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authorHans Verkuil <hverkuil@xs4all.nl>2009-02-14 09:54:23 -0500
committerMauro Carvalho Chehab <mchehab@redhat.com>2009-03-30 11:42:50 -0400
commit3a63e4492fbc7aa7f99d4368822da1382ec6fe03 (patch)
treed9d50f32757e7acde5f7ce3ecb22866b1cf51023
parent62cfdacc9431cad7f9093e91b17ea68d684188ae (diff)
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>
-rw-r--r--Documentation/video4linux/v4l2-framework.txt10
-rw-r--r--drivers/media/video/v4l2-device.c37
-rw-r--r--include/media/v4l2-device.h31
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:
84 v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev); 84 v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev);
85 85
86Registration will initialize the v4l2_device struct and link dev->driver_data 86Registration will initialize the v4l2_device struct and link dev->driver_data
87to v4l2_dev. Registration will also set v4l2_dev->name to a value derived from 87to v4l2_dev. If v4l2_dev->name is empty then it will be set to a value derived
88dev (driver name followed by the bus_id, to be precise). You may change the 88from dev (driver name followed by the bus_id, to be precise). If you set it
89name after registration if you want. 89up before calling v4l2_device_register then it will be untouched. If dev is
90NULL, then you *must* setup v4l2_dev->name before calling v4l2_device_register.
90 91
91The first 'dev' argument is normally the struct device pointer of a pci_dev, 92The first 'dev' argument is normally the struct device pointer of a pci_dev,
92usb_device or platform_device. 93usb_device or platform_device. It is rare for dev to be NULL, but it happens
94with ISA devices, for example.
93 95
94You unregister with: 96You unregister with:
95 97
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 @@
26 26
27int v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev) 27int v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev)
28{ 28{
29 if (dev == NULL || v4l2_dev == NULL) 29 if (v4l2_dev == NULL)
30 return -EINVAL; 30 return -EINVAL;
31 /* Warn if we apparently re-register a device */ 31
32 WARN_ON(dev_get_drvdata(dev) != NULL);
33 INIT_LIST_HEAD(&v4l2_dev->subdevs); 32 INIT_LIST_HEAD(&v4l2_dev->subdevs);
34 spin_lock_init(&v4l2_dev->lock); 33 spin_lock_init(&v4l2_dev->lock);
35 v4l2_dev->dev = dev; 34 v4l2_dev->dev = dev;
36 snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), "%s %s", 35 if (dev == NULL) {
36 /* If dev == NULL, then name must be filled in by the caller */
37 WARN_ON(!v4l2_dev->name[0]);
38 return 0;
39 }
40
41 /* Set name to driver name + device name if it is empty. */
42 if (!v4l2_dev->name[0])
43 snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), "%s %s",
37 dev->driver->name, dev_name(dev)); 44 dev->driver->name, dev_name(dev));
45 if (dev_get_drvdata(dev))
46 v4l2_warn(v4l2_dev, "Non-NULL drvdata on register\n");
38 dev_set_drvdata(dev, v4l2_dev); 47 dev_set_drvdata(dev, v4l2_dev);
39 return 0; 48 return 0;
40} 49}
@@ -44,10 +53,11 @@ void v4l2_device_unregister(struct v4l2_device *v4l2_dev)
44{ 53{
45 struct v4l2_subdev *sd, *next; 54 struct v4l2_subdev *sd, *next;
46 55
47 if (v4l2_dev == NULL || v4l2_dev->dev == NULL) 56 if (v4l2_dev == NULL)
48 return; 57 return;
49 dev_set_drvdata(v4l2_dev->dev, NULL); 58 if (v4l2_dev->dev)
50 /* unregister subdevs */ 59 dev_set_drvdata(v4l2_dev->dev, NULL);
60 /* Unregister subdevs */
51 list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list) 61 list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list)
52 v4l2_device_unregister_subdev(sd); 62 v4l2_device_unregister_subdev(sd);
53 63
@@ -55,19 +65,20 @@ void v4l2_device_unregister(struct v4l2_device *v4l2_dev)
55} 65}
56EXPORT_SYMBOL_GPL(v4l2_device_unregister); 66EXPORT_SYMBOL_GPL(v4l2_device_unregister);
57 67
58int v4l2_device_register_subdev(struct v4l2_device *dev, struct v4l2_subdev *sd) 68int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
69 struct v4l2_subdev *sd)
59{ 70{
60 /* Check for valid input */ 71 /* Check for valid input */
61 if (dev == NULL || sd == NULL || !sd->name[0]) 72 if (v4l2_dev == NULL || sd == NULL || !sd->name[0])
62 return -EINVAL; 73 return -EINVAL;
63 /* Warn if we apparently re-register a subdev */ 74 /* Warn if we apparently re-register a subdev */
64 WARN_ON(sd->dev != NULL); 75 WARN_ON(sd->dev != NULL);
65 if (!try_module_get(sd->owner)) 76 if (!try_module_get(sd->owner))
66 return -ENODEV; 77 return -ENODEV;
67 sd->dev = dev; 78 sd->dev = v4l2_dev;
68 spin_lock(&dev->lock); 79 spin_lock(&v4l2_dev->lock);
69 list_add_tail(&sd->list, &dev->subdevs); 80 list_add_tail(&sd->list, &v4l2_dev->subdevs);
70 spin_unlock(&dev->lock); 81 spin_unlock(&v4l2_dev->lock);
71 return 0; 82 return 0;
72} 83}
73EXPORT_SYMBOL_GPL(v4l2_device_register_subdev); 84EXPORT_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 @@
33#define V4L2_DEVICE_NAME_SIZE (BUS_ID_SIZE + 16) 33#define V4L2_DEVICE_NAME_SIZE (BUS_ID_SIZE + 16)
34 34
35struct v4l2_device { 35struct v4l2_device {
36 /* dev->driver_data points to this struct */ 36 /* dev->driver_data points to this struct.
37 Note: dev might be NULL if there is no parent device
38 as is the case with e.g. ISA devices. */
37 struct device *dev; 39 struct device *dev;
38 /* used to keep track of the registered subdevs */ 40 /* used to keep track of the registered subdevs */
39 struct list_head subdevs; 41 struct list_head subdevs;
@@ -44,7 +46,9 @@ struct v4l2_device {
44 char name[V4L2_DEVICE_NAME_SIZE]; 46 char name[V4L2_DEVICE_NAME_SIZE];
45}; 47};
46 48
47/* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev */ 49/* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev.
50 dev may be NULL in rare cases (ISA devices). In that case you
51 must fill in the v4l2_dev->name field before calling this function. */
48int __must_check v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev); 52int __must_check v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev);
49/* Set v4l2_dev->dev->driver_data to NULL and unregister all sub-devices */ 53/* Set v4l2_dev->dev->driver_data to NULL and unregister all sub-devices */
50void v4l2_device_unregister(struct v4l2_device *v4l2_dev); 54void v4l2_device_unregister(struct v4l2_device *v4l2_dev);
@@ -52,23 +56,24 @@ void v4l2_device_unregister(struct v4l2_device *v4l2_dev);
52/* Register a subdev with a v4l2 device. While registered the subdev module 56/* Register a subdev with a v4l2 device. While registered the subdev module
53 is marked as in-use. An error is returned if the module is no longer 57 is marked as in-use. An error is returned if the module is no longer
54 loaded when you attempt to register it. */ 58 loaded when you attempt to register it. */
55int __must_check v4l2_device_register_subdev(struct v4l2_device *dev, struct v4l2_subdev *sd); 59int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
60 struct v4l2_subdev *sd);
56/* Unregister a subdev with a v4l2 device. Can also be called if the subdev 61/* Unregister a subdev with a v4l2 device. Can also be called if the subdev
57 wasn't registered. In that case it will do nothing. */ 62 wasn't registered. In that case it will do nothing. */
58void v4l2_device_unregister_subdev(struct v4l2_subdev *sd); 63void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
59 64
60/* Iterate over all subdevs. */ 65/* Iterate over all subdevs. */
61#define v4l2_device_for_each_subdev(sd, dev) \ 66#define v4l2_device_for_each_subdev(sd, v4l2_dev) \
62 list_for_each_entry(sd, &(dev)->subdevs, list) 67 list_for_each_entry(sd, &(v4l2_dev)->subdevs, list)
63 68
64/* Call the specified callback for all subdevs matching the condition. 69/* Call the specified callback for all subdevs matching the condition.
65 Ignore any errors. Note that you cannot add or delete a subdev 70 Ignore any errors. Note that you cannot add or delete a subdev
66 while walking the subdevs list. */ 71 while walking the subdevs list. */
67#define __v4l2_device_call_subdevs(dev, cond, o, f, args...) \ 72#define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...) \
68 do { \ 73 do { \
69 struct v4l2_subdev *sd; \ 74 struct v4l2_subdev *sd; \
70 \ 75 \
71 list_for_each_entry(sd, &(dev)->subdevs, list) \ 76 list_for_each_entry(sd, &(v4l2_dev)->subdevs, list) \
72 if ((cond) && sd->ops->o && sd->ops->o->f) \ 77 if ((cond) && sd->ops->o && sd->ops->o->f) \
73 sd->ops->o->f(sd , ##args); \ 78 sd->ops->o->f(sd , ##args); \
74 } while (0) 79 } while (0)
@@ -77,12 +82,12 @@ void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
77 If the callback returns an error other than 0 or -ENOIOCTLCMD, then 82 If the callback returns an error other than 0 or -ENOIOCTLCMD, then
78 return with that error code. Note that you cannot add or delete a 83 return with that error code. Note that you cannot add or delete a
79 subdev while walking the subdevs list. */ 84 subdev while walking the subdevs list. */
80#define __v4l2_device_call_subdevs_until_err(dev, cond, o, f, args...) \ 85#define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \
81({ \ 86({ \
82 struct v4l2_subdev *sd; \ 87 struct v4l2_subdev *sd; \
83 long err = 0; \ 88 long err = 0; \
84 \ 89 \
85 list_for_each_entry(sd, &(dev)->subdevs, list) { \ 90 list_for_each_entry(sd, &(v4l2_dev)->subdevs, list) { \
86 if ((cond) && sd->ops->o && sd->ops->o->f) \ 91 if ((cond) && sd->ops->o && sd->ops->o->f) \
87 err = sd->ops->o->f(sd , ##args); \ 92 err = sd->ops->o->f(sd , ##args); \
88 if (err && err != -ENOIOCTLCMD) \ 93 if (err && err != -ENOIOCTLCMD) \
@@ -94,16 +99,16 @@ void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
94/* Call the specified callback for all subdevs matching grp_id (if 0, then 99/* Call the specified callback for all subdevs matching grp_id (if 0, then
95 match them all). Ignore any errors. Note that you cannot add or delete 100 match them all). Ignore any errors. Note that you cannot add or delete
96 a subdev while walking the subdevs list. */ 101 a subdev while walking the subdevs list. */
97#define v4l2_device_call_all(dev, grpid, o, f, args...) \ 102#define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...) \
98 __v4l2_device_call_subdevs(dev, \ 103 __v4l2_device_call_subdevs(v4l2_dev, \
99 !(grpid) || sd->grp_id == (grpid), o, f , ##args) 104 !(grpid) || sd->grp_id == (grpid), o, f , ##args)
100 105
101/* Call the specified callback for all subdevs matching grp_id (if 0, then 106/* Call the specified callback for all subdevs matching grp_id (if 0, then
102 match them all). If the callback returns an error other than 0 or 107 match them all). If the callback returns an error other than 0 or
103 -ENOIOCTLCMD, then return with that error code. Note that you cannot 108 -ENOIOCTLCMD, then return with that error code. Note that you cannot
104 add or delete a subdev while walking the subdevs list. */ 109 add or delete a subdev while walking the subdevs list. */
105#define v4l2_device_call_until_err(dev, grpid, o, f, args...) \ 110#define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...) \
106 __v4l2_device_call_subdevs_until_err(dev, \ 111 __v4l2_device_call_subdevs_until_err(v4l2_dev, \
107 !(grpid) || sd->grp_id == (grpid), o, f , ##args) 112 !(grpid) || sd->grp_id == (grpid), o, f , ##args)
108 113
109#endif 114#endif