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