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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 | 63 | int of_get_named_gpio_flags(struct device_node *np, const char *propname, |
9ccb1a26 | 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 AV |
90 | |
91 | /** | |
b908b53d | 92 | * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags |
a19e3da5 | 93 | * @gc: pointer to the gpio_chip structure |
863fbf49 AV |
94 | * @np: device node of the GPIO chip |
95 | * @gpio_spec: gpio specifier as found in the device tree | |
b908b53d | 96 | * @flags: a flags pointer to fill in |
863fbf49 AV |
97 | * |
98 | * This is simple translation function, suitable for the most 1:1 mapped | |
99 | * gpio chips. This function performs only one sanity check: whether gpio | |
100 | * is less than ngpios (that is specified in the gpio_chip). | |
101 | */ | |
15c9a0ac GL |
102 | int of_gpio_simple_xlate(struct gpio_chip *gc, |
103 | const struct of_phandle_args *gpiospec, u32 *flags) | |
863fbf49 | 104 | { |
b908b53d AV |
105 | /* |
106 | * We're discouraging gpio_cells < 2, since that way you'll have to | |
107 | * write your own xlate function (that will have to retrive the GPIO | |
108 | * number and the flags from a single gpio cell -- this is possible, | |
109 | * but not recommended). | |
110 | */ | |
a19e3da5 | 111 | if (gc->of_gpio_n_cells < 2) { |
b908b53d AV |
112 | WARN_ON(1); |
113 | return -EINVAL; | |
114 | } | |
115 | ||
15c9a0ac GL |
116 | if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells)) |
117 | return -EINVAL; | |
118 | ||
6270d830 | 119 | if (gpiospec->args[0] >= gc->ngpio) |
863fbf49 AV |
120 | return -EINVAL; |
121 | ||
b908b53d | 122 | if (flags) |
15c9a0ac | 123 | *flags = gpiospec->args[1]; |
b908b53d | 124 | |
15c9a0ac | 125 | return gpiospec->args[0]; |
863fbf49 | 126 | } |
3038bbdf | 127 | EXPORT_SYMBOL(of_gpio_simple_xlate); |
863fbf49 | 128 | |
863fbf49 AV |
129 | /** |
130 | * of_mm_gpiochip_add - Add memory mapped GPIO chip (bank) | |
131 | * @np: device node of the GPIO chip | |
132 | * @mm_gc: pointer to the of_mm_gpio_chip allocated structure | |
133 | * | |
134 | * To use this function you should allocate and fill mm_gc with: | |
135 | * | |
136 | * 1) In the gpio_chip structure: | |
137 | * - all the callbacks | |
a19e3da5 AV |
138 | * - of_gpio_n_cells |
139 | * - of_xlate callback (optional) | |
863fbf49 AV |
140 | * |
141 | * 3) In the of_mm_gpio_chip structure: | |
142 | * - save_regs callback (optional) | |
143 | * | |
144 | * If succeeded, this function will map bank's memory and will | |
145 | * do all necessary work for you. Then you'll able to use .regs | |
146 | * to manage GPIOs from the callbacks. | |
147 | */ | |
148 | int of_mm_gpiochip_add(struct device_node *np, | |
149 | struct of_mm_gpio_chip *mm_gc) | |
150 | { | |
151 | int ret = -ENOMEM; | |
a19e3da5 | 152 | struct gpio_chip *gc = &mm_gc->gc; |
863fbf49 AV |
153 | |
154 | gc->label = kstrdup(np->full_name, GFP_KERNEL); | |
155 | if (!gc->label) | |
156 | goto err0; | |
157 | ||
158 | mm_gc->regs = of_iomap(np, 0); | |
159 | if (!mm_gc->regs) | |
160 | goto err1; | |
161 | ||
21451155 | 162 | gc->base = -1; |
863fbf49 | 163 | |
863fbf49 AV |
164 | if (mm_gc->save_regs) |
165 | mm_gc->save_regs(mm_gc); | |
166 | ||
a19e3da5 | 167 | mm_gc->gc.of_node = np; |
863fbf49 AV |
168 | |
169 | ret = gpiochip_add(gc); | |
170 | if (ret) | |
171 | goto err2; | |
172 | ||
863fbf49 AV |
173 | return 0; |
174 | err2: | |
863fbf49 AV |
175 | iounmap(mm_gc->regs); |
176 | err1: | |
177 | kfree(gc->label); | |
178 | err0: | |
179 | pr_err("%s: GPIO chip registration failed with status %d\n", | |
180 | np->full_name, ret); | |
181 | return ret; | |
182 | } | |
183 | EXPORT_SYMBOL(of_mm_gpiochip_add); | |
594fa265 | 184 | |
f23f1516 | 185 | #ifdef CONFIG_PINCTRL |
167c1af9 | 186 | static void of_gpiochip_add_pin_range(struct gpio_chip *chip) |
f23f1516 SH |
187 | { |
188 | struct device_node *np = chip->of_node; | |
f23f1516 | 189 | struct of_phandle_args pinspec; |
1e63d7b9 | 190 | struct pinctrl_dev *pctldev; |
f23f1516 SH |
191 | int index = 0, ret; |
192 | ||
193 | if (!np) | |
194 | return; | |
195 | ||
196 | do { | |
197 | ret = of_parse_phandle_with_args(np, "gpio-ranges", | |
198 | "#gpio-range-cells", index, &pinspec); | |
199 | if (ret) | |
200 | break; | |
201 | ||
1e63d7b9 LW |
202 | pctldev = of_pinctrl_get(pinspec.np); |
203 | if (!pctldev) | |
f23f1516 | 204 | break; |
f23f1516 | 205 | |
3f0f8670 LW |
206 | /* |
207 | * This assumes that the n GPIO pins are consecutive in the | |
208 | * GPIO number space, and that the pins are also consecutive | |
209 | * in their local number space. Currently it is not possible | |
210 | * to add different ranges for one and the same GPIO chip, | |
211 | * as the code assumes that we have one consecutive range | |
212 | * on both, mapping 1-to-1. | |
213 | * | |
214 | * TODO: make the OF bindings handle multiple sparse ranges | |
215 | * on the same GPIO chip. | |
216 | */ | |
1e63d7b9 | 217 | ret = gpiochip_add_pin_range(chip, |
ef5e3eef | 218 | pinctrl_dev_get_devname(pctldev), |
3f0f8670 | 219 | 0, /* offset in gpiochip */ |
1e63d7b9 LW |
220 | pinspec.args[0], |
221 | pinspec.args[1]); | |
f23f1516 | 222 | |
1e63d7b9 LW |
223 | if (ret) |
224 | break; | |
f23f1516 SH |
225 | |
226 | } while (index++); | |
227 | } | |
228 | ||
f23f1516 | 229 | #else |
167c1af9 | 230 | static void of_gpiochip_add_pin_range(struct gpio_chip *chip) {} |
f23f1516 SH |
231 | #endif |
232 | ||
391c970c AV |
233 | void of_gpiochip_add(struct gpio_chip *chip) |
234 | { | |
235 | if ((!chip->of_node) && (chip->dev)) | |
236 | chip->of_node = chip->dev->of_node; | |
237 | ||
238 | if (!chip->of_node) | |
239 | return; | |
240 | ||
241 | if (!chip->of_xlate) { | |
242 | chip->of_gpio_n_cells = 2; | |
243 | chip->of_xlate = of_gpio_simple_xlate; | |
244 | } | |
245 | ||
f23f1516 | 246 | of_gpiochip_add_pin_range(chip); |
391c970c AV |
247 | of_node_get(chip->of_node); |
248 | } | |
249 | ||
250 | void of_gpiochip_remove(struct gpio_chip *chip) | |
251 | { | |
e93fa3f2 | 252 | gpiochip_remove_pin_ranges(chip); |
f23f1516 | 253 | |
391c970c AV |
254 | if (chip->of_node) |
255 | of_node_put(chip->of_node); | |
256 | } |