RE: [PATCH v11 2/8] Input: goodix - reset device at init

["Tirdea, Irina" <irina.tirdea@intel.com>]

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> -----Original Message-----
> From: Bastien Nocera [mailto:hadess@hadess.net]
> Sent: 19 November, 2015 17:25
> To: Tirdea, Irina; Dmitry Torokhov; Aleksei Mamlin; Karsten Merker; linux-input@vger.kernel.org
> Cc: Mark Rutland; Rob Herring; Purdila, Octavian; linux-kernel@vger.kernel.org; devicetree@vger.kernel.org
> Subject: Re: [PATCH v11 2/8] Input: goodix - reset device at init
> 
> On Thu, 2015-11-19 at 14:26 +0200, Irina Tirdea wrote:
> > After power on, it is recommended that the driver resets the device.
> > The reset procedure timing is described in the datasheet and is used
> > at device init (before writing device configuration) and
> > for power management. It is a sequence of setting the interrupt
> > and reset pins high/low at specific timing intervals. This procedure
> > also includes setting the slave address to the one specified in the
> > ACPI/device tree.
> 
> This fails on a 4.3 kernel with an ACPI device (WinBook TW100):
> Goodix-TS: probe of i2c-GDIX1001:00 failed with error -16
> 
> Can you please document which upstream commit is necessary to make this
> behave properly?
> 

You need the patch that fixes the GPIO API [1] so that
devm_gpiod_get_optional works properly (I mentioned that in the cover
letter). This patch just got merged in the gpio tree, so it will take a
while until it will be merged in the main kernel tree or input tree. 

Thanks,
Irina

 [1] https://lkml.org/lkml/2015/11/11/465

> I'll test again with a newer kernel.
> 
> Cheers
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