New patch to review for coreboot: 16f64af AMD cimx/sb800: Set SPI frequency and prefetch

[Kyösti Mälkki]

Kyösti Mälkki ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/5089

-gerrit

commit 16f64af25cc2b79975698598ab57a40ff8110d15
Author: Kyösti Mälkki 
Date:   Fri Jan 31 20:32:54 2014 +0200

AMD cimx/sb800: Set SPI frequency and prefetch

Broken with/since commit d1cb0eec.

Original intention was to set the frequency for 'Fast Read' command
    in bits 15..14, and enable 'Fast Read' command.

Modified register contains SPI frequency for 'Normal Read' command
    in bits 13..12. Default for this is 11b for 16.5 MHz. Existing code
    unintentionally clears these bits, increasing SPI frequency to 66MHz
    for 'Normal Read' command.

This is above specifications for many common SPI flash components
    and also makes flashrom older than 0.9.7-r1750 to operate unreliably
    on read/write/erase for these platforms.

Change-Id: I30109e2a0410c0bb0bdc968ea71787396b32e761
    Signed-off-by: Kyösti Mälkki 
---
 src/southbridge/amd/cimx/sb800/bootblock.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/southbridge/amd/cimx/sb800/bootblock.c b/src/southbridge/amd/cimx/sb800/bootblock.c
index ac9351e..4fd2739 100644
--- a/src/southbridge/amd/cimx/sb800/bootblock.c
+++ b/src/southbridge/amd/cimx/sb800/bootblock.c
@@ -66,7 +66,6 @@ static void enable_prefetch(void)

static void enable_spi_fast_mode(void)
 {
-	u8 byte;
    u32 dword;
    device_t dev = PCI_DEV(0, 0x14, 0x03);

@@ -76,8 +75,8 @@ static void enable_spi_fast_mode(void)
    pci_io_write_config32(dev, 0xa0, (u32) spi_base | 2);

// early enable of SPI 33 MHz fast mode read
-	byte = spi_base[3];
-	spi_base[3] = (byte & ~(3 << 14)) | (1 << 14);
+	dword = spi_base[3];
+	spi_base[3] = (dword & ~(3 << 14)) | (1 << 14);
    spi_base[0] = spi_base[0] | (1 << 18);	// fast read enable

pci_io_write_config32(dev, 0xa0, save);