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, &current_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 	mutex_destroy(&led->lock);
448 
449 	return regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
450 			   LM3601X_ENABLE_MASK,
451 			   LM3601X_MODE_STANDBY);
452 }
453 
454 static const struct i2c_device_id lm3601x_id[] = {
455 	{ "LM36010", CHIP_LM36010 },
456 	{ "LM36011", CHIP_LM36011 },
457 	{ }
458 };
459 MODULE_DEVICE_TABLE(i2c, lm3601x_id);
460 
461 static const struct of_device_id of_lm3601x_leds_match[] = {
462 	{ .compatible = "ti,lm36010", },
463 	{ .compatible = "ti,lm36011", },
464 	{ }
465 };
466 MODULE_DEVICE_TABLE(of, of_lm3601x_leds_match);
467 
468 static struct i2c_driver lm3601x_i2c_driver = {
469 	.driver = {
470 		.name = "lm3601x",
471 		.of_match_table = of_lm3601x_leds_match,
472 	},
473 	.probe_new = lm3601x_probe,
474 	.remove = lm3601x_remove,
475 	.id_table = lm3601x_id,
476 };
477 module_i2c_driver(lm3601x_i2c_driver);
478 
479 MODULE_DESCRIPTION("Texas Instruments Flash Lighting driver for LM3601X");
480 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
481 MODULE_LICENSE("GPL v2");
482