Messages in this thread | | | Subject | Re: [BUG] i2c-hid: ELAN Touchpad does not work on ASUS X580GD | From | Jarkko Nikula <> | Date | Fri, 18 May 2018 13:58:02 +0300 |
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On 05/18/2018 01:20 PM, Andy Shevchenko wrote: > On Fri, 2018-05-18 at 11:37 +0300, Andy Shevchenko wrote: >> 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. >> > Nope. The specification I have mention the I2C input clock in Broxton is fixed 133 MHz but in Cannon Lake it is derived through non-SW visible divider.
> Hans, can your reporters try the following patch? Depending on the > result I may send it out ASAP. > > --- a/drivers/mfd/intel-lpss-pci.c > +++ b/drivers/mfd/intel-lpss-pci.c > @@ -120,7 +120,7 @@ static struct property_entry apl_i2c_properties[] = > { > }; > > static const struct intel_lpss_platform_info apl_i2c_info = { > - .clk_rate = 133000000, > + .clk_rate = 216000000, > .properties = apl_i2c_properties, > }; > Nack. The Apollo Lake HW here shows expected I2C bus clock on oscilloscope so it is indeed clocked at 133 MHz.
-- Jarkko
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