Hello Thomas,
Thanks for working on this.
On 4/13/22 11:24, Thomas Zimmermann wrote:
> Create a platform device for each OF-declared framebuffer and have
> offb bind to these devices. Allows for real hot-unplugging and other
> drivers besides offb.
>
> Originally, offb created framebuffer devices while initializing its
> module by parsing the OF device tree. No actual Linux device was set
> up. This tied OF framebuffers to offb and makes writing other drivers
> for the OF framebuffers complicated. The absence of a Linux device
> prevented real hot-unplugging. Adding a distinct platform device for
> each OF framebuffer solves both problems. Specifically, a DRM drivers
> can now provide graphics output with modern userspace.
>
> Some of the offb init code is now located in the OF initialization.
> There's now also an implementation of of_platform_default_populate_init(),
> which was missing before. The OF side creates different devices for
> either OF display nodes or bootx displays as they require different
> handling by the driver. The offb drivers picks up each type of device
> and runs the appropriate fbdev initialization.
>
> Tested with OF display nodes on qemu's ppc64le target.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
> ---
[snip]
> + for_each_node_by_type(node, "display") {
> + if (!of_get_property(node, "linux,opened", NULL) ||
> + !of_get_property(node, "linux,boot-display", NULL))
> + continue;
> + dev = of_platform_device_create(node, "of-display", NULL);
> + if (WARN_ON(!dev))
> + return -ENOMEM;
> + boot_display = node;
> + break;
> + }
> + for_each_node_by_type(node, "display") {
> + if (!of_get_property(node, "linux,opened", NULL) || node == boot_display)
> + continue;
> + of_platform_device_create(node, "of-display", NULL);
Shouldn't check for the return value here too ?
Other than this small nit, it looks good to me.
Reviewed-by: Javier Martinez Canillas <javierm@xxxxxxxxxx>
--
Best regards,
Javier Martinez Canillas
Linux Engineering
Red Hat
