V4L/DVB (8898): pvrusb2: Be able to programmatically retrieve a control's default value

The pvrusb2 control mechanism up until now has used a constant int to
hold a control's default value.  This change makes it possible to
retrieve the control's default through some other means, e.g. as a
result of a query from lower level software.
Signed-off-by: Mike Isely <isely@pobox.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/pvrusb2/pvrusb2-ctrl.c

@@ -134,13 +134,19 @@ int pvr2_ctrl_get_min(struct pvr2_ctrl *cptr)
 
 
 /* Retrieve control's default value (any type) */
-int pvr2_ctrl_get_def(struct pvr2_ctrl *cptr)
+int pvr2_ctrl_get_def(struct pvr2_ctrl *cptr, int *valptr)
 {
 	int ret = 0;
 	if (!cptr) return 0;
 	LOCK_TAKE(cptr->hdw->big_lock); do {
 		if (cptr->info->type == pvr2_ctl_int) {
-			ret = cptr->info->default_value;
+			if (cptr->info->get_def_value) {
+				/* Comment to keep checkpatch.pl quiet */
+				ret = cptr->info->get_def_value(cptr, valptr);
+			} else {
+				/* Comment to keep checkpatch.pl quiet */
+				*valptr = cptr->info->default_value;
+			}
 		}
 	} while(0); LOCK_GIVE(cptr->hdw->big_lock);
 	return ret;

drivers/media/video/pvrusb2/pvrusb2-ctrl.h

@@ -49,7 +49,7 @@ int pvr2_ctrl_get_max(struct pvr2_ctrl *);
 int pvr2_ctrl_get_min(struct pvr2_ctrl *);
 
 /* Retrieve control's default value (any type) */
-int pvr2_ctrl_get_def(struct pvr2_ctrl *);
+int pvr2_ctrl_get_def(struct pvr2_ctrl *, int *valptr);
 
 /* Retrieve control's enumeration count (enum only) */
 int pvr2_ctrl_get_cnt(struct pvr2_ctrl *);

drivers/media/video/pvrusb2/pvrusb2-hdw-internal.h

@@ -82,6 +82,7 @@ struct pvr2_ctl_info {
 
 	/* Control's implementation */
 	pvr2_ctlf_get_value get_value;      /* Get its value */
+	pvr2_ctlf_get_value get_def_value;  /* Get its default value */
 	pvr2_ctlf_get_value get_min_value;  /* Get minimum allowed value */
 	pvr2_ctlf_get_value get_max_value;  /* Get maximum allowed value */
 	pvr2_ctlf_set_value set_value;      /* Set its value */

drivers/media/video/pvrusb2/pvrusb2-v4l2.c

@@ -533,7 +533,7 @@ static int pvr2_v4l2_do_ioctl(struct inode *inode, struct file *file,
 
 			lmin = pvr2_ctrl_get_min(hcp);
 			lmax = pvr2_ctrl_get_max(hcp);
-			ldef = pvr2_ctrl_get_def(hcp);
+			pvr2_ctrl_get_def(hcp, &ldef);
 			if (w == -1) {
 				w = ldef;
 			} else if (w < lmin) {
@@ -543,7 +543,7 @@ static int pvr2_v4l2_do_ioctl(struct inode *inode, struct file *file,
 			}
 			lmin = pvr2_ctrl_get_min(vcp);
 			lmax = pvr2_ctrl_get_max(vcp);
-			ldef = pvr2_ctrl_get_def(vcp);
+			pvr2_ctrl_get_def(vcp, &ldef);
 			if (h == -1) {
 				h = ldef;
 			} else if (h < lmin) {
@@ -604,6 +604,7 @@ static int pvr2_v4l2_do_ioctl(struct inode *inode, struct file *file,
 	case VIDIOC_QUERYCTRL:
 	{
 		struct pvr2_ctrl *cptr;
+		int val;
 		struct v4l2_queryctrl *vc = (struct v4l2_queryctrl *)arg;
 		ret = 0;
 		if (vc->id & V4L2_CTRL_FLAG_NEXT_CTRL) {
@@ -627,7 +628,8 @@ static int pvr2_v4l2_do_ioctl(struct inode *inode, struct file *file,
 			   pvr2_ctrl_get_desc(cptr));
 		strlcpy(vc->name,pvr2_ctrl_get_desc(cptr),sizeof(vc->name));
 		vc->flags = pvr2_ctrl_get_v4lflags(cptr);
-		vc->default_value = pvr2_ctrl_get_def(cptr);
+		pvr2_ctrl_get_def(cptr, &val);
+		vc->default_value = val;
 		switch (pvr2_ctrl_get_type(cptr)) {
 		case pvr2_ctl_enum:
 			vc->type = V4L2_CTRL_TYPE_MENU;