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

From: Marc Kleine-Budde
Date: Wed Mar 20 2024 - 05:50:47 EST

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.

> + 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

--
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