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References: <20240417105605.836705-1-quic_varada@quicinc.com> <20240417105605.836705-6-quic_varada@quicinc.com>
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From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Date: Wed, 17 Apr 2024 14:29:03 +0300
Message-ID: <CAA8EJpq75LhY3BD4JEqAOVAt1SxTvSOsdJTTb2bZD9rj15FmGA@mail.gmail.com>
Subject: Re: [PATCH v8 5/7] clk: qcom: common: Add interconnect clocks support
To: Varadarajan Narayanan <quic_varada@quicinc.com>
Cc: andersson@kernel.org, mturquette@baylibre.com, sboyd@kernel.org, 
	robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, 
	konrad.dybcio@linaro.org, djakov@kernel.org, quic_anusha@quicinc.com, 
	linux-arm-msm@vger.kernel.org, linux-clk@vger.kernel.org, 
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, 
	linux-pm@vger.kernel.org
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On Wed, 17 Apr 2024 at 13:57, Varadarajan Narayanan
<quic_varada@quicinc.com> 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@quicinc.com>
> ---
> 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.

> +               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.

> +
>  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