staging/bcm2835-camera: Set ourselves up as a platform driver.

This allows bcm2835-camera to automatically probe after VCHI has
loaded, rather than only successfully probing if the arbitrary probe
order chooses us after VCHI.
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vc04_services/bcm2835-camera/TODO

@@ -21,14 +21,3 @@ less copy it needed to do.
 The bulk_receive() does some manual cache flushing that are 32-bit ARM
 only, which we should convert to proper cross-platform APIs.
 
-4) Convert to be a platform driver.
-
-Right now when the module probes, it tries to initialize VCHI and
-errors out if it wasn't ready yet.  If bcm2835-v4l2 was built in, then
-VCHI generally isn't ready because it depends on both the firmware and
-mailbox drivers having already loaded.
-
-We should have VCHI create a platform device once it's initialized,
-and have this driver bind to it, so that we automatically load the
-v4l2 module after VCHI loads.
-

drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c

@@ -23,6 +23,7 @@
 #include <media/v4l2-event.h>
 #include <media/v4l2-common.h>
 #include <linux/delay.h>
+#include <linux/platform_device.h>
 
 #include "mmal-common.h"
 #include "mmal-encodings.h"
@@ -1803,7 +1804,7 @@ static struct v4l2_format default_v4l2_format = {
 	.fmt.pix.sizeimage = 1024 * 768,
 };
 
-static int __init bm2835_mmal_init(void)
+static int __init bcm2835_mmal_probe(struct platform_device *pdev)
 {
 	int ret;
 	struct bm2835_mmal_dev *dev;
@@ -1923,7 +1924,7 @@ static int __init bm2835_mmal_init(void)
 	return ret;
 }
 
-static void __exit bm2835_mmal_exit(void)
+static int bcm2835_mmal_remove(struct platform_device *pdev)
 {
 	int camera;
 	struct vchiq_mmal_instance *instance = gdev[0]->instance;
@@ -1933,7 +1934,16 @@ static void __exit bm2835_mmal_exit(void)
 		gdev[camera] = NULL;
 	}
 	vchiq_mmal_finalise(instance);
+
+	return 0;
 }
 
-module_init(bm2835_mmal_init);
-module_exit(bm2835_mmal_exit);
+static struct platform_driver bcm2835_camera_driver = {
+	.probe		= bcm2835_mmal_probe,
+	.remove		= bcm2835_mmal_remove,
+	.driver		= {
+		.name	= "bcm2835-camera",
+	},
+};
+
+module_platform_driver(bcm2835_camera_driver)