xref: /openbmc/linux/drivers/leds/leds-tca6507.c (revision 842ed298)
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 #ifdef CONFIG_GPIOLIB
96 	int gpio_base;
97 #endif
98 };
99 
100 #define	TCA6507_MAKE_GPIO 1
101 
102 enum {
103 	BANK0,
104 	BANK1,
105 	MASTER,
106 };
107 static int bank_source[3] = {
108 	TCA6507_LS_LED_PWM0,
109 	TCA6507_LS_LED_PWM1,
110 	TCA6507_LS_LED_MIR,
111 };
112 static int blink_source[2] = {
113 	TCA6507_LS_BLINK0,
114 	TCA6507_LS_BLINK1,
115 };
116 
117 /* PWM registers */
118 #define	TCA6507_REG_CNT			11
119 
120 /*
121  * 0x00, 0x01, 0x02 encode the TCA6507_LS_* values, each output
122  * owns one bit in each register
123  */
124 #define	TCA6507_FADE_ON			0x03
125 #define	TCA6507_FULL_ON			0x04
126 #define	TCA6507_FADE_OFF		0x05
127 #define	TCA6507_FIRST_OFF		0x06
128 #define	TCA6507_SECOND_OFF		0x07
129 #define	TCA6507_MAX_INTENSITY		0x08
130 #define	TCA6507_MASTER_INTENSITY	0x09
131 #define	TCA6507_INITIALIZE		0x0A
132 
133 #define	INIT_CODE			0x8
134 
135 #define TIMECODES 16
136 static int time_codes[TIMECODES] = {
137 	0, 64, 128, 192, 256, 384, 512, 768,
138 	1024, 1536, 2048, 3072, 4096, 5760, 8128, 16320
139 };
140 
141 /* Convert an led.brightness level (0..255) to a TCA6507 level (0..15) */
142 static inline int TO_LEVEL(int brightness)
143 {
144 	return brightness >> 4;
145 }
146 
147 /* ...and convert back */
148 static inline int TO_BRIGHT(int level)
149 {
150 	if (level)
151 		return (level << 4) | 0xf;
152 	return 0;
153 }
154 
155 #define NUM_LEDS 7
156 struct tca6507_chip {
157 	int			reg_set;	/* One bit per register where
158 						 * a '1' means the register
159 						 * should be written */
160 	u8			reg_file[TCA6507_REG_CNT];
161 	/* Bank 2 is Master Intensity and doesn't use times */
162 	struct bank {
163 		int level;
164 		int ontime, offtime;
165 		int on_dflt, off_dflt;
166 		int time_use, level_use;
167 	} bank[3];
168 	struct i2c_client	*client;
169 	struct work_struct	work;
170 	spinlock_t		lock;
171 
172 	struct tca6507_led {
173 		struct tca6507_chip	*chip;
174 		struct led_classdev	led_cdev;
175 		int			num;
176 		int			ontime, offtime;
177 		int			on_dflt, off_dflt;
178 		int			bank;	/* Bank used, or -1 */
179 		int			blink;	/* Set if hardware-blinking */
180 	} leds[NUM_LEDS];
181 #ifdef CONFIG_GPIOLIB
182 	struct gpio_chip		gpio;
183 	int				gpio_map[NUM_LEDS];
184 #endif
185 };
186 
187 static const struct i2c_device_id tca6507_id[] = {
188 	{ "tca6507" },
189 	{ }
190 };
191 MODULE_DEVICE_TABLE(i2c, tca6507_id);
192 
193 static int choose_times(int msec, int *c1p, int *c2p)
194 {
195 	/*
196 	 * Choose two timecodes which add to 'msec' as near as
197 	 * possible.  The first returned is the 'on' or 'off' time.
198 	 * The second is to be used as a 'fade-on' or 'fade-off' time.
199 	 * If 'msec' is even, the first will not be smaller than the
200 	 * second.  If 'msec' is odd, the first will not be larger
201 	 * than the second.
202 	 * If we cannot get a sum within 1/8 of 'msec' fail with
203 	 * -EINVAL, otherwise return the sum that was achieved, plus 1
204 	 * if the first is smaller.
205 	 * If two possibilities are equally good (e.g. 512+0,
206 	 * 256+256), choose the first pair so there is more
207 	 * change-time visible (i.e. it is softer).
208 	 */
209 	int c1, c2;
210 	int tmax = msec * 9 / 8;
211 	int tmin = msec * 7 / 8;
212 	int diff = 65536;
213 
214 	/* We start at '1' to ensure we never even think of choosing a
215 	 * total time of '0'.
216 	 */
217 	for (c1 = 1; c1 < TIMECODES; c1++) {
218 		int t = time_codes[c1];
219 		if (t*2 < tmin)
220 			continue;
221 		if (t > tmax)
222 			break;
223 		for (c2 = 0; c2 <= c1; c2++) {
224 			int tt = t + time_codes[c2];
225 			int d;
226 			if (tt < tmin)
227 				continue;
228 			if (tt > tmax)
229 				break;
230 			/* This works! */
231 			d = abs(msec - tt);
232 			if (d >= diff)
233 				continue;
234 			/* Best yet */
235 			*c1p = c1;
236 			*c2p = c2;
237 			diff = d;
238 			if (d == 0)
239 				return msec;
240 		}
241 	}
242 	if (diff < 65536) {
243 		int actual;
244 		if (msec & 1) {
245 			c1 = *c2p;
246 			*c2p = *c1p;
247 			*c1p = c1;
248 		}
249 		actual = time_codes[*c1p] + time_codes[*c2p];
250 		if (*c1p < *c2p)
251 			return actual + 1;
252 		else
253 			return actual;
254 	}
255 	/* No close match */
256 	return -EINVAL;
257 }
258 
259 /*
260  * Update the register file with the appropriate 3-bit state for the
261  * given led.
262  */
263 static void set_select(struct tca6507_chip *tca, int led, int val)
264 {
265 	int mask = (1 << led);
266 	int bit;
267 
268 	for (bit = 0; bit < 3; bit++) {
269 		int n = tca->reg_file[bit] & ~mask;
270 		if (val & (1 << bit))
271 			n |= mask;
272 		if (tca->reg_file[bit] != n) {
273 			tca->reg_file[bit] = n;
274 			tca->reg_set |= (1 << bit);
275 		}
276 	}
277 }
278 
279 /* Update the register file with the appropriate 4-bit code for one
280  * bank or other.  This can be used for timers, for levels, or for
281  * initialization.
282  */
283 static void set_code(struct tca6507_chip *tca, int reg, int bank, int new)
284 {
285 	int mask = 0xF;
286 	int n;
287 	if (bank) {
288 		mask <<= 4;
289 		new <<= 4;
290 	}
291 	n = tca->reg_file[reg] & ~mask;
292 	n |= new;
293 	if (tca->reg_file[reg] != n) {
294 		tca->reg_file[reg] = n;
295 		tca->reg_set |= 1 << reg;
296 	}
297 }
298 
299 /* Update brightness level. */
300 static void set_level(struct tca6507_chip *tca, int bank, int level)
301 {
302 	switch (bank) {
303 	case BANK0:
304 	case BANK1:
305 		set_code(tca, TCA6507_MAX_INTENSITY, bank, level);
306 		break;
307 	case MASTER:
308 		set_code(tca, TCA6507_MASTER_INTENSITY, 0, level);
309 		break;
310 	}
311 	tca->bank[bank].level = level;
312 }
313 
314 /* Record all relevant time codes for a given bank */
315 static void set_times(struct tca6507_chip *tca, int bank)
316 {
317 	int c1, c2;
318 	int result;
319 
320 	result = choose_times(tca->bank[bank].ontime, &c1, &c2);
321 	if (result < 0)
322 		return;
323 	dev_dbg(&tca->client->dev,
324 		"Chose on  times %d(%d) %d(%d) for %dms\n",
325 		c1, time_codes[c1],
326 		c2, time_codes[c2], tca->bank[bank].ontime);
327 	set_code(tca, TCA6507_FADE_ON, bank, c2);
328 	set_code(tca, TCA6507_FULL_ON, bank, c1);
329 	tca->bank[bank].ontime = result;
330 
331 	result = choose_times(tca->bank[bank].offtime, &c1, &c2);
332 	dev_dbg(&tca->client->dev,
333 		"Chose off times %d(%d) %d(%d) for %dms\n",
334 		c1, time_codes[c1],
335 		c2, time_codes[c2], tca->bank[bank].offtime);
336 	set_code(tca, TCA6507_FADE_OFF, bank, c2);
337 	set_code(tca, TCA6507_FIRST_OFF, bank, c1);
338 	set_code(tca, TCA6507_SECOND_OFF, bank, c1);
339 	tca->bank[bank].offtime = result;
340 
341 	set_code(tca, TCA6507_INITIALIZE, bank, INIT_CODE);
342 }
343 
344 /* Write all needed register of tca6507 */
345 
346 static void tca6507_work(struct work_struct *work)
347 {
348 	struct tca6507_chip *tca = container_of(work, struct tca6507_chip,
349 						work);
350 	struct i2c_client *cl = tca->client;
351 	int set;
352 	u8 file[TCA6507_REG_CNT];
353 	int r;
354 
355 	spin_lock_irq(&tca->lock);
356 	set = tca->reg_set;
357 	memcpy(file, tca->reg_file, TCA6507_REG_CNT);
358 	tca->reg_set = 0;
359 	spin_unlock_irq(&tca->lock);
360 
361 	for (r = 0; r < TCA6507_REG_CNT; r++)
362 		if (set & (1<<r))
363 			i2c_smbus_write_byte_data(cl, r, file[r]);
364 }
365 
366 static void led_release(struct tca6507_led *led)
367 {
368 	/* If led owns any resource, release it. */
369 	struct tca6507_chip *tca = led->chip;
370 	if (led->bank >= 0) {
371 		struct bank *b = tca->bank + led->bank;
372 		if (led->blink)
373 			b->time_use--;
374 		b->level_use--;
375 	}
376 	led->blink = 0;
377 	led->bank = -1;
378 }
379 
380 static int led_prepare(struct tca6507_led *led)
381 {
382 	/* Assign this led to a bank, configuring that bank if
383 	 * necessary. */
384 	int level = TO_LEVEL(led->led_cdev.brightness);
385 	struct tca6507_chip *tca = led->chip;
386 	int c1, c2;
387 	int i;
388 	struct bank *b;
389 	int need_init = 0;
390 
391 	led->led_cdev.brightness = TO_BRIGHT(level);
392 	if (level == 0) {
393 		set_select(tca, led->num, TCA6507_LS_LED_OFF);
394 		return 0;
395 	}
396 
397 	if (led->ontime == 0 || led->offtime == 0) {
398 		/*
399 		 * Just set the brightness, choosing first usable
400 		 * bank.  If none perfect, choose best.  Count
401 		 * backwards so we check MASTER bank first to avoid
402 		 * wasting a timer.
403 		 */
404 		int best = -1;/* full-on */
405 		int diff = 15-level;
406 
407 		if (level == 15) {
408 			set_select(tca, led->num, TCA6507_LS_LED_ON);
409 			return 0;
410 		}
411 
412 		for (i = MASTER; i >= BANK0; i--) {
413 			int d;
414 			if (tca->bank[i].level == level ||
415 			    tca->bank[i].level_use == 0) {
416 				best = i;
417 				break;
418 			}
419 			d = abs(level - tca->bank[i].level);
420 			if (d < diff) {
421 				diff = d;
422 				best = i;
423 			}
424 		}
425 		if (best == -1) {
426 			/* Best brightness is full-on */
427 			set_select(tca, led->num, TCA6507_LS_LED_ON);
428 			led->led_cdev.brightness = LED_FULL;
429 			return 0;
430 		}
431 
432 		if (!tca->bank[best].level_use)
433 			set_level(tca, best, level);
434 
435 		tca->bank[best].level_use++;
436 		led->bank = best;
437 		set_select(tca, led->num, bank_source[best]);
438 		led->led_cdev.brightness = TO_BRIGHT(tca->bank[best].level);
439 		return 0;
440 	}
441 
442 	/*
443 	 * We have on/off time so we need to try to allocate a timing
444 	 * bank.  First check if times are compatible with hardware
445 	 * and give up if not.
446 	 */
447 	if (choose_times(led->ontime, &c1, &c2) < 0)
448 		return -EINVAL;
449 	if (choose_times(led->offtime, &c1, &c2) < 0)
450 		return -EINVAL;
451 
452 	for (i = BANK0; i <= BANK1; i++) {
453 		if (tca->bank[i].level_use == 0)
454 			/* not in use - it is ours! */
455 			break;
456 		if (tca->bank[i].level != level)
457 			/* Incompatible level - skip */
458 			/* FIX: if timer matches we maybe should consider
459 			 * this anyway...
460 			 */
461 			continue;
462 
463 		if (tca->bank[i].time_use == 0)
464 			/* Timer not in use, and level matches - use it */
465 			break;
466 
467 		if (!(tca->bank[i].on_dflt ||
468 		      led->on_dflt ||
469 		      tca->bank[i].ontime == led->ontime))
470 			/* on time is incompatible */
471 			continue;
472 
473 		if (!(tca->bank[i].off_dflt ||
474 		      led->off_dflt ||
475 		      tca->bank[i].offtime == led->offtime))
476 			/* off time is incompatible */
477 			continue;
478 
479 		/* looks like a suitable match */
480 		break;
481 	}
482 
483 	if (i > BANK1)
484 		/* Nothing matches - how sad */
485 		return -EINVAL;
486 
487 	b = &tca->bank[i];
488 	if (b->level_use == 0)
489 		set_level(tca, i, level);
490 	b->level_use++;
491 	led->bank = i;
492 
493 	if (b->on_dflt ||
494 	    !led->on_dflt ||
495 	    b->time_use == 0) {
496 		b->ontime = led->ontime;
497 		b->on_dflt = led->on_dflt;
498 		need_init = 1;
499 	}
500 
501 	if (b->off_dflt ||
502 	    !led->off_dflt ||
503 	    b->time_use == 0) {
504 		b->offtime = led->offtime;
505 		b->off_dflt = led->off_dflt;
506 		need_init = 1;
507 	}
508 
509 	if (need_init)
510 		set_times(tca, i);
511 
512 	led->ontime = b->ontime;
513 	led->offtime = b->offtime;
514 
515 	b->time_use++;
516 	led->blink = 1;
517 	led->led_cdev.brightness = TO_BRIGHT(b->level);
518 	set_select(tca, led->num, blink_source[i]);
519 	return 0;
520 }
521 
522 static int led_assign(struct tca6507_led *led)
523 {
524 	struct tca6507_chip *tca = led->chip;
525 	int err;
526 	unsigned long flags;
527 
528 	spin_lock_irqsave(&tca->lock, flags);
529 	led_release(led);
530 	err = led_prepare(led);
531 	if (err) {
532 		/*
533 		 * Can only fail on timer setup.  In that case we need
534 		 * to re-establish as steady level.
535 		 */
536 		led->ontime = 0;
537 		led->offtime = 0;
538 		led_prepare(led);
539 	}
540 	spin_unlock_irqrestore(&tca->lock, flags);
541 
542 	if (tca->reg_set)
543 		schedule_work(&tca->work);
544 	return err;
545 }
546 
547 static void tca6507_brightness_set(struct led_classdev *led_cdev,
548 				   enum led_brightness brightness)
549 {
550 	struct tca6507_led *led = container_of(led_cdev, struct tca6507_led,
551 					       led_cdev);
552 	led->led_cdev.brightness = brightness;
553 	led->ontime = 0;
554 	led->offtime = 0;
555 	led_assign(led);
556 }
557 
558 static int tca6507_blink_set(struct led_classdev *led_cdev,
559 			     unsigned long *delay_on,
560 			     unsigned long *delay_off)
561 {
562 	struct tca6507_led *led = container_of(led_cdev, struct tca6507_led,
563 					       led_cdev);
564 
565 	if (*delay_on == 0)
566 		led->on_dflt = 1;
567 	else if (delay_on != &led_cdev->blink_delay_on)
568 		led->on_dflt = 0;
569 	led->ontime = *delay_on;
570 
571 	if (*delay_off == 0)
572 		led->off_dflt = 1;
573 	else if (delay_off != &led_cdev->blink_delay_off)
574 		led->off_dflt = 0;
575 	led->offtime = *delay_off;
576 
577 	if (led->ontime == 0)
578 		led->ontime = 512;
579 	if (led->offtime == 0)
580 		led->offtime = 512;
581 
582 	if (led->led_cdev.brightness == LED_OFF)
583 		led->led_cdev.brightness = LED_FULL;
584 	if (led_assign(led) < 0) {
585 		led->ontime = 0;
586 		led->offtime = 0;
587 		led->led_cdev.brightness = LED_OFF;
588 		return -EINVAL;
589 	}
590 	*delay_on = led->ontime;
591 	*delay_off = led->offtime;
592 	return 0;
593 }
594 
595 #ifdef CONFIG_GPIOLIB
596 static void tca6507_gpio_set_value(struct gpio_chip *gc,
597 				   unsigned offset, int val)
598 {
599 	struct tca6507_chip *tca = gpiochip_get_data(gc);
600 	unsigned long flags;
601 
602 	spin_lock_irqsave(&tca->lock, flags);
603 	/*
604 	 * 'OFF' is floating high, and 'ON' is pulled down, so it has
605 	 * the inverse sense of 'val'.
606 	 */
607 	set_select(tca, tca->gpio_map[offset],
608 		   val ? TCA6507_LS_LED_OFF : TCA6507_LS_LED_ON);
609 	spin_unlock_irqrestore(&tca->lock, flags);
610 	if (tca->reg_set)
611 		schedule_work(&tca->work);
612 }
613 
614 static int tca6507_gpio_direction_output(struct gpio_chip *gc,
615 					  unsigned offset, int val)
616 {
617 	tca6507_gpio_set_value(gc, offset, val);
618 	return 0;
619 }
620 
621 static int tca6507_probe_gpios(struct device *dev,
622 			       struct tca6507_chip *tca,
623 			       struct tca6507_platform_data *pdata)
624 {
625 	int err;
626 	int i = 0;
627 	int gpios = 0;
628 
629 	for (i = 0; i < NUM_LEDS; i++)
630 		if (pdata->leds.leds[i].name && pdata->leds.leds[i].flags) {
631 			/* Configure as a gpio */
632 			tca->gpio_map[gpios] = i;
633 			gpios++;
634 		}
635 
636 	if (!gpios)
637 		return 0;
638 
639 	tca->gpio.label = "gpio-tca6507";
640 	tca->gpio.ngpio = gpios;
641 	tca->gpio.base = pdata->gpio_base;
642 	tca->gpio.owner = THIS_MODULE;
643 	tca->gpio.direction_output = tca6507_gpio_direction_output;
644 	tca->gpio.set = tca6507_gpio_set_value;
645 	tca->gpio.parent = dev;
646 #ifdef CONFIG_OF_GPIO
647 	tca->gpio.of_node = of_node_get(dev_of_node(dev));
648 #endif
649 	err = gpiochip_add_data(&tca->gpio, tca);
650 	if (err) {
651 		tca->gpio.ngpio = 0;
652 		return err;
653 	}
654 	return 0;
655 }
656 
657 static void tca6507_remove_gpio(struct tca6507_chip *tca)
658 {
659 	if (tca->gpio.ngpio)
660 		gpiochip_remove(&tca->gpio);
661 }
662 #else /* CONFIG_GPIOLIB */
663 static int tca6507_probe_gpios(struct device *dev,
664 			       struct tca6507_chip *tca,
665 			       struct tca6507_platform_data *pdata)
666 {
667 	return 0;
668 }
669 static void tca6507_remove_gpio(struct tca6507_chip *tca)
670 {
671 }
672 #endif /* CONFIG_GPIOLIB */
673 
674 static struct tca6507_platform_data *
675 tca6507_led_dt_init(struct device *dev)
676 {
677 	struct tca6507_platform_data *pdata;
678 	struct fwnode_handle *child;
679 	struct led_info *tca_leds;
680 	int count;
681 
682 	count = device_get_child_node_count(dev);
683 	if (!count || count > NUM_LEDS)
684 		return ERR_PTR(-ENODEV);
685 
686 	tca_leds = devm_kcalloc(dev, NUM_LEDS, sizeof(struct led_info),
687 				GFP_KERNEL);
688 	if (!tca_leds)
689 		return ERR_PTR(-ENOMEM);
690 
691 	device_for_each_child_node(dev, child) {
692 		struct led_info led;
693 		u32 reg;
694 		int ret;
695 
696 		if (fwnode_property_read_string(child, "label", &led.name))
697 			led.name = fwnode_get_name(child);
698 
699 		fwnode_property_read_string(child, "linux,default-trigger",
700 					    &led.default_trigger);
701 
702 		led.flags = 0;
703 		if (fwnode_property_match_string(child, "compatible",
704 						 "gpio") >= 0)
705 			led.flags |= TCA6507_MAKE_GPIO;
706 
707 		ret = fwnode_property_read_u32(child, "reg", &reg);
708 		if (ret || reg >= NUM_LEDS) {
709 			fwnode_handle_put(child);
710 			return ERR_PTR(ret ? : -EINVAL);
711 		}
712 
713 		tca_leds[reg] = led;
714 	}
715 
716 	pdata = devm_kzalloc(dev, sizeof(struct tca6507_platform_data),
717 			     GFP_KERNEL);
718 	if (!pdata)
719 		return ERR_PTR(-ENOMEM);
720 
721 	pdata->leds.leds = tca_leds;
722 	pdata->leds.num_leds = NUM_LEDS;
723 #ifdef CONFIG_GPIOLIB
724 	pdata->gpio_base = -1;
725 #endif
726 
727 	return pdata;
728 }
729 
730 static const struct of_device_id __maybe_unused of_tca6507_leds_match[] = {
731 	{ .compatible = "ti,tca6507", },
732 	{},
733 };
734 MODULE_DEVICE_TABLE(of, of_tca6507_leds_match);
735 
736 static int tca6507_probe(struct i2c_client *client,
737 		const struct i2c_device_id *id)
738 {
739 	struct device *dev = &client->dev;
740 	struct i2c_adapter *adapter;
741 	struct tca6507_chip *tca;
742 	struct tca6507_platform_data *pdata;
743 	int err;
744 	int i = 0;
745 
746 	adapter = client->adapter;
747 
748 	if (!i2c_check_functionality(adapter, I2C_FUNC_I2C))
749 		return -EIO;
750 
751 	pdata = tca6507_led_dt_init(dev);
752 	if (IS_ERR(pdata)) {
753 		dev_err(dev, "Need %d entries in platform-data list\n", NUM_LEDS);
754 		return PTR_ERR(pdata);
755 	}
756 	tca = devm_kzalloc(dev, sizeof(*tca), GFP_KERNEL);
757 	if (!tca)
758 		return -ENOMEM;
759 
760 	tca->client = client;
761 	INIT_WORK(&tca->work, tca6507_work);
762 	spin_lock_init(&tca->lock);
763 	i2c_set_clientdata(client, tca);
764 
765 	for (i = 0; i < NUM_LEDS; i++) {
766 		struct tca6507_led *l = tca->leds + i;
767 
768 		l->chip = tca;
769 		l->num = i;
770 		if (pdata->leds.leds[i].name && !pdata->leds.leds[i].flags) {
771 			l->led_cdev.name = pdata->leds.leds[i].name;
772 			l->led_cdev.default_trigger
773 				= pdata->leds.leds[i].default_trigger;
774 			l->led_cdev.brightness_set = tca6507_brightness_set;
775 			l->led_cdev.blink_set = tca6507_blink_set;
776 			l->bank = -1;
777 			err = led_classdev_register(dev, &l->led_cdev);
778 			if (err < 0)
779 				goto exit;
780 		}
781 	}
782 	err = tca6507_probe_gpios(dev, tca, pdata);
783 	if (err)
784 		goto exit;
785 	/* set all registers to known state - zero */
786 	tca->reg_set = 0x7f;
787 	schedule_work(&tca->work);
788 
789 	return 0;
790 exit:
791 	while (i--) {
792 		if (tca->leds[i].led_cdev.name)
793 			led_classdev_unregister(&tca->leds[i].led_cdev);
794 	}
795 	return err;
796 }
797 
798 static int tca6507_remove(struct i2c_client *client)
799 {
800 	int i;
801 	struct tca6507_chip *tca = i2c_get_clientdata(client);
802 	struct tca6507_led *tca_leds = tca->leds;
803 
804 	for (i = 0; i < NUM_LEDS; i++) {
805 		if (tca_leds[i].led_cdev.name)
806 			led_classdev_unregister(&tca_leds[i].led_cdev);
807 	}
808 	tca6507_remove_gpio(tca);
809 	cancel_work_sync(&tca->work);
810 
811 	return 0;
812 }
813 
814 static struct i2c_driver tca6507_driver = {
815 	.driver   = {
816 		.name    = "leds-tca6507",
817 		.of_match_table = of_match_ptr(of_tca6507_leds_match),
818 	},
819 	.probe    = tca6507_probe,
820 	.remove   = tca6507_remove,
821 	.id_table = tca6507_id,
822 };
823 
824 module_i2c_driver(tca6507_driver);
825 
826 MODULE_AUTHOR("NeilBrown <neilb@suse.de>");
827 MODULE_DESCRIPTION("TCA6507 LED/GPO driver");
828 MODULE_LICENSE("GPL v2");
829