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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> |
863fbf49 | 25 | |
1bd6b601 | 26 | #include "gpiolib.h" |
af8b6375 | 27 | |
0df2c999 | 28 | /* Private data structure for of_gpiochip_find_and_xlate */ |
3d0f7cf0 GL |
29 | struct gg_data { |
30 | enum of_gpio_flags *flags; | |
31 | struct of_phandle_args gpiospec; | |
32 | ||
af8b6375 | 33 | struct gpio_desc *out_gpio; |
3d0f7cf0 GL |
34 | }; |
35 | ||
36 | /* Private function for resolving node pointer to gpio_chip */ | |
37 | static 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 | ||
ccd9726e | 51 | gg_data->out_gpio = gpiochip_get_desc(gc, ret); |
3d0f7cf0 GL |
52 | return true; |
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 | { |
4fbb0022 RS |
69 | /* Return -EPROBE_DEFER to support probe() functions to be called |
70 | * later when the GPIO actually becomes available | |
71 | */ | |
af8b6375 AC |
72 | struct gg_data gg_data = { |
73 | .flags = flags, | |
74 | .out_gpio = ERR_PTR(-EPROBE_DEFER) | |
75 | }; | |
64b60e09 | 76 | int ret; |
3d0f7cf0 GL |
77 | |
78 | /* .of_xlate might decide to not fill in the flags, so clear it. */ | |
79 | if (flags) | |
80 | *flags = 0; | |
863fbf49 | 81 | |
15c9a0ac | 82 | ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index, |
3d0f7cf0 | 83 | &gg_data.gpiospec); |
64b60e09 | 84 | if (ret) { |
85ea29ac TB |
85 | pr_debug("%s: can't parse '%s' property of node '%s[%d]'\n", |
86 | __func__, propname, np->full_name, index); | |
af8b6375 | 87 | return ERR_PTR(ret); |
863fbf49 AV |
88 | } |
89 | ||
3d0f7cf0 | 90 | gpiochip_find(&gg_data, of_gpiochip_find_and_xlate); |
863fbf49 | 91 | |
3d0f7cf0 | 92 | of_node_put(gg_data.gpiospec.np); |
85ea29ac TB |
93 | pr_debug("%s: parsed '%s' property of node '%s[%d]' - status (%d)\n", |
94 | __func__, propname, np->full_name, index, | |
bea4dbee | 95 | PTR_ERR_OR_ZERO(gg_data.out_gpio)); |
3d0f7cf0 | 96 | return gg_data.out_gpio; |
863fbf49 | 97 | } |
863fbf49 | 98 | |
f01d9075 AC |
99 | int of_get_named_gpio_flags(struct device_node *np, const char *list_name, |
100 | int index, enum of_gpio_flags *flags) | |
101 | { | |
102 | struct gpio_desc *desc; | |
103 | ||
104 | desc = of_get_named_gpiod_flags(np, list_name, index, flags); | |
105 | ||
106 | if (IS_ERR(desc)) | |
107 | return PTR_ERR(desc); | |
108 | else | |
109 | return desc_to_gpio(desc); | |
110 | } | |
111 | EXPORT_SYMBOL(of_get_named_gpio_flags); | |
112 | ||
863fbf49 | 113 | /** |
b908b53d | 114 | * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags |
a19e3da5 | 115 | * @gc: pointer to the gpio_chip structure |
863fbf49 AV |
116 | * @np: device node of the GPIO chip |
117 | * @gpio_spec: gpio specifier as found in the device tree | |
b908b53d | 118 | * @flags: a flags pointer to fill in |
863fbf49 AV |
119 | * |
120 | * This is simple translation function, suitable for the most 1:1 mapped | |
121 | * gpio chips. This function performs only one sanity check: whether gpio | |
122 | * is less than ngpios (that is specified in the gpio_chip). | |
123 | */ | |
15c9a0ac GL |
124 | int of_gpio_simple_xlate(struct gpio_chip *gc, |
125 | const struct of_phandle_args *gpiospec, u32 *flags) | |
863fbf49 | 126 | { |
b908b53d AV |
127 | /* |
128 | * We're discouraging gpio_cells < 2, since that way you'll have to | |
129 | * write your own xlate function (that will have to retrive the GPIO | |
130 | * number and the flags from a single gpio cell -- this is possible, | |
131 | * but not recommended). | |
132 | */ | |
a19e3da5 | 133 | if (gc->of_gpio_n_cells < 2) { |
b908b53d AV |
134 | WARN_ON(1); |
135 | return -EINVAL; | |
136 | } | |
137 | ||
15c9a0ac GL |
138 | if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells)) |
139 | return -EINVAL; | |
140 | ||
6270d830 | 141 | if (gpiospec->args[0] >= gc->ngpio) |
863fbf49 AV |
142 | return -EINVAL; |
143 | ||
b908b53d | 144 | if (flags) |
15c9a0ac | 145 | *flags = gpiospec->args[1]; |
b908b53d | 146 | |
15c9a0ac | 147 | return gpiospec->args[0]; |
863fbf49 | 148 | } |
3038bbdf | 149 | EXPORT_SYMBOL(of_gpio_simple_xlate); |
863fbf49 | 150 | |
863fbf49 AV |
151 | /** |
152 | * of_mm_gpiochip_add - Add memory mapped GPIO chip (bank) | |
153 | * @np: device node of the GPIO chip | |
154 | * @mm_gc: pointer to the of_mm_gpio_chip allocated structure | |
155 | * | |
156 | * To use this function you should allocate and fill mm_gc with: | |
157 | * | |
158 | * 1) In the gpio_chip structure: | |
159 | * - all the callbacks | |
a19e3da5 AV |
160 | * - of_gpio_n_cells |
161 | * - of_xlate callback (optional) | |
863fbf49 AV |
162 | * |
163 | * 3) In the of_mm_gpio_chip structure: | |
164 | * - save_regs callback (optional) | |
165 | * | |
166 | * If succeeded, this function will map bank's memory and will | |
167 | * do all necessary work for you. Then you'll able to use .regs | |
168 | * to manage GPIOs from the callbacks. | |
169 | */ | |
170 | int of_mm_gpiochip_add(struct device_node *np, | |
171 | struct of_mm_gpio_chip *mm_gc) | |
172 | { | |
173 | int ret = -ENOMEM; | |
a19e3da5 | 174 | struct gpio_chip *gc = &mm_gc->gc; |
863fbf49 AV |
175 | |
176 | gc->label = kstrdup(np->full_name, GFP_KERNEL); | |
177 | if (!gc->label) | |
178 | goto err0; | |
179 | ||
180 | mm_gc->regs = of_iomap(np, 0); | |
181 | if (!mm_gc->regs) | |
182 | goto err1; | |
183 | ||
21451155 | 184 | gc->base = -1; |
863fbf49 | 185 | |
863fbf49 AV |
186 | if (mm_gc->save_regs) |
187 | mm_gc->save_regs(mm_gc); | |
188 | ||
a19e3da5 | 189 | mm_gc->gc.of_node = np; |
863fbf49 AV |
190 | |
191 | ret = gpiochip_add(gc); | |
192 | if (ret) | |
193 | goto err2; | |
194 | ||
863fbf49 AV |
195 | return 0; |
196 | err2: | |
863fbf49 AV |
197 | iounmap(mm_gc->regs); |
198 | err1: | |
199 | kfree(gc->label); | |
200 | err0: | |
201 | pr_err("%s: GPIO chip registration failed with status %d\n", | |
202 | np->full_name, ret); | |
203 | return ret; | |
204 | } | |
205 | EXPORT_SYMBOL(of_mm_gpiochip_add); | |
594fa265 | 206 | |
f23f1516 | 207 | #ifdef CONFIG_PINCTRL |
167c1af9 | 208 | static void of_gpiochip_add_pin_range(struct gpio_chip *chip) |
f23f1516 SH |
209 | { |
210 | struct device_node *np = chip->of_node; | |
f23f1516 | 211 | struct of_phandle_args pinspec; |
1e63d7b9 | 212 | struct pinctrl_dev *pctldev; |
f23f1516 | 213 | int index = 0, ret; |
586a87e6 CR |
214 | const char *name; |
215 | static const char group_names_propname[] = "gpio-ranges-group-names"; | |
216 | struct property *group_names; | |
f23f1516 SH |
217 | |
218 | if (!np) | |
219 | return; | |
220 | ||
586a87e6 CR |
221 | group_names = of_find_property(np, group_names_propname, NULL); |
222 | ||
ad4e1a7c | 223 | for (;; index++) { |
d9fe0039 SW |
224 | ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3, |
225 | index, &pinspec); | |
f23f1516 SH |
226 | if (ret) |
227 | break; | |
228 | ||
1e63d7b9 LW |
229 | pctldev = of_pinctrl_get(pinspec.np); |
230 | if (!pctldev) | |
f23f1516 | 231 | break; |
f23f1516 | 232 | |
586a87e6 CR |
233 | if (pinspec.args[2]) { |
234 | if (group_names) { | |
235 | ret = of_property_read_string_index(np, | |
236 | group_names_propname, | |
237 | index, &name); | |
238 | if (strlen(name)) { | |
239 | pr_err("%s: Group name of numeric GPIO ranges must be the empty string.\n", | |
240 | np->full_name); | |
241 | break; | |
242 | } | |
243 | } | |
244 | /* npins != 0: linear range */ | |
245 | ret = gpiochip_add_pin_range(chip, | |
246 | pinctrl_dev_get_devname(pctldev), | |
247 | pinspec.args[0], | |
248 | pinspec.args[1], | |
249 | pinspec.args[2]); | |
250 | if (ret) | |
251 | break; | |
252 | } else { | |
253 | /* npins == 0: special range */ | |
254 | if (pinspec.args[1]) { | |
255 | pr_err("%s: Illegal gpio-range format.\n", | |
256 | np->full_name); | |
257 | break; | |
258 | } | |
259 | ||
260 | if (!group_names) { | |
261 | pr_err("%s: GPIO group range requested but no %s property.\n", | |
262 | np->full_name, group_names_propname); | |
263 | break; | |
264 | } | |
265 | ||
266 | ret = of_property_read_string_index(np, | |
267 | group_names_propname, | |
268 | index, &name); | |
269 | if (ret) | |
270 | break; | |
271 | ||
272 | if (!strlen(name)) { | |
273 | pr_err("%s: Group name of GPIO group range cannot be the empty string.\n", | |
274 | np->full_name); | |
275 | break; | |
276 | } | |
277 | ||
278 | ret = gpiochip_add_pingroup_range(chip, pctldev, | |
279 | pinspec.args[0], name); | |
280 | if (ret) | |
281 | break; | |
282 | } | |
ad4e1a7c | 283 | } |
f23f1516 SH |
284 | } |
285 | ||
f23f1516 | 286 | #else |
167c1af9 | 287 | static void of_gpiochip_add_pin_range(struct gpio_chip *chip) {} |
f23f1516 SH |
288 | #endif |
289 | ||
391c970c AV |
290 | void of_gpiochip_add(struct gpio_chip *chip) |
291 | { | |
292 | if ((!chip->of_node) && (chip->dev)) | |
293 | chip->of_node = chip->dev->of_node; | |
294 | ||
295 | if (!chip->of_node) | |
296 | return; | |
297 | ||
298 | if (!chip->of_xlate) { | |
299 | chip->of_gpio_n_cells = 2; | |
300 | chip->of_xlate = of_gpio_simple_xlate; | |
301 | } | |
302 | ||
f23f1516 | 303 | of_gpiochip_add_pin_range(chip); |
391c970c AV |
304 | of_node_get(chip->of_node); |
305 | } | |
306 | ||
307 | void of_gpiochip_remove(struct gpio_chip *chip) | |
308 | { | |
e93fa3f2 | 309 | gpiochip_remove_pin_ranges(chip); |
8a691550 | 310 | of_node_put(chip->of_node); |
391c970c | 311 | } |