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Pawel Osciake23ccc02010-10-11 10:56:41 -03001/*
2 * videobuf2-core.c - V4L2 driver helper framework
3 *
4 * Copyright (C) 2010 Samsung Electronics
5 *
Pawel Osciak95072082011-03-13 15:23:32 -03006 * Author: Pawel Osciak <pawel@osciak.com>
Pawel Osciake23ccc02010-10-11 10:56:41 -03007 * Marek Szyprowski <m.szyprowski@samsung.com>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation.
12 */
13
14#include <linux/err.h>
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/mm.h>
18#include <linux/poll.h>
19#include <linux/slab.h>
20#include <linux/sched.h>
21
22#include <media/videobuf2-core.h>
23
24static int debug;
25module_param(debug, int, 0644);
26
27#define dprintk(level, fmt, arg...) \
28 do { \
29 if (debug >= level) \
30 printk(KERN_DEBUG "vb2: " fmt, ## arg); \
31 } while (0)
32
33#define call_memop(q, plane, op, args...) \
34 (((q)->mem_ops->op) ? \
35 ((q)->mem_ops->op(args)) : 0)
36
37#define call_qop(q, op, args...) \
38 (((q)->ops->op) ? ((q)->ops->op(args)) : 0)
39
Marek Szyprowskiea42c8e2011-04-12 10:14:13 -030040#define V4L2_BUFFER_STATE_FLAGS (V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -030041 V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \
42 V4L2_BUF_FLAG_PREPARED)
Marek Szyprowskiea42c8e2011-04-12 10:14:13 -030043
Pawel Osciake23ccc02010-10-11 10:56:41 -030044/**
45 * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
46 */
Marek Szyprowskic1426bc2011-08-24 06:36:26 -030047static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
Pawel Osciake23ccc02010-10-11 10:56:41 -030048{
49 struct vb2_queue *q = vb->vb2_queue;
50 void *mem_priv;
51 int plane;
52
53 /* Allocate memory for all planes in this buffer */
54 for (plane = 0; plane < vb->num_planes; ++plane) {
55 mem_priv = call_memop(q, plane, alloc, q->alloc_ctx[plane],
Marek Szyprowskic1426bc2011-08-24 06:36:26 -030056 q->plane_sizes[plane]);
Guennadi Liakhovetski62a79432011-03-22 09:24:58 -030057 if (IS_ERR_OR_NULL(mem_priv))
Pawel Osciake23ccc02010-10-11 10:56:41 -030058 goto free;
59
60 /* Associate allocator private data with this plane */
61 vb->planes[plane].mem_priv = mem_priv;
Marek Szyprowskic1426bc2011-08-24 06:36:26 -030062 vb->v4l2_planes[plane].length = q->plane_sizes[plane];
Pawel Osciake23ccc02010-10-11 10:56:41 -030063 }
64
65 return 0;
66free:
67 /* Free already allocated memory if one of the allocations failed */
68 for (; plane > 0; --plane)
69 call_memop(q, plane, put, vb->planes[plane - 1].mem_priv);
70
71 return -ENOMEM;
72}
73
74/**
75 * __vb2_buf_mem_free() - free memory of the given buffer
76 */
77static void __vb2_buf_mem_free(struct vb2_buffer *vb)
78{
79 struct vb2_queue *q = vb->vb2_queue;
80 unsigned int plane;
81
82 for (plane = 0; plane < vb->num_planes; ++plane) {
83 call_memop(q, plane, put, vb->planes[plane].mem_priv);
84 vb->planes[plane].mem_priv = NULL;
85 dprintk(3, "Freed plane %d of buffer %d\n",
86 plane, vb->v4l2_buf.index);
87 }
88}
89
90/**
91 * __vb2_buf_userptr_put() - release userspace memory associated with
92 * a USERPTR buffer
93 */
94static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
95{
96 struct vb2_queue *q = vb->vb2_queue;
97 unsigned int plane;
98
99 for (plane = 0; plane < vb->num_planes; ++plane) {
100 void *mem_priv = vb->planes[plane].mem_priv;
101
102 if (mem_priv) {
103 call_memop(q, plane, put_userptr, mem_priv);
104 vb->planes[plane].mem_priv = NULL;
105 }
106 }
107}
108
109/**
110 * __setup_offsets() - setup unique offsets ("cookies") for every plane in
111 * every buffer on the queue
112 */
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300113static void __setup_offsets(struct vb2_queue *q, unsigned int n)
Pawel Osciake23ccc02010-10-11 10:56:41 -0300114{
115 unsigned int buffer, plane;
116 struct vb2_buffer *vb;
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300117 unsigned long off;
Pawel Osciake23ccc02010-10-11 10:56:41 -0300118
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300119 if (q->num_buffers) {
120 struct v4l2_plane *p;
121 vb = q->bufs[q->num_buffers - 1];
122 p = &vb->v4l2_planes[vb->num_planes - 1];
123 off = PAGE_ALIGN(p->m.mem_offset + p->length);
124 } else {
125 off = 0;
126 }
127
128 for (buffer = q->num_buffers; buffer < q->num_buffers + n; ++buffer) {
Pawel Osciake23ccc02010-10-11 10:56:41 -0300129 vb = q->bufs[buffer];
130 if (!vb)
131 continue;
132
133 for (plane = 0; plane < vb->num_planes; ++plane) {
Marek Szyprowski49076022011-10-13 07:07:24 -0300134 vb->v4l2_planes[plane].length = q->plane_sizes[plane];
Pawel Osciake23ccc02010-10-11 10:56:41 -0300135 vb->v4l2_planes[plane].m.mem_offset = off;
136
137 dprintk(3, "Buffer %d, plane %d offset 0x%08lx\n",
138 buffer, plane, off);
139
140 off += vb->v4l2_planes[plane].length;
141 off = PAGE_ALIGN(off);
142 }
143 }
144}
145
146/**
147 * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
148 * video buffer memory for all buffers/planes on the queue and initializes the
149 * queue
150 *
151 * Returns the number of buffers successfully allocated.
152 */
153static int __vb2_queue_alloc(struct vb2_queue *q, enum v4l2_memory memory,
Marek Szyprowskic1426bc2011-08-24 06:36:26 -0300154 unsigned int num_buffers, unsigned int num_planes)
Pawel Osciake23ccc02010-10-11 10:56:41 -0300155{
156 unsigned int buffer;
157 struct vb2_buffer *vb;
158 int ret;
159
160 for (buffer = 0; buffer < num_buffers; ++buffer) {
161 /* Allocate videobuf buffer structures */
162 vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
163 if (!vb) {
164 dprintk(1, "Memory alloc for buffer struct failed\n");
165 break;
166 }
167
168 /* Length stores number of planes for multiplanar buffers */
169 if (V4L2_TYPE_IS_MULTIPLANAR(q->type))
170 vb->v4l2_buf.length = num_planes;
171
172 vb->state = VB2_BUF_STATE_DEQUEUED;
173 vb->vb2_queue = q;
174 vb->num_planes = num_planes;
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300175 vb->v4l2_buf.index = q->num_buffers + buffer;
Pawel Osciake23ccc02010-10-11 10:56:41 -0300176 vb->v4l2_buf.type = q->type;
177 vb->v4l2_buf.memory = memory;
178
179 /* Allocate video buffer memory for the MMAP type */
180 if (memory == V4L2_MEMORY_MMAP) {
Marek Szyprowskic1426bc2011-08-24 06:36:26 -0300181 ret = __vb2_buf_mem_alloc(vb);
Pawel Osciake23ccc02010-10-11 10:56:41 -0300182 if (ret) {
183 dprintk(1, "Failed allocating memory for "
184 "buffer %d\n", buffer);
185 kfree(vb);
186 break;
187 }
188 /*
189 * Call the driver-provided buffer initialization
190 * callback, if given. An error in initialization
191 * results in queue setup failure.
192 */
193 ret = call_qop(q, buf_init, vb);
194 if (ret) {
195 dprintk(1, "Buffer %d %p initialization"
196 " failed\n", buffer, vb);
197 __vb2_buf_mem_free(vb);
198 kfree(vb);
199 break;
200 }
201 }
202
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300203 q->bufs[q->num_buffers + buffer] = vb;
Pawel Osciake23ccc02010-10-11 10:56:41 -0300204 }
205
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300206 __setup_offsets(q, buffer);
Pawel Osciake23ccc02010-10-11 10:56:41 -0300207
208 dprintk(1, "Allocated %d buffers, %d plane(s) each\n",
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300209 buffer, num_planes);
Pawel Osciake23ccc02010-10-11 10:56:41 -0300210
211 return buffer;
212}
213
214/**
215 * __vb2_free_mem() - release all video buffer memory for a given queue
216 */
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300217static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
Pawel Osciake23ccc02010-10-11 10:56:41 -0300218{
219 unsigned int buffer;
220 struct vb2_buffer *vb;
221
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300222 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
223 ++buffer) {
Pawel Osciake23ccc02010-10-11 10:56:41 -0300224 vb = q->bufs[buffer];
225 if (!vb)
226 continue;
227
228 /* Free MMAP buffers or release USERPTR buffers */
229 if (q->memory == V4L2_MEMORY_MMAP)
230 __vb2_buf_mem_free(vb);
231 else
232 __vb2_buf_userptr_put(vb);
233 }
234}
235
236/**
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300237 * __vb2_queue_free() - free buffers at the end of the queue - video memory and
238 * related information, if no buffers are left return the queue to an
239 * uninitialized state. Might be called even if the queue has already been freed.
Pawel Osciake23ccc02010-10-11 10:56:41 -0300240 */
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300241static void __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
Pawel Osciake23ccc02010-10-11 10:56:41 -0300242{
243 unsigned int buffer;
244
245 /* Call driver-provided cleanup function for each buffer, if provided */
246 if (q->ops->buf_cleanup) {
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300247 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
248 ++buffer) {
Pawel Osciake23ccc02010-10-11 10:56:41 -0300249 if (NULL == q->bufs[buffer])
250 continue;
251 q->ops->buf_cleanup(q->bufs[buffer]);
252 }
253 }
254
255 /* Release video buffer memory */
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300256 __vb2_free_mem(q, buffers);
Pawel Osciake23ccc02010-10-11 10:56:41 -0300257
258 /* Free videobuf buffers */
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300259 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
260 ++buffer) {
Pawel Osciake23ccc02010-10-11 10:56:41 -0300261 kfree(q->bufs[buffer]);
262 q->bufs[buffer] = NULL;
263 }
264
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300265 q->num_buffers -= buffers;
266 if (!q->num_buffers)
267 q->memory = 0;
Marek Szyprowskibd50d992011-10-25 03:07:59 -0300268 INIT_LIST_HEAD(&q->queued_list);
Pawel Osciake23ccc02010-10-11 10:56:41 -0300269}
270
271/**
272 * __verify_planes_array() - verify that the planes array passed in struct
273 * v4l2_buffer from userspace can be safely used
274 */
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300275static int __verify_planes_array(struct vb2_buffer *vb, const struct v4l2_buffer *b)
Pawel Osciake23ccc02010-10-11 10:56:41 -0300276{
277 /* Is memory for copying plane information present? */
278 if (NULL == b->m.planes) {
279 dprintk(1, "Multi-planar buffer passed but "
280 "planes array not provided\n");
281 return -EINVAL;
282 }
283
284 if (b->length < vb->num_planes || b->length > VIDEO_MAX_PLANES) {
285 dprintk(1, "Incorrect planes array length, "
286 "expected %d, got %d\n", vb->num_planes, b->length);
287 return -EINVAL;
288 }
289
290 return 0;
291}
292
293/**
Marek Szyprowski25a27d92011-08-24 06:49:35 -0300294 * __buffer_in_use() - return true if the buffer is in use and
295 * the queue cannot be freed (by the means of REQBUFS(0)) call
296 */
297static bool __buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
298{
299 unsigned int plane;
300 for (plane = 0; plane < vb->num_planes; ++plane) {
Marek Szyprowski2c2dd6ac2011-10-12 13:09:53 -0300301 void *mem_priv = vb->planes[plane].mem_priv;
Marek Szyprowski25a27d92011-08-24 06:49:35 -0300302 /*
303 * If num_users() has not been provided, call_memop
304 * will return 0, apparently nobody cares about this
305 * case anyway. If num_users() returns more than 1,
306 * we are not the only user of the plane's memory.
307 */
Marek Szyprowski2c2dd6ac2011-10-12 13:09:53 -0300308 if (mem_priv && call_memop(q, plane, num_users, mem_priv) > 1)
Marek Szyprowski25a27d92011-08-24 06:49:35 -0300309 return true;
310 }
311 return false;
312}
313
314/**
315 * __buffers_in_use() - return true if any buffers on the queue are in use and
316 * the queue cannot be freed (by the means of REQBUFS(0)) call
317 */
318static bool __buffers_in_use(struct vb2_queue *q)
319{
320 unsigned int buffer;
321 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
322 if (__buffer_in_use(q, q->bufs[buffer]))
323 return true;
324 }
325 return false;
326}
327
328/**
Pawel Osciake23ccc02010-10-11 10:56:41 -0300329 * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
330 * returned to userspace
331 */
332static int __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
333{
334 struct vb2_queue *q = vb->vb2_queue;
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300335 int ret;
Pawel Osciake23ccc02010-10-11 10:56:41 -0300336
Marek Szyprowskiea42c8e2011-04-12 10:14:13 -0300337 /* Copy back data such as timestamp, flags, input, etc. */
Pawel Osciake23ccc02010-10-11 10:56:41 -0300338 memcpy(b, &vb->v4l2_buf, offsetof(struct v4l2_buffer, m));
339 b->input = vb->v4l2_buf.input;
340 b->reserved = vb->v4l2_buf.reserved;
341
342 if (V4L2_TYPE_IS_MULTIPLANAR(q->type)) {
343 ret = __verify_planes_array(vb, b);
344 if (ret)
345 return ret;
346
347 /*
348 * Fill in plane-related data if userspace provided an array
349 * for it. The memory and size is verified above.
350 */
351 memcpy(b->m.planes, vb->v4l2_planes,
352 b->length * sizeof(struct v4l2_plane));
353 } else {
354 /*
355 * We use length and offset in v4l2_planes array even for
356 * single-planar buffers, but userspace does not.
357 */
358 b->length = vb->v4l2_planes[0].length;
359 b->bytesused = vb->v4l2_planes[0].bytesused;
360 if (q->memory == V4L2_MEMORY_MMAP)
361 b->m.offset = vb->v4l2_planes[0].m.mem_offset;
362 else if (q->memory == V4L2_MEMORY_USERPTR)
363 b->m.userptr = vb->v4l2_planes[0].m.userptr;
364 }
365
Marek Szyprowskiea42c8e2011-04-12 10:14:13 -0300366 /*
367 * Clear any buffer state related flags.
368 */
369 b->flags &= ~V4L2_BUFFER_STATE_FLAGS;
Pawel Osciake23ccc02010-10-11 10:56:41 -0300370
371 switch (vb->state) {
372 case VB2_BUF_STATE_QUEUED:
373 case VB2_BUF_STATE_ACTIVE:
374 b->flags |= V4L2_BUF_FLAG_QUEUED;
375 break;
376 case VB2_BUF_STATE_ERROR:
377 b->flags |= V4L2_BUF_FLAG_ERROR;
378 /* fall through */
379 case VB2_BUF_STATE_DONE:
380 b->flags |= V4L2_BUF_FLAG_DONE;
381 break;
Guennadi Liakhovetskiebc087d2011-08-31 06:51:10 -0300382 case VB2_BUF_STATE_PREPARED:
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300383 b->flags |= V4L2_BUF_FLAG_PREPARED;
384 break;
385 case VB2_BUF_STATE_DEQUEUED:
Pawel Osciake23ccc02010-10-11 10:56:41 -0300386 /* nothing */
387 break;
388 }
389
Marek Szyprowski25a27d92011-08-24 06:49:35 -0300390 if (__buffer_in_use(q, vb))
Pawel Osciake23ccc02010-10-11 10:56:41 -0300391 b->flags |= V4L2_BUF_FLAG_MAPPED;
392
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300393 return 0;
Pawel Osciake23ccc02010-10-11 10:56:41 -0300394}
395
396/**
397 * vb2_querybuf() - query video buffer information
398 * @q: videobuf queue
399 * @b: buffer struct passed from userspace to vidioc_querybuf handler
400 * in driver
401 *
402 * Should be called from vidioc_querybuf ioctl handler in driver.
403 * This function will verify the passed v4l2_buffer structure and fill the
404 * relevant information for the userspace.
405 *
406 * The return values from this function are intended to be directly returned
407 * from vidioc_querybuf handler in driver.
408 */
409int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
410{
411 struct vb2_buffer *vb;
412
413 if (b->type != q->type) {
414 dprintk(1, "querybuf: wrong buffer type\n");
415 return -EINVAL;
416 }
417
418 if (b->index >= q->num_buffers) {
419 dprintk(1, "querybuf: buffer index out of range\n");
420 return -EINVAL;
421 }
422 vb = q->bufs[b->index];
423
424 return __fill_v4l2_buffer(vb, b);
425}
426EXPORT_SYMBOL(vb2_querybuf);
427
428/**
429 * __verify_userptr_ops() - verify that all memory operations required for
430 * USERPTR queue type have been provided
431 */
432static int __verify_userptr_ops(struct vb2_queue *q)
433{
434 if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
435 !q->mem_ops->put_userptr)
436 return -EINVAL;
437
438 return 0;
439}
440
441/**
442 * __verify_mmap_ops() - verify that all memory operations required for
443 * MMAP queue type have been provided
444 */
445static int __verify_mmap_ops(struct vb2_queue *q)
446{
447 if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
448 !q->mem_ops->put || !q->mem_ops->mmap)
449 return -EINVAL;
450
451 return 0;
452}
453
454/**
Pawel Osciake23ccc02010-10-11 10:56:41 -0300455 * vb2_reqbufs() - Initiate streaming
456 * @q: videobuf2 queue
457 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
458 *
459 * Should be called from vidioc_reqbufs ioctl handler of a driver.
460 * This function:
461 * 1) verifies streaming parameters passed from the userspace,
462 * 2) sets up the queue,
463 * 3) negotiates number of buffers and planes per buffer with the driver
464 * to be used during streaming,
465 * 4) allocates internal buffer structures (struct vb2_buffer), according to
466 * the agreed parameters,
467 * 5) for MMAP memory type, allocates actual video memory, using the
468 * memory handling/allocation routines provided during queue initialization
469 *
470 * If req->count is 0, all the memory will be freed instead.
471 * If the queue has been allocated previously (by a previous vb2_reqbufs) call
472 * and the queue is not busy, memory will be reallocated.
473 *
474 * The return values from this function are intended to be directly returned
475 * from vidioc_reqbufs handler in driver.
476 */
477int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
478{
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300479 unsigned int num_buffers, allocated_buffers, num_planes = 0;
Pawel Osciake23ccc02010-10-11 10:56:41 -0300480 int ret = 0;
481
Marek Szyprowskib25748f2010-12-06 05:56:55 -0300482 if (q->fileio) {
483 dprintk(1, "reqbufs: file io in progress\n");
484 return -EBUSY;
485 }
486
Pawel Osciake23ccc02010-10-11 10:56:41 -0300487 if (req->memory != V4L2_MEMORY_MMAP
488 && req->memory != V4L2_MEMORY_USERPTR) {
489 dprintk(1, "reqbufs: unsupported memory type\n");
490 return -EINVAL;
491 }
492
493 if (req->type != q->type) {
494 dprintk(1, "reqbufs: requested type is incorrect\n");
495 return -EINVAL;
496 }
497
498 if (q->streaming) {
499 dprintk(1, "reqbufs: streaming active\n");
500 return -EBUSY;
501 }
502
503 /*
504 * Make sure all the required memory ops for given memory type
505 * are available.
506 */
507 if (req->memory == V4L2_MEMORY_MMAP && __verify_mmap_ops(q)) {
508 dprintk(1, "reqbufs: MMAP for current setup unsupported\n");
509 return -EINVAL;
510 }
511
512 if (req->memory == V4L2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
513 dprintk(1, "reqbufs: USERPTR for current setup unsupported\n");
514 return -EINVAL;
515 }
516
Marek Szyprowski29e3fbd2011-03-09 14:03:24 -0300517 if (req->count == 0 || q->num_buffers != 0 || q->memory != req->memory) {
Pawel Osciake23ccc02010-10-11 10:56:41 -0300518 /*
519 * We already have buffers allocated, so first check if they
520 * are not in use and can be freed.
521 */
522 if (q->memory == V4L2_MEMORY_MMAP && __buffers_in_use(q)) {
523 dprintk(1, "reqbufs: memory in use, cannot free\n");
524 return -EBUSY;
525 }
526
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300527 __vb2_queue_free(q, q->num_buffers);
Marek Szyprowski29e3fbd2011-03-09 14:03:24 -0300528
529 /*
530 * In case of REQBUFS(0) return immediately without calling
531 * driver's queue_setup() callback and allocating resources.
532 */
533 if (req->count == 0)
534 return 0;
Pawel Osciake23ccc02010-10-11 10:56:41 -0300535 }
536
537 /*
538 * Make sure the requested values and current defaults are sane.
539 */
540 num_buffers = min_t(unsigned int, req->count, VIDEO_MAX_FRAME);
Marek Szyprowskic1426bc2011-08-24 06:36:26 -0300541 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
Pawel Osciake23ccc02010-10-11 10:56:41 -0300542 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
Marek Szyprowski13b14092011-04-14 07:17:44 -0300543 q->memory = req->memory;
Pawel Osciake23ccc02010-10-11 10:56:41 -0300544
545 /*
546 * Ask the driver how many buffers and planes per buffer it requires.
547 * Driver also sets the size and allocator context for each plane.
548 */
Guennadi Liakhovetskifc714e72011-08-24 10:30:21 -0300549 ret = call_qop(q, queue_setup, q, NULL, &num_buffers, &num_planes,
Marek Szyprowskic1426bc2011-08-24 06:36:26 -0300550 q->plane_sizes, q->alloc_ctx);
Pawel Osciake23ccc02010-10-11 10:56:41 -0300551 if (ret)
552 return ret;
553
554 /* Finally, allocate buffers and video memory */
Marek Szyprowskic1426bc2011-08-24 06:36:26 -0300555 ret = __vb2_queue_alloc(q, req->memory, num_buffers, num_planes);
Marek Szyprowski66072d42011-06-28 08:29:02 -0300556 if (ret == 0) {
557 dprintk(1, "Memory allocation failed\n");
558 return -ENOMEM;
Pawel Osciake23ccc02010-10-11 10:56:41 -0300559 }
560
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300561 allocated_buffers = ret;
562
Pawel Osciake23ccc02010-10-11 10:56:41 -0300563 /*
564 * Check if driver can handle the allocated number of buffers.
565 */
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300566 if (allocated_buffers < num_buffers) {
567 num_buffers = allocated_buffers;
Pawel Osciake23ccc02010-10-11 10:56:41 -0300568
Guennadi Liakhovetskifc714e72011-08-24 10:30:21 -0300569 ret = call_qop(q, queue_setup, q, NULL, &num_buffers,
570 &num_planes, q->plane_sizes, q->alloc_ctx);
Pawel Osciake23ccc02010-10-11 10:56:41 -0300571
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300572 if (!ret && allocated_buffers < num_buffers)
Pawel Osciake23ccc02010-10-11 10:56:41 -0300573 ret = -ENOMEM;
Pawel Osciake23ccc02010-10-11 10:56:41 -0300574
575 /*
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300576 * Either the driver has accepted a smaller number of buffers,
577 * or .queue_setup() returned an error
Pawel Osciake23ccc02010-10-11 10:56:41 -0300578 */
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300579 }
580
581 q->num_buffers = allocated_buffers;
582
583 if (ret < 0) {
584 __vb2_queue_free(q, allocated_buffers);
585 return ret;
Pawel Osciake23ccc02010-10-11 10:56:41 -0300586 }
587
Pawel Osciake23ccc02010-10-11 10:56:41 -0300588 /*
589 * Return the number of successfully allocated buffers
590 * to the userspace.
591 */
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300592 req->count = allocated_buffers;
Pawel Osciake23ccc02010-10-11 10:56:41 -0300593
594 return 0;
Pawel Osciake23ccc02010-10-11 10:56:41 -0300595}
596EXPORT_SYMBOL_GPL(vb2_reqbufs);
597
598/**
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300599 * vb2_create_bufs() - Allocate buffers and any required auxiliary structs
600 * @q: videobuf2 queue
601 * @create: creation parameters, passed from userspace to vidioc_create_bufs
602 * handler in driver
603 *
604 * Should be called from vidioc_create_bufs ioctl handler of a driver.
605 * This function:
606 * 1) verifies parameter sanity
607 * 2) calls the .queue_setup() queue operation
608 * 3) performs any necessary memory allocations
609 *
610 * The return values from this function are intended to be directly returned
611 * from vidioc_create_bufs handler in driver.
612 */
613int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
614{
615 unsigned int num_planes = 0, num_buffers, allocated_buffers;
616 int ret = 0;
617
618 if (q->fileio) {
619 dprintk(1, "%s(): file io in progress\n", __func__);
620 return -EBUSY;
621 }
622
623 if (create->memory != V4L2_MEMORY_MMAP
624 && create->memory != V4L2_MEMORY_USERPTR) {
625 dprintk(1, "%s(): unsupported memory type\n", __func__);
626 return -EINVAL;
627 }
628
629 if (create->format.type != q->type) {
630 dprintk(1, "%s(): requested type is incorrect\n", __func__);
631 return -EINVAL;
632 }
633
634 /*
635 * Make sure all the required memory ops for given memory type
636 * are available.
637 */
638 if (create->memory == V4L2_MEMORY_MMAP && __verify_mmap_ops(q)) {
639 dprintk(1, "%s(): MMAP for current setup unsupported\n", __func__);
640 return -EINVAL;
641 }
642
643 if (create->memory == V4L2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
644 dprintk(1, "%s(): USERPTR for current setup unsupported\n", __func__);
645 return -EINVAL;
646 }
647
648 if (q->num_buffers == VIDEO_MAX_FRAME) {
649 dprintk(1, "%s(): maximum number of buffers already allocated\n",
650 __func__);
651 return -ENOBUFS;
652 }
653
654 create->index = q->num_buffers;
655
656 if (!q->num_buffers) {
657 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
658 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
659 q->memory = create->memory;
660 }
661
662 num_buffers = min(create->count, VIDEO_MAX_FRAME - q->num_buffers);
663
664 /*
665 * Ask the driver, whether the requested number of buffers, planes per
666 * buffer and their sizes are acceptable
667 */
668 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
669 &num_planes, q->plane_sizes, q->alloc_ctx);
670 if (ret)
671 return ret;
672
673 /* Finally, allocate buffers and video memory */
674 ret = __vb2_queue_alloc(q, create->memory, num_buffers,
675 num_planes);
676 if (ret < 0) {
677 dprintk(1, "Memory allocation failed with error: %d\n", ret);
678 return ret;
679 }
680
681 allocated_buffers = ret;
682
683 /*
684 * Check if driver can handle the so far allocated number of buffers.
685 */
686 if (ret < num_buffers) {
687 num_buffers = ret;
688
689 /*
690 * q->num_buffers contains the total number of buffers, that the
691 * queue driver has set up
692 */
693 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
694 &num_planes, q->plane_sizes, q->alloc_ctx);
695
696 if (!ret && allocated_buffers < num_buffers)
697 ret = -ENOMEM;
698
699 /*
700 * Either the driver has accepted a smaller number of buffers,
701 * or .queue_setup() returned an error
702 */
703 }
704
705 q->num_buffers += allocated_buffers;
706
707 if (ret < 0) {
708 __vb2_queue_free(q, allocated_buffers);
709 return ret;
710 }
711
712 /*
713 * Return the number of successfully allocated buffers
714 * to the userspace.
715 */
716 create->count = allocated_buffers;
717
718 return 0;
719}
720EXPORT_SYMBOL_GPL(vb2_create_bufs);
721
722/**
Pawel Osciake23ccc02010-10-11 10:56:41 -0300723 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
724 * @vb: vb2_buffer to which the plane in question belongs to
725 * @plane_no: plane number for which the address is to be returned
726 *
727 * This function returns a kernel virtual address of a given plane if
728 * such a mapping exist, NULL otherwise.
729 */
730void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
731{
732 struct vb2_queue *q = vb->vb2_queue;
733
734 if (plane_no > vb->num_planes)
735 return NULL;
736
737 return call_memop(q, plane_no, vaddr, vb->planes[plane_no].mem_priv);
738
739}
740EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
741
742/**
743 * vb2_plane_cookie() - Return allocator specific cookie for the given plane
744 * @vb: vb2_buffer to which the plane in question belongs to
745 * @plane_no: plane number for which the cookie is to be returned
746 *
747 * This function returns an allocator specific cookie for a given plane if
748 * available, NULL otherwise. The allocator should provide some simple static
749 * inline function, which would convert this cookie to the allocator specific
750 * type that can be used directly by the driver to access the buffer. This can
751 * be for example physical address, pointer to scatter list or IOMMU mapping.
752 */
753void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
754{
755 struct vb2_queue *q = vb->vb2_queue;
756
757 if (plane_no > vb->num_planes)
758 return NULL;
759
760 return call_memop(q, plane_no, cookie, vb->planes[plane_no].mem_priv);
761}
762EXPORT_SYMBOL_GPL(vb2_plane_cookie);
763
764/**
765 * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
766 * @vb: vb2_buffer returned from the driver
767 * @state: either VB2_BUF_STATE_DONE if the operation finished successfully
768 * or VB2_BUF_STATE_ERROR if the operation finished with an error
769 *
770 * This function should be called by the driver after a hardware operation on
771 * a buffer is finished and the buffer may be returned to userspace. The driver
772 * cannot use this buffer anymore until it is queued back to it by videobuf
773 * by the means of buf_queue callback. Only buffers previously queued to the
774 * driver by buf_queue can be passed to this function.
775 */
776void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
777{
778 struct vb2_queue *q = vb->vb2_queue;
779 unsigned long flags;
780
781 if (vb->state != VB2_BUF_STATE_ACTIVE)
782 return;
783
784 if (state != VB2_BUF_STATE_DONE && state != VB2_BUF_STATE_ERROR)
785 return;
786
787 dprintk(4, "Done processing on buffer %d, state: %d\n",
788 vb->v4l2_buf.index, vb->state);
789
790 /* Add the buffer to the done buffers list */
791 spin_lock_irqsave(&q->done_lock, flags);
792 vb->state = state;
793 list_add_tail(&vb->done_entry, &q->done_list);
794 atomic_dec(&q->queued_count);
795 spin_unlock_irqrestore(&q->done_lock, flags);
796
797 /* Inform any processes that may be waiting for buffers */
798 wake_up(&q->done_wq);
799}
800EXPORT_SYMBOL_GPL(vb2_buffer_done);
801
802/**
803 * __fill_vb2_buffer() - fill a vb2_buffer with information provided in
804 * a v4l2_buffer by the userspace
805 */
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300806static int __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b,
Pawel Osciake23ccc02010-10-11 10:56:41 -0300807 struct v4l2_plane *v4l2_planes)
808{
809 unsigned int plane;
810 int ret;
811
812 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
813 /*
814 * Verify that the userspace gave us a valid array for
815 * plane information.
816 */
817 ret = __verify_planes_array(vb, b);
818 if (ret)
819 return ret;
820
821 /* Fill in driver-provided information for OUTPUT types */
822 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
823 /*
824 * Will have to go up to b->length when API starts
825 * accepting variable number of planes.
826 */
827 for (plane = 0; plane < vb->num_planes; ++plane) {
828 v4l2_planes[plane].bytesused =
829 b->m.planes[plane].bytesused;
830 v4l2_planes[plane].data_offset =
831 b->m.planes[plane].data_offset;
832 }
833 }
834
835 if (b->memory == V4L2_MEMORY_USERPTR) {
836 for (plane = 0; plane < vb->num_planes; ++plane) {
837 v4l2_planes[plane].m.userptr =
838 b->m.planes[plane].m.userptr;
839 v4l2_planes[plane].length =
840 b->m.planes[plane].length;
841 }
842 }
843 } else {
844 /*
845 * Single-planar buffers do not use planes array,
846 * so fill in relevant v4l2_buffer struct fields instead.
847 * In videobuf we use our internal V4l2_planes struct for
848 * single-planar buffers as well, for simplicity.
849 */
850 if (V4L2_TYPE_IS_OUTPUT(b->type))
851 v4l2_planes[0].bytesused = b->bytesused;
852
853 if (b->memory == V4L2_MEMORY_USERPTR) {
854 v4l2_planes[0].m.userptr = b->m.userptr;
855 v4l2_planes[0].length = b->length;
856 }
857 }
858
859 vb->v4l2_buf.field = b->field;
860 vb->v4l2_buf.timestamp = b->timestamp;
Marek Szyprowskiea42c8e2011-04-12 10:14:13 -0300861 vb->v4l2_buf.input = b->input;
862 vb->v4l2_buf.flags = b->flags & ~V4L2_BUFFER_STATE_FLAGS;
Pawel Osciake23ccc02010-10-11 10:56:41 -0300863
864 return 0;
865}
866
867/**
868 * __qbuf_userptr() - handle qbuf of a USERPTR buffer
869 */
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300870static int __qbuf_userptr(struct vb2_buffer *vb, const struct v4l2_buffer *b)
Pawel Osciake23ccc02010-10-11 10:56:41 -0300871{
872 struct v4l2_plane planes[VIDEO_MAX_PLANES];
873 struct vb2_queue *q = vb->vb2_queue;
874 void *mem_priv;
875 unsigned int plane;
876 int ret;
877 int write = !V4L2_TYPE_IS_OUTPUT(q->type);
878
879 /* Verify and copy relevant information provided by the userspace */
880 ret = __fill_vb2_buffer(vb, b, planes);
881 if (ret)
882 return ret;
883
884 for (plane = 0; plane < vb->num_planes; ++plane) {
885 /* Skip the plane if already verified */
Marek Szyprowskif0b7c7f2011-11-16 15:09:40 -0300886 if (vb->v4l2_planes[plane].m.userptr &&
887 vb->v4l2_planes[plane].m.userptr == planes[plane].m.userptr
Pawel Osciake23ccc02010-10-11 10:56:41 -0300888 && vb->v4l2_planes[plane].length == planes[plane].length)
889 continue;
890
891 dprintk(3, "qbuf: userspace address for plane %d changed, "
892 "reacquiring memory\n", plane);
893
Marek Szyprowskic1426bc2011-08-24 06:36:26 -0300894 /* Check if the provided plane buffer is large enough */
895 if (planes[plane].length < q->plane_sizes[plane]) {
Marek Szyprowski4c2625d2011-10-03 03:21:45 -0300896 ret = -EINVAL;
Marek Szyprowskic1426bc2011-08-24 06:36:26 -0300897 goto err;
898 }
899
Pawel Osciake23ccc02010-10-11 10:56:41 -0300900 /* Release previously acquired memory if present */
901 if (vb->planes[plane].mem_priv)
902 call_memop(q, plane, put_userptr,
903 vb->planes[plane].mem_priv);
904
905 vb->planes[plane].mem_priv = NULL;
Marek Szyprowskic1426bc2011-08-24 06:36:26 -0300906 vb->v4l2_planes[plane].m.userptr = 0;
907 vb->v4l2_planes[plane].length = 0;
Pawel Osciake23ccc02010-10-11 10:56:41 -0300908
909 /* Acquire each plane's memory */
910 if (q->mem_ops->get_userptr) {
911 mem_priv = q->mem_ops->get_userptr(q->alloc_ctx[plane],
912 planes[plane].m.userptr,
913 planes[plane].length,
914 write);
915 if (IS_ERR(mem_priv)) {
916 dprintk(1, "qbuf: failed acquiring userspace "
917 "memory for plane %d\n", plane);
918 ret = PTR_ERR(mem_priv);
919 goto err;
920 }
921 vb->planes[plane].mem_priv = mem_priv;
922 }
923 }
924
925 /*
926 * Call driver-specific initialization on the newly acquired buffer,
927 * if provided.
928 */
929 ret = call_qop(q, buf_init, vb);
930 if (ret) {
931 dprintk(1, "qbuf: buffer initialization failed\n");
932 goto err;
933 }
934
935 /*
936 * Now that everything is in order, copy relevant information
937 * provided by userspace.
938 */
939 for (plane = 0; plane < vb->num_planes; ++plane)
940 vb->v4l2_planes[plane] = planes[plane];
941
942 return 0;
943err:
944 /* In case of errors, release planes that were already acquired */
Marek Szyprowskic1426bc2011-08-24 06:36:26 -0300945 for (plane = 0; plane < vb->num_planes; ++plane) {
946 if (vb->planes[plane].mem_priv)
947 call_memop(q, plane, put_userptr,
948 vb->planes[plane].mem_priv);
949 vb->planes[plane].mem_priv = NULL;
950 vb->v4l2_planes[plane].m.userptr = 0;
951 vb->v4l2_planes[plane].length = 0;
Pawel Osciake23ccc02010-10-11 10:56:41 -0300952 }
953
954 return ret;
955}
956
957/**
958 * __qbuf_mmap() - handle qbuf of an MMAP buffer
959 */
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300960static int __qbuf_mmap(struct vb2_buffer *vb, const struct v4l2_buffer *b)
Pawel Osciake23ccc02010-10-11 10:56:41 -0300961{
962 return __fill_vb2_buffer(vb, b, vb->v4l2_planes);
963}
964
965/**
966 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
967 */
968static void __enqueue_in_driver(struct vb2_buffer *vb)
969{
970 struct vb2_queue *q = vb->vb2_queue;
971
972 vb->state = VB2_BUF_STATE_ACTIVE;
973 atomic_inc(&q->queued_count);
974 q->ops->buf_queue(vb);
975}
976
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -0300977static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b)
Guennadi Liakhovetskiebc087d2011-08-31 06:51:10 -0300978{
979 struct vb2_queue *q = vb->vb2_queue;
980 int ret;
981
982 switch (q->memory) {
983 case V4L2_MEMORY_MMAP:
984 ret = __qbuf_mmap(vb, b);
985 break;
986 case V4L2_MEMORY_USERPTR:
987 ret = __qbuf_userptr(vb, b);
988 break;
989 default:
990 WARN(1, "Invalid queue type\n");
991 ret = -EINVAL;
992 }
993
994 if (!ret)
995 ret = call_qop(q, buf_prepare, vb);
996 if (ret)
997 dprintk(1, "qbuf: buffer preparation failed: %d\n", ret);
998 else
999 vb->state = VB2_BUF_STATE_PREPARED;
1000
1001 return ret;
1002}
1003
Pawel Osciake23ccc02010-10-11 10:56:41 -03001004/**
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -03001005 * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
1006 * @q: videobuf2 queue
1007 * @b: buffer structure passed from userspace to vidioc_prepare_buf
1008 * handler in driver
1009 *
1010 * Should be called from vidioc_prepare_buf ioctl handler of a driver.
1011 * This function:
1012 * 1) verifies the passed buffer,
1013 * 2) calls buf_prepare callback in the driver (if provided), in which
1014 * driver-specific buffer initialization can be performed,
1015 *
1016 * The return values from this function are intended to be directly returned
1017 * from vidioc_prepare_buf handler in driver.
1018 */
1019int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
1020{
1021 struct vb2_buffer *vb;
1022 int ret;
1023
1024 if (q->fileio) {
1025 dprintk(1, "%s(): file io in progress\n", __func__);
1026 return -EBUSY;
1027 }
1028
1029 if (b->type != q->type) {
1030 dprintk(1, "%s(): invalid buffer type\n", __func__);
1031 return -EINVAL;
1032 }
1033
1034 if (b->index >= q->num_buffers) {
1035 dprintk(1, "%s(): buffer index out of range\n", __func__);
1036 return -EINVAL;
1037 }
1038
1039 vb = q->bufs[b->index];
1040 if (NULL == vb) {
1041 /* Should never happen */
1042 dprintk(1, "%s(): buffer is NULL\n", __func__);
1043 return -EINVAL;
1044 }
1045
1046 if (b->memory != q->memory) {
1047 dprintk(1, "%s(): invalid memory type\n", __func__);
1048 return -EINVAL;
1049 }
1050
1051 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1052 dprintk(1, "%s(): invalid buffer state %d\n", __func__, vb->state);
1053 return -EINVAL;
1054 }
1055
1056 ret = __buf_prepare(vb, b);
1057 if (ret < 0)
1058 return ret;
1059
1060 __fill_v4l2_buffer(vb, b);
1061
1062 return 0;
1063}
1064EXPORT_SYMBOL_GPL(vb2_prepare_buf);
1065
1066/**
Pawel Osciake23ccc02010-10-11 10:56:41 -03001067 * vb2_qbuf() - Queue a buffer from userspace
1068 * @q: videobuf2 queue
1069 * @b: buffer structure passed from userspace to vidioc_qbuf handler
1070 * in driver
1071 *
1072 * Should be called from vidioc_qbuf ioctl handler of a driver.
1073 * This function:
1074 * 1) verifies the passed buffer,
Guennadi Liakhovetskiebc087d2011-08-31 06:51:10 -03001075 * 2) if necessary, calls buf_prepare callback in the driver (if provided), in
1076 * which driver-specific buffer initialization can be performed,
Pawel Osciake23ccc02010-10-11 10:56:41 -03001077 * 3) if streaming is on, queues the buffer in driver by the means of buf_queue
1078 * callback for processing.
1079 *
1080 * The return values from this function are intended to be directly returned
1081 * from vidioc_qbuf handler in driver.
1082 */
1083int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
1084{
1085 struct vb2_buffer *vb;
Guennadi Liakhovetskiebc087d2011-08-31 06:51:10 -03001086 int ret;
Pawel Osciake23ccc02010-10-11 10:56:41 -03001087
Marek Szyprowskib25748f2010-12-06 05:56:55 -03001088 if (q->fileio) {
1089 dprintk(1, "qbuf: file io in progress\n");
1090 return -EBUSY;
1091 }
1092
Pawel Osciake23ccc02010-10-11 10:56:41 -03001093 if (b->type != q->type) {
1094 dprintk(1, "qbuf: invalid buffer type\n");
1095 return -EINVAL;
1096 }
1097
1098 if (b->index >= q->num_buffers) {
1099 dprintk(1, "qbuf: buffer index out of range\n");
1100 return -EINVAL;
1101 }
1102
1103 vb = q->bufs[b->index];
1104 if (NULL == vb) {
1105 /* Should never happen */
1106 dprintk(1, "qbuf: buffer is NULL\n");
1107 return -EINVAL;
1108 }
1109
1110 if (b->memory != q->memory) {
1111 dprintk(1, "qbuf: invalid memory type\n");
1112 return -EINVAL;
1113 }
1114
Guennadi Liakhovetskiebc087d2011-08-31 06:51:10 -03001115 switch (vb->state) {
1116 case VB2_BUF_STATE_DEQUEUED:
1117 ret = __buf_prepare(vb, b);
1118 if (ret)
1119 return ret;
1120 case VB2_BUF_STATE_PREPARED:
1121 break;
1122 default:
Pawel Osciake23ccc02010-10-11 10:56:41 -03001123 dprintk(1, "qbuf: buffer already in use\n");
1124 return -EINVAL;
1125 }
1126
Pawel Osciake23ccc02010-10-11 10:56:41 -03001127 /*
1128 * Add to the queued buffers list, a buffer will stay on it until
1129 * dequeued in dqbuf.
1130 */
1131 list_add_tail(&vb->queued_entry, &q->queued_list);
1132 vb->state = VB2_BUF_STATE_QUEUED;
1133
1134 /*
1135 * If already streaming, give the buffer to driver for processing.
1136 * If not, the buffer will be given to driver on next streamon.
1137 */
1138 if (q->streaming)
1139 __enqueue_in_driver(vb);
1140
Guennadi Liakhovetski21db3e02011-09-28 07:23:27 -03001141 /* Fill buffer information for the userspace */
1142 __fill_v4l2_buffer(vb, b);
1143
Pawel Osciake23ccc02010-10-11 10:56:41 -03001144 dprintk(1, "qbuf of buffer %d succeeded\n", vb->v4l2_buf.index);
1145 return 0;
1146}
1147EXPORT_SYMBOL_GPL(vb2_qbuf);
1148
1149/**
1150 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1151 * for dequeuing
1152 *
1153 * Will sleep if required for nonblocking == false.
1154 */
1155static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1156{
1157 /*
1158 * All operations on vb_done_list are performed under done_lock
1159 * spinlock protection. However, buffers may be removed from
1160 * it and returned to userspace only while holding both driver's
1161 * lock and the done_lock spinlock. Thus we can be sure that as
1162 * long as we hold the driver's lock, the list will remain not
1163 * empty if list_empty() check succeeds.
1164 */
1165
1166 for (;;) {
1167 int ret;
1168
1169 if (!q->streaming) {
1170 dprintk(1, "Streaming off, will not wait for buffers\n");
1171 return -EINVAL;
1172 }
1173
1174 if (!list_empty(&q->done_list)) {
1175 /*
1176 * Found a buffer that we were waiting for.
1177 */
1178 break;
1179 }
1180
1181 if (nonblocking) {
1182 dprintk(1, "Nonblocking and no buffers to dequeue, "
1183 "will not wait\n");
1184 return -EAGAIN;
1185 }
1186
1187 /*
1188 * We are streaming and blocking, wait for another buffer to
1189 * become ready or for streamoff. Driver's lock is released to
1190 * allow streamoff or qbuf to be called while waiting.
1191 */
1192 call_qop(q, wait_prepare, q);
1193
1194 /*
1195 * All locks have been released, it is safe to sleep now.
1196 */
1197 dprintk(3, "Will sleep waiting for buffers\n");
1198 ret = wait_event_interruptible(q->done_wq,
1199 !list_empty(&q->done_list) || !q->streaming);
1200
1201 /*
1202 * We need to reevaluate both conditions again after reacquiring
1203 * the locks or return an error if one occurred.
1204 */
1205 call_qop(q, wait_finish, q);
1206 if (ret)
1207 return ret;
1208 }
1209 return 0;
1210}
1211
1212/**
1213 * __vb2_get_done_vb() - get a buffer ready for dequeuing
1214 *
1215 * Will sleep if required for nonblocking == false.
1216 */
1217static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1218 int nonblocking)
1219{
1220 unsigned long flags;
1221 int ret;
1222
1223 /*
1224 * Wait for at least one buffer to become available on the done_list.
1225 */
1226 ret = __vb2_wait_for_done_vb(q, nonblocking);
1227 if (ret)
1228 return ret;
1229
1230 /*
1231 * Driver's lock has been held since we last verified that done_list
1232 * is not empty, so no need for another list_empty(done_list) check.
1233 */
1234 spin_lock_irqsave(&q->done_lock, flags);
1235 *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1236 list_del(&(*vb)->done_entry);
1237 spin_unlock_irqrestore(&q->done_lock, flags);
1238
1239 return 0;
1240}
1241
1242/**
1243 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2
1244 * @q: videobuf2 queue
1245 *
1246 * This function will wait until all buffers that have been given to the driver
1247 * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call
1248 * wait_prepare, wait_finish pair. It is intended to be called with all locks
1249 * taken, for example from stop_streaming() callback.
1250 */
1251int vb2_wait_for_all_buffers(struct vb2_queue *q)
1252{
1253 if (!q->streaming) {
1254 dprintk(1, "Streaming off, will not wait for buffers\n");
1255 return -EINVAL;
1256 }
1257
1258 wait_event(q->done_wq, !atomic_read(&q->queued_count));
1259 return 0;
1260}
1261EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
1262
1263/**
1264 * vb2_dqbuf() - Dequeue a buffer to the userspace
1265 * @q: videobuf2 queue
1266 * @b: buffer structure passed from userspace to vidioc_dqbuf handler
1267 * in driver
1268 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
1269 * buffers ready for dequeuing are present. Normally the driver
1270 * would be passing (file->f_flags & O_NONBLOCK) here
1271 *
1272 * Should be called from vidioc_dqbuf ioctl handler of a driver.
1273 * This function:
1274 * 1) verifies the passed buffer,
1275 * 2) calls buf_finish callback in the driver (if provided), in which
1276 * driver can perform any additional operations that may be required before
1277 * returning the buffer to userspace, such as cache sync,
1278 * 3) the buffer struct members are filled with relevant information for
1279 * the userspace.
1280 *
1281 * The return values from this function are intended to be directly returned
1282 * from vidioc_dqbuf handler in driver.
1283 */
1284int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
1285{
1286 struct vb2_buffer *vb = NULL;
1287 int ret;
1288
Marek Szyprowskib25748f2010-12-06 05:56:55 -03001289 if (q->fileio) {
1290 dprintk(1, "dqbuf: file io in progress\n");
1291 return -EBUSY;
1292 }
1293
Pawel Osciake23ccc02010-10-11 10:56:41 -03001294 if (b->type != q->type) {
1295 dprintk(1, "dqbuf: invalid buffer type\n");
1296 return -EINVAL;
1297 }
1298
1299 ret = __vb2_get_done_vb(q, &vb, nonblocking);
1300 if (ret < 0) {
1301 dprintk(1, "dqbuf: error getting next done buffer\n");
1302 return ret;
1303 }
1304
1305 ret = call_qop(q, buf_finish, vb);
1306 if (ret) {
1307 dprintk(1, "dqbuf: buffer finish failed\n");
1308 return ret;
1309 }
1310
1311 switch (vb->state) {
1312 case VB2_BUF_STATE_DONE:
1313 dprintk(3, "dqbuf: Returning done buffer\n");
1314 break;
1315 case VB2_BUF_STATE_ERROR:
1316 dprintk(3, "dqbuf: Returning done buffer with errors\n");
1317 break;
1318 default:
1319 dprintk(1, "dqbuf: Invalid buffer state\n");
1320 return -EINVAL;
1321 }
1322
1323 /* Fill buffer information for the userspace */
1324 __fill_v4l2_buffer(vb, b);
1325 /* Remove from videobuf queue */
1326 list_del(&vb->queued_entry);
1327
1328 dprintk(1, "dqbuf of buffer %d, with state %d\n",
1329 vb->v4l2_buf.index, vb->state);
1330
1331 vb->state = VB2_BUF_STATE_DEQUEUED;
1332 return 0;
1333}
1334EXPORT_SYMBOL_GPL(vb2_dqbuf);
1335
1336/**
Pawel Osciake23ccc02010-10-11 10:56:41 -03001337 * __vb2_queue_cancel() - cancel and stop (pause) streaming
1338 *
1339 * Removes all queued buffers from driver's queue and all buffers queued by
1340 * userspace from videobuf's queue. Returns to state after reqbufs.
1341 */
1342static void __vb2_queue_cancel(struct vb2_queue *q)
1343{
1344 unsigned int i;
1345
1346 /*
1347 * Tell driver to stop all transactions and release all queued
1348 * buffers.
1349 */
1350 if (q->streaming)
1351 call_qop(q, stop_streaming, q);
1352 q->streaming = 0;
1353
1354 /*
1355 * Remove all buffers from videobuf's list...
1356 */
1357 INIT_LIST_HEAD(&q->queued_list);
1358 /*
1359 * ...and done list; userspace will not receive any buffers it
1360 * has not already dequeued before initiating cancel.
1361 */
1362 INIT_LIST_HEAD(&q->done_list);
Marek Szyprowskiafdea8b2011-06-10 08:58:42 -03001363 atomic_set(&q->queued_count, 0);
Pawel Osciake23ccc02010-10-11 10:56:41 -03001364 wake_up_all(&q->done_wq);
1365
1366 /*
1367 * Reinitialize all buffers for next use.
1368 */
1369 for (i = 0; i < q->num_buffers; ++i)
1370 q->bufs[i]->state = VB2_BUF_STATE_DEQUEUED;
1371}
1372
1373/**
Marek Szyprowskibd323e22011-08-29 08:51:49 -03001374 * vb2_streamon - start streaming
1375 * @q: videobuf2 queue
1376 * @type: type argument passed from userspace to vidioc_streamon handler
1377 *
1378 * Should be called from vidioc_streamon handler of a driver.
1379 * This function:
1380 * 1) verifies current state
1381 * 2) passes any previously queued buffers to the driver and starts streaming
1382 *
1383 * The return values from this function are intended to be directly returned
1384 * from vidioc_streamon handler in the driver.
1385 */
1386int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
1387{
1388 struct vb2_buffer *vb;
1389 int ret;
1390
1391 if (q->fileio) {
1392 dprintk(1, "streamon: file io in progress\n");
1393 return -EBUSY;
1394 }
1395
1396 if (type != q->type) {
1397 dprintk(1, "streamon: invalid stream type\n");
1398 return -EINVAL;
1399 }
1400
1401 if (q->streaming) {
1402 dprintk(1, "streamon: already streaming\n");
1403 return -EBUSY;
1404 }
1405
1406 /*
1407 * If any buffers were queued before streamon,
1408 * we can now pass them to driver for processing.
1409 */
1410 list_for_each_entry(vb, &q->queued_list, queued_entry)
1411 __enqueue_in_driver(vb);
1412
1413 /*
1414 * Let driver notice that streaming state has been enabled.
1415 */
1416 ret = call_qop(q, start_streaming, q, atomic_read(&q->queued_count));
1417 if (ret) {
1418 dprintk(1, "streamon: driver refused to start streaming\n");
1419 __vb2_queue_cancel(q);
1420 return ret;
1421 }
1422
1423 q->streaming = 1;
1424
1425 dprintk(3, "Streamon successful\n");
1426 return 0;
1427}
1428EXPORT_SYMBOL_GPL(vb2_streamon);
1429
1430
1431/**
Pawel Osciake23ccc02010-10-11 10:56:41 -03001432 * vb2_streamoff - stop streaming
1433 * @q: videobuf2 queue
1434 * @type: type argument passed from userspace to vidioc_streamoff handler
1435 *
1436 * Should be called from vidioc_streamoff handler of a driver.
1437 * This function:
1438 * 1) verifies current state,
1439 * 2) stop streaming and dequeues any queued buffers, including those previously
1440 * passed to the driver (after waiting for the driver to finish).
1441 *
1442 * This call can be used for pausing playback.
1443 * The return values from this function are intended to be directly returned
1444 * from vidioc_streamoff handler in the driver
1445 */
1446int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
1447{
Marek Szyprowskib25748f2010-12-06 05:56:55 -03001448 if (q->fileio) {
1449 dprintk(1, "streamoff: file io in progress\n");
1450 return -EBUSY;
1451 }
1452
Pawel Osciake23ccc02010-10-11 10:56:41 -03001453 if (type != q->type) {
1454 dprintk(1, "streamoff: invalid stream type\n");
1455 return -EINVAL;
1456 }
1457
1458 if (!q->streaming) {
1459 dprintk(1, "streamoff: not streaming\n");
1460 return -EINVAL;
1461 }
1462
1463 /*
1464 * Cancel will pause streaming and remove all buffers from the driver
1465 * and videobuf, effectively returning control over them to userspace.
1466 */
1467 __vb2_queue_cancel(q);
1468
1469 dprintk(3, "Streamoff successful\n");
1470 return 0;
1471}
1472EXPORT_SYMBOL_GPL(vb2_streamoff);
1473
1474/**
1475 * __find_plane_by_offset() - find plane associated with the given offset off
1476 */
1477static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
1478 unsigned int *_buffer, unsigned int *_plane)
1479{
1480 struct vb2_buffer *vb;
1481 unsigned int buffer, plane;
1482
1483 /*
1484 * Go over all buffers and their planes, comparing the given offset
1485 * with an offset assigned to each plane. If a match is found,
1486 * return its buffer and plane numbers.
1487 */
1488 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
1489 vb = q->bufs[buffer];
1490
1491 for (plane = 0; plane < vb->num_planes; ++plane) {
1492 if (vb->v4l2_planes[plane].m.mem_offset == off) {
1493 *_buffer = buffer;
1494 *_plane = plane;
1495 return 0;
1496 }
1497 }
1498 }
1499
1500 return -EINVAL;
1501}
1502
1503/**
1504 * vb2_mmap() - map video buffers into application address space
1505 * @q: videobuf2 queue
1506 * @vma: vma passed to the mmap file operation handler in the driver
1507 *
1508 * Should be called from mmap file operation handler of a driver.
1509 * This function maps one plane of one of the available video buffers to
1510 * userspace. To map whole video memory allocated on reqbufs, this function
1511 * has to be called once per each plane per each buffer previously allocated.
1512 *
1513 * When the userspace application calls mmap, it passes to it an offset returned
1514 * to it earlier by the means of vidioc_querybuf handler. That offset acts as
1515 * a "cookie", which is then used to identify the plane to be mapped.
1516 * This function finds a plane with a matching offset and a mapping is performed
1517 * by the means of a provided memory operation.
1518 *
1519 * The return values from this function are intended to be directly returned
1520 * from the mmap handler in driver.
1521 */
1522int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
1523{
1524 unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
1525 struct vb2_plane *vb_plane;
1526 struct vb2_buffer *vb;
1527 unsigned int buffer, plane;
1528 int ret;
1529
1530 if (q->memory != V4L2_MEMORY_MMAP) {
1531 dprintk(1, "Queue is not currently set up for mmap\n");
1532 return -EINVAL;
1533 }
1534
1535 /*
1536 * Check memory area access mode.
1537 */
1538 if (!(vma->vm_flags & VM_SHARED)) {
1539 dprintk(1, "Invalid vma flags, VM_SHARED needed\n");
1540 return -EINVAL;
1541 }
1542 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
1543 if (!(vma->vm_flags & VM_WRITE)) {
1544 dprintk(1, "Invalid vma flags, VM_WRITE needed\n");
1545 return -EINVAL;
1546 }
1547 } else {
1548 if (!(vma->vm_flags & VM_READ)) {
1549 dprintk(1, "Invalid vma flags, VM_READ needed\n");
1550 return -EINVAL;
1551 }
1552 }
1553
1554 /*
1555 * Find the plane corresponding to the offset passed by userspace.
1556 */
1557 ret = __find_plane_by_offset(q, off, &buffer, &plane);
1558 if (ret)
1559 return ret;
1560
1561 vb = q->bufs[buffer];
1562 vb_plane = &vb->planes[plane];
1563
1564 ret = q->mem_ops->mmap(vb_plane->mem_priv, vma);
1565 if (ret)
1566 return ret;
1567
Pawel Osciake23ccc02010-10-11 10:56:41 -03001568 dprintk(3, "Buffer %d, plane %d successfully mapped\n", buffer, plane);
1569 return 0;
1570}
1571EXPORT_SYMBOL_GPL(vb2_mmap);
1572
Scott Jiang6f524ec2011-09-21 09:25:23 -03001573#ifndef CONFIG_MMU
1574unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
1575 unsigned long addr,
1576 unsigned long len,
1577 unsigned long pgoff,
1578 unsigned long flags)
1579{
1580 unsigned long off = pgoff << PAGE_SHIFT;
1581 struct vb2_buffer *vb;
1582 unsigned int buffer, plane;
1583 int ret;
1584
1585 if (q->memory != V4L2_MEMORY_MMAP) {
1586 dprintk(1, "Queue is not currently set up for mmap\n");
1587 return -EINVAL;
1588 }
1589
1590 /*
1591 * Find the plane corresponding to the offset passed by userspace.
1592 */
1593 ret = __find_plane_by_offset(q, off, &buffer, &plane);
1594 if (ret)
1595 return ret;
1596
1597 vb = q->bufs[buffer];
1598
1599 return (unsigned long)vb2_plane_vaddr(vb, plane);
1600}
1601EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
1602#endif
1603
Marek Szyprowskib25748f2010-12-06 05:56:55 -03001604static int __vb2_init_fileio(struct vb2_queue *q, int read);
1605static int __vb2_cleanup_fileio(struct vb2_queue *q);
Pawel Osciake23ccc02010-10-11 10:56:41 -03001606
1607/**
1608 * vb2_poll() - implements poll userspace operation
1609 * @q: videobuf2 queue
1610 * @file: file argument passed to the poll file operation handler
1611 * @wait: wait argument passed to the poll file operation handler
1612 *
1613 * This function implements poll file operation handler for a driver.
1614 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
1615 * be informed that the file descriptor of a video device is available for
1616 * reading.
1617 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
1618 * will be reported as available for writing.
1619 *
1620 * The return values from this function are intended to be directly returned
1621 * from poll handler in driver.
1622 */
1623unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
1624{
1625 unsigned long flags;
Marek Szyprowskib25748f2010-12-06 05:56:55 -03001626 unsigned int ret;
Pawel Osciake23ccc02010-10-11 10:56:41 -03001627 struct vb2_buffer *vb = NULL;
1628
1629 /*
Pawel Osciak4ffabdb2011-03-20 18:17:34 -03001630 * Start file I/O emulator only if streaming API has not been used yet.
Marek Szyprowskib25748f2010-12-06 05:56:55 -03001631 */
1632 if (q->num_buffers == 0 && q->fileio == NULL) {
1633 if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ)) {
1634 ret = __vb2_init_fileio(q, 1);
1635 if (ret)
Pawel Osciak4ffabdb2011-03-20 18:17:34 -03001636 return POLLERR;
Marek Szyprowskib25748f2010-12-06 05:56:55 -03001637 }
1638 if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE)) {
1639 ret = __vb2_init_fileio(q, 0);
1640 if (ret)
Pawel Osciak4ffabdb2011-03-20 18:17:34 -03001641 return POLLERR;
Marek Szyprowskib25748f2010-12-06 05:56:55 -03001642 /*
1643 * Write to OUTPUT queue can be done immediately.
1644 */
1645 return POLLOUT | POLLWRNORM;
1646 }
1647 }
1648
1649 /*
Pawel Osciake23ccc02010-10-11 10:56:41 -03001650 * There is nothing to wait for if no buffers have already been queued.
1651 */
1652 if (list_empty(&q->queued_list))
1653 return POLLERR;
1654
1655 poll_wait(file, &q->done_wq, wait);
1656
1657 /*
1658 * Take first buffer available for dequeuing.
1659 */
1660 spin_lock_irqsave(&q->done_lock, flags);
1661 if (!list_empty(&q->done_list))
1662 vb = list_first_entry(&q->done_list, struct vb2_buffer,
1663 done_entry);
1664 spin_unlock_irqrestore(&q->done_lock, flags);
1665
1666 if (vb && (vb->state == VB2_BUF_STATE_DONE
1667 || vb->state == VB2_BUF_STATE_ERROR)) {
1668 return (V4L2_TYPE_IS_OUTPUT(q->type)) ? POLLOUT | POLLWRNORM :
1669 POLLIN | POLLRDNORM;
1670 }
1671 return 0;
1672}
1673EXPORT_SYMBOL_GPL(vb2_poll);
1674
1675/**
1676 * vb2_queue_init() - initialize a videobuf2 queue
1677 * @q: videobuf2 queue; this structure should be allocated in driver
1678 *
1679 * The vb2_queue structure should be allocated by the driver. The driver is
1680 * responsible of clearing it's content and setting initial values for some
1681 * required entries before calling this function.
1682 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
1683 * to the struct vb2_queue description in include/media/videobuf2-core.h
1684 * for more information.
1685 */
1686int vb2_queue_init(struct vb2_queue *q)
1687{
1688 BUG_ON(!q);
1689 BUG_ON(!q->ops);
1690 BUG_ON(!q->mem_ops);
1691 BUG_ON(!q->type);
1692 BUG_ON(!q->io_modes);
1693
1694 BUG_ON(!q->ops->queue_setup);
1695 BUG_ON(!q->ops->buf_queue);
1696
1697 INIT_LIST_HEAD(&q->queued_list);
1698 INIT_LIST_HEAD(&q->done_list);
1699 spin_lock_init(&q->done_lock);
1700 init_waitqueue_head(&q->done_wq);
1701
1702 if (q->buf_struct_size == 0)
1703 q->buf_struct_size = sizeof(struct vb2_buffer);
1704
1705 return 0;
1706}
1707EXPORT_SYMBOL_GPL(vb2_queue_init);
1708
1709/**
1710 * vb2_queue_release() - stop streaming, release the queue and free memory
1711 * @q: videobuf2 queue
1712 *
1713 * This function stops streaming and performs necessary clean ups, including
1714 * freeing video buffer memory. The driver is responsible for freeing
1715 * the vb2_queue structure itself.
1716 */
1717void vb2_queue_release(struct vb2_queue *q)
1718{
Marek Szyprowskib25748f2010-12-06 05:56:55 -03001719 __vb2_cleanup_fileio(q);
Pawel Osciake23ccc02010-10-11 10:56:41 -03001720 __vb2_queue_cancel(q);
Guennadi Liakhovetski2d864012011-09-28 09:23:02 -03001721 __vb2_queue_free(q, q->num_buffers);
Pawel Osciake23ccc02010-10-11 10:56:41 -03001722}
1723EXPORT_SYMBOL_GPL(vb2_queue_release);
1724
Marek Szyprowskib25748f2010-12-06 05:56:55 -03001725/**
1726 * struct vb2_fileio_buf - buffer context used by file io emulator
1727 *
1728 * vb2 provides a compatibility layer and emulator of file io (read and
1729 * write) calls on top of streaming API. This structure is used for
1730 * tracking context related to the buffers.
1731 */
1732struct vb2_fileio_buf {
1733 void *vaddr;
1734 unsigned int size;
1735 unsigned int pos;
1736 unsigned int queued:1;
1737};
1738
1739/**
1740 * struct vb2_fileio_data - queue context used by file io emulator
1741 *
1742 * vb2 provides a compatibility layer and emulator of file io (read and
1743 * write) calls on top of streaming API. For proper operation it required
1744 * this structure to save the driver state between each call of the read
1745 * or write function.
1746 */
1747struct vb2_fileio_data {
1748 struct v4l2_requestbuffers req;
1749 struct v4l2_buffer b;
1750 struct vb2_fileio_buf bufs[VIDEO_MAX_FRAME];
1751 unsigned int index;
1752 unsigned int q_count;
1753 unsigned int dq_count;
1754 unsigned int flags;
1755};
1756
1757/**
1758 * __vb2_init_fileio() - initialize file io emulator
1759 * @q: videobuf2 queue
1760 * @read: mode selector (1 means read, 0 means write)
1761 */
1762static int __vb2_init_fileio(struct vb2_queue *q, int read)
1763{
1764 struct vb2_fileio_data *fileio;
1765 int i, ret;
1766 unsigned int count = 0;
1767
1768 /*
1769 * Sanity check
1770 */
1771 if ((read && !(q->io_modes & VB2_READ)) ||
1772 (!read && !(q->io_modes & VB2_WRITE)))
1773 BUG();
1774
1775 /*
1776 * Check if device supports mapping buffers to kernel virtual space.
1777 */
1778 if (!q->mem_ops->vaddr)
1779 return -EBUSY;
1780
1781 /*
1782 * Check if streaming api has not been already activated.
1783 */
1784 if (q->streaming || q->num_buffers > 0)
1785 return -EBUSY;
1786
1787 /*
1788 * Start with count 1, driver can increase it in queue_setup()
1789 */
1790 count = 1;
1791
1792 dprintk(3, "setting up file io: mode %s, count %d, flags %08x\n",
1793 (read) ? "read" : "write", count, q->io_flags);
1794
1795 fileio = kzalloc(sizeof(struct vb2_fileio_data), GFP_KERNEL);
1796 if (fileio == NULL)
1797 return -ENOMEM;
1798
1799 fileio->flags = q->io_flags;
1800
1801 /*
1802 * Request buffers and use MMAP type to force driver
1803 * to allocate buffers by itself.
1804 */
1805 fileio->req.count = count;
1806 fileio->req.memory = V4L2_MEMORY_MMAP;
1807 fileio->req.type = q->type;
1808 ret = vb2_reqbufs(q, &fileio->req);
1809 if (ret)
1810 goto err_kfree;
1811
1812 /*
1813 * Check if plane_count is correct
1814 * (multiplane buffers are not supported).
1815 */
1816 if (q->bufs[0]->num_planes != 1) {
1817 fileio->req.count = 0;
1818 ret = -EBUSY;
1819 goto err_reqbufs;
1820 }
1821
1822 /*
1823 * Get kernel address of each buffer.
1824 */
1825 for (i = 0; i < q->num_buffers; i++) {
1826 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
1827 if (fileio->bufs[i].vaddr == NULL)
1828 goto err_reqbufs;
1829 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
1830 }
1831
1832 /*
1833 * Read mode requires pre queuing of all buffers.
1834 */
1835 if (read) {
1836 /*
1837 * Queue all buffers.
1838 */
1839 for (i = 0; i < q->num_buffers; i++) {
1840 struct v4l2_buffer *b = &fileio->b;
1841 memset(b, 0, sizeof(*b));
1842 b->type = q->type;
1843 b->memory = q->memory;
1844 b->index = i;
1845 ret = vb2_qbuf(q, b);
1846 if (ret)
1847 goto err_reqbufs;
1848 fileio->bufs[i].queued = 1;
1849 }
1850
1851 /*
1852 * Start streaming.
1853 */
1854 ret = vb2_streamon(q, q->type);
1855 if (ret)
1856 goto err_reqbufs;
1857 }
1858
1859 q->fileio = fileio;
1860
1861 return ret;
1862
1863err_reqbufs:
1864 vb2_reqbufs(q, &fileio->req);
1865
1866err_kfree:
1867 kfree(fileio);
1868 return ret;
1869}
1870
1871/**
1872 * __vb2_cleanup_fileio() - free resourced used by file io emulator
1873 * @q: videobuf2 queue
1874 */
1875static int __vb2_cleanup_fileio(struct vb2_queue *q)
1876{
1877 struct vb2_fileio_data *fileio = q->fileio;
1878
1879 if (fileio) {
1880 /*
1881 * Hack fileio context to enable direct calls to vb2 ioctl
1882 * interface.
1883 */
1884 q->fileio = NULL;
1885
1886 vb2_streamoff(q, q->type);
1887 fileio->req.count = 0;
1888 vb2_reqbufs(q, &fileio->req);
1889 kfree(fileio);
1890 dprintk(3, "file io emulator closed\n");
1891 }
1892 return 0;
1893}
1894
1895/**
1896 * __vb2_perform_fileio() - perform a single file io (read or write) operation
1897 * @q: videobuf2 queue
1898 * @data: pointed to target userspace buffer
1899 * @count: number of bytes to read or write
1900 * @ppos: file handle position tracking pointer
1901 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
1902 * @read: access mode selector (1 means read, 0 means write)
1903 */
1904static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
1905 loff_t *ppos, int nonblock, int read)
1906{
1907 struct vb2_fileio_data *fileio;
1908 struct vb2_fileio_buf *buf;
1909 int ret, index;
1910
Mauro Carvalho Chehab08b99e22011-01-11 17:12:34 -03001911 dprintk(3, "file io: mode %s, offset %ld, count %zd, %sblocking\n",
Marek Szyprowskib25748f2010-12-06 05:56:55 -03001912 read ? "read" : "write", (long)*ppos, count,
1913 nonblock ? "non" : "");
1914
1915 if (!data)
1916 return -EINVAL;
1917
1918 /*
1919 * Initialize emulator on first call.
1920 */
1921 if (!q->fileio) {
1922 ret = __vb2_init_fileio(q, read);
1923 dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
1924 if (ret)
1925 return ret;
1926 }
1927 fileio = q->fileio;
1928
1929 /*
1930 * Hack fileio context to enable direct calls to vb2 ioctl interface.
1931 * The pointer will be restored before returning from this function.
1932 */
1933 q->fileio = NULL;
1934
1935 index = fileio->index;
1936 buf = &fileio->bufs[index];
1937
1938 /*
1939 * Check if we need to dequeue the buffer.
1940 */
1941 if (buf->queued) {
1942 struct vb2_buffer *vb;
1943
1944 /*
1945 * Call vb2_dqbuf to get buffer back.
1946 */
1947 memset(&fileio->b, 0, sizeof(fileio->b));
1948 fileio->b.type = q->type;
1949 fileio->b.memory = q->memory;
1950 fileio->b.index = index;
1951 ret = vb2_dqbuf(q, &fileio->b, nonblock);
1952 dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
1953 if (ret)
1954 goto end;
1955 fileio->dq_count += 1;
1956
1957 /*
1958 * Get number of bytes filled by the driver
1959 */
1960 vb = q->bufs[index];
1961 buf->size = vb2_get_plane_payload(vb, 0);
1962 buf->queued = 0;
1963 }
1964
1965 /*
1966 * Limit count on last few bytes of the buffer.
1967 */
1968 if (buf->pos + count > buf->size) {
1969 count = buf->size - buf->pos;
Mauro Carvalho Chehab08b99e22011-01-11 17:12:34 -03001970 dprintk(5, "reducing read count: %zd\n", count);
Marek Szyprowskib25748f2010-12-06 05:56:55 -03001971 }
1972
1973 /*
1974 * Transfer data to userspace.
1975 */
Mauro Carvalho Chehab08b99e22011-01-11 17:12:34 -03001976 dprintk(3, "file io: copying %zd bytes - buffer %d, offset %u\n",
Marek Szyprowskib25748f2010-12-06 05:56:55 -03001977 count, index, buf->pos);
1978 if (read)
1979 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
1980 else
1981 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
1982 if (ret) {
1983 dprintk(3, "file io: error copying data\n");
1984 ret = -EFAULT;
1985 goto end;
1986 }
1987
1988 /*
1989 * Update counters.
1990 */
1991 buf->pos += count;
1992 *ppos += count;
1993
1994 /*
1995 * Queue next buffer if required.
1996 */
1997 if (buf->pos == buf->size ||
1998 (!read && (fileio->flags & VB2_FILEIO_WRITE_IMMEDIATELY))) {
1999 /*
2000 * Check if this is the last buffer to read.
2001 */
2002 if (read && (fileio->flags & VB2_FILEIO_READ_ONCE) &&
2003 fileio->dq_count == 1) {
2004 dprintk(3, "file io: read limit reached\n");
2005 /*
2006 * Restore fileio pointer and release the context.
2007 */
2008 q->fileio = fileio;
2009 return __vb2_cleanup_fileio(q);
2010 }
2011
2012 /*
2013 * Call vb2_qbuf and give buffer to the driver.
2014 */
2015 memset(&fileio->b, 0, sizeof(fileio->b));
2016 fileio->b.type = q->type;
2017 fileio->b.memory = q->memory;
2018 fileio->b.index = index;
2019 fileio->b.bytesused = buf->pos;
2020 ret = vb2_qbuf(q, &fileio->b);
2021 dprintk(5, "file io: vb2_dbuf result: %d\n", ret);
2022 if (ret)
2023 goto end;
2024
2025 /*
2026 * Buffer has been queued, update the status
2027 */
2028 buf->pos = 0;
2029 buf->queued = 1;
2030 buf->size = q->bufs[0]->v4l2_planes[0].length;
2031 fileio->q_count += 1;
2032
2033 /*
2034 * Switch to the next buffer
2035 */
2036 fileio->index = (index + 1) % q->num_buffers;
2037
2038 /*
2039 * Start streaming if required.
2040 */
2041 if (!read && !q->streaming) {
2042 ret = vb2_streamon(q, q->type);
2043 if (ret)
2044 goto end;
2045 }
2046 }
2047
2048 /*
2049 * Return proper number of bytes processed.
2050 */
2051 if (ret == 0)
2052 ret = count;
2053end:
2054 /*
2055 * Restore the fileio context and block vb2 ioctl interface.
2056 */
2057 q->fileio = fileio;
2058 return ret;
2059}
2060
2061size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
2062 loff_t *ppos, int nonblocking)
2063{
2064 return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
2065}
2066EXPORT_SYMBOL_GPL(vb2_read);
2067
2068size_t vb2_write(struct vb2_queue *q, char __user *data, size_t count,
2069 loff_t *ppos, int nonblocking)
2070{
2071 return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 0);
2072}
2073EXPORT_SYMBOL_GPL(vb2_write);
2074
Pawel Osciake23ccc02010-10-11 10:56:41 -03002075MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
Pawel Osciak95072082011-03-13 15:23:32 -03002076MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
Pawel Osciake23ccc02010-10-11 10:56:41 -03002077MODULE_LICENSE("GPL");