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1/*
2 * OF helpers for the GPIO API
3 *
4 * Copyright (c) 2007-2008 MontaVista Software, Inc.
5 *
6 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
7 *
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.
12 */
13
14#include <linux/device.h>
15#include <linux/err.h>
16#include <linux/errno.h>
17#include <linux/module.h>
18#include <linux/io.h>
19#include <linux/gpio/consumer.h>
20#include <linux/of.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
26struct gpio_desc;
27
28/* Private data structure for of_gpiochip_find_and_xlate */
29struct gg_data {
30 enum of_gpio_flags *flags;
31 struct of_phandle_args gpiospec;
32
33 struct gpio_desc *out_gpio;
34};
35
36/* Private function for resolving node pointer to gpio_chip */
37static int of_gpiochip_find_and_xlate(struct gpio_chip *gc, void *data)
38{
39 struct gg_data *gg_data = data;
40 int ret;
41
42 if ((gc->of_node != gg_data->gpiospec.np) ||
43 (gc->of_gpio_n_cells != gg_data->gpiospec.args_count) ||
44 (!gc->of_xlate))
45 return false;
46
47 ret = gc->of_xlate(gc, &gg_data->gpiospec, gg_data->flags);
48 if (ret < 0)
49 return false;
50
51 gg_data->out_gpio = gpio_to_desc(ret + gc->base);
52 return true;
53}
54
55/**
56 * of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API
57 * @np: device node to get GPIO from
58 * @propname: property name containing gpio specifier(s)
59 * @index: index of the GPIO
60 * @flags: a flags pointer to fill in
61 *
62 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
63 * value on the error condition. If @flags is not NULL the function also fills
64 * in flags for the GPIO.
65 */
66struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
67 const char *propname, int index, enum of_gpio_flags *flags)
68{
69 /* Return -EPROBE_DEFER to support probe() functions to be called
70 * later when the GPIO actually becomes available
71 */
72 struct gg_data gg_data = {
73 .flags = flags,
74 .out_gpio = ERR_PTR(-EPROBE_DEFER)
75 };
76 int ret;
77
78 /* .of_xlate might decide to not fill in the flags, so clear it. */
79 if (flags)
80 *flags = 0;
81
82 ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index,
83 &gg_data.gpiospec);
84 if (ret) {
85 pr_debug("%s: can't parse gpios property of node '%s[%d]'\n",
86 __func__, np->full_name, index);
87 return ERR_PTR(ret);
88 }
89
90 gpiochip_find(&gg_data, of_gpiochip_find_and_xlate);
91
92 of_node_put(gg_data.gpiospec.np);
93 pr_debug("%s exited with status %d\n", __func__,
94 PTR_ERR_OR_ZERO(gg_data.out_gpio));
95 return gg_data.out_gpio;
96}
97EXPORT_SYMBOL(of_get_named_gpiod_flags);
98
99/**
100 * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags
101 * @gc: pointer to the gpio_chip structure
102 * @np: device node of the GPIO chip
103 * @gpio_spec: gpio specifier as found in the device tree
104 * @flags: a flags pointer to fill in
105 *
106 * This is simple translation function, suitable for the most 1:1 mapped
107 * gpio chips. This function performs only one sanity check: whether gpio
108 * is less than ngpios (that is specified in the gpio_chip).
109 */
110int of_gpio_simple_xlate(struct gpio_chip *gc,
111 const struct of_phandle_args *gpiospec, u32 *flags)
112{
113 /*
114 * We're discouraging gpio_cells < 2, since that way you'll have to
115 * write your own xlate function (that will have to retrive the GPIO
116 * number and the flags from a single gpio cell -- this is possible,
117 * but not recommended).
118 */
119 if (gc->of_gpio_n_cells < 2) {
120 WARN_ON(1);
121 return -EINVAL;
122 }
123
124 if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
125 return -EINVAL;
126
127 if (gpiospec->args[0] >= gc->ngpio)
128 return -EINVAL;
129
130 if (flags)
131 *flags = gpiospec->args[1];
132
133 return gpiospec->args[0];
134}
135EXPORT_SYMBOL(of_gpio_simple_xlate);
136
137/**
138 * of_mm_gpiochip_add - Add memory mapped GPIO chip (bank)
139 * @np: device node of the GPIO chip
140 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure
141 *
142 * To use this function you should allocate and fill mm_gc with:
143 *
144 * 1) In the gpio_chip structure:
145 * - all the callbacks
146 * - of_gpio_n_cells
147 * - of_xlate callback (optional)
148 *
149 * 3) In the of_mm_gpio_chip structure:
150 * - save_regs callback (optional)
151 *
152 * If succeeded, this function will map bank's memory and will
153 * do all necessary work for you. Then you'll able to use .regs
154 * to manage GPIOs from the callbacks.
155 */
156int of_mm_gpiochip_add(struct device_node *np,
157 struct of_mm_gpio_chip *mm_gc)
158{
159 int ret = -ENOMEM;
160 struct gpio_chip *gc = &mm_gc->gc;
161
162 gc->label = kstrdup(np->full_name, GFP_KERNEL);
163 if (!gc->label)
164 goto err0;
165
166 mm_gc->regs = of_iomap(np, 0);
167 if (!mm_gc->regs)
168 goto err1;
169
170 gc->base = -1;
171
172 if (mm_gc->save_regs)
173 mm_gc->save_regs(mm_gc);
174
175 mm_gc->gc.of_node = np;
176
177 ret = gpiochip_add(gc);
178 if (ret)
179 goto err2;
180
181 return 0;
182err2:
183 iounmap(mm_gc->regs);
184err1:
185 kfree(gc->label);
186err0:
187 pr_err("%s: GPIO chip registration failed with status %d\n",
188 np->full_name, ret);
189 return ret;
190}
191EXPORT_SYMBOL(of_mm_gpiochip_add);
192
193#ifdef CONFIG_PINCTRL
194static void of_gpiochip_add_pin_range(struct gpio_chip *chip)
195{
196 struct device_node *np = chip->of_node;
197 struct of_phandle_args pinspec;
198 struct pinctrl_dev *pctldev;
199 int index = 0, ret;
200 const char *name;
201 static const char group_names_propname[] = "gpio-ranges-group-names";
202 struct property *group_names;
203
204 if (!np)
205 return;
206
207 group_names = of_find_property(np, group_names_propname, NULL);
208
209 for (;; index++) {
210 ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
211 index, &pinspec);
212 if (ret)
213 break;
214
215 pctldev = of_pinctrl_get(pinspec.np);
216 if (!pctldev)
217 break;
218
219 if (pinspec.args[2]) {
220 if (group_names) {
221 ret = of_property_read_string_index(np,
222 group_names_propname,
223 index, &name);
224 if (strlen(name)) {
225 pr_err("%s: Group name of numeric GPIO ranges must be the empty string.\n",
226 np->full_name);
227 break;
228 }
229 }
230 /* npins != 0: linear range */
231 ret = gpiochip_add_pin_range(chip,
232 pinctrl_dev_get_devname(pctldev),
233 pinspec.args[0],
234 pinspec.args[1],
235 pinspec.args[2]);
236 if (ret)
237 break;
238 } else {
239 /* npins == 0: special range */
240 if (pinspec.args[1]) {
241 pr_err("%s: Illegal gpio-range format.\n",
242 np->full_name);
243 break;
244 }
245
246 if (!group_names) {
247 pr_err("%s: GPIO group range requested but no %s property.\n",
248 np->full_name, group_names_propname);
249 break;
250 }
251
252 ret = of_property_read_string_index(np,
253 group_names_propname,
254 index, &name);
255 if (ret)
256 break;
257
258 if (!strlen(name)) {
259 pr_err("%s: Group name of GPIO group range cannot be the empty string.\n",
260 np->full_name);
261 break;
262 }
263
264 ret = gpiochip_add_pingroup_range(chip, pctldev,
265 pinspec.args[0], name);
266 if (ret)
267 break;
268 }
269 }
270}
271
272#else
273static void of_gpiochip_add_pin_range(struct gpio_chip *chip) {}
274#endif
275
276void of_gpiochip_add(struct gpio_chip *chip)
277{
278 if ((!chip->of_node) && (chip->dev))
279 chip->of_node = chip->dev->of_node;
280
281 if (!chip->of_node)
282 return;
283
284 if (!chip->of_xlate) {
285 chip->of_gpio_n_cells = 2;
286 chip->of_xlate = of_gpio_simple_xlate;
287 }
288
289 of_gpiochip_add_pin_range(chip);
290 of_node_get(chip->of_node);
291}
292
293void of_gpiochip_remove(struct gpio_chip *chip)
294{
295 gpiochip_remove_pin_ranges(chip);
296
297 if (chip->of_node)
298 of_node_put(chip->of_node);
299}
1/*
2 * OF helpers for the GPIO API
3 *
4 * Copyright (c) 2007-2008 MontaVista Software, Inc.
5 *
6 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
7 *
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.
12 */
13
14#include <linux/device.h>
15#include <linux/err.h>
16#include <linux/errno.h>
17#include <linux/module.h>
18#include <linux/io.h>
19#include <linux/gpio/consumer.h>
20#include <linux/of.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>
26
27#include "gpiolib.h"
28
29static int of_gpiochip_match_node_and_xlate(struct gpio_chip *chip, void *data)
30{
31 struct of_phandle_args *gpiospec = data;
32
33 return chip->gpiodev->dev.of_node == gpiospec->np &&
34 chip->of_xlate(chip, gpiospec, NULL) >= 0;
35}
36
37static struct gpio_chip *of_find_gpiochip_by_xlate(
38 struct of_phandle_args *gpiospec)
39{
40 return gpiochip_find(gpiospec, of_gpiochip_match_node_and_xlate);
41}
42
43static 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)
46{
47 int ret;
48
49 if (chip->of_gpio_n_cells != gpiospec->args_count)
50 return ERR_PTR(-EINVAL);
51
52 ret = chip->of_xlate(chip, gpiospec, flags);
53 if (ret < 0)
54 return ERR_PTR(ret);
55
56 return gpiochip_get_desc(chip, ret);
57}
58
59/**
60 * of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API
61 * @np: device node to get GPIO from
62 * @propname: property name containing gpio specifier(s)
63 * @index: index of the GPIO
64 * @flags: a flags pointer to fill in
65 *
66 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
67 * value on the error condition. If @flags is not NULL the function also fills
68 * in flags for the GPIO.
69 */
70struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
71 const char *propname, int index, enum of_gpio_flags *flags)
72{
73 struct of_phandle_args gpiospec;
74 struct gpio_chip *chip;
75 struct gpio_desc *desc;
76 int ret;
77
78 ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index,
79 &gpiospec);
80 if (ret) {
81 pr_debug("%s: can't parse '%s' property of node '%s[%d]'\n",
82 __func__, propname, np->full_name, index);
83 return ERR_PTR(ret);
84 }
85
86 chip = of_find_gpiochip_by_xlate(&gpiospec);
87 if (!chip) {
88 desc = ERR_PTR(-EPROBE_DEFER);
89 goto out;
90 }
91
92 desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, flags);
93 if (IS_ERR(desc))
94 goto out;
95
96 pr_debug("%s: parsed '%s' property of node '%s[%d]' - status (%d)\n",
97 __func__, propname, np->full_name, index,
98 PTR_ERR_OR_ZERO(desc));
99
100out:
101 of_node_put(gpiospec.np);
102
103 return desc;
104}
105
106int of_get_named_gpio_flags(struct device_node *np, const char *list_name,
107 int index, enum of_gpio_flags *flags)
108{
109 struct gpio_desc *desc;
110
111 desc = of_get_named_gpiod_flags(np, list_name, index, flags);
112
113 if (IS_ERR(desc))
114 return PTR_ERR(desc);
115 else
116 return desc_to_gpio(desc);
117}
118EXPORT_SYMBOL(of_get_named_gpio_flags);
119
120struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
121 unsigned int idx,
122 enum gpio_lookup_flags *flags)
123{
124 char prop_name[32]; /* 32 is max size of property name */
125 enum of_gpio_flags of_flags;
126 struct gpio_desc *desc;
127 unsigned int i;
128
129 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
130 if (con_id)
131 snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
132 gpio_suffixes[i]);
133 else
134 snprintf(prop_name, sizeof(prop_name), "%s",
135 gpio_suffixes[i]);
136
137 desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
138 &of_flags);
139 if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
140 break;
141 }
142
143 if (IS_ERR(desc))
144 return desc;
145
146 if (of_flags & OF_GPIO_ACTIVE_LOW)
147 *flags |= GPIO_ACTIVE_LOW;
148
149 if (of_flags & OF_GPIO_SINGLE_ENDED) {
150 if (of_flags & OF_GPIO_ACTIVE_LOW)
151 *flags |= GPIO_OPEN_DRAIN;
152 else
153 *flags |= GPIO_OPEN_SOURCE;
154 }
155
156 return desc;
157}
158
159/**
160 * of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API
161 * @np: device node to get GPIO from
162 * @chip: GPIO chip whose hog is parsed
163 * @name: GPIO line name
164 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
165 * of_parse_own_gpio()
166 * @dflags: gpiod_flags - optional GPIO initialization flags
167 *
168 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
169 * value on the error condition.
170 */
171static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
172 struct gpio_chip *chip,
173 const char **name,
174 enum gpio_lookup_flags *lflags,
175 enum gpiod_flags *dflags)
176{
177 struct device_node *chip_np;
178 enum of_gpio_flags xlate_flags;
179 struct of_phandle_args gpiospec;
180 struct gpio_desc *desc;
181 u32 tmp;
182 int ret;
183
184 chip_np = chip->of_node;
185 if (!chip_np)
186 return ERR_PTR(-EINVAL);
187
188 xlate_flags = 0;
189 *lflags = 0;
190 *dflags = 0;
191
192 ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp);
193 if (ret)
194 return ERR_PTR(ret);
195
196 gpiospec.np = chip_np;
197 gpiospec.args_count = tmp;
198
199 ret = of_property_read_u32_array(np, "gpios", gpiospec.args, tmp);
200 if (ret)
201 return ERR_PTR(ret);
202
203 desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, &xlate_flags);
204 if (IS_ERR(desc))
205 return desc;
206
207 if (xlate_flags & OF_GPIO_ACTIVE_LOW)
208 *lflags |= GPIO_ACTIVE_LOW;
209
210 if (of_property_read_bool(np, "input"))
211 *dflags |= GPIOD_IN;
212 else if (of_property_read_bool(np, "output-low"))
213 *dflags |= GPIOD_OUT_LOW;
214 else if (of_property_read_bool(np, "output-high"))
215 *dflags |= GPIOD_OUT_HIGH;
216 else {
217 pr_warn("GPIO line %d (%s): no hogging state specified, bailing out\n",
218 desc_to_gpio(desc), np->name);
219 return ERR_PTR(-EINVAL);
220 }
221
222 if (name && of_property_read_string(np, "line-name", name))
223 *name = np->name;
224
225 return desc;
226}
227
228/**
229 * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions
230 * @chip: gpio chip to act on
231 *
232 * This is only used by of_gpiochip_add to request/set GPIO initial
233 * configuration.
234 * It retures error if it fails otherwise 0 on success.
235 */
236static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
237{
238 struct gpio_desc *desc = NULL;
239 struct device_node *np;
240 const char *name;
241 enum gpio_lookup_flags lflags;
242 enum gpiod_flags dflags;
243 int ret;
244
245 for_each_available_child_of_node(chip->of_node, np) {
246 if (!of_property_read_bool(np, "gpio-hog"))
247 continue;
248
249 desc = of_parse_own_gpio(np, chip, &name, &lflags, &dflags);
250 if (IS_ERR(desc))
251 continue;
252
253 ret = gpiod_hog(desc, name, lflags, dflags);
254 if (ret < 0) {
255 of_node_put(np);
256 return ret;
257 }
258 }
259
260 return 0;
261}
262
263/**
264 * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags
265 * @gc: pointer to the gpio_chip structure
266 * @np: device node of the GPIO chip
267 * @gpio_spec: gpio specifier as found in the device tree
268 * @flags: a flags pointer to fill in
269 *
270 * This is simple translation function, suitable for the most 1:1 mapped
271 * gpio chips. This function performs only one sanity check: whether gpio
272 * is less than ngpios (that is specified in the gpio_chip).
273 */
274int of_gpio_simple_xlate(struct gpio_chip *gc,
275 const struct of_phandle_args *gpiospec, u32 *flags)
276{
277 /*
278 * We're discouraging gpio_cells < 2, since that way you'll have to
279 * write your own xlate function (that will have to retrieve the GPIO
280 * number and the flags from a single gpio cell -- this is possible,
281 * but not recommended).
282 */
283 if (gc->of_gpio_n_cells < 2) {
284 WARN_ON(1);
285 return -EINVAL;
286 }
287
288 if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
289 return -EINVAL;
290
291 if (gpiospec->args[0] >= gc->ngpio)
292 return -EINVAL;
293
294 if (flags)
295 *flags = gpiospec->args[1];
296
297 return gpiospec->args[0];
298}
299EXPORT_SYMBOL(of_gpio_simple_xlate);
300
301/**
302 * of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank)
303 * @np: device node of the GPIO chip
304 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure
305 * @data: driver data to store in the struct gpio_chip
306 *
307 * To use this function you should allocate and fill mm_gc with:
308 *
309 * 1) In the gpio_chip structure:
310 * - all the callbacks
311 * - of_gpio_n_cells
312 * - of_xlate callback (optional)
313 *
314 * 3) In the of_mm_gpio_chip structure:
315 * - save_regs callback (optional)
316 *
317 * If succeeded, this function will map bank's memory and will
318 * do all necessary work for you. Then you'll able to use .regs
319 * to manage GPIOs from the callbacks.
320 */
321int of_mm_gpiochip_add_data(struct device_node *np,
322 struct of_mm_gpio_chip *mm_gc,
323 void *data)
324{
325 int ret = -ENOMEM;
326 struct gpio_chip *gc = &mm_gc->gc;
327
328 gc->label = kstrdup(np->full_name, GFP_KERNEL);
329 if (!gc->label)
330 goto err0;
331
332 mm_gc->regs = of_iomap(np, 0);
333 if (!mm_gc->regs)
334 goto err1;
335
336 gc->base = -1;
337
338 if (mm_gc->save_regs)
339 mm_gc->save_regs(mm_gc);
340
341 mm_gc->gc.of_node = np;
342
343 ret = gpiochip_add_data(gc, data);
344 if (ret)
345 goto err2;
346
347 return 0;
348err2:
349 iounmap(mm_gc->regs);
350err1:
351 kfree(gc->label);
352err0:
353 pr_err("%s: GPIO chip registration failed with status %d\n",
354 np->full_name, ret);
355 return ret;
356}
357EXPORT_SYMBOL(of_mm_gpiochip_add_data);
358
359/**
360 * of_mm_gpiochip_remove - Remove memory mapped GPIO chip (bank)
361 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure
362 */
363void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc)
364{
365 struct gpio_chip *gc = &mm_gc->gc;
366
367 if (!mm_gc)
368 return;
369
370 gpiochip_remove(gc);
371 iounmap(mm_gc->regs);
372 kfree(gc->label);
373}
374EXPORT_SYMBOL(of_mm_gpiochip_remove);
375
376#ifdef CONFIG_PINCTRL
377static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
378{
379 struct device_node *np = chip->of_node;
380 struct of_phandle_args pinspec;
381 struct pinctrl_dev *pctldev;
382 int index = 0, ret;
383 const char *name;
384 static const char group_names_propname[] = "gpio-ranges-group-names";
385 struct property *group_names;
386
387 if (!np)
388 return 0;
389
390 group_names = of_find_property(np, group_names_propname, NULL);
391
392 for (;; index++) {
393 ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
394 index, &pinspec);
395 if (ret)
396 break;
397
398 pctldev = of_pinctrl_get(pinspec.np);
399 of_node_put(pinspec.np);
400 if (!pctldev)
401 return -EPROBE_DEFER;
402
403 if (pinspec.args[2]) {
404 if (group_names) {
405 of_property_read_string_index(np,
406 group_names_propname,
407 index, &name);
408 if (strlen(name)) {
409 pr_err("%s: Group name of numeric GPIO ranges must be the empty string.\n",
410 np->full_name);
411 break;
412 }
413 }
414 /* npins != 0: linear range */
415 ret = gpiochip_add_pin_range(chip,
416 pinctrl_dev_get_devname(pctldev),
417 pinspec.args[0],
418 pinspec.args[1],
419 pinspec.args[2]);
420 if (ret)
421 return ret;
422 } else {
423 /* npins == 0: special range */
424 if (pinspec.args[1]) {
425 pr_err("%s: Illegal gpio-range format.\n",
426 np->full_name);
427 break;
428 }
429
430 if (!group_names) {
431 pr_err("%s: GPIO group range requested but no %s property.\n",
432 np->full_name, group_names_propname);
433 break;
434 }
435
436 ret = of_property_read_string_index(np,
437 group_names_propname,
438 index, &name);
439 if (ret)
440 break;
441
442 if (!strlen(name)) {
443 pr_err("%s: Group name of GPIO group range cannot be the empty string.\n",
444 np->full_name);
445 break;
446 }
447
448 ret = gpiochip_add_pingroup_range(chip, pctldev,
449 pinspec.args[0], name);
450 if (ret)
451 return ret;
452 }
453 }
454
455 return 0;
456}
457
458#else
459static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; }
460#endif
461
462int of_gpiochip_add(struct gpio_chip *chip)
463{
464 int status;
465
466 if ((!chip->of_node) && (chip->parent))
467 chip->of_node = chip->parent->of_node;
468
469 if (!chip->of_node)
470 return 0;
471
472 if (!chip->of_xlate) {
473 chip->of_gpio_n_cells = 2;
474 chip->of_xlate = of_gpio_simple_xlate;
475 }
476
477 if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS)
478 return -EINVAL;
479
480 status = of_gpiochip_add_pin_range(chip);
481 if (status)
482 return status;
483
484 /* If the chip defines names itself, these take precedence */
485 if (!chip->names)
486 devprop_gpiochip_set_names(chip);
487
488 of_node_get(chip->of_node);
489
490 return of_gpiochip_scan_gpios(chip);
491}
492
493void of_gpiochip_remove(struct gpio_chip *chip)
494{
495 gpiochip_remove_pin_ranges(chip);
496 of_node_put(chip->of_node);
497}