Re: [PATCH v3 1/5] dt-bindings: remoteproc: Add PRU consumer bindings

[Roger Quadros <rogerq@kernel.org>]

On 03/06/2022 13:14, Puranjay Mohan wrote:
> Hi Roger,
> 
> On 03/06/22 13:41, Roger Quadros wrote:
>> Hi Puranjay,
>>
>> On 02/06/2022 08:28, Puranjay Mohan wrote:
>>> Hi Rob,
>>>
>>> On 03/05/22 01:26, Rob Herring wrote:
>>>> On Mon, Apr 18, 2022 at 04:11:14PM +0530, Puranjay Mohan wrote:
>>>>> From: Suman Anna <s-anna@ti.com>
>>>>>
>>>>> Add a YAML binding document for PRU consumers. The binding includes
>>>>> all the common properties that can be used by different PRU consumer
>>>>> or application nodes and supported by the PRU remoteproc driver.
>>>>> These are used to configure the PRU hardware for specific user
>>>>> applications.
>>>>>
>>>>> The application nodes themselves should define their own bindings.
>>>>>
>>>>> Co-developed-by: Tero Kristo <t-kristo@ti.com>
>>>>> Signed-off-by: Tero Kristo <t-kristo@ti.com>
>>>>> Signed-off-by: Suman Anna <s-anna@ti.com>
>>>>> Co-developed-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
>>>>> Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
>>>>> Signed-off-by: Puranjay Mohan <p-mohan@ti.com>
>>>>> ---
>>>>>  .../bindings/remoteproc/ti,pru-consumer.yaml  | 70 +++++++++++++++++++
>>>>>  1 file changed, 70 insertions(+)
>>>>>  create mode 100644 Documentation/devicetree/bindings/remoteproc/ti,pru-consumer.yaml
>>>>>
>>>>> diff --git a/Documentation/devicetree/bindings/remoteproc/ti,pru-consumer.yaml b/Documentation/devicetree/bindings/remoteproc/ti,pru-consumer.yaml
>>>>> new file mode 100644
>>>>> index 000000000000..5b1f1cb2f098
>>>>> --- /dev/null
>>>>> +++ b/Documentation/devicetree/bindings/remoteproc/ti,pru-consumer.yaml
>>>>> @@ -0,0 +1,70 @@
>>>>> +# SPDX-License-Identifier: (GPL-2.0-only or BSD-2-Clause)
>>>>> +%YAML 1.2
>>>>> +---
>>>>> +$id: http://devicetree.org/schemas/remoteproc/ti,pru-consumer.yaml#
>>>>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>>>>> +
>>>>> +title: Common TI PRU Consumer Binding
>>>>> +
>>>>> +maintainers:
>>>>> +  - Suman Anna <s-anna@ti.com>
>>>>> +
>>>>> +description: |
>>>>> +  A PRU application/consumer/user node typically uses one or more PRU device
>>>>> +  nodes to implement a PRU application/functionality. Each application/client
>>>>> +  node would need a reference to at least a PRU node, and optionally define
>>>>> +  some properties needed for hardware/firmware configuration. The below
>>>>> +  properties are a list of common properties supported by the PRU remoteproc
>>>>> +  infrastructure.
>>>>> +
>>>>> +  The application nodes shall define their own bindings like regular platform
>>>>> +  devices, so below are in addition to each node's bindings.
>>>>> +
>>>>> +properties:
>>>>> +  ti,prus:
>>>>> +    $ref: /schemas/types.yaml#/definitions/phandle-array
>>>>> +    description: phandles to the PRU, RTU or Tx_PRU nodes used
>>>>> +    minItems: 1
>>>>> +    maxItems: 6
>>>>> +    items:
>>>>> +      maxItems: 1
>>>>> +
>>>>> +  firmware-name:
>>>>> +    $ref: /schemas/types.yaml#/definitions/string-array
>>>>> +    description: |
>>>>> +      firmwares for the PRU cores, the default firmware for the core from
>>>>> +      the PRU node will be used if not provided. The firmware names should
>>>>> +      correspond to the PRU cores listed in the 'ti,prus' property
>>>>
>>>> So should be the name number of entries?:
>>>>
>>>> minItems: 1
>>>> maxItems: 6
>>>
>>> will add in v4
>>>
>>>>
>>>>> +
>>>>> +  ti,pruss-gp-mux-sel:
>>>>> +    $ref: /schemas/types.yaml#/definitions/uint32-array
>>>>
>>>> minItems: 1
>>>
>>> will add in v4
>>>
>>>>
>>>>> +    maxItems: 6
>>>>> +    items:
>>>>> +      enum: [0, 1, 2, 3, 4]
>>>>> +    description: |
>>>>> +      array of values for the GP_MUX_SEL under PRUSS_GPCFG register for a PRU.
>>>>> +      This selects the internal muxing scheme for the PRU instance. Values
>>>>> +      should correspond to the PRU cores listed in the 'ti,prus' property. The
>>>>> +      GP_MUX_SEL setting is a per-slice setting (one setting for PRU0, RTU0,
>>>>> +      and Tx_PRU0 on K3 SoCs). Use the same value for all cores within the
>>>>> +      same slice in the associative array. If the array size is smaller than
>>>>> +      the size of 'ti,prus' property, the default out-of-reset value (0) for the
>>>>> +      PRU core is used.
>>>>> +
>>>>> +required:
>>>>> +  - ti,prus
>>>>> +
>>>>> +dependencies:
>>>>> +  firmware-name: [ 'ti,prus' ]
>>>>> +  ti,pruss-gp-mux-sel: [ 'ti,prus' ]
>>>>
>>>> This doesn't make sense because 'ti,prus' is already required. Should 
>>>> all 3 properties always be required?
>>>
>>> All three of these are always required, so, I will remove the
>>
>> Are you sure? It should not be required and remoteproc driver should use
>> default name if not provided in DT.
>> In patch 5 see what is being done in pru_rproc_get().
>> It doesn't error out if firmware-name is not provided.
> 
> Yes, you are right, I missed this part.
> So, only 'ti,prus' is required and 'firmware-name',
> 'ti,pruss-gp-mux-sel' are optional but are dependent on 'ti,prus'
> 
> So, as 'ti,prus' is always required we don't need the dependencies tag
> to show that 'firmware-name', 'ti,pruss-gp-mux-sel' are dependent on
> 'ti,prus'
> 
> So, the change that I will be making in v4 is the removal of the
> dependencies tag. This seems right?

Look good to me.
> 
>>
>> Same for ti,pruss-gp-mux-sel. Did you miss the patch that adds support for this
>> in this series?
> 
> Yes, the patch you are referring to was not a part of v2 so I didn't add
> it in v3. I will add it in v4 now as it make more sense to add it with
> the series.

Alright. Thanks!

> 
>>
>>> "dependencies:" tag and add all three of them to "required:" in v4
>>> Will it be the correct way to do it?
>>>
>>>>
>>>>> +
>>>>> +additionalProperties: true
>>>>> +
>>>>> +examples:
>>>>> +  - |
>>>>> +    /* PRU application node example */
>>>>> +    pru-app {
>>>>> +        ti,prus = <&pru0>, <&pru1>;
>>>>> +        firmware-name = "pruss-app-fw0", "pruss-app-fw1";
>>>>> +        ti,pruss-gp-mux-sel = <2>, <1>;
>>>>
>>>> This example never validates, but okay I guess.
>>>>
>>>>> +    };
>>>>> -- 
>>>>> 2.17.1
>>>>>
>>>>>
>>>
>>> Thanks,
>>> Puranjay Mohan
>>
>> cheers,
>> -roger
> 
> Thanks,
> Puranjay Mohan

cheers,
-roger