Here is an RFC patch adding support for 'fraction_bits'. It's lacking documentation, but it can be used for testing.
It was rather a pain logging fixed point number in a reasonable format, but I think it is OK.
In userspace (where you can use floating point) it is a lot easier:
printf("%.*g\n", fraction_bits, (double)v * (1.0 / (1ULL << fraction_bits)));
I decided to only expose fraction_bits in struct v4l2_query_ext_ctrl. I could add it to struct v4l2_queryctrl, but I did not think that was necessary. Other opinions are welcome.
In the meantime, let me know if this works for your patch series. If it does, then I can clean this up.
Regards,
Hans
Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl --- drivers/media/v4l2-core/v4l2-ctrls-api.c | 1 + drivers/media/v4l2-core/v4l2-ctrls-core.c | 72 +++++++++++++++++++---- include/media/v4l2-ctrls.h | 7 ++- include/uapi/linux/videodev2.h | 20 ++++++- 4 files changed, 85 insertions(+), 15 deletions(-)
diff --git a/drivers/media/v4l2-core/v4l2-ctrls-api.c b/drivers/media/v4l2-core/v4l2-ctrls-api.c index 002ea6588edf..3132df315b17 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 a662fb60f73f..0e08a371af5c 100644 --- a/drivers/media/v4l2-core/v4l2-ctrls-core.c +++ b/drivers/media/v4l2-core/v4l2-ctrls-core.c @@ -252,12 +252,42 @@ 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 = v4l2_fp_integer(v, fraction_bits); + s64 f = v4l2_fp_fraction(v, fraction_bits); + + 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 +296,10 @@ 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); + if (!ctrl->fraction_bits) + pr_cont("%d", *ptr.p_s32); + else + 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 +314,31 @@ 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); + if (!ctrl->fraction_bits) + pr_cont("%lld", *ptr.p_s64); + else + 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); + if (!ctrl->fraction_bits) + pr_cont("%u", (unsigned int)*ptr.p_u8); + else + v4l2_ctrl_log_fp((unsigned int)*ptr.p_u8, ctrl->fraction_bits); break; case V4L2_CTRL_TYPE_U16: - pr_cont("%u", (unsigned)*ptr.p_u16); + if (!ctrl->fraction_bits) + pr_cont("%u", (unsigned int)*ptr.p_u16); + else + v4l2_ctrl_log_fp((unsigned int)*ptr.p_u16, ctrl->fraction_bits); break; case V4L2_CTRL_TYPE_U32: - pr_cont("%u", (unsigned)*ptr.p_u32); + if (!ctrl->fraction_bits) + pr_cont("%u", (unsigned int)*ptr.p_u32); + else + v4l2_ctrl_log_fp((unsigned int)*ptr.p_u32, ctrl->fraction_bits); break; case V4L2_CTRL_TYPE_H264_SPS: pr_cont("H264_SPS"); @@ -1752,7 +1797,7 @@ 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) { @@ -1939,6 +1984,7 @@ 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; @@ -2037,7 +2083,7 @@ 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; @@ -2062,7 +2108,7 @@ 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); @@ -2095,7 +2141,7 @@ 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); @@ -2127,7 +2173,7 @@ 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);
} @@ -2149,7 +2195,7 @@ 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); @@ -2173,7 +2219,7 @@ 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 c3d4e490ce7c..26ecac19722a 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -1944,9 +1944,27 @@ 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]; };
+static inline __s64 v4l2_fp_compose(__s64 i, __s64 f, unsigned int fraction_bits) +{ + return (i << fraction_bits) + f; +} + +static inline __s64 v4l2_fp_integer(__s64 v, unsigned int fraction_bits) +{ + return v / (1LL << fraction_bits); +} + +static inline __s64 v4l2_fp_fraction(__s64 v, unsigned int fraction_bits) +{ + __u64 mask = (1ULL << fraction_bits) - 1; + + return v < 0 ? -((-v) & mask) : (v & mask); +} + /* Used in the VIDIOC_QUERYMENU ioctl for querying menu items */ struct v4l2_querymenu { __u32 id;