intel/common/smbus: increase spd read performance

This change increases the spd read performance by using smbus word
access.

BUG=b:67021853
TEST=boot to os and find 80~100 ms boot time improvement on one dimm

Change-Id: I98fe67642d8ccd428bccbca7f6390331d6055d14
Signed-off-by: Kane Chen <kane.chen@intel.com>
Reviewed-on: https://review.coreboot.org/22072
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/src/soc/intel/common/block/smbus/smbus_early.c b/src/soc/intel/common/block/smbus/smbus_early.c
index e0c4d9c649..9e6afc4563 100644
--- a/src/soc/intel/common/block/smbus/smbus_early.c
+++ b/src/soc/intel/common/block/smbus/smbus_early.c
@@ -36,6 +36,11 @@ static const struct reg_script smbus_init_script[] = {
 	REG_SCRIPT_END,
 };
 
+u16 smbus_read_word(u32 smbus_dev, u8 addr, u8 offset)
+{
+	return smbus_read16(SMBUS_IO_BASE, addr, offset);
+}
+
 u8 smbus_read_byte(u32 smbus_dev, u8 addr, u8 offset)
 {
 	return smbus_read8(SMBUS_IO_BASE, addr, offset);