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 &&
35 chip->of_xlate(chip, gpiospec, NULL) >= 0;
38 static struct gpio_chip *of_find_gpiochip_by_xlate(
39 struct of_phandle_args *gpiospec)
41 return gpiochip_find(gpiospec, of_gpiochip_match_node_and_xlate);
44 static struct gpio_desc *of_xlate_and_get_gpiod_flags(struct gpio_chip *chip,
45 struct of_phandle_args *gpiospec,
46 enum of_gpio_flags *flags)
50 if (chip->of_gpio_n_cells != gpiospec->args_count)
51 return ERR_PTR(-EINVAL);
53 ret = chip->of_xlate(chip, gpiospec, flags);
57 return gpiochip_get_desc(chip, ret);
61 * of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API
62 * @np: device node to get GPIO from
63 * @propname: property name containing gpio specifier(s)
64 * @index: index of the GPIO
65 * @flags: a flags pointer to fill in
67 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
68 * value on the error condition. If @flags is not NULL the function also fills
69 * in flags for the GPIO.
71 struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
72 const char *propname, int index, enum of_gpio_flags *flags)
74 struct of_phandle_args gpiospec;
75 struct gpio_chip *chip;
76 struct gpio_desc *desc;
79 ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index,
82 pr_debug("%s: can't parse '%s' property of node '%pOF[%d]'\n",
83 __func__, propname, np, index);
87 chip = of_find_gpiochip_by_xlate(&gpiospec);
89 desc = ERR_PTR(-EPROBE_DEFER);
93 desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, flags);
97 pr_debug("%s: parsed '%s' property of node '%pOF[%d]' - status (%d)\n",
98 __func__, propname, np, index,
99 PTR_ERR_OR_ZERO(desc));
102 of_node_put(gpiospec.np);
107 int of_get_named_gpio_flags(struct device_node *np, const char *list_name,
108 int index, enum of_gpio_flags *flags)
110 struct gpio_desc *desc;
112 desc = of_get_named_gpiod_flags(np, list_name, index, flags);
115 return PTR_ERR(desc);
117 return desc_to_gpio(desc);
119 EXPORT_SYMBOL(of_get_named_gpio_flags);
121 struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
123 enum gpio_lookup_flags *flags)
125 char prop_name[32]; /* 32 is max size of property name */
126 enum of_gpio_flags of_flags;
127 struct gpio_desc *desc;
130 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
132 snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
135 snprintf(prop_name, sizeof(prop_name), "%s",
138 desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
140 if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
147 if (of_flags & OF_GPIO_ACTIVE_LOW)
148 *flags |= GPIO_ACTIVE_LOW;
150 if (of_flags & OF_GPIO_SINGLE_ENDED) {
151 if (of_flags & OF_GPIO_OPEN_DRAIN)
152 *flags |= GPIO_OPEN_DRAIN;
154 *flags |= GPIO_OPEN_SOURCE;
157 if (of_flags & OF_GPIO_SLEEP_MAY_LOOSE_VALUE)
158 *flags |= GPIO_SLEEP_MAY_LOOSE_VALUE;
164 * of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API
165 * @np: device node to get GPIO from
166 * @chip: GPIO chip whose hog is parsed
167 * @idx: Index of the GPIO to parse
168 * @name: GPIO line name
169 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
170 * of_parse_own_gpio()
171 * @dflags: gpiod_flags - optional GPIO initialization flags
173 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
174 * value on the error condition.
176 static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
177 struct gpio_chip *chip,
178 unsigned int idx, const char **name,
179 enum gpio_lookup_flags *lflags,
180 enum gpiod_flags *dflags)
182 struct device_node *chip_np;
183 enum of_gpio_flags xlate_flags;
184 struct of_phandle_args gpiospec;
185 struct gpio_desc *desc;
190 chip_np = chip->of_node;
192 return ERR_PTR(-EINVAL);
198 ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp);
202 gpiospec.np = chip_np;
203 gpiospec.args_count = tmp;
205 for (i = 0; i < tmp; i++) {
206 ret = of_property_read_u32_index(np, "gpios", idx * tmp + i,
212 desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, &xlate_flags);
216 if (xlate_flags & OF_GPIO_ACTIVE_LOW)
217 *lflags |= GPIO_ACTIVE_LOW;
219 if (of_property_read_bool(np, "input"))
221 else if (of_property_read_bool(np, "output-low"))
222 *dflags |= GPIOD_OUT_LOW;
223 else if (of_property_read_bool(np, "output-high"))
224 *dflags |= GPIOD_OUT_HIGH;
226 pr_warn("GPIO line %d (%s): no hogging state specified, bailing out\n",
227 desc_to_gpio(desc), np->name);
228 return ERR_PTR(-EINVAL);
231 if (name && of_property_read_string(np, "line-name", name))
238 * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions
239 * @chip: gpio chip to act on
241 * This is only used by of_gpiochip_add to request/set GPIO initial
243 * It returns error if it fails otherwise 0 on success.
245 static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
247 struct gpio_desc *desc = NULL;
248 struct device_node *np;
250 enum gpio_lookup_flags lflags;
251 enum gpiod_flags dflags;
255 for_each_available_child_of_node(chip->of_node, np) {
256 if (!of_property_read_bool(np, "gpio-hog"))
260 desc = of_parse_own_gpio(np, chip, i, &name, &lflags,
265 ret = gpiod_hog(desc, name, lflags, dflags);
277 * of_gpio_simple_xlate - translate gpiospec to the GPIO number and flags
278 * @gc: pointer to the gpio_chip structure
279 * @gpiospec: GPIO specifier as found in the device tree
280 * @flags: a flags pointer to fill in
282 * This is simple translation function, suitable for the most 1:1 mapped
283 * GPIO chips. This function performs only one sanity check: whether GPIO
284 * is less than ngpios (that is specified in the gpio_chip).
286 int of_gpio_simple_xlate(struct gpio_chip *gc,
287 const struct of_phandle_args *gpiospec, u32 *flags)
290 * We're discouraging gpio_cells < 2, since that way you'll have to
291 * write your own xlate function (that will have to retrieve the GPIO
292 * number and the flags from a single gpio cell -- this is possible,
293 * but not recommended).
295 if (gc->of_gpio_n_cells < 2) {
300 if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
303 if (gpiospec->args[0] >= gc->ngpio)
307 *flags = gpiospec->args[1];
309 return gpiospec->args[0];
311 EXPORT_SYMBOL(of_gpio_simple_xlate);
314 * of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank)
315 * @np: device node of the GPIO chip
316 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure
317 * @data: driver data to store in the struct gpio_chip
319 * To use this function you should allocate and fill mm_gc with:
321 * 1) In the gpio_chip structure:
322 * - all the callbacks
324 * - of_xlate callback (optional)
326 * 3) In the of_mm_gpio_chip structure:
327 * - save_regs callback (optional)
329 * If succeeded, this function will map bank's memory and will
330 * do all necessary work for you. Then you'll able to use .regs
331 * to manage GPIOs from the callbacks.
333 int of_mm_gpiochip_add_data(struct device_node *np,
334 struct of_mm_gpio_chip *mm_gc,
338 struct gpio_chip *gc = &mm_gc->gc;
340 gc->label = kasprintf(GFP_KERNEL, "%pOF", np);
344 mm_gc->regs = of_iomap(np, 0);
350 if (mm_gc->save_regs)
351 mm_gc->save_regs(mm_gc);
353 of_node_put(mm_gc->gc.of_node);
354 mm_gc->gc.of_node = of_node_get(np);
356 ret = gpiochip_add_data(gc, data);
363 iounmap(mm_gc->regs);
367 pr_err("%pOF: GPIO chip registration failed with status %d\n", np, ret);
370 EXPORT_SYMBOL(of_mm_gpiochip_add_data);
373 * of_mm_gpiochip_remove - Remove memory mapped GPIO chip (bank)
374 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure
376 void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc)
378 struct gpio_chip *gc = &mm_gc->gc;
384 iounmap(mm_gc->regs);
387 EXPORT_SYMBOL(of_mm_gpiochip_remove);
389 #ifdef CONFIG_PINCTRL
390 static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
392 struct device_node *np = chip->of_node;
393 struct of_phandle_args pinspec;
394 struct pinctrl_dev *pctldev;
397 static const char group_names_propname[] = "gpio-ranges-group-names";
398 struct property *group_names;
403 group_names = of_find_property(np, group_names_propname, NULL);
406 ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
411 pctldev = of_pinctrl_get(pinspec.np);
412 of_node_put(pinspec.np);
414 return -EPROBE_DEFER;
416 if (pinspec.args[2]) {
418 of_property_read_string_index(np,
419 group_names_propname,
422 pr_err("%pOF: Group name of numeric GPIO ranges must be the empty string.\n",
427 /* npins != 0: linear range */
428 ret = gpiochip_add_pin_range(chip,
429 pinctrl_dev_get_devname(pctldev),
436 /* npins == 0: special range */
437 if (pinspec.args[1]) {
438 pr_err("%pOF: Illegal gpio-range format.\n",
444 pr_err("%pOF: GPIO group range requested but no %s property.\n",
445 np, group_names_propname);
449 ret = of_property_read_string_index(np,
450 group_names_propname,
456 pr_err("%pOF: Group name of GPIO group range cannot be the empty string.\n",
461 ret = gpiochip_add_pingroup_range(chip, pctldev,
462 pinspec.args[0], name);
472 static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; }
475 int of_gpiochip_add(struct gpio_chip *chip)
479 if ((!chip->of_node) && (chip->parent))
480 chip->of_node = chip->parent->of_node;
485 if (!chip->of_xlate) {
486 chip->of_gpio_n_cells = 2;
487 chip->of_xlate = of_gpio_simple_xlate;
490 if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS)
493 status = of_gpiochip_add_pin_range(chip);
497 /* If the chip defines names itself, these take precedence */
499 devprop_gpiochip_set_names(chip,
500 of_fwnode_handle(chip->of_node));
502 of_node_get(chip->of_node);
504 status = of_gpiochip_scan_gpios(chip);
506 of_node_put(chip->of_node);
507 gpiochip_remove_pin_ranges(chip);
513 void of_gpiochip_remove(struct gpio_chip *chip)
515 gpiochip_remove_pin_ranges(chip);
516 of_node_put(chip->of_node);