summaryrefslogtreecommitdiff
path: root/drivers/leds/leds-lm3692x.c
blob: 87cd24ce3f955d05fb31f404b18e9f3d8e4aa95e (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
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
// SPDX-License-Identifier: GPL-2.0
// TI LM3692x LED chip family driver
// Copyright (C) 2017-18 Texas Instruments Incorporated - https://www.ti.com/

#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/leds.h>
#include <linux/log2.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>

#define LM36922_MODEL	0
#define LM36923_MODEL	1

#define LM3692X_REV		0x0
#define LM3692X_RESET		0x1
#define LM3692X_EN		0x10
#define LM3692X_BRT_CTRL	0x11
#define LM3692X_PWM_CTRL	0x12
#define LM3692X_BOOST_CTRL	0x13
#define LM3692X_AUTO_FREQ_HI	0x15
#define LM3692X_AUTO_FREQ_LO	0x16
#define LM3692X_BL_ADJ_THRESH	0x17
#define LM3692X_BRT_LSB		0x18
#define LM3692X_BRT_MSB		0x19
#define LM3692X_FAULT_CTRL	0x1e
#define LM3692X_FAULT_FLAGS	0x1f

#define LM3692X_SW_RESET	BIT(0)
#define LM3692X_DEVICE_EN	BIT(0)
#define LM3692X_LED1_EN		BIT(1)
#define LM3692X_LED2_EN		BIT(2)
#define LM36923_LED3_EN		BIT(3)
#define LM3692X_ENABLE_MASK	(LM3692X_DEVICE_EN | LM3692X_LED1_EN | \
				 LM3692X_LED2_EN | LM36923_LED3_EN)

/* Brightness Control Bits */
#define LM3692X_BL_ADJ_POL	BIT(0)
#define LM3692X_RAMP_RATE_125us	0x00
#define LM3692X_RAMP_RATE_250us	BIT(1)
#define LM3692X_RAMP_RATE_500us BIT(2)
#define LM3692X_RAMP_RATE_1ms	(BIT(1) | BIT(2))
#define LM3692X_RAMP_RATE_2ms	BIT(3)
#define LM3692X_RAMP_RATE_4ms	(BIT(3) | BIT(1))
#define LM3692X_RAMP_RATE_8ms	(BIT(2) | BIT(3))
#define LM3692X_RAMP_RATE_16ms	(BIT(1) | BIT(2) | BIT(3))
#define LM3692X_RAMP_EN		BIT(4)
#define LM3692X_BRHT_MODE_REG	0x00
#define LM3692X_BRHT_MODE_PWM	BIT(5)
#define LM3692X_BRHT_MODE_MULTI_RAMP BIT(6)
#define LM3692X_BRHT_MODE_RAMP_MULTI (BIT(5) | BIT(6))
#define LM3692X_MAP_MODE_EXP	BIT(7)

/* PWM Register Bits */
#define LM3692X_PWM_FILTER_100	BIT(0)
#define LM3692X_PWM_FILTER_150	BIT(1)
#define LM3692X_PWM_FILTER_200	(BIT(0) | BIT(1))
#define LM3692X_PWM_HYSTER_1LSB BIT(2)
#define LM3692X_PWM_HYSTER_2LSB	BIT(3)
#define LM3692X_PWM_HYSTER_3LSB (BIT(3) | BIT(2))
#define LM3692X_PWM_HYSTER_4LSB BIT(4)
#define LM3692X_PWM_HYSTER_5LSB (BIT(4) | BIT(2))
#define LM3692X_PWM_HYSTER_6LSB (BIT(4) | BIT(3))
#define LM3692X_PWM_POLARITY	BIT(5)
#define LM3692X_PWM_SAMP_4MHZ	BIT(6)
#define LM3692X_PWM_SAMP_24MHZ	BIT(7)

/* Boost Control Bits */
#define LM3692X_OCP_PROT_1A	BIT(0)
#define LM3692X_OCP_PROT_1_25A	BIT(1)
#define LM3692X_OCP_PROT_1_5A	(BIT(0) | BIT(1))
#define LM3692X_OVP_21V		BIT(2)
#define LM3692X_OVP_25V		BIT(3)
#define LM3692X_OVP_29V		(BIT(2) | BIT(3))
#define LM3692X_MIN_IND_22UH	BIT(4)
#define LM3692X_BOOST_SW_1MHZ	BIT(5)
#define LM3692X_BOOST_SW_NO_SHIFT	BIT(6)

/* Fault Control Bits */
#define LM3692X_FAULT_CTRL_OVP BIT(0)
#define LM3692X_FAULT_CTRL_OCP BIT(1)
#define LM3692X_FAULT_CTRL_TSD BIT(2)
#define LM3692X_FAULT_CTRL_OPEN BIT(3)

/* Fault Flag Bits */
#define LM3692X_FAULT_FLAG_OVP BIT(0)
#define LM3692X_FAULT_FLAG_OCP BIT(1)
#define LM3692X_FAULT_FLAG_TSD BIT(2)
#define LM3692X_FAULT_FLAG_SHRT BIT(3)
#define LM3692X_FAULT_FLAG_OPEN BIT(4)

/**
 * struct lm3692x_led
 * @lock: Lock for reading/writing the device
 * @client: Pointer to the I2C client
 * @led_dev: LED class device pointer
 * @regmap: Devices register map
 * @enable_gpio: VDDIO/EN gpio to enable communication interface
 * @regulator: LED supply regulator pointer
 * @led_enable: LED sync to be enabled
 * @model_id: Current device model ID enumerated
 */
struct lm3692x_led {
	struct mutex lock;
	struct i2c_client *client;
	struct led_classdev led_dev;
	struct regmap *regmap;
	struct gpio_desc *enable_gpio;
	struct regulator *regulator;
	int led_enable;
	int model_id;

	u8 boost_ctrl, brightness_ctrl;
	bool enabled;
};

static const struct reg_default lm3692x_reg_defs[] = {
	{LM3692X_EN, 0xf},
	{LM3692X_BRT_CTRL, 0x61},
	{LM3692X_PWM_CTRL, 0x73},
	{LM3692X_BOOST_CTRL, 0x6f},
	{LM3692X_AUTO_FREQ_HI, 0x0},
	{LM3692X_AUTO_FREQ_LO, 0x0},
	{LM3692X_BL_ADJ_THRESH, 0x0},
	{LM3692X_BRT_LSB, 0x7},
	{LM3692X_BRT_MSB, 0xff},
	{LM3692X_FAULT_CTRL, 0x7},
};

static const struct regmap_config lm3692x_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,

	.max_register = LM3692X_FAULT_FLAGS,
	.reg_defaults = lm3692x_reg_defs,
	.num_reg_defaults = ARRAY_SIZE(lm3692x_reg_defs),
	.cache_type = REGCACHE_RBTREE,
};

static int lm3692x_fault_check(struct lm3692x_led *led)
{
	int ret;
	unsigned int read_buf;

	ret = regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
	if (ret)
		return ret;

	if (read_buf)
		dev_err(&led->client->dev, "Detected a fault 0x%X\n", read_buf);

	/* The first read may clear the fault.  Check again to see if the fault
	 * still exits and return that value.
	 */
	regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
	if (read_buf)
		dev_err(&led->client->dev, "Second read of fault flags 0x%X\n",
			read_buf);

	return read_buf;
}

static int lm3692x_leds_enable(struct lm3692x_led *led)
{
	int enable_state;
	int ret, reg_ret;

	if (led->enabled)
		return 0;

	if (led->regulator) {
		ret = regulator_enable(led->regulator);
		if (ret) {
			dev_err(&led->client->dev,
				"Failed to enable regulator: %d\n", ret);
			return ret;
		}
	}

	if (led->enable_gpio)
		gpiod_direction_output(led->enable_gpio, 1);

	ret = lm3692x_fault_check(led);
	if (ret) {
		dev_err(&led->client->dev, "Cannot read/clear faults: %d\n",
			ret);
		goto out;
	}

	ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 0x00);
	if (ret)
		goto out;

	/*
	 * For glitch free operation, the following data should
	 * only be written while LEDx enable bits are 0 and the device enable
	 * bit is set to 1.
	 * per Section 7.5.14 of the data sheet
	 */
	ret = regmap_write(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN);
	if (ret)
		goto out;

	/* Set the brightness to 0 so when enabled the LEDs do not come
	 * on with full brightness.
	 */
	ret = regmap_write(led->regmap, LM3692X_BRT_MSB, 0);
	if (ret)
		goto out;

	ret = regmap_write(led->regmap, LM3692X_BRT_LSB, 0);
	if (ret)
		goto out;

	ret = regmap_write(led->regmap, LM3692X_PWM_CTRL,
		LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ);
	if (ret)
		goto out;

	ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL, led->boost_ctrl);
	if (ret)
		goto out;

	ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00);
	if (ret)
		goto out;

	ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_LO, 0x00);
	if (ret)
		goto out;

	ret = regmap_write(led->regmap, LM3692X_BL_ADJ_THRESH, 0x00);
	if (ret)
		goto out;

	ret = regmap_write(led->regmap, LM3692X_BRT_CTRL,
			LM3692X_BL_ADJ_POL | LM3692X_RAMP_EN);
	if (ret)
		goto out;

	switch (led->led_enable) {
	case 0:
	default:
		if (led->model_id == LM36923_MODEL)
			enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN |
			       LM36923_LED3_EN;
		else
			enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN;

		break;
	case 1:
		enable_state = LM3692X_LED1_EN;
		break;
	case 2:
		enable_state = LM3692X_LED2_EN;
		break;

	case 3:
		if (led->model_id == LM36923_MODEL) {
			enable_state = LM36923_LED3_EN;
			break;
		}

		ret = -EINVAL;
		dev_err(&led->client->dev,
			"LED3 sync not available on this device\n");
		goto out;
	}

	ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_ENABLE_MASK,
				 enable_state | LM3692X_DEVICE_EN);

	led->enabled = true;
	return ret;
out:
	dev_err(&led->client->dev, "Fail writing initialization values\n");

	if (led->enable_gpio)
		gpiod_direction_output(led->enable_gpio, 0);

	if (led->regulator) {
		reg_ret = regulator_disable(led->regulator);
		if (reg_ret)
			dev_err(&led->client->dev,
				"Failed to disable regulator: %d\n", reg_ret);
	}

	return ret;
}

static int lm3692x_leds_disable(struct lm3692x_led *led)
{
	int ret;

	if (!led->enabled)
		return 0;

	ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN, 0);
	if (ret) {
		dev_err(&led->client->dev, "Failed to disable regulator: %d\n",
			ret);
		return ret;
	}

	if (led->enable_gpio)
		gpiod_direction_output(led->enable_gpio, 0);

	if (led->regulator) {
		ret = regulator_disable(led->regulator);
		if (ret)
			dev_err(&led->client->dev,
				"Failed to disable regulator: %d\n", ret);
	}

	led->enabled = false;
	return ret;
}

static int lm3692x_brightness_set(struct led_classdev *led_cdev,
				enum led_brightness brt_val)
{
	struct lm3692x_led *led =
			container_of(led_cdev, struct lm3692x_led, led_dev);
	int ret;
	int led_brightness_lsb = (brt_val >> 5);

	mutex_lock(&led->lock);

	if (brt_val == 0) {
		ret = lm3692x_leds_disable(led);
		goto out;
	} else {
		lm3692x_leds_enable(led);
	}

	ret = lm3692x_fault_check(led);
	if (ret) {
		dev_err(&led->client->dev, "Cannot read/clear faults: %d\n",
			ret);
		goto out;
	}

	ret = regmap_write(led->regmap, LM3692X_BRT_MSB, brt_val);
	if (ret) {
		dev_err(&led->client->dev, "Cannot write MSB: %d\n", ret);
		goto out;
	}

	ret = regmap_write(led->regmap, LM3692X_BRT_LSB, led_brightness_lsb);
	if (ret) {
		dev_err(&led->client->dev, "Cannot write LSB: %d\n", ret);
		goto out;
	}
out:
	mutex_unlock(&led->lock);
	return ret;
}

static enum led_brightness lm3692x_max_brightness(struct lm3692x_led *led,
						  u32 max_cur)
{
	u32 max_code;

	/* see p.12 of LM36922 data sheet for brightness formula */
	max_code = ((max_cur * 1000) - 37806) / 12195;
	if (max_code > 0x7FF)
		max_code = 0x7FF;

	return max_code >> 3;
}

static int lm3692x_probe_dt(struct lm3692x_led *led)
{
	struct fwnode_handle *child = NULL;
	struct led_init_data init_data = {};
	u32 ovp, max_cur;
	int ret;

	led->enable_gpio = devm_gpiod_get_optional(&led->client->dev,
						   "enable", GPIOD_OUT_LOW);
	if (IS_ERR(led->enable_gpio)) {
		ret = PTR_ERR(led->enable_gpio);
		dev_err(&led->client->dev, "Failed to get enable gpio: %d\n",
			ret);
		return ret;
	}

	led->regulator = devm_regulator_get_optional(&led->client->dev, "vled");
	if (IS_ERR(led->regulator)) {
		ret = PTR_ERR(led->regulator);
		if (ret != -ENODEV)
			return dev_err_probe(&led->client->dev, ret,
					     "Failed to get vled regulator\n");

		led->regulator = NULL;
	}

	led->boost_ctrl = LM3692X_BOOST_SW_1MHZ |
		LM3692X_BOOST_SW_NO_SHIFT |
		LM3692X_OCP_PROT_1_5A;
	ret = device_property_read_u32(&led->client->dev,
				       "ti,ovp-microvolt", &ovp);
	if (ret) {
		led->boost_ctrl |= LM3692X_OVP_29V;
	} else {
		switch (ovp) {
		case 17000000:
			break;
		case 21000000:
			led->boost_ctrl |= LM3692X_OVP_21V;
			break;
		case 25000000:
			led->boost_ctrl |= LM3692X_OVP_25V;
			break;
		case 29000000:
			led->boost_ctrl |= LM3692X_OVP_29V;
			break;
		default:
			dev_err(&led->client->dev, "Invalid OVP %d\n", ovp);
			return -EINVAL;
		}
	}

	child = device_get_next_child_node(&led->client->dev, child);
	if (!child) {
		dev_err(&led->client->dev, "No LED Child node\n");
		return -ENODEV;
	}

	ret = fwnode_property_read_u32(child, "reg", &led->led_enable);
	if (ret) {
		fwnode_handle_put(child);
		dev_err(&led->client->dev, "reg DT property missing\n");
		return ret;
	}

	ret = fwnode_property_read_u32(child, "led-max-microamp", &max_cur);
	led->led_dev.max_brightness = ret ? LED_FULL :
		lm3692x_max_brightness(led, max_cur);

	init_data.fwnode = child;
	init_data.devicename = led->client->name;
	init_data.default_label = ":";

	ret = devm_led_classdev_register_ext(&led->client->dev, &led->led_dev,
					     &init_data);
	if (ret)
		dev_err(&led->client->dev, "led register err: %d\n", ret);

	fwnode_handle_put(init_data.fwnode);
	return ret;
}

static int lm3692x_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	struct lm3692x_led *led;
	int ret;

	led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
	if (!led)
		return -ENOMEM;

	mutex_init(&led->lock);
	led->client = client;
	led->led_dev.brightness_set_blocking = lm3692x_brightness_set;
	led->model_id = id->driver_data;
	i2c_set_clientdata(client, led);

	led->regmap = devm_regmap_init_i2c(client, &lm3692x_regmap_config);
	if (IS_ERR(led->regmap)) {
		ret = PTR_ERR(led->regmap);
		dev_err(&client->dev, "Failed to allocate register map: %d\n",
			ret);
		return ret;
	}

	ret = lm3692x_probe_dt(led);
	if (ret)
		return ret;

	ret = lm3692x_leds_enable(led);
	if (ret)
		return ret;

	return 0;
}

static int lm3692x_remove(struct i2c_client *client)
{
	struct lm3692x_led *led = i2c_get_clientdata(client);

	lm3692x_leds_disable(led);
	mutex_destroy(&led->lock);

	return 0;
}

static const struct i2c_device_id lm3692x_id[] = {
	{ "lm36922", LM36922_MODEL },
	{ "lm36923", LM36923_MODEL },
	{ }
};
MODULE_DEVICE_TABLE(i2c, lm3692x_id);

static const struct of_device_id of_lm3692x_leds_match[] = {
	{ .compatible = "ti,lm36922", },
	{ .compatible = "ti,lm36923", },
	{},
};
MODULE_DEVICE_TABLE(of, of_lm3692x_leds_match);

static struct i2c_driver lm3692x_driver = {
	.driver = {
		.name	= "lm3692x",
		.of_match_table = of_lm3692x_leds_match,
	},
	.probe		= lm3692x_probe,
	.remove		= lm3692x_remove,
	.id_table	= lm3692x_id,
};
module_i2c_driver(lm3692x_driver);

MODULE_DESCRIPTION("Texas Instruments LM3692X LED driver");
MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
MODULE_LICENSE("GPL v2");