Root/
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 | |
14 | #include <linux/device.h> |
15 | #include <linux/errno.h> |
16 | #include <linux/module.h> |
17 | #include <linux/io.h> |
18 | #include <linux/gpio.h> |
19 | #include <linux/of.h> |
20 | #include <linux/of_address.h> |
21 | #include <linux/of_gpio.h> |
22 | #include <linux/pinctrl/pinctrl.h> |
23 | #include <linux/slab.h> |
24 | |
25 | /* Private data structure for of_gpiochip_find_and_xlate */ |
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 | |
52 | /** |
53 | * of_get_named_gpio_flags() - Get a GPIO number and flags to use with GPIO API |
54 | * @np: device node to get GPIO from |
55 | * @propname: property name containing gpio specifier(s) |
56 | * @index: index of the GPIO |
57 | * @flags: a flags pointer to fill in |
58 | * |
59 | * Returns GPIO number to use with Linux generic GPIO API, or one of the errno |
60 | * value on the error condition. If @flags is not NULL the function also fills |
61 | * in flags for the GPIO. |
62 | */ |
63 | int of_get_named_gpio_flags(struct device_node *np, const char *propname, |
64 | int index, enum of_gpio_flags *flags) |
65 | { |
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 }; |
70 | int ret; |
71 | |
72 | /* .of_xlate might decide to not fill in the flags, so clear it. */ |
73 | if (flags) |
74 | *flags = 0; |
75 | |
76 | ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index, |
77 | &gg_data.gpiospec); |
78 | if (ret) { |
79 | pr_debug("%s: can't parse gpios property\n", __func__); |
80 | return ret; |
81 | } |
82 | |
83 | gpiochip_find(&gg_data, of_gpiochip_find_and_xlate); |
84 | |
85 | of_node_put(gg_data.gpiospec.np); |
86 | pr_debug("%s exited with status %d\n", __func__, gg_data.out_gpio); |
87 | return gg_data.out_gpio; |
88 | } |
89 | EXPORT_SYMBOL(of_get_named_gpio_flags); |
90 | |
91 | /** |
92 | * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags |
93 | * @gc: pointer to the gpio_chip structure |
94 | * @np: device node of the GPIO chip |
95 | * @gpio_spec: gpio specifier as found in the device tree |
96 | * @flags: a flags pointer to fill in |
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 | */ |
102 | int of_gpio_simple_xlate(struct gpio_chip *gc, |
103 | const struct of_phandle_args *gpiospec, u32 *flags) |
104 | { |
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 | */ |
111 | if (gc->of_gpio_n_cells < 2) { |
112 | WARN_ON(1); |
113 | return -EINVAL; |
114 | } |
115 | |
116 | if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells)) |
117 | return -EINVAL; |
118 | |
119 | if (gpiospec->args[0] >= gc->ngpio) |
120 | return -EINVAL; |
121 | |
122 | if (flags) |
123 | *flags = gpiospec->args[1]; |
124 | |
125 | return gpiospec->args[0]; |
126 | } |
127 | EXPORT_SYMBOL(of_gpio_simple_xlate); |
128 | |
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 |
138 | * - of_gpio_n_cells |
139 | * - of_xlate callback (optional) |
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; |
152 | struct gpio_chip *gc = &mm_gc->gc; |
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 | |
162 | gc->base = -1; |
163 | |
164 | if (mm_gc->save_regs) |
165 | mm_gc->save_regs(mm_gc); |
166 | |
167 | mm_gc->gc.of_node = np; |
168 | |
169 | ret = gpiochip_add(gc); |
170 | if (ret) |
171 | goto err2; |
172 | |
173 | return 0; |
174 | err2: |
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); |
184 | |
185 | #ifdef CONFIG_PINCTRL |
186 | static void of_gpiochip_add_pin_range(struct gpio_chip *chip) |
187 | { |
188 | struct device_node *np = chip->of_node; |
189 | struct of_phandle_args pinspec; |
190 | struct pinctrl_dev *pctldev; |
191 | int index = 0, ret; |
192 | |
193 | if (!np) |
194 | return; |
195 | |
196 | for (;; index++) { |
197 | ret = of_parse_phandle_with_args(np, "gpio-ranges", |
198 | "#gpio-range-cells", index, &pinspec); |
199 | if (ret) |
200 | break; |
201 | |
202 | pctldev = of_pinctrl_get(pinspec.np); |
203 | if (!pctldev) |
204 | break; |
205 | |
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 | */ |
217 | ret = gpiochip_add_pin_range(chip, |
218 | pinctrl_dev_get_devname(pctldev), |
219 | 0, /* offset in gpiochip */ |
220 | pinspec.args[0], |
221 | pinspec.args[1]); |
222 | |
223 | if (ret) |
224 | break; |
225 | } |
226 | } |
227 | |
228 | #else |
229 | static void of_gpiochip_add_pin_range(struct gpio_chip *chip) {} |
230 | #endif |
231 | |
232 | void of_gpiochip_add(struct gpio_chip *chip) |
233 | { |
234 | if ((!chip->of_node) && (chip->dev)) |
235 | chip->of_node = chip->dev->of_node; |
236 | |
237 | if (!chip->of_node) |
238 | return; |
239 | |
240 | if (!chip->of_xlate) { |
241 | chip->of_gpio_n_cells = 2; |
242 | chip->of_xlate = of_gpio_simple_xlate; |
243 | } |
244 | |
245 | of_gpiochip_add_pin_range(chip); |
246 | of_node_get(chip->of_node); |
247 | } |
248 | |
249 | void of_gpiochip_remove(struct gpio_chip *chip) |
250 | { |
251 | gpiochip_remove_pin_ranges(chip); |
252 | |
253 | if (chip->of_node) |
254 | of_node_put(chip->of_node); |
255 | } |
256 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9