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Mark Brown0081e802008-12-04 16:52:33 +00001/*
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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090019#include <linux/slab.h>
Mark Brown0081e802008-12-04 16:52:33 +000020
21/* Microamps */
22static const int isink_cur[] = {
23 4,
24 5,
25 6,
26 7,
27 8,
28 10,
29 11,
30 14,
31 16,
32 19,
33 23,
34 27,
35 32,
36 39,
37 46,
38 54,
39 65,
40 77,
41 92,
42 109,
43 130,
44 154,
45 183,
46 218,
47 259,
48 308,
49 367,
50 436,
51 518,
52 616,
53 733,
54 872,
55 1037,
56 1233,
57 1466,
58 1744,
59 2073,
60 2466,
61 2933,
62 3487,
63 4147,
64 4932,
65 5865,
66 6975,
67 8294,
68 9864,
69 11730,
70 13949,
71 16589,
72 19728,
73 23460,
74 27899,
75 33178,
76 39455,
77 46920,
78 55798,
79 66355,
80 78910,
81 93840,
82 111596,
83 132710,
84 157820,
85 187681,
86 223191
87};
88
89#define to_wm8350_led(led_cdev) \
90 container_of(led_cdev, struct wm8350_led, cdev)
91
92static void wm8350_led_enable(struct wm8350_led *led)
93{
94 int ret;
95
96 if (led->enabled)
97 return;
98
99 ret = regulator_enable(led->isink);
100 if (ret != 0) {
101 dev_err(led->cdev.dev, "Failed to enable ISINK: %d\n", ret);
102 return;
103 }
104
105 ret = regulator_enable(led->dcdc);
106 if (ret != 0) {
107 dev_err(led->cdev.dev, "Failed to enable DCDC: %d\n", ret);
108 regulator_disable(led->isink);
109 return;
110 }
111
112 led->enabled = 1;
113}
114
115static void wm8350_led_disable(struct wm8350_led *led)
116{
117 int ret;
118
119 if (!led->enabled)
120 return;
121
122 ret = regulator_disable(led->dcdc);
123 if (ret != 0) {
124 dev_err(led->cdev.dev, "Failed to disable DCDC: %d\n", ret);
125 return;
126 }
127
128 ret = regulator_disable(led->isink);
129 if (ret != 0) {
130 dev_err(led->cdev.dev, "Failed to disable ISINK: %d\n", ret);
131 regulator_enable(led->dcdc);
132 return;
133 }
134
135 led->enabled = 0;
136}
137
138static void led_work(struct work_struct *work)
139{
140 struct wm8350_led *led = container_of(work, struct wm8350_led, work);
141 int ret;
142 int uA;
143 unsigned long flags;
144
145 mutex_lock(&led->mutex);
146
147 spin_lock_irqsave(&led->value_lock, flags);
148
149 if (led->value == LED_OFF) {
150 spin_unlock_irqrestore(&led->value_lock, flags);
151 wm8350_led_disable(led);
152 goto out;
153 }
154
155 /* This scales linearly into the index of valid current
156 * settings which results in a linear scaling of perceived
157 * brightness due to the non-linear current settings provided
158 * by the hardware.
159 */
160 uA = (led->max_uA_index * led->value) / LED_FULL;
161 spin_unlock_irqrestore(&led->value_lock, flags);
162 BUG_ON(uA >= ARRAY_SIZE(isink_cur));
163
164 ret = regulator_set_current_limit(led->isink, isink_cur[uA],
165 isink_cur[uA]);
166 if (ret != 0)
167 dev_err(led->cdev.dev, "Failed to set %duA: %d\n",
168 isink_cur[uA], ret);
169
170 wm8350_led_enable(led);
171
172out:
173 mutex_unlock(&led->mutex);
174}
175
176static void wm8350_led_set(struct led_classdev *led_cdev,
177 enum led_brightness value)
178{
179 struct wm8350_led *led = to_wm8350_led(led_cdev);
180 unsigned long flags;
181
182 spin_lock_irqsave(&led->value_lock, flags);
183 led->value = value;
184 schedule_work(&led->work);
185 spin_unlock_irqrestore(&led->value_lock, flags);
186}
187
Mark Brown0081e802008-12-04 16:52:33 +0000188static void wm8350_led_shutdown(struct platform_device *pdev)
189{
190 struct wm8350_led *led = platform_get_drvdata(pdev);
191
192 mutex_lock(&led->mutex);
193 led->value = LED_OFF;
194 wm8350_led_disable(led);
195 mutex_unlock(&led->mutex);
196}
197
198static int wm8350_led_probe(struct platform_device *pdev)
199{
200 struct regulator *isink, *dcdc;
201 struct wm8350_led *led;
202 struct wm8350_led_platform_data *pdata = pdev->dev.platform_data;
203 int ret, i;
204
205 if (pdata == NULL) {
206 dev_err(&pdev->dev, "no platform data\n");
207 return -ENODEV;
208 }
209
210 if (pdata->max_uA < isink_cur[0]) {
211 dev_err(&pdev->dev, "Invalid maximum current %duA\n",
212 pdata->max_uA);
213 return -EINVAL;
214 }
215
216 isink = regulator_get(&pdev->dev, "led_isink");
217 if (IS_ERR(isink)) {
218 printk(KERN_ERR "%s: cant get ISINK\n", __func__);
219 return PTR_ERR(isink);
220 }
221
222 dcdc = regulator_get(&pdev->dev, "led_vcc");
223 if (IS_ERR(dcdc)) {
224 printk(KERN_ERR "%s: cant get DCDC\n", __func__);
225 ret = PTR_ERR(dcdc);
226 goto err_isink;
227 }
228
229 led = kzalloc(sizeof(*led), GFP_KERNEL);
230 if (led == NULL) {
231 ret = -ENOMEM;
232 goto err_dcdc;
233 }
234
235 led->cdev.brightness_set = wm8350_led_set;
236 led->cdev.default_trigger = pdata->default_trigger;
237 led->cdev.name = pdata->name;
Richard Purdie859cb7f2009-01-08 17:55:03 +0000238 led->cdev.flags |= LED_CORE_SUSPENDRESUME;
Mark Brown0081e802008-12-04 16:52:33 +0000239 led->enabled = regulator_is_enabled(isink);
240 led->isink = isink;
241 led->dcdc = dcdc;
242
243 for (i = 0; i < ARRAY_SIZE(isink_cur) - 1; i++)
244 if (isink_cur[i] >= pdata->max_uA)
245 break;
246 led->max_uA_index = i;
247 if (pdata->max_uA != isink_cur[i])
248 dev_warn(&pdev->dev,
249 "Maximum current %duA is not directly supported,"
250 " check platform data\n",
251 pdata->max_uA);
252
253 spin_lock_init(&led->value_lock);
254 mutex_init(&led->mutex);
255 INIT_WORK(&led->work, led_work);
256 led->value = LED_OFF;
257 platform_set_drvdata(pdev, led);
258
259 ret = led_classdev_register(&pdev->dev, &led->cdev);
260 if (ret < 0)
261 goto err_led;
262
263 return 0;
264
265 err_led:
266 kfree(led);
267 err_dcdc:
268 regulator_put(dcdc);
269 err_isink:
270 regulator_put(isink);
271 return ret;
272}
273
274static int wm8350_led_remove(struct platform_device *pdev)
275{
276 struct wm8350_led *led = platform_get_drvdata(pdev);
277
278 led_classdev_unregister(&led->cdev);
279 flush_scheduled_work();
280 wm8350_led_disable(led);
281 regulator_put(led->dcdc);
282 regulator_put(led->isink);
283 kfree(led);
284 return 0;
285}
286
287static struct platform_driver wm8350_led_driver = {
288 .driver = {
289 .name = "wm8350-led",
290 .owner = THIS_MODULE,
291 },
292 .probe = wm8350_led_probe,
293 .remove = wm8350_led_remove,
294 .shutdown = wm8350_led_shutdown,
Mark Brown0081e802008-12-04 16:52:33 +0000295};
296
297static int __devinit wm8350_led_init(void)
298{
299 return platform_driver_register(&wm8350_led_driver);
300}
301module_init(wm8350_led_init);
302
303static void wm8350_led_exit(void)
304{
305 platform_driver_unregister(&wm8350_led_driver);
306}
307module_exit(wm8350_led_exit);
308
309MODULE_AUTHOR("Mark Brown");
310MODULE_DESCRIPTION("WM8350 LED driver");
311MODULE_LICENSE("GPL");
312MODULE_ALIAS("platform:wm8350-led");