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
);