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In-Reply-To: <20240319073540.2zvwq7fvft3h6mbr@pengutronix.de>
From: Shengjiu Wang <shengjiu.wang@gmail.com>
Date: Wed, 20 Mar 2024 10:11:28 +0800
Message-ID: <CAA+D8APofupb5UdnKuzwkvRhj544kQ8yKBU_84esTQDN=MKzBQ@mail.gmail.com>
Subject: Re: [PATCH] clk: imx: imx8mp: Add pm_runtime support for power saving
To: Marco Felsch <m.felsch@pengutronix.de>
Cc: Peng Fan <peng.fan@nxp.com>, "S.J. Wang" <shengjiu.wang@nxp.com>, 
	"abelvesa@kernel.org" <abelvesa@kernel.org>, "mturquette@baylibre.com" <mturquette@baylibre.com>, 
	"sboyd@kernel.org" <sboyd@kernel.org>, "shawnguo@kernel.org" <shawnguo@kernel.org>, 
	"s.hauer@pengutronix.de" <s.hauer@pengutronix.de>, "kernel@pengutronix.de" <kernel@pengutronix.de>, 
	"festevam@gmail.com" <festevam@gmail.com>, dl-linux-imx <linux-imx@nxp.com>, 
	"linux-clk@vger.kernel.org" <linux-clk@vger.kernel.org>, 
	"linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org>, 
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
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On Tue, Mar 19, 2024 at 3:35=E2=80=AFPM Marco Felsch <m.felsch@pengutronix.=
de> wrote:
>
> On 24-03-18, Peng Fan wrote:
> > > Subject: [PATCH] clk: imx: imx8mp: Add pm_runtime support for power
> > > saving
> > >
> > > Add pm_runtime support for power saving. In pm runtime suspend state =
the
> > > registers will be reseted, so add registers save in pm runtime suspen=
d and
> > > restore them in pm runtime resume.
>
> We had similar patches in our downstream repo but didn't upstream yet
> since there was an clk-handing issue. IIRC the issue was regarding the
> global clock-prepare lock and a circular dependency on it. Is this
> resolved now?

Seems I didn't meet the issue you mentioned.

But I found another issue with my implementation that the pm_runtime_enable
need to move before the clk registered, Otherwise the core->rpm_enabled
is not ture at clk registering.

I will update in next version.

Best regards
Shengjiu Wang
>
> Regards,
>   Marco
>
> > > Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
> >
> > Reviewed-by: Peng Fan <peng.fan@nxp.com>
> > > ---
> > >  drivers/clk/imx/clk-imx8mp-audiomix.c | 99 +++++++++++++++++++++++++=
+-
> > >  1 file changed, 96 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/clk/imx/clk-imx8mp-audiomix.c b/drivers/clk/imx/=
clk-
> > > imx8mp-audiomix.c
> > > index 55ed211a5e0b..d2bf53e2aacf 100644
> > > --- a/drivers/clk/imx/clk-imx8mp-audiomix.c
> > > +++ b/drivers/clk/imx/clk-imx8mp-audiomix.c
> > > @@ -7,10 +7,12 @@
> > >
> > >  #include <linux/clk-provider.h>
> > >  #include <linux/device.h>
> > > +#include <linux/io.h>
> > >  #include <linux/mod_devicetable.h>
> > >  #include <linux/module.h>
> > >  #include <linux/of.h>
> > >  #include <linux/platform_device.h>
> > > +#include <linux/pm_runtime.h>
> > >
> > >  #include <dt-bindings/clock/imx8mp-clock.h>
> > >
> > > @@ -18,6 +20,7 @@
> > >
> > >  #define CLKEN0                     0x000
> > >  #define CLKEN1                     0x004
> > > +#define EARC                       0x200
> > >  #define SAI1_MCLK_SEL              0x300
> > >  #define SAI2_MCLK_SEL              0x304
> > >  #define SAI3_MCLK_SEL              0x308
> > > @@ -26,6 +29,12 @@
> > >  #define SAI7_MCLK_SEL              0x314
> > >  #define PDM_SEL                    0x318
> > >  #define SAI_PLL_GNRL_CTL   0x400
> > > +#define SAI_PLL_FDIVL_CTL0 0x404
> > > +#define SAI_PLL_FDIVL_CTL1 0x408
> > > +#define SAI_PLL_SSCG_CTL   0x40C
> > > +#define SAI_PLL_MNIT_CTL   0x410
> > > +#define IPG_LP_CTRL                0x504
> > > +#define REGS_NUM           16
> > >
> > >  #define SAIn_MCLK1_PARENT(n)                                        =
       \
> > >  static const struct clk_parent_data                                 =
       \
> > > @@ -182,13 +191,65 @@ static struct clk_imx8mp_audiomix_sel sels[] =
=3D {
> > >     CLK_SAIn(7)
> > >  };
> > >
> > > +struct clk_imx8mp_audiomix_regs {
> > > +   u32 regs_num;
> > > +   u32 regs_off[];
> > > +};
> > > +
> > > +static const struct clk_imx8mp_audiomix_regs audiomix_regs =3D {
> > > +   .regs_num =3D REGS_NUM,
> > > +   .regs_off =3D {
> > > +           CLKEN0,
> > > +           CLKEN1,
> > > +           EARC,
> > > +           SAI1_MCLK_SEL,
> > > +           SAI2_MCLK_SEL,
> > > +           SAI3_MCLK_SEL,
> > > +           SAI5_MCLK_SEL,
> > > +           SAI6_MCLK_SEL,
> > > +           SAI7_MCLK_SEL,
> > > +           PDM_SEL,
> > > +           SAI_PLL_GNRL_CTL,
> > > +           SAI_PLL_FDIVL_CTL0,
> > > +           SAI_PLL_FDIVL_CTL1,
> > > +           SAI_PLL_SSCG_CTL,
> > > +           SAI_PLL_MNIT_CTL,
> > > +           IPG_LP_CTRL
> > > +   },
> > > +};
> > > +
> > > +struct clk_imx8mp_audiomix_drvdata {
> > > +   void __iomem *base;
> > > +   u32 regs_save[REGS_NUM];
> > > +};
> > > +
> > > +static void clk_imx8mp_audiomix_save_restore(struct device *dev, boo=
l
> > > +save) {
> > > +   struct clk_imx8mp_audiomix_drvdata *drvdata =3D
> > > dev_get_drvdata(dev);
> > > +   void __iomem *base =3D drvdata->base;
> > > +   int i;
> > > +
> > > +   if (save) {
> > > +           for (i =3D 0; i < audiomix_regs.regs_num; i++)
> > > +                   drvdata->regs_save[i] =3D readl(base +
> > > audiomix_regs.regs_off[i]);
> > > +   } else {
> > > +           for (i =3D 0; i < audiomix_regs.regs_num; i++)
> > > +                   writel(drvdata->regs_save[i], base +
> > > audiomix_regs.regs_off[i]);
> > > +   }
> > > +}
> > > +
> > >  static int clk_imx8mp_audiomix_probe(struct platform_device *pdev)  =
{
> > > +   struct clk_imx8mp_audiomix_drvdata *drvdata;
> > >     struct clk_hw_onecell_data *priv;
> > >     struct device *dev =3D &pdev->dev;
> > >     void __iomem *base;
> > >     struct clk_hw *hw;
> > > -   int i;
> > > +   int i, ret;
> > > +
> > > +   drvdata =3D devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
> > > +   if (!drvdata)
> > > +           return -ENOMEM;
> > >
> > >     priv =3D devm_kzalloc(dev,
> > >                         struct_size(priv, hws,
> > > IMX8MP_CLK_AUDIOMIX_END), @@ -202,6 +263,9 @@ static int
> > > clk_imx8mp_audiomix_probe(struct platform_device *pdev)
> > >     if (IS_ERR(base))
> > >             return PTR_ERR(base);
> > >
> > > +   drvdata->base =3D base;
> > > +   dev_set_drvdata(dev, drvdata);
> > > +
> > >     for (i =3D 0; i < ARRAY_SIZE(sels); i++) {
> > >             if (sels[i].num_parents =3D=3D 1) {
> > >                     hw =3D devm_clk_hw_register_gate_parent_data(dev,
> > > @@ -257,10 +321,38 @@ static int clk_imx8mp_audiomix_probe(struct
> > > platform_device *pdev)
> > >     if (IS_ERR(hw))
> > >             return PTR_ERR(hw);
> > >
> > > -   return devm_of_clk_add_hw_provider(&pdev->dev,
> > > of_clk_hw_onecell_get,
> > > -                                      priv);
> > > +   ret =3D devm_of_clk_add_hw_provider(&pdev->dev,
> > > of_clk_hw_onecell_get,
> > > +                                     priv);
> > > +   if (ret)
> > > +           return ret;
> > > +
> > > +   pm_runtime_enable(&pdev->dev);
> > > +   clk_imx8mp_audiomix_save_restore(&pdev->dev, true);
> > > +
> > > +   return 0;
> > >  }
> > >
> > > +static int clk_imx8mp_audiomix_runtime_suspend(struct device *dev) {
> > > +   clk_imx8mp_audiomix_save_restore(dev, true);
> > > +
> > > +   return 0;
> > > +}
> > > +
> > > +static int clk_imx8mp_audiomix_runtime_resume(struct device *dev) {
> > > +   clk_imx8mp_audiomix_save_restore(dev, false);
> > > +
> > > +   return 0;
> > > +}
> > > +
> > > +static const struct dev_pm_ops clk_imx8mp_audiomix_pm_ops =3D {
> > > +   SET_RUNTIME_PM_OPS(clk_imx8mp_audiomix_runtime_suspend,
> > > +                      clk_imx8mp_audiomix_runtime_resume, NULL)
> > > +   SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> > > +                                 pm_runtime_force_resume)
> > > +};
> > > +
> > >  static const struct of_device_id clk_imx8mp_audiomix_of_match[] =3D =
{
> > >     { .compatible =3D "fsl,imx8mp-audio-blk-ctrl" },
> > >     { /* sentinel */ }
> > > @@ -272,6 +364,7 @@ static struct platform_driver
> > > clk_imx8mp_audiomix_driver =3D {
> > >     .driver =3D {
> > >             .name =3D "imx8mp-audio-blk-ctrl",
> > >             .of_match_table =3D clk_imx8mp_audiomix_of_match,
> > > +           .pm =3D &clk_imx8mp_audiomix_pm_ops,
> > >     },
> > >  };
> > >
> > > --
> > > 2.34.1
> >
> >
> >