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Date: Wed, 20 Mar 2024 10:50:12 +0100
From: Marc Kleine-Budde <mkl@pengutronix.de>
To: Shengjiu Wang <shengjiu.wang@nxp.com>
Cc: abelvesa@kernel.org, peng.fan@nxp.com, mturquette@baylibre.com, 
	sboyd@kernel.org, shawnguo@kernel.org, s.hauer@pengutronix.de, 
	kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com, shengjiu.wang@gmail.com, 
	linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org, 
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] clk: imx: imx8mp: Add pm_runtime support for power
 saving
Message-ID: <20240320-posing-quit-ab4b13557cc9-mkl@pengutronix.de>
References: <1710925851-5643-1-git-send-email-shengjiu.wang@nxp.com>
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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.
>=20
> Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
> Reviewed-by: Peng Fan <peng.fan@nxp.com>
> ---
> changes in v2:
> - move pm_runtime_enable before the clk register
>=20
>  drivers/clk/imx/clk-imx8mp-audiomix.c | 150 +++++++++++++++++++++++---
>  1 file changed, 137 insertions(+), 13 deletions(-)
>=20
> 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 @@
> =20
>  #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>
> =20
>  #include <dt-bindings/clock/imx8mp-clock.h>
> =20
> @@ -18,6 +20,7 @@
> =20
>  #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

> =20
>  #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)
>  };
> =20
> +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 =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
> +	},
> +};

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 sa=
ve)
> +{
> +	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);

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;
> =20
>  	priv =3D 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);
> =20
> +	drvdata->base =3D 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 =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,
> @@ -216,8 +289,10 @@ static int clk_imx8mp_audiomix_probe(struct platform=
_device *pdev)
>  				0, NULL, NULL);
>  		}
> =20
> -		if (IS_ERR(hw))
> -			return PTR_ERR(hw);
> +		if (IS_ERR(hw)) {
> +			ret =3D PTR_ERR(hw);
> +			goto err_clk_register;
> +		}
> =20
>  		priv->hws[sels[i].clkid] =3D hw;
>  	}
> @@ -232,8 +307,10 @@ static int clk_imx8mp_audiomix_probe(struct platform=
_device *pdev)
> =20
>  	hw =3D 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 =3D PTR_ERR(hw);
> +		goto err_clk_register;
> +	}
>  	priv->hws[IMX8MP_CLK_AUDIOMIX_SAI_PLL] =3D hw;
> =20
>  	hw =3D devm_clk_hw_register_mux_parent_data_table(dev,
> @@ -241,26 +318,71 @@ static int clk_imx8mp_audiomix_probe(struct platfor=
m_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 =3D PTR_ERR(hw);
> +		goto err_clk_register;
> +	}
> +
>  	priv->hws[IMX8MP_CLK_AUDIOMIX_SAI_PLL_BYPASS] =3D hw;
> =20
>  	hw =3D 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 =3D PTR_ERR(hw);
> +		goto err_clk_register;
> +	}
>  	priv->hws[IMX8MP_CLK_AUDIOMIX_SAI_PLL_OUT] =3D hw;
> =20
>  	hw =3D 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 =3D PTR_ERR(hw);
> +		goto err_clk_register;
> +	}
> +
> +	ret =3D 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);
> =20
> -	return devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_onecell_get,
> -					   priv);
> +	return 0;
>  }
> =20
> +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 */ }
> @@ -269,9 +391,11 @@ MODULE_DEVICE_TABLE(of, clk_imx8mp_audiomix_of_match=
);
> =20
>  static struct platform_driver clk_imx8mp_audiomix_driver =3D {
>  	.probe	=3D clk_imx8mp_audiomix_probe,
> +	.remove =3D clk_imx8mp_audiomix_remove,
>  	.driver =3D {
>  		.name =3D "imx8mp-audio-blk-ctrl",
>  		.of_match_table =3D clk_imx8mp_audiomix_of_match,
> +		.pm =3D &clk_imx8mp_audiomix_pm_ops,
>  	},
>  };
> =20
> --=20
> 2.34.1
>=20
>=20
>=20

regards,
Marc

--=20
Pengutronix e.K.                 | Marc Kleine-Budde          |
Embedded Linux                   | https://www.pengutronix.de |
Vertretung N=C3=BCrnberg              | Phone: +49-5121-206917-129 |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-9   |

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