[PATCH v3] ARM: pxa: magician: Add support for ADS7846 touchscreen

[Robert Jarzmik]

Petr Cvek <petr.cvek at tul.cz> writes:

> This patch adds a support for ADS7846 touchscreen driver.
>
> The basic functionality was tested, x_plate_ohms and y_plate_ohms were
> physically measured. The value pressure_max was empirically set to match
> the measured range, which is affected by x_plate_ohms and ADS samples.
>
> The value of keep_vref_on should be set. A tested model (T-Mobile MDA
> Compact PM10A) doesn't seem to use Vref pin as the input from an external
> source. On this model the unset keep_vref_on cause high jitter of measured
> values.
>
> SPI framing pin (gpio_cs) must be used in GPIO mode due to an incompatible
> autoframing of PXA27x controller and ADS7846 device.
>
> Signed-off-by: Petr Cvek <petr.cvek at tul.cz>
Applied to pxa/for-next, unless Philipp objects in the next couple of days,
thanks.

Cheers.

--
Robert