cx88: Add support for stereo and sap detection for A2

From: Marton Balint <cus@fazekas.hu>

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.

Priority: normal

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

4 files changed, 77 insertions, 36 deletions

diff --git a/linux/drivers/media/video/cx88/Makefile b/linux/drivers/media/video/cx88/Makefile
index b06b1275a..5b7e26761 100644
--- a/linux/drivers/media/video/cx88/Makefile
+++ b/linux/drivers/media/video/cx88/Makefile
@@ -1,5 +1,5 @@
 cx88xx-objs	:= cx88-cards.o cx88-core.o cx88-i2c.o cx88-tvaudio.o \
-		   cx88-input.o
+		   cx88-dsp.o cx88-input.o
 cx8800-objs	:= cx88-video.o cx88-vbi.o
 cx8802-objs	:= cx88-mpeg.o
 
diff --git a/linux/drivers/media/video/cx88/cx88-core.c b/linux/drivers/media/video/cx88/cx88-core.c
index 71dccf6af..39cbd152a 100644
--- a/linux/drivers/media/video/cx88/cx88-core.c
+++ b/linux/drivers/media/video/cx88/cx88-core.c
@@ -232,7 +232,7 @@ cx88_free_buffer(struct videobuf_queue *q, struct cx88_buffer *buf)
  * can use the whole SDRAM for the DMA fifos.  To simplify things, we
  * use a static memory layout.  That surely will waste memory in case
  * we don't use all DMA channels at the same time (which will be the
- * case most of the time).  But that still gives us enougth FIFO space
+ * case most of the time).  But that still gives us enough FIFO space
  * to be able to deal with insane long pci latencies ...
  *
  * FIFO space allocations:
@@ -242,6 +242,7 @@ cx88_free_buffer(struct videobuf_queue *q, struct cx88_buffer *buf)
  *    channel  24    (vbi)      -  4.0k
  *    channels 25+26 (audio)    -  4.0k
  *    channel  28    (mpeg)     -  4.0k
+ *    channel  27    (audio rds)-  3.0k
  *    TOTAL                     = 29.0k
  *
  * Every channel has 160 bytes control data (64 bytes instruction
@@ -338,6 +339,18 @@ struct sram_channel cx88_sram_channels[] = {
 		.cnt1_reg   = MO_DMA28_CNT1,
 		.cnt2_reg   = MO_DMA28_CNT2,
 	},
+	[SRAM_CH27] = {
+		.name       = "audio rds",
+		.cmds_start = 0x1801C0,
+		.ctrl_start = 0x180860,
+		.cdt        = 0x180860 + 64,
+		.fifo_start = 0x187400,
+		.fifo_size  = 0x000C00,
+		.ptr1_reg   = MO_DMA27_PTR1,
+		.ptr2_reg   = MO_DMA27_PTR2,
+		.cnt1_reg   = MO_DMA27_CNT1,
+		.cnt2_reg   = MO_DMA27_CNT2,
+	},
 };
 
 int cx88_sram_channel_setup(struct cx88_core *core,
@@ -623,6 +636,7 @@ int cx88_reset(struct cx88_core *core)
 	cx88_sram_channel_setup(core, &cx88_sram_channels[SRAM_CH25], 128, 0);
 	cx88_sram_channel_setup(core, &cx88_sram_channels[SRAM_CH26], 128, 0);
 	cx88_sram_channel_setup(core, &cx88_sram_channels[SRAM_CH28], 188*4, 0);
+	cx88_sram_channel_setup(core, &cx88_sram_channels[SRAM_CH27], 128, 0);
 
 	/* misc init ... */
 	cx_write(MO_INPUT_FORMAT, ((1 << 13) |   // agc enable
@@ -821,6 +835,8 @@ int cx88_start_audio_dma(struct cx88_core *core)
 	/* constant 128 made buzz in analog Nicam-stereo for bigger fifo_size */
 	int bpl = cx88_sram_channels[SRAM_CH25].fifo_size/4;
 
+	int rds_bpl = cx88_sram_channels[SRAM_CH27].fifo_size/AUD_RDS_LINES;
+
 	/* If downstream RISC is enabled, bail out; ALSA is managing DMA */
 	if (cx_read(MO_AUD_DMACNTRL) & 0x10)
 		return 0;
@@ -828,12 +844,14 @@ int cx88_start_audio_dma(struct cx88_core *core)
 	/* setup fifo + format */
 	cx88_sram_channel_setup(core, &cx88_sram_channels[SRAM_CH25], bpl, 0);
 	cx88_sram_channel_setup(core, &cx88_sram_channels[SRAM_CH26], bpl, 0);
+	cx88_sram_channel_setup(core, &cx88_sram_channels[SRAM_CH27],
+				rds_bpl, 0);
 
 	cx_write(MO_AUDD_LNGTH, bpl); /* fifo bpl size */
-	cx_write(MO_AUDR_LNGTH, bpl); /* fifo bpl size */
+	cx_write(MO_AUDR_LNGTH, rds_bpl); /* fifo bpl size */
 
-	/* start dma */
-	cx_write(MO_AUD_DMACNTRL, 0x0003); /* Up and Down fifo enable */
+	/* enable Up, Down and Audio RDS fifo */
+	cx_write(MO_AUD_DMACNTRL, 0x0007);
 
 	return 0;
 }
diff --git a/linux/drivers/media/video/cx88/cx88-tvaudio.c b/linux/drivers/media/video/cx88/cx88-tvaudio.c
index 0039354cf..71a127dce 100644
--- a/linux/drivers/media/video/cx88/cx88-tvaudio.c
+++ b/linux/drivers/media/video/cx88/cx88-tvaudio.c
@@ -167,6 +167,8 @@ 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;
 }
 
 /* ----------------------------------------------------------- */
@@ -749,6 +751,7 @@ 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 */
@@ -760,6 +763,7 @@ 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;
@@ -791,6 +795,7 @@ 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)
@@ -809,44 +814,42 @@ 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.
-*/
-
-# if 0
 	t->capability = V4L2_TUNER_CAP_STEREO | V4L2_TUNER_CAP_SAP |
 	    V4L2_TUNER_CAP_LANG1 | V4L2_TUNER_CAP_LANG2;
-	t->rxsubchans = V4L2_TUNER_SUB_MONO;
+	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:
-		t->capability = V4L2_TUNER_CAP_STEREO | V4L2_TUNER_CAP_SAP;
-		t->rxsubchans = V4L2_TUNER_SUB_STEREO;
-		if (1 == pilot) {
-			/* SAP */
-			t->rxsubchans |= V4L2_TUNER_SUB_SAP;
-		}
-		break;
-	case WW_A2_BG:
-	case WW_A2_DK:
-	case WW_A2_M:
-		if (1 == pilot) {
-			/* stereo */
-			t->rxsubchans =
-			    V4L2_TUNER_SUB_MONO | V4L2_TUNER_SUB_STEREO;
-			if (0 == mode)
-				t->audmode = V4L2_TUNER_MODE_STEREO;
-		}
-		if (2 == pilot) {
-			/* dual language -- FIXME */
-			t->rxsubchans =
-			    V4L2_TUNER_SUB_LANG1 | V4L2_TUNER_SUB_LANG2;
-			t->audmode = V4L2_TUNER_MODE_LANG1;
+	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;
+# if 0
+	/* TODO
+		Reading from AUD_STATUS is not enough
+		for auto-detecting sap/dual-fm/nicam.
+	*/
 	case WW_NICAM_BGDKL:
 		if (0 == mode) {
 			t->audmode = V4L2_TUNER_MODE_STEREO;
@@ -859,11 +862,20 @@ void cx88_get_stereo(struct cx88_core *core, struct v4l2_tuner *t)
 			t->rxsubchans |= V4L2_TUNER_SUB_STEREO;
 		}
 		break;
+# endif
 	default:
 		/* nothing */
 		break;
 	}
-# endif
+
+	/* 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;
 }
 
@@ -900,6 +912,7 @@ 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) {
diff --git a/linux/drivers/media/video/cx88/cx88.h b/linux/drivers/media/video/cx88/cx88.h
index a34f6ee0c..1cf6900e0 100644
--- a/linux/drivers/media/video/cx88/cx88.h
+++ b/linux/drivers/media/video/cx88/cx88.h
@@ -66,6 +66,8 @@
 #define VBI_LINE_COUNT              17
 #define VBI_LINE_LENGTH           2048
 
+#define AUD_RDS_LINES		     4
+
 /* need "shadow" registers for some write-only ones ... */
 #define SHADOW_AUD_VOL_CTL           1
 #define SHADOW_AUD_BAL_CTL           2
@@ -133,6 +135,7 @@ struct cx88_ctrl {
 #define SRAM_CH25 4   /* audio */
 #define SRAM_CH26 5
 #define SRAM_CH28 6   /* mpeg */
+#define SRAM_CH27 7   /* audio rds */
 /* more */
 
 struct sram_channel {
@@ -354,6 +357,7 @@ struct cx88_core {
 	u32                        input;
 	u32                        astat;
 	u32			   use_nicam;
+	unsigned long		   last_change;
 
 	/* IR remote control state */
 	struct cx88_IR             *ir;
@@ -673,6 +677,7 @@ extern void cx88_setup_xc3028(struct cx88_core *core, struct xc2028_ctrl *ctl);
 #define WW_I2SPT	 8
 #define WW_FM		 9
 #define WW_I2SADC	 10
+#define WW_M		 11
 
 void cx88_set_tvaudio(struct cx88_core *core);
 void cx88_newstation(struct cx88_core *core);
@@ -686,6 +691,11 @@ struct cx8802_dev *cx8802_get_device(int minor);
 struct cx8802_driver * cx8802_get_driver(struct cx8802_dev *dev, enum cx88_board_type btype);
 
 /* ----------------------------------------------------------- */
+/* cx88-dsp.c                                                  */
+
+s32 cx88_dsp_detect_stereo_sap(struct cx88_core *core);
+
+/* ----------------------------------------------------------- */
 /* cx88-input.c                                                */
 
 int cx88_ir_init(struct cx88_core *core, struct pci_dev *pci);