media: radio: Critical interrupt bugfix for si470x over i2c

Fixed si470x_start() disabling the interrupt signal, causing tune
operations to never complete. This does not affect USB radios
because they poll the registers instead of using the IRQ line.
Signed-off-by: Douglas Fischer <fischerdouglasc@gmail.com>
[hans.verkuil@cisco.com: fixed 80 column checkpatch warning]
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/radio/si470x/radio-si470x-common.c

@@ -386,8 +386,12 @@ int si470x_start(struct si470x_device *radio)
 		goto done;
 
 	/* sysconfig 1 */
-	radio->registers[SYSCONFIG1] =
-		(de << 11) & SYSCONFIG1_DE;		/* DE*/
+	radio->registers[SYSCONFIG1] |= SYSCONFIG1_RDSIEN | SYSCONFIG1_STCIEN |
+					SYSCONFIG1_RDS;
+	radio->registers[SYSCONFIG1] &= ~SYSCONFIG1_GPIO2;
+	radio->registers[SYSCONFIG1] |= SYSCONFIG1_GPIO2_INT;
+	if (de)
+		radio->registers[SYSCONFIG1] |= SYSCONFIG1_DE;
 	retval = si470x_set_register(radio, SYSCONFIG1);
 	if (retval < 0)
 		goto done;

drivers/media/radio/si470x/radio-si470x.h

@@ -79,6 +79,8 @@
 #define SYSCONFIG1_BLNDADJ	0x00c0	/* bits 07..06: Stereo/Mono Blend Level Adjustment */
 #define SYSCONFIG1_GPIO3	0x0030	/* bits 05..04: General Purpose I/O 3 */
 #define SYSCONFIG1_GPIO2	0x000c	/* bits 03..02: General Purpose I/O 2 */
+#define SYSCONFIG1_GPIO2_DIS	0x0000	/* Disable GPIO 2 interrupt */
+#define SYSCONFIG1_GPIO2_INT	0x0004	/* Enable STC/RDS interrupt */
 #define SYSCONFIG1_GPIO1	0x0003	/* bits 01..00: General Purpose I/O 1 */
 
 #define SYSCONFIG2		5	/* System Configuration 2 */