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Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[cris-mirror.git] / drivers / gpio / gpiolib-of.c
blob564bb7a31da43b4e924daf7501c36ec9a4eb8fc2
1 /*
2 * OF helpers for the GPIO API
3 *
4 * Copyright (c) 2007-2008 MontaVista Software, Inc.
5 *
6 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 */
13
14 #include <linux/device.h>
15 #include <linux/err.h>
16 #include <linux/errno.h>
17 #include <linux/module.h>
18 #include <linux/io.h>
19 #include <linux/gpio/consumer.h>
20 #include <linux/of.h>
21 #include <linux/of_address.h>
22 #include <linux/of_gpio.h>
23 #include <linux/pinctrl/pinctrl.h>
24 #include <linux/slab.h>
25 #include <linux/gpio/machine.h>
26
27 #include "gpiolib.h"
28
29 static int of_gpiochip_match_node_and_xlate(struct gpio_chip *chip, void *data)
30 {
31 struct of_phandle_args *gpiospec = data;
32
33 return chip->gpiodev->dev.of_node == gpiospec->np &&
34 chip->of_xlate(chip, gpiospec, NULL) >= 0;
35 }
36
37 static struct gpio_chip *of_find_gpiochip_by_xlate(
38 struct of_phandle_args *gpiospec)
39 {
40 return gpiochip_find(gpiospec, of_gpiochip_match_node_and_xlate);
41 }
42
43 static struct gpio_desc *of_xlate_and_get_gpiod_flags(struct gpio_chip *chip,
44 struct of_phandle_args *gpiospec,
45 enum of_gpio_flags *flags)
46 {
47 int ret;
48
49 if (chip->of_gpio_n_cells != gpiospec->args_count)
50 return ERR_PTR(-EINVAL);
51
52 ret = chip->of_xlate(chip, gpiospec, flags);
53 if (ret < 0)
54 return ERR_PTR(ret);
55
56 return gpiochip_get_desc(chip, ret);
57 }
58
59 static void of_gpio_flags_quirks(struct device_node *np,
60 enum of_gpio_flags *flags)
61 {
62 /*
63 * Some GPIO fixed regulator quirks.
64 * Note that active low is the default.
65 */
66 if (IS_ENABLED(CONFIG_REGULATOR) &&
67 (of_device_is_compatible(np, "reg-fixed-voltage") ||
68 of_device_is_compatible(np, "regulator-gpio"))) {
69 /*
70 * The regulator GPIO handles are specified such that the
71 * presence or absence of "enable-active-high" solely controls
72 * the polarity of the GPIO line. Any phandle flags must
73 * be actively ignored.
74 */
75 if (*flags & OF_GPIO_ACTIVE_LOW) {
76 pr_warn("%s GPIO handle specifies active low - ignored\n",
77 of_node_full_name(np));
78 *flags &= ~OF_GPIO_ACTIVE_LOW;
79 }
80 if (!of_property_read_bool(np, "enable-active-high"))
81 *flags |= OF_GPIO_ACTIVE_LOW;
82 }
83 /*
84 * Legacy open drain handling for fixed voltage regulators.
85 */
86 if (IS_ENABLED(CONFIG_REGULATOR) &&
87 of_device_is_compatible(np, "reg-fixed-voltage") &&
88 of_property_read_bool(np, "gpio-open-drain")) {
89 *flags |= (OF_GPIO_SINGLE_ENDED | OF_GPIO_OPEN_DRAIN);
90 pr_info("%s uses legacy open drain flag - update the DTS if you can\n",
91 of_node_full_name(np));
92 }
93 }
94
95 /**
96 * of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API
97 * @np: device node to get GPIO from
98 * @propname: property name containing gpio specifier(s)
99 * @index: index of the GPIO
100 * @flags: a flags pointer to fill in
101 *
102 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
103 * value on the error condition. If @flags is not NULL the function also fills
104 * in flags for the GPIO.
105 */
106 struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
107 const char *propname, int index, enum of_gpio_flags *flags)
108 {
109 struct of_phandle_args gpiospec;
110 struct gpio_chip *chip;
111 struct gpio_desc *desc;
112 int ret;
113
114 ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index,
115 &gpiospec);
116 if (ret) {
117 pr_debug("%s: can't parse '%s' property of node '%pOF[%d]'\n",
118 __func__, propname, np, index);
119 return ERR_PTR(ret);
120 }
121
122 chip = of_find_gpiochip_by_xlate(&gpiospec);
123 if (!chip) {
124 desc = ERR_PTR(-EPROBE_DEFER);
125 goto out;
126 }
127
128 desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, flags);
129 if (IS_ERR(desc))
130 goto out;
131
132 if (flags)
133 of_gpio_flags_quirks(np, flags);
134
135 pr_debug("%s: parsed '%s' property of node '%pOF[%d]' - status (%d)\n",
136 __func__, propname, np, index,
137 PTR_ERR_OR_ZERO(desc));
138
139 out:
140 of_node_put(gpiospec.np);
141
142 return desc;
143 }
144
145 int of_get_named_gpio_flags(struct device_node *np, const char *list_name,
146 int index, enum of_gpio_flags *flags)
147 {
148 struct gpio_desc *desc;
149
150 desc = of_get_named_gpiod_flags(np, list_name, index, flags);
151
152 if (IS_ERR(desc))
153 return PTR_ERR(desc);
154 else
155 return desc_to_gpio(desc);
156 }
157 EXPORT_SYMBOL(of_get_named_gpio_flags);
158
159 /*
160 * The SPI GPIO bindings happened before we managed to establish that GPIO
161 * properties should be named "foo-gpios" so we have this special kludge for
162 * them.
163 */
164 static struct gpio_desc *of_find_spi_gpio(struct device *dev, const char *con_id,
165 enum of_gpio_flags *of_flags)
166 {
167 char prop_name[32]; /* 32 is max size of property name */
168 struct device_node *np = dev->of_node;
169 struct gpio_desc *desc;
170
171 /*
172 * Hopefully the compiler stubs the rest of the function if this
173 * is false.
174 */
175 if (!IS_ENABLED(CONFIG_SPI_MASTER))
176 return ERR_PTR(-ENOENT);
177
178 /* Allow this specifically for "spi-gpio" devices */
179 if (!of_device_is_compatible(np, "spi-gpio") || !con_id)
180 return ERR_PTR(-ENOENT);
181
182 /* Will be "gpio-sck", "gpio-mosi" or "gpio-miso" */
183 snprintf(prop_name, sizeof(prop_name), "%s-%s", "gpio", con_id);
184
185 desc = of_get_named_gpiod_flags(np, prop_name, 0, of_flags);
186 return desc;
187 }
188
189 /*
190 * Some regulator bindings happened before we managed to establish that GPIO
191 * properties should be named "foo-gpios" so we have this special kludge for
192 * them.
193 */
194 static struct gpio_desc *of_find_regulator_gpio(struct device *dev, const char *con_id,
195 enum of_gpio_flags *of_flags)
196 {
197 /* These are the connection IDs we accept as legacy GPIO phandles */
198 const char *whitelist[] = {
199 "wlf,ldoena", /* Arizona */
200 "wlf,ldo1ena", /* WM8994 */
201 "wlf,ldo2ena", /* WM8994 */
202 };
203 struct device_node *np = dev->of_node;
204 struct gpio_desc *desc;
205 int i;
206
207 if (!IS_ENABLED(CONFIG_REGULATOR))
208 return ERR_PTR(-ENOENT);
209
210 if (!con_id)
211 return ERR_PTR(-ENOENT);
212
213 for (i = 0; i < ARRAY_SIZE(whitelist); i++)
214 if (!strcmp(con_id, whitelist[i]))
215 break;
216
217 if (i == ARRAY_SIZE(whitelist))
218 return ERR_PTR(-ENOENT);
219
220 desc = of_get_named_gpiod_flags(np, con_id, 0, of_flags);
221 return desc;
222 }
223
224 struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
225 unsigned int idx,
226 enum gpio_lookup_flags *flags)
227 {
228 char prop_name[32]; /* 32 is max size of property name */
229 enum of_gpio_flags of_flags;
230 struct gpio_desc *desc;
231 unsigned int i;
232
233 /* Try GPIO property "foo-gpios" and "foo-gpio" */
234 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
235 if (con_id)
236 snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
237 gpio_suffixes[i]);
238 else
239 snprintf(prop_name, sizeof(prop_name), "%s",
240 gpio_suffixes[i]);
241
242 desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
243 &of_flags);
244 if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
245 break;
246 }
247
248 /* Special handling for SPI GPIOs if used */
249 if (IS_ERR(desc))
250 desc = of_find_spi_gpio(dev, con_id, &of_flags);
251
252 /* Special handling for regulator GPIOs if used */
253 if (IS_ERR(desc))
254 desc = of_find_regulator_gpio(dev, con_id, &of_flags);
255
256 if (IS_ERR(desc))
257 return desc;
258
259 if (of_flags & OF_GPIO_ACTIVE_LOW)
260 *flags |= GPIO_ACTIVE_LOW;
261
262 if (of_flags & OF_GPIO_SINGLE_ENDED) {
263 if (of_flags & OF_GPIO_OPEN_DRAIN)
264 *flags |= GPIO_OPEN_DRAIN;
265 else
266 *flags |= GPIO_OPEN_SOURCE;
267 }
268
269 if (of_flags & OF_GPIO_TRANSITORY)
270 *flags |= GPIO_TRANSITORY;
271
272 return desc;
273 }
274
275 /**
276 * of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API
277 * @np: device node to get GPIO from
278 * @chip: GPIO chip whose hog is parsed
279 * @idx: Index of the GPIO to parse
280 * @name: GPIO line name
281 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
282 * of_parse_own_gpio()
283 * @dflags: gpiod_flags - optional GPIO initialization flags
284 *
285 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
286 * value on the error condition.
287 */
288 static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
289 struct gpio_chip *chip,
290 unsigned int idx, const char **name,
291 enum gpio_lookup_flags *lflags,
292 enum gpiod_flags *dflags)
293 {
294 struct device_node *chip_np;
295 enum of_gpio_flags xlate_flags;
296 struct of_phandle_args gpiospec;
297 struct gpio_desc *desc;
298 unsigned int i;
299 u32 tmp;
300 int ret;
301
302 chip_np = chip->of_node;
303 if (!chip_np)
304 return ERR_PTR(-EINVAL);
305
306 xlate_flags = 0;
307 *lflags = 0;
308 *dflags = 0;
309
310 ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp);
311 if (ret)
312 return ERR_PTR(ret);
313
314 gpiospec.np = chip_np;
315 gpiospec.args_count = tmp;
316
317 for (i = 0; i < tmp; i++) {
318 ret = of_property_read_u32_index(np, "gpios", idx * tmp + i,
319 &gpiospec.args[i]);
320 if (ret)
321 return ERR_PTR(ret);
322 }
323
324 desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, &xlate_flags);
325 if (IS_ERR(desc))
326 return desc;
327
328 if (xlate_flags & OF_GPIO_ACTIVE_LOW)
329 *lflags |= GPIO_ACTIVE_LOW;
330 if (xlate_flags & OF_GPIO_TRANSITORY)
331 *lflags |= GPIO_TRANSITORY;
332
333 if (of_property_read_bool(np, "input"))
334 *dflags |= GPIOD_IN;
335 else if (of_property_read_bool(np, "output-low"))
336 *dflags |= GPIOD_OUT_LOW;
337 else if (of_property_read_bool(np, "output-high"))
338 *dflags |= GPIOD_OUT_HIGH;
339 else {
340 pr_warn("GPIO line %d (%s): no hogging state specified, bailing out\n",
341 desc_to_gpio(desc), np->name);
342 return ERR_PTR(-EINVAL);
343 }
344
345 if (name && of_property_read_string(np, "line-name", name))
346 *name = np->name;
347
348 return desc;
349 }
350
351 /**
352 * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions
353 * @chip: gpio chip to act on
354 *
355 * This is only used by of_gpiochip_add to request/set GPIO initial
356 * configuration.
357 * It returns error if it fails otherwise 0 on success.
358 */
359 static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
360 {
361 struct gpio_desc *desc = NULL;
362 struct device_node *np;
363 const char *name;
364 enum gpio_lookup_flags lflags;
365 enum gpiod_flags dflags;
366 unsigned int i;
367 int ret;
368
369 for_each_available_child_of_node(chip->of_node, np) {
370 if (!of_property_read_bool(np, "gpio-hog"))
371 continue;
372
373 for (i = 0;; i++) {
374 desc = of_parse_own_gpio(np, chip, i, &name, &lflags,
375 &dflags);
376 if (IS_ERR(desc))
377 break;
378
379 ret = gpiod_hog(desc, name, lflags, dflags);
380 if (ret < 0) {
381 of_node_put(np);
382 return ret;
383 }
384 }
385 }
386
387 return 0;
388 }
389
390 /**
391 * of_gpio_simple_xlate - translate gpiospec to the GPIO number and flags
392 * @gc: pointer to the gpio_chip structure
393 * @gpiospec: GPIO specifier as found in the device tree
394 * @flags: a flags pointer to fill in
395 *
396 * This is simple translation function, suitable for the most 1:1 mapped
397 * GPIO chips. This function performs only one sanity check: whether GPIO
398 * is less than ngpios (that is specified in the gpio_chip).
399 */
400 int of_gpio_simple_xlate(struct gpio_chip *gc,
401 const struct of_phandle_args *gpiospec, u32 *flags)
402 {
403 /*
404 * We're discouraging gpio_cells < 2, since that way you'll have to
405 * write your own xlate function (that will have to retrieve the GPIO
406 * number and the flags from a single gpio cell -- this is possible,
407 * but not recommended).
408 */
409 if (gc->of_gpio_n_cells < 2) {
410 WARN_ON(1);
411 return -EINVAL;
412 }
413
414 if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
415 return -EINVAL;
416
417 if (gpiospec->args[0] >= gc->ngpio)
418 return -EINVAL;
419
420 if (flags)
421 *flags = gpiospec->args[1];
422
423 return gpiospec->args[0];
424 }
425 EXPORT_SYMBOL(of_gpio_simple_xlate);
426
427 /**
428 * of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank)
429 * @np: device node of the GPIO chip
430 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure
431 * @data: driver data to store in the struct gpio_chip
432 *
433 * To use this function you should allocate and fill mm_gc with:
434 *
435 * 1) In the gpio_chip structure:
436 * - all the callbacks
437 * - of_gpio_n_cells
438 * - of_xlate callback (optional)
439 *
440 * 3) In the of_mm_gpio_chip structure:
441 * - save_regs callback (optional)
442 *
443 * If succeeded, this function will map bank's memory and will
444 * do all necessary work for you. Then you'll able to use .regs
445 * to manage GPIOs from the callbacks.
446 */
447 int of_mm_gpiochip_add_data(struct device_node *np,
448 struct of_mm_gpio_chip *mm_gc,
449 void *data)
450 {
451 int ret = -ENOMEM;
452 struct gpio_chip *gc = &mm_gc->gc;
453
454 gc->label = kasprintf(GFP_KERNEL, "%pOF", np);
455 if (!gc->label)
456 goto err0;
457
458 mm_gc->regs = of_iomap(np, 0);
459 if (!mm_gc->regs)
460 goto err1;
461
462 gc->base = -1;
463
464 if (mm_gc->save_regs)
465 mm_gc->save_regs(mm_gc);
466
467 mm_gc->gc.of_node = np;
468
469 ret = gpiochip_add_data(gc, data);
470 if (ret)
471 goto err2;
472
473 return 0;
474 err2:
475 iounmap(mm_gc->regs);
476 err1:
477 kfree(gc->label);
478 err0:
479 pr_err("%pOF: GPIO chip registration failed with status %d\n", np, ret);
480 return ret;
481 }
482 EXPORT_SYMBOL(of_mm_gpiochip_add_data);
483
484 /**
485 * of_mm_gpiochip_remove - Remove memory mapped GPIO chip (bank)
486 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure
487 */
488 void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc)
489 {
490 struct gpio_chip *gc = &mm_gc->gc;
491
492 if (!mm_gc)
493 return;
494
495 gpiochip_remove(gc);
496 iounmap(mm_gc->regs);
497 kfree(gc->label);
498 }
499 EXPORT_SYMBOL(of_mm_gpiochip_remove);
500
501 #ifdef CONFIG_PINCTRL
502 static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
503 {
504 struct device_node *np = chip->of_node;
505 struct of_phandle_args pinspec;
506 struct pinctrl_dev *pctldev;
507 int index = 0, ret;
508 const char *name;
509 static const char group_names_propname[] = "gpio-ranges-group-names";
510 struct property *group_names;
511
512 if (!np)
513 return 0;
514
515 group_names = of_find_property(np, group_names_propname, NULL);
516
517 for (;; index++) {
518 ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
519 index, &pinspec);
520 if (ret)
521 break;
522
523 pctldev = of_pinctrl_get(pinspec.np);
524 of_node_put(pinspec.np);
525 if (!pctldev)
526 return -EPROBE_DEFER;
527
528 if (pinspec.args[2]) {
529 if (group_names) {
530 of_property_read_string_index(np,
531 group_names_propname,
532 index, &name);
533 if (strlen(name)) {
534 pr_err("%pOF: Group name of numeric GPIO ranges must be the empty string.\n",
535 np);
536 break;
537 }
538 }
539 /* npins != 0: linear range */
540 ret = gpiochip_add_pin_range(chip,
541 pinctrl_dev_get_devname(pctldev),
542 pinspec.args[0],
543 pinspec.args[1],
544 pinspec.args[2]);
545 if (ret)
546 return ret;
547 } else {
548 /* npins == 0: special range */
549 if (pinspec.args[1]) {
550 pr_err("%pOF: Illegal gpio-range format.\n",
551 np);
552 break;
553 }
554
555 if (!group_names) {
556 pr_err("%pOF: GPIO group range requested but no %s property.\n",
557 np, group_names_propname);
558 break;
559 }
560
561 ret = of_property_read_string_index(np,
562 group_names_propname,
563 index, &name);
564 if (ret)
565 break;
566
567 if (!strlen(name)) {
568 pr_err("%pOF: Group name of GPIO group range cannot be the empty string.\n",
569 np);
570 break;
571 }
572
573 ret = gpiochip_add_pingroup_range(chip, pctldev,
574 pinspec.args[0], name);
575 if (ret)
576 return ret;
577 }
578 }
579
580 return 0;
581 }
582
583 #else
584 static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; }
585 #endif
586
587 int of_gpiochip_add(struct gpio_chip *chip)
588 {
589 int status;
590
591 if ((!chip->of_node) && (chip->parent))
592 chip->of_node = chip->parent->of_node;
593
594 if (!chip->of_node)
595 return 0;
596
597 if (!chip->of_xlate) {
598 chip->of_gpio_n_cells = 2;
599 chip->of_xlate = of_gpio_simple_xlate;
600 }
601
602 if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS)
603 return -EINVAL;
604
605 status = of_gpiochip_add_pin_range(chip);
606 if (status)
607 return status;
608
609 /* If the chip defines names itself, these take precedence */
610 if (!chip->names)
611 devprop_gpiochip_set_names(chip,
612 of_fwnode_handle(chip->of_node));
613
614 of_node_get(chip->of_node);
615
616 return of_gpiochip_scan_gpios(chip);
617 }
618
619 void of_gpiochip_remove(struct gpio_chip *chip)
620 {
621 gpiochip_remove_pin_ranges(chip);
622 of_node_put(chip->of_node);
623 }
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