1 /*
2 * LED driver for WM8350 driven LEDS.
3 *
4 * Copyright(C) 2007, 2008 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/leds.h>
16 #include <linux/err.h>
17 #include <linux/mfd/wm8350/pmic.h>
18 #include <linux/regulator/consumer.h>
19
20 /* Microamps */
21 static const int isink_cur[] = {
22 4,
23 5,
24 6,
25 7,
26 8,
27 10,
28 11,
29 14,
30 16,
31 19,
32 23,
33 27,
34 32,
35 39,
36 46,
37 54,
38 65,
39 77,
40 92,
41 109,
42 130,
43 154,
44 183,
45 218,
46 259,
47 308,
48 367,
49 436,
50 518,
51 616,
52 733,
53 872,
54 1037,
55 1233,
56 1466,
57 1744,
58 2073,
59 2466,
60 2933,
61 3487,
62 4147,
63 4932,
64 5865,
65 6975,
66 8294,
67 9864,
68 11730,
69 13949,
70 16589,
71 19728,
72 23460,
73 27899,
74 33178,
75 39455,
76 46920,
77 55798,
78 66355,
79 78910,
80 93840,
81 111596,
82 132710,
83 157820,
84 187681,
85 223191
86 };
87
88 #define to_wm8350_led(led_cdev) \
89 container_of(led_cdev, struct wm8350_led, cdev)
90
91 static void wm8350_led_enable(struct wm8350_led *led)
92 {
93 int ret;
94
95 if (led->enabled)
96 return;
97
98 ret = regulator_enable(led->isink);
99 if (ret != 0) {
100 dev_err(led->cdev.dev, "Failed to enable ISINK: %d\n", ret);
101 return;
102 }
103
104 ret = regulator_enable(led->dcdc);
105 if (ret != 0) {
106 dev_err(led->cdev.dev, "Failed to enable DCDC: %d\n", ret);
107 regulator_disable(led->isink);
108 return;
109 }
110
111 led->enabled = 1;
112 }
113
114 static void wm8350_led_disable(struct wm8350_led *led)
115 {
116 int ret;
117
118 if (!led->enabled)
119 return;
120
121 ret = regulator_disable(led->dcdc);
122 if (ret != 0) {
123 dev_err(led->cdev.dev, "Failed to disable DCDC: %d\n", ret);
124 return;
125 }
126
127 ret = regulator_disable(led->isink);
128 if (ret != 0) {
129 dev_err(led->cdev.dev, "Failed to disable ISINK: %d\n", ret);
130 regulator_enable(led->dcdc);
131 return;
132 }
133
134 led->enabled = 0;
135 }
136
137 static void led_work(struct work_struct *work)
138 {
139 struct wm8350_led *led = container_of(work, struct wm8350_led, work);
140 int ret;
141 int uA;
142 unsigned long flags;
143
144 mutex_lock(&led->mutex);
145
146 spin_lock_irqsave(&led->value_lock, flags);
147
148 if (led->value == LED_OFF) {
149 spin_unlock_irqrestore(&led->value_lock, flags);
150 wm8350_led_disable(led);
151 goto out;
152 }
153
154 /* This scales linearly into the index of valid current
155 * settings which results in a linear scaling of perceived
156 * brightness due to the non-linear current settings provided
157 * by the hardware.
158 */
159 uA = (led->max_uA_index * led->value) / LED_FULL;
160 spin_unlock_irqrestore(&led->value_lock, flags);
161 BUG_ON(uA >= ARRAY_SIZE(isink_cur));
162
163 ret = regulator_set_current_limit(led->isink, isink_cur[uA],
164 isink_cur[uA]);
165 if (ret != 0)
166 dev_err(led->cdev.dev, "Failed to set %duA: %d\n",
167 isink_cur[uA], ret);
168
169 wm8350_led_enable(led);
170
171 out:
172 mutex_unlock(&led->mutex);
173 }
174
175 static void wm8350_led_set(struct led_classdev *led_cdev,
176 enum led_brightness value)
177 {
178 struct wm8350_led *led = to_wm8350_led(led_cdev);
179 unsigned long flags;
180
181 spin_lock_irqsave(&led->value_lock, flags);
182 led->value = value;
183 schedule_work(&led->work);
184 spin_unlock_irqrestore(&led->value_lock, flags);
185 }
186
187 static void wm8350_led_shutdown(struct platform_device *pdev)
188 {
189 struct wm8350_led *led = platform_get_drvdata(pdev);
190
191 mutex_lock(&led->mutex);
192 led->value = LED_OFF;
193 wm8350_led_disable(led);
194 mutex_unlock(&led->mutex);
195 }
196
197 static int wm8350_led_probe(struct platform_device *pdev)
198 {
199 struct regulator *isink, *dcdc;
200 struct wm8350_led *led;
201 struct wm8350_led_platform_data *pdata = pdev->dev.platform_data;
202 int ret, i;
203
204 if (pdata == NULL) {
205 dev_err(&pdev->dev, "no platform data\n");
206 return -ENODEV;
207 }
208
209 if (pdata->max_uA < isink_cur[0]) {
210 dev_err(&pdev->dev, "Invalid maximum current %duA\n",
211 pdata->max_uA);
212 return -EINVAL;
213 }
214
215 isink = regulator_get(&pdev->dev, "led_isink");
216 if (IS_ERR(isink)) {
217 printk(KERN_ERR "%s: cant get ISINK\n", __func__);
218 return PTR_ERR(isink);
219 }
220
221 dcdc = regulator_get(&pdev->dev, "led_vcc");
222 if (IS_ERR(dcdc)) {
223 printk(KERN_ERR "%s: cant get DCDC\n", __func__);
224 ret = PTR_ERR(dcdc);
225 goto err_isink;
226 }
227
228 led = kzalloc(sizeof(*led), GFP_KERNEL);
229 if (led == NULL) {
230 ret = -ENOMEM;
231 goto err_dcdc;
232 }
233
234 led->cdev.brightness_set = wm8350_led_set;
235 led->cdev.default_trigger = pdata->default_trigger;
236 led->cdev.name = pdata->name;
237 led->cdev.flags |= LED_CORE_SUSPENDRESUME;
238 led->enabled = regulator_is_enabled(isink);
239 led->isink = isink;
240 led->dcdc = dcdc;
241
242 for (i = 0; i < ARRAY_SIZE(isink_cur) - 1; i++)
243 if (isink_cur[i] >= pdata->max_uA)
244 break;
245 led->max_uA_index = i;
246 if (pdata->max_uA != isink_cur[i])
247 dev_warn(&pdev->dev,
248 "Maximum current %duA is not directly supported,"
249 " check platform data\n",
250 pdata->max_uA);
251
252 spin_lock_init(&led->value_lock);
253 mutex_init(&led->mutex);
254 INIT_WORK(&led->work, led_work);
255 led->value = LED_OFF;
256 platform_set_drvdata(pdev, led);
257
258 ret = led_classdev_register(&pdev->dev, &led->cdev);
259 if (ret < 0)
260 goto err_led;
261
262 return 0;
263
264 err_led:
265 kfree(led);
266 err_dcdc:
267 regulator_put(dcdc);
268 err_isink:
269 regulator_put(isink);
270 return ret;
271 }
272
273 static int wm8350_led_remove(struct platform_device *pdev)
274 {
275 struct wm8350_led *led = platform_get_drvdata(pdev);
276
277 led_classdev_unregister(&led->cdev);
278 flush_scheduled_work();
279 wm8350_led_disable(led);
280 regulator_put(led->dcdc);
281 regulator_put(led->isink);
282 kfree(led);
283 return 0;
284 }
285
286 static struct platform_driver wm8350_led_driver = {
287 .driver = {
288 .name = "wm8350-led",
289 .owner = THIS_MODULE,
290 },
291 .probe = wm8350_led_probe,
292 .remove = wm8350_led_remove,
293 .shutdown = wm8350_led_shutdown,
294 };
295
296 static int __devinit wm8350_led_init(void)
297 {
298 return platform_driver_register(&wm8350_led_driver);
299 }
300 module_init(wm8350_led_init);
301
302 static void wm8350_led_exit(void)
303 {
304 platform_driver_unregister(&wm8350_led_driver);
305 }
306 module_exit(wm8350_led_exit);
307
308 MODULE_AUTHOR("Mark Brown");
309 MODULE_DESCRIPTION("WM8350 LED driver");
310 MODULE_LICENSE("GPL");
311 MODULE_ALIAS("platform:wm8350-led");
312
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