Change in coreboot[master]: soc/amd/common/block/i2c/i23c_pad_ctrl: only configure mode and voltage

[Felix Held (Code Review)]

Felix Held has submitted this change. ( https://review.coreboot.org/c/coreboot/+/63234 )

Change subject: soc/amd/common/block/i2c/i23c_pad_ctrl: only configure mode and voltage
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soc/amd/common/block/i2c/i23c_pad_ctrl: only configure mode and voltage

The fch_i23c_pad_init implementation was written without looking at any
reference code and turned out to not work properly on hardware. Before
this function writes to the MISC_I23C_PAD_CTRL registers, the value read
back is 0x3000003c which results in the I2C bus communication to work
while the 0x300003fc the code writes to the register breaks the I2C
communication. Removing the code that sets bits 6..9 fixes the I2C bus
communication.

Signed-off-by: Felix Held 
Tested-by: Karthikeyan Ramasubramanian 
Change-Id: Ie6758b3d13c59b20ce810225fca8a365713b7a2b
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63234
Reviewed-by: Karthik Ramasubramanian 
Reviewed-by: Fred Reitberger 
Reviewed-by: Raul Rangel 
Tested-by: build bot (Jenkins) 
---
M src/soc/amd/common/block/i2c/i23c_pad_ctrl.c
1 file changed, 0 insertions(+), 7 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Raul Rangel: Looks good to me, approved
  Karthik Ramasubramanian: Looks good to me, approved
  Fred Reitberger: Looks good to me, but someone else must approve

diff --git a/src/soc/amd/common/block/i2c/i23c_pad_ctrl.c b/src/soc/amd/common/block/i2c/i23c_pad_ctrl.c
index 2439054..bff6223 100644
--- a/src/soc/amd/common/block/i2c/i23c_pad_ctrl.c
+++ b/src/soc/amd/common/block/i2c/i23c_pad_ctrl.c
@@ -44,12 +44,5 @@
    	break;
    }

-	pad_ctrl &= ~I23C_PAD_CTRL_FALLSLEW_SEL_MASK;
-	pad_ctrl |= speed == I2C_SPEED_STANDARD ?
-		I23C_PAD_CTRL_FALLSLEW_SEL_STD : I23C_PAD_CTRL_FALLSLEW_SEL_LOW;
-
-	pad_ctrl &= ~I23C_PAD_CTRL_SLEW_N_MASK;
-	pad_ctrl |= I23C_PAD_CTRL_SLEW_N_FAST;
-
    misc_write32(MISC_I23C_PAD_CTRL(bus), pad_ctrl);
 }