diff options
Diffstat (limited to 'drivers/mtd/spi/eeprom_m95xxx.c')
-rw-r--r-- | drivers/mtd/spi/eeprom_m95xxx.c | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/drivers/mtd/spi/eeprom_m95xxx.c b/drivers/mtd/spi/eeprom_m95xxx.c new file mode 100644 index 0000000..59f80e3 --- /dev/null +++ b/drivers/mtd/spi/eeprom_m95xxx.c @@ -0,0 +1,117 @@ +/* + * 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; +} |