the following patch was just integrated into master: commit 222381e390191d7a4476642ae0e544c96349a096 Author: Duncan Laurie dlaurie@chromium.org Date: Tue Jun 21 10:41:19 2016 -0700
skylake: Generate ACPI timing values for I2C devices
Have the Skylake SOC generate ACPI timing values for the enabled I2C controllers instead of passing it in the DSDT with static timings.
The timing values are generated from the controller clock speed and are more accurate than the hardcoded values that were in the ASL which were originally copied from Broadwell where the controller is running at a different clock speed...
Additionally it is now possible for a board to override the values using devicetree.cb. If zero is passed in for SCL HCNT or LCNT then the kernel will generate its own timing using the same forumla, but if the SDA hold time value is zero the kernel will NOT generate a correct value and the SDA hold time may be incorrect.
This was tested on the Chell platform to ensure all the I2C devices on the board are still operational with these new timing values.
Change-Id: I4feb3df9e083592792f8fadd7105e081a984a906 Signed-off-by: Duncan Laurie dlaurie@chromium.org Reviewed-on: https://review.coreboot.org/15291 Tested-by: build bot (Jenkins) Reviewed-by: Aaron Durbin adurbin@chromium.org
See https://review.coreboot.org/15291 for details.
-gerrit