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Date:   Fri, 9 Apr 2021 14:30:45 -0700
From:   Moritz Fischer <mdf@kernel.org>
To:     Nava kishore Manne <nava.manne@xilinx.com>
Cc:     mdf@kernel.org, trix@redhat.com, robh+dt@kernel.org,
        michal.simek@xilinx.com, linux-fpga@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, git@xilinx.com
Subject: Re: [PATCH 3/3] fpga: region: Adds runtime PM support
Message-ID: <YHDHhf1tQo6vI49W@epycbox.lan>
References: <20210402092049.479-1-nava.manne@xilinx.com>
 <20210402092049.479-4-nava.manne@xilinx.com>
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In-Reply-To: <20210402092049.479-4-nava.manne@xilinx.com>
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On Fri, Apr 02, 2021 at 02:50:49PM +0530, Nava kishore Manne wrote:
> Adds support to handle FPGA/PL power domain. With this patch,
> the PL power domain will be turned on before loading the bitstream
> and turned off while removing/unloading the bitstream using overlays.
> This can be achieved by adding the runtime PM support.
> 
> Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com>
> ---
>  drivers/fpga/of-fpga-region.c | 18 +++++++++++++++++-
>  1 file changed, 17 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/fpga/of-fpga-region.c b/drivers/fpga/of-fpga-region.c
> index e405309baadc..35fc2f3d4bd8 100644
> --- a/drivers/fpga/of-fpga-region.c
> +++ b/drivers/fpga/of-fpga-region.c
> @@ -15,6 +15,7 @@
>  #include <linux/of_platform.h>
>  #include <linux/slab.h>
>  #include <linux/spinlock.h>
> +#include <linux/pm_runtime.h>
>  
>  static const struct of_device_id fpga_region_of_match[] = {
>  	{ .compatible = "fpga-region", },
> @@ -302,6 +303,7 @@ static int of_fpga_region_notify_pre_apply(struct fpga_region *region,
>  	}
>  
>  	region->info = info;
> +	pm_runtime_get_sync(dev->parent);
>  	ret = fpga_region_program_fpga(region);
>  	if (ret) {
>  		/* error; reject overlay */
> @@ -324,10 +326,13 @@ static int of_fpga_region_notify_pre_apply(struct fpga_region *region,
>  static void of_fpga_region_notify_post_remove(struct fpga_region *region,
>  					      struct of_overlay_notify_data *nd)
>  {
> +	struct device *dev = &region->dev;
> +
>  	fpga_bridges_disable(&region->bridge_list);
>  	fpga_bridges_put(&region->bridge_list);
>  	fpga_image_info_free(region->info);
>  	region->info = NULL;
> +	pm_runtime_put(dev->parent);
>  }
>  
>  /**
> @@ -411,9 +416,16 @@ static int of_fpga_region_probe(struct platform_device *pdev)
>  		goto eprobe_mgr_put;
>  	}
>  
> +	pm_runtime_enable(&pdev->dev);
> +	ret = pm_runtime_get_sync(&pdev->dev);
> +	if (ret < 0)
> +		goto err_pm;
> +
> +	pm_runtime_put(&pdev->dev);
> +
>  	ret = fpga_region_register(region);
>  	if (ret)
> -		goto eprobe_mgr_put;
> +		goto err_pm;
>  
>  	of_platform_populate(np, fpga_region_of_match, NULL, &region->dev);
>  	platform_set_drvdata(pdev, region);
> @@ -422,6 +434,9 @@ static int of_fpga_region_probe(struct platform_device *pdev)
>  
>  	return 0;
>  
> +err_pm:
> +	pm_runtime_put(&pdev->dev);
> +	pm_runtime_disable(&pdev->dev);
>  eprobe_mgr_put:
>  	fpga_mgr_put(mgr);
>  	return ret;
> @@ -434,6 +449,7 @@ static int of_fpga_region_remove(struct platform_device *pdev)
>  
>  	fpga_region_unregister(region);
>  	fpga_mgr_put(mgr);
> +	pm_runtime_disable(region->dev.parent);
>  
>  	return 0;
>  }
> -- 
> 2.18.0
> 

Does this add a dependency on CONFIG_PM?

Thanks,
Moritz