xref: /openbmc/linux/drivers/leds/leds-lp8860.c (revision a9a08845)
1 /*
2  * TI LP8860 4-Channel LED Driver
3  *
4  * Copyright (C) 2014 Texas Instruments
5  *
6  * Author: Dan Murphy <dmurphy@ti.com>
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License
10  * version 2 as published by the Free Software Foundation.
11  *
12  */
13 
14 #include <linux/i2c.h>
15 #include <linux/init.h>
16 #include <linux/leds.h>
17 #include <linux/regmap.h>
18 #include <linux/regulator/consumer.h>
19 #include <linux/module.h>
20 #include <linux/mutex.h>
21 #include <linux/of.h>
22 #include <linux/of_gpio.h>
23 #include <linux/gpio/consumer.h>
24 #include <linux/slab.h>
25 #include <uapi/linux/uleds.h>
26 
27 #define LP8860_DISP_CL1_BRT_MSB		0x00
28 #define LP8860_DISP_CL1_BRT_LSB		0x01
29 #define LP8860_DISP_CL1_CURR_MSB	0x02
30 #define LP8860_DISP_CL1_CURR_LSB	0x03
31 #define LP8860_CL2_BRT_MSB		0x04
32 #define LP8860_CL2_BRT_LSB		0x05
33 #define LP8860_CL2_CURRENT		0x06
34 #define LP8860_CL3_BRT_MSB		0x07
35 #define LP8860_CL3_BRT_LSB		0x08
36 #define LP8860_CL3_CURRENT		0x09
37 #define LP8860_CL4_BRT_MSB		0x0a
38 #define LP8860_CL4_BRT_LSB		0x0b
39 #define LP8860_CL4_CURRENT		0x0c
40 #define LP8860_CONFIG			0x0d
41 #define LP8860_STATUS			0x0e
42 #define LP8860_FAULT			0x0f
43 #define LP8860_LED_FAULT		0x10
44 #define LP8860_FAULT_CLEAR		0x11
45 #define LP8860_ID			0x12
46 #define LP8860_TEMP_MSB			0x13
47 #define LP8860_TEMP_LSB			0x14
48 #define LP8860_DISP_LED_CURR_MSB	0x15
49 #define LP8860_DISP_LED_CURR_LSB	0x16
50 #define LP8860_DISP_LED_PWM_MSB		0x17
51 #define LP8860_DISP_LED_PWM_LSB		0x18
52 #define LP8860_EEPROM_CNTRL		0x19
53 #define LP8860_EEPROM_UNLOCK		0x1a
54 
55 #define LP8860_EEPROM_REG_0		0x60
56 #define LP8860_EEPROM_REG_1		0x61
57 #define LP8860_EEPROM_REG_2		0x62
58 #define LP8860_EEPROM_REG_3		0x63
59 #define LP8860_EEPROM_REG_4		0x64
60 #define LP8860_EEPROM_REG_5		0x65
61 #define LP8860_EEPROM_REG_6		0x66
62 #define LP8860_EEPROM_REG_7		0x67
63 #define LP8860_EEPROM_REG_8		0x68
64 #define LP8860_EEPROM_REG_9		0x69
65 #define LP8860_EEPROM_REG_10		0x6a
66 #define LP8860_EEPROM_REG_11		0x6b
67 #define LP8860_EEPROM_REG_12		0x6c
68 #define LP8860_EEPROM_REG_13		0x6d
69 #define LP8860_EEPROM_REG_14		0x6e
70 #define LP8860_EEPROM_REG_15		0x6f
71 #define LP8860_EEPROM_REG_16		0x70
72 #define LP8860_EEPROM_REG_17		0x71
73 #define LP8860_EEPROM_REG_18		0x72
74 #define LP8860_EEPROM_REG_19		0x73
75 #define LP8860_EEPROM_REG_20		0x74
76 #define LP8860_EEPROM_REG_21		0x75
77 #define LP8860_EEPROM_REG_22		0x76
78 #define LP8860_EEPROM_REG_23		0x77
79 #define LP8860_EEPROM_REG_24		0x78
80 
81 #define LP8860_LOCK_EEPROM		0x00
82 #define LP8860_UNLOCK_EEPROM		0x01
83 #define LP8860_PROGRAM_EEPROM		0x02
84 #define LP8860_EEPROM_CODE_1		0x08
85 #define LP8860_EEPROM_CODE_2		0xba
86 #define LP8860_EEPROM_CODE_3		0xef
87 
88 #define LP8860_CLEAR_FAULTS		0x01
89 
90 /**
91  * struct lp8860_led -
92  * @lock - Lock for reading/writing the device
93  * @client - Pointer to the I2C client
94  * @led_dev - led class device pointer
95  * @regmap - Devices register map
96  * @eeprom_regmap - EEPROM register map
97  * @enable_gpio - VDDIO/EN gpio to enable communication interface
98  * @regulator - LED supply regulator pointer
99  * @label - LED label
100  */
101 struct lp8860_led {
102 	struct mutex lock;
103 	struct i2c_client *client;
104 	struct led_classdev led_dev;
105 	struct regmap *regmap;
106 	struct regmap *eeprom_regmap;
107 	struct gpio_desc *enable_gpio;
108 	struct regulator *regulator;
109 	char label[LED_MAX_NAME_SIZE];
110 };
111 
112 struct lp8860_eeprom_reg {
113 	uint8_t reg;
114 	uint8_t value;
115 };
116 
117 static struct lp8860_eeprom_reg lp8860_eeprom_disp_regs[] = {
118 	{ LP8860_EEPROM_REG_0, 0xed },
119 	{ LP8860_EEPROM_REG_1, 0xdf },
120 	{ LP8860_EEPROM_REG_2, 0xdc },
121 	{ LP8860_EEPROM_REG_3, 0xf0 },
122 	{ LP8860_EEPROM_REG_4, 0xdf },
123 	{ LP8860_EEPROM_REG_5, 0xe5 },
124 	{ LP8860_EEPROM_REG_6, 0xf2 },
125 	{ LP8860_EEPROM_REG_7, 0x77 },
126 	{ LP8860_EEPROM_REG_8, 0x77 },
127 	{ LP8860_EEPROM_REG_9, 0x71 },
128 	{ LP8860_EEPROM_REG_10, 0x3f },
129 	{ LP8860_EEPROM_REG_11, 0xb7 },
130 	{ LP8860_EEPROM_REG_12, 0x17 },
131 	{ LP8860_EEPROM_REG_13, 0xef },
132 	{ LP8860_EEPROM_REG_14, 0xb0 },
133 	{ LP8860_EEPROM_REG_15, 0x87 },
134 	{ LP8860_EEPROM_REG_16, 0xce },
135 	{ LP8860_EEPROM_REG_17, 0x72 },
136 	{ LP8860_EEPROM_REG_18, 0xe5 },
137 	{ LP8860_EEPROM_REG_19, 0xdf },
138 	{ LP8860_EEPROM_REG_20, 0x35 },
139 	{ LP8860_EEPROM_REG_21, 0x06 },
140 	{ LP8860_EEPROM_REG_22, 0xdc },
141 	{ LP8860_EEPROM_REG_23, 0x88 },
142 	{ LP8860_EEPROM_REG_24, 0x3E },
143 };
144 
145 static int lp8860_unlock_eeprom(struct lp8860_led *led, int lock)
146 {
147 	int ret;
148 
149 	mutex_lock(&led->lock);
150 
151 	if (lock == LP8860_UNLOCK_EEPROM) {
152 		ret = regmap_write(led->regmap,
153 			LP8860_EEPROM_UNLOCK,
154 			LP8860_EEPROM_CODE_1);
155 		if (ret) {
156 			dev_err(&led->client->dev, "EEPROM Unlock failed\n");
157 			goto out;
158 		}
159 
160 		ret = regmap_write(led->regmap,
161 			LP8860_EEPROM_UNLOCK,
162 			LP8860_EEPROM_CODE_2);
163 		if (ret) {
164 			dev_err(&led->client->dev, "EEPROM Unlock failed\n");
165 			goto out;
166 		}
167 		ret = regmap_write(led->regmap,
168 			LP8860_EEPROM_UNLOCK,
169 			LP8860_EEPROM_CODE_3);
170 		if (ret) {
171 			dev_err(&led->client->dev, "EEPROM Unlock failed\n");
172 			goto out;
173 		}
174 	} else {
175 		ret = regmap_write(led->regmap,
176 			LP8860_EEPROM_UNLOCK,
177 			LP8860_LOCK_EEPROM);
178 	}
179 
180 out:
181 	mutex_unlock(&led->lock);
182 	return ret;
183 }
184 
185 static int lp8860_fault_check(struct lp8860_led *led)
186 {
187 	int ret, fault;
188 	unsigned int read_buf;
189 
190 	ret = regmap_read(led->regmap, LP8860_LED_FAULT, &read_buf);
191 	if (ret)
192 		goto out;
193 
194 	fault = read_buf;
195 
196 	ret = regmap_read(led->regmap, LP8860_FAULT, &read_buf);
197 	if (ret)
198 		goto out;
199 
200 	fault |= read_buf;
201 
202 	/* Attempt to clear any faults */
203 	if (fault)
204 		ret = regmap_write(led->regmap, LP8860_FAULT_CLEAR,
205 			LP8860_CLEAR_FAULTS);
206 out:
207 	return ret;
208 }
209 
210 static int lp8860_brightness_set(struct led_classdev *led_cdev,
211 				enum led_brightness brt_val)
212 {
213 	struct lp8860_led *led =
214 			container_of(led_cdev, struct lp8860_led, led_dev);
215 	int disp_brightness = brt_val * 255;
216 	int ret;
217 
218 	mutex_lock(&led->lock);
219 
220 	ret = lp8860_fault_check(led);
221 	if (ret) {
222 		dev_err(&led->client->dev, "Cannot read/clear faults\n");
223 		goto out;
224 	}
225 
226 	ret = regmap_write(led->regmap, LP8860_DISP_CL1_BRT_MSB,
227 			(disp_brightness & 0xff00) >> 8);
228 	if (ret) {
229 		dev_err(&led->client->dev, "Cannot write CL1 MSB\n");
230 		goto out;
231 	}
232 
233 	ret = regmap_write(led->regmap, LP8860_DISP_CL1_BRT_LSB,
234 			disp_brightness & 0xff);
235 	if (ret) {
236 		dev_err(&led->client->dev, "Cannot write CL1 LSB\n");
237 		goto out;
238 	}
239 out:
240 	mutex_unlock(&led->lock);
241 	return ret;
242 }
243 
244 static int lp8860_init(struct lp8860_led *led)
245 {
246 	unsigned int read_buf;
247 	int ret, i, reg_count;
248 
249 	if (led->regulator) {
250 		ret = regulator_enable(led->regulator);
251 		if (ret) {
252 			dev_err(&led->client->dev,
253 				"Failed to enable regulator\n");
254 			return ret;
255 		}
256 	}
257 
258 	if (led->enable_gpio)
259 		gpiod_direction_output(led->enable_gpio, 1);
260 
261 	ret = lp8860_fault_check(led);
262 	if (ret)
263 		goto out;
264 
265 	ret = regmap_read(led->regmap, LP8860_STATUS, &read_buf);
266 	if (ret)
267 		goto out;
268 
269 	ret = lp8860_unlock_eeprom(led, LP8860_UNLOCK_EEPROM);
270 	if (ret) {
271 		dev_err(&led->client->dev, "Failed unlocking EEPROM\n");
272 		goto out;
273 	}
274 
275 	reg_count = ARRAY_SIZE(lp8860_eeprom_disp_regs) / sizeof(lp8860_eeprom_disp_regs[0]);
276 	for (i = 0; i < reg_count; i++) {
277 		ret = regmap_write(led->eeprom_regmap,
278 				lp8860_eeprom_disp_regs[i].reg,
279 				lp8860_eeprom_disp_regs[i].value);
280 		if (ret) {
281 			dev_err(&led->client->dev, "Failed writing EEPROM\n");
282 			goto out;
283 		}
284 	}
285 
286 	ret = lp8860_unlock_eeprom(led, LP8860_LOCK_EEPROM);
287 	if (ret)
288 		goto out;
289 
290 	ret = regmap_write(led->regmap,
291 			LP8860_EEPROM_CNTRL,
292 			LP8860_PROGRAM_EEPROM);
293 	if (ret) {
294 		dev_err(&led->client->dev, "Failed programming EEPROM\n");
295 		goto out;
296 	}
297 
298 	return ret;
299 
300 out:
301 	if (ret)
302 		if (led->enable_gpio)
303 			gpiod_direction_output(led->enable_gpio, 0);
304 
305 	if (led->regulator) {
306 		ret = regulator_disable(led->regulator);
307 		if (ret)
308 			dev_err(&led->client->dev,
309 				"Failed to disable regulator\n");
310 	}
311 
312 	return ret;
313 }
314 
315 static const struct reg_default lp8860_reg_defs[] = {
316 	{ LP8860_DISP_CL1_BRT_MSB, 0x00},
317 	{ LP8860_DISP_CL1_BRT_LSB, 0x00},
318 	{ LP8860_DISP_CL1_CURR_MSB, 0x00},
319 	{ LP8860_DISP_CL1_CURR_LSB, 0x00},
320 	{ LP8860_CL2_BRT_MSB, 0x00},
321 	{ LP8860_CL2_BRT_LSB, 0x00},
322 	{ LP8860_CL2_CURRENT, 0x00},
323 	{ LP8860_CL3_BRT_MSB, 0x00},
324 	{ LP8860_CL3_BRT_LSB, 0x00},
325 	{ LP8860_CL3_CURRENT, 0x00},
326 	{ LP8860_CL4_BRT_MSB, 0x00},
327 	{ LP8860_CL4_BRT_LSB, 0x00},
328 	{ LP8860_CL4_CURRENT, 0x00},
329 	{ LP8860_CONFIG, 0x00},
330 	{ LP8860_FAULT_CLEAR, 0x00},
331 	{ LP8860_EEPROM_CNTRL, 0x80},
332 	{ LP8860_EEPROM_UNLOCK, 0x00},
333 };
334 
335 static const struct regmap_config lp8860_regmap_config = {
336 	.reg_bits = 8,
337 	.val_bits = 8,
338 
339 	.max_register = LP8860_EEPROM_UNLOCK,
340 	.reg_defaults = lp8860_reg_defs,
341 	.num_reg_defaults = ARRAY_SIZE(lp8860_reg_defs),
342 	.cache_type = REGCACHE_NONE,
343 };
344 
345 static const struct reg_default lp8860_eeprom_defs[] = {
346 	{ LP8860_EEPROM_REG_0, 0x00 },
347 	{ LP8860_EEPROM_REG_1, 0x00 },
348 	{ LP8860_EEPROM_REG_2, 0x00 },
349 	{ LP8860_EEPROM_REG_3, 0x00 },
350 	{ LP8860_EEPROM_REG_4, 0x00 },
351 	{ LP8860_EEPROM_REG_5, 0x00 },
352 	{ LP8860_EEPROM_REG_6, 0x00 },
353 	{ LP8860_EEPROM_REG_7, 0x00 },
354 	{ LP8860_EEPROM_REG_8, 0x00 },
355 	{ LP8860_EEPROM_REG_9, 0x00 },
356 	{ LP8860_EEPROM_REG_10, 0x00 },
357 	{ LP8860_EEPROM_REG_11, 0x00 },
358 	{ LP8860_EEPROM_REG_12, 0x00 },
359 	{ LP8860_EEPROM_REG_13, 0x00 },
360 	{ LP8860_EEPROM_REG_14, 0x00 },
361 	{ LP8860_EEPROM_REG_15, 0x00 },
362 	{ LP8860_EEPROM_REG_16, 0x00 },
363 	{ LP8860_EEPROM_REG_17, 0x00 },
364 	{ LP8860_EEPROM_REG_18, 0x00 },
365 	{ LP8860_EEPROM_REG_19, 0x00 },
366 	{ LP8860_EEPROM_REG_20, 0x00 },
367 	{ LP8860_EEPROM_REG_21, 0x00 },
368 	{ LP8860_EEPROM_REG_22, 0x00 },
369 	{ LP8860_EEPROM_REG_23, 0x00 },
370 	{ LP8860_EEPROM_REG_24, 0x00 },
371 };
372 
373 static const struct regmap_config lp8860_eeprom_regmap_config = {
374 	.reg_bits = 8,
375 	.val_bits = 8,
376 
377 	.max_register = LP8860_EEPROM_REG_24,
378 	.reg_defaults = lp8860_eeprom_defs,
379 	.num_reg_defaults = ARRAY_SIZE(lp8860_eeprom_defs),
380 	.cache_type = REGCACHE_NONE,
381 };
382 
383 static int lp8860_probe(struct i2c_client *client,
384 			const struct i2c_device_id *id)
385 {
386 	int ret;
387 	struct lp8860_led *led;
388 	struct device_node *np = client->dev.of_node;
389 	struct device_node *child_node;
390 	const char *name;
391 
392 	led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
393 	if (!led)
394 		return -ENOMEM;
395 
396 	for_each_available_child_of_node(np, child_node) {
397 		led->led_dev.default_trigger = of_get_property(child_node,
398 						    "linux,default-trigger",
399 						    NULL);
400 
401 		ret = of_property_read_string(child_node, "label", &name);
402 		if (!ret)
403 			snprintf(led->label, sizeof(led->label), "%s:%s",
404 				 id->name, name);
405 		else
406 			snprintf(led->label, sizeof(led->label),
407 				"%s::display_cluster", id->name);
408 	}
409 
410 	led->enable_gpio = devm_gpiod_get_optional(&client->dev,
411 						   "enable", GPIOD_OUT_LOW);
412 	if (IS_ERR(led->enable_gpio)) {
413 		ret = PTR_ERR(led->enable_gpio);
414 		dev_err(&client->dev, "Failed to get enable gpio: %d\n", ret);
415 		return ret;
416 	}
417 
418 	led->regulator = devm_regulator_get(&client->dev, "vled");
419 	if (IS_ERR(led->regulator))
420 		led->regulator = NULL;
421 
422 	led->client = client;
423 	led->led_dev.name = led->label;
424 	led->led_dev.brightness_set_blocking = lp8860_brightness_set;
425 
426 	mutex_init(&led->lock);
427 
428 	i2c_set_clientdata(client, led);
429 
430 	led->regmap = devm_regmap_init_i2c(client, &lp8860_regmap_config);
431 	if (IS_ERR(led->regmap)) {
432 		ret = PTR_ERR(led->regmap);
433 		dev_err(&client->dev, "Failed to allocate register map: %d\n",
434 			ret);
435 		return ret;
436 	}
437 
438 	led->eeprom_regmap = devm_regmap_init_i2c(client, &lp8860_eeprom_regmap_config);
439 	if (IS_ERR(led->eeprom_regmap)) {
440 		ret = PTR_ERR(led->eeprom_regmap);
441 		dev_err(&client->dev, "Failed to allocate register map: %d\n",
442 			ret);
443 		return ret;
444 	}
445 
446 	ret = lp8860_init(led);
447 	if (ret)
448 		return ret;
449 
450 	ret = devm_led_classdev_register(&client->dev, &led->led_dev);
451 	if (ret) {
452 		dev_err(&client->dev, "led register err: %d\n", ret);
453 		return ret;
454 	}
455 
456 	return 0;
457 }
458 
459 static int lp8860_remove(struct i2c_client *client)
460 {
461 	struct lp8860_led *led = i2c_get_clientdata(client);
462 	int ret;
463 
464 	if (led->enable_gpio)
465 		gpiod_direction_output(led->enable_gpio, 0);
466 
467 	if (led->regulator) {
468 		ret = regulator_disable(led->regulator);
469 		if (ret)
470 			dev_err(&led->client->dev,
471 				"Failed to disable regulator\n");
472 	}
473 
474 	mutex_destroy(&led->lock);
475 
476 	return 0;
477 }
478 
479 static const struct i2c_device_id lp8860_id[] = {
480 	{ "lp8860", 0 },
481 	{ }
482 };
483 MODULE_DEVICE_TABLE(i2c, lp8860_id);
484 
485 static const struct of_device_id of_lp8860_leds_match[] = {
486 	{ .compatible = "ti,lp8860", },
487 	{},
488 };
489 MODULE_DEVICE_TABLE(of, of_lp8860_leds_match);
490 
491 static struct i2c_driver lp8860_driver = {
492 	.driver = {
493 		.name	= "lp8860",
494 		.of_match_table = of_lp8860_leds_match,
495 	},
496 	.probe		= lp8860_probe,
497 	.remove		= lp8860_remove,
498 	.id_table	= lp8860_id,
499 };
500 module_i2c_driver(lp8860_driver);
501 
502 MODULE_DESCRIPTION("Texas Instruments LP8860 LED driver");
503 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
504 MODULE_LICENSE("GPL v2");
505