summaryrefslogtreecommitdiffstats
path: root/drivers/video/backlight/lm3630a_bl.c
blob: 35fe4825a4546012702a56efac3bc57803b93a0c (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
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
/*
* Simple driver for Texas Instruments LM3630A Backlight driver chip
* Copyright (C) 2012 Texas Instruments
*
* 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/module.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/backlight.h>
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/uaccess.h>
#include <linux/interrupt.h>
#include <linux/regmap.h>
#include <linux/pwm.h>
#include <linux/platform_data/lm3630a_bl.h>

#define REG_CTRL	0x00
#define REG_BOOST	0x02
#define REG_CONFIG	0x01
#define REG_BRT_A	0x03
#define REG_BRT_B	0x04
#define REG_I_A		0x05
#define REG_I_B		0x06
#define REG_INT_STATUS	0x09
#define REG_INT_EN	0x0A
#define REG_FAULT	0x0B
#define REG_PWM_OUTLOW	0x12
#define REG_PWM_OUTHIGH	0x13
#define REG_MAX		0x1F

#define INT_DEBOUNCE_MSEC	10
struct lm3630a_chip {
	struct device *dev;
	struct delayed_work work;

	int irq;
	struct workqueue_struct *irqthread;
	struct lm3630a_platform_data *pdata;
	struct backlight_device *bleda;
	struct backlight_device *bledb;
	struct regmap *regmap;
	struct pwm_device *pwmd;
};

/* i2c access */
static int lm3630a_read(struct lm3630a_chip *pchip, unsigned int reg)
{
	int rval;
	unsigned int reg_val;

	rval = regmap_read(pchip->regmap, reg, &reg_val);
	if (rval < 0)
		return rval;
	return reg_val & 0xFF;
}

static int lm3630a_write(struct lm3630a_chip *pchip,
			 unsigned int reg, unsigned int data)
{
	return regmap_write(pchip->regmap, reg, data);
}

static int lm3630a_update(struct lm3630a_chip *pchip,
			  unsigned int reg, unsigned int mask,
			  unsigned int data)
{
	return regmap_update_bits(pchip->regmap, reg, mask, data);
}

/* initialize chip */
static int lm3630a_chip_init(struct lm3630a_chip *pchip)
{
	int rval;
	struct lm3630a_platform_data *pdata = pchip->pdata;

	usleep_range(1000, 2000);
	/* set Filter Strength Register */
	rval = lm3630a_write(pchip, 0x50, 0x03);
	/* set Cofig. register */
	rval |= lm3630a_update(pchip, REG_CONFIG, 0x07, pdata->pwm_ctrl);
	/* set boost control */
	rval |= lm3630a_write(pchip, REG_BOOST, 0x38);
	/* set current A */
	rval |= lm3630a_update(pchip, REG_I_A, 0x1F, 0x1F);
	/* set current B */
	rval |= lm3630a_write(pchip, REG_I_B, 0x1F);
	/* set control */
	rval |= lm3630a_update(pchip, REG_CTRL, 0x14, pdata->leda_ctrl);
	rval |= lm3630a_update(pchip, REG_CTRL, 0x0B, pdata->ledb_ctrl);
	usleep_range(1000, 2000);
	/* set brightness A and B */
	rval |= lm3630a_write(pchip, REG_BRT_A, pdata->leda_init_brt);
	rval |= lm3630a_write(pchip, REG_BRT_B, pdata->ledb_init_brt);

	if (rval < 0)
		dev_err(pchip->dev, "i2c failed to access register\n");
	return rval;
}

/* interrupt handling */
static void lm3630a_delayed_func(struct work_struct *work)
{
	int rval;
	struct lm3630a_chip *pchip;

	pchip = container_of(work, struct lm3630a_chip, work.work);

	rval = lm3630a_read(pchip, REG_INT_STATUS);
	if (rval < 0) {
		dev_err(pchip->dev,
			"i2c failed to access REG_INT_STATUS Register\n");
		return;
	}

	dev_info(pchip->dev, "REG_INT_STATUS Register is 0x%x\n", rval);
}

static irqreturn_t lm3630a_isr_func(int irq, void *chip)
{
	int rval;
	struct lm3630a_chip *pchip = chip;
	unsigned long delay = msecs_to_jiffies(INT_DEBOUNCE_MSEC);

	queue_delayed_work(pchip->irqthread, &pchip->work, delay);

	rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
	if (rval < 0) {
		dev_err(pchip->dev, "i2c failed to access register\n");
		return IRQ_NONE;
	}
	return IRQ_HANDLED;
}

static int lm3630a_intr_config(struct lm3630a_chip *pchip)
{
	int rval;

	rval = lm3630a_write(pchip, REG_INT_EN, 0x87);
	if (rval < 0)
		return rval;

	INIT_DELAYED_WORK(&pchip->work, lm3630a_delayed_func);
	pchip->irqthread = create_singlethread_workqueue("lm3630a-irqthd");
	if (!pchip->irqthread) {
		dev_err(pchip->dev, "create irq thread fail\n");
		return -ENOMEM;
	}
	if (request_threaded_irq
	    (pchip->irq, NULL, lm3630a_isr_func,
	     IRQF_TRIGGER_FALLING | IRQF_ONESHOT, "lm3630a_irq", pchip)) {
		dev_err(pchip->dev, "request threaded irq fail\n");
		destroy_workqueue(pchip->irqthread);
		return -ENOMEM;
	}
	return rval;
}

static void lm3630a_pwm_ctrl(struct lm3630a_chip *pchip, int br, int br_max)
{
	unsigned int period = pwm_get_period(pchip->pwmd);
	unsigned int duty = br * period / br_max;

	pwm_config(pchip->pwmd, duty, period);
	if (duty)
		pwm_enable(pchip->pwmd);
	else
		pwm_disable(pchip->pwmd);
}

/* update and get brightness */
static int lm3630a_bank_a_update_status(struct backlight_device *bl)
{
	int ret;
	struct lm3630a_chip *pchip = bl_get_data(bl);
	enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;

	/* pwm control */
	if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) {
		lm3630a_pwm_ctrl(pchip, bl->props.brightness,
				 bl->props.max_brightness);
		return bl->props.brightness;
	}

	/* disable sleep */
	ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
	if (ret < 0)
		goto out_i2c_err;
	usleep_range(1000, 2000);
	/* minimum brightness is 0x04 */
	ret = lm3630a_write(pchip, REG_BRT_A, bl->props.brightness);
	if (bl->props.brightness < 0x4)
		ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDA_ENABLE, 0);
	else
		ret |= lm3630a_update(pchip, REG_CTRL,
				      LM3630A_LEDA_ENABLE, LM3630A_LEDA_ENABLE);
	if (ret < 0)
		goto out_i2c_err;
	return bl->props.brightness;

out_i2c_err:
	dev_err(pchip->dev, "i2c failed to access\n");
	return bl->props.brightness;
}

static int lm3630a_bank_a_get_brightness(struct backlight_device *bl)
{
	int brightness, rval;
	struct lm3630a_chip *pchip = bl_get_data(bl);
	enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;

	if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) {
		rval = lm3630a_read(pchip, REG_PWM_OUTHIGH);
		if (rval < 0)
			goto out_i2c_err;
		brightness = (rval & 0x01) << 8;
		rval = lm3630a_read(pchip, REG_PWM_OUTLOW);
		if (rval < 0)
			goto out_i2c_err;
		brightness |= rval;
		goto out;
	}

	/* disable sleep */
	rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
	if (rval < 0)
		goto out_i2c_err;
	usleep_range(1000, 2000);
	rval = lm3630a_read(pchip, REG_BRT_A);
	if (rval < 0)
		goto out_i2c_err;
	brightness = rval;

out:
	bl->props.brightness = brightness;
	return bl->props.brightness;
out_i2c_err:
	dev_err(pchip->dev, "i2c failed to access register\n");
	return 0;
}

static const struct backlight_ops lm3630a_bank_a_ops = {
	.options = BL_CORE_SUSPENDRESUME,
	.update_status = lm3630a_bank_a_update_status,
	.get_brightness = lm3630a_bank_a_get_brightness,
};

/* update and get brightness */
static int lm3630a_bank_b_update_status(struct backlight_device *bl)
{
	int ret;
	struct lm3630a_chip *pchip = bl_get_data(bl);
	enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;

	/* pwm control */
	if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) {
		lm3630a_pwm_ctrl(pchip, bl->props.brightness,
				 bl->props.max_brightness);
		return bl->props.brightness;
	}

	/* disable sleep */
	ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
	if (ret < 0)
		goto out_i2c_err;
	usleep_range(1000, 2000);
	/* minimum brightness is 0x04 */
	ret = lm3630a_write(pchip, REG_BRT_B, bl->props.brightness);
	if (bl->props.brightness < 0x4)
		ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDB_ENABLE, 0);
	else
		ret |= lm3630a_update(pchip, REG_CTRL,
				      LM3630A_LEDB_ENABLE, LM3630A_LEDB_ENABLE);
	if (ret < 0)
		goto out_i2c_err;
	return bl->props.brightness;

out_i2c_err:
	dev_err(pchip->dev, "i2c failed to access REG_CTRL\n");
	return bl->props.brightness;
}

static int lm3630a_bank_b_get_brightness(struct backlight_device *bl)
{
	int brightness, rval;
	struct lm3630a_chip *pchip = bl_get_data(bl);
	enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;

	if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) {
		rval = lm3630a_read(pchip, REG_PWM_OUTHIGH);
		if (rval < 0)
			goto out_i2c_err;
		brightness = (rval & 0x01) << 8;
		rval = lm3630a_read(pchip, REG_PWM_OUTLOW);
		if (rval < 0)
			goto out_i2c_err;
		brightness |= rval;
		goto out;
	}

	/* disable sleep */
	rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
	if (rval < 0)
		goto out_i2c_err;
	usleep_range(1000, 2000);
	rval = lm3630a_read(pchip, REG_BRT_B);
	if (rval < 0)
		goto out_i2c_err;
	brightness = rval;

out:
	bl->props.brightness = brightness;
	return bl->props.brightness;
out_i2c_err:
	dev_err(pchip->dev, "i2c failed to access register\n");
	return 0;
}

static const struct backlight_ops lm3630a_bank_b_ops = {
	.options = BL_CORE_SUSPENDRESUME,
	.update_status = lm3630a_bank_b_update_status,
	.get_brightness = lm3630a_bank_b_get_brightness,
};

static int lm3630a_backlight_register(struct lm3630a_chip *pchip)
{
	struct backlight_properties props;
	struct lm3630a_platform_data *pdata = pchip->pdata;

	props.type = BACKLIGHT_RAW;
	if (pdata->leda_ctrl != LM3630A_LEDA_DISABLE) {
		props.brightness = pdata->leda_init_brt;
		props.max_brightness = pdata->leda_max_brt;
		pchip->bleda =
		    devm_backlight_device_register(pchip->dev, "lm3630a_leda",
						   pchip->dev, pchip,
						   &lm3630a_bank_a_ops, &props);
		if (IS_ERR(pchip->bleda))
			return PTR_ERR(pchip->bleda);
	}

	if ((pdata->ledb_ctrl != LM3630A_LEDB_DISABLE) &&
	    (pdata->ledb_ctrl != LM3630A_LEDB_ON_A)) {
		props.brightness = pdata->ledb_init_brt;
		props.max_brightness = pdata->ledb_max_brt;
		pchip->bledb =
		    devm_backlight_device_register(pchip->dev, "lm3630a_ledb",
						   pchip->dev, pchip,
						   &lm3630a_bank_b_ops, &props);
		if (IS_ERR(pchip->bledb))
			return PTR_ERR(pchip->bledb);
	}
	return 0;
}

static const struct regmap_config lm3630a_regmap = {
	.reg_bits = 8,
	.val_bits = 8,
	.max_register = REG_MAX,
};

static int lm3630a_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{
	struct lm3630a_platform_data *pdata = dev_get_platdata(&client->dev);
	struct lm3630a_chip *pchip;
	int rval;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
		dev_err(&client->dev, "fail : i2c functionality check\n");
		return -EOPNOTSUPP;
	}

	pchip = devm_kzalloc(&client->dev, sizeof(struct lm3630a_chip),
			     GFP_KERNEL);
	if (!pchip)
		return -ENOMEM;
	pchip->dev = &client->dev;

	pchip->regmap = devm_regmap_init_i2c(client, &lm3630a_regmap);
	if (IS_ERR(pchip->regmap)) {
		rval = PTR_ERR(pchip->regmap);
		dev_err(&client->dev, "fail : allocate reg. map: %d\n", rval);
		return rval;
	}

	i2c_set_clientdata(client, pchip);
	if (pdata == NULL) {
		pdata = devm_kzalloc(pchip->dev,
				     sizeof(struct lm3630a_platform_data),
				     GFP_KERNEL);
		if (pdata == NULL)
			return -ENOMEM;
		/* default values */
		pdata->leda_ctrl = LM3630A_LEDA_ENABLE;
		pdata->ledb_ctrl = LM3630A_LEDB_ENABLE;
		pdata->leda_max_brt = LM3630A_MAX_BRIGHTNESS;
		pdata->ledb_max_brt = LM3630A_MAX_BRIGHTNESS;
		pdata->leda_init_brt = LM3630A_MAX_BRIGHTNESS;
		pdata->ledb_init_brt = LM3630A_MAX_BRIGHTNESS;
	}
	pchip->pdata = pdata;

	/* chip initialize */
	rval = lm3630a_chip_init(pchip);
	if (rval < 0) {
		dev_err(&client->dev, "fail : init chip\n");
		return rval;
	}
	/* backlight register */
	rval = lm3630a_backlight_register(pchip);
	if (rval < 0) {
		dev_err(&client->dev, "fail : backlight register.\n");
		return rval;
	}
	/* pwm */
	if (pdata->pwm_ctrl != LM3630A_PWM_DISABLE) {
		pchip->pwmd = devm_pwm_get(pchip->dev, "lm3630a-pwm");
		if (IS_ERR(pchip->pwmd)) {
			dev_err(&client->dev, "fail : get pwm device\n");
			return PTR_ERR(pchip->pwmd);
		}
	}
	pchip->pwmd->period = pdata->pwm_period;

	/* interrupt enable  : irq 0 is not allowed */
	pchip->irq = client->irq;
	if (pchip->irq) {
		rval = lm3630a_intr_config(pchip);
		if (rval < 0)
			return rval;
	}
	dev_info(&client->dev, "LM3630A backlight register OK.\n");
	return 0;
}

static int lm3630a_remove(struct i2c_client *client)
{
	int rval;
	struct lm3630a_chip *pchip = i2c_get_clientdata(client);

	rval = lm3630a_write(pchip, REG_BRT_A, 0);
	if (rval < 0)
		dev_err(pchip->dev, "i2c failed to access register\n");

	rval = lm3630a_write(pchip, REG_BRT_B, 0);
	if (rval < 0)
		dev_err(pchip->dev, "i2c failed to access register\n");

	if (pchip->irq) {
		free_irq(pchip->irq, pchip);
		flush_workqueue(pchip->irqthread);
		destroy_workqueue(pchip->irqthread);
	}
	return 0;
}

static const struct i2c_device_id lm3630a_id[] = {
	{LM3630A_NAME, 0},
	{}
};

MODULE_DEVICE_TABLE(i2c, lm3630a_id);

static struct i2c_driver lm3630a_i2c_driver = {
	.driver = {
		   .name = LM3630A_NAME,
		   },
	.probe = lm3630a_probe,
	.remove = lm3630a_remove,
	.id_table = lm3630a_id,
};

module_i2c_driver(lm3630a_i2c_driver);

MODULE_DESCRIPTION("Texas Instruments Backlight driver for LM3630A");
MODULE_AUTHOR("Daniel Jeong <gshark.jeong@gmail.com>");
MODULE_AUTHOR("LDD MLP <ldd-mlp@list.ti.com>");
MODULE_LICENSE("GPL v2");
OpenPOWER on IntegriCloud