omap24xx_i2c.c 19.5 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
/*
 * Basic I2C functions
 *
 * Copyright (c) 2004 Texas Instruments
 *
 * This package is free software;  you can redistribute it and/or
 * modify it under the terms of the license found in the file
 * named COPYING that should have accompanied this file.
 *
 * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Author: Jian Zhang jzhang@ti.com, Texas Instruments
 *
 * Copyright (c) 2003 Wolfgang Denk, wd@denx.de
 * Rewritten to fit into the current U-Boot framework
 *
 * Adapted for OMAP2420 I2C, r-woodruff2@ti.com
 *
 * Copyright (c) 2013 Lubomir Popov <lpopov@mm-sol.com>, MM Solutions
 * New i2c_read, i2c_write and i2c_probe functions, tested on OMAP4
 * (4430/60/70), OMAP5 (5430) and AM335X (3359); should work on older
 * OMAPs and derivatives as well. The only anticipated exception would
 * be the OMAP2420, which shall require driver modification.
 * - Rewritten i2c_read to operate correctly with all types of chips
 *   (old function could not read consistent data from some I2C slaves).
 * - Optimized i2c_write.
 * - New i2c_probe, performs write access vs read. The old probe could
 *   hang the system under certain conditions (e.g. unconfigured pads).
 * - The read/write/probe functions try to identify unconfigured bus.
 * - Status functions now read irqstatus_raw as per TRM guidelines
 *   (except for OMAP243X and OMAP34XX).
 * - Driver now supports up to I2C5 (OMAP5).
 *
 * Copyright (c) 2014 Hannes Petermaier <oe5hpm@oevsv.at>, B&R
 * - Added support for set_speed
 *
 */

#include <common.h>
#include <i2c.h>

#include <asm/arch/i2c.h>
#include <asm/io.h>

#include "omap24xx_i2c.h"

DECLARE_GLOBAL_DATA_PTR;

#define I2C_TIMEOUT	1000

/* Absolutely safe for status update at 100 kHz I2C: */
#define I2C_WAIT	200

static int wait_for_bb(struct i2c_adapter *adap);
static struct i2c *omap24_get_base(struct i2c_adapter *adap);
static u16 wait_for_event(struct i2c_adapter *adap);
static void flush_fifo(struct i2c_adapter *adap);
static int omap24_i2c_findpsc(u32 *pscl, u32 *psch, uint speed)
{
	unsigned int sampleclk, prescaler;
	int fsscll, fssclh;

	speed <<= 1;
	prescaler = 0;
	/*
	 * some divisors may cause a precission loss, but shouldn't
	 * be a big thing, because i2c_clk is then allready very slow.
	 */
	while (prescaler <= 0xFF) {
		sampleclk = I2C_IP_CLK / (prescaler+1);

		fsscll = sampleclk / speed;
		fssclh = fsscll;
		fsscll -= I2C_FASTSPEED_SCLL_TRIM;
		fssclh -= I2C_FASTSPEED_SCLH_TRIM;

		if (((fsscll > 0) && (fssclh > 0)) &&
		    ((fsscll <= (255-I2C_FASTSPEED_SCLL_TRIM)) &&
		    (fssclh <= (255-I2C_FASTSPEED_SCLH_TRIM)))) {
			if (pscl)
				*pscl = fsscll;
			if (psch)
				*psch = fssclh;

			return prescaler;
		}
		prescaler++;
	}
	return -1;
}
static uint omap24_i2c_setspeed(struct i2c_adapter *adap, uint speed)
{
	struct i2c *i2c_base = omap24_get_base(adap);
	int psc, fsscll = 0, fssclh = 0;
	int hsscll = 0, hssclh = 0;
	u32 scll = 0, sclh = 0;

	if (speed >= OMAP_I2C_HIGH_SPEED) {
		/* High speed */
		psc = I2C_IP_CLK / I2C_INTERNAL_SAMPLING_CLK;
		psc -= 1;
		if (psc < I2C_PSC_MIN) {
			printf("Error : I2C unsupported prescaler %d\n", psc);
			return -1;
		}

		/* For first phase of HS mode */
		fsscll = I2C_INTERNAL_SAMPLING_CLK / (2 * speed);

		fssclh = fsscll;

		fsscll -= I2C_HIGHSPEED_PHASE_ONE_SCLL_TRIM;
		fssclh -= I2C_HIGHSPEED_PHASE_ONE_SCLH_TRIM;
		if (((fsscll < 0) || (fssclh < 0)) ||
		    ((fsscll > 255) || (fssclh > 255))) {
			puts("Error : I2C initializing first phase clock\n");
			return -1;
		}

		/* For second phase of HS mode */
		hsscll = hssclh = I2C_INTERNAL_SAMPLING_CLK / (2 * speed);

		hsscll -= I2C_HIGHSPEED_PHASE_TWO_SCLL_TRIM;
		hssclh -= I2C_HIGHSPEED_PHASE_TWO_SCLH_TRIM;
		if (((fsscll < 0) || (fssclh < 0)) ||
		    ((fsscll > 255) || (fssclh > 255))) {
			puts("Error : I2C initializing second phase clock\n");
			return -1;
		}

		scll = (unsigned int)hsscll << 8 | (unsigned int)fsscll;
		sclh = (unsigned int)hssclh << 8 | (unsigned int)fssclh;

	} else {
		/* Standard and fast speed */
		psc = omap24_i2c_findpsc(&scll, &sclh, speed);
		if (0 > psc) {
			puts("Error : I2C initializing clock\n");
			return -1;
		}
	}

	adap->speed	= speed;
	adap->waitdelay = (10000000 / speed) * 2; /* wait for 20 clkperiods */
	writew(0, &i2c_base->con);
	writew(psc, &i2c_base->psc);
	writew(scll, &i2c_base->scll);
	writew(sclh, &i2c_base->sclh);
	writew(I2C_CON_EN, &i2c_base->con);
	writew(0xFFFF, &i2c_base->stat);	/* clear all pending status */

	return 0;
}

static void omap24_i2c_deblock(struct i2c_adapter *adap)
{
	struct i2c *i2c_base = omap24_get_base(adap);
	int i;
	u16 systest;
	u16 orgsystest;

	/* set test mode ST_EN = 1 */
	orgsystest = readw(&i2c_base->systest);
	systest = orgsystest;
	/* enable testmode */
	systest |= I2C_SYSTEST_ST_EN;
	writew(systest, &i2c_base->systest);
	systest &= ~I2C_SYSTEST_TMODE_MASK;
	systest |= 3 << I2C_SYSTEST_TMODE_SHIFT;
	writew(systest, &i2c_base->systest);

	/* set SCL, SDA  = 1 */
	systest |= I2C_SYSTEST_SCL_O | I2C_SYSTEST_SDA_O;
	writew(systest, &i2c_base->systest);
	udelay(10);

	/* toggle scl 9 clocks */
	for (i = 0; i < 9; i++) {
		/* SCL = 0 */
		systest &= ~I2C_SYSTEST_SCL_O;
		writew(systest, &i2c_base->systest);
		udelay(10);
		/* SCL = 1 */
		systest |= I2C_SYSTEST_SCL_O;
		writew(systest, &i2c_base->systest);
		udelay(10);
	}

	/* send stop */
	systest &= ~I2C_SYSTEST_SDA_O;
	writew(systest, &i2c_base->systest);
	udelay(10);
	systest |= I2C_SYSTEST_SCL_O | I2C_SYSTEST_SDA_O;
	writew(systest, &i2c_base->systest);
	udelay(10);

	/* restore original mode */
	writew(orgsystest, &i2c_base->systest);
}

static void omap24_i2c_init(struct i2c_adapter *adap, int speed, int slaveadd)
{
	struct i2c *i2c_base = omap24_get_base(adap);
	int timeout = I2C_TIMEOUT;
	int deblock = 1;

retry:
	if (readw(&i2c_base->con) & I2C_CON_EN) {
		writew(0, &i2c_base->con);
		udelay(50000);
	}

	writew(0x2, &i2c_base->sysc); /* for ES2 after soft reset */
	udelay(1000);

	writew(I2C_CON_EN, &i2c_base->con);
	while (!(readw(&i2c_base->syss) & I2C_SYSS_RDONE) && timeout--) {
		if (timeout <= 0) {
			puts("ERROR: Timeout in soft-reset\n");
			return;
		}
		udelay(1000);
	}

	if (0 != omap24_i2c_setspeed(adap, speed)) {
		printf("ERROR: failed to setup I2C bus-speed!\n");
		return;
	}

	/* own address */
	writew(slaveadd, &i2c_base->oa);

#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
	/*
	 * Have to enable interrupts for OMAP2/3, these IPs don't have
	 * an 'irqstatus_raw' register and we shall have to poll 'stat'
	 */
	writew(I2C_IE_XRDY_IE | I2C_IE_RRDY_IE | I2C_IE_ARDY_IE |
	       I2C_IE_NACK_IE | I2C_IE_AL_IE, &i2c_base->ie);
#endif
	udelay(1000);
	flush_fifo(adap);
	writew(0xFFFF, &i2c_base->stat);

	/* Handle possible failed I2C state */
	if (wait_for_bb(adap))
		if (deblock == 1) {
			omap24_i2c_deblock(adap);
			deblock = 0;
			goto retry;
		}
}

static void flush_fifo(struct i2c_adapter *adap)
{
	struct i2c *i2c_base = omap24_get_base(adap);
	u16 stat;

	/*
	 * note: if you try and read data when its not there or ready
	 * you get a bus error
	 */
	while (1) {
		stat = readw(&i2c_base->stat);
		if (stat == I2C_STAT_RRDY) {
			readb(&i2c_base->data);
			writew(I2C_STAT_RRDY, &i2c_base->stat);
			udelay(1000);
		} else
			break;
	}
}

/*
 * i2c_probe: Use write access. Allows to identify addresses that are
 *            write-only (like the config register of dual-port EEPROMs)
 */
static int omap24_i2c_probe(struct i2c_adapter *adap, uchar chip)
{
	struct i2c *i2c_base = omap24_get_base(adap);
	u16 status;
	int res = 1; /* default = fail */

	if (chip == readw(&i2c_base->oa))
		return res;

	/* Wait until bus is free */
	if (wait_for_bb(adap))
		return res;

	/* No data transfer, slave addr only */
	writew(chip, &i2c_base->sa);
	/* Stop bit needed here */
	writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX |
	       I2C_CON_STP, &i2c_base->con);

	status = wait_for_event(adap);

	if ((status & ~I2C_STAT_XRDY) == 0 || (status & I2C_STAT_AL)) {
		/*
		 * With current high-level command implementation, notifying
		 * the user shall flood the console with 127 messages. If
		 * silent exit is desired upon unconfigured bus, remove the
		 * following 'if' section:
		 */
		if (status == I2C_STAT_XRDY)
			printf("i2c_probe: pads on bus %d probably not configured (status=0x%x)\n",
			       adap->hwadapnr, status);

		goto pr_exit;
	}

	/* Check for ACK (!NAK) */
	if (!(status & I2C_STAT_NACK)) {
		res = 0;				/* Device found */
		udelay(adap->waitdelay);/* Required by AM335X in SPL */
		/* Abort transfer (force idle state) */
		writew(I2C_CON_MST | I2C_CON_TRX, &i2c_base->con); /* Reset */
		udelay(1000);
		writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_TRX |
		       I2C_CON_STP, &i2c_base->con);		/* STP */
	}
pr_exit:
	flush_fifo(adap);
	writew(0xFFFF, &i2c_base->stat);
	return res;
}

/*
 * i2c_read: Function now uses a single I2C read transaction with bulk transfer
 *           of the requested number of bytes (note that the 'i2c md' command
 *           limits this to 16 bytes anyway). If CONFIG_I2C_REPEATED_START is
 *           defined in the board config header, this transaction shall be with
 *           Repeated Start (Sr) between the address and data phases; otherwise
 *           Stop-Start (P-S) shall be used (some I2C chips do require a P-S).
 *           The address (reg offset) may be 0, 1 or 2 bytes long.
 *           Function now reads correctly from chips that return more than one
 *           byte of data per addressed register (like TI temperature sensors),
 *           or that do not need a register address at all (such as some clock
 *           distributors).
 */
static int omap24_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
			   int alen, uchar *buffer, int len)
{
	struct i2c *i2c_base = omap24_get_base(adap);
	int i2c_error = 0;
	u16 status;

	if (alen < 0) {
		puts("I2C read: addr len < 0\n");
		return 1;
	}
	if (len < 0) {
		puts("I2C read: data len < 0\n");
		return 1;
	}
	if (buffer == NULL) {
		puts("I2C read: NULL pointer passed\n");
		return 1;
	}

	if (alen > 2) {
		printf("I2C read: addr len %d not supported\n", alen);
		return 1;
	}

	if (addr + len > (1 << 16)) {
		puts("I2C read: address out of range\n");
		return 1;
	}

	/* Wait until bus not busy */
	if (wait_for_bb(adap))
		return 1;

	/* Zero, one or two bytes reg address (offset) */
	writew(alen, &i2c_base->cnt);
	/* Set slave address */
	writew(chip, &i2c_base->sa);

	if (alen) {
		/* Must write reg offset first */
#ifdef CONFIG_I2C_REPEATED_START
		/* No stop bit, use Repeated Start (Sr) */
		writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT |
		       I2C_CON_TRX, &i2c_base->con);
#else
		/* Stop - Start (P-S) */
		writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_STP |
		       I2C_CON_TRX, &i2c_base->con);
#endif
		/* Send register offset */
		while (1) {
			status = wait_for_event(adap);
			/* Try to identify bus that is not padconf'd for I2C */
			if (status == I2C_STAT_XRDY) {
				i2c_error = 2;
				printf("i2c_read (addr phase): pads on bus %d probably not configured (status=0x%x)\n",
				       adap->hwadapnr, status);
				goto rd_exit;
			}
			if (status == 0 || (status & I2C_STAT_NACK)) {
				i2c_error = 1;
				printf("i2c_read: error waiting for addr ACK (status=0x%x)\n",
				       status);
				goto rd_exit;
			}
			if (alen) {
				if (status & I2C_STAT_XRDY) {
					alen--;
					/* Do we have to use byte access? */
					writeb((addr >> (8 * alen)) & 0xff,
					       &i2c_base->data);
					writew(I2C_STAT_XRDY, &i2c_base->stat);
				}
			}
			if (status & I2C_STAT_ARDY) {
				writew(I2C_STAT_ARDY, &i2c_base->stat);
				break;
			}
		}
	}
	/* Set slave address */
	writew(chip, &i2c_base->sa);
	/* Read len bytes from slave */
	writew(len, &i2c_base->cnt);
	/* Need stop bit here */
	writew(I2C_CON_EN | I2C_CON_MST |
	       I2C_CON_STT | I2C_CON_STP,
	       &i2c_base->con);

	/* Receive data */
	while (1) {
		status = wait_for_event(adap);
		/*
		 * Try to identify bus that is not padconf'd for I2C. This
		 * state could be left over from previous transactions if
		 * the address phase is skipped due to alen=0.
		 */
		if (status == I2C_STAT_XRDY) {
			i2c_error = 2;
			printf("i2c_read (data phase): pads on bus %d probably not configured (status=0x%x)\n",
			       adap->hwadapnr, status);
			goto rd_exit;
		}
		if (status == 0 || (status & I2C_STAT_NACK)) {
			i2c_error = 1;
			goto rd_exit;
		}
		if (status & I2C_STAT_RRDY) {
			*buffer++ = readb(&i2c_base->data);
			writew(I2C_STAT_RRDY, &i2c_base->stat);
		}
		if (status & I2C_STAT_ARDY) {
			writew(I2C_STAT_ARDY, &i2c_base->stat);
			break;
		}
	}

rd_exit:
	flush_fifo(adap);
	writew(0xFFFF, &i2c_base->stat);
	return i2c_error;
}

/* i2c_write: Address (reg offset) may be 0, 1 or 2 bytes long. */
static int omap24_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
			    int alen, uchar *buffer, int len)
{
	struct i2c *i2c_base = omap24_get_base(adap);
	int i;
	u16 status;
	int i2c_error = 0;
	int timeout = I2C_TIMEOUT;

	if (alen < 0) {
		puts("I2C write: addr len < 0\n");
		return 1;
	}

	if (len < 0) {
		puts("I2C write: data len < 0\n");
		return 1;
	}

	if (buffer == NULL) {
		puts("I2C write: NULL pointer passed\n");
		return 1;
	}

	if (alen > 2) {
		printf("I2C write: addr len %d not supported\n", alen);
		return 1;
	}

	if (addr + len > (1 << 16)) {
		printf("I2C write: address 0x%x + 0x%x out of range\n",
		       addr, len);
		return 1;
	}

	/* Wait until bus not busy */
	if (wait_for_bb(adap))
		return 1;

	/* Start address phase - will write regoffset + len bytes data */
	writew(alen + len, &i2c_base->cnt);
	/* Set slave address */
	writew(chip, &i2c_base->sa);
	/* Stop bit needed here */
	writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX |
	       I2C_CON_STP, &i2c_base->con);

	while (alen) {
		/* Must write reg offset (one or two bytes) */
		status = wait_for_event(adap);
		/* Try to identify bus that is not padconf'd for I2C */
		if (status == I2C_STAT_XRDY) {
			i2c_error = 2;
			printf("i2c_write: pads on bus %d probably not configured (status=0x%x)\n",
			       adap->hwadapnr, status);
			goto wr_exit;
		}
		if (status == 0 || (status & I2C_STAT_NACK)) {
			i2c_error = 1;
			printf("i2c_write: error waiting for addr ACK (status=0x%x)\n",
			       status);
			goto wr_exit;
		}
		if (status & I2C_STAT_XRDY) {
			alen--;
			writeb((addr >> (8 * alen)) & 0xff, &i2c_base->data);
			writew(I2C_STAT_XRDY, &i2c_base->stat);
		} else {
			i2c_error = 1;
			printf("i2c_write: bus not ready for addr Tx (status=0x%x)\n",
			       status);
			goto wr_exit;
		}
	}
	/* Address phase is over, now write data */
	for (i = 0; i < len; i++) {
		status = wait_for_event(adap);
		if (status == 0 || (status & I2C_STAT_NACK)) {
			i2c_error = 1;
			printf("i2c_write: error waiting for data ACK (status=0x%x)\n",
			       status);
			goto wr_exit;
		}
		if (status & I2C_STAT_XRDY) {
			writeb(buffer[i], &i2c_base->data);
			writew(I2C_STAT_XRDY, &i2c_base->stat);
		} else {
			i2c_error = 1;
			printf("i2c_write: bus not ready for data Tx (i=%d)\n",
			       i);
			goto wr_exit;
		}
	}
	/*
	 * poll ARDY bit for making sure that last byte really has been
	 * transferred on the bus.
	 */
	do {
		status = wait_for_event(adap);
	} while (!(status & I2C_STAT_ARDY) && timeout--);
	if (timeout <= 0)
		printf("i2c_write: timed out writig last byte!\n");

wr_exit:
	flush_fifo(adap);
	writew(0xFFFF, &i2c_base->stat);
	return i2c_error;
}

/*
 * Wait for the bus to be free by checking the Bus Busy (BB)
 * bit to become clear
 */
static int wait_for_bb(struct i2c_adapter *adap)
{
	struct i2c *i2c_base = omap24_get_base(adap);
	int timeout = I2C_TIMEOUT;
	u16 stat;

	writew(0xFFFF, &i2c_base->stat);	/* clear current interrupts...*/
#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
	while ((stat = readw(&i2c_base->stat) & I2C_STAT_BB) && timeout--) {
#else
	/* Read RAW status */
	while ((stat = readw(&i2c_base->irqstatus_raw) &
		I2C_STAT_BB) && timeout--) {
#endif
		writew(stat, &i2c_base->stat);
		udelay(adap->waitdelay);
	}

	if (timeout <= 0) {
		printf("Timed out in wait_for_bb: status=%04x\n",
		       stat);
		return 1;
	}
	writew(0xFFFF, &i2c_base->stat);	 /* clear delayed stuff*/
	return 0;
}

/*
 * Wait for the I2C controller to complete current action
 * and update status
 */
static u16 wait_for_event(struct i2c_adapter *adap)
{
	struct i2c *i2c_base = omap24_get_base(adap);
	u16 status;
	int timeout = I2C_TIMEOUT;

	do {
		udelay(adap->waitdelay);
#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
		status = readw(&i2c_base->stat);
#else
		/* Read RAW status */
		status = readw(&i2c_base->irqstatus_raw);
#endif
	} while (!(status &
		   (I2C_STAT_ROVR | I2C_STAT_XUDF | I2C_STAT_XRDY |
		    I2C_STAT_RRDY | I2C_STAT_ARDY | I2C_STAT_NACK |
		    I2C_STAT_AL)) && timeout--);

	if (timeout <= 0) {
		printf("Timed out in wait_for_event: status=%04x\n",
		       status);
		/*
		 * If status is still 0 here, probably the bus pads have
		 * not been configured for I2C, and/or pull-ups are missing.
		 */
		printf("Check if pads/pull-ups of bus %d are properly configured\n",
		       adap->hwadapnr);
		writew(0xFFFF, &i2c_base->stat);
		status = 0;
	}

	return status;
}

static struct i2c *omap24_get_base(struct i2c_adapter *adap)
{
	switch (adap->hwadapnr) {
	case 0:
		return (struct i2c *)I2C_BASE1;
		break;
	case 1:
		return (struct i2c *)I2C_BASE2;
		break;
#if (I2C_BUS_MAX > 2)
	case 2:
		return (struct i2c *)I2C_BASE3;
		break;
#if (I2C_BUS_MAX > 3)
	case 3:
		return (struct i2c *)I2C_BASE4;
		break;
#if (I2C_BUS_MAX > 4)
	case 4:
		return (struct i2c *)I2C_BASE5;
		break;
#endif
#endif
#endif
	default:
		printf("wrong hwadapnr: %d\n", adap->hwadapnr);
		break;
	}
	return NULL;
}

#if !defined(CONFIG_SYS_OMAP24_I2C_SPEED1)
#define CONFIG_SYS_OMAP24_I2C_SPEED1 CONFIG_SYS_OMAP24_I2C_SPEED
#endif
#if !defined(CONFIG_SYS_OMAP24_I2C_SLAVE1)
#define CONFIG_SYS_OMAP24_I2C_SLAVE1 CONFIG_SYS_OMAP24_I2C_SLAVE
#endif

U_BOOT_I2C_ADAP_COMPLETE(omap24_0, omap24_i2c_init, omap24_i2c_probe,
			 omap24_i2c_read, omap24_i2c_write, omap24_i2c_setspeed,
			 CONFIG_SYS_OMAP24_I2C_SPEED,
			 CONFIG_SYS_OMAP24_I2C_SLAVE,
			 0)
U_BOOT_I2C_ADAP_COMPLETE(omap24_1, omap24_i2c_init, omap24_i2c_probe,
			 omap24_i2c_read, omap24_i2c_write, omap24_i2c_setspeed,
			 CONFIG_SYS_OMAP24_I2C_SPEED1,
			 CONFIG_SYS_OMAP24_I2C_SLAVE1,
			 1)
#if (I2C_BUS_MAX > 2)
#if !defined(CONFIG_SYS_OMAP24_I2C_SPEED2)
#define CONFIG_SYS_OMAP24_I2C_SPEED2 CONFIG_SYS_OMAP24_I2C_SPEED
#endif
#if !defined(CONFIG_SYS_OMAP24_I2C_SLAVE2)
#define CONFIG_SYS_OMAP24_I2C_SLAVE2 CONFIG_SYS_OMAP24_I2C_SLAVE
#endif

U_BOOT_I2C_ADAP_COMPLETE(omap24_2, omap24_i2c_init, omap24_i2c_probe,
			 omap24_i2c_read, omap24_i2c_write, NULL,
			 CONFIG_SYS_OMAP24_I2C_SPEED2,
			 CONFIG_SYS_OMAP24_I2C_SLAVE2,
			 2)
#if (I2C_BUS_MAX > 3)
#if !defined(CONFIG_SYS_OMAP24_I2C_SPEED3)
#define CONFIG_SYS_OMAP24_I2C_SPEED3 CONFIG_SYS_OMAP24_I2C_SPEED
#endif
#if !defined(CONFIG_SYS_OMAP24_I2C_SLAVE3)
#define CONFIG_SYS_OMAP24_I2C_SLAVE3 CONFIG_SYS_OMAP24_I2C_SLAVE
#endif

U_BOOT_I2C_ADAP_COMPLETE(omap24_3, omap24_i2c_init, omap24_i2c_probe,
			 omap24_i2c_read, omap24_i2c_write, NULL,
			 CONFIG_SYS_OMAP24_I2C_SPEED3,
			 CONFIG_SYS_OMAP24_I2C_SLAVE3,
			 3)
#if (I2C_BUS_MAX > 4)
#if !defined(CONFIG_SYS_OMAP24_I2C_SPEED4)
#define CONFIG_SYS_OMAP24_I2C_SPEED4 CONFIG_SYS_OMAP24_I2C_SPEED
#endif
#if !defined(CONFIG_SYS_OMAP24_I2C_SLAVE4)
#define CONFIG_SYS_OMAP24_I2C_SLAVE4 CONFIG_SYS_OMAP24_I2C_SLAVE
#endif

U_BOOT_I2C_ADAP_COMPLETE(omap24_4, omap24_i2c_init, omap24_i2c_probe,
			 omap24_i2c_read, omap24_i2c_write, NULL,
			 CONFIG_SYS_OMAP24_I2C_SPEED4,
			 CONFIG_SYS_OMAP24_I2C_SLAVE4,
			 4)
#endif
#endif
#endif