diff options
Diffstat (limited to 'drivers/media/v4l2-core/videobuf-core.c')
| -rw-r--r-- | drivers/media/v4l2-core/videobuf-core.c | 1189 |
1 files changed, 1189 insertions, 0 deletions
diff --git a/drivers/media/v4l2-core/videobuf-core.c b/drivers/media/v4l2-core/videobuf-core.c new file mode 100644 index 00000000000..bf7a326b1cd --- /dev/null +++ b/drivers/media/v4l2-core/videobuf-core.c @@ -0,0 +1,1189 @@ +/* + * generic helper functions for handling video4linux capture buffers + * + * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org> + * + * Highly based on video-buf written originally by: + * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org> + * (c) 2006 Mauro Carvalho Chehab, <mchehab@infradead.org> + * (c) 2006 Ted Walther and John Sokol + * + * 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 + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/mm.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/interrupt.h> + +#include <media/videobuf-core.h> + +#define MAGIC_BUFFER 0x20070728 +#define MAGIC_CHECK(is, should) \ + do { \ + if (unlikely((is) != (should))) { \ + printk(KERN_ERR \ + "magic mismatch: %x (expected %x)\n", \ + is, should); \ + BUG(); \ + } \ + } while (0) + +static int debug; +module_param(debug, int, 0644); + +MODULE_DESCRIPTION("helper module to manage video4linux buffers"); +MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>"); +MODULE_LICENSE("GPL"); + +#define dprintk(level, fmt, arg...) \ + do { \ + if (debug >= level) \ + printk(KERN_DEBUG "vbuf: " fmt, ## arg); \ + } while (0) + +/* --------------------------------------------------------------------- */ + +#define CALL(q, f, arg...) \ + ((q->int_ops->f) ? q->int_ops->f(arg) : 0) + +struct videobuf_buffer *videobuf_alloc_vb(struct videobuf_queue *q) +{ + struct videobuf_buffer *vb; + + BUG_ON(q->msize < sizeof(*vb)); + + if (!q->int_ops || !q->int_ops->alloc_vb) { + printk(KERN_ERR "No specific ops defined!\n"); + BUG(); + } + + vb = q->int_ops->alloc_vb(q->msize); + if (NULL != vb) { + init_waitqueue_head(&vb->done); + vb->magic = MAGIC_BUFFER; + } + + return vb; +} +EXPORT_SYMBOL_GPL(videobuf_alloc_vb); + +static int is_state_active_or_queued(struct videobuf_queue *q, struct videobuf_buffer *vb) +{ + unsigned long flags; + bool rc; + + spin_lock_irqsave(q->irqlock, flags); + rc = vb->state != VIDEOBUF_ACTIVE && vb->state != VIDEOBUF_QUEUED; + spin_unlock_irqrestore(q->irqlock, flags); + return rc; +}; + +int videobuf_waiton(struct videobuf_queue *q, struct videobuf_buffer *vb, + int non_blocking, int intr) +{ + bool is_ext_locked; + int ret = 0; + + MAGIC_CHECK(vb->magic, MAGIC_BUFFER); + + if (non_blocking) { + if (is_state_active_or_queued(q, vb)) + return 0; + return -EAGAIN; + } + + is_ext_locked = q->ext_lock && mutex_is_locked(q->ext_lock); + + /* Release vdev lock to prevent this wait from blocking outside access to + the device. */ + if (is_ext_locked) + mutex_unlock(q->ext_lock); + if (intr) + ret = wait_event_interruptible(vb->done, is_state_active_or_queued(q, vb)); + else + wait_event(vb->done, is_state_active_or_queued(q, vb)); + /* Relock */ + if (is_ext_locked) + mutex_lock(q->ext_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(videobuf_waiton); + +int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb, + struct v4l2_framebuffer *fbuf) +{ + MAGIC_CHECK(vb->magic, MAGIC_BUFFER); + MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS); + + return CALL(q, iolock, q, vb, fbuf); +} +EXPORT_SYMBOL_GPL(videobuf_iolock); + +void *videobuf_queue_to_vaddr(struct videobuf_queue *q, + struct videobuf_buffer *buf) +{ + if (q->int_ops->vaddr) + return q->int_ops->vaddr(buf); + return NULL; +} +EXPORT_SYMBOL_GPL(videobuf_queue_to_vaddr); + +/* --------------------------------------------------------------------- */ + + +void videobuf_queue_core_init(struct videobuf_queue *q, + const struct videobuf_queue_ops *ops, + struct device *dev, + spinlock_t *irqlock, + enum v4l2_buf_type type, + enum v4l2_field field, + unsigned int msize, + void *priv, + struct videobuf_qtype_ops *int_ops, + struct mutex *ext_lock) +{ + BUG_ON(!q); + memset(q, 0, sizeof(*q)); + q->irqlock = irqlock; + q->ext_lock = ext_lock; + q->dev = dev; + q->type = type; + q->field = field; + q->msize = msize; + q->ops = ops; + q->priv_data = priv; + q->int_ops = int_ops; + + /* All buffer operations are mandatory */ + BUG_ON(!q->ops->buf_setup); + BUG_ON(!q->ops->buf_prepare); + BUG_ON(!q->ops->buf_queue); + BUG_ON(!q->ops->buf_release); + + /* Lock is mandatory for queue_cancel to work */ + BUG_ON(!irqlock); + + /* Having implementations for abstract methods are mandatory */ + BUG_ON(!q->int_ops); + + mutex_init(&q->vb_lock); + init_waitqueue_head(&q->wait); + INIT_LIST_HEAD(&q->stream); +} +EXPORT_SYMBOL_GPL(videobuf_queue_core_init); + +/* Locking: Only usage in bttv unsafe find way to remove */ +int videobuf_queue_is_busy(struct videobuf_queue *q) +{ + int i; + + MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS); + + if (q->streaming) { + dprintk(1, "busy: streaming active\n"); + return 1; + } + if (q->reading) { + dprintk(1, "busy: pending read #1\n"); + return 1; + } + if (q->read_buf) { + dprintk(1, "busy: pending read #2\n"); + return 1; + } + for (i = 0; i < VIDEO_MAX_FRAME; i++) { + if (NULL == q->bufs[i]) + continue; + if (q->bufs[i]->map) { + dprintk(1, "busy: buffer #%d mapped\n", i); + return 1; + } + if (q->bufs[i]->state == VIDEOBUF_QUEUED) { + dprintk(1, "busy: buffer #%d queued\n", i); + return 1; + } + if (q->bufs[i]->state == VIDEOBUF_ACTIVE) { + dprintk(1, "busy: buffer #%d avtive\n", i); + return 1; + } + } + return 0; +} +EXPORT_SYMBOL_GPL(videobuf_queue_is_busy); + +/** + * __videobuf_free() - free all the buffers and their control structures + * + * This function can only be called if streaming/reading is off, i.e. no buffers + * are under control of the driver. + */ +/* Locking: Caller holds q->vb_lock */ +static int __videobuf_free(struct videobuf_queue *q) +{ + int i; + + dprintk(1, "%s\n", __func__); + if (!q) + return 0; + + if (q->streaming || q->reading) { + dprintk(1, "Cannot free buffers when streaming or reading\n"); + return -EBUSY; + } + + MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS); + + for (i = 0; i < VIDEO_MAX_FRAME; i++) + if (q->bufs[i] && q->bufs[i]->map) { + dprintk(1, "Cannot free mmapped buffers\n"); + return -EBUSY; + } + + for (i = 0; i < VIDEO_MAX_FRAME; i++) { + if (NULL == q->bufs[i]) + continue; + q->ops->buf_release(q, q->bufs[i]); + kfree(q->bufs[i]); + q->bufs[i] = NULL; + } + + return 0; +} + +/* Locking: Caller holds q->vb_lock */ +void videobuf_queue_cancel(struct videobuf_queue *q) +{ + unsigned long flags = 0; + int i; + + q->streaming = 0; + q->reading = 0; + wake_up_interruptible_sync(&q->wait); + + /* remove queued buffers from list */ + spin_lock_irqsave(q->irqlock, flags); + for (i = 0; i < VIDEO_MAX_FRAME; i++) { + if (NULL == q->bufs[i]) + continue; + if (q->bufs[i]->state == VIDEOBUF_QUEUED) { + list_del(&q->bufs[i]->queue); + q->bufs[i]->state = VIDEOBUF_ERROR; + wake_up_all(&q->bufs[i]->done); + } + } + spin_unlock_irqrestore(q->irqlock, flags); + + /* free all buffers + clear queue */ + for (i = 0; i < VIDEO_MAX_FRAME; i++) { + if (NULL == q->bufs[i]) + continue; + q->ops->buf_release(q, q->bufs[i]); + } + INIT_LIST_HEAD(&q->stream); +} +EXPORT_SYMBOL_GPL(videobuf_queue_cancel); + +/* --------------------------------------------------------------------- */ + +/* Locking: Caller holds q->vb_lock */ +enum v4l2_field videobuf_next_field(struct videobuf_queue *q) +{ + enum v4l2_field field = q->field; + + BUG_ON(V4L2_FIELD_ANY == field); + + if (V4L2_FIELD_ALTERNATE == field) { + if (V4L2_FIELD_TOP == q->last) { + field = V4L2_FIELD_BOTTOM; + q->last = V4L2_FIELD_BOTTOM; + } else { + field = V4L2_FIELD_TOP; + q->last = V4L2_FIELD_TOP; + } + } + return field; +} +EXPORT_SYMBOL_GPL(videobuf_next_field); + +/* Locking: Caller holds q->vb_lock */ +static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b, + struct videobuf_buffer *vb, enum v4l2_buf_type type) +{ + MAGIC_CHECK(vb->magic, MAGIC_BUFFER); + MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS); + + b->index = vb->i; + b->type = type; + + b->memory = vb->memory; + switch (b->memory) { + case V4L2_MEMORY_MMAP: + b->m.offset = vb->boff; + b->length = vb->bsize; + break; + case V4L2_MEMORY_USERPTR: + b->m.userptr = vb->baddr; + b->length = vb->bsize; + break; + case V4L2_MEMORY_OVERLAY: + b->m.offset = vb->boff; + break; + } + + b->flags = 0; + if (vb->map) + b->flags |= V4L2_BUF_FLAG_MAPPED; + + switch (vb->state) { + case VIDEOBUF_PREPARED: + case VIDEOBUF_QUEUED: + case VIDEOBUF_ACTIVE: + b->flags |= V4L2_BUF_FLAG_QUEUED; + break; + case VIDEOBUF_ERROR: + b->flags |= V4L2_BUF_FLAG_ERROR; + /* fall through */ + case VIDEOBUF_DONE: + b->flags |= V4L2_BUF_FLAG_DONE; + break; + case VIDEOBUF_NEEDS_INIT: + case VIDEOBUF_IDLE: + /* nothing */ + break; + } + + b->field = vb->field; + b->timestamp = vb->ts; + b->bytesused = vb->size; + b->sequence = vb->field_count >> 1; +} + +int videobuf_mmap_free(struct videobuf_queue *q) +{ + int ret; + videobuf_queue_lock(q); + ret = __videobuf_free(q); + videobuf_queue_unlock(q); + return ret; +} +EXPORT_SYMBOL_GPL(videobuf_mmap_free); + +/* Locking: Caller holds q->vb_lock */ +int __videobuf_mmap_setup(struct videobuf_queue *q, + unsigned int bcount, unsigned int bsize, + enum v4l2_memory memory) +{ + unsigned int i; + int err; + + MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS); + + err = __videobuf_free(q); + if (0 != err) + return err; + + /* Allocate and initialize buffers */ + for (i = 0; i < bcount; i++) { + q->bufs[i] = videobuf_alloc_vb(q); + + if (NULL == q->bufs[i]) + break; + + q->bufs[i]->i = i; + q->bufs[i]->memory = memory; + q->bufs[i]->bsize = bsize; + switch (memory) { + case V4L2_MEMORY_MMAP: + q->bufs[i]->boff = PAGE_ALIGN(bsize) * i; + break; + case V4L2_MEMORY_USERPTR: + case V4L2_MEMORY_OVERLAY: + /* nothing */ + break; + } + } + + if (!i) + return -ENOMEM; + + dprintk(1, "mmap setup: %d buffers, %d bytes each\n", i, bsize); + + return i; +} +EXPORT_SYMBOL_GPL(__videobuf_mmap_setup); + +int videobuf_mmap_setup(struct videobuf_queue *q, + unsigned int bcount, unsigned int bsize, + enum v4l2_memory memory) +{ + int ret; + videobuf_queue_lock(q); + ret = __videobuf_mmap_setup(q, bcount, bsize, memory); + videobuf_queue_unlock(q); + return ret; +} +EXPORT_SYMBOL_GPL(videobuf_mmap_setup); + +int videobuf_reqbufs(struct videobuf_queue *q, + struct v4l2_requestbuffers *req) +{ + unsigned int size, count; + int retval; + + if (req->count < 1) { + dprintk(1, "reqbufs: count invalid (%d)\n", req->count); + return -EINVAL; + } + + if (req->memory != V4L2_MEMORY_MMAP && + req->memory != V4L2_MEMORY_USERPTR && + req->memory != V4L2_MEMORY_OVERLAY) { + dprintk(1, "reqbufs: memory type invalid\n"); + return -EINVAL; + } + + videobuf_queue_lock(q); + if (req->type != q->type) { + dprintk(1, "reqbufs: queue type invalid\n"); + retval = -EINVAL; + goto done; + } + + if (q->streaming) { + dprintk(1, "reqbufs: streaming already exists\n"); + retval = -EBUSY; + goto done; + } + if (!list_empty(&q->stream)) { + dprintk(1, "reqbufs: stream running\n"); + retval = -EBUSY; + goto done; + } + + count = req->count; + if (count > VIDEO_MAX_FRAME) + count = VIDEO_MAX_FRAME; + size = 0; + q->ops->buf_setup(q, &count, &size); + dprintk(1, "reqbufs: bufs=%d, size=0x%x [%u pages total]\n", + count, size, + (unsigned int)((count * PAGE_ALIGN(size)) >> PAGE_SHIFT)); + + retval = __videobuf_mmap_setup(q, count, size, req->memory); + if (retval < 0) { + dprintk(1, "reqbufs: mmap setup returned %d\n", retval); + goto done; + } + + req->count = retval; + retval = 0; + + done: + videobuf_queue_unlock(q); + return retval; +} +EXPORT_SYMBOL_GPL(videobuf_reqbufs); + +int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b) +{ + int ret = -EINVAL; + + videobuf_queue_lock(q); + if (unlikely(b->type != q->type)) { + dprintk(1, "querybuf: Wrong type.\n"); + goto done; + } + if (unlikely(b->index >= VIDEO_MAX_FRAME)) { + dprintk(1, "querybuf: index out of range.\n"); + goto done; + } + if (unlikely(NULL == q->bufs[b->index])) { + dprintk(1, "querybuf: buffer is null.\n"); + goto done; + } + + videobuf_status(q, b, q->bufs[b->index], q->type); + + ret = 0; +done: + videobuf_queue_unlock(q); + return ret; +} +EXPORT_SYMBOL_GPL(videobuf_querybuf); + +int videobuf_qbuf(struct videobuf_queue *q, struct v4l2_buffer *b) +{ + struct videobuf_buffer *buf; + enum v4l2_field field; + unsigned long flags = 0; + int retval; + + MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS); + + if (b->memory == V4L2_MEMORY_MMAP) + down_read(¤t->mm->mmap_sem); + + videobuf_queue_lock(q); + retval = -EBUSY; + if (q->reading) { + dprintk(1, "qbuf: Reading running...\n"); + goto done; + } + retval = -EINVAL; + if (b->type != q->type) { + dprintk(1, "qbuf: Wrong type.\n"); + goto done; + } + if (b->index >= VIDEO_MAX_FRAME) { + dprintk(1, "qbuf: index out of range.\n"); + goto done; + } + buf = q->bufs[b->index]; + if (NULL == buf) { + dprintk(1, "qbuf: buffer is null.\n"); + goto done; + } + MAGIC_CHECK(buf->magic, MAGIC_BUFFER); + if (buf->memory != b->memory) { + dprintk(1, "qbuf: memory type is wrong.\n"); + goto done; + } + if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) { + dprintk(1, "qbuf: buffer is already queued or active.\n"); + goto done; + } + + switch (b->memory) { + case V4L2_MEMORY_MMAP: + if (0 == buf->baddr) { + dprintk(1, "qbuf: mmap requested " + "but buffer addr is zero!\n"); + goto done; + } + if (q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT + || q->type == V4L2_BUF_TYPE_VBI_OUTPUT + || q->type == V4L2_BUF_TYPE_SLICED_VBI_OUTPUT) { + buf->size = b->bytesused; + buf->field = b->field; + buf->ts = b->timestamp; + } + break; + case V4L2_MEMORY_USERPTR: + if (b->length < buf->bsize) { + dprintk(1, "qbuf: buffer length is not enough\n"); + goto done; + } + if (VIDEOBUF_NEEDS_INIT != buf->state && + buf->baddr != b->m.userptr) + q->ops->buf_release(q, buf); + buf->baddr = b->m.userptr; + break; + case V4L2_MEMORY_OVERLAY: + buf->boff = b->m.offset; + break; + default: + dprintk(1, "qbuf: wrong memory type\n"); + goto done; + } + + dprintk(1, "qbuf: requesting next field\n"); + field = videobuf_next_field(q); + retval = q->ops->buf_prepare(q, buf, field); + if (0 != retval) { + dprintk(1, "qbuf: buffer_prepare returned %d\n", retval); + goto done; + } + + list_add_tail(&buf->stream, &q->stream); + if (q->streaming) { + spin_lock_irqsave(q->irqlock, flags); + q->ops->buf_queue(q, buf); + spin_unlock_irqrestore(q->irqlock, flags); + } + dprintk(1, "qbuf: succeeded\n"); + retval = 0; + wake_up_interruptible_sync(&q->wait); + +done: + videobuf_queue_unlock(q); + + if (b->memory == V4L2_MEMORY_MMAP) + up_read(¤t->mm->mmap_sem); + + return retval; +} +EXPORT_SYMBOL_GPL(videobuf_qbuf); + +/* Locking: Caller holds q->vb_lock */ +static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock) +{ + int retval; + +checks: + if (!q->streaming) { + dprintk(1, "next_buffer: Not streaming\n"); + retval = -EINVAL; + goto done; + } + + if (list_empty(&q->stream)) { + if (noblock) { + retval = -EAGAIN; + dprintk(2, "next_buffer: no buffers to dequeue\n"); + goto done; + } else { + dprintk(2, "next_buffer: waiting on buffer\n"); + + /* Drop lock to avoid deadlock with qbuf */ + videobuf_queue_unlock(q); + + /* Checking list_empty and streaming is safe without + * locks because we goto checks to validate while + * holding locks before proceeding */ + retval = wait_event_interruptible(q->wait, + !list_empty(&q->stream) || !q->streaming); + videobuf_queue_lock(q); + + if (retval) + goto done; + + goto checks; + } + } + + retval = 0; + +done: + return retval; +} + +/* Locking: Caller holds q->vb_lock */ +static int stream_next_buffer(struct videobuf_queue *q, + struct videobuf_buffer **vb, int nonblocking) +{ + int retval; + struct videobuf_buffer *buf = NULL; + + retval = stream_next_buffer_check_queue(q, nonblocking); + if (retval) + goto done; + + buf = list_entry(q->stream.next, struct videobuf_buffer, stream); + retval = videobuf_waiton(q, buf, nonblocking, 1); + if (retval < 0) + goto done; + + *vb = buf; +done: + return retval; +} + +int videobuf_dqbuf(struct videobuf_queue *q, + struct v4l2_buffer *b, int nonblocking) +{ + struct videobuf_buffer *buf = NULL; + int retval; + + MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS); + + memset(b, 0, sizeof(*b)); + videobuf_queue_lock(q); + + retval = stream_next_buffer(q, &buf, nonblocking); + if (retval < 0) { + dprintk(1, "dqbuf: next_buffer error: %i\n", retval); + goto done; + } + + switch (buf->state) { + case VIDEOBUF_ERROR: + dprintk(1, "dqbuf: state is error\n"); + break; + case VIDEOBUF_DONE: + dprintk(1, "dqbuf: state is done\n"); + break; + default: + dprintk(1, "dqbuf: state invalid\n"); + retval = -EINVAL; + goto done; + } + CALL(q, sync, q, buf); + videobuf_status(q, b, buf, q->type); + list_del(&buf->stream); + buf->state = VIDEOBUF_IDLE; + b->flags &= ~V4L2_BUF_FLAG_DONE; +done: + videobuf_queue_unlock(q); + return retval; +} +EXPORT_SYMBOL_GPL(videobuf_dqbuf); + +int videobuf_streamon(struct videobuf_queue *q) +{ + struct videobuf_buffer *buf; + unsigned long flags = 0; + int retval; + + videobuf_queue_lock(q); + retval = -EBUSY; + if (q->reading) + goto done; + retval = 0; + if (q->streaming) + goto done; + q->streaming = 1; + spin_lock_irqsave(q->irqlock, flags); + list_for_each_entry(buf, &q->stream, stream) + if (buf->state == VIDEOBUF_PREPARED) + q->ops->buf_queue(q, buf); + spin_unlock_irqrestore(q->irqlock, flags); + + wake_up_interruptible_sync(&q->wait); +done: + videobuf_queue_unlock(q); + return retval; +} +EXPORT_SYMBOL_GPL(videobuf_streamon); + +/* Locking: Caller holds q->vb_lock */ +static int __videobuf_streamoff(struct videobuf_queue *q) +{ + if (!q->streaming) + return -EINVAL; + + videobuf_queue_cancel(q); + + return 0; +} + +int videobuf_streamoff(struct videobuf_queue *q) +{ + int retval; + + videobuf_queue_lock(q); + retval = __videobuf_streamoff(q); + videobuf_queue_unlock(q); + + return retval; +} +EXPORT_SYMBOL_GPL(videobuf_streamoff); + +/* Locking: Caller holds q->vb_lock */ +static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q, + char __user *data, + size_t count, loff_t *ppos) +{ + enum v4l2_field field; + unsigned long flags = 0; + int retval; + + MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS); + + /* setup stuff */ + q->read_buf = videobuf_alloc_vb(q); + if (NULL == q->read_buf) + return -ENOMEM; + + q->read_buf->memory = V4L2_MEMORY_USERPTR; + q->read_buf->baddr = (unsigned long)data; + q->read_buf->bsize = count; + + field = videobuf_next_field(q); + retval = q->ops->buf_prepare(q, q->read_buf, field); + if (0 != retval) + goto done; + + /* start capture & wait */ + spin_lock_irqsave(q->irqlock, flags); + q->ops->buf_queue(q, q->read_buf); + spin_unlock_irqrestore(q->irqlock, flags); + retval = videobuf_waiton(q, q->read_buf, 0, 0); + if (0 == retval) { + CALL(q, sync, q, q->read_buf); + if (VIDEOBUF_ERROR == q->read_buf->state) + retval = -EIO; + else + retval = q->read_buf->size; + } + +done: + /* cleanup */ + q->ops->buf_release(q, q->read_buf); + kfree(q->read_buf); + q->read_buf = NULL; + return retval; +} + +static int __videobuf_copy_to_user(struct videobuf_queue *q, + struct videobuf_buffer *buf, + char __user *data, size_t count, + int nonblocking) +{ + void *vaddr = CALL(q, vaddr, buf); + + /* copy to userspace */ + if (count > buf->size - q->read_off) + count = buf->size - q->read_off; + + if (copy_to_user(data, vaddr + q->read_off, count)) + return -EFAULT; + + return count; +} + +static int __videobuf_copy_stream(struct videobuf_queue *q, + struct videobuf_buffer *buf, + char __user *data, size_t count, size_t pos, + int vbihack, int nonblocking) +{ + unsigned int *fc = CALL(q, vaddr, buf); + + if (vbihack) { + /* dirty, undocumented hack -- pass the frame counter + * within the last four bytes of each vbi data block. + * We need that one to maintain backward compatibility + * to all vbi decoding software out there ... */ + fc += (buf->size >> 2) - 1; + *fc = buf->field_count >> 1; + dprintk(1, "vbihack: %d\n", *fc); + } + + /* copy stuff using the common method */ + count = __videobuf_copy_to_user(q, buf, data, count, nonblocking); + + if ((count == -EFAULT) && (pos == 0)) + return -EFAULT; + + return count; +} + +ssize_t videobuf_read_one(struct videobuf_queue *q, + char __user *data, size_t count, loff_t *ppos, + int nonblocking) +{ + enum v4l2_field field; + unsigned long flags = 0; + unsigned size = 0, nbufs = 1; + int retval; + + MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS); + + videobuf_queue_lock(q); + + q->ops->buf_setup(q, &nbufs, &size); + + if (NULL == q->read_buf && + count >= size && + !nonblocking) { + retval = videobuf_read_zerocopy(q, data, count, ppos); + if (retval >= 0 || retval == -EIO) + /* ok, all done */ + goto done; + /* fallback to kernel bounce buffer on failures */ + } + + if (NULL == q->read_buf) { + /* need to capture a new frame */ + retval = -ENOMEM; + q->read_buf = videobuf_alloc_vb(q); + + dprintk(1, "video alloc=0x%p\n", q->read_buf); + if (NULL == q->read_buf) + goto done; + q->read_buf->memory = V4L2_MEMORY_USERPTR; + q->read_buf->bsize = count; /* preferred size */ + field = videobuf_next_field(q); + retval = q->ops->buf_prepare(q, q->read_buf, field); + + if (0 != retval) { + kfree(q->read_buf); + q->read_buf = NULL; + goto done; + } + + spin_lock_irqsave(q->irqlock, flags); + q->ops->buf_queue(q, q->read_buf); + spin_unlock_irqrestore(q->irqlock, flags); + + q->read_off = 0; + } + + /* wait until capture is done */ + retval = videobuf_waiton(q, q->read_buf, nonblocking, 1); + if (0 != retval) + goto done; + + CALL(q, sync, q, q->read_buf); + + if (VIDEOBUF_ERROR == q->read_buf->state) { + /* catch I/O errors */ + q->ops->buf_release(q, q->read_buf); + kfree(q->read_buf); + q->read_buf = NULL; + retval = -EIO; + goto done; + } + + /* Copy to userspace */ + retval = __videobuf_copy_to_user(q, q->read_buf, data, count, nonblocking); + if (retval < 0) + goto done; + + q->read_off += retval; + if (q->read_off == q->read_buf->size) { + /* all data copied, cleanup */ + q->ops->buf_release(q, q->read_buf); + kfree(q->read_buf); + q->read_buf = NULL; + } + +done: + videobuf_queue_unlock(q); + return retval; +} +EXPORT_SYMBOL_GPL(videobuf_read_one); + +/* Locking: Caller holds q->vb_lock */ +static int __videobuf_read_start(struct videobuf_queue *q) +{ + enum v4l2_field field; + unsigned long flags = 0; + unsigned int count = 0, size = 0; + int err, i; + + q->ops->buf_setup(q, &count, &size); + if (count < 2) + count = 2; + if (count > VIDEO_MAX_FRAME) + count = VIDEO_MAX_FRAME; + size = PAGE_ALIGN(size); + + err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR); + if (err < 0) + return err; + + count = err; + + for (i = 0; i < count; i++) { + field = videobuf_next_field(q); + err = q->ops->buf_prepare(q, q->bufs[i], field); + if (err) + return err; + list_add_tail(&q->bufs[i]->stream, &q->stream); + } + spin_lock_irqsave(q->irqlock, flags); + for (i = 0; i < count; i++) + q->ops->buf_queue(q, q->bufs[i]); + spin_unlock_irqrestore(q->irqlock, flags); + q->reading = 1; + return 0; +} + +static void __videobuf_read_stop(struct videobuf_queue *q) +{ + int i; + + videobuf_queue_cancel(q); + __videobuf_free(q); + INIT_LIST_HEAD(&q->stream); + for (i = 0; i < VIDEO_MAX_FRAME; i++) { + if (NULL == q->bufs[i]) + continue; + kfree(q->bufs[i]); + q->bufs[i] = NULL; + } + q->read_buf = NULL; +} + +int videobuf_read_start(struct videobuf_queue *q) +{ + int rc; + + videobuf_queue_lock(q); + rc = __videobuf_read_start(q); + videobuf_queue_unlock(q); + + return rc; +} +EXPORT_SYMBOL_GPL(videobuf_read_start); + +void videobuf_read_stop(struct videobuf_queue *q) +{ + videobuf_queue_lock(q); + __videobuf_read_stop(q); + videobuf_queue_unlock(q); +} +EXPORT_SYMBOL_GPL(videobuf_read_stop); + +void videobuf_stop(struct videobuf_queue *q) +{ + videobuf_queue_lock(q); + + if (q->streaming) + __videobuf_streamoff(q); + + if (q->reading) + __videobuf_read_stop(q); + + videobuf_queue_unlock(q); +} +EXPORT_SYMBOL_GPL(videobuf_stop); + +ssize_t videobuf_read_stream(struct videobuf_queue *q, + char __user *data, size_t count, loff_t *ppos, + int vbihack, int nonblocking) +{ + int rc, retval; + unsigned long flags = 0; + + MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS); + + dprintk(2, "%s\n", __func__); + videobuf_queue_lock(q); + retval = -EBUSY; + if (q->streaming) + goto done; + if (!q->reading) { + retval = __videobuf_read_start(q); + if (retval < 0) + goto done; + } + + retval = 0; + while (count > 0) { + /* get / wait for data */ + if (NULL == q->read_buf) { + q->read_buf = list_entry(q->stream.next, + struct videobuf_buffer, + stream); + list_del(&q->read_buf->stream); + q->read_off = 0; + } + rc = videobuf_waiton(q, q->read_buf, nonblocking, 1); + if (rc < 0) { + if (0 == retval) + retval = rc; + break; + } + + if (q->read_buf->state == VIDEOBUF_DONE) { + rc = __videobuf_copy_stream(q, q->read_buf, data + retval, count, + retval, vbihack, nonblocking); + if (rc < 0) { + retval = rc; + break; + } + retval += rc; + count -= rc; + q->read_off += rc; + } else { + /* some error */ + q->read_off = q->read_buf->size; + if (0 == retval) + retval = -EIO; + } + + /* requeue buffer when done with copying */ + if (q->read_off == q->read_buf->size) { + list_add_tail(&q->read_buf->stream, + &q->stream); + spin_lock_irqsave(q->irqlock, flags); + q->ops->buf_queue(q, q->read_buf); + spin_unlock_irqrestore(q->irqlock, flags); + q->read_buf = NULL; + } + if (retval < 0) + break; + } + +done: + videobuf_queue_unlock(q); + return retval; +} +EXPORT_SYMBOL_GPL(videobuf_read_stream); + +unsigned int videobuf_poll_stream(struct file *file, + struct videobuf_queue *q, + poll_table *wait) +{ + unsigned long req_events = poll_requested_events(wait); + struct videobuf_buffer *buf = NULL; + unsigned int rc = 0; + + videobuf_queue_lock(q); + if (q->streaming) { + if (!list_empty(&q->stream)) + buf = list_entry(q->stream.next, + struct videobuf_buffer, stream); + } else if (req_events & (POLLIN | POLLRDNORM)) { + if (!q->reading) + __videobuf_read_start(q); + if (!q->reading) { + rc = POLLERR; + } else if (NULL == q->read_buf) { + q->read_buf = list_entry(q->stream.next, + struct videobuf_buffer, + stream); + list_del(&q->read_buf->stream); + q->read_off = 0; + } + buf = q->read_buf; + } + if (!buf) + rc = POLLERR; + + if (0 == rc) { + poll_wait(file, &buf->done, wait); + if (buf->state == VIDEOBUF_DONE || + buf->state == VIDEOBUF_ERROR) { + switch (q->type) { + case V4L2_BUF_TYPE_VIDEO_OUTPUT: + case V4L2_BUF_TYPE_VBI_OUTPUT: + case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT: + rc = POLLOUT | POLLWRNORM; + break; + default: + rc = POLLIN | POLLRDNORM; + break; + } + } + } + videobuf_queue_unlock(q); + return rc; +} +EXPORT_SYMBOL_GPL(videobuf_poll_stream); + +int videobuf_mmap_mapper(struct videobuf_queue *q, struct vm_area_struct *vma) +{ + int rc = -EINVAL; + int i; + + MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS); + + if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED)) { + dprintk(1, "mmap appl bug: PROT_WRITE and MAP_SHARED are required\n"); + return -EINVAL; + } + + videobuf_queue_lock(q); + for (i = 0; i < VIDEO_MAX_FRAME; i++) { + struct videobuf_buffer *buf = q->bufs[i]; + + if (buf && buf->memory == V4L2_MEMORY_MMAP && + buf->boff == (vma->vm_pgoff << PAGE_SHIFT)) { + rc = CALL(q, mmap_mapper, q, buf, vma); + break; + } + } + videobuf_queue_unlock(q); + + return rc; +} +EXPORT_SYMBOL_GPL(videobuf_mmap_mapper); |