xref: /linux/drivers/leds/leds-tca6507.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * leds-tca6507
4  *
5  * The TCA6507 is a programmable LED controller that can drive 7
6  * separate lines either by holding them low, or by pulsing them
7  * with modulated width.
8  * The modulation can be varied in a simple pattern to produce a
9  * blink or double-blink.
10  *
11  * This driver can configure each line either as a 'GPIO' which is
12  * out-only (pull-up resistor required) or as an LED with variable
13  * brightness and hardware-assisted blinking.
14  *
15  * Apart from OFF and ON there are three programmable brightness
16  * levels which can be programmed from 0 to 15 and indicate how many
17  * 500usec intervals in each 8msec that the led is 'on'.  The levels
18  * are named MASTER, BANK0 and BANK1.
19  *
20  * There are two different blink rates that can be programmed, each
21  * with separate time for rise, on, fall, off and second-off.  Thus if
22  * 3 or more different non-trivial rates are required, software must
23  * be used for the extra rates. The two different blink rates must
24  * align with the two levels BANK0 and BANK1.  This driver does not
25  * support double-blink so 'second-off' always matches 'off'.
26  *
27  * Only 16 different times can be programmed in a roughly logarithmic
28  * scale from 64ms to 16320ms.  To be precise the possible times are:
29  *    0, 64, 128, 192, 256, 384, 512, 768,
30  *    1024, 1536, 2048, 3072, 4096, 5760, 8128, 16320
31  *
32  * Times that cannot be closely matched with these must be handled in
33  * software.  This driver allows 12.5% error in matching.
34  *
35  * This driver does not allow rise/fall rates to be set explicitly.
36  * When trying to match a given 'on' or 'off' period, an appropriate
37  * pair of 'change' and 'hold' times are chosen to get a close match.
38  * If the target delay is even, the 'change' number will be the
39  * smaller; if odd, the 'hold' number will be the smaller.
40 
41  * Choosing pairs of delays with 12.5% errors allows us to match
42  * delays in the ranges: 56-72, 112-144, 168-216, 224-27504,
43  * 28560-36720.
44  * 26% of the achievable sums can be matched by multiple pairings.
45  * For example 1536 == 1536+0, 1024+512, or 768+768.
46  * This driver will always choose the pairing with the least
47  * maximum - 768+768 in this case.  Other pairings are not available.
48  *
49  * Access to the 3 levels and 2 blinks are on a first-come,
50  * first-served basis.  Access can be shared by multiple leds if they
51  * have the same level and either same blink rates, or some don't
52  * blink.  When a led changes, it relinquishes access and tries again,
53  * so it might lose access to hardware blink.
54  *
55  * If a blink engine cannot be allocated, software blink is used.  If
56  * the desired brightness cannot be allocated, the closest available
57  * non-zero brightness is used.  As 'full' is always available, the
58  * worst case would be to have two different blink rates at '1', with
59  * Max at '2', then other leds will have to choose between '2' and
60  * '16'.  Hopefully this is not likely.
61  *
62  * Each bank (BANK0 and BANK1) has two usage counts - LEDs using the
63  * brightness and LEDs using the blink.  It can only be reprogrammed
64  * when the appropriate counter is zero.  The MASTER level has a
65  * single usage count.
66  *
67  * Each LED has programmable 'on' and 'off' time as milliseconds.
68  * With each there is a flag saying if it was explicitly requested or
69  * defaulted.  Similarly the banks know if each time was explicit or a
70  * default.  Defaults are permitted to be changed freely - they are
71  * not recognised when matching.
72  */
73 
74 #include <linux/module.h>
75 #include <linux/slab.h>
76 #include <linux/leds.h>
77 #include <linux/err.h>
78 #include <linux/i2c.h>
79 #include <linux/gpio/driver.h>
80 #include <linux/property.h>
81 #include <linux/workqueue.h>
82 
83 /* LED select registers determine the source that drives LED outputs */
84 #define TCA6507_LS_LED_OFF	0x0	/* Output HI-Z (off) */
85 #define TCA6507_LS_LED_OFF1	0x1	/* Output HI-Z (off) - not used */
86 #define TCA6507_LS_LED_PWM0	0x2	/* Output LOW with Bank0 rate */
87 #define TCA6507_LS_LED_PWM1	0x3	/* Output LOW with Bank1 rate */
88 #define TCA6507_LS_LED_ON	0x4	/* Output LOW (on) */
89 #define TCA6507_LS_LED_MIR	0x5	/* Output LOW with Master Intensity */
90 #define TCA6507_LS_BLINK0	0x6	/* Blink at Bank0 rate */
91 #define TCA6507_LS_BLINK1	0x7	/* Blink at Bank1 rate */
92 
93 struct tca6507_platform_data {
94 	struct led_platform_data leds;
95 };
96 
97 #define	TCA6507_MAKE_GPIO 1
98 
99 enum {
100 	BANK0,
101 	BANK1,
102 	MASTER,
103 };
104 static int bank_source[3] = {
105 	TCA6507_LS_LED_PWM0,
106 	TCA6507_LS_LED_PWM1,
107 	TCA6507_LS_LED_MIR,
108 };
109 static int blink_source[2] = {
110 	TCA6507_LS_BLINK0,
111 	TCA6507_LS_BLINK1,
112 };
113 
114 /* PWM registers */
115 #define	TCA6507_REG_CNT			11
116 
117 /*
118  * 0x00, 0x01, 0x02 encode the TCA6507_LS_* values, each output
119  * owns one bit in each register
120  */
121 #define	TCA6507_FADE_ON			0x03
122 #define	TCA6507_FULL_ON			0x04
123 #define	TCA6507_FADE_OFF		0x05
124 #define	TCA6507_FIRST_OFF		0x06
125 #define	TCA6507_SECOND_OFF		0x07
126 #define	TCA6507_MAX_INTENSITY		0x08
127 #define	TCA6507_MASTER_INTENSITY	0x09
128 #define	TCA6507_INITIALIZE		0x0A
129 
130 #define	INIT_CODE			0x8
131 
132 #define TIMECODES 16
133 static int time_codes[TIMECODES] = {
134 	0, 64, 128, 192, 256, 384, 512, 768,
135 	1024, 1536, 2048, 3072, 4096, 5760, 8128, 16320
136 };
137 
138 /* Convert an led.brightness level (0..255) to a TCA6507 level (0..15) */
139 static inline int TO_LEVEL(int brightness)
140 {
141 	return brightness >> 4;
142 }
143 
144 /* ...and convert back */
145 static inline int TO_BRIGHT(int level)
146 {
147 	if (level)
148 		return (level << 4) | 0xf;
149 	return 0;
150 }
151 
152 #define NUM_LEDS 7
153 struct tca6507_chip {
154 	int			reg_set;	/* One bit per register where
155 						 * a '1' means the register
156 						 * should be written */
157 	u8			reg_file[TCA6507_REG_CNT];
158 	/* Bank 2 is Master Intensity and doesn't use times */
159 	struct bank {
160 		int level;
161 		int ontime, offtime;
162 		int on_dflt, off_dflt;
163 		int time_use, level_use;
164 	} bank[3];
165 	struct i2c_client	*client;
166 	struct work_struct	work;
167 	spinlock_t		lock;
168 
169 	struct tca6507_led {
170 		struct tca6507_chip	*chip;
171 		struct led_classdev	led_cdev;
172 		int			num;
173 		int			ontime, offtime;
174 		int			on_dflt, off_dflt;
175 		int			bank;	/* Bank used, or -1 */
176 		int			blink;	/* Set if hardware-blinking */
177 	} leds[NUM_LEDS];
178 #ifdef CONFIG_GPIOLIB
179 	struct gpio_chip		gpio;
180 	int				gpio_map[NUM_LEDS];
181 #endif
182 };
183 
184 static const struct i2c_device_id tca6507_id[] = {
185 	{ "tca6507" },
186 	{ }
187 };
188 MODULE_DEVICE_TABLE(i2c, tca6507_id);
189 
190 static int choose_times(int msec, int *c1p, int *c2p)
191 {
192 	/*
193 	 * Choose two timecodes which add to 'msec' as near as
194 	 * possible.  The first returned is the 'on' or 'off' time.
195 	 * The second is to be used as a 'fade-on' or 'fade-off' time.
196 	 * If 'msec' is even, the first will not be smaller than the
197 	 * second.  If 'msec' is odd, the first will not be larger
198 	 * than the second.
199 	 * If we cannot get a sum within 1/8 of 'msec' fail with
200 	 * -EINVAL, otherwise return the sum that was achieved, plus 1
201 	 * if the first is smaller.
202 	 * If two possibilities are equally good (e.g. 512+0,
203 	 * 256+256), choose the first pair so there is more
204 	 * change-time visible (i.e. it is softer).
205 	 */
206 	int c1, c2;
207 	int tmax = msec * 9 / 8;
208 	int tmin = msec * 7 / 8;
209 	int diff = 65536;
210 
211 	/* We start at '1' to ensure we never even think of choosing a
212 	 * total time of '0'.
213 	 */
214 	for (c1 = 1; c1 < TIMECODES; c1++) {
215 		int t = time_codes[c1];
216 		if (t*2 < tmin)
217 			continue;
218 		if (t > tmax)
219 			break;
220 		for (c2 = 0; c2 <= c1; c2++) {
221 			int tt = t + time_codes[c2];
222 			int d;
223 			if (tt < tmin)
224 				continue;
225 			if (tt > tmax)
226 				break;
227 			/* This works! */
228 			d = abs(msec - tt);
229 			if (d >= diff)
230 				continue;
231 			/* Best yet */
232 			*c1p = c1;
233 			*c2p = c2;
234 			diff = d;
235 			if (d == 0)
236 				return msec;
237 		}
238 	}
239 	if (diff < 65536) {
240 		int actual;
241 		if (msec & 1) {
242 			swap(*c2p, *c1p);
243 		}
244 		actual = time_codes[*c1p] + time_codes[*c2p];
245 		if (*c1p < *c2p)
246 			return actual + 1;
247 		else
248 			return actual;
249 	}
250 	/* No close match */
251 	return -EINVAL;
252 }
253 
254 /*
255  * Update the register file with the appropriate 3-bit state for the
256  * given led.
257  */
258 static void set_select(struct tca6507_chip *tca, int led, int val)
259 {
260 	int mask = (1 << led);
261 	int bit;
262 
263 	for (bit = 0; bit < 3; bit++) {
264 		int n = tca->reg_file[bit] & ~mask;
265 		if (val & (1 << bit))
266 			n |= mask;
267 		if (tca->reg_file[bit] != n) {
268 			tca->reg_file[bit] = n;
269 			tca->reg_set |= (1 << bit);
270 		}
271 	}
272 }
273 
274 /* Update the register file with the appropriate 4-bit code for one
275  * bank or other.  This can be used for timers, for levels, or for
276  * initialization.
277  */
278 static void set_code(struct tca6507_chip *tca, int reg, int bank, int new)
279 {
280 	int mask = 0xF;
281 	int n;
282 	if (bank) {
283 		mask <<= 4;
284 		new <<= 4;
285 	}
286 	n = tca->reg_file[reg] & ~mask;
287 	n |= new;
288 	if (tca->reg_file[reg] != n) {
289 		tca->reg_file[reg] = n;
290 		tca->reg_set |= 1 << reg;
291 	}
292 }
293 
294 /* Update brightness level. */
295 static void set_level(struct tca6507_chip *tca, int bank, int level)
296 {
297 	switch (bank) {
298 	case BANK0:
299 	case BANK1:
300 		set_code(tca, TCA6507_MAX_INTENSITY, bank, level);
301 		break;
302 	case MASTER:
303 		set_code(tca, TCA6507_MASTER_INTENSITY, 0, level);
304 		break;
305 	}
306 	tca->bank[bank].level = level;
307 }
308 
309 /* Record all relevant time codes for a given bank */
310 static void set_times(struct tca6507_chip *tca, int bank)
311 {
312 	int c1, c2;
313 	int result;
314 
315 	result = choose_times(tca->bank[bank].ontime, &c1, &c2);
316 	if (result < 0)
317 		return;
318 	dev_dbg(&tca->client->dev,
319 		"Chose on  times %d(%d) %d(%d) for %dms\n",
320 		c1, time_codes[c1],
321 		c2, time_codes[c2], tca->bank[bank].ontime);
322 	set_code(tca, TCA6507_FADE_ON, bank, c2);
323 	set_code(tca, TCA6507_FULL_ON, bank, c1);
324 	tca->bank[bank].ontime = result;
325 
326 	result = choose_times(tca->bank[bank].offtime, &c1, &c2);
327 	dev_dbg(&tca->client->dev,
328 		"Chose off times %d(%d) %d(%d) for %dms\n",
329 		c1, time_codes[c1],
330 		c2, time_codes[c2], tca->bank[bank].offtime);
331 	set_code(tca, TCA6507_FADE_OFF, bank, c2);
332 	set_code(tca, TCA6507_FIRST_OFF, bank, c1);
333 	set_code(tca, TCA6507_SECOND_OFF, bank, c1);
334 	tca->bank[bank].offtime = result;
335 
336 	set_code(tca, TCA6507_INITIALIZE, bank, INIT_CODE);
337 }
338 
339 /* Write all needed register of tca6507 */
340 
341 static void tca6507_work(struct work_struct *work)
342 {
343 	struct tca6507_chip *tca = container_of(work, struct tca6507_chip,
344 						work);
345 	struct i2c_client *cl = tca->client;
346 	int set;
347 	u8 file[TCA6507_REG_CNT];
348 	int r;
349 
350 	spin_lock_irq(&tca->lock);
351 	set = tca->reg_set;
352 	memcpy(file, tca->reg_file, TCA6507_REG_CNT);
353 	tca->reg_set = 0;
354 	spin_unlock_irq(&tca->lock);
355 
356 	for (r = 0; r < TCA6507_REG_CNT; r++)
357 		if (set & (1<<r))
358 			i2c_smbus_write_byte_data(cl, r, file[r]);
359 }
360 
361 static void led_release(struct tca6507_led *led)
362 {
363 	/* If led owns any resource, release it. */
364 	struct tca6507_chip *tca = led->chip;
365 	if (led->bank >= 0) {
366 		struct bank *b = tca->bank + led->bank;
367 		if (led->blink)
368 			b->time_use--;
369 		b->level_use--;
370 	}
371 	led->blink = 0;
372 	led->bank = -1;
373 }
374 
375 static int led_prepare(struct tca6507_led *led)
376 {
377 	/* Assign this led to a bank, configuring that bank if
378 	 * necessary. */
379 	int level = TO_LEVEL(led->led_cdev.brightness);
380 	struct tca6507_chip *tca = led->chip;
381 	int c1, c2;
382 	int i;
383 	struct bank *b;
384 	int need_init = 0;
385 
386 	led->led_cdev.brightness = TO_BRIGHT(level);
387 	if (level == 0) {
388 		set_select(tca, led->num, TCA6507_LS_LED_OFF);
389 		return 0;
390 	}
391 
392 	if (led->ontime == 0 || led->offtime == 0) {
393 		/*
394 		 * Just set the brightness, choosing first usable
395 		 * bank.  If none perfect, choose best.  Count
396 		 * backwards so we check MASTER bank first to avoid
397 		 * wasting a timer.
398 		 */
399 		int best = -1;/* full-on */
400 		int diff = 15-level;
401 
402 		if (level == 15) {
403 			set_select(tca, led->num, TCA6507_LS_LED_ON);
404 			return 0;
405 		}
406 
407 		for (i = MASTER; i >= BANK0; i--) {
408 			int d;
409 			if (tca->bank[i].level == level ||
410 			    tca->bank[i].level_use == 0) {
411 				best = i;
412 				break;
413 			}
414 			d = abs(level - tca->bank[i].level);
415 			if (d < diff) {
416 				diff = d;
417 				best = i;
418 			}
419 		}
420 		if (best == -1) {
421 			/* Best brightness is full-on */
422 			set_select(tca, led->num, TCA6507_LS_LED_ON);
423 			led->led_cdev.brightness = LED_FULL;
424 			return 0;
425 		}
426 
427 		if (!tca->bank[best].level_use)
428 			set_level(tca, best, level);
429 
430 		tca->bank[best].level_use++;
431 		led->bank = best;
432 		set_select(tca, led->num, bank_source[best]);
433 		led->led_cdev.brightness = TO_BRIGHT(tca->bank[best].level);
434 		return 0;
435 	}
436 
437 	/*
438 	 * We have on/off time so we need to try to allocate a timing
439 	 * bank.  First check if times are compatible with hardware
440 	 * and give up if not.
441 	 */
442 	if (choose_times(led->ontime, &c1, &c2) < 0)
443 		return -EINVAL;
444 	if (choose_times(led->offtime, &c1, &c2) < 0)
445 		return -EINVAL;
446 
447 	for (i = BANK0; i <= BANK1; i++) {
448 		if (tca->bank[i].level_use == 0)
449 			/* not in use - it is ours! */
450 			break;
451 		if (tca->bank[i].level != level)
452 			/* Incompatible level - skip */
453 			/* FIX: if timer matches we maybe should consider
454 			 * this anyway...
455 			 */
456 			continue;
457 
458 		if (tca->bank[i].time_use == 0)
459 			/* Timer not in use, and level matches - use it */
460 			break;
461 
462 		if (!(tca->bank[i].on_dflt ||
463 		      led->on_dflt ||
464 		      tca->bank[i].ontime == led->ontime))
465 			/* on time is incompatible */
466 			continue;
467 
468 		if (!(tca->bank[i].off_dflt ||
469 		      led->off_dflt ||
470 		      tca->bank[i].offtime == led->offtime))
471 			/* off time is incompatible */
472 			continue;
473 
474 		/* looks like a suitable match */
475 		break;
476 	}
477 
478 	if (i > BANK1)
479 		/* Nothing matches - how sad */
480 		return -EINVAL;
481 
482 	b = &tca->bank[i];
483 	if (b->level_use == 0)
484 		set_level(tca, i, level);
485 	b->level_use++;
486 	led->bank = i;
487 
488 	if (b->on_dflt ||
489 	    !led->on_dflt ||
490 	    b->time_use == 0) {
491 		b->ontime = led->ontime;
492 		b->on_dflt = led->on_dflt;
493 		need_init = 1;
494 	}
495 
496 	if (b->off_dflt ||
497 	    !led->off_dflt ||
498 	    b->time_use == 0) {
499 		b->offtime = led->offtime;
500 		b->off_dflt = led->off_dflt;
501 		need_init = 1;
502 	}
503 
504 	if (need_init)
505 		set_times(tca, i);
506 
507 	led->ontime = b->ontime;
508 	led->offtime = b->offtime;
509 
510 	b->time_use++;
511 	led->blink = 1;
512 	led->led_cdev.brightness = TO_BRIGHT(b->level);
513 	set_select(tca, led->num, blink_source[i]);
514 	return 0;
515 }
516 
517 static int led_assign(struct tca6507_led *led)
518 {
519 	struct tca6507_chip *tca = led->chip;
520 	int err;
521 	unsigned long flags;
522 
523 	spin_lock_irqsave(&tca->lock, flags);
524 	led_release(led);
525 	err = led_prepare(led);
526 	if (err) {
527 		/*
528 		 * Can only fail on timer setup.  In that case we need
529 		 * to re-establish as steady level.
530 		 */
531 		led->ontime = 0;
532 		led->offtime = 0;
533 		led_prepare(led);
534 	}
535 	spin_unlock_irqrestore(&tca->lock, flags);
536 
537 	if (tca->reg_set)
538 		schedule_work(&tca->work);
539 	return err;
540 }
541 
542 static void tca6507_brightness_set(struct led_classdev *led_cdev,
543 				   enum led_brightness brightness)
544 {
545 	struct tca6507_led *led = container_of(led_cdev, struct tca6507_led,
546 					       led_cdev);
547 	led->led_cdev.brightness = brightness;
548 	led->ontime = 0;
549 	led->offtime = 0;
550 	led_assign(led);
551 }
552 
553 static int tca6507_blink_set(struct led_classdev *led_cdev,
554 			     unsigned long *delay_on,
555 			     unsigned long *delay_off)
556 {
557 	struct tca6507_led *led = container_of(led_cdev, struct tca6507_led,
558 					       led_cdev);
559 
560 	if (*delay_on == 0)
561 		led->on_dflt = 1;
562 	else if (delay_on != &led_cdev->blink_delay_on)
563 		led->on_dflt = 0;
564 	led->ontime = *delay_on;
565 
566 	if (*delay_off == 0)
567 		led->off_dflt = 1;
568 	else if (delay_off != &led_cdev->blink_delay_off)
569 		led->off_dflt = 0;
570 	led->offtime = *delay_off;
571 
572 	if (led->ontime == 0)
573 		led->ontime = 512;
574 	if (led->offtime == 0)
575 		led->offtime = 512;
576 
577 	if (led->led_cdev.brightness == LED_OFF)
578 		led->led_cdev.brightness = LED_FULL;
579 	if (led_assign(led) < 0) {
580 		led->ontime = 0;
581 		led->offtime = 0;
582 		led->led_cdev.brightness = LED_OFF;
583 		return -EINVAL;
584 	}
585 	*delay_on = led->ontime;
586 	*delay_off = led->offtime;
587 	return 0;
588 }
589 
590 #ifdef CONFIG_GPIOLIB
591 static void tca6507_gpio_set_value(struct gpio_chip *gc,
592 				   unsigned offset, int val)
593 {
594 	struct tca6507_chip *tca = gpiochip_get_data(gc);
595 	unsigned long flags;
596 
597 	spin_lock_irqsave(&tca->lock, flags);
598 	/*
599 	 * 'OFF' is floating high, and 'ON' is pulled down, so it has
600 	 * the inverse sense of 'val'.
601 	 */
602 	set_select(tca, tca->gpio_map[offset],
603 		   val ? TCA6507_LS_LED_OFF : TCA6507_LS_LED_ON);
604 	spin_unlock_irqrestore(&tca->lock, flags);
605 	if (tca->reg_set)
606 		schedule_work(&tca->work);
607 }
608 
609 static int tca6507_gpio_direction_output(struct gpio_chip *gc,
610 					  unsigned offset, int val)
611 {
612 	tca6507_gpio_set_value(gc, offset, val);
613 	return 0;
614 }
615 
616 static int tca6507_probe_gpios(struct device *dev,
617 			       struct tca6507_chip *tca,
618 			       struct tca6507_platform_data *pdata)
619 {
620 	int err;
621 	int i = 0;
622 	int gpios = 0;
623 
624 	for (i = 0; i < NUM_LEDS; i++)
625 		if (pdata->leds.leds[i].name && pdata->leds.leds[i].flags) {
626 			/* Configure as a gpio */
627 			tca->gpio_map[gpios] = i;
628 			gpios++;
629 		}
630 
631 	if (!gpios)
632 		return 0;
633 
634 	tca->gpio.label = "gpio-tca6507";
635 	tca->gpio.ngpio = gpios;
636 	tca->gpio.base = -1;
637 	tca->gpio.owner = THIS_MODULE;
638 	tca->gpio.direction_output = tca6507_gpio_direction_output;
639 	tca->gpio.set = tca6507_gpio_set_value;
640 	tca->gpio.parent = dev;
641 	err = devm_gpiochip_add_data(dev, &tca->gpio, tca);
642 	if (err) {
643 		tca->gpio.ngpio = 0;
644 		return err;
645 	}
646 	return 0;
647 }
648 #else /* CONFIG_GPIOLIB */
649 static int tca6507_probe_gpios(struct device *dev,
650 			       struct tca6507_chip *tca,
651 			       struct tca6507_platform_data *pdata)
652 {
653 	return 0;
654 }
655 #endif /* CONFIG_GPIOLIB */
656 
657 static struct tca6507_platform_data *
658 tca6507_led_dt_init(struct device *dev)
659 {
660 	struct tca6507_platform_data *pdata;
661 	struct led_info *tca_leds;
662 	int count;
663 
664 	count = device_get_child_node_count(dev);
665 	if (!count || count > NUM_LEDS)
666 		return ERR_PTR(-ENODEV);
667 
668 	tca_leds = devm_kcalloc(dev, NUM_LEDS, sizeof(struct led_info),
669 				GFP_KERNEL);
670 	if (!tca_leds)
671 		return ERR_PTR(-ENOMEM);
672 
673 	device_for_each_child_node_scoped(dev, child) {
674 		struct led_info led;
675 		u32 reg;
676 		int ret;
677 
678 		if (fwnode_property_read_string(child, "label", &led.name))
679 			led.name = fwnode_get_name(child);
680 
681 		if (fwnode_property_read_string(child, "linux,default-trigger",
682 						&led.default_trigger))
683 			led.default_trigger = NULL;
684 
685 		led.flags = 0;
686 		if (fwnode_device_is_compatible(child, "gpio"))
687 			led.flags |= TCA6507_MAKE_GPIO;
688 
689 		ret = fwnode_property_read_u32(child, "reg", &reg);
690 		if (ret || reg >= NUM_LEDS)
691 			return ERR_PTR(ret ? : -EINVAL);
692 
693 		tca_leds[reg] = led;
694 	}
695 
696 	pdata = devm_kzalloc(dev, sizeof(struct tca6507_platform_data),
697 			     GFP_KERNEL);
698 	if (!pdata)
699 		return ERR_PTR(-ENOMEM);
700 
701 	pdata->leds.leds = tca_leds;
702 	pdata->leds.num_leds = NUM_LEDS;
703 
704 	return pdata;
705 }
706 
707 static const struct of_device_id __maybe_unused of_tca6507_leds_match[] = {
708 	{ .compatible = "ti,tca6507", },
709 	{},
710 };
711 MODULE_DEVICE_TABLE(of, of_tca6507_leds_match);
712 
713 static int tca6507_probe(struct i2c_client *client)
714 {
715 	struct device *dev = &client->dev;
716 	struct i2c_adapter *adapter;
717 	struct tca6507_chip *tca;
718 	struct tca6507_platform_data *pdata;
719 	int err;
720 	int i = 0;
721 
722 	adapter = client->adapter;
723 
724 	if (!i2c_check_functionality(adapter, I2C_FUNC_I2C))
725 		return -EIO;
726 
727 	pdata = tca6507_led_dt_init(dev);
728 	if (IS_ERR(pdata)) {
729 		dev_err(dev, "Need %d entries in platform-data list\n", NUM_LEDS);
730 		return PTR_ERR(pdata);
731 	}
732 	tca = devm_kzalloc(dev, sizeof(*tca), GFP_KERNEL);
733 	if (!tca)
734 		return -ENOMEM;
735 
736 	tca->client = client;
737 	INIT_WORK(&tca->work, tca6507_work);
738 	spin_lock_init(&tca->lock);
739 	i2c_set_clientdata(client, tca);
740 
741 	for (i = 0; i < NUM_LEDS; i++) {
742 		struct tca6507_led *l = tca->leds + i;
743 
744 		l->chip = tca;
745 		l->num = i;
746 		if (pdata->leds.leds[i].name && !pdata->leds.leds[i].flags) {
747 			l->led_cdev.name = pdata->leds.leds[i].name;
748 			l->led_cdev.default_trigger
749 				= pdata->leds.leds[i].default_trigger;
750 			l->led_cdev.brightness_set = tca6507_brightness_set;
751 			l->led_cdev.blink_set = tca6507_blink_set;
752 			l->bank = -1;
753 			err = devm_led_classdev_register(dev, &l->led_cdev);
754 			if (err < 0)
755 				return err;
756 		}
757 	}
758 	err = tca6507_probe_gpios(dev, tca, pdata);
759 	if (err)
760 		return err;
761 	/* set all registers to known state - zero */
762 	tca->reg_set = 0x7f;
763 	schedule_work(&tca->work);
764 
765 	return 0;
766 }
767 
768 static void tca6507_remove(struct i2c_client *client)
769 {
770 	struct tca6507_chip *tca = i2c_get_clientdata(client);
771 
772 	cancel_work_sync(&tca->work);
773 }
774 
775 static struct i2c_driver tca6507_driver = {
776 	.driver   = {
777 		.name    = "leds-tca6507",
778 		.of_match_table = of_match_ptr(of_tca6507_leds_match),
779 	},
780 	.probe    = tca6507_probe,
781 	.remove   = tca6507_remove,
782 	.id_table = tca6507_id,
783 };
784 
785 module_i2c_driver(tca6507_driver);
786 
787 MODULE_AUTHOR("NeilBrown <neilb@suse.de>");
788 MODULE_DESCRIPTION("TCA6507 LED/GPO driver");
789 MODULE_LICENSE("GPL v2");
790