diff options
author | Arjan van de Ven <arjan@linux.intel.com> | 2008-10-17 09:20:26 -0700 |
---|---|---|
committer | Arjan van de Ven <arjan@linux.intel.com> | 2008-10-17 09:20:26 -0700 |
commit | 651dab4264e4ba0e563f5ff56f748127246e9065 (patch) | |
tree | 016630974bdcb00fe529b673f96d389e0fd6dc94 /drivers/media/video/v4l2-dev.c | |
parent | 40b8606253552109815786e5d4b0de98782d31f5 (diff) | |
parent | 2e532d68a2b3e2aa6b19731501222069735c741c (diff) |
Merge commit 'linus/master' into merge-linus
Conflicts:
arch/x86/kvm/i8254.c
Diffstat (limited to 'drivers/media/video/v4l2-dev.c')
-rw-r--r-- | drivers/media/video/v4l2-dev.c | 300 |
1 files changed, 150 insertions, 150 deletions
diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c index 155fdec9ac7..ccd6566a515 100644 --- a/drivers/media/video/v4l2-dev.c +++ b/drivers/media/video/v4l2-dev.c @@ -42,6 +42,7 @@ static ssize_t show_index(struct device *cd, struct device_attribute *attr, char *buf) { struct video_device *vfd = container_of(cd, struct video_device, dev); + return sprintf(buf, "%i\n", vfd->index); } @@ -49,6 +50,7 @@ static ssize_t show_name(struct device *cd, struct device_attribute *attr, char *buf) { struct video_device *vfd = container_of(cd, struct video_device, dev); + return sprintf(buf, "%.*s\n", (int)sizeof(vfd->name), vfd->name); } @@ -58,12 +60,16 @@ static struct device_attribute video_device_attrs[] = { __ATTR_NULL }; +/* + * Active devices + */ +static struct video_device *video_device[VIDEO_NUM_DEVICES]; +static DEFINE_MUTEX(videodev_lock); +static DECLARE_BITMAP(video_nums[VFL_TYPE_MAX], VIDEO_NUM_DEVICES); + struct video_device *video_device_alloc(void) { - struct video_device *vfd; - - vfd = kzalloc(sizeof(*vfd), GFP_KERNEL); - return vfd; + return kzalloc(sizeof(struct video_device), GFP_KERNEL); } EXPORT_SYMBOL(video_device_alloc); @@ -73,16 +79,52 @@ void video_device_release(struct video_device *vfd) } EXPORT_SYMBOL(video_device_release); +void video_device_release_empty(struct video_device *vfd) +{ + /* Do nothing */ + /* Only valid when the video_device struct is a static. */ +} +EXPORT_SYMBOL(video_device_release_empty); + +/* Called when the last user of the character device is gone. */ +static void v4l2_chardev_release(struct kobject *kobj) +{ + struct video_device *vfd = container_of(kobj, struct video_device, cdev.kobj); + + mutex_lock(&videodev_lock); + if (video_device[vfd->minor] != vfd) { + mutex_unlock(&videodev_lock); + BUG(); + return; + } + + /* Free up this device for reuse */ + video_device[vfd->minor] = NULL; + clear_bit(vfd->num, video_nums[vfd->vfl_type]); + mutex_unlock(&videodev_lock); + + /* Release the character device */ + vfd->cdev_release(kobj); + /* Release video_device and perform other + cleanups as needed. */ + if (vfd->release) + vfd->release(vfd); +} + +/* The new kobj_type for the character device */ +static struct kobj_type v4l2_ktype_cdev_default = { + .release = v4l2_chardev_release, +}; + static void video_release(struct device *cd) { struct video_device *vfd = container_of(cd, struct video_device, dev); -#if 1 - /* needed until all drivers are fixed */ - if (!vfd->release) - return; -#endif - vfd->release(vfd); + /* It's now safe to delete the char device. + This will either trigger the v4l2_chardev_release immediately (if + the refcount goes to 0) or later when the last user of the + character device closes it. */ + cdev_del(&vfd->cdev); } static struct class video_class = { @@ -91,87 +133,12 @@ static struct class video_class = { .dev_release = video_release, }; -/* - * Active devices - */ - -static struct video_device *video_device[VIDEO_NUM_DEVICES]; -static DEFINE_MUTEX(videodev_lock); - struct video_device *video_devdata(struct file *file) { return video_device[iminor(file->f_path.dentry->d_inode)]; } EXPORT_SYMBOL(video_devdata); -/* - * Open a video device - FIXME: Obsoleted - */ -static int video_open(struct inode *inode, struct file *file) -{ - unsigned int minor = iminor(inode); - int err = 0; - struct video_device *vfl; - const struct file_operations *old_fops; - - if (minor >= VIDEO_NUM_DEVICES) - return -ENODEV; - lock_kernel(); - mutex_lock(&videodev_lock); - vfl = video_device[minor]; - if (vfl == NULL) { - mutex_unlock(&videodev_lock); - request_module("char-major-%d-%d", VIDEO_MAJOR, minor); - mutex_lock(&videodev_lock); - vfl = video_device[minor]; - if (vfl == NULL) { - mutex_unlock(&videodev_lock); - unlock_kernel(); - return -ENODEV; - } - } - old_fops = file->f_op; - file->f_op = fops_get(vfl->fops); - if (file->f_op->open) - err = file->f_op->open(inode, file); - if (err) { - fops_put(file->f_op); - file->f_op = fops_get(old_fops); - } - fops_put(old_fops); - mutex_unlock(&videodev_lock); - unlock_kernel(); - return err; -} - -/* - * open/release helper functions -- handle exclusive opens - * Should be removed soon - */ -int video_exclusive_open(struct inode *inode, struct file *file) -{ - struct video_device *vfl = video_devdata(file); - int retval = 0; - - mutex_lock(&vfl->lock); - if (vfl->users) - retval = -EBUSY; - else - vfl->users++; - mutex_unlock(&vfl->lock); - return retval; -} -EXPORT_SYMBOL(video_exclusive_open); - -int video_exclusive_release(struct inode *inode, struct file *file) -{ - struct video_device *vfl = video_devdata(file); - - vfl->users--; - return 0; -} -EXPORT_SYMBOL(video_exclusive_release); - /** * get_index - assign stream number based on parent device * @vdev: video_device to assign index number to, vdev->dev should be assigned @@ -252,33 +219,29 @@ int video_register_device_index(struct video_device *vfd, int type, int nr, int index) { int i = 0; - int base; - int end; int ret; - char *name_base; + int minor_offset = 0; + int minor_cnt = VIDEO_NUM_DEVICES; + const char *name_base; + void *priv = video_get_drvdata(vfd); + + /* the release callback MUST be present */ + BUG_ON(!vfd->release); if (vfd == NULL) return -EINVAL; switch (type) { case VFL_TYPE_GRABBER: - base = MINOR_VFL_TYPE_GRABBER_MIN; - end = MINOR_VFL_TYPE_GRABBER_MAX+1; name_base = "video"; break; case VFL_TYPE_VTX: - base = MINOR_VFL_TYPE_VTX_MIN; - end = MINOR_VFL_TYPE_VTX_MAX+1; name_base = "vtx"; break; case VFL_TYPE_VBI: - base = MINOR_VFL_TYPE_VBI_MIN; - end = MINOR_VFL_TYPE_VBI_MAX+1; name_base = "vbi"; break; case VFL_TYPE_RADIO: - base = MINOR_VFL_TYPE_RADIO_MIN; - end = MINOR_VFL_TYPE_RADIO_MAX+1; name_base = "radio"; break; default: @@ -287,28 +250,70 @@ int video_register_device_index(struct video_device *vfd, int type, int nr, return -EINVAL; } + vfd->vfl_type = type; + +#ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES + /* Keep the ranges for the first four types for historical + * reasons. + * Newer devices (not yet in place) should use the range + * of 128-191 and just pick the first free minor there + * (new style). */ + switch (type) { + case VFL_TYPE_GRABBER: + minor_offset = 0; + minor_cnt = 64; + break; + case VFL_TYPE_RADIO: + minor_offset = 64; + minor_cnt = 64; + break; + case VFL_TYPE_VTX: + minor_offset = 192; + minor_cnt = 32; + break; + case VFL_TYPE_VBI: + minor_offset = 224; + minor_cnt = 32; + break; + default: + minor_offset = 128; + minor_cnt = 64; + break; + } +#endif + + /* Initialize the character device */ + cdev_init(&vfd->cdev, vfd->fops); + vfd->cdev.owner = vfd->fops->owner; /* pick a minor number */ mutex_lock(&videodev_lock); - if (nr >= 0 && nr < end-base) { - /* use the one the driver asked for */ - i = base + nr; - if (NULL != video_device[i]) { - mutex_unlock(&videodev_lock); - return -ENFILE; - } - } else { - /* use first free */ - for (i = base; i < end; i++) - if (NULL == video_device[i]) - break; - if (i == end) { - mutex_unlock(&videodev_lock); - return -ENFILE; - } + nr = find_next_zero_bit(video_nums[type], minor_cnt, nr == -1 ? 0 : nr); + if (nr == minor_cnt) + nr = find_first_zero_bit(video_nums[type], minor_cnt); + if (nr == minor_cnt) { + printk(KERN_ERR "could not get a free kernel number\n"); + mutex_unlock(&videodev_lock); + return -ENFILE; } - video_device[i] = vfd; - vfd->vfl_type = type; - vfd->minor = i; +#ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES + /* 1-on-1 mapping of kernel number to minor number */ + i = nr; +#else + /* The kernel number and minor numbers are independent */ + for (i = 0; i < VIDEO_NUM_DEVICES; i++) + if (video_device[i] == NULL) + break; + if (i == VIDEO_NUM_DEVICES) { + mutex_unlock(&videodev_lock); + printk(KERN_ERR "could not get a free minor\n"); + return -ENFILE; + } +#endif + vfd->minor = i + minor_offset; + vfd->num = nr; + set_bit(nr, video_nums[type]); + BUG_ON(video_device[vfd->minor]); + video_device[vfd->minor] = vfd; ret = get_index(vfd, index); vfd->index = ret; @@ -320,35 +325,41 @@ int video_register_device_index(struct video_device *vfd, int type, int nr, goto fail_minor; } - mutex_init(&vfd->lock); - + ret = cdev_add(&vfd->cdev, MKDEV(VIDEO_MAJOR, vfd->minor), 1); + if (ret < 0) { + printk(KERN_ERR "%s: cdev_add failed\n", __func__); + goto fail_minor; + } /* sysfs class */ - memset(&vfd->dev, 0x00, sizeof(vfd->dev)); + memset(&vfd->dev, 0, sizeof(vfd->dev)); + /* The memset above cleared the device's drvdata, so + put back the copy we made earlier. */ + video_set_drvdata(vfd, priv); vfd->dev.class = &video_class; vfd->dev.devt = MKDEV(VIDEO_MAJOR, vfd->minor); if (vfd->parent) vfd->dev.parent = vfd->parent; - sprintf(vfd->dev.bus_id, "%s%d", name_base, i - base); + sprintf(vfd->dev.bus_id, "%s%d", name_base, nr); ret = device_register(&vfd->dev); if (ret < 0) { printk(KERN_ERR "%s: device_register failed\n", __func__); - goto fail_minor; + goto del_cdev; } - -#if 1 - /* needed until all drivers are fixed */ - if (!vfd->release) - printk(KERN_WARNING "videodev: \"%s\" has no release callback. " - "Please fix your driver for proper sysfs support, see " - "http://lwn.net/Articles/36850/\n", vfd->name); -#endif + /* Remember the cdev's release function */ + vfd->cdev_release = vfd->cdev.kobj.ktype->release; + /* Install our own */ + vfd->cdev.kobj.ktype = &v4l2_ktype_cdev_default; return 0; +del_cdev: + cdev_del(&vfd->cdev); + fail_minor: mutex_lock(&videodev_lock); video_device[vfd->minor] = NULL; - vfd->minor = -1; + clear_bit(vfd->num, video_nums[type]); mutex_unlock(&videodev_lock); + vfd->minor = -1; return ret; } EXPORT_SYMBOL(video_register_device_index); @@ -363,42 +374,29 @@ EXPORT_SYMBOL(video_register_device_index); void video_unregister_device(struct video_device *vfd) { - mutex_lock(&videodev_lock); - if (video_device[vfd->minor] != vfd) - panic("videodev: bad unregister"); - - video_device[vfd->minor] = NULL; device_unregister(&vfd->dev); - mutex_unlock(&videodev_lock); } EXPORT_SYMBOL(video_unregister_device); /* - * Video fs operations - */ -static const struct file_operations video_fops = { - .owner = THIS_MODULE, - .llseek = no_llseek, - .open = video_open, -}; - -/* * Initialise video for linux */ - static int __init videodev_init(void) { + dev_t dev = MKDEV(VIDEO_MAJOR, 0); int ret; printk(KERN_INFO "Linux video capture interface: v2.00\n"); - if (register_chrdev(VIDEO_MAJOR, VIDEO_NAME, &video_fops)) { - printk(KERN_WARNING "video_dev: unable to get major %d\n", VIDEO_MAJOR); - return -EIO; + ret = register_chrdev_region(dev, VIDEO_NUM_DEVICES, VIDEO_NAME); + if (ret < 0) { + printk(KERN_WARNING "videodev: unable to get major %d\n", + VIDEO_MAJOR); + return ret; } ret = class_register(&video_class); if (ret < 0) { - unregister_chrdev(VIDEO_MAJOR, VIDEO_NAME); + unregister_chrdev_region(dev, VIDEO_NUM_DEVICES); printk(KERN_WARNING "video_dev: class_register failed\n"); return -EIO; } @@ -408,8 +406,10 @@ static int __init videodev_init(void) static void __exit videodev_exit(void) { + dev_t dev = MKDEV(VIDEO_MAJOR, 0); + class_unregister(&video_class); - unregister_chrdev(VIDEO_MAJOR, VIDEO_NAME); + unregister_chrdev_region(dev, VIDEO_NUM_DEVICES); } module_init(videodev_init) |