V4L/DVB (9790): soc-camera: pixel format negotiation - core support

Allocate and fill a list of formats, supported by this specific
camera-host combination. Use it for format enumeration. Take care to stay
backwards-compatible.

Camera hosts rely on sensor formats available, as well as
host specific translations. We add a structure so that hosts
can define a translation table and use it for format check
and setup.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 81 insertions, 12 deletions

diff --git a/drivers/media/video/soc_camera.c b/drivers/media/video/soc_camera.c
index 9db66a4fd1a3..5e48c2cc1a44 100644
--- a/drivers/media/video/soc_camera.c
+++ b/drivers/media/video/soc_camera.c
@@ -47,6 +47,18 @@ const struct soc_camera_data_format *soc_camera_format_by_fourcc(
 }
 EXPORT_SYMBOL(soc_camera_format_by_fourcc);
 
+const struct soc_camera_format_xlate *soc_camera_xlate_by_fourcc(
+        struct soc_camera_device *icd, unsigned int fourcc)
+{
+        unsigned int i;
+
+        for (i = 0; i < icd->num_user_formats; i++)
+                if (icd->user_formats[i].host_fmt->fourcc == fourcc)
+                        return icd->user_formats + i;
+        return NULL;
+}
+EXPORT_SYMBOL(soc_camera_xlate_by_fourcc);
+
 static int soc_camera_try_fmt_vid_cap(struct file *file, void *priv,
                                       struct v4l2_format *f)
 {
@@ -161,6 +173,59 @@ static int soc_camera_dqbuf(struct file *file, void *priv,
         return videobuf_dqbuf(&icf->vb_vidq, p, file->f_flags & O_NONBLOCK);
 }
 
+static int soc_camera_init_user_formats(struct soc_camera_device *icd)
+{
+        struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
+        int i, fmts = 0;
+
+        if (!ici->ops->get_formats)
+                /*
+                 * Fallback mode - the host will have to serve all
+                 * sensor-provided formats one-to-one to the user
+                 */
+                fmts = icd->num_formats;
+        else
+                /*
+                 * First pass - only count formats this host-sensor
+                 * configuration can provide
+                 */
+                for (i = 0; i < icd->num_formats; i++)
+                        fmts += ici->ops->get_formats(icd, i, NULL);
+
+        if (!fmts)
+                return -ENXIO;
+
+        icd->user_formats =
+                vmalloc(fmts * sizeof(struct soc_camera_format_xlate));
+        if (!icd->user_formats)
+                return -ENOMEM;
+
+        icd->num_user_formats = fmts;
+        fmts = 0;
+
+        dev_dbg(&icd->dev, "Found %d supported formats.\n", fmts);
+
+        /* Second pass - actually fill data formats */
+        for (i = 0; i < icd->num_formats; i++)
+                if (!ici->ops->get_formats) {
+                        icd->user_formats[i].host_fmt = icd->formats + i;
+                        icd->user_formats[i].cam_fmt = icd->formats + i;
+                        icd->user_formats[i].buswidth = icd->formats[i].depth;
+                } else {
+                        fmts += ici->ops->get_formats(icd, i,
+                                                      &icd->user_formats[fmts]);
+                }
+
+        icd->current_fmt = icd->user_formats[0].host_fmt;
+
+        return 0;
+}
+
+static void soc_camera_free_user_formats(struct soc_camera_device *icd)
+{
+        vfree(icd->user_formats);
+}
+
 static int soc_camera_open(struct inode *inode, struct file *file)
 {
         struct video_device *vdev;
@@ -197,10 +262,12 @@ static int soc_camera_open(struct inode *inode, struct file *file)
 
         /* Now we really have to activate the camera */
         if (icd->use_count == 1) {
+                ret = soc_camera_init_user_formats(icd);
+                if (ret < 0)
+                        goto eiufmt;
                 ret = ici->ops->add(icd);
                 if (ret < 0) {
                         dev_err(&icd->dev, "Couldn't activate the camera: %d\n", ret);
-                        icd->use_count--;
                         goto eiciadd;
                 }
         }
@@ -216,6 +283,9 @@ static int soc_camera_open(struct inode *inode, struct file *file)
 
         /* All errors are entered with the video_lock held */
 eiciadd:
+        soc_camera_free_user_formats(icd);
+eiufmt:
+        icd->use_count--;
         module_put(ici->ops->owner);
 emgi:
         module_put(icd->ops->owner);
@@ -234,8 +304,10 @@ static int soc_camera_close(struct inode *inode, struct file *file)
 
         mutex_lock(&video_lock);
         icd->use_count--;
-        if (!icd->use_count)
+        if (!icd->use_count) {
                 ici->ops->remove(icd);
+                soc_camera_free_user_formats(icd);
+        }
         module_put(icd->ops->owner);
         module_put(ici->ops->owner);
         mutex_unlock(&video_lock);
@@ -311,6 +383,7 @@ static int soc_camera_s_fmt_vid_cap(struct file *file, void *priv,
         struct soc_camera_device *icd = icf->icd;
         struct soc_camera_host *ici =
                 to_soc_camera_host(icd->dev.parent);
+        __u32 pixfmt = f->fmt.pix.pixelformat;
         int ret;
         struct v4l2_rect rect;
 
@@ -328,14 +401,12 @@ static int soc_camera_s_fmt_vid_cap(struct file *file, void *priv,
         if (ret < 0) {
                 return ret;
         } else if (!icd->current_fmt ||
-                   icd->current_fmt->fourcc != f->fmt.pix.pixelformat) {
-                dev_err(&ici->dev, "Host driver hasn't set up current "
-                        "format correctly!\n");
+                   icd->current_fmt->fourcc != pixfmt) {
+                dev_err(&ici->dev,
+                        "Host driver hasn't set up current format correctly!\n");
                 return -EINVAL;
         }
 
-        /* buswidth may be further adjusted by the ici */
-        icd->buswidth           = icd->current_fmt->depth;
         icd->width              = rect.width;
         icd->height             = rect.height;
         icf->vb_vidq.field      = f->fmt.pix.field;
@@ -347,7 +418,7 @@ static int soc_camera_s_fmt_vid_cap(struct file *file, void *priv,
                 icd->width, icd->height);
 
         /* set physical bus parameters */
-        return ici->ops->set_bus_param(icd, f->fmt.pix.pixelformat);
+        return ici->ops->set_bus_param(icd, pixfmt);
 }
 
 static int soc_camera_enum_fmt_vid_cap(struct file *file, void  *priv,
@@ -359,10 +430,10 @@ static int soc_camera_enum_fmt_vid_cap(struct file *file, void  *priv,
 
         WARN_ON(priv != file->private_data);
 
-        if (f->index >= icd->num_formats)
+        if (f->index >= icd->num_user_formats)
                 return -EINVAL;
 
-        format = &icd->formats[f->index];
+        format = icd->user_formats[f->index].host_fmt;
 
         strlcpy(f->description, format->name, sizeof(f->description));
         f->pixelformat = format->fourcc;
@@ -919,8 +990,6 @@ int soc_camera_video_start(struct soc_camera_device *icd)
         vdev->minor             = -1;
         vdev->tvnorms           = V4L2_STD_UNKNOWN,
 
-        icd->current_fmt = &icd->formats[0];
-
         err = video_register_device(vdev, VFL_TYPE_GRABBER, vdev->minor);
         if (err < 0) {
                 dev_err(vdev->parent, "video_register_device failed\n");