diff options
| -rw-r--r-- | Documentation/video4linux/v4l2-framework.txt | 10 | ||||
| -rw-r--r-- | drivers/media/video/v4l2-device.c | 37 | ||||
| -rw-r--r-- | include/media/v4l2-device.h | 31 |
3 files changed, 48 insertions, 30 deletions
diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt index 48cdf86248cb..e1620e2a38ff 100644 --- a/Documentation/video4linux/v4l2-framework.txt +++ b/Documentation/video4linux/v4l2-framework.txt @@ -84,12 +84,14 @@ You must register the device instance: v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev); Registration will initialize the v4l2_device struct and link dev->driver_data -to v4l2_dev. Registration will also set v4l2_dev->name to a value derived from -dev (driver name followed by the bus_id, to be precise). You may change the -name after registration if you want. +to v4l2_dev. If v4l2_dev->name is empty then it will be set to a value derived +from dev (driver name followed by the bus_id, to be precise). If you set it +up before calling v4l2_device_register then it will be untouched. If dev is +NULL, then you *must* setup v4l2_dev->name before calling v4l2_device_register. The first 'dev' argument is normally the struct device pointer of a pci_dev, -usb_device or platform_device. +usb_device or platform_device. It is rare for dev to be NULL, but it happens +with ISA devices, for example. You unregister with: diff --git a/drivers/media/video/v4l2-device.c b/drivers/media/video/v4l2-device.c index 8a4b74f3129f..3330ffb7d010 100644 --- a/drivers/media/video/v4l2-device.c +++ b/drivers/media/video/v4l2-device.c @@ -26,15 +26,24 @@ int v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev) { - if (dev == NULL || v4l2_dev == NULL) + if (v4l2_dev == NULL) return -EINVAL; - /* Warn if we apparently re-register a device */ - WARN_ON(dev_get_drvdata(dev) != NULL); + INIT_LIST_HEAD(&v4l2_dev->subdevs); spin_lock_init(&v4l2_dev->lock); v4l2_dev->dev = dev; - snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), "%s %s", + if (dev == NULL) { + /* If dev == NULL, then name must be filled in by the caller */ + WARN_ON(!v4l2_dev->name[0]); + return 0; + } + + /* Set name to driver name + device name if it is empty. */ + if (!v4l2_dev->name[0]) + snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), "%s %s", dev->driver->name, dev_name(dev)); + if (dev_get_drvdata(dev)) + v4l2_warn(v4l2_dev, "Non-NULL drvdata on register\n"); dev_set_drvdata(dev, v4l2_dev); return 0; } @@ -44,10 +53,11 @@ void v4l2_device_unregister(struct v4l2_device *v4l2_dev) { struct v4l2_subdev *sd, *next; - if (v4l2_dev == NULL || v4l2_dev->dev == NULL) + if (v4l2_dev == NULL) return; - dev_set_drvdata(v4l2_dev->dev, NULL); - /* unregister subdevs */ + if (v4l2_dev->dev) + dev_set_drvdata(v4l2_dev->dev, NULL); + /* Unregister subdevs */ list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list) v4l2_device_unregister_subdev(sd); @@ -55,19 +65,20 @@ void v4l2_device_unregister(struct v4l2_device *v4l2_dev) } EXPORT_SYMBOL_GPL(v4l2_device_unregister); -int v4l2_device_register_subdev(struct v4l2_device *dev, struct v4l2_subdev *sd) +int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev, + struct v4l2_subdev *sd) { /* Check for valid input */ - if (dev == NULL || sd == NULL || !sd->name[0]) + if (v4l2_dev == NULL || sd == NULL || !sd->name[0]) return -EINVAL; /* Warn if we apparently re-register a subdev */ WARN_ON(sd->dev != NULL); if (!try_module_get(sd->owner)) return -ENODEV; - sd->dev = dev; - spin_lock(&dev->lock); - list_add_tail(&sd->list, &dev->subdevs); - spin_unlock(&dev->lock); + sd->dev = v4l2_dev; + spin_lock(&v4l2_dev->lock); + list_add_tail(&sd->list, &v4l2_dev->subdevs); + spin_unlock(&v4l2_dev->lock); return 0; } EXPORT_SYMBOL_GPL(v4l2_device_register_subdev); 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 |