Messages in this thread | | | Date | Wed, 6 Jan 2016 09:02:56 -0600 | From | Rob Herring <> | Subject | Re: [PATCH v2 2/3] Input: cyttsp - add device tree support |
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On Tue, Jan 05, 2016 at 01:59:14PM +0100, Oreste Salerno wrote: > Add support for retrieving the platform data from the device > tree.
Converting platform data to DT as is is typically not the right thing to do. There's some overlap, but it is not typically 1-1.
> Signed-off-by: Oreste Salerno <oreste.salerno@tomtom.com> > --- > .../bindings/input/touchscreen/cyttsp.txt | 73 ++++++++++++++ > drivers/input/touchscreen/cyttsp_core.c | 108 +++++++++++++++++++-- > include/linux/input/cyttsp.h | 3 + > 3 files changed, 177 insertions(+), 7 deletions(-) > create mode 100644 Documentation/devicetree/bindings/input/touchscreen/cyttsp.txt > > diff --git a/Documentation/devicetree/bindings/input/touchscreen/cyttsp.txt b/Documentation/devicetree/bindings/input/touchscreen/cyttsp.txt > new file mode 100644 > index 0000000..8e0bcc73 > --- /dev/null > +++ b/Documentation/devicetree/bindings/input/touchscreen/cyttsp.txt > @@ -0,0 +1,73 @@ > +* Cypress cyttsp touchscreen controller > + > +Required properties: > +- compatible : must be "cypress,cyttsp-i2c" or "cypress,cyttsp-spi" > +- reg : Device address
...or SPI chip select number
> +- spi-max-frequency : Maximum SPI clocking speed of the device (for cyttsp-spi) > +- interrupt-parent : the phandle for the gpio controller > + (see interrupt binding[0]). > +- interrupts : (gpio) interrupt to which the chip is connected > + (see interrupt binding[0]). > +- reset-gpios : the reset gpio the chip is connected to > + (see GPIO binding[1] for more details). > +- maxx : horizontal resolution of touchscreen (in pixels) > +- maxy : vertical resolution of touchscreen (in pixels)
IIRC, we have standard properties for these. Touchscreens don't really have pixels...
> +- bootloader-key : the bootloader key used to exit bootloader mode
I don't understand what this is.
> + > +Optional properties: > +- use_hndshk : enable handshake bit > +- act_dist : active distance > +- act_intrvl : active refresh interval in ms
Is this sampling frequency?
> +- tch_tmout : active touch timeout in ms > +- lp_intrvl : low power refresh interval in ms
Look whether other touchscreens bindings have similar properties already and copy those. These need better definitions in general.
Don't use '_' in property names and append units to the name of properties that have units (e.g. ms).
> +Example: > + &i2c1 { > + /* ... */ > + cyttsp@a { > + compatible = "cypress,cyttsp-i2c"; > + reg = <0xa>; > + interrupt-parent = <&msm_gpio>; > + interrupts = <13 0x2008>; > + reset-gpios = <&msm_gpio 12 0x00>; > + > + maxx = <800>; > + maxy = <480>; > + bootloader-key = /bits/ 8 <0x01 0x02 0x03 0x04 0x05 0x06 0x07 0x08>; > + > + use_hndshk; > + act_dist = /bits/ 8 <0xF8>; > + act_intrvl = /bits/ 8 <0x00>; > + tch_tmout = /bits/ 8 <0xFF>; > + lp_intrvl = /bits/ 8 <0x0A>;
If the size is not 32-bits, you need to state that in the description. There is not really much point in making these 8-bit though.
Rob
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