Re: [PATCH v7 1/5] dt-bindings: interconnect: Add Qualcomm IPQ9574 support

[Krzysztof Kozlowski]

On 09/04/2024 09:41, Varadarajan Narayanan wrote:
> On Thu, Apr 04, 2024 at 02:25:06PM +0530, Varadarajan Narayanan wrote:
>> On Wed, Apr 03, 2024 at 04:59:40PM +0200, Krzysztof Kozlowski wrote:
>>> On 03/04/2024 12:42, Varadarajan Narayanan wrote:
>>>> Add interconnect-cells to clock provider so that it can be
>>>> used as icc provider.
>>>>
>>>> Add master/slave ids for Qualcomm IPQ9574 Network-On-Chip
>>>> interfaces. This will be used by the gcc-ipq9574 driver
>>>> that will for providing interconnect services using the
>>>> icc-clk framework.
>>>>
>>>> Signed-off-by: Varadarajan Narayanan <quic_varada@xxxxxxxxxxx>
>>>> ---
>>>> v7:
>>>> Fix macro names to be consistent with other bindings
>>>> v6:
>>>> Removed Reviewed-by: Krzysztof Kozlowski
>>>> Redefine the bindings such that driver and DT can share them
>>>>
>>>> v3:
>>>> Squash Documentation/ and include/ changes into same patch
>>>>
>>>> qcom,ipq9574.h
>>>> 	Move 'first id' to clock driver
>>>>
>>>> ---
>>>>  .../bindings/clock/qcom,ipq9574-gcc.yaml      |  3 +
>>>>  .../dt-bindings/interconnect/qcom,ipq9574.h   | 87 +++++++++++++++++++
>>>>  2 files changed, 90 insertions(+)
>>>>  create mode 100644 include/dt-bindings/interconnect/qcom,ipq9574.h
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/clock/qcom,ipq9574-gcc.yaml b/Documentation/devicetree/bindings/clock/qcom,ipq9574-gcc.yaml
>>>> index 944a0ea79cd6..824781cbdf34 100644
>>>> --- a/Documentation/devicetree/bindings/clock/qcom,ipq9574-gcc.yaml
>>>> +++ b/Documentation/devicetree/bindings/clock/qcom,ipq9574-gcc.yaml
>>>> @@ -33,6 +33,9 @@ properties:
>>>>        - description: PCIE30 PHY3 pipe clock source
>>>>        - description: USB3 PHY pipe clock source
>>>>
>>>> +  '#interconnect-cells':
>>>> +    const: 1
>>>> +
>>>>  required:
>>>>    - compatible
>>>>    - clocks
>>>> diff --git a/include/dt-bindings/interconnect/qcom,ipq9574.h b/include/dt-bindings/interconnect/qcom,ipq9574.h
>>>> new file mode 100644
>>>> index 000000000000..0b076b0cf880
>>>> --- /dev/null
>>>> +++ b/include/dt-bindings/interconnect/qcom,ipq9574.h
>>>> @@ -0,0 +1,87 @@
>>>> +/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
>>>> +#ifndef INTERCONNECT_QCOM_IPQ9574_H
>>>> +#define INTERCONNECT_QCOM_IPQ9574_H
>>>> +
>>>> +#define ICC_ANOC_PCIE0		0
>>>> +#define ICC_SNOC_PCIE0		1
>>>> +#define ICC_ANOC_PCIE1		2
>>>> +#define ICC_SNOC_PCIE1		3
>>>> +#define ICC_ANOC_PCIE2		4
>>>> +#define ICC_SNOC_PCIE2		5
>>>> +#define ICC_ANOC_PCIE3		6
>>>> +#define ICC_SNOC_PCIE3		7
>>>> +#define ICC_SNOC_USB		8
>>>> +#define ICC_ANOC_USB_AXI	9
>>>> +#define ICC_NSSNOC_NSSCC	10
>>>> +#define ICC_NSSNOC_SNOC_0	11
>>>> +#define ICC_NSSNOC_SNOC_1	12
>>>> +#define ICC_NSSNOC_PCNOC_1	13
>>>> +#define ICC_NSSNOC_QOSGEN_REF	14
>>>> +#define ICC_NSSNOC_TIMEOUT_REF	15
>>>> +#define ICC_NSSNOC_XO_DCD	16
>>>> +#define ICC_NSSNOC_ATB		17
>>>> +#define ICC_MEM_NOC_NSSNOC	18
>>>> +#define ICC_NSSNOC_MEMNOC	19
>>>> +#define ICC_NSSNOC_MEM_NOC_1	20
>>>> +
>>>> +#define ICC_NSSNOC_PPE		0
>>>> +#define ICC_NSSNOC_PPE_CFG	1
>>>> +#define ICC_NSSNOC_NSS_CSR	2
>>>> +#define ICC_NSSNOC_IMEM_QSB	3
>>>> +#define ICC_NSSNOC_IMEM_AHB	4
>>>> +
>>>> +#define MASTER_ANOC_PCIE0		(ICC_ANOC_PCIE0 * 2)
>>>> +#define SLAVE_ANOC_PCIE0		((ICC_ANOC_PCIE0 * 2) + 1)
>>>
>>> Which existing Qualcomm platform has such code?
>>
>> Existing Qualcomm platforms don't use icc-clk. They use icc-rpm
>> or icc-rpmh. clk-cbf-msm8996.c is the only driver that uses icc-clk.
>>
>> The icc_clk_register automatically creates master & slave nodes
>> for each clk entry provided as input with the node-ids 'n' and
>> 'n+1'. Since clk-cbf-msm8996.c has only one entry, it could just
>> define MASTER_CBF_M4M and SLAVE_CBF_M4M with 0 and 1 and avoid these
>> calculations.
>>
>> However, ipq9574 gives an array of clock entries as input to
>> icc_clk_register. To tie the order/sequence of these clock
>> entries correctly with the node-ids, this calculation is needed.
>>
>>> This is the third time I am asking for consistent headers. Open
>>> existing, recently added headers and look how it is done there. Why?
>>> Because I am against such calculations and see no reason for them.
>>
>> Apologies. Regret that I have to trouble you.
>>
>> In this ipq9574 case, have to reconcile between the following
>> feedbacks.
>>
>> 1. https://lore.kernel.org/linux-arm-msm/fe40b307-26d0-4b2a-869b-5d093415b9d1@xxxxxxxxxx/
>>    We could probably use indexed identifiers here to avoid confusion:
>>    [ICC_BINDING_NAME] = CLK_BINDING_NAME
>>
>> 2. https://lore.kernel.org/linux-arm-msm/95f4e99a60cc97770fc3cee850b62faf.sboyd@xxxxxxxxxx/
>>    Are these supposed to be in a dt-binding header?
>>
>> 3. https://lore.kernel.org/linux-arm-msm/031d0a35-b192-4161-beef-97b89d5d1da6@xxxxxxxxxx/
>>    Do you use them as well in the DTS?
>>
>> Having the defines (with the calculations) seemed to to comply
>> with the above three feedbacks.
>>
>> Please let me know if this can be handled in a different way that
>> would be consistent with other Qualcomm platforms.
> 
> Krzysztof,
> 
> Is this ok? Can I post a new version addressing other review comments?

I don't understand and you did not answered before, why you have to do
it differently than all other Qualcomm interconnect providers. Maybe the
code here needs it, maybe not, but I don't see any argument proving this.

Best regards,
Krzysztof