
1436 | } | |
165adc9c LW |
1437 | EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges); |
1438 | ||
1439 | #endif /* CONFIG_PINCTRL */ | |
f23f1516 | 1440 | |
d2876d08 DB |
1441 | /* These "optional" allocation calls help prevent drivers from stomping |
1442 | * on each other, and help provide better diagnostics in debugfs. | |
1443 | * They're called even less than the "set direction" calls. | |
1444 | */ | |
372e722e | 1445 | static int gpiod_request(struct gpio_desc *desc, const char *label) |
d2876d08 | 1446 | { |
35e8bb51 | 1447 | struct gpio_chip *chip; |
e9354576 | 1448 | int status = -EPROBE_DEFER; |
d2876d08 DB |
1449 | unsigned long flags; |
1450 | ||
0204df47 | 1451 | if (!desc) { |
bcabdef1 AC |
1452 | pr_warn("%s: invalid GPIO\n", __func__); |
1453 | return -EINVAL; | |
ad2fab36 | 1454 | } |
bcabdef1 AC |
1455 | |
1456 | spin_lock_irqsave(&gpio_lock, flags); | |
1457 | ||
35e8bb51 | 1458 | chip = desc->chip; |
0204df47 AC |
1459 | if (chip == NULL) |
1460 | goto done; | |
d2876d08 | 1461 | |
35e8bb51 | 1462 | if (!try_module_get(chip->owner)) |
438d8908 GL |
1463 | goto done; |
1464 | ||
d2876d08 | 1465 | /* NOTE: gpio_request() can be called in early boot, |
35e8bb51 | 1466 | * before IRQs are enabled, for non-sleeping (SOC) GPIOs. |
d2876d08 DB |
1467 | */ |
1468 | ||
1469 | if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) { | |
1470 | desc_set_label(desc, label ? : "?"); | |
1471 | status = 0; | |
438d8908 | 1472 | } else { |
d2876d08 | 1473 | status = -EBUSY; |
35e8bb51 | 1474 | module_put(chip->owner); |
7460db56 | 1475 | goto done; |
35e8bb51 DB |
1476 | } |
1477 | ||
1478 | if (chip->request) { | |
1479 | /* chip->request may sleep */ | |
1480 | spin_unlock_irqrestore(&gpio_lock, flags); | |
372e722e | 1481 | status = chip->request(chip, gpio_chip_hwgpio(desc)); |
35e8bb51 DB |
1482 | spin_lock_irqsave(&gpio_lock, flags); |
1483 | ||
1484 | if (status < 0) { | |
1485 | desc_set_label(desc, NULL); | |
1486 | module_put(chip->owner); | |
1487 | clear_bit(FLAG_REQUESTED, &desc->flags); | |
80b0a602 | 1488 | goto done; |
35e8bb51 | 1489 | } |
438d8908 | 1490 | } |
80b0a602 MN |
1491 | if (chip->get_direction) { |
1492 | /* chip->get_direction may sleep */ | |
1493 | spin_unlock_irqrestore(&gpio_lock, flags); | |
372e722e | 1494 | gpiod_get_direction(desc); |
80b0a602 MN |
1495 | spin_lock_irqsave(&gpio_lock, flags); |
1496 | } | |
d2876d08 DB |
1497 | done: |
1498 | if (status) | |
372e722e | 1499 | pr_debug("_gpio_request: gpio-%d (%s) status %d\n", |
bcabdef1 | 1500 | desc_to_gpio(desc), label ? : "?", status); |
d2876d08 DB |
1501 | spin_unlock_irqrestore(&gpio_lock, flags); |
1502 | return status; | |
1503 | } | |
372e722e AC |
1504 | |
1505 | int gpio_request(unsigned gpio, const char *label) | |
1506 | { | |
1507 | return gpiod_request(gpio_to_desc(gpio), label); | |
1508 | } | |
d2876d08 DB |
1509 | EXPORT_SYMBOL_GPL(gpio_request); |
1510 | ||
372e722e | 1511 | static void gpiod_free(struct gpio_desc *desc) |
d2876d08 DB |
1512 | { |
1513 | unsigned long flags; | |
35e8bb51 | 1514 | struct gpio_chip *chip; |
d2876d08 | 1515 | |
3d599d1c UKK |
1516 | might_sleep(); |
1517 | ||
372e722e | 1518 | if (!desc) { |
d2876d08 DB |
1519 | WARN_ON(extra_checks); |
1520 | return; | |
1521 | } | |
1522 | ||
372e722e | 1523 | gpiod_unexport(desc); |
d8f388d8 | 1524 | |
d2876d08 DB |
1525 | spin_lock_irqsave(&gpio_lock, flags); |
1526 | ||
35e8bb51 DB |
1527 | chip = desc->chip; |
1528 | if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) { | |
1529 | if (chip->free) { | |
1530 | spin_unlock_irqrestore(&gpio_lock, flags); | |
9c4ba946 | 1531 | might_sleep_if(chip->can_sleep); |
372e722e | 1532 | chip->free(chip, gpio_chip_hwgpio(desc)); |
35e8bb51 DB |
1533 | spin_lock_irqsave(&gpio_lock, flags); |
1534 | } | |
d2876d08 | 1535 | desc_set_label(desc, NULL); |
438d8908 | 1536 | module_put(desc->chip->owner); |
07697461 | 1537 | clear_bit(FLAG_ACTIVE_LOW, &desc->flags); |
35e8bb51 | 1538 | clear_bit(FLAG_REQUESTED, &desc->flags); |
aca5ce14 | 1539 | clear_bit(FLAG_OPEN_DRAIN, &desc->flags); |
25553ff0 | 1540 | clear_bit(FLAG_OPEN_SOURCE, &desc->flags); |
438d8908 | 1541 | } else |
d2876d08 DB |
1542 | WARN_ON(extra_checks); |
1543 | ||
1544 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1545 | } | |
372e722e AC |
1546 | |
1547 | void gpio_free(unsigned gpio) | |
1548 | { | |
1549 | gpiod_free(gpio_to_desc(gpio)); | |
1550 | } | |
d2876d08 DB |
1551 | EXPORT_SYMBOL_GPL(gpio_free); |
1552 | ||
3e45f1d1 EM |
1553 | /** |
1554 | * gpio_request_one - request a single GPIO with initial configuration | |
1555 | * @gpio: the GPIO number | |
1556 | * @flags: GPIO configuration as specified by GPIOF_* | |
1557 | * @label: a literal description string of this GPIO | |
1558 | */ | |
1559 | int gpio_request_one(unsigned gpio, unsigned long flags, const char *label) | |
1560 | { | |
372e722e | 1561 | struct gpio_desc *desc; |
3e45f1d1 EM |
1562 | int err; |
1563 | ||
372e722e AC |
1564 | desc = gpio_to_desc(gpio); |
1565 | ||
1566 | err = gpiod_request(desc, label); | |
3e45f1d1 EM |
1567 | if (err) |
1568 | return err; | |
1569 | ||
aca5ce14 | 1570 | if (flags & GPIOF_OPEN_DRAIN) |
372e722e | 1571 | set_bit(FLAG_OPEN_DRAIN, &desc->flags); |
aca5ce14 | 1572 | |
25553ff0 | 1573 | if (flags & GPIOF_OPEN_SOURCE) |
372e722e | 1574 | set_bit(FLAG_OPEN_SOURCE, &desc->flags); |
25553ff0 | 1575 | |
3e45f1d1 | 1576 | if (flags & GPIOF_DIR_IN) |
372e722e | 1577 | err = gpiod_direction_input(desc); |
3e45f1d1 | 1578 | else |
372e722e | 1579 | err = gpiod_direction_output(desc, |
3e45f1d1 EM |
1580 | (flags & GPIOF_INIT_HIGH) ? 1 : 0); |
1581 | ||
e254811c | 1582 | if (err) |
fc3a1f04 WS |
1583 | goto free_gpio; |
1584 | ||
1585 | if (flags & GPIOF_EXPORT) { | |
372e722e | 1586 | err = gpiod_export(desc, flags & GPIOF_EXPORT_CHANGEABLE); |
fc3a1f04 WS |
1587 | if (err) |
1588 | goto free_gpio; | |
1589 | } | |
1590 | ||
1591 | return 0; | |
e254811c | 1592 | |
fc3a1f04 | 1593 | free_gpio: |
372e722e | 1594 | gpiod_free(desc); |
3e45f1d1 EM |
1595 | return err; |
1596 | } | |
1597 | EXPORT_SYMBOL_GPL(gpio_request_one); | |
1598 | ||
1599 | /** | |
1600 | * gpio_request_array - request multiple GPIOs in a single call | |
1601 | * @array: array of the 'struct gpio' | |
1602 | * @num: how many GPIOs in the array | |
1603 | */ | |
7c295975 | 1604 | int gpio_request_array(const struct gpio *array, size_t num) |
3e45f1d1 EM |
1605 | { |
1606 | int i, err; | |
1607 | ||
1608 | for (i = 0; i < num; i++, array++) { | |
1609 | err = gpio_request_one(array->gpio, array->flags, array->label); | |
1610 | if (err) | |
1611 | goto err_free; | |
1612 | } | |
1613 | return 0; | |
1614 | ||
1615 | err_free: | |
1616 | while (i--) | |
1617 | gpio_free((--array)->gpio); | |
1618 | return err; | |
1619 | } | |
1620 | EXPORT_SYMBOL_GPL(gpio_request_array); | |
1621 | ||
1622 | /** | |
1623 | * gpio_free_array - release multiple GPIOs in a single call | |
1624 | * @array: array of the 'struct gpio' | |
1625 | * @num: how many GPIOs in the array | |
1626 | */ | |
7c295975 | 1627 | void gpio_free_array(const struct gpio *array, size_t num) |
3e45f1d1 EM |
1628 | { |
1629 | while (num--) | |
1630 | gpio_free((array++)->gpio); | |
1631 | } | |
1632 | EXPORT_SYMBOL_GPL(gpio_free_array); | |
d2876d08 DB |
1633 | |
1634 | /** | |
1635 | * gpiochip_is_requested - return string iff signal was requested | |
1636 | * @chip: controller managing the signal | |
1637 | * @offset: of signal within controller's 0..(ngpio - 1) range | |
1638 | * | |
1639 | * Returns NULL if the GPIO is not currently requested, else a string. | |
1640 | * If debugfs support is enabled, the string returned is the label passed | |
1641 | * to gpio_request(); otherwise it is a meaningless constant. | |
1642 | * | |
1643 | * This function is for use by GPIO controller drivers. The label can | |
1644 | * help with diagnostics, and knowing that the signal is used as a GPIO | |
1645 | * can help avoid accidentally multiplexing it to another controller. | |
1646 | */ | |
1647 | const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset) | |
1648 | { | |
6c0b4e6c | 1649 | struct gpio_desc *desc; |
d2876d08 | 1650 | |
6c0b4e6c | 1651 | if (!GPIO_OFFSET_VALID(chip, offset)) |
d2876d08 | 1652 | return NULL; |
6c0b4e6c AC |
1653 | |
1654 | desc = &chip->desc[offset]; | |
1655 | ||
372e722e | 1656 | if (test_bit(FLAG_REQUESTED, &desc->flags) == 0) |
d2876d08 DB |
1657 | return NULL; |
1658 | #ifdef CONFIG_DEBUG_FS | |
372e722e | 1659 | return desc->label; |
d2876d08 DB |
1660 | #else |
1661 | return "?"; | |
1662 | #endif | |
1663 | } | |
1664 | EXPORT_SYMBOL_GPL(gpiochip_is_requested); | |
1665 | ||
1666 | ||
1667 | /* Drivers MUST set GPIO direction before making get/set calls. In | |
1668 | * some cases this is done in early boot, before IRQs are enabled. | |
1669 | * | |
1670 | * As a rule these aren't called more than once (except for drivers | |
1671 | * using the open-drain emulation idiom) so these are natural places | |
1672 | * to accumulate extra debugging checks. Note that we can't (yet) | |
1673 | * rely on gpio_request() having been called beforehand. | |
1674 | */ | |
1675 | ||
79a9becd AC |
1676 | /** |
1677 | * gpiod_direction_input - set the GPIO direction to input | |
1678 | * @desc: GPIO to set to input | |
1679 | * | |
1680 | * Set the direction of the passed GPIO to input, such as gpiod_get_value() can | |
1681 | * be called safely on it. | |
1682 | * | |
1683 | * Return 0 in case of success, else an error code. | |
1684 | */ | |
1685 | int gpiod_direction_input(struct gpio_desc *desc) | |
d2876d08 DB |
1686 | { |
1687 | unsigned long flags; | |
1688 | struct gpio_chip *chip; | |
d2876d08 | 1689 | int status = -EINVAL; |
372e722e | 1690 | int offset; |
d2876d08 | 1691 | |
be1a4b13 | 1692 | if (!desc || !desc->chip) { |
bcabdef1 AC |
1693 | pr_warn("%s: invalid GPIO\n", __func__); |
1694 | return -EINVAL; | |
1695 | } | |
1696 | ||
be1a4b13 LW |
1697 | chip = desc->chip; |
1698 | if (!chip->get || !chip->direction_input) { | |
6424de5a MB |
1699 | gpiod_warn(desc, |
1700 | "%s: missing get() or direction_input() operations\n", | |
1701 | __func__); | |
be1a4b13 LW |
1702 | return -EIO; |
1703 | } | |
1704 | ||
d2876d08 DB |
1705 | spin_lock_irqsave(&gpio_lock, flags); |
1706 | ||
372e722e | 1707 | status = gpio_ensure_requested(desc); |
35e8bb51 DB |
1708 | if (status < 0) |
1709 | goto fail; | |
d2876d08 DB |
1710 | |
1711 | /* now we know the gpio is valid and chip won't vanish */ | |
1712 | ||
1713 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1714 | ||
9c4ba946 | 1715 | might_sleep_if(chip->can_sleep); |
d2876d08 | 1716 | |
372e722e | 1717 | offset = gpio_chip_hwgpio(desc); |
35e8bb51 | 1718 | if (status) { |
372e722e | 1719 | status = chip->request(chip, offset); |
35e8bb51 | 1720 | if (status < 0) { |
6424de5a | 1721 | gpiod_dbg(desc, "chip request fail, %d\n", status); |
35e8bb51 DB |
1722 | /* and it's not available to anyone else ... |
1723 | * gpio_request() is the fully clean solution. | |
1724 | */ | |
1725 | goto lose; | |
1726 | } | |
1727 | } | |
1728 | ||
372e722e | 1729 | status = chip->direction_input(chip, offset); |
d2876d08 DB |
1730 | if (status == 0) |
1731 | clear_bit(FLAG_IS_OUT, &desc->flags); | |
3f397c21 | 1732 | |
372e722e | 1733 | trace_gpio_direction(desc_to_gpio(desc), 1, status); |
35e8bb51 | 1734 | lose: |
d2876d08 DB |
1735 | return status; |
1736 | fail: | |
1737 | spin_unlock_irqrestore(&gpio_lock, flags); | |
bcabdef1 | 1738 | if (status) |
6424de5a | 1739 | gpiod_dbg(desc, "%s status %d\n", __func__, status); |
d2876d08 DB |
1740 | return status; |
1741 | } | |
79a9becd | 1742 | EXPORT_SYMBOL_GPL(gpiod_direction_input); |
372e722e | 1743 | |
79a9becd AC |
1744 | /** |
1745 | * gpiod_direction_output - set the GPIO direction to input | |
1746 | * @desc: GPIO to set to output | |
1747 | * @value: initial output value of the GPIO | |
1748 | * | |
1749 | * Set the direction of the passed GPIO to output, such as gpiod_set_value() can | |
1750 | * be called safely on it. The initial value of the output must be specified. | |
1751 | * | |
1752 | * Return 0 in case of success, else an error code. | |
1753 | */ | |
1754 | int gpiod_direction_output(struct gpio_desc *desc, int value) | |
d2876d08 DB |
1755 | { |
1756 | unsigned long flags; | |
1757 | struct gpio_chip *chip; | |
d2876d08 | 1758 | int status = -EINVAL; |
372e722e | 1759 | int offset; |
d2876d08 | 1760 | |
be1a4b13 | 1761 | if (!desc || !desc->chip) { |
bcabdef1 AC |
1762 | pr_warn("%s: invalid GPIO\n", __func__); |
1763 | return -EINVAL; | |
1764 | } | |
1765 | ||
d468bf9e LW |
1766 | /* GPIOs used for IRQs shall not be set as output */ |
1767 | if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) { | |
1768 | gpiod_err(desc, | |
1769 | "%s: tried to set a GPIO tied to an IRQ as output\n", | |
1770 | __func__); | |
1771 | return -EIO; | |
1772 | } | |
1773 | ||
aca5ce14 LD |
1774 | /* Open drain pin should not be driven to 1 */ |
1775 | if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags)) | |
372e722e | 1776 | return gpiod_direction_input(desc); |
aca5ce14 | 1777 | |
25553ff0 LD |
1778 | /* Open source pin should not be driven to 0 */ |
1779 | if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags)) | |
372e722e | 1780 | return gpiod_direction_input(desc); |
25553ff0 | 1781 | |
be1a4b13 LW |
1782 | chip = desc->chip; |
1783 | if (!chip->set || !chip->direction_output) { | |
6424de5a MB |
1784 | gpiod_warn(desc, |
1785 | "%s: missing set() or direction_output() operations\n", | |
1786 | __func__); | |
be1a4b13 LW |
1787 | return -EIO; |
1788 | } | |
1789 | ||
d2876d08 DB |
1790 | spin_lock_irqsave(&gpio_lock, flags); |
1791 | ||
372e722e | 1792 | status = gpio_ensure_requested(desc); |
35e8bb51 DB |
1793 | if (status < 0) |
1794 | goto fail; | |
d2876d08 DB |
1795 | |
1796 | /* now we know the gpio is valid and chip won't vanish */ | |
1797 | ||
1798 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1799 | ||
9c4ba946 | 1800 | might_sleep_if(chip->can_sleep); |
d2876d08 | 1801 | |
372e722e | 1802 | offset = gpio_chip_hwgpio(desc); |
35e8bb51 | 1803 | if (status) { |
372e722e | 1804 | status = chip->request(chip, offset); |
35e8bb51 | 1805 | if (status < 0) { |
6424de5a | 1806 | gpiod_dbg(desc, "chip request fail, %d\n", status); |
35e8bb51 DB |
1807 | /* and it's not available to anyone else ... |
1808 | * gpio_request() is the fully clean solution. | |
1809 | */ | |
1810 | goto lose; | |
1811 | } | |
1812 | } | |
1813 | ||
372e722e | 1814 | status = chip->direction_output(chip, offset, value); |
d2876d08 DB |
1815 | if (status == 0) |
1816 | set_bit(FLAG_IS_OUT, &desc->flags); | |
372e722e AC |
1817 | trace_gpio_value(desc_to_gpio(desc), 0, value); |
1818 | trace_gpio_direction(desc_to_gpio(desc), 0, status); | |
35e8bb51 | 1819 | lose: |
d2876d08 DB |
1820 | return status; |
1821 | fail: | |
1822 | spin_unlock_irqrestore(&gpio_lock, flags); | |
bcabdef1 | 1823 | if (status) |
6424de5a | 1824 | gpiod_dbg(desc, "%s: gpio status %d\n", __func__, status); |
d2876d08 DB |
1825 | return status; |
1826 | } | |
79a9becd | 1827 | EXPORT_SYMBOL_GPL(gpiod_direction_output); |
d2876d08 | 1828 | |
c4b5be98 | 1829 | /** |
79a9becd | 1830 | * gpiod_set_debounce - sets @debounce time for a @gpio |
c4b5be98 FB |
1831 | * @gpio: the gpio to set debounce time |
1832 | * @debounce: debounce time is microseconds | |
65d87656 LW |
1833 | * |
1834 | * returns -ENOTSUPP if the controller does not support setting | |
1835 | * debounce. | |
c4b5be98 | 1836 | */ |
79a9becd | 1837 | int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) |
c4b5be98 FB |
1838 | { |
1839 | unsigned long flags; | |
1840 | struct gpio_chip *chip; | |
c4b5be98 | 1841 | int status = -EINVAL; |
372e722e | 1842 | int offset; |
c4b5be98 | 1843 | |
be1a4b13 | 1844 | if (!desc || !desc->chip) { |
bcabdef1 AC |
1845 | pr_warn("%s: invalid GPIO\n", __func__); |
1846 | return -EINVAL; | |
1847 | } | |
1848 | ||
c4b5be98 | 1849 | chip = desc->chip; |
be1a4b13 | 1850 | if (!chip->set || !chip->set_debounce) { |
6424de5a MB |
1851 | gpiod_dbg(desc, |
1852 | "%s: missing set() or set_debounce() operations\n", | |
1853 | __func__); | |
65d87656 | 1854 | return -ENOTSUPP; |
be1a4b13 LW |
1855 | } |
1856 | ||
1857 | spin_lock_irqsave(&gpio_lock, flags); | |
372e722e AC |
1858 | |
1859 | status = gpio_ensure_requested(desc); | |
c4b5be98 FB |
1860 | if (status < 0) |
1861 | goto fail; | |
1862 | ||
1863 | /* now we know the gpio is valid and chip won't vanish */ | |
1864 | ||
1865 | spin_unlock_irqrestore(&gpio_lock, flags); | |
1866 | ||
9c4ba946 | 1867 | might_sleep_if(chip->can_sleep); |
c4b5be98 | 1868 | |
372e722e AC |
1869 | offset = gpio_chip_hwgpio(desc); |
1870 | return chip->set_debounce(chip, offset, debounce); | |
c4b5be98 FB |
1871 | |
1872 | fail: | |
1873 | spin_unlock_irqrestore(&gpio_lock, flags); | |
bcabdef1 | 1874 | if (status) |
6424de5a | 1875 | gpiod_dbg(desc, "%s: status %d\n", __func__, status); |
c4b5be98 FB |
1876 | |
1877 | return status; | |
1878 | } | |
79a9becd | 1879 | EXPORT_SYMBOL_GPL(gpiod_set_debounce); |
372e722e | 1880 | |
79a9becd AC |
1881 | /** |
1882 | * gpiod_is_active_low - test whether a GPIO is active-low or not | |
1883 | * @desc: the gpio descriptor to test | |
1884 | * | |
1885 | * Returns 1 if the GPIO is active-low, 0 otherwise. | |
1886 | */ | |
1887 | int gpiod_is_active_low(const struct gpio_desc *desc) | |
372e722e | 1888 | { |
79a9becd | 1889 | return test_bit(FLAG_ACTIVE_LOW, &desc->flags); |
372e722e | 1890 | } |
79a9becd | 1891 | EXPORT_SYMBOL_GPL(gpiod_is_active_low); |
d2876d08 DB |
1892 | |
1893 | /* I/O calls are only valid after configuration completed; the relevant | |
1894 | * "is this a valid GPIO" error checks should already have been done. | |
1895 | * | |
1896 | * "Get" operations are often inlinable as reading a pin value register, | |
1897 | * and masking the relevant bit in that register. | |
1898 | * | |
1899 | * When "set" operations are inlinable, they involve writing that mask to | |
1900 | * one register to set a low value, or a different register to set it high. | |
1901 | * Otherwise locking is needed, so there may be little value to inlining. | |
1902 | * | |
1903 | *------------------------------------------------------------------------ | |
1904 | * | |
1905 | * IMPORTANT!!! The hot paths -- get/set value -- assume that callers | |
1906 | * have requested the GPIO. That can include implicit requesting by | |
1907 | * a direction setting call. Marking a gpio as requested locks its chip | |
1908 | * in memory, guaranteeing that these table lookups need no more locking | |
1909 | * and that gpiochip_remove() will fail. | |
1910 | * | |
1911 | * REVISIT when debugging, consider adding some instrumentation to ensure | |
1912 | * that the GPIO was actually requested. | |
1913 | */ | |
1914 | ||
79a9becd | 1915 | static int _gpiod_get_raw_value(const struct gpio_desc *desc) |
d2876d08 DB |
1916 | { |
1917 | struct gpio_chip *chip; | |
3f397c21 | 1918 | int value; |
372e722e | 1919 | int offset; |
d2876d08 | 1920 | |
372e722e AC |
1921 | chip = desc->chip; |
1922 | offset = gpio_chip_hwgpio(desc); | |
372e722e AC |
1923 | value = chip->get ? chip->get(chip, offset) : 0; |
1924 | trace_gpio_value(desc_to_gpio(desc), 1, value); | |
3f397c21 | 1925 | return value; |
d2876d08 | 1926 | } |
372e722e | 1927 | |
d2876d08 | 1928 | /** |
79a9becd AC |
1929 | * gpiod_get_raw_value() - return a gpio's raw value |
1930 | * @desc: gpio whose value will be returned | |
d2876d08 | 1931 | * |
79a9becd AC |
1932 | * Return the GPIO's raw value, i.e. the value of the physical line disregarding |
1933 | * its ACTIVE_LOW status. | |
1934 | * | |
1935 | * This function should be called from contexts where we cannot sleep, and will | |
1936 | * complain if the GPIO chip functions potentially sleep. | |
d2876d08 | 1937 | */ |
79a9becd | 1938 | int gpiod_get_raw_value(const struct gpio_desc *desc) |
d2876d08 | 1939 | { |
bcabdef1 AC |
1940 | if (!desc) |
1941 | return 0; | |
e4e449e8 | 1942 | /* Should be using gpio_get_value_cansleep() */ |
d8e0ac08 | 1943 | WARN_ON(desc->chip->can_sleep); |
79a9becd | 1944 | return _gpiod_get_raw_value(desc); |
d2876d08 | 1945 | } |
79a9becd | 1946 | EXPORT_SYMBOL_GPL(gpiod_get_raw_value); |
372e722e | 1947 | |
79a9becd AC |
1948 | /** |
1949 | * gpiod_get_value() - return a gpio's value | |
1950 | * @desc: gpio whose value will be returned | |
1951 | * | |
1952 | * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into | |
1953 | * account. | |
1954 | * | |
1955 | * This function should be called from contexts where we cannot sleep, and will | |
1956 | * complain if the GPIO chip functions potentially sleep. | |
1957 | */ | |
1958 | int gpiod_get_value(const struct gpio_desc *desc) | |
372e722e | 1959 | { |
79a9becd AC |
1960 | int value; |
1961 | if (!desc) | |
1962 | return 0; | |
1963 | /* Should be using gpio_get_value_cansleep() */ | |
1964 | WARN_ON(desc->chip->can_sleep); | |
1965 | ||
1966 | value = _gpiod_get_raw_value(desc); | |
1967 | if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) | |
1968 | value = !value; | |
1969 | ||
1970 | return value; | |
372e722e | 1971 | } |
79a9becd | 1972 | EXPORT_SYMBOL_GPL(gpiod_get_value); |
d2876d08 | 1973 | |
aca5ce14 LD |
1974 | /* |
1975 | * _gpio_set_open_drain_value() - Set the open drain gpio's value. | |
79a9becd | 1976 | * @desc: gpio descriptor whose state need to be set. |
aca5ce14 LD |
1977 | * @value: Non-zero for setting it HIGH otherise it will set to LOW. |
1978 | */ | |
372e722e | 1979 | static void _gpio_set_open_drain_value(struct gpio_desc *desc, int value) |
aca5ce14 LD |
1980 | { |
1981 | int err = 0; | |
372e722e AC |
1982 | struct gpio_chip *chip = desc->chip; |
1983 | int offset = gpio_chip_hwgpio(desc); | |
1984 | ||
aca5ce14 | 1985 | if (value) { |
372e722e | 1986 | err = chip->direction_input(chip, offset); |
aca5ce14 | 1987 | if (!err) |
372e722e | 1988 | clear_bit(FLAG_IS_OUT, &desc->flags); |
aca5ce14 | 1989 | } else { |
372e722e | 1990 | err = chip->direction_output(chip, offset, 0); |
aca5ce14 | 1991 | if (!err) |
372e722e | 1992 | set_bit(FLAG_IS_OUT, &desc->flags); |
aca5ce14 | 1993 | } |
372e722e | 1994 | trace_gpio_direction(desc_to_gpio(desc), value, err); |
aca5ce14 | 1995 | if (err < 0) |
6424de5a MB |
1996 | gpiod_err(desc, |
1997 | "%s: Error in set_value for open drain err %d\n", | |
1998 | __func__, err); | |
aca5ce14 LD |
1999 | } |
2000 | ||
25553ff0 | 2001 | /* |
79a9becd AC |
2002 | * _gpio_set_open_source_value() - Set the open source gpio's value. |
2003 | * @desc: gpio descriptor whose state need to be set. | |
25553ff0 LD |
2004 | * @value: Non-zero for setting it HIGH otherise it will set to LOW. |
2005 | */ | |
372e722e | 2006 | static void _gpio_set_open_source_value(struct gpio_desc *desc, int value) |
25553ff0 LD |
2007 | { |
2008 | int err = 0; | |
372e722e AC |
2009 | struct gpio_chip *chip = desc->chip; |
2010 | int offset = gpio_chip_hwgpio(desc); | |
2011 | ||
25553ff0 | 2012 | if (value) { |
372e722e | 2013 | err = chip->direction_output(chip, offset, 1); |
25553ff0 | 2014 | if (!err) |
372e722e | 2015 | set_bit(FLAG_IS_OUT, &desc->flags); |
25553ff0 | 2016 | } else { |
372e722e | 2017 | err = chip->direction_input(chip, offset); |
25553ff0 | 2018 | if (!err) |
372e722e | 2019 | clear_bit(FLAG_IS_OUT, &desc->flags); |
25553ff0 | 2020 | } |
372e722e | 2021 | trace_gpio_direction(desc_to_gpio(desc), !value, err); |
25553ff0 | 2022 | if (err < 0) |
6424de5a MB |
2023 | gpiod_err(desc, |
2024 | "%s: Error in set_value for open source err %d\n", | |
2025 | __func__, err); | |
25553ff0 LD |
2026 | } |
2027 | ||
79a9becd | 2028 | static void _gpiod_set_raw_value(struct gpio_desc *desc, int value) |
d2876d08 DB |
2029 | { |
2030 | struct gpio_chip *chip; | |
2031 | ||
372e722e | 2032 | chip = desc->chip; |
372e722e AC |
2033 | trace_gpio_value(desc_to_gpio(desc), 0, value); |
2034 | if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) | |
2035 | _gpio_set_open_drain_value(desc, value); | |
2036 | else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) | |
2037 | _gpio_set_open_source_value(desc, value); | |
aca5ce14 | 2038 | else |
372e722e AC |
2039 | chip->set(chip, gpio_chip_hwgpio(desc), value); |
2040 | } | |
2041 | ||
d2876d08 | 2042 | /** |
79a9becd AC |
2043 | * gpiod_set_raw_value() - assign a gpio's raw value |
2044 | * @desc: gpio whose value will be assigned | |
d2876d08 | 2045 | * @value: value to assign |
d2876d08 | 2046 | * |
79a9becd AC |
2047 | * Set the raw value of the GPIO, i.e. the value of its physical line without |
2048 | * regard for its ACTIVE_LOW status. | |
2049 | * | |
2050 | * This function should be called from contexts where we cannot sleep, and will | |
2051 | * complain if the GPIO chip functions potentially sleep. | |
d2876d08 | 2052 | */ |
79a9becd | 2053 | void gpiod_set_raw_value(struct gpio_desc *desc, int value) |
372e722e | 2054 | { |
bcabdef1 AC |
2055 | if (!desc) |
2056 | return; | |
e4e449e8 | 2057 | /* Should be using gpio_set_value_cansleep() */ |
d8e0ac08 | 2058 | WARN_ON(desc->chip->can_sleep); |
79a9becd | 2059 | _gpiod_set_raw_value(desc, value); |
d2876d08 | 2060 | } |
79a9becd | 2061 | EXPORT_SYMBOL_GPL(gpiod_set_raw_value); |
d2876d08 DB |
2062 | |
2063 | /** | |
79a9becd AC |
2064 | * gpiod_set_value() - assign a gpio's value |
2065 | * @desc: gpio whose value will be assigned | |
2066 | * @value: value to assign | |
2067 | * | |
2068 | * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into | |
2069 | * account | |
d2876d08 | 2070 | * |
79a9becd AC |
2071 | * This function should be called from contexts where we cannot sleep, and will |
2072 | * complain if the GPIO chip functions potentially sleep. | |
d2876d08 | 2073 | */ |
79a9becd | 2074 | void gpiod_set_value(struct gpio_desc *desc, int value) |
d2876d08 | 2075 | { |
bcabdef1 | 2076 | if (!desc) |
79a9becd AC |
2077 | return; |
2078 | /* Should be using gpio_set_value_cansleep() */ | |
2079 | WARN_ON(desc->chip->can_sleep); | |
2080 | if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) | |
2081 | value = !value; | |
2082 | _gpiod_set_raw_value(desc, value); | |
372e722e | 2083 | } |
79a9becd | 2084 | EXPORT_SYMBOL_GPL(gpiod_set_value); |
d2876d08 | 2085 | |
d2876d08 | 2086 | /** |
79a9becd AC |
2087 | * gpiod_cansleep() - report whether gpio value access may sleep |
2088 | * @desc: gpio to check | |
d2876d08 | 2089 | * |
d2876d08 | 2090 | */ |
79a9becd | 2091 | int gpiod_cansleep(const struct gpio_desc *desc) |
372e722e | 2092 | { |
bcabdef1 AC |
2093 | if (!desc) |
2094 | return 0; | |
372e722e | 2095 | return desc->chip->can_sleep; |
d2876d08 | 2096 | } |
79a9becd | 2097 | EXPORT_SYMBOL_GPL(gpiod_cansleep); |
d2876d08 | 2098 | |
0f6d504e | 2099 | /** |
79a9becd AC |
2100 | * gpiod_to_irq() - return the IRQ corresponding to a GPIO |
2101 | * @desc: gpio whose IRQ will be returned (already requested) | |
0f6d504e | 2102 | * |
79a9becd AC |
2103 | * Return the IRQ corresponding to the passed GPIO, or an error code in case of |
2104 | * error. | |
0f6d504e | 2105 | */ |
79a9becd | 2106 | int gpiod_to_irq(const struct gpio_desc *desc) |
0f6d504e DB |
2107 | { |
2108 | struct gpio_chip *chip; | |
372e722e | 2109 | int offset; |
0f6d504e | 2110 | |
bcabdef1 AC |
2111 | if (!desc) |
2112 | return -EINVAL; | |
372e722e AC |
2113 | chip = desc->chip; |
2114 | offset = gpio_chip_hwgpio(desc); | |
2115 | return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO; | |
0f6d504e | 2116 | } |
79a9becd | 2117 | EXPORT_SYMBOL_GPL(gpiod_to_irq); |
0f6d504e | 2118 | |
d468bf9e LW |
2119 | /** |
2120 | * gpiod_lock_as_irq() - lock a GPIO to be used as IRQ | |
2121 | * @gpio: the GPIO line to lock as used for IRQ | |
2122 | * | |
2123 | * This is used directly by GPIO drivers that want to lock down | |
2124 | * a certain GPIO line to be used as IRQs, for example in the | |
2125 | * .to_irq() callback of their gpio_chip, or in the .irq_enable() | |
2126 | * of its irq_chip implementation if the GPIO is known from that | |
2127 | * code. | |
2128 | */ | |
79a9becd | 2129 | int gpiod_lock_as_irq(struct gpio_desc *desc) |
372e722e | 2130 | { |
d468bf9e LW |
2131 | if (!desc) |
2132 | return -EINVAL; | |
2133 | ||
2134 | if (test_bit(FLAG_IS_OUT, &desc->flags)) { | |
2135 | gpiod_err(desc, | |
2136 | "%s: tried to flag a GPIO set as output for IRQ\n", | |
2137 | __func__); | |
2138 | return -EIO; | |
2139 | } | |
2140 | ||
2141 | set_bit(FLAG_USED_AS_IRQ, &desc->flags); | |
2142 | return 0; | |
372e722e | 2143 | } |
79a9becd | 2144 | EXPORT_SYMBOL_GPL(gpiod_lock_as_irq); |
d2876d08 | 2145 | |
d468bf9e LW |
2146 | int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset) |
2147 | { | |
2148 | return gpiod_lock_as_irq(gpiochip_offset_to_desc(chip, offset)); | |
2149 | } | |
2150 | EXPORT_SYMBOL_GPL(gpio_lock_as_irq); | |
d2876d08 | 2151 | |
d468bf9e LW |
2152 | /** |
2153 | * gpiod_unlock_as_irq() - unlock a GPIO used as IRQ | |
2154 | * @gpio: the GPIO line to unlock from IRQ usage | |
2155 | * | |
2156 | * This is used directly by GPIO drivers that want to indicate | |
2157 | * that a certain GPIO is no longer used exclusively for IRQ. | |
d2876d08 | 2158 | */ |
79a9becd | 2159 | void gpiod_unlock_as_irq(struct gpio_desc *desc) |
d468bf9e LW |
2160 | { |
2161 | if (!desc) | |
2162 | return; | |
d2876d08 | 2163 | |
d468bf9e LW |
2164 | clear_bit(FLAG_USED_AS_IRQ, &desc->flags); |
2165 | } | |
79a9becd | 2166 | EXPORT_SYMBOL_GPL(gpiod_unlock_as_irq); |
d468bf9e LW |
2167 | |
2168 | void gpio_unlock_as_irq(struct gpio_chip *chip, unsigned int offset) | |
2169 | { | |
2170 | return gpiod_unlock_as_irq(gpiochip_offset_to_desc(chip, offset)); | |
2171 | } | |
2172 | EXPORT_SYMBOL_GPL(gpio_unlock_as_irq); | |
d2876d08 | 2173 | |
79a9becd AC |
2174 | /** |
2175 | * gpiod_get_raw_value_cansleep() - return a gpio's raw value | |
2176 | * @desc: gpio whose value will be returned | |
2177 | * | |
2178 | * Return the GPIO's raw value, i.e. the value of the physical line disregarding | |
2179 | * its ACTIVE_LOW status. | |
2180 | * | |
2181 | * This function is to be called from contexts that can sleep. | |
d2876d08 | 2182 | */ |
79a9becd | 2183 | int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc) |
d2876d08 | 2184 | { |
d2876d08 | 2185 | might_sleep_if(extra_checks); |
bcabdef1 AC |
2186 | if (!desc) |
2187 | return 0; | |
79a9becd | 2188 | return _gpiod_get_raw_value(desc); |
d2876d08 | 2189 | } |
79a9becd | 2190 | EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep); |
372e722e | 2191 | |
79a9becd AC |
2192 | /** |
2193 | * gpiod_get_value_cansleep() - return a gpio's value | |
2194 | * @desc: gpio whose value will be returned | |
2195 | * | |
2196 | * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into | |
2197 | * account. | |
2198 | * | |
2199 | * This function is to be called from contexts that can sleep. | |
2200 | */ | |
2201 | int gpiod_get_value_cansleep(const struct gpio_desc *desc) | |
d2876d08 | 2202 | { |
3f397c21 | 2203 | int value; |
d2876d08 DB |
2204 | |
2205 | might_sleep_if(extra_checks); | |
bcabdef1 AC |
2206 | if (!desc) |
2207 | return 0; | |
79a9becd AC |
2208 | |
2209 | value = _gpiod_get_raw_value(desc); | |
2210 | if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) | |
2211 | value = !value; | |
2212 | ||
3f397c21 | 2213 | return value; |
d2876d08 | 2214 | } |
79a9becd | 2215 | EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep); |
372e722e | 2216 | |
79a9becd AC |
2217 | /** |
2218 | * gpiod_set_raw_value_cansleep() - assign a gpio's raw value | |
2219 | * @desc: gpio whose value will be assigned | |
2220 | * @value: value to assign | |
2221 | * | |
2222 | * Set the raw value of the GPIO, i.e. the value of its physical line without | |
2223 | * regard for its ACTIVE_LOW status. | |
2224 | * | |
2225 | * This function is to be called from contexts that can sleep. | |
2226 | */ | |
2227 | void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value) | |
372e722e | 2228 | { |
d2876d08 | 2229 | might_sleep_if(extra_checks); |
bcabdef1 AC |
2230 | if (!desc) |
2231 | return; | |
79a9becd | 2232 | _gpiod_set_raw_value(desc, value); |
372e722e | 2233 | } |
79a9becd | 2234 | EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep); |
d2876d08 | 2235 | |
79a9becd AC |
2236 | /** |
2237 | * gpiod_set_value_cansleep() - assign a gpio's value | |
2238 | * @desc: gpio whose value will be assigned | |
2239 | * @value: value to assign | |
2240 | * | |
2241 | * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into | |
2242 | * account | |
2243 | * | |
2244 | * This function is to be called from contexts that can sleep. | |
2245 | */ | |
2246 | void gpiod_set_value_cansleep(struct gpio_desc *desc, int value) | |
d2876d08 | 2247 | { |
d2876d08 | 2248 | might_sleep_if(extra_checks); |
bcabdef1 AC |
2249 | if (!desc) |
2250 | return; | |
79a9becd AC |
2251 | |
2252 | if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) | |
2253 | value = !value; | |
2254 | _gpiod_set_raw_value(desc, value); | |
372e722e | 2255 | } |
79a9becd | 2256 | EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep); |
d2876d08 | 2257 | |
bae48da2 AC |
2258 | /** |
2259 | * gpiod_add_table() - register GPIO device consumers | |
2260 | * @table: array of consumers to register | |
2261 | * @num: number of consumers in table | |
2262 | */ | |
2263 | void gpiod_add_table(struct gpiod_lookup *table, size_t size) | |
2264 | { | |
2265 | mutex_lock(&gpio_lookup_lock); | |
2266 | ||
2267 | while (size--) { | |
2268 | list_add_tail(&table->list, &gpio_lookup_list); | |
2269 | table++; | |
2270 | } | |
2271 | ||
2272 | mutex_unlock(&gpio_lookup_lock); | |
2273 | } | |
2274 | ||
bae48da2 AC |
2275 | #ifdef CONFIG_OF |
2276 | static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, | |
2277 | unsigned int idx, unsigned long *flags) | |
2278 | { | |
2279 | char prop_name[32]; /* 32 is max size of property name */ | |
2280 | enum of_gpio_flags of_flags; | |
2281 | struct gpio_desc *desc; | |
2282 | ||
2283 | if (con_id) | |
2284 | snprintf(prop_name, 32, "%s-gpios", con_id); | |
aca5ce14 | 2285 | else |
bae48da2 AC |
2286 | snprintf(prop_name, 32, "gpios"); |
2287 | ||
2288 | desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx, | |
2289 | &of_flags); | |
2290 | ||
2291 | if (IS_ERR(desc)) | |
2292 | return desc; | |
2293 | ||
2294 | if (of_flags & OF_GPIO_ACTIVE_LOW) | |
2295 | *flags |= GPIOF_ACTIVE_LOW; | |
2296 | ||
2297 | return desc; | |
2298 | } | |
2299 | #else | |
2300 | static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, | |
2301 | unsigned int idx, unsigned long *flags) | |
2302 | { | |
2303 | return ERR_PTR(-ENODEV); | |
d2876d08 | 2304 | } |
bae48da2 | 2305 | #endif |
d2876d08 | 2306 | |
81f59e9d MW |
2307 | static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id, |
2308 | unsigned int idx, unsigned long *flags) | |
372e722e | 2309 | { |
e01f440a MW |
2310 | struct acpi_gpio_info info; |
2311 | struct gpio_desc *desc; | |
2312 | ||
2313 | desc = acpi_get_gpiod_by_index(dev, idx, &info); | |
2314 | if (IS_ERR(desc)) | |
2315 | return desc; | |
2316 | ||
2317 | if (info.gpioint && info.active_low) | |
2318 | *flags |= GPIOF_ACTIVE_LOW; | |
2319 | ||
2320 | return desc; | |
81f59e9d MW |
2321 | } |
2322 | ||
bae48da2 AC |
2323 | static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id, |
2324 | unsigned int idx, unsigned long *flags) | |
2325 | { | |
2326 | const char *dev_id = dev ? dev_name(dev) : NULL; | |
2327 | struct gpio_desc *desc = ERR_PTR(-ENODEV); | |
2328 | unsigned int match, best = 0; | |
2329 | struct gpiod_lookup *p; | |
2330 | ||
2331 | mutex_lock(&gpio_lookup_lock); | |
2332 | ||
2333 | list_for_each_entry(p, &gpio_lookup_list, list) { | |
2334 | match = 0; | |
2335 | ||
2336 | if (p->dev_id) { | |
2337 | if (!dev_id || strcmp(p->dev_id, dev_id)) | |
2338 | continue; | |
2339 | ||
2340 | match += 2; | |
2341 | } | |
2342 | ||
2343 | if (p->con_id) { | |
2344 | if (!con_id || strcmp(p->con_id, con_id)) | |
2345 | continue; | |
2346 | ||
2347 | match += 1; | |
2348 | } | |
2349 | ||
2350 | if (p->idx != idx) | |
2351 | continue; | |
2352 | ||
2353 | if (match > best) { | |
2354 | struct gpio_chip *chip; | |
2355 | ||
2356 | chip = find_chip_by_name(p->chip_label); | |
2357 | ||
2358 | if (!chip) { | |
2359 | dev_warn(dev, "cannot find GPIO chip %s\n", | |
2360 | p->chip_label); | |
2361 | continue; | |
2362 | } | |
2363 | ||
2364 | if (chip->ngpio >= p->chip_hwnum) { | |
2365 | dev_warn(dev, "GPIO chip %s has %d GPIOs\n", | |
2366 | chip->label, chip->ngpio); | |
2367 | continue; | |
2368 | } | |
2369 | ||
2370 | desc = gpio_to_desc(chip->base + p->chip_hwnum); | |
2371 | *flags = p->flags; | |
2372 | ||
2373 | if (match != 3) | |
2374 | best = match; | |
2375 | else | |
2376 | break; | |
2377 | } | |
2378 | } | |
2379 | ||
2380 | mutex_unlock(&gpio_lookup_lock); | |
2381 | ||
2382 | return desc; | |
2383 | } | |
2384 | ||
2385 | /** | |
2386 | * gpio_get - obtain a GPIO for a given GPIO function | |
2387 | * @dev: GPIO consumer | |
2388 | * @con_id: function within the GPIO consumer | |
2389 | * | |
2390 | * Return the GPIO descriptor corresponding to the function con_id of device | |
2391 | * dev, or an IS_ERR() condition if an error occured. | |
2392 | */ | |
2393 | struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id) | |
2394 | { | |
2395 | return gpiod_get_index(dev, con_id, 0); | |
2396 | } | |
2397 | EXPORT_SYMBOL_GPL(gpiod_get); | |
2398 | ||
2399 | /** | |
2400 | * gpiod_get_index - obtain a GPIO from a multi-index GPIO function | |
2401 | * @dev: GPIO consumer | |
2402 | * @con_id: function within the GPIO consumer | |
2403 | * @idx: index of the GPIO to obtain in the consumer | |
2404 | * | |
2405 | * This variant of gpiod_get() allows to access GPIOs other than the first | |
2406 | * defined one for functions that define several GPIOs. | |
2407 | * | |
2408 | * Return a valid GPIO descriptor, or an IS_ERR() condition in case of error. | |
2409 | */ | |
2410 | struct gpio_desc *__must_check gpiod_get_index(struct device *dev, | |
2411 | const char *con_id, | |
2412 | unsigned int idx) | |
2413 | { | |
2414 | struct gpio_desc *desc; | |
2415 | int status; | |
2416 | unsigned long flags = 0; | |
2417 | ||
2418 | dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id); | |
2419 | ||
2420 | /* Using device tree? */ | |
2421 | if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) { | |
2422 | dev_dbg(dev, "using device tree for GPIO lookup\n"); | |
2423 | desc = of_find_gpio(dev, con_id, idx, &flags); | |
81f59e9d MW |
2424 | } else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev)) { |
2425 | dev_dbg(dev, "using ACPI for GPIO lookup\n"); | |
2426 | desc = acpi_find_gpio(dev, con_id, idx, &flags); | |
bae48da2 AC |
2427 | } else { |
2428 | dev_dbg(dev, "using lookup tables for GPIO lookup"); | |
2429 | desc = gpiod_find(dev, con_id, idx, &flags); | |
2430 | } | |
2431 | ||
2432 | if (IS_ERR(desc)) { | |
2433 | dev_warn(dev, "lookup for GPIO %s failed\n", con_id); | |
2434 | return desc; | |
2435 | } | |
2436 | ||
2437 | status = gpiod_request(desc, con_id); | |
2438 | ||
2439 | if (status < 0) | |
2440 | return ERR_PTR(status); | |
2441 | ||
2442 | if (flags & GPIOF_ACTIVE_LOW) | |
2443 | set_bit(FLAG_ACTIVE_LOW, &desc->flags); | |
2444 | ||
2445 | return desc; | |
2446 | } | |
2447 | EXPORT_SYMBOL_GPL(gpiod_get_index); | |
2448 | ||
2449 | /** | |
2450 | * gpiod_put - dispose of a GPIO descriptor | |
2451 | * @desc: GPIO descriptor to dispose of | |
2452 | * | |
2453 | * No descriptor can be used after gpiod_put() has been called on it. | |
2454 | */ | |
2455 | void gpiod_put(struct gpio_desc *desc) | |
2456 | { | |
2457 | gpiod_free(desc); | |
372e722e | 2458 | } |
bae48da2 | 2459 | EXPORT_SYMBOL_GPL(gpiod_put); |
d2876d08 DB |
2460 | |
2461 | #ifdef CONFIG_DEBUG_FS | |
2462 | ||
d2876d08 DB |
2463 | static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) |
2464 | { | |
2465 | unsigned i; | |
2466 | unsigned gpio = chip->base; | |
6c0b4e6c | 2467 | struct gpio_desc *gdesc = &chip->desc[0]; |
d2876d08 | 2468 | int is_out; |
d468bf9e | 2469 | int is_irq; |
d2876d08 DB |
2470 | |
2471 | for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) { | |
2472 | if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) | |
2473 | continue; | |
2474 | ||
372e722e | 2475 | gpiod_get_direction(gdesc); |
d2876d08 | 2476 | is_out = test_bit(FLAG_IS_OUT, &gdesc->flags); |
d468bf9e LW |
2477 | is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags); |
2478 | seq_printf(s, " gpio-%-3d (%-20.20s) %s %s %s", | |
d2876d08 DB |
2479 | gpio, gdesc->label, |
2480 | is_out ? "out" : "in ", | |
2481 | chip->get | |
2482 | ? (chip->get(chip, i) ? "hi" : "lo") | |
d468bf9e LW |
2483 | : "? ", |
2484 | is_irq ? "IRQ" : " "); | |
d2876d08 DB |
2485 | seq_printf(s, "\n"); |
2486 | } | |
2487 | } | |
2488 | ||
f9c4a31f | 2489 | static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos) |
d2876d08 | 2490 | { |
362432ae | 2491 | unsigned long flags; |
f9c4a31f | 2492 | struct gpio_chip *chip = NULL; |
cb1650d4 | 2493 | loff_t index = *pos; |
d2876d08 | 2494 | |
f9c4a31f | 2495 | s->private = ""; |
d2876d08 | 2496 | |
362432ae | 2497 | spin_lock_irqsave(&gpio_lock, flags); |
cb1650d4 | 2498 | list_for_each_entry(chip, &gpio_chips, list) |
362432ae GL |
2499 | if (index-- == 0) { |
2500 | spin_unlock_irqrestore(&gpio_lock, flags); | |
cb1650d4 | 2501 | return chip; |
f9c4a31f | 2502 | } |
362432ae | 2503 | spin_unlock_irqrestore(&gpio_lock, flags); |
f9c4a31f | 2504 | |
cb1650d4 | 2505 | return NULL; |
f9c4a31f TR |
2506 | } |
2507 | ||
2508 | static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
2509 | { | |
362432ae | 2510 | unsigned long flags; |
f9c4a31f | 2511 | struct gpio_chip *chip = v; |
f9c4a31f TR |
2512 | void *ret = NULL; |
2513 | ||
362432ae | 2514 | spin_lock_irqsave(&gpio_lock, flags); |
cb1650d4 AC |
2515 | if (list_is_last(&chip->list, &gpio_chips)) |
2516 | ret = NULL; | |
2517 | else | |
2518 | ret = list_entry(chip->list.next, struct gpio_chip, list); | |
362432ae | 2519 | spin_unlock_irqrestore(&gpio_lock, flags); |
f9c4a31f TR |
2520 | |
2521 | s->private = "\n"; | |
2522 | ++*pos; | |
2523 | ||
2524 | return ret; | |
2525 | } | |
2526 | ||
2527 | static void gpiolib_seq_stop(struct seq_file *s, void *v) | |
2528 | { | |
2529 | } | |
2530 | ||
2531 | static int gpiolib_seq_show(struct seq_file *s, void *v) | |
2532 | { | |
2533 | struct gpio_chip *chip = v; | |
2534 | struct device *dev; | |
2535 | ||
2536 | seq_printf(s, "%sGPIOs %d-%d", (char *)s->private, | |
2537 | chip->base, chip->base + chip->ngpio - 1); | |
2538 | dev = chip->dev; | |
2539 | if (dev) | |
2540 | seq_printf(s, ", %s/%s", dev->bus ? dev->bus->name : "no-bus", | |
2541 | dev_name(dev)); | |
2542 | if (chip->label) | |
2543 | seq_printf(s, ", %s", chip->label); | |
2544 | if (chip->can_sleep) | |
2545 | seq_printf(s, ", can sleep"); | |
2546 | seq_printf(s, ":\n"); | |
2547 | ||
2548 | if (chip->dbg_show) | |
2549 | chip->dbg_show(s, chip); | |
2550 | else | |
2551 | gpiolib_dbg_show(s, chip); | |
2552 | ||
d2876d08 DB |
2553 | return 0; |
2554 | } | |
2555 | ||
f9c4a31f TR |
2556 | static const struct seq_operations gpiolib_seq_ops = { |
2557 | .start = gpiolib_seq_start, | |
2558 | .next = gpiolib_seq_next, | |
2559 | .stop = gpiolib_seq_stop, | |
2560 | .show = gpiolib_seq_show, | |
2561 | }; | |
2562 | ||
d2876d08 DB |
2563 | static int gpiolib_open(struct inode *inode, struct file *file) |
2564 | { | |
f9c4a31f | 2565 | return seq_open(file, &gpiolib_seq_ops); |
d2876d08 DB |
2566 | } |
2567 | ||
828c0950 | 2568 | static const struct file_operations gpiolib_operations = { |
f9c4a31f | 2569 | .owner = THIS_MODULE, |
d2876d08 DB |
2570 | .open = gpiolib_open, |
2571 | .read = seq_read, | |
2572 | .llseek = seq_lseek, | |
f9c4a31f | 2573 | .release = seq_release, |
d2876d08 DB |
2574 | }; |
2575 | ||
2576 | static int __init gpiolib_debugfs_init(void) | |
2577 | { | |
2578 | /* /sys/kernel/debug/gpio */ | |
2579 | (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO, | |
2580 | NULL, NULL, &gpiolib_operations); | |
2581 | return 0; | |
2582 | } | |
2583 | subsys_initcall(gpiolib_debugfs_init); | |
2584 | ||
2585 | #endif /* DEBUG_FS */ |