[media] v4l2-ioctl.c: v4l2-ioctl: add debug and callback/offset functionality

Add the necessary plumbing to make it possible to replace the switch by a
table driven implementation.

The ioctls ops can either be called directly, or by calling a small function
that does some additional work if needed.

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

diff --git a/drivers/media/video/v4l2-ioctl.c b/drivers/media/video/v4l2-ioctl.c
index e2f77bc159545a422eb2dc18d2feba1aa51a8ab4..7a15f351395f507f72ecc1ddab37306fbb9518e6 100644 (file)
--- a/drivers/media/video/v4l2-ioctl.c
+++ b/drivers/media/video/v4l2-ioctl.c
@@ -396,12 +396,22 @@ struct v4l2_ioctl_info {
        unsigned int ioctl;
        u32 flags;
        const char * const name;
+       union {
+               u32 offset;
+               int (*func)(const struct v4l2_ioctl_ops *ops,
+                               struct file *file, void *fh, void *p);
+       };
+       void (*debug)(const void *arg, bool write_only);
 };
 
 /* This control needs a priority check */
 #define INFO_FL_PRIO   (1 << 0)
 /* This control can be valid if the filehandle passes a control handler. */
 #define INFO_FL_CTRL   (1 << 1)
+/* This is a standard ioctl, no need for special code */
+#define INFO_FL_STD    (1 << 2)
+/* This is ioctl has its own function */
+#define INFO_FL_FUNC   (1 << 3)
 /* Zero struct from after the field to the end */
 #define INFO_FL_CLEAR(v4l2_struct, field)                      \
        ((offsetof(struct v4l2_struct, field) +                 \
@@ -414,6 +424,24 @@ struct v4l2_ioctl_info {
        .name = #_ioctl,                                        \
 }
 
+#define IOCTL_INFO_STD(_ioctl, _vidioc, _debug, _flags)                        \
+       [_IOC_NR(_ioctl)] = {                                           \
+               .ioctl = _ioctl,                                        \
+               .flags = _flags | INFO_FL_STD,                          \
+               .name = #_ioctl,                                        \
+               .offset = offsetof(struct v4l2_ioctl_ops, _vidioc),     \
+               .debug = _debug,                                        \
+       }
+
+#define IOCTL_INFO_FNC(_ioctl, _func, _debug, _flags)                  \
+       [_IOC_NR(_ioctl)] = {                                           \
+               .ioctl = _ioctl,                                        \
+               .flags = _flags | INFO_FL_FUNC,                         \
+               .name = #_ioctl,                                        \
+               .func = _func,                                          \
+               .debug = _debug,                                        \
+       }
+
 static struct v4l2_ioctl_info v4l2_ioctls[] = {
        IOCTL_INFO(VIDIOC_QUERYCAP, 0),
        IOCTL_INFO(VIDIOC_ENUM_FMT, INFO_FL_CLEAR(v4l2_fmtdesc, type)),
@@ -512,7 +540,7 @@ bool v4l2_is_known_ioctl(unsigned int cmd)
    external ioctl messages as well as internal V4L ioctl */
 void v4l_printk_ioctl(unsigned int cmd)
 {
-       char *dir, *type;
+       const char *dir, *type;
 
        switch (_IOC_TYPE(cmd)) {
        case 'd':
@@ -523,10 +551,11 @@ void v4l_printk_ioctl(unsigned int cmd)
                        type = "v4l2";
                        break;
                }
-               printk("%s", v4l2_ioctls[_IOC_NR(cmd)].name);
+               pr_cont("%s", v4l2_ioctls[_IOC_NR(cmd)].name);
                return;
        default:
                type = "unknown";
+               break;
        }
 
        switch (_IOC_DIR(cmd)) {
@@ -536,7 +565,7 @@ void v4l_printk_ioctl(unsigned int cmd)
        case _IOC_READ | _IOC_WRITE: dir = "rw"; break;
        default:                     dir = "*ERR*"; break;
        }
-       printk("%s ioctl '%c', dir=%s, #%d (0x%08x)",
+       pr_cont("%s ioctl '%c', dir=%s, #%d (0x%08x)",
                type, _IOC_TYPE(cmd), dir, _IOC_NR(cmd), cmd);
 }
 EXPORT_SYMBOL(v4l_printk_ioctl);
@@ -546,6 +575,9 @@ static long __video_do_ioctl(struct file *file,
 {
        struct video_device *vfd = video_devdata(file);
        const struct v4l2_ioctl_ops *ops = vfd->ioctl_ops;
+       bool write_only = false;
+       struct v4l2_ioctl_info default_info;
+       const struct v4l2_ioctl_info *info;
        void *fh = file->private_data;
        struct v4l2_fh *vfh = NULL;
        int use_fh_prio = 0;
@@ -563,23 +595,40 @@ static long __video_do_ioctl(struct file *file,
        }
 
        if (v4l2_is_known_ioctl(cmd)) {
-               struct v4l2_ioctl_info *info = &v4l2_ioctls[_IOC_NR(cmd)];
+               info = &v4l2_ioctls[_IOC_NR(cmd)];
 
                if (!test_bit(_IOC_NR(cmd), vfd->valid_ioctls) &&
                    !((info->flags & INFO_FL_CTRL) && vfh && vfh->ctrl_handler))
-                       return -ENOTTY;
+                       goto done;
 
                if (use_fh_prio && (info->flags & INFO_FL_PRIO)) {
                        ret = v4l2_prio_check(vfd->prio, vfh->prio);
                        if (ret)
-                               return ret;
+                               goto done;
                }
+       } else {
+               default_info.ioctl = cmd;
+               default_info.flags = 0;
+               default_info.debug = NULL;
+               info = &default_info;
        }
 
-       if ((vfd->debug & V4L2_DEBUG_IOCTL) &&
-                               !(vfd->debug & V4L2_DEBUG_IOCTL_ARG)) {
+       write_only = _IOC_DIR(cmd) == _IOC_WRITE;
+       if (info->debug && write_only && vfd->debug > V4L2_DEBUG_IOCTL) {
                v4l_print_ioctl(vfd->name, cmd);
-               printk(KERN_CONT "\n");
+               pr_cont(": ");
+               info->debug(arg, write_only);
+       }
+       if (info->flags & INFO_FL_STD) {
+               typedef int (*vidioc_op)(struct file *file, void *fh, void *p);
+               const void *p = vfd->ioctl_ops;
+               const vidioc_op *vidioc = p + info->offset;
+
+               ret = (*vidioc)(file, fh, arg);
+               goto done;
+       } else if (info->flags & INFO_FL_FUNC) {
+               ret = info->func(ops, file, fh, arg);
+               goto done;
        }
 
        switch (cmd) {
@@ -2101,10 +2150,26 @@ static long __video_do_ioctl(struct file *file,
                break;
        } /* switch */
 
-       if (vfd->debug & V4L2_DEBUG_IOCTL_ARG) {
-               if (ret < 0) {
-                       v4l_print_ioctl(vfd->name, cmd);
-                       printk(KERN_CONT " error %ld\n", ret);
+done:
+       if (vfd->debug) {
+               if (write_only && vfd->debug > V4L2_DEBUG_IOCTL) {
+                       if (ret < 0)
+                               printk(KERN_DEBUG "%s: error %ld\n",
+                                       video_device_node_name(vfd), ret);
+                       return ret;
+               }
+               v4l_print_ioctl(vfd->name, cmd);
+               if (ret < 0)
+                       pr_cont(": error %ld\n", ret);
+               else if (vfd->debug == V4L2_DEBUG_IOCTL)
+                       pr_cont("\n");
+               else if (!info->debug)
+                       return ret;
+               else if (_IOC_DIR(cmd) == _IOC_NONE)
+                       info->debug(arg, write_only);
+               else {
+                       pr_cont(": ");
+                       info->debug(arg, write_only);
                }
        }