/* *	uvc_queue.c  --  USB Video Class driver - Buffers management * *	Copyright (C) 2005-2010 *	    Laurent Pinchart (laurent.pinchart@ideasonboard.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 <linux/atomic.h>#include <linux/kernel.h>#include <linux/mm.h>#include <linux/list.h>#include <linux/module.h>#include <linux/usb.h>#include <linux/videodev2.h>#include <linux/vmalloc.h>#include <linux/wait.h> #include <media/v4l2-common.h>#include <media/videobuf2-vmalloc.h> #include "uvc.h" /* ------------------------------------------------------------------------ * Video buffers queue management. * * Video queues is initialized by uvcg_queue_init(). The function performs * basic initialization of the uvc_video_queue struct and never fails. * * Video buffers are managed by videobuf2. The driver uses a mutex to protect * the videobuf2 queue operations by serializing calls to videobuf2 and a * spinlock to protect the IRQ queue that holds the buffers to be processed by * the driver. */ /* ----------------------------------------------------------------------------- * videobuf2 queue operations */ static int uvc_queue_setup(struct vb2_queue *vq,			   unsigned int *nbuffers, unsigned int *nplanes,			   unsigned int sizes[], struct device *alloc_devs[]){	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);	struct uvc_video *video = container_of(queue, struct uvc_video, queue); 	if (*nbuffers > UVC_MAX_VIDEO_BUFFERS)		*nbuffers = UVC_MAX_VIDEO_BUFFERS; 	*nplanes = 1; 	sizes[0] = video->imagesize; 	return 0;} static int uvc_buffer_prepare(struct vb2_buffer *vb){	struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);	struct uvc_buffer *buf = container_of(vbuf, struct uvc_buffer, buf); 	if (vb->type == V4L2_BUF_TYPE_VIDEO_OUTPUT &&	    vb2_get_plane_payload(vb, 0) > vb2_plane_size(vb, 0)) {		uvc_trace(UVC_TRACE_CAPTURE, "[E] Bytes used out of bounds.\n");		return -EINVAL;	} 	if (unlikely(queue->flags & UVC_QUEUE_DISCONNECTED))		return -ENODEV; 	buf->state = UVC_BUF_STATE_QUEUED;	buf->mem = vb2_plane_vaddr(vb, 0);	buf->length = vb2_plane_size(vb, 0);	if (vb->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)		buf->bytesused = 0;	else		buf->bytesused = vb2_get_plane_payload(vb, 0); 	return 0;} static void uvc_buffer_queue(struct vb2_buffer *vb){	struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);	struct uvc_buffer *buf = container_of(vbuf, struct uvc_buffer, buf);	unsigned long flags; 	spin_lock_irqsave(&queue->irqlock, flags); 	if (likely(!(queue->flags & UVC_QUEUE_DISCONNECTED))) {		list_add_tail(&buf->queue, &queue->irqqueue);	} else {		/* If the device is disconnected return the buffer to userspace		 * directly. The next QBUF call will fail with -ENODEV.		 */		buf->state = UVC_BUF_STATE_ERROR;		vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);	} 	spin_unlock_irqrestore(&queue->irqlock, flags);} static struct vb2_ops uvc_queue_qops = {	.queue_setup = uvc_queue_setup,	.buf_prepare = uvc_buffer_prepare,	.buf_queue = uvc_buffer_queue,	.wait_prepare = vb2_ops_wait_prepare,	.wait_finish = vb2_ops_wait_finish,}; int uvcg_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type,		    struct mutex *lock){	int ret; 	queue->queue.type = type;	queue->queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;	queue->queue.drv_priv = queue;	queue->queue.buf_struct_size = sizeof(struct uvc_buffer);	queue->queue.ops = &uvc_queue_qops;	queue->queue.lock = lock;	queue->queue.mem_ops = &vb2_vmalloc_memops;	queue->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC				     | V4L2_BUF_FLAG_TSTAMP_SRC_EOF;	ret = vb2_queue_init(&queue->queue);	if (ret)		return ret; 	spin_lock_init(&queue->irqlock);	INIT_LIST_HEAD(&queue->irqqueue);	queue->flags = 0; 	return 0;} /* * Free the video buffers. */void uvcg_free_buffers(struct uvc_video_queue *queue){	vb2_queue_release(&queue->queue);} /* * Allocate the video buffers. */int uvcg_alloc_buffers(struct uvc_video_queue *queue,			      struct v4l2_requestbuffers *rb){	int ret; 	ret = vb2_reqbufs(&queue->queue, rb); 	return ret ? ret : rb->count;} int uvcg_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf){	return vb2_querybuf(&queue->queue, buf);} int uvcg_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf){	unsigned long flags;	int ret; 	ret = vb2_qbuf(&queue->queue, buf);	if (ret < 0)		return ret; 	spin_lock_irqsave(&queue->irqlock, flags);	ret = (queue->flags & UVC_QUEUE_PAUSED) != 0;	queue->flags &= ~UVC_QUEUE_PAUSED;	spin_unlock_irqrestore(&queue->irqlock, flags);	return ret;} /* * Dequeue a video buffer. If nonblocking is false, block until a buffer is * available. */int uvcg_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf,			int nonblocking){	return vb2_dqbuf(&queue->queue, buf, nonblocking);} /* * Poll the video queue. * * This function implements video queue polling and is intended to be used by * the device poll handler. */unsigned int uvcg_queue_poll(struct uvc_video_queue *queue, struct file *file,			     poll_table *wait){	return vb2_poll(&queue->queue, file, wait);} int uvcg_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma){	return vb2_mmap(&queue->queue, vma);} #ifndef CONFIG_MMU/* * Get unmapped area. * * NO-MMU arch need this function to make mmap() work correctly. */unsigned long uvcg_queue_get_unmapped_area(struct uvc_video_queue *queue,					   unsigned long pgoff){	return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);}#endif /* * Cancel the video buffers queue. * * Cancelling the queue marks all buffers on the irq queue as erroneous, * wakes them up and removes them from the queue. * * If the disconnect parameter is set, further calls to uvc_queue_buffer will * fail with -ENODEV. * * This function acquires the irq spinlock and can be called from interrupt * context. */void uvcg_queue_cancel(struct uvc_video_queue *queue, int disconnect){	struct uvc_buffer *buf;	unsigned long flags; 	spin_lock_irqsave(&queue->irqlock, flags);	while (!list_empty(&queue->irqqueue)) {		buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,				       queue);		list_del(&buf->queue);		buf->state = UVC_BUF_STATE_ERROR;		vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_ERROR);	}	/* This must be protected by the irqlock spinlock to avoid race	 * conditions between uvc_queue_buffer and the disconnection event that	 * could result in an interruptible wait in uvc_dequeue_buffer. Do not	 * blindly replace this logic by checking for the UVC_DEV_DISCONNECTED	 * state outside the queue code.	 */	if (disconnect)		queue->flags |= UVC_QUEUE_DISCONNECTED;	spin_unlock_irqrestore(&queue->irqlock, flags);} /* * Enable or disable the video buffers queue. * * The queue must be enabled before starting video acquisition and must be * disabled after stopping it. This ensures that the video buffers queue * state can be properly initialized before buffers are accessed from the * interrupt handler. * * Enabling the video queue initializes parameters (such as sequence number, * sync pattern, ...). If the queue is already enabled, return -EBUSY. * * Disabling the video queue cancels the queue and removes all buffers from * the main queue. * * This function can't be called from interrupt context. Use * uvcg_queue_cancel() instead. */int uvcg_queue_enable(struct uvc_video_queue *queue, int enable){	unsigned long flags;	int ret = 0; 	if (enable) {		ret = vb2_streamon(&queue->queue, queue->queue.type);		if (ret < 0)			return ret; 		queue->sequence = 0;		queue->buf_used = 0;	} else {		ret = vb2_streamoff(&queue->queue, queue->queue.type);		if (ret < 0)			return ret; 		spin_lock_irqsave(&queue->irqlock, flags);		INIT_LIST_HEAD(&queue->irqqueue); 		/*		 * FIXME: We need to clear the DISCONNECTED flag to ensure that		 * applications will be able to queue buffers for the next		 * streaming run. However, clearing it here doesn't guarantee		 * that the device will be reconnected in the meantime.		 */		queue->flags &= ~UVC_QUEUE_DISCONNECTED;		spin_unlock_irqrestore(&queue->irqlock, flags);	} 	return ret;} /* called with &queue_irqlock held.. */struct uvc_buffer *uvcg_queue_next_buffer(struct uvc_video_queue *queue,					  struct uvc_buffer *buf){	struct uvc_buffer *nextbuf; 	if ((queue->flags & UVC_QUEUE_DROP_INCOMPLETE) &&	     buf->length != buf->bytesused) {		buf->state = UVC_BUF_STATE_QUEUED;		vb2_set_plane_payload(&buf->buf.vb2_buf, 0, 0);		return buf;	} 	list_del(&buf->queue);	if (!list_empty(&queue->irqqueue))		nextbuf = list_first_entry(&queue->irqqueue, struct uvc_buffer,					   queue);	else		nextbuf = NULL; 	buf->buf.field = V4L2_FIELD_NONE;	buf->buf.sequence = queue->sequence++;	buf->buf.vb2_buf.timestamp = ktime_get_ns(); 	vb2_set_plane_payload(&buf->buf.vb2_buf, 0, buf->bytesused);	vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_DONE); 	return nextbuf;} struct uvc_buffer *uvcg_queue_head(struct uvc_video_queue *queue){	struct uvc_buffer *buf = NULL; 	if (!list_empty(&queue->irqqueue))		buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,				       queue);	else		queue->flags |= UVC_QUEUE_PAUSED; 	return buf;}