V4L/DVB (3709): Improve line-in handling

- improve handling of the EXTERN input: don't start an unnecessary carrier scan
- improve the LOG_STATUS output
- ensure that a carrier scan is started again when switching back to the tuner.
- set correct prescale for L-NICAM
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

drivers/media/video/msp3400-driver.c

@@ -674,22 +674,31 @@ static int msp_command(struct i2c_client *client, unsigned int cmd, void *arg)
 		int sc1_out = rt->output & 0xf;
 		int sc2_out = (rt->output >> 4) & 0xf;
 		u16 val, reg;
+		int i;
+		int extern_input = 1;
 
 		if (state->routing.input == rt->input &&
 		    state->routing.output == rt->output)
 			break;
 		state->routing = *rt;
+		/* check if the tuner input is used */
+		for (i = 0; i < 5; i++) {
+			if (((rt->input >> (4 + i * 4)) & 0xf) == 0)
+				extern_input = 0;
+		}
+		if (extern_input)
+			state->mode = MSP_MODE_EXTERN;
+		else
+			state->mode = MSP_MODE_AM_DETECT;
 		msp_set_scart(client, sc_in, 0);
 		msp_set_scart(client, sc1_out, 1);
 		msp_set_scart(client, sc2_out, 2);
 		msp_set_audmode(client);
 		reg = (state->opmode == OPMODE_AUTOSELECT) ? 0x30 : 0xbb;
 		val = msp_read_dem(client, reg);
-		if (tuner != ((val >> 8) & 1)) {
 		msp_write_dem(client, reg, (val & ~0x100) | (tuner << 8));
-			/* wake thread when a new tuner input is chosen */
+		/* wake thread when a new input is chosen */
 		msp_wake_thread(client);
-		}
 		break;
 	}
 
@@ -794,7 +803,9 @@ static int msp_command(struct i2c_client *client, unsigned int cmd, void *arg)
 		case MSP_MODE_EXTERN: p = "External input"; break;
 		default: p = "unknown"; break;
 		}
-		if (state->opmode == OPMODE_MANUAL) {
+		if (state->mode == MSP_MODE_EXTERN) {
+			v4l_info(client, "Mode:     %s\n", p);
+		} else if (state->opmode == OPMODE_MANUAL) {
 			v4l_info(client, "Mode:     %s (%s%s)\n", p,
 				(state->rxsubchans & V4L2_TUNER_SUB_STEREO) ? "stereo" : "mono",
 				(state->rxsubchans & V4L2_TUNER_SUB_LANG2) ? ", dual" : "");

drivers/media/video/msp3400-kthreads.c

@@ -244,6 +244,7 @@ static void msp3400c_set_audmode(struct i2c_client *client)
 	   the hardware does not support SAP. So the rxsubchans combination
 	   of STEREO | LANG2 does not occur. */
 
+	if (state->mode != MSP_MODE_EXTERN) {
 		/* switch to mono if only mono is available */
 		if (state->rxsubchans == V4L2_TUNER_SUB_MONO)
 			audmode = V4L2_TUNER_MODE_MONO;
@@ -257,6 +258,7 @@ static void msp3400c_set_audmode(struct i2c_client *client)
 		/* if stereo, and audmode is not mono, then switch to stereo */
 		else if (audmode != V4L2_TUNER_MODE_MONO)
 			audmode = V4L2_TUNER_MODE_STEREO;
+	}
 
 	/* switch demodulator */
 	switch (state->mode) {
@@ -481,6 +483,7 @@ int msp3400c_thread(void *data)
 			/* no carrier scan, just unmute */
 			v4l_dbg(1, msp_debug, client, "thread: no carrier scan\n");
 			state->scan_in_progress = 0;
+			state->rxsubchans = V4L2_TUNER_SUB_STEREO;
 			msp_set_audio(client);
 			continue;
 		}
@@ -947,6 +950,14 @@ int msp34xxg_thread(void *data)
 		if (kthread_should_stop())
 			break;
 
+		if (state->mode == MSP_MODE_EXTERN) {
+			/* no carrier scan needed, just unmute */
+			v4l_dbg(1, msp_debug, client, "thread: no carrier scan\n");
+			state->scan_in_progress = 0;
+			msp_set_audio(client);
+			continue;
+		}
+
 		/* setup the chip*/
 		msp34xxg_reset(client);
 		state->std = state->radio ? 0x40 : msp_standard;
@@ -978,6 +989,11 @@ int msp34xxg_thread(void *data)
 		v4l_dbg(1, msp_debug, client, "detected standard: %s (0x%04x)\n",
 			msp_standard_std_name(state->std), state->std);
 
+		if (state->std == 9) {
+			/* AM NICAM mode */
+			msp_write_dsp(client, 0x0e, 0x7c00);
+		}
+
 		/* unmute: dispatch sound to scart output, set scart volume */
 		msp_set_audio(client);