Hi Marek,
On 29/05/2019 12:09, Marek Vasut wrote:
On 5/29/19 1:04 PM, Ian Arkver wrote:
Hi,
On 29/05/2019 11:41, Marek Vasut wrote:
On 5/29/19 8:28 AM, Jacopo Mondi wrote:
[...]
[1]
https://www.renesas.com/eu/en/products/audio-video/video-decoders-encoders/video-decoders/device/ISL79987.html
+Required Properties:
+- compatible: value should be "isil,isl79987"
And here you might want to have 2 different compatibles for 79987 and
79988.
The 79988 is not supported yet, do we want to have it in the binding
doc?
I got mislead by the isl7998x naming scheme you used...
I would say that's up to you, the two chips seems very similar,
and it might make sense to provide bindings that support both. At the
same time, as long as the here defined bindings does not prevent
future expansions to include the ISL79988, its support could be safely
post-poned. In that case please s/isl7998x/isl79987/ in this document
and do not mention BT565 in the description.
Right
[...]
I see from the example you only support one output port? How do you
model the input ones.
I don't . Do we model analog inputs now somehow ?
I really think so, please see:
Documentation/devicetree/bindings/display/connector/analog-tv-connector.txt
And as an example of a board device tree using connectors to model
analog input see how the cvbs input on Salvator-X is described:
cvbs-in {
compatible = "composite-video-connector";
label = "CVBS IN";
port {
cvbs_con: endpoint {
remote-endpoint = <&adv7482_ain7>;
};
};
};
I think you should provide 4 input ports, where to connect input from
the analog connectors, and derive the number of enabled inputs from
the number of endpoints connected to an active remote.
Deriving the number of active physical inputs from some existing
binding
makes sense.
However unlike the adv7482, the isl79987 does not support remapping the
physical inputs to ADCs in the chip. It does support some remapping of
physical inputs to MIPI CSI2 channels, but that's probably not very
useful.
I understand, but I will now use against you the argument you have
correctly pointed out here below that DT should describe hardware, and
the hardware has indeed 4 input ports..
My question here is whether it makes sense to describe the ports even if
they cannot be muxed to different ADC. Does it ?
Each input port can be either differential CVBS or single ended with a
2:1 input select mux. It would be nice to be able to describe this.
Where do you see that ?
Bits 0 and 1 of each channel page's Differential Clamping Control 4
(0x39, ISL7998x_REG_Px_DEC_DIFF_CLMP_CTL_4).
I don't think you change it from the default (single ended on the first
input).
Regards,
Ian
You cannot remap the inputs to different ADCs, but you can remap the
ADCs to different VC IDs using the
ISL7998x_REG_P5_LI_ENGINE_VC_ASSIGNMENT register. Describing each input
would proivde somewhere to specify the vc-id.
I think Jacopo mentioned above the input muxing and the MIPI CSI2 VC
muxing are two separate things. But I have to wonder, do we have a way
of muxing the VCs in the DT or via the media controller yet ?
