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Mark Browne4b736f2009-07-27 14:46:00 +01001/*
2 * wm831x-gpio.c -- gpiolib support for Wolfson WM831x PMICs
3 *
4 * Copyright 2009 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/module.h>
17#include <linux/gpio.h>
18#include <linux/mfd/core.h>
19#include <linux/platform_device.h>
20#include <linux/seq_file.h>
21
22#include <linux/mfd/wm831x/core.h>
23#include <linux/mfd/wm831x/pdata.h>
24#include <linux/mfd/wm831x/gpio.h>
25
26#define WM831X_GPIO_MAX 16
27
28struct wm831x_gpio {
29 struct wm831x *wm831x;
30 struct gpio_chip gpio_chip;
31};
32
33static inline struct wm831x_gpio *to_wm831x_gpio(struct gpio_chip *chip)
34{
35 return container_of(chip, struct wm831x_gpio, gpio_chip);
36}
37
38static int wm831x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
39{
40 struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
41 struct wm831x *wm831x = wm831x_gpio->wm831x;
42
43 return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
44 WM831X_GPN_DIR | WM831X_GPN_TRI,
45 WM831X_GPN_DIR);
46}
47
48static int wm831x_gpio_get(struct gpio_chip *chip, unsigned offset)
49{
50 struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
51 struct wm831x *wm831x = wm831x_gpio->wm831x;
52 int ret;
53
54 ret = wm831x_reg_read(wm831x, WM831X_GPIO_LEVEL);
55 if (ret < 0)
56 return ret;
57
58 if (ret & 1 << offset)
59 return 1;
60 else
61 return 0;
62}
63
64static int wm831x_gpio_direction_out(struct gpio_chip *chip,
65 unsigned offset, int value)
66{
67 struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
68 struct wm831x *wm831x = wm831x_gpio->wm831x;
69
70 return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
71 WM831X_GPN_DIR | WM831X_GPN_TRI, 0);
72}
73
74static void wm831x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
75{
76 struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
77 struct wm831x *wm831x = wm831x_gpio->wm831x;
78
79 wm831x_set_bits(wm831x, WM831X_GPIO_LEVEL, 1 << offset,
80 value << offset);
81}
82
83#ifdef CONFIG_DEBUG_FS
84static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
85{
86 struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
87 struct wm831x *wm831x = wm831x_gpio->wm831x;
88 int i;
89
90 for (i = 0; i < chip->ngpio; i++) {
91 int gpio = i + chip->base;
92 int reg;
93 const char *label, *pull, *powerdomain;
94
95 /* We report the GPIO even if it's not requested since
96 * we're also reporting things like alternate
97 * functions which apply even when the GPIO is not in
98 * use as a GPIO.
99 */
100 label = gpiochip_is_requested(chip, i);
101 if (!label)
102 label = "Unrequested";
103
104 seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
105
106 reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i);
107 if (reg < 0) {
108 dev_err(wm831x->dev,
109 "GPIO control %d read failed: %d\n",
110 gpio, reg);
111 seq_printf(s, "\n");
112 continue;
113 }
114
115 switch (reg & WM831X_GPN_PULL_MASK) {
116 case WM831X_GPIO_PULL_NONE:
117 pull = "nopull";
118 break;
119 case WM831X_GPIO_PULL_DOWN:
120 pull = "pulldown";
121 break;
122 case WM831X_GPIO_PULL_UP:
123 pull = "pullup";
124 default:
125 pull = "INVALID PULL";
126 break;
127 }
128
129 switch (i + 1) {
130 case 1 ... 3:
131 case 7 ... 9:
132 if (reg & WM831X_GPN_PWR_DOM)
133 powerdomain = "VPMIC";
134 else
135 powerdomain = "DBVDD";
136 break;
137
138 case 4 ... 6:
139 case 10 ... 12:
140 if (reg & WM831X_GPN_PWR_DOM)
141 powerdomain = "SYSVDD";
142 else
143 powerdomain = "DBVDD";
144 break;
145
146 case 13 ... 16:
147 powerdomain = "TPVDD";
148 break;
149
150 default:
151 BUG();
152 break;
153 }
154
155 seq_printf(s, " %s %s %s %s%s\n"
156 " %s%s (0x%4x)\n",
157 reg & WM831X_GPN_DIR ? "in" : "out",
158 wm831x_gpio_get(chip, i) ? "high" : "low",
159 pull,
160 powerdomain,
161 reg & WM831X_GPN_POL ? " inverted" : "",
162 reg & WM831X_GPN_OD ? "open-drain" : "CMOS",
163 reg & WM831X_GPN_TRI ? " tristated" : "",
164 reg);
165 }
166}
167#else
168#define wm831x_gpio_dbg_show NULL
169#endif
170
171static struct gpio_chip template_chip = {
172 .label = "wm831x",
173 .owner = THIS_MODULE,
174 .direction_input = wm831x_gpio_direction_in,
175 .get = wm831x_gpio_get,
176 .direction_output = wm831x_gpio_direction_out,
177 .set = wm831x_gpio_set,
178 .dbg_show = wm831x_gpio_dbg_show,
179 .can_sleep = 1,
180};
181
182static int __devinit wm831x_gpio_probe(struct platform_device *pdev)
183{
184 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
185 struct wm831x_pdata *pdata = wm831x->dev->platform_data;
186 struct wm831x_gpio *wm831x_gpio;
187 int ret;
188
189 wm831x_gpio = kzalloc(sizeof(*wm831x_gpio), GFP_KERNEL);
190 if (wm831x_gpio == NULL)
191 return -ENOMEM;
192
193 wm831x_gpio->wm831x = wm831x;
194 wm831x_gpio->gpio_chip = template_chip;
195 wm831x_gpio->gpio_chip.ngpio = WM831X_GPIO_MAX;
196 wm831x_gpio->gpio_chip.dev = &pdev->dev;
197 if (pdata && pdata->gpio_base)
198 wm831x_gpio->gpio_chip.base = pdata->gpio_base;
199 else
200 wm831x_gpio->gpio_chip.base = -1;
201
202 ret = gpiochip_add(&wm831x_gpio->gpio_chip);
203 if (ret < 0) {
204 dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
205 ret);
206 goto err;
207 }
208
209 platform_set_drvdata(pdev, wm831x_gpio);
210
211 return ret;
212
213err:
214 kfree(wm831x_gpio);
215 return ret;
216}
217
218static int __devexit wm831x_gpio_remove(struct platform_device *pdev)
219{
220 struct wm831x_gpio *wm831x_gpio = platform_get_drvdata(pdev);
221 int ret;
222
223 ret = gpiochip_remove(&wm831x_gpio->gpio_chip);
224 if (ret == 0)
225 kfree(wm831x_gpio);
226
227 return ret;
228}
229
230static struct platform_driver wm831x_gpio_driver = {
231 .driver.name = "wm831x-gpio",
232 .driver.owner = THIS_MODULE,
233 .probe = wm831x_gpio_probe,
234 .remove = __devexit_p(wm831x_gpio_remove),
235};
236
237static int __init wm831x_gpio_init(void)
238{
239 return platform_driver_register(&wm831x_gpio_driver);
240}
241subsys_initcall(wm831x_gpio_init);
242
243static void __exit wm831x_gpio_exit(void)
244{
245 platform_driver_unregister(&wm831x_gpio_driver);
246}
247module_exit(wm831x_gpio_exit);
248
249MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
250MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
251MODULE_LICENSE("GPL");
252MODULE_ALIAS("platform:wm831x-gpio");