pvrusb2: Implement signal routing schemes

From: Mike Isely <isely@pobox.com>

The exact routing of video and audio signals within a device is a
device-specific attribute.  Hauppauge devices do it one way; other
types of device may route things differently.  Unfortunately it is
rather impractical to define chip-specific routing at the device
attribute level, so instead what happens here is that "schemes" are
defined.  Each chip level interface implements its part of a given
scheme and the scheme as a whole is made into a device specific
attribute controlled via a table entry in pvrusb2-devattr.c.  The only
scheme defined here is for Hauppauge devices, but clearly this opens
the door for other possibilities to follow.

Signed-off-by: Mike Isely <isely@pobox.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/linux/drivers/media/video/pvrusb2/pvrusb2-devattr.h b/linux/drivers/media/video/pvrusb2/pvrusb2-devattr.h
index f63c3ddb8..05eb2c669 100644
--- a/linux/drivers/media/video/pvrusb2/pvrusb2-devattr.h
+++ b/linux/drivers/media/video/pvrusb2/pvrusb2-devattr.h
@@ -35,6 +35,7 @@ struct pvr2_string_table {
 	unsigned int cnt;
 };
 
+#define PVR2_ROUTING_SCHEME_HAUPPAUGE 0
 
 /* This describes a particular hardware type (except for the USB device ID
    which must live in a separate structure due to environmental
@@ -55,6 +56,14 @@ struct pvr2_device_desc {
 	   was initialized from internal ROM. */
 	struct pvr2_string_table fx2_firmware;
 
+	/* Signal routing scheme used by device, contains one of
+	   PVR2_ROUTING_SCHEME_XXX.  Schemes have to be defined as we
+	   encounter them.  This is an arbitrary integer scheme id; its
+	   meaning is contained entirely within the driver and is
+	   interpreted by logic which must send commands to the chip-level
+	   drivers (search for things which touch this field). */
+	unsigned int signal_routing_scheme;
+
 	/* V4L tuner type ID to use with this device (only used if the
 	   driver could not discover the type any other way). */
 	int default_tuner_type;