mb/google/dedede/var/storo: Configure I2C times for I2C devices
Configure I2C high / low time in device tree to ensure I2C
CLK runs accurately at I2C_SPEED_FAST (400 kHz).
Measured I2C frequency just as below after tuning:
touchpad:371.63 kHz
touchpanel:368.24 kHz
audio codec RT5682:369.13 kHz
speaker AMP L:366.21 kHz
speaker AMP R:365.8 kHz
P-sensor:368.34 kHz
MIPI Camera:363.35 kHz
BUG=b:181589325
BRANCH=dedede
TEST=Build and check after tuning I2C clock is under 400kHz
Signed-off-by: Tao Xia <xiatao5@huaqin.corp-partner.google.com>
Change-Id: I1a755a54540e106b41ac427f84989ed7e8037558
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51624
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/mainboard/google/dedede/variants/storo/overridetree.cb b/src/mainboard/google/dedede/variants/storo/overridetree.cb
index 0025fec..b3a8e22 100644
--- a/src/mainboard/google/dedede/variants/storo/overridetree.cb
+++ b/src/mainboard/google/dedede/variants/storo/overridetree.cb
@@ -26,21 +26,31 @@
},
.i2c[0] = {
.speed = I2C_SPEED_FAST,
+ .rise_time_ns = 125,
+ .fall_time_ns = 19,
},
.i2c[1] = {
.speed = I2C_SPEED_FAST,
},
.i2c[2] = {
.speed = I2C_SPEED_FAST,
+ .rise_time_ns = 86,
+ .fall_time_ns = 5,
},
.i2c[3] = {
.speed = I2C_SPEED_FAST,
+ .rise_time_ns = 84,
+ .fall_time_ns = 4,
},
.i2c[4] = {
.speed = I2C_SPEED_FAST,
+ .rise_time_ns = 69,
+ .fall_time_ns = 3,
},
.i2c[5] = {
.speed = I2C_SPEED_FAST,
+ .rise_time_ns = 129,
+ .fall_time_ns = 4,
},
}"