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?
-Add a new ioctl VIDIOC_INITIAL_EXT_CTRLS, with the same API as
G_EXT_CTRLS, but that returns the initial value of a given control
*This code is not splited in different patches and there is no doc!
Yes, at this point I want your feedback about the ioctl, and an initial
piece of code could help the disscussion. Of course, once we agreed I
will provide the documentation and a properly build patchset.
So, shoot me: What do you think?
THANKS!
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@xxxxxxxxx>
---
drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 4 ++
drivers/media/v4l2-core/v4l2-ctrls.c | 65 ++++++++++++++++++++++++---
drivers/media/v4l2-core/v4l2-ioctl.c | 20 +++++++++
drivers/media/v4l2-core/v4l2-subdev.c | 3 ++
include/media/v4l2-ctrls.h | 2 +
include/media/v4l2-ioctl.h | 2 +
include/uapi/linux/videodev2.h | 4 +-
7 files changed, 92 insertions(+), 8 deletions(-)
diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
index af635430524e..1e3272e28b2d 100644
--- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
+++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
@@ -817,6 +817,7 @@ static int put_v4l2_edid32(struct v4l2_edid *kp, struct v4l2_edid32 __user *up)
#define VIDIOC_DQEVENT32 _IOR ('V', 89, struct v4l2_event32)
#define VIDIOC_CREATE_BUFS32 _IOWR('V', 92, struct v4l2_create_buffers32)
#define VIDIOC_PREPARE_BUF32 _IOWR('V', 93, struct v4l2_buffer32)
+#define VIDIOC_INITIAL_EXT_CTRLS32 _IOWR('V', 104, struct v4l2_ext_controls32)
#define VIDIOC_OVERLAY32 _IOW ('V', 14, s32)
#define VIDIOC_STREAMON32 _IOW ('V', 18, s32)
@@ -859,6 +860,7 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
case VIDIOC_TRY_FMT32: cmd = VIDIOC_TRY_FMT; break;
case VIDIOC_G_EXT_CTRLS32: cmd = VIDIOC_G_EXT_CTRLS; break;
case VIDIOC_S_EXT_CTRLS32: cmd = VIDIOC_S_EXT_CTRLS; break;
+ case VIDIOC_INITIAL_EXT_CTRLS32: cmd = VIDIOC_INITIAL_EXT_CTRLS; break;
case VIDIOC_TRY_EXT_CTRLS32: cmd = VIDIOC_TRY_EXT_CTRLS; break;
case VIDIOC_DQEVENT32: cmd = VIDIOC_DQEVENT; break;
case VIDIOC_OVERLAY32: cmd = VIDIOC_OVERLAY; break;
@@ -937,6 +939,7 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
case VIDIOC_G_EXT_CTRLS:
case VIDIOC_S_EXT_CTRLS:
case VIDIOC_TRY_EXT_CTRLS:
+ case VIDIOC_INITIAL_EXT_CTRLS:
err = get_v4l2_ext_controls32(&karg.v2ecs, up);
compatible_arg = 0;
break;
@@ -964,6 +967,7 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
case VIDIOC_G_EXT_CTRLS:
case VIDIOC_S_EXT_CTRLS:
case VIDIOC_TRY_EXT_CTRLS:
+ case VIDIOC_INITIAL_EXT_CTRLS:
if (put_v4l2_ext_controls32(&karg.v2ecs, up))
err = -EFAULT;
break;
diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index b462165a7f0c..465f73acc644 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -1449,6 +1449,40 @@ static const struct v4l2_ctrl_type_ops std_type_ops = {
.validate = std_validate,
};
+/* Helper function: copy the initial value back to the caller */
+static int init_to_user(struct v4l2_ext_control *c, struct v4l2_ctrl *ctrl)
+{
+ int idx;
+ int ret;
+ long size;
+ union v4l2_ctrl_ptr ptr;
+
+ if (!ctrl->is_ptr){
+ ptr.p = &c->value;
+ ctrl->type_ops->init(ctrl, 0, ptr);
+ return 0;
+ }
+
+ size = ctrl->elem_size * ctrl->elems;
+ if (c->size < size){
+ c->size = size;
+ return -ENOSPC;
+ }
+
+ ptr.p = kzalloc(size, GFP_KERNEL);
+ if (!ptr.p)
+ return -ENOMEM;
+
+ for (idx=0; idx<ctrl->elems; idx++)
+ ctrl->type_ops->init(ctrl, idx, ptr);
+
+ ret = copy_to_user(c->ptr, ptr.p, size);
+
+ kfree(ptr.p);
+
+ return ret ? -EFAULT : 0;
+}
+
/* Helper function: copy the given control value back to the caller */
static int ptr_to_user(struct v4l2_ext_control *c,
struct v4l2_ctrl *ctrl,
@@ -2806,10 +2840,10 @@ static int class_check(struct v4l2_ctrl_handler *hdl, u32 ctrl_class)
return find_ref_lock(hdl, ctrl_class | 1) ? 0 : -EINVAL;
}
-
-
/* Get extended controls. Allocates the helpers array if needed. */
-int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs)
+static int v4l2_g_ext_ctrls_initial(struct v4l2_ctrl_handler *hdl,
+ struct v4l2_ext_controls *cs,
+ bool initial_value)
{
struct v4l2_ctrl_helper helper[4];
struct v4l2_ctrl_helper *helpers = helper;
@@ -2840,10 +2874,11 @@ int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs
ret = -EACCES;
for (i = 0; !ret && i < cs->count; i++) {
- int (*ctrl_to_user)(struct v4l2_ext_control *c,
- struct v4l2_ctrl *ctrl) = cur_to_user;
+ int (*ctrl_to_user)(struct v4l2_ext_control *c, struct v4l2_ctrl *ctrl);
struct v4l2_ctrl *master;
+ ctrl_to_user = initial_value ? init_to_user : cur_to_user;
+
if (helpers[i].mref == NULL)
continue;
@@ -2853,8 +2888,9 @@ 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 ((!(master->flags & V4L2_CTRL_FLAG_VOLATILE) ||
+ (master->has_volatiles && !is_cur_manual(master))) &&
+ !initial_value) {
for (j = 0; j < master->ncontrols; j++)
cur_to_new(master->cluster[j]);
ret = call_op(master, g_volatile_ctrl);
@@ -2879,6 +2915,10 @@ int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs
kfree(helpers);
return ret;
}
+
+int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs){
+ return v4l2_g_ext_ctrls_initial(hdl, cs, false);
+}
EXPORT_SYMBOL(v4l2_g_ext_ctrls);
int v4l2_subdev_g_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs)
@@ -2887,6 +2927,17 @@ int v4l2_subdev_g_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs
}
EXPORT_SYMBOL(v4l2_subdev_g_ext_ctrls);
+int v4l2_initial_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs){
+ return v4l2_g_ext_ctrls_initial(hdl, cs, true);
+}
+EXPORT_SYMBOL(v4l2_initial_ext_ctrls);
+
+int v4l2_subdev_initial_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs)
+{
+ return v4l2_initial_ext_ctrls(sd->ctrl_handler, cs);
+}
+EXPORT_SYMBOL(v4l2_subdev_initial_ext_ctrls);
+
/* Helper function to get a single control */
static int get_ctrl(struct v4l2_ctrl *ctrl, struct v4l2_ext_control *c)
{
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index 8712168a3b0a..e68d9ec8832a 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -1812,6 +1812,25 @@ static int v4l_g_ext_ctrls(const struct v4l2_ioctl_ops *ops,
-EINVAL;
}
+static int v4l_initial_ext_ctrls(const struct v4l2_ioctl_ops *ops,
+ struct file *file, void *fh, void *arg)
+{
+ struct video_device *vfd = video_devdata(file);
+ struct v4l2_ext_controls *p = arg;
+ struct v4l2_fh *vfh =
+ test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags) ? fh : NULL;
+
+ p->error_idx = p->count;
+ if (vfh && vfh->ctrl_handler)
+ return v4l2_initial_ext_ctrls(vfh->ctrl_handler, p);
+ if (vfd->ctrl_handler)
+ return v4l2_initial_ext_ctrls(vfd->ctrl_handler, p);
+ if (ops->vidioc_initial_ext_ctrls == NULL)
+ return -ENOTTY;
+ return check_ext_ctrls(p, 0) ? ops->vidioc_initial_ext_ctrls(file, fh, p) :
+ -EINVAL;
+}
+
static int v4l_s_ext_ctrls(const struct v4l2_ioctl_ops *ops,
struct file *file, void *fh, void *arg)
{
@@ -2285,6 +2304,7 @@ static struct v4l2_ioctl_info v4l2_ioctls[] = {
IOCTL_INFO_FNC(VIDIOC_G_SLICED_VBI_CAP, v4l_g_sliced_vbi_cap, v4l_print_sliced_vbi_cap, INFO_FL_CLEAR(v4l2_sliced_vbi_cap, type)),
IOCTL_INFO_FNC(VIDIOC_LOG_STATUS, v4l_log_status, v4l_print_newline, 0),
IOCTL_INFO_FNC(VIDIOC_G_EXT_CTRLS, v4l_g_ext_ctrls, v4l_print_ext_controls, INFO_FL_CTRL),
+ IOCTL_INFO_FNC(VIDIOC_INITIAL_EXT_CTRLS, v4l_initial_ext_ctrls, v4l_print_ext_controls, INFO_FL_CTRL),
IOCTL_INFO_FNC(VIDIOC_S_EXT_CTRLS, v4l_s_ext_ctrls, v4l_print_ext_controls, INFO_FL_PRIO | INFO_FL_CTRL),
IOCTL_INFO_FNC(VIDIOC_TRY_EXT_CTRLS, v4l_try_ext_ctrls, v4l_print_ext_controls, INFO_FL_CTRL),
IOCTL_INFO_STD(VIDIOC_ENUM_FRAMESIZES, vidioc_enum_framesizes, v4l_print_frmsizeenum, INFO_FL_CLEAR(v4l2_frmsizeenum, pixel_format)),
diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index 19a034e79be4..6ed308df9d2f 100644
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -206,6 +206,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg)
case VIDIOC_G_EXT_CTRLS:
return v4l2_g_ext_ctrls(vfh->ctrl_handler, arg);
+ case VIDIOC_INITIAL_EXT_CTRLS:
+ return v4l2_initial_ext_ctrls(vfh->ctrl_handler, arg);
+
case VIDIOC_S_EXT_CTRLS:
return v4l2_s_ext_ctrls(vfh, vfh->ctrl_handler, arg);
diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
index ec63d8c44f4e..6521f54718ca 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -815,6 +815,7 @@ int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *ctrl);
int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
struct v4l2_control *ctrl);
int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c);
+int v4l2_initial_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c);
int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *c);
int v4l2_s_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
struct v4l2_ext_controls *c);
@@ -824,6 +825,7 @@ int v4l2_s_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
int v4l2_subdev_queryctrl(struct v4l2_subdev *sd, struct v4l2_queryctrl *qc);
int v4l2_subdev_querymenu(struct v4l2_subdev *sd, struct v4l2_querymenu *qm);
int v4l2_subdev_g_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs);
+int v4l2_subdev_initial_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs);
int v4l2_subdev_try_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs);
int v4l2_subdev_s_ext_ctrls(struct v4l2_subdev *sd, struct v4l2_ext_controls *cs);
int v4l2_subdev_g_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl);
diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h
index 8537983b9b22..16a289bc46b1 100644
--- a/include/media/v4l2-ioctl.h
+++ b/include/media/v4l2-ioctl.h
@@ -166,6 +166,8 @@ struct v4l2_ioctl_ops {
struct v4l2_control *a);
int (*vidioc_g_ext_ctrls) (struct file *file, void *fh,
struct v4l2_ext_controls *a);
+ int (*vidioc_initial_ext_ctrls)(struct file *file, void *fh,
+ struct v4l2_ext_controls *a);
int (*vidioc_s_ext_ctrls) (struct file *file, void *fh,
struct v4l2_ext_controls *a);
int (*vidioc_try_ext_ctrls) (struct file *file, void *fh,
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 2b26d23f9b04..9b84f1755d5f 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -2204,8 +2204,10 @@ struct v4l2_create_buffers {
#define VIDIOC_QUERY_EXT_CTRL _IOWR('V', 103, struct v4l2_query_ext_ctrl)
+#define VIDIOC_INITIAL_EXT_CTRLS _IOWR('V', 104, struct v4l2_ext_controls)
+
/* Reminder: when adding new ioctls please add support for them to
- drivers/media/video/v4l2-compat-ioctl32.c as well! */
+ drivers/media/v4l2-core/v4l2-compat-ioctl32.c as well! */
#define BASE_VIDIOC_PRIVATE 192 /* 192-255 are private */
--
2.1.4
--
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