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SPI: Configure Software Sequence SPI Freq to match descriptor 

Right now the SPI bus is getting set to 20mhz for transactions
initiated with the software sequence interface.

In order to be able to do reasonable fastread/write/erase we
can bump this up to a higher value at boot before it gets
locked at 20mhz.

To do this read out the speed set in the SPI descriptor for
hardware sequencing and apply it to software sequencing.

Change-Id: I79aa2fe7f30f734785d61955ed81329fc654f4a4
Signed-off-by: Duncan Laurie <dlaurie@google.com>
Reviewed-on: http://review.coreboot.org/1773
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
This commit is contained in:
Duncan Laurie 2012-10-08 15:26:54 -07:00 committed by Stefan Reinauer
parent 924342bb2b
commit 2a700ec163
1 changed files with 21 additions and 0 deletions
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21
src/southbridge/intel/bd82x6x/bootblock.c
View File

@ -65,6 +65,26 @@ static void enable_port80_on_lpc(void)
#endif
}
static void set_spi_speed(void)
{
u32 fdod;
u8 ssfc;
/* Observe SPI Descriptor Component Section 0 */
RCBA32(0x38b0) = 0x1000;
/* Extract the Write/Erase SPI Frequency from descriptor */
fdod = RCBA32(0x38b4);
fdod >>= 24;
fdod &= 7;
/* Set Software Sequence frequency to match */
ssfc = RCBA8(0x3893);
ssfc &= ~7;
ssfc |= fdod;
RCBA8(0x3893) = ssfc;
}
static void bootblock_southbridge_init(void)
{
#if CONFIG_COLLECT_TIMESTAMPS
@ -72,6 +92,7 @@ static void bootblock_southbridge_init(void)
#endif
enable_spi_prefetch();
enable_port80_on_lpc();
set_spi_speed();
/* Enable upper 128bytes of CMOS */
RCBA32(RC) = (1 << 2);