[PATCH RFC 0/4] Better handle pads for tuning/decoder part of the devices

[PATCH RFC 0/4] Better handle pads for tuning/decoder part of the devices

[Mauro Carvalho Chehab]

At PC consumer devices, it is very common that the bridge same driver 
to be attached to different types of tuners and demods. We need a way
for the Kernel to properly identify what kind of signal is provided by each
PAD, in order to properly setup the pipelines.

The previous approach were to hardcode a fixed number of PADs for all
elements of the same type. This is not good, as different devices may 
actually have a different number of pads.

It was acceptable in the past, as there were a promisse of adding "soon"
a properties API that would allow to identify the type for each PADs, but
this was never merged (or even a patchset got submitted).

So, replace this approach by another one: add a "taint" mark to pads that
contain different types of signals.

I tried to minimize the number of signals, in order to make it simpler to
convert from the past way. However, I'm not inspired today to give
names to the signals each pad contain. So, feel free to give better
suggestions if this one doesn't fit too well.

For now, this is just a RFC, compile-tested only, as the main goal here is to
discuss about an approach. Once I get enough feedback, I'll do some
tests.


Mauro Carvalho Chehab (4):
  media: v4l2: remove VBI output pad
  media: v4l2: taint pads with the signal types for consumer devices
  v4l2-mc: switch it to use the new approach to setup pipelines
  media: dvb: use signals to discover pads

 drivers/media/dvb-core/dvbdev.c              | 37 ++++++++-
 drivers/media/dvb-frontends/au8522_decoder.c |  4 +-
 drivers/media/i2c/msp3400-driver.c           |  2 +
 drivers/media/i2c/saa7115.c                  |  3 +-
 drivers/media/i2c/tvp5150.c                  |  3 +-
 drivers/media/pci/saa7134/saa7134-core.c     |  3 +-
 drivers/media/tuners/si2157.c                |  3 +
 drivers/media/usb/dvb-usb-v2/mxl111sf.c      |  2 +
 drivers/media/v4l2-core/tuner-core.c         |  5 ++
 drivers/media/v4l2-core/v4l2-mc.c            | 87 ++++++++++++++++----
 include/media/media-entity.h                 | 33 ++++++++
 include/media/v4l2-mc.h                      |  2 -
 12 files changed, 158 insertions(+), 26 deletions(-)

-- 
2.17.1

[PATCH RFC 1/4] media: v4l2: remove VBI output pad

[Mauro Carvalho Chehab]

The signal there is the same as the video output (well,
except for sliced VBI, but let's simplify the model and ignore
it, at least for now - as it is routed together with raw
VBI).

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
---
 drivers/media/dvb-frontends/au8522_decoder.c | 1 -
 drivers/media/i2c/saa7115.c                  | 1 -
 drivers/media/i2c/tvp5150.c                  | 1 -
 drivers/media/pci/saa7134/saa7134-core.c     | 1 -
 drivers/media/v4l2-core/v4l2-mc.c            | 2 +-
 include/media/v4l2-mc.h                      | 2 --
 6 files changed, 1 insertion(+), 7 deletions(-)

diff --git a/drivers/media/dvb-frontends/au8522_decoder.c b/drivers/media/dvb-frontends/au8522_decoder.c
index 343dc92ef54e..30cd2bd7aec2 100644
--- a/drivers/media/dvb-frontends/au8522_decoder.c
+++ b/drivers/media/dvb-frontends/au8522_decoder.c
@@ -722,7 +722,6 @@ static int au8522_probe(struct i2c_client *client,
 
 	state->pads[DEMOD_PAD_IF_INPUT].flags = MEDIA_PAD_FL_SINK;
 	state->pads[DEMOD_PAD_VID_OUT].flags = MEDIA_PAD_FL_SOURCE;
-	state->pads[DEMOD_PAD_VBI_OUT].flags = MEDIA_PAD_FL_SOURCE;
 	state->pads[DEMOD_PAD_AUDIO_OUT].flags = MEDIA_PAD_FL_SOURCE;
 	sd->entity.function = MEDIA_ENT_F_ATV_DECODER;
 
diff --git a/drivers/media/i2c/saa7115.c b/drivers/media/i2c/saa7115.c
index b07114b5efb2..4c72db58dfd2 100644
--- a/drivers/media/i2c/saa7115.c
+++ b/drivers/media/i2c/saa7115.c
@@ -1836,7 +1836,6 @@ static int saa711x_probe(struct i2c_client *client,
 #if defined(CONFIG_MEDIA_CONTROLLER)
 	state->pads[DEMOD_PAD_IF_INPUT].flags = MEDIA_PAD_FL_SINK;
 	state->pads[DEMOD_PAD_VID_OUT].flags = MEDIA_PAD_FL_SOURCE;
-	state->pads[DEMOD_PAD_VBI_OUT].flags = MEDIA_PAD_FL_SOURCE;
 
 	sd->entity.function = MEDIA_ENT_F_ATV_DECODER;
 
diff --git a/drivers/media/i2c/tvp5150.c b/drivers/media/i2c/tvp5150.c
index 1734ed4ede33..1414c2c14639 100644
--- a/drivers/media/i2c/tvp5150.c
+++ b/drivers/media/i2c/tvp5150.c
@@ -1496,7 +1496,6 @@ static int tvp5150_probe(struct i2c_client *c,
 #if defined(CONFIG_MEDIA_CONTROLLER)
 	core->pads[DEMOD_PAD_IF_INPUT].flags = MEDIA_PAD_FL_SINK;
 	core->pads[DEMOD_PAD_VID_OUT].flags = MEDIA_PAD_FL_SOURCE;
-	core->pads[DEMOD_PAD_VBI_OUT].flags = MEDIA_PAD_FL_SOURCE;
 
 	sd->entity.function = MEDIA_ENT_F_ATV_DECODER;
 
diff --git a/drivers/media/pci/saa7134/saa7134-core.c b/drivers/media/pci/saa7134/saa7134-core.c
index 9e76de2411ae..267d143c3a48 100644
--- a/drivers/media/pci/saa7134/saa7134-core.c
+++ b/drivers/media/pci/saa7134/saa7134-core.c
@@ -847,7 +847,6 @@ static void saa7134_create_entities(struct saa7134_dev *dev)
 		dev->demod.name = "saa713x";
 		dev->demod_pad[DEMOD_PAD_IF_INPUT].flags = MEDIA_PAD_FL_SINK;
 		dev->demod_pad[DEMOD_PAD_VID_OUT].flags = MEDIA_PAD_FL_SOURCE;
-		dev->demod_pad[DEMOD_PAD_VBI_OUT].flags = MEDIA_PAD_FL_SOURCE;
 		dev->demod.function = MEDIA_ENT_F_ATV_DECODER;
 
 		ret = media_entity_pads_init(&dev->demod, DEMOD_NUM_PADS,
diff --git a/drivers/media/v4l2-core/v4l2-mc.c b/drivers/media/v4l2-core/v4l2-mc.c
index 0fc185a2ce90..982bab3530f6 100644
--- a/drivers/media/v4l2-core/v4l2-mc.c
+++ b/drivers/media/v4l2-core/v4l2-mc.c
@@ -147,7 +147,7 @@ int v4l2_mc_create_media_graph(struct media_device *mdev)
 	}
 
 	if (io_vbi) {
-		ret = media_create_pad_link(decoder, DEMOD_PAD_VBI_OUT,
+		ret = media_create_pad_link(decoder, DEMOD_PAD_VID_OUT,
 					    io_vbi, 0,
 					    MEDIA_LNK_FL_ENABLED);
 		if (ret)
diff --git a/include/media/v4l2-mc.h b/include/media/v4l2-mc.h
index 2634d9dc9916..7c9c781b16a9 100644
--- a/include/media/v4l2-mc.h
+++ b/include/media/v4l2-mc.h
@@ -89,14 +89,12 @@ enum if_aud_dec_pad_index {
  *
  * @DEMOD_PAD_IF_INPUT:	IF input sink pad.
  * @DEMOD_PAD_VID_OUT:	Video output source pad.
- * @DEMOD_PAD_VBI_OUT:	Vertical Blank Interface (VBI) output source pad.
  * @DEMOD_PAD_AUDIO_OUT: Audio output source pad.
  * @DEMOD_NUM_PADS:	Maximum number of output pads.
  */
 enum demod_pad_index {
 	DEMOD_PAD_IF_INPUT,
 	DEMOD_PAD_VID_OUT,
-	DEMOD_PAD_VBI_OUT,
 	DEMOD_PAD_AUDIO_OUT,
 	DEMOD_NUM_PADS
 };
-- 
2.17.1

[PATCH RFC 2/4] media: v4l2: taint pads with the signal types for consumer devices

[Mauro Carvalho Chehab]

Consumer devices are provided with a wide diferent range of types
supported by the same driver, allowing different configutations.

In order to make easier to setup media controller links, "taint"
pads with the signal type it carries.

While here, get rid of DEMOD_PAD_VBI_OUT, as the signal it carries
is actually the same as the normal video output.

The difference happens at the video/VBI interface:
	- for VBI, only the hidden lines are streamed;
	- for video, the stream is usually cropped to hide the
	  vbi lines.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
---
 drivers/media/dvb-frontends/au8522_decoder.c |  3 ++
 drivers/media/i2c/msp3400-driver.c           |  2 ++
 drivers/media/i2c/saa7115.c                  |  2 ++
 drivers/media/i2c/tvp5150.c                  |  2 ++
 drivers/media/pci/saa7134/saa7134-core.c     |  2 ++
 drivers/media/tuners/si2157.c                |  3 ++
 drivers/media/usb/dvb-usb-v2/mxl111sf.c      |  2 ++
 drivers/media/v4l2-core/tuner-core.c         |  5 +++
 include/media/media-entity.h                 | 33 ++++++++++++++++++++
 9 files changed, 54 insertions(+)

diff --git a/drivers/media/dvb-frontends/au8522_decoder.c b/drivers/media/dvb-frontends/au8522_decoder.c
index 30cd2bd7aec2..f4df9ab3d8b0 100644
--- a/drivers/media/dvb-frontends/au8522_decoder.c
+++ b/drivers/media/dvb-frontends/au8522_decoder.c
@@ -721,8 +721,11 @@ static int au8522_probe(struct i2c_client *client,
 #if defined(CONFIG_MEDIA_CONTROLLER)
 
 	state->pads[DEMOD_PAD_IF_INPUT].flags = MEDIA_PAD_FL_SINK;
+	state->pads[DEMOD_PAD_IF_INPUT].sig_type = PAD_SIGNAL_RF;
 	state->pads[DEMOD_PAD_VID_OUT].flags = MEDIA_PAD_FL_SOURCE;
+	state->pads[DEMOD_PAD_VID_OUT].sig_type = PAD_SIGNAL_ATV_VIDEO;
 	state->pads[DEMOD_PAD_AUDIO_OUT].flags = MEDIA_PAD_FL_SOURCE;
+	state->pads[DEMOD_PAD_AUDIO_OUT].sig_type = PAD_SIGNAL_AUDIO;
 	sd->entity.function = MEDIA_ENT_F_ATV_DECODER;
 
 	ret = media_entity_pads_init(&sd->entity, ARRAY_SIZE(state->pads),
diff --git a/drivers/media/i2c/msp3400-driver.c b/drivers/media/i2c/msp3400-driver.c
index 3db966db83eb..3b9c729fbd52 100644
--- a/drivers/media/i2c/msp3400-driver.c
+++ b/drivers/media/i2c/msp3400-driver.c
@@ -704,7 +704,9 @@ static int msp_probe(struct i2c_client *client, const struct i2c_device_id *id)
 
 #if defined(CONFIG_MEDIA_CONTROLLER)
 	state->pads[IF_AUD_DEC_PAD_IF_INPUT].flags = MEDIA_PAD_FL_SINK;
+	state->pads[IF_AUD_DEC_PAD_IF_INPUT].sig_type = PAD_SIGNAL_AUDIO;
 	state->pads[IF_AUD_DEC_PAD_OUT].flags = MEDIA_PAD_FL_SOURCE;
+	state->pads[IF_AUD_DEC_PAD_OUT].sig_type = PAD_SIGNAL_AUDIO;
 
 	sd->entity.function = MEDIA_ENT_F_IF_AUD_DECODER;
 
diff --git a/drivers/media/i2c/saa7115.c b/drivers/media/i2c/saa7115.c
index 4c72db58dfd2..0b298aa34a7c 100644
--- a/drivers/media/i2c/saa7115.c
+++ b/drivers/media/i2c/saa7115.c
@@ -1835,7 +1835,9 @@ static int saa711x_probe(struct i2c_client *client,
 
 #if defined(CONFIG_MEDIA_CONTROLLER)
 	state->pads[DEMOD_PAD_IF_INPUT].flags = MEDIA_PAD_FL_SINK;
+	state->pads[DEMOD_PAD_IF_INPUT].sig_type = PAD_SIGNAL_RF;
 	state->pads[DEMOD_PAD_VID_OUT].flags = MEDIA_PAD_FL_SOURCE;
+	state->pads[DEMOD_PAD_VID_OUT].sig_type = PAD_SIGNAL_ATV_VIDEO;
 
 	sd->entity.function = MEDIA_ENT_F_ATV_DECODER;
 
diff --git a/drivers/media/i2c/tvp5150.c b/drivers/media/i2c/tvp5150.c
index 1414c2c14639..dab83a774e73 100644
--- a/drivers/media/i2c/tvp5150.c
+++ b/drivers/media/i2c/tvp5150.c
@@ -1495,7 +1495,9 @@ static int tvp5150_probe(struct i2c_client *c,
 
 #if defined(CONFIG_MEDIA_CONTROLLER)
 	core->pads[DEMOD_PAD_IF_INPUT].flags = MEDIA_PAD_FL_SINK;
+	core->pads[DEMOD_PAD_IF_INPUT].sig_type = PAD_SIGNAL_RF;
 	core->pads[DEMOD_PAD_VID_OUT].flags = MEDIA_PAD_FL_SOURCE;
+	core->pads[DEMOD_PAD_VID_OUT].sig_type = PAD_SIGNAL_ATV_VIDEO;
 
 	sd->entity.function = MEDIA_ENT_F_ATV_DECODER;
 
diff --git a/drivers/media/pci/saa7134/saa7134-core.c b/drivers/media/pci/saa7134/saa7134-core.c
index 267d143c3a48..322e2ac00066 100644
--- a/drivers/media/pci/saa7134/saa7134-core.c
+++ b/drivers/media/pci/saa7134/saa7134-core.c
@@ -846,7 +846,9 @@ static void saa7134_create_entities(struct saa7134_dev *dev)
 	if (!decoder) {
 		dev->demod.name = "saa713x";
 		dev->demod_pad[DEMOD_PAD_IF_INPUT].flags = MEDIA_PAD_FL_SINK;
+		dev->demod_pad[DEMOD_PAD_IF_INPUT].sig_type = PAD_SIGNAL_RF;
 		dev->demod_pad[DEMOD_PAD_VID_OUT].flags = MEDIA_PAD_FL_SOURCE;
+		dev->demod_pad[DEMOD_PAD_VID_OUT].sig_type = PAD_SIGNAL_ATV_VIDEO;
 		dev->demod.function = MEDIA_ENT_F_ATV_DECODER;
 
 		ret = media_entity_pads_init(&dev->demod, DEMOD_NUM_PADS,
diff --git a/drivers/media/tuners/si2157.c b/drivers/media/tuners/si2157.c
index 9e34d31d724d..85e9ea9059a3 100644
--- a/drivers/media/tuners/si2157.c
+++ b/drivers/media/tuners/si2157.c
@@ -469,8 +469,11 @@ static int si2157_probe(struct i2c_client *client,
 		dev->ent.function = MEDIA_ENT_F_TUNER;
 
 		dev->pad[TUNER_PAD_RF_INPUT].flags = MEDIA_PAD_FL_SINK;
+		dev->pad[TUNER_PAD_RF_INPUT].sig_type = PAD_SIGNAL_RF;
 		dev->pad[TUNER_PAD_OUTPUT].flags = MEDIA_PAD_FL_SOURCE;
+		dev->pad[TUNER_PAD_OUTPUT].sig_type = PAD_SIGNAL_CARRIERS;
 		dev->pad[TUNER_PAD_AUD_OUT].flags = MEDIA_PAD_FL_SOURCE;
+		dev->pad[TUNER_PAD_AUD_OUT].sig_type = PAD_SIGNAL_AUDIO;
 
 		ret = media_entity_pads_init(&dev->ent, TUNER_NUM_PADS,
 					     &dev->pad[0]);
diff --git a/drivers/media/usb/dvb-usb-v2/mxl111sf.c b/drivers/media/usb/dvb-usb-v2/mxl111sf.c
index 67953360fda5..9161064b7718 100644
--- a/drivers/media/usb/dvb-usb-v2/mxl111sf.c
+++ b/drivers/media/usb/dvb-usb-v2/mxl111sf.c
@@ -893,7 +893,9 @@ static int mxl111sf_attach_tuner(struct dvb_usb_adapter *adap)
 	state->tuner.function = MEDIA_ENT_F_TUNER;
 	state->tuner.name = "mxl111sf tuner";
 	state->tuner_pads[TUNER_PAD_RF_INPUT].flags = MEDIA_PAD_FL_SINK;
+	state->tuner_pads[TUNER_PAD_RF_INPUT].sig_type = PAD_SIGNAL_RF;
 	state->tuner_pads[TUNER_PAD_OUTPUT].flags = MEDIA_PAD_FL_SOURCE;
+	state->tuner_pads[TUNER_PAD_OUTPUT].sig_type = PAD_SIGNAL_CARRIERS;
 
 	ret = media_entity_pads_init(&state->tuner,
 				     TUNER_NUM_PADS, state->tuner_pads);
diff --git a/drivers/media/v4l2-core/tuner-core.c b/drivers/media/v4l2-core/tuner-core.c
index 7f858c39753c..4c09c30e6ea1 100644
--- a/drivers/media/v4l2-core/tuner-core.c
+++ b/drivers/media/v4l2-core/tuner-core.c
@@ -685,15 +685,20 @@ static int tuner_probe(struct i2c_client *client,
 	 */
 	if (t->type == TUNER_TDA9887) {
 		t->pad[IF_VID_DEC_PAD_IF_INPUT].flags = MEDIA_PAD_FL_SINK;
+		t->pad[IF_VID_DEC_PAD_IF_INPUT].sig_type = PAD_SIGNAL_RF;
 		t->pad[IF_VID_DEC_PAD_OUT].flags = MEDIA_PAD_FL_SOURCE;
+		t->pad[IF_VID_DEC_PAD_OUT].sig_type = PAD_SIGNAL_ATV_VIDEO;
 		ret = media_entity_pads_init(&t->sd.entity,
 					     IF_VID_DEC_PAD_NUM_PADS,
 					     &t->pad[0]);
 		t->sd.entity.function = MEDIA_ENT_F_IF_VID_DECODER;
 	} else {
 		t->pad[TUNER_PAD_RF_INPUT].flags = MEDIA_PAD_FL_SINK;
+		t->pad[TUNER_PAD_RF_INPUT].sig_type = PAD_SIGNAL_RF;
 		t->pad[TUNER_PAD_OUTPUT].flags = MEDIA_PAD_FL_SOURCE;
+		t->pad[TUNER_PAD_OUTPUT].sig_type = PAD_SIGNAL_CARRIERS;
 		t->pad[TUNER_PAD_AUD_OUT].flags = MEDIA_PAD_FL_SOURCE;
+		t->pad[TUNER_PAD_AUD_OUT].sig_type = PAD_SIGNAL_AUDIO;
 		ret = media_entity_pads_init(&t->sd.entity, TUNER_NUM_PADS,
 					     &t->pad[0]);
 		t->sd.entity.function = MEDIA_ENT_F_TUNER;
diff --git a/include/media/media-entity.h b/include/media/media-entity.h
index a732af1dbba0..bf0604d315ef 100644
--- a/include/media/media-entity.h
+++ b/include/media/media-entity.h
@@ -155,6 +155,38 @@ struct media_link {
 	bool is_backlink;
 };
 
+/**
+ * struct media_pad_signal_type - type of the signal inside a media pad
+ *
+ * @PAD_SIGNAL_DEFAULT
+ *	Default signal. Use this when all inputs or all outputs are
+ *	uniquely identified by just its number and all carries the same
+ *	signal type
+ * @PAD_SIGNAL_RF
+ *	The pad contains a Radio Frequency, Intermediate Frequency or
+ *	baseband signal.
+ *	All Tuner sinks should use it.
+ *	On tuner sources, this is used for digital TV demodulators and for
+ *	IF-PLL demodulator like tda9887.
+ * @PAD_SIGNAL_CARRIERS
+ *	The pad contains analog signals carrying either a digital or an analog
+ *	modulated (or baseband) signal. This is provided by tuner source
+ *	pads and used by analog TV standard decoders and by digital tv demods.
+ * @PAD_SIGNAL_ATV_VIDEO
+ *	Contains a bitstream of samples from an analog TV video source, with
+ *	usually contains the VBI data on it.
+ * @PAD_SIGNAL_AUDIO
+ *	Contains an Intermediate Frequency analog signal from an audio
+ *	sub-carrier or an audio bitstream. Provided by tuners and consumed by audio AM/FM decoders.
+ */
+enum media_pad_signal_type {
+	PAD_SIGNAL_DEFAULT = 0,
+	PAD_SIGNAL_RF,
+	PAD_SIGNAL_CARRIERS,
+	PAD_SIGNAL_ATV_VIDEO,
+	PAD_SIGNAL_AUDIO,
+};
+
 /**
  * struct media_pad - A media pad graph object.
  *
@@ -169,6 +201,7 @@ struct media_pad {
 	struct media_gobj graph_obj;	/* must be first field in struct */
 	struct media_entity *entity;
 	u16 index;
+	enum media_pad_signal_type sig_type;
 	unsigned long flags;
 };
 
-- 
2.17.1

[PATCH RFC 3/4] v4l2-mc: switch it to use the new approach to setup pipelines

[Mauro Carvalho Chehab]

Instead of relying on a static map for pids, use the new sig_type
"taint" type to setup the pipelines with the same tipe between
different entities.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
---
 drivers/media/v4l2-core/v4l2-mc.c | 87 +++++++++++++++++++++++++------
 1 file changed, 71 insertions(+), 16 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-mc.c b/drivers/media/v4l2-core/v4l2-mc.c
index 982bab3530f6..8640f656f9ae 100644
--- a/drivers/media/v4l2-core/v4l2-mc.c
+++ b/drivers/media/v4l2-core/v4l2-mc.c
@@ -19,6 +19,28 @@
 #include <media/v4l2-subdev.h>
 #include <media/videobuf2-core.h>
 
+static int get_pad_index(struct media_entity *entity, bool is_sink,
+			 enum media_pad_signal_type sig_type)
+{
+	int i;
+	bool pad_is_sink;
+
+	for (i = 0; i < entity->num_pads; i++) {
+		if (entity->pads[i].flags == MEDIA_PAD_FL_SINK)
+			pad_is_sink = true;
+		else if (entity->pads[i].flags == MEDIA_PAD_FL_SOURCE)
+			pad_is_sink = false;
+		else
+			continue;	/* This is an error! */
+
+		if (pad_is_sink != is_sink)
+			continue;
+		if (entity->pads[i].sig_type == sig_type)
+			return i;
+	}
+	return -EINVAL;
+}
+
 int v4l2_mc_create_media_graph(struct media_device *mdev)
 
 {
@@ -28,7 +50,7 @@ int v4l2_mc_create_media_graph(struct media_device *mdev)
 	struct media_entity *io_v4l = NULL, *io_vbi = NULL, *io_swradio = NULL;
 	bool is_webcam = false;
 	u32 flags;
-	int ret;
+	int ret, pad_sink, pad_source;
 
 	if (!mdev)
 		return 0;
@@ -97,29 +119,48 @@ int v4l2_mc_create_media_graph(struct media_device *mdev)
 	/* Link the tuner and IF video output pads */
 	if (tuner) {
 		if (if_vid) {
-			ret = media_create_pad_link(tuner, TUNER_PAD_OUTPUT,
-						    if_vid,
-						    IF_VID_DEC_PAD_IF_INPUT,
+			pad_source = get_pad_index(tuner, false, PAD_SIGNAL_RF);
+			pad_sink = get_pad_index(if_vid, true, PAD_SIGNAL_RF);
+			if (pad_source < 0 || pad_sink < 0)
+				return -EINVAL;
+			ret = media_create_pad_link(tuner, pad_source,
+						    if_vid, pad_sink,
 						    MEDIA_LNK_FL_ENABLED);
 			if (ret)
 				return ret;
-			ret = media_create_pad_link(if_vid, IF_VID_DEC_PAD_OUT,
-						decoder, DEMOD_PAD_IF_INPUT,
+
+			pad_source = get_pad_index(if_vid, false,
+						   PAD_SIGNAL_ATV_VIDEO);
+			pad_sink = get_pad_index(decoder, true,
+						 PAD_SIGNAL_ATV_VIDEO);
+			if (pad_source < 0 || pad_sink < 0)
+				return -EINVAL;
+			ret = media_create_pad_link(if_vid, pad_source,
+						decoder, pad_sink,
 						MEDIA_LNK_FL_ENABLED);
 			if (ret)
 				return ret;
 		} else {
-			ret = media_create_pad_link(tuner, TUNER_PAD_OUTPUT,
-						decoder, DEMOD_PAD_IF_INPUT,
+			pad_source = get_pad_index(tuner, false, PAD_SIGNAL_RF);
+			pad_sink = get_pad_index(decoder, true, PAD_SIGNAL_RF);
+			if (pad_source < 0 || pad_sink < 0)
+				return -EINVAL;
+			ret = media_create_pad_link(tuner, pad_source,
+						decoder, pad_sink,
 						MEDIA_LNK_FL_ENABLED);
 			if (ret)
 				return ret;
 		}
 
 		if (if_aud) {
-			ret = media_create_pad_link(tuner, TUNER_PAD_AUD_OUT,
-						    if_aud,
-						    IF_AUD_DEC_PAD_IF_INPUT,
+			pad_source = get_pad_index(tuner, false,
+						   PAD_SIGNAL_AUDIO);
+			pad_sink = get_pad_index(decoder, true,
+						 PAD_SIGNAL_AUDIO);
+			if (pad_source < 0 || pad_sink < 0)
+				return -EINVAL;
+			ret = media_create_pad_link(tuner, pad_source,
+						    if_aud, pad_sink,
 						    MEDIA_LNK_FL_ENABLED);
 			if (ret)
 				return ret;
@@ -131,7 +172,10 @@ int v4l2_mc_create_media_graph(struct media_device *mdev)
 
 	/* Create demod to V4L, VBI and SDR radio links */
 	if (io_v4l) {
-		ret = media_create_pad_link(decoder, DEMOD_PAD_VID_OUT,
+		pad_source = get_pad_index(tuner, false, PAD_SIGNAL_ATV_VIDEO);
+		if (pad_source < 0)
+			return -EINVAL;
+		ret = media_create_pad_link(decoder, pad_source,
 					io_v4l, 0,
 					MEDIA_LNK_FL_ENABLED);
 		if (ret)
@@ -139,7 +183,10 @@ int v4l2_mc_create_media_graph(struct media_device *mdev)
 	}
 
 	if (io_swradio) {
-		ret = media_create_pad_link(decoder, DEMOD_PAD_VID_OUT,
+		pad_source = get_pad_index(tuner, false, PAD_SIGNAL_ATV_VIDEO);
+		if (pad_source < 0)
+			return -EINVAL;
+		ret = media_create_pad_link(decoder, pad_source,
 					io_swradio, 0,
 					MEDIA_LNK_FL_ENABLED);
 		if (ret)
@@ -147,7 +194,10 @@ int v4l2_mc_create_media_graph(struct media_device *mdev)
 	}
 
 	if (io_vbi) {
-		ret = media_create_pad_link(decoder, DEMOD_PAD_VID_OUT,
+		pad_source = get_pad_index(tuner, false, PAD_SIGNAL_ATV_VIDEO);
+		if (pad_source < 0)
+			return -EINVAL;
+		ret = media_create_pad_link(decoder, pad_source,
 					    io_vbi, 0,
 					    MEDIA_LNK_FL_ENABLED);
 		if (ret)
@@ -161,13 +211,18 @@ int v4l2_mc_create_media_graph(struct media_device *mdev)
 		case MEDIA_ENT_F_CONN_RF:
 			if (!tuner)
 				continue;
-
+			pad_source = get_pad_index(tuner, false, PAD_SIGNAL_RF);
+			if (pad_source < 0)
+				return -EINVAL;
 			ret = media_create_pad_link(entity, 0, tuner,
-						    TUNER_PAD_RF_INPUT,
+						    pad_source,
 						    flags);
 			break;
 		case MEDIA_ENT_F_CONN_SVIDEO:
 		case MEDIA_ENT_F_CONN_COMPOSITE:
+			pad_sink = get_pad_index(decoder, true, PAD_SIGNAL_RF);
+			if (pad_sink < 0)
+				return -EINVAL;
 			ret = media_create_pad_link(entity, 0, decoder,
 						    DEMOD_PAD_IF_INPUT,
 						    flags);
-- 
2.17.1

[PATCH RFC 4/4] media: dvb: use signals to discover pads

[Mauro Carvalho Chehab]

On tuner pads, multiple signals are present. Be sure to get
the right PAD by using them.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
---
 drivers/media/dvb-core/dvbdev.c | 37 +++++++++++++++++++++++++++++----
 1 file changed, 33 insertions(+), 4 deletions(-)

diff --git a/drivers/media/dvb-core/dvbdev.c b/drivers/media/dvb-core/dvbdev.c
index 787fe06df217..5c39bd328835 100644
--- a/drivers/media/dvb-core/dvbdev.c
+++ b/drivers/media/dvb-core/dvbdev.c
@@ -607,6 +607,28 @@ static int dvb_create_io_intf_links(struct dvb_adapter *adap,
 	return 0;
 }
 
+static int get_pad_index(struct media_entity *entity, bool is_sink,
+			 enum media_pad_signal_type sig_type)
+{
+	int i;
+	bool pad_is_sink;
+
+	for (i = 0; i < entity->num_pads; i++) {
+		if (entity->pads[i].flags == MEDIA_PAD_FL_SINK)
+			pad_is_sink = true;
+		else if (entity->pads[i].flags == MEDIA_PAD_FL_SOURCE)
+			pad_is_sink = false;
+		else
+			continue;	/* This is an error! */
+
+		if (pad_is_sink != is_sink)
+			continue;
+		if (entity->pads[i].sig_type == sig_type)
+			return i;
+	}
+	return -EINVAL;
+}
+
 int dvb_create_media_graph(struct dvb_adapter *adap,
 			   bool create_rf_connector)
 {
@@ -618,7 +640,7 @@ int dvb_create_media_graph(struct dvb_adapter *adap,
 	unsigned demux_pad = 0;
 	unsigned dvr_pad = 0;
 	unsigned ntuner = 0, ndemod = 0;
-	int ret;
+	int ret, pad_source, pad_sink;
 	static const char *connector_name = "Television";
 
 	if (!mdev)
@@ -678,7 +700,7 @@ int dvb_create_media_graph(struct dvb_adapter *adap,
 		if (ret)
 			return ret;
 
-		if (!ntuner)
+		if (!ntuner) {
 			ret = media_create_pad_links(mdev,
 						     MEDIA_ENT_F_CONN_RF,
 						     conn, 0,
@@ -686,19 +708,26 @@ int dvb_create_media_graph(struct dvb_adapter *adap,
 						     demod, 0,
 						     MEDIA_LNK_FL_ENABLED,
 						     false);
-		else
+		} else {
+			pad_sink = get_pad_index(tuner, true, PAD_SIGNAL_RF);
+			if (pad_sink < 0)
+				return -EINVAL;
 			ret = media_create_pad_links(mdev,
 						     MEDIA_ENT_F_CONN_RF,
 						     conn, 0,
 						     MEDIA_ENT_F_TUNER,
-						     tuner, TUNER_PAD_RF_INPUT,
+						     tuner, pad_sink,
 						     MEDIA_LNK_FL_ENABLED,
 						     false);
+		}
 		if (ret)
 			return ret;
 	}
 
 	if (ntuner && ndemod) {
+		pad_source = get_pad_index(tuner, true, PAD_SIGNAL_RF);
+		if (pad_source)
+			return -EINVAL;
 		ret = media_create_pad_links(mdev,
 					     MEDIA_ENT_F_TUNER,
 					     tuner, TUNER_PAD_OUTPUT,
-- 
2.17.1