2 * OF helpers for the GPIO API
4 * Copyright (c) 2007-2008 MontaVista Software, Inc.
6 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
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.
14 #include <linux/device.h>
15 #include <linux/err.h>
16 #include <linux/errno.h>
17 #include <linux/module.h>
19 #include <linux/gpio/consumer.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>
29 static int of_gpiochip_match_node_and_xlate(struct gpio_chip *chip, void *data)
31 struct of_phandle_args *gpiospec = data;
33 return chip->gpiodev->dev.of_node == gpiospec->np &&
34 chip->of_xlate(chip, gpiospec, NULL) >= 0;
37 static struct gpio_chip *of_find_gpiochip_by_xlate(
38 struct of_phandle_args *gpiospec)
40 return gpiochip_find(gpiospec, of_gpiochip_match_node_and_xlate);
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)
49 if (chip->of_gpio_n_cells != gpiospec->args_count)
50 return ERR_PTR(-EINVAL);
52 ret = chip->of_xlate(chip, gpiospec, flags);
56 return gpiochip_get_desc(chip, ret);
59 static void of_gpio_flags_quirks(struct device_node *np,
60 enum of_gpio_flags *flags)
63 * Some GPIO fixed regulator quirks.
64 * Note that active low is the default.
66 if (IS_ENABLED(CONFIG_REGULATOR) &&
67 (of_device_is_compatible(np, "reg-fixed-voltage") ||
68 of_device_is_compatible(np, "regulator-gpio"))) {
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.
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;
80 if (!of_property_read_bool(np, "enable-active-high"))
81 *flags |= OF_GPIO_ACTIVE_LOW;
84 * Legacy open drain handling for fixed voltage regulators.
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));
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
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.
106 struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
107 const char *propname, int index, enum of_gpio_flags *flags)
109 struct of_phandle_args gpiospec;
110 struct gpio_chip *chip;
111 struct gpio_desc *desc;
114 ret = of_parse_phandle_with_args_map(np, propname, "gpio", index,
117 pr_debug("%s: can't parse '%s' property of node '%pOF[%d]'\n",
118 __func__, propname, np, index);
122 chip = of_find_gpiochip_by_xlate(&gpiospec);
124 desc = ERR_PTR(-EPROBE_DEFER);
128 desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, flags);
133 of_gpio_flags_quirks(np, flags);
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));
140 of_node_put(gpiospec.np);
145 int of_get_named_gpio_flags(struct device_node *np, const char *list_name,
146 int index, enum of_gpio_flags *flags)
148 struct gpio_desc *desc;
150 desc = of_get_named_gpiod_flags(np, list_name, index, flags);
153 return PTR_ERR(desc);
155 return desc_to_gpio(desc);
157 EXPORT_SYMBOL(of_get_named_gpio_flags);
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
164 static struct gpio_desc *of_find_spi_gpio(struct device *dev, const char *con_id,
165 enum of_gpio_flags *of_flags)
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;
172 * Hopefully the compiler stubs the rest of the function if this
175 if (!IS_ENABLED(CONFIG_SPI_MASTER))
176 return ERR_PTR(-ENOENT);
178 /* Allow this specifically for "spi-gpio" devices */
179 if (!of_device_is_compatible(np, "spi-gpio") || !con_id)
180 return ERR_PTR(-ENOENT);
182 /* Will be "gpio-sck", "gpio-mosi" or "gpio-miso" */
183 snprintf(prop_name, sizeof(prop_name), "%s-%s", "gpio", con_id);
185 desc = of_get_named_gpiod_flags(np, prop_name, 0, of_flags);
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
194 static struct gpio_desc *of_find_regulator_gpio(struct device *dev, const char *con_id,
195 enum of_gpio_flags *of_flags)
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 */
203 struct device_node *np = dev->of_node;
204 struct gpio_desc *desc;
207 if (!IS_ENABLED(CONFIG_REGULATOR))
208 return ERR_PTR(-ENOENT);
211 return ERR_PTR(-ENOENT);
213 i = match_string(whitelist, ARRAY_SIZE(whitelist), con_id);
215 return ERR_PTR(-ENOENT);
217 desc = of_get_named_gpiod_flags(np, con_id, 0, of_flags);
221 struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
223 enum gpio_lookup_flags *flags)
225 char prop_name[32]; /* 32 is max size of property name */
226 enum of_gpio_flags of_flags;
227 struct gpio_desc *desc;
230 /* Try GPIO property "foo-gpios" and "foo-gpio" */
231 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
233 snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
236 snprintf(prop_name, sizeof(prop_name), "%s",
239 desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
242 * -EPROBE_DEFER in our case means that we found a
243 * valid GPIO property, but no controller has been
246 * This means we don't need to look any further for
247 * alternate name conventions, and we should really
248 * preserve the return code for our user to be able to
249 * retry probing later.
251 if (IS_ERR(desc) && PTR_ERR(desc) == -EPROBE_DEFER)
254 if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
258 /* Special handling for SPI GPIOs if used */
260 desc = of_find_spi_gpio(dev, con_id, &of_flags);
262 /* Special handling for regulator GPIOs if used */
263 if (IS_ERR(desc) && PTR_ERR(desc) != -EPROBE_DEFER)
264 desc = of_find_regulator_gpio(dev, con_id, &of_flags);
269 if (of_flags & OF_GPIO_ACTIVE_LOW)
270 *flags |= GPIO_ACTIVE_LOW;
272 if (of_flags & OF_GPIO_SINGLE_ENDED) {
273 if (of_flags & OF_GPIO_OPEN_DRAIN)
274 *flags |= GPIO_OPEN_DRAIN;
276 *flags |= GPIO_OPEN_SOURCE;
279 if (of_flags & OF_GPIO_TRANSITORY)
280 *flags |= GPIO_TRANSITORY;
286 * of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API
287 * @np: device node to get GPIO from
288 * @chip: GPIO chip whose hog is parsed
289 * @idx: Index of the GPIO to parse
290 * @name: GPIO line name
291 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
292 * of_parse_own_gpio()
293 * @dflags: gpiod_flags - optional GPIO initialization flags
295 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
296 * value on the error condition.
298 static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
299 struct gpio_chip *chip,
300 unsigned int idx, const char **name,
301 enum gpio_lookup_flags *lflags,
302 enum gpiod_flags *dflags)
304 struct device_node *chip_np;
305 enum of_gpio_flags xlate_flags;
306 struct of_phandle_args gpiospec;
307 struct gpio_desc *desc;
312 chip_np = chip->of_node;
314 return ERR_PTR(-EINVAL);
320 ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp);
324 gpiospec.np = chip_np;
325 gpiospec.args_count = tmp;
327 for (i = 0; i < tmp; i++) {
328 ret = of_property_read_u32_index(np, "gpios", idx * tmp + i,
334 desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, &xlate_flags);
338 if (xlate_flags & OF_GPIO_ACTIVE_LOW)
339 *lflags |= GPIO_ACTIVE_LOW;
340 if (xlate_flags & OF_GPIO_TRANSITORY)
341 *lflags |= GPIO_TRANSITORY;
343 if (of_property_read_bool(np, "input"))
345 else if (of_property_read_bool(np, "output-low"))
346 *dflags |= GPIOD_OUT_LOW;
347 else if (of_property_read_bool(np, "output-high"))
348 *dflags |= GPIOD_OUT_HIGH;
350 pr_warn("GPIO line %d (%s): no hogging state specified, bailing out\n",
351 desc_to_gpio(desc), np->name);
352 return ERR_PTR(-EINVAL);
355 if (name && of_property_read_string(np, "line-name", name))
362 * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions
363 * @chip: gpio chip to act on
365 * This is only used by of_gpiochip_add to request/set GPIO initial
367 * It returns error if it fails otherwise 0 on success.
369 static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
371 struct gpio_desc *desc = NULL;
372 struct device_node *np;
374 enum gpio_lookup_flags lflags;
375 enum gpiod_flags dflags;
379 for_each_available_child_of_node(chip->of_node, np) {
380 if (!of_property_read_bool(np, "gpio-hog"))
384 desc = of_parse_own_gpio(np, chip, i, &name, &lflags,
389 ret = gpiod_hog(desc, name, lflags, dflags);
401 * of_gpio_simple_xlate - translate gpiospec to the GPIO number and flags
402 * @gc: pointer to the gpio_chip structure
403 * @gpiospec: GPIO specifier as found in the device tree
404 * @flags: a flags pointer to fill in
406 * This is simple translation function, suitable for the most 1:1 mapped
407 * GPIO chips. This function performs only one sanity check: whether GPIO
408 * is less than ngpios (that is specified in the gpio_chip).
410 int of_gpio_simple_xlate(struct gpio_chip *gc,
411 const struct of_phandle_args *gpiospec, u32 *flags)
414 * We're discouraging gpio_cells < 2, since that way you'll have to
415 * write your own xlate function (that will have to retrieve the GPIO
416 * number and the flags from a single gpio cell -- this is possible,
417 * but not recommended).
419 if (gc->of_gpio_n_cells < 2) {
424 if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
427 if (gpiospec->args[0] >= gc->ngpio)
431 *flags = gpiospec->args[1];
433 return gpiospec->args[0];
435 EXPORT_SYMBOL(of_gpio_simple_xlate);
438 * of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank)
439 * @np: device node of the GPIO chip
440 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure
441 * @data: driver data to store in the struct gpio_chip
443 * To use this function you should allocate and fill mm_gc with:
445 * 1) In the gpio_chip structure:
446 * - all the callbacks
448 * - of_xlate callback (optional)
450 * 3) In the of_mm_gpio_chip structure:
451 * - save_regs callback (optional)
453 * If succeeded, this function will map bank's memory and will
454 * do all necessary work for you. Then you'll able to use .regs
455 * to manage GPIOs from the callbacks.
457 int of_mm_gpiochip_add_data(struct device_node *np,
458 struct of_mm_gpio_chip *mm_gc,
462 struct gpio_chip *gc = &mm_gc->gc;
464 gc->label = kasprintf(GFP_KERNEL, "%pOF", np);
468 mm_gc->regs = of_iomap(np, 0);
474 if (mm_gc->save_regs)
475 mm_gc->save_regs(mm_gc);
477 mm_gc->gc.of_node = np;
479 ret = gpiochip_add_data(gc, data);
485 iounmap(mm_gc->regs);
489 pr_err("%pOF: GPIO chip registration failed with status %d\n", np, ret);
492 EXPORT_SYMBOL(of_mm_gpiochip_add_data);
495 * of_mm_gpiochip_remove - Remove memory mapped GPIO chip (bank)
496 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure
498 void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc)
500 struct gpio_chip *gc = &mm_gc->gc;
506 iounmap(mm_gc->regs);
509 EXPORT_SYMBOL(of_mm_gpiochip_remove);
511 static void of_gpiochip_init_valid_mask(struct gpio_chip *chip)
515 struct device_node *np = chip->of_node;
517 len = of_property_count_u32_elems(np, "gpio-reserved-ranges");
518 if (len < 0 || len % 2 != 0)
521 for (i = 0; i < len; i += 2) {
522 of_property_read_u32_index(np, "gpio-reserved-ranges",
524 of_property_read_u32_index(np, "gpio-reserved-ranges",
526 if (start >= chip->ngpio || start + count >= chip->ngpio)
529 bitmap_clear(chip->valid_mask, start, count);
533 #ifdef CONFIG_PINCTRL
534 static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
536 struct device_node *np = chip->of_node;
537 struct of_phandle_args pinspec;
538 struct pinctrl_dev *pctldev;
541 static const char group_names_propname[] = "gpio-ranges-group-names";
542 struct property *group_names;
547 group_names = of_find_property(np, group_names_propname, NULL);
550 ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
555 pctldev = of_pinctrl_get(pinspec.np);
556 of_node_put(pinspec.np);
558 return -EPROBE_DEFER;
560 if (pinspec.args[2]) {
562 of_property_read_string_index(np,
563 group_names_propname,
566 pr_err("%pOF: Group name of numeric GPIO ranges must be the empty string.\n",
571 /* npins != 0: linear range */
572 ret = gpiochip_add_pin_range(chip,
573 pinctrl_dev_get_devname(pctldev),
580 /* npins == 0: special range */
581 if (pinspec.args[1]) {
582 pr_err("%pOF: Illegal gpio-range format.\n",
588 pr_err("%pOF: GPIO group range requested but no %s property.\n",
589 np, group_names_propname);
593 ret = of_property_read_string_index(np,
594 group_names_propname,
600 pr_err("%pOF: Group name of GPIO group range cannot be the empty string.\n",
605 ret = gpiochip_add_pingroup_range(chip, pctldev,
606 pinspec.args[0], name);
616 static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; }
619 int of_gpiochip_add(struct gpio_chip *chip)
623 if ((!chip->of_node) && (chip->parent))
624 chip->of_node = chip->parent->of_node;
629 if (!chip->of_xlate) {
630 chip->of_gpio_n_cells = 2;
631 chip->of_xlate = of_gpio_simple_xlate;
634 if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS)
637 of_gpiochip_init_valid_mask(chip);
639 status = of_gpiochip_add_pin_range(chip);
643 /* If the chip defines names itself, these take precedence */
645 devprop_gpiochip_set_names(chip,
646 of_fwnode_handle(chip->of_node));
648 of_node_get(chip->of_node);
650 return of_gpiochip_scan_gpios(chip);
653 void of_gpiochip_remove(struct gpio_chip *chip)
655 gpiochip_remove_pin_ranges(chip);
656 of_node_put(chip->of_node);