aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/leds/leds-lm3530.c
blob: 4d7ce7631acf93eca1d0e3eaf88d8bfac7414c79 (plain) (blame)
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
/*
 * Copyright (C) 2011 ST-Ericsson SA.
 * Copyright (C) 2009 Motorola, Inc.
 *
 * License Terms: GNU General Public License v2
 *
 * Simple driver for National Semiconductor LM3530 Backlight driver chip
 *
 * Author: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>
 * based on leds-lm3530.c by Dan Murphy <D.Murphy@motorola.com>
 */

#include <linux/i2c.h>
#include <linux/leds.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/led-lm3530.h>
#include <linux/types.h>
#include <linux/regulator/consumer.h>

#define LM3530_LED_DEV "lcd-backlight"
#define LM3530_NAME "lm3530-led"

#define LM3530_GEN_CONFIG		0x10
#define LM3530_ALS_CONFIG		0x20
#define LM3530_BRT_RAMP_RATE		0x30
#define LM3530_ALS_ZONE_REG		0x40
#define LM3530_ALS_IMP_SELECT		0x41
#define LM3530_BRT_CTRL_REG		0xA0
#define LM3530_ALS_ZB0_REG		0x60
#define LM3530_ALS_ZB1_REG		0x61
#define LM3530_ALS_ZB2_REG		0x62
#define LM3530_ALS_ZB3_REG		0x63
#define LM3530_ALS_Z0T_REG		0x70
#define LM3530_ALS_Z1T_REG		0x71
#define LM3530_ALS_Z2T_REG		0x72
#define LM3530_ALS_Z3T_REG		0x73
#define LM3530_ALS_Z4T_REG		0x74
#define LM3530_REG_MAX			15

/* General Control Register */
#define LM3530_EN_I2C_SHIFT		(0)
#define LM3530_RAMP_LAW_SHIFT		(1)
#define LM3530_MAX_CURR_SHIFT		(2)
#define LM3530_EN_PWM_SHIFT		(5)
#define LM3530_PWM_POL_SHIFT		(6)
#define LM3530_EN_PWM_SIMPLE_SHIFT	(7)

#define LM3530_ENABLE_I2C		(1 << LM3530_EN_I2C_SHIFT)
#define LM3530_ENABLE_PWM		(1 << LM3530_EN_PWM_SHIFT)
#define LM3530_POL_LOW			(1 << LM3530_PWM_POL_SHIFT)
#define LM3530_ENABLE_PWM_SIMPLE	(1 << LM3530_EN_PWM_SIMPLE_SHIFT)

/* ALS Config Register Options */
#define LM3530_ALS_AVG_TIME_SHIFT	(0)
#define LM3530_EN_ALS_SHIFT		(3)
#define LM3530_ALS_SEL_SHIFT		(5)

#define LM3530_ENABLE_ALS		(3 << LM3530_EN_ALS_SHIFT)

/* Brightness Ramp Rate Register */
#define LM3530_BRT_RAMP_FALL_SHIFT	(0)
#define LM3530_BRT_RAMP_RISE_SHIFT	(3)

/* ALS Resistor Select */
#define LM3530_ALS1_IMP_SHIFT		(0)
#define LM3530_ALS2_IMP_SHIFT		(4)

/* Zone Boundary Register defaults */
#define LM3530_DEF_ZB_0			(0x33)
#define LM3530_DEF_ZB_1			(0x66)
#define LM3530_DEF_ZB_2			(0x99)
#define LM3530_DEF_ZB_3			(0xCC)

/* Zone Target Register defaults */
#define LM3530_DEF_ZT_0			(0x19)
#define LM3530_DEF_ZT_1			(0x33)
#define LM3530_DEF_ZT_2			(0x4C)
#define LM3530_DEF_ZT_3			(0x66)
#define LM3530_DEF_ZT_4			(0x7F)

struct lm3530_mode_map {
	const char *mode;
	enum lm3530_mode mode_val;
};

static struct lm3530_mode_map mode_map[] = {
	{ "man", LM3530_BL_MODE_MANUAL },
	{ "als", LM3530_BL_MODE_ALS },
	{ "pwm", LM3530_BL_MODE_PWM },
};

/**
 * struct lm3530_data
 * @led_dev: led class device
 * @client: i2c client
 * @pdata: LM3530 platform data
 * @mode: mode of operation - manual, ALS, PWM
 * @regulator: regulator
 * @brighness: previous brightness value
 * @enable: regulator is enabled
 */
struct lm3530_data {
	struct led_classdev led_dev;
	struct i2c_client *client;
	struct lm3530_platform_data *pdata;
	enum lm3530_mode mode;
	struct regulator *regulator;
	enum led_brightness brightness;
	bool enable;
};

static const u8 lm3530_reg[LM3530_REG_MAX] = {
	LM3530_GEN_CONFIG,
	LM3530_ALS_CONFIG,
	LM3530_BRT_RAMP_RATE,
	LM3530_ALS_ZONE_REG,
	LM3530_ALS_IMP_SELECT,
	LM3530_BRT_CTRL_REG,
	LM3530_ALS_ZB0_REG,
	LM3530_ALS_ZB1_REG,
	LM3530_ALS_ZB2_REG,
	LM3530_ALS_ZB3_REG,
	LM3530_ALS_Z0T_REG,
	LM3530_ALS_Z1T_REG,
	LM3530_ALS_Z2T_REG,
	LM3530_ALS_Z3T_REG,
	LM3530_ALS_Z4T_REG,
};

static int lm3530_get_mode_from_str(const char *str)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(mode_map); i++)
		if (sysfs_streq(str, mode_map[i].mode))
			return mode_map[i].mode_val;

	return -1;
}

static int lm3530_init_registers(struct lm3530_data *drvdata)
{
	int ret = 0;
	int i;
	u8 gen_config;
	u8 als_config = 0;
	u8 brt_ramp;
	u8 als_imp_sel = 0;
	u8 brightness;
	u8 reg_val[LM3530_REG_MAX];
	struct lm3530_platform_data *pltfm = drvdata->pdata;
	struct i2c_client *client = drvdata->client;

	gen_config = (pltfm->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) |
			((pltfm->max_current & 7) << LM3530_MAX_CURR_SHIFT);

	if (drvdata->mode == LM3530_BL_MODE_MANUAL ||
	    drvdata->mode == LM3530_BL_MODE_ALS)
		gen_config |= (LM3530_ENABLE_I2C);

	if (drvdata->mode == LM3530_BL_MODE_ALS) {
		als_config =
			(pltfm->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |
			(LM3530_ENABLE_ALS) |
			(pltfm->als_input_mode << LM3530_ALS_SEL_SHIFT);

		als_imp_sel =
			(pltfm->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |
			(pltfm->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);
	}

	if (drvdata->mode == LM3530_BL_MODE_PWM)
		gen_config |= (LM3530_ENABLE_PWM) |
				(pltfm->pwm_pol_hi << LM3530_PWM_POL_SHIFT) |
				(LM3530_ENABLE_PWM_SIMPLE);

	brt_ramp = (pltfm->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |
			(pltfm->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);

	if (drvdata->brightness)
		brightness = drvdata->brightness;
	else
		brightness = drvdata->brightness = pltfm->brt_val;

	reg_val[0] = gen_config;	/* LM3530_GEN_CONFIG */
	reg_val[1] = als_config;	/* LM3530_ALS_CONFIG */
	reg_val[2] = brt_ramp;		/* LM3530_BRT_RAMP_RATE */
	reg_val[3] = 0x00;		/* LM3530_ALS_ZONE_REG */
	reg_val[4] = als_imp_sel;	/* LM3530_ALS_IMP_SELECT */
	reg_val[5] = brightness;	/* LM3530_BRT_CTRL_REG */
	reg_val[6] = LM3530_DEF_ZB_0;	/* LM3530_ALS_ZB0_REG */
	reg_val[7] = LM3530_DEF_ZB_1;	/* LM3530_ALS_ZB1_REG */
	reg_val[8] = LM3530_DEF_ZB_2;	/* LM3530_ALS_ZB2_REG */
	reg_val[9] = LM3530_DEF_ZB_3;	/* LM3530_ALS_ZB3_REG */
	reg_val[10] = LM3530_DEF_ZT_0;	/* LM3530_ALS_Z0T_REG */
	reg_val[11] = LM3530_DEF_ZT_1;	/* LM3530_ALS_Z1T_REG */
	reg_val[12] = LM3530_DEF_ZT_2;	/* LM3530_ALS_Z2T_REG */
	reg_val[13] = LM3530_DEF_ZT_3;	/* LM3530_ALS_Z3T_REG */
	reg_val[14] = LM3530_DEF_ZT_4;	/* LM3530_ALS_Z4T_REG */

	if (!drvdata->enable) {
		ret = regulator_enable(drvdata->regulator);
		if (ret) {
			dev_err(&drvdata->client->dev,
					"Enable regulator failed\n");
			return ret;
		}
		drvdata->enable = true;
	}

	for (i = 0; i < LM3530_REG_MAX; i++) {
		ret = i2c_smbus_write_byte_data(client,
				lm3530_reg[i], reg_val[i]);
		if (ret)
			break;
	}

	return ret;
}

static void lm3530_brightness_set(struct led_classdev *led_cdev,
				     enum led_brightness brt_val)
{
	int err;
	struct lm3530_data *drvdata =
	    container_of(led_cdev, struct lm3530_data, led_dev);

	switch (drvdata->mode) {
	case LM3530_BL_MODE_MANUAL:

		if (!drvdata->enable) {
			err = lm3530_init_registers(drvdata);
			if (err) {
				dev_err(&drvdata->client->dev,
					"Register Init failed: %d\n", err);
				break;
			}
		}

		/* set the brightness in brightness control register*/
		err = i2c_smbus_write_byte_data(drvdata->client,
				LM3530_BRT_CTRL_REG, brt_val / 2);
		if (err)
			dev_err(&drvdata->client->dev,
				"Unable to set brightness: %d\n", err);
		else
			drvdata->brightness = brt_val / 2;

		if (brt_val == 0) {
			err = regulator_disable(drvdata->regulator);
			if (err)
				dev_err(&drvdata->client->dev,
					"Disable regulator failed\n");
			drvdata->enable = false;
		}
		break;
	case LM3530_BL_MODE_ALS:
		break;
	case LM3530_BL_MODE_PWM:
		break;
	default:
		break;
	}
}


static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute
				   *attr, const char *buf, size_t size)
{
	int err;
	struct i2c_client *client = container_of(
					dev->parent, struct i2c_client, dev);
	struct lm3530_data *drvdata = i2c_get_clientdata(client);
	int mode;

	mode = lm3530_get_mode_from_str(buf);
	if (mode < 0) {
		dev_err(dev, "Invalid mode\n");
		return -EINVAL;
	}

	if (mode == LM3530_BL_MODE_MANUAL)
		drvdata->mode = LM3530_BL_MODE_MANUAL;
	else if (mode == LM3530_BL_MODE_ALS)
		drvdata->mode = LM3530_BL_MODE_ALS;
	else if (mode == LM3530_BL_MODE_PWM) {
		dev_err(dev, "PWM mode not supported\n");
		return -EINVAL;
	}

	err = lm3530_init_registers(drvdata);
	if (err) {
		dev_err(dev, "Setting %s Mode failed :%d\n", buf, err);
		return err;
	}

	return sizeof(drvdata->mode);
}

static DEVICE_ATTR(mode, 0644, NULL, lm3530_mode_set);

static int __devinit lm3530_probe(struct i2c_client *client,
			   const struct i2c_device_id *id)
{
	struct lm3530_platform_data *pdata = client->dev.platform_data;
	struct lm3530_data *drvdata;
	int err = 0;

	if (pdata == NULL) {
		dev_err(&client->dev, "platform data required\n");
		err = -ENODEV;
		goto err_out;
	}

	/* BL mode */
	if (pdata->mode > LM3530_BL_MODE_PWM) {
		dev_err(&client->dev, "Illegal Mode request\n");
		err = -EINVAL;
		goto err_out;
	}

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
		dev_err(&client->dev, "I2C_FUNC_I2C not supported\n");
		err = -EIO;
		goto err_out;
	}

	drvdata = kzalloc(sizeof(struct lm3530_data), GFP_KERNEL);
	if (drvdata == NULL) {
		err = -ENOMEM;
		goto err_out;
	}

	drvdata->mode = pdata->mode;
	drvdata->client = client;
	drvdata->pdata = pdata;
	drvdata->brightness = LED_OFF;
	drvdata->enable = false;
	drvdata->led_dev.name = LM3530_LED_DEV;
	drvdata->led_dev.brightness_set = lm3530_brightness_set;

	i2c_set_clientdata(client, drvdata);

	drvdata->regulator = regulator_get(&client->dev, "vin");
	if (IS_ERR(drvdata->regulator)) {
		dev_err(&client->dev, "regulator get failed\n");
		err = PTR_ERR(drvdata->regulator);
		drvdata->regulator = NULL;
		goto err_regulator_get;
	}

	if (drvdata->pdata->brt_val) {
		err = lm3530_init_registers(drvdata);
		if (err < 0) {
			dev_err(&client->dev,
				"Register Init failed: %d\n", err);
			err = -ENODEV;
			goto err_reg_init;
		}
	}
	err = led_classdev_register(&client->dev, &drvdata->led_dev);
	if (err < 0) {
		dev_err(&client->dev, "Register led class failed: %d\n", err);
		err = -ENODEV;
		goto err_class_register;
	}

	err = device_create_file(drvdata->led_dev.dev, &dev_attr_mode);
	if (err < 0) {
		dev_err(&client->dev, "File device creation failed: %d\n", err);
		err = -ENODEV;
		goto err_create_file;
	}

	return 0;

err_create_file:
	led_classdev_unregister(&drvdata->led_dev);
err_class_register:
err_reg_init:
	regulator_put(drvdata->regulator);
err_regulator_get:
	i2c_set_clientdata(client, NULL);
	kfree(drvdata);
err_out:
	return err;
}

static int __devexit lm3530_remove(struct i2c_client *client)
{
	struct lm3530_data *drvdata = i2c_get_clientdata(client);

	device_remove_file(drvdata->led_dev.dev, &dev_attr_mode);

	if (drvdata->enable)
		regulator_disable(drvdata->regulator);
	regulator_put(drvdata->regulator);
	led_classdev_unregister(&drvdata->led_dev);
	kfree(drvdata);
	return 0;
}

static const struct i2c_device_id lm3530_id[] = {
	{LM3530_NAME, 0},
	{}
};
MODULE_DEVICE_TABLE(i2c, lm3530_id);

static struct i2c_driver lm3530_i2c_driver = {
	.probe = lm3530_probe,
	.remove = lm3530_remove,
	.id_table = lm3530_id,
	.driver = {
		.name = LM3530_NAME,
		.owner = THIS_MODULE,
	},
};

static int __init lm3530_init(void)
{
	return i2c_add_driver(&lm3530_i2c_driver);
}

static void __exit lm3530_exit(void)
{
	i2c_del_driver(&lm3530_i2c_driver);
}

module_init(lm3530_init);
module_exit(lm3530_exit);

MODULE_DESCRIPTION("Back Light driver for LM3530");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");