From 242cb3b601396a5178680f7731b8d5f9d257c646 Mon Sep 17 00:00:00 2001 From: Aaron Durbin Date: Thu, 3 Nov 2016 08:34:23 -0500 Subject: reef: tune tpm i2c frequency to 400kHz This brings the frequency down to 400kHz which is spec for fast i2c. BUG=chrome-os-partner:58889 Change-Id: I8689a062b5457aa431eaa7fb688a7170dad83fcf Signed-off-by: Aaron Durbin Reviewed-on: https://review.coreboot.org/17214 Reviewed-by: Duncan Laurie Tested-by: build bot (Jenkins) Reviewed-by: Paul Menzel --- src/mainboard/google/reef/variants/baseboard/devicetree.cb | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) (limited to 'src') diff --git a/src/mainboard/google/reef/variants/baseboard/devicetree.cb b/src/mainboard/google/reef/variants/baseboard/devicetree.cb index 30d61f63d4..559b0071be 100644 --- a/src/mainboard/google/reef/variants/baseboard/devicetree.cb +++ b/src/mainboard/google/reef/variants/baseboard/devicetree.cb @@ -71,8 +71,18 @@ chip soc/intel/apollolake register "gpe0_dw2" = "PMC_GPE_N_63_32" register "gpe0_dw3" = "PMC_GPE_SW_31_0" - # Enable I2C2 bus early for TPM access - register "i2c[2].early_init" = "1" + # Enable I2C2 bus early for TPM access and configure as 400kHz + # with manually tuned values. + register "i2c[2]" = "{ + .early_init = 1, + .speed = I2C_SPEED_FAST, + .speed_config[0] = { + .speed = I2C_SPEED_FAST, + .scl_lcnt = 0xd0, + .scl_hcnt = 0x68, + .sda_hold = 0x27, + } + }" # Minimum SLP S3 assertion width 28ms. register "slp_s3_assertion_width_usecs" = "28000" -- cgit v1.2.3