[PATCH v2 3/3] fpga: region: Add runtime PM support

[Manne, Nava kishore]

Ping!

> -----Original Message-----
> From: Nava kishore Manne <nava.manne at xilinx.com>
> Sent: Monday, May 23, 2022 7:15 PM
> To: mdf at kernel.org; hao.wu at intel.com; yilun.xu at intel.com;
> trix at redhat.com; robh+dt at kernel.org; krzysztof.kozlowski+dt at linaro.org;
> Michal Simek <michals at xilinx.com>; Nava kishore Manne
> <navam at xilinx.com>; linux-fpga at vger.kernel.org;
> devicetree at vger.kernel.org; linux-kernel at vger.kernel.org; linux-arm-
> kernel at lists.infradead.org; git <git at xilinx.com>
> Subject: [PATCH v2 3/3] fpga: region: Add runtime PM support
> 
> Add support to handle FPGA/PL power domain. With this patch, the PL
> power domain will be turned on before loading the bitstream into the
> targeted region and turned off while removing/unloading the bitstream from
> the targeted region using overlays. This can be achieved by adding the
> runtime PM support to the fpga regions.
> 
> Signed-off-by: Nava kishore Manne <nava.manne at xilinx.com>
> ---
> Changes for v2:
>               - Updated commit message.
>               - Updated runtime PM handling logic to fix the PM ref count
>                 imbalance issues.
> 
>  drivers/fpga/of-fpga-region.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/drivers/fpga/of-fpga-region.c b/drivers/fpga/of-fpga-region.c
> index ae82532fc127..f14bb5916d97 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", },
> @@ -301,10 +302,17 @@ static int of_fpga_region_notify_pre_apply(struct
> fpga_region *region,
>  		return -EINVAL;
>  	}
> 
> +	ret = pm_runtime_resume_and_get(dev->parent);
> +	if (ret < 0) {
> +		fpga_image_info_free(info);
> +		return ret;
> +	}
> +
>  	region->info = info;
>  	ret = fpga_region_program_fpga(region);
>  	if (ret) {
>  		/* error; reject overlay */
> +		pm_runtime_put_sync(dev->parent);
>  		fpga_image_info_free(info);
>  		region->info = NULL;
>  	}
> @@ -324,10 +332,13 @@ 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_sync(dev->parent);
>  }
> 
>  /**
> @@ -411,6 +422,8 @@ static int of_fpga_region_probe(struct
> platform_device *pdev)
>  		goto eprobe_mgr_put;
>  	}
> 
> +	pm_runtime_enable(&pdev->dev);
> +
>  	of_platform_populate(np, fpga_region_of_match, NULL, &region-
> >dev);
>  	platform_set_drvdata(pdev, region);
> 
> @@ -430,6 +443,7 @@ 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;
>  }
> --
> 2.25.1