Re: [PATCH 3/4] OMAPDSS: panel-sharp-ls037v7dw01: add device tree support

[Tony Lindgren <tony@atomide.com>]

* Tomi Valkeinen <tomi.valkeinen@ti.com> [140509 00:24]:
> On 09/05/14 02:33, Tony Lindgren wrote:
> > +Example when connected to a omap2+ based device:
> > +
> > +	lcd0: display {
> > +		compatible = "sharp,ls037v7dw01";
> > +		power-supply = <&lcd_3v3>;
> > +		enable-gpios = <&gpio5 24 GPIO_ACTIVE_HIGH>;	/* gpio152, lcd INI */
> > +		reset-gpios = <&gpio5 27 GPIO_ACTIVE_HIGH>;	/* gpio155, lcd RESB */
> > +		mode-gpios = <&gpio5 26 GPIO_ACTIVE_HIGH	/* gpio154, lcd MO */
> > +			      &gpio1 2 GPIO_ACTIVE_HIGH		/* gpio2, lcd LR */
> > +			      &gpio1 3 GPIO_ACTIVE_HIGH>;	/* gpio3, lcd UD */
> > +
> > +		panel-timing {
> > +			clock-frequency = <19200000>;
> > +			hback-porch = <28>;
> > +			hactive = <480>;
> > +			hfront-porch = <1>;
> > +			hsync-len = <2>;
> > +			vback-porch = <1>;
> > +			vactive = <640>;
> > +			vfront-porch = <1>;
> > +			vsync-len = <1>;
> > +			hsync-active = <0>;
> > +			vsync-active = <0>;
> > +			de-active = <1>;
> > +			pixelclk-active = <1>;
> > +		};
> 
> I don't think we should define panel-timing here. We know it's
> sharp,ls037v7dw01, so the driver knows the video timings. Also, if we
> would extend the driver to support both resolution modes, it needs to
> support two different timings, so the above doesn't work in that case
> either.

OK. It seems we can have at least two different timings for this panel,
the VGA timing above and the QVGA timings that LDP uses that are listed
in the .dts changes.
 
> Although if the MO gpio is not controlled by the driver, we should tell
> the driver whether that gpio is high or low.

What do you have in mind for telling that? We should also tell the
orientation of the panel:

EVM	VGA	omapfb.rotate=3
LDP	QVGA	omapfb.rotate=0

Do you have something in mind for that?
 
> At the moment our display drivers are OMAP specific, and for that reason
> we should prefix the compatible strings with "omapdss,". For example,
> drivers/video/fbdev/omap2/displays-new/panel-dsi-cm.c:
> 
> 	{ .compatible = "omapdss,panel-dsi-cm", },
> 
> But we should still have the right compatible string in the .dts, so we
> convert the compatible name in arch/arm/mach-omap2/display.c, with
> 'dss_compat_conv_list' array, to which this panel's name should be added.

Oh so what do you want to have in the .dts file then?

Regards,

Tony