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863fbf49 AV |
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 | ||
2e13cba8 | 14 | #include <linux/device.h> |
bea4dbee | 15 | #include <linux/err.h> |
863fbf49 | 16 | #include <linux/errno.h> |
2e13cba8 | 17 | #include <linux/module.h> |
863fbf49 | 18 | #include <linux/io.h> |
af8b6375 | 19 | #include <linux/gpio/consumer.h> |
863fbf49 | 20 | #include <linux/of.h> |
2e13cba8 | 21 | #include <linux/of_address.h> |
863fbf49 | 22 | #include <linux/of_gpio.h> |
f23f1516 | 23 | #include <linux/pinctrl/pinctrl.h> |
2e13cba8 | 24 | #include <linux/slab.h> |
f625d460 | 25 | #include <linux/gpio/machine.h> |
863fbf49 | 26 | |
1bd6b601 | 27 | #include "gpiolib.h" |
af8b6375 | 28 | |
0df2c999 | 29 | /* Private data structure for of_gpiochip_find_and_xlate */ |
3d0f7cf0 GL |
30 | struct gg_data { |
31 | enum of_gpio_flags *flags; | |
32 | struct of_phandle_args gpiospec; | |
33 | ||
af8b6375 | 34 | struct gpio_desc *out_gpio; |
3d0f7cf0 GL |
35 | }; |
36 | ||
37 | /* Private function for resolving node pointer to gpio_chip */ | |
38 | static int of_gpiochip_find_and_xlate(struct gpio_chip *gc, void *data) | |
39 | { | |
40 | struct gg_data *gg_data = data; | |
41 | int ret; | |
42 | ||
43 | if ((gc->of_node != gg_data->gpiospec.np) || | |
44 | (gc->of_gpio_n_cells != gg_data->gpiospec.args_count) || | |
45 | (!gc->of_xlate)) | |
46 | return false; | |
47 | ||
48 | ret = gc->of_xlate(gc, &gg_data->gpiospec, gg_data->flags); | |
7b8792bb | 49 | if (ret < 0) { |
9cf75e9e HH |
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. | |
7b8792bb HH |
54 | */ |
55 | gg_data->out_gpio = ERR_PTR(ret); | |
9cf75e9e | 56 | return false; |
7b8792bb | 57 | } |
3d0f7cf0 | 58 | |
ccd9726e | 59 | gg_data->out_gpio = gpiochip_get_desc(gc, ret); |
3d0f7cf0 GL |
60 | return true; |
61 | } | |
62 | ||
863fbf49 | 63 | /** |
af8b6375 | 64 | * of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API |
863fbf49 | 65 | * @np: device node to get GPIO from |
a6b09191 | 66 | * @propname: property name containing gpio specifier(s) |
863fbf49 | 67 | * @index: index of the GPIO |
b908b53d | 68 | * @flags: a flags pointer to fill in |
863fbf49 | 69 | * |
af8b6375 | 70 | * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno |
b908b53d AV |
71 | * value on the error condition. If @flags is not NULL the function also fills |
72 | * in flags for the GPIO. | |
863fbf49 | 73 | */ |
af8b6375 AC |
74 | struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np, |
75 | const char *propname, int index, enum of_gpio_flags *flags) | |
863fbf49 | 76 | { |
4fbb0022 RS |
77 | /* Return -EPROBE_DEFER to support probe() functions to be called |
78 | * later when the GPIO actually becomes available | |
79 | */ | |
af8b6375 AC |
80 | struct gg_data gg_data = { |
81 | .flags = flags, | |
82 | .out_gpio = ERR_PTR(-EPROBE_DEFER) | |
83 | }; | |
64b60e09 | 84 | int ret; |
3d0f7cf0 GL |
85 | |
86 | /* .of_xlate might decide to not fill in the flags, so clear it. */ | |
87 | if (flags) | |
88 | *flags = 0; | |
863fbf49 | 89 | |
15c9a0ac | 90 | ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index, |
3d0f7cf0 | 91 | &gg_data.gpiospec); |
64b60e09 | 92 | if (ret) { |
85ea29ac TB |
93 | pr_debug("%s: can't parse '%s' property of node '%s[%d]'\n", |
94 | __func__, propname, np->full_name, index); | |
af8b6375 | 95 | return ERR_PTR(ret); |
863fbf49 AV |
96 | } |
97 | ||
3d0f7cf0 | 98 | gpiochip_find(&gg_data, of_gpiochip_find_and_xlate); |
863fbf49 | 99 | |
3d0f7cf0 | 100 | of_node_put(gg_data.gpiospec.np); |
85ea29ac TB |
101 | pr_debug("%s: parsed '%s' property of node '%s[%d]' - status (%d)\n", |
102 | __func__, propname, np->full_name, index, | |
bea4dbee | 103 | PTR_ERR_OR_ZERO(gg_data.out_gpio)); |
3d0f7cf0 | 104 | return gg_data.out_gpio; |
863fbf49 | 105 | } |
863fbf49 | 106 | |
f01d9075 AC |
107 | int of_get_named_gpio_flags(struct device_node *np, const char *list_name, |
108 | int index, enum of_gpio_flags *flags) | |
109 | { | |
110 | struct gpio_desc *desc; | |
111 | ||
112 | desc = of_get_named_gpiod_flags(np, list_name, index, flags); | |
113 | ||
114 | if (IS_ERR(desc)) | |
115 | return PTR_ERR(desc); | |
116 | else | |
117 | return desc_to_gpio(desc); | |
118 | } | |
119 | EXPORT_SYMBOL(of_get_named_gpio_flags); | |
120 | ||
f625d460 | 121 | /** |
fd7337fd | 122 | * of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API |
f625d460 BP |
123 | * @np: device node to get GPIO from |
124 | * @name: GPIO line name | |
125 | * @lflags: gpio_lookup_flags - returned from of_find_gpio() or | |
fd7337fd | 126 | * of_parse_own_gpio() |
f625d460 BP |
127 | * @dflags: gpiod_flags - optional GPIO initialization flags |
128 | * | |
129 | * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno | |
130 | * value on the error condition. | |
131 | */ | |
fd7337fd MP |
132 | static struct gpio_desc *of_parse_own_gpio(struct device_node *np, |
133 | const char **name, | |
134 | enum gpio_lookup_flags *lflags, | |
135 | enum gpiod_flags *dflags) | |
f625d460 BP |
136 | { |
137 | struct device_node *chip_np; | |
138 | enum of_gpio_flags xlate_flags; | |
f625d460 BP |
139 | struct gg_data gg_data = { |
140 | .flags = &xlate_flags, | |
141 | }; | |
142 | u32 tmp; | |
143 | int i, ret; | |
144 | ||
145 | chip_np = np->parent; | |
146 | if (!chip_np) | |
147 | return ERR_PTR(-EINVAL); | |
148 | ||
149 | xlate_flags = 0; | |
150 | *lflags = 0; | |
151 | *dflags = 0; | |
152 | ||
153 | ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp); | |
154 | if (ret) | |
155 | return ERR_PTR(ret); | |
156 | ||
157 | if (tmp > MAX_PHANDLE_ARGS) | |
158 | return ERR_PTR(-EINVAL); | |
159 | ||
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]); | |
165 | if (ret) | |
166 | return ERR_PTR(ret); | |
167 | } | |
168 | ||
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); | |
173 | else | |
174 | return ERR_PTR(-EINVAL); | |
175 | } | |
176 | ||
177 | if (xlate_flags & OF_GPIO_ACTIVE_LOW) | |
178 | *lflags |= GPIO_ACTIVE_LOW; | |
179 | ||
180 | if (of_property_read_bool(np, "input")) | |
181 | *dflags |= GPIOD_IN; | |
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; | |
186 | else { | |
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); | |
190 | } | |
191 | ||
192 | if (name && of_property_read_string(np, "line-name", name)) | |
193 | *name = np->name; | |
194 | ||
39561e8b | 195 | return gg_data.out_gpio; |
f625d460 BP |
196 | } |
197 | ||
fd9c5531 LW |
198 | /** |
199 | * of_gpiochip_set_names() - set up the names of the lines | |
200 | * @chip: GPIO chip whose lines should be named, if possible | |
201 | */ | |
202 | static void of_gpiochip_set_names(struct gpio_chip *gc) | |
203 | { | |
204 | struct gpio_device *gdev = gc->gpiodev; | |
205 | struct device_node *np = gc->of_node; | |
206 | int i; | |
207 | int nstrings; | |
208 | ||
209 | nstrings = of_property_count_strings(np, "gpio-line-names"); | |
210 | if (nstrings <= 0) | |
211 | /* Lines names not present */ | |
212 | return; | |
213 | ||
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); | |
219 | ||
220 | /* | |
221 | * Make sure to not index beyond the end of the number of descriptors | |
222 | * of the GPIO device. | |
223 | */ | |
224 | for (i = 0; i < gdev->ngpio; i++) { | |
225 | const char *name; | |
226 | int ret; | |
227 | ||
228 | ret = of_property_read_string_index(np, | |
229 | "gpio-line-names", | |
230 | i, | |
231 | &name); | |
232 | if (ret) { | |
233 | if (ret != -ENODATA) | |
234 | dev_err(&gdev->dev, | |
235 | "unable to name line %d: %d\n", | |
236 | i, ret); | |
237 | break; | |
238 | } | |
239 | gdev->descs[i].name = name; | |
240 | } | |
241 | } | |
242 | ||
f625d460 | 243 | /** |
fd7337fd | 244 | * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions |
f625d460 BP |
245 | * @chip: gpio chip to act on |
246 | * | |
247 | * This is only used by of_gpiochip_add to request/set GPIO initial | |
248 | * configuration. | |
dfbd379b | 249 | * It retures error if it fails otherwise 0 on success. |
f625d460 | 250 | */ |
dfbd379b | 251 | static int of_gpiochip_scan_gpios(struct gpio_chip *chip) |
f625d460 BP |
252 | { |
253 | struct gpio_desc *desc = NULL; | |
254 | struct device_node *np; | |
255 | const char *name; | |
256 | enum gpio_lookup_flags lflags; | |
257 | enum gpiod_flags dflags; | |
dfbd379b | 258 | int ret; |
f625d460 | 259 | |
d1279d94 | 260 | for_each_available_child_of_node(chip->of_node, np) { |
f625d460 BP |
261 | if (!of_property_read_bool(np, "gpio-hog")) |
262 | continue; | |
263 | ||
fd7337fd | 264 | desc = of_parse_own_gpio(np, &name, &lflags, &dflags); |
f625d460 BP |
265 | if (IS_ERR(desc)) |
266 | continue; | |
267 | ||
dfbd379b LD |
268 | ret = gpiod_hog(desc, name, lflags, dflags); |
269 | if (ret < 0) | |
270 | return ret; | |
f625d460 | 271 | } |
dfbd379b LD |
272 | |
273 | return 0; | |
f625d460 BP |
274 | } |
275 | ||
863fbf49 | 276 | /** |
b908b53d | 277 | * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags |
a19e3da5 | 278 | * @gc: pointer to the gpio_chip structure |
863fbf49 AV |
279 | * @np: device node of the GPIO chip |
280 | * @gpio_spec: gpio specifier as found in the device tree | |
b908b53d | 281 | * @flags: a flags pointer to fill in |
863fbf49 AV |
282 | * |
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). | |
286 | */ | |
15c9a0ac GL |
287 | int of_gpio_simple_xlate(struct gpio_chip *gc, |
288 | const struct of_phandle_args *gpiospec, u32 *flags) | |
863fbf49 | 289 | { |
b908b53d AV |
290 | /* |
291 | * We're discouraging gpio_cells < 2, since that way you'll have to | |
20a8a968 | 292 | * write your own xlate function (that will have to retrieve the GPIO |
b908b53d AV |
293 | * number and the flags from a single gpio cell -- this is possible, |
294 | * but not recommended). | |
295 | */ | |
a19e3da5 | 296 | if (gc->of_gpio_n_cells < 2) { |
b908b53d AV |
297 | WARN_ON(1); |
298 | return -EINVAL; | |
299 | } | |
300 | ||
15c9a0ac GL |
301 | if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells)) |
302 | return -EINVAL; | |
303 | ||
6270d830 | 304 | if (gpiospec->args[0] >= gc->ngpio) |
863fbf49 AV |
305 | return -EINVAL; |
306 | ||
b908b53d | 307 | if (flags) |
15c9a0ac | 308 | *flags = gpiospec->args[1]; |
b908b53d | 309 | |
15c9a0ac | 310 | return gpiospec->args[0]; |
863fbf49 | 311 | } |
3038bbdf | 312 | EXPORT_SYMBOL(of_gpio_simple_xlate); |
863fbf49 | 313 | |
863fbf49 | 314 | /** |
3208b0f0 | 315 | * of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank) |
863fbf49 AV |
316 | * @np: device node of the GPIO chip |
317 | * @mm_gc: pointer to the of_mm_gpio_chip allocated structure | |
3208b0f0 | 318 | * @data: driver data to store in the struct gpio_chip |
863fbf49 AV |
319 | * |
320 | * To use this function you should allocate and fill mm_gc with: | |
321 | * | |
322 | * 1) In the gpio_chip structure: | |
323 | * - all the callbacks | |
a19e3da5 AV |
324 | * - of_gpio_n_cells |
325 | * - of_xlate callback (optional) | |
863fbf49 AV |
326 | * |
327 | * 3) In the of_mm_gpio_chip structure: | |
328 | * - save_regs callback (optional) | |
329 | * | |
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. | |
333 | */ | |
3208b0f0 LW |
334 | int of_mm_gpiochip_add_data(struct device_node *np, |
335 | struct of_mm_gpio_chip *mm_gc, | |
336 | void *data) | |
863fbf49 AV |
337 | { |
338 | int ret = -ENOMEM; | |
a19e3da5 | 339 | struct gpio_chip *gc = &mm_gc->gc; |
863fbf49 AV |
340 | |
341 | gc->label = kstrdup(np->full_name, GFP_KERNEL); | |
342 | if (!gc->label) | |
343 | goto err0; | |
344 | ||
345 | mm_gc->regs = of_iomap(np, 0); | |
346 | if (!mm_gc->regs) | |
347 | goto err1; | |
348 | ||
21451155 | 349 | gc->base = -1; |
863fbf49 | 350 | |
863fbf49 AV |
351 | if (mm_gc->save_regs) |
352 | mm_gc->save_regs(mm_gc); | |
353 | ||
a19e3da5 | 354 | mm_gc->gc.of_node = np; |
863fbf49 | 355 | |
3208b0f0 | 356 | ret = gpiochip_add_data(gc, data); |
863fbf49 AV |
357 | if (ret) |
358 | goto err2; | |
359 | ||
863fbf49 AV |
360 | return 0; |
361 | err2: | |
863fbf49 AV |
362 | iounmap(mm_gc->regs); |
363 | err1: | |
364 | kfree(gc->label); | |
365 | err0: | |
366 | pr_err("%s: GPIO chip registration failed with status %d\n", | |
367 | np->full_name, ret); | |
368 | return ret; | |
369 | } | |
3208b0f0 | 370 | EXPORT_SYMBOL(of_mm_gpiochip_add_data); |
594fa265 | 371 | |
d621e8ba RRD |
372 | /** |
373 | * of_mm_gpiochip_remove - Remove memory mapped GPIO chip (bank) | |
374 | * @mm_gc: pointer to the of_mm_gpio_chip allocated structure | |
375 | */ | |
376 | void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc) | |
377 | { | |
378 | struct gpio_chip *gc = &mm_gc->gc; | |
379 | ||
380 | if (!mm_gc) | |
381 | return; | |
382 | ||
383 | gpiochip_remove(gc); | |
384 | iounmap(mm_gc->regs); | |
385 | kfree(gc->label); | |
386 | } | |
387 | EXPORT_SYMBOL(of_mm_gpiochip_remove); | |
388 | ||
f23f1516 | 389 | #ifdef CONFIG_PINCTRL |
28355f81 | 390 | static int of_gpiochip_add_pin_range(struct gpio_chip *chip) |
f23f1516 SH |
391 | { |
392 | struct device_node *np = chip->of_node; | |
f23f1516 | 393 | struct of_phandle_args pinspec; |
1e63d7b9 | 394 | struct pinctrl_dev *pctldev; |
f23f1516 | 395 | int index = 0, ret; |
586a87e6 CR |
396 | const char *name; |
397 | static const char group_names_propname[] = "gpio-ranges-group-names"; | |
398 | struct property *group_names; | |
f23f1516 SH |
399 | |
400 | if (!np) | |
28355f81 | 401 | return 0; |
f23f1516 | 402 | |
586a87e6 CR |
403 | group_names = of_find_property(np, group_names_propname, NULL); |
404 | ||
ad4e1a7c | 405 | for (;; index++) { |
d9fe0039 SW |
406 | ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3, |
407 | index, &pinspec); | |
f23f1516 SH |
408 | if (ret) |
409 | break; | |
410 | ||
1e63d7b9 | 411 | pctldev = of_pinctrl_get(pinspec.np); |
602cf638 | 412 | of_node_put(pinspec.np); |
1e63d7b9 | 413 | if (!pctldev) |
28355f81 | 414 | return -EPROBE_DEFER; |
f23f1516 | 415 | |
586a87e6 CR |
416 | if (pinspec.args[2]) { |
417 | if (group_names) { | |
72858602 | 418 | of_property_read_string_index(np, |
586a87e6 CR |
419 | group_names_propname, |
420 | index, &name); | |
421 | if (strlen(name)) { | |
422 | pr_err("%s: Group name of numeric GPIO ranges must be the empty string.\n", | |
423 | np->full_name); | |
424 | break; | |
425 | } | |
426 | } | |
427 | /* npins != 0: linear range */ | |
428 | ret = gpiochip_add_pin_range(chip, | |
429 | pinctrl_dev_get_devname(pctldev), | |
430 | pinspec.args[0], | |
431 | pinspec.args[1], | |
432 | pinspec.args[2]); | |
433 | if (ret) | |
28355f81 | 434 | return ret; |
586a87e6 CR |
435 | } else { |
436 | /* npins == 0: special range */ | |
437 | if (pinspec.args[1]) { | |
438 | pr_err("%s: Illegal gpio-range format.\n", | |
439 | np->full_name); | |
440 | break; | |
441 | } | |
442 | ||
443 | if (!group_names) { | |
444 | pr_err("%s: GPIO group range requested but no %s property.\n", | |
445 | np->full_name, group_names_propname); | |
446 | break; | |
447 | } | |
448 | ||
449 | ret = of_property_read_string_index(np, | |
450 | group_names_propname, | |
451 | index, &name); | |
452 | if (ret) | |
453 | break; | |
454 | ||
455 | if (!strlen(name)) { | |
456 | pr_err("%s: Group name of GPIO group range cannot be the empty string.\n", | |
457 | np->full_name); | |
458 | break; | |
459 | } | |
460 | ||
461 | ret = gpiochip_add_pingroup_range(chip, pctldev, | |
462 | pinspec.args[0], name); | |
463 | if (ret) | |
28355f81 | 464 | return ret; |
586a87e6 | 465 | } |
ad4e1a7c | 466 | } |
28355f81 TV |
467 | |
468 | return 0; | |
f23f1516 SH |
469 | } |
470 | ||
f23f1516 | 471 | #else |
28355f81 | 472 | static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; } |
f23f1516 SH |
473 | #endif |
474 | ||
28355f81 | 475 | int of_gpiochip_add(struct gpio_chip *chip) |
391c970c | 476 | { |
28355f81 TV |
477 | int status; |
478 | ||
58383c78 LW |
479 | if ((!chip->of_node) && (chip->parent)) |
480 | chip->of_node = chip->parent->of_node; | |
391c970c AV |
481 | |
482 | if (!chip->of_node) | |
28355f81 | 483 | return 0; |
391c970c AV |
484 | |
485 | if (!chip->of_xlate) { | |
486 | chip->of_gpio_n_cells = 2; | |
487 | chip->of_xlate = of_gpio_simple_xlate; | |
488 | } | |
489 | ||
28355f81 TV |
490 | status = of_gpiochip_add_pin_range(chip); |
491 | if (status) | |
492 | return status; | |
493 | ||
fd9c5531 LW |
494 | /* If the chip defines names itself, these take precedence */ |
495 | if (!chip->names) | |
496 | of_gpiochip_set_names(chip); | |
497 | ||
391c970c | 498 | of_node_get(chip->of_node); |
f625d460 | 499 | |
dfbd379b | 500 | return of_gpiochip_scan_gpios(chip); |
391c970c AV |
501 | } |
502 | ||
503 | void of_gpiochip_remove(struct gpio_chip *chip) | |
504 | { | |
e93fa3f2 | 505 | gpiochip_remove_pin_ranges(chip); |
8a691550 | 506 | of_node_put(chip->of_node); |
391c970c | 507 | } |