input: goodix - support Goodix gt5688

>From what I've seen in vendor trees it's fine to treat this as gt1x¹.

[1]: https://github.com/TadiT7/android_kernel_mtk-4.4/tree/master/drivers/input/touchscreen/mediatek/GT5688

Signed-off-by: Guido Günther <agx@sigxcpu.org>
---
 Documentation/devicetree/bindings/input/touchscreen/goodix.txt | 1 +
 drivers/input/touchscreen/goodix.c                             | 2 ++
 2 files changed, 3 insertions(+)

On Mon, 2019-01-28 at 18:03 +0100, Guido Günther wrote:
> From what I've seen in vendor trees it's fine to treat this as gt1x¹.
> 
> [1]: https://github.com/TadiT7/android_kernel_mtk-4.4/tree/master/drivers/input/touchscreen/mediatek/GT5688

Can you please point to the exact line of code that makes you say that?
I'm not saying it's not compatible, but it's not the same driver that
the current goodix.c was based on, or even goodix.c.

Can you please elaborate?

Finding that data in the specs would also be fine:
https://github.com/hadess/gt9xx/tree/master/specifications

Cheers

[1]: original driver:
https://github.com/hadess/gt9xx/commit/82b141220e8bce00060e0de697735d0a70af2678

> Signed-off-by: Guido Günther <agx@sigxcpu.org>
> ---
>  Documentation/devicetree/bindings/input/touchscreen/goodix.txt | 1 +
>  drivers/input/touchscreen/goodix.c                             | 2
> ++
>  2 files changed, 3 insertions(+)
> 
> diff --git
> a/Documentation/devicetree/bindings/input/touchscreen/goodix.txt
> b/Documentation/devicetree/bindings/input/touchscreen/goodix.txt
> index f7e95c52f3c7..57d3d8870a09 100644
> --- a/Documentation/devicetree/bindings/input/touchscreen/goodix.txt
> +++ b/Documentation/devicetree/bindings/input/touchscreen/goodix.txt
> @@ -3,6 +3,7 @@ Device tree bindings for Goodix GT9xx series
> touchscreen controller
>  Required properties:
>  
>   - compatible		: Should be "goodix,gt1151"
> +				 or "goodix,gt5688"
>  				 or "goodix,gt911"
>  				 or "goodix,gt9110"
>  				 or "goodix,gt912"
> diff --git a/drivers/input/touchscreen/goodix.c
> b/drivers/input/touchscreen/goodix.c
> index f2d9c2c41885..47b1ced41576 100644
> --- a/drivers/input/touchscreen/goodix.c
> +++ b/drivers/input/touchscreen/goodix.c
> @@ -216,6 +216,7 @@ static const struct goodix_chip_data
> *goodix_get_chip_data(u16 id)
>  {
>  	switch (id) {
>  	case 1151:
> +	case 5688:
>  		return &gt1x_chip_data;
>  
>  	case 911:
> @@ -942,6 +943,7 @@ MODULE_DEVICE_TABLE(acpi, goodix_acpi_match);
>  #ifdef CONFIG_OF
>  static const struct of_device_id goodix_of_match[] = {
>  	{ .compatible = "goodix,gt1151" },
> +	{ .compatible = "goodix,gt5688" },
>  	{ .compatible = "goodix,gt911" },
>  	{ .compatible = "goodix,gt9110" },
>  	{ .compatible = "goodix,gt912" },

Hi,
On Mon, Jan 28, 2019 at 07:24:33PM +0100, Bastien Nocera wrote:
> On Mon, 2019-01-28 at 18:03 +0100, Guido Günther wrote:
> > From what I've seen in vendor trees it's fine to treat this as gt1x¹.
> > 
> > [1]: https://github.com/TadiT7/android_kernel_mtk-4.4/tree/master/drivers/input/touchscreen/mediatek/GT5688
> 
> Can you please point to the exact line of code that makes you say that?
> I'm not saying it's not compatible, but it's not the same driver that
> the current goodix.c was based on, or even goodix.c.
>
> Can you please elaborate?

I basically looked at the registers uses for the config update:

https://github.com/TadiT7/android_kernel_mtk-4.4/blob/master/drivers/input/touchscreen/mediatek/GT5688/include/gt1x_tpd_common.h#L152
https://github.com/TadiT7/android_kernel_mtk-4.4/blob/master/drivers/input/touchscreen/mediatek/GT5688/gt1x_generic.c#L430

That and the fact that the driver is doing it's job well made me believe
that's good for base support. Things like hotknot, gesture wakeup and
proximity sensor will need additional work.

> Finding that data in the specs would also be fine:
> https://github.com/hadess/gt9xx/tree/master/specifications

https://github.com/hadess/gt9xx/pull/3

Cheers,
 -- Guido

On Tue, 2019-01-29 at 10:16 +0100, Guido Günther wrote:
> Hi,
> On Mon, Jan 28, 2019 at 07:24:33PM +0100, Bastien Nocera wrote:
> > On Mon, 2019-01-28 at 18:03 +0100, Guido Günther wrote:
> > > From what I've seen in vendor trees it's fine to treat this as
> > > gt1x¹.
> > > 
> > > [1]: 
> > > https://github.com/TadiT7/android_kernel_mtk-4.4/tree/master/drivers/input/touchscreen/mediatek/GT5688
> > 
> > Can you please point to the exact line of code that makes you say
> > that?
> > I'm not saying it's not compatible, but it's not the same driver
> > that
> > the current goodix.c was based on, or even goodix.c.
> > 
> > Can you please elaborate?
> 
> I basically looked at the registers uses for the config update:
> 
> https://github.com/TadiT7/android_kernel_mtk-4.4/blob/master/drivers/input/touchscreen/mediatek/GT5688/include/gt1x_tpd_common.h#L152
> https://github.com/TadiT7/android_kernel_mtk-4.4/blob/master/drivers/input/touchscreen/mediatek/GT5688/gt1x_generic.c#L430

I'm not sure that's good enough to say that the touchscreen models are
compatible.

> That and the fact that the driver is doing it's job well made me
> believe
> that's good for base support.

If you've tested it, that's better. Can you please add a reference to
the device that you've tested this on in the commit message?

>  Things like hotknot, gesture wakeup and
> proximity sensor will need additional work.
> 
> > Finding that data in the specs would also be fine:
> > https://github.com/hadess/gt9xx/tree/master/specifications
> 
> https://github.com/hadess/gt9xx/pull/3

Merged that, thanks

Cheers