[RFC 0/8] MIPS: CI20: add HDMI out support

[Rob Herring]

On Thu, Feb 27, 2020 at 01:56:56PM +0100, H. Nikolaus Schaller wrote:
> Hi Sam,
> 
> > Am 27.02.2020 um 13:23 schrieb Sam Ravnborg <sam at ravnborg.org>:
> > 
> > Hi Nikolaus.
> > 
> > On Wed, Feb 26, 2020 at 08:12:52PM +0100, H. Nikolaus Schaller wrote:
> >> This patch series adds HDMI output to the jz4780/CI20 board.
> >> 
> >> It is based on taking the old 3.18 vendor kernel and trying
> >> to achieve the same with modern DTS setup and new/modified
> >> drivers.
> >> 
> >> Unfortunately, in this first RFC, only EDID and creation of
> >> /dev/fb0 are working. Also, HDMI hot plugging is detected.
> >> 
> >> But there is no HDMI output signal. So some tiny piece seems
> >> to be missing to enable/configure the Synposys HDMI controller.
> >> 
> >> We need help from the community to fix this.
> >> 
> >> Note: device tree bindings are from 2015 and still seem to
> >> fit - except they are not in yaml format.
> >> 
> >> Original authors of most patches are
> >> * Paul Boddie <paul at boddie.org.uk>
> >> * Zubair Lutfullah Kakakhel <Zubair.Kakakhel at imgtec.com>
> >> 
> >> 
> >> H. Nikolaus Schaller (2):
> >>  drm: ingenic-drm: add MODULE_DEVICE_TABLE
> >>  MIPS: CI20: defconfig: configure for DRM_DW_HDMI_JZ4780
> >> 
> >> Paul Boddie (4):
> >>  drm: ingenic: add jz4780 Synopsys HDMI driver.
> >>  pinctrl: ingenic: add hdmi-ddc pin control group
> >>  MIPS: DTS: jz4780: account for Synopsys HDMI driver and LCD controller
> >>  MIPS: DTS: CI20: add HDMI setup
> >> 
> >> Zubair Lutfullah Kakakhel (2):
> >>  dt-bindings: video: Add jz4780-lcd binding
> >>  dt-bindings: video: Add jz4780-hdmi binding
> >> 
> >> .../bindings/display/ingenic-jz4780-hdmi.txt  |  41 ++++++
> >> .../bindings/display/ingenic-jz4780-lcd.txt   |  39 ++++++
> > New bindings in DT Schema format please...
> > We want to have then in a formal launguage so we can use these
> > to verify the DT files.
> 
> Yes, I know. And I fully support the goal.
> 
> But I personally do not have the time to learn the (IMHO brain-twisting)
> way the Schema format is working. Especially, I am not interested
> in becoming volunteer translator for .txt based schemas developed
> by someone else.
> 
> So I hope that someone from the community can and is willing to do
> that.
> 
> Or that there will appear good tools soon. E.g. some GUI
> based editor tool would be very helpful so that you don't have
> to fight with the yaml indentation rules. Like there are XML
> and DTD editors. And even HTML is rarely written manually any more.
> 
> IMHO such tools should have been developed and in place *before*
> the rule to provide DT schemata is enforced.

You mean tools like what is discussed here:

https://www.redhat.com/sysadmin/yaml-tips

There's also yaml-format in the dtschema repo which will reformat a file 
to the desired formatting. It is just a wrapper around ruamel yaml 
library.

Rob