V4L/DVB (12534): soc-camera: V4L2 API compliant scaling (S_FMT) and cropping (S_CROP)

The initial soc-camera scaling and cropping implementation turned out to be
incompliant with the V4L2 API, e.g., it expected the user to specify cropping
in output window pixels, instead of input window pixels. This patch converts
the soc-camera core and all drivers to comply with the standard.

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

1 files changed, 95 insertions, 17 deletions

diff --git a/drivers/media/video/mt9m111.c b/drivers/media/video/mt9m111.c
index 3637376da755..920dd53c4cfa 100644
--- a/drivers/media/video/mt9m111.c
+++ b/drivers/media/video/mt9m111.c
@@ -194,7 +194,7 @@ static int mt9m111_reg_read(struct i2c_client *client, const u16 reg)
 
         ret = reg_page_map_set(client, reg);
         if (!ret)
-                ret = swab16(i2c_smbus_read_word_data(client, (reg & 0xff)));
+                ret = swab16(i2c_smbus_read_word_data(client, reg & 0xff));
 
         dev_dbg(&client->dev, "read  reg.%03x -> %04x\n", reg, ret);
         return ret;
@@ -257,8 +257,8 @@ static int mt9m111_setup_rect(struct i2c_client *client,
         int width = rect->width;
         int height = rect->height;
 
-        if ((mt9m111->pixfmt == V4L2_PIX_FMT_SBGGR8)
-            || (mt9m111->pixfmt == V4L2_PIX_FMT_SBGGR16))
+        if (mt9m111->pixfmt == V4L2_PIX_FMT_SBGGR8 ||
+            mt9m111->pixfmt == V4L2_PIX_FMT_SBGGR16)
                 is_raw_format = 1;
         else
                 is_raw_format = 0;
@@ -395,23 +395,85 @@ static int mt9m111_set_bus_param(struct soc_camera_device *icd, unsigned long f)
         return 0;
 }
 
+static int mt9m111_make_rect(struct i2c_client *client,
+                             struct v4l2_rect *rect)
+{
+        struct mt9m111 *mt9m111 = to_mt9m111(client);
+
+        if (mt9m111->pixfmt == V4L2_PIX_FMT_SBGGR8 ||
+            mt9m111->pixfmt == V4L2_PIX_FMT_SBGGR16) {
+                /* Bayer format - even size lengths */
+                rect->width     = ALIGN(rect->width, 2);
+                rect->height    = ALIGN(rect->height, 2);
+                /* Let the user play with the starting pixel */
+        }
+
+        /* FIXME: the datasheet doesn't specify minimum sizes */
+        soc_camera_limit_side(&rect->left, &rect->width,
+                     MT9M111_MIN_DARK_COLS, 2, MT9M111_MAX_WIDTH);
+
+        soc_camera_limit_side(&rect->top, &rect->height,
+                     MT9M111_MIN_DARK_ROWS, 2, MT9M111_MAX_HEIGHT);
+
+        return mt9m111_setup_rect(client, rect);
+}
+
 static int mt9m111_s_crop(struct v4l2_subdev *sd, struct v4l2_crop *a)
 {
-        struct v4l2_rect *rect = &a->c;
+        struct v4l2_rect rect = a->c;
         struct i2c_client *client = sd->priv;
         struct mt9m111 *mt9m111 = to_mt9m111(client);
         int ret;
 
         dev_dbg(&client->dev, "%s left=%d, top=%d, width=%d, height=%d\n",
-                __func__, rect->left, rect->top, rect->width,
-                rect->height);
+                __func__, rect.left, rect.top, rect.width, rect.height);
 
-        ret = mt9m111_setup_rect(client, rect);
+        ret = mt9m111_make_rect(client, &rect);
         if (!ret)
-                mt9m111->rect = *rect;
+                mt9m111->rect = rect;
         return ret;
 }
 
+static int mt9m111_g_crop(struct v4l2_subdev *sd, struct v4l2_crop *a)
+{
+        struct i2c_client *client = sd->priv;
+        struct mt9m111 *mt9m111 = to_mt9m111(client);
+
+        a->c    = mt9m111->rect;
+        a->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+
+        return 0;
+}
+
+static int mt9m111_cropcap(struct v4l2_subdev *sd, struct v4l2_cropcap *a)
+{
+        a->bounds.left                  = MT9M111_MIN_DARK_COLS;
+        a->bounds.top                   = MT9M111_MIN_DARK_ROWS;
+        a->bounds.width                 = MT9M111_MAX_WIDTH;
+        a->bounds.height                = MT9M111_MAX_HEIGHT;
+        a->defrect                      = a->bounds;
+        a->type                         = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+        a->pixelaspect.numerator        = 1;
+        a->pixelaspect.denominator      = 1;
+
+        return 0;
+}
+
+static int mt9m111_g_fmt(struct v4l2_subdev *sd, struct v4l2_format *f)
+{
+        struct i2c_client *client = sd->priv;
+        struct mt9m111 *mt9m111 = to_mt9m111(client);
+        struct v4l2_pix_format *pix = &f->fmt.pix;
+
+        pix->width              = mt9m111->rect.width;
+        pix->height             = mt9m111->rect.height;
+        pix->pixelformat        = mt9m111->pixfmt;
+        pix->field              = V4L2_FIELD_NONE;
+        pix->colorspace         = V4L2_COLORSPACE_SRGB;
+
+        return 0;
+}
+
 static int mt9m111_set_pixfmt(struct i2c_client *client, u32 pixfmt)
 {
         struct mt9m111 *mt9m111 = to_mt9m111(client);
@@ -478,7 +540,7 @@ static int mt9m111_s_fmt(struct v4l2_subdev *sd, struct v4l2_format *f)
                 __func__, pix->pixelformat, rect.left, rect.top, rect.width,
                 rect.height);
 
-        ret = mt9m111_setup_rect(client, &rect);
+        ret = mt9m111_make_rect(client, &rect);
         if (!ret)
                 ret = mt9m111_set_pixfmt(client, pix->pixelformat);
         if (!ret)
@@ -489,11 +551,27 @@ static int mt9m111_s_fmt(struct v4l2_subdev *sd, struct v4l2_format *f)
 static int mt9m111_try_fmt(struct v4l2_subdev *sd, struct v4l2_format *f)
 {
         struct v4l2_pix_format *pix = &f->fmt.pix;
+        bool bayer = pix->pixelformat == V4L2_PIX_FMT_SBGGR8 ||
+                pix->pixelformat == V4L2_PIX_FMT_SBGGR16;
+
+        /*
+         * With Bayer format enforce even side lengths, but let the user play
+         * with the starting pixel
+         */
 
         if (pix->height > MT9M111_MAX_HEIGHT)
                 pix->height = MT9M111_MAX_HEIGHT;
+        else if (pix->height < 2)
+                pix->height = 2;
+        else if (bayer)
+                pix->height = ALIGN(pix->height, 2);
+
         if (pix->width > MT9M111_MAX_WIDTH)
                 pix->width = MT9M111_MAX_WIDTH;
+        else if (pix->width < 2)
+                pix->width = 2;
+        else if (bayer)
+                pix->width = ALIGN(pix->width, 2);
 
         return 0;
 }
@@ -906,8 +984,11 @@ static struct v4l2_subdev_core_ops mt9m111_subdev_core_ops = {
 
 static struct v4l2_subdev_video_ops mt9m111_subdev_video_ops = {
         .s_fmt          = mt9m111_s_fmt,
+        .g_fmt          = mt9m111_g_fmt,
         .try_fmt        = mt9m111_try_fmt,
         .s_crop         = mt9m111_s_crop,
+        .g_crop         = mt9m111_g_crop,
+        .cropcap        = mt9m111_cropcap,
 };
 
 static struct v4l2_subdev_ops mt9m111_subdev_ops = {
@@ -949,16 +1030,13 @@ static int mt9m111_probe(struct i2c_client *client,
 
         /* Second stage probe - when a capture adapter is there */
         icd->ops                = &mt9m111_ops;
-        icd->rect_max.left      = MT9M111_MIN_DARK_COLS;
-        icd->rect_max.top       = MT9M111_MIN_DARK_ROWS;
-        icd->rect_max.width     = MT9M111_MAX_WIDTH;
-        icd->rect_max.height    = MT9M111_MAX_HEIGHT;
-        icd->rect_current.left  = icd->rect_max.left;
-        icd->rect_current.top   = icd->rect_max.top;
-        icd->width_min          = MT9M111_MIN_DARK_ROWS;
-        icd->height_min         = MT9M111_MIN_DARK_COLS;
         icd->y_skip_top         = 0;
 
+        mt9m111->rect.left      = MT9M111_MIN_DARK_COLS;
+        mt9m111->rect.top       = MT9M111_MIN_DARK_ROWS;
+        mt9m111->rect.width     = MT9M111_MAX_WIDTH;
+        mt9m111->rect.height    = MT9M111_MAX_HEIGHT;
+
         ret = mt9m111_video_probe(icd, client);
         if (ret) {
                 icd->ops = NULL;