V4L/DVB (5146): Make VIDIOC_INT_[SG]_REGISTER ioctls no longer internal only

The direct register access ioctls were defined as kernel internal only,
but they are very useful for debugging hardware from userspace and are
used as such.  Officially export them.

VIDIOC_INT_[SG]_REGISTER is renamed to VIDIOC_DBG_[SG]_REGISTER 
Definition of ioctl and struct v4l2_register is moved from v4l2-common.h 
to videodev2.h.

Types used in struct v4l2_register are changed to the userspace 
exportable versions (u32 -> __u32, etc). 

Use of VIDIOC_DBG_S_REGISTER requires CAP_SYS_ADMIN permission, so move 
the check into the video_ioctl2() dispatcher so it doesn't need to be 
duplicated in each driver's call-back function. CAP_SYS_ADMIN check is 
added to pvrusb2 (which doesn't use video_ioctl2).

Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

3 files changed, 15 insertions, 13 deletions

diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
index 112b28c1f63a..fe6ccdfa9d48 100644
--- a/include/linux/videodev2.h
+++ b/include/linux/videodev2.h
@@ -1271,6 +1271,17 @@ struct v4l2_streamparm
 };
 
 /*
+ *	A D V A N C E D   D E B U G G I N G
+ */
+
+/* VIDIOC_DBG_G_REGISTER and VIDIOC_DBG_S_REGISTER */
+struct v4l2_register {
+	__u32 i2c_id; /* I2C driver ID of the I2C chip, or 0 for the host */
+	__u32 reg;
+	__u32 val;
+};
+
+/*
  *	I O C T L   C O D E S   F O R   V I D E O   D E V I C E S
  *
  */
@@ -1339,6 +1350,9 @@ struct v4l2_streamparm
 #define VIDIOC_ENUM_FRAMESIZES	_IOWR ('V', 74, struct v4l2_frmsizeenum)
 #define VIDIOC_ENUM_FRAMEINTERVALS	_IOWR ('V', 75, struct v4l2_frmivalenum)
 #endif
+/* only implemented if CONFIG_VIDEO_ADV_DEBUG is defined */
+#define	VIDIOC_DBG_S_REGISTER 	_IOW ('d', 100, struct v4l2_register)
+#define	VIDIOC_DBG_G_REGISTER 	_IOWR('d', 101, struct v4l2_register)
 
 #ifdef __OLD_VIDIOC_
 /* for compatibility, will go away some day */
diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h
index 91b19921f958..959e6f6a4eff 100644
--- a/include/media/v4l2-common.h
+++ b/include/media/v4l2-common.h
@@ -99,13 +99,6 @@ u32 v4l2_ctrl_next(const u32 * const *ctrl_classes, u32 id);
 
 /* Internal ioctls */
 
-/* VIDIOC_INT_G_REGISTER and VIDIOC_INT_S_REGISTER */
-struct v4l2_register {
-	u32 i2c_id; 		/* I2C driver ID of the I2C chip. 0 for the I2C adapter. */
-	unsigned long reg;
-	u32 val;
-};
-
 /* VIDIOC_INT_DECODE_VBI_LINE */
 struct v4l2_decode_vbi_line {
 	u32 is_second_field;	/* Set to 0 for the first (odd) field,
@@ -175,9 +168,7 @@ enum v4l2_chip_ident {
    Replacement of TUNER_SET_STANDBY. */
 #define VIDIOC_INT_S_STANDBY 	     _IOW('d', 94, u32)
 
-/* only implemented if CONFIG_VIDEO_ADV_DEBUG is defined */
-#define	VIDIOC_INT_S_REGISTER 		_IOW ('d', 100, struct v4l2_register)
-#define	VIDIOC_INT_G_REGISTER 		_IOWR('d', 101, struct v4l2_register)
+/* 100, 101 used by  VIDIOC_DBG_[SG]_REGISTER */
 
 /* Generic reset command. The argument selects which subsystems to reset.
    Passing 0 will always reset the whole chip. */
diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
index 46eb71f5653c..aeec56992ef5 100644
--- a/include/media/v4l2-dev.h
+++ b/include/media/v4l2-dev.h
@@ -77,9 +77,6 @@ int v4l_compat_translate_ioctl(struct inode *inode, struct file *file,
 extern long v4l_compat_ioctl32(struct file *file, unsigned int cmd,
 				unsigned long arg);
 
-/* Forward definition of v4l2-common.h defined structure */
-struct v4l2_register;
-
 /*
  * Newer version of video_device, handled by videodev2.c
  * 	This version moves redundant code from video device code to