leds-tca6507.c 20.2 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779
/*
 * leds-tca6507
 *
 * The TCA6507 is a programmable LED controller that can drive 7
 * separate lines either by holding them low, or by pulsing them
 * with modulated width.
 * The modulation can be varied in a simple pattern to produce a blink or
 * double-blink.
 *
 * This driver can configure each line either as a 'GPIO' which is out-only
 * (no pull-up) or as an LED with variable brightness and hardware-assisted
 * blinking.
 *
 * Apart from OFF and ON there are three programmable brightness levels which
 * can be programmed from 0 to 15 and indicate how many 500usec intervals in
 * each 8msec that the led is 'on'.  The levels are named MASTER, BANK0 and
 * BANK1.
 *
 * There are two different blink rates that can be programmed, each with
 * separate time for rise, on, fall, off and second-off.  Thus if 3 or more
 * different non-trivial rates are required, software must be used for the extra
 * rates. The two different blink rates must align with the two levels BANK0 and
 * BANK1.
 * This driver does not support double-blink so 'second-off' always matches
 * 'off'.
 *
 * Only 16 different times can be programmed in a roughly logarithmic scale from
 * 64ms to 16320ms.  To be precise the possible times are:
 *    0, 64, 128, 192, 256, 384, 512, 768,
 *    1024, 1536, 2048, 3072, 4096, 5760, 8128, 16320
 *
 * Times that cannot be closely matched with these must be
 * handled in software.  This driver allows 12.5% error in matching.
 *
 * This driver does not allow rise/fall rates to be set explicitly.  When trying
 * to match a given 'on' or 'off' period, an appropriate pair of 'change' and
 * 'hold' times are chosen to get a close match.  If the target delay is even,
 * the 'change' number will be the smaller; if odd, the 'hold' number will be
 * the smaller.

 * Choosing pairs of delays with 12.5% errors allows us to match delays in the
 * ranges: 56-72, 112-144, 168-216, 224-27504, 28560-36720.
 * 26% of the achievable sums can be matched by multiple pairings. For example
 * 1536 == 1536+0, 1024+512, or 768+768.  This driver will always choose the
 * pairing with the least maximum - 768+768 in this case.  Other pairings are
 * not available.
 *
 * Access to the 3 levels and 2 blinks are on a first-come, first-served basis.
 * Access can be shared by multiple leds if they have the same level and
 * either same blink rates, or some don't blink.
 * When a led changes, it relinquishes access and tries again, so it might
 * lose access to hardware blink.
 * If a blink engine cannot be allocated, software blink is used.
 * If the desired brightness cannot be allocated, the closest available non-zero
 * brightness is used.  As 'full' is always available, the worst case would be
 * to have two different blink rates at '1', with Max at '2', then other leds
 * will have to choose between '2' and '16'.  Hopefully this is not likely.
 *
 * Each bank (BANK0 and BANK1) has two usage counts - LEDs using the brightness
 * and LEDs using the blink.  It can only be reprogrammed when the appropriate
 * counter is zero.  The MASTER level has a single usage count.
 *
 * Each Led has programmable 'on' and 'off' time as milliseconds.  With each
 * there is a flag saying if it was explicitly requested or defaulted.
 * Similarly the banks know if each time was explicit or a default.  Defaults
 * are permitted to be changed freely - they are not recognised when matching.
 *
 *
 * An led-tca6507 device must be provided with platform data.  This data
 * lists for each output: the name, default trigger, and whether the signal
 * is being used as a GPiO rather than an led.  'struct led_plaform_data'
 * is used for this.  If 'name' is NULL, the output isn't used.  If 'flags'
 * is TCA6507_MAKE_CPIO, the output is a GPO.
 * The "struct led_platform_data" can be embedded in a
 * "struct tca6507_platform_data" which adds a 'gpio_base' for the GPiOs,
 * and a 'setup' callback which is called once the GPiOs are available.
 *
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/leds.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/gpio.h>
#include <linux/workqueue.h>
#include <linux/leds-tca6507.h>

/* LED select registers determine the source that drives LED outputs */
#define TCA6507_LS_LED_OFF	0x0	/* Output HI-Z (off) */
#define TCA6507_LS_LED_OFF1	0x1	/* Output HI-Z (off) - not used */
#define TCA6507_LS_LED_PWM0	0x2	/* Output LOW with Bank0 rate */
#define TCA6507_LS_LED_PWM1	0x3	/* Output LOW with Bank1 rate */
#define TCA6507_LS_LED_ON	0x4	/* Output LOW (on) */
#define TCA6507_LS_LED_MIR	0x5	/* Output LOW with Master Intensity */
#define TCA6507_LS_BLINK0	0x6	/* Blink at Bank0 rate */
#define TCA6507_LS_BLINK1	0x7	/* Blink at Bank1 rate */

enum {
	BANK0,
	BANK1,
	MASTER,
};
static int bank_source[3] = {
	TCA6507_LS_LED_PWM0,
	TCA6507_LS_LED_PWM1,
	TCA6507_LS_LED_MIR,
};
static int blink_source[2] = {
	TCA6507_LS_BLINK0,
	TCA6507_LS_BLINK1,
};

/* PWM registers */
#define	TCA6507_REG_CNT			11

/*
 * 0x00, 0x01, 0x02 encode the TCA6507_LS_* values, each output
 * owns one bit in each register
 */
#define	TCA6507_FADE_ON			0x03
#define	TCA6507_FULL_ON			0x04
#define	TCA6507_FADE_OFF		0x05
#define	TCA6507_FIRST_OFF		0x06
#define	TCA6507_SECOND_OFF		0x07
#define	TCA6507_MAX_INTENSITY		0x08
#define	TCA6507_MASTER_INTENSITY	0x09
#define	TCA6507_INITIALIZE		0x0A

#define	INIT_CODE			0x8

#define TIMECODES 16
static int time_codes[TIMECODES] = {
	0, 64, 128, 192, 256, 384, 512, 768,
	1024, 1536, 2048, 3072, 4096, 5760, 8128, 16320
};

/* Convert an led.brightness level (0..255) to a TCA6507 level (0..15) */
static inline int TO_LEVEL(int brightness)
{
	return brightness >> 4;
}

/* ...and convert back */
static inline int TO_BRIGHT(int level)
{
	if (level)
		return (level << 4) | 0xf;
	return 0;
}

#define NUM_LEDS 7
struct tca6507_chip {
	int			reg_set;	/* One bit per register where
						 * a '1' means the register
						 * should be written */
	u8			reg_file[TCA6507_REG_CNT];
	/* Bank 2 is Master Intensity and doesn't use times */
	struct bank {
		int level;
		int ontime, offtime;
		int on_dflt, off_dflt;
		int time_use, level_use;
	} bank[3];
	struct i2c_client	*client;
	struct work_struct	work;
	spinlock_t		lock;

	struct tca6507_led {
		struct tca6507_chip	*chip;
		struct led_classdev	led_cdev;
		int			num;
		int			ontime, offtime;
		int			on_dflt, off_dflt;
		int			bank;	/* Bank used, or -1 */
		int			blink;	/* Set if hardware-blinking */
	} leds[NUM_LEDS];
#ifdef CONFIG_GPIOLIB
	struct gpio_chip		gpio;
	const char			*gpio_name[NUM_LEDS];
	int				gpio_map[NUM_LEDS];
#endif
};

static const struct i2c_device_id tca6507_id[] = {
	{ "tca6507" },
	{ }
};
MODULE_DEVICE_TABLE(i2c, tca6507_id);

static int choose_times(int msec, int *c1p, int *c2p)
{
	/*
	 * Choose two timecodes which add to 'msec' as near as possible.
	 * The first returned is the 'on' or 'off' time.  The second is to be
	 * used as a 'fade-on' or 'fade-off' time.  If 'msec' is even,
	 * the first will not be smaller than the second.  If 'msec' is odd,
	 * the first will not be larger than the second.
	 * If we cannot get a sum within 1/8 of 'msec' fail with -EINVAL,
	 * otherwise return the sum that was achieved, plus 1 if the first is
	 * smaller.
	 * If two possibilities are equally good (e.g. 512+0, 256+256), choose
	 * the first pair so there is more change-time visible (i.e. it is
	 * softer).
	 */
	int c1, c2;
	int tmax = msec * 9 / 8;
	int tmin = msec * 7 / 8;
	int diff = 65536;

	/* We start at '1' to ensure we never even think of choosing a
	 * total time of '0'.
	 */
	for (c1 = 1; c1 < TIMECODES; c1++) {
		int t = time_codes[c1];
		if (t*2 < tmin)
			continue;
		if (t > tmax)
			break;
		for (c2 = 0; c2 <= c1; c2++) {
			int tt = t + time_codes[c2];
			int d;
			if (tt < tmin)
				continue;
			if (tt > tmax)
				break;
			/* This works! */
			d = abs(msec - tt);
			if (d >= diff)
				continue;
			/* Best yet */
			*c1p = c1;
			*c2p = c2;
			diff = d;
			if (d == 0)
				return msec;
		}
	}
	if (diff < 65536) {
		int actual;
		if (msec & 1) {
			c1 = *c2p;
			*c2p = *c1p;
			*c1p = c1;
		}
		actual = time_codes[*c1p] + time_codes[*c2p];
		if (*c1p < *c2p)
			return actual + 1;
		else
			return actual;
	}
	/* No close match */
	return -EINVAL;
}

/*
 * Update the register file with the appropriate 3-bit state for
 * the given led.
 */
static void set_select(struct tca6507_chip *tca, int led, int val)
{
	int mask = (1 << led);
	int bit;

	for (bit = 0; bit < 3; bit++) {
		int n = tca->reg_file[bit] & ~mask;
		if (val & (1 << bit))
			n |= mask;
		if (tca->reg_file[bit] != n) {
			tca->reg_file[bit] = n;
			tca->reg_set |= (1 << bit);
		}
	}
}

/* Update the register file with the appropriate 4-bit code for
 * one bank or other.  This can be used for timers, for levels, or
 * for initialisation.
 */
static void set_code(struct tca6507_chip *tca, int reg, int bank, int new)
{
	int mask = 0xF;
	int n;
	if (bank) {
		mask <<= 4;
		new <<= 4;
	}
	n = tca->reg_file[reg] & ~mask;
	n |= new;
	if (tca->reg_file[reg] != n) {
		tca->reg_file[reg] = n;
		tca->reg_set |= 1 << reg;
	}
}

/* Update brightness level. */
static void set_level(struct tca6507_chip *tca, int bank, int level)
{
	switch (bank) {
	case BANK0:
	case BANK1:
		set_code(tca, TCA6507_MAX_INTENSITY, bank, level);
		break;
	case MASTER:
		set_code(tca, TCA6507_MASTER_INTENSITY, 0, level);
		break;
	}
	tca->bank[bank].level = level;
}

/* Record all relevant time code for a given bank */
static void set_times(struct tca6507_chip *tca, int bank)
{
	int c1, c2;
	int result;

	result = choose_times(tca->bank[bank].ontime, &c1, &c2);
	dev_dbg(&tca->client->dev,
		"Chose on  times %d(%d) %d(%d) for %dms\n", c1, time_codes[c1],
		c2, time_codes[c2], tca->bank[bank].ontime);
	set_code(tca, TCA6507_FADE_ON, bank, c2);
	set_code(tca, TCA6507_FULL_ON, bank, c1);
	tca->bank[bank].ontime = result;

	result = choose_times(tca->bank[bank].offtime, &c1, &c2);
	dev_dbg(&tca->client->dev,
		"Chose off times %d(%d) %d(%d) for %dms\n", c1, time_codes[c1],
		c2, time_codes[c2], tca->bank[bank].offtime);
	set_code(tca, TCA6507_FADE_OFF, bank, c2);
	set_code(tca, TCA6507_FIRST_OFF, bank, c1);
	set_code(tca, TCA6507_SECOND_OFF, bank, c1);
	tca->bank[bank].offtime = result;

	set_code(tca, TCA6507_INITIALIZE, bank, INIT_CODE);
}

/* Write all needed register of tca6507 */

static void tca6507_work(struct work_struct *work)
{
	struct tca6507_chip *tca = container_of(work, struct tca6507_chip,
						work);
	struct i2c_client *cl = tca->client;
	int set;
	u8 file[TCA6507_REG_CNT];
	int r;

	spin_lock_irq(&tca->lock);
	set = tca->reg_set;
	memcpy(file, tca->reg_file, TCA6507_REG_CNT);
	tca->reg_set = 0;
	spin_unlock_irq(&tca->lock);

	for (r = 0; r < TCA6507_REG_CNT; r++)
		if (set & (1<<r))
			i2c_smbus_write_byte_data(cl, r, file[r]);
}

static void led_release(struct tca6507_led *led)
{
	/* If led owns any resource, release it. */
	struct tca6507_chip *tca = led->chip;
	if (led->bank >= 0) {
		struct bank *b = tca->bank + led->bank;
		if (led->blink)
			b->time_use--;
		b->level_use--;
	}
	led->blink = 0;
	led->bank = -1;
}

static int led_prepare(struct tca6507_led *led)
{
	/* Assign this led to a bank, configuring that bank if necessary. */
	int level = TO_LEVEL(led->led_cdev.brightness);
	struct tca6507_chip *tca = led->chip;
	int c1, c2;
	int i;
	struct bank *b;
	int need_init = 0;

	led->led_cdev.brightness = TO_BRIGHT(level);
	if (level == 0) {
		set_select(tca, led->num, TCA6507_LS_LED_OFF);
		return 0;
	}

	if (led->ontime == 0 || led->offtime == 0) {
		/*
		 * Just set the brightness, choosing first usable bank.
		 * If none perfect, choose best.
		 * Count backwards so we check MASTER bank first
		 * to avoid wasting a timer.
		 */
		int best = -1;/* full-on */
		int diff = 15-level;

		if (level == 15) {
			set_select(tca, led->num, TCA6507_LS_LED_ON);
			return 0;
		}

		for (i = MASTER; i >= BANK0; i--) {
			int d;
			if (tca->bank[i].level == level ||
			    tca->bank[i].level_use == 0) {
				best = i;
				break;
			}
			d = abs(level - tca->bank[i].level);
			if (d < diff) {
				diff = d;
				best = i;
			}
		}
		if (best == -1) {
			/* Best brightness is full-on */
			set_select(tca, led->num, TCA6507_LS_LED_ON);
			led->led_cdev.brightness = LED_FULL;
			return 0;
		}

		if (!tca->bank[best].level_use)
			set_level(tca, best, level);

		tca->bank[best].level_use++;
		led->bank = best;
		set_select(tca, led->num, bank_source[best]);
		led->led_cdev.brightness = TO_BRIGHT(tca->bank[best].level);
		return 0;
	}

	/*
	 * We have on/off time so we need to try to allocate a timing bank.
	 * First check if times are compatible with hardware and give up if
	 * not.
	 */
	if (choose_times(led->ontime, &c1, &c2) < 0)
		return -EINVAL;
	if (choose_times(led->offtime, &c1, &c2) < 0)
		return -EINVAL;

	for (i = BANK0; i <= BANK1; i++) {
		if (tca->bank[i].level_use == 0)
			/* not in use - it is ours! */
			break;
		if (tca->bank[i].level != level)
			/* Incompatible level - skip */
			/* FIX: if timer matches we maybe should consider
			 * this anyway...
			 */
			continue;

		if (tca->bank[i].time_use == 0)
			/* Timer not in use, and level matches - use it */
			break;

		if (!(tca->bank[i].on_dflt ||
		      led->on_dflt ||
		      tca->bank[i].ontime == led->ontime))
			/* on time is incompatible */
			continue;

		if (!(tca->bank[i].off_dflt ||
		      led->off_dflt ||
		      tca->bank[i].offtime == led->offtime))
			/* off time is incompatible */
			continue;

		/* looks like a suitable match */
		break;
	}

	if (i > BANK1)
		/* Nothing matches - how sad */
		return -EINVAL;

	b = &tca->bank[i];
	if (b->level_use == 0)
		set_level(tca, i, level);
	b->level_use++;
	led->bank = i;

	if (b->on_dflt ||
	    !led->on_dflt ||
	    b->time_use == 0) {
		b->ontime = led->ontime;
		b->on_dflt = led->on_dflt;
		need_init = 1;
	}

	if (b->off_dflt ||
	    !led->off_dflt ||
	    b->time_use == 0) {
		b->offtime = led->offtime;
		b->off_dflt = led->off_dflt;
		need_init = 1;
	}

	if (need_init)
		set_times(tca, i);

	led->ontime = b->ontime;
	led->offtime = b->offtime;

	b->time_use++;
	led->blink = 1;
	led->led_cdev.brightness = TO_BRIGHT(b->level);
	set_select(tca, led->num, blink_source[i]);
	return 0;
}

static int led_assign(struct tca6507_led *led)
{
	struct tca6507_chip *tca = led->chip;
	int err;
	unsigned long flags;

	spin_lock_irqsave(&tca->lock, flags);
	led_release(led);
	err = led_prepare(led);
	if (err) {
		/*
		 * Can only fail on timer setup.  In that case we need to
		 * re-establish as steady level.
		 */
		led->ontime = 0;
		led->offtime = 0;
		led_prepare(led);
	}
	spin_unlock_irqrestore(&tca->lock, flags);

	if (tca->reg_set)
		schedule_work(&tca->work);
	return err;
}

static void tca6507_brightness_set(struct led_classdev *led_cdev,
				   enum led_brightness brightness)
{
	struct tca6507_led *led = container_of(led_cdev, struct tca6507_led,
					       led_cdev);
	led->led_cdev.brightness = brightness;
	led->ontime = 0;
	led->offtime = 0;
	led_assign(led);
}

static int tca6507_blink_set(struct led_classdev *led_cdev,
			     unsigned long *delay_on,
			     unsigned long *delay_off)
{
	struct tca6507_led *led = container_of(led_cdev, struct tca6507_led,
					       led_cdev);

	if (*delay_on == 0)
		led->on_dflt = 1;
	else if (delay_on != &led_cdev->blink_delay_on)
		led->on_dflt = 0;
	led->ontime = *delay_on;

	if (*delay_off == 0)
		led->off_dflt = 1;
	else if (delay_off != &led_cdev->blink_delay_off)
		led->off_dflt = 0;
	led->offtime = *delay_off;

	if (led->ontime == 0)
		led->ontime = 512;
	if (led->offtime == 0)
		led->offtime = 512;

	if (led->led_cdev.brightness == LED_OFF)
		led->led_cdev.brightness = LED_FULL;
	if (led_assign(led) < 0) {
		led->ontime = 0;
		led->offtime = 0;
		led->led_cdev.brightness = LED_OFF;
		return -EINVAL;
	}
	*delay_on = led->ontime;
	*delay_off = led->offtime;
	return 0;
}

#ifdef CONFIG_GPIOLIB
static void tca6507_gpio_set_value(struct gpio_chip *gc,
				   unsigned offset, int val)
{
	struct tca6507_chip *tca = container_of(gc, struct tca6507_chip, gpio);
	unsigned long flags;

	spin_lock_irqsave(&tca->lock, flags);
	/*
	 * 'OFF' is floating high, and 'ON' is pulled down, so it has the
	 * inverse sense of 'val'.
	 */
	set_select(tca, tca->gpio_map[offset],
		   val ? TCA6507_LS_LED_OFF : TCA6507_LS_LED_ON);
	spin_unlock_irqrestore(&tca->lock, flags);
	if (tca->reg_set)
		schedule_work(&tca->work);
}

static int tca6507_gpio_direction_output(struct gpio_chip *gc,
					  unsigned offset, int val)
{
	tca6507_gpio_set_value(gc, offset, val);
	return 0;
}

static int tca6507_probe_gpios(struct i2c_client *client,
			       struct tca6507_chip *tca,
			       struct tca6507_platform_data *pdata)
{
	int err;
	int i = 0;
	int gpios = 0;

	for (i = 0; i < NUM_LEDS; i++)
		if (pdata->leds.leds[i].name && pdata->leds.leds[i].flags) {
			/* Configure as a gpio */
			tca->gpio_name[gpios] = pdata->leds.leds[i].name;
			tca->gpio_map[gpios] = i;
			gpios++;
		}

	if (!gpios)
		return 0;

	tca->gpio.label = "gpio-tca6507";
	tca->gpio.names = tca->gpio_name;
	tca->gpio.ngpio = gpios;
	tca->gpio.base = pdata->gpio_base;
	tca->gpio.owner = THIS_MODULE;
	tca->gpio.direction_output = tca6507_gpio_direction_output;
	tca->gpio.set = tca6507_gpio_set_value;
	tca->gpio.dev = &client->dev;
	err = gpiochip_add(&tca->gpio);
	if (err) {
		tca->gpio.ngpio = 0;
		return err;
	}
	if (pdata->setup)
		pdata->setup(tca->gpio.base, tca->gpio.ngpio);
	return 0;
}

static void tca6507_remove_gpio(struct tca6507_chip *tca)
{
	if (tca->gpio.ngpio) {
		int err = gpiochip_remove(&tca->gpio);
		dev_err(&tca->client->dev, "%s failed, %d\n",
			"gpiochip_remove()", err);
	}
}
#else /* CONFIG_GPIOLIB */
static int tca6507_probe_gpios(struct i2c_client *client,
			       struct tca6507_chip *tca,
			       struct tca6507_platform_data *pdata)
{
	return 0;
}
static void tca6507_remove_gpio(struct tca6507_chip *tca)
{
}
#endif /* CONFIG_GPIOLIB */

static int __devinit tca6507_probe(struct i2c_client *client,
				   const struct i2c_device_id *id)
{
	struct tca6507_chip *tca;
	struct i2c_adapter *adapter;
	struct tca6507_platform_data *pdata;
	int err;
	int i = 0;

	adapter = to_i2c_adapter(client->dev.parent);
	pdata = client->dev.platform_data;

	if (!i2c_check_functionality(adapter, I2C_FUNC_I2C))
		return -EIO;

	if (!pdata || pdata->leds.num_leds != NUM_LEDS) {
		dev_err(&client->dev, "Need %d entries in platform-data list\n",
			NUM_LEDS);
		return -ENODEV;
	}
	err = -ENOMEM;
	tca = kzalloc(sizeof(*tca), GFP_KERNEL);
	if (!tca)
		goto exit;

	tca->client = client;
	INIT_WORK(&tca->work, tca6507_work);
	spin_lock_init(&tca->lock);
	i2c_set_clientdata(client, tca);

	for (i = 0; i < NUM_LEDS; i++) {
		struct tca6507_led *l = tca->leds + i;

		l->chip = tca;
		l->num = i;
		if (pdata->leds.leds[i].name && !pdata->leds.leds[i].flags) {
			l->led_cdev.name = pdata->leds.leds[i].name;
			l->led_cdev.default_trigger
				= pdata->leds.leds[i].default_trigger;
			l->led_cdev.brightness_set = tca6507_brightness_set;
			l->led_cdev.blink_set = tca6507_blink_set;
			l->bank = -1;
			err = led_classdev_register(&client->dev,
						    &l->led_cdev);
			if (err < 0)
				goto exit;
		}
	}
	err = tca6507_probe_gpios(client, tca, pdata);
	if (err)
		goto exit;
	/* set all registers to known state - zero */
	tca->reg_set = 0x7f;
	schedule_work(&tca->work);

	return 0;
exit:
	while (i--)
		if (tca->leds[i].led_cdev.name)
			led_classdev_unregister(&tca->leds[i].led_cdev);
	cancel_work_sync(&tca->work);
	i2c_set_clientdata(client, NULL);
	kfree(tca);
	return err;
}

static int __devexit tca6507_remove(struct i2c_client *client)
{
	int i;
	struct tca6507_chip *tca = i2c_get_clientdata(client);
	struct tca6507_led *tca_leds = tca->leds;

	for (i = 0; i < NUM_LEDS; i++) {
		if (tca_leds[i].led_cdev.name)
			led_classdev_unregister(&tca_leds[i].led_cdev);
	}
	tca6507_remove_gpio(tca);
	cancel_work_sync(&tca->work);
	i2c_set_clientdata(client, NULL);
	kfree(tca);

	return 0;
}

static struct i2c_driver tca6507_driver = {
	.driver   = {
		.name    = "leds-tca6507",
		.owner   = THIS_MODULE,
	},
	.probe    = tca6507_probe,
	.remove   = __devexit_p(tca6507_remove),
	.id_table = tca6507_id,
};

static int __init tca6507_leds_init(void)
{
	return i2c_add_driver(&tca6507_driver);
}

static void __exit tca6507_leds_exit(void)
{
	i2c_del_driver(&tca6507_driver);
}

module_init(tca6507_leds_init);
module_exit(tca6507_leds_exit);

MODULE_AUTHOR("NeilBrown <neilb@suse.de>");
MODULE_DESCRIPTION("TCA6507 LED/GPO driver");
MODULE_LICENSE("GPL v2");