Re: [PATCH v2] clk: imx: imx8mp: Add pm_runtime support for power saving

From: Shengjiu Wang
Date: Wed Mar 20 2024 - 22:37:24 EST


On Wed, Mar 20, 2024 at 5:50 PM Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> wrote:
>
> On 20.03.2024 17:10:51, Shengjiu Wang wrote:
> > 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.
> >
> > Signed-off-by: Shengjiu Wang <shengjiu.wang@xxxxxxx>
> > Reviewed-by: Peng Fan <peng.fan@xxxxxxx>
> > ---
> > changes in v2:
> > - move pm_runtime_enable before the clk register
> >
> > drivers/clk/imx/clk-imx8mp-audiomix.c | 150 +++++++++++++++++++++++---
> > 1 file changed, 137 insertions(+), 13 deletions(-)
> >
> > diff --git a/drivers/clk/imx/clk-imx8mp-audiomix.c b/drivers/clk/imx/clk-imx8mp-audiomix.c
> > index 55ed211a5e0b..6042280d6404 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
>
> not needed
>
> >
> > #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[];
>
> nitpick: if the offsets fit into an u16 you can save some space.
>
> > +};
> > +
> > +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
> > + },
> > +};
>
> You only need an array with the offsets, use ARRAY_SIZE() to get the
> number of entries in the array.
>
> > +
> > +struct clk_imx8mp_audiomix_drvdata {
> > + void __iomem *base;
> > + u32 regs_save[REGS_NUM];
>
> make use of ARRAY_SIZE() here
>
> > +};
> > +
> > +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);
>
> You already allocate memory with devm_kzalloc() below. Why not increase
> the size?
>
> Rename clk_imx8mp_audiomix_drvdata to clk_imx8mp_audiomix_priv
> and add struct clk_hw_onecell_data to it.

Ok, I will update according to all the comments in the next version.

best regards
wang shengjiu

>
> > + if (!drvdata)
> > + return -ENOMEM;
> >
> > priv = devm_kzalloc(dev,
> > struct_size(priv, hws, IMX8MP_CLK_AUDIOMIX_END),
> > @@ -202,6 +263,18 @@ 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);
> > +
> > + /*
> > + * pm_runtime_enable needs to be called before clk register.
> > + * That is to make core->rpm_enabled to be true for clock
> > + * usage.
> > + */
> > + pm_runtime_get_noresume(dev);
> > + pm_runtime_set_active(dev);
> > + pm_runtime_enable(dev);
> > +
> > for (i = 0; i < ARRAY_SIZE(sels); i++) {
> > if (sels[i].num_parents == 1) {
> > hw = devm_clk_hw_register_gate_parent_data(dev,
> > @@ -216,8 +289,10 @@ static int clk_imx8mp_audiomix_probe(struct platform_device *pdev)
> > 0, NULL, NULL);
> > }
> >
> > - if (IS_ERR(hw))
> > - return PTR_ERR(hw);
> > + if (IS_ERR(hw)) {
> > + ret = PTR_ERR(hw);
> > + goto err_clk_register;
> > + }
> >
> > priv->hws[sels[i].clkid] = hw;
> > }
> > @@ -232,8 +307,10 @@ static int clk_imx8mp_audiomix_probe(struct platform_device *pdev)
> >
> > hw = imx_dev_clk_hw_pll14xx(dev, "sai_pll", "sai_pll_ref_sel",
> > base + 0x400, &imx_1443x_pll);
> > - if (IS_ERR(hw))
> > - return PTR_ERR(hw);
> > + if (IS_ERR(hw)) {
> > + ret = PTR_ERR(hw);
> > + goto err_clk_register;
> > + }
> > priv->hws[IMX8MP_CLK_AUDIOMIX_SAI_PLL] = hw;
> >
> > hw = devm_clk_hw_register_mux_parent_data_table(dev,
> > @@ -241,26 +318,71 @@ static int clk_imx8mp_audiomix_probe(struct platform_device *pdev)
> > ARRAY_SIZE(clk_imx8mp_audiomix_pll_bypass_sels),
> > CLK_SET_RATE_NO_REPARENT | CLK_SET_RATE_PARENT,
> > base + SAI_PLL_GNRL_CTL, 16, 1, 0, NULL, NULL);
> > - if (IS_ERR(hw))
> > - return PTR_ERR(hw);
> > + if (IS_ERR(hw)) {
> > + ret = PTR_ERR(hw);
> > + goto err_clk_register;
> > + }
> > +
> > priv->hws[IMX8MP_CLK_AUDIOMIX_SAI_PLL_BYPASS] = hw;
> >
> > hw = devm_clk_hw_register_gate(dev, "sai_pll_out", "sai_pll_bypass",
> > 0, base + SAI_PLL_GNRL_CTL, 13,
> > 0, NULL);
> > - if (IS_ERR(hw))
> > - return PTR_ERR(hw);
> > + if (IS_ERR(hw)) {
> > + ret = PTR_ERR(hw);
> > + goto err_clk_register;
> > + }
> > priv->hws[IMX8MP_CLK_AUDIOMIX_SAI_PLL_OUT] = hw;
> >
> > hw = devm_clk_hw_register_fixed_factor(dev, "sai_pll_out_div2",
> > "sai_pll_out", 0, 1, 2);
> > - if (IS_ERR(hw))
> > - return PTR_ERR(hw);
> > + if (IS_ERR(hw)) {
> > + ret = PTR_ERR(hw);
> > + goto err_clk_register;
> > + }
> > +
> > + ret = devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_onecell_get,
> > + priv);
> > + if (ret)
> > + goto err_clk_register;
> > +
> > + pm_runtime_put_sync(dev);
> > + return 0;
> > +
> > +err_clk_register:
> > + pm_runtime_put_sync(dev);
> > + pm_runtime_disable(dev);
> > + return ret;
> > +}
> > +
> > +static int clk_imx8mp_audiomix_remove(struct platform_device *pdev)
> > +{
> > + pm_runtime_disable(&pdev->dev);
> >
> > - return devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_onecell_get,
> > - priv);
> > + 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 */ }
> > @@ -269,9 +391,11 @@ MODULE_DEVICE_TABLE(of, clk_imx8mp_audiomix_of_match);
> >
> > static struct platform_driver clk_imx8mp_audiomix_driver = {
> > .probe = clk_imx8mp_audiomix_probe,
> > + .remove = clk_imx8mp_audiomix_remove,
> > .driver = {
> > .name = "imx8mp-audio-blk-ctrl",
> > .of_match_table = clk_imx8mp_audiomix_of_match,
> > + .pm = &clk_imx8mp_audiomix_pm_ops,
> > },
> > };
> >
> > --
> > 2.34.1
> >
> >
> >
>
> regards,
> Marc
>
> --
> Pengutronix e.K. | Marc Kleine-Budde |
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