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, "regulator-fixed") ||
68 of_device_is_compatible(np, "reg-fixed-voltage") ||
69 of_device_is_compatible(np, "regulator-gpio"))) {
71 * The regulator GPIO handles are specified such that the
72 * presence or absence of "enable-active-high" solely controls
73 * the polarity of the GPIO line. Any phandle flags must
74 * be actively ignored.
76 if (*flags & OF_GPIO_ACTIVE_LOW) {
77 pr_warn("%s GPIO handle specifies active low - ignored\n",
78 of_node_full_name(np));
79 *flags &= ~OF_GPIO_ACTIVE_LOW;
81 if (!of_property_read_bool(np, "enable-active-high"))
82 *flags |= OF_GPIO_ACTIVE_LOW;
85 * Legacy open drain handling for fixed voltage regulators.
87 if (IS_ENABLED(CONFIG_REGULATOR) &&
88 of_device_is_compatible(np, "reg-fixed-voltage") &&
89 of_property_read_bool(np, "gpio-open-drain")) {
90 *flags |= (OF_GPIO_SINGLE_ENDED | OF_GPIO_OPEN_DRAIN);
91 pr_info("%s uses legacy open drain flag - update the DTS if you can\n",
92 of_node_full_name(np));
97 * of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API
98 * @np: device node to get GPIO from
99 * @propname: property name containing gpio specifier(s)
100 * @index: index of the GPIO
101 * @flags: a flags pointer to fill in
103 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
104 * value on the error condition. If @flags is not NULL the function also fills
105 * in flags for the GPIO.
107 struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
108 const char *propname, int index, enum of_gpio_flags *flags)
110 struct of_phandle_args gpiospec;
111 struct gpio_chip *chip;
112 struct gpio_desc *desc;
115 ret = of_parse_phandle_with_args_map(np, propname, "gpio", index,
118 pr_debug("%s: can't parse '%s' property of node '%pOF[%d]'\n",
119 __func__, propname, np, index);
123 chip = of_find_gpiochip_by_xlate(&gpiospec);
125 desc = ERR_PTR(-EPROBE_DEFER);
129 desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, flags);
134 of_gpio_flags_quirks(np, flags);
136 pr_debug("%s: parsed '%s' property of node '%pOF[%d]' - status (%d)\n",
137 __func__, propname, np, index,
138 PTR_ERR_OR_ZERO(desc));
141 of_node_put(gpiospec.np);
146 int of_get_named_gpio_flags(struct device_node *np, const char *list_name,
147 int index, enum of_gpio_flags *flags)
149 struct gpio_desc *desc;
151 desc = of_get_named_gpiod_flags(np, list_name, index, flags);
154 return PTR_ERR(desc);
156 return desc_to_gpio(desc);
158 EXPORT_SYMBOL(of_get_named_gpio_flags);
161 * The SPI GPIO bindings happened before we managed to establish that GPIO
162 * properties should be named "foo-gpios" so we have this special kludge for
165 static struct gpio_desc *of_find_spi_gpio(struct device *dev, const char *con_id,
166 enum of_gpio_flags *of_flags)
168 char prop_name[32]; /* 32 is max size of property name */
169 struct device_node *np = dev->of_node;
170 struct gpio_desc *desc;
173 * Hopefully the compiler stubs the rest of the function if this
176 if (!IS_ENABLED(CONFIG_SPI_MASTER))
177 return ERR_PTR(-ENOENT);
179 /* Allow this specifically for "spi-gpio" devices */
180 if (!of_device_is_compatible(np, "spi-gpio") || !con_id)
181 return ERR_PTR(-ENOENT);
183 /* Will be "gpio-sck", "gpio-mosi" or "gpio-miso" */
184 snprintf(prop_name, sizeof(prop_name), "%s-%s", "gpio", con_id);
186 desc = of_get_named_gpiod_flags(np, prop_name, 0, of_flags);
191 * Some regulator bindings happened before we managed to establish that GPIO
192 * properties should be named "foo-gpios" so we have this special kludge for
195 static struct gpio_desc *of_find_regulator_gpio(struct device *dev, const char *con_id,
196 enum of_gpio_flags *of_flags)
198 /* These are the connection IDs we accept as legacy GPIO phandles */
199 const char *whitelist[] = {
200 "wlf,ldoena", /* Arizona */
201 "wlf,ldo1ena", /* WM8994 */
202 "wlf,ldo2ena", /* WM8994 */
204 struct device_node *np = dev->of_node;
205 struct gpio_desc *desc;
208 if (!IS_ENABLED(CONFIG_REGULATOR))
209 return ERR_PTR(-ENOENT);
212 return ERR_PTR(-ENOENT);
214 i = match_string(whitelist, ARRAY_SIZE(whitelist), con_id);
216 return ERR_PTR(-ENOENT);
218 desc = of_get_named_gpiod_flags(np, con_id, 0, of_flags);
222 struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
224 enum gpio_lookup_flags *flags)
226 char prop_name[32]; /* 32 is max size of property name */
227 enum of_gpio_flags of_flags;
228 struct gpio_desc *desc;
231 /* Try GPIO property "foo-gpios" and "foo-gpio" */
232 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
234 snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
237 snprintf(prop_name, sizeof(prop_name), "%s",
240 desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
243 * -EPROBE_DEFER in our case means that we found a
244 * valid GPIO property, but no controller has been
247 * This means we don't need to look any further for
248 * alternate name conventions, and we should really
249 * preserve the return code for our user to be able to
250 * retry probing later.
252 if (IS_ERR(desc) && PTR_ERR(desc) == -EPROBE_DEFER)
255 if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
259 /* Special handling for SPI GPIOs if used */
261 desc = of_find_spi_gpio(dev, con_id, &of_flags);
263 /* Special handling for regulator GPIOs if used */
264 if (IS_ERR(desc) && PTR_ERR(desc) != -EPROBE_DEFER)
265 desc = of_find_regulator_gpio(dev, con_id, &of_flags);
270 if (of_flags & OF_GPIO_ACTIVE_LOW)
271 *flags |= GPIO_ACTIVE_LOW;
273 if (of_flags & OF_GPIO_SINGLE_ENDED) {
274 if (of_flags & OF_GPIO_OPEN_DRAIN)
275 *flags |= GPIO_OPEN_DRAIN;
277 *flags |= GPIO_OPEN_SOURCE;
280 if (of_flags & OF_GPIO_TRANSITORY)
281 *flags |= GPIO_TRANSITORY;
287 * of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API
288 * @np: device node to get GPIO from
289 * @chip: GPIO chip whose hog is parsed
290 * @idx: Index of the GPIO to parse
291 * @name: GPIO line name
292 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
293 * of_parse_own_gpio()
294 * @dflags: gpiod_flags - optional GPIO initialization flags
296 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
297 * value on the error condition.
299 static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
300 struct gpio_chip *chip,
301 unsigned int idx, const char **name,
302 enum gpio_lookup_flags *lflags,
303 enum gpiod_flags *dflags)
305 struct device_node *chip_np;
306 enum of_gpio_flags xlate_flags;
307 struct of_phandle_args gpiospec;
308 struct gpio_desc *desc;
313 chip_np = chip->of_node;
315 return ERR_PTR(-EINVAL);
321 ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp);
325 gpiospec.np = chip_np;
326 gpiospec.args_count = tmp;
328 for (i = 0; i < tmp; i++) {
329 ret = of_property_read_u32_index(np, "gpios", idx * tmp + i,
335 desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, &xlate_flags);
339 if (xlate_flags & OF_GPIO_ACTIVE_LOW)
340 *lflags |= GPIO_ACTIVE_LOW;
341 if (xlate_flags & OF_GPIO_TRANSITORY)
342 *lflags |= GPIO_TRANSITORY;
344 if (of_property_read_bool(np, "input"))
346 else if (of_property_read_bool(np, "output-low"))
347 *dflags |= GPIOD_OUT_LOW;
348 else if (of_property_read_bool(np, "output-high"))
349 *dflags |= GPIOD_OUT_HIGH;
351 pr_warn("GPIO line %d (%s): no hogging state specified, bailing out\n",
352 desc_to_gpio(desc), np->name);
353 return ERR_PTR(-EINVAL);
356 if (name && of_property_read_string(np, "line-name", name))
363 * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions
364 * @chip: gpio chip to act on
366 * This is only used by of_gpiochip_add to request/set GPIO initial
368 * It returns error if it fails otherwise 0 on success.
370 static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
372 struct gpio_desc *desc = NULL;
373 struct device_node *np;
375 enum gpio_lookup_flags lflags;
376 enum gpiod_flags dflags;
380 for_each_available_child_of_node(chip->of_node, np) {
381 if (!of_property_read_bool(np, "gpio-hog"))
385 desc = of_parse_own_gpio(np, chip, i, &name, &lflags,
390 ret = gpiod_hog(desc, name, lflags, dflags);
402 * of_gpio_simple_xlate - translate gpiospec to the GPIO number and flags
403 * @gc: pointer to the gpio_chip structure
404 * @gpiospec: GPIO specifier as found in the device tree
405 * @flags: a flags pointer to fill in
407 * This is simple translation function, suitable for the most 1:1 mapped
408 * GPIO chips. This function performs only one sanity check: whether GPIO
409 * is less than ngpios (that is specified in the gpio_chip).
411 int of_gpio_simple_xlate(struct gpio_chip *gc,
412 const struct of_phandle_args *gpiospec, u32 *flags)
415 * We're discouraging gpio_cells < 2, since that way you'll have to
416 * write your own xlate function (that will have to retrieve the GPIO
417 * number and the flags from a single gpio cell -- this is possible,
418 * but not recommended).
420 if (gc->of_gpio_n_cells < 2) {
425 if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
428 if (gpiospec->args[0] >= gc->ngpio)
432 *flags = gpiospec->args[1];
434 return gpiospec->args[0];
436 EXPORT_SYMBOL(of_gpio_simple_xlate);
439 * of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank)
440 * @np: device node of the GPIO chip
441 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure
442 * @data: driver data to store in the struct gpio_chip
444 * To use this function you should allocate and fill mm_gc with:
446 * 1) In the gpio_chip structure:
447 * - all the callbacks
449 * - of_xlate callback (optional)
451 * 3) In the of_mm_gpio_chip structure:
452 * - save_regs callback (optional)
454 * If succeeded, this function will map bank's memory and will
455 * do all necessary work for you. Then you'll able to use .regs
456 * to manage GPIOs from the callbacks.
458 int of_mm_gpiochip_add_data(struct device_node *np,
459 struct of_mm_gpio_chip *mm_gc,
463 struct gpio_chip *gc = &mm_gc->gc;
465 gc->label = kasprintf(GFP_KERNEL, "%pOF", np);
469 mm_gc->regs = of_iomap(np, 0);
475 if (mm_gc->save_regs)
476 mm_gc->save_regs(mm_gc);
478 mm_gc->gc.of_node = np;
480 ret = gpiochip_add_data(gc, data);
486 iounmap(mm_gc->regs);
490 pr_err("%pOF: GPIO chip registration failed with status %d\n", np, ret);
493 EXPORT_SYMBOL(of_mm_gpiochip_add_data);
496 * of_mm_gpiochip_remove - Remove memory mapped GPIO chip (bank)
497 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure
499 void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc)
501 struct gpio_chip *gc = &mm_gc->gc;
507 iounmap(mm_gc->regs);
510 EXPORT_SYMBOL(of_mm_gpiochip_remove);
512 static void of_gpiochip_init_valid_mask(struct gpio_chip *chip)
516 struct device_node *np = chip->of_node;
518 len = of_property_count_u32_elems(np, "gpio-reserved-ranges");
519 if (len < 0 || len % 2 != 0)
522 for (i = 0; i < len; i += 2) {
523 of_property_read_u32_index(np, "gpio-reserved-ranges",
525 of_property_read_u32_index(np, "gpio-reserved-ranges",
527 if (start >= chip->ngpio || start + count >= chip->ngpio)
530 bitmap_clear(chip->valid_mask, start, count);
534 #ifdef CONFIG_PINCTRL
535 static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
537 struct device_node *np = chip->of_node;
538 struct of_phandle_args pinspec;
539 struct pinctrl_dev *pctldev;
542 static const char group_names_propname[] = "gpio-ranges-group-names";
543 struct property *group_names;
548 group_names = of_find_property(np, group_names_propname, NULL);
551 ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
556 pctldev = of_pinctrl_get(pinspec.np);
557 of_node_put(pinspec.np);
559 return -EPROBE_DEFER;
561 if (pinspec.args[2]) {
563 of_property_read_string_index(np,
564 group_names_propname,
567 pr_err("%pOF: Group name of numeric GPIO ranges must be the empty string.\n",
572 /* npins != 0: linear range */
573 ret = gpiochip_add_pin_range(chip,
574 pinctrl_dev_get_devname(pctldev),
581 /* npins == 0: special range */
582 if (pinspec.args[1]) {
583 pr_err("%pOF: Illegal gpio-range format.\n",
589 pr_err("%pOF: GPIO group range requested but no %s property.\n",
590 np, group_names_propname);
594 ret = of_property_read_string_index(np,
595 group_names_propname,
601 pr_err("%pOF: Group name of GPIO group range cannot be the empty string.\n",
606 ret = gpiochip_add_pingroup_range(chip, pctldev,
607 pinspec.args[0], name);
617 static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; }
620 int of_gpiochip_add(struct gpio_chip *chip)
627 if (!chip->of_xlate) {
628 chip->of_gpio_n_cells = 2;
629 chip->of_xlate = of_gpio_simple_xlate;
632 if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS)
635 of_gpiochip_init_valid_mask(chip);
637 status = of_gpiochip_add_pin_range(chip);
641 /* If the chip defines names itself, these take precedence */
643 devprop_gpiochip_set_names(chip,
644 of_fwnode_handle(chip->of_node));
646 of_node_get(chip->of_node);
648 return of_gpiochip_scan_gpios(chip);
651 void of_gpiochip_remove(struct gpio_chip *chip)
653 gpiochip_remove_pin_ranges(chip);
654 of_node_put(chip->of_node);