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Date:   Wed, 8 Apr 2020 13:37:25 +0200
From:   Paul Kocialkowski <paul.kocialkowski@bootlin.com>
To:     Samuel Holland <samuel@sholland.org>
Cc:     Maxime Ripard <mripard@kernel.org>, Chen-Yu Tsai <wens@csie.org>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-media@vger.kernel.org, linux-sunxi@googlegroups.com
Subject: Re: [PATCH] media: cedrus: Implement runtime PM
Message-ID: <20200408113725.GA1439687@collins>
References: <20200408010232.48432-1-samuel@sholland.org>
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In-Reply-To: <20200408010232.48432-1-samuel@sholland.org>
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Hi,

On Tue 07 Apr 20, 20:02, Samuel Holland wrote:
> This allows the VE clocks and PLL_VE to be disabled most of the time.
> 
> Since the device is stateless, each frame gets a separate runtime PM
> reference. Enable autosuspend so the PM callbacks are not run before and
> after every frame.

Looks good, thanks for the contribution :)

Acked-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>

Cheers,

Paul

> Signed-off-by: Samuel Holland <samuel@sholland.org>
> ---
> 
> I tested this with v4l2-request-test. I don't have the setup to do
> anything more complicated at the moment.
> 
> ---
>  drivers/staging/media/sunxi/cedrus/cedrus.c   |   7 ++
>  .../staging/media/sunxi/cedrus/cedrus_hw.c    | 115 ++++++++++++------
>  .../staging/media/sunxi/cedrus/cedrus_hw.h    |   3 +
>  3 files changed, 88 insertions(+), 37 deletions(-)
> 
> diff --git a/drivers/staging/media/sunxi/cedrus/cedrus.c b/drivers/staging/media/sunxi/cedrus/cedrus.c
> index 3fad5edccd17..9aa1fc8a6c26 100644
> --- a/drivers/staging/media/sunxi/cedrus/cedrus.c
> +++ b/drivers/staging/media/sunxi/cedrus/cedrus.c
> @@ -16,6 +16,7 @@
>  #include <linux/platform_device.h>
>  #include <linux/module.h>
>  #include <linux/of.h>
> +#include <linux/pm.h>
>  
>  #include <media/v4l2-device.h>
>  #include <media/v4l2-ioctl.h>
> @@ -474,6 +475,11 @@ static int cedrus_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> +static const struct dev_pm_ops cedrus_dev_pm_ops = {
> +	SET_RUNTIME_PM_OPS(cedrus_hw_suspend,
> +			   cedrus_hw_resume, NULL)
> +};
> +
>  static const struct cedrus_variant sun4i_a10_cedrus_variant = {
>  	.mod_rate	= 320000000,
>  };
> @@ -559,6 +565,7 @@ static struct platform_driver cedrus_driver = {
>  	.driver		= {
>  		.name		= CEDRUS_NAME,
>  		.of_match_table	= of_match_ptr(cedrus_dt_match),
> +		.pm		= &cedrus_dev_pm_ops,
>  	},
>  };
>  module_platform_driver(cedrus_driver);
> diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_hw.c b/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
> index daf5f244f93b..b84814d5afe4 100644
> --- a/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
> +++ b/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
> @@ -19,6 +19,7 @@
>  #include <linux/dma-mapping.h>
>  #include <linux/interrupt.h>
>  #include <linux/clk.h>
> +#include <linux/pm_runtime.h>
>  #include <linux/regmap.h>
>  #include <linux/reset.h>
>  #include <linux/soc/sunxi/sunxi_sram.h>
> @@ -63,6 +64,8 @@ int cedrus_engine_enable(struct cedrus_ctx *ctx, enum cedrus_codec codec)
>  	if (ctx->src_fmt.width > 2048)
>  		reg |= VE_MODE_PIC_WIDTH_MORE_2048;
>  
> +	pm_runtime_get_sync(ctx->dev->dev);
> +
>  	cedrus_write(ctx->dev, VE_MODE, reg);
>  
>  	return 0;
> @@ -71,6 +74,9 @@ int cedrus_engine_enable(struct cedrus_ctx *ctx, enum cedrus_codec codec)
>  void cedrus_engine_disable(struct cedrus_dev *dev)
>  {
>  	cedrus_write(dev, VE_MODE, VE_MODE_DISABLED);
> +
> +	pm_runtime_mark_last_busy(dev->dev);
> +	pm_runtime_put_autosuspend(dev->dev);
>  }
>  
>  void cedrus_dst_format_set(struct cedrus_dev *dev,
> @@ -134,12 +140,72 @@ static irqreturn_t cedrus_irq(int irq, void *data)
>  	else
>  		state = VB2_BUF_STATE_DONE;
>  
> +	cedrus_engine_disable(dev);
> +
>  	v4l2_m2m_buf_done_and_job_finish(ctx->dev->m2m_dev, ctx->fh.m2m_ctx,
>  					 state);
>  
>  	return IRQ_HANDLED;
>  }
>  
> +int cedrus_hw_resume(struct device *d)
> +{
> +	struct cedrus_dev *dev = dev_get_drvdata(d);
> +	int ret;
> +
> +	ret = clk_prepare_enable(dev->ahb_clk);
> +	if (ret) {
> +		dev_err(dev->dev, "Failed to enable AHB clock\n");
> +
> +		return ret;
> +	}
> +
> +	ret = clk_prepare_enable(dev->mod_clk);
> +	if (ret) {
> +		dev_err(dev->dev, "Failed to enable MOD clock\n");
> +
> +		goto err_ahb_clk;
> +	}
> +
> +	ret = clk_prepare_enable(dev->ram_clk);
> +	if (ret) {
> +		dev_err(dev->dev, "Failed to enable RAM clock\n");
> +
> +		goto err_mod_clk;
> +	}
> +
> +	ret = reset_control_reset(dev->rstc);
> +	if (ret) {
> +		dev_err(dev->dev, "Failed to apply reset\n");
> +
> +		goto err_ram_clk;
> +	}
> +
> +	return 0;
> +
> +err_ram_clk:
> +	clk_disable_unprepare(dev->ram_clk);
> +err_mod_clk:
> +	clk_disable_unprepare(dev->mod_clk);
> +err_ahb_clk:
> +	clk_disable_unprepare(dev->ahb_clk);
> +
> +	return ret;
> +}
> +
> +int cedrus_hw_suspend(struct device *d)
> +{
> +	struct cedrus_dev *dev = dev_get_drvdata(d);
> +
> +	reset_control_assert(dev->rstc);
> +
> +	clk_disable_unprepare(dev->ram_clk);
> +	clk_disable_unprepare(dev->mod_clk);
> +	clk_disable_unprepare(dev->ahb_clk);
> +
> +	return 0;
> +}
> +
>  int cedrus_hw_probe(struct cedrus_dev *dev)
>  {
>  	const struct cedrus_variant *variant;
> @@ -236,42 +302,19 @@ int cedrus_hw_probe(struct cedrus_dev *dev)
>  		goto err_sram;
>  	}
>  
> -	ret = clk_prepare_enable(dev->ahb_clk);
> -	if (ret) {
> -		dev_err(dev->dev, "Failed to enable AHB clock\n");
> -
> -		goto err_sram;
> -	}
> -
> -	ret = clk_prepare_enable(dev->mod_clk);
> -	if (ret) {
> -		dev_err(dev->dev, "Failed to enable MOD clock\n");
> -
> -		goto err_ahb_clk;
> -	}
> -
> -	ret = clk_prepare_enable(dev->ram_clk);
> -	if (ret) {
> -		dev_err(dev->dev, "Failed to enable RAM clock\n");
> -
> -		goto err_mod_clk;
> -	}
> -
> -	ret = reset_control_reset(dev->rstc);
> -	if (ret) {
> -		dev_err(dev->dev, "Failed to apply reset\n");
> -
> -		goto err_ram_clk;
> +	pm_runtime_set_autosuspend_delay(dev->dev, 1000);
> +	pm_runtime_use_autosuspend(dev->dev);
> +	pm_runtime_enable(dev->dev);
> +	if (!pm_runtime_enabled(dev->dev)) {
> +		ret = cedrus_hw_resume(dev->dev);
> +		if (ret)
> +			goto err_pm;
>  	}
>  
>  	return 0;
>  
> -err_ram_clk:
> -	clk_disable_unprepare(dev->ram_clk);
> -err_mod_clk:
> -	clk_disable_unprepare(dev->mod_clk);
> -err_ahb_clk:
> -	clk_disable_unprepare(dev->ahb_clk);
> +err_pm:
> +	pm_runtime_disable(dev->dev);
>  err_sram:
>  	sunxi_sram_release(dev->dev);
>  err_mem:
> @@ -282,11 +325,9 @@ int cedrus_hw_probe(struct cedrus_dev *dev)
>  
>  void cedrus_hw_remove(struct cedrus_dev *dev)
>  {
> -	reset_control_assert(dev->rstc);
> -
> -	clk_disable_unprepare(dev->ram_clk);
> -	clk_disable_unprepare(dev->mod_clk);
> -	clk_disable_unprepare(dev->ahb_clk);
> +	pm_runtime_disable(dev->dev);
> +	if (!pm_runtime_status_suspended(dev->dev))
> +		cedrus_hw_suspend(dev->dev);
>  
>  	sunxi_sram_release(dev->dev);
>  
> diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_hw.h b/drivers/staging/media/sunxi/cedrus/cedrus_hw.h
> index 604ff932fbf5..17822b470a1e 100644
> --- a/drivers/staging/media/sunxi/cedrus/cedrus_hw.h
> +++ b/drivers/staging/media/sunxi/cedrus/cedrus_hw.h
> @@ -22,6 +22,9 @@ void cedrus_engine_disable(struct cedrus_dev *dev);
>  void cedrus_dst_format_set(struct cedrus_dev *dev,
>  			   struct v4l2_pix_format *fmt);
>  
> +int cedrus_hw_resume(struct device *dev);
> +int cedrus_hw_suspend(struct device *dev);
> +
>  int cedrus_hw_probe(struct cedrus_dev *dev);
>  void cedrus_hw_remove(struct cedrus_dev *dev);
>  
> -- 
> 2.24.1
>