Re: [PATCH] clk: imx: imx8mp: Add pm_runtime support for power saving

From: Shengjiu Wang
Date: Tue Mar 19 2024 - 22:11:49 EST

On Tue, Mar 19, 2024 at 3:35 PM Marco Felsch <m.felsch@xxxxxxxxxxxxxx> 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 suspend 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@xxxxxxx>
> >
> > Reviewed-by: Peng Fan <peng.fan@xxxxxxx>
> > > ---
> > > 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[] = {
> > > CLK_SAIn(7)
> > > };
> > >
> > > +struct clk_imx8mp_audiomix_regs {
> > > + u32 regs_num;
> > > + u32 regs_off[];
> > > +};
> > > +
> > > +static const struct clk_imx8mp_audiomix_regs audiomix_regs = {
> > > + .regs_num = REGS_NUM,
> > > + .regs_off = {
> > > + 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, bool
> > > +save) {
> > > + struct clk_imx8mp_audiomix_drvdata *drvdata =
> > > dev_get_drvdata(dev);
> > > + void __iomem *base = drvdata->base;
> > > + int i;
> > > +
> > > + if (save) {
> > > + for (i = 0; i < audiomix_regs.regs_num; i++)
> > > + drvdata->regs_save[i] = readl(base +
> > > audiomix_regs.regs_off[i]);
> > > + } else {
> > > + for (i = 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 = &pdev->dev;
> > > void __iomem *base;
> > > struct clk_hw *hw;
> > > - int i;
> > > + int i, ret;
> > > +
> > > + drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
> > > + if (!drvdata)
> > > + return -ENOMEM;
> > >
> > > priv = 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 = base;
> > > + dev_set_drvdata(dev, drvdata);
> > > +
> > > for (i = 0; i < ARRAY_SIZE(sels); i++) {
> > > if (sels[i].num_parents == 1) {
> > > hw = 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 = 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 = {
> > > + 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[] = {
> > > { .compatible = "fsl,imx8mp-audio-blk-ctrl" },
> > > { /* sentinel */ }
> > > @@ -272,6 +364,7 @@ static struct platform_driver
> > > clk_imx8mp_audiomix_driver = {
> > > .driver = {
> > > .name = "imx8mp-audio-blk-ctrl",
> > > .of_match_table = clk_imx8mp_audiomix_of_match,
> > > + .pm = &clk_imx8mp_audiomix_pm_ops,
> > > },
> > > };
> > >
> > > --
> > > 2.34.1
> >
> >
> >