Jyri Sarha 103cd8bc1c drm/tilcdc: Add support for external tda998x encoder
Add support for an external compontised DRM encoder. The external
encoder can be connected to tilcdc trough device tree graph binding.
The binding document for tilcdc has been updated. The current
implementation supports only tda998x encoder.

To be able to filter out the unsupported video modes the tilcdc driver
needs to hijack the external connectors helper functions. The tilcdc
installes new helper functions that are otherwise identical to
orignals, but the mode_valid() call-back check the mode first localy,
before calling the original call-back. The tilcdc dirver restores the
original helper functions before it is unbound from the external
device.

I got the idea and some lines of code from Jean-Francois Moine's
"drm/tilcdc: Change the interface with the tda998x driver"-patch.

Signed-off-by: Jyri Sarha <jsarha@ti.com>
Acked-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
2015-05-27 13:13:32 +03:00

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Device-Tree bindings for tilcdc DRM driver
Required properties:
- compatible: value should be "ti,am33xx-tilcdc".
- interrupts: the interrupt number
- reg: base address and size of the LCDC device
Recommended properties:
- interrupt-parent: the phandle for the interrupt controller that
services interrupts for this device.
- ti,hwmods: Name of the hwmod associated to the LCDC
Optional properties:
- max-bandwidth: The maximum pixels per second that the memory
interface / lcd controller combination can sustain
- max-width: The maximum horizontal pixel width supported by
the lcd controller.
- max-pixelclock: The maximum pixel clock that can be supported
by the lcd controller in KHz.
Optional nodes:
- port/ports: to describe a connection to an external encoder. The
binding follows Documentation/devicetree/bindings/graph.txt and
suppors a single port with a single endpoint.
Example:
fb: fb@4830e000 {
compatible = "ti,am33xx-tilcdc";
reg = <0x4830e000 0x1000>;
interrupt-parent = <&intc>;
interrupts = <36>;
ti,hwmods = "lcdc";
port {
lcdc_0: endpoint@0 {
remote-endpoint = <&hdmi_0>;
};
};
};
tda19988: tda19988 {
compatible = "nxp,tda998x";
reg = <0x70>;
pinctrl-names = "default", "off";
pinctrl-0 = <&nxp_hdmi_bonelt_pins>;
pinctrl-1 = <&nxp_hdmi_bonelt_off_pins>;
port {
hdmi_0: endpoint@0 {
remote-endpoint = <&lcdc_0>;
};
};
};