RE: [PATCH v2 5/9] dt-bindings: display: bridge: Add ITE IT6263 LVDS to HDMI converter

[Biju Das]

> -----Original Message-----
> From: Biju Das
> Sent: Monday, October 14, 2024 8:39 AM
> To: Liu Ying <victor.liu@xxxxxxx>; Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
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> Subject: RE: [PATCH v2 5/9] dt-bindings: display: bridge: Add ITE IT6263 LVDS to HDMI converter
> 
> Hi Liu and Dmitry,
> 
> > -----Original Message-----
> > From: Liu Ying <victor.liu@xxxxxxx>
> > Sent: Monday, October 14, 2024 6:34 AM
> > Subject: Re: [PATCH v2 5/9] dt-bindings: display: bridge: Add ITE
> > IT6263 LVDS to HDMI converter
> >
> > On 10/14/2024, Dmitry Baryshkov wrote:
> > > On Sat, Oct 12, 2024 at 05:14:13PM +0800, Liu Ying wrote:
> > >> On 10/12/2024, Dmitry Baryshkov wrote:
> > >>> On Sat, Oct 12, 2024 at 03:35:39PM +0800, Liu Ying wrote:
> > >>>> Document ITE IT6263 LVDS to HDMI converter.
> > >>>>
> > >>>> Product link:
> > >>>> https://www.ite.com.tw/en/product/cate1/IT6263
> > >>>>
> > >>>> Signed-off-by: Liu Ying <victor.liu@xxxxxxx>
> > >>>> ---
> > >>>> v2:
> > >>>> * Document number of LVDS link data lanes.  (Biju)
> > >>>> * Simplify ports property by dropping "oneOf".  (Rob)
> > >>>>
> > >>>>  .../bindings/display/bridge/ite,it6263.yaml   | 276 ++++++++++++++++++
> > >>>>  1 file changed, 276 insertions(+)  create mode 100644
> > >>>> Documentation/devicetree/bindings/display/bridge/ite,it6263.yaml
> > >>>>
> > >>>> diff --git
> > >>>> a/Documentation/devicetree/bindings/display/bridge/ite,it6263.yam
> > >>>> l
> > >>>> b/Documentation/devicetree/bindings/display/bridge/ite,it6263.yam
> > >>>> l
> > >>>> new file mode 100644
> > >>>> index 000000000000..bc2bbec07623
> > >>>> --- /dev/null
> > >>>> +++ b/Documentation/devicetree/bindings/display/bridge/ite,it6263
> > >>>> +++ .y
> > >>>> +++ aml
> > >>>> @@ -0,0 +1,276 @@
> > >>>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) %YAML
> > >>>> +1.2
> > >>>> +---
> > >>>> +$id:
> > >>>> +http://devicetree.org/schemas/display/bridge/ite,it6263.yaml#
> > >>>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > >>>> +
> > >>>> +title: ITE IT6263 LVDS to HDMI converter
> > >>>> +
> > >>>> +maintainers:
> > >>>> +  - Liu Ying <victor.liu@xxxxxxx>
> > >>>> +
> > >>>> +description: |
> > >>>> +  The IT6263 is a high-performance single-chip De-SSC(De-Spread
> > >>>> +Spectrum) LVDS
> > >>>> +  to HDMI converter.  Combined with LVDS receiver and HDMI 1.4a
> > >>>> +transmitter,
> > >>>> +  the IT6263 supports LVDS input and HDMI 1.4 output by conversion function.
> > >>>> +  The built-in LVDS receiver can support single-link and
> > >>>> +dual-link LVDS inputs,
> > >>>> +  and the built-in HDMI transmitter is fully compliant with HDMI
> > >>>> +1.4a/3D, HDCP
> > >>>> +  1.2 and backward compatible with DVI 1.0 specification.
> > >>>> +
> > >>>> +  The IT6263 also encodes and transmits up to 8 channels of I2S
> > >>>> + digital audio,  with sampling rate up to 192KHz and sample size
> > >>>> + up to 24 bits. In addition,  an S/PDIF input port takes in
> > >>>> + compressed audio of up to 192KHz
> > frame rate.
> > >>>> +
> > >>>> +  The newly supported High-Bit Rate(HBR) audio by HDMI
> > >>>> + specifications v1.3 is  provided by the IT6263 in two interfaces:
> > >>>> + the four I2S input ports or the  S/PDIF input port.  With both
> > >>>> + interfaces the highest possible HBR frame rate  is supported at up to 768KHz.
> > >>>> +
> > >>>> +properties:
> > >>>
> > >>> No LVDS data-mapping support?
> > >>
> > >> It is enough to document number of LVDS link data lanes because OS
> > >> should be able to determine the data-mapping by looking at the
> > >> number and the data-mapping capability of the other side of the LVDS link.
> > >
> > > From what I can see, data-mapping is specified on the consumer sink
> > > side of the LVDS link. This means it should go to the bridge's device node.
> >
> > Then, I won't define data-lanes, because data-mapping implies it,
> > e.g., jeida-24 implies data lanes 0/1/2/3, see lvds-data-mapping.yaml.
> >
> > Please let me know which one you prefer.
> 
> Assume a top level use case where a user changes the format from JEDAI to VESA using On screen display
> or modetest(if some one adds support for lvds-mapping) then setting of the lvds data mapping should be
> dynamic.
> 
> Maybe for initial version hardcode with JEDAI or VESA as default and provide a way to override the
> host driver and bridge with requested lvds-data mapping dynamically later??
> 

Maybe use ret = drm_of_lvds_get_data_mapping(bus_node); to get LVDS data mapping see LVDS panel driver??
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/gpu/drm/bridge/lvds-codec.c?h=next-20241011#n173

Cheeers,
Biju