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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * OF helpers for the GPIO API
4 *
5 * Copyright (c) 2007-2008 MontaVista Software, Inc.
6 *
7 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
8 */
9
10#include <linux/device.h>
11#include <linux/err.h>
12#include <linux/errno.h>
13#include <linux/module.h>
14#include <linux/io.h>
15#include <linux/gpio/consumer.h>
16#include <linux/of.h>
17#include <linux/of_address.h>
18#include <linux/of_gpio.h>
19#include <linux/pinctrl/pinctrl.h>
20#include <linux/slab.h>
21#include <linux/gpio/machine.h>
22
23#include "gpiolib.h"
24#include "gpiolib-of.h"
25
26/**
27 * of_gpio_spi_cs_get_count() - special GPIO counting for SPI
28 * @dev: Consuming device
29 * @con_id: Function within the GPIO consumer
30 *
31 * Some elder GPIO controllers need special quirks. Currently we handle
32 * the Freescale and PPC GPIO controller with bindings that doesn't use the
33 * established "cs-gpios" for chip selects but instead rely on
34 * "gpios" for the chip select lines. If we detect this, we redirect
35 * the counting of "cs-gpios" to count "gpios" transparent to the
36 * driver.
37 */
38static int of_gpio_spi_cs_get_count(struct device *dev, const char *con_id)
39{
40 struct device_node *np = dev->of_node;
41
42 if (!IS_ENABLED(CONFIG_SPI_MASTER))
43 return 0;
44 if (!con_id || strcmp(con_id, "cs"))
45 return 0;
46 if (!of_device_is_compatible(np, "fsl,spi") &&
47 !of_device_is_compatible(np, "aeroflexgaisler,spictrl") &&
48 !of_device_is_compatible(np, "ibm,ppc4xx-spi"))
49 return 0;
50 return of_gpio_named_count(np, "gpios");
51}
52
53/*
54 * This is used by external users of of_gpio_count() from <linux/of_gpio.h>
55 *
56 * FIXME: get rid of those external users by converting them to GPIO
57 * descriptors and let them all use gpiod_count()
58 */
59int of_gpio_get_count(struct device *dev, const char *con_id)
60{
61 int ret;
62 char propname[32];
63 unsigned int i;
64
65 ret = of_gpio_spi_cs_get_count(dev, con_id);
66 if (ret > 0)
67 return ret;
68
69 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
70 if (con_id)
71 snprintf(propname, sizeof(propname), "%s-%s",
72 con_id, gpio_suffixes[i]);
73 else
74 snprintf(propname, sizeof(propname), "%s",
75 gpio_suffixes[i]);
76
77 ret = of_gpio_named_count(dev->of_node, propname);
78 if (ret > 0)
79 break;
80 }
81 return ret ? ret : -ENOENT;
82}
83
84static int of_gpiochip_match_node_and_xlate(struct gpio_chip *chip, void *data)
85{
86 struct of_phandle_args *gpiospec = data;
87
88 return chip->gpiodev->dev.of_node == gpiospec->np &&
89 chip->of_xlate &&
90 chip->of_xlate(chip, gpiospec, NULL) >= 0;
91}
92
93static struct gpio_chip *of_find_gpiochip_by_xlate(
94 struct of_phandle_args *gpiospec)
95{
96 return gpiochip_find(gpiospec, of_gpiochip_match_node_and_xlate);
97}
98
99static struct gpio_desc *of_xlate_and_get_gpiod_flags(struct gpio_chip *chip,
100 struct of_phandle_args *gpiospec,
101 enum of_gpio_flags *flags)
102{
103 int ret;
104
105 if (chip->of_gpio_n_cells != gpiospec->args_count)
106 return ERR_PTR(-EINVAL);
107
108 ret = chip->of_xlate(chip, gpiospec, flags);
109 if (ret < 0)
110 return ERR_PTR(ret);
111
112 return gpiochip_get_desc(chip, ret);
113}
114
115/**
116 * of_gpio_need_valid_mask() - figure out if the OF GPIO driver needs
117 * to set the .valid_mask
118 * @gc: the target gpio_chip
119 *
120 * Return: true if the valid mask needs to be set
121 */
122bool of_gpio_need_valid_mask(const struct gpio_chip *gc)
123{
124 int size;
125 struct device_node *np = gc->of_node;
126
127 size = of_property_count_u32_elems(np, "gpio-reserved-ranges");
128 if (size > 0 && size % 2 == 0)
129 return true;
130 return false;
131}
132
133static void of_gpio_flags_quirks(struct device_node *np,
134 const char *propname,
135 enum of_gpio_flags *flags,
136 int index)
137{
138 /*
139 * Some GPIO fixed regulator quirks.
140 * Note that active low is the default.
141 */
142 if (IS_ENABLED(CONFIG_REGULATOR) &&
143 (of_device_is_compatible(np, "regulator-fixed") ||
144 of_device_is_compatible(np, "reg-fixed-voltage") ||
145 (!(strcmp(propname, "enable-gpio") &&
146 strcmp(propname, "enable-gpios")) &&
147 of_device_is_compatible(np, "regulator-gpio")))) {
148 bool active_low = !of_property_read_bool(np,
149 "enable-active-high");
150 /*
151 * The regulator GPIO handles are specified such that the
152 * presence or absence of "enable-active-high" solely controls
153 * the polarity of the GPIO line. Any phandle flags must
154 * be actively ignored.
155 */
156 if ((*flags & OF_GPIO_ACTIVE_LOW) && !active_low) {
157 pr_warn("%s GPIO handle specifies active low - ignored\n",
158 of_node_full_name(np));
159 *flags &= ~OF_GPIO_ACTIVE_LOW;
160 }
161 if (active_low)
162 *flags |= OF_GPIO_ACTIVE_LOW;
163 }
164 /*
165 * Legacy open drain handling for fixed voltage regulators.
166 */
167 if (IS_ENABLED(CONFIG_REGULATOR) &&
168 of_device_is_compatible(np, "reg-fixed-voltage") &&
169 of_property_read_bool(np, "gpio-open-drain")) {
170 *flags |= (OF_GPIO_SINGLE_ENDED | OF_GPIO_OPEN_DRAIN);
171 pr_info("%s uses legacy open drain flag - update the DTS if you can\n",
172 of_node_full_name(np));
173 }
174
175 /*
176 * Legacy handling of SPI active high chip select. If we have a
177 * property named "cs-gpios" we need to inspect the child node
178 * to determine if the flags should have inverted semantics.
179 */
180 if (IS_ENABLED(CONFIG_SPI_MASTER) && !strcmp(propname, "cs-gpios") &&
181 of_property_read_bool(np, "cs-gpios")) {
182 struct device_node *child;
183 u32 cs;
184 int ret;
185
186 for_each_child_of_node(np, child) {
187 ret = of_property_read_u32(child, "reg", &cs);
188 if (ret)
189 continue;
190 if (cs == index) {
191 /*
192 * SPI children have active low chip selects
193 * by default. This can be specified negatively
194 * by just omitting "spi-cs-high" in the
195 * device node, or actively by tagging on
196 * GPIO_ACTIVE_LOW as flag in the device
197 * tree. If the line is simultaneously
198 * tagged as active low in the device tree
199 * and has the "spi-cs-high" set, we get a
200 * conflict and the "spi-cs-high" flag will
201 * take precedence.
202 */
203 if (of_property_read_bool(child, "spi-cs-high")) {
204 if (*flags & OF_GPIO_ACTIVE_LOW) {
205 pr_warn("%s GPIO handle specifies active low - ignored\n",
206 of_node_full_name(child));
207 *flags &= ~OF_GPIO_ACTIVE_LOW;
208 }
209 } else {
210 if (!(*flags & OF_GPIO_ACTIVE_LOW))
211 pr_info("%s enforce active low on chipselect handle\n",
212 of_node_full_name(child));
213 *flags |= OF_GPIO_ACTIVE_LOW;
214 }
215 of_node_put(child);
216 break;
217 }
218 }
219 }
220
221 /* Legacy handling of stmmac's active-low PHY reset line */
222 if (IS_ENABLED(CONFIG_STMMAC_ETH) &&
223 !strcmp(propname, "snps,reset-gpio") &&
224 of_property_read_bool(np, "snps,reset-active-low"))
225 *flags |= OF_GPIO_ACTIVE_LOW;
226}
227
228/**
229 * of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API
230 * @np: device node to get GPIO from
231 * @propname: property name containing gpio specifier(s)
232 * @index: index of the GPIO
233 * @flags: a flags pointer to fill in
234 *
235 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
236 * value on the error condition. If @flags is not NULL the function also fills
237 * in flags for the GPIO.
238 */
239static struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
240 const char *propname, int index, enum of_gpio_flags *flags)
241{
242 struct of_phandle_args gpiospec;
243 struct gpio_chip *chip;
244 struct gpio_desc *desc;
245 int ret;
246
247 ret = of_parse_phandle_with_args_map(np, propname, "gpio", index,
248 &gpiospec);
249 if (ret) {
250 pr_debug("%s: can't parse '%s' property of node '%pOF[%d]'\n",
251 __func__, propname, np, index);
252 return ERR_PTR(ret);
253 }
254
255 chip = of_find_gpiochip_by_xlate(&gpiospec);
256 if (!chip) {
257 desc = ERR_PTR(-EPROBE_DEFER);
258 goto out;
259 }
260
261 desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, flags);
262 if (IS_ERR(desc))
263 goto out;
264
265 if (flags)
266 of_gpio_flags_quirks(np, propname, flags, index);
267
268 pr_debug("%s: parsed '%s' property of node '%pOF[%d]' - status (%d)\n",
269 __func__, propname, np, index,
270 PTR_ERR_OR_ZERO(desc));
271
272out:
273 of_node_put(gpiospec.np);
274
275 return desc;
276}
277
278int of_get_named_gpio_flags(struct device_node *np, const char *list_name,
279 int index, enum of_gpio_flags *flags)
280{
281 struct gpio_desc *desc;
282
283 desc = of_get_named_gpiod_flags(np, list_name, index, flags);
284
285 if (IS_ERR(desc))
286 return PTR_ERR(desc);
287 else
288 return desc_to_gpio(desc);
289}
290EXPORT_SYMBOL_GPL(of_get_named_gpio_flags);
291
292/**
293 * gpiod_get_from_of_node() - obtain a GPIO from an OF node
294 * @node: handle of the OF node
295 * @propname: name of the DT property representing the GPIO
296 * @index: index of the GPIO to obtain for the consumer
297 * @dflags: GPIO initialization flags
298 * @label: label to attach to the requested GPIO
299 *
300 * Returns:
301 * On successful request the GPIO pin is configured in accordance with
302 * provided @dflags.
303 *
304 * In case of error an ERR_PTR() is returned.
305 */
306struct gpio_desc *gpiod_get_from_of_node(struct device_node *node,
307 const char *propname, int index,
308 enum gpiod_flags dflags,
309 const char *label)
310{
311 unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
312 struct gpio_desc *desc;
313 enum of_gpio_flags flags;
314 bool active_low = false;
315 bool single_ended = false;
316 bool open_drain = false;
317 bool transitory = false;
318 int ret;
319
320 desc = of_get_named_gpiod_flags(node, propname,
321 index, &flags);
322
323 if (!desc || IS_ERR(desc)) {
324 return desc;
325 }
326
327 active_low = flags & OF_GPIO_ACTIVE_LOW;
328 single_ended = flags & OF_GPIO_SINGLE_ENDED;
329 open_drain = flags & OF_GPIO_OPEN_DRAIN;
330 transitory = flags & OF_GPIO_TRANSITORY;
331
332 ret = gpiod_request(desc, label);
333 if (ret == -EBUSY && (dflags & GPIOD_FLAGS_BIT_NONEXCLUSIVE))
334 return desc;
335 if (ret)
336 return ERR_PTR(ret);
337
338 if (active_low)
339 lflags |= GPIO_ACTIVE_LOW;
340
341 if (single_ended) {
342 if (open_drain)
343 lflags |= GPIO_OPEN_DRAIN;
344 else
345 lflags |= GPIO_OPEN_SOURCE;
346 }
347
348 if (transitory)
349 lflags |= GPIO_TRANSITORY;
350
351 if (flags & OF_GPIO_PULL_UP)
352 lflags |= GPIO_PULL_UP;
353
354 if (flags & OF_GPIO_PULL_DOWN)
355 lflags |= GPIO_PULL_DOWN;
356
357 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
358 if (ret < 0) {
359 gpiod_put(desc);
360 return ERR_PTR(ret);
361 }
362
363 return desc;
364}
365EXPORT_SYMBOL_GPL(gpiod_get_from_of_node);
366
367/*
368 * The SPI GPIO bindings happened before we managed to establish that GPIO
369 * properties should be named "foo-gpios" so we have this special kludge for
370 * them.
371 */
372static struct gpio_desc *of_find_spi_gpio(struct device *dev, const char *con_id,
373 enum of_gpio_flags *of_flags)
374{
375 char prop_name[32]; /* 32 is max size of property name */
376 struct device_node *np = dev->of_node;
377 struct gpio_desc *desc;
378
379 /*
380 * Hopefully the compiler stubs the rest of the function if this
381 * is false.
382 */
383 if (!IS_ENABLED(CONFIG_SPI_MASTER))
384 return ERR_PTR(-ENOENT);
385
386 /* Allow this specifically for "spi-gpio" devices */
387 if (!of_device_is_compatible(np, "spi-gpio") || !con_id)
388 return ERR_PTR(-ENOENT);
389
390 /* Will be "gpio-sck", "gpio-mosi" or "gpio-miso" */
391 snprintf(prop_name, sizeof(prop_name), "%s-%s", "gpio", con_id);
392
393 desc = of_get_named_gpiod_flags(np, prop_name, 0, of_flags);
394 return desc;
395}
396
397/*
398 * The old Freescale bindings use simply "gpios" as name for the chip select
399 * lines rather than "cs-gpios" like all other SPI hardware. Account for this
400 * with a special quirk.
401 */
402static struct gpio_desc *of_find_spi_cs_gpio(struct device *dev,
403 const char *con_id,
404 unsigned int idx,
405 unsigned long *flags)
406{
407 struct device_node *np = dev->of_node;
408
409 if (!IS_ENABLED(CONFIG_SPI_MASTER))
410 return ERR_PTR(-ENOENT);
411
412 /* Allow this specifically for Freescale and PPC devices */
413 if (!of_device_is_compatible(np, "fsl,spi") &&
414 !of_device_is_compatible(np, "aeroflexgaisler,spictrl") &&
415 !of_device_is_compatible(np, "ibm,ppc4xx-spi"))
416 return ERR_PTR(-ENOENT);
417 /* Allow only if asking for "cs-gpios" */
418 if (!con_id || strcmp(con_id, "cs"))
419 return ERR_PTR(-ENOENT);
420
421 /*
422 * While all other SPI controllers use "cs-gpios" the Freescale
423 * uses just "gpios" so translate to that when "cs-gpios" is
424 * requested.
425 */
426 return of_find_gpio(dev, NULL, idx, flags);
427}
428
429/*
430 * Some regulator bindings happened before we managed to establish that GPIO
431 * properties should be named "foo-gpios" so we have this special kludge for
432 * them.
433 */
434static struct gpio_desc *of_find_regulator_gpio(struct device *dev, const char *con_id,
435 enum of_gpio_flags *of_flags)
436{
437 /* These are the connection IDs we accept as legacy GPIO phandles */
438 const char *whitelist[] = {
439 "wlf,ldoena", /* Arizona */
440 "wlf,ldo1ena", /* WM8994 */
441 "wlf,ldo2ena", /* WM8994 */
442 };
443 struct device_node *np = dev->of_node;
444 struct gpio_desc *desc;
445 int i;
446
447 if (!IS_ENABLED(CONFIG_REGULATOR))
448 return ERR_PTR(-ENOENT);
449
450 if (!con_id)
451 return ERR_PTR(-ENOENT);
452
453 i = match_string(whitelist, ARRAY_SIZE(whitelist), con_id);
454 if (i < 0)
455 return ERR_PTR(-ENOENT);
456
457 desc = of_get_named_gpiod_flags(np, con_id, 0, of_flags);
458 return desc;
459}
460
461static struct gpio_desc *of_find_arizona_gpio(struct device *dev,
462 const char *con_id,
463 enum of_gpio_flags *of_flags)
464{
465 if (!IS_ENABLED(CONFIG_MFD_ARIZONA))
466 return ERR_PTR(-ENOENT);
467
468 if (!con_id || strcmp(con_id, "wlf,reset"))
469 return ERR_PTR(-ENOENT);
470
471 return of_get_named_gpiod_flags(dev->of_node, con_id, 0, of_flags);
472}
473
474static struct gpio_desc *of_find_usb_gpio(struct device *dev,
475 const char *con_id,
476 enum of_gpio_flags *of_flags)
477{
478 /*
479 * Currently this USB quirk is only for the Fairchild FUSB302 host which is using
480 * an undocumented DT GPIO line named "fcs,int_n" without the compulsory "-gpios"
481 * suffix.
482 */
483 if (!IS_ENABLED(CONFIG_TYPEC_FUSB302))
484 return ERR_PTR(-ENOENT);
485
486 if (!con_id || strcmp(con_id, "fcs,int_n"))
487 return ERR_PTR(-ENOENT);
488
489 return of_get_named_gpiod_flags(dev->of_node, con_id, 0, of_flags);
490}
491
492struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
493 unsigned int idx, unsigned long *flags)
494{
495 char prop_name[32]; /* 32 is max size of property name */
496 enum of_gpio_flags of_flags;
497 struct gpio_desc *desc;
498 unsigned int i;
499
500 /* Try GPIO property "foo-gpios" and "foo-gpio" */
501 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
502 if (con_id)
503 snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
504 gpio_suffixes[i]);
505 else
506 snprintf(prop_name, sizeof(prop_name), "%s",
507 gpio_suffixes[i]);
508
509 desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
510 &of_flags);
511
512 if (!IS_ERR(desc) || PTR_ERR(desc) != -ENOENT)
513 break;
514 }
515
516 if (PTR_ERR(desc) == -ENOENT) {
517 /* Special handling for SPI GPIOs if used */
518 desc = of_find_spi_gpio(dev, con_id, &of_flags);
519 }
520
521 if (PTR_ERR(desc) == -ENOENT) {
522 /* This quirk looks up flags and all */
523 desc = of_find_spi_cs_gpio(dev, con_id, idx, flags);
524 if (!IS_ERR(desc))
525 return desc;
526 }
527
528 if (PTR_ERR(desc) == -ENOENT) {
529 /* Special handling for regulator GPIOs if used */
530 desc = of_find_regulator_gpio(dev, con_id, &of_flags);
531 }
532
533 if (PTR_ERR(desc) == -ENOENT)
534 desc = of_find_arizona_gpio(dev, con_id, &of_flags);
535
536 if (PTR_ERR(desc) == -ENOENT)
537 desc = of_find_usb_gpio(dev, con_id, &of_flags);
538
539 if (IS_ERR(desc))
540 return desc;
541
542 if (of_flags & OF_GPIO_ACTIVE_LOW)
543 *flags |= GPIO_ACTIVE_LOW;
544
545 if (of_flags & OF_GPIO_SINGLE_ENDED) {
546 if (of_flags & OF_GPIO_OPEN_DRAIN)
547 *flags |= GPIO_OPEN_DRAIN;
548 else
549 *flags |= GPIO_OPEN_SOURCE;
550 }
551
552 if (of_flags & OF_GPIO_TRANSITORY)
553 *flags |= GPIO_TRANSITORY;
554
555 if (of_flags & OF_GPIO_PULL_UP)
556 *flags |= GPIO_PULL_UP;
557 if (of_flags & OF_GPIO_PULL_DOWN)
558 *flags |= GPIO_PULL_DOWN;
559
560 return desc;
561}
562
563/**
564 * of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API
565 * @np: device node to get GPIO from
566 * @chip: GPIO chip whose hog is parsed
567 * @idx: Index of the GPIO to parse
568 * @name: GPIO line name
569 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
570 * of_find_gpio() or of_parse_own_gpio()
571 * @dflags: gpiod_flags - optional GPIO initialization flags
572 *
573 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
574 * value on the error condition.
575 */
576static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
577 struct gpio_chip *chip,
578 unsigned int idx, const char **name,
579 unsigned long *lflags,
580 enum gpiod_flags *dflags)
581{
582 struct device_node *chip_np;
583 enum of_gpio_flags xlate_flags;
584 struct of_phandle_args gpiospec;
585 struct gpio_desc *desc;
586 unsigned int i;
587 u32 tmp;
588 int ret;
589
590 chip_np = chip->of_node;
591 if (!chip_np)
592 return ERR_PTR(-EINVAL);
593
594 xlate_flags = 0;
595 *lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
596 *dflags = 0;
597
598 ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp);
599 if (ret)
600 return ERR_PTR(ret);
601
602 gpiospec.np = chip_np;
603 gpiospec.args_count = tmp;
604
605 for (i = 0; i < tmp; i++) {
606 ret = of_property_read_u32_index(np, "gpios", idx * tmp + i,
607 &gpiospec.args[i]);
608 if (ret)
609 return ERR_PTR(ret);
610 }
611
612 desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, &xlate_flags);
613 if (IS_ERR(desc))
614 return desc;
615
616 if (xlate_flags & OF_GPIO_ACTIVE_LOW)
617 *lflags |= GPIO_ACTIVE_LOW;
618 if (xlate_flags & OF_GPIO_TRANSITORY)
619 *lflags |= GPIO_TRANSITORY;
620 if (xlate_flags & OF_GPIO_PULL_UP)
621 *lflags |= GPIO_PULL_UP;
622 if (xlate_flags & OF_GPIO_PULL_DOWN)
623 *lflags |= GPIO_PULL_DOWN;
624
625 if (of_property_read_bool(np, "input"))
626 *dflags |= GPIOD_IN;
627 else if (of_property_read_bool(np, "output-low"))
628 *dflags |= GPIOD_OUT_LOW;
629 else if (of_property_read_bool(np, "output-high"))
630 *dflags |= GPIOD_OUT_HIGH;
631 else {
632 pr_warn("GPIO line %d (%pOFn): no hogging state specified, bailing out\n",
633 desc_to_gpio(desc), np);
634 return ERR_PTR(-EINVAL);
635 }
636
637 if (name && of_property_read_string(np, "line-name", name))
638 *name = np->name;
639
640 return desc;
641}
642
643/**
644 * of_gpiochip_add_hog - Add all hogs in a hog device node
645 * @chip: gpio chip to act on
646 * @hog: device node describing the hogs
647 *
648 * Returns error if it fails otherwise 0 on success.
649 */
650static int of_gpiochip_add_hog(struct gpio_chip *chip, struct device_node *hog)
651{
652 enum gpiod_flags dflags;
653 struct gpio_desc *desc;
654 unsigned long lflags;
655 const char *name;
656 unsigned int i;
657 int ret;
658
659 for (i = 0;; i++) {
660 desc = of_parse_own_gpio(hog, chip, i, &name, &lflags, &dflags);
661 if (IS_ERR(desc))
662 break;
663
664 ret = gpiod_hog(desc, name, lflags, dflags);
665 if (ret < 0)
666 return ret;
667
668#ifdef CONFIG_OF_DYNAMIC
669 desc->hog = hog;
670#endif
671 }
672
673 return 0;
674}
675
676/**
677 * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions
678 * @chip: gpio chip to act on
679 *
680 * This is only used by of_gpiochip_add to request/set GPIO initial
681 * configuration.
682 * It returns error if it fails otherwise 0 on success.
683 */
684static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
685{
686 struct device_node *np;
687 int ret;
688
689 for_each_available_child_of_node(chip->of_node, np) {
690 if (!of_property_read_bool(np, "gpio-hog"))
691 continue;
692
693 ret = of_gpiochip_add_hog(chip, np);
694 if (ret < 0) {
695 of_node_put(np);
696 return ret;
697 }
698
699 of_node_set_flag(np, OF_POPULATED);
700 }
701
702 return 0;
703}
704
705#ifdef CONFIG_OF_DYNAMIC
706/**
707 * of_gpiochip_remove_hog - Remove all hogs in a hog device node
708 * @chip: gpio chip to act on
709 * @hog: device node describing the hogs
710 */
711static void of_gpiochip_remove_hog(struct gpio_chip *chip,
712 struct device_node *hog)
713{
714 struct gpio_desc *descs = chip->gpiodev->descs;
715 unsigned int i;
716
717 for (i = 0; i < chip->ngpio; i++) {
718 if (test_bit(FLAG_IS_HOGGED, &descs[i].flags) &&
719 descs[i].hog == hog)
720 gpiochip_free_own_desc(&descs[i]);
721 }
722}
723
724static int of_gpiochip_match_node(struct gpio_chip *chip, void *data)
725{
726 return chip->gpiodev->dev.of_node == data;
727}
728
729static struct gpio_chip *of_find_gpiochip_by_node(struct device_node *np)
730{
731 return gpiochip_find(np, of_gpiochip_match_node);
732}
733
734static int of_gpio_notify(struct notifier_block *nb, unsigned long action,
735 void *arg)
736{
737 struct of_reconfig_data *rd = arg;
738 struct gpio_chip *chip;
739 int ret;
740
741 /*
742 * This only supports adding and removing complete gpio-hog nodes.
743 * Modifying an existing gpio-hog node is not supported (except for
744 * changing its "status" property, which is treated the same as
745 * addition/removal).
746 */
747 switch (of_reconfig_get_state_change(action, arg)) {
748 case OF_RECONFIG_CHANGE_ADD:
749 if (!of_property_read_bool(rd->dn, "gpio-hog"))
750 return NOTIFY_OK; /* not for us */
751
752 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED))
753 return NOTIFY_OK;
754
755 chip = of_find_gpiochip_by_node(rd->dn->parent);
756 if (chip == NULL)
757 return NOTIFY_OK; /* not for us */
758
759 ret = of_gpiochip_add_hog(chip, rd->dn);
760 if (ret < 0) {
761 pr_err("%s: failed to add hogs for %pOF\n", __func__,
762 rd->dn);
763 of_node_clear_flag(rd->dn, OF_POPULATED);
764 return notifier_from_errno(ret);
765 }
766 break;
767
768 case OF_RECONFIG_CHANGE_REMOVE:
769 if (!of_node_check_flag(rd->dn, OF_POPULATED))
770 return NOTIFY_OK; /* already depopulated */
771
772 chip = of_find_gpiochip_by_node(rd->dn->parent);
773 if (chip == NULL)
774 return NOTIFY_OK; /* not for us */
775
776 of_gpiochip_remove_hog(chip, rd->dn);
777 of_node_clear_flag(rd->dn, OF_POPULATED);
778 break;
779 }
780
781 return NOTIFY_OK;
782}
783
784struct notifier_block gpio_of_notifier = {
785 .notifier_call = of_gpio_notify,
786};
787#endif /* CONFIG_OF_DYNAMIC */
788
789/**
790 * of_gpio_simple_xlate - translate gpiospec to the GPIO number and flags
791 * @gc: pointer to the gpio_chip structure
792 * @gpiospec: GPIO specifier as found in the device tree
793 * @flags: a flags pointer to fill in
794 *
795 * This is simple translation function, suitable for the most 1:1 mapped
796 * GPIO chips. This function performs only one sanity check: whether GPIO
797 * is less than ngpios (that is specified in the gpio_chip).
798 */
799static int of_gpio_simple_xlate(struct gpio_chip *gc,
800 const struct of_phandle_args *gpiospec,
801 u32 *flags)
802{
803 /*
804 * We're discouraging gpio_cells < 2, since that way you'll have to
805 * write your own xlate function (that will have to retrieve the GPIO
806 * number and the flags from a single gpio cell -- this is possible,
807 * but not recommended).
808 */
809 if (gc->of_gpio_n_cells < 2) {
810 WARN_ON(1);
811 return -EINVAL;
812 }
813
814 if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
815 return -EINVAL;
816
817 if (gpiospec->args[0] >= gc->ngpio)
818 return -EINVAL;
819
820 if (flags)
821 *flags = gpiospec->args[1];
822
823 return gpiospec->args[0];
824}
825
826/**
827 * of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank)
828 * @np: device node of the GPIO chip
829 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure
830 * @data: driver data to store in the struct gpio_chip
831 *
832 * To use this function you should allocate and fill mm_gc with:
833 *
834 * 1) In the gpio_chip structure:
835 * - all the callbacks
836 * - of_gpio_n_cells
837 * - of_xlate callback (optional)
838 *
839 * 3) In the of_mm_gpio_chip structure:
840 * - save_regs callback (optional)
841 *
842 * If succeeded, this function will map bank's memory and will
843 * do all necessary work for you. Then you'll able to use .regs
844 * to manage GPIOs from the callbacks.
845 */
846int of_mm_gpiochip_add_data(struct device_node *np,
847 struct of_mm_gpio_chip *mm_gc,
848 void *data)
849{
850 int ret = -ENOMEM;
851 struct gpio_chip *gc = &mm_gc->gc;
852
853 gc->label = kasprintf(GFP_KERNEL, "%pOF", np);
854 if (!gc->label)
855 goto err0;
856
857 mm_gc->regs = of_iomap(np, 0);
858 if (!mm_gc->regs)
859 goto err1;
860
861 gc->base = -1;
862
863 if (mm_gc->save_regs)
864 mm_gc->save_regs(mm_gc);
865
866 mm_gc->gc.of_node = np;
867
868 ret = gpiochip_add_data(gc, data);
869 if (ret)
870 goto err2;
871
872 return 0;
873err2:
874 iounmap(mm_gc->regs);
875err1:
876 kfree(gc->label);
877err0:
878 pr_err("%pOF: GPIO chip registration failed with status %d\n", np, ret);
879 return ret;
880}
881EXPORT_SYMBOL_GPL(of_mm_gpiochip_add_data);
882
883/**
884 * of_mm_gpiochip_remove - Remove memory mapped GPIO chip (bank)
885 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure
886 */
887void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc)
888{
889 struct gpio_chip *gc = &mm_gc->gc;
890
891 if (!mm_gc)
892 return;
893
894 gpiochip_remove(gc);
895 iounmap(mm_gc->regs);
896 kfree(gc->label);
897}
898EXPORT_SYMBOL_GPL(of_mm_gpiochip_remove);
899
900static void of_gpiochip_init_valid_mask(struct gpio_chip *chip)
901{
902 int len, i;
903 u32 start, count;
904 struct device_node *np = chip->of_node;
905
906 len = of_property_count_u32_elems(np, "gpio-reserved-ranges");
907 if (len < 0 || len % 2 != 0)
908 return;
909
910 for (i = 0; i < len; i += 2) {
911 of_property_read_u32_index(np, "gpio-reserved-ranges",
912 i, &start);
913 of_property_read_u32_index(np, "gpio-reserved-ranges",
914 i + 1, &count);
915 if (start >= chip->ngpio || start + count >= chip->ngpio)
916 continue;
917
918 bitmap_clear(chip->valid_mask, start, count);
919 }
920};
921
922#ifdef CONFIG_PINCTRL
923static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
924{
925 struct device_node *np = chip->of_node;
926 struct of_phandle_args pinspec;
927 struct pinctrl_dev *pctldev;
928 int index = 0, ret;
929 const char *name;
930 static const char group_names_propname[] = "gpio-ranges-group-names";
931 struct property *group_names;
932
933 if (!np)
934 return 0;
935
936 group_names = of_find_property(np, group_names_propname, NULL);
937
938 for (;; index++) {
939 ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
940 index, &pinspec);
941 if (ret)
942 break;
943
944 pctldev = of_pinctrl_get(pinspec.np);
945 of_node_put(pinspec.np);
946 if (!pctldev)
947 return -EPROBE_DEFER;
948
949 if (pinspec.args[2]) {
950 if (group_names) {
951 of_property_read_string_index(np,
952 group_names_propname,
953 index, &name);
954 if (strlen(name)) {
955 pr_err("%pOF: Group name of numeric GPIO ranges must be the empty string.\n",
956 np);
957 break;
958 }
959 }
960 /* npins != 0: linear range */
961 ret = gpiochip_add_pin_range(chip,
962 pinctrl_dev_get_devname(pctldev),
963 pinspec.args[0],
964 pinspec.args[1],
965 pinspec.args[2]);
966 if (ret)
967 return ret;
968 } else {
969 /* npins == 0: special range */
970 if (pinspec.args[1]) {
971 pr_err("%pOF: Illegal gpio-range format.\n",
972 np);
973 break;
974 }
975
976 if (!group_names) {
977 pr_err("%pOF: GPIO group range requested but no %s property.\n",
978 np, group_names_propname);
979 break;
980 }
981
982 ret = of_property_read_string_index(np,
983 group_names_propname,
984 index, &name);
985 if (ret)
986 break;
987
988 if (!strlen(name)) {
989 pr_err("%pOF: Group name of GPIO group range cannot be the empty string.\n",
990 np);
991 break;
992 }
993
994 ret = gpiochip_add_pingroup_range(chip, pctldev,
995 pinspec.args[0], name);
996 if (ret)
997 return ret;
998 }
999 }
1000
1001 return 0;
1002}
1003
1004#else
1005static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; }
1006#endif
1007
1008int of_gpiochip_add(struct gpio_chip *chip)
1009{
1010 int ret;
1011
1012 if (!chip->of_node)
1013 return 0;
1014
1015 if (!chip->of_xlate) {
1016 chip->of_gpio_n_cells = 2;
1017 chip->of_xlate = of_gpio_simple_xlate;
1018 }
1019
1020 if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS)
1021 return -EINVAL;
1022
1023 of_gpiochip_init_valid_mask(chip);
1024
1025 ret = of_gpiochip_add_pin_range(chip);
1026 if (ret)
1027 return ret;
1028
1029 /* If the chip defines names itself, these take precedence */
1030 if (!chip->names)
1031 devprop_gpiochip_set_names(chip,
1032 of_fwnode_handle(chip->of_node));
1033
1034 of_node_get(chip->of_node);
1035
1036 ret = of_gpiochip_scan_gpios(chip);
1037 if (ret)
1038 of_node_put(chip->of_node);
1039
1040 return ret;
1041}
1042
1043void of_gpiochip_remove(struct gpio_chip *chip)
1044{
1045 of_node_put(chip->of_node);
1046}