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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> |
863fbf49 | 15 | #include <linux/errno.h> |
2e13cba8 | 16 | #include <linux/module.h> |
863fbf49 | 17 | #include <linux/io.h> |
3d0f7cf0 | 18 | #include <linux/gpio.h> |
863fbf49 | 19 | #include <linux/of.h> |
2e13cba8 | 20 | #include <linux/of_address.h> |
863fbf49 | 21 | #include <linux/of_gpio.h> |
f23f1516 | 22 | #include <linux/pinctrl/pinctrl.h> |
2e13cba8 | 23 | #include <linux/slab.h> |
863fbf49 | 24 | |
0df2c999 | 25 | /* Private data structure for of_gpiochip_find_and_xlate */ |
3d0f7cf0 GL |
26 | struct gg_data { |
27 | enum of_gpio_flags *flags; | |
28 | struct of_phandle_args gpiospec; | |
29 | ||
30 | int out_gpio; | |
31 | }; | |
32 | ||
33 | /* Private function for resolving node pointer to gpio_chip */ | |
34 | static int of_gpiochip_find_and_xlate(struct gpio_chip *gc, void *data) | |
35 | { | |
36 | struct gg_data *gg_data = data; | |
37 | int ret; | |
38 | ||
39 | if ((gc->of_node != gg_data->gpiospec.np) || | |
40 | (gc->of_gpio_n_cells != gg_data->gpiospec.args_count) || | |
41 | (!gc->of_xlate)) | |
42 | return false; | |
43 | ||
44 | ret = gc->of_xlate(gc, &gg_data->gpiospec, gg_data->flags); | |
45 | if (ret < 0) | |
46 | return false; | |
47 | ||
48 | gg_data->out_gpio = ret + gc->base; | |
49 | return true; | |
50 | } | |
51 | ||
863fbf49 | 52 | /** |
a6b09191 | 53 | * of_get_named_gpio_flags() - Get a GPIO number and flags to use with GPIO API |
863fbf49 | 54 | * @np: device node to get GPIO from |
a6b09191 | 55 | * @propname: property name containing gpio specifier(s) |
863fbf49 | 56 | * @index: index of the GPIO |
b908b53d | 57 | * @flags: a flags pointer to fill in |
863fbf49 AV |
58 | * |
59 | * Returns GPIO number to use with Linux generic GPIO API, or one of the errno | |
b908b53d AV |
60 | * value on the error condition. If @flags is not NULL the function also fills |
61 | * in flags for the GPIO. | |
863fbf49 | 62 | */ |
a6b09191 JB |
63 | int of_get_named_gpio_flags(struct device_node *np, const char *propname, |
64 | int index, enum of_gpio_flags *flags) | |
863fbf49 | 65 | { |
4fbb0022 RS |
66 | /* Return -EPROBE_DEFER to support probe() functions to be called |
67 | * later when the GPIO actually becomes available | |
68 | */ | |
69 | struct gg_data gg_data = { .flags = flags, .out_gpio = -EPROBE_DEFER }; | |
64b60e09 | 70 | int ret; |
3d0f7cf0 GL |
71 | |
72 | /* .of_xlate might decide to not fill in the flags, so clear it. */ | |
73 | if (flags) | |
74 | *flags = 0; | |
863fbf49 | 75 | |
15c9a0ac | 76 | ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index, |
3d0f7cf0 | 77 | &gg_data.gpiospec); |
64b60e09 AV |
78 | if (ret) { |
79 | pr_debug("%s: can't parse gpios property\n", __func__); | |
41920d16 | 80 | return ret; |
863fbf49 AV |
81 | } |
82 | ||
3d0f7cf0 | 83 | gpiochip_find(&gg_data, of_gpiochip_find_and_xlate); |
863fbf49 | 84 | |
3d0f7cf0 | 85 | of_node_put(gg_data.gpiospec.np); |
c61307a7 | 86 | pr_debug("%s exited with status %d\n", __func__, gg_data.out_gpio); |
3d0f7cf0 | 87 | return gg_data.out_gpio; |
863fbf49 | 88 | } |
a6b09191 | 89 | EXPORT_SYMBOL(of_get_named_gpio_flags); |
863fbf49 | 90 | |
74982092 | 91 | /** |
ff64abef | 92 | * of_gpio_named_count - Count GPIOs for a device |
74982092 | 93 | * @np: device node to count GPIOs for |
ff64abef | 94 | * @propname: property name containing gpio specifier(s) |
74982092 AV |
95 | * |
96 | * The function returns the count of GPIOs specified for a node. | |
97 | * | |
98 | * Note that the empty GPIO specifiers counts too. For example, | |
99 | * | |
100 | * gpios = <0 | |
101 | * &pio1 1 2 | |
102 | * 0 | |
103 | * &pio2 3 4>; | |
104 | * | |
105 | * defines four GPIOs (so this function will return 4), two of which | |
106 | * are not specified. | |
107 | */ | |
ff64abef | 108 | unsigned int of_gpio_named_count(struct device_node *np, const char* propname) |
74982092 AV |
109 | { |
110 | unsigned int cnt = 0; | |
111 | ||
112 | do { | |
113 | int ret; | |
114 | ||
ff64abef | 115 | ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", |
15c9a0ac | 116 | cnt, NULL); |
74982092 AV |
117 | /* A hole in the gpios = <> counts anyway. */ |
118 | if (ret < 0 && ret != -EEXIST) | |
119 | break; | |
120 | } while (++cnt); | |
121 | ||
122 | return cnt; | |
123 | } | |
ff64abef | 124 | EXPORT_SYMBOL(of_gpio_named_count); |
74982092 | 125 | |
863fbf49 | 126 | /** |
b908b53d | 127 | * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags |
a19e3da5 | 128 | * @gc: pointer to the gpio_chip structure |
863fbf49 AV |
129 | * @np: device node of the GPIO chip |
130 | * @gpio_spec: gpio specifier as found in the device tree | |
b908b53d | 131 | * @flags: a flags pointer to fill in |
863fbf49 AV |
132 | * |
133 | * This is simple translation function, suitable for the most 1:1 mapped | |
134 | * gpio chips. This function performs only one sanity check: whether gpio | |
135 | * is less than ngpios (that is specified in the gpio_chip). | |
136 | */ | |
15c9a0ac GL |
137 | int of_gpio_simple_xlate(struct gpio_chip *gc, |
138 | const struct of_phandle_args *gpiospec, u32 *flags) | |
863fbf49 | 139 | { |
b908b53d AV |
140 | /* |
141 | * We're discouraging gpio_cells < 2, since that way you'll have to | |
142 | * write your own xlate function (that will have to retrive the GPIO | |
143 | * number and the flags from a single gpio cell -- this is possible, | |
144 | * but not recommended). | |
145 | */ | |
a19e3da5 | 146 | if (gc->of_gpio_n_cells < 2) { |
b908b53d AV |
147 | WARN_ON(1); |
148 | return -EINVAL; | |
149 | } | |
150 | ||
15c9a0ac GL |
151 | if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells)) |
152 | return -EINVAL; | |
153 | ||
6270d830 | 154 | if (gpiospec->args[0] >= gc->ngpio) |
863fbf49 AV |
155 | return -EINVAL; |
156 | ||
b908b53d | 157 | if (flags) |
15c9a0ac | 158 | *flags = gpiospec->args[1]; |
b908b53d | 159 | |
15c9a0ac | 160 | return gpiospec->args[0]; |
863fbf49 | 161 | } |
3038bbdf | 162 | EXPORT_SYMBOL(of_gpio_simple_xlate); |
863fbf49 | 163 | |
863fbf49 AV |
164 | /** |
165 | * of_mm_gpiochip_add - Add memory mapped GPIO chip (bank) | |
166 | * @np: device node of the GPIO chip | |
167 | * @mm_gc: pointer to the of_mm_gpio_chip allocated structure | |
168 | * | |
169 | * To use this function you should allocate and fill mm_gc with: | |
170 | * | |
171 | * 1) In the gpio_chip structure: | |
172 | * - all the callbacks | |
a19e3da5 AV |
173 | * - of_gpio_n_cells |
174 | * - of_xlate callback (optional) | |
863fbf49 AV |
175 | * |
176 | * 3) In the of_mm_gpio_chip structure: | |
177 | * - save_regs callback (optional) | |
178 | * | |
179 | * If succeeded, this function will map bank's memory and will | |
180 | * do all necessary work for you. Then you'll able to use .regs | |
181 | * to manage GPIOs from the callbacks. | |
182 | */ | |
183 | int of_mm_gpiochip_add(struct device_node *np, | |
184 | struct of_mm_gpio_chip *mm_gc) | |
185 | { | |
186 | int ret = -ENOMEM; | |
a19e3da5 | 187 | struct gpio_chip *gc = &mm_gc->gc; |
863fbf49 AV |
188 | |
189 | gc->label = kstrdup(np->full_name, GFP_KERNEL); | |
190 | if (!gc->label) | |
191 | goto err0; | |
192 | ||
193 | mm_gc->regs = of_iomap(np, 0); | |
194 | if (!mm_gc->regs) | |
195 | goto err1; | |
196 | ||
21451155 | 197 | gc->base = -1; |
863fbf49 | 198 | |
863fbf49 AV |
199 | if (mm_gc->save_regs) |
200 | mm_gc->save_regs(mm_gc); | |
201 | ||
a19e3da5 | 202 | mm_gc->gc.of_node = np; |
863fbf49 AV |
203 | |
204 | ret = gpiochip_add(gc); | |
205 | if (ret) | |
206 | goto err2; | |
207 | ||
863fbf49 AV |
208 | return 0; |
209 | err2: | |
863fbf49 AV |
210 | iounmap(mm_gc->regs); |
211 | err1: | |
212 | kfree(gc->label); | |
213 | err0: | |
214 | pr_err("%s: GPIO chip registration failed with status %d\n", | |
215 | np->full_name, ret); | |
216 | return ret; | |
217 | } | |
218 | EXPORT_SYMBOL(of_mm_gpiochip_add); | |
594fa265 | 219 | |
f23f1516 | 220 | #ifdef CONFIG_PINCTRL |
167c1af9 | 221 | static void of_gpiochip_add_pin_range(struct gpio_chip *chip) |
f23f1516 SH |
222 | { |
223 | struct device_node *np = chip->of_node; | |
224 | struct gpio_pin_range *pin_range; | |
225 | struct of_phandle_args pinspec; | |
226 | int index = 0, ret; | |
227 | ||
228 | if (!np) | |
229 | return; | |
230 | ||
231 | do { | |
232 | ret = of_parse_phandle_with_args(np, "gpio-ranges", | |
233 | "#gpio-range-cells", index, &pinspec); | |
234 | if (ret) | |
235 | break; | |
236 | ||
237 | pin_range = devm_kzalloc(chip->dev, sizeof(*pin_range), | |
238 | GFP_KERNEL); | |
239 | if (!pin_range) { | |
240 | pr_err("%s: GPIO chip: failed to allocate pin ranges\n", | |
241 | chip->label); | |
242 | break; | |
243 | } | |
244 | ||
245 | pin_range->range.name = chip->label; | |
246 | pin_range->range.base = chip->base; | |
247 | pin_range->range.pin_base = pinspec.args[0]; | |
248 | pin_range->range.npins = pinspec.args[1]; | |
249 | pin_range->pctldev = of_pinctrl_add_gpio_range(pinspec.np, | |
250 | &pin_range->range); | |
251 | ||
252 | list_add_tail(&pin_range->node, &chip->pin_ranges); | |
253 | ||
254 | } while (index++); | |
255 | } | |
256 | ||
f23f1516 | 257 | #else |
167c1af9 | 258 | static void of_gpiochip_add_pin_range(struct gpio_chip *chip) {} |
f23f1516 SH |
259 | #endif |
260 | ||
391c970c AV |
261 | void of_gpiochip_add(struct gpio_chip *chip) |
262 | { | |
263 | if ((!chip->of_node) && (chip->dev)) | |
264 | chip->of_node = chip->dev->of_node; | |
265 | ||
266 | if (!chip->of_node) | |
267 | return; | |
268 | ||
269 | if (!chip->of_xlate) { | |
270 | chip->of_gpio_n_cells = 2; | |
271 | chip->of_xlate = of_gpio_simple_xlate; | |
272 | } | |
273 | ||
f23f1516 | 274 | of_gpiochip_add_pin_range(chip); |
391c970c AV |
275 | of_node_get(chip->of_node); |
276 | } | |
277 | ||
278 | void of_gpiochip_remove(struct gpio_chip *chip) | |
279 | { | |
e93fa3f2 | 280 | gpiochip_remove_pin_ranges(chip); |
f23f1516 | 281 | |
391c970c AV |
282 | if (chip->of_node) |
283 | of_node_put(chip->of_node); | |
284 | } |