rcu: Fix wrong check in list_splice_init_rcu()
[linux-2.6.git] / drivers / gpio / gpio-wm8994.c
1 /*
2  * 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>
16 #include <linux/slab.h>
17 #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
28 struct wm8994_gpio {
29         struct wm8994 *wm8994;
30         struct gpio_chip gpio_chip;
31 };
32
33 static inline struct wm8994_gpio *to_wm8994_gpio(struct gpio_chip *chip)
34 {
35         return container_of(chip, struct wm8994_gpio, gpio_chip);
36 }
37
38 static int wm8994_gpio_request(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         switch (wm8994->type) {
44         case WM8958:
45                 switch (offset) {
46                 case 1:
47                 case 2:
48                 case 3:
49                 case 4:
50                 case 6:
51                         return -EINVAL;
52                 }
53                 break;
54         default:
55                 break;
56         }
57
58         return 0;
59 }
60
61 static int wm8994_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
62 {
63         struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
64         struct wm8994 *wm8994 = wm8994_gpio->wm8994;
65
66         return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
67                                WM8994_GPN_DIR, WM8994_GPN_DIR);
68 }
69
70 static int wm8994_gpio_get(struct gpio_chip *chip, unsigned offset)
71 {
72         struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
73         struct wm8994 *wm8994 = wm8994_gpio->wm8994;
74         int ret;
75
76         ret = wm8994_reg_read(wm8994, WM8994_GPIO_1 + offset);
77         if (ret < 0)
78                 return ret;
79
80         if (ret & WM8994_GPN_LVL)
81                 return 1;
82         else
83                 return 0;
84 }
85
86 static int wm8994_gpio_direction_out(struct gpio_chip *chip,
87                                      unsigned offset, int value)
88 {
89         struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
90         struct wm8994 *wm8994 = wm8994_gpio->wm8994;
91
92         return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
93                                WM8994_GPN_DIR, 0);
94 }
95
96 static void wm8994_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
97 {
98         struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
99         struct wm8994 *wm8994 = wm8994_gpio->wm8994;
100
101         if (value)
102                 value = WM8994_GPN_LVL;
103
104         wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset, WM8994_GPN_LVL, value);
105 }
106
107 static int wm8994_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
108 {
109         struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
110         struct wm8994 *wm8994 = wm8994_gpio->wm8994;
111
112         if (!wm8994->irq_base)
113                 return -EINVAL;
114
115         return wm8994->irq_base + offset;
116 }
117
118
119 #ifdef CONFIG_DEBUG_FS
120 static void wm8994_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
121 {
122         struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
123         struct wm8994 *wm8994 = wm8994_gpio->wm8994;
124         int i;
125
126         for (i = 0; i < chip->ngpio; i++) {
127                 int gpio = i + chip->base;
128                 int reg;
129                 const char *label;
130
131                 /* We report the GPIO even if it's not requested since
132                  * we're also reporting things like alternate
133                  * functions which apply even when the GPIO is not in
134                  * use as a GPIO.
135                  */
136                 label = gpiochip_is_requested(chip, i);
137                 if (!label)
138                         label = "Unrequested";
139
140                 seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
141
142                 reg = wm8994_reg_read(wm8994, WM8994_GPIO_1 + i);
143                 if (reg < 0) {
144                         dev_err(wm8994->dev,
145                                 "GPIO control %d read failed: %d\n",
146                                 gpio, reg);
147                         seq_printf(s, "\n");
148                         continue;
149                 }
150
151                 /* No decode yet; note that GPIO2 is special */
152                 seq_printf(s, "(%x)\n", reg);
153         }
154 }
155 #else
156 #define wm8994_gpio_dbg_show NULL
157 #endif
158
159 static struct gpio_chip template_chip = {
160         .label                  = "wm8994",
161         .owner                  = THIS_MODULE,
162         .request                = wm8994_gpio_request,
163         .direction_input        = wm8994_gpio_direction_in,
164         .get                    = wm8994_gpio_get,
165         .direction_output       = wm8994_gpio_direction_out,
166         .set                    = wm8994_gpio_set,
167         .to_irq                 = wm8994_gpio_to_irq,
168         .dbg_show               = wm8994_gpio_dbg_show,
169         .can_sleep              = 1,
170 };
171
172 static int __devinit wm8994_gpio_probe(struct platform_device *pdev)
173 {
174         struct wm8994 *wm8994 = dev_get_drvdata(pdev->dev.parent);
175         struct wm8994_pdata *pdata = wm8994->dev->platform_data;
176         struct wm8994_gpio *wm8994_gpio;
177         int ret;
178
179         wm8994_gpio = kzalloc(sizeof(*wm8994_gpio), GFP_KERNEL);
180         if (wm8994_gpio == NULL)
181                 return -ENOMEM;
182
183         wm8994_gpio->wm8994 = wm8994;
184         wm8994_gpio->gpio_chip = template_chip;
185         wm8994_gpio->gpio_chip.ngpio = WM8994_GPIO_MAX;
186         wm8994_gpio->gpio_chip.dev = &pdev->dev;
187         if (pdata && pdata->gpio_base)
188                 wm8994_gpio->gpio_chip.base = pdata->gpio_base;
189         else
190                 wm8994_gpio->gpio_chip.base = -1;
191
192         ret = gpiochip_add(&wm8994_gpio->gpio_chip);
193         if (ret < 0) {
194                 dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
195                         ret);
196                 goto err;
197         }
198
199         platform_set_drvdata(pdev, wm8994_gpio);
200
201         return ret;
202
203 err:
204         kfree(wm8994_gpio);
205         return ret;
206 }
207
208 static int __devexit wm8994_gpio_remove(struct platform_device *pdev)
209 {
210         struct wm8994_gpio *wm8994_gpio = platform_get_drvdata(pdev);
211         int ret;
212
213         ret = gpiochip_remove(&wm8994_gpio->gpio_chip);
214         if (ret == 0)
215                 kfree(wm8994_gpio);
216
217         return ret;
218 }
219
220 static struct platform_driver wm8994_gpio_driver = {
221         .driver.name    = "wm8994-gpio",
222         .driver.owner   = THIS_MODULE,
223         .probe          = wm8994_gpio_probe,
224         .remove         = __devexit_p(wm8994_gpio_remove),
225 };
226
227 static int __init wm8994_gpio_init(void)
228 {
229         return platform_driver_register(&wm8994_gpio_driver);
230 }
231 subsys_initcall(wm8994_gpio_init);
232
233 static void __exit wm8994_gpio_exit(void)
234 {
235         platform_driver_unregister(&wm8994_gpio_driver);
236 }
237 module_exit(wm8994_gpio_exit);
238
239 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
240 MODULE_DESCRIPTION("GPIO interface for WM8994");
241 MODULE_LICENSE("GPL");
242 MODULE_ALIAS("platform:wm8994-gpio");