diff options
| author | Richard Spiegel <richard.spiegel@amd.corp-partner.google.com> | 2018-10-24 12:51:21 -0700 |
|---|---|---|
| committer | Patrick Georgi <pgeorgi@google.com> | 2019-01-30 11:01:37 +0000 |
| commit | b40e193948c0af380e9dc19c06a5c93ff8b4f2f0 (patch) | |
| tree | 3de92e0841b9ef7e2c2c3a86e6b4cfd404f827dd /src/soc/amd/stoneyridge/southbridge.c | |
| parent | 9ca43191ab454c777102f9634b5d40478cd4dc58 (diff) | |
soc/amd/stoneyridge: Access SMBUS through MMIO
Currently SMBUS registers are accessed through IO, but with stoneyridge
they can be accessed through MMIO. This reduces the time of execution by
a tiny amount (MMIO write is faster than IO write, though MMIO read is about
as fast as IO read) as most of the time consumed is actually transaction
time. Convert code to MMIO access.
BUG=b:117754784
TEST=Used IO to write and MMIO to read, to confirm a one to one relationship
between IO and MMIO. Then build and boot grunt.
Change-Id: Ibe1471d1d578611e7d666f70bc97de4c3b74d7f8
Signed-off-by: Richard Spiegel <richard.spiegel@silverbackltd.com>
Reviewed-on: https://review.coreboot.org/c/29258
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>
Diffstat (limited to 'src/soc/amd/stoneyridge/southbridge.c')
| -rw-r--r-- | src/soc/amd/stoneyridge/southbridge.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/src/soc/amd/stoneyridge/southbridge.c b/src/soc/amd/stoneyridge/southbridge.c index eb4188219b..c8d66ac3f2 100644 --- a/src/soc/amd/stoneyridge/southbridge.c +++ b/src/soc/amd/stoneyridge/southbridge.c @@ -28,6 +28,7 @@ #include <amdblocks/agesawrapper.h> #include <amdblocks/reset.h> #include <soc/southbridge.h> +#include <soc/smbus.h> #include <soc/smi.h> #include <soc/amd_pci_int_defs.h> #include <delay.h> @@ -619,6 +620,17 @@ static void setup_misc(int *reboot) } } +static void fch_smbus_init(void) +{ + pm_write8(SMB_ASF_IO_BASE, SMB_BASE_ADDR >> 8); + smbus_write8(SMBUS_MMIO_BASE, SMBTIMING, SMB_SPEED_400KHZ); + /* Clear all SMBUS status bits */ + smbus_write8(SMBUS_MMIO_BASE, SMBHSTSTAT, SMBHST_STAT_CLEAR); + smbus_write8(SMBUS_MMIO_BASE, SMBSLVSTAT, SMBSLV_STAT_CLEAR); + smbus_write8(ASF_MMIO_BASE, SMBHSTSTAT, SMBHST_STAT_CLEAR); + smbus_write8(ASF_MMIO_BASE, SMBSLVSTAT, SMBSLV_STAT_CLEAR); +} + /* Before console init */ void bootblock_fch_early_init(void) { @@ -631,6 +643,7 @@ void bootblock_fch_early_init(void) sb_spibase(); sb_disable_4dw_burst(); /* Must be disabled on CZ(ST) */ sb_acpi_mmio_decode(); + fch_smbus_init(); sb_enable_cf9_io(); setup_spread_spectrum(&reboot); setup_misc(&reboot); |