On Tue 1 October 2013 10:26:56 Ricardo Ribalda Delgado wrote:
> Extend v4l2 selection API to support multiple selection areas, this way
> sensors that support multiple readout areas can work with multiple areas
> of insterest.
>
> The struct v4l2_selection and v4l2_subdev_selection has been extented
> with a new field rectangles. If it is value is different than zero the
> pr array is used instead of the r field.
>
> A new structure v4l2_ext_rect has been defined, containing 4 reserved
> fields for future improvements, as suggested by Hans.
>
> Two helper functiona are also added, to help the drivers that support
> a single selection.
>
> This Patch ONLY adds the modification to the core. Once it is agreed, a
> new version including changes on the drivers that handle the selection
> api will come.
>
> struct v4l2_selection has the same size on 32 and 64 bits, therefore I
> dont think that any change on v4l2-compat-ioctl32 is needed.
Yes, you do. The pr pointer is 32-bit for a 32-bit application and the
compat code is needed to convert it to a 64-bit pointer. The struct as a
whole may have the same size, but the pointer in the union definitely has
a different size.
>
> ricardo@neopili:/tmp$ gcc kk.c -m32
> ricardo@neopili:/tmp$ ./a.out
> Size of v4l2_selection=64
> ricardo@neopili:/tmp$ gcc kk.c
> ricardo@neopili:/tmp$ ./a.out
> Size of v4l2_selection=64
>
> This patch includes all the comments by Hans Verkuil.
>
> Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@xxxxxxxxx>
> ---
> drivers/media/v4l2-core/v4l2-common.c | 39 +++++++++++++++++++++++++++++++++++
> drivers/media/v4l2-core/v4l2-ioctl.c | 37 ++++++++++++++++++++++++++++-----
> include/media/v4l2-common.h | 4 ++++
> include/uapi/linux/v4l2-subdev.h | 10 +++++++--
> include/uapi/linux/videodev2.h | 21 +++++++++++++++----
> 5 files changed, 100 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
> index a95e5e2..007ab32 100644
> --- a/drivers/media/v4l2-core/v4l2-common.c
> +++ b/drivers/media/v4l2-core/v4l2-common.c
> @@ -886,3 +886,42 @@ void v4l2_get_timestamp(struct timeval *tv)
> tv->tv_usec = ts.tv_nsec / NSEC_PER_USEC;
> }
> EXPORT_SYMBOL_GPL(v4l2_get_timestamp);
> +
> +int v4l2_selection_get_rect(struct v4l2_selection *s, struct v4l2_ext_rect *r)
> +{
> + if (s->rectangles > 1)
> + return -EINVAL;
> + if (s->rectangles == 1) {
> + *r = s->pr[0];
> + return 0;
> + }
> + if (s->r.width < 0 || s->r.height < 0)
> + return -EINVAL;
> + r->left = s->r.left;
> + r->top = s->r.top;
> + r->width = s->r.width;
> + r->height = s->r.height;
> + memset(r->reserved, 0, sizeof(r->reserved));
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(v4l2_selection_get_rect);
> +
> +int v4l2_selection_set_rect(struct v4l2_ext_rect *r, struct v4l2_selection *s)
> +{
> + if (s->rectangles == 0) {
> + if (s->r.width > UINT_MAX || s->r.height > UINT_MAX)
> + return -EINVAL;
This makes no sense. You probably mean r->width > INT_MAX, but I would just
skip this whole test: it is the driver that will set these values, and you
can assume that it is correct. You can never rely on what you get from userspace,
but I think this is reasonably in this case to assume that the rectangle is
a reasonable size.
That also means that this can be a void function.
> + s->r.left = r->left;
> + s->r.top = r->top;
> + s->r.width = r->width;
> + s->r.height = r->height;
> + return 0;
> + }
> + if (s->rectangles > 1) {
> + s->pr[0] = *r;
> + s->rectangles = 1;
> + return 0;
> + }
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(v4l2_selection_set_rect);
> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> index 68e6b5e..29f7cf1 100644
> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> @@ -572,11 +572,22 @@ static void v4l_print_crop(const void *arg, bool write_only)
> static void v4l_print_selection(const void *arg, bool write_only)
> {
> const struct v4l2_selection *p = arg;
> + int i;
>
> - pr_cont("type=%s, target=%d, flags=0x%x, wxh=%dx%d, x,y=%d,%d\n",
> - prt_names(p->type, v4l2_type_names),
> - p->target, p->flags,
> - p->r.width, p->r.height, p->r.left, p->r.top);
> + if (p->rectangles == 0)
> + pr_cont("type=%s, target=%d, flags=0x%x, wxh=%dx%d, x,y=%d,%d\n",
> + prt_names(p->type, v4l2_type_names),
> + p->target, p->flags,
> + p->r.width, p->r.height, p->r.left, p->r.top);
> + else{
> + pr_cont("type=%s, target=%d, flags=0x%x rectangles=%d\n",
> + prt_names(p->type, v4l2_type_names),
> + p->target, p->flags, p->rectangles);
> + for (i = 0; i < p->rectangles; i++)
> + pr_cont("rectangle %d: wxh=%dx%d, x,y=%d,%d\n",
> + i, p->r.width, p->r.height,
> + p->r.left, p->r.top);
> + }
> }
>
> static void v4l_print_jpegcompression(const void *arg, bool write_only)
> @@ -1692,7 +1703,9 @@ static int v4l_cropcap(const struct v4l2_ioctl_ops *ops,
> struct file *file, void *fh, void *arg)
> {
> struct v4l2_cropcap *p = arg;
> - struct v4l2_selection s = { .type = p->type };
> + struct v4l2_selection s = {
> + .type = p->type,
> + };
> int ret;
>
> if (ops->vidioc_cropcap)
> @@ -2253,6 +2266,20 @@ static int check_array_args(unsigned int cmd, void *parg, size_t *array_size,
> }
> break;
> }
> +
> + case VIDIOC_G_SELECTION:
> + case VIDIOC_S_SELECTION: {
> + struct v4l2_selection *s = parg;
> +
> + if (s->rectangles) {
> + *user_ptr = (void __user *)s->pr;
> + kernel_ptr = (void *)&s->pr;
> + array_size = sizeof(struct v4l2_ext_rect)
> + * s->rectangles;
> + ret = 1;
> + }
> + break;
> + }
> }
>
> return ret;
> diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h
> index 015ff82..dc96861 100644
> --- a/include/media/v4l2-common.h
> +++ b/include/media/v4l2-common.h
> @@ -216,4 +216,8 @@ struct v4l2_fract v4l2_calc_aspect_ratio(u8 hor_landscape, u8 vert_portrait);
>
> void v4l2_get_timestamp(struct timeval *tv);
>
> +int v4l2_selection_get_rect(struct v4l2_selection *s, struct v4l2_ext_rect *r);
> +
> +int v4l2_selection_set_rect(struct v4l2_ext_rect *r, struct v4l2_selection *s);
Swap the arguments to be consistent with get_rect. The v4l2_ext_rect argument can
be const as well since you don't want set_rect to modify *r.
> +
> #endif /* V4L2_COMMON_H_ */
> diff --git a/include/uapi/linux/v4l2-subdev.h b/include/uapi/linux/v4l2-subdev.h
> index a33c4da..c02a886 100644
> --- a/include/uapi/linux/v4l2-subdev.h
> +++ b/include/uapi/linux/v4l2-subdev.h
> @@ -133,6 +133,8 @@ struct v4l2_subdev_frame_interval_enum {
> * defined in v4l2-common.h; V4L2_SEL_TGT_* .
> * @flags: constraint flags, defined in v4l2-common.h; V4L2_SEL_FLAG_*.
> * @r: coordinates of the selection window
> + * @pr: array of rectangles containing the selection windows
> + * @rectangles: Number of rectangles in pr structure. If zero, r is used instead
> * @reserved: for future use, set to zero for now
> *
> * Hardware may use multiple helper windows to process a video stream.
> @@ -144,8 +146,12 @@ struct v4l2_subdev_selection {
> __u32 pad;
> __u32 target;
> __u32 flags;
> - struct v4l2_rect r;
> - __u32 reserved[8];
> + union {
> + struct v4l2_rect r;
> + struct v4l2_ext_rect *pr;
> + };
> + __u32 rectangles;
> + __u32 reserved[7];
> };
>
> struct v4l2_subdev_edid {
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 95ef455..a4a7902 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -211,6 +211,14 @@ struct v4l2_rect {
> __s32 height;
> };
>
> +struct v4l2_ext_rect {
> + __s32 left;
> + __s32 top;
> + __u32 width;
> + __u32 height;
> + __u32 reserved[4];
> +};
> +
> struct v4l2_fract {
> __u32 numerator;
> __u32 denominator;
> @@ -804,6 +812,8 @@ struct v4l2_crop {
> * defined in v4l2-common.h; V4L2_SEL_TGT_* .
> * @flags: constraints flags, defined in v4l2-common.h; V4L2_SEL_FLAG_*.
> * @r: coordinates of selection window
> + * @pr: array of rectangles containing the selection windows
> + * @rectangles: Number of rectangles in pr structure. If zero, r is used instead
> * @reserved: for future use, rounds structure size to 64 bytes, set to zero
> *
> * Hardware may use multiple helper windows to process a video stream.
> @@ -814,10 +824,13 @@ struct v4l2_selection {
> __u32 type;
> __u32 target;
> __u32 flags;
> - struct v4l2_rect r;
> - __u32 reserved[9];
> -};
> -
> + union {
> + struct v4l2_rect r;
> + struct v4l2_ext_rect *pr;
> + };
> + __u32 rectangles;
> + __u32 reserved[8];
> +} __packed;
>
> /*
> * A N A L O G V I D E O S T A N D A R D
>
Regards,
Hans
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