[media] v4l: Unify selection targets across V4L2 and V4L2 subdev interfaces

Change the users of V4L2_SUBDEV_SEL_TGT_* targets to use V4L2_SEL_TGT_*
instead. The common definitions are moved to a new header file,
include/linux/v4l2-common.h.

Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

10 files changed, 103 insertions, 79 deletions

diff --git a/drivers/media/video/omap3isp/ispccdc.c b/drivers/media/video/omap3isp/ispccdc.c
index f19774f8396a..82df7a06dc36 100644
--- a/drivers/media/video/omap3isp/ispccdc.c
+++ b/drivers/media/video/omap3isp/ispccdc.c
@@ -2014,7 +2014,7 @@ static int ccdc_get_selection(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh,
                 return -EINVAL;
 
         switch (sel->target) {
-        case V4L2_SUBDEV_SEL_TGT_CROP_BOUNDS:
+        case V4L2_SEL_TGT_CROP_BOUNDS:
                 sel->r.left = 0;
                 sel->r.top = 0;
                 sel->r.width = INT_MAX;
@@ -2024,7 +2024,7 @@ static int ccdc_get_selection(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh,
                 ccdc_try_crop(ccdc, format, &sel->r);
                 break;
 
-        case V4L2_SUBDEV_SEL_TGT_CROP:
+        case V4L2_SEL_TGT_CROP:
                 sel->r = *__ccdc_get_crop(ccdc, fh, sel->which);
                 break;
 
@@ -2052,7 +2052,7 @@ static int ccdc_set_selection(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh,
         struct isp_ccdc_device *ccdc = v4l2_get_subdevdata(sd);
         struct v4l2_mbus_framefmt *format;
 
-        if (sel->target != V4L2_SUBDEV_SEL_TGT_CROP ||
+        if (sel->target != V4L2_SEL_TGT_CROP ||
             sel->pad != CCDC_PAD_SOURCE_OF)
                 return -EINVAL;
 
diff --git a/drivers/media/video/omap3isp/isppreview.c b/drivers/media/video/omap3isp/isppreview.c
index 1086f6a9ff76..6fa70f4e8ea4 100644
--- a/drivers/media/video/omap3isp/isppreview.c
+++ b/drivers/media/video/omap3isp/isppreview.c
@@ -1949,7 +1949,7 @@ static int preview_get_selection(struct v4l2_subdev *sd,
                 return -EINVAL;
 
         switch (sel->target) {
-        case V4L2_SUBDEV_SEL_TGT_CROP_BOUNDS:
+        case V4L2_SEL_TGT_CROP_BOUNDS:
                 sel->r.left = 0;
                 sel->r.top = 0;
                 sel->r.width = INT_MAX;
@@ -1960,7 +1960,7 @@ static int preview_get_selection(struct v4l2_subdev *sd,
                 preview_try_crop(prev, format, &sel->r);
                 break;
 
-        case V4L2_SUBDEV_SEL_TGT_CROP:
+        case V4L2_SEL_TGT_CROP:
                 sel->r = *__preview_get_crop(prev, fh, sel->which);
                 break;
 
@@ -1988,7 +1988,7 @@ static int preview_set_selection(struct v4l2_subdev *sd,
         struct isp_prev_device *prev = v4l2_get_subdevdata(sd);
         struct v4l2_mbus_framefmt *format;
 
-        if (sel->target != V4L2_SUBDEV_SEL_TGT_CROP ||
+        if (sel->target != V4L2_SEL_TGT_CROP ||
             sel->pad != PREV_PAD_SINK)
                 return -EINVAL;
 
diff --git a/drivers/media/video/omap3isp/ispresizer.c b/drivers/media/video/omap3isp/ispresizer.c
index 945665295571..ae17d917f77b 100644
--- a/drivers/media/video/omap3isp/ispresizer.c
+++ b/drivers/media/video/omap3isp/ispresizer.c
@@ -1249,7 +1249,7 @@ static int resizer_get_selection(struct v4l2_subdev *sd,
                                              sel->which);
 
         switch (sel->target) {
-        case V4L2_SUBDEV_SEL_TGT_CROP_BOUNDS:
+        case V4L2_SEL_TGT_CROP_BOUNDS:
                 sel->r.left = 0;
                 sel->r.top = 0;
                 sel->r.width = INT_MAX;
@@ -1259,7 +1259,7 @@ static int resizer_get_selection(struct v4l2_subdev *sd,
                 resizer_calc_ratios(res, &sel->r, format_source, &ratio);
                 break;
 
-        case V4L2_SUBDEV_SEL_TGT_CROP:
+        case V4L2_SEL_TGT_CROP:
                 sel->r = *__resizer_get_crop(res, fh, sel->which);
                 resizer_calc_ratios(res, &sel->r, format_source, &ratio);
                 break;
@@ -1293,7 +1293,7 @@ static int resizer_set_selection(struct v4l2_subdev *sd,
         struct v4l2_mbus_framefmt *format_sink, *format_source;
         struct resizer_ratio ratio;
 
-        if (sel->target != V4L2_SUBDEV_SEL_TGT_CROP ||
+        if (sel->target != V4L2_SEL_TGT_CROP ||
             sel->pad != RESZ_PAD_SINK)
                 return -EINVAL;
 
diff --git a/drivers/media/video/s5p-fimc/fimc-capture.c b/drivers/media/video/s5p-fimc/fimc-capture.c
index a3cd78d33913..521e3715b9ee 100644
--- a/drivers/media/video/s5p-fimc/fimc-capture.c
+++ b/drivers/media/video/s5p-fimc/fimc-capture.c
@@ -1429,9 +1429,9 @@ static int fimc_subdev_get_selection(struct v4l2_subdev *sd,
         mutex_lock(&fimc->lock);
 
         switch (sel->target) {
-        case V4L2_SUBDEV_SEL_TGT_COMPOSE_BOUNDS:
+        case V4L2_SEL_TGT_COMPOSE_BOUNDS:
                 f = &ctx->d_frame;
-        case V4L2_SUBDEV_SEL_TGT_CROP_BOUNDS:
+        case V4L2_SEL_TGT_CROP_BOUNDS:
                 r->width = f->o_width;
                 r->height = f->o_height;
                 r->left = 0;
@@ -1439,10 +1439,10 @@ static int fimc_subdev_get_selection(struct v4l2_subdev *sd,
                 mutex_unlock(&fimc->lock);
                 return 0;
 
-        case V4L2_SUBDEV_SEL_TGT_CROP_ACTUAL:
+        case V4L2_SEL_TGT_CROP:
                 try_sel = v4l2_subdev_get_try_crop(fh, sel->pad);
                 break;
-        case V4L2_SUBDEV_SEL_TGT_COMPOSE_ACTUAL:
+        case V4L2_SEL_TGT_COMPOSE:
                 try_sel = v4l2_subdev_get_try_compose(fh, sel->pad);
                 f = &ctx->d_frame;
                 break;
@@ -1486,9 +1486,9 @@ static int fimc_subdev_set_selection(struct v4l2_subdev *sd,
         fimc_capture_try_selection(ctx, r, V4L2_SEL_TGT_CROP);
 
         switch (sel->target) {
-        case V4L2_SUBDEV_SEL_TGT_COMPOSE_BOUNDS:
+        case V4L2_SEL_TGT_COMPOSE_BOUNDS:
                 f = &ctx->d_frame;
-        case V4L2_SUBDEV_SEL_TGT_CROP_BOUNDS:
+        case V4L2_SEL_TGT_CROP_BOUNDS:
                 r->width = f->o_width;
                 r->height = f->o_height;
                 r->left = 0;
@@ -1496,10 +1496,10 @@ static int fimc_subdev_set_selection(struct v4l2_subdev *sd,
                 mutex_unlock(&fimc->lock);
                 return 0;
 
-        case V4L2_SUBDEV_SEL_TGT_CROP_ACTUAL:
+        case V4L2_SEL_TGT_CROP:
                 try_sel = v4l2_subdev_get_try_crop(fh, sel->pad);
                 break;
-        case V4L2_SUBDEV_SEL_TGT_COMPOSE_ACTUAL:
+        case V4L2_SEL_TGT_COMPOSE:
                 try_sel = v4l2_subdev_get_try_compose(fh, sel->pad);
                 f = &ctx->d_frame;
                 break;
@@ -1515,7 +1515,7 @@ static int fimc_subdev_set_selection(struct v4l2_subdev *sd,
                 set_frame_crop(f, r->left, r->top, r->width, r->height);
                 set_bit(ST_CAPT_APPLY_CFG, &fimc->state);
                 spin_unlock_irqrestore(&fimc->slock, flags);
-                if (sel->target == V4L2_SUBDEV_SEL_TGT_COMPOSE_ACTUAL)
+                if (sel->target == V4L2_SEL_TGT_COMPOSE)
                         ctx->state |= FIMC_COMPOSE;
         }
 
diff --git a/drivers/media/video/s5p-fimc/fimc-lite.c b/drivers/media/video/s5p-fimc/fimc-lite.c
index 52ede56e0758..8785089c4460 100644
--- a/drivers/media/video/s5p-fimc/fimc-lite.c
+++ b/drivers/media/video/s5p-fimc/fimc-lite.c
@@ -1086,9 +1086,9 @@ static int fimc_lite_subdev_get_selection(struct v4l2_subdev *sd,
         struct fimc_lite *fimc = v4l2_get_subdevdata(sd);
         struct flite_frame *f = &fimc->inp_frame;
 
-        if ((sel->target != V4L2_SUBDEV_SEL_TGT_CROP_ACTUAL &&
-             sel->target != V4L2_SUBDEV_SEL_TGT_CROP_BOUNDS) ||
-            sel->pad != FLITE_SD_PAD_SINK)
+        if ((sel->target != V4L2_SEL_TGT_CROP &&
+             sel->target != V4L2_SEL_TGT_CROP_BOUNDS) ||
+             sel->pad != FLITE_SD_PAD_SINK)
                 return -EINVAL;
 
         if (sel->which == V4L2_SUBDEV_FORMAT_TRY) {
@@ -1097,7 +1097,7 @@ static int fimc_lite_subdev_get_selection(struct v4l2_subdev *sd,
         }
 
         mutex_lock(&fimc->lock);
-        if (sel->target == V4L2_SUBDEV_SEL_TGT_CROP_ACTUAL) {
+        if (sel->target == V4L2_SEL_TGT_CROP) {
                 sel->r = f->rect;
         } else {
                 sel->r.left = 0;
@@ -1122,8 +1122,7 @@ static int fimc_lite_subdev_set_selection(struct v4l2_subdev *sd,
         struct flite_frame *f = &fimc->inp_frame;
         int ret = 0;
 
-        if (sel->target != V4L2_SUBDEV_SEL_TGT_CROP_ACTUAL ||
-            sel->pad != FLITE_SD_PAD_SINK)
+        if (sel->target != V4L2_SEL_TGT_CROP || sel->pad != FLITE_SD_PAD_SINK)
                 return -EINVAL;
 
         mutex_lock(&fimc->lock);
diff --git a/drivers/media/video/smiapp/smiapp-core.c b/drivers/media/video/smiapp/smiapp-core.c
index 37622bb6c667..9bbb5d3f003b 100644
--- a/drivers/media/video/smiapp/smiapp-core.c
+++ b/drivers/media/video/smiapp/smiapp-core.c
@@ -1630,7 +1630,7 @@ static void smiapp_propagate(struct v4l2_subdev *subdev,
         smiapp_get_crop_compose(subdev, fh, crops, &comp, which);
 
         switch (target) {
-        case V4L2_SUBDEV_SEL_TGT_CROP:
+        case V4L2_SEL_TGT_CROP:
                 comp->width = crops[SMIAPP_PAD_SINK]->width;
                 comp->height = crops[SMIAPP_PAD_SINK]->height;
                 if (which == V4L2_SUBDEV_FORMAT_ACTIVE) {
@@ -1646,7 +1646,7 @@ static void smiapp_propagate(struct v4l2_subdev *subdev,
                         }
                 }
                 /* Fall through */
-        case V4L2_SUBDEV_SEL_TGT_COMPOSE:
+        case V4L2_SEL_TGT_COMPOSE:
                 *crops[SMIAPP_PAD_SRC] = *comp;
                 break;
         default:
@@ -1722,7 +1722,7 @@ static int smiapp_set_format(struct v4l2_subdev *subdev,
         if (fmt->which == V4L2_SUBDEV_FORMAT_ACTIVE)
                 ssd->sink_fmt = *crops[ssd->sink_pad];
         smiapp_propagate(subdev, fh, fmt->which,
-                         V4L2_SUBDEV_SEL_TGT_CROP);
+                         V4L2_SEL_TGT_CROP);
 
         mutex_unlock(&sensor->mutex);
 
@@ -1957,7 +1957,7 @@ static int smiapp_set_compose(struct v4l2_subdev *subdev,
 
         *comp = sel->r;
         smiapp_propagate(subdev, fh, sel->which,
-                         V4L2_SUBDEV_SEL_TGT_COMPOSE);
+                         V4L2_SEL_TGT_COMPOSE);
 
         if (sel->which == V4L2_SUBDEV_FORMAT_ACTIVE)
                 return smiapp_update_mode(sensor);
@@ -1973,8 +1973,8 @@ static int __smiapp_sel_supported(struct v4l2_subdev *subdev,
 
         /* We only implement crop in three places. */
         switch (sel->target) {
-        case V4L2_SUBDEV_SEL_TGT_CROP:
-        case V4L2_SUBDEV_SEL_TGT_CROP_BOUNDS:
+        case V4L2_SEL_TGT_CROP:
+        case V4L2_SEL_TGT_CROP_BOUNDS:
                 if (ssd == sensor->pixel_array
                     && sel->pad == SMIAPP_PA_PAD_SRC)
                         return 0;
@@ -1987,8 +1987,8 @@ static int __smiapp_sel_supported(struct v4l2_subdev *subdev,
                     == SMIAPP_DIGITAL_CROP_CAPABILITY_INPUT_CROP)
                         return 0;
                 return -EINVAL;
-        case V4L2_SUBDEV_SEL_TGT_COMPOSE:
-        case V4L2_SUBDEV_SEL_TGT_COMPOSE_BOUNDS:
+        case V4L2_SEL_TGT_COMPOSE:
+        case V4L2_SEL_TGT_COMPOSE_BOUNDS:
                 if (sel->pad == ssd->source_pad)
                         return -EINVAL;
                 if (ssd == sensor->binner)
@@ -2050,7 +2050,7 @@ static int smiapp_set_crop(struct v4l2_subdev *subdev,
 
         if (ssd != sensor->pixel_array && sel->pad == SMIAPP_PAD_SINK)
                 smiapp_propagate(subdev, fh, sel->which,
-                                 V4L2_SUBDEV_SEL_TGT_CROP);
+                                 V4L2_SEL_TGT_CROP);
 
         return 0;
 }
@@ -2084,7 +2084,7 @@ static int __smiapp_get_selection(struct v4l2_subdev *subdev,
         }
 
         switch (sel->target) {
-        case V4L2_SUBDEV_SEL_TGT_CROP_BOUNDS:
+        case V4L2_SEL_TGT_CROP_BOUNDS:
                 if (ssd == sensor->pixel_array) {
                         sel->r.width =
                                 sensor->limits[SMIAPP_LIMIT_X_ADDR_MAX] + 1;
@@ -2096,11 +2096,11 @@ static int __smiapp_get_selection(struct v4l2_subdev *subdev,
                         sel->r = *comp;
                 }
                 break;
-        case V4L2_SUBDEV_SEL_TGT_CROP:
-        case V4L2_SUBDEV_SEL_TGT_COMPOSE_BOUNDS:
+        case V4L2_SEL_TGT_CROP:
+        case V4L2_SEL_TGT_COMPOSE_BOUNDS:
                 sel->r = *crops[sel->pad];
                 break;
-        case V4L2_SUBDEV_SEL_TGT_COMPOSE:
+        case V4L2_SEL_TGT_COMPOSE:
                 sel->r = *comp;
                 break;
         }
@@ -2147,10 +2147,10 @@ static int smiapp_set_selection(struct v4l2_subdev *subdev,
                               sel->r.height);
 
         switch (sel->target) {
-        case V4L2_SUBDEV_SEL_TGT_CROP:
+        case V4L2_SEL_TGT_CROP:
                 ret = smiapp_set_crop(subdev, fh, sel);
                 break;
-        case V4L2_SUBDEV_SEL_TGT_COMPOSE:
+        case V4L2_SEL_TGT_COMPOSE:
                 ret = smiapp_set_compose(subdev, fh, sel);
                 break;
         default:
diff --git a/drivers/media/video/v4l2-subdev.c b/drivers/media/video/v4l2-subdev.c
index cd86f0c3ec74..9182f81deb5b 100644
--- a/drivers/media/video/v4l2-subdev.c
+++ b/drivers/media/video/v4l2-subdev.c
@@ -245,7 +245,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg)
                 memset(&sel, 0, sizeof(sel));
                 sel.which = crop->which;
                 sel.pad = crop->pad;
-                sel.target = V4L2_SUBDEV_SEL_TGT_CROP;
+                sel.target = V4L2_SEL_TGT_CROP;
 
                 rval = v4l2_subdev_call(
                         sd, pad, get_selection, subdev_fh, &sel);
@@ -274,7 +274,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg)
                 memset(&sel, 0, sizeof(sel));
                 sel.which = crop->which;
                 sel.pad = crop->pad;
-                sel.target = V4L2_SUBDEV_SEL_TGT_CROP;
+                sel.target = V4L2_SEL_TGT_CROP;
                 sel.r = crop->rect;
 
                 rval = v4l2_subdev_call(
diff --git a/include/linux/v4l2-common.h b/include/linux/v4l2-common.h
new file mode 100644
index 000000000000..e85bf15b5994
--- /dev/null
+++ b/include/linux/v4l2-common.h
@@ -0,0 +1,57 @@
+/*
+ * include/linux/v4l2-common.h
+ *
+ * Common V4L2 and V4L2 subdev definitions.
+ *
+ * Users are advised to #include this file either through videodev2.h
+ * (V4L2) or through v4l2-subdev.h (V4L2 subdev) rather than to refer
+ * to this file directly.
+ *
+ * Copyright (C) 2012 Nokia Corporation
+ * Contact: Sakari Ailus <sakari.ailus@iki.fi>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#ifndef __V4L2_COMMON__
+#define __V4L2_COMMON__
+
+/* Selection target definitions */
+
+/* Current cropping area */
+#define V4L2_SEL_TGT_CROP               0x0000
+/* Default cropping area */
+#define V4L2_SEL_TGT_CROP_DEFAULT       0x0001
+/* Cropping bounds */
+#define V4L2_SEL_TGT_CROP_BOUNDS        0x0002
+/* Current composing area */
+#define V4L2_SEL_TGT_COMPOSE            0x0100
+/* Default composing area */
+#define V4L2_SEL_TGT_COMPOSE_DEFAULT    0x0101
+/* Composing bounds */
+#define V4L2_SEL_TGT_COMPOSE_BOUNDS     0x0102
+/* Current composing area plus all padding pixels */
+#define V4L2_SEL_TGT_COMPOSE_PADDED     0x0103
+
+/* Backward compatibility definitions */
+#define V4L2_SEL_TGT_CROP_ACTIVE        V4L2_SEL_TGT_CROP
+#define V4L2_SEL_TGT_COMPOSE_ACTIVE     V4L2_SEL_TGT_COMPOSE
+#define V4L2_SUBDEV_SEL_TGT_CROP_ACTUAL \
+        V4L2_SEL_TGT_CROP
+#define V4L2_SUBDEV_SEL_TGT_COMPOSE_ACTUAL \
+        V4L2_SEL_TGT_COMPOSE
+
+#endif /* __V4L2_COMMON__  */
diff --git a/include/linux/v4l2-subdev.h b/include/linux/v4l2-subdev.h
index 3cbe6889fcb5..1d7d45739260 100644
--- a/include/linux/v4l2-subdev.h
+++ b/include/linux/v4l2-subdev.h
@@ -25,6 +25,7 @@
 
 #include <linux/ioctl.h>
 #include <linux/types.h>
+#include <linux/v4l2-common.h>
 #include <linux/v4l2-mediabus.h>
 
 /**
@@ -127,27 +128,13 @@ struct v4l2_subdev_frame_interval_enum {
 #define V4L2_SUBDEV_SEL_FLAG_SIZE_LE                    (1 << 1)
 #define V4L2_SUBDEV_SEL_FLAG_KEEP_CONFIG                (1 << 2)
 
-/* active cropping area */
-#define V4L2_SUBDEV_SEL_TGT_CROP                        0x0000
-/* cropping bounds */
-#define V4L2_SUBDEV_SEL_TGT_CROP_BOUNDS                 0x0002
-/* current composing area */
-#define V4L2_SUBDEV_SEL_TGT_COMPOSE                     0x0100
-/* composing bounds */
-#define V4L2_SUBDEV_SEL_TGT_COMPOSE_BOUNDS              0x0102
-
-/* backward compatibility definitions */
-#define V4L2_SUBDEV_SEL_TGT_CROP_ACTUAL \
-        V4L2_SUBDEV_SEL_TGT_CROP
-#define V4L2_SUBDEV_SEL_TGT_COMPOSE_ACTUAL \
-        V4L2_SUBDEV_SEL_TGT_COMPOSE
-
 /**
  * struct v4l2_subdev_selection - selection info
  *
  * @which: either V4L2_SUBDEV_FORMAT_ACTIVE or V4L2_SUBDEV_FORMAT_TRY
  * @pad: pad number, as reported by the media API
- * @target: selection target, used to choose one of possible rectangles
+ * @target: Selection target, used to choose one of possible rectangles,
+ *          defined in v4l2-common.h; V4L2_SEL_TGT_* .
  * @flags: constraint flags
  * @r: coordinates of the selection window
  * @reserved: for future use, set to zero for now
diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
index ac1ad33ba3e0..7fdb8710c831 100644
--- a/include/linux/videodev2.h
+++ b/include/linux/videodev2.h
@@ -64,6 +64,7 @@
 #include <linux/compiler.h>
 #include <linux/ioctl.h>
 #include <linux/types.h>
+#include <linux/v4l2-common.h>
 
 /*
  * Common stuff for both V4L1 and V4L2
@@ -764,31 +765,11 @@ struct v4l2_crop {
 #define V4L2_SEL_FLAG_GE        0x00000001
 #define V4L2_SEL_FLAG_LE        0x00000002
 
-/* Selection targets */
-
-/* Current cropping area */
-#define V4L2_SEL_TGT_CROP               0x0000
-/* Default cropping area */
-#define V4L2_SEL_TGT_CROP_DEFAULT       0x0001
-/* Cropping bounds */
-#define V4L2_SEL_TGT_CROP_BOUNDS        0x0002
-/* Current composing area */
-#define V4L2_SEL_TGT_COMPOSE            0x0100
-/* Default composing area */
-#define V4L2_SEL_TGT_COMPOSE_DEFAULT    0x0101
-/* Composing bounds */
-#define V4L2_SEL_TGT_COMPOSE_BOUNDS     0x0102
-/* Current composing area plus all padding pixels */
-#define V4L2_SEL_TGT_COMPOSE_PADDED     0x0103
-
-/* Backward compatibility definitions */
-#define V4L2_SEL_TGT_CROP_ACTIVE        V4L2_SEL_TGT_CROP
-#define V4L2_SEL_TGT_COMPOSE_ACTIVE     V4L2_SEL_TGT_COMPOSE
-
 /**
  * struct v4l2_selection - selection info
  * @type:       buffer type (do not use *_MPLANE types)
- * @target:     selection target, used to choose one of possible rectangles
+ * @target:     Selection target, used to choose one of possible rectangles;
+ *              defined in v4l2-common.h; V4L2_SEL_TGT_* .
  * @flags:      constraints flags
  * @r:          coordinates of selection window
  * @reserved:   for future use, rounds structure size to 64 bytes, set to zero