Re: [PATCH v8 5/7] clk: qcom: common: Add interconnect clocks support

From: Dmitry Baryshkov
Date: Wed Apr 17 2024 - 14:23:15 EST

On Wed, 17 Apr 2024 at 19:34, Varadarajan Narayanan
<quic_varada@xxxxxxxxxxx> wrote:
>
> On Wed, Apr 17, 2024 at 02:29:03PM +0300, Dmitry Baryshkov wrote:
> > On Wed, 17 Apr 2024 at 13:57, Varadarajan Narayanan
> > <quic_varada@xxxxxxxxxxx> 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>
> > > ---
> > > v8: Explicitly set master and slave ids
> > > v7: Restore clk_get
> > > v6: first_id -> icc_first_node_id
> > > Remove clock get so that the peripheral that uses the clock
> > > can do the clock get
> > > v5: Split changes in common.c to separate patch
> > > Fix error handling
> > > Use devm_icc_clk_register instead of icc_clk_register
> > > v4: Use clk_hw instead of indices
> > > Do icc register in qcom_cc_probe() call stream
> > > Add icc clock info to qcom_cc_desc structure
> > > v3: Use indexed identifiers here to avoid confusion
> > > Fix error messages and move to common.c
> > > v2: Move DTS to separate patch
> > > Update commit log
> > > Auto select CONFIG_INTERCONNECT & CONFIG_INTERCONNECT_CLK to fix build error
> > > ---
> > > drivers/clk/qcom/common.c | 35 ++++++++++++++++++++++++++++++++++-
> > > drivers/clk/qcom/common.h | 16 ++++++++++++++++
> > > 2 files changed, 50 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/clk/qcom/common.c b/drivers/clk/qcom/common.c
> > > index 75f09e6e057e..a6410b1828ca 100644
> > > --- a/drivers/clk/qcom/common.c
> > > +++ b/drivers/clk/qcom/common.c
> > > @@ -8,6 +8,7 @@
> > > #include <linux/regmap.h>
> > > #include <linux/platform_device.h>
> > > #include <linux/clk-provider.h>
> > > +#include <linux/interconnect-clk.h>
> > > #include <linux/reset-controller.h>
> > > #include <linux/of.h>
> > >
> > > @@ -234,6 +235,38 @@ static struct clk_hw *qcom_cc_clk_hw_get(struct of_phandle_args *clkspec,
> > > return cc->rclks[idx] ? &cc->rclks[idx]->hw : NULL;
> > > }
> > >
> > > +static int qcom_cc_icc_register(struct device *dev,
> > > + const struct qcom_cc_desc *desc)
> > > +{
> > > + struct icc_clk_data *icd;
> > > + struct clk_hw *hws;
> > > + int i;
> > > +
> > > + if (!IS_ENABLED(CONFIG_INTERCONNECT_CLK))
> > > + return 0;
> > > +
> > > + if (!desc->icc_hws)
> > > + return 0;
> > > +
> > > + icd = devm_kcalloc(dev, desc->num_icc_hws, sizeof(*icd), GFP_KERNEL);
> > > + if (!icd)
> > > + return -ENOMEM;
> > > +
> > > + for (i = 0; i < desc->num_icc_hws; i++) {
> > > + icd[i].master_id = desc->icc_hws[i].master_id;
> > > + icd[i].slave_id = desc->icc_hws[i].slave_id;
> > > + hws = &desc->clks[desc->icc_hws[i].clk_id]->hw;
> >
> > I think I keep on repeating this again and again. Instead of passing
> > indices please pass clk_hw pointers.
>
> I'm sorry. Based on the following feedback for v7 from you I changed it to
> use indices instead of clk_hw pointers. Am I missing something?
>
> https://lore.kernel.org/linux-arm-msm/CAA8EJpohAe-aW1QqVkE9NBRU0DpZR7UiwdUKk6rS_YFAhenZZA@xxxxxxxxxxxxxx/
> <quote>
> > + struct clk_hw **icc_hws;
>
> Still we are passing hws here. We already have all the hws in a
> different array. Can we just pass the indices?
> </quote>
>
> Please confirm.

Ok, it's fine then.

>
> > > + icd[i].clk = devm_clk_hw_get_clk(dev, hws, "icc");
> > > + if (!icd[i].clk)
> > > + return dev_err_probe(dev, -ENOENT,
> > > + "(%d) clock entry is null\n", i);
> > > + icd[i].name = clk_hw_get_name(hws);
> > > + }
> > > +
> > > + return devm_icc_clk_register(dev, desc->icc_first_node_id,
> > > + desc->num_icc_hws, icd);
> > > +}
> > > +
> > > int qcom_cc_really_probe(struct platform_device *pdev,
> > > const struct qcom_cc_desc *desc, struct regmap *regmap)
> > > {
> > > @@ -303,7 +336,7 @@ int qcom_cc_really_probe(struct platform_device *pdev,
> > > if (ret)
> > > return ret;
> > >
> > > - return 0;
> > > + return qcom_cc_icc_register(dev, desc);
> > > }
> > > EXPORT_SYMBOL_GPL(qcom_cc_really_probe);
> > >
> > > diff --git a/drivers/clk/qcom/common.h b/drivers/clk/qcom/common.h
> > > index 9c8f7b798d9f..f6b25df1ca17 100644
> > > --- a/drivers/clk/qcom/common.h
> > > +++ b/drivers/clk/qcom/common.h
> > > @@ -19,6 +19,19 @@ struct clk_hw;
> > > #define PLL_VOTE_FSM_ENA BIT(20)
> > > #define PLL_VOTE_FSM_RESET BIT(21)
> > >
> > > +struct qcom_icc_hws_data {
> > > + int master_id;
> > > + int slave_id;
> > > + int clk_id;
> > > +};
> > > +
> > > +#define HWS_DATA(_b, _c) \
> > > +{ \
> > > + .master_id = MASTER_##_b, \
> > > + .slave_id = SLAVE_##_b, \
> > > + .clk_id = _c, \
> > > +}
> >
> > This shouldn't be a part of this commit. It is not used in it.
>
> Ok.
>
> Thanks
> Varada
>
> > > +
> > > struct qcom_cc_desc {
> > > const struct regmap_config *config;
> > > struct clk_regmap **clks;
> > > @@ -29,6 +42,9 @@ struct qcom_cc_desc {
> > > size_t num_gdscs;
> > > struct clk_hw **clk_hws;
> > > size_t num_clk_hws;
> > > + struct qcom_icc_hws_data *icc_hws;
> > > + size_t num_icc_hws;
> > > + unsigned int icc_first_node_id;
> > > };
> > >
> > > /**
> > > --
> > > 2.34.1
> > >
> >
> >
> > --
> > With best wishes
> > Dmitry



--
With best wishes
Dmitry