V4L/DVB (7616): em28xx-dvb: Properly selects digital mode at the right place

The driver should be switched to digital mode, when trying to access the
frontend or when streaming.

This patch provides the correct code to support this feature.
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

drivers/media/video/em28xx/em28xx-dvb.c

@@ -201,6 +201,18 @@ static int stop_feed(struct dvb_demux_feed *feed)
 }
 
 
+
+/* ------------------------------------------------------------------ */
+static int em28xx_dvb_bus_ctrl(struct dvb_frontend *fe, int acquire)
+{
+	struct em28xx *dev = fe->dvb->priv;
+
+	if (acquire)
+		return em28xx_set_mode(dev, EM28XX_DIGITAL_MODE);
+	else
+		return em28xx_set_mode(dev, EM28XX_MODE_UNDEFINED);
+}
+
 /* ------------------------------------------------------------------ */
 
 static struct lgdt330x_config em2880_lgdt3303_dev = {
@@ -268,6 +280,10 @@ int register_dvb(struct em28xx_dvb *dvb,
 		       dev->name, result);
 		goto fail_adapter;
 	}
+
+	/* Ensure all frontends negotiate bus access */
+	dvb->frontend->ops.ts_bus_ctrl = em28xx_dvb_bus_ctrl;
+
 	dvb->adapter.priv = dev;
 
 	/* register frontend */
@@ -287,6 +303,7 @@ int register_dvb(struct em28xx_dvb *dvb,
 	dvb->demux.feednum    = 256;
 	dvb->demux.start_feed = start_feed;
 	dvb->demux.stop_feed  = stop_feed;
+
 	result = dvb_dmx_init(&dvb->demux);
 	if (result < 0) {
 		printk(KERN_WARNING "%s: dvb_dmx_init failed (errno = %d)\n",