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 -
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 * @led_name: LED label for the Torch or IR LED
79 * @flash_timeout: the timeout for the flash
80 * @last_flag: last known flags register value
81 * @torch_current_max: maximum current for the torch
82 * @flash_current_max: maximum current for the flash
83 * @max_flash_timeout: maximum timeout for the flash
84 * @led_mode: The mode to enable either IR or Torch
85 */
86 struct lm3601x_led {
87 struct led_classdev_flash fled_cdev;
88 struct i2c_client *client;
89 struct regmap *regmap;
90 struct mutex lock;
91
92 unsigned int flash_timeout;
93 unsigned int last_flag;
94
95 u32 torch_current_max;
96 u32 flash_current_max;
97 u32 max_flash_timeout;
98
99 u32 led_mode;
100 };
101
102 static const struct reg_default lm3601x_regmap_defs[] = {
103 { LM3601X_ENABLE_REG, 0x20 },
104 { LM3601X_CFG_REG, 0x15 },
105 { LM3601X_LED_FLASH_REG, 0x00 },
106 { LM3601X_LED_TORCH_REG, 0x00 },
107 };
108
lm3601x_volatile_reg(struct device * dev,unsigned int reg)109 static bool lm3601x_volatile_reg(struct device *dev, unsigned int reg)
110 {
111 switch (reg) {
112 case LM3601X_FLAGS_REG:
113 return true;
114 default:
115 return false;
116 }
117 }
118
119 static const struct regmap_config lm3601x_regmap = {
120 .reg_bits = 8,
121 .val_bits = 8,
122
123 .max_register = LM3601X_DEV_ID_REG,
124 .reg_defaults = lm3601x_regmap_defs,
125 .num_reg_defaults = ARRAY_SIZE(lm3601x_regmap_defs),
126 .cache_type = REGCACHE_RBTREE,
127 .volatile_reg = lm3601x_volatile_reg,
128 };
129
fled_cdev_to_led(struct led_classdev_flash * fled_cdev)130 static struct lm3601x_led *fled_cdev_to_led(struct led_classdev_flash *fled_cdev)
131 {
132 return container_of(fled_cdev, struct lm3601x_led, fled_cdev);
133 }
134
lm3601x_read_faults(struct lm3601x_led * led)135 static int lm3601x_read_faults(struct lm3601x_led *led)
136 {
137 int flags_val;
138 int ret;
139
140 ret = regmap_read(led->regmap, LM3601X_FLAGS_REG, &flags_val);
141 if (ret < 0)
142 return -EIO;
143
144 led->last_flag = 0;
145
146 if (flags_val & LM36010_OVP_FAULT)
147 led->last_flag |= LED_FAULT_OVER_VOLTAGE;
148
149 if (flags_val & (LM3601X_THERM_SHUTDOWN | LM3601X_THERM_CURR))
150 led->last_flag |= LED_FAULT_OVER_TEMPERATURE;
151
152 if (flags_val & LM3601X_SHORT_FAULT)
153 led->last_flag |= LED_FAULT_SHORT_CIRCUIT;
154
155 if (flags_val & LM36010_CURR_LIMIT)
156 led->last_flag |= LED_FAULT_OVER_CURRENT;
157
158 if (flags_val & LM3601X_UVLO_FAULT)
159 led->last_flag |= LED_FAULT_UNDER_VOLTAGE;
160
161 if (flags_val & LM3601X_IVFM_TRIP)
162 led->last_flag |= LED_FAULT_INPUT_VOLTAGE;
163
164 if (flags_val & LM3601X_THERM_SHUTDOWN)
165 led->last_flag |= LED_FAULT_LED_OVER_TEMPERATURE;
166
167 return led->last_flag;
168 }
169
lm3601x_brightness_set(struct led_classdev * cdev,enum led_brightness brightness)170 static int lm3601x_brightness_set(struct led_classdev *cdev,
171 enum led_brightness brightness)
172 {
173 struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(cdev);
174 struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
175 int ret, led_mode_val;
176
177 mutex_lock(&led->lock);
178
179 ret = lm3601x_read_faults(led);
180 if (ret < 0)
181 goto out;
182
183 if (led->led_mode == LM3601X_LED_TORCH)
184 led_mode_val = LM3601X_MODE_TORCH;
185 else
186 led_mode_val = LM3601X_MODE_IR_DRV;
187
188 if (brightness == LED_OFF) {
189 ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
190 led_mode_val, LED_OFF);
191 goto out;
192 }
193
194 ret = regmap_write(led->regmap, LM3601X_LED_TORCH_REG, brightness);
195 if (ret < 0)
196 goto out;
197
198 ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
199 LM3601X_MODE_TORCH | LM3601X_MODE_IR_DRV,
200 led_mode_val);
201 out:
202 mutex_unlock(&led->lock);
203 return ret;
204 }
205
lm3601x_strobe_set(struct led_classdev_flash * fled_cdev,bool state)206 static int lm3601x_strobe_set(struct led_classdev_flash *fled_cdev,
207 bool state)
208 {
209 struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
210 int timeout_reg_val;
211 int current_timeout;
212 int ret;
213
214 mutex_lock(&led->lock);
215
216 ret = regmap_read(led->regmap, LM3601X_CFG_REG, ¤t_timeout);
217 if (ret < 0)
218 goto out;
219
220 if (led->flash_timeout >= LM3601X_TIMEOUT_XOVER_US)
221 timeout_reg_val = led->flash_timeout / LM3601X_UPPER_STEP_US + 0x07;
222 else
223 timeout_reg_val = led->flash_timeout / LM3601X_LOWER_STEP_US - 0x01;
224
225 if (led->flash_timeout != current_timeout)
226 ret = regmap_update_bits(led->regmap, LM3601X_CFG_REG,
227 LM3601X_TIMEOUT_MASK, timeout_reg_val);
228
229 if (state)
230 ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
231 LM3601X_MODE_TORCH | LM3601X_MODE_IR_DRV,
232 LM3601X_MODE_STROBE);
233 else
234 ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
235 LM3601X_MODE_STROBE, LED_OFF);
236
237 ret = lm3601x_read_faults(led);
238 out:
239 mutex_unlock(&led->lock);
240 return ret;
241 }
242
lm3601x_flash_brightness_set(struct led_classdev_flash * fled_cdev,u32 brightness)243 static int lm3601x_flash_brightness_set(struct led_classdev_flash *fled_cdev,
244 u32 brightness)
245 {
246 struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
247 u8 brightness_val;
248 int ret;
249
250 mutex_lock(&led->lock);
251 ret = lm3601x_read_faults(led);
252 if (ret < 0)
253 goto out;
254
255 if (brightness == LED_OFF) {
256 ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
257 LM3601X_MODE_STROBE, LED_OFF);
258 goto out;
259 }
260
261 brightness_val = brightness / LM3601X_STROBE_REG_DIV;
262
263 ret = regmap_write(led->regmap, LM3601X_LED_FLASH_REG, brightness_val);
264 out:
265 mutex_unlock(&led->lock);
266 return ret;
267 }
268
lm3601x_flash_timeout_set(struct led_classdev_flash * fled_cdev,u32 timeout)269 static int lm3601x_flash_timeout_set(struct led_classdev_flash *fled_cdev,
270 u32 timeout)
271 {
272 struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
273
274 mutex_lock(&led->lock);
275
276 led->flash_timeout = timeout;
277
278 mutex_unlock(&led->lock);
279
280 return 0;
281 }
282
lm3601x_strobe_get(struct led_classdev_flash * fled_cdev,bool * state)283 static int lm3601x_strobe_get(struct led_classdev_flash *fled_cdev, bool *state)
284 {
285 struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
286 int strobe_state;
287 int ret;
288
289 mutex_lock(&led->lock);
290
291 ret = regmap_read(led->regmap, LM3601X_ENABLE_REG, &strobe_state);
292 if (ret < 0)
293 goto out;
294
295 *state = strobe_state & LM3601X_MODE_STROBE;
296
297 out:
298 mutex_unlock(&led->lock);
299 return ret;
300 }
301
lm3601x_flash_fault_get(struct led_classdev_flash * fled_cdev,u32 * fault)302 static int lm3601x_flash_fault_get(struct led_classdev_flash *fled_cdev,
303 u32 *fault)
304 {
305 struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
306
307 lm3601x_read_faults(led);
308
309 *fault = led->last_flag;
310
311 return 0;
312 }
313
314 static const struct led_flash_ops flash_ops = {
315 .flash_brightness_set = lm3601x_flash_brightness_set,
316 .strobe_set = lm3601x_strobe_set,
317 .strobe_get = lm3601x_strobe_get,
318 .timeout_set = lm3601x_flash_timeout_set,
319 .fault_get = lm3601x_flash_fault_get,
320 };
321
lm3601x_register_leds(struct lm3601x_led * led,struct fwnode_handle * fwnode)322 static int lm3601x_register_leds(struct lm3601x_led *led,
323 struct fwnode_handle *fwnode)
324 {
325 struct led_classdev *led_cdev;
326 struct led_flash_setting *setting;
327 struct led_init_data init_data = {};
328
329 led->fled_cdev.ops = &flash_ops;
330
331 setting = &led->fled_cdev.timeout;
332 setting->min = LM3601X_MIN_TIMEOUT_US;
333 setting->max = led->max_flash_timeout;
334 setting->step = LM3601X_LOWER_STEP_US;
335 setting->val = led->max_flash_timeout;
336
337 setting = &led->fled_cdev.brightness;
338 setting->min = LM3601X_MIN_STROBE_I_UA;
339 setting->max = led->flash_current_max;
340 setting->step = LM3601X_TORCH_REG_DIV;
341 setting->val = led->flash_current_max;
342
343 led_cdev = &led->fled_cdev.led_cdev;
344 led_cdev->brightness_set_blocking = lm3601x_brightness_set;
345 led_cdev->max_brightness = DIV_ROUND_UP(led->torch_current_max,
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 ret = fwnode_property_read_u32(child, "flash-max-microamp",
391 &led->flash_current_max);
392 if (ret) {
393 dev_warn(&led->client->dev,
394 "flash-max-microamp DT property missing\n");
395 goto out_err;
396 }
397
398 ret = fwnode_property_read_u32(child, "flash-max-timeout-us",
399 &led->max_flash_timeout);
400 if (ret) {
401 dev_warn(&led->client->dev,
402 "flash-max-timeout-us DT property missing\n");
403 goto out_err;
404 }
405
406 *fwnode = child;
407
408 out_err:
409 fwnode_handle_put(child);
410 return ret;
411 }
412
lm3601x_probe(struct i2c_client * client)413 static int lm3601x_probe(struct i2c_client *client)
414 {
415 struct lm3601x_led *led;
416 struct fwnode_handle *fwnode;
417 int ret;
418
419 led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
420 if (!led)
421 return -ENOMEM;
422
423 led->client = client;
424 i2c_set_clientdata(client, led);
425
426 ret = lm3601x_parse_node(led, &fwnode);
427 if (ret)
428 return -ENODEV;
429
430 led->regmap = devm_regmap_init_i2c(client, &lm3601x_regmap);
431 if (IS_ERR(led->regmap)) {
432 ret = PTR_ERR(led->regmap);
433 dev_err(&client->dev,
434 "Failed to allocate register map: %d\n", ret);
435 return ret;
436 }
437
438 mutex_init(&led->lock);
439
440 return lm3601x_register_leds(led, fwnode);
441 }
442
lm3601x_remove(struct i2c_client * client)443 static int lm3601x_remove(struct i2c_client *client)
444 {
445 struct lm3601x_led *led = i2c_get_clientdata(client);
446
447 return regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
448 LM3601X_ENABLE_MASK,
449 LM3601X_MODE_STANDBY);
450 }
451
452 static const struct i2c_device_id lm3601x_id[] = {
453 { "LM36010", CHIP_LM36010 },
454 { "LM36011", CHIP_LM36011 },
455 { }
456 };
457 MODULE_DEVICE_TABLE(i2c, lm3601x_id);
458
459 static const struct of_device_id of_lm3601x_leds_match[] = {
460 { .compatible = "ti,lm36010", },
461 { .compatible = "ti,lm36011", },
462 { }
463 };
464 MODULE_DEVICE_TABLE(of, of_lm3601x_leds_match);
465
466 static struct i2c_driver lm3601x_i2c_driver = {
467 .driver = {
468 .name = "lm3601x",
469 .of_match_table = of_lm3601x_leds_match,
470 },
471 .probe_new = lm3601x_probe,
472 .remove = lm3601x_remove,
473 .id_table = lm3601x_id,
474 };
475 module_i2c_driver(lm3601x_i2c_driver);
476
477 MODULE_DESCRIPTION("Texas Instruments Flash Lighting driver for LM3601X");
478 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
479 MODULE_LICENSE("GPL v2");
480