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