diff options
Diffstat (limited to 'drivers/media/video/v4l2-mem2mem.c')
| -rw-r--r-- | drivers/media/video/v4l2-mem2mem.c | 633 |
1 files changed, 633 insertions, 0 deletions
diff --git a/drivers/media/video/v4l2-mem2mem.c b/drivers/media/video/v4l2-mem2mem.c new file mode 100644 index 000000000000..f45f9405ea39 --- /dev/null +++ b/drivers/media/video/v4l2-mem2mem.c @@ -0,0 +1,633 @@ +/* + * 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, <p.osciak@samsung.com> + * Marek Szyprowski, <m.szyprowski@samsung.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/module.h> +#include <linux/sched.h> +#include <linux/slab.h> + +#include <media/videobuf-core.h> +#include <media/v4l2-mem2mem.h> + +MODULE_DESCRIPTION("Mem to mem device framework for videobuf"); +MODULE_AUTHOR("Pawel Osciak, <p.osciak@samsung.com>"); +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); + |