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 (of_device_is_compatible(np, "regulator-gpio") &&
90 !(strcmp(propname, "enable-gpio") &&
91 strcmp(propname, "enable-gpios"))))) {
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 if (IS_ENABLED(CONFIG_SPI_MASTER) &&
123 of_property_read_bool(np, "cs-gpios") &&
124 !strcmp(propname, "cs-gpios")) {
125 struct device_node *child;
129 for_each_child_of_node(np, child) {
130 ret = of_property_read_u32(child, "reg", &cs);
135 * SPI children have active low chip selects
136 * by default. This can be specified negatively
137 * by just omitting "spi-cs-high" in the
138 * device node, or actively by tagging on
139 * GPIO_ACTIVE_LOW as flag in the device
140 * tree. If the line is simultaneously
141 * tagged as active low in the device tree
142 * and has the "spi-cs-high" set, we get a
143 * conflict and the "spi-cs-high" flag will
146 if (of_property_read_bool(child, "spi-cs-high")) {
147 if (*flags & OF_GPIO_ACTIVE_LOW) {
148 pr_warn("%s GPIO handle specifies active low - ignored\n",
149 of_node_full_name(child));
150 *flags &= ~OF_GPIO_ACTIVE_LOW;
153 if (!(*flags & OF_GPIO_ACTIVE_LOW))
154 pr_info("%s enforce active low on chipselect handle\n",
155 of_node_full_name(child));
156 *flags |= OF_GPIO_ACTIVE_LOW;
165 * of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API
166 * @np: device node to get GPIO from
167 * @propname: property name containing gpio specifier(s)
168 * @index: index of the GPIO
169 * @flags: a flags pointer to fill in
171 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
172 * value on the error condition. If @flags is not NULL the function also fills
173 * in flags for the GPIO.
175 struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
176 const char *propname, int index, enum of_gpio_flags *flags)
178 struct of_phandle_args gpiospec;
179 struct gpio_chip *chip;
180 struct gpio_desc *desc;
183 ret = of_parse_phandle_with_args_map(np, propname, "gpio", index,
186 pr_debug("%s: can't parse '%s' property of node '%pOF[%d]'\n",
187 __func__, propname, np, index);
191 chip = of_find_gpiochip_by_xlate(&gpiospec);
193 desc = ERR_PTR(-EPROBE_DEFER);
197 desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, flags);
202 of_gpio_flags_quirks(np, propname, flags, index);
204 pr_debug("%s: parsed '%s' property of node '%pOF[%d]' - status (%d)\n",
205 __func__, propname, np, index,
206 PTR_ERR_OR_ZERO(desc));
209 of_node_put(gpiospec.np);
214 int of_get_named_gpio_flags(struct device_node *np, const char *list_name,
215 int index, enum of_gpio_flags *flags)
217 struct gpio_desc *desc;
219 desc = of_get_named_gpiod_flags(np, list_name, index, flags);
222 return PTR_ERR(desc);
224 return desc_to_gpio(desc);
226 EXPORT_SYMBOL(of_get_named_gpio_flags);
229 * The SPI GPIO bindings happened before we managed to establish that GPIO
230 * properties should be named "foo-gpios" so we have this special kludge for
233 static struct gpio_desc *of_find_spi_gpio(struct device *dev, const char *con_id,
234 enum of_gpio_flags *of_flags)
236 char prop_name[32]; /* 32 is max size of property name */
237 struct device_node *np = dev->of_node;
238 struct gpio_desc *desc;
241 * Hopefully the compiler stubs the rest of the function if this
244 if (!IS_ENABLED(CONFIG_SPI_MASTER))
245 return ERR_PTR(-ENOENT);
247 /* Allow this specifically for "spi-gpio" devices */
248 if (!of_device_is_compatible(np, "spi-gpio") || !con_id)
249 return ERR_PTR(-ENOENT);
251 /* Will be "gpio-sck", "gpio-mosi" or "gpio-miso" */
252 snprintf(prop_name, sizeof(prop_name), "%s-%s", "gpio", con_id);
254 desc = of_get_named_gpiod_flags(np, prop_name, 0, of_flags);
259 * Some regulator bindings happened before we managed to establish that GPIO
260 * properties should be named "foo-gpios" so we have this special kludge for
263 static struct gpio_desc *of_find_regulator_gpio(struct device *dev, const char *con_id,
264 enum of_gpio_flags *of_flags)
266 /* These are the connection IDs we accept as legacy GPIO phandles */
267 const char *whitelist[] = {
268 "wlf,ldoena", /* Arizona */
269 "wlf,ldo1ena", /* WM8994 */
270 "wlf,ldo2ena", /* WM8994 */
272 struct device_node *np = dev->of_node;
273 struct gpio_desc *desc;
276 if (!IS_ENABLED(CONFIG_REGULATOR))
277 return ERR_PTR(-ENOENT);
280 return ERR_PTR(-ENOENT);
282 i = match_string(whitelist, ARRAY_SIZE(whitelist), con_id);
284 return ERR_PTR(-ENOENT);
286 desc = of_get_named_gpiod_flags(np, con_id, 0, of_flags);
290 struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
292 enum gpio_lookup_flags *flags)
294 char prop_name[32]; /* 32 is max size of property name */
295 enum of_gpio_flags of_flags;
296 struct gpio_desc *desc;
299 /* Try GPIO property "foo-gpios" and "foo-gpio" */
300 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
302 snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
305 snprintf(prop_name, sizeof(prop_name), "%s",
308 desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
311 * -EPROBE_DEFER in our case means that we found a
312 * valid GPIO property, but no controller has been
315 * This means we don't need to look any further for
316 * alternate name conventions, and we should really
317 * preserve the return code for our user to be able to
318 * retry probing later.
320 if (IS_ERR(desc) && PTR_ERR(desc) == -EPROBE_DEFER)
323 if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
327 /* Special handling for SPI GPIOs if used */
329 desc = of_find_spi_gpio(dev, con_id, &of_flags);
331 /* Special handling for regulator GPIOs if used */
332 if (IS_ERR(desc) && PTR_ERR(desc) != -EPROBE_DEFER)
333 desc = of_find_regulator_gpio(dev, con_id, &of_flags);
338 if (of_flags & OF_GPIO_ACTIVE_LOW)
339 *flags |= GPIO_ACTIVE_LOW;
341 if (of_flags & OF_GPIO_SINGLE_ENDED) {
342 if (of_flags & OF_GPIO_OPEN_DRAIN)
343 *flags |= GPIO_OPEN_DRAIN;
345 *flags |= GPIO_OPEN_SOURCE;
348 if (of_flags & OF_GPIO_TRANSITORY)
349 *flags |= GPIO_TRANSITORY;
351 if (of_flags & OF_GPIO_PULL_UP)
352 *flags |= GPIO_PULL_UP;
353 if (of_flags & OF_GPIO_PULL_DOWN)
354 *flags |= GPIO_PULL_DOWN;
360 * of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API
361 * @np: device node to get GPIO from
362 * @chip: GPIO chip whose hog is parsed
363 * @idx: Index of the GPIO to parse
364 * @name: GPIO line name
365 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
366 * of_parse_own_gpio()
367 * @dflags: gpiod_flags - optional GPIO initialization flags
369 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
370 * value on the error condition.
372 static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
373 struct gpio_chip *chip,
374 unsigned int idx, const char **name,
375 enum gpio_lookup_flags *lflags,
376 enum gpiod_flags *dflags)
378 struct device_node *chip_np;
379 enum of_gpio_flags xlate_flags;
380 struct of_phandle_args gpiospec;
381 struct gpio_desc *desc;
386 chip_np = chip->of_node;
388 return ERR_PTR(-EINVAL);
394 ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp);
398 gpiospec.np = chip_np;
399 gpiospec.args_count = tmp;
401 for (i = 0; i < tmp; i++) {
402 ret = of_property_read_u32_index(np, "gpios", idx * tmp + i,
408 desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, &xlate_flags);
412 if (xlate_flags & OF_GPIO_ACTIVE_LOW)
413 *lflags |= GPIO_ACTIVE_LOW;
414 if (xlate_flags & OF_GPIO_TRANSITORY)
415 *lflags |= GPIO_TRANSITORY;
417 if (of_property_read_bool(np, "input"))
419 else if (of_property_read_bool(np, "output-low"))
420 *dflags |= GPIOD_OUT_LOW;
421 else if (of_property_read_bool(np, "output-high"))
422 *dflags |= GPIOD_OUT_HIGH;
424 pr_warn("GPIO line %d (%pOFn): no hogging state specified, bailing out\n",
425 desc_to_gpio(desc), np);
426 return ERR_PTR(-EINVAL);
429 if (name && of_property_read_string(np, "line-name", name))
436 * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions
437 * @chip: gpio chip to act on
439 * This is only used by of_gpiochip_add to request/set GPIO initial
441 * It returns error if it fails otherwise 0 on success.
443 static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
445 struct gpio_desc *desc = NULL;
446 struct device_node *np;
448 enum gpio_lookup_flags lflags;
449 enum gpiod_flags dflags;
453 for_each_available_child_of_node(chip->of_node, np) {
454 if (!of_property_read_bool(np, "gpio-hog"))
458 desc = of_parse_own_gpio(np, chip, i, &name, &lflags,
463 ret = gpiod_hog(desc, name, lflags, dflags);
475 * of_gpio_simple_xlate - translate gpiospec to the GPIO number and flags
476 * @gc: pointer to the gpio_chip structure
477 * @gpiospec: GPIO specifier as found in the device tree
478 * @flags: a flags pointer to fill in
480 * This is simple translation function, suitable for the most 1:1 mapped
481 * GPIO chips. This function performs only one sanity check: whether GPIO
482 * is less than ngpios (that is specified in the gpio_chip).
484 int of_gpio_simple_xlate(struct gpio_chip *gc,
485 const struct of_phandle_args *gpiospec, u32 *flags)
488 * We're discouraging gpio_cells < 2, since that way you'll have to
489 * write your own xlate function (that will have to retrieve the GPIO
490 * number and the flags from a single gpio cell -- this is possible,
491 * but not recommended).
493 if (gc->of_gpio_n_cells < 2) {
498 if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
501 if (gpiospec->args[0] >= gc->ngpio)
505 *flags = gpiospec->args[1];
507 return gpiospec->args[0];
509 EXPORT_SYMBOL(of_gpio_simple_xlate);
512 * of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank)
513 * @np: device node of the GPIO chip
514 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure
515 * @data: driver data to store in the struct gpio_chip
517 * To use this function you should allocate and fill mm_gc with:
519 * 1) In the gpio_chip structure:
520 * - all the callbacks
522 * - of_xlate callback (optional)
524 * 3) In the of_mm_gpio_chip structure:
525 * - save_regs callback (optional)
527 * If succeeded, this function will map bank's memory and will
528 * do all necessary work for you. Then you'll able to use .regs
529 * to manage GPIOs from the callbacks.
531 int of_mm_gpiochip_add_data(struct device_node *np,
532 struct of_mm_gpio_chip *mm_gc,
536 struct gpio_chip *gc = &mm_gc->gc;
538 gc->label = kasprintf(GFP_KERNEL, "%pOF", np);
542 mm_gc->regs = of_iomap(np, 0);
548 if (mm_gc->save_regs)
549 mm_gc->save_regs(mm_gc);
551 mm_gc->gc.of_node = np;
553 ret = gpiochip_add_data(gc, data);
559 iounmap(mm_gc->regs);
563 pr_err("%pOF: GPIO chip registration failed with status %d\n", np, ret);
566 EXPORT_SYMBOL(of_mm_gpiochip_add_data);
569 * of_mm_gpiochip_remove - Remove memory mapped GPIO chip (bank)
570 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure
572 void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc)
574 struct gpio_chip *gc = &mm_gc->gc;
580 iounmap(mm_gc->regs);
583 EXPORT_SYMBOL(of_mm_gpiochip_remove);
585 static void of_gpiochip_init_valid_mask(struct gpio_chip *chip)
589 struct device_node *np = chip->of_node;
591 len = of_property_count_u32_elems(np, "gpio-reserved-ranges");
592 if (len < 0 || len % 2 != 0)
595 for (i = 0; i < len; i += 2) {
596 of_property_read_u32_index(np, "gpio-reserved-ranges",
598 of_property_read_u32_index(np, "gpio-reserved-ranges",
600 if (start >= chip->ngpio || start + count >= chip->ngpio)
603 bitmap_clear(chip->valid_mask, start, count);
607 #ifdef CONFIG_PINCTRL
608 static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
610 struct device_node *np = chip->of_node;
611 struct of_phandle_args pinspec;
612 struct pinctrl_dev *pctldev;
615 static const char group_names_propname[] = "gpio-ranges-group-names";
616 struct property *group_names;
621 group_names = of_find_property(np, group_names_propname, NULL);
624 ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
629 pctldev = of_pinctrl_get(pinspec.np);
630 of_node_put(pinspec.np);
632 return -EPROBE_DEFER;
634 if (pinspec.args[2]) {
636 of_property_read_string_index(np,
637 group_names_propname,
640 pr_err("%pOF: Group name of numeric GPIO ranges must be the empty string.\n",
645 /* npins != 0: linear range */
646 ret = gpiochip_add_pin_range(chip,
647 pinctrl_dev_get_devname(pctldev),
654 /* npins == 0: special range */
655 if (pinspec.args[1]) {
656 pr_err("%pOF: Illegal gpio-range format.\n",
662 pr_err("%pOF: GPIO group range requested but no %s property.\n",
663 np, group_names_propname);
667 ret = of_property_read_string_index(np,
668 group_names_propname,
674 pr_err("%pOF: Group name of GPIO group range cannot be the empty string.\n",
679 ret = gpiochip_add_pingroup_range(chip, pctldev,
680 pinspec.args[0], name);
690 static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; }
693 int of_gpiochip_add(struct gpio_chip *chip)
700 if (!chip->of_xlate) {
701 chip->of_gpio_n_cells = 2;
702 chip->of_xlate = of_gpio_simple_xlate;
705 if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS)
708 of_gpiochip_init_valid_mask(chip);
710 status = of_gpiochip_add_pin_range(chip);
714 /* If the chip defines names itself, these take precedence */
716 devprop_gpiochip_set_names(chip,
717 of_fwnode_handle(chip->of_node));
719 of_node_get(chip->of_node);
721 status = of_gpiochip_scan_gpios(chip);
723 of_node_put(chip->of_node);
724 gpiochip_remove_pin_ranges(chip);
730 void of_gpiochip_remove(struct gpio_chip *chip)
732 gpiochip_remove_pin_ranges(chip);
733 of_node_put(chip->of_node);