xref: /openbmc/linux/drivers/leds/leds-lm3692x.c (revision f125e2d4)
1 // SPDX-License-Identifier: GPL-2.0
2 // TI LM3692x LED chip family driver
3 // Copyright (C) 2017-18 Texas Instruments Incorporated - http://www.ti.com/
4 
5 #include <linux/gpio/consumer.h>
6 #include <linux/i2c.h>
7 #include <linux/init.h>
8 #include <linux/leds.h>
9 #include <linux/log2.h>
10 #include <linux/module.h>
11 #include <linux/mutex.h>
12 #include <linux/of.h>
13 #include <linux/of_gpio.h>
14 #include <linux/regmap.h>
15 #include <linux/regulator/consumer.h>
16 #include <linux/slab.h>
17 
18 #define LM36922_MODEL	0
19 #define LM36923_MODEL	1
20 
21 #define LM3692X_REV		0x0
22 #define LM3692X_RESET		0x1
23 #define LM3692X_EN		0x10
24 #define LM3692X_BRT_CTRL	0x11
25 #define LM3692X_PWM_CTRL	0x12
26 #define LM3692X_BOOST_CTRL	0x13
27 #define LM3692X_AUTO_FREQ_HI	0x15
28 #define LM3692X_AUTO_FREQ_LO	0x16
29 #define LM3692X_BL_ADJ_THRESH	0x17
30 #define LM3692X_BRT_LSB		0x18
31 #define LM3692X_BRT_MSB		0x19
32 #define LM3692X_FAULT_CTRL	0x1e
33 #define LM3692X_FAULT_FLAGS	0x1f
34 
35 #define LM3692X_SW_RESET	BIT(0)
36 #define LM3692X_DEVICE_EN	BIT(0)
37 #define LM3692X_LED1_EN		BIT(1)
38 #define LM3692X_LED2_EN		BIT(2)
39 #define LM36923_LED3_EN		BIT(3)
40 #define LM3692X_ENABLE_MASK	(LM3692X_DEVICE_EN | LM3692X_LED1_EN | \
41 				 LM3692X_LED2_EN | LM36923_LED3_EN)
42 
43 /* Brightness Control Bits */
44 #define LM3692X_BL_ADJ_POL	BIT(0)
45 #define LM3692X_RAMP_RATE_125us	0x00
46 #define LM3692X_RAMP_RATE_250us	BIT(1)
47 #define LM3692X_RAMP_RATE_500us BIT(2)
48 #define LM3692X_RAMP_RATE_1ms	(BIT(1) | BIT(2))
49 #define LM3692X_RAMP_RATE_2ms	BIT(3)
50 #define LM3692X_RAMP_RATE_4ms	(BIT(3) | BIT(1))
51 #define LM3692X_RAMP_RATE_8ms	(BIT(2) | BIT(3))
52 #define LM3692X_RAMP_RATE_16ms	(BIT(1) | BIT(2) | BIT(3))
53 #define LM3692X_RAMP_EN		BIT(4)
54 #define LM3692X_BRHT_MODE_REG	0x00
55 #define LM3692X_BRHT_MODE_PWM	BIT(5)
56 #define LM3692X_BRHT_MODE_MULTI_RAMP BIT(6)
57 #define LM3692X_BRHT_MODE_RAMP_MULTI (BIT(5) | BIT(6))
58 #define LM3692X_MAP_MODE_EXP	BIT(7)
59 
60 /* PWM Register Bits */
61 #define LM3692X_PWM_FILTER_100	BIT(0)
62 #define LM3692X_PWM_FILTER_150	BIT(1)
63 #define LM3692X_PWM_FILTER_200	(BIT(0) | BIT(1))
64 #define LM3692X_PWM_HYSTER_1LSB BIT(2)
65 #define LM3692X_PWM_HYSTER_2LSB	BIT(3)
66 #define LM3692X_PWM_HYSTER_3LSB (BIT(3) | BIT(2))
67 #define LM3692X_PWM_HYSTER_4LSB BIT(4)
68 #define LM3692X_PWM_HYSTER_5LSB (BIT(4) | BIT(2))
69 #define LM3692X_PWM_HYSTER_6LSB (BIT(4) | BIT(3))
70 #define LM3692X_PWM_POLARITY	BIT(5)
71 #define LM3692X_PWM_SAMP_4MHZ	BIT(6)
72 #define LM3692X_PWM_SAMP_24MHZ	BIT(7)
73 
74 /* Boost Control Bits */
75 #define LM3692X_OCP_PROT_1A	BIT(0)
76 #define LM3692X_OCP_PROT_1_25A	BIT(1)
77 #define LM3692X_OCP_PROT_1_5A	(BIT(0) | BIT(1))
78 #define LM3692X_OVP_21V		BIT(2)
79 #define LM3692X_OVP_25V		BIT(3)
80 #define LM3692X_OVP_29V		(BIT(2) | BIT(3))
81 #define LM3692X_MIN_IND_22UH	BIT(4)
82 #define LM3692X_BOOST_SW_1MHZ	BIT(5)
83 #define LM3692X_BOOST_SW_NO_SHIFT	BIT(6)
84 
85 /* Fault Control Bits */
86 #define LM3692X_FAULT_CTRL_OVP BIT(0)
87 #define LM3692X_FAULT_CTRL_OCP BIT(1)
88 #define LM3692X_FAULT_CTRL_TSD BIT(2)
89 #define LM3692X_FAULT_CTRL_OPEN BIT(3)
90 
91 /* Fault Flag Bits */
92 #define LM3692X_FAULT_FLAG_OVP BIT(0)
93 #define LM3692X_FAULT_FLAG_OCP BIT(1)
94 #define LM3692X_FAULT_FLAG_TSD BIT(2)
95 #define LM3692X_FAULT_FLAG_SHRT BIT(3)
96 #define LM3692X_FAULT_FLAG_OPEN BIT(4)
97 
98 /**
99  * struct lm3692x_led -
100  * @lock - Lock for reading/writing the device
101  * @client - Pointer to the I2C client
102  * @led_dev - LED class device pointer
103  * @regmap - Devices register map
104  * @enable_gpio - VDDIO/EN gpio to enable communication interface
105  * @regulator - LED supply regulator pointer
106  * @led_enable - LED sync to be enabled
107  * @model_id - Current device model ID enumerated
108  */
109 struct lm3692x_led {
110 	struct mutex lock;
111 	struct i2c_client *client;
112 	struct led_classdev led_dev;
113 	struct regmap *regmap;
114 	struct gpio_desc *enable_gpio;
115 	struct regulator *regulator;
116 	int led_enable;
117 	int model_id;
118 
119 	u8 boost_ctrl, brightness_ctrl;
120 	bool enabled;
121 };
122 
123 static const struct reg_default lm3692x_reg_defs[] = {
124 	{LM3692X_EN, 0xf},
125 	{LM3692X_BRT_CTRL, 0x61},
126 	{LM3692X_PWM_CTRL, 0x73},
127 	{LM3692X_BOOST_CTRL, 0x6f},
128 	{LM3692X_AUTO_FREQ_HI, 0x0},
129 	{LM3692X_AUTO_FREQ_LO, 0x0},
130 	{LM3692X_BL_ADJ_THRESH, 0x0},
131 	{LM3692X_BRT_LSB, 0x7},
132 	{LM3692X_BRT_MSB, 0xff},
133 	{LM3692X_FAULT_CTRL, 0x7},
134 };
135 
136 static const struct regmap_config lm3692x_regmap_config = {
137 	.reg_bits = 8,
138 	.val_bits = 8,
139 
140 	.max_register = LM3692X_FAULT_FLAGS,
141 	.reg_defaults = lm3692x_reg_defs,
142 	.num_reg_defaults = ARRAY_SIZE(lm3692x_reg_defs),
143 	.cache_type = REGCACHE_RBTREE,
144 };
145 
146 static int lm3692x_fault_check(struct lm3692x_led *led)
147 {
148 	int ret;
149 	unsigned int read_buf;
150 
151 	ret = regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
152 	if (ret)
153 		return ret;
154 
155 	if (read_buf)
156 		dev_err(&led->client->dev, "Detected a fault 0x%X\n", read_buf);
157 
158 	/* The first read may clear the fault.  Check again to see if the fault
159 	 * still exits and return that value.
160 	 */
161 	regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
162 	if (read_buf)
163 		dev_err(&led->client->dev, "Second read of fault flags 0x%X\n",
164 			read_buf);
165 
166 	return read_buf;
167 }
168 
169 static int lm3692x_leds_enable(struct lm3692x_led *led)
170 {
171 	int enable_state;
172 	int ret, reg_ret;
173 
174 	if (led->enabled)
175 		return 0;
176 
177 	if (led->regulator) {
178 		ret = regulator_enable(led->regulator);
179 		if (ret) {
180 			dev_err(&led->client->dev,
181 				"Failed to enable regulator: %d\n", ret);
182 			return ret;
183 		}
184 	}
185 
186 	if (led->enable_gpio)
187 		gpiod_direction_output(led->enable_gpio, 1);
188 
189 	ret = lm3692x_fault_check(led);
190 	if (ret) {
191 		dev_err(&led->client->dev, "Cannot read/clear faults: %d\n",
192 			ret);
193 		goto out;
194 	}
195 
196 	ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 0x00);
197 	if (ret)
198 		goto out;
199 
200 	/*
201 	 * For glitch free operation, the following data should
202 	 * only be written while LEDx enable bits are 0 and the device enable
203 	 * bit is set to 1.
204 	 * per Section 7.5.14 of the data sheet
205 	 */
206 	ret = regmap_write(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN);
207 	if (ret)
208 		goto out;
209 
210 	/* Set the brightness to 0 so when enabled the LEDs do not come
211 	 * on with full brightness.
212 	 */
213 	ret = regmap_write(led->regmap, LM3692X_BRT_MSB, 0);
214 	if (ret)
215 		goto out;
216 
217 	ret = regmap_write(led->regmap, LM3692X_BRT_LSB, 0);
218 	if (ret)
219 		goto out;
220 
221 	ret = regmap_write(led->regmap, LM3692X_PWM_CTRL,
222 		LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ);
223 	if (ret)
224 		goto out;
225 
226 	ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL, led->boost_ctrl);
227 	if (ret)
228 		goto out;
229 
230 	ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00);
231 	if (ret)
232 		goto out;
233 
234 	ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_LO, 0x00);
235 	if (ret)
236 		goto out;
237 
238 	ret = regmap_write(led->regmap, LM3692X_BL_ADJ_THRESH, 0x00);
239 	if (ret)
240 		goto out;
241 
242 	ret = regmap_write(led->regmap, LM3692X_BRT_CTRL,
243 			LM3692X_BL_ADJ_POL | LM3692X_RAMP_EN);
244 	if (ret)
245 		goto out;
246 
247 	switch (led->led_enable) {
248 	case 0:
249 	default:
250 		if (led->model_id == LM36923_MODEL)
251 			enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN |
252 			       LM36923_LED3_EN;
253 		else
254 			enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN;
255 
256 		break;
257 	case 1:
258 		enable_state = LM3692X_LED1_EN;
259 		break;
260 	case 2:
261 		enable_state = LM3692X_LED2_EN;
262 		break;
263 
264 	case 3:
265 		if (led->model_id == LM36923_MODEL) {
266 			enable_state = LM36923_LED3_EN;
267 			break;
268 		}
269 
270 		ret = -EINVAL;
271 		dev_err(&led->client->dev,
272 			"LED3 sync not available on this device\n");
273 		goto out;
274 	}
275 
276 	ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_ENABLE_MASK,
277 				 enable_state | LM3692X_DEVICE_EN);
278 
279 	led->enabled = true;
280 	return ret;
281 out:
282 	dev_err(&led->client->dev, "Fail writing initialization values\n");
283 
284 	if (led->enable_gpio)
285 		gpiod_direction_output(led->enable_gpio, 0);
286 
287 	if (led->regulator) {
288 		reg_ret = regulator_disable(led->regulator);
289 		if (reg_ret)
290 			dev_err(&led->client->dev,
291 				"Failed to disable regulator: %d\n", reg_ret);
292 	}
293 
294 	return ret;
295 }
296 
297 static int lm3692x_leds_disable(struct lm3692x_led *led)
298 {
299 	int ret;
300 
301 	if (!led->enabled)
302 		return 0;
303 
304 	ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN, 0);
305 	if (ret) {
306 		dev_err(&led->client->dev, "Failed to disable regulator: %d\n",
307 			ret);
308 		return ret;
309 	}
310 
311 	if (led->enable_gpio)
312 		gpiod_direction_output(led->enable_gpio, 0);
313 
314 	if (led->regulator) {
315 		ret = regulator_disable(led->regulator);
316 		if (ret)
317 			dev_err(&led->client->dev,
318 				"Failed to disable regulator: %d\n", ret);
319 	}
320 
321 	led->enabled = false;
322 	return ret;
323 }
324 
325 static int lm3692x_brightness_set(struct led_classdev *led_cdev,
326 				enum led_brightness brt_val)
327 {
328 	struct lm3692x_led *led =
329 			container_of(led_cdev, struct lm3692x_led, led_dev);
330 	int ret;
331 	int led_brightness_lsb = (brt_val >> 5);
332 
333 	mutex_lock(&led->lock);
334 
335 	if (brt_val == 0) {
336 		ret = lm3692x_leds_disable(led);
337 		goto out;
338 	} else {
339 		lm3692x_leds_enable(led);
340 	}
341 
342 	ret = lm3692x_fault_check(led);
343 	if (ret) {
344 		dev_err(&led->client->dev, "Cannot read/clear faults: %d\n",
345 			ret);
346 		goto out;
347 	}
348 
349 	ret = regmap_write(led->regmap, LM3692X_BRT_MSB, brt_val);
350 	if (ret) {
351 		dev_err(&led->client->dev, "Cannot write MSB: %d\n", ret);
352 		goto out;
353 	}
354 
355 	ret = regmap_write(led->regmap, LM3692X_BRT_LSB, led_brightness_lsb);
356 	if (ret) {
357 		dev_err(&led->client->dev, "Cannot write LSB: %d\n", ret);
358 		goto out;
359 	}
360 out:
361 	mutex_unlock(&led->lock);
362 	return ret;
363 }
364 
365 static enum led_brightness lm3692x_max_brightness(struct lm3692x_led *led,
366 						  u32 max_cur)
367 {
368 	u32 max_code;
369 
370 	/* see p.12 of LM36922 data sheet for brightness formula */
371 	max_code = ((max_cur * 1000) - 37806) / 12195;
372 	if (max_code > 0x7FF)
373 		max_code = 0x7FF;
374 
375 	return max_code >> 3;
376 }
377 
378 static int lm3692x_probe_dt(struct lm3692x_led *led)
379 {
380 	struct fwnode_handle *child = NULL;
381 	struct led_init_data init_data = {};
382 	u32 ovp, max_cur;
383 	int ret;
384 
385 	led->enable_gpio = devm_gpiod_get_optional(&led->client->dev,
386 						   "enable", GPIOD_OUT_LOW);
387 	if (IS_ERR(led->enable_gpio)) {
388 		ret = PTR_ERR(led->enable_gpio);
389 		dev_err(&led->client->dev, "Failed to get enable gpio: %d\n",
390 			ret);
391 		return ret;
392 	}
393 
394 	led->regulator = devm_regulator_get_optional(&led->client->dev, "vled");
395 	if (IS_ERR(led->regulator)) {
396 		ret = PTR_ERR(led->regulator);
397 		if (ret != -ENODEV) {
398 			if (ret != -EPROBE_DEFER)
399 				dev_err(&led->client->dev,
400 					"Failed to get vled regulator: %d\n",
401 					ret);
402 			return ret;
403 		}
404 		led->regulator = NULL;
405 	}
406 
407 	led->boost_ctrl = LM3692X_BOOST_SW_1MHZ |
408 		LM3692X_BOOST_SW_NO_SHIFT |
409 		LM3692X_OCP_PROT_1_5A;
410 	ret = device_property_read_u32(&led->client->dev,
411 				       "ti,ovp-microvolt", &ovp);
412 	if (ret) {
413 		led->boost_ctrl |= LM3692X_OVP_29V;
414 	} else {
415 		switch (ovp) {
416 		case 17000000:
417 			break;
418 		case 21000000:
419 			led->boost_ctrl |= LM3692X_OVP_21V;
420 			break;
421 		case 25000000:
422 			led->boost_ctrl |= LM3692X_OVP_25V;
423 			break;
424 		case 29000000:
425 			led->boost_ctrl |= LM3692X_OVP_29V;
426 			break;
427 		default:
428 			dev_err(&led->client->dev, "Invalid OVP %d\n", ovp);
429 			return -EINVAL;
430 		}
431 	}
432 
433 	child = device_get_next_child_node(&led->client->dev, child);
434 	if (!child) {
435 		dev_err(&led->client->dev, "No LED Child node\n");
436 		return -ENODEV;
437 	}
438 
439 	fwnode_property_read_string(child, "linux,default-trigger",
440 				    &led->led_dev.default_trigger);
441 
442 	ret = fwnode_property_read_u32(child, "reg", &led->led_enable);
443 	if (ret) {
444 		dev_err(&led->client->dev, "reg DT property missing\n");
445 		return ret;
446 	}
447 
448 	ret = fwnode_property_read_u32(child, "led-max-microamp", &max_cur);
449 	led->led_dev.max_brightness = ret ? LED_FULL :
450 		lm3692x_max_brightness(led, max_cur);
451 
452 	init_data.fwnode = child;
453 	init_data.devicename = led->client->name;
454 	init_data.default_label = ":";
455 
456 	ret = devm_led_classdev_register_ext(&led->client->dev, &led->led_dev,
457 					     &init_data);
458 	if (ret) {
459 		dev_err(&led->client->dev, "led register err: %d\n", ret);
460 		return ret;
461 	}
462 
463 	return 0;
464 }
465 
466 static int lm3692x_probe(struct i2c_client *client,
467 			const struct i2c_device_id *id)
468 {
469 	struct lm3692x_led *led;
470 	int ret;
471 
472 	led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
473 	if (!led)
474 		return -ENOMEM;
475 
476 	mutex_init(&led->lock);
477 	led->client = client;
478 	led->led_dev.brightness_set_blocking = lm3692x_brightness_set;
479 	led->model_id = id->driver_data;
480 	i2c_set_clientdata(client, led);
481 
482 	led->regmap = devm_regmap_init_i2c(client, &lm3692x_regmap_config);
483 	if (IS_ERR(led->regmap)) {
484 		ret = PTR_ERR(led->regmap);
485 		dev_err(&client->dev, "Failed to allocate register map: %d\n",
486 			ret);
487 		return ret;
488 	}
489 
490 	ret = lm3692x_probe_dt(led);
491 	if (ret)
492 		return ret;
493 
494 	ret = lm3692x_leds_enable(led);
495 	if (ret)
496 		return ret;
497 
498 	return 0;
499 }
500 
501 static int lm3692x_remove(struct i2c_client *client)
502 {
503 	struct lm3692x_led *led = i2c_get_clientdata(client);
504 	int ret;
505 
506 	ret = lm3692x_leds_disable(led);
507 	if (ret)
508 		return ret;
509 	mutex_destroy(&led->lock);
510 
511 	return 0;
512 }
513 
514 static const struct i2c_device_id lm3692x_id[] = {
515 	{ "lm36922", LM36922_MODEL },
516 	{ "lm36923", LM36923_MODEL },
517 	{ }
518 };
519 MODULE_DEVICE_TABLE(i2c, lm3692x_id);
520 
521 static const struct of_device_id of_lm3692x_leds_match[] = {
522 	{ .compatible = "ti,lm36922", },
523 	{ .compatible = "ti,lm36923", },
524 	{},
525 };
526 MODULE_DEVICE_TABLE(of, of_lm3692x_leds_match);
527 
528 static struct i2c_driver lm3692x_driver = {
529 	.driver = {
530 		.name	= "lm3692x",
531 		.of_match_table = of_lm3692x_leds_match,
532 	},
533 	.probe		= lm3692x_probe,
534 	.remove		= lm3692x_remove,
535 	.id_table	= lm3692x_id,
536 };
537 module_i2c_driver(lm3692x_driver);
538 
539 MODULE_DESCRIPTION("Texas Instruments LM3692X LED driver");
540 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
541 MODULE_LICENSE("GPL v2");
542