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authorTimothy Pearson <tpearson@raptorengineering.com>2016-08-23 15:41:05 -0500
committerTimothy Pearson <tpearson@raptorengineering.com>2016-08-26 18:22:33 +0200
commit6e5421d2a887737fc7c8a916d54151f9b1706f6d (patch)
tree9cb049060ca5393f5ef8adea1ff0cb010cc78c61 /src/southbridge
parent3b0e761dd5008b9b87d207f9c7d7571fc880a523 (diff)
sb/amd/sb700: Add option to increase SPI speed to 33MHz
Some SB700-based systems and ROMs support high speed (33MHz) SPI access instead of the power-on default 16.5MHz. Add an option to enable high speed SPI access in the bootblock, and set the default value to Disabled. This greatly decreases boot time on SB700-based systems, especiall when a large payload is in use. On a KGPE-D16 with a Petitboot (Linux + initramfs) payload, the command prompt was accessible within 20 seconds of power on, which incidentally is faster than the proprietary BIOS on the same machine could even reach the GRUB bootloader. Change-Id: Iadbd9bb611754262ef75a5e5a6ee4390a46e45cf Signed-off-by: Timothy Pearson <tpearson@raptorengineering.com> Test: Booted KGPE-D16 with Linux payload Reviewed-on: https://review.coreboot.org/16306 Tested-by: build bot (Jenkins) Tested-by: Raptor Engineering Automated Test Stand <noreply@raptorengineeringinc.com> Reviewed-by: Martin Roth <martinroth@google.com>
Diffstat (limited to 'src/southbridge')
-rw-r--r--src/southbridge/amd/sb700/Kconfig10
-rw-r--r--src/southbridge/amd/sb700/bootblock.c34
2 files changed, 44 insertions, 0 deletions
diff --git a/src/southbridge/amd/sb700/Kconfig b/src/southbridge/amd/sb700/Kconfig
index 9a988a90f8..353c2a46c7 100644
--- a/src/southbridge/amd/sb700/Kconfig
+++ b/src/southbridge/amd/sb700/Kconfig
@@ -25,6 +25,16 @@ config SOUTHBRIDGE_SPECIFIC_OPTIONS # dummy
select HAVE_HARD_RESET
select SMBUS_HAS_AUX_CHANNELS
+config SOUTHBRIDGE_AMD_SB700_33MHZ_SPI
+ bool "Enable high speed SPI clock"
+ default n
+ help
+ When set, the SPI clock will run at 33MHz instead
+ of the compatibility mode 16.5MHz. Note that not
+ all ROMs are capable of 33MHz operation, so you
+ will need to verify this option is appropriate for
+ the ROM you are using.
+
# Set for southbridge SP5100 which also uses SB700 driver
config SOUTHBRIDGE_AMD_SUBTYPE_SP5100
bool
diff --git a/src/southbridge/amd/sb700/bootblock.c b/src/southbridge/amd/sb700/bootblock.c
index 97e749ce08..dfa4102953 100644
--- a/src/southbridge/amd/sb700/bootblock.c
+++ b/src/southbridge/amd/sb700/bootblock.c
@@ -20,6 +20,10 @@
#define IO_MEM_PORT_DECODE_ENABLE_5 0x48
#define IO_MEM_PORT_DECODE_ENABLE_6 0x4a
+#define SPI_BASE_ADDRESS 0xa0
+
+#define SPI_CONTROL_1 0xc
+#define TEMPORARY_SPI_BASE_ADDRESS 0xfec10000
/*
* Enable 4MB (LPC) ROM access at 0xFFC00000 - 0xFFFFFFFF.
@@ -92,7 +96,37 @@ static void sb700_enable_rom(void)
pci_io_write_config8(dev, IO_MEM_PORT_DECODE_ENABLE_6, reg8);
}
+static void sb700_configure_rom(void)
+{
+ pci_devfn_t dev;
+ uint32_t dword;
+
+ dev = PCI_DEV(0, 0x14, 3);
+
+ if (IS_ENABLED(CONFIG_SOUTHBRIDGE_AMD_SB700_33MHZ_SPI)) {
+ uint32_t prev_spi_cfg;
+ volatile uint32_t *spi_mmio;
+
+ /* Temporarily set up SPI access to change SPI speed */
+ prev_spi_cfg = dword = pci_io_read_config32(dev, SPI_BASE_ADDRESS);
+ dword &= ~(0x7ffffff << 5); /* SPI_BaseAddr */
+ dword |= TEMPORARY_SPI_BASE_ADDRESS & (0x7ffffff << 5);
+ dword |= (0x1 << 1); /* SpiRomEnable = 1 */
+ pci_io_write_config32(dev, SPI_BASE_ADDRESS, dword);
+
+ spi_mmio = (void *)(TEMPORARY_SPI_BASE_ADDRESS + SPI_CONTROL_1);
+ dword = *spi_mmio;
+ dword &= ~(0x3 << 12); /* NormSpeed = 0x1 */
+ dword |= (0x1 << 12);
+ *spi_mmio = dword;
+
+ /* Restore previous SPI access */
+ pci_io_write_config32(dev, SPI_BASE_ADDRESS, prev_spi_cfg);
+ }
+}
+
static void bootblock_southbridge_init(void)
{
sb700_enable_rom();
+ sb700_configure_rom();
}