diff options
Diffstat (limited to 'drivers/media/video/v4l2-dev.c')
| -rw-r--r-- | drivers/media/video/v4l2-dev.c | 96 |
1 files changed, 65 insertions, 31 deletions
diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c index 7addf2fd55d..ccd6566a515 100644 --- a/drivers/media/video/v4l2-dev.c +++ b/drivers/media/video/v4l2-dev.c @@ -65,6 +65,7 @@ static struct device_attribute video_device_attrs[] = { */ 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) { @@ -99,6 +100,7 @@ static void v4l2_chardev_release(struct kobject *kobj) /* 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 */ @@ -217,10 +219,10 @@ 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 */ @@ -231,23 +233,15 @@ int video_register_device_index(struct video_device *vfd, int type, int nr, 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: @@ -256,31 +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; @@ -306,7 +339,7 @@ int video_register_device_index(struct video_device *vfd, int type, int nr, 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__); @@ -324,6 +357,7 @@ del_cdev: fail_minor: mutex_lock(&videodev_lock); video_device[vfd->minor] = NULL; + clear_bit(vfd->num, video_nums[type]); mutex_unlock(&videodev_lock); vfd->minor = -1; return ret; |