media: adv748x: csi2: Link AFE with TXA and TXB

The ADV748x chip supports routing AFE output to either TXA or TXB.
In order to support run-time configuration of video stream path, create an
additional (not enabled) "AFE:8->TXA:0" link, and remove the IMMUTABLE flag
from existing ones.

Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

1 files changed, 23 insertions, 21 deletions

diff --git a/drivers/media/i2c/adv748x/adv748x-csi2.c b/drivers/media/i2c/adv748x/adv748x-csi2.c
index b6b5d8c7ea7c..8c3714495e11 100644
--- a/drivers/media/i2c/adv748x/adv748x-csi2.c
+++ b/drivers/media/i2c/adv748x/adv748x-csi2.c
@@ -27,6 +27,7 @@ static int adv748x_csi2_set_virtual_channel(struct adv748x_csi2 *tx,
  * @v4l2_dev: Video registration device
  * @src: Source subdevice to establish link
  * @src_pad: Pad number of source to link to this @tx
+ * @enable: Link enabled flag
  *
  * Ensure that the subdevice is registered against the v4l2_device, and link the
  * source pad to the sink pad of the CSI2 bus entity.
@@ -34,17 +35,11 @@ static int adv748x_csi2_set_virtual_channel(struct adv748x_csi2 *tx,
 static int adv748x_csi2_register_link(struct adv748x_csi2 *tx,
                                       struct v4l2_device *v4l2_dev,
                                       struct v4l2_subdev *src,
-                                      unsigned int src_pad)
+                                      unsigned int src_pad,
+                                      bool enable)
 {
-        int enabled = MEDIA_LNK_FL_ENABLED;
         int ret;
 
-        /*
-         * Dynamic linking of the AFE is not supported.
-         * Register the links as immutable.
-         */
-        enabled |= MEDIA_LNK_FL_IMMUTABLE;
-
         if (!src->v4l2_dev) {
                 ret = v4l2_device_register_subdev(v4l2_dev, src);
                 if (ret)
@@ -53,7 +48,7 @@ static int adv748x_csi2_register_link(struct adv748x_csi2 *tx,
 
         return media_create_pad_link(&src->entity, src_pad,
                                      &tx->sd.entity, ADV748X_CSI2_SINK,
-                                     enabled);
+                                     enable ? MEDIA_LNK_FL_ENABLED : 0);
 }
 
 /* -----------------------------------------------------------------------------
@@ -68,25 +63,32 @@ static int adv748x_csi2_registered(struct v4l2_subdev *sd)
 {
         struct adv748x_csi2 *tx = adv748x_sd_to_csi2(sd);
         struct adv748x_state *state = tx->state;
+        int ret;
 
         adv_dbg(state, "Registered %s (%s)", is_txa(tx) ? "TXA":"TXB",
                         sd->name);
 
         /*
-         * The adv748x hardware allows the AFE to route through the TXA, however
-         * this is not currently supported in this driver.
+         * Link TXA to AFE and HDMI, and TXB to AFE only as TXB cannot output
+         * HDMI.
          *
-         * Link HDMI->TXA, and AFE->TXB directly.
+         * The HDMI->TXA link is enabled by default, as is the AFE->TXB one.
          */
-        if (is_txa(tx) && is_hdmi_enabled(state))
-                return adv748x_csi2_register_link(tx, sd->v4l2_dev,
-                                                  &state->hdmi.sd,
-                                                  ADV748X_HDMI_SOURCE);
-        if (is_txb(tx) && is_afe_enabled(state))
-                return adv748x_csi2_register_link(tx, sd->v4l2_dev,
-                                                  &state->afe.sd,
-                                                  ADV748X_AFE_SOURCE);
-        return 0;
+        if (is_afe_enabled(state)) {
+                ret = adv748x_csi2_register_link(tx, sd->v4l2_dev,
+                                                 &state->afe.sd,
+                                                 ADV748X_AFE_SOURCE,
+                                                 is_txb(tx));
+                if (ret)
+                        return ret;
+        }
+
+        /* Register link to HDMI for TXA only. */
+        if (is_txb(tx) || !is_hdmi_enabled(state))
+                return 0;
+
+        return adv748x_csi2_register_link(tx, sd->v4l2_dev, &state->hdmi.sd,
+                                          ADV748X_HDMI_SOURCE, true);
 }
 
 static const struct v4l2_subdev_internal_ops adv748x_csi2_internal_ops = {