[PATCH 2/3] drm: pl111: Simplify vexpress init

[Sam Ravnborg]

Hi Rob.

On Wed, Apr 08, 2020 at 07:39:46PM -0600, Rob Herring wrote:
> The init VExpress variants currently instantiates a 'muxfpga' driver for
> the sole purpose of getting a regmap for it. There's no reason to
> instantiate a driver and doing so just complicates things. The muxfpga
> driver also isn't unregistered properly on module unload. Let's
> just simplify all this this by just calling
> devm_regmap_init_vexpress_config() directly.
> 
> Cc: Eric Anholt <eric at anholt.net>
> Cc: dri-devel at lists.freedesktop.org
> Signed-off-by: Rob Herring <robh at kernel.org>

Procastinating, so I took a look at this.
Nice simplification - on nit below.
Acked-by: Sam Ravnborg <sam at ravnborg.org>
> ---
>  drivers/gpu/drm/pl111/pl111_versatile.c | 21 +++----------
>  drivers/gpu/drm/pl111/pl111_vexpress.c  | 42 -------------------------
>  drivers/gpu/drm/pl111/pl111_vexpress.h  |  7 -----
>  3 files changed, 4 insertions(+), 66 deletions(-)
> 
> diff --git a/drivers/gpu/drm/pl111/pl111_versatile.c b/drivers/gpu/drm/pl111/pl111_versatile.c
> index 09aeaffb7660..8c2551088f26 100644
> --- a/drivers/gpu/drm/pl111/pl111_versatile.c
> +++ b/drivers/gpu/drm/pl111/pl111_versatile.c
> @@ -8,6 +8,7 @@
>  #include <linux/of.h>
>  #include <linux/of_platform.h>
>  #include <linux/regmap.h>
> +#include <linux/vexpress.h>
>  
>  #include "pl111_versatile.h"
>  #include "pl111_vexpress.h"
> @@ -325,17 +326,8 @@ int pl111_versatile_init(struct device *dev, struct pl111_drm_dev_private *priv)
>  	versatile_clcd_type = (enum versatile_clcd)clcd_id->data;
>  
>  	/* Versatile Express special handling */
> -	if (versatile_clcd_type == VEXPRESS_CLCD_V2M) {
> +	if (IS_ENABLED(CONFIG_VEXPRESS_CONFIG) && versatile_clcd_type == VEXPRESS_CLCD_V2M) {
>  		struct platform_device *pdev;
> -
> -		/* Registers a driver for the muxfpga */
> -		ret = vexpress_muxfpga_init();
> -		if (ret) {
> -			dev_err(dev, "unable to initialize muxfpga driver\n");
> -			of_node_put(np);
> -			return ret;
> -		}
> -
>  		/* Call into deep Vexpress configuration API */
>  		pdev = of_find_device_by_node(np);
>  		if (!pdev) {
> @@ -343,13 +335,8 @@ int pl111_versatile_init(struct device *dev, struct pl111_drm_dev_private *priv)
>  			of_node_put(np);
>  			return -EPROBE_DEFER;
>  		}
> -		map = dev_get_drvdata(&pdev->dev);
> -		if (!map) {
> -			dev_err(dev, "sysreg has not yet probed\n");
> -			platform_device_put(pdev);
> -			of_node_put(np);
> -			return -EPROBE_DEFER;
> -		}
> +		map = devm_regmap_init_vexpress_config(&pdev->dev);
> +		platform_device_put(pdev);
>  	} else {
>  		map = syscon_node_to_regmap(np);
>  	}

On the following line there is:
	if (IS_ERR(map)) {
                dev_err(dev, "no Versatile syscon regmap\n");
                return PTR_ERR(map);
        }

The error message no longer tell if this was
devm_regmap_init_vexpress_config() or syscon_node_to_regmap() that
caused the error.

	Sam

> diff --git a/drivers/gpu/drm/pl111/pl111_vexpress.c b/drivers/gpu/drm/pl111/pl111_vexpress.c
> index 350570fe06b5..37ed3f1da820 100644
> --- a/drivers/gpu/drm/pl111/pl111_vexpress.c
> +++ b/drivers/gpu/drm/pl111/pl111_vexpress.c
> @@ -94,45 +94,3 @@ int pl111_vexpress_clcd_init(struct device *dev,
>  
>  	return 0;
>  }
> -
> -/*
> - * This sets up the regmap pointer that will then be retrieved by
> - * the detection code in pl111_versatile.c and passed in to the
> - * pl111_vexpress_clcd_init() function above.
> - */
> -static int vexpress_muxfpga_probe(struct platform_device *pdev)
> -{
> -	struct device *dev = &pdev->dev;
> -	struct regmap *map;
> -
> -	map = devm_regmap_init_vexpress_config(&pdev->dev);
> -	if (IS_ERR(map))
> -		return PTR_ERR(map);
> -	dev_set_drvdata(dev, map);
> -
> -	return 0;
> -}
> -
> -static const struct of_device_id vexpress_muxfpga_match[] = {
> -	{ .compatible = "arm,vexpress-muxfpga", },
> -	{}
> -};
> -
> -static struct platform_driver vexpress_muxfpga_driver = {
> -	.driver = {
> -		.name = "vexpress-muxfpga",
> -		.of_match_table = of_match_ptr(vexpress_muxfpga_match),
> -	},
> -	.probe = vexpress_muxfpga_probe,
> -};
> -
> -int vexpress_muxfpga_init(void)
> -{
> -	int ret;
> -
> -	ret = platform_driver_register(&vexpress_muxfpga_driver);
> -	/* -EBUSY just means this driver is already registered */
> -	if (ret == -EBUSY)
> -		ret = 0;
> -	return ret;
> -}
> diff --git a/drivers/gpu/drm/pl111/pl111_vexpress.h b/drivers/gpu/drm/pl111/pl111_vexpress.h
> index 5d3681bb4c00..bb54864ca91e 100644
> --- a/drivers/gpu/drm/pl111/pl111_vexpress.h
> +++ b/drivers/gpu/drm/pl111/pl111_vexpress.h
> @@ -10,8 +10,6 @@ int pl111_vexpress_clcd_init(struct device *dev,
>  			     struct pl111_drm_dev_private *priv,
>  			     struct regmap *map);
>  
> -int vexpress_muxfpga_init(void);
> -
>  #else
>  
>  static inline int pl111_vexpress_clcd_init(struct device *dev,
> @@ -21,9 +19,4 @@ static inline int pl111_vexpress_clcd_init(struct device *dev,
>  	return -ENODEV;
>  }
>  
> -static inline int vexpress_muxfpga_init(void)
> -{
> -	return 0;
> -}
> -
>  #endif
> -- 
> 2.20.1
> 
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