[media] soc-camera: add host clock callbacks to start and stop the master clock

Currently soc-camera uses a single camera host callback to activate the
interface master clock and to configure the interface for a specific
client. However, during probing we might not have the information about
a client, we just need to activate the clock. Add new camera host driver
callbacks to only start and stop the clock without and client-specific
configuration.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

2 files changed, 19 insertions, 2 deletions

diff --git a/drivers/media/platform/soc_camera/soc_camera.c b/drivers/media/platform/soc_camera/soc_camera.c
index 1e831009f914..3cc086036070 100644
--- a/drivers/media/platform/soc_camera/soc_camera.c
+++ b/drivers/media/platform/soc_camera/soc_camera.c
@@ -512,10 +512,23 @@ static int soc_camera_add_device(struct soc_camera_device *icd)
         if (ici->icd)
                 return -EBUSY;
 
+        if (ici->ops->clock_start) {
+                ret = ici->ops->clock_start(ici);
+                if (ret < 0)
+                        return ret;
+        }
+
         ret = ici->ops->add(icd);
-        if (!ret)
-                ici->icd = icd;
+        if (ret < 0)
+                goto eadd;
+
+        ici->icd = icd;
 
+        return 0;
+
+eadd:
+        if (ici->ops->clock_stop)
+                ici->ops->clock_stop(ici);
         return ret;
 }
 
@@ -527,6 +540,8 @@ static void soc_camera_remove_device(struct soc_camera_device *icd)
                 return;
 
         ici->ops->remove(icd);
+        if (ici->ops->clock_stop)
+                ici->ops->clock_stop(ici);
         ici->icd = NULL;
 }
 
diff --git a/include/media/soc_camera.h b/include/media/soc_camera.h
index db23a8f0c26b..dfa24df960df 100644
--- a/include/media/soc_camera.h
+++ b/include/media/soc_camera.h
@@ -74,6 +74,8 @@ struct soc_camera_host_ops {
         struct module *owner;
         int (*add)(struct soc_camera_device *);
         void (*remove)(struct soc_camera_device *);
+        int (*clock_start)(struct soc_camera_host *);
+        void (*clock_stop)(struct soc_camera_host *);
         /*
          * .get_formats() is called for each client device format, but
          * .put_formats() is only called once. Further, if any of the calls to