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

[Varadarajan Narayanan <quic_varada@quicinc.com>]

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@quicinc.com>
> > > ---
> > > 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@linaro.org/
>    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@kernel.org/
>    Are these supposed to be in a dt-binding header?
>
> 3. https://lore.kernel.org/linux-arm-msm/031d0a35-b192-4161-beef-97b89d5d1da6@linaro.org/
>    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?

Thanks
Varada