[media] soc-camera: Support user-configurable line stride

Add a capabilities field to the soc_camera_host structure to flag hosts
that support user-configurable line strides. soc_camera_try_fmt() then
passes the user-provided bytesperline and sizeimage format fields to
such hosts, and expects the host to check (and fix if needed) the
values.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
[g.liakhovetski@gmx.de: fix a typo in mx2_camera.c]
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

3 files changed, 10 insertions, 2 deletions

diff --git a/drivers/media/video/mx2_camera.c b/drivers/media/video/mx2_camera.c
index b63168781cfe..ecd83faf9038 100644
--- a/drivers/media/video/mx2_camera.c
+++ b/drivers/media/video/mx2_camera.c
@@ -1787,6 +1787,8 @@ static int __devinit mx2_camera_probe(struct platform_device *pdev)
         pcdev->soc_host.priv            = pcdev;
         pcdev->soc_host.v4l2_dev.dev    = &pdev->dev;
         pcdev->soc_host.nr              = pdev->id;
+        if (cpu_is_mx25())
+                pcdev->soc_host.capabilities = SOCAM_HOST_CAP_STRIDE;
 
         pcdev->alloc_ctx = vb2_dma_contig_init_ctx(&pdev->dev);
         if (IS_ERR(pcdev->alloc_ctx)) {
diff --git a/drivers/media/video/soc_camera.c b/drivers/media/video/soc_camera.c
index 5e3274e55756..cfac53544ba6 100644
--- a/drivers/media/video/soc_camera.c
+++ b/drivers/media/video/soc_camera.c
@@ -171,8 +171,10 @@ static int soc_camera_try_fmt(struct soc_camera_device *icd,
         dev_dbg(icd->pdev, "TRY_FMT(%c%c%c%c, %ux%u)\n",
                 pixfmtstr(pix->pixelformat), pix->width, pix->height);
 
-        pix->bytesperline = 0;
-        pix->sizeimage = 0;
+        if (!(ici->capabilities & SOCAM_HOST_CAP_STRIDE)) {
+                pix->bytesperline = 0;
+                pix->sizeimage = 0;
+        }
 
         ret = ici->ops->try_fmt(icd, f);
         if (ret < 0)
diff --git a/include/media/soc_camera.h b/include/media/soc_camera.h
index a87062c393b5..d865dcf9879f 100644
--- a/include/media/soc_camera.h
+++ b/include/media/soc_camera.h
@@ -56,11 +56,15 @@ struct soc_camera_device {
         };
 };
 
+/* Host supports programmable stride */
+#define SOCAM_HOST_CAP_STRIDE           (1 << 0)
+
 struct soc_camera_host {
         struct v4l2_device v4l2_dev;
         struct list_head list;
         struct mutex host_lock;         /* Protect during probing */
         unsigned char nr;               /* Host number */
+        u32 capabilities;
         void *priv;
         const char *drv_name;
         struct soc_camera_host_ops *ops;