[media] v4l2: add new VIDIOC_DBG_G_CHIP_NAME ioctl

Simplify the debugging ioctls by creating the VIDIOC_DBG_G_CHIP_NAME ioctl.
This will eventually replace VIDIOC_DBG_G_CHIP_IDENT. Chip matching is done
by the name or index of subdevices or an index to a bridge chip. Most of this
can all be done automatically, so most drivers just need to provide get/set
register ops.
In particular, it is now possible to get/set subdev registers without
requiring assistance of the bridge driver.

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

2 files changed, 28 insertions, 9 deletions

diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h
index e10c2432f90..75a7dfc07de 100644
--- a/include/media/v4l2-ioctl.h
+++ b/include/media/v4l2-ioctl.h
@@ -247,6 +247,9 @@ struct v4l2_ioctl_ops {
 	int (*vidioc_g_chip_ident)     (struct file *file, void *fh,
 					struct v4l2_dbg_chip_ident *chip);
 
+	int (*vidioc_g_chip_name)      (struct file *file, void *fh,
+					struct v4l2_dbg_chip_name *chip);
+
 	int (*vidioc_enum_framesizes)   (struct file *file, void *fh,
 					 struct v4l2_frmsizeenum *fsize);
 
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 9d57dba2741..e9c49c5e641 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -1807,10 +1807,13 @@ struct v4l2_event_subscription {
 
 /* VIDIOC_DBG_G_REGISTER and VIDIOC_DBG_S_REGISTER */
 
-#define V4L2_CHIP_MATCH_HOST       0  /* Match against chip ID on host (0 for the host) */
-#define V4L2_CHIP_MATCH_I2C_DRIVER 1  /* Match against I2C driver name */
-#define V4L2_CHIP_MATCH_I2C_ADDR   2  /* Match against I2C 7-bit address */
-#define V4L2_CHIP_MATCH_AC97       3  /* Match against anciliary AC97 chip */
+#define V4L2_CHIP_MATCH_BRIDGE      0  /* Match against chip ID on the bridge (0 for the bridge) */
+#define V4L2_CHIP_MATCH_HOST V4L2_CHIP_MATCH_BRIDGE
+#define V4L2_CHIP_MATCH_I2C_DRIVER  1  /* Match against I2C driver name */
+#define V4L2_CHIP_MATCH_I2C_ADDR    2  /* Match against I2C 7-bit address */
+#define V4L2_CHIP_MATCH_AC97        3  /* Match against anciliary AC97 chip */
+#define V4L2_CHIP_MATCH_SUBDEV_NAME 4  /* Match against subdev name */
+#define V4L2_CHIP_MATCH_SUBDEV_IDX  5  /* Match against subdev index */
 
 struct v4l2_dbg_match {
 	__u32 type; /* Match type */
@@ -1834,6 +1837,17 @@ struct v4l2_dbg_chip_ident {
 	__u32 revision;    /* chip revision, chip specific */
 } __attribute__ ((packed));
 
+#define V4L2_CHIP_FL_READABLE (1 << 0)
+#define V4L2_CHIP_FL_WRITABLE (1 << 1)
+
+/* VIDIOC_DBG_G_CHIP_NAME */
+struct v4l2_dbg_chip_name {
+	struct v4l2_dbg_match match;
+	char name[32];
+	__u32 flags;
+	__u32 reserved[8];
+} __attribute__ ((packed));
+
 /**
  * struct v4l2_create_buffers - VIDIOC_CREATE_BUFS argument
  * @index:	on return, index of the first created buffer
@@ -1911,15 +1925,12 @@ struct v4l2_create_buffers {
 #define VIDIOC_G_EXT_CTRLS	_IOWR('V', 71, struct v4l2_ext_controls)
 #define VIDIOC_S_EXT_CTRLS	_IOWR('V', 72, struct v4l2_ext_controls)
 #define VIDIOC_TRY_EXT_CTRLS	_IOWR('V', 73, struct v4l2_ext_controls)
-#if 1
 #define VIDIOC_ENUM_FRAMESIZES	_IOWR('V', 74, struct v4l2_frmsizeenum)
 #define VIDIOC_ENUM_FRAMEINTERVALS _IOWR('V', 75, struct v4l2_frmivalenum)
 #define VIDIOC_G_ENC_INDEX       _IOR('V', 76, struct v4l2_enc_idx)
 #define VIDIOC_ENCODER_CMD      _IOWR('V', 77, struct v4l2_encoder_cmd)
 #define VIDIOC_TRY_ENCODER_CMD  _IOWR('V', 78, struct v4l2_encoder_cmd)
-#endif
 
-#if 1
 /* Experimental, meant for debugging, testing and internal use.
    Only implemented if CONFIG_VIDEO_ADV_DEBUG is defined.
    You must be root to use these ioctls. Never use these in applications! */
@@ -1927,9 +1938,10 @@ struct v4l2_create_buffers {
 #define	VIDIOC_DBG_G_REGISTER 	_IOWR('V', 80, struct v4l2_dbg_register)
 
 /* Experimental, meant for debugging, testing and internal use.
-   Never use this ioctl in applications! */
+   Never use this ioctl in applications!
+   Note: this ioctl is deprecated in favor of VIDIOC_DBG_G_CHIP_NAME and
+   will go away in the future. */
 #define VIDIOC_DBG_G_CHIP_IDENT _IOWR('V', 81, struct v4l2_dbg_chip_ident)
-#endif
 
 #define VIDIOC_S_HW_FREQ_SEEK	 _IOW('V', 82, struct v4l2_hw_freq_seek)
 
@@ -1963,6 +1975,10 @@ struct v4l2_create_buffers {
    versions. */
 #define VIDIOC_ENUM_FREQ_BANDS	_IOWR('V', 101, struct v4l2_frequency_band)
 
+/* Experimental, meant for debugging, testing and internal use.
+   Never use these in applications! */
+#define VIDIOC_DBG_G_CHIP_NAME  _IOWR('V', 102, struct v4l2_dbg_chip_name)
+
 /* Reminder: when adding new ioctls please add support for them to
    drivers/media/video/v4l2-compat-ioctl32.c as well! */