[PATCH v8 1/8] media: v4l2-core: Implement v4l2_ctrl_new_std_compound

From: Ricardo Ribalda Delgado
Date: Mon Sep 30 2019 - 06:18:50 EST


From: Ricardo Ribalda Delgado <ricardo@xxxxxxxxxxx>

Currently compound controls do not have a simple way of initializing its
values. This results in ofuscated code with type_ops init.

This patch introduces a new field on the control with the default value
for the compound control that can be set with the brand new
v4l2_ctrl_new_std_compound function

Suggested-by: Hans Verkuil <hverkuil@xxxxxxxxx>
Signed-off-by: Ricardo Ribalda Delgado <ribalda@xxxxxxxxxx>
---
drivers/media/v4l2-core/v4l2-ctrls.c | 50 ++++++++++++++++++++++++----
include/media/v4l2-ctrls.h | 21 ++++++++++++
2 files changed, 64 insertions(+), 7 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index 1d8f38824631..219d8aeefa20 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -29,6 +29,8 @@
#define call_op(master, op) \
(has_op(master, op) ? master->ops->op(master) : 0)

+static const union v4l2_ctrl_ptr ptr_null;
+
/* Internal temporary helper struct, one for each v4l2_ext_control */
struct v4l2_ctrl_helper {
/* Pointer to the control reference of the master control */
@@ -1530,7 +1532,10 @@ static void std_init_compound(const struct v4l2_ctrl *ctrl, u32 idx,
struct v4l2_ctrl_mpeg2_slice_params *p_mpeg2_slice_params;
void *p = ptr.p + idx * ctrl->elem_size;

- memset(p, 0, ctrl->elem_size);
+ if (ctrl->p_def.p)
+ memcpy(p, ctrl->p_def.p, ctrl->elem_size);
+ else
+ memset(p, 0, ctrl->elem_size);

/*
* The cast is needed to get rid of a gcc warning complaining that
@@ -2354,7 +2359,8 @@ 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, void *priv)
+ const s64 *qmenu_int, const union v4l2_ctrl_ptr p_def,
+ void *priv)
{
struct v4l2_ctrl *ctrl;
unsigned sz_extra;
@@ -2460,6 +2466,9 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
is_array)
sz_extra += 2 * tot_ctrl_size;

+ if (type >= V4L2_CTRL_COMPOUND_TYPES && p_def.p)
+ sz_extra += elem_size;
+
ctrl = kvzalloc(sizeof(*ctrl) + sz_extra, GFP_KERNEL);
if (ctrl == NULL) {
handler_set_err(hdl, -ENOMEM);
@@ -2503,6 +2512,12 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
ctrl->p_new.p = &ctrl->val;
ctrl->p_cur.p = &ctrl->cur.val;
}
+
+ if (type >= V4L2_CTRL_COMPOUND_TYPES && p_def.p) {
+ ctrl->p_def.p = ctrl->p_cur.p + tot_ctrl_size;
+ memcpy(ctrl->p_def.p, p_def.p, elem_size);
+ }
+
for (idx = 0; idx < elems; idx++) {
ctrl->type_ops->init(ctrl, idx, ctrl->p_cur);
ctrl->type_ops->init(ctrl, idx, ctrl->p_new);
@@ -2554,7 +2569,7 @@ 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, priv);
+ flags, qmenu, qmenu_int, ptr_null, priv);
if (ctrl)
ctrl->is_private = cfg->is_private;
return ctrl;
@@ -2579,7 +2594,7 @@ 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, NULL);
+ flags, NULL, NULL, ptr_null, NULL);
}
EXPORT_SYMBOL(v4l2_ctrl_new_std);

@@ -2612,7 +2627,7 @@ 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, NULL);
+ flags, qmenu, qmenu_int, ptr_null, NULL);
}
EXPORT_SYMBOL(v4l2_ctrl_new_std_menu);

@@ -2644,11 +2659,32 @@ 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, NULL);
+ flags, qmenu, NULL, ptr_null, NULL);

}
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 char *name;
+ enum v4l2_ctrl_type type;
+ u32 flags;
+ s64 min, max, step, def;
+
+ v4l2_ctrl_fill(id, &name, &type, &min, &max, &step, &def, &flags);
+ if (type < V4L2_CTRL_COMPOUND_TYPES) {
+ handler_set_err(hdl, -EINVAL);
+ return NULL;
+ }
+ return v4l2_ctrl_new(hdl, ops, NULL, id, name, type,
+ min, max, step, def, NULL, 0,
+ flags, NULL, NULL, p_def, NULL);
+}
+EXPORT_SYMBOL(v4l2_ctrl_new_std_compound);
+
/* Helper function for standard integer menu controls */
struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl,
const struct v4l2_ctrl_ops *ops,
@@ -2669,7 +2705,7 @@ 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, NULL);
+ 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 570ff4b0205a..90a8ee48c2f3 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -200,6 +200,9 @@ typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv);
* not freed when the control is deleted. Should this be needed
* then a new internal bitfield can be added to tell the framework
* to free this pointer.
+ * @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_cur: The control's current value represented via a union which
* provides a standard way of accessing control types
* through a pointer.
@@ -254,6 +257,7 @@ struct v4l2_ctrl {
s32 val;
} cur;

+ union v4l2_ctrl_ptr p_def;
union v4l2_ctrl_ptr p_new;
union v4l2_ctrl_ptr p_cur;
};
@@ -646,6 +650,23 @@ struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
u64 mask, u8 def,
const char * const *qmenu);

+/**
+ * v4l2_ctrl_new_std_compound() - Allocate and initialize a new standard V4L2
+ * compound control.
+ *
+ * @hdl: The control handler.
+ * @ops: The control ops.
+ * @id: The control ID.
+ * @p_def: The control's default value.
+ *
+ * Sames as v4l2_ctrl_new_std(), but with support to compound controls, thanks
+ * to the @p_def field.
+ *
+ */
+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);
+
/**
* v4l2_ctrl_new_int_menu() - Create a new standard V4L2 integer menu control.
*
--
2.23.0