[media] v4l2-ioctl: make tuner 'type' check more strict for S_FREQUENCY

As per the feature removal document, make the tuner type check more strict
so that it is no longer possible to set the radio frequency through a video
node or the TV frequency through a radio node.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

Documentation/DocBook/media/v4l/vidioc-g-frequency.xml

@@ -98,8 +98,11 @@ the &v4l2-output; <structfield>modulator</structfield> field and the
 	    <entry>&v4l2-tuner-type;</entry>
 	    <entry><structfield>type</structfield></entry>
 	    <entry>The tuner type. This is the same value as in the
-&v4l2-tuner; <structfield>type</structfield> field. The field is not
-applicable to modulators, &ie; ignored by drivers.</entry>
+&v4l2-tuner; <structfield>type</structfield> field. The type must be set
+to <constant>V4L2_TUNER_RADIO</constant> for <filename>/dev/radioX</filename>
+device nodes, and to <constant>V4L2_TUNER_ANALOG_TV</constant>
+for all others. The field is not applicable to modulators, &ie; ignored
+by drivers.</entry>
 	  </row>
 	  <row>
 	    <entry>__u32</entry>

Documentation/feature-removal-schedule.txt

@@ -460,17 +460,6 @@ Who:	Jean Delvare <khali@linux-fr.org>
 
 ----------------------------
 
-What:	For VIDIOC_S_FREQUENCY the type field must match the device node's type.
-	If not, return -EINVAL.
-When:	3.2
-Why:	It makes no sense to switch the tuner to radio mode by calling
-	VIDIOC_S_FREQUENCY on a video node, or to switch the tuner to tv mode by
-	calling VIDIOC_S_FREQUENCY on a radio node. This is the first step of a
-	move to more consistent handling of tv and radio tuners.
-Who:	Hans Verkuil <hans.verkuil@cisco.com>
-
-----------------------------
-
 What:	Opening a radio device node will no longer automatically switch the
 	tuner mode from tv to radio.
 When:	3.3

drivers/media/video/v4l2-ioctl.c

@@ -1871,16 +1871,22 @@ static long __video_do_ioctl(struct file *file,
 	case VIDIOC_S_FREQUENCY:
 	{
 		struct v4l2_frequency *p = arg;
+		enum v4l2_tuner_type type;
 
 		if (!ops->vidioc_s_frequency)
 			break;
 		if (ret_prio) {
 			ret = ret_prio;
 			break;
 		}
+		type = (vfd->vfl_type == VFL_TYPE_RADIO) ?
+			V4L2_TUNER_RADIO : V4L2_TUNER_ANALOG_TV;
 		dbgarg(cmd, "tuner=%d, type=%d, frequency=%d\n",
 				p->tuner, p->type, p->frequency);
-		ret = ops->vidioc_s_frequency(file, fh, p);
+		if (p->type != type)
+			ret = -EINVAL;
+		else
+			ret = ops->vidioc_s_frequency(file, fh, p);
 		break;
 	}
 	case VIDIOC_G_SLICED_VBI_CAP: