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 /* Private data structure for of_gpiochip_find_and_xlate */
31 enum of_gpio_flags
*flags
;
32 struct of_phandle_args gpiospec
;
34 struct gpio_desc
*out_gpio
;
37 /* Private function for resolving node pointer to gpio_chip */
38 static int of_gpiochip_find_and_xlate(struct gpio_chip
*gc
, void *data
)
40 struct gg_data
*gg_data
= data
;
43 if ((gc
->of_node
!= gg_data
->gpiospec
.np
) ||
44 (gc
->of_gpio_n_cells
!= gg_data
->gpiospec
.args_count
) ||
48 ret
= gc
->of_xlate(gc
, &gg_data
->gpiospec
, gg_data
->flags
);
50 /* We've found a gpio chip, but the translation failed.
51 * Store translation error in out_gpio.
52 * Return false to keep looking, as more than one gpio chip
53 * could be registered per of-node.
55 gg_data
->out_gpio
= ERR_PTR(ret
);
59 gg_data
->out_gpio
= gpiochip_get_desc(gc
, ret
);
64 * of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API
65 * @np: device node to get GPIO from
66 * @propname: property name containing gpio specifier(s)
67 * @index: index of the GPIO
68 * @flags: a flags pointer to fill in
70 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
71 * value on the error condition. If @flags is not NULL the function also fills
72 * in flags for the GPIO.
74 struct gpio_desc
*of_get_named_gpiod_flags(struct device_node
*np
,
75 const char *propname
, int index
, enum of_gpio_flags
*flags
)
77 /* Return -EPROBE_DEFER to support probe() functions to be called
78 * later when the GPIO actually becomes available
80 struct gg_data gg_data
= {
82 .out_gpio
= ERR_PTR(-EPROBE_DEFER
)
86 /* .of_xlate might decide to not fill in the flags, so clear it. */
90 ret
= of_parse_phandle_with_args(np
, propname
, "#gpio-cells", index
,
93 pr_debug("%s: can't parse '%s' property of node '%s[%d]'\n",
94 __func__
, propname
, np
->full_name
, index
);
98 gpiochip_find(&gg_data
, of_gpiochip_find_and_xlate
);
100 of_node_put(gg_data
.gpiospec
.np
);
101 pr_debug("%s: parsed '%s' property of node '%s[%d]' - status (%d)\n",
102 __func__
, propname
, np
->full_name
, index
,
103 PTR_ERR_OR_ZERO(gg_data
.out_gpio
));
104 return gg_data
.out_gpio
;
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
);
122 * of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API
123 * @np: device node to get GPIO from
124 * @name: GPIO line name
125 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
126 * of_parse_own_gpio()
127 * @dflags: gpiod_flags - optional GPIO initialization flags
129 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
130 * value on the error condition.
132 static struct gpio_desc
*of_parse_own_gpio(struct device_node
*np
,
134 enum gpio_lookup_flags
*lflags
,
135 enum gpiod_flags
*dflags
)
137 struct device_node
*chip_np
;
138 enum of_gpio_flags xlate_flags
;
139 struct gg_data gg_data
= {
140 .flags
= &xlate_flags
,
145 chip_np
= np
->parent
;
147 return ERR_PTR(-EINVAL
);
153 ret
= of_property_read_u32(chip_np
, "#gpio-cells", &tmp
);
157 if (tmp
> MAX_PHANDLE_ARGS
)
158 return ERR_PTR(-EINVAL
);
160 gg_data
.gpiospec
.args_count
= tmp
;
161 gg_data
.gpiospec
.np
= chip_np
;
162 for (i
= 0; i
< tmp
; i
++) {
163 ret
= of_property_read_u32_index(np
, "gpios", i
,
164 &gg_data
.gpiospec
.args
[i
]);
169 gpiochip_find(&gg_data
, of_gpiochip_find_and_xlate
);
170 if (!gg_data
.out_gpio
) {
171 if (np
->parent
== np
)
172 return ERR_PTR(-ENXIO
);
174 return ERR_PTR(-EINVAL
);
177 if (xlate_flags
& OF_GPIO_ACTIVE_LOW
)
178 *lflags
|= GPIO_ACTIVE_LOW
;
180 if (of_property_read_bool(np
, "input"))
182 else if (of_property_read_bool(np
, "output-low"))
183 *dflags
|= GPIOD_OUT_LOW
;
184 else if (of_property_read_bool(np
, "output-high"))
185 *dflags
|= GPIOD_OUT_HIGH
;
187 pr_warn("GPIO line %d (%s): no hogging state specified, bailing out\n",
188 desc_to_gpio(gg_data
.out_gpio
), np
->name
);
189 return ERR_PTR(-EINVAL
);
192 if (name
&& of_property_read_string(np
, "line-name", name
))
195 return gg_data
.out_gpio
;
199 * of_gpiochip_set_names() - set up the names of the lines
200 * @chip: GPIO chip whose lines should be named, if possible
202 static void of_gpiochip_set_names(struct gpio_chip
*gc
)
204 struct gpio_device
*gdev
= gc
->gpiodev
;
205 struct device_node
*np
= gc
->of_node
;
209 nstrings
= of_property_count_strings(np
, "gpio-line-names");
211 /* Lines names not present */
214 /* This is normally not what you want */
215 if (gdev
->ngpio
!= nstrings
)
216 dev_info(&gdev
->dev
, "gpio-line-names specifies %d line "
217 "names but there are %d lines on the chip\n",
218 nstrings
, gdev
->ngpio
);
221 * Make sure to not index beyond the end of the number of descriptors
222 * of the GPIO device.
224 for (i
= 0; i
< gdev
->ngpio
; i
++) {
228 ret
= of_property_read_string_index(np
,
235 "unable to name line %d: %d\n",
239 gdev
->descs
[i
].name
= name
;
244 * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions
245 * @chip: gpio chip to act on
247 * This is only used by of_gpiochip_add to request/set GPIO initial
249 * It retures error if it fails otherwise 0 on success.
251 static int of_gpiochip_scan_gpios(struct gpio_chip
*chip
)
253 struct gpio_desc
*desc
= NULL
;
254 struct device_node
*np
;
256 enum gpio_lookup_flags lflags
;
257 enum gpiod_flags dflags
;
260 for_each_available_child_of_node(chip
->of_node
, np
) {
261 if (!of_property_read_bool(np
, "gpio-hog"))
264 desc
= of_parse_own_gpio(np
, &name
, &lflags
, &dflags
);
268 ret
= gpiod_hog(desc
, name
, lflags
, dflags
);
277 * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags
278 * @gc: pointer to the gpio_chip structure
279 * @np: device node of the GPIO chip
280 * @gpio_spec: gpio specifier as found in the device tree
281 * @flags: a flags pointer to fill in
283 * This is simple translation function, suitable for the most 1:1 mapped
284 * gpio chips. This function performs only one sanity check: whether gpio
285 * is less than ngpios (that is specified in the gpio_chip).
287 int of_gpio_simple_xlate(struct gpio_chip
*gc
,
288 const struct of_phandle_args
*gpiospec
, u32
*flags
)
291 * We're discouraging gpio_cells < 2, since that way you'll have to
292 * write your own xlate function (that will have to retrieve the GPIO
293 * number and the flags from a single gpio cell -- this is possible,
294 * but not recommended).
296 if (gc
->of_gpio_n_cells
< 2) {
301 if (WARN_ON(gpiospec
->args_count
< gc
->of_gpio_n_cells
))
304 if (gpiospec
->args
[0] >= gc
->ngpio
)
308 *flags
= gpiospec
->args
[1];
310 return gpiospec
->args
[0];
312 EXPORT_SYMBOL(of_gpio_simple_xlate
);
315 * of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank)
316 * @np: device node of the GPIO chip
317 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure
318 * @data: driver data to store in the struct gpio_chip
320 * To use this function you should allocate and fill mm_gc with:
322 * 1) In the gpio_chip structure:
323 * - all the callbacks
325 * - of_xlate callback (optional)
327 * 3) In the of_mm_gpio_chip structure:
328 * - save_regs callback (optional)
330 * If succeeded, this function will map bank's memory and will
331 * do all necessary work for you. Then you'll able to use .regs
332 * to manage GPIOs from the callbacks.
334 int of_mm_gpiochip_add_data(struct device_node
*np
,
335 struct of_mm_gpio_chip
*mm_gc
,
339 struct gpio_chip
*gc
= &mm_gc
->gc
;
341 gc
->label
= kstrdup(np
->full_name
, GFP_KERNEL
);
345 mm_gc
->regs
= of_iomap(np
, 0);
351 if (mm_gc
->save_regs
)
352 mm_gc
->save_regs(mm_gc
);
354 mm_gc
->gc
.of_node
= np
;
356 ret
= gpiochip_add_data(gc
, data
);
362 iounmap(mm_gc
->regs
);
366 pr_err("%s: GPIO chip registration failed with status %d\n",
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
);
413 return -EPROBE_DEFER
;
415 if (pinspec
.args
[2]) {
417 of_property_read_string_index(np
,
418 group_names_propname
,
421 pr_err("%s: Group name of numeric GPIO ranges must be the empty string.\n",
426 /* npins != 0: linear range */
427 ret
= gpiochip_add_pin_range(chip
,
428 pinctrl_dev_get_devname(pctldev
),
435 /* npins == 0: special range */
436 if (pinspec
.args
[1]) {
437 pr_err("%s: Illegal gpio-range format.\n",
443 pr_err("%s: GPIO group range requested but no %s property.\n",
444 np
->full_name
, group_names_propname
);
448 ret
= of_property_read_string_index(np
,
449 group_names_propname
,
455 pr_err("%s: Group name of GPIO group range cannot be the empty string.\n",
460 ret
= gpiochip_add_pingroup_range(chip
, pctldev
,
461 pinspec
.args
[0], name
);
471 static int of_gpiochip_add_pin_range(struct gpio_chip
*chip
) { return 0; }
474 int of_gpiochip_add(struct gpio_chip
*chip
)
478 if ((!chip
->of_node
) && (chip
->parent
))
479 chip
->of_node
= chip
->parent
->of_node
;
484 if (!chip
->of_xlate
) {
485 chip
->of_gpio_n_cells
= 2;
486 chip
->of_xlate
= of_gpio_simple_xlate
;
489 status
= of_gpiochip_add_pin_range(chip
);
493 /* If the chip defines names itself, these take precedence */
495 of_gpiochip_set_names(chip
);
497 of_node_get(chip
->of_node
);
499 return of_gpiochip_scan_gpios(chip
);
502 void of_gpiochip_remove(struct gpio_chip
*chip
)
504 gpiochip_remove_pin_ranges(chip
);
505 of_node_put(chip
->of_node
);