KVM: x86: always use "acknowledge interrupt on exit"
[linux/fpc-iii.git] / drivers / gpio / gpiolib-of.c
blobd22dcc38179dba153d3874e39847665a2811f8b9
1 /*
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>
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>
27 #include "gpiolib.h"
29 /* Private data structure for of_gpiochip_find_and_xlate */
30 struct gg_data {
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;
41 int ret;
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;
48 ret = gc->of_xlate(gc, &gg_data->gpiospec, gg_data->flags);
49 if (ret < 0) {
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);
56 return false;
59 gg_data->out_gpio = gpiochip_get_desc(gc, ret);
60 return true;
63 /**
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 = {
81 .flags = flags,
82 .out_gpio = ERR_PTR(-EPROBE_DEFER)
84 int ret;
86 /* .of_xlate might decide to not fill in the flags, so clear it. */
87 if (flags)
88 *flags = 0;
90 ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index,
91 &gg_data.gpiospec);
92 if (ret) {
93 pr_debug("%s: can't parse '%s' property of node '%s[%d]'\n",
94 __func__, propname, np->full_name, index);
95 return ERR_PTR(ret);
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);
114 if (IS_ERR(desc))
115 return PTR_ERR(desc);
116 else
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,
133 const char **name,
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,
142 u32 tmp;
143 int i, ret;
145 chip_np = np->parent;
146 if (!chip_np)
147 return ERR_PTR(-EINVAL);
149 xlate_flags = 0;
150 *lflags = 0;
151 *dflags = 0;
153 ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp);
154 if (ret)
155 return ERR_PTR(ret);
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]);
165 if (ret)
166 return ERR_PTR(ret);
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);
177 if (xlate_flags & OF_GPIO_ACTIVE_LOW)
178 *lflags |= GPIO_ACTIVE_LOW;
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);
192 if (name && of_property_read_string(np, "line-name", name))
193 *name = np->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;
206 int i;
207 int nstrings;
209 nstrings = of_property_count_strings(np, "gpio-line-names");
210 if (nstrings <= 0)
211 /* Lines names not present */
212 return;
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++) {
225 const char *name;
226 int ret;
228 ret = of_property_read_string_index(np,
229 "gpio-line-names",
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;
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
248 * configuration.
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;
255 const char *name;
256 enum gpio_lookup_flags lflags;
257 enum gpiod_flags dflags;
258 int ret;
260 for_each_available_child_of_node(chip->of_node, np) {
261 if (!of_property_read_bool(np, "gpio-hog"))
262 continue;
264 desc = of_parse_own_gpio(np, &name, &lflags, &dflags);
265 if (IS_ERR(desc))
266 continue;
268 ret = gpiod_hog(desc, name, lflags, dflags);
269 if (ret < 0)
270 return ret;
273 return 0;
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) {
297 WARN_ON(1);
298 return -EINVAL;
301 if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
302 return -EINVAL;
304 if (gpiospec->args[0] >= gc->ngpio)
305 return -EINVAL;
307 if (flags)
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
324 * - of_gpio_n_cells
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,
336 void *data)
338 int ret = -ENOMEM;
339 struct gpio_chip *gc = &mm_gc->gc;
341 gc->label = kstrdup(np->full_name, GFP_KERNEL);
342 if (!gc->label)
343 goto err0;
345 mm_gc->regs = of_iomap(np, 0);
346 if (!mm_gc->regs)
347 goto err1;
349 gc->base = -1;
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);
357 if (ret)
358 goto err2;
360 return 0;
361 err2:
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;
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;
380 if (!mm_gc)
381 return;
383 gpiochip_remove(gc);
384 iounmap(mm_gc->regs);
385 kfree(gc->label);
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;
395 int index = 0, ret;
396 const char *name;
397 static const char group_names_propname[] = "gpio-ranges-group-names";
398 struct property *group_names;
400 if (!np)
401 return 0;
403 group_names = of_find_property(np, group_names_propname, NULL);
405 for (;; index++) {
406 ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
407 index, &pinspec);
408 if (ret)
409 break;
411 pctldev = of_pinctrl_get(pinspec.np);
412 if (!pctldev)
413 return -EPROBE_DEFER;
415 if (pinspec.args[2]) {
416 if (group_names) {
417 of_property_read_string_index(np,
418 group_names_propname,
419 index, &name);
420 if (strlen(name)) {
421 pr_err("%s: Group name of numeric GPIO ranges must be the empty string.\n",
422 np->full_name);
423 break;
426 /* npins != 0: linear range */
427 ret = gpiochip_add_pin_range(chip,
428 pinctrl_dev_get_devname(pctldev),
429 pinspec.args[0],
430 pinspec.args[1],
431 pinspec.args[2]);
432 if (ret)
433 return ret;
434 } else {
435 /* npins == 0: special range */
436 if (pinspec.args[1]) {
437 pr_err("%s: Illegal gpio-range format.\n",
438 np->full_name);
439 break;
442 if (!group_names) {
443 pr_err("%s: GPIO group range requested but no %s property.\n",
444 np->full_name, group_names_propname);
445 break;
448 ret = of_property_read_string_index(np,
449 group_names_propname,
450 index, &name);
451 if (ret)
452 break;
454 if (!strlen(name)) {
455 pr_err("%s: Group name of GPIO group range cannot be the empty string.\n",
456 np->full_name);
457 break;
460 ret = gpiochip_add_pingroup_range(chip, pctldev,
461 pinspec.args[0], name);
462 if (ret)
463 return ret;
467 return 0;
470 #else
471 static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; }
472 #endif
474 int of_gpiochip_add(struct gpio_chip *chip)
476 int status;
478 if ((!chip->of_node) && (chip->parent))
479 chip->of_node = chip->parent->of_node;
481 if (!chip->of_node)
482 return 0;
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);
490 if (status)
491 return status;
493 /* If the chip defines names itself, these take precedence */
494 if (!chip->names)
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);