On Wed, 09 Feb 2022, Sascha Hauer s.hauer@pengutronix.de wrote:
David, Daniel,
I'll need a word from you regarding this patch. It's needed in patch 22/23 in this series. vop2_crtc_atomic_enable() needs to control the mux which routes the display output to the different encoders. Which encoder is used is described in the of_graph port, so I need a way to identify the encoder in the device tree.
I think the question is how useful is this going to be in general. IMO we should not be adding members that are useful in a single driver only.
For example i915 wraps encoders with:
struct intel_encoder { struct drm_encoder base;
/* i915 specific stuff here*/ };
So that we can add stuff of our own there. Of course, it does mean a bunch of overhead for the first time you need to do it. But adding driver specific stuff to struct drm_encoder adds overhead for everyone.
All that said, *I* don't know how useful the port member would be in drivers that use device tree. Maybe it's worth it.
BR, Jani.
Sascha
On Wed, Feb 09, 2022 at 10:53:28AM +0100, Sascha Hauer wrote:
Add a device node to drm_encoder which corresponds with the port node in the DT description of the encoder. This allows drivers to find the of_graph link between a crtc and an encoder.
Signed-off-by: Sascha Hauer s.hauer@pengutronix.de
include/drm/drm_encoder.h | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/include/drm/drm_encoder.h b/include/drm/drm_encoder.h index 6e91a0280f31..3acd054b1eb3 100644 --- a/include/drm/drm_encoder.h +++ b/include/drm/drm_encoder.h @@ -99,6 +99,8 @@ struct drm_encoder { struct drm_device *dev; struct list_head head;
- struct device_node *port;
- struct drm_mode_object base; char *name; /**
-- 2.30.2