V4L/DVB: sh_mobile_ceu_camera.c: preserve output window on VIDIOC_S_CROP

Current version of sh_mobile_ceu_camera.c interprets the V4L2 API specification
of the VIDIOC_S_CROP ioctl as "change input (for capture devices) area,
preserve scaling factors, therefore change output window," whereas a more
intuitive interpretation of the API is "change input area, preserve output
window." Switch sh_mobile_ceu_camera.c to use this interpretation.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 309 insertions, 292 deletions

diff --git a/drivers/media/video/sh_mobile_ceu_camera.c b/drivers/media/video/sh_mobile_ceu_camera.c
index 9a46f0a0c1bb..4ac3b482fbb4 100644
--- a/drivers/media/video/sh_mobile_ceu_camera.c
+++ b/drivers/media/video/sh_mobile_ceu_camera.c
@@ -115,9 +115,20 @@ struct sh_mobile_ceu_dev {
 };
 
 struct sh_mobile_ceu_cam {
-        struct v4l2_rect ceu_rect;
-        unsigned int cam_width;
-        unsigned int cam_height;
+        /* CEU offsets within scaled by the CEU camera output */
+        unsigned int ceu_left;
+        unsigned int ceu_top;
+        /* Client output, as seen by the CEU */
+        unsigned int width;
+        unsigned int height;
+        /*
+         * User window from S_CROP / G_CROP, produced by client cropping and
+         * scaling, CEU scaling and CEU cropping, mapped back onto the client
+         * input window
+         */
+        struct v4l2_rect subrect;
+        /* Camera cropping rectangle */
+        struct v4l2_rect rect;
         const struct soc_mbus_pixelfmt *extra_fmt;
         enum v4l2_mbus_pixelcode code;
 };
@@ -565,38 +576,36 @@ static u16 calc_scale(unsigned int src, unsigned int *dst)
 }
 
 /* rect is guaranteed to not exceed the scaled camera rectangle */
-static void sh_mobile_ceu_set_rect(struct soc_camera_device *icd,
-                                   unsigned int out_width,
-                                   unsigned int out_height)
+static void sh_mobile_ceu_set_rect(struct soc_camera_device *icd)
 {
         struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
         struct sh_mobile_ceu_cam *cam = icd->host_priv;
-        struct v4l2_rect *rect = &cam->ceu_rect;
         struct sh_mobile_ceu_dev *pcdev = ici->priv;
         unsigned int height, width, cdwdr_width, in_width, in_height;
         unsigned int left_offset, top_offset;
         u32 camor;
 
-        dev_dbg(icd->dev.parent, "Crop %ux%u@%u:%u\n",
-                rect->width, rect->height, rect->left, rect->top);
+        dev_geo(icd->dev.parent, "Crop %ux%u@%u:%u\n",
+                icd->user_width, icd->user_height, cam->ceu_left, cam->ceu_top);
 
-        left_offset     = rect->left;
-        top_offset      = rect->top;
+        left_offset     = cam->ceu_left;
+        top_offset      = cam->ceu_top;
 
+        /* CEU cropping (CFSZR) is applied _after_ the scaling filter (CFLCR) */
         if (pcdev->image_mode) {
-                in_width = rect->width;
+                in_width = cam->width;
                 if (!pcdev->is_16bit) {
                         in_width *= 2;
                         left_offset *= 2;
                 }
-                width = out_width;
-                cdwdr_width = out_width;
+                width = icd->user_width;
+                cdwdr_width = icd->user_width;
         } else {
-                int bytes_per_line = soc_mbus_bytes_per_line(out_width,
+                int bytes_per_line = soc_mbus_bytes_per_line(icd->user_width,
                                                 icd->current_fmt->host_fmt);
                 unsigned int w_factor;
 
-                width = out_width;
+                width = icd->user_width;
 
                 switch (icd->current_fmt->host_fmt->packing) {
                 case SOC_MBUS_PACKING_2X8_PADHI:
@@ -606,17 +615,17 @@ static void sh_mobile_ceu_set_rect(struct soc_camera_device *icd,
                         w_factor = 1;
                 }
 
-                in_width = rect->width * w_factor;
+                in_width = cam->width * w_factor;
                 left_offset = left_offset * w_factor;
 
                 if (bytes_per_line < 0)
-                        cdwdr_width = out_width;
+                        cdwdr_width = icd->user_width;
                 else
                         cdwdr_width = bytes_per_line;
         }
 
-        height = out_height;
-        in_height = rect->height;
+        height = icd->user_height;
+        in_height = cam->height;
         if (V4L2_FIELD_NONE != pcdev->field) {
                 height /= 2;
                 in_height /= 2;
@@ -775,9 +784,10 @@ static int sh_mobile_ceu_set_bus_param(struct soc_camera_device *icd,
         }
         ceu_write(pcdev, CAIFR, value);
 
-        sh_mobile_ceu_set_rect(icd, icd->user_width, icd->user_height);
+        sh_mobile_ceu_set_rect(icd);
         mdelay(1);
 
+        dev_geo(icd->dev.parent, "CFLCR 0x%x\n", pcdev->cflcr);
         ceu_write(pcdev, CFLCR, pcdev->cflcr);
 
         /*
@@ -866,6 +876,8 @@ static bool sh_mobile_ceu_packing_supported(const struct soc_mbus_pixelfmt *fmt)
                  fmt->packing == SOC_MBUS_PACKING_EXTEND16);
 }
 
+static int client_g_rect(struct v4l2_subdev *sd, struct v4l2_rect *rect);
+
 static int sh_mobile_ceu_get_formats(struct soc_camera_device *icd, int idx,
                                      struct soc_camera_format_xlate *xlate)
 {
@@ -894,10 +906,55 @@ static int sh_mobile_ceu_get_formats(struct soc_camera_device *icd, int idx,
                 return 0;
 
         if (!icd->host_priv) {
+                struct v4l2_mbus_framefmt mf;
+                struct v4l2_rect rect;
+                struct device *dev = icd->dev.parent;
+                int shift = 0;
+
+                /* FIXME: subwindow is lost between close / open */
+
+                /* Cache current client geometry */
+                ret = client_g_rect(sd, &rect);
+                if (ret < 0)
+                        return ret;
+
+                /* First time */
+                ret = v4l2_subdev_call(sd, video, g_mbus_fmt, &mf);
+                if (ret < 0)
+                        return ret;
+
+                while ((mf.width > 2560 || mf.height > 1920) && shift < 4) {
+                        /* Try 2560x1920, 1280x960, 640x480, 320x240 */
+                        mf.width        = 2560 >> shift;
+                        mf.height       = 1920 >> shift;
+                        ret = v4l2_subdev_call(sd, video, s_mbus_fmt, &mf);
+                        if (ret < 0)
+                                return ret;
+                        shift++;
+                }
+
+                if (shift == 4) {
+                        dev_err(dev, "Failed to configure the client below %ux%x\n",
+                                mf.width, mf.height);
+                        return -EIO;
+                }
+
+                dev_geo(dev, "camera fmt %ux%u\n", mf.width, mf.height);
+
                 cam = kzalloc(sizeof(*cam), GFP_KERNEL);
                 if (!cam)
                         return -ENOMEM;
 
+                /* We are called with current camera crop, initialise subrect with it */
+                cam->rect       = rect;
+                cam->subrect    = rect;
+
+                cam->width      = mf.width;
+                cam->height     = mf.height;
+
+                cam->width      = mf.width;
+                cam->height     = mf.height;
+
                 icd->host_priv = cam;
         } else {
                 cam = icd->host_priv;
@@ -979,16 +1036,12 @@ static unsigned int scale_down(unsigned int size, unsigned int scale)
         return (size * 4096 + scale / 2) / scale;
 }
 
-static unsigned int scale_up(unsigned int size, unsigned int scale)
-{
-        return (size * scale + 2048) / 4096;
-}
-
 static unsigned int calc_generic_scale(unsigned int input, unsigned int output)
 {
         return (input * 4096 + output / 2) / output;
 }
 
+/* Get and store current client crop */
 static int client_g_rect(struct v4l2_subdev *sd, struct v4l2_rect *rect)
 {
         struct v4l2_crop crop;
@@ -1007,25 +1060,51 @@ static int client_g_rect(struct v4l2_subdev *sd, struct v4l2_rect *rect)
         cap.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 
         ret = v4l2_subdev_call(sd, video, cropcap, &cap);
-        if (ret < 0)
-                return ret;
-
-        *rect = cap.defrect;
+        if (!ret)
+                *rect = cap.defrect;
 
         return ret;
 }
 
+/* Client crop has changed, update our sub-rectangle to remain within the area */
+static void update_subrect(struct sh_mobile_ceu_cam *cam)
+{
+        struct v4l2_rect *rect = &cam->rect, *subrect = &cam->subrect;
+
+        if (rect->width < subrect->width)
+                subrect->width = rect->width;
+
+        if (rect->height < subrect->height)
+                subrect->height = rect->height;
+
+        if (rect->left > subrect->left)
+                subrect->left = rect->left;
+        else if (rect->left + rect->width >
+                 subrect->left + subrect->width)
+                subrect->left = rect->left + rect->width -
+                        subrect->width;
+
+        if (rect->top > subrect->top)
+                subrect->top = rect->top;
+        else if (rect->top + rect->height >
+                 subrect->top + subrect->height)
+                subrect->top = rect->top + rect->height -
+                        subrect->height;
+}
+
 /*
  * The common for both scaling and cropping iterative approach is:
  * 1. try if the client can produce exactly what requested by the user
  * 2. if (1) failed, try to double the client image until we get one big enough
  * 3. if (2) failed, try to request the maximum image
  */
-static int client_s_crop(struct v4l2_subdev *sd, struct v4l2_crop *crop,
+static int client_s_crop(struct soc_camera_device *icd, struct v4l2_crop *crop,
                          struct v4l2_crop *cam_crop)
 {
+        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
         struct v4l2_rect *rect = &crop->c, *cam_rect = &cam_crop->c;
         struct device *dev = sd->v4l2_dev->dev;
+        struct sh_mobile_ceu_cam *cam = icd->host_priv;
         struct v4l2_cropcap cap;
         int ret;
         unsigned int width, height;
@@ -1043,6 +1122,7 @@ static int client_s_crop(struct v4l2_subdev *sd, struct v4l2_crop *crop,
                 /* Even if camera S_CROP failed, but camera rectangle matches */
                 dev_dbg(dev, "Camera S_CROP successful for %dx%d@%d:%d\n",
                         rect->width, rect->height, rect->left, rect->top);
+                cam->rect = *cam_rect;
                 return 0;
         }
 
@@ -1057,6 +1137,7 @@ static int client_s_crop(struct v4l2_subdev *sd, struct v4l2_crop *crop,
         if (ret < 0)
                 return ret;
 
+        /* Put user requested rectangle within sensor bounds */
         soc_camera_limit_side(&rect->left, &rect->width, cap.bounds.left, 2,
                               cap.bounds.width);
         soc_camera_limit_side(&rect->top, &rect->height, cap.bounds.top, 4,
@@ -1069,6 +1150,10 @@ static int client_s_crop(struct v4l2_subdev *sd, struct v4l2_crop *crop,
         width = max(cam_rect->width, 2);
         height = max(cam_rect->height, 2);
 
+        /*
+         * Loop as long as sensor is not covering the requested rectangle and
+         * is still within its bounds
+         */
         while (!ret && (is_smaller(cam_rect, rect) ||
                         is_inside(cam_rect, rect)) &&
                (cap.bounds.width > width || cap.bounds.height > height)) {
@@ -1086,6 +1171,7 @@ static int client_s_crop(struct v4l2_subdev *sd, struct v4l2_crop *crop,
                  * target left, set it to the middle point between the current
                  * left and minimum left. But that would add too much
                  * complexity: we would have to iterate each border separately.
+                 * Instead we just drop to the left and top bounds.
                  */
                 if (cam_rect->left > rect->left)
                         cam_rect->left = cap.bounds.left;
@@ -1122,77 +1208,19 @@ static int client_s_crop(struct v4l2_subdev *sd, struct v4l2_crop *crop,
                         cam_rect->left, cam_rect->top);
         }
 
-        return ret;
-}
-
-static int get_camera_scales(struct v4l2_subdev *sd, struct v4l2_rect *rect,
-                             unsigned int *scale_h, unsigned int *scale_v)
-{
-        struct v4l2_mbus_framefmt mf;
-        int ret;
-
-        ret = v4l2_subdev_call(sd, video, g_mbus_fmt, &mf);
-        if (ret < 0)
-                return ret;
-
-        *scale_h = calc_generic_scale(rect->width, mf.width);
-        *scale_v = calc_generic_scale(rect->height, mf.height);
-
-        return 0;
-}
-
-static int get_camera_subwin(struct soc_camera_device *icd,
-                             struct v4l2_rect *cam_subrect,
-                             unsigned int cam_hscale, unsigned int cam_vscale)
-{
-        struct sh_mobile_ceu_cam *cam = icd->host_priv;
-        struct v4l2_rect *ceu_rect = &cam->ceu_rect;
-
-        if (!ceu_rect->width) {
-                struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
-                struct device *dev = icd->dev.parent;
-                struct v4l2_mbus_framefmt mf;
-                int ret;
-                /* First time */
-
-                ret = v4l2_subdev_call(sd, video, g_mbus_fmt, &mf);
-                if (ret < 0)
-                        return ret;
-
-                dev_geo(dev, "camera fmt %ux%u\n", mf.width, mf.height);
-
-                if (mf.width > 2560) {
-                        ceu_rect->width  = 2560;
-                        ceu_rect->left   = (mf.width - 2560) / 2;
-                } else {
-                        ceu_rect->width  = mf.width;
-                        ceu_rect->left   = 0;
-                }
-
-                if (mf.height > 1920) {
-                        ceu_rect->height = 1920;
-                        ceu_rect->top    = (mf.height - 1920) / 2;
-                } else {
-                        ceu_rect->height = mf.height;
-                        ceu_rect->top    = 0;
-                }
-
-                dev_geo(dev, "initialised CEU rect %ux%u@%u:%u\n",
-                        ceu_rect->width, ceu_rect->height,
-                        ceu_rect->left, ceu_rect->top);
+        if (!ret) {
+                cam->rect = *cam_rect;
+                update_subrect(cam);
         }
 
-        cam_subrect->width      = scale_up(ceu_rect->width, cam_hscale);
-        cam_subrect->left       = scale_up(ceu_rect->left, cam_hscale);
-        cam_subrect->height     = scale_up(ceu_rect->height, cam_vscale);
-        cam_subrect->top        = scale_up(ceu_rect->top, cam_vscale);
-
-        return 0;
+        return ret;
 }
 
+/* Iterative s_mbus_fmt, also updates cached client crop on success */
 static int client_s_fmt(struct soc_camera_device *icd,
                         struct v4l2_mbus_framefmt *mf, bool ceu_can_scale)
 {
+        struct sh_mobile_ceu_cam *cam = icd->host_priv;
         struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
         struct device *dev = icd->dev.parent;
         unsigned int width = mf->width, height = mf->height, tmp_w, tmp_h;
@@ -1200,6 +1228,15 @@ static int client_s_fmt(struct soc_camera_device *icd,
         struct v4l2_cropcap cap;
         int ret;
 
+        ret = v4l2_subdev_call(sd, video, s_mbus_fmt, mf);
+        if (ret < 0)
+                return ret;
+
+        dev_geo(dev, "camera scaled to %ux%u\n", mf->width, mf->height);
+
+        if ((width == mf->width && height == mf->height) || !ceu_can_scale)
+                goto update_cache;
+
         cap.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 
         ret = v4l2_subdev_call(sd, video, cropcap, &cap);
@@ -1209,15 +1246,6 @@ static int client_s_fmt(struct soc_camera_device *icd,
         max_width = min(cap.bounds.width, 2560);
         max_height = min(cap.bounds.height, 1920);
 
-        ret = v4l2_subdev_call(sd, video, s_mbus_fmt, mf);
-        if (ret < 0)
-                return ret;
-
-        dev_geo(dev, "camera scaled to %ux%u\n", mf->width, mf->height);
-
-        if ((width == mf->width && height == mf->height) || !ceu_can_scale)
-                return 0;
-
         /* Camera set a format, but geometry is not precise, try to improve */
         tmp_w = mf->width;
         tmp_h = mf->height;
@@ -1239,26 +1267,37 @@ static int client_s_fmt(struct soc_camera_device *icd,
                 }
         }
 
+update_cache:
+        /* Update cache */
+        ret = client_g_rect(sd, &cam->rect);
+        if (ret < 0)
+                return ret;
+
+        update_subrect(cam);
+
         return 0;
 }
 
 /**
- * @rect        - camera cropped rectangle
- * @sub_rect    - CEU cropped rectangle, mapped back to camera input area
- * @ceu_rect    - on output calculated CEU crop rectangle
+ * @width       - on output: user width, mapped back to input
+ * @height      - on output: user height, mapped back to input
+ * @mf          - in- / output camera output window
  */
-static int client_scale(struct soc_camera_device *icd, struct v4l2_rect *rect,
-                        struct v4l2_rect *sub_rect, struct v4l2_rect *ceu_rect,
-                        struct v4l2_mbus_framefmt *mf, bool ceu_can_scale)
+static int client_scale(struct soc_camera_device *icd,
+                        struct v4l2_mbus_framefmt *mf,
+                        unsigned int *width, unsigned int *height,
+                        bool ceu_can_scale)
 {
-        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
         struct sh_mobile_ceu_cam *cam = icd->host_priv;
         struct device *dev = icd->dev.parent;
         struct v4l2_mbus_framefmt mf_tmp = *mf;
         unsigned int scale_h, scale_v;
         int ret;
 
-        /* 5. Apply iterative camera S_FMT for camera user window. */
+        /*
+         * 5. Apply iterative camera S_FMT for camera user window (also updates
+         *    client crop cache and the imaginary sub-rectangle).
+         */
         ret = client_s_fmt(icd, &mf_tmp, ceu_can_scale);
         if (ret < 0)
                 return ret;
@@ -1270,60 +1309,22 @@ static int client_scale(struct soc_camera_device *icd, struct v4l2_rect *rect,
 
         /* unneeded - it is already in "mf_tmp" */
 
-        /* 7. Calculate new camera scales. */
-        ret = get_camera_scales(sd, rect, &scale_h, &scale_v);
-        if (ret < 0)
-                return ret;
-
-        dev_geo(dev, "7: camera scales %u:%u\n", scale_h, scale_v);
+        /* 7. Calculate new client scales. */
+        scale_h = calc_generic_scale(cam->rect.width, mf_tmp.width);
+        scale_v = calc_generic_scale(cam->rect.height, mf_tmp.height);
 
-        cam->cam_width  = mf_tmp.width;
-        cam->cam_height = mf_tmp.height;
         mf->width       = mf_tmp.width;
         mf->height      = mf_tmp.height;
         mf->colorspace  = mf_tmp.colorspace;
 
         /*
          * 8. Calculate new CEU crop - apply camera scales to previously
-         *    calculated "effective" crop.
+         *    updated "effective" crop.
          */
-        ceu_rect->left = scale_down(sub_rect->left, scale_h);
-        ceu_rect->width = scale_down(sub_rect->width, scale_h);
-        ceu_rect->top = scale_down(sub_rect->top, scale_v);
-        ceu_rect->height = scale_down(sub_rect->height, scale_v);
+        *width = scale_down(cam->subrect.width, scale_h);
+        *height = scale_down(cam->subrect.height, scale_v);
 
-        dev_geo(dev, "8: new CEU rect %ux%u@%u:%u\n",
-                ceu_rect->width, ceu_rect->height,
-                ceu_rect->left, ceu_rect->top);
-
-        return 0;
-}
-
-/* Get combined scales */
-static int get_scales(struct soc_camera_device *icd,
-                      unsigned int *scale_h, unsigned int *scale_v)
-{
-        struct sh_mobile_ceu_cam *cam = icd->host_priv;
-        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
-        struct v4l2_crop cam_crop;
-        unsigned int width_in, height_in;
-        int ret;
-
-        cam_crop.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
-
-        ret = client_g_rect(sd, &cam_crop.c);
-        if (ret < 0)
-                return ret;
-
-        ret = get_camera_scales(sd, &cam_crop.c, scale_h, scale_v);
-        if (ret < 0)
-                return ret;
-
-        width_in = scale_up(cam->ceu_rect.width, *scale_h);
-        height_in = scale_up(cam->ceu_rect.height, *scale_v);
-
-        *scale_h = calc_generic_scale(width_in, icd->user_width);
-        *scale_v = calc_generic_scale(height_in, icd->user_height);
+        dev_geo(dev, "8: new client sub-window %ux%u\n", *width, *height);
 
         return 0;
 }
@@ -1342,115 +1343,165 @@ static int sh_mobile_ceu_set_crop(struct soc_camera_device *icd,
         struct sh_mobile_ceu_dev *pcdev = ici->priv;
         struct v4l2_crop cam_crop;
         struct sh_mobile_ceu_cam *cam = icd->host_priv;
-        struct v4l2_rect *cam_rect = &cam_crop.c, *ceu_rect = &cam->ceu_rect;
+        struct v4l2_rect *cam_rect = &cam_crop.c;
         struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
         struct device *dev = icd->dev.parent;
         struct v4l2_mbus_framefmt mf;
-        unsigned int scale_comb_h, scale_comb_v, scale_ceu_h, scale_ceu_v,
-                out_width, out_height;
+        unsigned int scale_cam_h, scale_cam_v, scale_ceu_h, scale_ceu_v,
+                out_width, out_height, scale_h, scale_v;
+        int interm_width, interm_height;
         u32 capsr, cflcr;
         int ret;
 
-        /* 1. Calculate current combined scales. */
-        ret = get_scales(icd, &scale_comb_h, &scale_comb_v);
-        if (ret < 0)
-                return ret;
+        dev_geo(dev, "S_CROP(%ux%u@%u:%u)\n", rect->width, rect->height,
+                rect->left, rect->top);
 
-        dev_geo(dev, "1: combined scales %u:%u\n", scale_comb_h, scale_comb_v);
+        /* During camera cropping its output window can change too, stop CEU */
+        capsr = capture_save_reset(pcdev);
+        dev_dbg(dev, "CAPSR 0x%x, CFLCR 0x%x\n", capsr, pcdev->cflcr);
 
-        /* 2. Apply iterative camera S_CROP for new input window. */
-        ret = client_s_crop(sd, a, &cam_crop);
+        /* 1. - 2. Apply iterative camera S_CROP for new input window. */
+        ret = client_s_crop(icd, a, &cam_crop);
         if (ret < 0)
                 return ret;
 
-        dev_geo(dev, "2: camera cropped to %ux%u@%u:%u\n",
+        dev_geo(dev, "1-2: camera cropped to %ux%u@%u:%u\n",
                 cam_rect->width, cam_rect->height,
                 cam_rect->left, cam_rect->top);
 
         /* On success cam_crop contains current camera crop */
 
-        /*
-         * 3. If old combined scales applied to new crop produce an impossible
-         *    user window, adjust scales to produce nearest possible window.
-         */
-        out_width       = scale_down(rect->width, scale_comb_h);
-        out_height      = scale_down(rect->height, scale_comb_v);
-
-        if (out_width > 2560)
-                out_width = 2560;
-        else if (out_width < 2)
-                out_width = 2;
-
-        if (out_height > 1920)
-                out_height = 1920;
-        else if (out_height < 4)
-                out_height = 4;
-
-        dev_geo(dev, "3: Adjusted output %ux%u\n", out_width, out_height);
-
-        /* 4. Use G_CROP to retrieve actual input window: already in cam_crop */
-
-        /*
-         * 5. Using actual input window and calculated combined scales calculate
-         *    camera target output window.
-         */
-        mf.width        = scale_down(cam_rect->width, scale_comb_h);
-        mf.height       = scale_down(cam_rect->height, scale_comb_v);
-
-        dev_geo(dev, "5: camera target %ux%u\n", mf.width, mf.height);
-
-        /* 6. - 9. */
-        mf.code         = cam->code;
-        mf.field        = pcdev->field;
-
-        capsr = capture_save_reset(pcdev);
-        dev_dbg(dev, "CAPSR 0x%x, CFLCR 0x%x\n", capsr, pcdev->cflcr);
+        /* 3. Retrieve camera output window */
+        ret = v4l2_subdev_call(sd, video, g_mbus_fmt, &mf);
+        if (ret < 0)
+                return ret;
 
-        /* Make relative to camera rectangle */
-        rect->left      -= cam_rect->left;
-        rect->top       -= cam_rect->top;
+        if (mf.width > 2560 || mf.height > 1920)
+                return -EINVAL;
 
-        ret = client_scale(icd, cam_rect, rect, ceu_rect, &mf,
-                           pcdev->image_mode &&
-                           V4L2_FIELD_NONE == pcdev->field);
+        /* Cache camera output window */
+        cam->width      = mf.width;
+        cam->height     = mf.height;
 
-        dev_geo(dev, "6-9: %d\n", ret);
+        /* 4. Calculate camera scales */
+        scale_cam_h     = calc_generic_scale(cam_rect->width, mf.width);
+        scale_cam_v     = calc_generic_scale(cam_rect->height, mf.height);
 
-        /* 10. Use CEU cropping to crop to the new window. */
-        sh_mobile_ceu_set_rect(icd, out_width, out_height);
+        /* Calculate intermediate window */
+        interm_width    = scale_down(rect->width, scale_cam_h);
+        interm_height   = scale_down(rect->height, scale_cam_v);
 
-        dev_geo(dev, "10: CEU cropped to %ux%u@%u:%u\n",
-                ceu_rect->width, ceu_rect->height,
-                ceu_rect->left, ceu_rect->top);
+        if (pcdev->image_mode) {
+                out_width       = min(interm_width, icd->user_width);
+                out_height      = min(interm_height, icd->user_height);
+        } else {
+                out_width       = interm_width;
+                out_height      = interm_height;
+        }
 
         /*
-         * 11. Calculate CEU scales from camera scales from results of (10) and
-         *     user window from (3)
+         * 5. Calculate CEU scales from camera scales from results of (5) and
+         *    the user window
          */
-        scale_ceu_h = calc_scale(ceu_rect->width, &out_width);
-        scale_ceu_v = calc_scale(ceu_rect->height, &out_height);
+        scale_ceu_h     = calc_scale(interm_width, &out_width);
+        scale_ceu_v     = calc_scale(interm_height, &out_height);
 
-        dev_geo(dev, "11: CEU scales %u:%u\n", scale_ceu_h, scale_ceu_v);
+        /* Calculate camera scales */
+        scale_h         = calc_generic_scale(cam_rect->width, out_width);
+        scale_v         = calc_generic_scale(cam_rect->height, out_height);
 
-        /* 12. Apply CEU scales. */
+        dev_geo(dev, "5: CEU scales %u:%u\n", scale_ceu_h, scale_ceu_v);
+
+        /* Apply CEU scales. */
         cflcr = scale_ceu_h | (scale_ceu_v << 16);
         if (cflcr != pcdev->cflcr) {
                 pcdev->cflcr = cflcr;
                 ceu_write(pcdev, CFLCR, cflcr);
         }
 
+        icd->user_width  = out_width;
+        icd->user_height = out_height;
+        cam->ceu_left    = scale_down(rect->left - cam_rect->left, scale_h) & ~1;
+        cam->ceu_top     = scale_down(rect->top - cam_rect->top, scale_v) & ~1;
+
+        /* 6. Use CEU cropping to crop to the new window. */
+        sh_mobile_ceu_set_rect(icd);
+
+        cam->subrect = *rect;
+
+        dev_geo(dev, "6: CEU cropped to %ux%u@%u:%u\n",
+                icd->user_width, icd->user_height,
+                cam->ceu_left, cam->ceu_top);
+
         /* Restore capture */
         if (pcdev->active)
                 capsr |= 1;
         capture_restore(pcdev, capsr);
 
-        icd->user_width = out_width;
-        icd->user_height = out_height;
-
         /* Even if only camera cropping succeeded */
         return ret;
 }
 
+static int sh_mobile_ceu_get_crop(struct soc_camera_device *icd,
+                                  struct v4l2_crop *a)
+{
+        struct sh_mobile_ceu_cam *cam = icd->host_priv;
+
+        a->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+        a->c = cam->subrect;
+
+        return 0;
+}
+
+/*
+ * Calculate real client output window by applying new scales to the current
+ * client crop. New scales are calculated from the requested output format and
+ * CEU crop, mapped backed onto the client input (subrect).
+ */
+static void calculate_client_output(struct soc_camera_device *icd,
+                struct v4l2_pix_format *pix, struct v4l2_mbus_framefmt *mf)
+{
+        struct sh_mobile_ceu_cam *cam = icd->host_priv;
+        struct device *dev = icd->dev.parent;
+        struct v4l2_rect *cam_subrect = &cam->subrect;
+        unsigned int scale_v, scale_h;
+
+        if (cam_subrect->width == cam->rect.width &&
+            cam_subrect->height == cam->rect.height) {
+                /* No sub-cropping */
+                mf->width       = pix->width;
+                mf->height      = pix->height;
+                return;
+        }
+
+        /* 1.-2. Current camera scales and subwin - cached. */
+
+        dev_geo(dev, "2: subwin %ux%u@%u:%u\n",
+                cam_subrect->width, cam_subrect->height,
+                cam_subrect->left, cam_subrect->top);
+
+        /*
+         * 3. Calculate new combined scales from input sub-window to requested
+         *    user window.
+         */
+
+        /*
+         * TODO: CEU cannot scale images larger than VGA to smaller than SubQCIF
+         * (128x96) or larger than VGA
+         */
+        scale_h = calc_generic_scale(cam_subrect->width, pix->width);
+        scale_v = calc_generic_scale(cam_subrect->height, pix->height);
+
+        dev_geo(dev, "3: scales %u:%u\n", scale_h, scale_v);
+
+        /*
+         * 4. Calculate client output window by applying combined scales to real
+         *    input window.
+         */
+        mf->width       = scale_down(cam->rect.width, scale_h);
+        mf->height      = scale_down(cam->rect.height, scale_v);
+}
+
 /* Similar to set_crop multistage iterative algorithm */
 static int sh_mobile_ceu_set_fmt(struct soc_camera_device *icd,
                                  struct v4l2_format *f)
@@ -1460,18 +1511,17 @@ static int sh_mobile_ceu_set_fmt(struct soc_camera_device *icd,
         struct sh_mobile_ceu_cam *cam = icd->host_priv;
         struct v4l2_pix_format *pix = &f->fmt.pix;
         struct v4l2_mbus_framefmt mf;
-        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
         struct device *dev = icd->dev.parent;
         __u32 pixfmt = pix->pixelformat;
         const struct soc_camera_format_xlate *xlate;
-        struct v4l2_crop cam_crop;
-        struct v4l2_rect *cam_rect = &cam_crop.c, cam_subrect, ceu_rect;
-        unsigned int scale_cam_h, scale_cam_v;
+        unsigned int ceu_sub_width, ceu_sub_height;
         u16 scale_v, scale_h;
         int ret;
         bool image_mode;
         enum v4l2_field field;
 
+        dev_geo(dev, "S_FMT(pix=0x%x, %ux%u)\n", pixfmt, pix->width, pix->height);
+
         switch (pix->field) {
         default:
                 pix->field = V4L2_FIELD_NONE;
@@ -1492,46 +1542,8 @@ static int sh_mobile_ceu_set_fmt(struct soc_camera_device *icd,
                 return -EINVAL;
         }
 
-        /* 1. Calculate current camera scales. */
-        cam_crop.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
-
-        ret = client_g_rect(sd, cam_rect);
-        if (ret < 0)
-                return ret;
-
-        ret = get_camera_scales(sd, cam_rect, &scale_cam_h, &scale_cam_v);
-        if (ret < 0)
-                return ret;
-
-        dev_geo(dev, "1: camera scales %u:%u\n", scale_cam_h, scale_cam_v);
-
-        /*
-         * 2. Calculate "effective" input crop (sensor subwindow) - CEU crop
-         *    scaled back at current camera scales onto input window.
-         */
-        ret = get_camera_subwin(icd, &cam_subrect, scale_cam_h, scale_cam_v);
-        if (ret < 0)
-                return ret;
-
-        dev_geo(dev, "2: subwin %ux%u@%u:%u\n",
-                cam_subrect.width, cam_subrect.height,
-                cam_subrect.left, cam_subrect.top);
-
-        /*
-         * 3. Calculate new combined scales from "effective" input window to
-         *    requested user window.
-         */
-        scale_h = calc_generic_scale(cam_subrect.width, pix->width);
-        scale_v = calc_generic_scale(cam_subrect.height, pix->height);
-
-        dev_geo(dev, "3: scales %u:%u\n", scale_h, scale_v);
-
-        /*
-         * 4. Calculate camera output window by applying combined scales to real
-         *    input window.
-         */
-        mf.width        = scale_down(cam_rect->width, scale_h);
-        mf.height       = scale_down(cam_rect->height, scale_v);
+        /* 1.-4. Calculate client output geometry */
+        calculate_client_output(icd, &f->fmt.pix, &mf);
         mf.field        = pix->field;
         mf.colorspace   = pix->colorspace;
         mf.code         = xlate->code;
@@ -1547,17 +1559,17 @@ static int sh_mobile_ceu_set_fmt(struct soc_camera_device *icd,
                 image_mode = false;
         }
 
-        dev_geo(dev, "4: camera output %ux%u\n", mf.width, mf.height);
+        dev_geo(dev, "4: request camera output %ux%u\n", mf.width, mf.height);
 
         /* 5. - 9. */
-        ret = client_scale(icd, cam_rect, &cam_subrect, &ceu_rect, &mf,
+        ret = client_scale(icd, &mf, &ceu_sub_width, &ceu_sub_height,
                            image_mode && V4L2_FIELD_NONE == field);
 
-        dev_geo(dev, "5-9: client scale %d\n", ret);
+        dev_geo(dev, "5-9: client scale return %d\n", ret);
 
         /* Done with the camera. Now see if we can improve the result */
 
-        dev_dbg(dev, "Camera %d fmt %ux%u, requested %ux%u\n",
+        dev_geo(dev, "Camera %d fmt %ux%u, requested %ux%u\n",
                 ret, mf.width, mf.height, pix->width, pix->height);
         if (ret < 0)
                 return ret;
@@ -1565,40 +1577,44 @@ static int sh_mobile_ceu_set_fmt(struct soc_camera_device *icd,
         if (mf.code != xlate->code)
                 return -EINVAL;
 
+        /* 9. Prepare CEU crop */
+        cam->width = mf.width;
+        cam->height = mf.height;
+
         /* 10. Use CEU scaling to scale to the requested user window. */
 
         /* We cannot scale up */
-        if (pix->width > mf.width)
-                pix->width = mf.width;
-        if (pix->width > ceu_rect.width)
-                pix->width = ceu_rect.width;
+        if (pix->width > ceu_sub_width)
+                ceu_sub_width = pix->width;
 
-        if (pix->height > mf.height)
-                pix->height = mf.height;
-        if (pix->height > ceu_rect.height)
-                pix->height = ceu_rect.height;
+        if (pix->height > ceu_sub_height)
+                ceu_sub_height = pix->height;
 
         pix->colorspace = mf.colorspace;
 
         if (image_mode) {
                 /* Scale pix->{width x height} down to width x height */
-                scale_h = calc_scale(ceu_rect.width, &pix->width);
-                scale_v = calc_scale(ceu_rect.height, &pix->height);
-
-                pcdev->cflcr = scale_h | (scale_v << 16);
+                scale_h         = calc_scale(ceu_sub_width, &pix->width);
+                scale_v         = calc_scale(ceu_sub_height, &pix->height);
         } else {
-                pix->width = ceu_rect.width;
-                pix->height = ceu_rect.height;
-                scale_h = scale_v = 0;
-                pcdev->cflcr = 0;
+                pix->width      = ceu_sub_width;
+                pix->height     = ceu_sub_height;
+                scale_h         = 0;
+                scale_v         = 0;
         }
 
+        pcdev->cflcr = scale_h | (scale_v << 16);
+
+        /*
+         * We have calculated CFLCR, the actual configuration will be performed
+         * in sh_mobile_ceu_set_bus_param()
+         */
+
         dev_geo(dev, "10: W: %u : 0x%x = %u, H: %u : 0x%x = %u\n",
-                ceu_rect.width, scale_h, pix->width,
-                ceu_rect.height, scale_v, pix->height);
+                ceu_sub_width, scale_h, pix->width,
+                ceu_sub_height, scale_v, pix->height);
 
         cam->code               = xlate->code;
-        cam->ceu_rect           = ceu_rect;
         icd->current_fmt        = xlate;
 
         pcdev->field = field;
@@ -1820,6 +1836,7 @@ static struct soc_camera_host_ops sh_mobile_ceu_host_ops = {
         .remove         = sh_mobile_ceu_remove_device,
         .get_formats    = sh_mobile_ceu_get_formats,
         .put_formats    = sh_mobile_ceu_put_formats,
+        .get_crop       = sh_mobile_ceu_get_crop,
         .set_crop       = sh_mobile_ceu_set_crop,
         .set_fmt        = sh_mobile_ceu_set_fmt,
         .try_fmt        = sh_mobile_ceu_try_fmt,