1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * LP5521/LP5523/LP55231/LP5562 Common Driver
4  *
5  * Copyright 2012 Texas Instruments
6  *
7  * Author: Milo(Woogyom) Kim <milo.kim@ti.com>
8  *
9  * Derived from leds-lp5521.c, leds-lp5523.c
10  */
11 
12 #include <linux/clk.h>
13 #include <linux/delay.h>
14 #include <linux/firmware.h>
15 #include <linux/i2c.h>
16 #include <linux/leds.h>
17 #include <linux/module.h>
18 #include <linux/platform_data/leds-lp55xx.h>
19 #include <linux/slab.h>
20 #include <linux/gpio/consumer.h>
21 
22 #include "leds-lp55xx-common.h"
23 
24 /* External clock rate */
25 #define LP55XX_CLK_32K			32768
26 
27 static struct lp55xx_led *cdev_to_lp55xx_led(struct led_classdev *cdev)
28 {
29 	return container_of(cdev, struct lp55xx_led, cdev);
30 }
31 
32 static struct lp55xx_led *dev_to_lp55xx_led(struct device *dev)
33 {
34 	return cdev_to_lp55xx_led(dev_get_drvdata(dev));
35 }
36 
37 static struct lp55xx_led *mcled_cdev_to_led(struct led_classdev_mc *mc_cdev)
38 {
39 	return container_of(mc_cdev, struct lp55xx_led, mc_cdev);
40 }
41 
42 static void lp55xx_reset_device(struct lp55xx_chip *chip)
43 {
44 	struct lp55xx_device_config *cfg = chip->cfg;
45 	u8 addr = cfg->reset.addr;
46 	u8 val  = cfg->reset.val;
47 
48 	/* no error checking here because no ACK from the device after reset */
49 	lp55xx_write(chip, addr, val);
50 }
51 
52 static int lp55xx_detect_device(struct lp55xx_chip *chip)
53 {
54 	struct lp55xx_device_config *cfg = chip->cfg;
55 	u8 addr = cfg->enable.addr;
56 	u8 val  = cfg->enable.val;
57 	int ret;
58 
59 	ret = lp55xx_write(chip, addr, val);
60 	if (ret)
61 		return ret;
62 
63 	usleep_range(1000, 2000);
64 
65 	ret = lp55xx_read(chip, addr, &val);
66 	if (ret)
67 		return ret;
68 
69 	if (val != cfg->enable.val)
70 		return -ENODEV;
71 
72 	return 0;
73 }
74 
75 static int lp55xx_post_init_device(struct lp55xx_chip *chip)
76 {
77 	struct lp55xx_device_config *cfg = chip->cfg;
78 
79 	if (!cfg->post_init_device)
80 		return 0;
81 
82 	return cfg->post_init_device(chip);
83 }
84 
85 static ssize_t led_current_show(struct device *dev,
86 			    struct device_attribute *attr,
87 			    char *buf)
88 {
89 	struct lp55xx_led *led = dev_to_lp55xx_led(dev);
90 
91 	return sysfs_emit(buf, "%d\n", led->led_current);
92 }
93 
94 static ssize_t led_current_store(struct device *dev,
95 			     struct device_attribute *attr,
96 			     const char *buf, size_t len)
97 {
98 	struct lp55xx_led *led = dev_to_lp55xx_led(dev);
99 	struct lp55xx_chip *chip = led->chip;
100 	unsigned long curr;
101 
102 	if (kstrtoul(buf, 0, &curr))
103 		return -EINVAL;
104 
105 	if (curr > led->max_current)
106 		return -EINVAL;
107 
108 	if (!chip->cfg->set_led_current)
109 		return len;
110 
111 	mutex_lock(&chip->lock);
112 	chip->cfg->set_led_current(led, (u8)curr);
113 	mutex_unlock(&chip->lock);
114 
115 	return len;
116 }
117 
118 static ssize_t max_current_show(struct device *dev,
119 			    struct device_attribute *attr,
120 			    char *buf)
121 {
122 	struct lp55xx_led *led = dev_to_lp55xx_led(dev);
123 
124 	return sysfs_emit(buf, "%d\n", led->max_current);
125 }
126 
127 static DEVICE_ATTR_RW(led_current);
128 static DEVICE_ATTR_RO(max_current);
129 
130 static struct attribute *lp55xx_led_attrs[] = {
131 	&dev_attr_led_current.attr,
132 	&dev_attr_max_current.attr,
133 	NULL,
134 };
135 ATTRIBUTE_GROUPS(lp55xx_led);
136 
137 static int lp55xx_set_mc_brightness(struct led_classdev *cdev,
138 				    enum led_brightness brightness)
139 {
140 	struct led_classdev_mc *mc_dev = lcdev_to_mccdev(cdev);
141 	struct lp55xx_led *led = mcled_cdev_to_led(mc_dev);
142 	struct lp55xx_device_config *cfg = led->chip->cfg;
143 
144 	led_mc_calc_color_components(&led->mc_cdev, brightness);
145 	return cfg->multicolor_brightness_fn(led);
146 
147 }
148 
149 static int lp55xx_set_brightness(struct led_classdev *cdev,
150 			     enum led_brightness brightness)
151 {
152 	struct lp55xx_led *led = cdev_to_lp55xx_led(cdev);
153 	struct lp55xx_device_config *cfg = led->chip->cfg;
154 
155 	led->brightness = (u8)brightness;
156 	return cfg->brightness_fn(led);
157 }
158 
159 static int lp55xx_init_led(struct lp55xx_led *led,
160 			struct lp55xx_chip *chip, int chan)
161 {
162 	struct lp55xx_platform_data *pdata = chip->pdata;
163 	struct lp55xx_device_config *cfg = chip->cfg;
164 	struct device *dev = &chip->cl->dev;
165 	int max_channel = cfg->max_channel;
166 	struct mc_subled *mc_led_info;
167 	struct led_classdev *led_cdev;
168 	char name[32];
169 	int i;
170 	int ret;
171 
172 	if (chan >= max_channel) {
173 		dev_err(dev, "invalid channel: %d / %d\n", chan, max_channel);
174 		return -EINVAL;
175 	}
176 
177 	if (pdata->led_config[chan].led_current == 0)
178 		return 0;
179 
180 	if (pdata->led_config[chan].name) {
181 		led->cdev.name = pdata->led_config[chan].name;
182 	} else {
183 		snprintf(name, sizeof(name), "%s:channel%d",
184 			pdata->label ? : chip->cl->name, chan);
185 		led->cdev.name = name;
186 	}
187 
188 	if (pdata->led_config[chan].num_colors > 1) {
189 		mc_led_info = devm_kcalloc(dev,
190 					   pdata->led_config[chan].num_colors,
191 					   sizeof(*mc_led_info), GFP_KERNEL);
192 		if (!mc_led_info)
193 			return -ENOMEM;
194 
195 		led_cdev = &led->mc_cdev.led_cdev;
196 		led_cdev->name = led->cdev.name;
197 		led_cdev->brightness_set_blocking = lp55xx_set_mc_brightness;
198 		led->mc_cdev.num_colors = pdata->led_config[chan].num_colors;
199 		for (i = 0; i < led->mc_cdev.num_colors; i++) {
200 			mc_led_info[i].color_index =
201 				pdata->led_config[chan].color_id[i];
202 			mc_led_info[i].channel =
203 					pdata->led_config[chan].output_num[i];
204 		}
205 
206 		led->mc_cdev.subled_info = mc_led_info;
207 	} else {
208 		led->cdev.brightness_set_blocking = lp55xx_set_brightness;
209 	}
210 
211 	led->cdev.groups = lp55xx_led_groups;
212 	led->cdev.default_trigger = pdata->led_config[chan].default_trigger;
213 	led->led_current = pdata->led_config[chan].led_current;
214 	led->max_current = pdata->led_config[chan].max_current;
215 	led->chan_nr = pdata->led_config[chan].chan_nr;
216 
217 	if (led->chan_nr >= max_channel) {
218 		dev_err(dev, "Use channel numbers between 0 and %d\n",
219 			max_channel - 1);
220 		return -EINVAL;
221 	}
222 
223 	if (pdata->led_config[chan].num_colors > 1)
224 		ret = devm_led_classdev_multicolor_register(dev, &led->mc_cdev);
225 	else
226 		ret = devm_led_classdev_register(dev, &led->cdev);
227 
228 	if (ret) {
229 		dev_err(dev, "led register err: %d\n", ret);
230 		return ret;
231 	}
232 
233 	return 0;
234 }
235 
236 static void lp55xx_firmware_loaded(const struct firmware *fw, void *context)
237 {
238 	struct lp55xx_chip *chip = context;
239 	struct device *dev = &chip->cl->dev;
240 	enum lp55xx_engine_index idx = chip->engine_idx;
241 
242 	if (!fw) {
243 		dev_err(dev, "firmware request failed\n");
244 		return;
245 	}
246 
247 	/* handling firmware data is chip dependent */
248 	mutex_lock(&chip->lock);
249 
250 	chip->engines[idx - 1].mode = LP55XX_ENGINE_LOAD;
251 	chip->fw = fw;
252 	if (chip->cfg->firmware_cb)
253 		chip->cfg->firmware_cb(chip);
254 
255 	mutex_unlock(&chip->lock);
256 
257 	/* firmware should be released for other channel use */
258 	release_firmware(chip->fw);
259 	chip->fw = NULL;
260 }
261 
262 static int lp55xx_request_firmware(struct lp55xx_chip *chip)
263 {
264 	const char *name = chip->cl->name;
265 	struct device *dev = &chip->cl->dev;
266 
267 	return request_firmware_nowait(THIS_MODULE, false, name, dev,
268 				GFP_KERNEL, chip, lp55xx_firmware_loaded);
269 }
270 
271 static ssize_t select_engine_show(struct device *dev,
272 			    struct device_attribute *attr,
273 			    char *buf)
274 {
275 	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
276 	struct lp55xx_chip *chip = led->chip;
277 
278 	return sprintf(buf, "%d\n", chip->engine_idx);
279 }
280 
281 static ssize_t select_engine_store(struct device *dev,
282 			     struct device_attribute *attr,
283 			     const char *buf, size_t len)
284 {
285 	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
286 	struct lp55xx_chip *chip = led->chip;
287 	unsigned long val;
288 	int ret;
289 
290 	if (kstrtoul(buf, 0, &val))
291 		return -EINVAL;
292 
293 	/* select the engine to be run */
294 
295 	switch (val) {
296 	case LP55XX_ENGINE_1:
297 	case LP55XX_ENGINE_2:
298 	case LP55XX_ENGINE_3:
299 		mutex_lock(&chip->lock);
300 		chip->engine_idx = val;
301 		ret = lp55xx_request_firmware(chip);
302 		mutex_unlock(&chip->lock);
303 		break;
304 	default:
305 		dev_err(dev, "%lu: invalid engine index. (1, 2, 3)\n", val);
306 		return -EINVAL;
307 	}
308 
309 	if (ret) {
310 		dev_err(dev, "request firmware err: %d\n", ret);
311 		return ret;
312 	}
313 
314 	return len;
315 }
316 
317 static inline void lp55xx_run_engine(struct lp55xx_chip *chip, bool start)
318 {
319 	if (chip->cfg->run_engine)
320 		chip->cfg->run_engine(chip, start);
321 }
322 
323 static ssize_t run_engine_store(struct device *dev,
324 			     struct device_attribute *attr,
325 			     const char *buf, size_t len)
326 {
327 	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
328 	struct lp55xx_chip *chip = led->chip;
329 	unsigned long val;
330 
331 	if (kstrtoul(buf, 0, &val))
332 		return -EINVAL;
333 
334 	/* run or stop the selected engine */
335 
336 	if (val <= 0) {
337 		lp55xx_run_engine(chip, false);
338 		return len;
339 	}
340 
341 	mutex_lock(&chip->lock);
342 	lp55xx_run_engine(chip, true);
343 	mutex_unlock(&chip->lock);
344 
345 	return len;
346 }
347 
348 static DEVICE_ATTR_RW(select_engine);
349 static DEVICE_ATTR_WO(run_engine);
350 
351 static struct attribute *lp55xx_engine_attributes[] = {
352 	&dev_attr_select_engine.attr,
353 	&dev_attr_run_engine.attr,
354 	NULL,
355 };
356 
357 static const struct attribute_group lp55xx_engine_attr_group = {
358 	.attrs = lp55xx_engine_attributes,
359 };
360 
361 int lp55xx_write(struct lp55xx_chip *chip, u8 reg, u8 val)
362 {
363 	return i2c_smbus_write_byte_data(chip->cl, reg, val);
364 }
365 EXPORT_SYMBOL_GPL(lp55xx_write);
366 
367 int lp55xx_read(struct lp55xx_chip *chip, u8 reg, u8 *val)
368 {
369 	s32 ret;
370 
371 	ret = i2c_smbus_read_byte_data(chip->cl, reg);
372 	if (ret < 0)
373 		return ret;
374 
375 	*val = ret;
376 	return 0;
377 }
378 EXPORT_SYMBOL_GPL(lp55xx_read);
379 
380 int lp55xx_update_bits(struct lp55xx_chip *chip, u8 reg, u8 mask, u8 val)
381 {
382 	int ret;
383 	u8 tmp;
384 
385 	ret = lp55xx_read(chip, reg, &tmp);
386 	if (ret)
387 		return ret;
388 
389 	tmp &= ~mask;
390 	tmp |= val & mask;
391 
392 	return lp55xx_write(chip, reg, tmp);
393 }
394 EXPORT_SYMBOL_GPL(lp55xx_update_bits);
395 
396 bool lp55xx_is_extclk_used(struct lp55xx_chip *chip)
397 {
398 	struct clk *clk;
399 	int err;
400 
401 	clk = devm_clk_get(&chip->cl->dev, "32k_clk");
402 	if (IS_ERR(clk))
403 		goto use_internal_clk;
404 
405 	err = clk_prepare_enable(clk);
406 	if (err)
407 		goto use_internal_clk;
408 
409 	if (clk_get_rate(clk) != LP55XX_CLK_32K) {
410 		clk_disable_unprepare(clk);
411 		goto use_internal_clk;
412 	}
413 
414 	dev_info(&chip->cl->dev, "%dHz external clock used\n",	LP55XX_CLK_32K);
415 
416 	chip->clk = clk;
417 	return true;
418 
419 use_internal_clk:
420 	dev_info(&chip->cl->dev, "internal clock used\n");
421 	return false;
422 }
423 EXPORT_SYMBOL_GPL(lp55xx_is_extclk_used);
424 
425 int lp55xx_init_device(struct lp55xx_chip *chip)
426 {
427 	struct lp55xx_platform_data *pdata;
428 	struct lp55xx_device_config *cfg;
429 	struct device *dev = &chip->cl->dev;
430 	int ret = 0;
431 
432 	WARN_ON(!chip);
433 
434 	pdata = chip->pdata;
435 	cfg = chip->cfg;
436 
437 	if (!pdata || !cfg)
438 		return -EINVAL;
439 
440 	if (pdata->enable_gpiod) {
441 		gpiod_direction_output(pdata->enable_gpiod, 0);
442 
443 		gpiod_set_consumer_name(pdata->enable_gpiod, "LP55xx enable");
444 		gpiod_set_value(pdata->enable_gpiod, 0);
445 		usleep_range(1000, 2000); /* Keep enable down at least 1ms */
446 		gpiod_set_value(pdata->enable_gpiod, 1);
447 		usleep_range(1000, 2000); /* 500us abs min. */
448 	}
449 
450 	lp55xx_reset_device(chip);
451 
452 	/*
453 	 * Exact value is not available. 10 - 20ms
454 	 * appears to be enough for reset.
455 	 */
456 	usleep_range(10000, 20000);
457 
458 	ret = lp55xx_detect_device(chip);
459 	if (ret) {
460 		dev_err(dev, "device detection err: %d\n", ret);
461 		goto err;
462 	}
463 
464 	/* chip specific initialization */
465 	ret = lp55xx_post_init_device(chip);
466 	if (ret) {
467 		dev_err(dev, "post init device err: %d\n", ret);
468 		goto err_post_init;
469 	}
470 
471 	return 0;
472 
473 err_post_init:
474 	lp55xx_deinit_device(chip);
475 err:
476 	return ret;
477 }
478 EXPORT_SYMBOL_GPL(lp55xx_init_device);
479 
480 void lp55xx_deinit_device(struct lp55xx_chip *chip)
481 {
482 	struct lp55xx_platform_data *pdata = chip->pdata;
483 
484 	if (chip->clk)
485 		clk_disable_unprepare(chip->clk);
486 
487 	if (pdata->enable_gpiod)
488 		gpiod_set_value(pdata->enable_gpiod, 0);
489 }
490 EXPORT_SYMBOL_GPL(lp55xx_deinit_device);
491 
492 int lp55xx_register_leds(struct lp55xx_led *led, struct lp55xx_chip *chip)
493 {
494 	struct lp55xx_platform_data *pdata = chip->pdata;
495 	struct lp55xx_device_config *cfg = chip->cfg;
496 	int num_channels = pdata->num_channels;
497 	struct lp55xx_led *each;
498 	u8 led_current;
499 	int ret;
500 	int i;
501 
502 	if (!cfg->brightness_fn) {
503 		dev_err(&chip->cl->dev, "empty brightness configuration\n");
504 		return -EINVAL;
505 	}
506 
507 	for (i = 0; i < num_channels; i++) {
508 
509 		/* do not initialize channels that are not connected */
510 		if (pdata->led_config[i].led_current == 0)
511 			continue;
512 
513 		led_current = pdata->led_config[i].led_current;
514 		each = led + i;
515 		ret = lp55xx_init_led(each, chip, i);
516 		if (ret)
517 			goto err_init_led;
518 
519 		chip->num_leds++;
520 		each->chip = chip;
521 
522 		/* setting led current at each channel */
523 		if (cfg->set_led_current)
524 			cfg->set_led_current(each, led_current);
525 	}
526 
527 	return 0;
528 
529 err_init_led:
530 	return ret;
531 }
532 EXPORT_SYMBOL_GPL(lp55xx_register_leds);
533 
534 int lp55xx_register_sysfs(struct lp55xx_chip *chip)
535 {
536 	struct device *dev = &chip->cl->dev;
537 	struct lp55xx_device_config *cfg = chip->cfg;
538 	int ret;
539 
540 	if (!cfg->run_engine || !cfg->firmware_cb)
541 		goto dev_specific_attrs;
542 
543 	ret = sysfs_create_group(&dev->kobj, &lp55xx_engine_attr_group);
544 	if (ret)
545 		return ret;
546 
547 dev_specific_attrs:
548 	return cfg->dev_attr_group ?
549 		sysfs_create_group(&dev->kobj, cfg->dev_attr_group) : 0;
550 }
551 EXPORT_SYMBOL_GPL(lp55xx_register_sysfs);
552 
553 void lp55xx_unregister_sysfs(struct lp55xx_chip *chip)
554 {
555 	struct device *dev = &chip->cl->dev;
556 	struct lp55xx_device_config *cfg = chip->cfg;
557 
558 	if (cfg->dev_attr_group)
559 		sysfs_remove_group(&dev->kobj, cfg->dev_attr_group);
560 
561 	sysfs_remove_group(&dev->kobj, &lp55xx_engine_attr_group);
562 }
563 EXPORT_SYMBOL_GPL(lp55xx_unregister_sysfs);
564 
565 static int lp55xx_parse_common_child(struct device_node *np,
566 				     struct lp55xx_led_config *cfg,
567 				     int led_number, int *chan_nr)
568 {
569 	int ret;
570 
571 	of_property_read_string(np, "chan-name",
572 				&cfg[led_number].name);
573 	of_property_read_u8(np, "led-cur",
574 			    &cfg[led_number].led_current);
575 	of_property_read_u8(np, "max-cur",
576 			    &cfg[led_number].max_current);
577 
578 	ret = of_property_read_u32(np, "reg", chan_nr);
579 	if (ret)
580 		return ret;
581 
582 	if (*chan_nr < 0 || *chan_nr > cfg->max_channel)
583 		return -EINVAL;
584 
585 	return 0;
586 }
587 
588 static int lp55xx_parse_multi_led_child(struct device_node *child,
589 					 struct lp55xx_led_config *cfg,
590 					 int child_number, int color_number)
591 {
592 	int chan_nr, color_id, ret;
593 
594 	ret = lp55xx_parse_common_child(child, cfg, child_number, &chan_nr);
595 	if (ret)
596 		return ret;
597 
598 	ret = of_property_read_u32(child, "color", &color_id);
599 	if (ret)
600 		return ret;
601 
602 	cfg[child_number].color_id[color_number] = color_id;
603 	cfg[child_number].output_num[color_number] = chan_nr;
604 
605 	return 0;
606 }
607 
608 static int lp55xx_parse_multi_led(struct device_node *np,
609 				  struct lp55xx_led_config *cfg,
610 				  int child_number)
611 {
612 	struct device_node *child;
613 	int num_colors = 0, ret;
614 
615 	for_each_available_child_of_node(np, child) {
616 		ret = lp55xx_parse_multi_led_child(child, cfg, child_number,
617 						   num_colors);
618 		if (ret) {
619 			of_node_put(child);
620 			return ret;
621 		}
622 		num_colors++;
623 	}
624 
625 	cfg[child_number].num_colors = num_colors;
626 
627 	return 0;
628 }
629 
630 static int lp55xx_parse_logical_led(struct device_node *np,
631 				   struct lp55xx_led_config *cfg,
632 				   int child_number)
633 {
634 	int led_color, ret;
635 	int chan_nr = 0;
636 
637 	cfg[child_number].default_trigger =
638 		of_get_property(np, "linux,default-trigger", NULL);
639 
640 	ret = of_property_read_u32(np, "color", &led_color);
641 	if (ret)
642 		return ret;
643 
644 	if (led_color == LED_COLOR_ID_RGB)
645 		return lp55xx_parse_multi_led(np, cfg, child_number);
646 
647 	ret =  lp55xx_parse_common_child(np, cfg, child_number, &chan_nr);
648 	if (ret < 0)
649 		return ret;
650 
651 	cfg[child_number].chan_nr = chan_nr;
652 
653 	return ret;
654 }
655 
656 struct lp55xx_platform_data *lp55xx_of_populate_pdata(struct device *dev,
657 						      struct device_node *np,
658 						      struct lp55xx_chip *chip)
659 {
660 	struct device_node *child;
661 	struct lp55xx_platform_data *pdata;
662 	struct lp55xx_led_config *cfg;
663 	int num_channels;
664 	int i = 0;
665 	int ret;
666 
667 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
668 	if (!pdata)
669 		return ERR_PTR(-ENOMEM);
670 
671 	num_channels = of_get_available_child_count(np);
672 	if (num_channels == 0) {
673 		dev_err(dev, "no LED channels\n");
674 		return ERR_PTR(-EINVAL);
675 	}
676 
677 	cfg = devm_kcalloc(dev, num_channels, sizeof(*cfg), GFP_KERNEL);
678 	if (!cfg)
679 		return ERR_PTR(-ENOMEM);
680 
681 	pdata->led_config = &cfg[0];
682 	pdata->num_channels = num_channels;
683 	cfg->max_channel = chip->cfg->max_channel;
684 
685 	for_each_available_child_of_node(np, child) {
686 		ret = lp55xx_parse_logical_led(child, cfg, i);
687 		if (ret) {
688 			of_node_put(child);
689 			return ERR_PTR(-EINVAL);
690 		}
691 		i++;
692 	}
693 
694 	of_property_read_string(np, "label", &pdata->label);
695 	of_property_read_u8(np, "clock-mode", &pdata->clock_mode);
696 
697 	pdata->enable_gpiod = devm_gpiod_get_optional(dev, "enable",
698 						      GPIOD_ASIS);
699 	if (IS_ERR(pdata->enable_gpiod))
700 		return ERR_CAST(pdata->enable_gpiod);
701 
702 	/* LP8501 specific */
703 	of_property_read_u8(np, "pwr-sel", (u8 *)&pdata->pwr_sel);
704 
705 	return pdata;
706 }
707 EXPORT_SYMBOL_GPL(lp55xx_of_populate_pdata);
708 
709 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
710 MODULE_DESCRIPTION("LP55xx Common Driver");
711 MODULE_LICENSE("GPL");
712