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 scnprintf(buf, PAGE_SIZE, "%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 scnprintf(buf, PAGE_SIZE, "%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, j = 0;
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 			j++;
205 		}
206 
207 		led->mc_cdev.subled_info = mc_led_info;
208 	} else {
209 		led->cdev.brightness_set_blocking = lp55xx_set_brightness;
210 	}
211 
212 	led->cdev.groups = lp55xx_led_groups;
213 	led->cdev.default_trigger = pdata->led_config[chan].default_trigger;
214 	led->led_current = pdata->led_config[chan].led_current;
215 	led->max_current = pdata->led_config[chan].max_current;
216 	led->chan_nr = pdata->led_config[chan].chan_nr;
217 
218 	if (led->chan_nr >= max_channel) {
219 		dev_err(dev, "Use channel numbers between 0 and %d\n",
220 			max_channel - 1);
221 		return -EINVAL;
222 	}
223 
224 	if (pdata->led_config[chan].num_colors > 1)
225 		ret = devm_led_classdev_multicolor_register(dev, &led->mc_cdev);
226 	else
227 		ret = devm_led_classdev_register(dev, &led->cdev);
228 
229 	if (ret) {
230 		dev_err(dev, "led register err: %d\n", ret);
231 		return ret;
232 	}
233 
234 	return 0;
235 }
236 
237 static void lp55xx_firmware_loaded(const struct firmware *fw, void *context)
238 {
239 	struct lp55xx_chip *chip = context;
240 	struct device *dev = &chip->cl->dev;
241 	enum lp55xx_engine_index idx = chip->engine_idx;
242 
243 	if (!fw) {
244 		dev_err(dev, "firmware request failed\n");
245 		return;
246 	}
247 
248 	/* handling firmware data is chip dependent */
249 	mutex_lock(&chip->lock);
250 
251 	chip->engines[idx - 1].mode = LP55XX_ENGINE_LOAD;
252 	chip->fw = fw;
253 	if (chip->cfg->firmware_cb)
254 		chip->cfg->firmware_cb(chip);
255 
256 	mutex_unlock(&chip->lock);
257 
258 	/* firmware should be released for other channel use */
259 	release_firmware(chip->fw);
260 	chip->fw = NULL;
261 }
262 
263 static int lp55xx_request_firmware(struct lp55xx_chip *chip)
264 {
265 	const char *name = chip->cl->name;
266 	struct device *dev = &chip->cl->dev;
267 
268 	return request_firmware_nowait(THIS_MODULE, false, name, dev,
269 				GFP_KERNEL, chip, lp55xx_firmware_loaded);
270 }
271 
272 static ssize_t select_engine_show(struct device *dev,
273 			    struct device_attribute *attr,
274 			    char *buf)
275 {
276 	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
277 	struct lp55xx_chip *chip = led->chip;
278 
279 	return sprintf(buf, "%d\n", chip->engine_idx);
280 }
281 
282 static ssize_t select_engine_store(struct device *dev,
283 			     struct device_attribute *attr,
284 			     const char *buf, size_t len)
285 {
286 	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
287 	struct lp55xx_chip *chip = led->chip;
288 	unsigned long val;
289 	int ret;
290 
291 	if (kstrtoul(buf, 0, &val))
292 		return -EINVAL;
293 
294 	/* select the engine to be run */
295 
296 	switch (val) {
297 	case LP55XX_ENGINE_1:
298 	case LP55XX_ENGINE_2:
299 	case LP55XX_ENGINE_3:
300 		mutex_lock(&chip->lock);
301 		chip->engine_idx = val;
302 		ret = lp55xx_request_firmware(chip);
303 		mutex_unlock(&chip->lock);
304 		break;
305 	default:
306 		dev_err(dev, "%lu: invalid engine index. (1, 2, 3)\n", val);
307 		return -EINVAL;
308 	}
309 
310 	if (ret) {
311 		dev_err(dev, "request firmware err: %d\n", ret);
312 		return ret;
313 	}
314 
315 	return len;
316 }
317 
318 static inline void lp55xx_run_engine(struct lp55xx_chip *chip, bool start)
319 {
320 	if (chip->cfg->run_engine)
321 		chip->cfg->run_engine(chip, start);
322 }
323 
324 static ssize_t run_engine_store(struct device *dev,
325 			     struct device_attribute *attr,
326 			     const char *buf, size_t len)
327 {
328 	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
329 	struct lp55xx_chip *chip = led->chip;
330 	unsigned long val;
331 
332 	if (kstrtoul(buf, 0, &val))
333 		return -EINVAL;
334 
335 	/* run or stop the selected engine */
336 
337 	if (val <= 0) {
338 		lp55xx_run_engine(chip, false);
339 		return len;
340 	}
341 
342 	mutex_lock(&chip->lock);
343 	lp55xx_run_engine(chip, true);
344 	mutex_unlock(&chip->lock);
345 
346 	return len;
347 }
348 
349 static DEVICE_ATTR_RW(select_engine);
350 static DEVICE_ATTR_WO(run_engine);
351 
352 static struct attribute *lp55xx_engine_attributes[] = {
353 	&dev_attr_select_engine.attr,
354 	&dev_attr_run_engine.attr,
355 	NULL,
356 };
357 
358 static const struct attribute_group lp55xx_engine_attr_group = {
359 	.attrs = lp55xx_engine_attributes,
360 };
361 
362 int lp55xx_write(struct lp55xx_chip *chip, u8 reg, u8 val)
363 {
364 	return i2c_smbus_write_byte_data(chip->cl, reg, val);
365 }
366 EXPORT_SYMBOL_GPL(lp55xx_write);
367 
368 int lp55xx_read(struct lp55xx_chip *chip, u8 reg, u8 *val)
369 {
370 	s32 ret;
371 
372 	ret = i2c_smbus_read_byte_data(chip->cl, reg);
373 	if (ret < 0)
374 		return ret;
375 
376 	*val = ret;
377 	return 0;
378 }
379 EXPORT_SYMBOL_GPL(lp55xx_read);
380 
381 int lp55xx_update_bits(struct lp55xx_chip *chip, u8 reg, u8 mask, u8 val)
382 {
383 	int ret;
384 	u8 tmp;
385 
386 	ret = lp55xx_read(chip, reg, &tmp);
387 	if (ret)
388 		return ret;
389 
390 	tmp &= ~mask;
391 	tmp |= val & mask;
392 
393 	return lp55xx_write(chip, reg, tmp);
394 }
395 EXPORT_SYMBOL_GPL(lp55xx_update_bits);
396 
397 bool lp55xx_is_extclk_used(struct lp55xx_chip *chip)
398 {
399 	struct clk *clk;
400 	int err;
401 
402 	clk = devm_clk_get(&chip->cl->dev, "32k_clk");
403 	if (IS_ERR(clk))
404 		goto use_internal_clk;
405 
406 	err = clk_prepare_enable(clk);
407 	if (err)
408 		goto use_internal_clk;
409 
410 	if (clk_get_rate(clk) != LP55XX_CLK_32K) {
411 		clk_disable_unprepare(clk);
412 		goto use_internal_clk;
413 	}
414 
415 	dev_info(&chip->cl->dev, "%dHz external clock used\n",	LP55XX_CLK_32K);
416 
417 	chip->clk = clk;
418 	return true;
419 
420 use_internal_clk:
421 	dev_info(&chip->cl->dev, "internal clock used\n");
422 	return false;
423 }
424 EXPORT_SYMBOL_GPL(lp55xx_is_extclk_used);
425 
426 int lp55xx_init_device(struct lp55xx_chip *chip)
427 {
428 	struct lp55xx_platform_data *pdata;
429 	struct lp55xx_device_config *cfg;
430 	struct device *dev = &chip->cl->dev;
431 	int ret = 0;
432 
433 	WARN_ON(!chip);
434 
435 	pdata = chip->pdata;
436 	cfg = chip->cfg;
437 
438 	if (!pdata || !cfg)
439 		return -EINVAL;
440 
441 	if (pdata->enable_gpiod) {
442 		gpiod_set_consumer_name(pdata->enable_gpiod, "LP55xx enable");
443 		gpiod_set_value(pdata->enable_gpiod, 0);
444 		usleep_range(1000, 2000); /* Keep enable down at least 1ms */
445 		gpiod_set_value(pdata->enable_gpiod, 1);
446 		usleep_range(1000, 2000); /* 500us abs min. */
447 	}
448 
449 	lp55xx_reset_device(chip);
450 
451 	/*
452 	 * Exact value is not available. 10 - 20ms
453 	 * appears to be enough for reset.
454 	 */
455 	usleep_range(10000, 20000);
456 
457 	ret = lp55xx_detect_device(chip);
458 	if (ret) {
459 		dev_err(dev, "device detection err: %d\n", ret);
460 		goto err;
461 	}
462 
463 	/* chip specific initialization */
464 	ret = lp55xx_post_init_device(chip);
465 	if (ret) {
466 		dev_err(dev, "post init device err: %d\n", ret);
467 		goto err_post_init;
468 	}
469 
470 	return 0;
471 
472 err_post_init:
473 	lp55xx_deinit_device(chip);
474 err:
475 	return ret;
476 }
477 EXPORT_SYMBOL_GPL(lp55xx_init_device);
478 
479 void lp55xx_deinit_device(struct lp55xx_chip *chip)
480 {
481 	struct lp55xx_platform_data *pdata = chip->pdata;
482 
483 	if (chip->clk)
484 		clk_disable_unprepare(chip->clk);
485 
486 	if (pdata->enable_gpiod)
487 		gpiod_set_value(pdata->enable_gpiod, 0);
488 }
489 EXPORT_SYMBOL_GPL(lp55xx_deinit_device);
490 
491 int lp55xx_register_leds(struct lp55xx_led *led, struct lp55xx_chip *chip)
492 {
493 	struct lp55xx_platform_data *pdata = chip->pdata;
494 	struct lp55xx_device_config *cfg = chip->cfg;
495 	int num_channels = pdata->num_channels;
496 	struct lp55xx_led *each;
497 	u8 led_current;
498 	int ret;
499 	int i;
500 
501 	if (!cfg->brightness_fn) {
502 		dev_err(&chip->cl->dev, "empty brightness configuration\n");
503 		return -EINVAL;
504 	}
505 
506 	for (i = 0; i < num_channels; i++) {
507 
508 		/* do not initialize channels that are not connected */
509 		if (pdata->led_config[i].led_current == 0)
510 			continue;
511 
512 		led_current = pdata->led_config[i].led_current;
513 		each = led + i;
514 		ret = lp55xx_init_led(each, chip, i);
515 		if (ret)
516 			goto err_init_led;
517 
518 		chip->num_leds++;
519 		each->chip = chip;
520 
521 		/* setting led current at each channel */
522 		if (cfg->set_led_current)
523 			cfg->set_led_current(each, led_current);
524 	}
525 
526 	return 0;
527 
528 err_init_led:
529 	return ret;
530 }
531 EXPORT_SYMBOL_GPL(lp55xx_register_leds);
532 
533 int lp55xx_register_sysfs(struct lp55xx_chip *chip)
534 {
535 	struct device *dev = &chip->cl->dev;
536 	struct lp55xx_device_config *cfg = chip->cfg;
537 	int ret;
538 
539 	if (!cfg->run_engine || !cfg->firmware_cb)
540 		goto dev_specific_attrs;
541 
542 	ret = sysfs_create_group(&dev->kobj, &lp55xx_engine_attr_group);
543 	if (ret)
544 		return ret;
545 
546 dev_specific_attrs:
547 	return cfg->dev_attr_group ?
548 		sysfs_create_group(&dev->kobj, cfg->dev_attr_group) : 0;
549 }
550 EXPORT_SYMBOL_GPL(lp55xx_register_sysfs);
551 
552 void lp55xx_unregister_sysfs(struct lp55xx_chip *chip)
553 {
554 	struct device *dev = &chip->cl->dev;
555 	struct lp55xx_device_config *cfg = chip->cfg;
556 
557 	if (cfg->dev_attr_group)
558 		sysfs_remove_group(&dev->kobj, cfg->dev_attr_group);
559 
560 	sysfs_remove_group(&dev->kobj, &lp55xx_engine_attr_group);
561 }
562 EXPORT_SYMBOL_GPL(lp55xx_unregister_sysfs);
563 
564 static int lp55xx_parse_common_child(struct device_node *np,
565 				     struct lp55xx_led_config *cfg,
566 				     int led_number, int *chan_nr)
567 {
568 	int ret;
569 
570 	of_property_read_string(np, "chan-name",
571 				&cfg[led_number].name);
572 	of_property_read_u8(np, "led-cur",
573 			    &cfg[led_number].led_current);
574 	of_property_read_u8(np, "max-cur",
575 			    &cfg[led_number].max_current);
576 
577 	ret = of_property_read_u32(np, "reg", chan_nr);
578 	if (ret)
579 		return ret;
580 
581 	if (*chan_nr < 0 || *chan_nr > cfg->max_channel)
582 		return -EINVAL;
583 
584 	return 0;
585 }
586 
587 static int lp55xx_parse_multi_led_child(struct device_node *child,
588 					 struct lp55xx_led_config *cfg,
589 					 int child_number, int color_number)
590 {
591 	int chan_nr, color_id, ret;
592 
593 	ret = lp55xx_parse_common_child(child, cfg, child_number, &chan_nr);
594 	if (ret)
595 		return ret;
596 
597 	ret = of_property_read_u32(child, "color", &color_id);
598 	if (ret)
599 		return ret;
600 
601 	cfg[child_number].color_id[color_number] = color_id;
602 	cfg[child_number].output_num[color_number] = chan_nr;
603 
604 	return 0;
605 }
606 
607 static int lp55xx_parse_multi_led(struct device_node *np,
608 				  struct lp55xx_led_config *cfg,
609 				  int child_number)
610 {
611 	struct device_node *child;
612 	int num_colors = 0, ret;
613 
614 	for_each_available_child_of_node(np, child) {
615 		ret = lp55xx_parse_multi_led_child(child, cfg, child_number,
616 						   num_colors);
617 		if (ret) {
618 			of_node_put(child);
619 			return ret;
620 		}
621 		num_colors++;
622 	}
623 
624 	cfg[child_number].num_colors = num_colors;
625 
626 	return 0;
627 }
628 
629 static int lp55xx_parse_logical_led(struct device_node *np,
630 				   struct lp55xx_led_config *cfg,
631 				   int child_number)
632 {
633 	int led_color, ret;
634 	int chan_nr = 0;
635 
636 	cfg[child_number].default_trigger =
637 		of_get_property(np, "linux,default-trigger", NULL);
638 
639 	ret = of_property_read_u32(np, "color", &led_color);
640 	if (ret)
641 		return ret;
642 
643 	if (led_color == LED_COLOR_ID_RGB)
644 		return lp55xx_parse_multi_led(np, cfg, child_number);
645 
646 	ret =  lp55xx_parse_common_child(np, cfg, child_number, &chan_nr);
647 	if (ret < 0)
648 		return ret;
649 
650 	cfg[child_number].chan_nr = chan_nr;
651 
652 	return ret;
653 }
654 
655 struct lp55xx_platform_data *lp55xx_of_populate_pdata(struct device *dev,
656 						      struct device_node *np,
657 						      struct lp55xx_chip *chip)
658 {
659 	struct device_node *child;
660 	struct lp55xx_platform_data *pdata;
661 	struct lp55xx_led_config *cfg;
662 	int num_channels;
663 	int i = 0;
664 	int ret;
665 
666 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
667 	if (!pdata)
668 		return ERR_PTR(-ENOMEM);
669 
670 	num_channels = of_get_available_child_count(np);
671 	if (num_channels == 0) {
672 		dev_err(dev, "no LED channels\n");
673 		return ERR_PTR(-EINVAL);
674 	}
675 
676 	cfg = devm_kcalloc(dev, num_channels, sizeof(*cfg), GFP_KERNEL);
677 	if (!cfg)
678 		return ERR_PTR(-ENOMEM);
679 
680 	pdata->led_config = &cfg[0];
681 	pdata->num_channels = num_channels;
682 	cfg->max_channel = chip->cfg->max_channel;
683 
684 	for_each_available_child_of_node(np, child) {
685 		ret = lp55xx_parse_logical_led(child, cfg, i);
686 		if (ret) {
687 			of_node_put(child);
688 			return ERR_PTR(-EINVAL);
689 		}
690 		i++;
691 	}
692 
693 	of_property_read_string(np, "label", &pdata->label);
694 	of_property_read_u8(np, "clock-mode", &pdata->clock_mode);
695 
696 	pdata->enable_gpiod = devm_gpiod_get_optional(dev, "enable",
697 						      GPIOD_OUT_LOW);
698 	if (IS_ERR(pdata->enable_gpiod))
699 		return ERR_CAST(pdata->enable_gpiod);
700 
701 	/* LP8501 specific */
702 	of_property_read_u8(np, "pwr-sel", (u8 *)&pdata->pwr_sel);
703 
704 	return pdata;
705 }
706 EXPORT_SYMBOL_GPL(lp55xx_of_populate_pdata);
707 
708 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
709 MODULE_DESCRIPTION("LP55xx Common Driver");
710 MODULE_LICENSE("GPL");
711