Re: [PATCH] dt-bindings: media: Add bindings for Imagination E5010 JPEG Encoder driver

[Devarsh Thakkar]

Hi Krzysztof,

Thanks for the quick review.

On 26/07/23 22:03, Krzysztof Kozlowski wrote:
> On 26/07/2023 18:26, Devarsh Thakkar wrote:
>> Add dt-bindings for Imagination E5010 JPEG Encoder driver which is
>> implemented as stateful V4L2 M2M driver.
>>
>> Co-developed-by: David Huang <d-huang@xxxxxx>
>> Signed-off-by: David Huang <d-huang@xxxxxx>
> 
> A nit, subject: drop second/last, redundant "bindings for". The
> "dt-bindings" prefix is already stating that these are bindings.
> 
> Drop also "driver". Bindings are for hardware, not drivers.
> 
> Prefix starts with media and then dt-bindings.
> 

Agreed.
> 
>> Signed-off-by: Devarsh Thakkar <devarsht@xxxxxx>
>> ---
>>  .../bindings/media/img,e5010-jpeg-enc.yaml    | 79 +++++++++++++++++++
>>  MAINTAINERS                                   |  5 ++
>>  2 files changed, 84 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/media/img,e5010-jpeg-enc.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/media/img,e5010-jpeg-enc.yaml b/Documentation/devicetree/bindings/media/img,e5010-jpeg-enc.yaml
>> new file mode 100644
>> index 000000000000..0060373eace7
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/media/img,e5010-jpeg-enc.yaml
>> @@ -0,0 +1,79 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/media/img,e5010-jpeg-enc.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Imagination E5010 JPEG Encoder
>> +
>> +maintainers:
>> +  - Devarsh Thakkar <devarsht@xxxxxx>
>> +
>> +description: |
>> +  The E5010 is a JPEG encoder from Imagination Technologies implemented on
>> +  TI's AM62A SoC. It is capable of real time encoding of YUV420 and YUV422
>> +  inputs to JPEG and M-JPEG. It supports baseline JPEG Encoding up to
>> +  8Kx8K resolution.
>> +
>> +properties:
>> +  compatible:
>> +    const: img,e5010-jpeg-enc
> 
> Your description suggests that this is part of TI SoC. Pretty often
> licensed blocks cannot be used on their own and need some
> customizations. Are you sure your block does not need any customization
> thus no dedicated compatible is needed?
>

There is a wrapper for interfacing this core with TI SoC, I will recheck this
interfacing but I believe nothing changes from programming perspective as
there is 1-to-1 maintained between the clocks and signals w.r.t actual E5010
core.

>> +
>> +  reg:
>> +    items:
>> +      - description: The E5010 main register region
>> +      - description: The E5010 mmu register region
>> +
>> +  reg-names:
>> +    items:
>> +      - const: regjasper
>> +      - const: regmmu
>> +
> 
> Drop reg from both
> 

Agreed.

>> +  power-domains:
>> +    maxItems: 1
>> +
>> +  resets:
>> +    maxItems: 1
>> +
>> +  clocks:
>> +    minItems: 1
>> +    maxItems: 2
> 
> You need to specify the items. Also, no variable number of clocks. Why
> would they vary if block is strictly defined?
> 

Agreed, I believe this version of E5010 core only supports single clock, so we
can get rid of maxItems: 2.

>> +
>> +  clock-names:
>> +    minItems: 1
>> +    maxItems: 2
> 
> Instead list the names.
> 

Agreed.

>> +
>> +  interrupts:
>> +    maxItems: 1
>> +
>> +required:
>> +  - compatible
>> +  - reg
>> +  - reg-names
>> +  - interrupts
>> +  - clocks
>> +  - clock-names
>> +  - power-domains
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> +  - |
>> +    #include <dt-bindings/soc/ti,sci_pm_domain.h>
>> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
>> +    #include <dt-bindings/interrupt-controller/irq.h>
>> +
>> +    cbass_main {
> 
> That's some weird name. Probably you meant soc. Anyway, underscores are
> not allowed.

Yes, I think I can put soc. cbass_main is specific to TI (soc interconnect bus).

> 
>> +      #address-cells = <2>;
>> +      #size-cells = <2>;
>> +      e5010: e5010@fd20000 {
> 
> Node names should be generic. See also an explanation and list of
> examples (not exhaustive) in DT specification:
> https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation
>

Yes, video-codec is the nearest one, but this is not really a codec as it only
supports encoding, is it fine to name node as jpeg-enc ?

> 
> Drop the label.
> 

Agreed.

Best Regards,
Devarsh

>> +          compatible = "img,e5010-jpeg-enc";
>> +          reg = <0x00 0xfd20000 0x00 0x100>,
>> +                <0x00 0xfd20200 0x00 0x200>;
>> +          reg-names = "regjasper", "regmmu";
>> +          clocks = <&k3_clks 201 0>;
>> +          clock-names = "core_clk";
>> +          power-domains = <&k3_pds 201 TI_SCI_PD_EXCLUSIVE>;
>> +          interrupts = <GIC_SPI 98 IRQ_TYPE_LEVEL_HIGH>;
>> +      };
>> +    };
> 
> 
> Best regards,
> Krzysztof
>