Re: [PATCH v14 06/11] v4l2-ctrls: add support for V4L2_CTRL_WHICH_MIN/MAX_VAL

Hans Verkuil
2023-12-01T08:32:30Z

On 01/12/2023 08:18, Yunke Cao wrote:
> From: Hans Verkuil <hverkuil-cisco@xs4all.nl>
>
> Add the capability of retrieving the min and max values of a
> compound control.
>
> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
> Signed-off-by: Yunke Cao <yunkec@google.com>
> ---
> Changelog since v13:
> - Updated comments of v4l2_ctrl_new_std_compound()
> Changelog since v12:
> - Addressed comments from Hans.
> Changelog since v11:
> - Added a flag V4L2_CTRL_FLAG_HAS_WHICH_MIN_MAX.
> - Modified std_min/max_compound() to be void function. Moved the check of
> whether WHICH_MIN/MAX_VAL into prepare_ext_ctrls(), and return EINVAL.
> - Modified documentations to reflect this change.
> Changelog since v10:
> - No change.
> Changelog since v9:
> - No change.
> Changelog since v8:
> - Return ENODATA when min/max is not implemented. Document this behavior.
> - Created a shared helper function __v4l2_ctrl_type_op_init that takes "which"
> as a parameter. Call it in def, min and max operations.
> Changelog since v7:
> - Document that the definition of the min/max are provided by compound controls
> are defined in control documentation.
> - Return error, instead of zeroed memory for v4l2_ctrl_ptr_create(NULL).
>
> .../media/v4l/vidioc-g-ext-ctrls.rst | 22 ++-
> .../media/v4l/vidioc-queryctrl.rst | 9 +-
> .../media/videodev2.h.rst.exceptions | 3 +
> drivers/media/i2c/imx214.c | 5 +-
> .../media/platform/qcom/venus/venc_ctrls.c | 9 +-
> drivers/media/v4l2-core/v4l2-ctrls-api.c | 54 +++++--
> drivers/media/v4l2-core/v4l2-ctrls-core.c | 151 +++++++++++++++---
> drivers/media/v4l2-core/v4l2-ioctl.c | 4 +-
> include/media/v4l2-ctrls.h | 36 ++++-
> include/uapi/linux/videodev2.h | 3 +
> 10 files changed, 248 insertions(+), 48 deletions(-)
>
> diff --git a/Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst b/Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst
> index 7b1001d11f9c..0b87c23e66ff 100644
> --- a/Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst
> +++ b/Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst
> @@ -330,14 +330,26 @@ still cause this situation.
> - Which value of the control to get/set/try.
> * - :cspan:`2` ``V4L2_CTRL_WHICH_CUR_VAL`` will return the current value of
> the control, ``V4L2_CTRL_WHICH_DEF_VAL`` will return the default
> - value of the control and ``V4L2_CTRL_WHICH_REQUEST_VAL`` indicates that
> - these controls have to be retrieved from a request or tried/set for
> - a request. In the latter case the ``request_fd`` field contains the
> + value of the control, ``V4L2_CTRL_WHICH_MIN_VAL`` will return the minimum
> + value of the control, and ``V4L2_CTRL_WHICH_MAX_VAL`` will return the maximum
> + value of the control. ``V4L2_CTRL_WHICH_REQUEST_VAL`` indicates that
> + the control value has to be retrieved from a request or tried/set for
> + a request. In that case the ``request_fd`` field contains the
> file descriptor of the request that should be used. If the device
> does not support requests, then ``EACCES`` will be returned.
>
> - When using ``V4L2_CTRL_WHICH_DEF_VAL`` be aware that you can only
> - get the default value of the control, you cannot set or try it.
> + When using ``V4L2_CTRL_WHICH_DEF_VAL``, ``V4L2_CTRL_WHICH_MIN_VAL``
> + or ``V4L2_CTRL_WHICH_MAX_VAL`` be aware that you can only get the
> + default/minimum/maximum value of the control, you cannot set or try it.
> +
> + Whether a control supports querying the minimum and maximum values using
> + ``V4L2_CTRL_WHICH_MIN_VAL`` and ``V4L2_CTRL_WHICH_MAX_VAL`` is indicated
> + by the ``V4L2_CTRL_FLAG_HAS_WHICH_MIN_MAX`` flag. Most non-compound
> + control types support this. For controls with compound types, the
> + definition of minimum/maximum values are provided by
> + the control documentation. If a compound control does not document the
> + meaning of minimum/maximum value, then querying the minimum or maximum
> + value will result in the error code -EINVAL.
>
> For backwards compatibility you can also use a control class here
> (see :ref:`ctrl-class`). In that case all controls have to
> diff --git a/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst b/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst
> index 56d5c8b0b88b..b39f7e27bbbe 100644
> --- a/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst
> +++ b/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst
> @@ -447,7 +447,10 @@ See also the examples in :ref:`control`.
> - n/a
> - A struct :c:type:`v4l2_rect`, containing a rectangle described by
> the position of its top-left corner, the width and the height. Units
> - depend on the use case.
> + depend on the use case. Support for ``V4L2_CTRL_WHICH_MIN_VAL`` and
> + ``V4L2_CTRL_WHICH_MAX_VAL`` is optional and depends on the
> + ``V4L2_CTRL_FLAG_HAS_WHICH_MIN_MAX`` flag. See the documentation of
> + the specific control on how to interpret the minimum and maximum values.
> * - ``V4L2_CTRL_TYPE_H264_SPS``
> - n/a
> - n/a
> @@ -664,6 +667,10 @@ See also the examples in :ref:`control`.
> ``dims[0]``. So setting the control with a differently sized
> array will change the ``elems`` field when the control is
> queried afterwards.
> + * - ``V4L2_CTRL_FLAG_HAS_WHICH_MIN_MAX``
> + - 0x1000
> + - This control supports getting minimum and maximum values using
> + vidioc_g_ext_ctrls with V4L2_CTRL_WHICH_MIN/MAX_VAL.
>
> Return Value
> ============
> diff --git a/Documentation/userspace-api/media/videodev2.h.rst.exceptions b/Documentation/userspace-api/media/videodev2.h.rst.exceptions
> index c46082ef0e4d..a417af25e9a4 100644
> --- a/Documentation/userspace-api/media/videodev2.h.rst.exceptions
> +++ b/Documentation/userspace-api/media/videodev2.h.rst.exceptions
> @@ -393,6 +393,7 @@ replace define V4L2_CTRL_FLAG_HAS_PAYLOAD control-flags
> replace define V4L2_CTRL_FLAG_EXECUTE_ON_WRITE control-flags
> replace define V4L2_CTRL_FLAG_MODIFY_LAYOUT control-flags
> replace define V4L2_CTRL_FLAG_DYNAMIC_ARRAY control-flags
> +replace define V4L2_CTRL_FLAG_HAS_WHICH_MIN_MAX control-flags
>
> replace define V4L2_CTRL_FLAG_NEXT_CTRL control
> replace define V4L2_CTRL_FLAG_NEXT_COMPOUND control
> @@ -567,6 +568,8 @@ ignore define V4L2_CTRL_DRIVER_PRIV
> ignore define V4L2_CTRL_MAX_DIMS
> ignore define V4L2_CTRL_WHICH_CUR_VAL
> ignore define V4L2_CTRL_WHICH_DEF_VAL
> +ignore define V4L2_CTRL_WHICH_MIN_VAL
> +ignore define V4L2_CTRL_WHICH_MAX_VAL
> ignore define V4L2_CTRL_WHICH_REQUEST_VAL
> ignore define V4L2_OUT_CAP_CUSTOM_TIMINGS
> ignore define V4L2_CID_MAX_CTRLS
> diff --git a/drivers/media/i2c/imx214.c b/drivers/media/i2c/imx214.c
> index 4f77ea02cc27..926b5cae12d8 100644
> --- a/drivers/media/i2c/imx214.c
> +++ b/drivers/media/i2c/imx214.c
> @@ -998,7 +998,10 @@ static int imx214_probe(struct i2c_client *client)
> imx214->unit_size = v4l2_ctrl_new_std_compound(&imx214->ctrls,
> NULL,
> V4L2_CID_UNIT_CELL_SIZE,
> - v4l2_ctrl_ptr_create((void *)&unit_size));
> + v4l2_ctrl_ptr_create((void *)&unit_size),
> + v4l2_ctrl_ptr_create(NULL),
> + v4l2_ctrl_ptr_create(NULL));
> +
> ret = imx214->ctrls.error;
> if (ret) {
> dev_err(&client->dev, "%s control init failed (%d)\n",
> diff --git a/drivers/media/platform/qcom/venus/venc_ctrls.c b/drivers/media/platform/qcom/venus/venc_ctrls.c
> index d9d2a293f3ef..7f370438d655 100644
> --- a/drivers/media/platform/qcom/venus/venc_ctrls.c
> +++ b/drivers/media/platform/qcom/venus/venc_ctrls.c
> @@ -607,11 +607,16 @@ int venc_ctrl_init(struct venus_inst *inst)
>
> v4l2_ctrl_new_std_compound(&inst->ctrl_handler, &venc_ctrl_ops,
> V4L2_CID_COLORIMETRY_HDR10_CLL_INFO,
> - v4l2_ctrl_ptr_create(&p_hdr10_cll));
> + v4l2_ctrl_ptr_create(&p_hdr10_cll),
> + v4l2_ctrl_ptr_create(NULL),
> + v4l2_ctrl_ptr_create(NULL));
>
> v4l2_ctrl_new_std_compound(&inst->ctrl_handler, &venc_ctrl_ops,
> V4L2_CID_COLORIMETRY_HDR10_MASTERING_DISPLAY,
> - v4l2_ctrl_ptr_create((void *)&p_hdr10_mastering));
> + v4l2_ctrl_ptr_create((void *)&p_hdr10_mastering),
> + v4l2_ctrl_ptr_create(NULL),
> + v4l2_ctrl_ptr_create(NULL));
> +
>
> v4l2_ctrl_new_std_menu(&inst->ctrl_handler, &venc_ctrl_ops,
> V4L2_CID_MPEG_VIDEO_INTRA_REFRESH_PERIOD_TYPE,
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls-api.c b/drivers/media/v4l2-core/v4l2-ctrls-api.c
> index 002ea6588edf..d022e1ed4835 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls-api.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls-api.c
> @@ -94,6 +94,22 @@ static int def_to_user(struct v4l2_ext_control *c, struct v4l2_ctrl *ctrl)
> return ptr_to_user(c, ctrl, ctrl->p_new);
> }
>
> +/* Helper function: copy the minimum control value back to the caller */
> +static int min_to_user(struct v4l2_ext_control *c, struct v4l2_ctrl *ctrl)
> +{
> + ctrl->type_ops->minimum(ctrl, 0, ctrl->p_new);
> +
> + return ptr_to_user(c, ctrl, ctrl->p_new);
> +}
> +
> +/* Helper function: copy the maximum control value back to the caller */
> +static int max_to_user(struct v4l2_ext_control *c, struct v4l2_ctrl *ctrl)
> +{
> + ctrl->type_ops->maximum(ctrl, 0, ctrl->p_new);
> +
> + return ptr_to_user(c, ctrl, ctrl->p_new);
> +}
> +
> /* Helper function: copy the caller-provider value as the new control value */
> static int user_to_new(struct v4l2_ext_control *c, struct v4l2_ctrl *ctrl)
> {
> @@ -229,8 +245,8 @@ static int prepare_ext_ctrls(struct v4l2_ctrl_handler *hdl,
> cs->error_idx = i;
>
> if (cs->which &&
> - cs->which != V4L2_CTRL_WHICH_DEF_VAL &&
> - cs->which != V4L2_CTRL_WHICH_REQUEST_VAL &&
> + (cs->which < V4L2_CTRL_WHICH_DEF_VAL ||
> + cs->which > V4L2_CTRL_WHICH_MAX_VAL) &&
> V4L2_CTRL_ID2WHICH(id) != cs->which) {
> dprintk(vdev,
> "invalid which 0x%x or control id 0x%x\n",
> @@ -259,6 +275,15 @@ static int prepare_ext_ctrls(struct v4l2_ctrl_handler *hdl,
> return -EINVAL;
> }
>
> + if (!(ctrl->flags & V4L2_CTRL_FLAG_HAS_WHICH_MIN_MAX) &&
> + (cs->which == V4L2_CTRL_WHICH_MIN_VAL ||
> + cs->which == V4L2_CTRL_WHICH_MAX_VAL)) {
> + dprintk(vdev,
> + "invalid which 0x%x or control id 0x%x\n",
> + cs->which, id);
> + return -EINVAL;
> + }
> +
> if (ctrl->cluster[0]->ncontrols > 1)
> have_clusters = true;
> if (ctrl->cluster[0] != ctrl)
> @@ -368,8 +393,8 @@ static int prepare_ext_ctrls(struct v4l2_ctrl_handler *hdl,
> */
> static int class_check(struct v4l2_ctrl_handler *hdl, u32 which)
> {
> - if (which == 0 || which == V4L2_CTRL_WHICH_DEF_VAL ||
> - which == V4L2_CTRL_WHICH_REQUEST_VAL)
> + if (which == 0 || (which >= V4L2_CTRL_WHICH_DEF_VAL &&
> + which <= V4L2_CTRL_WHICH_MAX_VAL))
> return 0;
> return find_ref_lock(hdl, which | 1) ? 0 : -EINVAL;
> }
> @@ -389,10 +414,12 @@ int v4l2_g_ext_ctrls_common(struct v4l2_ctrl_handler *hdl,
> struct v4l2_ctrl_helper *helpers = helper;
> int ret;
> int i, j;
> - bool is_default, is_request;
> + bool is_default, is_request, is_min, is_max;
>
> is_default = (cs->which == V4L2_CTRL_WHICH_DEF_VAL);
> is_request = (cs->which == V4L2_CTRL_WHICH_REQUEST_VAL);
> + is_min = (cs->which == V4L2_CTRL_WHICH_MIN_VAL);
> + is_max = (cs->which == V4L2_CTRL_WHICH_MAX_VAL);
>
> cs->error_idx = cs->count;
> cs->which = V4L2_CTRL_ID2WHICH(cs->which);
> @@ -432,13 +459,14 @@ int v4l2_g_ext_ctrls_common(struct v4l2_ctrl_handler *hdl,
>
> /*
> * g_volatile_ctrl will update the new control values.
> - * This makes no sense for V4L2_CTRL_WHICH_DEF_VAL and
> + * This makes no sense for V4L2_CTRL_WHICH_DEF_VAL,
> + * V4L2_CTRL_WHICH_MIN_VAL, V4L2_CTRL_WHICH_MAX_VAL and
> * V4L2_CTRL_WHICH_REQUEST_VAL. In the case of requests
> * it is v4l2_ctrl_request_complete() that copies the
> * volatile controls at the time of request completion
> * to the request, so you don't want to do that again.
> */
> - if (!is_default && !is_request &&
> + if (!is_default && !is_request && !is_min && !is_max &&
> ((master->flags & V4L2_CTRL_FLAG_VOLATILE) ||
> (master->has_volatiles && !is_cur_manual(master)))) {
> for (j = 0; j < master->ncontrols; j++)
> @@ -467,6 +495,10 @@ int v4l2_g_ext_ctrls_common(struct v4l2_ctrl_handler *hdl,
> ret = -ENOMEM;
> else if (is_request && ref->p_req_valid)
> ret = req_to_user(cs->controls + idx, ref);
> + else if (is_min)
> + ret = min_to_user(cs->controls + idx, ref->ctrl);
> + else if (is_max)
> + ret = max_to_user(cs->controls + idx, ref->ctrl);
> else if (is_volatile)
> ret = new_to_user(cs->controls + idx, ref->ctrl);
> else
> @@ -564,9 +596,11 @@ int try_set_ext_ctrls_common(struct v4l2_fh *fh,
>
> cs->error_idx = cs->count;
>
> - /* Default value cannot be changed */
> - if (cs->which == V4L2_CTRL_WHICH_DEF_VAL) {
> - dprintk(vdev, "%s: cannot change default value\n",
> + /* Default/minimum/maximum values cannot be changed */
> + if (cs->which == V4L2_CTRL_WHICH_DEF_VAL ||
> + cs->which == V4L2_CTRL_WHICH_MIN_VAL ||
> + cs->which == V4L2_CTRL_WHICH_MAX_VAL) {
> + dprintk(vdev, "%s: cannot change default/min/max value\n",
> video_device_node_name(vdev));
> return -EINVAL;
> }
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls-core.c b/drivers/media/v4l2-core/v4l2-ctrls-core.c
> index f1486ab032cf..ef418165e88d 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls-core.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls-core.c
> @@ -182,29 +182,66 @@ static void std_init_compound(const struct v4l2_ctrl *ctrl, u32 idx,
> }
> }
>
> -void v4l2_ctrl_type_op_init(const struct v4l2_ctrl *ctrl, u32 from_idx,
> +static void std_min_compound(const struct v4l2_ctrl *ctrl, u32 idx,
> + union v4l2_ctrl_ptr ptr)
> +{
> + void *p = ptr.p + idx * ctrl->elem_size;
> +
> + if (ctrl->p_min.p_const)
> + memcpy(p, ctrl->p_min.p_const, ctrl->elem_size);
> + else
> + memset(p, 0, ctrl->elem_size);
> +}
> +
> +static void std_max_compound(const struct v4l2_ctrl *ctrl, u32 idx,
> union v4l2_ctrl_ptr ptr)
> +{
> + void *p = ptr.p + idx * ctrl->elem_size;
> +
> + if (ctrl->p_max.p_const)
> + memcpy(p, ctrl->p_max.p_const, ctrl->elem_size);
> + else
> + memset(p, 0, ctrl->elem_size);
> +}
> +
> +static void __v4l2_ctrl_type_op_init(const struct v4l2_ctrl *ctrl, u32 from_idx,
> + u32 which, union v4l2_ctrl_ptr ptr)
> {
> unsigned int i;
> u32 tot_elems = ctrl->elems;
> u32 elems = tot_elems - from_idx;
> + s64 value;
>
> - if (from_idx >= tot_elems)
> + switch (which) {
> + case V4L2_CTRL_WHICH_DEF_VAL:
> + value = ctrl->default_value;
> + break;
> + case V4L2_CTRL_WHICH_MAX_VAL:
> + value = ctrl->maximum;
> + break;
> + case V4L2_CTRL_WHICH_MIN_VAL:
> + value = ctrl->minimum;
> + break;
> + default:
> return;
> + }
>
> switch (ctrl->type) {
> case V4L2_CTRL_TYPE_STRING:
> + if (which == V4L2_CTRL_WHICH_DEF_VAL)
> + value = ctrl->minimum;
> +
> for (i = from_idx; i < tot_elems; i++) {
> unsigned int offset = i * ctrl->elem_size;
>
> - memset(ptr.p_char + offset, ' ', ctrl->minimum);
> - ptr.p_char[offset + ctrl->minimum] = '\0';
> + memset(ptr.p_char + offset, ' ', value);
> + ptr.p_char[offset + value] = '\0';
> }
> break;
> case V4L2_CTRL_TYPE_INTEGER64:
> - if (ctrl->default_value) {
> + if (value) {
> for (i = from_idx; i < tot_elems; i++)
> - ptr.p_s64[i] = ctrl->default_value;
> + ptr.p_s64[i] = value;
> } else {
> memset(ptr.p_s64 + from_idx, 0, elems * sizeof(s64));
> }
> @@ -214,9 +251,9 @@ void v4l2_ctrl_type_op_init(const struct v4l2_ctrl *ctrl, u32 from_idx,
> case V4L2_CTRL_TYPE_MENU:
> case V4L2_CTRL_TYPE_BITMASK:
> case V4L2_CTRL_TYPE_BOOLEAN:
> - if (ctrl->default_value) {
> + if (value) {
> for (i = from_idx; i < tot_elems; i++)
> - ptr.p_s32[i] = ctrl->default_value;
> + ptr.p_s32[i] = value;
> } else {
> memset(ptr.p_s32 + from_idx, 0, elems * sizeof(s32));
> }
> @@ -226,32 +263,61 @@ void v4l2_ctrl_type_op_init(const struct v4l2_ctrl *ctrl, u32 from_idx,
> memset(ptr.p_s32 + from_idx, 0, elems * sizeof(s32));
> break;
> case V4L2_CTRL_TYPE_U8:
> - memset(ptr.p_u8 + from_idx, ctrl->default_value, elems);
> + memset(ptr.p_u8 + from_idx, value, elems);
> break;
> case V4L2_CTRL_TYPE_U16:
> - if (ctrl->default_value) {
> + if (value) {
> for (i = from_idx; i < tot_elems; i++)
> - ptr.p_u16[i] = ctrl->default_value;
> + ptr.p_u16[i] = value;
> } else {
> memset(ptr.p_u16 + from_idx, 0, elems * sizeof(u16));
> }
> break;
> case V4L2_CTRL_TYPE_U32:
> - if (ctrl->default_value) {
> + if (value) {
> for (i = from_idx; i < tot_elems; i++)
> - ptr.p_u32[i] = ctrl->default_value;
> + ptr.p_u32[i] = value;
> } else {
> memset(ptr.p_u32 + from_idx, 0, elems * sizeof(u32));
> }
> break;
> default:
> - for (i = from_idx; i < tot_elems; i++)
> - std_init_compound(ctrl, i, ptr);
> + for (i = from_idx; i < tot_elems; i++) {
> + switch (which) {
> + case V4L2_CTRL_WHICH_DEF_VAL:
> + std_init_compound(ctrl, i, ptr);
> + break;
> + case V4L2_CTRL_WHICH_MAX_VAL:
> + std_max_compound(ctrl, i, ptr);
> + break;
> + case V4L2_CTRL_WHICH_MIN_VAL:
> + std_min_compound(ctrl, i, ptr);
> + break;
> + }
> + }
> break;
> }
> }
> +
> +void v4l2_ctrl_type_op_init(const struct v4l2_ctrl *ctrl, u32 from_idx,
> + union v4l2_ctrl_ptr ptr)
> +{
> + __v4l2_ctrl_type_op_init(ctrl, from_idx, V4L2_CTRL_WHICH_DEF_VAL, ptr);
> +}
> EXPORT_SYMBOL(v4l2_ctrl_type_op_init);
>
> +void v4l2_ctrl_type_op_minimum(const struct v4l2_ctrl *ctrl, u32 from_idx,
> + union v4l2_ctrl_ptr ptr)
> +{
> + __v4l2_ctrl_type_op_init(ctrl, from_idx, V4L2_CTRL_WHICH_MIN_VAL, ptr);
> +}
> +
> +void v4l2_ctrl_type_op_maximum(const struct v4l2_ctrl *ctrl, u32 from_idx,
> + union v4l2_ctrl_ptr ptr)
> +{
> + __v4l2_ctrl_type_op_init(ctrl, from_idx, V4L2_CTRL_WHICH_MAX_VAL, ptr);
> +}
> +
> void v4l2_ctrl_type_op_log(const struct v4l2_ctrl *ctrl)
> {
> union v4l2_ctrl_ptr ptr = ctrl->p_cur;
> @@ -1293,6 +1359,8 @@ EXPORT_SYMBOL(v4l2_ctrl_type_op_validate);
> static const struct v4l2_ctrl_type_ops std_type_ops = {
> .equal = v4l2_ctrl_type_op_equal,
> .init = v4l2_ctrl_type_op_init,
> + .minimum = v4l2_ctrl_type_op_minimum,
> + .maximum = v4l2_ctrl_type_op_maximum,
> .log = v4l2_ctrl_type_op_log,
> .validate = v4l2_ctrl_type_op_validate,
> };
> @@ -1764,7 +1832,10 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
> s64 min, s64 max, u64 step, s64 def,
> const u32 dims[V4L2_CTRL_MAX_DIMS], u32 elem_size,
> u32 flags, const char * const *qmenu,
> - const s64 *qmenu_int, const union v4l2_ctrl_ptr p_def,
> + const s64 *qmenu_int,
> + const union v4l2_ctrl_ptr p_def,
> + const union v4l2_ctrl_ptr p_min,
> + const union v4l2_ctrl_ptr p_max,
> void *priv)
> {
> struct v4l2_ctrl *ctrl;
> @@ -1888,6 +1959,12 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
> break;
> }
>
> + if (type < V4L2_CTRL_COMPOUND_TYPES &&
> + type != V4L2_CTRL_TYPE_BUTTON &&
> + type != V4L2_CTRL_TYPE_CTRL_CLASS &&
> + type != V4L2_CTRL_TYPE_STRING)
> + flags |= V4L2_CTRL_FLAG_HAS_WHICH_MIN_MAX;
> +
> /* Sanity checks */
> if (id == 0 || name == NULL || !elem_size ||
> id >= V4L2_CID_PRIVATE_BASE ||
> @@ -1896,6 +1973,7 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
> handler_set_err(hdl, -ERANGE);
> return NULL;
> }
> +
> err = check_range(type, min, max, step, def);
> if (err) {
> handler_set_err(hdl, err);
> @@ -1937,6 +2015,10 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
>
> if (type >= V4L2_CTRL_COMPOUND_TYPES && p_def.p_const)
> sz_extra += elem_size;
> + if (type >= V4L2_CTRL_COMPOUND_TYPES && p_min.p_const)
> + sz_extra += elem_size;
> + if (type >= V4L2_CTRL_COMPOUND_TYPES && p_max.p_const)
> + sz_extra += elem_size;
>
> ctrl = kvzalloc(sizeof(*ctrl) + sz_extra, GFP_KERNEL);
> if (ctrl == NULL) {
> @@ -2002,6 +2084,22 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
> memcpy(ctrl->p_def.p, p_def.p_const, elem_size);
> }
>
> + if (flags & V4L2_CTRL_FLAG_HAS_WHICH_MIN_MAX) {
> + void *ptr = ctrl->p_def.p;
> +
> + if (p_min.p_const) {
> + ptr += elem_size;
> + ctrl->p_min.p = ptr;
> + memcpy(ctrl->p_min.p, p_min.p_const, elem_size);
> + }
> +
> + if (p_max.p_const) {
> + ptr += elem_size;
> + ctrl->p_max.p = ptr;
> + memcpy(ctrl->p_max.p, p_max.p_const, elem_size);
> + }
> + }
> +
> ctrl->type_ops->init(ctrl, 0, ctrl->p_cur);
> cur_to_new(ctrl);
>
> @@ -2052,7 +2150,8 @@ struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl,
> type, min, max,
> is_menu ? cfg->menu_skip_mask : step, def,
> cfg->dims, cfg->elem_size,
> - flags, qmenu, qmenu_int, cfg->p_def, priv);
> + flags, qmenu, qmenu_int, cfg->p_def, cfg->p_min,
> + cfg->p_max, priv);
> if (ctrl)
> ctrl->is_private = cfg->is_private;
> return ctrl;
> @@ -2077,7 +2176,8 @@ struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl,
> }
> return v4l2_ctrl_new(hdl, ops, NULL, id, name, type,
> min, max, step, def, NULL, 0,
> - flags, NULL, NULL, ptr_null, NULL);
> + flags, NULL, NULL, ptr_null, ptr_null,
> + ptr_null, NULL);
> }
> EXPORT_SYMBOL(v4l2_ctrl_new_std);
>
> @@ -2110,7 +2210,8 @@ struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
> }
> return v4l2_ctrl_new(hdl, ops, NULL, id, name, type,
> 0, max, mask, def, NULL, 0,
> - flags, qmenu, qmenu_int, ptr_null, NULL);
> + flags, qmenu, qmenu_int, ptr_null, ptr_null,
> + ptr_null, NULL);
> }
> EXPORT_SYMBOL(v4l2_ctrl_new_std_menu);
>
> @@ -2142,7 +2243,8 @@ struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
> }
> return v4l2_ctrl_new(hdl, ops, NULL, id, name, type,
> 0, max, mask, def, NULL, 0,
> - flags, qmenu, NULL, ptr_null, NULL);
> + flags, qmenu, NULL, ptr_null, ptr_null,
> + ptr_null, NULL);
>
> }
> EXPORT_SYMBOL(v4l2_ctrl_new_std_menu_items);
> @@ -2150,7 +2252,9 @@ EXPORT_SYMBOL(v4l2_ctrl_new_std_menu_items);
> /* Helper function for standard compound controls */
> struct v4l2_ctrl *v4l2_ctrl_new_std_compound(struct v4l2_ctrl_handler *hdl,
> const struct v4l2_ctrl_ops *ops, u32 id,
> - const union v4l2_ctrl_ptr p_def)
> + const union v4l2_ctrl_ptr p_def,
> + const union v4l2_ctrl_ptr p_min,
> + const union v4l2_ctrl_ptr p_max)
> {
> const char *name;
> enum v4l2_ctrl_type type;
> @@ -2164,7 +2268,7 @@ struct v4l2_ctrl *v4l2_ctrl_new_std_compound(struct v4l2_ctrl_handler *hdl,
> }
> return v4l2_ctrl_new(hdl, ops, NULL, id, name, type,
> min, max, step, def, NULL, 0,
> - flags, NULL, NULL, p_def, NULL);
> + flags, NULL, NULL, p_def, p_min, p_max, NULL);
> }
> EXPORT_SYMBOL(v4l2_ctrl_new_std_compound);
>
> @@ -2188,7 +2292,8 @@ struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl,
> }
> return v4l2_ctrl_new(hdl, ops, NULL, id, name, type,
> 0, max, 0, def, NULL, 0,
> - flags, NULL, qmenu_int, ptr_null, NULL);
> + flags, NULL, qmenu_int, ptr_null, ptr_null,
> + ptr_null, NULL);
> }
> EXPORT_SYMBOL(v4l2_ctrl_new_int_menu);
>
> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> index 9b1de54ce379..db5bd765db3c 100644
> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> @@ -884,7 +884,9 @@ static bool check_ext_ctrls(struct v4l2_ext_controls *c, unsigned long ioctl)
> return false;
> break;
> case V4L2_CTRL_WHICH_DEF_VAL:
> - /* Default value cannot be changed */
> + case V4L2_CTRL_WHICH_MIN_VAL:
> + case V4L2_CTRL_WHICH_MAX_VAL:
> + /* Default, minimum or maximum value cannot be changed */
> if (ioctl == VIDIOC_S_EXT_CTRLS ||
> ioctl == VIDIOC_TRY_EXT_CTRLS) {
> c->error_idx = c->count;
> diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
> index b0db167a3ac4..9ed7be1e696f 100644
> --- a/include/media/v4l2-ctrls.h
> +++ b/include/media/v4l2-ctrls.h
> @@ -133,6 +133,8 @@ struct v4l2_ctrl_ops {
> *
> * @equal: return true if all ctrl->elems array elements are equal.
> * @init: initialize the value for array elements from from_idx to ctrl->elems.
> + * @minimum: set the value to the minimum value of the control.
> + * @maximum: set the value to the maximum value of the control.
> * @log: log the value.
> * @validate: validate the value for ctrl->new_elems array elements.
> * Return 0 on success and a negative value otherwise.
> @@ -142,6 +144,10 @@ struct v4l2_ctrl_type_ops {
> union v4l2_ctrl_ptr ptr1, union v4l2_ctrl_ptr ptr2);
> void (*init)(const struct v4l2_ctrl *ctrl, u32 from_idx,
> union v4l2_ctrl_ptr ptr);
> + void (*minimum)(const struct v4l2_ctrl *ctrl, u32 idx,
> + union v4l2_ctrl_ptr ptr);
> + void (*maximum)(const struct v4l2_ctrl *ctrl, u32 idx,
> + union v4l2_ctrl_ptr ptr);
> void (*log)(const struct v4l2_ctrl *ctrl);
> int (*validate)(const struct v4l2_ctrl *ctrl, union v4l2_ctrl_ptr ptr);
> };
> @@ -247,6 +253,12 @@ typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv);
> * @p_def: The control's default value represented via a union which
> * provides a standard way of accessing control types
> * through a pointer (for compound controls only).
> + * @p_min: The control's minimum value represented via a union which
> + * provides a standard way of accessing control types
> + * through a pointer (for compound controls only).
> + * @p_max: The control's maximum value represented via a union which
> + * provides a standard way of accessing control types
> + * through a pointer (for compound controls only).
> * @p_cur: The control's current value represented via a union which
> * provides a standard way of accessing control types
> * through a pointer.
> @@ -306,6 +318,8 @@ struct v4l2_ctrl {
> } cur;
>
> union v4l2_ctrl_ptr p_def;
> + union v4l2_ctrl_ptr p_min;
> + union v4l2_ctrl_ptr p_max;
> union v4l2_ctrl_ptr p_new;
> union v4l2_ctrl_ptr p_cur;
> };
> @@ -425,6 +439,8 @@ struct v4l2_ctrl_handler {
> * @step: The control's step value for non-menu controls.
> * @def: The control's default value.
> * @p_def: The control's default value for compound controls.
> + * @p_min: The control's minimum value for compound controls.
> + * @p_max: The control's maximum value for compound controls.
> * @dims: The size of each dimension.
> * @elem_size: The size in bytes of the control.
> * @flags: The control's flags.
> @@ -454,6 +470,8 @@ struct v4l2_ctrl_config {
> u64 step;
> s64 def;
> union v4l2_ctrl_ptr p_def;
> + union v4l2_ctrl_ptr p_min;
> + union v4l2_ctrl_ptr p_max;
> u32 dims[V4L2_CTRL_MAX_DIMS];
> u32 elem_size;
> u32 flags;
> @@ -723,17 +741,25 @@ struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
> * @ops: The control ops.
> * @id: The control ID.
> * @p_def: The control's default value.
> + * @p_min: The control's minimum value.
> + * @p_max: The control's maximum value.
> *
> - * Sames as v4l2_ctrl_new_std(), but with support to compound controls, thanks
> - * to the @p_def field. Use v4l2_ctrl_ptr_create() to create @p_def from a
> - * pointer. Use v4l2_ctrl_ptr_create(NULL) if the default value of the
> - * compound control should be all zeroes.
> + * Same as v4l2_ctrl_new_std(), but with support for compound controls.
> + * To fill in the @p_def, @p_min and @p_max fields, use v4l2_ctrl_ptr_create()
> + * to convert a pointer to a const union v4l2_ctrl_ptr.
> + * Use v4l2_ctrl_ptr_create(NULL) if you want the default, minimum or maximum
> + * value of the compound control to be all zeroes.
> + * If the compound control does not set the ``V4L2_CTRL_FLAG_HAS_WHICH_MIN_MAX``
> + * flag, then it does not has minimum and maximum values. In that case just use

has -> have

Regards,

Hans

> + * v4l2_ctrl_ptr_create(NULL) for the @p_min and @p_max arguments.
> *
> */
> struct v4l2_ctrl *v4l2_ctrl_new_std_compound(struct v4l2_ctrl_handler *hdl,
> const struct v4l2_ctrl_ops *ops,
> u32 id,
> - const union v4l2_ctrl_ptr p_def);
> + const union v4l2_ctrl_ptr p_def,
> + const union v4l2_ctrl_ptr p_min,
> + const union v4l2_ctrl_ptr p_max);
>
> /**
> * v4l2_ctrl_new_int_menu() - Create a new standard V4L2 integer menu control.
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 82d86abcf89c..8fdeb5188af5 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -1866,6 +1866,8 @@ struct v4l2_ext_controls {
> #define V4L2_CTRL_WHICH_CUR_VAL 0
> #define V4L2_CTRL_WHICH_DEF_VAL 0x0f000000
> #define V4L2_CTRL_WHICH_REQUEST_VAL 0x0f010000
> +#define V4L2_CTRL_WHICH_MIN_VAL 0x0f020000
> +#define V4L2_CTRL_WHICH_MAX_VAL 0x0f030000
>
> enum v4l2_ctrl_type {
> V4L2_CTRL_TYPE_INTEGER = 1,
> @@ -1973,6 +1975,7 @@ struct v4l2_querymenu {
> #define V4L2_CTRL_FLAG_EXECUTE_ON_WRITE 0x0200
> #define V4L2_CTRL_FLAG_MODIFY_LAYOUT 0x0400
> #define V4L2_CTRL_FLAG_DYNAMIC_ARRAY 0x0800
> +#define V4L2_CTRL_FLAG_HAS_WHICH_MIN_MAX 0x1000
>
> /* Query flags, to be ORed with the control ID */
> #define V4L2_CTRL_FLAG_NEXT_CTRL 0x80000000