[PATCH 2/4] V4L: Int if: Dummy slave

[Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxxxxxxxxxxxxx>]

From: Sakari Ailus <sakari.ailus@xxxxxxxxx>

This patch implements a dummy slave that has no functionality. Helps
managing slaves in the OMAP 3 camera driver; no need to check for NULL
pointers.

Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxx>
---
 drivers/media/video/v4l2-int-device.c |   19 +++++++++++++++++++
 include/media/v4l2-int-device.h       |    2 ++
 2 files changed, 21 insertions(+), 0 deletions(-)

diff --git a/drivers/media/video/v4l2-int-device.c b/drivers/media/video/v4l2-int-device.c
index eb8dc84..483ee2e 100644
--- a/drivers/media/video/v4l2-int-device.c
+++ b/drivers/media/video/v4l2-int-device.c
@@ -67,6 +67,25 @@ static void __v4l2_int_device_try_attach_all(void)
 	}
 }
 
+static struct v4l2_int_slave dummy_slave = {
+	/* Dummy pointer to avoid underflow in find_ioctl. */
+	.ioctls = (void *)sizeof(struct v4l2_int_ioctl_desc),
+	.num_ioctls = 0,
+};
+
+static struct v4l2_int_device dummy = {
+	.type = v4l2_int_type_slave,
+	.u = {
+		.slave = &dummy_slave,
+	},
+};
+
+struct v4l2_int_device *v4l2_int_device_dummy()
+{
+	return &dummy;
+}
+EXPORT_SYMBOL_GPL(v4l2_int_device_dummy);
+
 void v4l2_int_device_try_attach_all(void)
 {
 	mutex_lock(&mutex);
diff --git a/include/media/v4l2-int-device.h b/include/media/v4l2-int-device.h
index fbf5855..5d254c4 100644
--- a/include/media/v4l2-int-device.h
+++ b/include/media/v4l2-int-device.h
@@ -84,6 +84,8 @@ struct v4l2_int_device {
 	void *priv;
 };
 
+struct v4l2_int_device *v4l2_int_device_dummy(void);
+
 void v4l2_int_device_try_attach_all(void);
 
 int v4l2_int_device_register(struct v4l2_int_device *d);
-- 
1.5.6.5

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