/*

   * (C) Copyright 2009
   * Sergey Kubushyn, himself, ksi@koi8.net
   *
   * Changes for unified multibus/multiadapter I2C support.
   *

   * (C) Copyright 2001
   * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
   *

   * SPDX-License-Identifier:	GPL-2.0+

   */
  
  /*
   * I2C Functions similar to the standard memory functions.
   *
   * There are several parameters in many of the commands that bear further
   * explanations:
   *

   * {i2c_chip} is the I2C chip address (the first byte sent on the bus).
   *   Each I2C chip on the bus has a unique address.  On the I2C data bus,
   *   the address is the upper seven bits and the LSB is the "read/write"
   *   bit.  Note that the {i2c_chip} address specified on the command
   *   line is not shifted up: e.g. a typical EEPROM memory chip may have
   *   an I2C address of 0x50, but the data put on the bus will be 0xA0
   *   for write and 0xA1 for read.  This "non shifted" address notation
   *   matches at least half of the data sheets :-/.
   *
   * {addr} is the address (or offset) within the chip.  Small memory
   *   chips have 8 bit addresses.  Large memory chips have 16 bit
   *   addresses.  Other memory chips have 9, 10, or 11 bit addresses.
   *   Many non-memory chips have multiple registers and {addr} is used
   *   as the register index.  Some non-memory chips have only one register
   *   and therefore don't need any {addr} parameter.
   *
   *   The default {addr} parameter is one byte (.1) which works well for
   *   memories and registers with 8 bits of address space.
   *
   *   You can specify the length of the {addr} field with the optional .0,
   *   .1, or .2 modifier (similar to the .b, .w, .l modifier).  If you are
   *   manipulating a single register device which doesn't use an address
   *   field, use "0.0" for the address and the ".0" length field will
   *   suppress the address in the I2C data stream.  This also works for
   *   successive reads using the I2C auto-incrementing memory pointer.
   *
   *   If you are manipulating a large memory with 2-byte addresses, use
   *   the .2 address modifier, e.g. 210.2 addresses location 528 (decimal).
   *
   *   Then there are the unfortunate memory chips that spill the most
   *   significant 1, 2, or 3 bits of address into the chip address byte.
   *   This effectively makes one chip (logically) look like 2, 4, or
   *   8 chips.  This is handled (awkwardly) by #defining

   *   CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW and using the .1 modifier on the

   *   {addr} field (since .1 is the default, it doesn't actually have to
   *   be specified).  Examples: given a memory chip at I2C chip address
   *   0x50, the following would happen...

   *     i2c md 50 0 10   display 16 bytes starting at 0x000

   *                      On the bus: <S> A0 00 <E> <S> A1 <rd> ... <rd>

   *     i2c md 50 100 10 display 16 bytes starting at 0x100

   *                      On the bus: <S> A2 00 <E> <S> A3 <rd> ... <rd>

   *     i2c md 50 210 10 display 16 bytes starting at 0x210

   *                      On the bus: <S> A4 10 <E> <S> A5 <rd> ... <rd>
   *   This is awfully ugly.  It would be nice if someone would think up
   *   a better way of handling this.
   *
   * Adapted from cmd_mem.c which is copyright Wolfgang Denk (wd@denx.de).
   */
  
  #include <common.h>
  #include <command.h>

  #include <edid.h>

  #include <environment.h>

  #include <i2c.h>

  #include <malloc.h>

  #include <asm/byteorder.h>

  #include <linux/compiler.h>

  DECLARE_GLOBAL_DATA_PTR;

  /* Display values from last command.
   * Memory modify remembered values are different from display memory.
   */
  static uchar	i2c_dp_last_chip;
  static uint	i2c_dp_last_addr;
  static uint	i2c_dp_last_alen;
  static uint	i2c_dp_last_length = 0x10;
  
  static uchar	i2c_mm_last_chip;
  static uint	i2c_mm_last_addr;
  static uint	i2c_mm_last_alen;

  /* If only one I2C bus is present, the list of devices to ignore when
   * the probe command is issued is represented by a 1D array of addresses.
   * When multiple buses are present, the list is an array of bus-address
   * pairs.  The following macros take care of this */

  #if defined(CONFIG_SYS_I2C_NOPROBES)

  #if defined(CONFIG_SYS_I2C) || defined(CONFIG_I2C_MULTI_BUS)

  static struct
  {
  	uchar	bus;
  	uchar	addr;

  } i2c_no_probes[] = CONFIG_SYS_I2C_NOPROBES;

  #define GET_BUS_NUM	i2c_get_bus_num()
  #define COMPARE_BUS(b,i)	(i2c_no_probes[(i)].bus == (b))
  #define COMPARE_ADDR(a,i)	(i2c_no_probes[(i)].addr == (a))
  #define NO_PROBE_ADDR(i)	i2c_no_probes[(i)].addr
  #else		/* single bus */

  static uchar i2c_no_probes[] = CONFIG_SYS_I2C_NOPROBES;

  #define GET_BUS_NUM	0
  #define COMPARE_BUS(b,i)	((b) == 0)	/* Make compiler happy */
  #define COMPARE_ADDR(a,i)	(i2c_no_probes[(i)] == (a))
  #define NO_PROBE_ADDR(i)	i2c_no_probes[(i)]

  #endif	/* defined(CONFIG_SYS_I2C) */

  #endif

  #define DISP_LINE_LEN	16

  /**
   * i2c_init_board() - Board-specific I2C bus init
   *
   * This function is the default no-op implementation of I2C bus
   * initialization. This function can be overriden by board-specific
   * implementation if needed.
   */

  __weak
  void i2c_init_board(void)

  {

  }

  /* TODO: Implement architecture-specific get/set functions */

  
  /**
   * i2c_get_bus_speed() - Return I2C bus speed
   *
   * This function is the default implementation of function for retrieveing
   * the current I2C bus speed in Hz.
   *
   * A driver implementing runtime switching of I2C bus speed must override
   * this function to report the speed correctly. Simple or legacy drivers
   * can use this fallback.
   *
   * Returns I2C bus speed in Hz.
   */

  #if !defined(CONFIG_SYS_I2C)
  /*
   * TODO: Implement architecture-specific get/set functions
   * Should go away, if we switched completely to new multibus support
   */

  __weak
  unsigned int i2c_get_bus_speed(void)

  {
  	return CONFIG_SYS_I2C_SPEED;
  }

  /**
   * i2c_set_bus_speed() - Configure I2C bus speed
   * @speed:	Newly set speed of the I2C bus in Hz
   *
   * This function is the default implementation of function for setting
   * the I2C bus speed in Hz.
   *
   * A driver implementing runtime switching of I2C bus speed must override
   * this function to report the speed correctly. Simple or legacy drivers
   * can use this fallback.
   *
   * Returns zero on success, negative value on error.
   */

  __weak
  int i2c_set_bus_speed(unsigned int speed)

  {
  	if (speed != CONFIG_SYS_I2C_SPEED)
  		return -1;
  
  	return 0;
  }

  #endif

  /**
   * get_alen() - Small parser helper function to get address length
   *
   * Returns the address length.

   */
  static uint get_alen(char *arg)
  {
  	int	j;
  	int	alen;
  
  	alen = 1;
  	for (j = 0; j < 8; j++) {
  		if (arg[j] == '.') {
  			alen = arg[j+1] - '0';

  			break;
  		} else if (arg[j] == '\0')
  			break;
  	}
  	return alen;
  }

  /**
   * do_i2c_read() - Handle the "i2c read" command-line command
   * @cmdtp:	Command data struct pointer
   * @flag:	Command flag
   * @argc:	Command-line argument count
   * @argv:	Array of command-line arguments
   *
   * Returns zero on success, CMD_RET_USAGE in case of misuse and negative
   * on error.
   *

   * Syntax:
   *	i2c read {i2c_chip} {devaddr}{.0, .1, .2} {len} {memaddr}
   */

  static int do_i2c_read ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])

  {
  	u_char	chip;
  	uint	devaddr, alen, length;
  	u_char  *memaddr;

  	if (argc != 5)

  		return CMD_RET_USAGE;

  
  	/*
  	 * I2C chip address
  	 */
  	chip = simple_strtoul(argv[1], NULL, 16);
  
  	/*
  	 * I2C data address within the chip.  This can be 1 or
  	 * 2 bytes long.  Some day it might be 3 bytes long :-).
  	 */
  	devaddr = simple_strtoul(argv[2], NULL, 16);

  	alen = get_alen(argv[2]);

  	if (alen > 3)

  		return CMD_RET_USAGE;

  
  	/*
  	 * Length is the number of objects, not number of bytes.
  	 */
  	length = simple_strtoul(argv[3], NULL, 16);
  
  	/*
  	 * memaddr is the address where to store things in memory
  	 */
  	memaddr = (u_char *)simple_strtoul(argv[4], NULL, 16);
  
  	if (i2c_read(chip, devaddr, alen, memaddr, length) != 0) {
  		puts ("Error reading the chip.
  ");
  		return 1;
  	}
  	return 0;
  }

  static int do_i2c_write(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
  {
  	u_char	chip;
  	uint	devaddr, alen, length;
  	u_char  *memaddr;
  
  	if (argc != 5)
  		return cmd_usage(cmdtp);
  
  	/*
  	 * memaddr is the address where to store things in memory
  	 */
  	memaddr = (u_char *)simple_strtoul(argv[1], NULL, 16);
  
  	/*
  	 * I2C chip address
  	 */
  	chip = simple_strtoul(argv[2], NULL, 16);
  
  	/*
  	 * I2C data address within the chip.  This can be 1 or
  	 * 2 bytes long.  Some day it might be 3 bytes long :-).
  	 */
  	devaddr = simple_strtoul(argv[3], NULL, 16);
  	alen = get_alen(argv[3]);
  	if (alen > 3)
  		return cmd_usage(cmdtp);
  
  	/*
  	 * Length is the number of objects, not number of bytes.
  	 */
  	length = simple_strtoul(argv[4], NULL, 16);
  
  	while (length-- > 0) {
  		if (i2c_write(chip, devaddr++, alen, memaddr++, 1) != 0) {
  			puts("Error writing to the chip.
  ");
  			return 1;
  		}
  /*
   * No write delay with FRAM devices.
   */
  #if !defined(CONFIG_SYS_I2C_FRAM)
  		udelay(11000);
  #endif
  	}
  	return 0;
  }

  /**
   * do_i2c_md() - Handle the "i2c md" command-line command
   * @cmdtp:	Command data struct pointer
   * @flag:	Command flag
   * @argc:	Command-line argument count
   * @argv:	Array of command-line arguments
   *
   * Returns zero on success, CMD_RET_USAGE in case of misuse and negative
   * on error.
   *

   * Syntax:
   *	i2c md {i2c_chip} {addr}{.0, .1, .2} {len}
   */

  static int do_i2c_md ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])

  {
  	u_char	chip;
  	uint	addr, alen, length;
  	int	j, nbytes, linebytes;
  
  	/* We use the last specified parameters, unless new ones are
  	 * entered.
  	 */
  	chip   = i2c_dp_last_chip;
  	addr   = i2c_dp_last_addr;
  	alen   = i2c_dp_last_alen;
  	length = i2c_dp_last_length;

  	if (argc < 3)

  		return CMD_RET_USAGE;

  
  	if ((flag & CMD_FLAG_REPEAT) == 0) {
  		/*
  		 * New command specified.
  		 */

  
  		/*
  		 * I2C chip address
  		 */
  		chip = simple_strtoul(argv[1], NULL, 16);
  
  		/*
  		 * I2C data address within the chip.  This can be 1 or
  		 * 2 bytes long.  Some day it might be 3 bytes long :-).
  		 */
  		addr = simple_strtoul(argv[2], NULL, 16);

  		alen = get_alen(argv[2]);

  		if (alen > 3)

  			return CMD_RET_USAGE;

  
  		/*
  		 * If another parameter, it is the length to display.
  		 * Length is the number of objects, not number of bytes.
  		 */
  		if (argc > 3)
  			length = simple_strtoul(argv[3], NULL, 16);
  	}
  
  	/*
  	 * Print the lines.
  	 *
  	 * We buffer all read data, so we can make sure data is read only
  	 * once.
  	 */
  	nbytes = length;
  	do {
  		unsigned char	linebuf[DISP_LINE_LEN];
  		unsigned char	*cp;
  
  		linebytes = (nbytes > DISP_LINE_LEN) ? DISP_LINE_LEN : nbytes;

  		if (i2c_read(chip, addr, alen, linebuf, linebytes) != 0)

  			puts ("Error reading the chip.
  ");

  		else {

  			printf("%04x:", addr);
  			cp = linebuf;
  			for (j=0; j<linebytes; j++) {
  				printf(" %02x", *cp++);
  				addr++;
  			}

  			puts ("    ");

  			cp = linebuf;
  			for (j=0; j<linebytes; j++) {
  				if ((*cp < 0x20) || (*cp > 0x7e))

  					puts (".");

  				else
  					printf("%c", *cp);
  				cp++;
  			}

  			putc ('
  ');

  		}
  		nbytes -= linebytes;
  	} while (nbytes > 0);
  
  	i2c_dp_last_chip   = chip;
  	i2c_dp_last_addr   = addr;
  	i2c_dp_last_alen   = alen;
  	i2c_dp_last_length = length;
  
  	return 0;
  }

  /**
   * do_i2c_mw() - Handle the "i2c mw" command-line command
   * @cmdtp:	Command data struct pointer
   * @flag:	Command flag
   * @argc:	Command-line argument count
   * @argv:	Array of command-line arguments
   *
   * Returns zero on success, CMD_RET_USAGE in case of misuse and negative
   * on error.

   *
   * Syntax:

   *	i2c mw {i2c_chip} {addr}{.0, .1, .2} {data} [{count}]

   */

  static int do_i2c_mw ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])

  {
  	uchar	chip;
  	ulong	addr;
  	uint	alen;
  	uchar	byte;
  	int	count;

  	if ((argc < 4) || (argc > 5))

  		return CMD_RET_USAGE;

  
  	/*

  	 * Chip is always specified.
  	 */

  	chip = simple_strtoul(argv[1], NULL, 16);
  
  	/*
  	 * Address is always specified.
  	 */
  	addr = simple_strtoul(argv[2], NULL, 16);

  	alen = get_alen(argv[2]);

  	if (alen > 3)

  		return CMD_RET_USAGE;

  
  	/*
  	 * Value to write is always specified.
  	 */
  	byte = simple_strtoul(argv[3], NULL, 16);
  
  	/*
  	 * Optional count
  	 */

  	if (argc == 5)

  		count = simple_strtoul(argv[4], NULL, 16);

  	else

  		count = 1;

  
  	while (count-- > 0) {

  		if (i2c_write(chip, addr++, alen, &byte, 1) != 0)

  			puts ("Error writing the chip.
  ");

  		/*
  		 * Wait for the write to complete.  The write can take
  		 * up to 10mSec (we allow a little more time).

  		 */

  /*
   * No write delay with FRAM devices.
   */

  #if !defined(CONFIG_SYS_I2C_FRAM)

  		udelay(11000);

  #endif

  	}

  	return 0;

  }

  /**
   * do_i2c_crc() - Handle the "i2c crc32" command-line command
   * @cmdtp:	Command data struct pointer
   * @flag:	Command flag
   * @argc:	Command-line argument count
   * @argv:	Array of command-line arguments
   *
   * Calculate a CRC on memory
   *
   * Returns zero on success, CMD_RET_USAGE in case of misuse and negative
   * on error.

   *
   * Syntax:

   *	i2c crc32 {i2c_chip} {addr}{.0, .1, .2} {count}

   */

  static int do_i2c_crc (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])

  {
  	uchar	chip;
  	ulong	addr;
  	uint	alen;
  	int	count;
  	uchar	byte;
  	ulong	crc;
  	ulong	err;

  	if (argc < 4)

  		return CMD_RET_USAGE;

  
  	/*

  	 * Chip is always specified.
  	 */

  	chip = simple_strtoul(argv[1], NULL, 16);
  
  	/*
  	 * Address is always specified.
  	 */
  	addr = simple_strtoul(argv[2], NULL, 16);

  	alen = get_alen(argv[2]);

  	if (alen > 3)

  		return CMD_RET_USAGE;

  
  	/*
  	 * Count is always specified
  	 */
  	count = simple_strtoul(argv[3], NULL, 16);
  
  	printf ("CRC32 for %08lx ... %08lx ==> ", addr, addr + count - 1);
  	/*
  	 * CRC a byte at a time.  This is going to be slooow, but hey, the
  	 * memories are small and slow too so hopefully nobody notices.
  	 */
  	crc = 0;
  	err = 0;

  	while (count-- > 0) {
  		if (i2c_read(chip, addr, alen, &byte, 1) != 0)

  			err++;

  		crc = crc32 (crc, &byte, 1);
  		addr++;
  	}

  	if (err > 0)

  		puts ("Error reading the chip,
  ");

  	else

  		printf ("%08lx
  ", crc);

  
  	return 0;
  }

  /**
   * mod_i2c_mem() - Handle the "i2c mm" and "i2c nm" command-line command
   * @cmdtp:	Command data struct pointer
   * @flag:	Command flag
   * @argc:	Command-line argument count
   * @argv:	Array of command-line arguments
   *
   * Modify memory.
   *
   * Returns zero on success, CMD_RET_USAGE in case of misuse and negative
   * on error.

   *
   * Syntax:

   *	i2c mm{.b, .w, .l} {i2c_chip} {addr}{.0, .1, .2}
   *	i2c nm{.b, .w, .l} {i2c_chip} {addr}{.0, .1, .2}

   */

  static int

  mod_i2c_mem(cmd_tbl_t *cmdtp, int incrflag, int flag, int argc, char * const argv[])

  {
  	uchar	chip;
  	ulong	addr;
  	uint	alen;
  	ulong	data;
  	int	size = 1;
  	int	nbytes;

  	if (argc != 3)

  		return CMD_RET_USAGE;

  
  #ifdef CONFIG_BOOT_RETRY_TIME
  	reset_cmd_timeout();	/* got a good command to get here */
  #endif
  	/*
  	 * We use the last specified parameters, unless new ones are
  	 * entered.
  	 */
  	chip = i2c_mm_last_chip;
  	addr = i2c_mm_last_addr;
  	alen = i2c_mm_last_alen;
  
  	if ((flag & CMD_FLAG_REPEAT) == 0) {
  		/*
  		 * New command specified.  Check for a size specification.
  		 * Defaults to byte if no or incorrect specification.
  		 */
  		size = cmd_get_data_size(argv[0], 1);
  
  		/*

  		 * Chip is always specified.
  		 */

  		chip = simple_strtoul(argv[1], NULL, 16);
  
  		/*
  		 * Address is always specified.
  		 */
  		addr = simple_strtoul(argv[2], NULL, 16);

  		alen = get_alen(argv[2]);

  		if (alen > 3)

  			return CMD_RET_USAGE;

  	}
  
  	/*
  	 * Print the address, followed by value.  Then accept input for
  	 * the next value.  A non-converted value exits.
  	 */
  	do {
  		printf("%08lx:", addr);

  		if (i2c_read(chip, addr, alen, (uchar *)&data, size) != 0)

  			puts ("
  Error reading the chip,
  ");

  		else {

  			data = cpu_to_be32(data);

  			if (size == 1)

  				printf(" %02lx", (data >> 24) & 0x000000FF);

  			else if (size == 2)

  				printf(" %04lx", (data >> 16) & 0x0000FFFF);

  			else

  				printf(" %08lx", data);

  		}
  
  		nbytes = readline (" ? ");
  		if (nbytes == 0) {
  			/*
  			 * <CR> pressed as only input, don't modify current
  			 * location and move to next.
  			 */
  			if (incrflag)
  				addr += size;
  			nbytes = size;
  #ifdef CONFIG_BOOT_RETRY_TIME
  			reset_cmd_timeout(); /* good enough to not time out */
  #endif
  		}
  #ifdef CONFIG_BOOT_RETRY_TIME

  		else if (nbytes == -2)

  			break;	/* timed out, exit the command	*/

  #endif
  		else {
  			char *endp;
  
  			data = simple_strtoul(console_buffer, &endp, 16);

  			if (size == 1)

  				data = data << 24;

  			else if (size == 2)

  				data = data << 16;

  			data = be32_to_cpu(data);
  			nbytes = endp - console_buffer;
  			if (nbytes) {
  #ifdef CONFIG_BOOT_RETRY_TIME
  				/*
  				 * good enough to not time out
  				 */
  				reset_cmd_timeout();
  #endif

  				if (i2c_write(chip, addr, alen, (uchar *)&data, size) != 0)

  					puts ("Error writing the chip.
  ");

  #ifdef CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS
  				udelay(CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS * 1000);

  #endif

  				if (incrflag)
  					addr += size;
  			}
  		}
  	} while (nbytes);

  	i2c_mm_last_chip = chip;
  	i2c_mm_last_addr = addr;
  	i2c_mm_last_alen = alen;

  
  	return 0;
  }

  /**
   * do_i2c_probe() - Handle the "i2c probe" command-line command
   * @cmdtp:	Command data struct pointer
   * @flag:	Command flag
   * @argc:	Command-line argument count
   * @argv:	Array of command-line arguments
   *
   * Returns zero on success, CMD_RET_USAGE in case of misuse and negative
   * on error.
   *

   * Syntax:

   *	i2c probe {addr}
   *
   * Returns zero (success) if one or more I2C devices was found

   */

  static int do_i2c_probe (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])

  {
  	int j;

  	int addr = -1;
  	int found = 0;

  #if defined(CONFIG_SYS_I2C_NOPROBES)

  	int k, skip;

  	unsigned int bus = GET_BUS_NUM;

  #endif	/* NOPROBES */

  	if (argc == 2)
  		addr = simple_strtol(argv[1], 0, 16);

  	puts ("Valid chip addresses:");

  	for (j = 0; j < 128; j++) {

  		if ((0 <= addr) && (j != addr))
  			continue;

  #if defined(CONFIG_SYS_I2C_NOPROBES)

  		skip = 0;

  		for (k = 0; k < ARRAY_SIZE(i2c_no_probes); k++) {

  			if (COMPARE_BUS(bus, k) && COMPARE_ADDR(j, k)) {

  				skip = 1;
  				break;
  			}
  		}
  		if (skip)
  			continue;
  #endif

  		if (i2c_probe(j) == 0) {

  			printf(" %02X", j);

  			found++;
  		}

  	}

  	putc ('
  ');

  #if defined(CONFIG_SYS_I2C_NOPROBES)

  	puts ("Excluded chip addresses:");

  	for (k = 0; k < ARRAY_SIZE(i2c_no_probes); k++) {

  		if (COMPARE_BUS(bus,k))

  			printf(" %02X", NO_PROBE_ADDR(k));
  	}

  	putc ('
  ');

  #endif

  	return (0 == found);

  }

  /**
   * do_i2c_loop() - Handle the "i2c loop" command-line command
   * @cmdtp:	Command data struct pointer
   * @flag:	Command flag
   * @argc:	Command-line argument count
   * @argv:	Array of command-line arguments
   *
   * Returns zero on success, CMD_RET_USAGE in case of misuse and negative
   * on error.
   *

   * Syntax:

   *	i2c loop {i2c_chip} {addr}{.0, .1, .2} [{length}] [{delay}]

   *	{length} - Number of bytes to read
   *	{delay}  - A DECIMAL number and defaults to 1000 uSec
   */

  static int do_i2c_loop(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])

  {
  	u_char	chip;
  	ulong	alen;
  	uint	addr;
  	uint	length;
  	u_char	bytes[16];
  	int	delay;

  	if (argc < 3)

  		return CMD_RET_USAGE;

  
  	/*
  	 * Chip is always specified.
  	 */
  	chip = simple_strtoul(argv[1], NULL, 16);
  
  	/*
  	 * Address is always specified.
  	 */
  	addr = simple_strtoul(argv[2], NULL, 16);

  	alen = get_alen(argv[2]);

  	if (alen > 3)

  		return CMD_RET_USAGE;

  
  	/*
  	 * Length is the number of objects, not number of bytes.
  	 */
  	length = 1;
  	length = simple_strtoul(argv[3], NULL, 16);

  	if (length > sizeof(bytes))

  		length = sizeof(bytes);

  
  	/*
  	 * The delay time (uSec) is optional.
  	 */
  	delay = 1000;

  	if (argc > 3)

  		delay = simple_strtoul(argv[4], NULL, 10);

  	/*
  	 * Run the loop...
  	 */

  	while (1) {
  		if (i2c_read(chip, addr, alen, bytes, length) != 0)

  			puts ("Error reading the chip.
  ");

  		udelay(delay);
  	}
  
  	/* NOTREACHED */
  	return 0;
  }

  /*
   * The SDRAM command is separately configured because many
   * (most?) embedded boards don't use SDRAM DIMMs.

   *
   * FIXME: Document and probably move elsewhere!

   */

  #if defined(CONFIG_CMD_SDRAM)

  static void print_ddr2_tcyc (u_char const b)
  {
  	printf ("%d.", (b >> 4) & 0x0F);
  	switch (b & 0x0F) {
  	case 0x0:
  	case 0x1:
  	case 0x2:
  	case 0x3:
  	case 0x4:
  	case 0x5:
  	case 0x6:
  	case 0x7:
  	case 0x8:
  	case 0x9:
  		printf ("%d ns
  ", b & 0x0F);
  		break;
  	case 0xA:
  		puts ("25 ns
  ");
  		break;
  	case 0xB:
  		puts ("33 ns
  ");
  		break;
  	case 0xC:
  		puts ("66 ns
  ");
  		break;
  	case 0xD:
  		puts ("75 ns
  ");
  		break;
  	default:
  		puts ("?? ns
  ");
  		break;
  	}
  }
  
  static void decode_bits (u_char const b, char const *str[], int const do_once)
  {
  	u_char mask;
  
  	for (mask = 0x80; mask != 0x00; mask >>= 1, ++str) {
  		if (b & mask) {
  			puts (*str);
  			if (do_once)
  				return;
  		}
  	}
  }

  
  /*
   * Syntax:

   *	i2c sdram {i2c_chip}

   */

  static int do_sdram (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])

  {

  	enum { unknown, EDO, SDRAM, DDR2 } type;

  	u_char	chip;
  	u_char	data[128];
  	u_char	cksum;
  	int	j;

  	static const char *decode_CAS_DDR2[] = {
  		" TBD", " 6", " 5", " 4", " 3", " 2", " TBD", " TBD"
  	};
  
  	static const char *decode_CAS_default[] = {
  		" TBD", " 7", " 6", " 5", " 4", " 3", " 2", " 1"
  	};
  
  	static const char *decode_CS_WE_default[] = {
  		" TBD", " 6", " 5", " 4", " 3", " 2", " 1", " 0"
  	};
  
  	static const char *decode_byte21_default[] = {
  		"  TBD (bit 7)
  ",
  		"  Redundant row address
  ",
  		"  Differential clock input
  ",
  		"  Registerd DQMB inputs
  ",
  		"  Buffered DQMB inputs
  ",
  		"  On-card PLL
  ",
  		"  Registered address/control lines
  ",
  		"  Buffered address/control lines
  "
  	};
  
  	static const char *decode_byte22_DDR2[] = {
  		"  TBD (bit 7)
  ",
  		"  TBD (bit 6)
  ",
  		"  TBD (bit 5)
  ",
  		"  TBD (bit 4)
  ",
  		"  TBD (bit 3)
  ",
  		"  Supports partial array self refresh
  ",
  		"  Supports 50 ohm ODT
  ",
  		"  Supports weak driver
  "
  	};
  
  	static const char *decode_row_density_DDR2[] = {
  		"512 MiB", "256 MiB", "128 MiB", "16 GiB",
  		"8 GiB", "4 GiB", "2 GiB", "1 GiB"
  	};
  
  	static const char *decode_row_density_default[] = {
  		"512 MiB", "256 MiB", "128 MiB", "64 MiB",
  		"32 MiB", "16 MiB", "8 MiB", "4 MiB"
  	};

  	if (argc < 2)

  		return CMD_RET_USAGE;

  	/*
  	 * Chip is always specified.

  	 */
  	chip = simple_strtoul (argv[1], NULL, 16);

  	if (i2c_read (chip, 0, 1, data, sizeof (data)) != 0) {

  		puts ("No SDRAM Serial Presence Detect found.
  ");

  		return 1;
  	}
  
  	cksum = 0;
  	for (j = 0; j < 63; j++) {
  		cksum += data[j];
  	}

  	if (cksum != data[63]) {

  		printf ("WARNING: Configuration data checksum failure:
  "

  			"  is 0x%02x, calculated 0x%02x
  ", data[63], cksum);

  	}

  	printf ("SPD data revision            %d.%d
  ",

  		(data[62] >> 4) & 0x0F, data[62] & 0x0F);

  	printf ("Bytes used                   0x%02X
  ", data[0]);
  	printf ("Serial memory size           0x%02X
  ", 1 << data[1]);

  	puts ("Memory type                  ");

  	switch (data[2]) {

  	case 2:
  		type = EDO;
  		puts ("EDO
  ");
  		break;
  	case 4:
  		type = SDRAM;
  		puts ("SDRAM
  ");
  		break;
  	case 8:
  		type = DDR2;
  		puts ("DDR2
  ");
  		break;
  	default:
  		type = unknown;
  		puts ("unknown
  ");
  		break;

  	}

  	puts ("Row address bits             ");

  	if ((data[3] & 0x00F0) == 0)

  		printf ("%d
  ", data[3] & 0x0F);

  	else

  		printf ("%d/%d
  ", data[3] & 0x0F, (data[3] >> 4) & 0x0F);

  	puts ("Column address bits          ");

  	if ((data[4] & 0x00F0) == 0)

  		printf ("%d
  ", data[4] & 0x0F);

  	else

  		printf ("%d/%d
  ", data[4] & 0x0F, (data[4] >> 4) & 0x0F);

  
  	switch (type) {
  	case DDR2:

  		printf ("Number of ranks              %d
  ",
  			(data[5] & 0x07) + 1);

  		break;
  	default:

  		printf ("Module rows                  %d
  ", data[5]);

  		break;
  	}
  
  	switch (type) {
  	case DDR2:

  		printf ("Module data width            %d bits
  ", data[6]);

  		break;
  	default:

  		printf ("Module data width            %d bits
  ",
  			(data[7] << 8) | data[6]);

  		break;
  	}

  	puts ("Interface signal levels      ");

  	switch(data[8]) {

  		case 0:  puts ("TTL 5.0 V
  ");	break;

  		case 1:  puts ("LVTTL
  ");	break;

  		case 2:  puts ("HSTL 1.5 V
  ");	break;
  		case 3:  puts ("SSTL 3.3 V
  ");	break;
  		case 4:  puts ("SSTL 2.5 V
  ");	break;
  		case 5:  puts ("SSTL 1.8 V
  ");	break;

  		default: puts ("unknown
  ");	break;

  	}

  
  	switch (type) {
  	case DDR2:

  		printf ("SDRAM cycle time             ");
  		print_ddr2_tcyc (data[9]);

  		break;
  	default:

  		printf ("SDRAM cycle time             %d.%d ns
  ",
  			(data[9] >> 4) & 0x0F, data[9] & 0x0F);

  		break;
  	}
  
  	switch (type) {
  	case DDR2:

  		printf ("SDRAM access time            0.%d%d ns
  ",
  			(data[10] >> 4) & 0x0F, data[10] & 0x0F);

  		break;
  	default:

  		printf ("SDRAM access time            %d.%d ns
  ",
  			(data[10] >> 4) & 0x0F, data[10] & 0x0F);

  		break;
  	}

  	puts ("EDC configuration            ");

  	switch (data[11]) {

  		case 0:  puts ("None
  ");	break;
  		case 1:  puts ("Parity
  ");	break;
  		case 2:  puts ("ECC
  ");	break;
  		default: puts ("unknown
  ");	break;

  	}

  	if ((data[12] & 0x80) == 0)

  		puts ("No self refresh, rate        ");

  	else

  		puts ("Self refresh, rate           ");

  	switch(data[12] & 0x7F) {

  		case 0:  puts ("15.625 us
  ");	break;
  		case 1:  puts ("3.9 us
  ");	break;
  		case 2:  puts ("7.8 us
  ");	break;
  		case 3:  puts ("31.3 us
  ");	break;
  		case 4:  puts ("62.5 us
  ");	break;
  		case 5:  puts ("125 us
  ");	break;

  		default: puts ("unknown
  ");	break;

  	}

  
  	switch (type) {
  	case DDR2:

  		printf ("SDRAM width (primary)        %d
  ", data[13]);

  		break;
  	default:

  		printf ("SDRAM width (primary)        %d
  ", data[13] & 0x7F);

  		if ((data[13] & 0x80) != 0) {

  			printf ("  (second bank)              %d
  ",
  				2 * (data[13] & 0x7F));

  		}
  		break;
  	}
  
  	switch (type) {
  	case DDR2:
  		if (data[14] != 0)

  			printf ("EDC width                    %d
  ", data[14]);

  		break;
  	default:
  		if (data[14] != 0) {

  			printf ("EDC width                    %d
  ",
  				data[14] & 0x7F);

  
  			if ((data[14] & 0x80) != 0) {

  				printf ("  (second bank)              %d
  ",
  					2 * (data[14] & 0x7F));

  			}
  		}
  		break;

  	}

  	if (DDR2 != type) {
  		printf ("Min clock delay, back-to-back random column addresses "
  			"%d
  ", data[15]);

  	}

  	puts ("Burst length(s)             ");
  	if (data[16] & 0x80) puts (" Page");
  	if (data[16] & 0x08) puts (" 8");
  	if (data[16] & 0x04) puts (" 4");
  	if (data[16] & 0x02) puts (" 2");
  	if (data[16] & 0x01) puts (" 1");
  	putc ('
  ');

  	printf ("Number of banks              %d
  ", data[17]);

  
  	switch (type) {
  	case DDR2:
  		puts ("CAS latency(s)              ");

  		decode_bits (data[18], decode_CAS_DDR2, 0);

  		putc ('
  ');
  		break;
  	default:
  		puts ("CAS latency(s)              ");

  		decode_bits (data[18], decode_CAS_default, 0);

  		putc ('
  ');
  		break;
  	}
  
  	if (DDR2 != type) {
  		puts ("CS latency(s)               ");

  		decode_bits (data[19], decode_CS_WE_default, 0);

  		putc ('
  ');
  	}
  
  	if (DDR2 != type) {
  		puts ("WE latency(s)               ");

  		decode_bits (data[20], decode_CS_WE_default, 0);

  		putc ('
  ');
  	}
  
  	switch (type) {
  	case DDR2:
  		puts ("Module attributes:
  ");
  		if (data[21] & 0x80)
  			puts ("  TBD (bit 7)
  ");
  		if (data[21] & 0x40)
  			puts ("  Analysis probe installed
  ");
  		if (data[21] & 0x20)
  			puts ("  TBD (bit 5)
  ");
  		if (data[21] & 0x10)
  			puts ("  FET switch external enable
  ");

  		printf ("  %d PLLs on DIMM
  ", (data[21] >> 2) & 0x03);

  		if (data[20] & 0x11) {

  			printf ("  %d active registers on DIMM
  ",
  				(data[21] & 0x03) + 1);

  		}
  		break;
  	default:
  		puts ("Module attributes:
  ");
  		if (!data[21])
  			puts ("  (none)
  ");

  		else
  			decode_bits (data[21], decode_byte21_default, 0);

  		break;
  	}
  
  	switch (type) {
  	case DDR2:

  		decode_bits (data[22], decode_byte22_DDR2, 0);

  		break;
  	default:
  		puts ("Device attributes:
  ");
  		if (data[22] & 0x80) puts ("  TBD (bit 7)
  ");
  		if (data[22] & 0x40) puts ("  TBD (bit 6)
  ");
  		if (data[22] & 0x20) puts ("  Upper Vcc tolerance 5%
  ");
  		else                 puts ("  Upper Vcc tolerance 10%
  ");
  		if (data[22] & 0x10) puts ("  Lower Vcc tolerance 5%
  ");
  		else                 puts ("  Lower Vcc tolerance 10%
  ");
  		if (data[22] & 0x08) puts ("  Supports write1/read burst
  ");
  		if (data[22] & 0x04) puts ("  Supports precharge all
  ");
  		if (data[22] & 0x02) puts ("  Supports auto precharge
  ");
  		if (data[22] & 0x01) puts ("  Supports early RAS# precharge
  ");
  		break;
  	}
  
  	switch (type) {
  	case DDR2:

  		printf ("SDRAM cycle time (2nd highest CAS latency)        ");
  		print_ddr2_tcyc (data[23]);

  		break;
  	default:

  		printf ("SDRAM cycle time (2nd highest CAS latency)        %d."
  			"%d ns
  ", (data[23] >> 4) & 0x0F, data[23] & 0x0F);

  		break;
  	}
  
  	switch (type) {
  	case DDR2:

  		printf ("SDRAM access from clock (2nd highest CAS latency) 0."
  			"%d%d ns
  ", (data[24] >> 4) & 0x0F, data[24] & 0x0F);

  		break;
  	default:

  		printf ("SDRAM access from clock (2nd highest CAS latency) %d."
  			"%d ns
  ", (data[24] >> 4) & 0x0F, data[24] & 0x0F);

  		break;
  	}
  
  	switch (type) {
  	case DDR2:

  		printf ("SDRAM cycle time (3rd highest CAS latency)        ");
  		print_ddr2_tcyc (data[25]);

  		break;
  	default:

  		printf ("SDRAM cycle time (3rd highest CAS latency)        %d."
  			"%d ns
  ", (data[25] >> 4) & 0x0F, data[25] & 0x0F);

  		break;
  	}
  
  	switch (type) {
  	case DDR2:

  		printf ("SDRAM access from clock (3rd highest CAS latency) 0."
  			"%d%d ns
  ", (data[26] >> 4) & 0x0F, data[26] & 0x0F);

  		break;
  	default:

  		printf ("SDRAM access from clock (3rd highest CAS latency) %d."
  			"%d ns
  ", (data[26] >> 4) & 0x0F, data[26] & 0x0F);

  		break;
  	}
  
  	switch (type) {
  	case DDR2:

  		printf ("Minimum row precharge        %d.%02d ns
  ",
  			(data[27] >> 2) & 0x3F, 25 * (data[27] & 0x03));

  		break;
  	default:

  		printf ("Minimum row precharge        %d ns
  ", data[27]);

  		break;
  	}
  
  	switch (type) {
  	case DDR2:

  		printf ("Row active to row active min %d.%02d ns
  ",
  			(data[28] >> 2) & 0x3F, 25 * (data[28] & 0x03));

  		break;
  	default:

  		printf ("Row active to row active min %d ns
  ", data[28]);

  		break;
  	}
  
  	switch (type) {
  	case DDR2:

  		printf ("RAS to CAS delay min         %d.%02d ns
  ",
  			(data[29] >> 2) & 0x3F, 25 * (data[29] & 0x03));

  		break;
  	default:

  		printf ("RAS to CAS delay min         %d ns
  ", data[29]);

  		break;
  	}

  	printf ("Minimum RAS pulse width      %d ns
  ", data[30]);

  
  	switch (type) {
  	case DDR2:

  		puts ("Density of each row          ");
  		decode_bits (data[31], decode_row_density_DDR2, 1);
  		putc ('
  ');

  		break;
  	default:

  		puts ("Density of each row          ");
  		decode_bits (data[31], decode_row_density_default, 1);
  		putc ('
  ');

  		break;
  	}
  
  	switch (type) {
  	case DDR2:

  		puts ("Command and Address setup    ");

  		if (data[32] >= 0xA0) {

  			printf ("1.%d%d ns
  ",
  				((data[32] >> 4) & 0x0F) - 10, data[32] & 0x0F);

  		} else {

  			printf ("0.%d%d ns
  ",
  				((data[32] >> 4) & 0x0F), data[32] & 0x0F);

  		}
  		break;
  	default:

  		printf ("Command and Address setup    %c%d.%d ns
  ",
  			(data[32] & 0x80) ? '-' : '+',
  			(data[32] >> 4) & 0x07, data[32] & 0x0F);

  		break;
  	}
  
  	switch (type) {
  	case DDR2:

  		puts ("Command and Address hold     ");

  		if (data[33] >= 0xA0) {

  			printf ("1.%d%d ns
  ",
  				((data[33] >> 4) & 0x0F) - 10, data[33] & 0x0F);

  		} else {

  			printf ("0.%d%d ns
  ",
  				((data[33] >> 4) & 0x0F), data[33] & 0x0F);

  		}
  		break;
  	default:

  		printf ("Command and Address hold     %c%d.%d ns
  ",
  			(data[33] & 0x80) ? '-' : '+',
  			(data[33] >> 4) & 0x07, data[33] & 0x0F);

  		break;
  	}
  
  	switch (type) {
  	case DDR2:

  		printf ("Data signal input setup      0.%d%d ns
  ",
  			(data[34] >> 4) & 0x0F, data[34] & 0x0F);

  		break;
  	default:

  		printf ("Data signal input setup      %c%d.%d ns
  ",
  			(data[34] & 0x80) ? '-' : '+',
  			(data[34] >> 4) & 0x07, data[34] & 0x0F);

  		break;
  	}
  
  	switch (type) {
  	case DDR2:

  		printf ("Data signal input hold       0.%d%d ns
  ",
  			(data[35] >> 4) & 0x0F, data[35] & 0x0F);

  		break;
  	default:

  		printf ("Data signal input hold       %c%d.%d ns
  ",
  			(data[35] & 0x80) ? '-' : '+',
  			(data[35] >> 4) & 0x07, data[35] & 0x0F);

  		break;
  	}

  	puts ("Manufacturer's JEDEC ID      ");

  	for (j = 64; j <= 71; j++)

  		printf ("%02X ", data[j]);

  	putc ('
  ');

  	printf ("Manufacturing Location       %02X
  ", data[72]);

  	puts ("Manufacturer's Part Number   ");

  	for (j = 73; j <= 90; j++)

  		printf ("%02X ", data[j]);

  	putc ('
  ');

  	printf ("Revision Code                %02X %02X
  ", data[91], data[92]);
  	printf ("Manufacturing Date           %02X %02X
  ", data[93], data[94]);

  	puts ("Assembly Serial Number       ");

  	for (j = 95; j <= 98; j++)

  		printf ("%02X ", data[j]);

  	putc ('
  ');

  	if (DDR2 != type) {

  		printf ("Speed rating                 PC%d
  ",
  			data[126] == 0x66 ? 66 : data[126]);

  	}

  	return 0;
  }

  #endif

  /*
   * Syntax:
   *	i2c edid {i2c_chip}
   */
  #if defined(CONFIG_I2C_EDID)
  int do_edid(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
  {
  	u_char chip;
  	struct edid1_info edid;
  
  	if (argc < 2) {
  		cmd_usage(cmdtp);
  		return 1;
  	}
  
  	chip = simple_strtoul(argv[1], NULL, 16);
  	if (i2c_read(chip, 0, 1, (uchar *)&edid, sizeof(edid)) != 0) {
  		puts("Error reading EDID content.
  ");
  		return 1;
  	}
  
  	if (edid_check_info(&edid)) {
  		puts("Content isn't valid EDID.
  ");
  		return 1;
  	}
  
  	edid_print_info(&edid);
  	return 0;
  
  }
  #endif /* CONFIG_I2C_EDID */

  /**

   * do_i2c_show_bus() - Handle the "i2c bus" command-line command

   * @cmdtp:	Command data struct pointer
   * @flag:	Command flag
   * @argc:	Command-line argument count
   * @argv:	Array of command-line arguments
   *
   * Returns zero always.
   */

  #if defined(CONFIG_SYS_I2C)
  int do_i2c_show_bus(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])

  {

  	int	i;
  #ifndef CONFIG_SYS_I2C_DIRECT_BUS
  	int	j;
  #endif

  
  	if (argc == 1) {
  		/* show all busses */

  		for (i = 0; i < CONFIG_SYS_NUM_I2C_BUSES; i++) {
  			printf("Bus %d:\t%s", i, I2C_ADAP_NR(i)->name);
  #ifndef CONFIG_SYS_I2C_DIRECT_BUS
  			for (j = 0; j < CONFIG_SYS_I2C_MAX_HOPS; j++) {
  				if (i2c_bus[i].next_hop[j].chip == 0)
  					break;
  				printf("->%s@0x%2x:%d",
  				       i2c_bus[i].next_hop[j].mux.name,
  				       i2c_bus[i].next_hop[j].chip,
  				       i2c_bus[i].next_hop[j].channel);

  			}

  #endif
  			printf("
  ");

  		}
  	} else {

  		/* show specific bus */
  		i = simple_strtoul(argv[1], NULL, 10);
  		if (i >= CONFIG_SYS_NUM_I2C_BUSES) {
  			printf("Invalid bus %d
  ", i);
  			return -1;
  		}
  		printf("Bus %d:\t%s", i, I2C_ADAP_NR(i)->name);
  #ifndef CONFIG_SYS_I2C_DIRECT_BUS
  			for (j = 0; j < CONFIG_SYS_I2C_MAX_HOPS; j++) {
  				if (i2c_bus[i].next_hop[j].chip == 0)
  					break;
  				printf("->%s@0x%2x:%d",
  				       i2c_bus[i].next_hop[j].mux.name,
  				       i2c_bus[i].next_hop[j].chip,
  				       i2c_bus[i].next_hop[j].channel);
  			}
  #endif
  		printf("
  ");

  	}

  
  	return 0;

  }

  #endif

  /**
   * do_i2c_bus_num() - Handle the "i2c dev" command-line command
   * @cmdtp:	Command data struct pointer
   * @flag:	Command flag
   * @argc:	Command-line argument count
   * @argv:	Array of command-line arguments
   *
   * Returns zero on success, CMD_RET_USAGE in case of misuse and negative
   * on error.
   */

  #if defined(CONFIG_SYS_I2C) || defined(CONFIG_I2C_MULTI_BUS)
  int do_i2c_bus_num(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])

  {

  	int		ret = 0;
  	unsigned int	bus_no;

  	if (argc == 1)
  		/* querying current setting */

  		printf("Current bus is %d
  ", i2c_get_bus_num());

  	else {

  		bus_no = simple_strtoul(argv[1], NULL, 10);

  #if defined(CONFIG_SYS_I2C)

  		if (bus_no >= CONFIG_SYS_NUM_I2C_BUSES) {
  			printf("Invalid bus %d
  ", bus_no);
  			return -1;
  		}

  #endif

  		printf("Setting bus to %d
  ", bus_no);
  		ret = i2c_set_bus_num(bus_no);

  		if (ret)

  			printf("Failure changing bus number (%d)
  ", ret);

  	}
  	return ret;
  }

  #endif  /* defined(CONFIG_SYS_I2C) */

  /**
   * do_i2c_bus_speed() - Handle the "i2c speed" command-line command
   * @cmdtp:	Command data struct pointer
   * @flag:	Command flag
   * @argc:	Command-line argument count
   * @argv:	Array of command-line arguments
   *
   * Returns zero on success, CMD_RET_USAGE in case of misuse and negative
   * on error.
   */

  static int do_i2c_bus_speed(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])

  {
  	int speed, ret=0;

  	if (argc == 1)
  		/* querying current speed */

  		printf("Current bus speed=%d
  ", i2c_get_bus_speed());

  	else {

  		speed = simple_strtoul(argv[1], NULL, 10);
  		printf("Setting bus speed to %d Hz
  ", speed);
  		ret = i2c_set_bus_speed(speed);

  		if (ret)

  			printf("Failure changing bus speed (%d)
  ", ret);

  	}
  	return ret;
  }

  /**
   * do_i2c_mm() - Handle the "i2c mm" command-line command
   * @cmdtp:	Command data struct pointer
   * @flag:	Command flag
   * @argc:	Command-line argument count
   * @argv:	Array of command-line arguments
   *
   * Returns zero on success, CMD_RET_USAGE in case of misuse and negative
   * on error.
   */

  static int do_i2c_mm(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])

  {

  	return mod_i2c_mem (cmdtp, 1, flag, argc, argv);
  }

  /**
   * do_i2c_nm() - Handle the "i2c nm" command-line command
   * @cmdtp:	Command data struct pointer
   * @flag:	Command flag
   * @argc:	Command-line argument count
   * @argv:	Array of command-line arguments
   *
   * Returns zero on success, CMD_RET_USAGE in case of misuse and negative
   * on error.
   */

  static int do_i2c_nm(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])

  {
  	return mod_i2c_mem (cmdtp, 0, flag, argc, argv);
  }

  /**
   * do_i2c_reset() - Handle the "i2c reset" command-line command
   * @cmdtp:	Command data struct pointer
   * @flag:	Command flag
   * @argc:	Command-line argument count
   * @argv:	Array of command-line arguments
   *
   * Returns zero always.
   */

  static int do_i2c_reset(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])

  {

  #if defined(CONFIG_SYS_I2C)
  	i2c_init(I2C_ADAP->speed, I2C_ADAP->slaveaddr);
  #else

  	i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);

  #endif

  	return 0;
  }
  
  static cmd_tbl_t cmd_i2c_sub[] = {

  #if defined(CONFIG_SYS_I2C)
  	U_BOOT_CMD_MKENT(bus, 1, 1, do_i2c_show_bus, "", ""),

  #endif

  	U_BOOT_CMD_MKENT(crc32, 3, 1, do_i2c_crc, "", ""),

  #if defined(CONFIG_SYS_I2C) || \
  	defined(CONFIG_I2C_MULTI_BUS)

  	U_BOOT_CMD_MKENT(dev, 1, 1, do_i2c_bus_num, "", ""),

  #endif  /* CONFIG_I2C_MULTI_BUS */

  #if defined(CONFIG_I2C_EDID)
  	U_BOOT_CMD_MKENT(edid, 1, 1, do_edid, "", ""),
  #endif  /* CONFIG_I2C_EDID */

  	U_BOOT_CMD_MKENT(loop, 3, 1, do_i2c_loop, "", ""),
  	U_BOOT_CMD_MKENT(md, 3, 1, do_i2c_md, "", ""),
  	U_BOOT_CMD_MKENT(mm, 2, 1, do_i2c_mm, "", ""),
  	U_BOOT_CMD_MKENT(mw, 3, 1, do_i2c_mw, "", ""),
  	U_BOOT_CMD_MKENT(nm, 2, 1, do_i2c_nm, "", ""),
  	U_BOOT_CMD_MKENT(probe, 0, 1, do_i2c_probe, "", ""),

  	U_BOOT_CMD_MKENT(read, 5, 1, do_i2c_read, "", ""),

  	U_BOOT_CMD_MKENT(write, 5, 0, do_i2c_write, "", ""),

  	U_BOOT_CMD_MKENT(reset, 0, 1, do_i2c_reset, "", ""),

  #if defined(CONFIG_CMD_SDRAM)

  	U_BOOT_CMD_MKENT(sdram, 1, 1, do_sdram, "", ""),

  #endif

  	U_BOOT_CMD_MKENT(speed, 1, 1, do_i2c_bus_speed, "", ""),
  };

  #ifdef CONFIG_NEEDS_MANUAL_RELOC

  void i2c_reloc(void) {
  	fixup_cmdtable(cmd_i2c_sub, ARRAY_SIZE(cmd_i2c_sub));
  }
  #endif

  /**
   * do_i2c() - Handle the "i2c" command-line command
   * @cmdtp:	Command data struct pointer
   * @flag:	Command flag
   * @argc:	Command-line argument count
   * @argv:	Array of command-line arguments
   *
   * Returns zero on success, CMD_RET_USAGE in case of misuse and negative
   * on error.
   */

  static int do_i2c(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])

  {
  	cmd_tbl_t *c;

  	if (argc < 2)

  		return CMD_RET_USAGE;

  	/* Strip off leading 'i2c' command argument */
  	argc--;
  	argv++;
  
  	c = find_cmd_tbl(argv[0], &cmd_i2c_sub[0], ARRAY_SIZE(cmd_i2c_sub));

  	if (c)

  		return c->cmd(cmdtp, flag, argc, argv);

  	else

  		return CMD_RET_USAGE;

  }

  
  /***************************************************/

  #ifdef CONFIG_SYS_LONGHELP
  static char i2c_help_text[] =

  #if defined(CONFIG_SYS_I2C)
  	"bus [muxtype:muxaddr:muxchannel] - show I2C bus info
  "

  #endif

  	"crc32 chip address[.0, .1, .2] count - compute CRC32 checksum
  "

  #if defined(CONFIG_SYS_I2C) || \
  	defined(CONFIG_I2C_MULTI_BUS)

  	"i2c dev [dev] - show or set current I2C bus
  "

  #endif  /* CONFIG_I2C_MULTI_BUS */

  #if defined(CONFIG_I2C_EDID)
  	"i2c edid chip - print EDID configuration information
  "
  #endif  /* CONFIG_I2C_EDID */

  	"i2c loop chip address[.0, .1, .2] [# of objects] - looping read of device
  "

  	"i2c md chip address[.0, .1, .2] [# of objects] - read from I2C device
  "
  	"i2c mm chip address[.0, .1, .2] - write to I2C device (auto-incrementing)
  "
  	"i2c mw chip address[.0, .1, .2] value [count] - write to I2C device (fill)
  "
  	"i2c nm chip address[.0, .1, .2] - write to I2C device (constant address)
  "

  	"i2c probe [address] - test for and show device(s) on the I2C bus
  "

  	"i2c read chip address[.0, .1, .2] length memaddress - read to memory 
  "

  	"i2c write memaddress chip address[.0, .1, .2] length - write memory to i2c
  "

  	"i2c reset - re-init the I2C Controller
  "

  #if defined(CONFIG_CMD_SDRAM)

  	"i2c sdram chip - print SDRAM configuration information
  "

  #endif

  	"i2c speed [speed] - show or set I2C bus speed";
  #endif
  
  U_BOOT_CMD(
  	i2c, 6, 1, do_i2c,
  	"I2C sub-system",
  	i2c_help_text

  );