Karthik Ramasubramanian submitted this change.
mb/google/dedede/var/sasuke: Configure I2C times for touchpad/audio
Configure I2C rise/fall time in device tree to ensure I2C CLK runs
accurately at I2C_SPEED_FAST (< 400 kHz).
Measured I2C frequency just as below after tuning:
I2C0(touchpad): 385 kHz
I2C4(audio): 380 kHz
BUG=b:180335053
BRANCH=dedede
TEST=Build and check after tuning I2C clock is under 400kHz
Change-Id: Ic92ee0379456e80260a8026bc38ee41325dad6d2
Signed-off-by: Seunghwan Kim <sh_.kim@samsung.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51335
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>
---
M src/mainboard/google/dedede/variants/sasuke/overridetree.cb
1 file changed, 4 insertions(+), 9 deletions(-)
diff --git a/src/mainboard/google/dedede/variants/sasuke/overridetree.cb b/src/mainboard/google/dedede/variants/sasuke/overridetree.cb
index 2fb1d61..bcc4b49 100644
--- a/src/mainboard/google/dedede/variants/sasuke/overridetree.cb
+++ b/src/mainboard/google/dedede/variants/sasuke/overridetree.cb
@@ -61,9 +61,8 @@
},
.i2c[0] = {
.speed = I2C_SPEED_FAST,
- .rise_time_ns = 66,
- .fall_time_ns = 90,
- .data_hold_time_ns = 350,
+ .rise_time_ns = 209,
+ .fall_time_ns = 12,
},
.i2c[1] = {
.speed = I2C_SPEED_FAST,
@@ -76,12 +75,8 @@
},
.i2c[4] = {
.speed = I2C_SPEED_FAST,
- .speed_config[0] = {
- .speed = I2C_SPEED_FAST,
- .scl_lcnt = 176,
- .scl_hcnt = 95,
- .sda_hold = 36,
- }
+ .rise_time_ns = 175,
+ .fall_time_ns = 8,
},
}"
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