1 // SPDX-License-Identifier: GPL-2.0
2 // Flash and torch driver for Texas Instruments LM3601X LED
3 // Flash driver chip family
4 // Copyright (C) 2018 Texas Instruments Incorporated - https://www.ti.com/
5
6 #include <linux/delay.h>
7 #include <linux/i2c.h>
8 #include <linux/leds.h>
9 #include <linux/led-class-flash.h>
10 #include <linux/module.h>
11 #include <linux/regmap.h>
12 #include <linux/slab.h>
13
14 #define LM3601X_LED_IR 0x0
15 #define LM3601X_LED_TORCH 0x1
16
17 /* Registers */
18 #define LM3601X_ENABLE_REG 0x01
19 #define LM3601X_CFG_REG 0x02
20 #define LM3601X_LED_FLASH_REG 0x03
21 #define LM3601X_LED_TORCH_REG 0x04
22 #define LM3601X_FLAGS_REG 0x05
23 #define LM3601X_DEV_ID_REG 0x06
24
25 #define LM3601X_SW_RESET BIT(7)
26
27 /* Enable Mode bits */
28 #define LM3601X_MODE_STANDBY 0x00
29 #define LM3601X_MODE_IR_DRV BIT(0)
30 #define LM3601X_MODE_TORCH BIT(1)
31 #define LM3601X_MODE_STROBE (BIT(0) | BIT(1))
32 #define LM3601X_STRB_EN BIT(2)
33 #define LM3601X_STRB_EDGE_TRIG BIT(3)
34 #define LM3601X_IVFM_EN BIT(4)
35
36 #define LM36010_BOOST_LIMIT_28 BIT(5)
37 #define LM36010_BOOST_FREQ_4MHZ BIT(6)
38 #define LM36010_BOOST_MODE_PASS BIT(7)
39
40 /* Flag Mask */
41 #define LM3601X_FLASH_TIME_OUT BIT(0)
42 #define LM3601X_UVLO_FAULT BIT(1)
43 #define LM3601X_THERM_SHUTDOWN BIT(2)
44 #define LM3601X_THERM_CURR BIT(3)
45 #define LM36010_CURR_LIMIT BIT(4)
46 #define LM3601X_SHORT_FAULT BIT(5)
47 #define LM3601X_IVFM_TRIP BIT(6)
48 #define LM36010_OVP_FAULT BIT(7)
49
50 #define LM3601X_MAX_TORCH_I_UA 376000
51 #define LM3601X_MIN_TORCH_I_UA 2400
52 #define LM3601X_TORCH_REG_DIV 2965
53
54 #define LM3601X_MAX_STROBE_I_UA 1500000
55 #define LM3601X_MIN_STROBE_I_UA 11000
56 #define LM3601X_STROBE_REG_DIV 11800
57
58 #define LM3601X_TIMEOUT_MASK 0x1e
59 #define LM3601X_ENABLE_MASK (LM3601X_MODE_IR_DRV | LM3601X_MODE_TORCH)
60
61 #define LM3601X_LOWER_STEP_US 40000
62 #define LM3601X_UPPER_STEP_US 200000
63 #define LM3601X_MIN_TIMEOUT_US 40000
64 #define LM3601X_MAX_TIMEOUT_US 1600000
65 #define LM3601X_TIMEOUT_XOVER_US 400000
66
67 enum lm3601x_type {
68 CHIP_LM36010 = 0,
69 CHIP_LM36011,
70 };
71
72 /**
73 * struct lm3601x_led - private lm3601x LED data
74 * @fled_cdev: flash LED class device pointer
75 * @client: Pointer to the I2C client
76 * @regmap: Devices register map
77 * @lock: Lock for reading/writing the device
78 * @flash_timeout: the timeout for the flash
79 * @last_flag: last known flags register value
80 * @torch_current_max: maximum current for the torch
81 * @flash_current_max: maximum current for the flash
82 * @max_flash_timeout: maximum timeout for the flash
83 * @led_mode: The mode to enable either IR or Torch
84 */
85 struct lm3601x_led {
86 struct led_classdev_flash fled_cdev;
87 struct i2c_client *client;
88 struct regmap *regmap;
89 struct mutex lock;
90
91 unsigned int flash_timeout;
92 unsigned int last_flag;
93
94 u32 torch_current_max;
95 u32 flash_current_max;
96 u32 max_flash_timeout;
97
98 u32 led_mode;
99 };
100
101 static const struct reg_default lm3601x_regmap_defs[] = {
102 { LM3601X_ENABLE_REG, 0x20 },
103 { LM3601X_CFG_REG, 0x15 },
104 { LM3601X_LED_FLASH_REG, 0x00 },
105 { LM3601X_LED_TORCH_REG, 0x00 },
106 };
107
lm3601x_volatile_reg(struct device * dev,unsigned int reg)108 static bool lm3601x_volatile_reg(struct device *dev, unsigned int reg)
109 {
110 switch (reg) {
111 case LM3601X_FLAGS_REG:
112 return true;
113 default:
114 return false;
115 }
116 }
117
118 static const struct regmap_config lm3601x_regmap = {
119 .reg_bits = 8,
120 .val_bits = 8,
121
122 .max_register = LM3601X_DEV_ID_REG,
123 .reg_defaults = lm3601x_regmap_defs,
124 .num_reg_defaults = ARRAY_SIZE(lm3601x_regmap_defs),
125 .cache_type = REGCACHE_MAPLE,
126 .volatile_reg = lm3601x_volatile_reg,
127 };
128
fled_cdev_to_led(struct led_classdev_flash * fled_cdev)129 static struct lm3601x_led *fled_cdev_to_led(struct led_classdev_flash *fled_cdev)
130 {
131 return container_of(fled_cdev, struct lm3601x_led, fled_cdev);
132 }
133
lm3601x_read_faults(struct lm3601x_led * led)134 static int lm3601x_read_faults(struct lm3601x_led *led)
135 {
136 int flags_val;
137 int ret;
138
139 ret = regmap_read(led->regmap, LM3601X_FLAGS_REG, &flags_val);
140 if (ret < 0)
141 return -EIO;
142
143 led->last_flag = 0;
144
145 if (flags_val & LM36010_OVP_FAULT)
146 led->last_flag |= LED_FAULT_OVER_VOLTAGE;
147
148 if (flags_val & (LM3601X_THERM_SHUTDOWN | LM3601X_THERM_CURR))
149 led->last_flag |= LED_FAULT_OVER_TEMPERATURE;
150
151 if (flags_val & LM3601X_SHORT_FAULT)
152 led->last_flag |= LED_FAULT_SHORT_CIRCUIT;
153
154 if (flags_val & LM36010_CURR_LIMIT)
155 led->last_flag |= LED_FAULT_OVER_CURRENT;
156
157 if (flags_val & LM3601X_UVLO_FAULT)
158 led->last_flag |= LED_FAULT_UNDER_VOLTAGE;
159
160 if (flags_val & LM3601X_IVFM_TRIP)
161 led->last_flag |= LED_FAULT_INPUT_VOLTAGE;
162
163 if (flags_val & LM3601X_THERM_SHUTDOWN)
164 led->last_flag |= LED_FAULT_LED_OVER_TEMPERATURE;
165
166 return led->last_flag;
167 }
168
lm3601x_brightness_set(struct led_classdev * cdev,enum led_brightness brightness)169 static int lm3601x_brightness_set(struct led_classdev *cdev,
170 enum led_brightness brightness)
171 {
172 struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(cdev);
173 struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
174 int ret, led_mode_val;
175
176 mutex_lock(&led->lock);
177
178 ret = lm3601x_read_faults(led);
179 if (ret < 0)
180 goto out;
181
182 if (led->led_mode == LM3601X_LED_TORCH)
183 led_mode_val = LM3601X_MODE_TORCH;
184 else
185 led_mode_val = LM3601X_MODE_IR_DRV;
186
187 if (brightness == LED_OFF) {
188 ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
189 led_mode_val, LED_OFF);
190 goto out;
191 }
192
193 ret = regmap_write(led->regmap, LM3601X_LED_TORCH_REG, brightness - 1);
194 if (ret < 0)
195 goto out;
196
197 ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
198 LM3601X_MODE_TORCH | LM3601X_MODE_IR_DRV,
199 led_mode_val);
200 out:
201 mutex_unlock(&led->lock);
202 return ret;
203 }
204
lm3601x_strobe_set(struct led_classdev_flash * fled_cdev,bool state)205 static int lm3601x_strobe_set(struct led_classdev_flash *fled_cdev,
206 bool state)
207 {
208 struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
209 int timeout_reg_val;
210 int current_timeout;
211 int ret;
212
213 mutex_lock(&led->lock);
214
215 ret = regmap_read(led->regmap, LM3601X_CFG_REG, ¤t_timeout);
216 if (ret < 0)
217 goto out;
218
219 if (led->flash_timeout >= LM3601X_TIMEOUT_XOVER_US)
220 timeout_reg_val = led->flash_timeout / LM3601X_UPPER_STEP_US + 0x07;
221 else
222 timeout_reg_val = led->flash_timeout / LM3601X_LOWER_STEP_US - 0x01;
223
224 if (led->flash_timeout != current_timeout)
225 ret = regmap_update_bits(led->regmap, LM3601X_CFG_REG,
226 LM3601X_TIMEOUT_MASK, timeout_reg_val);
227
228 if (state)
229 ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
230 LM3601X_MODE_TORCH | LM3601X_MODE_IR_DRV,
231 LM3601X_MODE_STROBE);
232 else
233 ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
234 LM3601X_MODE_STROBE, LED_OFF);
235
236 ret = lm3601x_read_faults(led);
237 out:
238 mutex_unlock(&led->lock);
239 return ret;
240 }
241
lm3601x_flash_brightness_set(struct led_classdev_flash * fled_cdev,u32 brightness)242 static int lm3601x_flash_brightness_set(struct led_classdev_flash *fled_cdev,
243 u32 brightness)
244 {
245 struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
246 u8 brightness_val;
247 int ret;
248
249 mutex_lock(&led->lock);
250 ret = lm3601x_read_faults(led);
251 if (ret < 0)
252 goto out;
253
254 if (brightness == LED_OFF) {
255 ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
256 LM3601X_MODE_STROBE, LED_OFF);
257 goto out;
258 }
259
260 brightness_val = brightness / LM3601X_STROBE_REG_DIV;
261
262 ret = regmap_write(led->regmap, LM3601X_LED_FLASH_REG, brightness_val);
263 out:
264 mutex_unlock(&led->lock);
265 return ret;
266 }
267
lm3601x_flash_timeout_set(struct led_classdev_flash * fled_cdev,u32 timeout)268 static int lm3601x_flash_timeout_set(struct led_classdev_flash *fled_cdev,
269 u32 timeout)
270 {
271 struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
272
273 mutex_lock(&led->lock);
274
275 led->flash_timeout = timeout;
276
277 mutex_unlock(&led->lock);
278
279 return 0;
280 }
281
lm3601x_strobe_get(struct led_classdev_flash * fled_cdev,bool * state)282 static int lm3601x_strobe_get(struct led_classdev_flash *fled_cdev, bool *state)
283 {
284 struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
285 int strobe_state;
286 int ret;
287
288 mutex_lock(&led->lock);
289
290 ret = regmap_read(led->regmap, LM3601X_ENABLE_REG, &strobe_state);
291 if (ret < 0)
292 goto out;
293
294 *state = strobe_state & LM3601X_MODE_STROBE;
295
296 out:
297 mutex_unlock(&led->lock);
298 return ret;
299 }
300
lm3601x_flash_fault_get(struct led_classdev_flash * fled_cdev,u32 * fault)301 static int lm3601x_flash_fault_get(struct led_classdev_flash *fled_cdev,
302 u32 *fault)
303 {
304 struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
305
306 lm3601x_read_faults(led);
307
308 *fault = led->last_flag;
309
310 return 0;
311 }
312
313 static const struct led_flash_ops flash_ops = {
314 .flash_brightness_set = lm3601x_flash_brightness_set,
315 .strobe_set = lm3601x_strobe_set,
316 .strobe_get = lm3601x_strobe_get,
317 .timeout_set = lm3601x_flash_timeout_set,
318 .fault_get = lm3601x_flash_fault_get,
319 };
320
lm3601x_register_leds(struct lm3601x_led * led,struct fwnode_handle * fwnode)321 static int lm3601x_register_leds(struct lm3601x_led *led,
322 struct fwnode_handle *fwnode)
323 {
324 struct led_classdev *led_cdev;
325 struct led_flash_setting *setting;
326 struct led_init_data init_data = {};
327
328 led->fled_cdev.ops = &flash_ops;
329
330 setting = &led->fled_cdev.timeout;
331 setting->min = LM3601X_MIN_TIMEOUT_US;
332 setting->max = led->max_flash_timeout;
333 setting->step = LM3601X_LOWER_STEP_US;
334 setting->val = led->max_flash_timeout;
335
336 setting = &led->fled_cdev.brightness;
337 setting->min = LM3601X_MIN_STROBE_I_UA;
338 setting->max = led->flash_current_max;
339 setting->step = LM3601X_TORCH_REG_DIV;
340 setting->val = led->flash_current_max;
341
342 led_cdev = &led->fled_cdev.led_cdev;
343 led_cdev->brightness_set_blocking = lm3601x_brightness_set;
344 led_cdev->max_brightness =
345 DIV_ROUND_UP(led->torch_current_max - LM3601X_MIN_TORCH_I_UA + 1,
346 LM3601X_TORCH_REG_DIV);
347 led_cdev->flags |= LED_DEV_CAP_FLASH;
348
349 init_data.fwnode = fwnode;
350 init_data.devicename = led->client->name;
351 init_data.default_label = (led->led_mode == LM3601X_LED_TORCH) ?
352 "torch" : "infrared";
353 return devm_led_classdev_flash_register_ext(&led->client->dev,
354 &led->fled_cdev, &init_data);
355 }
356
lm3601x_parse_node(struct lm3601x_led * led,struct fwnode_handle ** fwnode)357 static int lm3601x_parse_node(struct lm3601x_led *led,
358 struct fwnode_handle **fwnode)
359 {
360 struct fwnode_handle *child = NULL;
361 int ret = -ENODEV;
362
363 child = device_get_next_child_node(&led->client->dev, child);
364 if (!child) {
365 dev_err(&led->client->dev, "No LED Child node\n");
366 return ret;
367 }
368
369 ret = fwnode_property_read_u32(child, "reg", &led->led_mode);
370 if (ret) {
371 dev_err(&led->client->dev, "reg DT property missing\n");
372 goto out_err;
373 }
374
375 if (led->led_mode > LM3601X_LED_TORCH ||
376 led->led_mode < LM3601X_LED_IR) {
377 dev_warn(&led->client->dev, "Invalid led mode requested\n");
378 ret = -EINVAL;
379 goto out_err;
380 }
381
382 ret = fwnode_property_read_u32(child, "led-max-microamp",
383 &led->torch_current_max);
384 if (ret) {
385 dev_warn(&led->client->dev,
386 "led-max-microamp DT property missing\n");
387 goto out_err;
388 }
389
390 if (led->torch_current_max > LM3601X_MAX_TORCH_I_UA) {
391 dev_warn(&led->client->dev,
392 "Max torch current set too high (%d vs %d)\n",
393 led->torch_current_max,
394 LM3601X_MAX_TORCH_I_UA);
395 led->torch_current_max = LM3601X_MAX_TORCH_I_UA;
396 }
397
398 ret = fwnode_property_read_u32(child, "flash-max-microamp",
399 &led->flash_current_max);
400 if (ret) {
401 dev_warn(&led->client->dev,
402 "flash-max-microamp DT property missing\n");
403 goto out_err;
404 }
405
406 ret = fwnode_property_read_u32(child, "flash-max-timeout-us",
407 &led->max_flash_timeout);
408 if (ret) {
409 dev_warn(&led->client->dev,
410 "flash-max-timeout-us DT property missing\n");
411 goto out_err;
412 }
413
414 *fwnode = child;
415
416 out_err:
417 fwnode_handle_put(child);
418 return ret;
419 }
420
lm3601x_probe(struct i2c_client * client)421 static int lm3601x_probe(struct i2c_client *client)
422 {
423 struct lm3601x_led *led;
424 struct fwnode_handle *fwnode;
425 int ret;
426
427 led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
428 if (!led)
429 return -ENOMEM;
430
431 led->client = client;
432 i2c_set_clientdata(client, led);
433
434 ret = lm3601x_parse_node(led, &fwnode);
435 if (ret)
436 return -ENODEV;
437
438 led->regmap = devm_regmap_init_i2c(client, &lm3601x_regmap);
439 if (IS_ERR(led->regmap)) {
440 ret = PTR_ERR(led->regmap);
441 dev_err(&client->dev,
442 "Failed to allocate register map: %d\n", ret);
443 return ret;
444 }
445
446 ret = regmap_write(led->regmap, LM3601X_DEV_ID_REG, LM3601X_SW_RESET);
447 if (ret)
448 dev_warn(&client->dev, "Failed to reset the LED controller\n");
449
450 mutex_init(&led->lock);
451
452 return lm3601x_register_leds(led, fwnode);
453 }
454
lm3601x_remove(struct i2c_client * client)455 static void lm3601x_remove(struct i2c_client *client)
456 {
457 struct lm3601x_led *led = i2c_get_clientdata(client);
458 int ret;
459
460 ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
461 LM3601X_ENABLE_MASK, LM3601X_MODE_STANDBY);
462 if (ret)
463 dev_warn(&client->dev,
464 "Failed to put into standby (%pe)\n", ERR_PTR(ret));
465 }
466
467 static const struct i2c_device_id lm3601x_id[] = {
468 { "LM36010", CHIP_LM36010 },
469 { "LM36011", CHIP_LM36011 },
470 { }
471 };
472 MODULE_DEVICE_TABLE(i2c, lm3601x_id);
473
474 static const struct of_device_id of_lm3601x_leds_match[] = {
475 { .compatible = "ti,lm36010", },
476 { .compatible = "ti,lm36011", },
477 { }
478 };
479 MODULE_DEVICE_TABLE(of, of_lm3601x_leds_match);
480
481 static struct i2c_driver lm3601x_i2c_driver = {
482 .driver = {
483 .name = "lm3601x",
484 .of_match_table = of_lm3601x_leds_match,
485 },
486 .probe = lm3601x_probe,
487 .remove = lm3601x_remove,
488 .id_table = lm3601x_id,
489 };
490 module_i2c_driver(lm3601x_i2c_driver);
491
492 MODULE_DESCRIPTION("Texas Instruments Flash Lighting driver for LM3601X");
493 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
494 MODULE_LICENSE("GPL v2");
495