diff options
Diffstat (limited to 'src/soc/intel/baytrail/romstage/early_spi.c')
-rw-r--r-- | src/soc/intel/baytrail/romstage/early_spi.c | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/src/soc/intel/baytrail/romstage/early_spi.c b/src/soc/intel/baytrail/romstage/early_spi.c new file mode 100644 index 0000000000..6188f075fc --- /dev/null +++ b/src/soc/intel/baytrail/romstage/early_spi.c @@ -0,0 +1,65 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2014 Google Inc. All rights reserved. + * + * 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; version 2 of + * the License. + * + * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <arch/io.h> +#include <delay.h> +#include <console/console.h> + +#include <baytrail/iomap.h> +#include <baytrail/romstage.h> +#include <baytrail/spi.h> + +#define SPI_CYCLE_DELAY 10 /* 10us */ +#define SPI_CYCLE_TIMEOUT 400000 / SPI_CYCLE_DELAY /* 400ms */ + +#define SPI8(x) *((volatile u8 *)(SPI_BASE_ADDRESS + x)) +#define SPI16(x) *((volatile u16 *)(SPI_BASE_ADDRESS + x)) +#define SPI32(x) *((volatile u32 *)(SPI_BASE_ADDRESS + x)) + +/* Minimal set of commands to read wpsr from SPI. Don't use this code outside + * romstage -- it trashes the opmenu table. + * Returns 0 on success, < 0 on failure. */ +int early_spi_read_wpsr(u8 *sr) +{ + int timeout = SPI_CYCLE_TIMEOUT; + + /* No address associated with rdsr */ + SPI8(OPTYPE) = 0x0; + /* Setup opcode[0] = read wpsr */ + SPI8(OPMENU0) = 0x5; + + /* Start transaction */ + SPI16(SSFC) = DATA_CYCLE | SPI_CYCLE_GO; + + /* Wait for error / complete status */ + while(timeout--) { + u16 status = SPI16(SSFS); + if (status & FLASH_CYCLE_ERROR) { + printk(BIOS_ERR, "SPI rdsr failed\n"); + return -1; + } else if (status & CYCLE_DONE_STATUS) + break; + + udelay(SPI_CYCLE_DELAY); + } + + *sr = SPI32(FDATA0) & 0xff; + return 0; +} |