V4L/DVB (7538): Adds selectable adapter numbers as per module option

The adapter_nr module options can be used to allocate static adapter
numbers on a driver level. It avoids problems with changing DVB apapter
numbers after warm/cold boot or device unplugging and repluging.

Each driver holds DVB_MAX_ADAPTER long array of the preferred order of
adapter numbers.

options dvb-usb-dib0700 adapter_nr=7,6,5,4,3,2,1,0 would result in a
reversed allocation of adapter numbers.

With adapter_nr=2,5 it tries first to get adapter number 2 and 5. If
both are already in use it will allocate the lowest free adapter number.

Signed-off-by: Janne Grunau <janne-dvb@grunau.be>
Acked-by: Hermann Pitton <hermann.pitton@arcor.de>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/video/cx23885/cx23885-dvb.c b/drivers/media/video/cx23885/cx23885-dvb.c
index 74baa28..1a720ab 100644
--- a/drivers/media/video/cx23885/cx23885-dvb.c
+++ b/drivers/media/video/cx23885/cx23885-dvb.c
@@ -54,6 +54,8 @@
 module_param(alt_tuner, int, 0644);
 MODULE_PARM_DESC(alt_tuner, "Enable alternate tuner configuration");
 
+DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr);
+
 /* ------------------------------------------------------------------ */
 
 static int dvb_buf_setup(struct videobuf_queue *q,
@@ -333,7 +335,7 @@
 
 	/* register everything */
 	return videobuf_dvb_register(&port->dvb, THIS_MODULE, port,
-				     &dev->pci->dev);
+				     &dev->pci->dev, adapter_nr);
 }
 
 int cx23885_dvb_register(struct cx23885_tsport *port)