lm8323.c 22.5 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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871
/*
 * drivers/i2c/chips/lm8323.c
 *
 * Copyright (C) 2007-2009 Nokia Corporation
 *
 * Written by Daniel Stone <daniel.stone@nokia.com>
 *            Timo O. Karjalainen <timo.o.karjalainen@nokia.com>
 *
 * Updated by Felipe Balbi <felipe.balbi@nokia.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation (version 2 of the License only).
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/input.h>
#include <linux/leds.h>
#include <linux/pm.h>
#include <linux/i2c/lm8323.h>
#include <linux/slab.h>

/* Commands to send to the chip. */
#define LM8323_CMD_READ_ID		0x80 /* Read chip ID. */
#define LM8323_CMD_WRITE_CFG		0x81 /* Set configuration item. */
#define LM8323_CMD_READ_INT		0x82 /* Get interrupt status. */
#define LM8323_CMD_RESET		0x83 /* Reset, same as external one */
#define LM8323_CMD_WRITE_PORT_SEL	0x85 /* Set GPIO in/out. */
#define LM8323_CMD_WRITE_PORT_STATE	0x86 /* Set GPIO pullup. */
#define LM8323_CMD_READ_PORT_SEL	0x87 /* Get GPIO in/out. */
#define LM8323_CMD_READ_PORT_STATE	0x88 /* Get GPIO pullup. */
#define LM8323_CMD_READ_FIFO		0x89 /* Read byte from FIFO. */
#define LM8323_CMD_RPT_READ_FIFO	0x8a /* Read FIFO (no increment). */
#define LM8323_CMD_SET_ACTIVE		0x8b /* Set active time. */
#define LM8323_CMD_READ_ERR		0x8c /* Get error status. */
#define LM8323_CMD_READ_ROTATOR		0x8e /* Read rotator status. */
#define LM8323_CMD_SET_DEBOUNCE		0x8f /* Set debouncing time. */
#define LM8323_CMD_SET_KEY_SIZE		0x90 /* Set keypad size. */
#define LM8323_CMD_READ_KEY_SIZE	0x91 /* Get keypad size. */
#define LM8323_CMD_READ_CFG		0x92 /* Get configuration item. */
#define LM8323_CMD_WRITE_CLOCK		0x93 /* Set clock config. */
#define LM8323_CMD_READ_CLOCK		0x94 /* Get clock config. */
#define LM8323_CMD_PWM_WRITE		0x95 /* Write PWM script. */
#define LM8323_CMD_START_PWM		0x96 /* Start PWM engine. */
#define LM8323_CMD_STOP_PWM		0x97 /* Stop PWM engine. */

/* Interrupt status. */
#define INT_KEYPAD			0x01 /* Key event. */
#define INT_ROTATOR			0x02 /* Rotator event. */
#define INT_ERROR			0x08 /* Error: use CMD_READ_ERR. */
#define INT_NOINIT			0x10 /* Lost configuration. */
#define INT_PWM1			0x20 /* PWM1 stopped. */
#define INT_PWM2			0x40 /* PWM2 stopped. */
#define INT_PWM3			0x80 /* PWM3 stopped. */

/* Errors (signalled by INT_ERROR, read with CMD_READ_ERR). */
#define ERR_BADPAR			0x01 /* Bad parameter. */
#define ERR_CMDUNK			0x02 /* Unknown command. */
#define ERR_KEYOVR			0x04 /* Too many keys pressed. */
#define ERR_FIFOOVER			0x40 /* FIFO overflow. */

/* Configuration keys (CMD_{WRITE,READ}_CFG). */
#define CFG_MUX1SEL			0x01 /* Select MUX1_OUT input. */
#define CFG_MUX1EN			0x02 /* Enable MUX1_OUT. */
#define CFG_MUX2SEL			0x04 /* Select MUX2_OUT input. */
#define CFG_MUX2EN			0x08 /* Enable MUX2_OUT. */
#define CFG_PSIZE			0x20 /* Package size (must be 0). */
#define CFG_ROTEN			0x40 /* Enable rotator. */

/* Clock settings (CMD_{WRITE,READ}_CLOCK). */
#define CLK_RCPWM_INTERNAL		0x00
#define CLK_RCPWM_EXTERNAL		0x03
#define CLK_SLOWCLKEN			0x08 /* Enable 32.768kHz clock. */
#define CLK_SLOWCLKOUT			0x40 /* Enable slow pulse output. */

/* The possible addresses corresponding to CONFIG1 and CONFIG2 pin wirings. */
#define LM8323_I2C_ADDR00		(0x84 >> 1)	/* 1000 010x */
#define LM8323_I2C_ADDR01		(0x86 >> 1)	/* 1000 011x */
#define LM8323_I2C_ADDR10		(0x88 >> 1)	/* 1000 100x */
#define LM8323_I2C_ADDR11		(0x8A >> 1)	/* 1000 101x */

/* Key event fifo length */
#define LM8323_FIFO_LEN			15

/* Commands for PWM engine; feed in with PWM_WRITE. */
/* Load ramp counter from duty cycle field (range 0 - 0xff). */
#define PWM_SET(v)			(0x4000 | ((v) & 0xff))
/* Go to start of script. */
#define PWM_GOTOSTART			0x0000
/*
 * Stop engine (generates interrupt).  If reset is 1, clear the program
 * counter, else leave it.
 */
#define PWM_END(reset)			(0xc000 | (!!(reset) << 11))
/*
 * Ramp.  If s is 1, divide clock by 512, else divide clock by 16.
 * Take t clock scales (up to 63) per step, for n steps (up to 126).
 * If u is set, ramp up, else ramp down.
 */
#define PWM_RAMP(s, t, n, u)		((!!(s) << 14) | ((t) & 0x3f) << 8 | \
					 ((n) & 0x7f) | ((u) ? 0 : 0x80))
/*
 * Loop (i.e. jump back to pos) for a given number of iterations (up to 63).
 * If cnt is zero, execute until PWM_END is encountered.
 */
#define PWM_LOOP(cnt, pos)		(0xa000 | (((cnt) & 0x3f) << 7) | \
					 ((pos) & 0x3f))
/*
 * Wait for trigger.  Argument is a mask of channels, shifted by the channel
 * number, e.g. 0xa for channels 3 and 1.  Note that channels are numbered
 * from 1, not 0.
 */
#define PWM_WAIT_TRIG(chans)		(0xe000 | (((chans) & 0x7) << 6))
/* Send trigger.  Argument is same as PWM_WAIT_TRIG. */
#define PWM_SEND_TRIG(chans)		(0xe000 | ((chans) & 0x7))

struct lm8323_pwm {
	int			id;
	int			fade_time;
	int			brightness;
	int			desired_brightness;
	bool			enabled;
	bool			running;
	/* pwm lock */
	struct mutex		lock;
	struct work_struct	work;
	struct led_classdev	cdev;
	struct lm8323_chip	*chip;
};

struct lm8323_chip {
	/* device lock */
	struct mutex		lock;
	struct i2c_client	*client;
	struct input_dev	*idev;
	bool			kp_enabled;
	bool			pm_suspend;
	unsigned		keys_down;
	char			phys[32];
	unsigned short		keymap[LM8323_KEYMAP_SIZE];
	int			size_x;
	int			size_y;
	int			debounce_time;
	int			active_time;
	struct lm8323_pwm	pwm[LM8323_NUM_PWMS];
};

#define client_to_lm8323(c)	container_of(c, struct lm8323_chip, client)
#define dev_to_lm8323(d)	container_of(d, struct lm8323_chip, client->dev)
#define cdev_to_pwm(c)		container_of(c, struct lm8323_pwm, cdev)
#define work_to_pwm(w)		container_of(w, struct lm8323_pwm, work)

#define LM8323_MAX_DATA 8

/*
 * To write, we just access the chip's address in write mode, and dump the
 * command and data out on the bus.  The command byte and data are taken as
 * sequential u8s out of varargs, to a maximum of LM8323_MAX_DATA.
 */
static int lm8323_write(struct lm8323_chip *lm, int len, ...)
{
	int ret, i;
	va_list ap;
	u8 data[LM8323_MAX_DATA];

	va_start(ap, len);

	if (unlikely(len > LM8323_MAX_DATA)) {
		dev_err(&lm->client->dev, "tried to send %d bytes\n", len);
		va_end(ap);
		return 0;
	}

	for (i = 0; i < len; i++)
		data[i] = va_arg(ap, int);

	va_end(ap);

	/*
	 * If the host is asleep while we send the data, we can get a NACK
	 * back while it wakes up, so try again, once.
	 */
	ret = i2c_master_send(lm->client, data, len);
	if (unlikely(ret == -EREMOTEIO))
		ret = i2c_master_send(lm->client, data, len);
	if (unlikely(ret != len))
		dev_err(&lm->client->dev, "sent %d bytes of %d total\n",
			len, ret);

	return ret;
}

/*
 * To read, we first send the command byte to the chip and end the transaction,
 * then access the chip in read mode, at which point it will send the data.
 */
static int lm8323_read(struct lm8323_chip *lm, u8 cmd, u8 *buf, int len)
{
	int ret;

	/*
	 * If the host is asleep while we send the byte, we can get a NACK
	 * back while it wakes up, so try again, once.
	 */
	ret = i2c_master_send(lm->client, &cmd, 1);
	if (unlikely(ret == -EREMOTEIO))
		ret = i2c_master_send(lm->client, &cmd, 1);
	if (unlikely(ret != 1)) {
		dev_err(&lm->client->dev, "sending read cmd 0x%02x failed\n",
			cmd);
		return 0;
	}

	ret = i2c_master_recv(lm->client, buf, len);
	if (unlikely(ret != len))
		dev_err(&lm->client->dev, "wanted %d bytes, got %d\n",
			len, ret);

	return ret;
}

/*
 * Set the chip active time (idle time before it enters halt).
 */
static void lm8323_set_active_time(struct lm8323_chip *lm, int time)
{
	lm8323_write(lm, 2, LM8323_CMD_SET_ACTIVE, time >> 2);
}

/*
 * The signals are AT-style: the low 7 bits are the keycode, and the top
 * bit indicates the state (1 for down, 0 for up).
 */
static inline u8 lm8323_whichkey(u8 event)
{
	return event & 0x7f;
}

static inline int lm8323_ispress(u8 event)
{
	return (event & 0x80) ? 1 : 0;
}

static void process_keys(struct lm8323_chip *lm)
{
	u8 event;
	u8 key_fifo[LM8323_FIFO_LEN + 1];
	int old_keys_down = lm->keys_down;
	int ret;
	int i = 0;

	/*
	 * Read all key events from the FIFO at once. Next READ_FIFO clears the
	 * FIFO even if we didn't read all events previously.
	 */
	ret = lm8323_read(lm, LM8323_CMD_READ_FIFO, key_fifo, LM8323_FIFO_LEN);

	if (ret < 0) {
		dev_err(&lm->client->dev, "Failed reading fifo \n");
		return;
	}
	key_fifo[ret] = 0;

	while ((event = key_fifo[i++])) {
		u8 key = lm8323_whichkey(event);
		int isdown = lm8323_ispress(event);
		unsigned short keycode = lm->keymap[key];

		dev_vdbg(&lm->client->dev, "key 0x%02x %s\n",
			 key, isdown ? "down" : "up");

		if (lm->kp_enabled) {
			input_event(lm->idev, EV_MSC, MSC_SCAN, key);
			input_report_key(lm->idev, keycode, isdown);
			input_sync(lm->idev);
		}

		if (isdown)
			lm->keys_down++;
		else
			lm->keys_down--;
	}

	/*
	 * Errata: We need to ensure that the chip never enters halt mode
	 * during a keypress, so set active time to 0.  When it's released,
	 * we can enter halt again, so set the active time back to normal.
	 */
	if (!old_keys_down && lm->keys_down)
		lm8323_set_active_time(lm, 0);
	if (old_keys_down && !lm->keys_down)
		lm8323_set_active_time(lm, lm->active_time);
}

static void lm8323_process_error(struct lm8323_chip *lm)
{
	u8 error;

	if (lm8323_read(lm, LM8323_CMD_READ_ERR, &error, 1) == 1) {
		if (error & ERR_FIFOOVER)
			dev_vdbg(&lm->client->dev, "fifo overflow!\n");
		if (error & ERR_KEYOVR)
			dev_vdbg(&lm->client->dev,
					"more than two keys pressed\n");
		if (error & ERR_CMDUNK)
			dev_vdbg(&lm->client->dev,
					"unknown command submitted\n");
		if (error & ERR_BADPAR)
			dev_vdbg(&lm->client->dev, "bad command parameter\n");
	}
}

static void lm8323_reset(struct lm8323_chip *lm)
{
	/* The docs say we must pass 0xAA as the data byte. */
	lm8323_write(lm, 2, LM8323_CMD_RESET, 0xAA);
}

static int lm8323_configure(struct lm8323_chip *lm)
{
	int keysize = (lm->size_x << 4) | lm->size_y;
	int clock = (CLK_SLOWCLKEN | CLK_RCPWM_EXTERNAL);
	int debounce = lm->debounce_time >> 2;
	int active = lm->active_time >> 2;

	/*
	 * Active time must be greater than the debounce time: if it's
	 * a close-run thing, give ourselves a 12ms buffer.
	 */
	if (debounce >= active)
		active = debounce + 3;

	lm8323_write(lm, 2, LM8323_CMD_WRITE_CFG, 0);
	lm8323_write(lm, 2, LM8323_CMD_WRITE_CLOCK, clock);
	lm8323_write(lm, 2, LM8323_CMD_SET_KEY_SIZE, keysize);
	lm8323_set_active_time(lm, lm->active_time);
	lm8323_write(lm, 2, LM8323_CMD_SET_DEBOUNCE, debounce);
	lm8323_write(lm, 3, LM8323_CMD_WRITE_PORT_STATE, 0xff, 0xff);
	lm8323_write(lm, 3, LM8323_CMD_WRITE_PORT_SEL, 0, 0);

	/*
	 * Not much we can do about errors at this point, so just hope
	 * for the best.
	 */

	return 0;
}

static void pwm_done(struct lm8323_pwm *pwm)
{
	mutex_lock(&pwm->lock);
	pwm->running = false;
	if (pwm->desired_brightness != pwm->brightness)
		schedule_work(&pwm->work);
	mutex_unlock(&pwm->lock);
}

/*
 * Bottom half: handle the interrupt by posting key events, or dealing with
 * errors appropriately.
 */
static irqreturn_t lm8323_irq(int irq, void *_lm)
{
	struct lm8323_chip *lm = _lm;
	u8 ints;
	int i;

	mutex_lock(&lm->lock);

	while ((lm8323_read(lm, LM8323_CMD_READ_INT, &ints, 1) == 1) && ints) {
		if (likely(ints & INT_KEYPAD))
			process_keys(lm);
		if (ints & INT_ROTATOR) {
			/* We don't currently support the rotator. */
			dev_vdbg(&lm->client->dev, "rotator fired\n");
		}
		if (ints & INT_ERROR) {
			dev_vdbg(&lm->client->dev, "error!\n");
			lm8323_process_error(lm);
		}
		if (ints & INT_NOINIT) {
			dev_err(&lm->client->dev, "chip lost config; "
						  "reinitialising\n");
			lm8323_configure(lm);
		}
		for (i = 0; i < LM8323_NUM_PWMS; i++) {
			if (ints & (1 << (INT_PWM1 + i))) {
				dev_vdbg(&lm->client->dev,
					 "pwm%d engine completed\n", i);
				pwm_done(&lm->pwm[i]);
			}
		}
	}

	mutex_unlock(&lm->lock);

	return IRQ_HANDLED;
}

/*
 * Read the chip ID.
 */
static int lm8323_read_id(struct lm8323_chip *lm, u8 *buf)
{
	int bytes;

	bytes = lm8323_read(lm, LM8323_CMD_READ_ID, buf, 2);
	if (unlikely(bytes != 2))
		return -EIO;

	return 0;
}

static void lm8323_write_pwm_one(struct lm8323_pwm *pwm, int pos, u16 cmd)
{
	lm8323_write(pwm->chip, 4, LM8323_CMD_PWM_WRITE, (pos << 2) | pwm->id,
		     (cmd & 0xff00) >> 8, cmd & 0x00ff);
}

/*
 * Write a script into a given PWM engine, concluding with PWM_END.
 * If 'kill' is nonzero, the engine will be shut down at the end
 * of the script, producing a zero output. Otherwise the engine
 * will be kept running at the final PWM level indefinitely.
 */
static void lm8323_write_pwm(struct lm8323_pwm *pwm, int kill,
			     int len, const u16 *cmds)
{
	int i;

	for (i = 0; i < len; i++)
		lm8323_write_pwm_one(pwm, i, cmds[i]);

	lm8323_write_pwm_one(pwm, i++, PWM_END(kill));
	lm8323_write(pwm->chip, 2, LM8323_CMD_START_PWM, pwm->id);
	pwm->running = true;
}

static void lm8323_pwm_work(struct work_struct *work)
{
	struct lm8323_pwm *pwm = work_to_pwm(work);
	int div512, perstep, steps, hz, up, kill;
	u16 pwm_cmds[3];
	int num_cmds = 0;

	mutex_lock(&pwm->lock);

	/*
	 * Do nothing if we're already at the requested level,
	 * or previous setting is not yet complete. In the latter
	 * case we will be called again when the previous PWM script
	 * finishes.
	 */
	if (pwm->running || pwm->desired_brightness == pwm->brightness)
		goto out;

	kill = (pwm->desired_brightness == 0);
	up = (pwm->desired_brightness > pwm->brightness);
	steps = abs(pwm->desired_brightness - pwm->brightness);

	/*
	 * Convert time (in ms) into a divisor (512 or 16 on a refclk of
	 * 32768Hz), and number of ticks per step.
	 */
	if ((pwm->fade_time / steps) > (32768 / 512)) {
		div512 = 1;
		hz = 32768 / 512;
	} else {
		div512 = 0;
		hz = 32768 / 16;
	}

	perstep = (hz * pwm->fade_time) / (steps * 1000);

	if (perstep == 0)
		perstep = 1;
	else if (perstep > 63)
		perstep = 63;

	while (steps) {
		int s;

		s = min(126, steps);
		pwm_cmds[num_cmds++] = PWM_RAMP(div512, perstep, s, up);
		steps -= s;
	}

	lm8323_write_pwm(pwm, kill, num_cmds, pwm_cmds);
	pwm->brightness = pwm->desired_brightness;

 out:
	mutex_unlock(&pwm->lock);
}

static void lm8323_pwm_set_brightness(struct led_classdev *led_cdev,
				      enum led_brightness brightness)
{
	struct lm8323_pwm *pwm = cdev_to_pwm(led_cdev);
	struct lm8323_chip *lm = pwm->chip;

	mutex_lock(&pwm->lock);
	pwm->desired_brightness = brightness;
	mutex_unlock(&pwm->lock);

	if (in_interrupt()) {
		schedule_work(&pwm->work);
	} else {
		/*
		 * Schedule PWM work as usual unless we are going into suspend
		 */
		mutex_lock(&lm->lock);
		if (likely(!lm->pm_suspend))
			schedule_work(&pwm->work);
		else
			lm8323_pwm_work(&pwm->work);
		mutex_unlock(&lm->lock);
	}
}

static ssize_t lm8323_pwm_show_time(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct led_classdev *led_cdev = dev_get_drvdata(dev);
	struct lm8323_pwm *pwm = cdev_to_pwm(led_cdev);

	return sprintf(buf, "%d\n", pwm->fade_time);
}

static ssize_t lm8323_pwm_store_time(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t len)
{
	struct led_classdev *led_cdev = dev_get_drvdata(dev);
	struct lm8323_pwm *pwm = cdev_to_pwm(led_cdev);
	int ret, time;

	ret = kstrtoint(buf, 10, &time);
	/* Numbers only, please. */
	if (ret)
		return ret;

	pwm->fade_time = time;

	return strlen(buf);
}
static DEVICE_ATTR(time, 0644, lm8323_pwm_show_time, lm8323_pwm_store_time);

static int init_pwm(struct lm8323_chip *lm, int id, struct device *dev,
		    const char *name)
{
	struct lm8323_pwm *pwm;

	BUG_ON(id > 3);

	pwm = &lm->pwm[id - 1];

	pwm->id = id;
	pwm->fade_time = 0;
	pwm->brightness = 0;
	pwm->desired_brightness = 0;
	pwm->running = false;
	pwm->enabled = false;
	INIT_WORK(&pwm->work, lm8323_pwm_work);
	mutex_init(&pwm->lock);
	pwm->chip = lm;

	if (name) {
		pwm->cdev.name = name;
		pwm->cdev.brightness_set = lm8323_pwm_set_brightness;
		if (led_classdev_register(dev, &pwm->cdev) < 0) {
			dev_err(dev, "couldn't register PWM %d\n", id);
			return -1;
		}
		if (device_create_file(pwm->cdev.dev,
					&dev_attr_time) < 0) {
			dev_err(dev, "couldn't register time attribute\n");
			led_classdev_unregister(&pwm->cdev);
			return -1;
		}
		pwm->enabled = true;
	}

	return 0;
}

static struct i2c_driver lm8323_i2c_driver;

static ssize_t lm8323_show_disable(struct device *dev,
				   struct device_attribute *attr, char *buf)
{
	struct lm8323_chip *lm = dev_get_drvdata(dev);

	return sprintf(buf, "%u\n", !lm->kp_enabled);
}

static ssize_t lm8323_set_disable(struct device *dev,
				  struct device_attribute *attr,
				  const char *buf, size_t count)
{
	struct lm8323_chip *lm = dev_get_drvdata(dev);
	int ret;
	unsigned int i;

	ret = kstrtouint(buf, 10, &i);

	mutex_lock(&lm->lock);
	lm->kp_enabled = !i;
	mutex_unlock(&lm->lock);

	return count;
}
static DEVICE_ATTR(disable_kp, 0644, lm8323_show_disable, lm8323_set_disable);

static int __devinit lm8323_probe(struct i2c_client *client,
				  const struct i2c_device_id *id)
{
	struct lm8323_platform_data *pdata = client->dev.platform_data;
	struct input_dev *idev;
	struct lm8323_chip *lm;
	int pwm;
	int i, err;
	unsigned long tmo;
	u8 data[2];

	if (!pdata || !pdata->size_x || !pdata->size_y) {
		dev_err(&client->dev, "missing platform_data\n");
		return -EINVAL;
	}

	if (pdata->size_x > 8) {
		dev_err(&client->dev, "invalid x size %d specified\n",
			pdata->size_x);
		return -EINVAL;
	}

	if (pdata->size_y > 12) {
		dev_err(&client->dev, "invalid y size %d specified\n",
			pdata->size_y);
		return -EINVAL;
	}

	lm = kzalloc(sizeof *lm, GFP_KERNEL);
	idev = input_allocate_device();
	if (!lm || !idev) {
		err = -ENOMEM;
		goto fail1;
	}

	lm->client = client;
	lm->idev = idev;
	mutex_init(&lm->lock);

	lm->size_x = pdata->size_x;
	lm->size_y = pdata->size_y;
	dev_vdbg(&client->dev, "Keypad size: %d x %d\n",
		 lm->size_x, lm->size_y);

	lm->debounce_time = pdata->debounce_time;
	lm->active_time = pdata->active_time;

	lm8323_reset(lm);

	/* Nothing's set up to service the IRQ yet, so just spin for max.
	 * 100ms until we can configure. */
	tmo = jiffies + msecs_to_jiffies(100);
	while (lm8323_read(lm, LM8323_CMD_READ_INT, data, 1) == 1) {
		if (data[0] & INT_NOINIT)
			break;

		if (time_after(jiffies, tmo)) {
			dev_err(&client->dev,
				"timeout waiting for initialisation\n");
			break;
		}

		msleep(1);
	}

	lm8323_configure(lm);

	/* If a true probe check the device */
	if (lm8323_read_id(lm, data) != 0) {
		dev_err(&client->dev, "device not found\n");
		err = -ENODEV;
		goto fail1;
	}

	for (pwm = 0; pwm < LM8323_NUM_PWMS; pwm++) {
		err = init_pwm(lm, pwm + 1, &client->dev,
			       pdata->pwm_names[pwm]);
		if (err < 0)
			goto fail2;
	}

	lm->kp_enabled = true;
	err = device_create_file(&client->dev, &dev_attr_disable_kp);
	if (err < 0)
		goto fail2;

	idev->name = pdata->name ? : "LM8323 keypad";
	snprintf(lm->phys, sizeof(lm->phys),
		 "%s/input-kp", dev_name(&client->dev));
	idev->phys = lm->phys;

	idev->evbit[0] = BIT(EV_KEY) | BIT(EV_MSC);
	__set_bit(MSC_SCAN, idev->mscbit);
	for (i = 0; i < LM8323_KEYMAP_SIZE; i++) {
		__set_bit(pdata->keymap[i], idev->keybit);
		lm->keymap[i] = pdata->keymap[i];
	}
	__clear_bit(KEY_RESERVED, idev->keybit);

	if (pdata->repeat)
		__set_bit(EV_REP, idev->evbit);

	err = input_register_device(idev);
	if (err) {
		dev_dbg(&client->dev, "error registering input device\n");
		goto fail3;
	}

	err = request_threaded_irq(client->irq, NULL, lm8323_irq,
			  IRQF_TRIGGER_LOW|IRQF_ONESHOT, "lm8323", lm);
	if (err) {
		dev_err(&client->dev, "could not get IRQ %d\n", client->irq);
		goto fail4;
	}

	i2c_set_clientdata(client, lm);

	device_init_wakeup(&client->dev, 1);
	enable_irq_wake(client->irq);

	return 0;

fail4:
	input_unregister_device(idev);
	idev = NULL;
fail3:
	device_remove_file(&client->dev, &dev_attr_disable_kp);
fail2:
	while (--pwm >= 0)
		if (lm->pwm[pwm].enabled) {
			device_remove_file(lm->pwm[pwm].cdev.dev,
					   &dev_attr_time);
			led_classdev_unregister(&lm->pwm[pwm].cdev);
		}
fail1:
	input_free_device(idev);
	kfree(lm);
	return err;
}

static int __devexit lm8323_remove(struct i2c_client *client)
{
	struct lm8323_chip *lm = i2c_get_clientdata(client);
	int i;

	disable_irq_wake(client->irq);
	free_irq(client->irq, lm);

	input_unregister_device(lm->idev);

	device_remove_file(&lm->client->dev, &dev_attr_disable_kp);

	for (i = 0; i < 3; i++)
		if (lm->pwm[i].enabled) {
			device_remove_file(lm->pwm[i].cdev.dev, &dev_attr_time);
			led_classdev_unregister(&lm->pwm[i].cdev);
		}

	kfree(lm);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
/*
 * We don't need to explicitly suspend the chip, as it already switches off
 * when there's no activity.
 */
static int lm8323_suspend(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm8323_chip *lm = i2c_get_clientdata(client);
	int i;

	irq_set_irq_wake(client->irq, 0);
	disable_irq(client->irq);

	mutex_lock(&lm->lock);
	lm->pm_suspend = true;
	mutex_unlock(&lm->lock);

	for (i = 0; i < 3; i++)
		if (lm->pwm[i].enabled)
			led_classdev_suspend(&lm->pwm[i].cdev);

	return 0;
}

static int lm8323_resume(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm8323_chip *lm = i2c_get_clientdata(client);
	int i;

	mutex_lock(&lm->lock);
	lm->pm_suspend = false;
	mutex_unlock(&lm->lock);

	for (i = 0; i < 3; i++)
		if (lm->pwm[i].enabled)
			led_classdev_resume(&lm->pwm[i].cdev);

	enable_irq(client->irq);
	irq_set_irq_wake(client->irq, 1);

	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(lm8323_pm_ops, lm8323_suspend, lm8323_resume);

static const struct i2c_device_id lm8323_id[] = {
	{ "lm8323", 0 },
	{ }
};

static struct i2c_driver lm8323_i2c_driver = {
	.driver = {
		.name	= "lm8323",
		.pm	= &lm8323_pm_ops,
	},
	.probe		= lm8323_probe,
	.remove		= __devexit_p(lm8323_remove),
	.id_table	= lm8323_id,
};
MODULE_DEVICE_TABLE(i2c, lm8323_id);

static int __init lm8323_init(void)
{
	return i2c_add_driver(&lm8323_i2c_driver);
}
module_init(lm8323_init);

static void __exit lm8323_exit(void)
{
	i2c_del_driver(&lm8323_i2c_driver);
}
module_exit(lm8323_exit);

MODULE_AUTHOR("Timo O. Karjalainen <timo.o.karjalainen@nokia.com>");
MODULE_AUTHOR("Daniel Stone");
MODULE_AUTHOR("Felipe Balbi <felipe.balbi@nokia.com>");
MODULE_DESCRIPTION("LM8323 keypad driver");
MODULE_LICENSE("GPL");