Commit 2ccbe779 authored by Sylwester Nawrocki's avatar Sylwester Nawrocki Committed by Mauro Carvalho Chehab
Browse files

[media] v4l2-ctrl: Add helper function for the controls range update 

This patch adds a helper function that allows to modify range,
i.e. minimum, maximum, step and default value of a v4l2 control,
after the control has been created and initialized. This is helpful
in situations when range of a control depends on user configurable
parameters, e.g. camera sensor absolute exposure time depending on
an output image resolution and frame rate.
v4l2_ctrl_modify_range() function allows to modify range of an
INTEGER, BOOL, MENU, INTEGER_MENU and BITMASK type controls.
Based on a patch from Hans Verkuil http://patchwork.linuxtv.org/patch/8654

.

Signed-off-by: default avatarSylwester Nawrocki <sylvester.nawrocki@gmail.com>
Acked-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent af9bb33a

Documentation/DocBook/media/v4l/compat.xml

+4 −0
Original line number Diff line number Diff line
@@ -2486,6 +2486,10 @@ that used it. It was originally scheduled for removal in 2.6.35. 
	  <structname>v4l2_buffer</structname>. See <xref

	  linkend="buffer-flags" />.</para>

        </listitem>

        <listitem>

	  <para>Added <constant>V4L2_EVENT_CTRL_CH_RANGE</constant> control event

	  changes flag. See <xref linkend="changes-flags"/>.</para>

        </listitem>

      </orderedlist>

    </section>

Documentation/DocBook/media/v4l/v4l2.xml

+3 −1
Original line number Diff line number Diff line
@@ -142,10 +142,12 @@ applications. --> 
      <revision>

	<revnumber>3.9</revnumber>

	<date>2012-12-03</date>

	<authorinitials>sa</authorinitials>

	<authorinitials>sa, sn</authorinitials>

	<revremark>Added timestamp types to

	<structname>v4l2_buffer</structname>, see <xref

	linkend="buffer-flags" />.

	Added <constant>V4L2_EVENT_CTRL_CH_RANGE</constant> control

	event changes flag, see <xref linkend="changes-flags"/>.

	</revremark>

      </revision>

Documentation/DocBook/media/v4l/vidioc-dqevent.xml

+6 −0
Original line number Diff line number Diff line
@@ -261,6 +261,12 @@ 
	    <entry>This control event was triggered because the control flags

		changed.</entry>

	  </row>

	  <row>

	    <entry><constant>V4L2_EVENT_CTRL_CH_RANGE</constant></entry>

	    <entry>0x0004</entry>

	    <entry>This control event was triggered because the minimum,

	    maximum, step or the default value of the control changed.</entry>

	  </row>

	</tbody>

      </tgroup>

    </table>

drivers/media/v4l2-core/v4l2-ctrls.c

+104 −39
Original line number Diff line number Diff line
@@ -1158,8 +1158,7 @@ static int new_to_user(struct v4l2_ext_control *c, 
}



/* Copy the new value to the current value. */

static void new_to_cur(struct v4l2_fh *fh, struct v4l2_ctrl *ctrl,

						bool update_inactive)

static void new_to_cur(struct v4l2_fh *fh, struct v4l2_ctrl *ctrl, u32 ch_flags)

{

	bool changed = false;
@@ -1183,8 +1182,8 @@ static void new_to_cur(struct v4l2_fh *fh, struct v4l2_ctrl *ctrl, 
		ctrl->cur.val = ctrl->val;

		break;

	}

	if (update_inactive) {

		/* Note: update_inactive can only be true for auto clusters. */

	if (ch_flags & V4L2_EVENT_CTRL_CH_FLAGS) {

		/* Note: CH_FLAGS is only set for auto clusters. */

		ctrl->flags &=

			~(V4L2_CTRL_FLAG_INACTIVE | V4L2_CTRL_FLAG_VOLATILE);

		if (!is_cur_manual(ctrl->cluster[0])) {
@@ -1194,14 +1193,13 @@ static void new_to_cur(struct v4l2_fh *fh, struct v4l2_ctrl *ctrl, 
		}

		fh = NULL;

	}

	if (changed || update_inactive) {

	if (changed || ch_flags) {

		/* If a control was changed that was not one of the controls

		   modified by the application, then send the event to all. */

		if (!ctrl->is_new)

			fh = NULL;

		send_event(fh, ctrl,

			(changed ? V4L2_EVENT_CTRL_CH_VALUE : 0) |

			(update_inactive ? V4L2_EVENT_CTRL_CH_FLAGS : 0));

			(changed ? V4L2_EVENT_CTRL_CH_VALUE : 0) | ch_flags);

		if (ctrl->call_notify && changed && ctrl->handler->notify)

			ctrl->handler->notify(ctrl, ctrl->handler->notify_priv);

	}
@@ -1257,6 +1255,41 @@ static int cluster_changed(struct v4l2_ctrl *master) 
	return diff;

}



/* Control range checking */

static int check_range(enum v4l2_ctrl_type type,

		s32 min, s32 max, u32 step, s32 def)

{

	switch (type) {

	case V4L2_CTRL_TYPE_BOOLEAN:

		if (step != 1 || max > 1 || min < 0)

			return -ERANGE;

		/* fall through */

	case V4L2_CTRL_TYPE_INTEGER:

		if (step <= 0 || min > max || def < min || def > max)

			return -ERANGE;

		return 0;

	case V4L2_CTRL_TYPE_BITMASK:

		if (step || min || !max || (def & ~max))

			return -ERANGE;

		return 0;

	case V4L2_CTRL_TYPE_MENU:

	case V4L2_CTRL_TYPE_INTEGER_MENU:

		if (min > max || def < min || def > max)

			return -ERANGE;

		/* Note: step == menu_skip_mask for menu controls.

		   So here we check if the default value is masked out. */

		if (step && ((1 << def) & step))

			return -EINVAL;

		return 0;

	case V4L2_CTRL_TYPE_STRING:

		if (min > max || min < 0 || step < 1 || def)

			return -ERANGE;

		return 0;

	default:

		return 0;

	}

}



/* Validate a new control */

static int validate_new(const struct v4l2_ctrl *ctrl,

			struct v4l2_ext_control *c)
@@ -1529,30 +1562,21 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl, 
{

	struct v4l2_ctrl *ctrl;

	unsigned sz_extra = 0;

	int err;



	if (hdl->error)

		return NULL;



	/* Sanity checks */

	if (id == 0 || name == NULL || id >= V4L2_CID_PRIVATE_BASE ||

	    (type == V4L2_CTRL_TYPE_INTEGER && step == 0) ||

	    (type == V4L2_CTRL_TYPE_BITMASK && max == 0) ||

	    (type == V4L2_CTRL_TYPE_MENU && qmenu == NULL) ||

	    (type == V4L2_CTRL_TYPE_INTEGER_MENU && qmenu_int == NULL) ||

	    (type == V4L2_CTRL_TYPE_STRING && max == 0)) {

	    (type == V4L2_CTRL_TYPE_INTEGER_MENU && qmenu_int == NULL)) {

		handler_set_err(hdl, -ERANGE);

		return NULL;

	}

	if (type != V4L2_CTRL_TYPE_BITMASK && max < min) {

		handler_set_err(hdl, -ERANGE);

		return NULL;

	}

	if ((type == V4L2_CTRL_TYPE_INTEGER ||

	     type == V4L2_CTRL_TYPE_MENU ||

	     type == V4L2_CTRL_TYPE_INTEGER_MENU ||

	     type == V4L2_CTRL_TYPE_BOOLEAN) &&

	    (def < min || def > max)) {

		handler_set_err(hdl, -ERANGE);

	err = check_range(type, min, max, step, def);

	if (err) {

		handler_set_err(hdl, err);

		return NULL;

	}

	if (type == V4L2_CTRL_TYPE_BITMASK && ((def & ~max) || min || step)) {
@@ -2426,8 +2450,8 @@ EXPORT_SYMBOL(v4l2_ctrl_g_ctrl_int64); 
/* Core function that calls try/s_ctrl and ensures that the new value is

   copied to the current value on a set.

   Must be called with ctrl->handler->lock held. */

static int try_or_set_cluster(struct v4l2_fh *fh,

			      struct v4l2_ctrl *master, bool set)

static int try_or_set_cluster(struct v4l2_fh *fh, struct v4l2_ctrl *master,

			      bool set, u32 ch_flags)

{

	bool update_flag;

	int ret;
@@ -2465,7 +2489,8 @@ static int try_or_set_cluster(struct v4l2_fh *fh, 
	/* If OK, then make the new values permanent. */

	update_flag = is_cur_manual(master) != is_new_manual(master);

	for (i = 0; i < master->ncontrols; i++)

		new_to_cur(fh, master->cluster[i], update_flag && i > 0);

		new_to_cur(fh, master->cluster[i], ch_flags |

			((update_flag && i > 0) ? V4L2_EVENT_CTRL_CH_FLAGS : 0));

	return 0;

}
@@ -2592,7 +2617,7 @@ static int try_set_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl, 
		} while (!ret && idx);



		if (!ret)

			ret = try_or_set_cluster(fh, master, set);

			ret = try_or_set_cluster(fh, master, set, 0);



		/* Copy the new values back to userspace. */

		if (!ret) {
@@ -2638,10 +2663,9 @@ EXPORT_SYMBOL(v4l2_subdev_s_ext_ctrls); 


/* Helper function for VIDIOC_S_CTRL compatibility */

static int set_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl *ctrl,

		    struct v4l2_ext_control *c)

		    struct v4l2_ext_control *c, u32 ch_flags)

{

	struct v4l2_ctrl *master = ctrl->cluster[0];

	int ret;

	int i;



	/* String controls are not supported. The user_to_new() and
@@ -2651,12 +2675,6 @@ static int set_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl *ctrl, 
	if (ctrl->type == V4L2_CTRL_TYPE_STRING)

		return -EINVAL;



	ret = validate_new(ctrl, c);

	if (ret)

		return ret;



	v4l2_ctrl_lock(ctrl);



	/* Reset the 'is_new' flags of the cluster */

	for (i = 0; i < master->ncontrols; i++)

		if (master->cluster[i])
@@ -2670,10 +2688,22 @@ static int set_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl *ctrl, 
		update_from_auto_cluster(master);



	user_to_new(c, ctrl);

	ret = try_or_set_cluster(fh, master, true);

	cur_to_user(c, ctrl);

	return try_or_set_cluster(fh, master, true, ch_flags);

}



/* Helper function for VIDIOC_S_CTRL compatibility */

static int set_ctrl_lock(struct v4l2_fh *fh, struct v4l2_ctrl *ctrl,

			 struct v4l2_ext_control *c)

{

	int ret = validate_new(ctrl, c);



	if (!ret) {

		v4l2_ctrl_lock(ctrl);

		ret = set_ctrl(fh, ctrl, c, 0);

		if (!ret)

			cur_to_user(c, ctrl);

		v4l2_ctrl_unlock(ctrl);

	}

	return ret;

}
@@ -2691,7 +2721,7 @@ int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl, 
		return -EACCES;



	c.value = control->value;

	ret = set_ctrl(fh, ctrl, &c);

	ret = set_ctrl_lock(fh, ctrl, &c);

	control->value = c.value;

	return ret;

}
@@ -2710,7 +2740,7 @@ int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val) 
	/* It's a driver bug if this happens. */

	WARN_ON(!type_is_int(ctrl));

	c.value = val;

	return set_ctrl(NULL, ctrl, &c);

	return set_ctrl_lock(NULL, ctrl, &c);

}

EXPORT_SYMBOL(v4l2_ctrl_s_ctrl);
@@ -2721,7 +2751,7 @@ int v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val) 
	/* It's a driver bug if this happens. */

	WARN_ON(ctrl->type != V4L2_CTRL_TYPE_INTEGER64);

	c.value64 = val;

	return set_ctrl(NULL, ctrl, &c);

	return set_ctrl_lock(NULL, ctrl, &c);

}

EXPORT_SYMBOL(v4l2_ctrl_s_ctrl_int64);
@@ -2741,6 +2771,41 @@ void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl, v4l2_ctrl_notify_fnc notify, void 
}

EXPORT_SYMBOL(v4l2_ctrl_notify);



int v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,

			s32 min, s32 max, u32 step, s32 def)

{

	int ret = check_range(ctrl->type, min, max, step, def);

	struct v4l2_ext_control c;



	switch (ctrl->type) {

	case V4L2_CTRL_TYPE_INTEGER:

	case V4L2_CTRL_TYPE_BOOLEAN:

	case V4L2_CTRL_TYPE_MENU:

	case V4L2_CTRL_TYPE_INTEGER_MENU:

	case V4L2_CTRL_TYPE_BITMASK:

		if (ret)

			return ret;

		break;

	default:

		return -EINVAL;

	}

	v4l2_ctrl_lock(ctrl);

	ctrl->minimum = min;

	ctrl->maximum = max;

	ctrl->step = step;

	ctrl->default_value = def;

	c.value = ctrl->cur.val;

	if (validate_new(ctrl, &c))

		c.value = def;

	if (c.value != ctrl->cur.val)

		ret = set_ctrl(NULL, ctrl, &c, V4L2_EVENT_CTRL_CH_RANGE);

	else

		send_event(NULL, ctrl, V4L2_EVENT_CTRL_CH_RANGE);

	v4l2_ctrl_unlock(ctrl);

	return ret;

}

EXPORT_SYMBOL(v4l2_ctrl_modify_range);



static int v4l2_ctrl_add_event(struct v4l2_subscribed_event *sev, unsigned elems)

{

	struct v4l2_ctrl *ctrl = v4l2_ctrl_find(sev->fh->ctrl_handler, sev->id);

include/media/v4l2-ctrls.h

+20 −0
Original line number Diff line number Diff line
@@ -518,6 +518,26 @@ void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active); 
  */

void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed);



/** v4l2_ctrl_modify_range() - Update the range of a control.

  * @ctrl:	The control to update.

  * @min:	The control's minimum value.

  * @max:	The control's maximum value.

  * @step:	The control's step value

  * @def:	The control's default value.

  *

  * Update the range of a control on the fly. This works for control types

  * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the

  * @step value is interpreted as a menu_skip_mask.

  *

  * An error is returned if one of the range arguments is invalid for this

  * control type.

  *

  * This function assumes that the control handler is not locked and will

  * take the lock itself.

  */

int v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,

			s32 min, s32 max, u32 step, s32 def);



/** v4l2_ctrl_lock() - Helper function to lock the handler

  * associated with the control.

  * @ctrl:	The control to lock.

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