1 // SPDX-License-Identifier: GPL-2.0+
3 * OF helpers for the GPIO API
5 * Copyright (c) 2007-2008 MontaVista Software, Inc.
7 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
10 #include <linux/device.h>
11 #include <linux/err.h>
12 #include <linux/errno.h>
13 #include <linux/module.h>
15 #include <linux/gpio/consumer.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>
25 static int of_gpiochip_match_node_and_xlate(struct gpio_chip *chip, void *data)
27 struct of_phandle_args *gpiospec = data;
29 return chip->gpiodev->dev.of_node == gpiospec->np &&
31 chip->of_xlate(chip, gpiospec, NULL) >= 0;
34 static struct gpio_chip *of_find_gpiochip_by_xlate(
35 struct of_phandle_args *gpiospec)
37 return gpiochip_find(gpiospec, of_gpiochip_match_node_and_xlate);
40 static struct gpio_desc *of_xlate_and_get_gpiod_flags(struct gpio_chip *chip,
41 struct of_phandle_args *gpiospec,
42 enum of_gpio_flags *flags)
46 if (chip->of_gpio_n_cells != gpiospec->args_count)
47 return ERR_PTR(-EINVAL);
49 ret = chip->of_xlate(chip, gpiospec, flags);
53 return gpiochip_get_desc(chip, ret);
56 static void of_gpio_flags_quirks(struct device_node *np,
58 enum of_gpio_flags *flags,
62 * Handle MMC "cd-inverted" and "wp-inverted" semantics.
64 if (IS_ENABLED(CONFIG_MMC)) {
66 * Active low is the default according to the
67 * SDHCI specification and the device tree
68 * bindings. However the code in the current
69 * kernel was written such that the phandle
70 * flags were always respected, and "cd-inverted"
71 * would invert the flag from the device phandle.
73 if (!strcmp(propname, "cd-gpios")) {
74 if (of_property_read_bool(np, "cd-inverted"))
75 *flags ^= OF_GPIO_ACTIVE_LOW;
77 if (!strcmp(propname, "wp-gpios")) {
78 if (of_property_read_bool(np, "wp-inverted"))
79 *flags ^= OF_GPIO_ACTIVE_LOW;
83 * Some GPIO fixed regulator quirks.
84 * Note that active low is the default.
86 if (IS_ENABLED(CONFIG_REGULATOR) &&
87 (of_device_is_compatible(np, "regulator-fixed") ||
88 of_device_is_compatible(np, "reg-fixed-voltage") ||
89 (!(strcmp(propname, "enable-gpio") &&
90 strcmp(propname, "enable-gpios")) &&
91 of_device_is_compatible(np, "regulator-gpio")))) {
93 * The regulator GPIO handles are specified such that the
94 * presence or absence of "enable-active-high" solely controls
95 * the polarity of the GPIO line. Any phandle flags must
96 * be actively ignored.
98 if (*flags & OF_GPIO_ACTIVE_LOW) {
99 pr_warn("%s GPIO handle specifies active low - ignored\n",
100 of_node_full_name(np));
101 *flags &= ~OF_GPIO_ACTIVE_LOW;
103 if (!of_property_read_bool(np, "enable-active-high"))
104 *flags |= OF_GPIO_ACTIVE_LOW;
107 * Legacy open drain handling for fixed voltage regulators.
109 if (IS_ENABLED(CONFIG_REGULATOR) &&
110 of_device_is_compatible(np, "reg-fixed-voltage") &&
111 of_property_read_bool(np, "gpio-open-drain")) {
112 *flags |= (OF_GPIO_SINGLE_ENDED | OF_GPIO_OPEN_DRAIN);
113 pr_info("%s uses legacy open drain flag - update the DTS if you can\n",
114 of_node_full_name(np));
118 * Legacy handling of SPI active high chip select. If we have a
119 * property named "cs-gpios" we need to inspect the child node
120 * to determine if the flags should have inverted semantics.
122 * This does not apply to an SPI device named "spi-gpio", because
123 * these have traditionally obtained their own GPIOs by parsing
124 * the device tree directly and did not respect any "spi-cs-high"
125 * property on the SPI bus children.
127 if (IS_ENABLED(CONFIG_SPI_MASTER) &&
128 !strcmp(propname, "cs-gpios") &&
129 !of_device_is_compatible(np, "spi-gpio") &&
130 of_property_read_bool(np, "cs-gpios")) {
131 struct device_node *child;
135 for_each_child_of_node(np, child) {
136 ret = of_property_read_u32(child, "reg", &cs);
141 * SPI children have active low chip selects
142 * by default. This can be specified negatively
143 * by just omitting "spi-cs-high" in the
144 * device node, or actively by tagging on
145 * GPIO_ACTIVE_LOW as flag in the device
146 * tree. If the line is simultaneously
147 * tagged as active low in the device tree
148 * and has the "spi-cs-high" set, we get a
149 * conflict and the "spi-cs-high" flag will
152 if (of_property_read_bool(child, "spi-cs-high")) {
153 if (*flags & OF_GPIO_ACTIVE_LOW) {
154 pr_warn("%s GPIO handle specifies active low - ignored\n",
155 of_node_full_name(child));
156 *flags &= ~OF_GPIO_ACTIVE_LOW;
159 if (!(*flags & OF_GPIO_ACTIVE_LOW))
160 pr_info("%s enforce active low on chipselect handle\n",
161 of_node_full_name(child));
162 *flags |= OF_GPIO_ACTIVE_LOW;
171 * of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API
172 * @np: device node to get GPIO from
173 * @propname: property name containing gpio specifier(s)
174 * @index: index of the GPIO
175 * @flags: a flags pointer to fill in
177 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
178 * value on the error condition. If @flags is not NULL the function also fills
179 * in flags for the GPIO.
181 struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
182 const char *propname, int index, enum of_gpio_flags *flags)
184 struct of_phandle_args gpiospec;
185 struct gpio_chip *chip;
186 struct gpio_desc *desc;
189 ret = of_parse_phandle_with_args_map(np, propname, "gpio", index,
192 pr_debug("%s: can't parse '%s' property of node '%pOF[%d]'\n",
193 __func__, propname, np, index);
197 chip = of_find_gpiochip_by_xlate(&gpiospec);
199 desc = ERR_PTR(-EPROBE_DEFER);
203 desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, flags);
208 of_gpio_flags_quirks(np, propname, flags, index);
210 pr_debug("%s: parsed '%s' property of node '%pOF[%d]' - status (%d)\n",
211 __func__, propname, np, index,
212 PTR_ERR_OR_ZERO(desc));
215 of_node_put(gpiospec.np);
220 int of_get_named_gpio_flags(struct device_node *np, const char *list_name,
221 int index, enum of_gpio_flags *flags)
223 struct gpio_desc *desc;
225 desc = of_get_named_gpiod_flags(np, list_name, index, flags);
228 return PTR_ERR(desc);
230 return desc_to_gpio(desc);
232 EXPORT_SYMBOL(of_get_named_gpio_flags);
235 * The SPI GPIO bindings happened before we managed to establish that GPIO
236 * properties should be named "foo-gpios" so we have this special kludge for
239 static struct gpio_desc *of_find_spi_gpio(struct device *dev, const char *con_id,
240 enum of_gpio_flags *of_flags)
242 char prop_name[32]; /* 32 is max size of property name */
243 struct device_node *np = dev->of_node;
244 struct gpio_desc *desc;
247 * Hopefully the compiler stubs the rest of the function if this
250 if (!IS_ENABLED(CONFIG_SPI_MASTER))
251 return ERR_PTR(-ENOENT);
253 /* Allow this specifically for "spi-gpio" devices */
254 if (!of_device_is_compatible(np, "spi-gpio") || !con_id)
255 return ERR_PTR(-ENOENT);
257 /* Will be "gpio-sck", "gpio-mosi" or "gpio-miso" */
258 snprintf(prop_name, sizeof(prop_name), "%s-%s", "gpio", con_id);
260 desc = of_get_named_gpiod_flags(np, prop_name, 0, of_flags);
265 * Some regulator bindings happened before we managed to establish that GPIO
266 * properties should be named "foo-gpios" so we have this special kludge for
269 static struct gpio_desc *of_find_regulator_gpio(struct device *dev, const char *con_id,
270 enum of_gpio_flags *of_flags)
272 /* These are the connection IDs we accept as legacy GPIO phandles */
273 const char *whitelist[] = {
274 "wlf,ldoena", /* Arizona */
275 "wlf,ldo1ena", /* WM8994 */
276 "wlf,ldo2ena", /* WM8994 */
278 struct device_node *np = dev->of_node;
279 struct gpio_desc *desc;
282 if (!IS_ENABLED(CONFIG_REGULATOR))
283 return ERR_PTR(-ENOENT);
286 return ERR_PTR(-ENOENT);
288 i = match_string(whitelist, ARRAY_SIZE(whitelist), con_id);
290 return ERR_PTR(-ENOENT);
292 desc = of_get_named_gpiod_flags(np, con_id, 0, of_flags);
296 struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
297 unsigned int idx, unsigned long *flags)
299 char prop_name[32]; /* 32 is max size of property name */
300 enum of_gpio_flags of_flags;
301 struct gpio_desc *desc;
304 /* Try GPIO property "foo-gpios" and "foo-gpio" */
305 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
307 snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
310 snprintf(prop_name, sizeof(prop_name), "%s",
313 desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
316 * -EPROBE_DEFER in our case means that we found a
317 * valid GPIO property, but no controller has been
320 * This means we don't need to look any further for
321 * alternate name conventions, and we should really
322 * preserve the return code for our user to be able to
323 * retry probing later.
325 if (IS_ERR(desc) && PTR_ERR(desc) == -EPROBE_DEFER)
328 if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
332 /* Special handling for SPI GPIOs if used */
334 desc = of_find_spi_gpio(dev, con_id, &of_flags);
336 /* Special handling for regulator GPIOs if used */
337 if (IS_ERR(desc) && PTR_ERR(desc) != -EPROBE_DEFER)
338 desc = of_find_regulator_gpio(dev, con_id, &of_flags);
343 if (of_flags & OF_GPIO_ACTIVE_LOW)
344 *flags |= GPIO_ACTIVE_LOW;
346 if (of_flags & OF_GPIO_SINGLE_ENDED) {
347 if (of_flags & OF_GPIO_OPEN_DRAIN)
348 *flags |= GPIO_OPEN_DRAIN;
350 *flags |= GPIO_OPEN_SOURCE;
353 if (of_flags & OF_GPIO_TRANSITORY)
354 *flags |= GPIO_TRANSITORY;
356 if (of_flags & OF_GPIO_PULL_UP)
357 *flags |= GPIO_PULL_UP;
358 if (of_flags & OF_GPIO_PULL_DOWN)
359 *flags |= GPIO_PULL_DOWN;
365 * of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API
366 * @np: device node to get GPIO from
367 * @chip: GPIO chip whose hog is parsed
368 * @idx: Index of the GPIO to parse
369 * @name: GPIO line name
370 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
371 * of_find_gpio() or of_parse_own_gpio()
372 * @dflags: gpiod_flags - optional GPIO initialization flags
374 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
375 * value on the error condition.
377 static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
378 struct gpio_chip *chip,
379 unsigned int idx, const char **name,
380 unsigned long *lflags,
381 enum gpiod_flags *dflags)
383 struct device_node *chip_np;
384 enum of_gpio_flags xlate_flags;
385 struct of_phandle_args gpiospec;
386 struct gpio_desc *desc;
391 chip_np = chip->of_node;
393 return ERR_PTR(-EINVAL);
396 *lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
399 ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp);
403 gpiospec.np = chip_np;
404 gpiospec.args_count = tmp;
406 for (i = 0; i < tmp; i++) {
407 ret = of_property_read_u32_index(np, "gpios", idx * tmp + i,
413 desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, &xlate_flags);
417 if (xlate_flags & OF_GPIO_ACTIVE_LOW)
418 *lflags |= GPIO_ACTIVE_LOW;
419 if (xlate_flags & OF_GPIO_TRANSITORY)
420 *lflags |= GPIO_TRANSITORY;
422 if (of_property_read_bool(np, "input"))
424 else if (of_property_read_bool(np, "output-low"))
425 *dflags |= GPIOD_OUT_LOW;
426 else if (of_property_read_bool(np, "output-high"))
427 *dflags |= GPIOD_OUT_HIGH;
429 pr_warn("GPIO line %d (%pOFn): no hogging state specified, bailing out\n",
430 desc_to_gpio(desc), np);
431 return ERR_PTR(-EINVAL);
434 if (name && of_property_read_string(np, "line-name", name))
441 * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions
442 * @chip: gpio chip to act on
444 * This is only used by of_gpiochip_add to request/set GPIO initial
446 * It returns error if it fails otherwise 0 on success.
448 static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
450 struct gpio_desc *desc = NULL;
451 struct device_node *np;
453 unsigned long lflags;
454 enum gpiod_flags dflags;
458 for_each_available_child_of_node(chip->of_node, np) {
459 if (!of_property_read_bool(np, "gpio-hog"))
463 desc = of_parse_own_gpio(np, chip, i, &name, &lflags,
468 ret = gpiod_hog(desc, name, lflags, dflags);
480 * of_gpio_simple_xlate - translate gpiospec to the GPIO number and flags
481 * @gc: pointer to the gpio_chip structure
482 * @gpiospec: GPIO specifier as found in the device tree
483 * @flags: a flags pointer to fill in
485 * This is simple translation function, suitable for the most 1:1 mapped
486 * GPIO chips. This function performs only one sanity check: whether GPIO
487 * is less than ngpios (that is specified in the gpio_chip).
489 int of_gpio_simple_xlate(struct gpio_chip *gc,
490 const struct of_phandle_args *gpiospec, u32 *flags)
493 * We're discouraging gpio_cells < 2, since that way you'll have to
494 * write your own xlate function (that will have to retrieve the GPIO
495 * number and the flags from a single gpio cell -- this is possible,
496 * but not recommended).
498 if (gc->of_gpio_n_cells < 2) {
503 if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
506 if (gpiospec->args[0] >= gc->ngpio)
510 *flags = gpiospec->args[1];
512 return gpiospec->args[0];
514 EXPORT_SYMBOL(of_gpio_simple_xlate);
517 * of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank)
518 * @np: device node of the GPIO chip
519 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure
520 * @data: driver data to store in the struct gpio_chip
522 * To use this function you should allocate and fill mm_gc with:
524 * 1) In the gpio_chip structure:
525 * - all the callbacks
527 * - of_xlate callback (optional)
529 * 3) In the of_mm_gpio_chip structure:
530 * - save_regs callback (optional)
532 * If succeeded, this function will map bank's memory and will
533 * do all necessary work for you. Then you'll able to use .regs
534 * to manage GPIOs from the callbacks.
536 int of_mm_gpiochip_add_data(struct device_node *np,
537 struct of_mm_gpio_chip *mm_gc,
541 struct gpio_chip *gc = &mm_gc->gc;
543 gc->label = kasprintf(GFP_KERNEL, "%pOF", np);
547 mm_gc->regs = of_iomap(np, 0);
553 if (mm_gc->save_regs)
554 mm_gc->save_regs(mm_gc);
556 mm_gc->gc.of_node = np;
558 ret = gpiochip_add_data(gc, data);
564 iounmap(mm_gc->regs);
568 pr_err("%pOF: GPIO chip registration failed with status %d\n", np, ret);
571 EXPORT_SYMBOL(of_mm_gpiochip_add_data);
574 * of_mm_gpiochip_remove - Remove memory mapped GPIO chip (bank)
575 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure
577 void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc)
579 struct gpio_chip *gc = &mm_gc->gc;
585 iounmap(mm_gc->regs);
588 EXPORT_SYMBOL(of_mm_gpiochip_remove);
590 static void of_gpiochip_init_valid_mask(struct gpio_chip *chip)
594 struct device_node *np = chip->of_node;
596 len = of_property_count_u32_elems(np, "gpio-reserved-ranges");
597 if (len < 0 || len % 2 != 0)
600 for (i = 0; i < len; i += 2) {
601 of_property_read_u32_index(np, "gpio-reserved-ranges",
603 of_property_read_u32_index(np, "gpio-reserved-ranges",
605 if (start >= chip->ngpio || start + count >= chip->ngpio)
608 bitmap_clear(chip->valid_mask, start, count);
612 #ifdef CONFIG_PINCTRL
613 static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
615 struct device_node *np = chip->of_node;
616 struct of_phandle_args pinspec;
617 struct pinctrl_dev *pctldev;
620 static const char group_names_propname[] = "gpio-ranges-group-names";
621 struct property *group_names;
626 group_names = of_find_property(np, group_names_propname, NULL);
629 ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
634 pctldev = of_pinctrl_get(pinspec.np);
635 of_node_put(pinspec.np);
637 return -EPROBE_DEFER;
639 if (pinspec.args[2]) {
641 of_property_read_string_index(np,
642 group_names_propname,
645 pr_err("%pOF: Group name of numeric GPIO ranges must be the empty string.\n",
650 /* npins != 0: linear range */
651 ret = gpiochip_add_pin_range(chip,
652 pinctrl_dev_get_devname(pctldev),
659 /* npins == 0: special range */
660 if (pinspec.args[1]) {
661 pr_err("%pOF: Illegal gpio-range format.\n",
667 pr_err("%pOF: GPIO group range requested but no %s property.\n",
668 np, group_names_propname);
672 ret = of_property_read_string_index(np,
673 group_names_propname,
679 pr_err("%pOF: Group name of GPIO group range cannot be the empty string.\n",
684 ret = gpiochip_add_pingroup_range(chip, pctldev,
685 pinspec.args[0], name);
695 static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; }
698 int of_gpiochip_add(struct gpio_chip *chip)
705 if (!chip->of_xlate) {
706 chip->of_gpio_n_cells = 2;
707 chip->of_xlate = of_gpio_simple_xlate;
710 if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS)
713 of_gpiochip_init_valid_mask(chip);
715 status = of_gpiochip_add_pin_range(chip);
719 /* If the chip defines names itself, these take precedence */
721 devprop_gpiochip_set_names(chip,
722 of_fwnode_handle(chip->of_node));
724 of_node_get(chip->of_node);
726 status = of_gpiochip_scan_gpios(chip);
728 of_node_put(chip->of_node);
729 gpiochip_remove_pin_ranges(chip);
735 void of_gpiochip_remove(struct gpio_chip *chip)
737 gpiochip_remove_pin_ranges(chip);
738 of_node_put(chip->of_node);