[media] v4l2-subdev: replace v4l2_subdev_fh by v4l2_subdev_pad_config

If a subdevice pad op is called from a bridge driver, then there is
no v4l2_subdev_fh struct that can be passed to the subdevice. This
made it hard to use such subdevs from a bridge driver.

This patch replaces the v4l2_subdev_fh pointer by a v4l2_subdev_pad_config
pointer in the pad ops. This allows bridge drivers to use the various
try_ pad ops by creating a v4l2_subdev_pad_config struct and passing it
along to the pad op.

The v4l2_subdev_get_try_* macros had to be changed because of this, so
I also took the opportunity to use the full name of the v4l2_subdev_get_try_*
functions in the __V4L2_SUBDEV_MK_GET_TRY macro arguments: if you now do
'git grep v4l2_subdev_get_try_format' you will actually find the header
where it is defined.

One remark regarding the drivers/staging/media/davinci_vpfe patches: the
*_init_formats() functions assumed that fh could be NULL. However, that's
not true for this driver, it's always set. This is almost certainly a copy
and paste from the omap3isp driver. I've updated the code to reflect the
fact that fh is never NULL.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Tested-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index 19a034e..3c8b198 100644
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -262,7 +262,7 @@
 		if (rval)
 			return rval;
 
-		return v4l2_subdev_call(sd, pad, get_fmt, subdev_fh, format);
+		return v4l2_subdev_call(sd, pad, get_fmt, subdev_fh->pad, format);
 	}
 
 	case VIDIOC_SUBDEV_S_FMT: {
@@ -272,7 +272,7 @@
 		if (rval)
 			return rval;
 
-		return v4l2_subdev_call(sd, pad, set_fmt, subdev_fh, format);
+		return v4l2_subdev_call(sd, pad, set_fmt, subdev_fh->pad, format);
 	}
 
 	case VIDIOC_SUBDEV_G_CROP: {
@@ -289,7 +289,7 @@
 		sel.target = V4L2_SEL_TGT_CROP;
 
 		rval = v4l2_subdev_call(
-			sd, pad, get_selection, subdev_fh, &sel);
+			sd, pad, get_selection, subdev_fh->pad, &sel);
 
 		crop->rect = sel.r;
 
@@ -311,7 +311,7 @@
 		sel.r = crop->rect;
 
 		rval = v4l2_subdev_call(
-			sd, pad, set_selection, subdev_fh, &sel);
+			sd, pad, set_selection, subdev_fh->pad, &sel);
 
 		crop->rect = sel.r;
 
@@ -324,7 +324,7 @@
 		if (code->pad >= sd->entity.num_pads)
 			return -EINVAL;
 
-		return v4l2_subdev_call(sd, pad, enum_mbus_code, subdev_fh,
+		return v4l2_subdev_call(sd, pad, enum_mbus_code, subdev_fh->pad,
 					code);
 	}
 
@@ -334,7 +334,7 @@
 		if (fse->pad >= sd->entity.num_pads)
 			return -EINVAL;
 
-		return v4l2_subdev_call(sd, pad, enum_frame_size, subdev_fh,
+		return v4l2_subdev_call(sd, pad, enum_frame_size, subdev_fh->pad,
 					fse);
 	}
 
@@ -362,7 +362,7 @@
 		if (fie->pad >= sd->entity.num_pads)
 			return -EINVAL;
 
-		return v4l2_subdev_call(sd, pad, enum_frame_interval, subdev_fh,
+		return v4l2_subdev_call(sd, pad, enum_frame_interval, subdev_fh->pad,
 					fie);
 	}
 
@@ -374,7 +374,7 @@
 			return rval;
 
 		return v4l2_subdev_call(
-			sd, pad, get_selection, subdev_fh, sel);
+			sd, pad, get_selection, subdev_fh->pad, sel);
 	}
 
 	case VIDIOC_SUBDEV_S_SELECTION: {
@@ -385,7 +385,7 @@
 			return rval;
 
 		return v4l2_subdev_call(
-			sd, pad, set_selection, subdev_fh, sel);
+			sd, pad, set_selection, subdev_fh->pad, sel);
 	}
 
 	case VIDIOC_G_EDID: {