Hi
On 05/07/2018 11:07 AM, Chris Chiu wrote:
Besides, according to ASUS's input, they observed that after entering
the OS, the frequency of SCL is too fast (about 600kHz) and the SCL High
time is around 450ns, not following I2C spec which is 0.6us.
https://pasteboard.co/HjzSWXd.png
Some update, we can make the touchpad work by simply modifying the
clk_rate of spt_i2c_info from 120000000 to 133000000 in intel-lpss-pci.c for
specific PCI ID 8086:a368 ~ a36a (CoffeeLake). Is the clock setting different
for the CoffeeLake series?
Hmm.. at quick look it looks like to be 133 MHz but I want to double
check first from other specs. I'm also wondering why it results 600 kHz
instead of expected 133/120 * 400 kHz = 443 kHz. Need to check timing
parameters too.
--
Jarkko
