1/*
2 * leds-tca6507
3 *
4 * The TCA6507 is a programmable LED controller that can drive 7
5 * separate lines either by holding them low, or by pulsing them
6 * with modulated width.
7 * The modulation can be varied in a simple pattern to produce a
8 * blink or double-blink.
9 *
10 * This driver can configure each line either as a 'GPIO' which is
11 * out-only (pull-up resistor required) or as an LED with variable
12 * brightness and hardware-assisted blinking.
13 *
14 * Apart from OFF and ON there are three programmable brightness
15 * levels which can be programmed from 0 to 15 and indicate how many
16 * 500usec intervals in each 8msec that the led is 'on'.  The levels
17 * are named MASTER, BANK0 and BANK1.
18 *
19 * There are two different blink rates that can be programmed, each
20 * with separate time for rise, on, fall, off and second-off.  Thus if
21 * 3 or more different non-trivial rates are required, software must
22 * be used for the extra rates. The two different blink rates must
23 * align with the two levels BANK0 and BANK1.  This driver does not
24 * support double-blink so 'second-off' always matches 'off'.
25 *
26 * Only 16 different times can be programmed in a roughly logarithmic
27 * scale from 64ms to 16320ms.  To be precise the possible times are:
28 *    0, 64, 128, 192, 256, 384, 512, 768,
29 *    1024, 1536, 2048, 3072, 4096, 5760, 8128, 16320
30 *
31 * Times that cannot be closely matched with these must be handled in
32 * software.  This driver allows 12.5% error in matching.
33 *
34 * This driver does not allow rise/fall rates to be set explicitly.
35 * When trying to match a given 'on' or 'off' period, an appropriate
36 * pair of 'change' and 'hold' times are chosen to get a close match.
37 * If the target delay is even, the 'change' number will be the
38 * smaller; if odd, the 'hold' number will be the smaller.
39
40 * Choosing pairs of delays with 12.5% errors allows us to match
41 * delays in the ranges: 56-72, 112-144, 168-216, 224-27504,
42 * 28560-36720.
43 * 26% of the achievable sums can be matched by multiple pairings.
44 * For example 1536 == 1536+0, 1024+512, or 768+768.
45 * This driver will always choose the pairing with the least
46 * maximum - 768+768 in this case.  Other pairings are not available.
47 *
48 * Access to the 3 levels and 2 blinks are on a first-come,
49 * first-served basis.  Access can be shared by multiple leds if they
50 * have the same level and either same blink rates, or some don't
51 * blink.  When a led changes, it relinquishes access and tries again,
52 * so it might lose access to hardware blink.
53 *
54 * If a blink engine cannot be allocated, software blink is used.  If
55 * the desired brightness cannot be allocated, the closest available
56 * non-zero brightness is used.  As 'full' is always available, the
57 * worst case would be to have two different blink rates at '1', with
58 * Max at '2', then other leds will have to choose between '2' and
59 * '16'.  Hopefully this is not likely.
60 *
61 * Each bank (BANK0 and BANK1) has two usage counts - LEDs using the
62 * brightness and LEDs using the blink.  It can only be reprogrammed
63 * when the appropriate counter is zero.  The MASTER level has a
64 * single usage count.
65 *
66 * Each LED has programmable 'on' and 'off' time as milliseconds.
67 * With each there is a flag saying if it was explicitly requested or
68 * defaulted.  Similarly the banks know if each time was explicit or a
69 * default.  Defaults are permitted to be changed freely - they are
70 * not recognised when matching.
71 *
72 *
73 * An led-tca6507 device must be provided with platform data or
74 * configured via devicetree.
75 *
76 * The platform-data lists for each output: the name, default trigger,
77 * and whether the signal is being used as a GPIO rather than an LED.
78 * 'struct led_plaform_data' is used for this.  If 'name' is NULL, the
79 * output isn't used.  If 'flags' is TCA6507_MAKE_GPIO, the output is
80 * a GPO.  The "struct led_platform_data" can be embedded in a "struct
81 * tca6507_platform_data" which adds a 'gpio_base' for the GPIOs, and
82 * a 'setup' callback which is called once the GPIOs are available.
83 *
84 * When configured via devicetree there is one child for each output.
85 * The "reg" determines the output number and "compatible" determines
86 * whether it is an LED or a GPIO.  "linux,default-trigger" can set a
87 * default trigger.
88 */
89
90#include <linux/module.h>
91#include <linux/slab.h>
92#include <linux/leds.h>
93#include <linux/err.h>
94#include <linux/i2c.h>
95#include <linux/gpio.h>
96#include <linux/workqueue.h>
97#include <linux/leds-tca6507.h>
98#include <linux/of.h>
99
100/* LED select registers determine the source that drives LED outputs */
101#define TCA6507_LS_LED_OFF	0x0	/* Output HI-Z (off) */
102#define TCA6507_LS_LED_OFF1	0x1	/* Output HI-Z (off) - not used */
103#define TCA6507_LS_LED_PWM0	0x2	/* Output LOW with Bank0 rate */
104#define TCA6507_LS_LED_PWM1	0x3	/* Output LOW with Bank1 rate */
105#define TCA6507_LS_LED_ON	0x4	/* Output LOW (on) */
106#define TCA6507_LS_LED_MIR	0x5	/* Output LOW with Master Intensity */
107#define TCA6507_LS_BLINK0	0x6	/* Blink at Bank0 rate */
108#define TCA6507_LS_BLINK1	0x7	/* Blink at Bank1 rate */
109
110enum {
111	BANK0,
112	BANK1,
113	MASTER,
114};
115static int bank_source[3] = {
116	TCA6507_LS_LED_PWM0,
117	TCA6507_LS_LED_PWM1,
118	TCA6507_LS_LED_MIR,
119};
120static int blink_source[2] = {
121	TCA6507_LS_BLINK0,
122	TCA6507_LS_BLINK1,
123};
124
125/* PWM registers */
126#define	TCA6507_REG_CNT			11
127
128/*
129 * 0x00, 0x01, 0x02 encode the TCA6507_LS_* values, each output
130 * owns one bit in each register
131 */
132#define	TCA6507_FADE_ON			0x03
133#define	TCA6507_FULL_ON			0x04
134#define	TCA6507_FADE_OFF		0x05
135#define	TCA6507_FIRST_OFF		0x06
136#define	TCA6507_SECOND_OFF		0x07
137#define	TCA6507_MAX_INTENSITY		0x08
138#define	TCA6507_MASTER_INTENSITY	0x09
139#define	TCA6507_INITIALIZE		0x0A
140
141#define	INIT_CODE			0x8
142
143#define TIMECODES 16
144static int time_codes[TIMECODES] = {
145	0, 64, 128, 192, 256, 384, 512, 768,
146	1024, 1536, 2048, 3072, 4096, 5760, 8128, 16320
147};
148
149/* Convert an led.brightness level (0..255) to a TCA6507 level (0..15) */
150static inline int TO_LEVEL(int brightness)
151{
152	return brightness >> 4;
153}
154
155/* ...and convert back */
156static inline int TO_BRIGHT(int level)
157{
158	if (level)
159		return (level << 4) | 0xf;
160	return 0;
161}
162
163#define NUM_LEDS 7
164struct tca6507_chip {
165	int			reg_set;	/* One bit per register where
166						 * a '1' means the register
167						 * should be written */
168	u8			reg_file[TCA6507_REG_CNT];
169	/* Bank 2 is Master Intensity and doesn't use times */
170	struct bank {
171		int level;
172		int ontime, offtime;
173		int on_dflt, off_dflt;
174		int time_use, level_use;
175	} bank[3];
176	struct i2c_client	*client;
177	struct work_struct	work;
178	spinlock_t		lock;
179
180	struct tca6507_led {
181		struct tca6507_chip	*chip;
182		struct led_classdev	led_cdev;
183		int			num;
184		int			ontime, offtime;
185		int			on_dflt, off_dflt;
186		int			bank;	/* Bank used, or -1 */
187		int			blink;	/* Set if hardware-blinking */
188	} leds[NUM_LEDS];
189#ifdef CONFIG_GPIOLIB
190	struct gpio_chip		gpio;
191	const char			*gpio_name[NUM_LEDS];
192	int				gpio_map[NUM_LEDS];
193#endif
194};
195
196static const struct i2c_device_id tca6507_id[] = {
197	{ "tca6507" },
198	{ }
199};
200MODULE_DEVICE_TABLE(i2c, tca6507_id);
201
202static int choose_times(int msec, int *c1p, int *c2p)
203{
204	/*
205	 * Choose two timecodes which add to 'msec' as near as
206	 * possible.  The first returned is the 'on' or 'off' time.
207	 * The second is to be used as a 'fade-on' or 'fade-off' time.
208	 * If 'msec' is even, the first will not be smaller than the
209	 * second.  If 'msec' is odd, the first will not be larger
210	 * than the second.
211	 * If we cannot get a sum within 1/8 of 'msec' fail with
212	 * -EINVAL, otherwise return the sum that was achieved, plus 1
213	 * if the first is smaller.
214	 * If two possibilities are equally good (e.g. 512+0,
215	 * 256+256), choose the first pair so there is more
216	 * change-time visible (i.e. it is softer).
217	 */
218	int c1, c2;
219	int tmax = msec * 9 / 8;
220	int tmin = msec * 7 / 8;
221	int diff = 65536;
222
223	/* We start at '1' to ensure we never even think of choosing a
224	 * total time of '0'.
225	 */
226	for (c1 = 1; c1 < TIMECODES; c1++) {
227		int t = time_codes[c1];
228		if (t*2 < tmin)
229			continue;
230		if (t > tmax)
231			break;
232		for (c2 = 0; c2 <= c1; c2++) {
233			int tt = t + time_codes[c2];
234			int d;
235			if (tt < tmin)
236				continue;
237			if (tt > tmax)
238				break;
239			/* This works! */
240			d = abs(msec - tt);
241			if (d >= diff)
242				continue;
243			/* Best yet */
244			*c1p = c1;
245			*c2p = c2;
246			diff = d;
247			if (d == 0)
248				return msec;
249		}
250	}
251	if (diff < 65536) {
252		int actual;
253		if (msec & 1) {
254			c1 = *c2p;
255			*c2p = *c1p;
256			*c1p = c1;
257		}
258		actual = time_codes[*c1p] + time_codes[*c2p];
259		if (*c1p < *c2p)
260			return actual + 1;
261		else
262			return actual;
263	}
264	/* No close match */
265	return -EINVAL;
266}
267
268/*
269 * Update the register file with the appropriate 3-bit state for the
270 * given led.
271 */
272static void set_select(struct tca6507_chip *tca, int led, int val)
273{
274	int mask = (1 << led);
275	int bit;
276
277	for (bit = 0; bit < 3; bit++) {
278		int n = tca->reg_file[bit] & ~mask;
279		if (val & (1 << bit))
280			n |= mask;
281		if (tca->reg_file[bit] != n) {
282			tca->reg_file[bit] = n;
283			tca->reg_set |= (1 << bit);
284		}
285	}
286}
287
288/* Update the register file with the appropriate 4-bit code for one
289 * bank or other.  This can be used for timers, for levels, or for
290 * initialization.
291 */
292static void set_code(struct tca6507_chip *tca, int reg, int bank, int new)
293{
294	int mask = 0xF;
295	int n;
296	if (bank) {
297		mask <<= 4;
298		new <<= 4;
299	}
300	n = tca->reg_file[reg] & ~mask;
301	n |= new;
302	if (tca->reg_file[reg] != n) {
303		tca->reg_file[reg] = n;
304		tca->reg_set |= 1 << reg;
305	}
306}
307
308/* Update brightness level. */
309static void set_level(struct tca6507_chip *tca, int bank, int level)
310{
311	switch (bank) {
312	case BANK0:
313	case BANK1:
314		set_code(tca, TCA6507_MAX_INTENSITY, bank, level);
315		break;
316	case MASTER:
317		set_code(tca, TCA6507_MASTER_INTENSITY, 0, level);
318		break;
319	}
320	tca->bank[bank].level = level;
321}
322
323/* Record all relevant time codes for a given bank */
324static void set_times(struct tca6507_chip *tca, int bank)
325{
326	int c1, c2;
327	int result;
328
329	result = choose_times(tca->bank[bank].ontime, &c1, &c2);
330	dev_dbg(&tca->client->dev,
331		"Chose on  times %d(%d) %d(%d) for %dms\n",
332		c1, time_codes[c1],
333		c2, time_codes[c2], tca->bank[bank].ontime);
334	set_code(tca, TCA6507_FADE_ON, bank, c2);
335	set_code(tca, TCA6507_FULL_ON, bank, c1);
336	tca->bank[bank].ontime = result;
337
338	result = choose_times(tca->bank[bank].offtime, &c1, &c2);
339	dev_dbg(&tca->client->dev,
340		"Chose off times %d(%d) %d(%d) for %dms\n",
341		c1, time_codes[c1],
342		c2, time_codes[c2], tca->bank[bank].offtime);
343	set_code(tca, TCA6507_FADE_OFF, bank, c2);
344	set_code(tca, TCA6507_FIRST_OFF, bank, c1);
345	set_code(tca, TCA6507_SECOND_OFF, bank, c1);
346	tca->bank[bank].offtime = result;
347
348	set_code(tca, TCA6507_INITIALIZE, bank, INIT_CODE);
349}
350
351/* Write all needed register of tca6507 */
352
353static void tca6507_work(struct work_struct *work)
354{
355	struct tca6507_chip *tca = container_of(work, struct tca6507_chip,
356						work);
357	struct i2c_client *cl = tca->client;
358	int set;
359	u8 file[TCA6507_REG_CNT];
360	int r;
361
362	spin_lock_irq(&tca->lock);
363	set = tca->reg_set;
364	memcpy(file, tca->reg_file, TCA6507_REG_CNT);
365	tca->reg_set = 0;
366	spin_unlock_irq(&tca->lock);
367
368	for (r = 0; r < TCA6507_REG_CNT; r++)
369		if (set & (1<<r))
370			i2c_smbus_write_byte_data(cl, r, file[r]);
371}
372
373static void led_release(struct tca6507_led *led)
374{
375	/* If led owns any resource, release it. */
376	struct tca6507_chip *tca = led->chip;
377	if (led->bank >= 0) {
378		struct bank *b = tca->bank + led->bank;
379		if (led->blink)
380			b->time_use--;
381		b->level_use--;
382	}
383	led->blink = 0;
384	led->bank = -1;
385}
386
387static int led_prepare(struct tca6507_led *led)
388{
389	/* Assign this led to a bank, configuring that bank if
390	 * necessary. */
391	int level = TO_LEVEL(led->led_cdev.brightness);
392	struct tca6507_chip *tca = led->chip;
393	int c1, c2;
394	int i;
395	struct bank *b;
396	int need_init = 0;
397
398	led->led_cdev.brightness = TO_BRIGHT(level);
399	if (level == 0) {
400		set_select(tca, led->num, TCA6507_LS_LED_OFF);
401		return 0;
402	}
403
404	if (led->ontime == 0 || led->offtime == 0) {
405		/*
406		 * Just set the brightness, choosing first usable
407		 * bank.  If none perfect, choose best.  Count
408		 * backwards so we check MASTER bank first to avoid
409		 * wasting a timer.
410		 */
411		int best = -1;/* full-on */
412		int diff = 15-level;
413
414		if (level == 15) {
415			set_select(tca, led->num, TCA6507_LS_LED_ON);
416			return 0;
417		}
418
419		for (i = MASTER; i >= BANK0; i--) {
420			int d;
421			if (tca->bank[i].level == level ||
422			    tca->bank[i].level_use == 0) {
423				best = i;
424				break;
425			}
426			d = abs(level - tca->bank[i].level);
427			if (d < diff) {
428				diff = d;
429				best = i;
430			}
431		}
432		if (best == -1) {
433			/* Best brightness is full-on */
434			set_select(tca, led->num, TCA6507_LS_LED_ON);
435			led->led_cdev.brightness = LED_FULL;
436			return 0;
437		}
438
439		if (!tca->bank[best].level_use)
440			set_level(tca, best, level);
441
442		tca->bank[best].level_use++;
443		led->bank = best;
444		set_select(tca, led->num, bank_source[best]);
445		led->led_cdev.brightness = TO_BRIGHT(tca->bank[best].level);
446		return 0;
447	}
448
449	/*
450	 * We have on/off time so we need to try to allocate a timing
451	 * bank.  First check if times are compatible with hardware
452	 * and give up if not.
453	 */
454	if (choose_times(led->ontime, &c1, &c2) < 0)
455		return -EINVAL;
456	if (choose_times(led->offtime, &c1, &c2) < 0)
457		return -EINVAL;
458
459	for (i = BANK0; i <= BANK1; i++) {
460		if (tca->bank[i].level_use == 0)
461			/* not in use - it is ours! */
462			break;
463		if (tca->bank[i].level != level)
464			/* Incompatible level - skip */
465			/* FIX: if timer matches we maybe should consider
466			 * this anyway...
467			 */
468			continue;
469
470		if (tca->bank[i].time_use == 0)
471			/* Timer not in use, and level matches - use it */
472			break;
473
474		if (!(tca->bank[i].on_dflt ||
475		      led->on_dflt ||
476		      tca->bank[i].ontime == led->ontime))
477			/* on time is incompatible */
478			continue;
479
480		if (!(tca->bank[i].off_dflt ||
481		      led->off_dflt ||
482		      tca->bank[i].offtime == led->offtime))
483			/* off time is incompatible */
484			continue;
485
486		/* looks like a suitable match */
487		break;
488	}
489
490	if (i > BANK1)
491		/* Nothing matches - how sad */
492		return -EINVAL;
493
494	b = &tca->bank[i];
495	if (b->level_use == 0)
496		set_level(tca, i, level);
497	b->level_use++;
498	led->bank = i;
499
500	if (b->on_dflt ||
501	    !led->on_dflt ||
502	    b->time_use == 0) {
503		b->ontime = led->ontime;
504		b->on_dflt = led->on_dflt;
505		need_init = 1;
506	}
507
508	if (b->off_dflt ||
509	    !led->off_dflt ||
510	    b->time_use == 0) {
511		b->offtime = led->offtime;
512		b->off_dflt = led->off_dflt;
513		need_init = 1;
514	}
515
516	if (need_init)
517		set_times(tca, i);
518
519	led->ontime = b->ontime;
520	led->offtime = b->offtime;
521
522	b->time_use++;
523	led->blink = 1;
524	led->led_cdev.brightness = TO_BRIGHT(b->level);
525	set_select(tca, led->num, blink_source[i]);
526	return 0;
527}
528
529static int led_assign(struct tca6507_led *led)
530{
531	struct tca6507_chip *tca = led->chip;
532	int err;
533	unsigned long flags;
534
535	spin_lock_irqsave(&tca->lock, flags);
536	led_release(led);
537	err = led_prepare(led);
538	if (err) {
539		/*
540		 * Can only fail on timer setup.  In that case we need
541		 * to re-establish as steady level.
542		 */
543		led->ontime = 0;
544		led->offtime = 0;
545		led_prepare(led);
546	}
547	spin_unlock_irqrestore(&tca->lock, flags);
548
549	if (tca->reg_set)
550		schedule_work(&tca->work);
551	return err;
552}
553
554static void tca6507_brightness_set(struct led_classdev *led_cdev,
555				   enum led_brightness brightness)
556{
557	struct tca6507_led *led = container_of(led_cdev, struct tca6507_led,
558					       led_cdev);
559	led->led_cdev.brightness = brightness;
560	led->ontime = 0;
561	led->offtime = 0;
562	led_assign(led);
563}
564
565static int tca6507_blink_set(struct led_classdev *led_cdev,
566			     unsigned long *delay_on,
567			     unsigned long *delay_off)
568{
569	struct tca6507_led *led = container_of(led_cdev, struct tca6507_led,
570					       led_cdev);
571
572	if (*delay_on == 0)
573		led->on_dflt = 1;
574	else if (delay_on != &led_cdev->blink_delay_on)
575		led->on_dflt = 0;
576	led->ontime = *delay_on;
577
578	if (*delay_off == 0)
579		led->off_dflt = 1;
580	else if (delay_off != &led_cdev->blink_delay_off)
581		led->off_dflt = 0;
582	led->offtime = *delay_off;
583
584	if (led->ontime == 0)
585		led->ontime = 512;
586	if (led->offtime == 0)
587		led->offtime = 512;
588
589	if (led->led_cdev.brightness == LED_OFF)
590		led->led_cdev.brightness = LED_FULL;
591	if (led_assign(led) < 0) {
592		led->ontime = 0;
593		led->offtime = 0;
594		led->led_cdev.brightness = LED_OFF;
595		return -EINVAL;
596	}
597	*delay_on = led->ontime;
598	*delay_off = led->offtime;
599	return 0;
600}
601
602#ifdef CONFIG_GPIOLIB
603static void tca6507_gpio_set_value(struct gpio_chip *gc,
604				   unsigned offset, int val)
605{
606	struct tca6507_chip *tca = container_of(gc, struct tca6507_chip, gpio);
607	unsigned long flags;
608
609	spin_lock_irqsave(&tca->lock, flags);
610	/*
611	 * 'OFF' is floating high, and 'ON' is pulled down, so it has
612	 * the inverse sense of 'val'.
613	 */
614	set_select(tca, tca->gpio_map[offset],
615		   val ? TCA6507_LS_LED_OFF : TCA6507_LS_LED_ON);
616	spin_unlock_irqrestore(&tca->lock, flags);
617	if (tca->reg_set)
618		schedule_work(&tca->work);
619}
620
621static int tca6507_gpio_direction_output(struct gpio_chip *gc,
622					  unsigned offset, int val)
623{
624	tca6507_gpio_set_value(gc, offset, val);
625	return 0;
626}
627
628static int tca6507_probe_gpios(struct i2c_client *client,
629			       struct tca6507_chip *tca,
630			       struct tca6507_platform_data *pdata)
631{
632	int err;
633	int i = 0;
634	int gpios = 0;
635
636	for (i = 0; i < NUM_LEDS; i++)
637		if (pdata->leds.leds[i].name && pdata->leds.leds[i].flags) {
638			/* Configure as a gpio */
639			tca->gpio_name[gpios] = pdata->leds.leds[i].name;
640			tca->gpio_map[gpios] = i;
641			gpios++;
642		}
643
644	if (!gpios)
645		return 0;
646
647	tca->gpio.label = "gpio-tca6507";
648	tca->gpio.names = tca->gpio_name;
649	tca->gpio.ngpio = gpios;
650	tca->gpio.base = pdata->gpio_base;
651	tca->gpio.owner = THIS_MODULE;
652	tca->gpio.direction_output = tca6507_gpio_direction_output;
653	tca->gpio.set = tca6507_gpio_set_value;
654	tca->gpio.dev = &client->dev;
655#ifdef CONFIG_OF_GPIO
656	tca->gpio.of_node = of_node_get(client->dev.of_node);
657#endif
658	err = gpiochip_add(&tca->gpio);
659	if (err) {
660		tca->gpio.ngpio = 0;
661		return err;
662	}
663	if (pdata->setup)
664		pdata->setup(tca->gpio.base, tca->gpio.ngpio);
665	return 0;
666}
667
668static void tca6507_remove_gpio(struct tca6507_chip *tca)
669{
670	if (tca->gpio.ngpio)
671		gpiochip_remove(&tca->gpio);
672}
673#else /* CONFIG_GPIOLIB */
674static int tca6507_probe_gpios(struct i2c_client *client,
675			       struct tca6507_chip *tca,
676			       struct tca6507_platform_data *pdata)
677{
678	return 0;
679}
680static void tca6507_remove_gpio(struct tca6507_chip *tca)
681{
682}
683#endif /* CONFIG_GPIOLIB */
684
685#ifdef CONFIG_OF
686static struct tca6507_platform_data *
687tca6507_led_dt_init(struct i2c_client *client)
688{
689	struct device_node *np = client->dev.of_node, *child;
690	struct tca6507_platform_data *pdata;
691	struct led_info *tca_leds;
692	int count;
693
694	count = of_get_child_count(np);
695	if (!count || count > NUM_LEDS)
696		return ERR_PTR(-ENODEV);
697
698	tca_leds = devm_kzalloc(&client->dev,
699			sizeof(struct led_info) * NUM_LEDS, GFP_KERNEL);
700	if (!tca_leds)
701		return ERR_PTR(-ENOMEM);
702
703	for_each_child_of_node(np, child) {
704		struct led_info led;
705		u32 reg;
706		int ret;
707
708		led.name =
709			of_get_property(child, "label", NULL) ? : child->name;
710		led.default_trigger =
711			of_get_property(child, "linux,default-trigger", NULL);
712		led.flags = 0;
713		if (of_property_match_string(child, "compatible", "gpio") >= 0)
714			led.flags |= TCA6507_MAKE_GPIO;
715		ret = of_property_read_u32(child, "reg", &reg);
716		if (ret != 0 || reg < 0 || reg >= NUM_LEDS)
717			continue;
718
719		tca_leds[reg] = led;
720	}
721	pdata = devm_kzalloc(&client->dev,
722			sizeof(struct tca6507_platform_data), GFP_KERNEL);
723	if (!pdata)
724		return ERR_PTR(-ENOMEM);
725
726	pdata->leds.leds = tca_leds;
727	pdata->leds.num_leds = NUM_LEDS;
728#ifdef CONFIG_GPIOLIB
729	pdata->gpio_base = -1;
730#endif
731	return pdata;
732}
733
734static const struct of_device_id of_tca6507_leds_match[] = {
735	{ .compatible = "ti,tca6507", },
736	{},
737};
738
739#else
740static struct tca6507_platform_data *
741tca6507_led_dt_init(struct i2c_client *client)
742{
743	return ERR_PTR(-ENODEV);
744}
745
746#endif
747
748static int tca6507_probe(struct i2c_client *client,
749		const struct i2c_device_id *id)
750{
751	struct tca6507_chip *tca;
752	struct i2c_adapter *adapter;
753	struct tca6507_platform_data *pdata;
754	int err;
755	int i = 0;
756
757	adapter = to_i2c_adapter(client->dev.parent);
758	pdata = dev_get_platdata(&client->dev);
759
760	if (!i2c_check_functionality(adapter, I2C_FUNC_I2C))
761		return -EIO;
762
763	if (!pdata || pdata->leds.num_leds != NUM_LEDS) {
764		pdata = tca6507_led_dt_init(client);
765		if (IS_ERR(pdata)) {
766			dev_err(&client->dev, "Need %d entries in platform-data list\n",
767				NUM_LEDS);
768			return PTR_ERR(pdata);
769		}
770	}
771	tca = devm_kzalloc(&client->dev, sizeof(*tca), GFP_KERNEL);
772	if (!tca)
773		return -ENOMEM;
774
775	tca->client = client;
776	INIT_WORK(&tca->work, tca6507_work);
777	spin_lock_init(&tca->lock);
778	i2c_set_clientdata(client, tca);
779
780	for (i = 0; i < NUM_LEDS; i++) {
781		struct tca6507_led *l = tca->leds + i;
782
783		l->chip = tca;
784		l->num = i;
785		if (pdata->leds.leds[i].name && !pdata->leds.leds[i].flags) {
786			l->led_cdev.name = pdata->leds.leds[i].name;
787			l->led_cdev.default_trigger
788				= pdata->leds.leds[i].default_trigger;
789			l->led_cdev.brightness_set = tca6507_brightness_set;
790			l->led_cdev.blink_set = tca6507_blink_set;
791			l->bank = -1;
792			err = led_classdev_register(&client->dev,
793						    &l->led_cdev);
794			if (err < 0)
795				goto exit;
796		}
797	}
798	err = tca6507_probe_gpios(client, tca, pdata);
799	if (err)
800		goto exit;
801	/* set all registers to known state - zero */
802	tca->reg_set = 0x7f;
803	schedule_work(&tca->work);
804
805	return 0;
806exit:
807	while (i--) {
808		if (tca->leds[i].led_cdev.name)
809			led_classdev_unregister(&tca->leds[i].led_cdev);
810	}
811	return err;
812}
813
814static int tca6507_remove(struct i2c_client *client)
815{
816	int i;
817	struct tca6507_chip *tca = i2c_get_clientdata(client);
818	struct tca6507_led *tca_leds = tca->leds;
819
820	for (i = 0; i < NUM_LEDS; i++) {
821		if (tca_leds[i].led_cdev.name)
822			led_classdev_unregister(&tca_leds[i].led_cdev);
823	}
824	tca6507_remove_gpio(tca);
825	cancel_work_sync(&tca->work);
826
827	return 0;
828}
829
830static struct i2c_driver tca6507_driver = {
831	.driver   = {
832		.name    = "leds-tca6507",
833		.owner   = THIS_MODULE,
834		.of_match_table = of_match_ptr(of_tca6507_leds_match),
835	},
836	.probe    = tca6507_probe,
837	.remove   = tca6507_remove,
838	.id_table = tca6507_id,
839};
840
841module_i2c_driver(tca6507_driver);
842
843MODULE_AUTHOR("NeilBrown <neilb@suse.de>");
844MODULE_DESCRIPTION("TCA6507 LED/GPO driver");
845MODULE_LICENSE("GPL v2");
846