leds-ktd202x.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Kinetic KTD2026/7 RGB/White LED driver with I2C interface
  4 *
  5 * Copyright 2023 André Apitzsch <git@apitzsch.eu>
  6 *
  7 * Datasheet: https://www.kinet-ic.com/uploads/KTD2026-7-04h.pdf
  8 */
  9
 10#include <linux/i2c.h>
 11#include <linux/led-class-multicolor.h>
 12#include <linux/module.h>
 13#include <linux/mutex.h>
 14#include <linux/of.h>
 15#include <linux/of_device.h>
 16#include <linux/regmap.h>
 17#include <linux/regulator/consumer.h>
 18
 19#define KTD2026_NUM_LEDS 3
 20#define KTD2027_NUM_LEDS 4
 21#define KTD202X_MAX_LEDS 4
 22
 23/* Register bank */
 24#define KTD202X_REG_RESET_CONTROL	0x00
 25#define KTD202X_REG_FLASH_PERIOD	0x01
 26#define KTD202X_REG_PWM1_TIMER		0x02
 27#define KTD202X_REG_PWM2_TIMER		0x03
 28#define KTD202X_REG_CHANNEL_CTRL	0x04
 29#define KTD202X_REG_TRISE_FALL		0x05
 30#define KTD202X_REG_LED_IOUT(x)		(0x06 + (x))
 31
 32/* Register 0 */
 33#define KTD202X_TIMER_SLOT_CONTROL_TSLOT1	0x00
 34#define KTD202X_TIMER_SLOT_CONTROL_TSLOT2	0x01
 35#define KTD202X_TIMER_SLOT_CONTROL_TSLOT3	0x02
 36#define KTD202X_TIMER_SLOT_CONTROL_TSLOT4	0x03
 37#define KTD202X_RSTR_RESET			0x07
 38
 39#define KTD202X_ENABLE_CTRL_WAKE	0x00 /* SCL High & SDA High */
 40#define KTD202X_ENABLE_CTRL_SLEEP	0x08 /* SCL High & SDA Toggling */
 41
 42#define KTD202X_TRISE_FALL_SCALE_NORMAL		0x00
 43#define KTD202X_TRISE_FALL_SCALE_SLOW_X2	0x20
 44#define KTD202X_TRISE_FALL_SCALE_SLOW_X4	0x40
 45#define KTD202X_TRISE_FALL_SCALE_FAST_X8	0x60
 46
 47/* Register 1 */
 48#define KTD202X_FLASH_PERIOD_256_MS_LOG_RAMP	0x00
 49
 50/* Register 2-3 */
 51#define KTD202X_FLASH_ON_TIME_0_4_PERCENT	0x01
 52
 53/* Register 4 */
 54#define KTD202X_CHANNEL_CTRL_MASK(x) (BIT(2 * (x)) | BIT(2 * (x) + 1))
 55#define KTD202X_CHANNEL_CTRL_OFF 0x00
 56#define KTD202X_CHANNEL_CTRL_ON(x) BIT(2 * (x))
 57#define KTD202X_CHANNEL_CTRL_PWM1(x) BIT(2 * (x) + 1)
 58#define KTD202X_CHANNEL_CTRL_PWM2(x) (BIT(2 * (x)) | BIT(2 * (x) + 1))
 59
 60/* Register 5 */
 61#define KTD202X_RAMP_TIMES_2_MS			0x00
 62
 63/* Register 6-9 */
 64#define KTD202X_LED_CURRENT_10_mA		0x4f
 65
 66#define KTD202X_FLASH_PERIOD_MIN_MS 256
 67#define KTD202X_FLASH_PERIOD_STEP_MS 128
 68#define KTD202X_FLASH_PERIOD_MAX_STEPS 126
 69#define KTD202X_FLASH_ON_MAX 256
 70
 71#define KTD202X_MAX_BRIGHTNESS 192
 72
 73static const struct reg_default ktd202x_reg_defaults[] = {
 74	{ KTD202X_REG_RESET_CONTROL, KTD202X_TIMER_SLOT_CONTROL_TSLOT1 |
 75		KTD202X_ENABLE_CTRL_WAKE | KTD202X_TRISE_FALL_SCALE_NORMAL },
 76	{ KTD202X_REG_FLASH_PERIOD, KTD202X_FLASH_PERIOD_256_MS_LOG_RAMP },
 77	{ KTD202X_REG_PWM1_TIMER, KTD202X_FLASH_ON_TIME_0_4_PERCENT },
 78	{ KTD202X_REG_PWM2_TIMER, KTD202X_FLASH_ON_TIME_0_4_PERCENT },
 79	{ KTD202X_REG_CHANNEL_CTRL, KTD202X_CHANNEL_CTRL_OFF },
 80	{ KTD202X_REG_TRISE_FALL, KTD202X_RAMP_TIMES_2_MS },
 81	{ KTD202X_REG_LED_IOUT(0), KTD202X_LED_CURRENT_10_mA },
 82	{ KTD202X_REG_LED_IOUT(1), KTD202X_LED_CURRENT_10_mA },
 83	{ KTD202X_REG_LED_IOUT(2), KTD202X_LED_CURRENT_10_mA },
 84	{ KTD202X_REG_LED_IOUT(3), KTD202X_LED_CURRENT_10_mA },
 85};
 86
 87struct ktd202x_led {
 88	struct ktd202x *chip;
 89	union {
 90		struct led_classdev cdev;
 91		struct led_classdev_mc mcdev;
 92	};
 93	u32 index;
 94};
 95
 96struct ktd202x {
 97	struct mutex mutex;
 98	struct regulator_bulk_data regulators[2];
 99	struct device *dev;
100	struct regmap *regmap;
101	bool enabled;
102	unsigned long num_leds;
103	struct ktd202x_led leds[] __counted_by(num_leds);
104};
105
106static int ktd202x_chip_disable(struct ktd202x *chip)
107{
108	int ret;
109
110	if (!chip->enabled)
111		return 0;
112
113	regmap_write(chip->regmap, KTD202X_REG_RESET_CONTROL, KTD202X_ENABLE_CTRL_SLEEP);
114
115	ret = regulator_bulk_disable(ARRAY_SIZE(chip->regulators), chip->regulators);
116	if (ret) {
117		dev_err(chip->dev, "Failed to disable regulators: %d\n", ret);
118		return ret;
119	}
120
121	chip->enabled = false;
122	return 0;
123}
124
125static int ktd202x_chip_enable(struct ktd202x *chip)
126{
127	int ret;
128
129	if (chip->enabled)
130		return 0;
131
132	ret = regulator_bulk_enable(ARRAY_SIZE(chip->regulators), chip->regulators);
133	if (ret) {
134		dev_err(chip->dev, "Failed to enable regulators: %d\n", ret);
135		return ret;
136	}
137	chip->enabled = true;
138
139	ret = regmap_write(chip->regmap, KTD202X_REG_RESET_CONTROL, KTD202X_ENABLE_CTRL_WAKE);
140
141	if (ret) {
142		dev_err(chip->dev, "Failed to enable the chip: %d\n", ret);
143		ktd202x_chip_disable(chip);
144	}
145
146	return ret;
147}
148
149static bool ktd202x_chip_in_use(struct ktd202x *chip)
150{
151	int i;
152
153	for (i = 0; i < chip->num_leds; i++) {
154		if (chip->leds[i].cdev.brightness)
155			return true;
156	}
157
158	return false;
159}
160
161static int ktd202x_brightness_set(struct ktd202x_led *led,
162				  struct mc_subled *subleds,
163				  unsigned int num_channels)
164{
165	bool mode_blink = false;
166	int channel;
167	int state;
168	int ret;
169	int i;
170
171	if (ktd202x_chip_in_use(led->chip)) {
172		ret = ktd202x_chip_enable(led->chip);
173		if (ret)
174			return ret;
175	}
176
177	ret = regmap_read(led->chip->regmap, KTD202X_REG_CHANNEL_CTRL, &state);
178	if (ret)
179		return ret;
180
181	/*
182	 * In multicolor case, assume blink mode if PWM is set for at least one
183	 * channel because another channel cannot be in state ON at the same time
184	 */
185	for (i = 0; i < num_channels; i++) {
186		int channel_state;
187
188		channel = subleds[i].channel;
189		channel_state = (state >> 2 * channel) & KTD202X_CHANNEL_CTRL_MASK(0);
190		if (channel_state == KTD202X_CHANNEL_CTRL_OFF)
191			continue;
192		mode_blink = channel_state == KTD202X_CHANNEL_CTRL_PWM1(0);
193		break;
194	}
195
196	for (i = 0; i < num_channels; i++) {
197		enum led_brightness brightness;
198		int mode;
199
200		brightness = subleds[i].brightness;
201		channel = subleds[i].channel;
202
203		if (brightness) {
204			/* Register expects brightness between 0 and MAX_BRIGHTNESS - 1 */
205			ret = regmap_write(led->chip->regmap, KTD202X_REG_LED_IOUT(channel),
206					   brightness - 1);
207			if (ret)
208				return ret;
209
210			if (mode_blink)
211				mode = KTD202X_CHANNEL_CTRL_PWM1(channel);
212			else
213				mode = KTD202X_CHANNEL_CTRL_ON(channel);
214		} else {
215			mode = KTD202X_CHANNEL_CTRL_OFF;
216		}
217		ret = regmap_update_bits(led->chip->regmap, KTD202X_REG_CHANNEL_CTRL,
218					 KTD202X_CHANNEL_CTRL_MASK(channel), mode);
219		if (ret)
220			return ret;
221	}
222
223	if (!ktd202x_chip_in_use(led->chip))
224		return ktd202x_chip_disable(led->chip);
225
226	return 0;
227}
228
229static int ktd202x_brightness_single_set(struct led_classdev *cdev,
230					 enum led_brightness value)
231{
232	struct ktd202x_led *led = container_of(cdev, struct ktd202x_led, cdev);
233	struct mc_subled info;
234	int ret;
235
236	cdev->brightness = value;
237
238	mutex_lock(&led->chip->mutex);
239
240	info.brightness = value;
241	info.channel = led->index;
242	ret = ktd202x_brightness_set(led, &info, 1);
243
244	mutex_unlock(&led->chip->mutex);
245
246	return ret;
247}
248
249static int ktd202x_brightness_mc_set(struct led_classdev *cdev,
250				     enum led_brightness value)
251{
252	struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
253	struct ktd202x_led *led = container_of(mc, struct ktd202x_led, mcdev);
254	int ret;
255
256	cdev->brightness = value;
257
258	mutex_lock(&led->chip->mutex);
259
260	led_mc_calc_color_components(mc, value);
261	ret = ktd202x_brightness_set(led, mc->subled_info, mc->num_colors);
262
263	mutex_unlock(&led->chip->mutex);
264
265	return ret;
266}
267
268static int ktd202x_blink_set(struct ktd202x_led *led, unsigned long *delay_on,
269			     unsigned long *delay_off, struct mc_subled *subleds,
270			     unsigned int num_channels)
271{
272	unsigned long delay_total_ms;
273	int ret, num_steps, on;
274	u8 ctrl_mask = 0;
275	u8 ctrl_pwm1 = 0;
276	u8 ctrl_on = 0;
277	int i;
278
279	mutex_lock(&led->chip->mutex);
280
281	for (i = 0; i < num_channels; i++) {
282		int channel = subleds[i].channel;
283
284		ctrl_mask |= KTD202X_CHANNEL_CTRL_MASK(channel);
285		ctrl_on |= KTD202X_CHANNEL_CTRL_ON(channel);
286		ctrl_pwm1 |= KTD202X_CHANNEL_CTRL_PWM1(channel);
287	}
288
289	/* Never off - brightness is already set, disable blinking */
290	if (!*delay_off) {
291		ret = regmap_update_bits(led->chip->regmap, KTD202X_REG_CHANNEL_CTRL,
292					 ctrl_mask, ctrl_on);
293		goto out;
294	}
295
296	/* Convert into values the HW will understand. */
297
298	/* Integer representation of time of flash period */
299	num_steps = (*delay_on + *delay_off - KTD202X_FLASH_PERIOD_MIN_MS) /
300		    KTD202X_FLASH_PERIOD_STEP_MS;
301	num_steps = clamp(num_steps, 0, KTD202X_FLASH_PERIOD_MAX_STEPS);
302
303	/* Integer representation of percentage of LED ON time */
304	on = (*delay_on * KTD202X_FLASH_ON_MAX) / (*delay_on + *delay_off);
305
306	/* Actually used delay_{on,off} values */
307	delay_total_ms = num_steps * KTD202X_FLASH_PERIOD_STEP_MS + KTD202X_FLASH_PERIOD_MIN_MS;
308	*delay_on = (delay_total_ms * on) / KTD202X_FLASH_ON_MAX;
309	*delay_off = delay_total_ms - *delay_on;
310
311	/* Set timings */
312	ret = regmap_write(led->chip->regmap, KTD202X_REG_FLASH_PERIOD, num_steps);
313	if (ret)
314		goto out;
315
316	ret = regmap_write(led->chip->regmap, KTD202X_REG_PWM1_TIMER, on);
317	if (ret)
318		goto out;
319
320	ret = regmap_update_bits(led->chip->regmap, KTD202X_REG_CHANNEL_CTRL,
321				 ctrl_mask, ctrl_pwm1);
322out:
323	mutex_unlock(&led->chip->mutex);
324	return ret;
325}
326
327static int ktd202x_blink_single_set(struct led_classdev *cdev,
328				    unsigned long *delay_on,
329				    unsigned long *delay_off)
330{
331	struct ktd202x_led *led = container_of(cdev, struct ktd202x_led, cdev);
332	struct mc_subled info;
333	int ret;
334
335	if (!cdev->brightness) {
336		ret = ktd202x_brightness_single_set(cdev, KTD202X_MAX_BRIGHTNESS);
337		if (ret)
338			return ret;
339	}
340
341	/* If no blink specified, default to 1 Hz. */
342	if (!*delay_off && !*delay_on) {
343		*delay_off = 500;
344		*delay_on = 500;
345	}
346
347	/* Never on - just set to off */
348	if (!*delay_on)
349		return ktd202x_brightness_single_set(cdev, LED_OFF);
350
351	info.channel = led->index;
352
353	return ktd202x_blink_set(led, delay_on, delay_off, &info, 1);
354}
355
356static int ktd202x_blink_mc_set(struct led_classdev *cdev,
357				unsigned long *delay_on,
358				unsigned long *delay_off)
359{
360	struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
361	struct ktd202x_led *led = container_of(mc, struct ktd202x_led, mcdev);
362	int ret;
363
364	if (!cdev->brightness) {
365		ret = ktd202x_brightness_mc_set(cdev, KTD202X_MAX_BRIGHTNESS);
366		if (ret)
367			return ret;
368	}
369
370	/* If no blink specified, default to 1 Hz. */
371	if (!*delay_off && !*delay_on) {
372		*delay_off = 500;
373		*delay_on = 500;
374	}
375
376	/* Never on - just set to off */
377	if (!*delay_on)
378		return ktd202x_brightness_mc_set(cdev, LED_OFF);
379
380	return ktd202x_blink_set(led, delay_on, delay_off, mc->subled_info,
381				 mc->num_colors);
382}
383
384static int ktd202x_setup_led_rgb(struct ktd202x *chip, struct fwnode_handle *fwnode,
385				 struct ktd202x_led *led, struct led_init_data *init_data)
386{
387	struct fwnode_handle *child;
388	struct led_classdev *cdev;
389	struct mc_subled *info;
390	int num_channels;
391	int i = 0;
392
393	num_channels = 0;
394	fwnode_for_each_child_node(fwnode, child)
395		num_channels++;
396
397	if (!num_channels || num_channels > chip->num_leds)
398		return -EINVAL;
399
400	info = devm_kcalloc(chip->dev, num_channels, sizeof(*info), GFP_KERNEL);
401	if (!info)
402		return -ENOMEM;
403
404	fwnode_for_each_child_node(fwnode, child) {
405		u32 mono_color;
406		u32 reg;
407		int ret;
408
409		ret = fwnode_property_read_u32(child, "reg", &reg);
410		if (ret != 0 || reg >= chip->num_leds) {
411			dev_err(chip->dev, "invalid 'reg' of %pfw\n", child);
412			fwnode_handle_put(child);
413			return ret;
414		}
415
416		ret = fwnode_property_read_u32(child, "color", &mono_color);
417		if (ret < 0 && ret != -EINVAL) {
418			dev_err(chip->dev, "failed to parse 'color' of %pfw\n", child);
419			fwnode_handle_put(child);
420			return ret;
421		}
422
423		info[i].color_index = mono_color;
424		info[i].channel = reg;
425		info[i].intensity = KTD202X_MAX_BRIGHTNESS;
426		i++;
427	}
428
429	led->mcdev.subled_info = info;
430	led->mcdev.num_colors = num_channels;
431
432	cdev = &led->mcdev.led_cdev;
433	cdev->brightness_set_blocking = ktd202x_brightness_mc_set;
434	cdev->blink_set = ktd202x_blink_mc_set;
435
436	return devm_led_classdev_multicolor_register_ext(chip->dev, &led->mcdev, init_data);
437}
438
439static int ktd202x_setup_led_single(struct ktd202x *chip, struct fwnode_handle *fwnode,
440				    struct ktd202x_led *led, struct led_init_data *init_data)
441{
442	struct led_classdev *cdev;
443	u32 reg;
444	int ret;
445
446	ret = fwnode_property_read_u32(fwnode, "reg", &reg);
447	if (ret != 0 || reg >= chip->num_leds) {
448		dev_err(chip->dev, "invalid 'reg' of %pfw\n", fwnode);
449		return -EINVAL;
450	}
451	led->index = reg;
452
453	cdev = &led->cdev;
454	cdev->brightness_set_blocking = ktd202x_brightness_single_set;
455	cdev->blink_set = ktd202x_blink_single_set;
456
457	return devm_led_classdev_register_ext(chip->dev, &led->cdev, init_data);
458}
459
460static int ktd202x_add_led(struct ktd202x *chip, struct fwnode_handle *fwnode, unsigned int index)
461{
462	struct ktd202x_led *led = &chip->leds[index];
463	struct led_init_data init_data = {};
464	struct led_classdev *cdev;
465	u32 color;
466	int ret;
467
468	/* Color property is optional in single color case */
469	ret = fwnode_property_read_u32(fwnode, "color", &color);
470	if (ret < 0 && ret != -EINVAL) {
471		dev_err(chip->dev, "failed to parse 'color' of %pfw\n", fwnode);
472		return ret;
473	}
474
475	led->chip = chip;
476	init_data.fwnode = fwnode;
477
478	if (color == LED_COLOR_ID_RGB) {
479		cdev = &led->mcdev.led_cdev;
480		ret = ktd202x_setup_led_rgb(chip, fwnode, led, &init_data);
481	} else {
482		cdev = &led->cdev;
483		ret = ktd202x_setup_led_single(chip, fwnode, led, &init_data);
484	}
485
486	if (ret) {
487		dev_err(chip->dev, "unable to register %s\n", cdev->name);
488		return ret;
489	}
490
491	cdev->max_brightness = KTD202X_MAX_BRIGHTNESS;
492
493	return 0;
494}
495
496static int ktd202x_probe_fw(struct ktd202x *chip)
497{
498	struct device *dev = chip->dev;
499	int count;
500	int i = 0;
501
502	count = device_get_child_node_count(dev);
503	if (!count || count > chip->num_leds)
504		return -EINVAL;
505
506	regmap_write(chip->regmap, KTD202X_REG_RESET_CONTROL, KTD202X_RSTR_RESET);
507
508	/* Allow the device to execute the complete reset */
509	usleep_range(200, 300);
510
511	device_for_each_child_node_scoped(dev, child) {
512		int ret = ktd202x_add_led(chip, child, i);
513
514		if (ret)
515			return ret;
516
517		i++;
518	}
519
520	return 0;
521}
522
523static const struct regmap_config ktd202x_regmap_config = {
524	.reg_bits = 8,
525	.val_bits = 8,
526	.max_register = 0x09,
527	.cache_type = REGCACHE_FLAT,
528	.reg_defaults = ktd202x_reg_defaults,
529	.num_reg_defaults = ARRAY_SIZE(ktd202x_reg_defaults),
530};
531
532static int ktd202x_probe(struct i2c_client *client)
533{
534	struct device *dev = &client->dev;
535	struct ktd202x *chip;
536	int count;
537	int ret;
538
539	count = device_get_child_node_count(dev);
540	if (!count || count > KTD202X_MAX_LEDS)
541		return dev_err_probe(dev, -EINVAL, "Incorrect number of leds (%d)", count);
542
543	chip = devm_kzalloc(dev, struct_size(chip, leds, count), GFP_KERNEL);
544	if (!chip)
545		return -ENOMEM;
546
547	chip->dev = dev;
548	i2c_set_clientdata(client, chip);
549
550	chip->regmap = devm_regmap_init_i2c(client, &ktd202x_regmap_config);
551	if (IS_ERR(chip->regmap)) {
552		ret = dev_err_probe(dev, PTR_ERR(chip->regmap),
553				    "Failed to allocate register map.\n");
554		return ret;
555	}
556
557	ret = devm_mutex_init(dev, &chip->mutex);
558	if (ret)
559		return ret;
560
561	chip->num_leds = (unsigned long)i2c_get_match_data(client);
562
563	chip->regulators[0].supply = "vin";
564	chip->regulators[1].supply = "vio";
565	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(chip->regulators), chip->regulators);
566	if (ret < 0) {
567		dev_err_probe(dev, ret, "Failed to request regulators.\n");
568		return ret;
569	}
570
571	ret = regulator_bulk_enable(ARRAY_SIZE(chip->regulators), chip->regulators);
572	if (ret) {
573		dev_err_probe(dev, ret, "Failed to enable regulators.\n");
574		return ret;
575	}
576
577	ret = ktd202x_probe_fw(chip);
578	if (ret < 0) {
579		regulator_bulk_disable(ARRAY_SIZE(chip->regulators), chip->regulators);
580		return ret;
581	}
582
583	ret = regulator_bulk_disable(ARRAY_SIZE(chip->regulators), chip->regulators);
584	if (ret) {
585		dev_err_probe(dev, ret, "Failed to disable regulators.\n");
586		return ret;
587	}
588
589	return 0;
590}
591
592static void ktd202x_remove(struct i2c_client *client)
593{
594	struct ktd202x *chip = i2c_get_clientdata(client);
595
596	ktd202x_chip_disable(chip);
597}
598
599static void ktd202x_shutdown(struct i2c_client *client)
600{
601	struct ktd202x *chip = i2c_get_clientdata(client);
602
603	/* Reset registers to make sure all LEDs are off before shutdown */
604	regmap_write(chip->regmap, KTD202X_REG_RESET_CONTROL, KTD202X_RSTR_RESET);
605}
606
607static const struct i2c_device_id ktd202x_id[] = {
608	{"ktd2026", KTD2026_NUM_LEDS},
609	{"ktd2027", KTD2027_NUM_LEDS},
610	{}
611};
612MODULE_DEVICE_TABLE(i2c, ktd202x_id);
613
614static const struct of_device_id ktd202x_match_table[] = {
615	{ .compatible = "kinetic,ktd2026", .data = (void *)KTD2026_NUM_LEDS },
616	{ .compatible = "kinetic,ktd2027", .data = (void *)KTD2027_NUM_LEDS },
617	{}
618};
619MODULE_DEVICE_TABLE(of, ktd202x_match_table);
620
621static struct i2c_driver ktd202x_driver = {
622	.driver = {
623		.name = "leds-ktd202x",
624		.of_match_table = ktd202x_match_table,
625	},
626	.probe = ktd202x_probe,
627	.remove = ktd202x_remove,
628	.shutdown = ktd202x_shutdown,
629	.id_table = ktd202x_id,
630};
631module_i2c_driver(ktd202x_driver);
632
633MODULE_AUTHOR("André Apitzsch <git@apitzsch.eu>");
634MODULE_DESCRIPTION("Kinetic KTD2026/7 LED driver");
635MODULE_LICENSE("GPL");