1 // SPDX-License-Identifier: GPL-2.0
2 // TI LM3692x LED chip family driver
3 // Copyright (C) 2017-18 Texas Instruments Incorporated - https://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/mod_devicetable.h>
11 #include <linux/module.h>
12 #include <linux/mutex.h>
13 #include <linux/regmap.h>
14 #include <linux/regulator/consumer.h>
15 #include <linux/slab.h>
16
17 #define LM36922_MODEL 0
18 #define LM36923_MODEL 1
19
20 #define LM3692X_REV 0x0
21 #define LM3692X_RESET 0x1
22 #define LM3692X_EN 0x10
23 #define LM3692X_BRT_CTRL 0x11
24 #define LM3692X_PWM_CTRL 0x12
25 #define LM3692X_BOOST_CTRL 0x13
26 #define LM3692X_AUTO_FREQ_HI 0x15
27 #define LM3692X_AUTO_FREQ_LO 0x16
28 #define LM3692X_BL_ADJ_THRESH 0x17
29 #define LM3692X_BRT_LSB 0x18
30 #define LM3692X_BRT_MSB 0x19
31 #define LM3692X_FAULT_CTRL 0x1e
32 #define LM3692X_FAULT_FLAGS 0x1f
33
34 #define LM3692X_SW_RESET BIT(0)
35 #define LM3692X_DEVICE_EN BIT(0)
36 #define LM3692X_LED1_EN BIT(1)
37 #define LM3692X_LED2_EN BIT(2)
38 #define LM36923_LED3_EN BIT(3)
39 #define LM3692X_ENABLE_MASK (LM3692X_DEVICE_EN | LM3692X_LED1_EN | \
40 LM3692X_LED2_EN | LM36923_LED3_EN)
41
42 /* Brightness Control Bits */
43 #define LM3692X_BL_ADJ_POL BIT(0)
44 #define LM3692X_RAMP_RATE_125us 0x00
45 #define LM3692X_RAMP_RATE_250us BIT(1)
46 #define LM3692X_RAMP_RATE_500us BIT(2)
47 #define LM3692X_RAMP_RATE_1ms (BIT(1) | BIT(2))
48 #define LM3692X_RAMP_RATE_2ms BIT(3)
49 #define LM3692X_RAMP_RATE_4ms (BIT(3) | BIT(1))
50 #define LM3692X_RAMP_RATE_8ms (BIT(2) | BIT(3))
51 #define LM3692X_RAMP_RATE_16ms (BIT(1) | BIT(2) | BIT(3))
52 #define LM3692X_RAMP_EN BIT(4)
53 #define LM3692X_BRHT_MODE_REG 0x00
54 #define LM3692X_BRHT_MODE_PWM BIT(5)
55 #define LM3692X_BRHT_MODE_MULTI_RAMP BIT(6)
56 #define LM3692X_BRHT_MODE_RAMP_MULTI (BIT(5) | BIT(6))
57 #define LM3692X_MAP_MODE_EXP BIT(7)
58
59 /* PWM Register Bits */
60 #define LM3692X_PWM_FILTER_100 BIT(0)
61 #define LM3692X_PWM_FILTER_150 BIT(1)
62 #define LM3692X_PWM_FILTER_200 (BIT(0) | BIT(1))
63 #define LM3692X_PWM_HYSTER_1LSB BIT(2)
64 #define LM3692X_PWM_HYSTER_2LSB BIT(3)
65 #define LM3692X_PWM_HYSTER_3LSB (BIT(3) | BIT(2))
66 #define LM3692X_PWM_HYSTER_4LSB BIT(4)
67 #define LM3692X_PWM_HYSTER_5LSB (BIT(4) | BIT(2))
68 #define LM3692X_PWM_HYSTER_6LSB (BIT(4) | BIT(3))
69 #define LM3692X_PWM_POLARITY BIT(5)
70 #define LM3692X_PWM_SAMP_4MHZ BIT(6)
71 #define LM3692X_PWM_SAMP_24MHZ BIT(7)
72
73 /* Boost Control Bits */
74 #define LM3692X_OCP_PROT_1A BIT(0)
75 #define LM3692X_OCP_PROT_1_25A BIT(1)
76 #define LM3692X_OCP_PROT_1_5A (BIT(0) | BIT(1))
77 #define LM3692X_OVP_21V BIT(2)
78 #define LM3692X_OVP_25V BIT(3)
79 #define LM3692X_OVP_29V (BIT(2) | BIT(3))
80 #define LM3692X_MIN_IND_22UH BIT(4)
81 #define LM3692X_BOOST_SW_1MHZ BIT(5)
82 #define LM3692X_BOOST_SW_NO_SHIFT BIT(6)
83
84 /* Fault Control Bits */
85 #define LM3692X_FAULT_CTRL_OVP BIT(0)
86 #define LM3692X_FAULT_CTRL_OCP BIT(1)
87 #define LM3692X_FAULT_CTRL_TSD BIT(2)
88 #define LM3692X_FAULT_CTRL_OPEN BIT(3)
89
90 /* Fault Flag Bits */
91 #define LM3692X_FAULT_FLAG_OVP BIT(0)
92 #define LM3692X_FAULT_FLAG_OCP BIT(1)
93 #define LM3692X_FAULT_FLAG_TSD BIT(2)
94 #define LM3692X_FAULT_FLAG_SHRT BIT(3)
95 #define LM3692X_FAULT_FLAG_OPEN BIT(4)
96
97 /**
98 * struct lm3692x_led
99 * @lock: Lock for reading/writing the device
100 * @client: Pointer to the I2C client
101 * @led_dev: LED class device pointer
102 * @regmap: Devices register map
103 * @enable_gpio: VDDIO/EN gpio to enable communication interface
104 * @regulator: LED supply regulator pointer
105 * @led_enable: LED sync to be enabled
106 * @model_id: Current device model ID enumerated
107 */
108 struct lm3692x_led {
109 struct mutex lock;
110 struct i2c_client *client;
111 struct led_classdev led_dev;
112 struct regmap *regmap;
113 struct gpio_desc *enable_gpio;
114 struct regulator *regulator;
115 int led_enable;
116 int model_id;
117
118 u8 boost_ctrl, brightness_ctrl;
119 bool enabled;
120 };
121
122 static const struct reg_default lm3692x_reg_defs[] = {
123 {LM3692X_EN, 0xf},
124 {LM3692X_BRT_CTRL, 0x61},
125 {LM3692X_PWM_CTRL, 0x73},
126 {LM3692X_BOOST_CTRL, 0x6f},
127 {LM3692X_AUTO_FREQ_HI, 0x0},
128 {LM3692X_AUTO_FREQ_LO, 0x0},
129 {LM3692X_BL_ADJ_THRESH, 0x0},
130 {LM3692X_BRT_LSB, 0x7},
131 {LM3692X_BRT_MSB, 0xff},
132 {LM3692X_FAULT_CTRL, 0x7},
133 };
134
135 static const struct regmap_config lm3692x_regmap_config = {
136 .reg_bits = 8,
137 .val_bits = 8,
138
139 .max_register = LM3692X_FAULT_FLAGS,
140 .reg_defaults = lm3692x_reg_defs,
141 .num_reg_defaults = ARRAY_SIZE(lm3692x_reg_defs),
142 .cache_type = REGCACHE_RBTREE,
143 };
144
lm3692x_fault_check(struct lm3692x_led * led)145 static int lm3692x_fault_check(struct lm3692x_led *led)
146 {
147 int ret;
148 unsigned int read_buf;
149
150 ret = regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
151 if (ret)
152 return ret;
153
154 if (read_buf)
155 dev_err(&led->client->dev, "Detected a fault 0x%X\n", read_buf);
156
157 /* The first read may clear the fault. Check again to see if the fault
158 * still exits and return that value.
159 */
160 regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
161 if (read_buf)
162 dev_err(&led->client->dev, "Second read of fault flags 0x%X\n",
163 read_buf);
164
165 return read_buf;
166 }
167
lm3692x_leds_enable(struct lm3692x_led * led)168 static int lm3692x_leds_enable(struct lm3692x_led *led)
169 {
170 int enable_state;
171 int ret, reg_ret;
172
173 if (led->enabled)
174 return 0;
175
176 if (led->regulator) {
177 ret = regulator_enable(led->regulator);
178 if (ret) {
179 dev_err(&led->client->dev,
180 "Failed to enable regulator: %d\n", ret);
181 return ret;
182 }
183 }
184
185 if (led->enable_gpio)
186 gpiod_direction_output(led->enable_gpio, 1);
187
188 ret = lm3692x_fault_check(led);
189 if (ret) {
190 dev_err(&led->client->dev, "Cannot read/clear faults: %d\n",
191 ret);
192 goto out;
193 }
194
195 ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 0x00);
196 if (ret)
197 goto out;
198
199 /*
200 * For glitch free operation, the following data should
201 * only be written while LEDx enable bits are 0 and the device enable
202 * bit is set to 1.
203 * per Section 7.5.14 of the data sheet
204 */
205 ret = regmap_write(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN);
206 if (ret)
207 goto out;
208
209 /* Set the brightness to 0 so when enabled the LEDs do not come
210 * on with full brightness.
211 */
212 ret = regmap_write(led->regmap, LM3692X_BRT_MSB, 0);
213 if (ret)
214 goto out;
215
216 ret = regmap_write(led->regmap, LM3692X_BRT_LSB, 0);
217 if (ret)
218 goto out;
219
220 ret = regmap_write(led->regmap, LM3692X_PWM_CTRL,
221 LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ);
222 if (ret)
223 goto out;
224
225 ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL, led->boost_ctrl);
226 if (ret)
227 goto out;
228
229 ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00);
230 if (ret)
231 goto out;
232
233 ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_LO, 0x00);
234 if (ret)
235 goto out;
236
237 ret = regmap_write(led->regmap, LM3692X_BL_ADJ_THRESH, 0x00);
238 if (ret)
239 goto out;
240
241 ret = regmap_write(led->regmap, LM3692X_BRT_CTRL,
242 LM3692X_BL_ADJ_POL | LM3692X_RAMP_EN);
243 if (ret)
244 goto out;
245
246 switch (led->led_enable) {
247 case 0:
248 default:
249 if (led->model_id == LM36923_MODEL)
250 enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN |
251 LM36923_LED3_EN;
252 else
253 enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN;
254
255 break;
256 case 1:
257 enable_state = LM3692X_LED1_EN;
258 break;
259 case 2:
260 enable_state = LM3692X_LED2_EN;
261 break;
262
263 case 3:
264 if (led->model_id == LM36923_MODEL) {
265 enable_state = LM36923_LED3_EN;
266 break;
267 }
268
269 ret = -EINVAL;
270 dev_err(&led->client->dev,
271 "LED3 sync not available on this device\n");
272 goto out;
273 }
274
275 ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_ENABLE_MASK,
276 enable_state | LM3692X_DEVICE_EN);
277
278 led->enabled = true;
279 return ret;
280 out:
281 dev_err(&led->client->dev, "Fail writing initialization values\n");
282
283 if (led->enable_gpio)
284 gpiod_direction_output(led->enable_gpio, 0);
285
286 if (led->regulator) {
287 reg_ret = regulator_disable(led->regulator);
288 if (reg_ret)
289 dev_err(&led->client->dev,
290 "Failed to disable regulator: %d\n", reg_ret);
291 }
292
293 return ret;
294 }
295
lm3692x_leds_disable(struct lm3692x_led * led)296 static int lm3692x_leds_disable(struct lm3692x_led *led)
297 {
298 int ret;
299
300 if (!led->enabled)
301 return 0;
302
303 ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN, 0);
304 if (ret) {
305 dev_err(&led->client->dev, "Failed to disable regulator: %d\n",
306 ret);
307 return ret;
308 }
309
310 if (led->enable_gpio)
311 gpiod_direction_output(led->enable_gpio, 0);
312
313 if (led->regulator) {
314 ret = regulator_disable(led->regulator);
315 if (ret)
316 dev_err(&led->client->dev,
317 "Failed to disable regulator: %d\n", ret);
318 }
319
320 led->enabled = false;
321 return ret;
322 }
323
lm3692x_brightness_set(struct led_classdev * led_cdev,enum led_brightness brt_val)324 static int lm3692x_brightness_set(struct led_classdev *led_cdev,
325 enum led_brightness brt_val)
326 {
327 struct lm3692x_led *led =
328 container_of(led_cdev, struct lm3692x_led, led_dev);
329 int ret;
330 int led_brightness_lsb = (brt_val >> 5);
331
332 mutex_lock(&led->lock);
333
334 if (brt_val == 0) {
335 ret = lm3692x_leds_disable(led);
336 goto out;
337 } else {
338 lm3692x_leds_enable(led);
339 }
340
341 ret = lm3692x_fault_check(led);
342 if (ret) {
343 dev_err(&led->client->dev, "Cannot read/clear faults: %d\n",
344 ret);
345 goto out;
346 }
347
348 ret = regmap_write(led->regmap, LM3692X_BRT_MSB, brt_val);
349 if (ret) {
350 dev_err(&led->client->dev, "Cannot write MSB: %d\n", ret);
351 goto out;
352 }
353
354 ret = regmap_write(led->regmap, LM3692X_BRT_LSB, led_brightness_lsb);
355 if (ret) {
356 dev_err(&led->client->dev, "Cannot write LSB: %d\n", ret);
357 goto out;
358 }
359 out:
360 mutex_unlock(&led->lock);
361 return ret;
362 }
363
lm3692x_max_brightness(struct lm3692x_led * led,u32 max_cur)364 static enum led_brightness lm3692x_max_brightness(struct lm3692x_led *led,
365 u32 max_cur)
366 {
367 u32 max_code;
368
369 /* see p.12 of LM36922 data sheet for brightness formula */
370 max_code = ((max_cur * 1000) - 37806) / 12195;
371 if (max_code > 0x7FF)
372 max_code = 0x7FF;
373
374 return max_code >> 3;
375 }
376
lm3692x_probe_dt(struct lm3692x_led * led)377 static int lm3692x_probe_dt(struct lm3692x_led *led)
378 {
379 struct fwnode_handle *child = NULL;
380 struct led_init_data init_data = {};
381 u32 ovp, max_cur;
382 int ret;
383
384 led->enable_gpio = devm_gpiod_get_optional(&led->client->dev,
385 "enable", GPIOD_OUT_LOW);
386 if (IS_ERR(led->enable_gpio)) {
387 ret = PTR_ERR(led->enable_gpio);
388 dev_err(&led->client->dev, "Failed to get enable gpio: %d\n",
389 ret);
390 return ret;
391 }
392
393 led->regulator = devm_regulator_get_optional(&led->client->dev, "vled");
394 if (IS_ERR(led->regulator)) {
395 ret = PTR_ERR(led->regulator);
396 if (ret != -ENODEV)
397 return dev_err_probe(&led->client->dev, ret,
398 "Failed to get vled regulator\n");
399
400 led->regulator = NULL;
401 }
402
403 led->boost_ctrl = LM3692X_BOOST_SW_1MHZ |
404 LM3692X_BOOST_SW_NO_SHIFT |
405 LM3692X_OCP_PROT_1_5A;
406 ret = device_property_read_u32(&led->client->dev,
407 "ti,ovp-microvolt", &ovp);
408 if (ret) {
409 led->boost_ctrl |= LM3692X_OVP_29V;
410 } else {
411 switch (ovp) {
412 case 17000000:
413 break;
414 case 21000000:
415 led->boost_ctrl |= LM3692X_OVP_21V;
416 break;
417 case 25000000:
418 led->boost_ctrl |= LM3692X_OVP_25V;
419 break;
420 case 29000000:
421 led->boost_ctrl |= LM3692X_OVP_29V;
422 break;
423 default:
424 dev_err(&led->client->dev, "Invalid OVP %d\n", ovp);
425 return -EINVAL;
426 }
427 }
428
429 child = device_get_next_child_node(&led->client->dev, child);
430 if (!child) {
431 dev_err(&led->client->dev, "No LED Child node\n");
432 return -ENODEV;
433 }
434
435 ret = fwnode_property_read_u32(child, "reg", &led->led_enable);
436 if (ret) {
437 fwnode_handle_put(child);
438 dev_err(&led->client->dev, "reg DT property missing\n");
439 return ret;
440 }
441
442 ret = fwnode_property_read_u32(child, "led-max-microamp", &max_cur);
443 led->led_dev.max_brightness = ret ? LED_FULL :
444 lm3692x_max_brightness(led, max_cur);
445
446 init_data.fwnode = child;
447 init_data.devicename = led->client->name;
448 init_data.default_label = ":";
449
450 ret = devm_led_classdev_register_ext(&led->client->dev, &led->led_dev,
451 &init_data);
452 if (ret)
453 dev_err(&led->client->dev, "led register err: %d\n", ret);
454
455 fwnode_handle_put(init_data.fwnode);
456 return ret;
457 }
458
lm3692x_probe(struct i2c_client * client)459 static int lm3692x_probe(struct i2c_client *client)
460 {
461 const struct i2c_device_id *id = i2c_client_get_device_id(client);
462 struct lm3692x_led *led;
463 int ret;
464
465 led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
466 if (!led)
467 return -ENOMEM;
468
469 mutex_init(&led->lock);
470 led->client = client;
471 led->led_dev.brightness_set_blocking = lm3692x_brightness_set;
472 led->model_id = id->driver_data;
473 i2c_set_clientdata(client, led);
474
475 led->regmap = devm_regmap_init_i2c(client, &lm3692x_regmap_config);
476 if (IS_ERR(led->regmap)) {
477 ret = PTR_ERR(led->regmap);
478 dev_err(&client->dev, "Failed to allocate register map: %d\n",
479 ret);
480 return ret;
481 }
482
483 ret = lm3692x_probe_dt(led);
484 if (ret)
485 return ret;
486
487 ret = lm3692x_leds_enable(led);
488 if (ret)
489 return ret;
490
491 return 0;
492 }
493
lm3692x_remove(struct i2c_client * client)494 static void lm3692x_remove(struct i2c_client *client)
495 {
496 struct lm3692x_led *led = i2c_get_clientdata(client);
497
498 lm3692x_leds_disable(led);
499 mutex_destroy(&led->lock);
500 }
501
502 static const struct i2c_device_id lm3692x_id[] = {
503 { "lm36922", LM36922_MODEL },
504 { "lm36923", LM36923_MODEL },
505 { }
506 };
507 MODULE_DEVICE_TABLE(i2c, lm3692x_id);
508
509 static const struct of_device_id of_lm3692x_leds_match[] = {
510 { .compatible = "ti,lm36922", },
511 { .compatible = "ti,lm36923", },
512 {},
513 };
514 MODULE_DEVICE_TABLE(of, of_lm3692x_leds_match);
515
516 static struct i2c_driver lm3692x_driver = {
517 .driver = {
518 .name = "lm3692x",
519 .of_match_table = of_lm3692x_leds_match,
520 },
521 .probe = lm3692x_probe,
522 .remove = lm3692x_remove,
523 .id_table = lm3692x_id,
524 };
525 module_i2c_driver(lm3692x_driver);
526
527 MODULE_DESCRIPTION("Texas Instruments LM3692X LED driver");
528 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
529 MODULE_LICENSE("GPL v2");
530