Re: [PATCH v2 3/4] clk: qcom: add IPQ9574 interconnect clocks support

[Varadarajan Narayanan]

On Mon, Mar 25, 2024 at 08:42:21PM +0100, Konrad Dybcio wrote:
> On 25.03.2024 11:20 AM, Varadarajan Narayanan wrote:
> > Unlike MSM platforms that manage NoC related clocks and scaling
> > from RPM, IPQ SoCs dont involve RPM in managing NoC related
> > clocks and there is no NoC scaling.
> >
> > However, there is a requirement to enable some NoC interface
> > clocks for accessing the peripheral controllers present on
> > these NoCs. Though exposing these as normal clocks would work,
> > having a minimalistic interconnect driver to handle these clocks
> > would make it consistent with other Qualcomm platforms resulting
> > in common code paths.  This is similar to msm8996-cbf's usage of
> > icc-clk framework.
> >
> > Signed-off-by: Varadarajan Narayanan <quic_varada@xxxxxxxxxxx>
> > ---
>
> [...]
>
> >
> > +
> > +static struct icc_clk_data *icc_ipq9574;
> > +
>
> What does this help achieve?

Had it as a place holder in case if the provider pointer is needed
for any debug. Will remove it.

> > +static int noc_clks[] = {
>
> We could probably use indexed identifiers here to avoid confusion:
> [ICC_BINDING_NAME] = CLK_BINDING_NAME

ok.

> >  static int gcc_ipq9574_probe(struct platform_device *pdev)
> >  {
> > -	return qcom_cc_probe(pdev, &gcc_ipq9574_desc);
> > +	int ret = qcom_cc_probe(pdev, &gcc_ipq9574_desc);
> > +	struct icc_provider *provider;
> > +	struct icc_clk_data *icd;
> > +	int i;
> > +
> > +	if (ret)
>
> I'd personally prefer if you left ret uninitialized and assigned it
> above the if-statement.

ok

> > +		return dev_err_probe(&pdev->dev, ret, "%s failed\n", __func__);
>
> Please avoid the use of __func__ throughout your change and write
> a more useful error message.
>
> > +
> > +	icd = devm_kmalloc(&pdev->dev, ARRAY_SIZE(noc_clks) * sizeof(*icd),
> > +			   GFP_KERNEL);
>
> devm_kcalloc

ok

> > +
> > +	if (IS_ERR_OR_NULL(icd))
> > +		return dev_err_probe(&pdev->dev, PTR_ERR(icd),
> > +				     "%s malloc failed\n", __func__);
>
> ditto

ok

> > +
> > +	icc_ipq9574 = icd;
> > +
> > +	for (i = 0; i < ARRAY_SIZE(noc_clks); i++, icd++) {
> > +		icd->clk = gcc_ipq9574_clks[noc_clks[i]]->hw.clk;
> > +		if (IS_ERR_OR_NULL(icd->clk)) {
> > +			dev_err(&pdev->dev, "%s: %d clock not found\n",
> > +				__func__, noc_clks[i]);
> > +			return -ENOENT;
>
> return dev_err_probe

ok

> > +		}
> > +		icd->name = clk_hw_get_name(&gcc_ipq9574_clks[noc_clks[i]]->hw);
> > +	}
> > +
> > +	provider = icc_clk_register(&pdev->dev, IPQ_APPS_ID,
> > +				    ARRAY_SIZE(noc_clks), icc_ipq9574);
> > +	if (IS_ERR_OR_NULL(provider))
> > +		return dev_err_probe(&pdev->dev, PTR_ERR(provider),
> > +				     "%s: icc_clk_register failed\n", __func__);
>
> ditto

ok

> On a second thought, since I'm assuming you're going to expand this to other
> IPQ SoCs, it might be useful to factor this out into drivers/clk/qcom/common.c

Will move it.

Thanks
Varada