/* -*- c-file-style: "linux" -*-*/ /* * v4l2loopback.c -- video4linux2 loopback driver * * Copyright (C) 2005-2009 Vasily Levin (vasaka@gmail.com) * Copyright (C) 2010-2019 IOhannes m zmoelnig (zmoelnig@iem.at) * Copyright (C) 2011 Stefan Diewald (stefan.diewald@mytum.de) * Copyright (C) 2012 Anton Novikov (random.plant@gmail.com) * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * */ #include #include #include #include #include #include #include #include #include #include # define HAVE__V4L2_DEVICE # include # define HAVE__V4L2_CTRLS # include #if defined(timer_setup) && defined(from_timer) #define HAVE_TIMER_SETUP #endif #define V4L2LOOPBACK_VERSION_CODE KERNEL_VERSION(0, 12, 0) #define POLL_CLOSE_EVENT 0x50 MODULE_DESCRIPTION("V4L2 loopback video device"); MODULE_AUTHOR("Vasily Levin, " \ "IOhannes m zmoelnig ," \ "Stefan Diewald," \ "Anton Novikov" \ "et al." \ ); MODULE_LICENSE("GPL"); /* * helpers */ #define STRINGIFY(s) #s #define STRINGIFY2(s) STRINGIFY(s) #define MARK() \ do { if (debug > 1) { \ pr_err("%s:%d[%s]\n", __FILE__, __LINE__, __func__); \ } } while (0) /* * compatibility hacks */ #ifndef HAVE__V4L2_CTRLS struct v4l2_ctrl_handler { int error; }; struct v4l2_ctrl_config { void *ops; u32 id; const char *name; int type; s32 min; s32 max; u32 step; s32 def; }; int v4l2_ctrl_handler_init(struct v4l2_ctrl_handler *hdl, unsigned nr_of_controls_hint) { hdl->error = 0; return 0; } void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl) { } void *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl, const struct v4l2_ctrl_config *conf, void *priv) { return NULL; } #endif /* HAVE__V4L2_CTRLS */ #ifndef HAVE__V4L2_DEVICE /* dummy v4l2_device struct/functions */ # define V4L2_DEVICE_NAME_SIZE (20 + 16) struct v4l2_device { char name[V4L2_DEVICE_NAME_SIZE]; struct v4l2_ctrl_handler *ctrl_handler; }; static inline int v4l2_device_register(void *dev, void *v4l2_dev) { return 0; } static inline void v4l2_device_unregister(struct v4l2_device *v4l2_dev) { /* Nothing to return */ } #endif /* HAVE__V4L2_DEVICE */ # define v4l2l_vzalloc vzalloc /* module constants * can be overridden during he build process using something like * make KCPPFLAGS="-DMAX_DEVICES=100" */ /* maximum number of v4l2loopback devices that can be created */ #ifndef MAX_DEVICES # define MAX_DEVICES 8 #endif /* when a producer is considered to have gone stale */ #ifndef MAX_TIMEOUT # define MAX_TIMEOUT (100 * 1000) /* in msecs */ #endif /* max buffers that can be mapped, actually they * are all mapped to max_buffers buffers */ #ifndef MAX_BUFFERS # define MAX_BUFFERS 32 #endif /* module parameters */ static int debug; module_param(debug, int, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(debug, "debugging level (higher values == more verbose)"); static int max_buffers = 8; module_param(max_buffers, int, S_IRUGO); MODULE_PARM_DESC(max_buffers, "how many buffers should be allocated"); /* how many times a device can be opened * the per-module default value can be overridden on a per-device basis using * the /sys/devices interface * * note that max_openers should be at least 2 in order to get a working system: * one opener for the producer and one opener for the consumer * however, we leave that to the user */ static int max_openers = 10; module_param(max_openers, int, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(max_openers, "how many users can open loopback device"); static int devices = -1; module_param(devices, int, 0); MODULE_PARM_DESC(devices, "how many devices should be created"); static int video_nr[MAX_DEVICES] = { [0 ... (MAX_DEVICES - 1)] = -1 }; module_param_array(video_nr, int, NULL, 0444); MODULE_PARM_DESC(video_nr, "video device numbers (-1=auto, 0=/dev/video0, etc.)"); static char *card_label[MAX_DEVICES]; module_param_array(card_label, charp, NULL, 0000); MODULE_PARM_DESC(card_label, "card labels for every device"); static bool exclusive_caps[MAX_DEVICES] = { [0 ... (MAX_DEVICES - 1)] = 0 }; module_param_array(exclusive_caps, bool, NULL, 0444); /* FIXXME: wording */ MODULE_PARM_DESC(exclusive_caps, "whether to announce OUTPUT/CAPTURE capabilities exclusively or not"); /* format specifications */ #define V4L2LOOPBACK_SIZE_MIN_WIDTH 48 #define V4L2LOOPBACK_SIZE_MIN_HEIGHT 32 #define V4L2LOOPBACK_SIZE_MAX_WIDTH 8192 #define V4L2LOOPBACK_SIZE_MAX_HEIGHT 8192 #define V4L2LOOPBACK_SIZE_DEFAULT_WIDTH 640 #define V4L2LOOPBACK_SIZE_DEFAULT_HEIGHT 480 static int max_width = V4L2LOOPBACK_SIZE_MAX_WIDTH; module_param(max_width, int, S_IRUGO); MODULE_PARM_DESC(max_width, "maximum frame width"); static int max_height = V4L2LOOPBACK_SIZE_MAX_HEIGHT; module_param(max_height, int, S_IRUGO); MODULE_PARM_DESC(max_height, "maximum frame height"); /* control IDs */ #ifndef HAVE__V4L2_CTRLS # define V4L2LOOPBACK_CID_BASE (V4L2_CID_PRIVATE_BASE) #else # define V4L2LOOPBACK_CID_BASE (V4L2_CID_USER_BASE | 0xf000) #endif #define CID_KEEP_FORMAT (V4L2LOOPBACK_CID_BASE + 0) #define CID_SUSTAIN_FRAMERATE (V4L2LOOPBACK_CID_BASE + 1) #define CID_TIMEOUT (V4L2LOOPBACK_CID_BASE + 2) #define CID_TIMEOUT_IMAGE_IO (V4L2LOOPBACK_CID_BASE + 3) static int v4l2loopback_s_ctrl(struct v4l2_ctrl *ctrl); static const struct v4l2_ctrl_ops v4l2loopback_ctrl_ops = { .s_ctrl = v4l2loopback_s_ctrl, }; static const struct v4l2_ctrl_config v4l2loopback_ctrl_keepformat = { .ops = &v4l2loopback_ctrl_ops, .id = CID_KEEP_FORMAT, .name = "keep_format", .type = V4L2_CTRL_TYPE_BOOLEAN, .min = 0, .max = 1, .step = 1, .def = 0, }; static const struct v4l2_ctrl_config v4l2loopback_ctrl_sustainframerate = { .ops = &v4l2loopback_ctrl_ops, .id = CID_SUSTAIN_FRAMERATE, .name = "sustain_framerate", .type = V4L2_CTRL_TYPE_BOOLEAN, .min = 0, .max = 1, .step = 1, .def = 0, }; static const struct v4l2_ctrl_config v4l2loopback_ctrl_timeout = { .ops = &v4l2loopback_ctrl_ops, .id = CID_TIMEOUT, .name = "timeout", .type = V4L2_CTRL_TYPE_INTEGER, .min = 0, .max = MAX_TIMEOUT, .step = 1, .def = 0, }; static const struct v4l2_ctrl_config v4l2loopback_ctrl_timeoutimageio = { .ops = &v4l2loopback_ctrl_ops, .id = CID_TIMEOUT_IMAGE_IO, .name = "timeout_image_io", .type = V4L2_CTRL_TYPE_BOOLEAN, .min = 0, .max = 1, .step = 1, .def = 0, }; /* module structures */ struct v4l2loopback_private { int devicenr; }; /* TODO(vasaka) use typenames which are common to kernel, but first find out if * it is needed */ /* struct keeping state and settings of loopback device */ struct v4l2l_buffer { struct v4l2_buffer buffer; struct list_head list_head; int use_count; }; struct v4l2_loopback_device { struct v4l2_device v4l2_dev; struct v4l2_ctrl_handler ctrl_handler; struct video_device *vdev; /* pixel and stream format */ struct v4l2_pix_format pix_format; struct v4l2_captureparm capture_param; unsigned long frame_jiffies; /* ctrls */ int keep_format; /* CID_KEEP_FORMAT; stay ready_for_capture even when * all openers close() the device */ int sustain_framerate; /* CID_SUSTAIN_FRAMERATE; duplicate * frames to maintain (close to) * nominal framerate */ /* buffers stuff */ u8 *image; /* pointer to actual buffers data */ unsigned long int imagesize; /* size of buffers data */ int buffers_number; /* should not be big, 4 is a good choice */ struct v4l2l_buffer buffers[MAX_BUFFERS]; /* inner driver buffers */ int used_buffers; /* number of the actually used buffers */ int max_openers; /* how many times can this device be opened */ int write_position; /* number of last written frame + 1 */ struct list_head outbufs_list; /* buffers in output DQBUF order */ int bufpos2index[MAX_BUFFERS]; /* mapping of (read/write_position * % used_buffers) * to inner buffer index */ long buffer_size; /* sustain_framerate stuff */ struct timer_list sustain_timer; unsigned int reread_count; /* timeout stuff */ unsigned long timeout_jiffies; /* CID_TIMEOUT; 0 means disabled */ int timeout_image_io; /* CID_TIMEOUT_IMAGE_IO; next opener will * read/write to timeout_image */ u8 *timeout_image; /* copy of it will be captured when timeout passes */ struct v4l2l_buffer timeout_image_buffer; struct timer_list timeout_timer; int timeout_happened; /* sync stuff */ atomic_t open_count; int ready_for_capture;/* set to true when at least one writer opened * device and negotiated format */ int ready_for_output; /* set to true when no writer * is currently attached * this differs slightly from !ready_for_capture, * e.g. when using fallback images */ int announce_all_caps;/* set to false, if device caps (OUTPUT/CAPTURE) * should only be announced if the resp. "ready" * flag is set; default=TRUE */ /* Changes for back-channel method */ int streamon_complete; int close_complete; int streamon_check; int stream_close_check; wait_queue_head_t read_event; wait_queue_head_t write_event; spinlock_t lock; }; /* types of opener shows what opener wants to do with loopback */ enum opener_type { UNNEGOTIATED = 0, READER = 1, WRITER = 2, }; /* struct keeping state and type of opener */ struct v4l2_loopback_opener { enum opener_type type; int vidioc_enum_frameintervals_calls; int read_position; /* number of last processed frame + 1 or * write_position - 1 if reader went out of sync */ unsigned int reread_count; struct v4l2_buffer *buffers; int buffers_number; /* should not be big, 4 is a good choice */ int timeout_image_io; }; /* this is heavily inspired by the bttv driver found in the linux kernel */ struct v4l2l_format { char *name; int fourcc; /* video4linux 2 */ int depth; /* bit/pixel */ int flags; }; /* set the v4l2l_format.flags to PLANAR for non-packed formats */ #define FORMAT_FLAGS_PLANAR 0x01 #define FORMAT_FLAGS_COMPRESSED 0x02 #ifndef V4L2_PIX_FMT_VP9 #define V4L2_PIX_FMT_VP9 v4l2_fourcc('V', 'P', '9', '0') #endif #ifndef V4L2_PIX_FMT_HEVC #define V4L2_PIX_FMT_HEVC v4l2_fourcc('H', 'E', 'V', 'C') #endif static const struct v4l2l_format formats[] = { #include "v4l2loopback_formats.h" }; static const unsigned int FORMATS = ARRAY_SIZE(formats); static char *fourcc2str(unsigned int fourcc, char buf[4]) { buf[0] = (fourcc >> 0) & 0xFF; buf[1] = (fourcc >> 8) & 0xFF; buf[2] = (fourcc >> 16) & 0xFF; buf[3] = (fourcc >> 24) & 0xFF; return buf; } static const struct v4l2l_format *format_by_fourcc(int fourcc) { unsigned int i; for (i = 0; i < FORMATS; i++) { if (formats[i].fourcc == fourcc) return formats + i; } pr_err("unsupported format '%c%c%c%c'\n", (fourcc >> 0) & 0xFF, (fourcc >> 8) & 0xFF, (fourcc >> 16) & 0xFF, (fourcc >> 24) & 0xFF); return NULL; } static void pix_format_set_size(struct v4l2_pix_format *f, const struct v4l2l_format *fmt, unsigned int width, unsigned int height) { f->width = width; f->height = height; if (fmt->flags & FORMAT_FLAGS_PLANAR) { f->bytesperline = width; /* Y plane */ f->sizeimage = (width * height * fmt->depth) >> 3; } else if (fmt->flags & FORMAT_FLAGS_COMPRESSED) { /* doesn't make sense for compressed formats */ f->bytesperline = 0; f->sizeimage = (width * height * fmt->depth) >> 3; } else { f->bytesperline = (width * fmt->depth) >> 3; f->sizeimage = height * f->bytesperline; } } static int set_timeperframe(struct v4l2_loopback_device *dev, struct v4l2_fract *tpf) { if ((tpf->denominator < 1) || (tpf->numerator < 1)) return -EINVAL; dev->capture_param.timeperframe = *tpf; dev->frame_jiffies = max(1UL, msecs_to_jiffies(1000) * tpf->numerator / tpf->denominator); return 0; } static struct v4l2_loopback_device *v4l2loopback_cd2dev(struct device *cd); /* device attributes */ /* available via sysfs: /sys/devices/virtual/video4linux/video* */ static ssize_t attr_show_format(struct device *cd, struct device_attribute *attr, char *buf) { /* gets the current format as "FOURCC:WxH@f/s", * e.g. "YUYV:320x240@1000/30" */ struct v4l2_loopback_device *dev = v4l2loopback_cd2dev(cd); const struct v4l2_fract *tpf; char buf4cc[5], buf_fps[32]; if (!dev || !dev->ready_for_capture) return 0; tpf = &dev->capture_param.timeperframe; fourcc2str(dev->pix_format.pixelformat, buf4cc); buf4cc[4] = 0; if (tpf->numerator == 1) snprintf(buf_fps, sizeof(buf_fps), "%d", tpf->denominator); else snprintf(buf_fps, sizeof(buf_fps), "%d/%d", tpf->denominator, tpf->numerator); return snprintf(buf, sizeof(buf_fps), "%4s:%dx%d@%s\n", buf4cc, dev->pix_format.width, dev->pix_format.height, buf_fps); } static ssize_t attr_store_format(struct device *cd, struct device_attribute *attr, const char *buf, size_t len) { struct v4l2_loopback_device *dev = v4l2loopback_cd2dev(cd); int fps_num = 0, fps_den = 1; if (!dev) return -EINVAL; /* only fps changing is supported */ if (sscanf(buf, "@%d/%d", &fps_num, &fps_den) > 0) { struct v4l2_fract f = { .numerator = fps_den, .denominator = fps_num }; int err = 0; err = set_timeperframe(dev, &f); if (err < 0) return err; return len; } return -EINVAL; } static DEVICE_ATTR(format, S_IRUGO | S_IWUSR, attr_show_format, attr_store_format); static ssize_t attr_show_buffers(struct device *cd, struct device_attribute *attr, char *buf) { struct v4l2_loopback_device *dev = v4l2loopback_cd2dev(cd); if (dev == NULL) { pr_err("\ndev value is null\n"); return -EINVAL; } return snprintf(buf, sizeof(dev->used_buffers), "%d\n", dev->used_buffers); } static DEVICE_ATTR(buffers, S_IRUGO, attr_show_buffers, NULL); static ssize_t attr_show_maxopeners(struct device *cd, struct device_attribute *attr, char *buf) { struct v4l2_loopback_device *dev = v4l2loopback_cd2dev(cd); if (dev == NULL) { pr_err("\ndev value is null\n"); return -EINVAL; } return snprintf(buf, sizeof(dev->max_openers), "%d\n", dev->max_openers); } static ssize_t attr_store_maxopeners(struct device *cd, struct device_attribute *attr, const char *buf, size_t len) { struct v4l2_loopback_device *dev = NULL; unsigned long curr = 0; if (kstrtoul(buf, 0, &curr)) return -EINVAL; dev = v4l2loopback_cd2dev(cd); if (dev == NULL) { pr_err("\ndev value is null\n"); return -EINVAL; } if (dev->max_openers == curr) return len; if (dev->open_count.counter > curr) { /* request to limit to less openers as are * currently attached to us */ return -EINVAL; } dev->max_openers = (int)curr; return len; } static DEVICE_ATTR(max_openers, S_IRUGO | S_IWUSR, attr_show_maxopeners, attr_store_maxopeners); static void v4l2loopback_remove_sysfs(struct video_device *vdev) { #define V4L2_SYSFS_DESTROY(x) device_remove_file(&vdev->dev, &dev_attr_##x) if (vdev) { do { V4L2_SYSFS_DESTROY(format); V4L2_SYSFS_DESTROY(buffers); V4L2_SYSFS_DESTROY(max_openers); /* ... */ } while (0); } } static void v4l2loopback_create_sysfs(struct video_device *vdev) { int res = 0; #define V4L2_SYSFS_CREATE(x) \ do { \ res = device_create_file(&vdev->dev, &dev_attr_##x); \ if (res < 0) \ break; \ } while (0) \ if (!vdev) return; do { V4L2_SYSFS_CREATE(format); V4L2_SYSFS_CREATE(buffers); V4L2_SYSFS_CREATE(max_openers); /* ... */ } while (0); if (res >= 0) return; dev_err(&vdev->dev, "%s error: %d\n", __func__, res); } /* global module data */ static struct v4l2_loopback_device *devs[MAX_DEVICES]; static struct v4l2_loopback_device *v4l2loopback_cd2dev(struct device *cd) { struct video_device *loopdev = to_video_device(cd); struct v4l2loopback_private *ptr = (struct v4l2loopback_private *)video_get_drvdata(loopdev); int nr = ptr->devicenr; if (nr < 0 || nr >= devices) { pr_err("v4l2-loopback: illegal device %d\n", nr); return NULL; } return devs[nr]; } static struct v4l2_loopback_device *v4l2loopback_getdevice(struct file *f) { struct video_device *loopdev = video_devdata(f); struct v4l2loopback_private *ptr = (struct v4l2loopback_private *)video_get_drvdata(loopdev); int nr = ptr->devicenr; if (nr < 0 || nr >= devices) { pr_err("v4l2-loopback: illegal device %d\n", nr); return NULL; } return devs[nr]; } /* forward declarations */ static void init_buffers(struct v4l2_loopback_device *dev); static int allocate_buffers(struct v4l2_loopback_device *dev); static int free_buffers(struct v4l2_loopback_device *dev); static void try_free_buffers(struct v4l2_loopback_device *dev); static int allocate_timeout_image(struct v4l2_loopback_device *dev); static void check_timers(struct v4l2_loopback_device *dev); static const struct v4l2_file_operations v4l2_loopback_fops; static const struct v4l2_ioctl_ops v4l2_loopback_ioctl_ops; /* Queue helpers */ /* next functions sets buffer flags and adjusts counters accordingly */ static inline void set_done(struct v4l2l_buffer *buffer) { buffer->buffer.flags &= ~V4L2_BUF_FLAG_QUEUED; buffer->buffer.flags |= V4L2_BUF_FLAG_DONE; } static inline void set_queued(struct v4l2l_buffer *buffer) { buffer->buffer.flags &= ~V4L2_BUF_FLAG_DONE; buffer->buffer.flags |= V4L2_BUF_FLAG_QUEUED; } static inline void unset_flags(struct v4l2l_buffer *buffer) { buffer->buffer.flags &= ~V4L2_BUF_FLAG_QUEUED; buffer->buffer.flags &= ~V4L2_BUF_FLAG_DONE; } static void vidioc_fill_name(char *buf, int len, int nr) { if (card_label[nr] != NULL) snprintf(buf, len, "%s\n", card_label[nr]); else snprintf(buf, len, "Dummy video device (0x%04X)", nr); } /* V4L2 ioctl caps and params calls * returns device capabilities * called on VIDIOC_QUERYCAP */ static int vidioc_querycap(struct file *file, void *priv, struct v4l2_capability *cap) { struct v4l2_loopback_device *dev = v4l2loopback_getdevice(file); int devnr = ((struct v4l2loopback_private *) video_get_drvdata(dev->vdev))->devicenr; strlcpy(cap->driver, "v4l2 loopback", sizeof(cap->driver)); vidioc_fill_name(cap->card, sizeof(cap->card), devnr); snprintf(cap->bus_info, sizeof(cap->bus_info), "platform:v4l2loopback-%03d", devnr); /* since 3.1.0, the v4l2-core system is supposed to set the version */ cap->version = V4L2LOOPBACK_VERSION_CODE; cap->capabilities = V4L2_CAP_DEVICE_CAPS | V4L2_CAP_STREAMING | V4L2_CAP_READWRITE; #ifdef V4L2_CAP_VIDEO_M2M cap->capabilities |= V4L2_CAP_VIDEO_M2M; #endif /* V4L2_CAP_VIDEO_M2M */ if (dev->announce_all_caps) { cap->capabilities |= V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_VIDEO_OUTPUT; } else { if (dev->ready_for_capture) cap->capabilities |= V4L2_CAP_VIDEO_CAPTURE; if (dev->ready_for_output) cap->capabilities |= V4L2_CAP_VIDEO_OUTPUT; } cap->device_caps = (cap->capabilities & ~V4L2_CAP_DEVICE_CAPS); cap->device_caps = cap->capabilities; cap->capabilities |= V4L2_CAP_DEVICE_CAPS; memset(cap->reserved, 0, sizeof(cap->reserved)); return 0; } static int vidioc_enum_framesizes(struct file *file, void *fh, struct v4l2_frmsizeenum *argp) { struct v4l2_loopback_device *dev; /* LATER: what does the index really mean? * if it's about enumerating formats, we can safely ignore it * (CHECK) */ /* there can be only one... */ if (argp->index) return -EINVAL; dev = v4l2loopback_getdevice(file); if (dev->ready_for_capture) { /* format has already been negotiated * cannot change during runtime */ argp->type = V4L2_FRMSIZE_TYPE_DISCRETE; argp->discrete.width = dev->pix_format.width; argp->discrete.height = dev->pix_format.height; } else { /* if the format has not been negotiated yet, we accept anything */ argp->type = V4L2_FRMSIZE_TYPE_CONTINUOUS; argp->stepwise.min_width = V4L2LOOPBACK_SIZE_MIN_WIDTH; argp->stepwise.min_height = V4L2LOOPBACK_SIZE_MIN_HEIGHT; argp->stepwise.max_width = max_width; argp->stepwise.max_height = max_height; argp->stepwise.step_width = 1; argp->stepwise.step_height = 1; } return 0; } /* returns frameinterval (fps) for the set resolution * called on VIDIOC_ENUM_FRAMEINTERVALS */ static int vidioc_enum_frameintervals(struct file *file, void *fh, struct v4l2_frmivalenum *argp) { struct v4l2_loopback_device *dev = v4l2loopback_getdevice(file); struct v4l2_loopback_opener *opener = file->private_data; if (dev->ready_for_capture) { if (opener->vidioc_enum_frameintervals_calls > 0) return -EINVAL; if (argp->width == dev->pix_format.width && argp->height == dev->pix_format.height) { argp->type = V4L2_FRMIVAL_TYPE_DISCRETE; argp->discrete = dev->capture_param.timeperframe; opener->vidioc_enum_frameintervals_calls++; return 0; } return -EINVAL; } return 0; } /* ------------------ CAPTURE ----------------------- */ /* returns device formats * called on VIDIOC_ENUM_FMT, with v4l2_buf_type * set to V4L2_BUF_TYPE_VIDEO_CAPTURE */ static int vidioc_enum_fmt_cap(struct file *file, void *fh, struct v4l2_fmtdesc *f) { struct v4l2_loopback_device *dev; MARK(); dev = v4l2loopback_getdevice(file); if (f->index) return -EINVAL; if (dev->ready_for_capture) { const __u32 format = dev->pix_format.pixelformat; snprintf(f->description, sizeof(f->description), "[%c%c%c%c]", (format >> 0) & 0xFF, (format >> 8) & 0xFF, (format >> 16) & 0xFF, (format >> 24) & 0xFF); f->pixelformat = dev->pix_format.pixelformat; } else { return -EINVAL; } f->flags = 0; MARK(); return 0; } /* returns current video format format fmt * called on VIDIOC_G_FMT, with v4l2_buf_type * set to V4L2_BUF_TYPE_VIDEO_CAPTURE */ static int vidioc_g_fmt_cap(struct file *file, void *priv, struct v4l2_format *fmt) { struct v4l2_loopback_device *dev; MARK(); dev = v4l2loopback_getdevice(file); if (!dev->ready_for_capture) return -EINVAL; fmt->fmt.pix = dev->pix_format; MARK(); return 0; } /* checks if it is OK to change to format fmt; * actual check is done by inner_try_fmt_cap * just checking that pixelformat is OK and set other parameters, app should * obey this decision * called on VIDIOC_TRY_FMT, with v4l2_buf_type * set to V4L2_BUF_TYPE_VIDEO_CAPTURE */ static int vidioc_try_fmt_cap(struct file *file, void *priv, struct v4l2_format *fmt) { struct v4l2_loopback_device *dev; char buf[5]; dev = v4l2loopback_getdevice(file); if (dev->ready_for_capture == 0) { pr_err("setting fmt_cap not possible yet\n"); return -EBUSY; } if (fmt->fmt.pix.pixelformat != dev->pix_format.pixelformat) return -EINVAL; fmt->fmt.pix = dev->pix_format; buf[4] = 0; pr_debug("capFOURCC=%s\n", fourcc2str(dev->pix_format.pixelformat, buf)); return 0; } /* sets new output format, if possible * actually format is set by input and we even do not check it, just return * current one, but it is possible to set subregions of input TODO(vasaka) * called on VIDIOC_S_FMT, with v4l2_buf_type set to V4L2_BUF_TYPE_VIDEO_CAPTURE */ static int vidioc_s_fmt_cap(struct file *file, void *priv, struct v4l2_format *fmt) { return vidioc_try_fmt_cap(file, priv, fmt); } /* ------------------ OUTPUT ----------------------- */ /* returns device formats; * LATER: allow all formats * called on VIDIOC_ENUM_FMT, with v4l2_buf_type * set to V4L2_BUF_TYPE_VIDEO_OUTPUT */ static int vidioc_enum_fmt_out(struct file *file, void *fh, struct v4l2_fmtdesc *f) { struct v4l2_loopback_device *dev; const struct v4l2l_format *fmt; dev = v4l2loopback_getdevice(file); if (dev->ready_for_capture) { const __u32 format = dev->pix_format.pixelformat; /* format has been fixed by the writer, * so only one single format is supported */ if (f->index) return -EINVAL; fmt = format_by_fourcc(format); if (fmt == NULL) return -EINVAL; f->type = V4L2_BUF_TYPE_VIDEO_CAPTURE; /* f->flags = ??; */ snprintf(f->description, sizeof(f->description), "%s", fmt->name); f->pixelformat = dev->pix_format.pixelformat; } else { __u32 format; /* fill in a dummy format */ /* coverity[unsigned_compare] */ if (f->index < 0 || f->index >= FORMATS) return -EINVAL; fmt = &formats[f->index]; f->pixelformat = fmt->fourcc; format = f->pixelformat; snprintf(f->description, sizeof(f->description), "%s", fmt->name); } f->flags = 0; return 0; } /* returns current video format format fmt */ /* NOTE: this is called from the producer * so if format has not been negotiated yet, * it should return ALL of available formats, * called on VIDIOC_G_FMT, with v4l2_buf_type set to V4L2_BUF_TYPE_VIDEO_OUTPUT */ static int vidioc_g_fmt_out(struct file *file, void *priv, struct v4l2_format *fmt) { struct v4l2_loopback_device *dev; struct v4l2_loopback_opener *opener; MARK(); dev = v4l2loopback_getdevice(file); opener = file->private_data; /* * LATER: this should return the currently valid format * gstreamer doesn't like it, if this returns -EINVAL, as it * then concludes that there is _no_ valid format * CHECK whether this assumption is wrong, * or whether we have to always provide a valid format */ fmt->fmt.pix = dev->pix_format; return 0; } /* checks if it is OK to change to format fmt; * if format is negotiated do not change it * called on VIDIOC_TRY_FMT with v4l2_buf_type set to V4L2_BUF_TYPE_VIDEO_OUTPUT */ static int vidioc_try_fmt_out(struct file *file, void *priv, struct v4l2_format *fmt) { struct v4l2_loopback_device *dev; MARK(); dev = v4l2loopback_getdevice(file); /* TODO(vasaka) loopback does not care about formats writer want to set, * maybe it is a good idea to restrict format somehow */ if (dev->ready_for_capture) fmt->fmt.pix = dev->pix_format; else { __u32 w = fmt->fmt.pix.width; __u32 h = fmt->fmt.pix.height; __u32 pixfmt = fmt->fmt.pix.pixelformat; const struct v4l2l_format *format = format_by_fourcc(pixfmt); if (w > max_width) w = max_width; if (h > max_height) h = max_height; pr_debug("trying image %dx%d\n", w, h); if (w < 1) w = V4L2LOOPBACK_SIZE_DEFAULT_WIDTH; if (h < 1) h = V4L2LOOPBACK_SIZE_DEFAULT_HEIGHT; if (format == NULL) format = &formats[0]; pix_format_set_size(&fmt->fmt.pix, format, w, h); fmt->fmt.pix.pixelformat = format->fourcc; fmt->fmt.pix.colorspace = V4L2_COLORSPACE_SRGB; if (fmt->fmt.pix.field == V4L2_FIELD_ANY) fmt->fmt.pix.field = V4L2_FIELD_NONE; /* FIXXME: try_fmt should never modify the device-state */ dev->pix_format = fmt->fmt.pix; } return 0; } /* sets new output format, if possible; * allocate data here because we do not know if it will be streaming or * read/write IO * called on VIDIOC_S_FMT with v4l2_buf_type set to V4L2_BUF_TYPE_VIDEO_OUTPUT */ static int vidioc_s_fmt_out(struct file *file, void *priv, struct v4l2_format *fmt) { struct v4l2_loopback_device *dev; char buf[5]; int ret; MARK(); dev = v4l2loopback_getdevice(file); ret = vidioc_try_fmt_out(file, priv, fmt); pr_debug("s_fmt_out(%d) %d...%d\n", ret, dev->ready_for_capture, dev->pix_format.sizeimage); buf[4] = 0; pr_debug("outFOURCC=%s\n", fourcc2str(dev->pix_format.pixelformat, buf)); if (ret < 0) return ret; if (!dev->ready_for_capture) { dev->buffer_size = PAGE_ALIGN(dev->pix_format.sizeimage); fmt->fmt.pix.sizeimage = dev->buffer_size; allocate_buffers(dev); } return ret; } /*#define V4L2L_OVERLAY*/ #ifdef V4L2L_OVERLAY /* ------------------ OVERLAY ----------------------- */ /* currently unsupported */ /* GSTreamer's v4l2sink is buggy, as it requires the overlay to work * while it should only require it, if overlay is requested * once the gstreamer element is fixed, remove the overlay dummies */ #warning OVERLAY dummies static int vidioc_g_fmt_overlay(struct file *file, void *priv, struct v4l2_format *fmt) { return 0; } static int vidioc_s_fmt_overlay(struct file *file, void *priv, struct v4l2_format *fmt) { return 0; } #endif /* V4L2L_OVERLAY */ /* ------------------ PARAMs ----------------------- */ /* get some data flow parameters, only capability, fps and readbuffers has * effect on this driver * called on VIDIOC_G_PARM */ static int vidioc_g_parm(struct file *file, void *priv, struct v4l2_streamparm *parm) { /* do not care about type of opener, hope this enums would always be * compatible */ struct v4l2_loopback_device *dev; MARK(); dev = v4l2loopback_getdevice(file); parm->parm.capture = dev->capture_param; return 0; } /* get some data flow parameters, only capability, fps and readbuffers has * effect on this driver * called on VIDIOC_S_PARM */ static int vidioc_s_parm(struct file *file, void *priv, struct v4l2_streamparm *parm) { struct v4l2_loopback_device *dev; int err = 0; MARK(); dev = v4l2loopback_getdevice(file); pr_debug("vidioc_s_parm called frate=%d/%d\n", parm->parm.capture.timeperframe.numerator, parm->parm.capture.timeperframe.denominator); switch (parm->type) { case V4L2_BUF_TYPE_VIDEO_CAPTURE: err = set_timeperframe(dev, &parm->parm.capture.timeperframe); if (err < 0) return err; break; case V4L2_BUF_TYPE_VIDEO_OUTPUT: err = set_timeperframe(dev, &parm->parm.capture.timeperframe); if (err < 0) return err; break; default: return -EINVAL; } parm->parm.capture = dev->capture_param; return 0; } #ifdef V4L2LOOPBACK_WITH_STD /* sets a tv standard, actually we do not need to handle this any special way * added to support effecttv * called on VIDIOC_S_STD */ static int vidioc_s_std(struct file *file, void *private_data, v4l2_std_id *_std) { v4l2_std_id req_std = 0, supported_std = 0; const v4l2_std_id all_std = V4L2_STD_ALL, no_std = 0; if (_std) { req_std = *_std; *_std = all_std; } /* we support everything in V4L2_STD_ALL, but not more... */ supported_std = (all_std & req_std); if (no_std == supported_std) return -EINVAL; return 0; } /* gets a fake video standard * called on VIDIOC_G_STD */ static int vidioc_g_std(struct file *file, void *private_data, v4l2_std_id *norm) { if (norm) *norm = V4L2_STD_ALL; return 0; } /* gets a fake video standard * called on VIDIOC_QUERYSTD */ static int vidioc_querystd(struct file *file, void *private_data, v4l2_std_id *norm) { if (norm) *norm = V4L2_STD_ALL; return 0; } #endif /* V4L2LOOPBACK_WITH_STD */ /* get ctrls info * called on VIDIOC_QUERYCTRL */ static int vidioc_queryctrl(struct file *file, void *fh, struct v4l2_queryctrl *q) { const struct v4l2_ctrl_config *cnf = NULL; switch (q->id) { case CID_KEEP_FORMAT: cnf = &v4l2loopback_ctrl_keepformat; break; case CID_SUSTAIN_FRAMERATE: cnf = &v4l2loopback_ctrl_sustainframerate; break; case CID_TIMEOUT: cnf = &v4l2loopback_ctrl_timeout; break; case CID_TIMEOUT_IMAGE_IO: cnf = &v4l2loopback_ctrl_timeoutimageio; break; default: return -EINVAL; } if (!cnf) WARN_ON(1); strlcpy(q->name, cnf->name, sizeof(q->name)); q->default_value = cnf->def; q->type = cnf->type; q->minimum = cnf->min; q->maximum = cnf->max; q->step = cnf->step; memset(q->reserved, 0, sizeof(q->reserved)); return 0; } static int vidioc_g_ctrl(struct file *file, void *fh, struct v4l2_control *c) { struct v4l2_loopback_device *dev = v4l2loopback_getdevice(file); switch (c->id) { case CID_KEEP_FORMAT: c->value = dev->keep_format; break; case CID_SUSTAIN_FRAMERATE: c->value = dev->sustain_framerate; break; case CID_TIMEOUT: c->value = jiffies_to_msecs(dev->timeout_jiffies); break; case CID_TIMEOUT_IMAGE_IO: c->value = dev->timeout_image_io; break; default: return -EINVAL; } return 0; } static int v4l2loopback_set_ctrl(struct v4l2_loopback_device *dev, u32 id, s64 val) { switch (id) { case CID_KEEP_FORMAT: if (val < 0 || val > 1) return -EINVAL; dev->keep_format = val; try_free_buffers(dev); break; case CID_SUSTAIN_FRAMERATE: if (val < 0 || val > 1) return -EINVAL; spin_lock_bh(&dev->lock); dev->sustain_framerate = val; check_timers(dev); spin_unlock_bh(&dev->lock); break; case CID_TIMEOUT: if (val < 0 || val > MAX_TIMEOUT) return -EINVAL; spin_lock_bh(&dev->lock); dev->timeout_jiffies = msecs_to_jiffies(val); check_timers(dev); spin_unlock_bh(&dev->lock); allocate_timeout_image(dev); break; case CID_TIMEOUT_IMAGE_IO: if (val < 0 || val > 1) return -EINVAL; dev->timeout_image_io = val; break; default: return -EINVAL; } return 0; } static int v4l2loopback_s_ctrl(struct v4l2_ctrl *ctrl) { struct v4l2_loopback_device *dev = container_of(ctrl->handler, struct v4l2_loopback_device, ctrl_handler); return v4l2loopback_set_ctrl(dev, ctrl->id, ctrl->val); } static int vidioc_s_ctrl(struct file *file, void *fh, struct v4l2_control *c) { struct v4l2_loopback_device *dev = v4l2loopback_getdevice(file); return v4l2loopback_set_ctrl(dev, c->id, c->value); } /* returns set of device outputs, in our case there is only one * called on VIDIOC_ENUMOUTPUT */ static int vidioc_enum_output(struct file *file, void *fh, struct v4l2_output *outp) { __u32 index = outp->index; struct v4l2_loopback_device *dev = v4l2loopback_getdevice(file); MARK(); if (!dev->announce_all_caps && !dev->ready_for_output) return -ENOTTY; if (index != 0) return -EINVAL; /* clear all data (including the reserved fields) */ memset(outp, 0, sizeof(*outp)); outp->index = index; strlcpy(outp->name, "loopback in", sizeof(outp->name)); outp->type = V4L2_OUTPUT_TYPE_ANALOG; outp->audioset = 0; outp->modulator = 0; #ifdef V4L2LOOPBACK_WITH_STD outp->std = V4L2_STD_ALL; # ifdef V4L2_OUT_CAP_STD outp->capabilities |= V4L2_OUT_CAP_STD; # endif /* V4L2_OUT_CAP_STD */ #endif /* V4L2LOOPBACK_WITH_STD */ return 0; } /* which output is currently active, * called on VIDIOC_G_OUTPUT */ static int vidioc_g_output(struct file *file, void *fh, unsigned int *i) { struct v4l2_loopback_device *dev = v4l2loopback_getdevice(file); if (!dev->announce_all_caps && !dev->ready_for_output) return -ENOTTY; if (i) *i = 0; return 0; } /* set output, can make sense if we have more than one video src, * called on VIDIOC_S_OUTPUT */ static int vidioc_s_output(struct file *file, void *fh, unsigned int i) { struct v4l2_loopback_device *dev = v4l2loopback_getdevice(file); if (!dev->announce_all_caps && !dev->ready_for_output) return -ENOTTY; if (i) return -EINVAL; return 0; } /* returns set of device inputs, in our case there is only one, * but later I may add more * called on VIDIOC_ENUMINPUT */ static int vidioc_enum_input(struct file *file, void *fh, struct v4l2_input *inp) { __u32 index = inp->index; MARK(); if (index != 0) return -EINVAL; /* clear all data (including the reserved fields) */ memset(inp, 0, sizeof(*inp)); inp->index = index; strlcpy(inp->name, "loopback", sizeof(inp->name)); inp->type = V4L2_INPUT_TYPE_CAMERA; inp->audioset = 0; inp->tuner = 0; inp->status = 0; #ifdef V4L2LOOPBACK_WITH_STD inp->std = V4L2_STD_ALL; # ifdef V4L2_IN_CAP_STD inp->capabilities |= V4L2_IN_CAP_STD; # endif #endif /* V4L2LOOPBACK_WITH_STD */ return 0; } /* which input is currently active, * called on VIDIOC_G_INPUT */ static int vidioc_g_input(struct file *file, void *fh, unsigned int *i) { struct v4l2_loopback_device *dev = v4l2loopback_getdevice(file); if (!dev->announce_all_caps && !dev->ready_for_capture) return -ENOTTY; if (i) *i = 0; return 0; } /* set input, can make sense if we have more than one video src, * called on VIDIOC_S_INPUT */ static int vidioc_s_input(struct file *file, void *fh, unsigned int i) { struct v4l2_loopback_device *dev = v4l2loopback_getdevice(file); if (!dev->announce_all_caps && !dev->ready_for_capture) return -ENOTTY; if (i == 0) return 0; return -EINVAL; } /* --------------- V4L2 ioctl buffer related calls ----------------- */ /* negotiate buffer type * only mmap streaming supported * called on VIDIOC_REQBUFS */ static int vidioc_reqbufs(struct file *file, void *fh, struct v4l2_requestbuffers *b) { struct v4l2_loopback_device *dev; struct v4l2_loopback_opener *opener; int i; MARK(); dev = v4l2loopback_getdevice(file); opener = file->private_data; if (opener->timeout_image_io) { if (b->memory != V4L2_MEMORY_MMAP && b->memory != V4L2_MEMORY_USERPTR) return -EINVAL; b->count = 1; return 0; } init_buffers(dev); switch (b->memory) { case V4L2_MEMORY_USERPTR: case V4L2_MEMORY_MMAP: /* do nothing here, buffers are always allocated */ if (b->count < 1 || dev->buffers_number < 1) return 0; if (b->count > dev->buffers_number) b->count = dev->buffers_number; /* make sure that outbufs_list contains buffers * from 0 to used_buffers-1 actually, it will have been * already populated via v4l2_loopback_init() * at this point */ if (list_empty(&dev->outbufs_list)) { for (i = 0; i < dev->used_buffers; ++i) list_add_tail(&dev->buffers[i].list_head, &dev->outbufs_list); } /* also, if dev->used_buffers is going to be decreased, * we should remove out-of-range buffers from outbufs_list, * and fix bufpos2index mapping */ if (b->count < dev->used_buffers) { struct v4l2l_buffer *pos, *n; list_for_each_entry_safe(pos, n, &dev->outbufs_list, list_head) { if (pos->buffer.index >= b->count) list_del(&pos->list_head); } /* after we update dev->used_buffers, buffers * in outbufs_list will correspond to * dev->write_position + [0;b->count-1] range */ i = dev->write_position; list_for_each_entry(pos, &dev->outbufs_list, list_head) { dev->bufpos2index[i % b->count] = pos->buffer.index; ++i; } } opener->buffers_number = b->count; if (opener->buffers_number < dev->used_buffers) dev->used_buffers = opener->buffers_number; return 0; default: return -EINVAL; } } /* returns buffer asked for; * give app as many buffers as it wants, if it less than MAX, * but map them in our inner buffers * called on VIDIOC_QUERYBUF */ static int vidioc_querybuf(struct file *file, void *fh, struct v4l2_buffer *b) { enum v4l2_buf_type type; int index; struct v4l2_loopback_device *dev; struct v4l2_loopback_opener *opener; MARK(); type = b->type; index = b->index; dev = v4l2loopback_getdevice(file); opener = file->private_data; if ((b->type != V4L2_BUF_TYPE_VIDEO_CAPTURE) && (b->type != V4L2_BUF_TYPE_VIDEO_OUTPUT)) { return -EINVAL; } if (b->index > max_buffers) return -EINVAL; if (opener->timeout_image_io) *b = dev->timeout_image_buffer.buffer; else *b = dev->buffers[b->index % dev->used_buffers].buffer; b->type = type; b->index = index; pr_debug("buffer type: %d (of %d with size=%ld)\n", b->memory, dev->buffers_number, dev->buffer_size); /* Hopefully fix 'DQBUF return bad index if queue bigger * then 2 for capture' * https://github.com/umlaeute/v4l2loopback/issues/60 */ b->flags &= ~V4L2_BUF_FLAG_DONE; b->flags |= V4L2_BUF_FLAG_QUEUED; return 0; } static void buffer_written(struct v4l2_loopback_device *dev, struct v4l2l_buffer *buf) { del_timer_sync(&dev->sustain_timer); del_timer_sync(&dev->timeout_timer); spin_lock_bh(&dev->lock); dev->bufpos2index[dev->write_position % dev->used_buffers] = buf->buffer.index; list_move_tail(&buf->list_head, &dev->outbufs_list); ++dev->write_position; dev->reread_count = 0; check_timers(dev); spin_unlock_bh(&dev->lock); } /* put buffer to queue * called on VIDIOC_QBUF */ static int vidioc_qbuf(struct file *file, void *private_data, struct v4l2_buffer *buf) { struct v4l2_loopback_device *dev; struct v4l2_loopback_opener *opener; struct v4l2l_buffer *b; int index; dev = v4l2loopback_getdevice(file); opener = file->private_data; if (buf->index > max_buffers) return -EINVAL; if (opener->timeout_image_io) return 0; index = buf->index % dev->used_buffers; b = &dev->buffers[index]; switch (buf->type) { case V4L2_BUF_TYPE_VIDEO_CAPTURE: pr_debug("capture QBUF index: %d\n", index); set_queued(b); return 0; case V4L2_BUF_TYPE_VIDEO_OUTPUT: pr_debug("output QBUF pos: %d index: %d\n", dev->write_position, index); if (buf->timestamp.tv_sec == 0 && buf->timestamp.tv_usec == 0) do_gettimeofday(&b->buffer.timestamp); else b->buffer.timestamp = buf->timestamp; b->buffer.bytesused = buf->bytesused; set_done(b); buffer_written(dev, b); /* Hopefully fix 'DQBUF return bad index if queue * bigger then 2 for capture' * https://github.com/umlaeute/v4l2loopback/issues/60 */ buf->flags &= ~V4L2_BUF_FLAG_DONE; buf->flags |= V4L2_BUF_FLAG_QUEUED; wake_up_all(&dev->read_event); return 0; default: return -EINVAL; } } static int can_read(struct v4l2_loopback_device *dev, struct v4l2_loopback_opener *opener) { int ret; spin_lock_bh(&dev->lock); check_timers(dev); ret = dev->write_position > opener->read_position || dev->reread_count > opener->reread_count || dev->timeout_happened; spin_unlock_bh(&dev->lock); return ret; } static int can_read_start_stop(struct v4l2_loopback_device *dev, struct v4l2_loopback_opener *opener) { int ret; spin_lock_bh(&dev->lock); check_timers(dev); ret = dev->streamon_complete > 0 || dev->close_complete > 0; spin_unlock_bh(&dev->lock); pr_debug("Entering in wait for poll response from v4l2-loopback\n"); return ret; } static int get_capture_buffer(struct file *file) { struct v4l2_loopback_device *dev = v4l2loopback_getdevice(file); struct v4l2_loopback_opener *opener = file->private_data; int pos, ret; int timeout_happened; if ((file->f_flags & O_NONBLOCK) && (dev->write_position <= opener->read_position && dev->reread_count <= opener->reread_count && !dev->timeout_happened)) return -EAGAIN; wait_event_interruptible(dev->read_event, can_read(dev, opener)); spin_lock_bh(&dev->lock); if (dev->write_position == opener->read_position) { if (dev->reread_count > opener->reread_count + 2) opener->reread_count = dev->reread_count - 1; ++opener->reread_count; pos = (opener->read_position + dev->used_buffers - 1) % dev->used_buffers; } else { opener->reread_count = 0; if (dev->write_position > opener->read_position + 2) opener->read_position = dev->write_position - 1; pos = opener->read_position % dev->used_buffers; ++opener->read_position; } timeout_happened = dev->timeout_happened; dev->timeout_happened = 0; spin_unlock_bh(&dev->lock); ret = dev->bufpos2index[pos]; if (timeout_happened) { /* although allocated on-demand, timeout_image is freed only * in free_buffers(), so we don't need to worry about it being * deallocated suddenly */ memcpy(dev->image + dev->buffers[ret].buffer.m.offset, dev->timeout_image, dev->buffer_size); } return ret; } /* put buffer to dequeue * called on VIDIOC_DQBUF */ static int vidioc_dqbuf(struct file *file, void *private_data, struct v4l2_buffer *buf) { struct v4l2_loopback_device *dev; struct v4l2_loopback_opener *opener; int index; struct v4l2l_buffer *b; dev = v4l2loopback_getdevice(file); opener = file->private_data; if (opener->timeout_image_io) { *buf = dev->timeout_image_buffer.buffer; return 0; } switch (buf->type) { case V4L2_BUF_TYPE_VIDEO_CAPTURE: index = get_capture_buffer(file); if (index < 0) return index; pr_debug("capture DQBUF pos: %d index: %d\n", opener->read_position - 1, index); if (!(dev->buffers[index].buffer.flags&V4L2_BUF_FLAG_MAPPED)) pr_debug("trying to ret not mapped buf[%d]\n", index); unset_flags(&dev->buffers[index]); *buf = dev->buffers[index].buffer; return 0; case V4L2_BUF_TYPE_VIDEO_OUTPUT: b = list_entry(dev->outbufs_list.prev, struct v4l2l_buffer, list_head); list_move_tail(&b->list_head, &dev->outbufs_list); pr_debug("output DQBUF index: %d\n", b->buffer.index); unset_flags(b); *buf = b->buffer; buf->type = V4L2_BUF_TYPE_VIDEO_OUTPUT; return 0; default: return -EINVAL; } } /* ------------- STREAMING ------------------- */ /* start streaming * called on VIDIOC_STREAMON */ static int vidioc_streamon(struct file *file, void *private_data, enum v4l2_buf_type type) { struct v4l2_loopback_device *dev; struct v4l2_loopback_opener *opener; int ret; MARK(); dev = v4l2loopback_getdevice(file); opener = file->private_data; switch (type) { case V4L2_BUF_TYPE_VIDEO_OUTPUT: opener->type = WRITER; dev->ready_for_output = 0; if (!dev->ready_for_capture) { ret = allocate_buffers(dev); if (ret < 0) return ret; dev->ready_for_capture = 1; } return 0; case V4L2_BUF_TYPE_VIDEO_CAPTURE: opener->type = READER; if (!dev->ready_for_capture) return -EIO; spin_lock_bh(&dev->lock); if (dev->streamon_check == 0) { dev->streamon_complete = 1; dev->close_complete = 0; dev->stream_close_check = 0; wake_up_all(&dev->write_event); } spin_unlock_bh(&dev->lock); return 0; default: return -EINVAL; } } /* stop streaming * called on VIDIOC_STREAMOFF */ static int vidioc_streamoff(struct file *file, void *private_data, enum v4l2_buf_type type) { struct v4l2_loopback_device *dev; dev = v4l2loopback_getdevice(file); MARK(); spin_lock_bh(&dev->lock); if (dev->stream_close_check == 0) { dev->close_complete = 1; dev->streamon_check = 0; wake_up_all(&dev->write_event); } spin_unlock_bh(&dev->lock); pr_debug("Entering in v4l2 loopback streamoff api\n"); pr_debug("%d\n", type); return 0; } #ifdef CONFIG_VIDEO_V4L1_COMPAT static int vidiocgmbuf(struct file *file, void *fh, struct video_mbuf *p) { struct v4l2_loopback_device *dev; MARK(); dev = v4l2loopback_getdevice(file); p->frames = dev->buffers_number; p->offsets[0] = 0; p->offsets[1] = 0; p->size = dev->buffer_size; return 0; } #endif /* file operations */ static void vm_open(struct vm_area_struct *vma) { struct v4l2l_buffer *buf; MARK(); buf = vma->vm_private_data; buf->use_count++; } static void vm_close(struct vm_area_struct *vma) { struct v4l2l_buffer *buf; MARK(); buf = vma->vm_private_data; buf->use_count--; } static struct vm_operations_struct vm_ops = { .open = vm_open, .close = vm_close, }; static int v4l2_loopback_mmap(struct file *file, struct vm_area_struct *vma) { int i; unsigned long addr; unsigned long start; unsigned long size; struct v4l2_loopback_device *dev; struct v4l2_loopback_opener *opener; struct v4l2l_buffer *buffer = NULL; MARK(); start = (unsigned long) vma->vm_start; size = (unsigned long) (vma->vm_end - vma->vm_start); dev = v4l2loopback_getdevice(file); opener = file->private_data; if (size > dev->buffer_size) { pr_err("userspace tries to mmap too much, fail\n"); return -EINVAL; } if (opener->timeout_image_io) { /* we are going to map the timeout_image_buffer */ if ((vma->vm_pgoff << PAGE_SHIFT) != dev->buffer_size * MAX_BUFFERS) { pr_err("invalid mmap offset for timeout_image_io mode\n"); return -EINVAL; } } else if ((vma->vm_pgoff << PAGE_SHIFT) > dev->buffer_size * (dev->buffers_number - 1)) { pr_err("userspace tries to mmap too far, fail\n"); return -EINVAL; } /* FIXXXXXME: allocation should not happen here! */ if (dev->image == NULL) if (allocate_buffers(dev) < 0) return -EINVAL; if (opener->timeout_image_io) { buffer = &dev->timeout_image_buffer; addr = (unsigned long)dev->timeout_image; } else { for (i = 0; i < dev->buffers_number; ++i) { buffer = &dev->buffers[i]; if ((buffer->buffer.m.offset >> PAGE_SHIFT) == vma->vm_pgoff) break; } if (buffer == NULL) return -EINVAL; addr = (unsigned long) dev->image + (vma->vm_pgoff << PAGE_SHIFT); } while (size > 0) { struct page *page; page = (void *)vmalloc_to_page((void *)addr); if (!page || vm_insert_page(vma, start, page) < 0) return -EAGAIN; start += PAGE_SIZE; addr += PAGE_SIZE; size -= PAGE_SIZE; } vma->vm_ops = &vm_ops; vma->vm_private_data = buffer; buffer->buffer.flags |= V4L2_BUF_FLAG_MAPPED; vm_open(vma); MARK(); return 0; } static unsigned int v4l2_loopback_poll(struct file *file , struct poll_table_struct *pts) { struct v4l2_loopback_opener *opener; struct v4l2_loopback_device *dev; int ret_mask = 0; MARK(); opener = file->private_data; dev = v4l2loopback_getdevice(file); wait_event_interruptible(dev->write_event, can_read_start_stop(dev, opener)); spin_lock_bh(&dev->lock); if (dev->streamon_complete == 1 && dev->streamon_check == 0) { ret_mask = POLLIN | POLLRDNORM; dev->streamon_complete = 0; dev->streamon_check = 1; pr_debug("poll response from v4l2-loopback for streamon == %d\n" , ret_mask); } else if (dev->close_complete == 1 && dev->stream_close_check == 0) { ret_mask = POLL_CLOSE_EVENT; dev->close_complete = 0; dev->stream_close_check = 1; pr_debug("poll response from v4l2-loopback for close %d\n" , ret_mask); } else { pr_debug("poll response from v4l2-loopback in case of error\n"); ret_mask = -POLLERR; } spin_unlock_bh(&dev->lock); MARK(); return ret_mask; } /* do not want to limit device opens, it can be as many readers as user want, * writers are limited by means of setting writer field */ static int v4l2_loopback_open(struct file *file) { struct v4l2_loopback_device *dev; struct v4l2_loopback_opener *opener; MARK(); dev = v4l2loopback_getdevice(file); if (dev == NULL) { pr_err("\ndev value is null\n"); return -EINVAL; } if (dev->open_count.counter >= dev->max_openers) return -EBUSY; /* kfree on close */ opener = kzalloc(sizeof(*opener), GFP_KERNEL); if (opener == NULL) return -ENOMEM; file->private_data = opener; atomic_inc(&dev->open_count); opener->timeout_image_io = dev->timeout_image_io; dev->timeout_image_io = 0; if (opener->timeout_image_io) { int r = allocate_timeout_image(dev); if (r < 0) { pr_err("timeout image allocation failed\n"); return r; } } pr_debug("opened dev:%pK with image:%pK\n", dev, dev ? dev->image : NULL); MARK(); return 0; } static int v4l2_loopback_close(struct file *file) { struct v4l2_loopback_opener *opener; struct v4l2_loopback_device *dev; int iswriter = 0; MARK(); opener = file->private_data; dev = v4l2loopback_getdevice(file); if (opener->type == WRITER) iswriter = 1; atomic_dec(&dev->open_count); if (dev->open_count.counter == 0) { del_timer_sync(&dev->sustain_timer); del_timer_sync(&dev->timeout_timer); } try_free_buffers(dev); kfree(opener); if (iswriter) dev->ready_for_output = 1; MARK(); return 0; } static ssize_t v4l2_loopback_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { int read_index; struct v4l2_loopback_opener *opener; struct v4l2_loopback_device *dev; struct v4l2_buffer *b; MARK(); opener = file->private_data; dev = v4l2loopback_getdevice(file); read_index = get_capture_buffer(file); if (read_index < 0) return read_index; if (count > dev->buffer_size) { pr_err("v4l2-loopback_read(): Size is not equals to buf size\n"); count = dev->buffer_size; } b = &dev->buffers[read_index].buffer; if (count > b->bytesused) count = b->bytesused; if (copy_to_user((void __user *)buf, (void *)(dev->image + b->m.offset), count)) { pr_debug("v4l2-loopback: failed copy_to_user() in read buf\n"); return -EFAULT; } pr_debug("leave v4l2_loopback_read()\n"); return count; } static ssize_t v4l2_loopback_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { struct v4l2_loopback_device *dev; int write_index; struct v4l2_buffer *b; int ret; MARK(); dev = v4l2loopback_getdevice(file); /* there's at least one writer, * so don'stop announcing output capabilities */ dev->ready_for_output = 0; if (!dev->ready_for_capture) { ret = allocate_buffers(dev); if (ret < 0) return ret; dev->ready_for_capture = 1; } pr_debug("v4l2_loopback_write() trying to write %zu bytes\n", count); if (count > dev->buffer_size) { pr_err("v4l2-loopback_write(): Size is not equals to buf size\n"); count = dev->buffer_size; } write_index = dev->write_position % dev->used_buffers; b = &dev->buffers[write_index].buffer; if (copy_from_user((void *)(dev->image + b->m.offset), (void __user *)buf, count)) { pr_err("v4l2-loopback: failed copy_from_user() in write buf, could not write %zu\n", count); return -EFAULT; } do_gettimeofday(&b->timestamp); b->bytesused = count; b->sequence = dev->write_position; buffer_written(dev, &dev->buffers[write_index]); wake_up_all(&dev->read_event); pr_debug("leave v4l2_loopback_write()\n"); return count; } /* init functions */ /* frees buffers, if already allocated */ static int free_buffers(struct v4l2_loopback_device *dev) { MARK(); pr_debug("freeing image@%pK for dev:%pK\n" , dev ? dev->image : NULL, dev); if (dev == NULL) { pr_err("\ndev value is null\n"); return -EINVAL; } if (dev->image) { vfree(dev->image); dev->image = NULL; } if (dev->timeout_image) { vfree(dev->timeout_image); dev->timeout_image = NULL; } dev->imagesize = 0; return 0; } /* frees buffers, if they are no longer needed */ static void try_free_buffers(struct v4l2_loopback_device *dev) { MARK(); if ((dev->open_count.counter && !dev->keep_format) == 0) { free_buffers(dev); dev->ready_for_capture = 0; dev->buffer_size = 0; dev->write_position = 0; } } /* allocates buffers, if buffer_size is set */ static int allocate_buffers(struct v4l2_loopback_device *dev) { MARK(); /* vfree on close file operation in case no open handles left */ if (dev->buffer_size == 0) return -EINVAL; if (dev->image) { pr_debug("allocating buffers again: %ld %ld\n", dev->buffer_size * dev->buffers_number, dev->imagesize); /* FIXME: prevent double allocation more intelligently! */ if (dev->buffer_size * dev->buffers_number == dev->imagesize) return 0; /* if there is only one writer, no problem should occur */ if (dev->open_count.counter == 1) free_buffers(dev); else return -EINVAL; } dev->imagesize = dev->buffer_size * dev->buffers_number; pr_debug("allocating %ld = %ldx%d\n", dev->imagesize, dev->buffer_size, dev->buffers_number); dev->image = vmalloc(dev->imagesize); if (dev->timeout_jiffies > 0) allocate_timeout_image(dev); if (dev->image == NULL) return -ENOMEM; pr_debug("vmallocated %ld bytes\n", dev->imagesize); MARK(); init_buffers(dev); return 0; } /* init inner buffers, they are capture mode and flags are set as * for capture mod buffers */ static void init_buffers(struct v4l2_loopback_device *dev) { int i; int buffer_size; int bytesused; MARK(); buffer_size = dev->buffer_size; bytesused = dev->pix_format.sizeimage; for (i = 0; i < dev->buffers_number; ++i) { struct v4l2_buffer *b = &dev->buffers[i].buffer; b->index = i; b->bytesused = bytesused; b->length = buffer_size; b->field = V4L2_FIELD_NONE; b->flags = 0; b->m.offset = i * buffer_size; b->memory = V4L2_MEMORY_MMAP; b->sequence = 0; b->timestamp.tv_sec = 0; b->timestamp.tv_usec = 0; b->type = V4L2_BUF_TYPE_VIDEO_CAPTURE; do_gettimeofday(&b->timestamp); } dev->timeout_image_buffer = dev->buffers[0]; dev->timeout_image_buffer.buffer.m.offset = MAX_BUFFERS * buffer_size; MARK(); } static int allocate_timeout_image(struct v4l2_loopback_device *dev) { MARK(); if (dev->buffer_size <= 0) return -EINVAL; if (dev->timeout_image == NULL) { dev->timeout_image = v4l2l_vzalloc(dev->buffer_size); if (dev->timeout_image == NULL) return -ENOMEM; } return 0; } /* fills and register video device */ static void init_vdev(struct video_device *vdev, int nr) { MARK(); vidioc_fill_name(vdev->name, sizeof(vdev->name), nr); #ifdef V4L2LOOPBACK_WITH_STD vdev->tvnorms = V4L2_STD_ALL; #endif /* V4L2LOOPBACK_WITH_STD */ vdev->vfl_type = VFL_TYPE_GRABBER; vdev->fops = &v4l2_loopback_fops; vdev->ioctl_ops = &v4l2_loopback_ioctl_ops; vdev->release = &video_device_release; vdev->minor = -1; if (debug > 1) vdev->dev_debug = V4L2_DEV_DEBUG_IOCTL | V4L2_DEV_DEBUG_IOCTL_ARG; /* since kernel-3.7, there is a new field 'vfl_dir' that has to be * set to VFL_DIR_M2M for bidrectional devices */ vdev->vfl_dir = VFL_DIR_M2M; MARK(); } /* init default capture parameters, only fps may be changed in future */ static void init_capture_param(struct v4l2_captureparm *capture_param) { MARK(); capture_param->capability = 0; capture_param->capturemode = 0; capture_param->extendedmode = 0; capture_param->readbuffers = max_buffers; capture_param->timeperframe.numerator = 1; capture_param->timeperframe.denominator = 30; } static void check_timers(struct v4l2_loopback_device *dev) { if (!dev->ready_for_capture) return; if (dev->timeout_jiffies > 0 && !timer_pending(&dev->timeout_timer)) mod_timer(&dev->timeout_timer, jiffies + dev->timeout_jiffies); if (dev->sustain_framerate && !timer_pending(&dev->sustain_timer)) mod_timer(&dev->sustain_timer, jiffies + dev->frame_jiffies * 3 / 2); } #ifdef HAVE_TIMER_SETUP static void sustain_timer_clb(struct timer_list *t) { struct v4l2_loopback_device *dev = from_timer(dev, t, sustain_timer); #else static void sustain_timer_clb(unsigned long nr) { struct v4l2_loopback_device *dev = devs[nr]; #endif spin_lock(&dev->lock); if (dev->sustain_framerate) { dev->reread_count++; pr_debug("reread: %d %d\n", dev->write_position, dev->reread_count); if (dev->reread_count == 1) mod_timer(&dev->sustain_timer, jiffies + max(1UL, dev->frame_jiffies / 2)); else mod_timer(&dev->sustain_timer, jiffies + dev->frame_jiffies); wake_up_all(&dev->read_event); } spin_unlock(&dev->lock); } #ifdef HAVE_TIMER_SETUP static void timeout_timer_clb(struct timer_list *t) { struct v4l2_loopback_device *dev = from_timer(dev, t, timeout_timer); #else static void timeout_timer_clb(unsigned long nr) { struct v4l2_loopback_device *dev = devs[nr]; #endif spin_lock(&dev->lock); if (dev->timeout_jiffies > 0) { dev->timeout_happened = 1; mod_timer(&dev->timeout_timer, jiffies + dev->timeout_jiffies); wake_up_all(&dev->read_event); } spin_unlock(&dev->lock); } /* init loopback main structure */ static int v4l2_loopback_init(struct v4l2_loopback_device *dev, int nr) { int ret; struct v4l2_ctrl_handler *hdl = &dev->ctrl_handler; snprintf(dev->v4l2_dev.name, sizeof(dev->v4l2_dev.name), "v4l2loopback-%03d", nr); ret = v4l2_device_register(NULL, &dev->v4l2_dev); if (ret) return ret; MARK(); dev->vdev = video_device_alloc(); if (dev->vdev == NULL) { ret = -ENOMEM; goto error; } video_set_drvdata(dev->vdev, kzalloc(sizeof(struct v4l2loopback_private), GFP_KERNEL)); if (video_get_drvdata(dev->vdev) == NULL) { ret = -ENOMEM; goto error; } ((struct v4l2loopback_private *)video_get_drvdata (dev->vdev))->devicenr = nr; init_vdev(dev->vdev, nr); dev->vdev->v4l2_dev = &dev->v4l2_dev; init_capture_param(&dev->capture_param); set_timeperframe(dev, &dev->capture_param.timeperframe); dev->keep_format = 0; dev->sustain_framerate = 0; dev->buffers_number = max_buffers; dev->used_buffers = max_buffers; dev->max_openers = max_openers; dev->write_position = 0; spin_lock_init(&dev->lock); INIT_LIST_HEAD(&dev->outbufs_list); if (list_empty(&dev->outbufs_list)) { int i; for (i = 0; i < dev->used_buffers; ++i) list_add_tail(&dev->buffers[i].list_head, &dev->outbufs_list); } memset(dev->bufpos2index, 0, sizeof(dev->bufpos2index)); atomic_set(&dev->open_count, 0); dev->ready_for_capture = 0; dev->ready_for_output = 1; dev->announce_all_caps = (!exclusive_caps[nr]); dev->buffer_size = 0; dev->image = NULL; dev->imagesize = 0; #ifdef HAVE_TIMER_SETUP timer_setup(&dev->sustain_timer, sustain_timer_clb, 0); timer_setup(&dev->timeout_timer, timeout_timer_clb, 0); #else setup_timer(&dev->sustain_timer, sustain_timer_clb, nr); setup_timer(&dev->timeout_timer, timeout_timer_clb, nr); #endif dev->reread_count = 0; dev->timeout_jiffies = 0; dev->timeout_image = NULL; dev->timeout_happened = 0; ret = v4l2_ctrl_handler_init(hdl, 1); if (ret) goto error; v4l2_ctrl_new_custom(hdl, &v4l2loopback_ctrl_keepformat, NULL); v4l2_ctrl_new_custom(hdl, &v4l2loopback_ctrl_sustainframerate, NULL); v4l2_ctrl_new_custom(hdl, &v4l2loopback_ctrl_timeout, NULL); v4l2_ctrl_new_custom(hdl, &v4l2loopback_ctrl_timeoutimageio, NULL); if (hdl->error) { ret = hdl->error; goto error; } dev->v4l2_dev.ctrl_handler = hdl; /* FIXME set buffers to 0 */ /* Set initial format */ dev->pix_format.width = 0; /* V4L2LOOPBACK_SIZE_DEFAULT_WIDTH; */ dev->pix_format.height = 0; /* V4L2LOOPBACK_SIZE_DEFAULT_HEIGHT; */ dev->pix_format.pixelformat = formats[0].fourcc; dev->pix_format.colorspace = V4L2_COLORSPACE_SRGB; /* do we need to set this ? */ dev->pix_format.field = V4L2_FIELD_NONE; dev->buffer_size = PAGE_ALIGN(dev->pix_format.sizeimage); pr_debug("buffer_size = %ld (=%d)\n", dev->buffer_size, dev->pix_format.sizeimage); allocate_buffers(dev); init_waitqueue_head(&dev->read_event); init_waitqueue_head(&dev->write_event); MARK(); return 0; error: v4l2_ctrl_handler_free(&dev->ctrl_handler); v4l2_device_unregister(&dev->v4l2_dev); kfree(dev->vdev); return ret; }; /* LINUX KERNEL */ static const struct v4l2_file_operations v4l2_loopback_fops = { .owner = THIS_MODULE, .open = v4l2_loopback_open, .release = v4l2_loopback_close, .read = v4l2_loopback_read, .write = v4l2_loopback_write, .poll = v4l2_loopback_poll, .mmap = v4l2_loopback_mmap, .unlocked_ioctl = video_ioctl2, }; static const struct v4l2_ioctl_ops v4l2_loopback_ioctl_ops = { .vidioc_querycap = &vidioc_querycap, .vidioc_enum_framesizes = &vidioc_enum_framesizes, .vidioc_enum_frameintervals = &vidioc_enum_frameintervals, #ifndef HAVE__V4L2_CTRLS .vidioc_queryctrl = &vidioc_queryctrl, .vidioc_g_ctrl = &vidioc_g_ctrl, .vidioc_s_ctrl = &vidioc_s_ctrl, #endif /* HAVE__V4L2_CTRLS */ .vidioc_enum_output = &vidioc_enum_output, .vidioc_g_output = &vidioc_g_output, .vidioc_s_output = &vidioc_s_output, .vidioc_enum_input = &vidioc_enum_input, .vidioc_g_input = &vidioc_g_input, .vidioc_s_input = &vidioc_s_input, .vidioc_enum_fmt_vid_cap = &vidioc_enum_fmt_cap, .vidioc_g_fmt_vid_cap = &vidioc_g_fmt_cap, .vidioc_s_fmt_vid_cap = &vidioc_s_fmt_cap, .vidioc_try_fmt_vid_cap = &vidioc_try_fmt_cap, .vidioc_enum_fmt_vid_out = &vidioc_enum_fmt_out, .vidioc_s_fmt_vid_out = &vidioc_s_fmt_out, .vidioc_g_fmt_vid_out = &vidioc_g_fmt_out, .vidioc_try_fmt_vid_out = &vidioc_try_fmt_out, #ifdef V4L2L_OVERLAY .vidioc_s_fmt_vid_overlay = &vidioc_s_fmt_overlay, .vidioc_g_fmt_vid_overlay = &vidioc_g_fmt_overlay, #endif #ifdef V4L2LOOPBACK_WITH_STD .vidioc_s_std = &vidioc_s_std, .vidioc_g_std = &vidioc_g_std, .vidioc_querystd = &vidioc_querystd, #endif /* V4L2LOOPBACK_WITH_STD */ .vidioc_g_parm = &vidioc_g_parm, .vidioc_s_parm = &vidioc_s_parm, .vidioc_reqbufs = &vidioc_reqbufs, .vidioc_querybuf = &vidioc_querybuf, .vidioc_qbuf = &vidioc_qbuf, .vidioc_dqbuf = &vidioc_dqbuf, .vidioc_streamon = &vidioc_streamon, .vidioc_streamoff = &vidioc_streamoff, #ifdef CONFIG_VIDEO_V4L1_COMPAT .vidiocgmbuf = &vidiocgmbuf, #endif }; static void zero_devices(void) { int i; MARK(); for (i = 0; i < MAX_DEVICES; i++) devs[i] = NULL; } static void free_devices(void) { int i; MARK(); for (i = 0; i < devices; i++) { if (devs[i] != NULL) { free_buffers(devs[i]); v4l2loopback_remove_sysfs(devs[i]->vdev); kfree(video_get_drvdata(devs[i]->vdev)); video_unregister_device(devs[i]->vdev); v4l2_device_unregister(&devs[i]->v4l2_dev); v4l2_ctrl_handler_free(&devs[i]->ctrl_handler); kfree(devs[i]); devs[i] = NULL; } } } static int __init v4l2loopback_init_module(void) { int ret; int i; MARK(); zero_devices(); if (devices < 0) { devices = 1; /* try guessing the devices from the "video_nr" parameter */ for (i = MAX_DEVICES - 1; i >= 0; i--) { if (video_nr[i] >= 0) { devices = i + 1; break; } } } if (devices > MAX_DEVICES) { devices = MAX_DEVICES; pr_debug( "v4l2loopback: number of devices is limited to: %d\n" , MAX_DEVICES); } if (max_buffers > MAX_BUFFERS) { max_buffers = MAX_BUFFERS; pr_debug( "v4l2loopback: number of buffers is limited to: %d\n" , MAX_BUFFERS); } if (max_openers < 0) { pr_debug( "v4l2loopback: allowing %d openers rather than %d\n" , 2, max_openers); max_openers = 2; } if (max_width < 1) { max_width = V4L2LOOPBACK_SIZE_MAX_WIDTH; pr_debug("v4l2loopback: using max_width %d\n", max_width); } if (max_height < 1) { max_height = V4L2LOOPBACK_SIZE_MAX_HEIGHT; pr_debug("v4l2loopback: using max_height %d\n", max_height); } /* kfree on module release */ for (i = 0; i < devices; i++) { pr_debug("creating v4l2loopback-device #%d\n", i); devs[i] = kzalloc(sizeof(*devs[i]), GFP_KERNEL); if (devs[i] == NULL) { free_devices(); return -ENOMEM; } ret = v4l2_loopback_init(devs[i], i); if (ret < 0) { free_devices(); return ret; } /* register the device -> it creates /dev/video* */ if (video_register_device(devs[i]->vdev, VFL_TYPE_GRABBER, video_nr[i]) < 0) { video_device_release(devs[i]->vdev); pr_err( "v4l2loopback: failed video_register_device()\n"); free_devices(); return -EFAULT; } v4l2loopback_create_sysfs(devs[i]->vdev); } pr_info("module installed\n"); pr_info("v4l2loopback driver version %d.%d.%d loaded\n", (V4L2LOOPBACK_VERSION_CODE >> 16) & 0xff, (V4L2LOOPBACK_VERSION_CODE >> 8) & 0xff, (V4L2LOOPBACK_VERSION_CODE) & 0xff); return 0; } static void v4l2loopback_cleanup_module(void) { MARK(); /* unregister the device -> it deletes /dev/video* */ free_devices(); pr_info("module removed\n"); } #ifdef MODULE int __init init_module(void) { return v4l2loopback_init_module(); } void __exit cleanup_module(void) { return v4l2loopback_cleanup_module(); } #else late_initcall(v4l2loopback_init_module); #endif /* * fake usage of unused functions */ #ifdef HAVE__V4L2_CTRLS static int vidioc_queryctrl(struct file *file, void *fh, struct v4l2_queryctrl *q) __attribute__ ((unused)); static int vidioc_g_ctrl(struct file *file, void *fh, struct v4l2_control *c) __attribute__ ((unused)); static int vidioc_s_ctrl(struct file *file, void *fh, struct v4l2_control *c) __attribute__ ((unused)); #endif /* HAVE__V4L2_CTRLS */