V4L/DVB (10643): v4l2-device: allow a NULL parent device when registering.

Some drivers (e.g. for ISA devices) have no parent device because there
is no associated bus driver. Allow the parent device to be NULL in
those cases when registering v4l2_device.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 18 insertions, 13 deletions

diff --git a/include/media/v4l2-device.h b/include/media/v4l2-device.h
index 55e41afd95ef..5d7146dc2913 100644
--- a/include/media/v4l2-device.h
+++ b/include/media/v4l2-device.h
@@ -33,7 +33,9 @@
 #define V4L2_DEVICE_NAME_SIZE (BUS_ID_SIZE + 16)
 
 struct v4l2_device {
-        /* dev->driver_data points to this struct */
+        /* dev->driver_data points to this struct.
+           Note: dev might be NULL if there is no parent device
+           as is the case with e.g. ISA devices. */
         struct device *dev;
         /* used to keep track of the registered subdevs */
         struct list_head subdevs;
@@ -44,7 +46,9 @@ struct v4l2_device {
         char name[V4L2_DEVICE_NAME_SIZE];
 };
 
-/* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev */
+/* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev.
+   dev may be NULL in rare cases (ISA devices). In that case you
+   must fill in the v4l2_dev->name field before calling this function. */
 int __must_check v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev);
 /* Set v4l2_dev->dev->driver_data to NULL and unregister all sub-devices */
 void v4l2_device_unregister(struct v4l2_device *v4l2_dev);
@@ -52,23 +56,24 @@ void v4l2_device_unregister(struct v4l2_device *v4l2_dev);
 /* Register a subdev with a v4l2 device. While registered the subdev module
    is marked as in-use. An error is returned if the module is no longer
    loaded when you attempt to register it. */
-int __must_check v4l2_device_register_subdev(struct v4l2_device *dev, struct v4l2_subdev *sd);
+int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
+                                                struct v4l2_subdev *sd);
 /* Unregister a subdev with a v4l2 device. Can also be called if the subdev
    wasn't registered. In that case it will do nothing. */
 void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
 
 /* Iterate over all subdevs. */
-#define v4l2_device_for_each_subdev(sd, dev)                            \
-        list_for_each_entry(sd, &(dev)->subdevs, list)
+#define v4l2_device_for_each_subdev(sd, v4l2_dev)                       \
+        list_for_each_entry(sd, &(v4l2_dev)->subdevs, list)
 
 /* Call the specified callback for all subdevs matching the condition.
    Ignore any errors. Note that you cannot add or delete a subdev
    while walking the subdevs list. */
-#define __v4l2_device_call_subdevs(dev, cond, o, f, args...)            \
+#define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...)       \
         do {                                                            \
                 struct v4l2_subdev *sd;                                 \
                                                                         \
-                list_for_each_entry(sd, &(dev)->subdevs, list)          \
+                list_for_each_entry(sd, &(v4l2_dev)->subdevs, list)     \
                         if ((cond) && sd->ops->o && sd->ops->o->f)      \
                                 sd->ops->o->f(sd , ##args);             \
         } while (0)
@@ -77,12 +82,12 @@ void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
    If the callback returns an error other than 0 or -ENOIOCTLCMD, then
    return with that error code. Note that you cannot add or delete a
    subdev while walking the subdevs list. */
-#define __v4l2_device_call_subdevs_until_err(dev, cond, o, f, args...)  \
+#define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \
 ({                                                                      \
         struct v4l2_subdev *sd;                                         \
         long err = 0;                                                   \
                                                                         \
-        list_for_each_entry(sd, &(dev)->subdevs, list) {                \
+        list_for_each_entry(sd, &(v4l2_dev)->subdevs, list) {           \
                 if ((cond) && sd->ops->o && sd->ops->o->f)              \
                         err = sd->ops->o->f(sd , ##args);               \
                 if (err && err != -ENOIOCTLCMD)                         \
@@ -94,16 +99,16 @@ void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
 /* Call the specified callback for all subdevs matching grp_id (if 0, then
    match them all). Ignore any errors. Note that you cannot add or delete
    a subdev while walking the subdevs list. */
-#define v4l2_device_call_all(dev, grpid, o, f, args...)                 \
-        __v4l2_device_call_subdevs(dev,                                 \
+#define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...)            \
+        __v4l2_device_call_subdevs(v4l2_dev,                            \
                         !(grpid) || sd->grp_id == (grpid), o, f , ##args)
 
 /* Call the specified callback for all subdevs matching grp_id (if 0, then
    match them all). If the callback returns an error other than 0 or
    -ENOIOCTLCMD, then return with that error code. Note that you cannot
    add or delete a subdev while walking the subdevs list. */
-#define v4l2_device_call_until_err(dev, grpid, o, f, args...)           \
-        __v4l2_device_call_subdevs_until_err(dev,                       \
+#define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...)      \
+        __v4l2_device_call_subdevs_until_err(v4l2_dev,                  \
                        !(grpid) || sd->grp_id == (grpid), o, f , ##args)
 
 #endif