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>

diff --git a/drivers/media/video/soc_camera.c b/drivers/media/video/soc_camera.c
index 9db66a4..5e48c2c 100644 (file)
--- 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");

diff --git a/include/media/soc_camera.h b/include/media/soc_camera.h
index dddaf45..da57ffd 100644 (file)
--- a/include/media/soc_camera.h
+++ b/include/media/soc_camera.h
@@ -41,6 +41,8 @@ struct soc_camera_device {
        const struct soc_camera_data_format *current_fmt;
        const struct soc_camera_data_format *formats;
        int num_formats;
+       struct soc_camera_format_xlate *user_formats;
+       int num_user_formats;
        struct module *owner;
        void *host_priv;                /* per-device host private data */
        /* soc_camera.c private count. Only accessed with video_lock held */
@@ -65,8 +67,10 @@ struct soc_camera_host_ops {
        struct module *owner;
        int (*add)(struct soc_camera_device *);
        void (*remove)(struct soc_camera_device *);
-       int (*suspend)(struct soc_camera_device *, pm_message_t state);
+       int (*suspend)(struct soc_camera_device *, pm_message_t);
        int (*resume)(struct soc_camera_device *);
+       int (*get_formats)(struct soc_camera_device *, int,
+                          struct soc_camera_format_xlate *);
        int (*set_fmt)(struct soc_camera_device *, __u32, struct v4l2_rect *);
        int (*try_fmt)(struct soc_camera_device *, struct v4l2_format *);
        void (*init_videobuf)(struct videobuf_queue *,
@@ -107,6 +111,8 @@ extern void soc_camera_video_stop(struct soc_camera_device *icd);
 
 extern const struct soc_camera_data_format *soc_camera_format_by_fourcc(
        struct soc_camera_device *icd, unsigned int fourcc);
+extern const struct soc_camera_format_xlate *soc_camera_xlate_by_fourcc(
+       struct soc_camera_device *icd, unsigned int fourcc);
 
 struct soc_camera_data_format {
        const char *name;
@@ -115,6 +121,23 @@ struct soc_camera_data_format {
        enum v4l2_colorspace colorspace;
 };
 
+/**
+ * struct soc_camera_format_xlate - match between host and sensor formats
+ * @cam_fmt: sensor format provided by the sensor
+ * @host_fmt: host format after host translation from cam_fmt
+ * @buswidth: bus width for this format
+ *
+ * Host and sensor translation structure. Used in table of host and sensor
+ * formats matchings in soc_camera_device. A host can override the generic list
+ * generation by implementing get_formats(), and use it for format checks and
+ * format setup.
+ */
+struct soc_camera_format_xlate {
+       const struct soc_camera_data_format *cam_fmt;
+       const struct soc_camera_data_format *host_fmt;
+       unsigned char buswidth;
+};
+
 struct soc_camera_ops {
        struct module *owner;
        int (*probe)(struct soc_camera_device *);