On Fri, May 06, 2016 at 04:34:08PM +0200, Noralf Trønnes wrote: > > Den 06.05.2016 16:15, skrev Thierry Reding: > >On Fri, May 06, 2016 at 04:08:16PM +0200, Daniel Vetter wrote: > >>On Fri, May 06, 2016 at 04:03:47PM +0200, Thierry Reding wrote: > >>>On Thu, May 05, 2016 at 03:24:34PM +0200, Noralf Trønnes wrote: > >>>>Add function to create a simple connector for a panel. > >>>I'm not sure I see the usefulness of this. Typically you'd attach a > >>>panel to an encoder/connector, in which case you already have the > >>>connector. > >>> > >>>Perhaps it would become more obvious why we need this if you posted > >>>patches that show where this is used? > >>The other helpers give you a simple drm pipeline with plane, crtc & > >>encoder all baked into on drm_simple_pipeline structure. The only thing > >>variable you have to hook up to that is the drm_connector. And I think for > >>dead-simple panels avoiding the basic boilerplate in that does indeed make > >>some sense. > >Avoiding boilerplate is good, but I have a difficult time envisioning > >how you might want to use this. At the same time I'm asking myself how > >we know that this helper is any good if we haven't seen it used anywhere > >and actually see the boilerplate go away. > > I pulled out the patches from the tinydrm patchset that would go > into drm core and helpers. I'm not very good at juggling many patches > around in various version and getting it right. > I'm doing development in the downstream Raspberry Pi repo > on 4.5 to get all the pi drivers, and then apply it on linux-next... > > This is the tinydrm patch that will use it: > https://lists.freedesktop.org/archives/dri-devel/2016-April/104502.html > > Extract: > +int tinydrm_display_pipe_init(struct tinydrm_device *tdev, > + const uint32_t *formats, unsigned int format_count) > +{ > + struct drm_device *dev = tdev->base; > + struct drm_connector *connector; > + int ret; > + > + connector = drm_simple_kms_panel_connector_create(dev, &tdev->panel, > + DRM_MODE_CONNECTOR_VIRTUAL); > + if (IS_ERR(connector)) > + return PTR_ERR(connector); > + > + ret = drm_simple_display_pipe_init(dev, &tdev->pipe, > + &tinydrm_display_pipe_funcs, > + formats, format_count, > + connector); > + > + return ret; > +} > +EXPORT_SYMBOL(tinydrm_display_pipe_init); It's imo even more impressive when you show the entire driver, including all the hooks. Because there's just 4 of them iirc, all optional. And besides the tinydrm panel drivers in it's various editions we could also use this for simpledrm (the boot-up firmware kms driver from David Herrmann) and probably a few other super-simple display drivers. Essentially with this I think drm is now better suited for dumb&simple hardware than fbdev. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
