From: Hans Verkuil hverkuil@xs4all.nl
This adds support for the fraction_bits field, used with integer controls. This allows fixed point formats to be described.
The fraction_bits field is only exposed through VIDIOC_QUERY_EXT_CTRL.
For a given signed two's complement Qf fixed point value 'f' equals fraction_bits.
Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl --- .../media/v4l/vidioc-queryctrl.rst | 11 ++- drivers/media/v4l2-core/v4l2-ctrls-api.c | 1 + drivers/media/v4l2-core/v4l2-ctrls-core.c | 93 +++++++++++++++---- include/media/v4l2-ctrls.h | 7 +- include/uapi/linux/videodev2.h | 3 +- 5 files changed, 95 insertions(+), 20 deletions(-)
diff --git a/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst b/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst index 4d38acafe8e1..e65c7e5d78ec 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst @@ -267,7 +267,16 @@ See also the examples in :ref:`control`. - The size of each dimension. The first ``nr_of_dims`` elements of this array must be non-zero, all remaining elements must be zero. * - __u32 - - ``reserved``\ [32] + - ``fraction_bits`` + - The number of least significant bits of the control value that + form the fraction of the fixed point value. This is 0 if the value + is a regular integer. This can be used with all integer control types + (``INTEGER``, ``INTEGER64``, ``U8``, ``U16`` and ``U32``). + For the signed types the signed two's complement representation is used. + This field applies to the control value as well as the ``minimum``, + ``maximum``, ``step`` and ``default_value`` fields. + * - __u32 + - ``reserved``\ [31] - Reserved for future extensions. Applications and drivers must set the array to zero.
diff --git a/drivers/media/v4l2-core/v4l2-ctrls-api.c b/drivers/media/v4l2-core/v4l2-ctrls-api.c index d9a422017bd9..ef16b00421ec 100644 --- a/drivers/media/v4l2-core/v4l2-ctrls-api.c +++ b/drivers/media/v4l2-core/v4l2-ctrls-api.c @@ -1101,6 +1101,7 @@ int v4l2_query_ext_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_query_ext_ctr qc->elems = ctrl->elems; qc->nr_of_dims = ctrl->nr_of_dims; memcpy(qc->dims, ctrl->dims, qc->nr_of_dims * sizeof(qc->dims[0])); + qc->fraction_bits = ctrl->fraction_bits; qc->minimum = ctrl->minimum; qc->maximum = ctrl->maximum; qc->default_value = ctrl->default_value; diff --git a/drivers/media/v4l2-core/v4l2-ctrls-core.c b/drivers/media/v4l2-core/v4l2-ctrls-core.c index c4d995f32191..d83a37198bb5 100644 --- a/drivers/media/v4l2-core/v4l2-ctrls-core.c +++ b/drivers/media/v4l2-core/v4l2-ctrls-core.c @@ -252,12 +252,61 @@ void v4l2_ctrl_type_op_init(const struct v4l2_ctrl *ctrl, u32 from_idx, } EXPORT_SYMBOL(v4l2_ctrl_type_op_init);
+static void v4l2_ctrl_log_fp(s64 v, unsigned int fraction_bits) +{ + s64 i, f, mask; + + if (!fraction_bits) { + pr_cont("%lld", v); + return; + } + + mask = (1ULL << fraction_bits) - 1; + + /* + * Note: this function does not support fixed point u64 with + * fraction_bits set to 64. At the moment there is no U64 + * control type, but if that is added, then this code will have + * to add support for it. + */ + if (fraction_bits >= 63) + i = v < 0 ? -1 : 0; + else + i = div64_s64(v, 1LL << fraction_bits); + + f = v < 0 ? -((-v) & mask) : (v & mask); + + if (!f) { + pr_cont("%lld", i); + } else if (fraction_bits < 20) { + u64 div = 1ULL << fraction_bits; + + if (!i && f < 0) + pr_cont("-%lld/%llu", -f, div); + else if (!i) + pr_cont("%lld/%llu", f, div); + else if (i < 0 || f < 0) + pr_cont("-%lld-%llu/%llu", -i, -f, div); + else + pr_cont("%lld+%llu/%llu", i, f, div); + } else { + if (!i && f < 0) + pr_cont("-%lld/(2^%u)", -f, fraction_bits); + else if (!i) + pr_cont("%lld/(2^%u)", f, fraction_bits); + else if (i < 0 || f < 0) + pr_cont("-%lld-%llu/(2^%u)", -i, -f, fraction_bits); + else + pr_cont("%lld+%llu/(2^%u)", i, f, fraction_bits); + } +} + void v4l2_ctrl_type_op_log(const struct v4l2_ctrl *ctrl) { union v4l2_ctrl_ptr ptr = ctrl->p_cur;
if (ctrl->is_array) { - unsigned i; + unsigned int i;
for (i = 0; i < ctrl->nr_of_dims; i++) pr_cont("[%u]", ctrl->dims[i]); @@ -266,7 +315,7 @@ void v4l2_ctrl_type_op_log(const struct v4l2_ctrl *ctrl)
switch (ctrl->type) { case V4L2_CTRL_TYPE_INTEGER: - pr_cont("%d", *ptr.p_s32); + v4l2_ctrl_log_fp(*ptr.p_s32, ctrl->fraction_bits); break; case V4L2_CTRL_TYPE_BOOLEAN: pr_cont("%s", *ptr.p_s32 ? "true" : "false"); @@ -281,19 +330,19 @@ void v4l2_ctrl_type_op_log(const struct v4l2_ctrl *ctrl) pr_cont("0x%08x", *ptr.p_s32); break; case V4L2_CTRL_TYPE_INTEGER64: - pr_cont("%lld", *ptr.p_s64); + v4l2_ctrl_log_fp(*ptr.p_s64, ctrl->fraction_bits); break; case V4L2_CTRL_TYPE_STRING: pr_cont("%s", ptr.p_char); break; case V4L2_CTRL_TYPE_U8: - pr_cont("%u", (unsigned)*ptr.p_u8); + v4l2_ctrl_log_fp(*ptr.p_u8, ctrl->fraction_bits); break; case V4L2_CTRL_TYPE_U16: - pr_cont("%u", (unsigned)*ptr.p_u16); + v4l2_ctrl_log_fp(*ptr.p_u16, ctrl->fraction_bits); break; case V4L2_CTRL_TYPE_U32: - pr_cont("%u", (unsigned)*ptr.p_u32); + v4l2_ctrl_log_fp(*ptr.p_u32, ctrl->fraction_bits); break; case V4L2_CTRL_TYPE_H264_SPS: pr_cont("H264_SPS"); @@ -1753,11 +1802,12 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl, u32 id, const char *name, enum v4l2_ctrl_type type, s64 min, s64 max, u64 step, s64 def, const u32 dims[V4L2_CTRL_MAX_DIMS], u32 elem_size, - u32 flags, const char * const *qmenu, + u32 fraction_bits, u32 flags, const char * const *qmenu, const s64 *qmenu_int, const union v4l2_ctrl_ptr p_def, void *priv) { struct v4l2_ctrl *ctrl; + unsigned int max_fraction_bits = 0; unsigned sz_extra; unsigned nr_of_dims = 0; unsigned elems = 1; @@ -1779,20 +1829,28 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
/* Prefill elem_size for all types handled by std_type_ops */ switch ((u32)type) { + case V4L2_CTRL_TYPE_INTEGER: + elem_size = sizeof(s32); + max_fraction_bits = 31; + break; case V4L2_CTRL_TYPE_INTEGER64: elem_size = sizeof(s64); + max_fraction_bits = 63; break; case V4L2_CTRL_TYPE_STRING: elem_size = max + 1; break; case V4L2_CTRL_TYPE_U8: elem_size = sizeof(u8); + max_fraction_bits = 8; break; case V4L2_CTRL_TYPE_U16: elem_size = sizeof(u16); + max_fraction_bits = 16; break; case V4L2_CTRL_TYPE_U32: elem_size = sizeof(u32); + max_fraction_bits = 32; break; case V4L2_CTRL_TYPE_MPEG2_SEQUENCE: elem_size = sizeof(struct v4l2_ctrl_mpeg2_sequence); @@ -1876,10 +1934,10 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl, }
/* Sanity checks */ - if (id == 0 || name == NULL || !elem_size || - id >= V4L2_CID_PRIVATE_BASE || - (type == V4L2_CTRL_TYPE_MENU && qmenu == NULL) || - (type == V4L2_CTRL_TYPE_INTEGER_MENU && qmenu_int == NULL)) { + if (id == 0 || !name || !elem_size || + fraction_bits > max_fraction_bits || id >= V4L2_CID_PRIVATE_BASE || + (type == V4L2_CTRL_TYPE_MENU && !qmenu) || + (type == V4L2_CTRL_TYPE_INTEGER_MENU && !qmenu_int)) { handler_set_err(hdl, -ERANGE); return NULL; } @@ -1940,6 +1998,7 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl, ctrl->name = name; ctrl->type = type; ctrl->flags = flags; + ctrl->fraction_bits = fraction_bits; ctrl->minimum = min; ctrl->maximum = max; ctrl->step = step; @@ -2038,7 +2097,7 @@ struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl, ctrl = v4l2_ctrl_new(hdl, cfg->ops, cfg->type_ops, cfg->id, name, type, min, max, is_menu ? cfg->menu_skip_mask : step, def, - cfg->dims, cfg->elem_size, + cfg->dims, cfg->elem_size, cfg->fraction_bits, flags, qmenu, qmenu_int, cfg->p_def, priv); if (ctrl) ctrl->is_private = cfg->is_private; @@ -2063,7 +2122,7 @@ struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl, return NULL; } return v4l2_ctrl_new(hdl, ops, NULL, id, name, type, - min, max, step, def, NULL, 0, + min, max, step, def, NULL, 0, 0, flags, NULL, NULL, ptr_null, NULL); } EXPORT_SYMBOL(v4l2_ctrl_new_std); @@ -2096,7 +2155,7 @@ struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl, return NULL; } return v4l2_ctrl_new(hdl, ops, NULL, id, name, type, - 0, max, mask, def, NULL, 0, + 0, max, mask, def, NULL, 0, 0, flags, qmenu, qmenu_int, ptr_null, NULL); } EXPORT_SYMBOL(v4l2_ctrl_new_std_menu); @@ -2128,7 +2187,7 @@ struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl, return NULL; } return v4l2_ctrl_new(hdl, ops, NULL, id, name, type, - 0, max, mask, def, NULL, 0, + 0, max, mask, def, NULL, 0, 0, flags, qmenu, NULL, ptr_null, NULL);
} @@ -2150,7 +2209,7 @@ struct v4l2_ctrl *v4l2_ctrl_new_std_compound(struct v4l2_ctrl_handler *hdl, return NULL; } return v4l2_ctrl_new(hdl, ops, NULL, id, name, type, - min, max, step, def, NULL, 0, + min, max, step, def, NULL, 0, 0, flags, NULL, NULL, p_def, NULL); } EXPORT_SYMBOL(v4l2_ctrl_new_std_compound); @@ -2174,7 +2233,7 @@ struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl, return NULL; } return v4l2_ctrl_new(hdl, ops, NULL, id, name, type, - 0, max, 0, def, NULL, 0, + 0, max, 0, def, NULL, 0, 0, flags, NULL, qmenu_int, ptr_null, NULL); } EXPORT_SYMBOL(v4l2_ctrl_new_int_menu); diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h index 59679a42b3e7..c35514c5bf88 100644 --- a/include/media/v4l2-ctrls.h +++ b/include/media/v4l2-ctrls.h @@ -211,7 +211,8 @@ typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv); * except for dynamic arrays. In that case it is in the range of * 1 to @p_array_alloc_elems. * @dims: The size of each dimension. - * @nr_of_dims:The number of dimensions in @dims. + * @nr_of_dims: The number of dimensions in @dims. + * @fraction_bits: The number of fraction bits for fixed point values. * @menu_skip_mask: The control's skip mask for menu controls. This makes it * easy to skip menu items that are not valid. If bit X is set, * then menu item X is skipped. Of course, this only works for @@ -228,6 +229,7 @@ typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv); * :math:`ceil(\frac{maximum - minimum}{step}) + 1`. * Used only if the @type is %V4L2_CTRL_TYPE_INTEGER_MENU. * @flags: The control's flags. + * @fraction_bits: The number of fraction bits for fixed point values. * @priv: The control's private pointer. For use by the driver. It is * untouched by the control framework. Note that this pointer is * not freed when the control is deleted. Should this be needed @@ -286,6 +288,7 @@ struct v4l2_ctrl { u32 new_elems; u32 dims[V4L2_CTRL_MAX_DIMS]; u32 nr_of_dims; + u32 fraction_bits; union { u64 step; u64 menu_skip_mask; @@ -426,6 +429,7 @@ struct v4l2_ctrl_handler { * @dims: The size of each dimension. * @elem_size: The size in bytes of the control. * @flags: The control's flags. + * @fraction_bits: The number of fraction bits for fixed point values. * @menu_skip_mask: The control's skip mask for menu controls. This makes it * easy to skip menu items that are not valid. If bit X is set, * then menu item X is skipped. Of course, this only works for @@ -455,6 +459,7 @@ struct v4l2_ctrl_config { u32 dims[V4L2_CTRL_MAX_DIMS]; u32 elem_size; u32 flags; + u32 fraction_bits; u64 menu_skip_mask; const char * const *qmenu; const s64 *qmenu_int; diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h index a8015e5e7fa4..b8573e9ccde6 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -1947,7 +1947,8 @@ struct v4l2_query_ext_ctrl { __u32 elems; __u32 nr_of_dims; __u32 dims[V4L2_CTRL_MAX_DIMS]; - __u32 reserved[32]; + __u32 fraction_bits; + __u32 reserved[31]; };
/* Used in the VIDIOC_QUERYMENU ioctl for querying menu items */