[media] dvbdev: create links on devices with multiple frontends

Devices like mxl111sf-based WinTV Aero-m have multiple
frontends, all linked on the same demod. Currently, the
dvb_create_graph() function is not smart enough to create
multiple links. Fix it.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

2 files changed, 51 insertions, 13 deletions

diff --git a/drivers/media/dvb-core/dvbdev.c b/drivers/media/dvb-core/dvbdev.c
index 28e340583ede..560450a0b32a 100644
--- a/drivers/media/dvb-core/dvbdev.c
+++ b/drivers/media/dvb-core/dvbdev.c
@@ -576,6 +576,7 @@ int dvb_create_media_graph(struct dvb_adapter *adap,
         struct media_interface *intf;
         unsigned demux_pad = 0;
         unsigned dvr_pad = 0;
+        unsigned ntuner = 0, ndemod = 0;
         int ret;
         static const char *connector_name = "Television";
 
@@ -586,9 +587,11 @@ int dvb_create_media_graph(struct dvb_adapter *adap,
                 switch (entity->function) {
                 case MEDIA_ENT_F_TUNER:
                         tuner = entity;
+                        ntuner++;
                         break;
                 case MEDIA_ENT_F_DTV_DEMOD:
                         demod = entity;
+                        ndemod++;
                         break;
                 case MEDIA_ENT_F_TS_DEMUX:
                         demux = entity;
@@ -599,6 +602,18 @@ int dvb_create_media_graph(struct dvb_adapter *adap,
                 }
         }
 
+        /*
+         * Prepare to signalize to media_create_pad_links() that multiple
+         * entities of the same type exists and a 1:n or n:1 links need to be
+         * created.
+         * NOTE: if both tuner and demod have multiple instances, it is up
+         * to the caller driver to create such links.
+         */
+        if (ntuner > 1)
+                tuner = NULL;
+        if (ndemod > 1)
+                demod = NULL;
+
         if (create_rf_connector) {
                 conn = kzalloc(sizeof(*conn), GFP_KERNEL);
                 if (!conn)
@@ -623,28 +638,44 @@ int dvb_create_media_graph(struct dvb_adapter *adap,
                 if (ret)
                         return ret;
 
-                if (!tuner)
-                        ret = media_create_pad_link(conn, 0,
-                                                    demod, 0,
-                                                    MEDIA_LNK_FL_ENABLED);
+                if (!ntuner)
+                        ret = media_create_pad_links(mdev,
+                                                     MEDIA_ENT_F_CONN_RF,
+                                                     conn, 0,
+                                                     MEDIA_ENT_F_DTV_DEMOD,
+                                                     demod, 0,
+                                                     MEDIA_LNK_FL_ENABLED,
+                                                     false);
                 else
-                        ret = media_create_pad_link(conn, 0,
-                                                    tuner, TUNER_PAD_RF_INPUT,
-                                                    MEDIA_LNK_FL_ENABLED);
+                        ret = media_create_pad_links(mdev,
+                                                     MEDIA_ENT_F_CONN_RF,
+                                                     conn, 0,
+                                                     MEDIA_ENT_F_TUNER,
+                                                     tuner, TUNER_PAD_RF_INPUT,
+                                                     MEDIA_LNK_FL_ENABLED,
+                                                     false);
                 if (ret)
                         return ret;
         }
 
-        if (tuner && demod) {
-                ret = media_create_pad_link(tuner, TUNER_PAD_IF_OUTPUT,
-                                            demod, 0, MEDIA_LNK_FL_ENABLED);
+        if (ntuner && ndemod) {
+                ret = media_create_pad_links(mdev,
+                                             MEDIA_ENT_F_TUNER,
+                                             tuner, TUNER_PAD_IF_OUTPUT,
+                                             MEDIA_ENT_F_DTV_DEMOD,
+                                             demod, 0, MEDIA_LNK_FL_ENABLED,
+                                             false);
                 if (ret)
                         return ret;
         }
 
-        if (demod && demux) {
-                ret = media_create_pad_link(demod, 1, demux,
-                                            0, MEDIA_LNK_FL_ENABLED);
+        if (ndemod && demux) {
+                ret = media_create_pad_links(mdev,
+                                             MEDIA_ENT_F_DTV_DEMOD,
+                                             demod, 1,
+                                             MEDIA_ENT_F_TS_DEMUX,
+                                             demux, 0, MEDIA_LNK_FL_ENABLED,
+                                             false);
                 if (ret)
                         return -ENOMEM;
         }
diff --git a/drivers/media/dvb-core/dvbdev.h b/drivers/media/dvb-core/dvbdev.h
index b622d6a3b95e..d7c67baa885e 100644
--- a/drivers/media/dvb-core/dvbdev.h
+++ b/drivers/media/dvb-core/dvbdev.h
@@ -225,6 +225,13 @@ void dvb_unregister_device(struct dvb_device *dvbdev);
  *
  * @adap:                       pointer to struct dvb_adapter
  * @create_rf_connector:        if true, it creates the RF connector too
+ *
+ * This function checks all DVB-related functions at the media controller
+ * entities and creates the needed links for the media graph. It is
+ * capable of working with multiple tuners or multiple frontends, but it
+ * won't create links if the device has multiple tuners and multiple frontends
+ * or if the device has multiple muxes. In such case, the caller driver should
+ * manually create the remaining links.
  */
 __must_check int dvb_create_media_graph(struct dvb_adapter *adap,
                                         bool create_rf_connector);