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* [PATCH v2 05/10] media/v4l2-core: struct struct v4l2_ext_controls param which
@ 2015-08-21 14:26 Ricardo Ribalda Delgado
  0 siblings, 0 replies; 2+ messages in thread
From: Ricardo Ribalda Delgado @ 2015-08-21 14:26 UTC (permalink / raw)
  To: Mauro Carvalho Chehab, Mike Isely, Laurent Pinchart,
	Hans Verkuil, Steven Toth, Sakari Ailus, Vincent Palatin,
	linux-media, linux-kernel
  Cc: Ricardo Ribalda Delgado

Support for new field which on v4l2_ext_controls, used to get the
default value of one or more controls.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
---
I missed a ;... sorry about that


 drivers/media/v4l2-core/v4l2-ctrls.c | 34 +++++++++++++++++++++++++++++-----
 1 file changed, 29 insertions(+), 5 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index 580098ba5c0b..0caae655968e 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -1489,6 +1489,17 @@ static int new_to_user(struct v4l2_ext_control *c,
 	return ptr_to_user(c, ctrl, ctrl->p_new);
 }
 
+/* Helper function: copy the initial control value back to the caller */
+static int def_to_user(struct v4l2_ext_control *c, struct v4l2_ctrl *ctrl)
+{
+	int idx;
+
+	for (idx = 0; idx < ctrl->elems; idx++)
+		ctrl->type_ops->init(ctrl, idx, ctrl->p_new);
+
+	return ptr_to_user(c, ctrl, ctrl->p_new);
+}
+
 /* Helper function: copy the caller-provider value to the given control value */
 static int user_to_ptr(struct v4l2_ext_control *c,
 		       struct v4l2_ctrl *ctrl,
@@ -2708,7 +2719,9 @@ static int prepare_ext_ctrls(struct v4l2_ctrl_handler *hdl,
 
 		cs->error_idx = i;
 
-		if (cs->which && V4L2_CTRL_ID2WHICH(id) != cs->which)
+		if (cs->which &&
+		    cs->which != V4L2_CTRL_WHICH_DEF_VAL &&
+		    V4L2_CTRL_ID2WHICH(id) != cs->which)
 			return -EINVAL;
 
 		/* Old-style private controls are not allowed for
@@ -2787,7 +2800,7 @@ static int prepare_ext_ctrls(struct v4l2_ctrl_handler *hdl,
    whether there are any controls at all. */
 static int class_check(struct v4l2_ctrl_handler *hdl, u32 which)
 {
-	if (!which)
+	if (which == 0 || which == V4L2_CTRL_WHICH_DEF_VAL)
 		return list_empty(&hdl->ctrl_refs) ? -EINVAL : 0;
 	return find_ref_lock(hdl, which | 1) ? 0 : -EINVAL;
 }
@@ -2801,6 +2814,9 @@ int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs
 	struct v4l2_ctrl_helper *helpers = helper;
 	int ret;
 	int i, j;
+	bool def_value;
+
+	def_value = (cs->which == V4L2_CTRL_WHICH_DEF_VAL);
 
 	cs->error_idx = cs->count;
 	cs->which = V4L2_CTRL_ID2WHICH(cs->which);
@@ -2827,9 +2843,11 @@ int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs
 
 	for (i = 0; !ret && i < cs->count; i++) {
 		int (*ctrl_to_user)(struct v4l2_ext_control *c,
-				    struct v4l2_ctrl *ctrl) = cur_to_user;
+				    struct v4l2_ctrl *ctrl);
 		struct v4l2_ctrl *master;
 
+		ctrl_to_user = def_value ? def_to_user : cur_to_user;
+
 		if (helpers[i].mref == NULL)
 			continue;
 
@@ -2839,8 +2857,9 @@ int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs
 		v4l2_ctrl_lock(master);
 
 		/* g_volatile_ctrl will update the new control values */
-		if ((master->flags & V4L2_CTRL_FLAG_VOLATILE) ||
-			(master->has_volatiles && !is_cur_manual(master))) {
+		if (!def_value &&
+		    ((master->flags & V4L2_CTRL_FLAG_VOLATILE) ||
+		    (master->has_volatiles && !is_cur_manual(master)))) {
 			for (j = 0; j < master->ncontrols; j++)
 				cur_to_new(master->cluster[j]);
 			ret = call_op(master, g_volatile_ctrl);
@@ -3062,6 +3081,11 @@ static int try_set_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
 	int ret;
 
 	cs->error_idx = cs->count;
+
+	/* Default value cannot be changed */
+	if (cs->which == V4L2_CTRL_WHICH_DEF_VAL)
+		return -EINVAL;
+
 	cs->which = V4L2_CTRL_ID2WHICH(cs->which);
 
 	if (hdl == NULL)
-- 
2.5.0


^ permalink raw reply	[flat|nested] 2+ messages in thread
* [PATCH v2 00/10] Support getting default values from any control
@ 2015-08-21 13:19 Ricardo Ribalda Delgado
  2015-08-21 13:19 ` [PATCH v2 05/10] media/v4l2-core: struct struct v4l2_ext_controls param which Ricardo Ribalda Delgado
  0 siblings, 1 reply; 2+ messages in thread
From: Ricardo Ribalda Delgado @ 2015-08-21 13:19 UTC (permalink / raw)
  To: Mauro Carvalho Chehab, Mike Isely, Laurent Pinchart,
	Hans Verkuil, Steven Toth, Sakari Ailus, Vincent Palatin,
	linux-media, linux-kernel
  Cc: Ricardo Ribalda Delgado

Integer controls provide a way to get their default/initial value, but
any other control (p_u32, p_u8.....) provide no other way to get the
initial value than unloading the module and loading it back.

*What is the actual problem?
I have a custom control with WIDTH integer values. Every value
represents the calibrated FPN (fixed pattern noise) correction value for that
column
-Application A changes the FPN correction value
-Application B wants to restore the calibrated value but it cant :(

*What is the proposed solution?

(Kudos to Hans Verkuil!!!)

The key change is in struct v4l2_ext_controls where the __u32 ctrl_class field
is changed to:

        union {
                __u32 ctrl_class;
                __u32 which;
        };

And two new defines are added:

#define V4L2_CTRL_WHICH_CUR_VAL        0
#define V4L2_CTRL_WHICH_DEF_VAL        0x0f000000

The 'which' field tells you which controls are get/set/tried.

V4L2_CTRL_WHICH_CUR_VAL: the current value of the controls
V4L2_CTRL_WHICH_DEF_VAL: the default value of the controls
V4L2_CTRL_CLASS_*: the current value of the controls belonging to the specified class.
        Note: this is deprecated usage and is only there for backwards compatibility.
        Which is also why I don't think there is a need to add V4L2_CTRL_WHICH_
        aliases for these defines.


I have posted a copy of my working tree to

https://github.com/ribalda/linux/tree/which_def_v2

Changelog v2:

Suggested by Hans Verkuil <hverkuil@xs4all.nl>

Replace ctrls_class with which on all the codebase
Changes in Documentation
(Thanks!)

Ricardo Ribalda Delgado (10):
  videodev2.h: Fix typo in comment
  videodev2.h: Extend struct v4l2_ext_controls
  media/v4l2-compat-ioctl32: Simple stylechecks
  media/core: Replace ctrl_class with which
  media/v4l2-core: struct struct v4l2_ext_controls param which
  usb/uvc: Support for V4L2_CTRL_WHICH_DEF_VAL
  media/usb/pvrusb2: Support for V4L2_CTRL_WHICH_DEF_VAL
  media/pci/saa7164-encoder Support for V4L2_CTRL_WHICH_DEF_VAL
  media/pci/saa7164-vbi Support for V4L2_CTRL_WHICH_DEF_VAL
  Docbook: media: Document changes on struct v4l2_ext_controls

 Documentation/DocBook/media/v4l/v4l2.xml           |  9 ++++
 .../DocBook/media/v4l/vidioc-g-ext-ctrls.xml       | 28 ++++++++--
 drivers/media/pci/saa7164/saa7164-encoder.c        | 59 ++++++++++++---------
 drivers/media/pci/saa7164/saa7164-vbi.c            | 61 +++++++++++++---------
 drivers/media/platform/s5p-mfc/s5p_mfc_dec.c       |  2 +-
 drivers/media/platform/s5p-mfc/s5p_mfc_enc.c       |  2 +-
 drivers/media/usb/pvrusb2/pvrusb2-v4l2.c           | 17 +++++-
 drivers/media/usb/uvc/uvc_v4l2.c                   | 14 ++++-
 drivers/media/v4l2-core/v4l2-compat-ioctl32.c      | 17 +++---
 drivers/media/v4l2-core/v4l2-ctrls.c               | 54 +++++++++++++------
 drivers/media/v4l2-core/v4l2-ioctl.c               | 14 ++---
 include/uapi/linux/videodev2.h                     | 14 ++++-
 12 files changed, 200 insertions(+), 91 deletions(-)

-- 
2.5.0


^ permalink raw reply	[flat|nested] 2+ messages in thread
end of thread, other threads:[~2015-08-21 14:26 UTC | newest]

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2015-08-21 14:26 [PATCH v2 05/10] media/v4l2-core: struct struct v4l2_ext_controls param which Ricardo Ribalda Delgado
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2015-08-21 13:19 [PATCH v2 00/10] Support getting default values from any control Ricardo Ribalda Delgado
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