[PATCH 3/4] drm: Move exynos "match_add all devices matching my drivers" to core.

[Eric Anholt]

This is a really nice way to handle the component setup.  The
subsystem driver knows that it's got a bunch of component drivers, and
for any devices that matched its component drivers, it wants all of
those to bind to it as master.

Signed-off-by: Eric Anholt <eric at anholt.net>
---
 drivers/gpu/drm/drm_platform_helpers.c  | 33 +++++++++++++++++++++++++++++
 drivers/gpu/drm/exynos/exynos_drm_drv.c | 37 +++++++--------------------------
 include/drm/drmP.h                      |  5 +++++
 3 files changed, 45 insertions(+), 30 deletions(-)

diff --git a/drivers/gpu/drm/drm_platform_helpers.c b/drivers/gpu/drm/drm_platform_helpers.c
index a54c3e3..0819c49 100644
--- a/drivers/gpu/drm/drm_platform_helpers.c
+++ b/drivers/gpu/drm/drm_platform_helpers.c
@@ -7,6 +7,7 @@
  * option) any later version.
  */
 
+#include <linux/component.h>
 #include <drm/drmP.h>
 
 /**
@@ -43,3 +44,35 @@ void drm_platform_unregister_drivers(struct platform_driver *const *drv,
 		platform_driver_unregister(drv[count]);
 }
 EXPORT_SYMBOL_GPL(drm_platform_unregister_drivers);
+
+static int compare_dev(struct device *dev, void *data)
+{
+	return dev == (struct device *)data;
+}
+
+/**
+ * drm_platform_component_match_add_drivers - For each driver passed
+ * in, finds each device that matched to it and adds it as a component
+ * driver to the match list.
+ */
+void drm_platform_component_match_add_drivers(struct device *dev,
+					      struct component_match **match,
+					      struct platform_driver *const *drivers,
+					      int count)
+{
+	int i;
+
+	for (i = 0; i < count; i++) {
+		struct device_driver *drv = &drivers[i]->driver;
+		struct device *p = NULL, *d;
+
+		while ((d = bus_find_device(&platform_bus_type, p, drv,
+					    (void *)platform_bus_type.match))) {
+			put_device(p);
+			component_match_add(dev, match, compare_dev, d);
+			p = d;
+		}
+		put_device(p);
+	}
+}
+EXPORT_SYMBOL_GPL(drm_platform_component_match_add_drivers);
diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.c b/drivers/gpu/drm/exynos/exynos_drm_drv.c
index 83f829b..9151304 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_drv.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_drv.c
@@ -412,32 +412,6 @@ static struct platform_driver *const exynos_drm_drv_with_simple_dev[] = {
 };
 #define PDEV_COUNT ARRAY_SIZE(exynos_drm_drv_with_simple_dev)
 
-static int compare_dev(struct device *dev, void *data)
-{
-	return dev == (struct device *)data;
-}
-
-static struct component_match *exynos_drm_match_add(struct device *dev)
-{
-	struct component_match *match = NULL;
-	int i;
-
-	for (i = 0; i < ARRAY_SIZE(exynos_drm_kms_drivers); ++i) {
-		struct device_driver *drv = &exynos_drm_kms_drivers[i]->driver;
-		struct device *p = NULL, *d;
-
-		while ((d = bus_find_device(&platform_bus_type, p, drv,
-					    (void *)platform_bus_type.match))) {
-			put_device(p);
-			component_match_add(dev, &match, compare_dev, d);
-			p = d;
-		}
-		put_device(p);
-	}
-
-	return match ?: ERR_PTR(-ENODEV);
-}
-
 static int exynos_drm_bind(struct device *dev)
 {
 	return drm_platform_init(&exynos_drm_driver, to_platform_device(dev));
@@ -455,14 +429,17 @@ static const struct component_master_ops exynos_drm_ops = {
 
 static int exynos_drm_platform_probe(struct platform_device *pdev)
 {
-	struct component_match *match;
+	struct component_match *match = NULL;
 
 	pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
 	exynos_drm_driver.num_ioctls = ARRAY_SIZE(exynos_ioctls);
 
-	match = exynos_drm_match_add(&pdev->dev);
-	if (IS_ERR(match))
-		return PTR_ERR(match);
+	drm_platform_component_match_add_drivers(&pdev->dev, &match,
+						 exynos_drm_kms_drivers,
+						 ARRAY_SIZE(exynos_drm_kms_drivers));
+
+	if (!match)
+		return -ENODEV;
 
 	return component_master_add_with_match(&pdev->dev, &exynos_drm_ops,
 					       match);
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index a774574..b65d886 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -88,6 +88,7 @@ struct device_node;
 struct videomode;
 struct reservation_object;
 struct dma_buf_attachment;
+struct component_match;
 
 /*
  * 4 debug categories are defined:
@@ -1091,6 +1092,10 @@ int drm_platform_register_drivers(struct platform_driver *const *drv,
 				  int count);
 void drm_platform_unregister_drivers(struct platform_driver *const *drv,
 				     int count);
+void drm_platform_component_match_add_drivers(struct device *dev,
+					      struct component_match **match,
+					      struct platform_driver **drivers,
+					      int count);
 
 /* returns true if currently okay to sleep */
 static __inline__ bool drm_can_sleep(void)
-- 
2.1.4