cmd_i2c.c

/*
 * (C) Copyright 2001
 * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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; either version 2 of
 * the License, or (at your option) any later version.
 *
 * 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
 */

/*
 * I2C Functions similar to the standard memory functions.
 *
 * There are several parameters in many of the commands that bear further
 * explanations:
 *
 * Two of the commands (imm and imw) take a byte/word/long modifier
 * (e.g. imm.w specifies the word-length modifier).  This was done to
 * allow manipulating word-length registers.  It was not done on any other
 * commands because it was not deemed useful.
 *
 * {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
 *   CFG_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...
 *     imd 50 0 10      display 16 bytes starting at 0x000
 *                      On the bus: <S> A0 00 <E> <S> A1 <rd> ... <rd>
 *     imd 50 100 10    display 16 bytes starting at 0x100
 *                      On the bus: <S> A2 00 <E> <S> A3 <rd> ... <rd>
 *     imd 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 <i2c.h>
#include <asm/byteorder.h>

#if (CONFIG_COMMANDS & CFG_CMD_I2C)


/* 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(CFG_I2C_NOPROBES)
#if defined(CONFIG_I2C_MULTI_BUS)
static struct
{
	uchar	bus;
	uchar	addr;
} i2c_no_probes[] = CFG_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[] = CFG_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	/* CONFIG_MULTI_BUS */

#define NUM_ELEMENTS_NOPROBE (sizeof(i2c_no_probes)/sizeof(i2c_no_probes[0]))
#endif

static int
mod_i2c_mem(cmd_tbl_t *cmdtp, int incrflag, int flag, int argc, char *argv[]);
extern int cmd_get_data_size(char* arg, int default_size);

/*
 * Syntax:
 *	imd {i2c_chip} {addr}{.0, .1, .2} {len}
 */
#define DISP_LINE_LEN	16

int do_i2c_md ( cmd_tbl_t *cmdtp, int flag, int argc, char *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) {
		printf ("Usage:\n%s\n", cmdtp->usage);
		return 1;
	}

	if ((flag & CMD_FLAG_REPEAT) == 0) {
		/*
		 * New command specified.
		 */
		alen = 1;

		/*
		 * 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 = 1;
		for (j = 0; j < 8; j++) {
			if (argv[2][j] == '.') {
				alen = argv[2][j+1] - '0';
				if (alen > 4) {
					printf ("Usage:\n%s\n", cmdtp->usage);
					return 1;
				}
				break;
			} else if (argv[2][j] == '\0')
				break;
		}

		/*
		 * 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