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/module.h>
10 #include <linux/mutex.h>
11 #include <linux/of.h>
12 #include <linux/of_gpio.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
119 static const struct reg_default lm3692x_reg_defs[] = {
120 {LM3692X_EN, 0xf},
121 {LM3692X_BRT_CTRL, 0x61},
122 {LM3692X_PWM_CTRL, 0x73},
123 {LM3692X_BOOST_CTRL, 0x6f},
124 {LM3692X_AUTO_FREQ_HI, 0x0},
125 {LM3692X_AUTO_FREQ_LO, 0x0},
126 {LM3692X_BL_ADJ_THRESH, 0x0},
127 {LM3692X_BRT_LSB, 0x7},
128 {LM3692X_BRT_MSB, 0xff},
129 {LM3692X_FAULT_CTRL, 0x7},
130 };
131
132 static const struct regmap_config lm3692x_regmap_config = {
133 .reg_bits = 8,
134 .val_bits = 8,
135
136 .max_register = LM3692X_FAULT_FLAGS,
137 .reg_defaults = lm3692x_reg_defs,
138 .num_reg_defaults = ARRAY_SIZE(lm3692x_reg_defs),
139 .cache_type = REGCACHE_RBTREE,
140 };
141
lm3692x_fault_check(struct lm3692x_led * led)142 static int lm3692x_fault_check(struct lm3692x_led *led)
143 {
144 int ret;
145 unsigned int read_buf;
146
147 ret = regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
148 if (ret)
149 return ret;
150
151 if (read_buf)
152 dev_err(&led->client->dev, "Detected a fault 0x%X\n", read_buf);
153
154 /* The first read may clear the fault. Check again to see if the fault
155 * still exits and return that value.
156 */
157 regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
158 if (read_buf)
159 dev_err(&led->client->dev, "Second read of fault flags 0x%X\n",
160 read_buf);
161
162 return read_buf;
163 }
164
lm3692x_brightness_set(struct led_classdev * led_cdev,enum led_brightness brt_val)165 static int lm3692x_brightness_set(struct led_classdev *led_cdev,
166 enum led_brightness brt_val)
167 {
168 struct lm3692x_led *led =
169 container_of(led_cdev, struct lm3692x_led, led_dev);
170 int ret;
171 int led_brightness_lsb = (brt_val >> 5);
172
173 mutex_lock(&led->lock);
174
175 ret = lm3692x_fault_check(led);
176 if (ret) {
177 dev_err(&led->client->dev, "Cannot read/clear faults\n");
178 goto out;
179 }
180
181 ret = regmap_write(led->regmap, LM3692X_BRT_MSB, brt_val);
182 if (ret) {
183 dev_err(&led->client->dev, "Cannot write MSB\n");
184 goto out;
185 }
186
187 ret = regmap_write(led->regmap, LM3692X_BRT_LSB, led_brightness_lsb);
188 if (ret) {
189 dev_err(&led->client->dev, "Cannot write LSB\n");
190 goto out;
191 }
192 out:
193 mutex_unlock(&led->lock);
194 return ret;
195 }
196
lm3692x_init(struct lm3692x_led * led)197 static int lm3692x_init(struct lm3692x_led *led)
198 {
199 int enable_state;
200 int ret;
201
202 if (led->regulator) {
203 ret = regulator_enable(led->regulator);
204 if (ret) {
205 dev_err(&led->client->dev,
206 "Failed to enable regulator\n");
207 return ret;
208 }
209 }
210
211 if (led->enable_gpio)
212 gpiod_direction_output(led->enable_gpio, 1);
213
214 ret = lm3692x_fault_check(led);
215 if (ret) {
216 dev_err(&led->client->dev, "Cannot read/clear faults\n");
217 goto out;
218 }
219
220 ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 0x00);
221 if (ret)
222 goto out;
223
224 /*
225 * For glitch free operation, the following data should
226 * only be written while LEDx enable bits are 0 and the device enable
227 * bit is set to 1.
228 * per Section 7.5.14 of the data sheet
229 */
230 ret = regmap_write(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN);
231 if (ret)
232 goto out;
233
234 /* Set the brightness to 0 so when enabled the LEDs do not come
235 * on with full brightness.
236 */
237 ret = regmap_write(led->regmap, LM3692X_BRT_MSB, 0);
238 if (ret)
239 goto out;
240
241 ret = regmap_write(led->regmap, LM3692X_BRT_LSB, 0);
242 if (ret)
243 goto out;
244
245 ret = regmap_write(led->regmap, LM3692X_PWM_CTRL,
246 LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ);
247 if (ret)
248 goto out;
249
250 ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL,
251 LM3692X_BRHT_MODE_RAMP_MULTI |
252 LM3692X_BL_ADJ_POL |
253 LM3692X_RAMP_RATE_250us);
254 if (ret)
255 goto out;
256
257 ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00);
258 if (ret)
259 goto out;
260
261 ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_LO, 0x00);
262 if (ret)
263 goto out;
264
265 ret = regmap_write(led->regmap, LM3692X_BL_ADJ_THRESH, 0x00);
266 if (ret)
267 goto out;
268
269 ret = regmap_write(led->regmap, LM3692X_BRT_CTRL,
270 LM3692X_BL_ADJ_POL | LM3692X_PWM_HYSTER_4LSB);
271 if (ret)
272 goto out;
273
274 switch (led->led_enable) {
275 case 0:
276 default:
277 if (led->model_id == LM36923_MODEL)
278 enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN |
279 LM36923_LED3_EN;
280 else
281 enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN;
282
283 break;
284 case 1:
285 enable_state = LM3692X_LED1_EN;
286 break;
287 case 2:
288 enable_state = LM3692X_LED2_EN;
289 break;
290
291 case 3:
292 if (led->model_id == LM36923_MODEL) {
293 enable_state = LM36923_LED3_EN;
294 break;
295 }
296
297 ret = -EINVAL;
298 dev_err(&led->client->dev,
299 "LED3 sync not available on this device\n");
300 goto out;
301 }
302
303 ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_ENABLE_MASK,
304 enable_state | LM3692X_DEVICE_EN);
305
306 return ret;
307 out:
308 dev_err(&led->client->dev, "Fail writing initialization values\n");
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\n");
318 }
319
320 return ret;
321 }
lm3692x_probe_dt(struct lm3692x_led * led)322 static int lm3692x_probe_dt(struct lm3692x_led *led)
323 {
324 struct fwnode_handle *child = NULL;
325 struct led_init_data init_data = {};
326 int ret;
327
328 led->enable_gpio = devm_gpiod_get_optional(&led->client->dev,
329 "enable", GPIOD_OUT_LOW);
330 if (IS_ERR(led->enable_gpio)) {
331 ret = PTR_ERR(led->enable_gpio);
332 dev_err(&led->client->dev, "Failed to get enable gpio: %d\n",
333 ret);
334 return ret;
335 }
336
337 led->regulator = devm_regulator_get_optional(&led->client->dev, "vled");
338 if (IS_ERR(led->regulator)) {
339 ret = PTR_ERR(led->regulator);
340 if (ret != -ENODEV) {
341 if (ret != -EPROBE_DEFER)
342 dev_err(&led->client->dev,
343 "Failed to get vled regulator: %d\n",
344 ret);
345 return ret;
346 }
347 led->regulator = NULL;
348 }
349
350 child = device_get_next_child_node(&led->client->dev, child);
351 if (!child) {
352 dev_err(&led->client->dev, "No LED Child node\n");
353 return -ENODEV;
354 }
355
356 fwnode_property_read_string(child, "linux,default-trigger",
357 &led->led_dev.default_trigger);
358
359 ret = fwnode_property_read_u32(child, "reg", &led->led_enable);
360 if (ret) {
361 dev_err(&led->client->dev, "reg DT property missing\n");
362 return ret;
363 }
364
365 init_data.fwnode = child;
366 init_data.devicename = led->client->name;
367 init_data.default_label = ":";
368
369 ret = devm_led_classdev_register_ext(&led->client->dev, &led->led_dev,
370 &init_data);
371 if (ret) {
372 dev_err(&led->client->dev, "led register err: %d\n", ret);
373 return ret;
374 }
375
376 return 0;
377 }
378
lm3692x_probe(struct i2c_client * client,const struct i2c_device_id * id)379 static int lm3692x_probe(struct i2c_client *client,
380 const struct i2c_device_id *id)
381 {
382 struct lm3692x_led *led;
383 int ret;
384
385 led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
386 if (!led)
387 return -ENOMEM;
388
389 mutex_init(&led->lock);
390 led->client = client;
391 led->led_dev.brightness_set_blocking = lm3692x_brightness_set;
392 led->model_id = id->driver_data;
393 i2c_set_clientdata(client, led);
394
395 led->regmap = devm_regmap_init_i2c(client, &lm3692x_regmap_config);
396 if (IS_ERR(led->regmap)) {
397 ret = PTR_ERR(led->regmap);
398 dev_err(&client->dev, "Failed to allocate register map: %d\n",
399 ret);
400 return ret;
401 }
402
403 ret = lm3692x_probe_dt(led);
404 if (ret)
405 return ret;
406
407 ret = lm3692x_init(led);
408 if (ret)
409 return ret;
410
411 return 0;
412 }
413
lm3692x_remove(struct i2c_client * client)414 static int lm3692x_remove(struct i2c_client *client)
415 {
416 struct lm3692x_led *led = i2c_get_clientdata(client);
417 int ret;
418
419 ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN, 0);
420 if (ret) {
421 dev_err(&led->client->dev, "Failed to disable regulator\n");
422 return ret;
423 }
424
425 if (led->enable_gpio)
426 gpiod_direction_output(led->enable_gpio, 0);
427
428 if (led->regulator) {
429 ret = regulator_disable(led->regulator);
430 if (ret)
431 dev_err(&led->client->dev,
432 "Failed to disable regulator\n");
433 }
434
435 mutex_destroy(&led->lock);
436
437 return 0;
438 }
439
440 static const struct i2c_device_id lm3692x_id[] = {
441 { "lm36922", LM36922_MODEL },
442 { "lm36923", LM36923_MODEL },
443 { }
444 };
445 MODULE_DEVICE_TABLE(i2c, lm3692x_id);
446
447 static const struct of_device_id of_lm3692x_leds_match[] = {
448 { .compatible = "ti,lm36922", },
449 { .compatible = "ti,lm36923", },
450 {},
451 };
452 MODULE_DEVICE_TABLE(of, of_lm3692x_leds_match);
453
454 static struct i2c_driver lm3692x_driver = {
455 .driver = {
456 .name = "lm3692x",
457 .of_match_table = of_lm3692x_leds_match,
458 },
459 .probe = lm3692x_probe,
460 .remove = lm3692x_remove,
461 .id_table = lm3692x_id,
462 };
463 module_i2c_driver(lm3692x_driver);
464
465 MODULE_DESCRIPTION("Texas Instruments LM3692X LED driver");
466 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
467 MODULE_LICENSE("GPL v2");
468