[media] soc-camera: Make clock_start and clock_stop operations optional

Instead of forcing drivers to implement empty clock operations, make
them optional.

v4l2 clock registration in the soc-camera core should probably be
conditionned on the availability of those operations, but careful
review and/or testing of all drivers would be needed, so that should be
a separate step.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

1 files changed, 33 insertions, 29 deletions

diff --git a/drivers/media/platform/soc_camera/soc_camera.c b/drivers/media/platform/soc_camera/soc_camera.c
index 2a400d424637..78251329ed9f 100644
--- a/drivers/media/platform/soc_camera/soc_camera.c
+++ b/drivers/media/platform/soc_camera/soc_camera.c
@@ -177,6 +177,30 @@ static int __soc_camera_power_off(struct soc_camera_device *icd)
         return 0;
 }
 
+static int soc_camera_clock_start(struct soc_camera_host *ici)
+{
+        int ret;
+
+        if (!ici->ops->clock_start)
+                return 0;
+
+        mutex_lock(&ici->clk_lock);
+        ret = ici->ops->clock_start(ici);
+        mutex_unlock(&ici->clk_lock);
+
+        return ret;
+}
+
+static void soc_camera_clock_stop(struct soc_camera_host *ici)
+{
+        if (!ici->ops->clock_stop)
+                return;
+
+        mutex_lock(&ici->clk_lock);
+        ici->ops->clock_stop(ici);
+        mutex_unlock(&ici->clk_lock);
+}
+
 const struct soc_camera_format_xlate *soc_camera_xlate_by_fourcc(
         struct soc_camera_device *icd, unsigned int fourcc)
 {
@@ -584,9 +608,7 @@ static int soc_camera_add_device(struct soc_camera_device *icd)
                 return -EBUSY;
 
         if (!icd->clk) {
-                mutex_lock(&ici->clk_lock);
-                ret = ici->ops->clock_start(ici);
-                mutex_unlock(&ici->clk_lock);
+                ret = soc_camera_clock_start(ici);
                 if (ret < 0)
                         return ret;
         }
@@ -602,11 +624,8 @@ static int soc_camera_add_device(struct soc_camera_device *icd)
         return 0;
 
 eadd:
-        if (!icd->clk) {
-                mutex_lock(&ici->clk_lock);
-                ici->ops->clock_stop(ici);
-                mutex_unlock(&ici->clk_lock);
-        }
+        if (!icd->clk)
+                soc_camera_clock_stop(ici);
         return ret;
 }
 
@@ -619,11 +638,8 @@ static void soc_camera_remove_device(struct soc_camera_device *icd)
 
         if (ici->ops->remove)
                 ici->ops->remove(icd);
-        if (!icd->clk) {
-                mutex_lock(&ici->clk_lock);
-                ici->ops->clock_stop(ici);
-                mutex_unlock(&ici->clk_lock);
-        }
+        if (!icd->clk)
+                soc_camera_clock_stop(ici);
         ici->icd = NULL;
 }
 
@@ -1180,7 +1196,6 @@ static int soc_camera_clk_enable(struct v4l2_clk *clk)
 {
         struct soc_camera_device *icd = clk->priv;
         struct soc_camera_host *ici;
-        int ret;
 
         if (!icd || !icd->parent)
                 return -ENODEV;
@@ -1194,10 +1209,7 @@ static int soc_camera_clk_enable(struct v4l2_clk *clk)
          * If a different client is currently being probed, the host will tell
          * you to go
          */
-        mutex_lock(&ici->clk_lock);
-        ret = ici->ops->clock_start(ici);
-        mutex_unlock(&ici->clk_lock);
-        return ret;
+        return soc_camera_clock_start(ici);
 }
 
 static void soc_camera_clk_disable(struct v4l2_clk *clk)
@@ -1210,9 +1222,7 @@ static void soc_camera_clk_disable(struct v4l2_clk *clk)
 
         ici = to_soc_camera_host(icd->parent);
 
-        mutex_lock(&ici->clk_lock);
-        ici->ops->clock_stop(ici);
-        mutex_unlock(&ici->clk_lock);
+        soc_camera_clock_stop(ici);
 
         module_put(ici->ops->owner);
 }
@@ -1754,9 +1764,7 @@ static int soc_camera_probe(struct soc_camera_host *ici,
                 ret = -EINVAL;
                 goto eadd;
         } else {
-                mutex_lock(&ici->clk_lock);
-                ret = ici->ops->clock_start(ici);
-                mutex_unlock(&ici->clk_lock);
+                ret = soc_camera_clock_start(ici);
                 if (ret < 0)
                         goto eadd;
 
@@ -1796,9 +1804,7 @@ efinish:
                 module_put(control->driver->owner);
 enodrv:
 eadddev:
-                mutex_lock(&ici->clk_lock);
-                ici->ops->clock_stop(ici);
-                mutex_unlock(&ici->clk_lock);
+                soc_camera_clock_stop(ici);
         }
 eadd:
         if (icd->vdev) {
@@ -1936,8 +1942,6 @@ int soc_camera_host_register(struct soc_camera_host *ici)
             ((!ici->ops->init_videobuf ||
               !ici->ops->reqbufs) &&
              !ici->ops->init_videobuf2) ||
-            !ici->ops->clock_start ||
-            !ici->ops->clock_stop ||
             !ici->ops->poll ||
             !ici->v4l2_dev.dev)
                 return -EINVAL;