| #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "fillbuf.c" /* 队列操作a: 定义自旋锁、定时器、buf队列 */ static spinlock_t my_vivid_queue_slock; static struct timer_list my_vivid_timer; static struct videobuf_queue my_vivid_vb_vidqueue; static struct list_head my_vivid_vb_local_queue; static void my_vivid_timer_function(unsigned long data) { struct videobuf_buffer *vb; void *vbuf; struct timeval ts; printk("enter %s\n", __func__); /* 1. 构造数据: 从队列头部取出第1个videobuf, 填充数据 */ /* 1.1 从本地队列取出第1个videobuf */ if (list_empty(&my_vivid_vb_local_queue)) { goto out; } vb = list_entry(my_vivid_vb_local_queue.next, struct videobuf_buffer, queue); /* Nobody is waiting on this buffer, return */ if (!waitqueue_active(&vb->done)) goto out; /* 1.2 填充数据 */ vbuf = videobuf_to_vmalloc(vb); //memset(vbuf, 0xFF, vb->size); my_vivid_fillbuff(vb); vb->field_count++; do_gettimeofday(&ts); vb->ts = ts; vb->state = VIDEOBUF_DONE; /* 1.3 把videobuf从本地队列中删除 */ list_del(&vb->queue); /* 2. 唤醒进程: 唤醒videobuf->done上的进程 */ wake_up(&vb->done); out: /* 3. 修改timer的超时时间 : 30fps, 1秒里有30帧数据 * 每1/30 秒产生一帧数据 */ mod_timer(&my_vivid_timer, jiffies + HZ / 30); } /* 参考documentations/video4linux/v4l2-framework.txt: drivers\media\video\videobuf-core.c ops->buf_setup - calculates the size of the video buffers and avoid they to waste more than some maximum limit of RAM; ops->buf_prepare - fills the video buffer structs and calls videobuf_iolock() to alloc and prepare mmaped memory; ops->buf_queue - advices the driver that another buffer were requested (by read() or by QBUF); ops->buf_release - frees any buffer that were allocated. */ /* videobuf operations */ //APP调用ioctl VIDIOC_REQBUFS时会导致此函数被调用,它重新调整count和size static int my_vivid_buffer_setup(struct videobuf_queue *vq, unsigned int *count, unsigned int *size) { printk("enter %s\n", __func__); *size = my_vivid_format.fmt.pix.sizeimage; if (0 == *count) *count = 32; return 0; } //APP调用ioctlVIDIOC_QBUF时导致此函数被调用,它会填充video_buffer结构体并调用videobuf_iolock来分配内存 static int my_vivid_buffer_prepare(struct videobuf_queue *vq, struct videobuf_buffer *vb, enum v4l2_field field) { printk("enter %s\n", __func__); /* 1. 设置videobuf */ vb->size = my_vivid_format.fmt.pix.sizeimage; vb->bytesperline = my_vivid_format.fmt.pix.bytesperline; vb->width = my_vivid_format.fmt.pix.width; vb->height = my_vivid_format.fmt.pix.height; vb->field = field; /* 2. 做些准备工作 */ my_vivid_precalculate_bars(0); /* 3. 设置状态 */ vb->state = VIDEOBUF_PREPARED; return 0; } /* APP调用ioctl VIDIOC_QBUF时: * 1. 先调用buf_prepare进行一些准备工作 * 2. 把buf放入stream队列 * 3. 调用buf_queue(起通知、记录作用) */ static void my_vivid_buffer_queue(struct videobuf_queue *vq, struct videobuf_buffer *vb) { printk("enter %s\n", __func__); vb->state = VIDEOBUF_QUEUED; /* 把videobuf放入本地一个队列尾部 * 定时器处理函数就可以从本地队列取出videobuf */ list_add_tail(&vb->queue, &my_vivid_vb_local_queue); } /* APP不再使用队列时, 用它来释放内存 */ static void my_vivid_buffer_release(struct videobuf_queue *vq, struct videobuf_buffer *vb) { printk("enter %s\n", __func__); videobuf_vmalloc_free(vb); vb->state = VIDEOBUF_NEEDS_INIT; } static struct videobuf_queue_ops my_vivid_video_qops = { .buf_setup = my_vivid_buffer_setup, /* 计算大小以免浪费 */ .buf_prepare = my_vivid_buffer_prepare, .buf_queue = my_vivid_buffer_queue, .buf_release = my_vivid_buffer_release, }; /* v4l2_file_operations */ static int my_vivid_open(struct file *file) { printk("enter %s\n", __func__); //队列操作c:初始化 videobuf_queue_vmalloc_init(&my_vivid_vb_vidqueue, &my_vivid_video_qops, NULL, &my_vivid_queue_slock, V4L2_BUF_TYPE_VIDEO_CAPTURE, V4L2_FIELD_INTERLACED, sizeof(struct videobuf_buffer), NULL, NULL); /* 倒数第3个参数是buffer的头部大小 */ my_vivid_timer.expires = jiffies + 1; add_timer(&my_vivid_timer); return 0; } static int my_vivid_close(struct file *file) { printk("enter %s\n", __func__); del_timer(&my_vivid_timer); videobuf_stop(&my_vivid_vb_vidqueue); videobuf_mmap_free(&my_vivid_vb_vidqueue); return 0; } static int my_vivid_mmap(struct file *file, struct vm_area_struct *vma) { printk("enter %s\n", __func__); return videobuf_mmap_mapper(&my_vivid_vb_vidqueue, vma); } static unsigned int my_vivid_poll(struct file *file, struct poll_table_struct *wait) { printk("enter %s\n", __func__); return videobuf_poll_stream(file, &my_vivid_vb_vidqueue, wait); } /* v4l2_ioctl_ops */ static int my_vivid_vidioc_querycap(struct file *file, void *priv, struct v4l2_capability *cap) { printk("enter %s\n", __func__); strcpy(cap->driver, "my_vivid"); strcpy(cap->card, "my_vivid"); cap->version = 0x0001; cap->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING | V4L2_CAP_DEVICE_CAPS; cap->capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING | V4L2_CAP_DEVICE_CAPS; return 0; } static int my_vivid_vidioc_enum_fmt_vid_cap(struct file *file, void *priv, struct v4l2_fmtdesc *f) { printk("enter %s\n", __func__); if (f->index >= 1) return -EINVAL; strcpy(f->description, "4:2:2, packed, YUYV"); f->pixelformat = V4L2_PIX_FMT_YUYV; return 0; } static int my_vivid_vidioc_g_fmt_vid_cap(struct file *file, void *priv, struct v4l2_format *f) { printk("enter %s\n", __func__); memcpy(f, &my_vivid_format, sizeof(my_vivid_format)); return 0; } static int my_vivid_vidioc_try_fmt_vid_cap(struct file *file, void *priv, struct v4l2_format *f) { unsigned int maxw, maxh; enum v4l2_field field; printk("enter %s\n", __func__); if (f->fmt.pix.pixelformat != V4L2_PIX_FMT_YUYV) return -EINVAL; field = f->fmt.pix.field; if (field == V4L2_FIELD_ANY) { field = V4L2_FIELD_INTERLACED; } else if (V4L2_FIELD_INTERLACED != field) { return -EINVAL; } maxw = 1024; maxh = 768; /* 调整format的width, height, * 计算bytesperline, sizeimage */ v4l_bound_align_image(&f->fmt.pix.width, 48, maxw, 2, &f->fmt.pix.height, 32, maxh, 0, 0); f->fmt.pix.bytesperline = (f->fmt.pix.width * 16) >> 3; f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline; return 0; } static int my_vivid_vidioc_s_fmt_vid_cap(struct file *file, void *priv, struct v4l2_format *f) { int ret; printk("enter %s\n", __func__); ret = my_vivid_vidioc_try_fmt_vid_cap(file, NULL, f); if (ret < 0) return ret; memcpy(&my_vivid_format, f, sizeof(my_vivid_format)); return ret; } static int my_vivid_vidioc_reqbufs(struct file *file, void *priv, struct v4l2_requestbuffers *p) { printk("enter %s\n", __func__); return (videobuf_reqbufs(&my_vivid_vb_vidqueue, p)); } static int my_vivid_vidioc_querybuf(struct file *file, void *priv, struct v4l2_buffer *p) { printk("enter %s\n", __func__); return (videobuf_querybuf(&my_vivid_vb_vidqueue, p)); } static int my_vivid_vidioc_qbuf(struct file *file, void *priv, struct v4l2_buffer *p) { printk("enter %s\n", __func__); return (videobuf_qbuf(&my_vivid_vb_vidqueue, p)); } static int my_vivid_vidioc_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p) { printk("enter %s\n", __func__); return (videobuf_dqbuf(&my_vivid_vb_vidqueue, p, file->f_flags & O_NONBLOCK)); } static int my_vivid_vidioc_streamon(struct file *file, void *priv, enum v4l2_buf_type i) { printk("enter %s\n", __func__); return videobuf_streamon(&my_vivid_vb_vidqueue); } static int my_vivid_vidioc_streamoff(struct file *file, void *priv, enum v4l2_buf_type i) { printk("enter %s\n", __func__); videobuf_streamoff(&my_vivid_vb_vidqueue); return 0; } static const struct v4l2_ioctl_ops my_vivid_ioctl_ops = { // 表示它是一个摄像头设备 .vidioc_querycap = my_vivid_vidioc_querycap, /* 用于列举、获得、测试、设置摄像头的数据的格式 */ .vidioc_enum_fmt_vid_cap = my_vivid_vidioc_enum_fmt_vid_cap, .vidioc_g_fmt_vid_cap = my_vivid_vidioc_g_fmt_vid_cap, .vidioc_try_fmt_vid_cap = my_vivid_vidioc_try_fmt_vid_cap, .vidioc_s_fmt_vid_cap = my_vivid_vidioc_s_fmt_vid_cap, /* 缓冲区操作: 申请/查询/放入队列/取出队列 */ .vidioc_reqbufs = my_vivid_vidioc_reqbufs, .vidioc_querybuf = my_vivid_vidioc_querybuf, .vidioc_qbuf = my_vivid_vidioc_qbuf, .vidioc_dqbuf = my_vivid_vidioc_dqbuf, // 启动/停止 .vidioc_streamon = my_vivid_vidioc_streamon, .vidioc_streamoff = my_vivid_vidioc_streamoff, }; static const struct v4l2_file_operations my_vivid_fops = { .owner = THIS_MODULE, .open = my_vivid_open, .release = my_vivid_close, .mmap = my_vivid_mmap, .unlocked_ioctl = video_ioctl2, /* V4L2 ioctl handler */ .poll = my_vivid_poll, }; static struct video_device *my_vivid_dev; static struct v4l2_device v4l2_dev; static void my_vivid_dev_release(struct video_device *vdev) { printk("enter %s\n", __func__); } static int my_vivid_probe(struct platform_device *pdev) { int ret; printk("enter %s\n", __func__); /* 1.分配一个video_device结构体 */ my_vivid_dev = video_device_alloc(); if (NULL == my_vivid_dev) { printk("Failed to alloc video device (%d)\n", ret); return -ENOMEM; } /* 2.设置 */ my_vivid_dev->release = my_vivid_dev_release; my_vivid_dev->fops = &my_vivid_fops; my_vivid_dev->ioctl_ops = &my_vivid_ioctl_ops; my_vivid_dev->v4l2_dev = &v4l2_dev; //队列操作b:初始化自旋锁 spin_lock_init(&my_vivid_queue_slock); /* 3.注册 */ ret = video_register_device(my_vivid_dev, VFL_TYPE_GRABBER, -1); if (ret) { printk("Failed to register as video device (%d)\n", ret); goto err_register_dev; } //用定时器产生数据并唤醒进程 init_timer(&my_vivid_timer); my_vivid_timer.function = my_vivid_timer_function; INIT_LIST_HEAD(&my_vivid_vb_local_queue); return 0; err_register_dev: video_device_release(my_vivid_dev); return -ENODEV; } static int my_vivid_remove(struct platform_device *pdev) { printk("enter %s\n", __func__); v4l2_device_unregister(my_vivid_dev->v4l2_dev); video_device_release(my_vivid_dev); return 0; } static void my_vivid_pdev_release(struct device *dev) { printk("enter %s\n", __func__); } static struct platform_device my_vivid_pdev = { .name = "my_vivid", .dev.release = my_vivid_pdev_release, }; static struct platform_driver my_vivid_pdrv = { .probe = my_vivid_probe, .remove = my_vivid_remove, .driver = { .name = "my_vivid", }, }; static int my_vivid_init(void) { int ret; printk("enter %s\n", __func__); ret = platform_device_register(&my_vivid_pdev); if (ret) return ret; ret = platform_driver_register(&my_vivid_pdrv); if (ret) platform_device_unregister(&my_vivid_pdev); return ret; } static void my_vivid_exit(void) { printk("enter %s\n", __func__); platform_driver_unregister(&my_vivid_pdrv); platform_device_unregister(&my_vivid_pdev); } module_init(my_vivid_init); module_exit(my_vivid_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("hceng "); MODULE_DESCRIPTION("A Virtual Video Test Code For Learn."); MODULE_ALIAS("My vivid"); MODULE_VERSION("V1.0"); | 
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