/* * Memory-to-memory device framework for Video for Linux 2 and videobuf. * * Helper functions for devices that use videobuf buffers for both their * source and destination. * * Copyright (c) 2009-2010 Samsung Electronics Co., Ltd. * Pawel Osciak, * Marek Szyprowski, * * 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 MODULE_DESCRIPTION("Mem to mem device framework for videobuf"); MODULE_AUTHOR("Pawel Osciak, "); MODULE_LICENSE("GPL"); static bool debug; module_param(debug, bool, 0644); #define dprintk(fmt, arg...) \ do { \ if (debug) \ printk(KERN_DEBUG "%s: " fmt, __func__, ## arg);\ } while (0) /* Instance is already queued on the job_queue */ #define TRANS_QUEUED (1 << 0) /* Instance is currently running in hardware */ #define TRANS_RUNNING (1 << 1) /* Offset base for buffers on the destination queue - used to distinguish * between source and destination buffers when mmapping - they receive the same * offsets but for different queues */ #define DST_QUEUE_OFF_BASE (1 << 30) /** * struct v4l2_m2m_dev - per-device context * @curr_ctx: currently running instance * @job_queue: instances queued to run * @job_spinlock: protects job_queue * @m2m_ops: driver callbacks */ struct v4l2_m2m_dev { struct v4l2_m2m_ctx *curr_ctx; struct list_head job_queue; spinlock_t job_spinlock; struct v4l2_m2m_ops *m2m_ops; }; static struct v4l2_m2m_queue_ctx *get_queue_ctx(struct v4l2_m2m_ctx *m2m_ctx, enum v4l2_buf_type type) { switch (type) { case V4L2_BUF_TYPE_VIDEO_CAPTURE: return &m2m_ctx->cap_q_ctx; case V4L2_BUF_TYPE_VIDEO_OUTPUT: return &m2m_ctx->out_q_ctx; default: printk(KERN_ERR "Invalid buffer type\n"); return NULL; } } /** * v4l2_m2m_get_vq() - return videobuf_queue for the given type */ struct videobuf_queue *v4l2_m2m_get_vq(struct v4l2_m2m_ctx *m2m_ctx, enum v4l2_buf_type type) { struct v4l2_m2m_queue_ctx *q_ctx; q_ctx = get_queue_ctx(m2m_ctx, type); if (!q_ctx) return NULL; return &q_ctx->q; } EXPORT_SYMBOL(v4l2_m2m_get_vq); /** * v4l2_m2m_next_buf() - return next buffer from the list of ready buffers */ void *v4l2_m2m_next_buf(struct v4l2_m2m_ctx *m2m_ctx, enum v4l2_buf_type type) { struct v4l2_m2m_queue_ctx *q_ctx; struct videobuf_buffer *vb = NULL; unsigned long flags; q_ctx = get_queue_ctx(m2m_ctx, type); if (!q_ctx) return NULL; spin_lock_irqsave(q_ctx->q.irqlock, flags); if (list_empty(&q_ctx->rdy_queue)) goto end; vb = list_entry(q_ctx->rdy_queue.next, struct videobuf_buffer, queue); vb->state = VIDEOBUF_ACTIVE; end: spin_unlock_irqrestore(q_ctx->q.irqlock, flags); return vb; } EXPORT_SYMBOL_GPL(v4l2_m2m_next_buf); /** * v4l2_m2m_buf_remove() - take off a buffer from the list of ready buffers and * return it */ void *v4l2_m2m_buf_remove(struct v4l2_m2m_ctx *m2m_ctx, enum v4l2_buf_type type) { struct v4l2_m2m_queue_ctx *q_ctx; struct videobuf_buffer *vb = NULL; unsigned long flags; q_ctx = get_queue_ctx(m2m_ctx, type); if (!q_ctx) return NULL; spin_lock_irqsave(q_ctx->q.irqlock, flags); if (!list_empty(&q_ctx->rdy_queue)) { vb = list_entry(q_ctx->rdy_queue.next, struct videobuf_buffer, queue); list_del(&vb->queue); q_ctx->num_rdy--; } spin_unlock_irqrestore(q_ctx->q.irqlock, flags); return vb; } EXPORT_SYMBOL_GPL(v4l2_m2m_buf_remove); /* * Scheduling handlers */ /** * v4l2_m2m_get_curr_priv() - return driver private data for the currently * running instance or NULL if no instance is running */ void *v4l2_m2m_get_curr_priv(struct v4l2_m2m_dev *m2m_dev) { unsigned long flags; void *ret = NULL; spin_lock_irqsave(&m2m_dev->job_spinlock, flags); if (m2m_dev->curr_ctx) ret = m2m_dev->curr_ctx->priv; spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags); return ret; } EXPORT_SYMBOL(v4l2_m2m_get_curr_priv); /** * v4l2_m2m_try_run() - select next job to perform and run it if possible * * Get next transaction (if present) from the waiting jobs list and run it. */ static void v4l2_m2m_try_run(struct v4l2_m2m_dev *m2m_dev) { unsigned long flags; spin_lock_irqsave(&m2m_dev->job_spinlock, flags); if (NULL != m2m_dev->curr_ctx) { spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags); dprintk("Another instance is running, won't run now\n"); return; } if (list_empty(&m2m_dev->job_queue)) { spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags); dprintk("No job pending\n"); return; } m2m_dev->curr_ctx = list_entry(m2m_dev->job_queue.next, struct v4l2_m2m_ctx, queue); m2m_dev->curr_ctx->job_flags |= TRANS_RUNNING; spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags); m2m_dev->m2m_ops->device_run(m2m_dev->curr_ctx->priv); } /** * v4l2_m2m_try_schedule() - check whether an instance is ready to be added to * the pending job queue and add it if so. * @m2m_ctx: m2m context assigned to the instance to be checked * * There are three basic requirements an instance has to meet to be able to run: * 1) at least one source buffer has to be queued, * 2) at least one destination buffer has to be queued, * 3) streaming has to be on. * * There may also be additional, custom requirements. In such case the driver * should supply a custom callback (job_ready in v4l2_m2m_ops) that should * return 1 if the instance is ready. * An example of the above could be an instance that requires more than one * src/dst buffer per transaction. */ static void v4l2_m2m_try_schedule(struct v4l2_m2m_ctx *m2m_ctx) { struct v4l2_m2m_dev *m2m_dev; unsigned long flags_job, flags; m2m_dev = m2m_ctx->m2m_dev; dprintk("Trying to schedule a job for m2m_ctx: %p\n", m2m_ctx); if (!m2m_ctx->out_q_ctx.q.streaming || !m2m_ctx->cap_q_ctx.q.streaming) { dprintk("Streaming needs to be on for both queues\n"); return; } spin_lock_irqsave(&m2m_dev->job_spinlock, flags_job); if (m2m_ctx->job_flags & TRANS_QUEUED) { spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job); dprintk("On job queue already\n"); return; } spin_lock_irqsave(m2m_ctx->out_q_ctx.q.irqlock, flags); if (list_empty(&m2m_ctx->out_q_ctx.rdy_queue)) { spin_unlock_irqrestore(m2m_ctx->out_q_ctx.q.irqlock, flags); spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job); dprintk("No input buffers available\n"); return; } if (list_empty(&m2m_ctx->cap_q_ctx.rdy_queue)) { spin_unlock_irqrestore(m2m_ctx->out_q_ctx.q.irqlock, flags); spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job); dprintk("No output buffers available\n"); return; } spin_unlock_irqrestore(m2m_ctx->out_q_ctx.q.irqlock, flags); if (m2m_dev->m2m_ops->job_ready && (!m2m_dev->m2m_ops->job_ready(m2m_ctx->priv))) { spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job); dprintk("Driver not ready\n"); return; } list_add_tail(&m2m_ctx->queue, &m2m_dev->job_queue); m2m_ctx->job_flags |= TRANS_QUEUED; spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job); v4l2_m2m_try_run(m2m_dev); } /** * v4l2_m2m_job_finish() - inform the framework that a job has been finished * and have it clean up * * Called by a driver to yield back the device after it has finished with it. * Should be called as soon as possible after reaching a state which allows * other instances to take control of the device. * * This function has to be called only after device_run() callback has been * called on the driver. To prevent recursion, it should not be called directly * from the device_run() callback though. */ void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev, struct v4l2_m2m_ctx *m2m_ctx) { unsigned long flags; spin_lock_irqsave(&m2m_dev->job_spinlock, flags); if (!m2m_dev->curr_ctx || m2m_dev->curr_ctx != m2m_ctx) { spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags); dprintk("Called by an instance not currently running\n"); return; } list_del(&m2m_dev->curr_ctx->queue); m2m_dev->curr_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING); m2m_dev->curr_ctx = NULL; spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags); /* This instance might have more buffers ready, but since we do not * allow more than one job on the job_queue per instance, each has * to be scheduled separately after the previous one finishes. */ v4l2_m2m_try_schedule(m2m_ctx); v4l2_m2m_try_run(m2m_dev); } EXPORT_SYMBOL(v4l2_m2m_job_finish); /** * v4l2_m2m_reqbufs() - multi-queue-aware REQBUFS multiplexer */ int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, struct v4l2_requestbuffers *reqbufs) { struct videobuf_queue *vq; vq = v4l2_m2m_get_vq(m2m_ctx, reqbufs->type); return videobuf_reqbufs(vq, reqbufs); } EXPORT_SYMBOL_GPL(v4l2_m2m_reqbufs); /** * v4l2_m2m_querybuf() - multi-queue-aware QUERYBUF multiplexer * * See v4l2_m2m_mmap() documentation for details. */ int v4l2_m2m_querybuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, struct v4l2_buffer *buf) { struct videobuf_queue *vq; int ret; vq = v4l2_m2m_get_vq(m2m_ctx, buf->type); ret = videobuf_querybuf(vq, buf); if (buf->memory == V4L2_MEMORY_MMAP && vq->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) { buf->m.offset += DST_QUEUE_OFF_BASE; } return ret; } EXPORT_SYMBOL_GPL(v4l2_m2m_querybuf); /** * v4l2_m2m_qbuf() - enqueue a source or destination buffer, depending on * the type */ int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, struct v4l2_buffer *buf) { struct videobuf_queue *vq; int ret; vq = v4l2_m2m_get_vq(m2m_ctx, buf->type); ret = videobuf_qbuf(vq, buf); if (!ret) v4l2_m2m_try_schedule(m2m_ctx); return ret; } EXPORT_SYMBOL_GPL(v4l2_m2m_qbuf); /** * v4l2_m2m_dqbuf() - dequeue a source or destination buffer, depending on * the type */ int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, struct v4l2_buffer *buf) { struct videobuf_queue *vq; vq = v4l2_m2m_get_vq(m2m_ctx, buf->type); return videobuf_dqbuf(vq, buf, file->f_flags & O_NONBLOCK); } EXPORT_SYMBOL_GPL(v4l2_m2m_dqbuf); /** * v4l2_m2m_streamon() - turn on streaming for a video queue */ int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, enum v4l2_buf_type type) { struct videobuf_queue *vq; int ret; vq = v4l2_m2m_get_vq(m2m_ctx, type); ret = videobuf_streamon(vq); if (!ret) v4l2_m2m_try_schedule(m2m_ctx); return ret; } EXPORT_SYMBOL_GPL(v4l2_m2m_streamon); /** * v4l2_m2m_streamoff() - turn off streaming for a video queue */ int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, enum v4l2_buf_type type) { struct videobuf_queue *vq; vq = v4l2_m2m_get_vq(m2m_ctx, type); return videobuf_streamoff(vq); } EXPORT_SYMBOL_GPL(v4l2_m2m_streamoff); /** * v4l2_m2m_poll() - poll replacement, for destination buffers only * * Call from the driver's poll() function. Will poll both queues. If a buffer * is available to dequeue (with dqbuf) from the source queue, this will * indicate that a non-blocking write can be performed, while read will be * returned in case of the destination queue. */ unsigned int v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, struct poll_table_struct *wait) { struct videobuf_queue *src_q, *dst_q; struct videobuf_buffer *src_vb = NULL, *dst_vb = NULL; unsigned int rc = 0; src_q = v4l2_m2m_get_src_vq(m2m_ctx); dst_q = v4l2_m2m_get_dst_vq(m2m_ctx); mutex_lock(&src_q->vb_lock); mutex_lock(&dst_q->vb_lock); if (src_q->streaming && !list_empty(&src_q->stream)) src_vb = list_first_entry(&src_q->stream, struct videobuf_buffer, stream); if (dst_q->streaming && !list_empty(&dst_q->stream)) dst_vb = list_first_entry(&dst_q->stream, struct videobuf_buffer, stream); if (!src_vb && !dst_vb) { rc = POLLERR; goto end; } if (src_vb) { poll_wait(file, &src_vb->done, wait); if (src_vb->state == VIDEOBUF_DONE || src_vb->state == VIDEOBUF_ERROR) rc |= POLLOUT | POLLWRNORM; } if (dst_vb) { poll_wait(file, &dst_vb->done, wait); if (dst_vb->state == VIDEOBUF_DONE || dst_vb->state == VIDEOBUF_ERROR) rc |= POLLIN | POLLRDNORM; } end: mutex_unlock(&dst_q->vb_lock); mutex_unlock(&src_q->vb_lock); return rc; } EXPORT_SYMBOL_GPL(v4l2_m2m_poll); /** * v4l2_m2m_mmap() - source and destination queues-aware mmap multiplexer * * Call from driver's mmap() function. Will handle mmap() for both queues * seamlessly for videobuffer, which will receive normal per-queue offsets and * proper videobuf queue pointers. The differentiation is made outside videobuf * by adding a predefined offset to buffers from one of the queues and * subtracting it before passing it back to videobuf. Only drivers (and * thus applications) receive modified offsets. */ int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, struct vm_area_struct *vma) { unsigned long offset = vma->vm_pgoff << PAGE_SHIFT; struct videobuf_queue *vq; if (offset < DST_QUEUE_OFF_BASE) { vq = v4l2_m2m_get_src_vq(m2m_ctx); } else { vq = v4l2_m2m_get_dst_vq(m2m_ctx); vma->vm_pgoff -= (DST_QUEUE_OFF_BASE >> PAGE_SHIFT); } return videobuf_mmap_mapper(vq, vma); } EXPORT_SYMBOL(v4l2_m2m_mmap); /** * v4l2_m2m_init() - initialize per-driver m2m data * * Usually called from driver's probe() function. */ struct v4l2_m2m_dev *v4l2_m2m_init(struct v4l2_m2m_ops *m2m_ops) { struct v4l2_m2m_dev *m2m_dev; if (!m2m_ops) return ERR_PTR(-EINVAL); BUG_ON(!m2m_ops->device_run); BUG_ON(!m2m_ops->job_abort); m2m_dev = kzalloc(sizeof *m2m_dev, GFP_KERNEL); if (!m2m_dev) return ERR_PTR(-ENOMEM); m2m_dev->curr_ctx = NULL; m2m_dev->m2m_ops = m2m_ops; INIT_LIST_HEAD(&m2m_dev->job_queue); spin_lock_init(&m2m_dev->job_spinlock); return m2m_dev; } EXPORT_SYMBOL_GPL(v4l2_m2m_init); /** * v4l2_m2m_release() - cleans up and frees a m2m_dev structure * * Usually called from driver's remove() function. */ void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev) { kfree(m2m_dev); } EXPORT_SYMBOL_GPL(v4l2_m2m_release); /** * v4l2_m2m_ctx_init() - allocate and initialize a m2m context * @priv - driver's instance private data * @m2m_dev - a previously initialized m2m_dev struct * @vq_init - a callback for queue type-specific initialization function to be * used for initializing videobuf_queues * * Usually called from driver's open() function. */ struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(void *priv, struct v4l2_m2m_dev *m2m_dev, void (*vq_init)(void *priv, struct videobuf_queue *, enum v4l2_buf_type)) { struct v4l2_m2m_ctx *m2m_ctx; struct v4l2_m2m_queue_ctx *out_q_ctx, *cap_q_ctx; if (!vq_init) return ERR_PTR(-EINVAL); m2m_ctx = kzalloc(sizeof *m2m_ctx, GFP_KERNEL); if (!m2m_ctx) return ERR_PTR(-ENOMEM); m2m_ctx->priv = priv; m2m_ctx->m2m_dev = m2m_dev; out_q_ctx = get_queue_ctx(m2m_ctx, V4L2_BUF_TYPE_VIDEO_OUTPUT); cap_q_ctx = get_queue_ctx(m2m_ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE); INIT_LIST_HEAD(&out_q_ctx->rdy_queue); INIT_LIST_HEAD(&cap_q_ctx->rdy_queue); INIT_LIST_HEAD(&m2m_ctx->queue); vq_init(priv, &out_q_ctx->q, V4L2_BUF_TYPE_VIDEO_OUTPUT); vq_init(priv, &cap_q_ctx->q, V4L2_BUF_TYPE_VIDEO_CAPTURE); out_q_ctx->q.priv_data = cap_q_ctx->q.priv_data = priv; return m2m_ctx; } EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_init); /** * v4l2_m2m_ctx_release() - release m2m context * * Usually called from driver's release() function. */ void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx) { struct v4l2_m2m_dev *m2m_dev; struct videobuf_buffer *vb; unsigned long flags; m2m_dev = m2m_ctx->m2m_dev; spin_lock_irqsave(&m2m_dev->job_spinlock, flags); if (m2m_ctx->job_flags & TRANS_RUNNING) { spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags); m2m_dev->m2m_ops->job_abort(m2m_ctx->priv); dprintk("m2m_ctx %p running, will wait to complete", m2m_ctx); vb = v4l2_m2m_next_dst_buf(m2m_ctx); BUG_ON(NULL == vb); wait_event(vb->done, vb->state != VIDEOBUF_ACTIVE && vb->state != VIDEOBUF_QUEUED); } else if (m2m_ctx->job_flags & TRANS_QUEUED) { list_del(&m2m_ctx->queue); m2m_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING); spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags); dprintk("m2m_ctx: %p had been on queue and was removed\n", m2m_ctx); } else { /* Do nothing, was not on queue/running */ spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags); } videobuf_stop(&m2m_ctx->cap_q_ctx.q); videobuf_stop(&m2m_ctx->out_q_ctx.q); videobuf_mmap_free(&m2m_ctx->cap_q_ctx.q); videobuf_mmap_free(&m2m_ctx->out_q_ctx.q); kfree(m2m_ctx); } EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_release); /** * v4l2_m2m_buf_queue() - add a buffer to the proper ready buffers list. * * Call from buf_queue(), videobuf_queue_ops callback. * * Locking: Caller holds q->irqlock (taken by videobuf before calling buf_queue * callback in the driver). */ void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx, struct videobuf_queue *vq, struct videobuf_buffer *vb) { struct v4l2_m2m_queue_ctx *q_ctx; q_ctx = get_queue_ctx(m2m_ctx, vq->type); if (!q_ctx) return; list_add_tail(&vb->queue, &q_ctx->rdy_queue); q_ctx->num_rdy++; vb->state = VIDEOBUF_QUEUED; } EXPORT_SYMBOL_GPL(v4l2_m2m_buf_queue);