Commit 3ac374c0 authored by Albin Tonnerre's avatar Albin Tonnerre Committed by Wolfgang Denk
Browse files

Add driver for the ST M95xxx SPI EEPROM



This chip is used in a number of boards manufactured by Calao-Systems
which should be supported soon. This driver provides the necessary
spi_read and spi_write functions necessary to communicate with the chip.
Signed-off-by: default avatarAlbin Tonnerre <albin.tonnerre@free-electrons.com>
parent 30951960
......@@ -31,6 +31,7 @@ COBJS-$(CONFIG_SPI_FLASH_MACRONIX) += macronix.o
COBJS-$(CONFIG_SPI_FLASH_SPANSION) += spansion.o
COBJS-$(CONFIG_SPI_FLASH_SST) += sst.o
COBJS-$(CONFIG_SPI_FLASH_STMICRO) += stmicro.o
COBJS-$(CONFIG_SPI_M95XXX) += eeprom_m95xxx.o
COBJS := $(COBJS-y)
SRCS := $(COBJS:.o=.c)
......
/*
* Copyright (C) 2009
* Albin Tonnerre, Free Electrons <albin.tonnerre@free-electrons.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
*/
#include <common.h>
#include <spi.h>
#define SPI_EEPROM_WREN 0x06
#define SPI_EEPROM_RDSR 0x05
#define SPI_EEPROM_READ 0x03
#define SPI_EEPROM_WRITE 0x02
#ifndef CONFIG_DEFAULT_SPI_BUS
#define CONFIG_DEFAULT_SPI_BUS 0
#endif
#ifndef CONFIG_DEFAULT_SPI_MODE
#define CONFIG_DEFAULT_SPI_MODE SPI_MODE_0
#endif
ssize_t spi_read (uchar *addr, int alen, uchar *buffer, int len)
{
struct spi_slave *slave;
u8 cmd = SPI_EEPROM_READ;
slave = spi_setup_slave(CONFIG_DEFAULT_SPI_BUS, 1, 1000000,
CONFIG_DEFAULT_SPI_MODE);
spi_claim_bus(slave);
/* command */
if(spi_xfer(slave, 8, &cmd, NULL, SPI_XFER_BEGIN))
return -1;
/*
* if alen == 3, addr[0] is the block number, we never use it here. All we
* need are the lower 16 bits
*/
if (alen == 3)
addr++;
/* address, and data */
if(spi_xfer(slave, 16, addr, NULL, 0))
return -1;
if(spi_xfer(slave, 8 * len, NULL, buffer, SPI_XFER_END))
return -1;
spi_release_bus(slave);
spi_free_slave(slave);
return len;
}
ssize_t spi_write (uchar *addr, int alen, uchar *buffer, int len)
{
struct spi_slave *slave;
int i;
char buf[3];
slave = spi_setup_slave(CONFIG_DEFAULT_SPI_BUS, 1, 1000000,
CONFIG_DEFAULT_SPI_MODE);
spi_claim_bus(slave);
buf[0] = SPI_EEPROM_WREN;
if(spi_xfer(slave, 8, buf, NULL, SPI_XFER_BEGIN | SPI_XFER_END))
return -1;
buf[0] = SPI_EEPROM_WRITE;
/* As for reading, drop addr[0] if alen is 3 */
if (alen == 3) {
alen--;
addr++;
}
memcpy(buf + 1, addr, alen);
/* command + addr, then data */
if(spi_xfer(slave, 24, buf, NULL, SPI_XFER_BEGIN))
return -1;
if(spi_xfer(slave, len * 8, buffer, NULL, SPI_XFER_END))
return -1;
reset_timer_masked();
do {
buf[0] = SPI_EEPROM_RDSR;
buf[1] = 0;
spi_xfer(slave, 16, buf, buf, SPI_XFER_BEGIN | SPI_XFER_END);
if (!(buf[1] & 1))
break;
} while (get_timer_masked() < CONFIG_SYS_SPI_WRITE_TOUT);
if (buf[1] & 1)
printf ("*** spi_write: Time out while writing!\n");
spi_release_bus(slave);
spi_free_slave(slave);
return len;
}
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