Re: [PATCH v4 06/45] media: sun6i-csi: Use runtime pm for clocks and reset

["Jernej Škrabec" <jernej.skrabec@gmail.com>]

Hi!

Dne petek, 15. april 2022 ob 17:27:32 CEST je Paul Kocialkowski napisal(a):
> Wrap the clock and reset preparation into runtime pm functions
> for better organization of the code. Also fix the clock and
> reset enable order to first deassert reset, as recommended in
> Allwinner litterature.

s/litterature/literature/

Otherwise,
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>

Best regards,
Jernej

> 
> Make the driver depend on PM while at it since runtime pm is
> mandatory for the driver to work.
> 
> Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
> ---
>  .../media/platform/sunxi/sun6i-csi/Kconfig    |  2 +-
>  .../platform/sunxi/sun6i-csi/sun6i_csi.c      | 84 +++++++++++++------
>  2 files changed, 60 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/media/platform/sunxi/sun6i-csi/Kconfig
> b/drivers/media/platform/sunxi/sun6i-csi/Kconfig index
> 0345901617d4..965fbd937841 100644
> --- a/drivers/media/platform/sunxi/sun6i-csi/Kconfig
> +++ b/drivers/media/platform/sunxi/sun6i-csi/Kconfig
> @@ -2,7 +2,7 @@
>  config VIDEO_SUN6I_CSI
>  	tristate "Allwinner V3s Camera Sensor Interface driver"
>  	depends on V4L_PLATFORM_DRIVERS
> -	depends on VIDEO_DEV && COMMON_CLK  && HAS_DMA
> +	depends on VIDEO_DEV && COMMON_CLK  && HAS_DMA && PM
>  	depends on ARCH_SUNXI || COMPILE_TEST
>  	select MEDIA_CONTROLLER
>  	select VIDEO_V4L2_SUBDEV_API
> diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c index
> 46d92b925cc8..dcc9e7a125e2 100644
> --- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> @@ -152,40 +152,18 @@ int sun6i_csi_set_power(struct sun6i_csi_device
> *csi_dev, bool enable)
> 
>  	if (!enable) {
>  		regmap_update_bits(regmap, CSI_EN_REG, CSI_EN_CSI_EN, 
0);
> +		pm_runtime_put(dev);
> 
> -		clk_disable_unprepare(csi_dev->clock_ram);
> -		clk_disable_unprepare(csi_dev->clock_mod);
> -		reset_control_assert(csi_dev->reset);
>  		return 0;
>  	}
> 
> -	ret = clk_prepare_enable(csi_dev->clock_mod);
> -	if (ret) {
> -		dev_err(csi_dev->dev, "Enable csi clk err %d\n", ret);
> +	ret = pm_runtime_resume_and_get(dev);
> +	if (ret < 0)
>  		return ret;
> -	}
> -
> -	ret = clk_prepare_enable(csi_dev->clock_ram);
> -	if (ret) {
> -		dev_err(csi_dev->dev, "Enable clk_dram_csi clk err 
%d\n", ret);
> -		goto clk_mod_disable;
> -	}
> -
> -	ret = reset_control_deassert(csi_dev->reset);
> -	if (ret) {
> -		dev_err(csi_dev->dev, "reset err %d\n", ret);
> -		goto clk_ram_disable;
> -	}
> 
>  	regmap_update_bits(regmap, CSI_EN_REG, CSI_EN_CSI_EN, 
CSI_EN_CSI_EN);
> 
>  	return 0;
> -
> -clk_ram_disable:
> -	clk_disable_unprepare(csi_dev->clock_ram);
> -clk_mod_disable:
> -	clk_disable_unprepare(csi_dev->clock_mod);
> -	return ret;
>  }
> 
>  static enum csi_input_fmt get_csi_input_format(struct sun6i_csi_device
> *csi_dev, @@ -800,6 +778,56 @@ static irqreturn_t sun6i_csi_interrupt(int
> irq, void *private) return IRQ_HANDLED;
>  }
> 
> +static int sun6i_csi_suspend(struct device *dev)
> +{
> +	struct sun6i_csi_device *csi_dev = dev_get_drvdata(dev);
> +
> +	reset_control_assert(csi_dev->reset);
> +	clk_disable_unprepare(csi_dev->clock_ram);
> +	clk_disable_unprepare(csi_dev->clock_mod);
> +
> +	return 0;
> +}
> +
> +static int sun6i_csi_resume(struct device *dev)
> +{
> +	struct sun6i_csi_device *csi_dev = dev_get_drvdata(dev);
> +	int ret;
> +
> +	ret = reset_control_deassert(csi_dev->reset);
> +	if (ret) {
> +		dev_err(dev, "failed to deassert reset\n");
> +		return ret;
> +	}
> +
> +	ret = clk_prepare_enable(csi_dev->clock_mod);
> +	if (ret) {
> +		dev_err(dev, "failed to enable module clock\n");
> +		goto error_reset;
> +	}
> +
> +	ret = clk_prepare_enable(csi_dev->clock_ram);
> +	if (ret) {
> +		dev_err(dev, "failed to enable ram clock\n");
> +		goto error_clock_mod;
> +	}
> +
> +	return 0;
> +
> +error_clock_mod:
> +	clk_disable_unprepare(csi_dev->clock_mod);
> +
> +error_reset:
> +	reset_control_assert(csi_dev->reset);
> +
> +	return ret;
> +}
> +
> +static const struct dev_pm_ops sun6i_csi_pm_ops = {
> +	.runtime_suspend	= sun6i_csi_suspend,
> +	.runtime_resume		= sun6i_csi_resume,
> +};
> +
>  static const struct regmap_config sun6i_csi_regmap_config = {
>  	.reg_bits       = 32,
>  	.reg_stride     = 4,
> @@ -879,6 +907,10 @@ static int sun6i_csi_resources_setup(struct
> sun6i_csi_device *csi_dev, goto error_clock_rate_exclusive;
>  	}
> 
> +	/* Runtime PM */
> +
> +	pm_runtime_enable(dev);
> +
>  	return 0;
> 
>  error_clock_rate_exclusive:
> @@ -889,6 +921,7 @@ static int sun6i_csi_resources_setup(struct
> sun6i_csi_device *csi_dev,
> 
>  static void sun6i_csi_resources_cleanup(struct sun6i_csi_device *csi_dev)
>  {
> +	pm_runtime_disable(csi_dev->dev);
>  	clk_rate_exclusive_put(csi_dev->clock_mod);
>  }
> 
> @@ -971,6 +1004,7 @@ static struct platform_driver sun6i_csi_platform_driver
> = { .driver	= {
>  		.name		= SUN6I_CSI_NAME,
>  		.of_match_table	= 
of_match_ptr(sun6i_csi_of_match),
> +		.pm		= &sun6i_csi_pm_ops,
>  	},
>  };