Re: [PATCH v3 1/8] drivers:input:tsc2007: add new common binding names, pre-calibration, flipping and rotation

From: Rob Herring
Date: Fri Sep 23 2016 - 18:47:41 EST


On Fri, Sep 23, 2016 at 02:41:09PM +0200, H. Nikolaus Schaller wrote:
> commit b98abe52fa8e ("Input: add common DT binding for touchscreens")
> introduced common DT bindings for touchscreens [1] and a helper function to
> parse the DT.
>
> commit ed7c9870c9bc ("Input: of_touchscreen - add support for inverted / swapped axes")
> added another helper for parsing axis inversion and swapping
> and applying them to x and y coordinates.
>
> Both helpers have been integrated to accommodate any orientation of the
> touch panel in relation to the LCD.
>
> A new feature is to introduce scaling the min/max ADC values to the screen
> size.
>
> This makes it possible to pre-calibrate the touch so that is (almost)
> exactly matches the LCD pixel coordinates it is glued onto. This allows to
> well enough operate the touch before a user space calibration step can
> improve the precision.
>
> Finally, calculate_pressure has been renamed to calculate_resistance
> because that is what it is doing.

Seems like you are breaking compatibility with old DTs. I can't tell for
sure though.

>
> [1]: Documentation/devicetree/bindings/input/touchscreen/touchscreen.txt
>
> Signed-off-by: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>
> ---
> .../bindings/input/touchscreen/tsc2007.txt | 20 ++--
> drivers/input/touchscreen/tsc2007.c | 126 +++++++++++++++++----
> include/linux/i2c/tsc2007.h | 8 ++
> 3 files changed, 123 insertions(+), 31 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt b/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt
> index ec365e1..6e9fd55 100644
> --- a/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt
> +++ b/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt
> @@ -6,6 +6,7 @@ Required properties:
> - ti,x-plate-ohms: X-plate resistance in ohms.
>
> Optional properties:
> +- generic touch screen properties: see touchscreen binding [2].
> - gpios: the interrupt gpio the chip is connected to (trough the penirq pin).
> The penirq pin goes to low when the panel is touched.
> (see GPIO binding[1] for more details).
> @@ -13,17 +14,20 @@ Optional properties:
> (see interrupt binding[0]).
> - interrupts: (gpio) interrupt to which the chip is connected
> (see interrupt binding[0]).
> -- ti,max-rt: maximum pressure.
> -- ti,fuzzx: specifies the absolute input fuzz x value.
> - If set, it will permit noise in the data up to +- the value given to the fuzz
> - parameter, that is used to filter noise from the event stream.
> -- ti,fuzzy: specifies the absolute input fuzz y value.
> -- ti,fuzzz: specifies the absolute input fuzz z value.
> +- ti,max-rt: maximum pressure resistance above which samples are ignored
> + (default: 4095).
> +- ti,report-resistance: report resistance (no pressure = max_rt) instead
> + of pressure (no pressure = 0).
> +- ti,min-x: minimum value reported by X axis ADC (default 0).
> +- ti,max-x: maximum value reported by X axis ADC (default 4095).
> +- ti,min-y: minimum value reported by Y axis ADC (default 0).
> +- ti,max-y: maximum value reported by Y axis ADC (default 4095).

Seems like these could be common too. They make more sense than giving x
and y sizes in pixel units which really should come from the panel.

> - ti,poll-period: how much time to wait (in milliseconds) before reading again the
> - values from the tsc2007.
> + values from the tsc2007 (default 1).
>
> [0]: Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
> [1]: Documentation/devicetree/bindings/gpio/gpio.txt
> +[2]: Documentation/devicetree/bindings/input/touchscreen/touchscreen.txt
>
> Example:
> &i2c1 {
> @@ -35,6 +39,8 @@ Example:
> interrupts = <0x0 0x8>;
> gpios = <&gpio4 0 0>;
> ti,x-plate-ohms = <180>;
> + touchscreen-size-x = <640>;
> + touchscreen-size-y = <480>;
> };
>
> /* ... */