On 6/27/21 3:56 AM, Linus Walleij wrote:
> Hi Dipen,
>
> thanks a lot for this very interesting patch set!
>
> I'm gonna try to review properly, just pointing out some conceptual
> things to begin with. Bindings is a good place to start.
>
> On Sat, Jun 26, 2021 at 1:48 AM Dipen Patel <dipenp@xxxxxxxxxx> wrote:
>
>> +description: |
>> + HTE properties should be named "htes". The exact meaning of each htes
>> + property must be documented in the device tree binding for each device.
>> + An optional property "hte-names" may contain a list of strings to label
>> + each of the HTE devices listed in the "htes" property.
> I think this is a bit over-abbreviated. IIO has:
> io-channels =...
> io-channel-names =...
>
> Given DT:s infatuation with using english plural I would opt for:
> hardware-timestamps = ..
> hardware-timestamp-names = ...
I can change it to suggested names in next RFC series.
>
> The "engine" part is a bit of an nVidia:ism I think and a too generic
> term. Could as well be "processor" or "automata" but nVidia just
> happened to name it an engine. (DMA engine would be a precedent
> though, so no hard preference from my side.)
>
> When reading this it is pretty intuitively evident what is going on.
>
> Other than that it looks really good!
>
>> +++ b/Documentation/devicetree/bindings/hte/hte.yaml
> I would name this hardware-timestamp-common.yamp or so.
Sure, but do I have to change hte-consumer and other hte named
yaml as well in this directory? If yes, I am referring HTE everywhere in the
code (framework is named as hte itself), I hope that is fine and does not
create any confusion.
>
>> +title: HTE providers
> Spell this out: Hardware timestamp providers
Can I do hardware timestamp engine provider instead?
>
>> +properties:
>> + $nodename:
>> + pattern: "^hte(@.*|-[0-9a-f])*$"
> Likewise:
> hardware-timestamp@ ...
>
> I think this is good because it is very unambiguous.
>
>> +examples:
>> + - |
>> + tegra_hte_aon: hte@c1e0000 {
>> + compatible = "nvidia,tegra194-gte-aon";
>> + reg = <0xc1e0000 0x10000>;
>> + interrupts = <0 13 0x4>;
>> + int-threshold = <1>;
>> + slices = <3>;
>> + #hte-cells = <1>;
>> + };
> The examples can be kept to the tegra194 bindings I think, this
> generic binding doesn't need an example as such.
Ok, will remove it.
>
>> +$id: http://devicetree.org/schemas/hte/nvidia,tegra194-hte.yaml#
> This one should be named like this, that is great.
>
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Tegra194 on chip generic hardware timestamping engine (HTE)
> This is clear and nice.
>
>> + int-threshold:
>> + description:
>> + HTE device generates its interrupt based on this u32 FIFO threshold
>> + value. The recommended value is 1.
>> + minimum: 1
>> + maximum: 256
> Does this mean a single timestamp in the FIFO will generate an IRQ?
> Then spell that out so it is clear.
In the description I said that.
>
>> + slices:
>> + description:
>> + HTE lines are arranged in 32 bit slice where each bit represents different
>> + line/signal that it can enable/configure for the timestamp. It is u32
>> + property and depends on the HTE instance in the chip.
>> + oneOf:
>> + - items:
>> + - const: 3
>> + - items:
>> + - const: 11
> Can't you just use
> enum: [3, 11]
> ?
Sure, will change it.
>
>> + '#hte-cells':
>> + const: 1
> So IMO this would be something like
> #hardware-timestamp-cells
Sure.
>
> Other than this it overall looks very nice to me!
>
> Yours,
> Linus Walleij
