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Message-ID: <0f766b85-0d64-7f28-6139-ca5ed53edc94@ti.com>
Date:   Fri, 3 Jun 2022 15:44:41 +0530
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Subject: Re: [PATCH v3 1/5] dt-bindings: remoteproc: Add PRU consumer bindings
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To:     Roger Quadros <rogerq@kernel.org>, Rob Herring <robh@kernel.org>
CC:     <linux-kernel@vger.kernel.org>, <bjorn.andersson@linaro.org>,
        <mathieu.poirier@linaro.org>, <krzysztof.kozlowski+dt@linaro.org>,
        <linux-remoteproc@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <nm@ti.com>, <ssantosh@kernel.org>, <s-anna@ti.com>,
        <linux-arm-kernel@lists.infradead.org>, <grygorii.strashko@ti.com>,
        <vigneshr@ti.com>, <kishon@ti.com>
References: <20220418104118.12878-1-p-mohan@ti.com>
 <20220418104118.12878-2-p-mohan@ti.com> <YnA3dtaqptLgZBrV@robh.at.kernel.org>
 <6c054a1b-2842-a6f0-733a-92cfda76f828@ti.com>
 <5bf638ee-6cc8-d5cb-5795-a840d8d2bb87@kernel.org>
From:   Puranjay Mohan <p-mohan@ti.com>
In-Reply-To: <5bf638ee-6cc8-d5cb-5795-a840d8d2bb87@kernel.org>
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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?

> 
> 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.

> 
>> "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