Commit | Line | Data |
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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 | |
762c2e46 | 29 | static int of_gpiochip_match_node(struct gpio_chip *chip, void *data) |
3d0f7cf0 | 30 | { |
762c2e46 MY |
31 | return chip->gpiodev->dev.of_node == data; |
32 | } | |
3d0f7cf0 | 33 | |
762c2e46 MY |
34 | static struct gpio_chip *of_find_gpiochip_by_node(struct device_node *np) |
35 | { | |
36 | return gpiochip_find(np, of_gpiochip_match_node); | |
3d0f7cf0 | 37 | } |
3d0f7cf0 | 38 | |
99468c1a MY |
39 | static struct gpio_desc *of_xlate_and_get_gpiod_flags(struct gpio_chip *chip, |
40 | struct of_phandle_args *gpiospec, | |
41 | enum of_gpio_flags *flags) | |
3d0f7cf0 | 42 | { |
3d0f7cf0 GL |
43 | int ret; |
44 | ||
99468c1a MY |
45 | if (chip->of_gpio_n_cells != gpiospec->args_count) |
46 | return ERR_PTR(-EINVAL); | |
47 | ||
48 | ret = chip->of_xlate(chip, gpiospec, flags); | |
49 | if (ret < 0) | |
50 | return ERR_PTR(ret); | |
51 | ||
52 | return gpiochip_get_desc(chip, ret); | |
3d0f7cf0 GL |
53 | } |
54 | ||
863fbf49 | 55 | /** |
af8b6375 | 56 | * of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API |
863fbf49 | 57 | * @np: device node to get GPIO from |
a6b09191 | 58 | * @propname: property name containing gpio specifier(s) |
863fbf49 | 59 | * @index: index of the GPIO |
b908b53d | 60 | * @flags: a flags pointer to fill in |
863fbf49 | 61 | * |
af8b6375 | 62 | * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno |
b908b53d AV |
63 | * value on the error condition. If @flags is not NULL the function also fills |
64 | * in flags for the GPIO. | |
863fbf49 | 65 | */ |
af8b6375 AC |
66 | struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np, |
67 | const char *propname, int index, enum of_gpio_flags *flags) | |
863fbf49 | 68 | { |
762c2e46 MY |
69 | struct of_phandle_args gpiospec; |
70 | struct gpio_chip *chip; | |
71 | struct gpio_desc *desc; | |
64b60e09 | 72 | int ret; |
3d0f7cf0 | 73 | |
15c9a0ac | 74 | ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index, |
762c2e46 | 75 | &gpiospec); |
64b60e09 | 76 | if (ret) { |
85ea29ac TB |
77 | pr_debug("%s: can't parse '%s' property of node '%s[%d]'\n", |
78 | __func__, propname, np->full_name, index); | |
af8b6375 | 79 | return ERR_PTR(ret); |
863fbf49 AV |
80 | } |
81 | ||
762c2e46 MY |
82 | chip = of_find_gpiochip_by_node(gpiospec.np); |
83 | if (!chip) { | |
84 | desc = ERR_PTR(-EPROBE_DEFER); | |
85 | goto out; | |
86 | } | |
762c2e46 | 87 | |
99468c1a | 88 | desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, flags); |
762c2e46 MY |
89 | if (IS_ERR(desc)) |
90 | goto out; | |
863fbf49 | 91 | |
85ea29ac TB |
92 | pr_debug("%s: parsed '%s' property of node '%s[%d]' - status (%d)\n", |
93 | __func__, propname, np->full_name, index, | |
762c2e46 MY |
94 | PTR_ERR_OR_ZERO(desc)); |
95 | ||
96 | out: | |
97 | of_node_put(gpiospec.np); | |
98 | ||
99 | return desc; | |
863fbf49 | 100 | } |
863fbf49 | 101 | |
f01d9075 AC |
102 | int of_get_named_gpio_flags(struct device_node *np, const char *list_name, |
103 | int index, enum of_gpio_flags *flags) | |
104 | { | |
105 | struct gpio_desc *desc; | |
106 | ||
107 | desc = of_get_named_gpiod_flags(np, list_name, index, flags); | |
108 | ||
109 | if (IS_ERR(desc)) | |
110 | return PTR_ERR(desc); | |
111 | else | |
112 | return desc_to_gpio(desc); | |
113 | } | |
114 | EXPORT_SYMBOL(of_get_named_gpio_flags); | |
115 | ||
f625d460 | 116 | /** |
fd7337fd | 117 | * of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API |
f625d460 | 118 | * @np: device node to get GPIO from |
be715343 | 119 | * @chip: GPIO chip whose hog is parsed |
f625d460 BP |
120 | * @name: GPIO line name |
121 | * @lflags: gpio_lookup_flags - returned from of_find_gpio() or | |
fd7337fd | 122 | * of_parse_own_gpio() |
f625d460 BP |
123 | * @dflags: gpiod_flags - optional GPIO initialization flags |
124 | * | |
125 | * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno | |
126 | * value on the error condition. | |
127 | */ | |
fd7337fd | 128 | static struct gpio_desc *of_parse_own_gpio(struct device_node *np, |
be715343 | 129 | struct gpio_chip *chip, |
fd7337fd MP |
130 | const char **name, |
131 | enum gpio_lookup_flags *lflags, | |
132 | enum gpiod_flags *dflags) | |
f625d460 BP |
133 | { |
134 | struct device_node *chip_np; | |
135 | enum of_gpio_flags xlate_flags; | |
be715343 MY |
136 | struct of_phandle_args gpiospec; |
137 | struct gpio_desc *desc; | |
f625d460 | 138 | u32 tmp; |
3f9547e1 | 139 | int ret; |
f625d460 | 140 | |
be715343 | 141 | chip_np = chip->of_node; |
f625d460 BP |
142 | if (!chip_np) |
143 | return ERR_PTR(-EINVAL); | |
144 | ||
145 | xlate_flags = 0; | |
146 | *lflags = 0; | |
147 | *dflags = 0; | |
148 | ||
149 | ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp); | |
150 | if (ret) | |
151 | return ERR_PTR(ret); | |
152 | ||
be715343 MY |
153 | gpiospec.np = chip_np; |
154 | gpiospec.args_count = tmp; | |
f625d460 | 155 | |
be715343 | 156 | ret = of_property_read_u32_array(np, "gpios", gpiospec.args, tmp); |
3f9547e1 MY |
157 | if (ret) |
158 | return ERR_PTR(ret); | |
f625d460 | 159 | |
99468c1a | 160 | desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, &xlate_flags); |
be715343 MY |
161 | if (IS_ERR(desc)) |
162 | return desc; | |
f625d460 BP |
163 | |
164 | if (xlate_flags & OF_GPIO_ACTIVE_LOW) | |
165 | *lflags |= GPIO_ACTIVE_LOW; | |
166 | ||
167 | if (of_property_read_bool(np, "input")) | |
168 | *dflags |= GPIOD_IN; | |
169 | else if (of_property_read_bool(np, "output-low")) | |
170 | *dflags |= GPIOD_OUT_LOW; | |
171 | else if (of_property_read_bool(np, "output-high")) | |
172 | *dflags |= GPIOD_OUT_HIGH; | |
173 | else { | |
174 | pr_warn("GPIO line %d (%s): no hogging state specified, bailing out\n", | |
be715343 | 175 | desc_to_gpio(desc), np->name); |
f625d460 BP |
176 | return ERR_PTR(-EINVAL); |
177 | } | |
178 | ||
179 | if (name && of_property_read_string(np, "line-name", name)) | |
180 | *name = np->name; | |
181 | ||
be715343 | 182 | return desc; |
f625d460 BP |
183 | } |
184 | ||
fd9c5531 LW |
185 | /** |
186 | * of_gpiochip_set_names() - set up the names of the lines | |
187 | * @chip: GPIO chip whose lines should be named, if possible | |
188 | */ | |
189 | static void of_gpiochip_set_names(struct gpio_chip *gc) | |
190 | { | |
191 | struct gpio_device *gdev = gc->gpiodev; | |
192 | struct device_node *np = gc->of_node; | |
193 | int i; | |
194 | int nstrings; | |
195 | ||
196 | nstrings = of_property_count_strings(np, "gpio-line-names"); | |
197 | if (nstrings <= 0) | |
198 | /* Lines names not present */ | |
199 | return; | |
200 | ||
201 | /* This is normally not what you want */ | |
202 | if (gdev->ngpio != nstrings) | |
203 | dev_info(&gdev->dev, "gpio-line-names specifies %d line " | |
204 | "names but there are %d lines on the chip\n", | |
205 | nstrings, gdev->ngpio); | |
206 | ||
207 | /* | |
208 | * Make sure to not index beyond the end of the number of descriptors | |
209 | * of the GPIO device. | |
210 | */ | |
211 | for (i = 0; i < gdev->ngpio; i++) { | |
212 | const char *name; | |
213 | int ret; | |
214 | ||
215 | ret = of_property_read_string_index(np, | |
216 | "gpio-line-names", | |
217 | i, | |
218 | &name); | |
219 | if (ret) { | |
220 | if (ret != -ENODATA) | |
221 | dev_err(&gdev->dev, | |
222 | "unable to name line %d: %d\n", | |
223 | i, ret); | |
224 | break; | |
225 | } | |
226 | gdev->descs[i].name = name; | |
227 | } | |
228 | } | |
229 | ||
f625d460 | 230 | /** |
fd7337fd | 231 | * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions |
f625d460 BP |
232 | * @chip: gpio chip to act on |
233 | * | |
234 | * This is only used by of_gpiochip_add to request/set GPIO initial | |
235 | * configuration. | |
dfbd379b | 236 | * It retures error if it fails otherwise 0 on success. |
f625d460 | 237 | */ |
dfbd379b | 238 | static int of_gpiochip_scan_gpios(struct gpio_chip *chip) |
f625d460 BP |
239 | { |
240 | struct gpio_desc *desc = NULL; | |
241 | struct device_node *np; | |
242 | const char *name; | |
243 | enum gpio_lookup_flags lflags; | |
244 | enum gpiod_flags dflags; | |
dfbd379b | 245 | int ret; |
f625d460 | 246 | |
d1279d94 | 247 | for_each_available_child_of_node(chip->of_node, np) { |
f625d460 BP |
248 | if (!of_property_read_bool(np, "gpio-hog")) |
249 | continue; | |
250 | ||
be715343 | 251 | desc = of_parse_own_gpio(np, chip, &name, &lflags, &dflags); |
f625d460 BP |
252 | if (IS_ERR(desc)) |
253 | continue; | |
254 | ||
dfbd379b LD |
255 | ret = gpiod_hog(desc, name, lflags, dflags); |
256 | if (ret < 0) | |
257 | return ret; | |
f625d460 | 258 | } |
dfbd379b LD |
259 | |
260 | return 0; | |
f625d460 BP |
261 | } |
262 | ||
863fbf49 | 263 | /** |
b908b53d | 264 | * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags |
a19e3da5 | 265 | * @gc: pointer to the gpio_chip structure |
863fbf49 AV |
266 | * @np: device node of the GPIO chip |
267 | * @gpio_spec: gpio specifier as found in the device tree | |
b908b53d | 268 | * @flags: a flags pointer to fill in |
863fbf49 AV |
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 | */ | |
15c9a0ac GL |
274 | int of_gpio_simple_xlate(struct gpio_chip *gc, |
275 | const struct of_phandle_args *gpiospec, u32 *flags) | |
863fbf49 | 276 | { |
b908b53d AV |
277 | /* |
278 | * We're discouraging gpio_cells < 2, since that way you'll have to | |
20a8a968 | 279 | * write your own xlate function (that will have to retrieve the GPIO |
b908b53d AV |
280 | * number and the flags from a single gpio cell -- this is possible, |
281 | * but not recommended). | |
282 | */ | |
a19e3da5 | 283 | if (gc->of_gpio_n_cells < 2) { |
b908b53d AV |
284 | WARN_ON(1); |
285 | return -EINVAL; | |
286 | } | |
287 | ||
15c9a0ac GL |
288 | if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells)) |
289 | return -EINVAL; | |
290 | ||
6270d830 | 291 | if (gpiospec->args[0] >= gc->ngpio) |
863fbf49 AV |
292 | return -EINVAL; |
293 | ||
b908b53d | 294 | if (flags) |
15c9a0ac | 295 | *flags = gpiospec->args[1]; |
b908b53d | 296 | |
15c9a0ac | 297 | return gpiospec->args[0]; |
863fbf49 | 298 | } |
3038bbdf | 299 | EXPORT_SYMBOL(of_gpio_simple_xlate); |
863fbf49 | 300 | |
863fbf49 | 301 | /** |
3208b0f0 | 302 | * of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank) |
863fbf49 AV |
303 | * @np: device node of the GPIO chip |
304 | * @mm_gc: pointer to the of_mm_gpio_chip allocated structure | |
3208b0f0 | 305 | * @data: driver data to store in the struct gpio_chip |
863fbf49 AV |
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 | |
a19e3da5 AV |
311 | * - of_gpio_n_cells |
312 | * - of_xlate callback (optional) | |
863fbf49 AV |
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 | */ | |
3208b0f0 LW |
321 | int of_mm_gpiochip_add_data(struct device_node *np, |
322 | struct of_mm_gpio_chip *mm_gc, | |
323 | void *data) | |
863fbf49 AV |
324 | { |
325 | int ret = -ENOMEM; | |
a19e3da5 | 326 | struct gpio_chip *gc = &mm_gc->gc; |
863fbf49 AV |
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 | ||
21451155 | 336 | gc->base = -1; |
863fbf49 | 337 | |
863fbf49 AV |
338 | if (mm_gc->save_regs) |
339 | mm_gc->save_regs(mm_gc); | |
340 | ||
a19e3da5 | 341 | mm_gc->gc.of_node = np; |
863fbf49 | 342 | |
3208b0f0 | 343 | ret = gpiochip_add_data(gc, data); |
863fbf49 AV |
344 | if (ret) |
345 | goto err2; | |
346 | ||
863fbf49 AV |
347 | return 0; |
348 | err2: | |
863fbf49 AV |
349 | iounmap(mm_gc->regs); |
350 | err1: | |
351 | kfree(gc->label); | |
352 | err0: | |
353 | pr_err("%s: GPIO chip registration failed with status %d\n", | |
354 | np->full_name, ret); | |
355 | return ret; | |
356 | } | |
3208b0f0 | 357 | EXPORT_SYMBOL(of_mm_gpiochip_add_data); |
594fa265 | 358 | |
d621e8ba RRD |
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 | */ | |
363 | void 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 | } | |
374 | EXPORT_SYMBOL(of_mm_gpiochip_remove); | |
375 | ||
f23f1516 | 376 | #ifdef CONFIG_PINCTRL |
28355f81 | 377 | static int of_gpiochip_add_pin_range(struct gpio_chip *chip) |
f23f1516 SH |
378 | { |
379 | struct device_node *np = chip->of_node; | |
f23f1516 | 380 | struct of_phandle_args pinspec; |
1e63d7b9 | 381 | struct pinctrl_dev *pctldev; |
f23f1516 | 382 | int index = 0, ret; |
586a87e6 CR |
383 | const char *name; |
384 | static const char group_names_propname[] = "gpio-ranges-group-names"; | |
385 | struct property *group_names; | |
f23f1516 SH |
386 | |
387 | if (!np) | |
28355f81 | 388 | return 0; |
f23f1516 | 389 | |
586a87e6 CR |
390 | group_names = of_find_property(np, group_names_propname, NULL); |
391 | ||
ad4e1a7c | 392 | for (;; index++) { |
d9fe0039 SW |
393 | ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3, |
394 | index, &pinspec); | |
f23f1516 SH |
395 | if (ret) |
396 | break; | |
397 | ||
1e63d7b9 | 398 | pctldev = of_pinctrl_get(pinspec.np); |
602cf638 | 399 | of_node_put(pinspec.np); |
1e63d7b9 | 400 | if (!pctldev) |
28355f81 | 401 | return -EPROBE_DEFER; |
f23f1516 | 402 | |
586a87e6 CR |
403 | if (pinspec.args[2]) { |
404 | if (group_names) { | |
72858602 | 405 | of_property_read_string_index(np, |
586a87e6 CR |
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) | |
28355f81 | 421 | return ret; |
586a87e6 CR |
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) | |
28355f81 | 451 | return ret; |
586a87e6 | 452 | } |
ad4e1a7c | 453 | } |
28355f81 TV |
454 | |
455 | return 0; | |
f23f1516 SH |
456 | } |
457 | ||
f23f1516 | 458 | #else |
28355f81 | 459 | static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; } |
f23f1516 SH |
460 | #endif |
461 | ||
28355f81 | 462 | int of_gpiochip_add(struct gpio_chip *chip) |
391c970c | 463 | { |
28355f81 TV |
464 | int status; |
465 | ||
58383c78 LW |
466 | if ((!chip->of_node) && (chip->parent)) |
467 | chip->of_node = chip->parent->of_node; | |
391c970c AV |
468 | |
469 | if (!chip->of_node) | |
28355f81 | 470 | return 0; |
391c970c AV |
471 | |
472 | if (!chip->of_xlate) { | |
473 | chip->of_gpio_n_cells = 2; | |
474 | chip->of_xlate = of_gpio_simple_xlate; | |
475 | } | |
476 | ||
1020dfd1 MY |
477 | if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS) |
478 | return -EINVAL; | |
479 | ||
28355f81 TV |
480 | status = of_gpiochip_add_pin_range(chip); |
481 | if (status) | |
482 | return status; | |
483 | ||
fd9c5531 LW |
484 | /* If the chip defines names itself, these take precedence */ |
485 | if (!chip->names) | |
486 | of_gpiochip_set_names(chip); | |
487 | ||
391c970c | 488 | of_node_get(chip->of_node); |
f625d460 | 489 | |
dfbd379b | 490 | return of_gpiochip_scan_gpios(chip); |
391c970c AV |
491 | } |
492 | ||
493 | void of_gpiochip_remove(struct gpio_chip *chip) | |
494 | { | |
e93fa3f2 | 495 | gpiochip_remove_pin_ranges(chip); |
8a691550 | 496 | of_node_put(chip->of_node); |
391c970c | 497 | } |