1/*
2 * gpiolib support for Wolfson Arizona class devices
3 *
4 * Copyright 2012 Wolfson Microelectronics PLC.
5 *
6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation; either version 2 of the License, or (at your
11 * option) any later version.
12 *
13 */
14
15#include <linux/kernel.h>
16#include <linux/slab.h>
17#include <linux/module.h>
18#include <linux/gpio/driver.h>
19#include <linux/platform_device.h>
20#include <linux/pm_runtime.h>
21#include <linux/seq_file.h>
22
23#include <linux/mfd/arizona/core.h>
24#include <linux/mfd/arizona/pdata.h>
25#include <linux/mfd/arizona/registers.h>
26
27struct arizona_gpio {
28 struct arizona *arizona;
29 struct gpio_chip gpio_chip;
30};
31
32static int arizona_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
33{
34 struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
35 struct arizona *arizona = arizona_gpio->arizona;
36 bool persistent = gpiochip_line_is_persistent(chip, offset);
37 bool change;
38 int ret;
39
40 ret = regmap_update_bits_check(arizona->regmap,
41 ARIZONA_GPIO1_CTRL + offset,
42 ARIZONA_GPN_DIR, ARIZONA_GPN_DIR,
43 &change);
44 if (ret < 0)
45 return ret;
46
47 if (change && persistent) {
48 pm_runtime_mark_last_busy(chip->parent);
49 pm_runtime_put_autosuspend(chip->parent);
50 }
51
52 return 0;
53}
54
55static int arizona_gpio_get(struct gpio_chip *chip, unsigned offset)
56{
57 struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
58 struct arizona *arizona = arizona_gpio->arizona;
59 unsigned int reg, val;
60 int ret;
61
62 reg = ARIZONA_GPIO1_CTRL + offset;
63 ret = regmap_read(arizona->regmap, reg, &val);
64 if (ret < 0)
65 return ret;
66
67 /* Resume to read actual registers for input pins */
68 if (val & ARIZONA_GPN_DIR) {
69 ret = pm_runtime_get_sync(chip->parent);
70 if (ret < 0) {
71 dev_err(chip->parent, "Failed to resume: %d\n", ret);
72 return ret;
73 }
74
75 /* Register is cached, drop it to ensure a physical read */
76 ret = regcache_drop_region(arizona->regmap, reg, reg);
77 if (ret < 0) {
78 dev_err(chip->parent, "Failed to drop cache: %d\n",
79 ret);
80 return ret;
81 }
82
83 ret = regmap_read(arizona->regmap, reg, &val);
84 if (ret < 0)
85 return ret;
86
87 pm_runtime_mark_last_busy(chip->parent);
88 pm_runtime_put_autosuspend(chip->parent);
89 }
90
91 if (val & ARIZONA_GPN_LVL)
92 return 1;
93 else
94 return 0;
95}
96
97static int arizona_gpio_direction_out(struct gpio_chip *chip,
98 unsigned offset, int value)
99{
100 struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
101 struct arizona *arizona = arizona_gpio->arizona;
102 bool persistent = gpiochip_line_is_persistent(chip, offset);
103 unsigned int val;
104 int ret;
105
106 ret = regmap_read(arizona->regmap, ARIZONA_GPIO1_CTRL + offset, &val);
107 if (ret < 0)
108 return ret;
109
110 if ((val & ARIZONA_GPN_DIR) && persistent) {
111 ret = pm_runtime_get_sync(chip->parent);
112 if (ret < 0) {
113 dev_err(chip->parent, "Failed to resume: %d\n", ret);
114 return ret;
115 }
116 }
117
118 if (value)
119 value = ARIZONA_GPN_LVL;
120
121 return regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset,
122 ARIZONA_GPN_DIR | ARIZONA_GPN_LVL, value);
123}
124
125static void arizona_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
126{
127 struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
128 struct arizona *arizona = arizona_gpio->arizona;
129
130 if (value)
131 value = ARIZONA_GPN_LVL;
132
133 regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset,
134 ARIZONA_GPN_LVL, value);
135}
136
137static const struct gpio_chip template_chip = {
138 .label = "arizona",
139 .owner = THIS_MODULE,
140 .direction_input = arizona_gpio_direction_in,
141 .get = arizona_gpio_get,
142 .direction_output = arizona_gpio_direction_out,
143 .set = arizona_gpio_set,
144 .can_sleep = true,
145};
146
147static int arizona_gpio_probe(struct platform_device *pdev)
148{
149 struct arizona *arizona = dev_get_drvdata(pdev->dev.parent);
150 struct arizona_pdata *pdata = dev_get_platdata(arizona->dev);
151 struct arizona_gpio *arizona_gpio;
152 int ret;
153
154 arizona_gpio = devm_kzalloc(&pdev->dev, sizeof(*arizona_gpio),
155 GFP_KERNEL);
156 if (!arizona_gpio)
157 return -ENOMEM;
158
159 arizona_gpio->arizona = arizona;
160 arizona_gpio->gpio_chip = template_chip;
161 arizona_gpio->gpio_chip.parent = &pdev->dev;
162#ifdef CONFIG_OF_GPIO
163 arizona_gpio->gpio_chip.of_node = arizona->dev->of_node;
164#endif
165
166 switch (arizona->type) {
167 case WM5102:
168 case WM5110:
169 case WM8280:
170 case WM8997:
171 case WM8998:
172 case WM1814:
173 arizona_gpio->gpio_chip.ngpio = 5;
174 break;
175 case WM1831:
176 case CS47L24:
177 arizona_gpio->gpio_chip.ngpio = 2;
178 break;
179 default:
180 dev_err(&pdev->dev, "Unknown chip variant %d\n",
181 arizona->type);
182 return -EINVAL;
183 }
184
185 if (pdata && pdata->gpio_base)
186 arizona_gpio->gpio_chip.base = pdata->gpio_base;
187 else
188 arizona_gpio->gpio_chip.base = -1;
189
190 pm_runtime_enable(&pdev->dev);
191
192 ret = devm_gpiochip_add_data(&pdev->dev, &arizona_gpio->gpio_chip,
193 arizona_gpio);
194 if (ret < 0) {
195 dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
196 ret);
197 return ret;
198 }
199
200 return 0;
201}
202
203static struct platform_driver arizona_gpio_driver = {
204 .driver.name = "arizona-gpio",
205 .probe = arizona_gpio_probe,
206};
207
208module_platform_driver(arizona_gpio_driver);
209
210MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
211MODULE_DESCRIPTION("GPIO interface for Arizona devices");
212MODULE_LICENSE("GPL");
213MODULE_ALIAS("platform:arizona-gpio");
214