Re: [PATCH v8 5/5] clk: samsung: exynos-audss: Add support for runtime PM

[Chanwoo Choi <cw00.choi@samsung.com>]

Hi,

On 2017년 08월 09일 19:35, Marek Szyprowski wrote:
> This patch adds support for runtime PM to Exynos Audio SubSystem driver to
> enable full support for audio power domain on Exynos5 SoCs. The main change
> is moving register saving and restoring code from system sleep PM ops to
> runtime PM ops and implementing system sleep PM ops with generic
> pm_runtime_force_suspend/resume helpers. Runtime PM of the Exynos AudSS
> device is managed from clock core depending on the preparation status
> of the provided clocks.
> 
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
> ---
>  .../devicetree/bindings/clock/clk-exynos-audss.txt |  6 +++
>  drivers/clk/samsung/clk-exynos-audss.c             | 51 ++++++++++++++--------
>  2 files changed, 40 insertions(+), 17 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/clock/clk-exynos-audss.txt b/Documentation/devicetree/bindings/clock/clk-exynos-audss.txt
> index 0c3d6015868d..f3635d5aeba4 100644
> --- a/Documentation/devicetree/bindings/clock/clk-exynos-audss.txt
> +++ b/Documentation/devicetree/bindings/clock/clk-exynos-audss.txt
> @@ -33,6 +33,12 @@ Required Properties:
>  - clock-names: Aliases for the above clocks. They should be "pll_ref",
>    "pll_in", "cdclk", "sclk_audio", and "sclk_pcm_in" respectively.
>  
> +Optional Properties:
> +
> +  - power-domains: a phandle to respective power domain node as described by
> +    generic PM domain bindings (see power/power_domain.txt for more
> +    information).
> +
>  The following is the list of clocks generated by the controller. Each clock is
>  assigned an identifier and client nodes use this identifier to specify the
>  clock which they consume. Some of the clocks are available only on a particular
> diff --git a/drivers/clk/samsung/clk-exynos-audss.c b/drivers/clk/samsung/clk-exynos-audss.c
> index 6be52fb46ff3..ab494c104ce6 100644
> --- a/drivers/clk/samsung/clk-exynos-audss.c
> +++ b/drivers/clk/samsung/clk-exynos-audss.c
> @@ -18,6 +18,7 @@
>  #include <linux/syscore_ops.h>
>  #include <linux/module.h>
>  #include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
>  
>  #include <dt-bindings/clock/exynos-audss-clk.h>
>  
> @@ -36,14 +37,13 @@
>  #define ASS_CLK_DIV 0x4
>  #define ASS_CLK_GATE 0x8
>  
> -#ifdef CONFIG_PM_SLEEP
>  static unsigned long reg_save[][2] = {
>  	{ ASS_CLK_SRC,  0 },
>  	{ ASS_CLK_DIV,  0 },
>  	{ ASS_CLK_GATE, 0 },
>  };
>  
> -static int exynos_audss_clk_suspend(struct device *dev)
> +static int __maybe_unused exynos_audss_clk_suspend(struct device *dev)
>  {
>  	int i;
>  
> @@ -53,7 +53,7 @@ static int exynos_audss_clk_suspend(struct device *dev)
>  	return 0;
>  }
>  
> -static int exynos_audss_clk_resume(struct device *dev)
> +static int __maybe_unused exynos_audss_clk_resume(struct device *dev)
>  {
>  	int i;
>  
> @@ -62,7 +62,6 @@ static int exynos_audss_clk_resume(struct device *dev)
>  
>  	return 0;
>  }
> -#endif /* CONFIG_PM_SLEEP */
>  
>  struct exynos_audss_clk_drvdata {
>  	unsigned int has_adma_clk:1;
> @@ -179,7 +178,18 @@ static int exynos_audss_clk_probe(struct platform_device *pdev)
>  			}
>  		}
>  	}
> -	clk_table[EXYNOS_MOUT_AUDSS] = clk_hw_register_mux(NULL, "mout_audss",
> +
> +	/*
> +	 * Enable runtime PM here to allow the clock core using runtime PM
> +	 * for the registered clocks. Additionally, we increase the runtime
> +	 * PM usage count before registering the clocks, to prevent the
> +	 * clock core from runtime suspending the device.
> +	 */
> +	pm_runtime_get_noresume(dev);
> +	pm_runtime_set_active(dev);
> +	pm_runtime_enable(dev);
> +
> +	clk_table[EXYNOS_MOUT_AUDSS] = clk_hw_register_mux(dev, "mout_audss",
>  				mout_audss_p, ARRAY_SIZE(mout_audss_p),
>  				CLK_SET_RATE_NO_REPARENT,
>  				reg_base + ASS_CLK_SRC, 0, 1, 0, &lock);
> @@ -190,48 +200,48 @@ static int exynos_audss_clk_probe(struct platform_device *pdev)
>  		mout_i2s_p[1] = __clk_get_name(cdclk);
>  	if (!IS_ERR(sclk_audio))
>  		mout_i2s_p[2] = __clk_get_name(sclk_audio);
> -	clk_table[EXYNOS_MOUT_I2S] = clk_hw_register_mux(NULL, "mout_i2s",
> +	clk_table[EXYNOS_MOUT_I2S] = clk_hw_register_mux(dev, "mout_i2s",
>  				mout_i2s_p, ARRAY_SIZE(mout_i2s_p),
>  				CLK_SET_RATE_NO_REPARENT,
>  				reg_base + ASS_CLK_SRC, 2, 2, 0, &lock);
>  
> -	clk_table[EXYNOS_DOUT_SRP] = clk_hw_register_divider(NULL, "dout_srp",
> +	clk_table[EXYNOS_DOUT_SRP] = clk_hw_register_divider(dev, "dout_srp",
>  				"mout_audss", 0, reg_base + ASS_CLK_DIV, 0, 4,
>  				0, &lock);
>  
> -	clk_table[EXYNOS_DOUT_AUD_BUS] = clk_hw_register_divider(NULL,
> +	clk_table[EXYNOS_DOUT_AUD_BUS] = clk_hw_register_divider(dev,
>  				"dout_aud_bus", "dout_srp", 0,
>  				reg_base + ASS_CLK_DIV, 4, 4, 0, &lock);
>  
> -	clk_table[EXYNOS_DOUT_I2S] = clk_hw_register_divider(NULL, "dout_i2s",
> +	clk_table[EXYNOS_DOUT_I2S] = clk_hw_register_divider(dev, "dout_i2s",
>  				"mout_i2s", 0, reg_base + ASS_CLK_DIV, 8, 4, 0,
>  				&lock);
>  
> -	clk_table[EXYNOS_SRP_CLK] = clk_hw_register_gate(NULL, "srp_clk",
> +	clk_table[EXYNOS_SRP_CLK] = clk_hw_register_gate(dev, "srp_clk",
>  				"dout_srp", CLK_SET_RATE_PARENT,
>  				reg_base + ASS_CLK_GATE, 0, 0, &lock);
>  
> -	clk_table[EXYNOS_I2S_BUS] = clk_hw_register_gate(NULL, "i2s_bus",
> +	clk_table[EXYNOS_I2S_BUS] = clk_hw_register_gate(dev, "i2s_bus",
>  				"dout_aud_bus", CLK_SET_RATE_PARENT,
>  				reg_base + ASS_CLK_GATE, 2, 0, &lock);
>  
> -	clk_table[EXYNOS_SCLK_I2S] = clk_hw_register_gate(NULL, "sclk_i2s",
> +	clk_table[EXYNOS_SCLK_I2S] = clk_hw_register_gate(dev, "sclk_i2s",
>  				"dout_i2s", CLK_SET_RATE_PARENT,
>  				reg_base + ASS_CLK_GATE, 3, 0, &lock);
>  
> -	clk_table[EXYNOS_PCM_BUS] = clk_hw_register_gate(NULL, "pcm_bus",
> +	clk_table[EXYNOS_PCM_BUS] = clk_hw_register_gate(dev, "pcm_bus",
>  				 "sclk_pcm", CLK_SET_RATE_PARENT,
>  				reg_base + ASS_CLK_GATE, 4, 0, &lock);
>  
>  	sclk_pcm_in = devm_clk_get(dev, "sclk_pcm_in");
>  	if (!IS_ERR(sclk_pcm_in))
>  		sclk_pcm_p = __clk_get_name(sclk_pcm_in);
> -	clk_table[EXYNOS_SCLK_PCM] = clk_hw_register_gate(NULL, "sclk_pcm",
> +	clk_table[EXYNOS_SCLK_PCM] = clk_hw_register_gate(dev, "sclk_pcm",
>  				sclk_pcm_p, CLK_SET_RATE_PARENT,
>  				reg_base + ASS_CLK_GATE, 5, 0, &lock);
>  
>  	if (variant->has_adma_clk) {
> -		clk_table[EXYNOS_ADMA] = clk_hw_register_gate(NULL, "adma",
> +		clk_table[EXYNOS_ADMA] = clk_hw_register_gate(dev, "adma",
>  				"dout_srp", CLK_SET_RATE_PARENT,
>  				reg_base + ASS_CLK_GATE, 9, 0, &lock);
>  	}
> @@ -251,10 +261,14 @@ static int exynos_audss_clk_probe(struct platform_device *pdev)
>  		goto unregister;
>  	}
>  
> +	pm_runtime_put_sync(dev);
> +
>  	return 0;
>  
>  unregister:
>  	exynos_audss_clk_teardown();
> +	pm_runtime_put_sync(dev);
> +	pm_runtime_disable(dev);
>  
>  	if (!IS_ERR(epll))
>  		clk_disable_unprepare(epll);
> @@ -267,6 +281,7 @@ static int exynos_audss_clk_remove(struct platform_device *pdev)
>  	of_clk_del_provider(pdev->dev.of_node);
>  
>  	exynos_audss_clk_teardown();
> +	pm_runtime_disable(&pdev->dev);
>  
>  	if (!IS_ERR(epll))
>  		clk_disable_unprepare(epll);
> @@ -275,8 +290,10 @@ static int exynos_audss_clk_remove(struct platform_device *pdev)
>  }
>  
>  static const struct dev_pm_ops exynos_audss_clk_pm_ops = {
> -	SET_LATE_SYSTEM_SLEEP_PM_OPS(exynos_audss_clk_suspend,
> -				     exynos_audss_clk_resume)
> +	SET_RUNTIME_PM_OPS(exynos_audss_clk_suspend, exynos_audss_clk_resume,
> +			   NULL)
> +	SET_LATE_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> +				     pm_runtime_force_resume)
>  };
>  
>  static struct platform_driver exynos_audss_clk_driver = {
> 

Looks good to me.
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>

-- 
Best Regards,
Chanwoo Choi
Samsung Electronics