drm: pl111: Simplify vexpress init

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@anholt.net>
Cc: dri-devel@lists.freedesktop.org
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200409013947.12667-3-robh@kernel.org

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"
@@ -391,17 +392,8 @@ int pl111_versatile_init(struct device *dev, struct pl111_drm_dev_private *priv)
 	}
 
 	/* 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) {
@@ -409,13 +401,8 @@ 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");
+		map = devm_regmap_init_vexpress_config(&pdev->dev);
 		platform_device_put(pdev);
-			of_node_put(np);
-			return -EPROBE_DEFER;
-		}
 	} else {
 		map = syscon_node_to_regmap(np);
 	}

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;
-}

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