summaryrefslogtreecommitdiffstats
path: root/drivers/leds/leds-wm8350.c
blob: 846ed978103f13537af8b6b418f6fe921ff5a4ac (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
/*
 * LED driver for WM8350 driven LEDS.
 *
 * Copyright(C) 2007, 2008 Wolfson Microelectronics PLC.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/leds.h>
#include <linux/err.h>
#include <linux/mfd/wm8350/pmic.h>
#include <linux/regulator/consumer.h>

/* Microamps */
static const int isink_cur[] = {
	4,
	5,
	6,
	7,
	8,
	10,
	11,
	14,
	16,
	19,
	23,
	27,
	32,
	39,
	46,
	54,
	65,
	77,
	92,
	109,
	130,
	154,
	183,
	218,
	259,
	308,
	367,
	436,
	518,
	616,
	733,
	872,
	1037,
	1233,
	1466,
	1744,
	2073,
	2466,
	2933,
	3487,
	4147,
	4932,
	5865,
	6975,
	8294,
	9864,
	11730,
	13949,
	16589,
	19728,
	23460,
	27899,
	33178,
	39455,
	46920,
	55798,
	66355,
	78910,
	93840,
	111596,
	132710,
	157820,
	187681,
	223191
};

#define to_wm8350_led(led_cdev) \
	container_of(led_cdev, struct wm8350_led, cdev)

static void wm8350_led_enable(struct wm8350_led *led)
{
	int ret;

	if (led->enabled)
		return;

	ret = regulator_enable(led->isink);
	if (ret != 0) {
		dev_err(led->cdev.dev, "Failed to enable ISINK: %d\n", ret);
		return;
	}

	ret = regulator_enable(led->dcdc);
	if (ret != 0) {
		dev_err(led->cdev.dev, "Failed to enable DCDC: %d\n", ret);
		regulator_disable(led->isink);
		return;
	}

	led->enabled = 1;
}

static void wm8350_led_disable(struct wm8350_led *led)
{
	int ret;

	if (!led->enabled)
		return;

	ret = regulator_disable(led->dcdc);
	if (ret != 0) {
		dev_err(led->cdev.dev, "Failed to disable DCDC: %d\n", ret);
		return;
	}

	ret = regulator_disable(led->isink);
	if (ret != 0) {
		dev_err(led->cdev.dev, "Failed to disable ISINK: %d\n", ret);
		regulator_enable(led->dcdc);
		return;
	}

	led->enabled = 0;
}

static void led_work(struct work_struct *work)
{
	struct wm8350_led *led = container_of(work, struct wm8350_led, work);
	int ret;
	int uA;
	unsigned long flags;

	mutex_lock(&led->mutex);

	spin_lock_irqsave(&led->value_lock, flags);

	if (led->value == LED_OFF) {
		spin_unlock_irqrestore(&led->value_lock, flags);
		wm8350_led_disable(led);
		goto out;
	}

	/* This scales linearly into the index of valid current
	 * settings which results in a linear scaling of perceived
	 * brightness due to the non-linear current settings provided
	 * by the hardware.
	 */
	uA = (led->max_uA_index * led->value) / LED_FULL;
	spin_unlock_irqrestore(&led->value_lock, flags);
	BUG_ON(uA >= ARRAY_SIZE(isink_cur));

	ret = regulator_set_current_limit(led->isink, isink_cur[uA],
					  isink_cur[uA]);
	if (ret != 0)
		dev_err(led->cdev.dev, "Failed to set %duA: %d\n",
			isink_cur[uA], ret);

	wm8350_led_enable(led);

out:
	mutex_unlock(&led->mutex);
}

static void wm8350_led_set(struct led_classdev *led_cdev,
			   enum led_brightness value)
{
	struct wm8350_led *led = to_wm8350_led(led_cdev);
	unsigned long flags;

	spin_lock_irqsave(&led->value_lock, flags);
	led->value = value;
	schedule_work(&led->work);
	spin_unlock_irqrestore(&led->value_lock, flags);
}

#ifdef CONFIG_PM
static int wm8350_led_suspend(struct platform_device *pdev, pm_message_t state)
{
	struct wm8350_led *led = platform_get_drvdata(pdev);

	led_classdev_suspend(&led->cdev);
	return 0;
}

static int wm8350_led_resume(struct platform_device *pdev)
{
	struct wm8350_led *led = platform_get_drvdata(pdev);

	led_classdev_resume(&led->cdev);
	return 0;
}
#else
#define wm8350_led_suspend NULL
#define wm8350_led_resume NULL
#endif

static void wm8350_led_shutdown(struct platform_device *pdev)
{
	struct wm8350_led *led = platform_get_drvdata(pdev);

	mutex_lock(&led->mutex);
	led->value = LED_OFF;
	wm8350_led_disable(led);
	mutex_unlock(&led->mutex);
}

static int wm8350_led_probe(struct platform_device *pdev)
{
	struct regulator *isink, *dcdc;
	struct wm8350_led *led;
	struct wm8350_led_platform_data *pdata = pdev->dev.platform_data;
	int ret, i;

	if (pdata == NULL) {
		dev_err(&pdev->dev, "no platform data\n");
		return -ENODEV;
	}

	if (pdata->max_uA < isink_cur[0]) {
		dev_err(&pdev->dev, "Invalid maximum current %duA\n",
			pdata->max_uA);
		return -EINVAL;
	}

	isink = regulator_get(&pdev->dev, "led_isink");
	if (IS_ERR(isink)) {
		printk(KERN_ERR "%s: cant get ISINK\n", __func__);
		return PTR_ERR(isink);
	}

	dcdc = regulator_get(&pdev->dev, "led_vcc");
	if (IS_ERR(dcdc)) {
		printk(KERN_ERR "%s: cant get DCDC\n", __func__);
		ret = PTR_ERR(dcdc);
		goto err_isink;
	}

	led = kzalloc(sizeof(*led), GFP_KERNEL);
	if (led == NULL) {
		ret = -ENOMEM;
		goto err_dcdc;
	}

	led->cdev.brightness_set = wm8350_led_set;
	led->cdev.default_trigger = pdata->default_trigger;
	led->cdev.name = pdata->name;
	led->enabled = regulator_is_enabled(isink);
	led->isink = isink;
	led->dcdc = dcdc;

	for (i = 0; i < ARRAY_SIZE(isink_cur) - 1; i++)
		if (isink_cur[i] >= pdata->max_uA)
			break;
	led->max_uA_index = i;
	if (pdata->max_uA != isink_cur[i])
		dev_warn(&pdev->dev,
			 "Maximum current %duA is not directly supported,"
			 " check platform data\n",
			 pdata->max_uA);

	spin_lock_init(&led->value_lock);
	mutex_init(&led->mutex);
	INIT_WORK(&led->work, led_work);
	led->value = LED_OFF;
	platform_set_drvdata(pdev, led);

	ret = led_classdev_register(&pdev->dev, &led->cdev);
	if (ret < 0)
		goto err_led;

	return 0;

 err_led:
	kfree(led);
 err_dcdc:
	regulator_put(dcdc);
 err_isink:
	regulator_put(isink);
	return ret;
}

static int wm8350_led_remove(struct platform_device *pdev)
{
	struct wm8350_led *led = platform_get_drvdata(pdev);

	led_classdev_unregister(&led->cdev);
	flush_scheduled_work();
	wm8350_led_disable(led);
	regulator_put(led->dcdc);
	regulator_put(led->isink);
	kfree(led);
	return 0;
}

static struct platform_driver wm8350_led_driver = {
	.driver = {
		   .name = "wm8350-led",
		   .owner = THIS_MODULE,
		   },
	.probe = wm8350_led_probe,
	.remove = wm8350_led_remove,
	.shutdown = wm8350_led_shutdown,
	.suspend = wm8350_led_suspend,
	.resume = wm8350_led_resume,
};

static int __devinit wm8350_led_init(void)
{
	return platform_driver_register(&wm8350_led_driver);
}
module_init(wm8350_led_init);

static void wm8350_led_exit(void)
{
	platform_driver_unregister(&wm8350_led_driver);
}
module_exit(wm8350_led_exit);

MODULE_AUTHOR("Mark Brown");
MODULE_DESCRIPTION("WM8350 LED driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:wm8350-led");
OpenPOWER on IntegriCloud