Merge branch 'xen/xenbus' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen
[pandora-kernel.git] / drivers / leds / leds-wm831x-status.c
1 /*
2  * LED driver for WM831x status LEDs
3  *
4  * Copyright(C) 2009 Wolfson Microelectronics PLC.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  */
11
12 #include <linux/kernel.h>
13 #include <linux/init.h>
14 #include <linux/platform_device.h>
15 #include <linux/slab.h>
16 #include <linux/leds.h>
17 #include <linux/err.h>
18 #include <linux/mfd/wm831x/core.h>
19 #include <linux/mfd/wm831x/pdata.h>
20 #include <linux/mfd/wm831x/status.h>
21
22
23 struct wm831x_status {
24         struct led_classdev cdev;
25         struct wm831x *wm831x;
26         struct work_struct work;
27         struct mutex mutex;
28
29         spinlock_t value_lock;
30         int reg;     /* Control register */
31         int reg_val; /* Control register value */
32
33         int blink;
34         int blink_time;
35         int blink_cyc;
36         int src;
37         enum led_brightness brightness;
38 };
39
40 #define to_wm831x_status(led_cdev) \
41         container_of(led_cdev, struct wm831x_status, cdev)
42
43 static void wm831x_status_work(struct work_struct *work)
44 {
45         struct wm831x_status *led = container_of(work, struct wm831x_status,
46                                                  work);
47         unsigned long flags;
48
49         mutex_lock(&led->mutex);
50
51         led->reg_val &= ~(WM831X_LED_SRC_MASK | WM831X_LED_MODE_MASK |
52                           WM831X_LED_DUTY_CYC_MASK | WM831X_LED_DUR_MASK);
53
54         spin_lock_irqsave(&led->value_lock, flags);
55
56         led->reg_val |= led->src << WM831X_LED_SRC_SHIFT;
57         if (led->blink) {
58                 led->reg_val |= 2 << WM831X_LED_MODE_SHIFT;
59                 led->reg_val |= led->blink_time << WM831X_LED_DUR_SHIFT;
60                 led->reg_val |= led->blink_cyc;
61         } else {
62                 if (led->brightness != LED_OFF)
63                         led->reg_val |= 1 << WM831X_LED_MODE_SHIFT;
64         }
65
66         spin_unlock_irqrestore(&led->value_lock, flags);
67
68         wm831x_reg_write(led->wm831x, led->reg, led->reg_val);
69
70         mutex_unlock(&led->mutex);
71 }
72
73 static void wm831x_status_set(struct led_classdev *led_cdev,
74                            enum led_brightness value)
75 {
76         struct wm831x_status *led = to_wm831x_status(led_cdev);
77         unsigned long flags;
78
79         spin_lock_irqsave(&led->value_lock, flags);
80         led->brightness = value;
81         if (value == LED_OFF)
82                 led->blink = 0;
83         schedule_work(&led->work);
84         spin_unlock_irqrestore(&led->value_lock, flags);
85 }
86
87 static int wm831x_status_blink_set(struct led_classdev *led_cdev,
88                                    unsigned long *delay_on,
89                                    unsigned long *delay_off)
90 {
91         struct wm831x_status *led = to_wm831x_status(led_cdev);
92         unsigned long flags;
93         int ret = 0;
94
95         /* Pick some defaults if we've not been given times */
96         if (*delay_on == 0 && *delay_off == 0) {
97                 *delay_on = 250;
98                 *delay_off = 250;
99         }
100
101         spin_lock_irqsave(&led->value_lock, flags);
102
103         /* We only have a limited selection of settings, see if we can
104          * support the configuration we're being given */
105         switch (*delay_on) {
106         case 1000:
107                 led->blink_time = 0;
108                 break;
109         case 250:
110                 led->blink_time = 1;
111                 break;
112         case 125:
113                 led->blink_time = 2;
114                 break;
115         case 62:
116         case 63:
117                 /* Actually 62.5ms */
118                 led->blink_time = 3;
119                 break;
120         default:
121                 ret = -EINVAL;
122                 break;
123         }
124
125         if (ret == 0) {
126                 switch (*delay_off / *delay_on) {
127                 case 1:
128                         led->blink_cyc = 0;
129                         break;
130                 case 3:
131                         led->blink_cyc = 1;
132                         break;
133                 case 4:
134                         led->blink_cyc = 2;
135                         break;
136                 case 8:
137                         led->blink_cyc = 3;
138                         break;
139                 default:
140                         ret = -EINVAL;
141                         break;
142                 }
143         }
144
145         if (ret == 0)
146                 led->blink = 1;
147         else
148                 led->blink = 0;
149
150         /* Always update; if we fail turn off blinking since we expect
151          * a software fallback. */
152         schedule_work(&led->work);
153
154         spin_unlock_irqrestore(&led->value_lock, flags);
155
156         return ret;
157 }
158
159 static const char *led_src_texts[] = {
160         "otp",
161         "power",
162         "charger",
163         "soft",
164 };
165
166 static ssize_t wm831x_status_src_show(struct device *dev,
167                                       struct device_attribute *attr, char *buf)
168 {
169         struct led_classdev *led_cdev = dev_get_drvdata(dev);
170         struct wm831x_status *led = to_wm831x_status(led_cdev);
171         int i;
172         ssize_t ret = 0;
173
174         mutex_lock(&led->mutex);
175
176         for (i = 0; i < ARRAY_SIZE(led_src_texts); i++)
177                 if (i == led->src)
178                         ret += sprintf(&buf[ret], "[%s] ", led_src_texts[i]);
179                 else
180                         ret += sprintf(&buf[ret], "%s ", led_src_texts[i]);
181
182         mutex_unlock(&led->mutex);
183
184         ret += sprintf(&buf[ret], "\n");
185
186         return ret;
187 }
188
189 static ssize_t wm831x_status_src_store(struct device *dev,
190                                        struct device_attribute *attr,
191                                        const char *buf, size_t size)
192 {
193         struct led_classdev *led_cdev = dev_get_drvdata(dev);
194         struct wm831x_status *led = to_wm831x_status(led_cdev);
195         char name[20];
196         int i;
197         size_t len;
198
199         name[sizeof(name) - 1] = '\0';
200         strncpy(name, buf, sizeof(name) - 1);
201         len = strlen(name);
202
203         if (len && name[len - 1] == '\n')
204                 name[len - 1] = '\0';
205
206         for (i = 0; i < ARRAY_SIZE(led_src_texts); i++) {
207                 if (!strcmp(name, led_src_texts[i])) {
208                         mutex_lock(&led->mutex);
209
210                         led->src = i;
211                         schedule_work(&led->work);
212
213                         mutex_unlock(&led->mutex);
214                 }
215         }
216
217         return size;
218 }
219
220 static DEVICE_ATTR(src, 0644, wm831x_status_src_show, wm831x_status_src_store);
221
222 static int wm831x_status_probe(struct platform_device *pdev)
223 {
224         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
225         struct wm831x_pdata *chip_pdata;
226         struct wm831x_status_pdata pdata;
227         struct wm831x_status *drvdata;
228         struct resource *res;
229         int id = pdev->id % ARRAY_SIZE(chip_pdata->status);
230         int ret;
231
232         res = platform_get_resource(pdev, IORESOURCE_IO, 0);
233         if (res == NULL) {
234                 dev_err(&pdev->dev, "No I/O resource\n");
235                 ret = -EINVAL;
236                 goto err;
237         }
238
239         drvdata = kzalloc(sizeof(struct wm831x_status), GFP_KERNEL);
240         if (!drvdata)
241                 return -ENOMEM;
242         dev_set_drvdata(&pdev->dev, drvdata);
243
244         drvdata->wm831x = wm831x;
245         drvdata->reg = res->start;
246
247         if (wm831x->dev->platform_data)
248                 chip_pdata = wm831x->dev->platform_data;
249         else
250                 chip_pdata = NULL;
251
252         memset(&pdata, 0, sizeof(pdata));
253         if (chip_pdata && chip_pdata->status[id])
254                 memcpy(&pdata, chip_pdata->status[id], sizeof(pdata));
255         else
256                 pdata.name = dev_name(&pdev->dev);
257
258         mutex_init(&drvdata->mutex);
259         INIT_WORK(&drvdata->work, wm831x_status_work);
260         spin_lock_init(&drvdata->value_lock);
261
262         /* We cache the configuration register and read startup values
263          * from it. */
264         drvdata->reg_val = wm831x_reg_read(wm831x, drvdata->reg);
265
266         if (drvdata->reg_val & WM831X_LED_MODE_MASK)
267                 drvdata->brightness = LED_FULL;
268         else
269                 drvdata->brightness = LED_OFF;
270
271         /* Set a default source if configured, otherwise leave the
272          * current hardware setting.
273          */
274         if (pdata.default_src == WM831X_STATUS_PRESERVE) {
275                 drvdata->src = drvdata->reg_val;
276                 drvdata->src &= WM831X_LED_SRC_MASK;
277                 drvdata->src >>= WM831X_LED_SRC_SHIFT;
278         } else {
279                 drvdata->src = pdata.default_src - 1;
280         }
281
282         drvdata->cdev.name = pdata.name;
283         drvdata->cdev.default_trigger = pdata.default_trigger;
284         drvdata->cdev.brightness_set = wm831x_status_set;
285         drvdata->cdev.blink_set = wm831x_status_blink_set;
286
287         ret = led_classdev_register(wm831x->dev, &drvdata->cdev);
288         if (ret < 0) {
289                 dev_err(&pdev->dev, "Failed to register LED: %d\n", ret);
290                 goto err_led;
291         }
292
293         ret = device_create_file(drvdata->cdev.dev, &dev_attr_src);
294         if (ret != 0)
295                 dev_err(&pdev->dev,
296                         "No source control for LED: %d\n", ret);
297
298         return 0;
299
300 err_led:
301         led_classdev_unregister(&drvdata->cdev);
302         kfree(drvdata);
303 err:
304         return ret;
305 }
306
307 static int wm831x_status_remove(struct platform_device *pdev)
308 {
309         struct wm831x_status *drvdata = platform_get_drvdata(pdev);
310
311         device_remove_file(drvdata->cdev.dev, &dev_attr_src);
312         led_classdev_unregister(&drvdata->cdev);
313         kfree(drvdata);
314
315         return 0;
316 }
317
318 static struct platform_driver wm831x_status_driver = {
319         .driver = {
320                    .name = "wm831x-status",
321                    .owner = THIS_MODULE,
322                    },
323         .probe = wm831x_status_probe,
324         .remove = wm831x_status_remove,
325 };
326
327 static int __devinit wm831x_status_init(void)
328 {
329         return platform_driver_register(&wm831x_status_driver);
330 }
331 module_init(wm831x_status_init);
332
333 static void wm831x_status_exit(void)
334 {
335         platform_driver_unregister(&wm831x_status_driver);
336 }
337 module_exit(wm831x_status_exit);
338
339 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
340 MODULE_DESCRIPTION("WM831x status LED driver");
341 MODULE_LICENSE("GPL");
342 MODULE_ALIAS("platform:wm831x-status");