[media] v4l2-mc: add a generic function to create the media graph
The em28xx_v4l2_create_media_graph() is almost generic enough to
be at the core, as an ancillary function. Make it even more generic,
by getting rid of em28xx-specific code, relying only at the
media_device, in order to discover all entities found on PC-customer's
hardware and add it at the V4L2 core.
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
diff --git a/drivers/media/v4l2-core/v4l2-mc.c b/drivers/media/v4l2-core/v4l2-mc.c
new file mode 100644
index 0000000..e6d2a71
--- /dev/null
+++ b/drivers/media/v4l2-core/v4l2-mc.c
@@ -0,0 +1,186 @@
+/*
+ * Media Controller ancillary functions
+ *
+ * (c) 2016 Mauro Carvalho Chehab <mchehab@osg.samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <media/media-entity.h>
+#include <media/v4l2-mc.h>
+
+int v4l2_mc_create_media_graph(struct media_device *mdev)
+
+{
+ struct media_entity *entity;
+ struct media_entity *if_vid = NULL, *if_aud = NULL, *sensor = NULL;
+ struct media_entity *tuner = NULL, *decoder = NULL;
+ struct media_entity *io_v4l = NULL, *io_vbi = NULL, *io_swradio = NULL;
+ bool is_webcam = false;
+ u32 flags;
+ int ret;
+
+ if (!mdev)
+ return 0;
+
+ media_device_for_each_entity(entity, mdev) {
+ switch (entity->function) {
+ case MEDIA_ENT_F_IF_VID_DECODER:
+ if_vid = entity;
+ break;
+ case MEDIA_ENT_F_IF_AUD_DECODER:
+ if_aud = entity;
+ break;
+ case MEDIA_ENT_F_TUNER:
+ tuner = entity;
+ break;
+ case MEDIA_ENT_F_ATV_DECODER:
+ decoder = entity;
+ break;
+ case MEDIA_ENT_F_IO_V4L:
+ io_v4l = entity;
+ break;
+ case MEDIA_ENT_F_IO_VBI:
+ io_vbi = entity;
+ break;
+ case MEDIA_ENT_F_IO_SWRADIO:
+ io_swradio = entity;
+ break;
+ case MEDIA_ENT_F_CAM_SENSOR:
+ sensor = entity;
+ is_webcam = true;
+ break;
+ }
+ }
+
+ /* It should have at least one I/O entity */
+ if (!io_v4l && !io_vbi && !io_swradio)
+ return -EINVAL;
+
+ /*
+ * Here, webcams are modelled on a very simple way: the sensor is
+ * connected directly to the I/O entity. All dirty details, like
+ * scaler and crop HW are hidden. While such mapping is not enough
+ * for mc-centric hardware, it is enough for v4l2 interface centric
+ * PC-consumer's hardware.
+ */
+ if (is_webcam) {
+ if (!io_v4l)
+ return -EINVAL;
+
+ media_device_for_each_entity(entity, mdev) {
+ if (entity->function != MEDIA_ENT_F_CAM_SENSOR)
+ continue;
+ ret = media_create_pad_link(entity, 0,
+ io_v4l, 0,
+ MEDIA_LNK_FL_ENABLED);
+ if (ret)
+ return ret;
+ }
+ if (!decoder)
+ return 0;
+ }
+
+ /* The device isn't a webcam. So, it should have a decoder */
+ if (!decoder)
+ return -EINVAL;
+
+ /* 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,
+ 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,
+ MEDIA_LNK_FL_ENABLED);
+ if (ret)
+ return ret;
+ } else {
+ ret = media_create_pad_link(tuner, TUNER_PAD_OUTPUT,
+ decoder, DEMOD_PAD_IF_INPUT,
+ 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,
+ MEDIA_LNK_FL_ENABLED);
+ if (ret)
+ return ret;
+ } else {
+ if_aud = tuner;
+ }
+
+ }
+
+ /* Create demod to V4L, VBI and SDR radio links */
+ if (io_v4l) {
+ ret = media_create_pad_link(decoder, DEMOD_PAD_VID_OUT,
+ io_v4l, 0,
+ MEDIA_LNK_FL_ENABLED);
+ if (ret)
+ return ret;
+ }
+
+ if (io_swradio) {
+ ret = media_create_pad_link(decoder, DEMOD_PAD_VID_OUT,
+ io_swradio, 0,
+ MEDIA_LNK_FL_ENABLED);
+ if (ret)
+ return ret;
+ }
+
+ if (io_vbi) {
+ ret = media_create_pad_link(decoder, DEMOD_PAD_VBI_OUT,
+ io_vbi, 0,
+ MEDIA_LNK_FL_ENABLED);
+ if (ret)
+ return ret;
+ }
+
+ /* Create links for the media connectors */
+ flags = MEDIA_LNK_FL_ENABLED;
+ media_device_for_each_entity(entity, mdev) {
+ switch (entity->function) {
+ case MEDIA_ENT_F_CONN_RF:
+ if (!tuner)
+ continue;
+
+ ret = media_create_pad_link(entity, 0, tuner,
+ TUNER_PAD_RF_INPUT,
+ flags);
+ break;
+ case MEDIA_ENT_F_CONN_SVIDEO:
+ case MEDIA_ENT_F_CONN_COMPOSITE:
+ case MEDIA_ENT_F_CONN_TEST:
+ ret = media_create_pad_link(entity, 0, decoder,
+ DEMOD_PAD_IF_INPUT,
+ flags);
+ break;
+ default:
+ continue;
+ }
+ if (ret)
+ return ret;
+
+ flags = 0;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_mc_create_media_graph);