Martin Roth has submitted this change and it was merged. ( https://review.coreboot.org/c/coreboot/+/34559 )
Change subject: mb/google/hatch: Fine-tune Kohaku I2C CLK frequency ......................................................................
mb/google/hatch: Fine-tune Kohaku I2C CLK frequency
Add rise time / fall time to I2C config in device tree to ensure I2C CLK runs accurately at I2C_SPEED_FAST (400 kHz).
BUG=b:138258384 BRANCH=none TEST=probe I2C0/I2C2/I2C3 SCL on Kohaku board, verify all of them run at 395-399 kHz.
Change-Id: Id98079e717f0db3fdcb88f85e45693925d11d7fd Signed-off-by: Philip Chen philipchen@google.com Reviewed-on: https://review.coreboot.org/c/coreboot/+/34559 Reviewed-by: Tim Wawrzynczak twawrzynczak@chromium.org Reviewed-by: Furquan Shaikh furquan@google.com Reviewed-by: Paul Fagerburg pfagerburg@chromium.org Tested-by: build bot (Jenkins) no-reply@coreboot.org --- M src/mainboard/google/hatch/variants/kohaku/overridetree.cb 1 file changed, 6 insertions(+), 0 deletions(-)
Approvals: build bot (Jenkins): Verified Furquan Shaikh: Looks good to me, approved Tim Wawrzynczak: Looks good to me, approved Paul Fagerburg: Looks good to me, but someone else must approve
diff --git a/src/mainboard/google/hatch/variants/kohaku/overridetree.cb b/src/mainboard/google/hatch/variants/kohaku/overridetree.cb index fa64d60..b3ae1bc 100644 --- a/src/mainboard/google/hatch/variants/kohaku/overridetree.cb +++ b/src/mainboard/google/hatch/variants/kohaku/overridetree.cb @@ -32,15 +32,21 @@ register "common_soc_config" = "{ .i2c[0] = { .speed = I2C_SPEED_FAST, + .rise_time_ns = 135, + .fall_time_ns = 45, }, .i2c[1] = { .speed = I2C_SPEED_FAST, }, .i2c[2] = { .speed = I2C_SPEED_FAST, + .rise_time_ns = 95, + .fall_time_ns = 55, }, .i2c[4] = { .speed = I2C_SPEED_FAST, + .rise_time_ns = 100, + .fall_time_ns = 20, }, .gspi[0] = { .speed_mhz = 1,