Hi

On 05/17/2017 11:41 AM, 劉嘉駿 wrote:

I have tried to install three versions of Chromium OS(R58-9334, R59-9351,
R60-9554) respectively,
all of them runs kernel v4.4 and all of them can see nothing for my device
by “ls /sys/bus/i2c/devices”.
The output file is as “Chromum_v4.4.52_dev_bus_i2c_devices_0517.jpg”.
I guess the underlying drivers(I2C bus, ACPI DSDT table) could be failed to
recognize my I2C device.

Is this Intel Skylake ix-6xxx based laptop?

My guess is that based on your finding that i2c touchscreen works in 
Ubuntu that Chromium kernel may not have needed drivers enabled.

If you have access to kernel config of Chromium image could you check 
does it have these MFD_INTEL_LPSS configurations on? I have them as 
built-in but should work when built as modules too.

CONFIG_MFD_INTEL_LPSS=y
CONFIG_MFD_INTEL_LPSS_ACPI=y
CONFIG_MFD_INTEL_LPSS_PCI=y

I suppose these I2C_DESIGNWARE options are already on since I know there 
are Intel Baytrail based Chromebooks out there.

CONFIG_I2C_DESIGNWARE_CORE=m
CONFIG_I2C_DESIGNWARE_PLATFORM=m
CONFIG_I2C_DESIGNWARE_PCI=m
CONFIG_I2C_DESIGNWARE_BAYTRAIL=y

-- 
Jarkko