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Mark Brown2955c302010-01-29 18:20:30 +00001/*
2 * wm8994-gpio.c -- gpiolib support for Wolfson WM8994
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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090016#include <linux/slab.h>
Mark Brown2955c302010-01-29 18:20:30 +000017#include <linux/module.h>
18#include <linux/gpio.h>
19#include <linux/mfd/core.h>
20#include <linux/platform_device.h>
21#include <linux/seq_file.h>
22
23#include <linux/mfd/wm8994/core.h>
24#include <linux/mfd/wm8994/pdata.h>
25#include <linux/mfd/wm8994/gpio.h>
26#include <linux/mfd/wm8994/registers.h>
27
28struct wm8994_gpio {
29 struct wm8994 *wm8994;
30 struct gpio_chip gpio_chip;
31};
32
33static inline struct wm8994_gpio *to_wm8994_gpio(struct gpio_chip *chip)
34{
35 return container_of(chip, struct wm8994_gpio, gpio_chip);
36}
37
38static int wm8994_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
39{
40 struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
41 struct wm8994 *wm8994 = wm8994_gpio->wm8994;
42
43 return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
44 WM8994_GPN_DIR, WM8994_GPN_DIR);
45}
46
47static int wm8994_gpio_get(struct gpio_chip *chip, unsigned offset)
48{
49 struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
50 struct wm8994 *wm8994 = wm8994_gpio->wm8994;
51 int ret;
52
53 ret = wm8994_reg_read(wm8994, WM8994_GPIO_1 + offset);
54 if (ret < 0)
55 return ret;
56
57 if (ret & WM8994_GPN_LVL)
58 return 1;
59 else
60 return 0;
61}
62
63static int wm8994_gpio_direction_out(struct gpio_chip *chip,
64 unsigned offset, int value)
65{
66 struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
67 struct wm8994 *wm8994 = wm8994_gpio->wm8994;
68
69 return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
70 WM8994_GPN_DIR, 0);
71}
72
73static void wm8994_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
74{
75 struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
76 struct wm8994 *wm8994 = wm8994_gpio->wm8994;
77
78 if (value)
79 value = WM8994_GPN_LVL;
80
81 wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset, WM8994_GPN_LVL, value);
82}
83
84#ifdef CONFIG_DEBUG_FS
85static void wm8994_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
86{
87 struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
88 struct wm8994 *wm8994 = wm8994_gpio->wm8994;
89 int i;
90
91 for (i = 0; i < chip->ngpio; i++) {
92 int gpio = i + chip->base;
93 int reg;
94 const char *label;
95
96 /* We report the GPIO even if it's not requested since
97 * we're also reporting things like alternate
98 * functions which apply even when the GPIO is not in
99 * use as a GPIO.
100 */
101 label = gpiochip_is_requested(chip, i);
102 if (!label)
103 label = "Unrequested";
104
105 seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
106
107 reg = wm8994_reg_read(wm8994, WM8994_GPIO_1 + i);
108 if (reg < 0) {
109 dev_err(wm8994->dev,
110 "GPIO control %d read failed: %d\n",
111 gpio, reg);
112 seq_printf(s, "\n");
113 continue;
114 }
115
116 /* No decode yet; note that GPIO2 is special */
117 seq_printf(s, "(%x)\n", reg);
118 }
119}
120#else
121#define wm8994_gpio_dbg_show NULL
122#endif
123
124static struct gpio_chip template_chip = {
125 .label = "wm8994",
126 .owner = THIS_MODULE,
127 .direction_input = wm8994_gpio_direction_in,
128 .get = wm8994_gpio_get,
129 .direction_output = wm8994_gpio_direction_out,
130 .set = wm8994_gpio_set,
131 .dbg_show = wm8994_gpio_dbg_show,
132 .can_sleep = 1,
133};
134
135static int __devinit wm8994_gpio_probe(struct platform_device *pdev)
136{
137 struct wm8994 *wm8994 = dev_get_drvdata(pdev->dev.parent);
138 struct wm8994_pdata *pdata = wm8994->dev->platform_data;
139 struct wm8994_gpio *wm8994_gpio;
140 int ret;
141
142 wm8994_gpio = kzalloc(sizeof(*wm8994_gpio), GFP_KERNEL);
143 if (wm8994_gpio == NULL)
144 return -ENOMEM;
145
146 wm8994_gpio->wm8994 = wm8994;
147 wm8994_gpio->gpio_chip = template_chip;
148 wm8994_gpio->gpio_chip.ngpio = WM8994_GPIO_MAX;
149 wm8994_gpio->gpio_chip.dev = &pdev->dev;
150 if (pdata && pdata->gpio_base)
151 wm8994_gpio->gpio_chip.base = pdata->gpio_base;
152 else
153 wm8994_gpio->gpio_chip.base = -1;
154
155 ret = gpiochip_add(&wm8994_gpio->gpio_chip);
156 if (ret < 0) {
157 dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
158 ret);
159 goto err;
160 }
161
162 platform_set_drvdata(pdev, wm8994_gpio);
163
164 return ret;
165
166err:
167 kfree(wm8994_gpio);
168 return ret;
169}
170
171static int __devexit wm8994_gpio_remove(struct platform_device *pdev)
172{
173 struct wm8994_gpio *wm8994_gpio = platform_get_drvdata(pdev);
174 int ret;
175
176 ret = gpiochip_remove(&wm8994_gpio->gpio_chip);
177 if (ret == 0)
178 kfree(wm8994_gpio);
179
180 return ret;
181}
182
183static struct platform_driver wm8994_gpio_driver = {
184 .driver.name = "wm8994-gpio",
185 .driver.owner = THIS_MODULE,
186 .probe = wm8994_gpio_probe,
187 .remove = __devexit_p(wm8994_gpio_remove),
188};
189
190static int __init wm8994_gpio_init(void)
191{
192 return platform_driver_register(&wm8994_gpio_driver);
193}
194subsys_initcall(wm8994_gpio_init);
195
196static void __exit wm8994_gpio_exit(void)
197{
198 platform_driver_unregister(&wm8994_gpio_driver);
199}
200module_exit(wm8994_gpio_exit);
201
202MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
203MODULE_DESCRIPTION("GPIO interface for WM8994");
204MODULE_LICENSE("GPL");
205MODULE_ALIAS("platform:wm8994-gpio");