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Anton Vorontsov863fbf42008-04-11 23:06:45 +10001/*
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
Grant Likely2e13cba2010-07-05 16:11:55 -060014#include <linux/device.h>
Anton Vorontsov863fbf42008-04-11 23:06:45 +100015#include <linux/errno.h>
Grant Likely2e13cba2010-07-05 16:11:55 -060016#include <linux/module.h>
Anton Vorontsov863fbf42008-04-11 23:06:45 +100017#include <linux/io.h>
18#include <linux/of.h>
Grant Likely2e13cba2010-07-05 16:11:55 -060019#include <linux/of_address.h>
Anton Vorontsov863fbf42008-04-11 23:06:45 +100020#include <linux/of_gpio.h>
Grant Likely2e13cba2010-07-05 16:11:55 -060021#include <linux/slab.h>
Anton Vorontsov863fbf42008-04-11 23:06:45 +100022
23/**
John Bonesioa6b09192011-06-27 16:49:57 -070024 * of_get_named_gpio_flags() - Get a GPIO number and flags to use with GPIO API
Anton Vorontsov863fbf42008-04-11 23:06:45 +100025 * @np: device node to get GPIO from
John Bonesioa6b09192011-06-27 16:49:57 -070026 * @propname: property name containing gpio specifier(s)
Anton Vorontsov863fbf42008-04-11 23:06:45 +100027 * @index: index of the GPIO
Anton Vorontsovb908b532008-12-01 06:30:04 +000028 * @flags: a flags pointer to fill in
Anton Vorontsov863fbf42008-04-11 23:06:45 +100029 *
30 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
Anton Vorontsovb908b532008-12-01 06:30:04 +000031 * value on the error condition. If @flags is not NULL the function also fills
32 * in flags for the GPIO.
Anton Vorontsov863fbf42008-04-11 23:06:45 +100033 */
John Bonesioa6b09192011-06-27 16:49:57 -070034int of_get_named_gpio_flags(struct device_node *np, const char *propname,
35 int index, enum of_gpio_flags *flags)
Anton Vorontsov863fbf42008-04-11 23:06:45 +100036{
Anton Vorontsov64b60e02008-10-10 04:43:17 +000037 int ret;
Anton Vorontsova19e3da2010-06-08 07:48:16 -060038 struct gpio_chip *gc;
Grant Likely15c9a0a2011-12-12 09:25:57 -070039 struct of_phandle_args gpiospec;
Anton Vorontsov863fbf42008-04-11 23:06:45 +100040
Grant Likely15c9a0a2011-12-12 09:25:57 -070041 ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index,
42 &gpiospec);
Anton Vorontsov64b60e02008-10-10 04:43:17 +000043 if (ret) {
44 pr_debug("%s: can't parse gpios property\n", __func__);
Anton Vorontsov863fbf42008-04-11 23:06:45 +100045 goto err0;
46 }
Anton Vorontsov863fbf42008-04-11 23:06:45 +100047
Grant Likely15c9a0a2011-12-12 09:25:57 -070048 gc = of_node_to_gpiochip(gpiospec.np);
Anton Vorontsova19e3da2010-06-08 07:48:16 -060049 if (!gc) {
Anton Vorontsov64b60e02008-10-10 04:43:17 +000050 pr_debug("%s: gpio controller %s isn't registered\n",
Grant Likely15c9a0a2011-12-12 09:25:57 -070051 np->full_name, gpiospec.np->full_name);
Anton Vorontsov64b60e02008-10-10 04:43:17 +000052 ret = -ENODEV;
53 goto err1;
54 }
55
Grant Likely15c9a0a2011-12-12 09:25:57 -070056 if (gpiospec.args_count != gc->of_gpio_n_cells) {
Anton Vorontsov64b60e02008-10-10 04:43:17 +000057 pr_debug("%s: wrong #gpio-cells for %s\n",
Grant Likely15c9a0a2011-12-12 09:25:57 -070058 np->full_name, gpiospec.np->full_name);
Anton Vorontsov64b60e02008-10-10 04:43:17 +000059 ret = -EINVAL;
60 goto err1;
Anton Vorontsov863fbf42008-04-11 23:06:45 +100061 }
62
Anton Vorontsovb908b532008-12-01 06:30:04 +000063 /* .xlate might decide to not fill in the flags, so clear it. */
64 if (flags)
65 *flags = 0;
66
Grant Likely15c9a0a2011-12-12 09:25:57 -070067 ret = gc->of_xlate(gc, &gpiospec, flags);
Anton Vorontsov863fbf42008-04-11 23:06:45 +100068 if (ret < 0)
69 goto err1;
70
Anton Vorontsova19e3da2010-06-08 07:48:16 -060071 ret += gc->base;
Anton Vorontsov863fbf42008-04-11 23:06:45 +100072err1:
Grant Likely15c9a0a2011-12-12 09:25:57 -070073 of_node_put(gpiospec.np);
Anton Vorontsov863fbf42008-04-11 23:06:45 +100074err0:
75 pr_debug("%s exited with status %d\n", __func__, ret);
76 return ret;
77}
John Bonesioa6b09192011-06-27 16:49:57 -070078EXPORT_SYMBOL(of_get_named_gpio_flags);
Anton Vorontsov863fbf42008-04-11 23:06:45 +100079
80/**
Jean-Christophe PLAGNIOL-VILLARDff64abe2012-02-02 16:20:01 +010081 * of_gpio_named_count - Count GPIOs for a device
Anton Vorontsov74982092008-12-05 08:15:54 +000082 * @np: device node to count GPIOs for
Jean-Christophe PLAGNIOL-VILLARDff64abe2012-02-02 16:20:01 +010083 * @propname: property name containing gpio specifier(s)
Anton Vorontsov74982092008-12-05 08:15:54 +000084 *
85 * The function returns the count of GPIOs specified for a node.
86 *
87 * Note that the empty GPIO specifiers counts too. For example,
88 *
89 * gpios = <0
90 * &pio1 1 2
91 * 0
92 * &pio2 3 4>;
93 *
94 * defines four GPIOs (so this function will return 4), two of which
95 * are not specified.
96 */
Jean-Christophe PLAGNIOL-VILLARDff64abe2012-02-02 16:20:01 +010097unsigned int of_gpio_named_count(struct device_node *np, const char* propname)
Anton Vorontsov74982092008-12-05 08:15:54 +000098{
99 unsigned int cnt = 0;
100
101 do {
102 int ret;
103
Jean-Christophe PLAGNIOL-VILLARDff64abe2012-02-02 16:20:01 +0100104 ret = of_parse_phandle_with_args(np, propname, "#gpio-cells",
Grant Likely15c9a0a2011-12-12 09:25:57 -0700105 cnt, NULL);
Anton Vorontsov74982092008-12-05 08:15:54 +0000106 /* A hole in the gpios = <> counts anyway. */
107 if (ret < 0 && ret != -EEXIST)
108 break;
109 } while (++cnt);
110
111 return cnt;
112}
Jean-Christophe PLAGNIOL-VILLARDff64abe2012-02-02 16:20:01 +0100113EXPORT_SYMBOL(of_gpio_named_count);
Anton Vorontsov74982092008-12-05 08:15:54 +0000114
115/**
Anton Vorontsovb908b532008-12-01 06:30:04 +0000116 * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags
Anton Vorontsova19e3da2010-06-08 07:48:16 -0600117 * @gc: pointer to the gpio_chip structure
Anton Vorontsov863fbf42008-04-11 23:06:45 +1000118 * @np: device node of the GPIO chip
119 * @gpio_spec: gpio specifier as found in the device tree
Anton Vorontsovb908b532008-12-01 06:30:04 +0000120 * @flags: a flags pointer to fill in
Anton Vorontsov863fbf42008-04-11 23:06:45 +1000121 *
122 * This is simple translation function, suitable for the most 1:1 mapped
123 * gpio chips. This function performs only one sanity check: whether gpio
124 * is less than ngpios (that is specified in the gpio_chip).
125 */
Grant Likely15c9a0a2011-12-12 09:25:57 -0700126int of_gpio_simple_xlate(struct gpio_chip *gc,
127 const struct of_phandle_args *gpiospec, u32 *flags)
Anton Vorontsov863fbf42008-04-11 23:06:45 +1000128{
Anton Vorontsovb908b532008-12-01 06:30:04 +0000129 /*
130 * We're discouraging gpio_cells < 2, since that way you'll have to
131 * write your own xlate function (that will have to retrive the GPIO
132 * number and the flags from a single gpio cell -- this is possible,
133 * but not recommended).
134 */
Anton Vorontsova19e3da2010-06-08 07:48:16 -0600135 if (gc->of_gpio_n_cells < 2) {
Anton Vorontsovb908b532008-12-01 06:30:04 +0000136 WARN_ON(1);
137 return -EINVAL;
138 }
139
Grant Likely15c9a0a2011-12-12 09:25:57 -0700140 if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
141 return -EINVAL;
142
143 if (gpiospec->args[0] > gc->ngpio)
Anton Vorontsov863fbf42008-04-11 23:06:45 +1000144 return -EINVAL;
145
Anton Vorontsovb908b532008-12-01 06:30:04 +0000146 if (flags)
Grant Likely15c9a0a2011-12-12 09:25:57 -0700147 *flags = gpiospec->args[1];
Anton Vorontsovb908b532008-12-01 06:30:04 +0000148
Grant Likely15c9a0a2011-12-12 09:25:57 -0700149 return gpiospec->args[0];
Anton Vorontsov863fbf42008-04-11 23:06:45 +1000150}
Jamie Iles3038bbd2011-07-28 16:25:41 +0100151EXPORT_SYMBOL(of_gpio_simple_xlate);
Anton Vorontsov863fbf42008-04-11 23:06:45 +1000152
Anton Vorontsov863fbf42008-04-11 23:06:45 +1000153/**
154 * of_mm_gpiochip_add - Add memory mapped GPIO chip (bank)
155 * @np: device node of the GPIO chip
156 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure
157 *
158 * To use this function you should allocate and fill mm_gc with:
159 *
160 * 1) In the gpio_chip structure:
161 * - all the callbacks
Anton Vorontsova19e3da2010-06-08 07:48:16 -0600162 * - of_gpio_n_cells
163 * - of_xlate callback (optional)
Anton Vorontsov863fbf42008-04-11 23:06:45 +1000164 *
165 * 3) In the of_mm_gpio_chip structure:
166 * - save_regs callback (optional)
167 *
168 * If succeeded, this function will map bank's memory and will
169 * do all necessary work for you. Then you'll able to use .regs
170 * to manage GPIOs from the callbacks.
171 */
172int of_mm_gpiochip_add(struct device_node *np,
173 struct of_mm_gpio_chip *mm_gc)
174{
175 int ret = -ENOMEM;
Anton Vorontsova19e3da2010-06-08 07:48:16 -0600176 struct gpio_chip *gc = &mm_gc->gc;
Anton Vorontsov863fbf42008-04-11 23:06:45 +1000177
178 gc->label = kstrdup(np->full_name, GFP_KERNEL);
179 if (!gc->label)
180 goto err0;
181
182 mm_gc->regs = of_iomap(np, 0);
183 if (!mm_gc->regs)
184 goto err1;
185
Anton Vorontsov21451152008-04-30 00:05:24 +1000186 gc->base = -1;
Anton Vorontsov863fbf42008-04-11 23:06:45 +1000187
Anton Vorontsov863fbf42008-04-11 23:06:45 +1000188 if (mm_gc->save_regs)
189 mm_gc->save_regs(mm_gc);
190
Anton Vorontsova19e3da2010-06-08 07:48:16 -0600191 mm_gc->gc.of_node = np;
Anton Vorontsov863fbf42008-04-11 23:06:45 +1000192
193 ret = gpiochip_add(gc);
194 if (ret)
195 goto err2;
196
Anton Vorontsov863fbf42008-04-11 23:06:45 +1000197 return 0;
198err2:
Anton Vorontsov863fbf42008-04-11 23:06:45 +1000199 iounmap(mm_gc->regs);
200err1:
201 kfree(gc->label);
202err0:
203 pr_err("%s: GPIO chip registration failed with status %d\n",
204 np->full_name, ret);
205 return ret;
206}
207EXPORT_SYMBOL(of_mm_gpiochip_add);
Grant Likely594fa262010-06-08 07:48:16 -0600208
Anton Vorontsov391c9702010-06-08 07:48:17 -0600209void of_gpiochip_add(struct gpio_chip *chip)
210{
211 if ((!chip->of_node) && (chip->dev))
212 chip->of_node = chip->dev->of_node;
213
214 if (!chip->of_node)
215 return;
216
217 if (!chip->of_xlate) {
218 chip->of_gpio_n_cells = 2;
219 chip->of_xlate = of_gpio_simple_xlate;
220 }
221
222 of_node_get(chip->of_node);
223}
224
225void of_gpiochip_remove(struct gpio_chip *chip)
226{
227 if (chip->of_node)
228 of_node_put(chip->of_node);
229}
230
Grant Likely594fa262010-06-08 07:48:16 -0600231/* Private function for resolving node pointer to gpio_chip */
Grant Likely6e2cf652012-03-02 15:56:03 -0700232static int of_gpiochip_is_match(struct gpio_chip *chip, const void *data)
Grant Likely594fa262010-06-08 07:48:16 -0600233{
234 return chip->of_node == data;
235}
236
237struct gpio_chip *of_node_to_gpiochip(struct device_node *np)
238{
239 return gpiochip_find(np, of_gpiochip_is_match);
240}