V4L/DVB (11394): cx88: Add support for stereo and sap detection for A2

The patch implements reliable stereo and sap detection for the A2 sound
standard.  This is achieved by processing the samples of the audio RDS fifo of
the cx2388x chip. A2M, EIAJ and BTSC stereo/sap detection is also possible with
this new approach, but it's not implemented yet. Stereo detection when alsa
handles the sound also does not work yet.

Signed-off-by: Marton Balint <cus@fazekas.hu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 49 insertions, 5 deletions

diff --git a/drivers/media/video/cx88/cx88-tvaudio.c b/drivers/media/video/cx88/cx88-tvaudio.c
index 7dd506b..f9501eb 100644
--- a/drivers/media/video/cx88/cx88-tvaudio.c
+++ b/drivers/media/video/cx88/cx88-tvaudio.c
@@ -163,6 +163,8 @@ static void set_audio_finish(struct cx88_core *core, u32 ctl)
 	/* unmute */
 	volume = cx_sread(SHADOW_AUD_VOL_CTL);
 	cx_swrite(SHADOW_AUD_VOL_CTL, AUD_VOL_CTL, volume);
+
+	core->last_change = jiffies;
 }
 
 /* ----------------------------------------------------------- */
@@ -745,6 +747,7 @@ void cx88_set_tvaudio(struct cx88_core *core)
 		break;
 	case WW_BG:
 	case WW_DK:
+	case WW_M:
 	case WW_I:
 	case WW_L:
 		/* prepare all dsp registers */
@@ -756,6 +759,7 @@ void cx88_set_tvaudio(struct cx88_core *core)
 		if (0 == cx88_detect_nicam(core)) {
 			/* fall back to fm / am mono */
 			set_audio_standard_A2(core, EN_A2_FORCE_MONO1);
+			core->audiomode_current = V4L2_TUNER_MODE_MONO;
 			core->use_nicam = 0;
 		} else {
 			core->use_nicam = 1;
@@ -787,6 +791,7 @@ void cx88_set_tvaudio(struct cx88_core *core)
 void cx88_newstation(struct cx88_core *core)
 {
 	core->audiomode_manual = UNSET;
+	core->last_change = jiffies;
 }
 
 void cx88_get_stereo(struct cx88_core *core, struct v4l2_tuner *t)
@@ -805,12 +810,50 @@ void cx88_get_stereo(struct cx88_core *core, struct v4l2_tuner *t)
 			aud_ctl_names[cx_read(AUD_CTL) & 63]);
 	core->astat = reg;
 
-/* TODO
-	Reading from AUD_STATUS is not enough
-	for auto-detecting sap/dual-fm/nicam.
-	Add some code here later.
-*/
+	t->capability = V4L2_TUNER_CAP_STEREO | V4L2_TUNER_CAP_SAP |
+	    V4L2_TUNER_CAP_LANG1 | V4L2_TUNER_CAP_LANG2;
+	t->rxsubchans = UNSET;
+	t->audmode = V4L2_TUNER_MODE_MONO;
 
+	switch (mode) {
+	case 0:
+		t->audmode = V4L2_TUNER_MODE_STEREO;
+		break;
+	case 1:
+		t->audmode = V4L2_TUNER_MODE_LANG2;
+		break;
+	case 2:
+		t->audmode = V4L2_TUNER_MODE_MONO;
+		break;
+	case 3:
+		t->audmode = V4L2_TUNER_MODE_SAP;
+		break;
+	}
+
+	switch (core->tvaudio) {
+	case WW_BTSC:
+	case WW_BG:
+	case WW_DK:
+	case WW_M:
+	case WW_EIAJ:
+		if (!core->use_nicam) {
+			t->rxsubchans = cx88_dsp_detect_stereo_sap(core);
+			break;
+		}
+		break;
+	default:
+		/* nothing */
+		break;
+	}
+
+	/* If software stereo detection is not supported... */
+	if (UNSET == t->rxsubchans) {
+		t->rxsubchans = V4L2_TUNER_SUB_MONO;
+		/* If the hardware itself detected stereo, also return
+		   stereo as an available subchannel */
+		if (V4L2_TUNER_MODE_STEREO == t->audmode)
+			t->rxsubchans |= V4L2_TUNER_SUB_STEREO;
+	}
 	return;
 }
 
@@ -847,6 +890,7 @@ void cx88_set_stereo(struct cx88_core *core, u32 mode, int manual)
 		break;
 	case WW_BG:
 	case WW_DK:
+	case WW_M:
 	case WW_I:
 	case WW_L:
 		if (1 == core->use_nicam) {