Re: [PATCH 1/4] dt-bindings: simplefb: Specify node location and handoff related properties

Hi,

On 11/13/2014 09:38 AM, Geert Uytterhoeven wrote:

On Wed, Nov 12, 2014 at 11:08 PM, Hans de Goede [off-list ref] wrote:

quoted

Since simplefb nodes do not relate directly to hw typically they have been
placed in the root of the devicetree. As the represent runtime information
having them as sub-nodes of /chosen is more logical, specify this.

Also specify when to set the chosen stdout-path property to a simplefb node.

For reliable handover to a hardware specific driver, that driver needs to
know which simplefb to unregister when taking over, specify how the hw driver
can find the matching simplefb node.

Last add some advice on how to fill and use simplefb nodes from a firmware
pov.

Signed-off-by: Hans de Goede <redacted>

Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>

Thanks.

quoted

---
 .../bindings/video/simple-framebuffer.txt          | 37 +++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/video/simple-framebuffer.txt b/Documentation/devicetree/bindings/video/simple-framebuffer.txt
index 8f35718..95fe284 100644
--- a/Documentation/devicetree/bindings/video/simple-framebuffer.txt
+++ b/Documentation/devicetree/bindings/video/simple-framebuffer.txt

@@ -4,6 +4,26 @@ A simple frame-buffer describes a frame-buffer setup by firmware or
 the bootloader, with the assumption that the display hardware has already
 been set up to scan out from the memory pointed to by the reg property.

+Since simplefb nodes represent runtime information they must be sub-nodes of
+the chosen node (*). The primary display node must be named framebuffer0,
+additional nodes must be called framebuffer1, etc.
+
+If a simplefb node represents the preferred console for user interaction,
+then the chosen node's stdout-path property must point to it.

You may want to add an stdout-path property to the example.

That is a good idea, done for v2.

Regards,

Hans