Re: [BUG] i2c-hid: ELAN Touchpad does not work on ASUS X580GD

[Andy Shevchenko]

On Fri, 2018-05-18 at 09:48 +0200, Hans de Goede wrote:


> Could it be the i2c input clock definition in drivers/mfd/intel-lpss-
> pci.c
> is also wrong for Apollo Lake (N3450) ?  There are lots of people
> having
> various issues with i2c attached touchpads on Apollo Lake devices,
> this bug:
> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1728244
> 
> Is sort of a collection bug for these. Various models laptops, lots of
> reporters. Note not sure thie is an i2c-designware issue, but it would
> be good to double check the input clock on Apollo Lake.
> 
> I've checked the datasheet and the datasheet mentions 133MHz as
> "serial input clk" in the lpio_bxt_regs Registers Summary, which is
> also part of the LPSS, no clk is mentioned in the "Summary of
> DW_apb_i2c_mem_map_DW_apb_i2c_addr_block1 Registers".

The internal datasheet we have access to mentioned in this case for
Broxton and Cannonlake together. So, your assumption might be quite
close to the truth and the issue is inherited from Broxton.

-- 
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Intel Finland Oy