Pawel Osciak | e23ccc0 | 2010-10-11 10:56:41 -0300 | [diff] [blame^] | 1 | /* |
| 2 | * videobuf2-core.c - V4L2 driver helper framework |
| 3 | * |
| 4 | * Copyright (C) 2010 Samsung Electronics |
| 5 | * |
| 6 | * Author: Pawel Osciak <p.osciak@samsung.com> |
| 7 | * 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 | |
| 24 | static int debug; |
| 25 | module_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 | |
| 40 | /** |
| 41 | * __vb2_buf_mem_alloc() - allocate video memory for the given buffer |
| 42 | */ |
| 43 | static int __vb2_buf_mem_alloc(struct vb2_buffer *vb, |
| 44 | unsigned long *plane_sizes) |
| 45 | { |
| 46 | struct vb2_queue *q = vb->vb2_queue; |
| 47 | void *mem_priv; |
| 48 | int plane; |
| 49 | |
| 50 | /* Allocate memory for all planes in this buffer */ |
| 51 | for (plane = 0; plane < vb->num_planes; ++plane) { |
| 52 | mem_priv = call_memop(q, plane, alloc, q->alloc_ctx[plane], |
| 53 | plane_sizes[plane]); |
| 54 | if (!mem_priv) |
| 55 | goto free; |
| 56 | |
| 57 | /* Associate allocator private data with this plane */ |
| 58 | vb->planes[plane].mem_priv = mem_priv; |
| 59 | vb->v4l2_planes[plane].length = plane_sizes[plane]; |
| 60 | } |
| 61 | |
| 62 | return 0; |
| 63 | free: |
| 64 | /* Free already allocated memory if one of the allocations failed */ |
| 65 | for (; plane > 0; --plane) |
| 66 | call_memop(q, plane, put, vb->planes[plane - 1].mem_priv); |
| 67 | |
| 68 | return -ENOMEM; |
| 69 | } |
| 70 | |
| 71 | /** |
| 72 | * __vb2_buf_mem_free() - free memory of the given buffer |
| 73 | */ |
| 74 | static void __vb2_buf_mem_free(struct vb2_buffer *vb) |
| 75 | { |
| 76 | struct vb2_queue *q = vb->vb2_queue; |
| 77 | unsigned int plane; |
| 78 | |
| 79 | for (plane = 0; plane < vb->num_planes; ++plane) { |
| 80 | call_memop(q, plane, put, vb->planes[plane].mem_priv); |
| 81 | vb->planes[plane].mem_priv = NULL; |
| 82 | dprintk(3, "Freed plane %d of buffer %d\n", |
| 83 | plane, vb->v4l2_buf.index); |
| 84 | } |
| 85 | } |
| 86 | |
| 87 | /** |
| 88 | * __vb2_buf_userptr_put() - release userspace memory associated with |
| 89 | * a USERPTR buffer |
| 90 | */ |
| 91 | static void __vb2_buf_userptr_put(struct vb2_buffer *vb) |
| 92 | { |
| 93 | struct vb2_queue *q = vb->vb2_queue; |
| 94 | unsigned int plane; |
| 95 | |
| 96 | for (plane = 0; plane < vb->num_planes; ++plane) { |
| 97 | void *mem_priv = vb->planes[plane].mem_priv; |
| 98 | |
| 99 | if (mem_priv) { |
| 100 | call_memop(q, plane, put_userptr, mem_priv); |
| 101 | vb->planes[plane].mem_priv = NULL; |
| 102 | } |
| 103 | } |
| 104 | } |
| 105 | |
| 106 | /** |
| 107 | * __setup_offsets() - setup unique offsets ("cookies") for every plane in |
| 108 | * every buffer on the queue |
| 109 | */ |
| 110 | static void __setup_offsets(struct vb2_queue *q) |
| 111 | { |
| 112 | unsigned int buffer, plane; |
| 113 | struct vb2_buffer *vb; |
| 114 | unsigned long off = 0; |
| 115 | |
| 116 | for (buffer = 0; buffer < q->num_buffers; ++buffer) { |
| 117 | vb = q->bufs[buffer]; |
| 118 | if (!vb) |
| 119 | continue; |
| 120 | |
| 121 | for (plane = 0; plane < vb->num_planes; ++plane) { |
| 122 | vb->v4l2_planes[plane].m.mem_offset = off; |
| 123 | |
| 124 | dprintk(3, "Buffer %d, plane %d offset 0x%08lx\n", |
| 125 | buffer, plane, off); |
| 126 | |
| 127 | off += vb->v4l2_planes[plane].length; |
| 128 | off = PAGE_ALIGN(off); |
| 129 | } |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | /** |
| 134 | * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type) |
| 135 | * video buffer memory for all buffers/planes on the queue and initializes the |
| 136 | * queue |
| 137 | * |
| 138 | * Returns the number of buffers successfully allocated. |
| 139 | */ |
| 140 | static int __vb2_queue_alloc(struct vb2_queue *q, enum v4l2_memory memory, |
| 141 | unsigned int num_buffers, unsigned int num_planes, |
| 142 | unsigned long plane_sizes[]) |
| 143 | { |
| 144 | unsigned int buffer; |
| 145 | struct vb2_buffer *vb; |
| 146 | int ret; |
| 147 | |
| 148 | for (buffer = 0; buffer < num_buffers; ++buffer) { |
| 149 | /* Allocate videobuf buffer structures */ |
| 150 | vb = kzalloc(q->buf_struct_size, GFP_KERNEL); |
| 151 | if (!vb) { |
| 152 | dprintk(1, "Memory alloc for buffer struct failed\n"); |
| 153 | break; |
| 154 | } |
| 155 | |
| 156 | /* Length stores number of planes for multiplanar buffers */ |
| 157 | if (V4L2_TYPE_IS_MULTIPLANAR(q->type)) |
| 158 | vb->v4l2_buf.length = num_planes; |
| 159 | |
| 160 | vb->state = VB2_BUF_STATE_DEQUEUED; |
| 161 | vb->vb2_queue = q; |
| 162 | vb->num_planes = num_planes; |
| 163 | vb->v4l2_buf.index = buffer; |
| 164 | vb->v4l2_buf.type = q->type; |
| 165 | vb->v4l2_buf.memory = memory; |
| 166 | |
| 167 | /* Allocate video buffer memory for the MMAP type */ |
| 168 | if (memory == V4L2_MEMORY_MMAP) { |
| 169 | ret = __vb2_buf_mem_alloc(vb, plane_sizes); |
| 170 | if (ret) { |
| 171 | dprintk(1, "Failed allocating memory for " |
| 172 | "buffer %d\n", buffer); |
| 173 | kfree(vb); |
| 174 | break; |
| 175 | } |
| 176 | /* |
| 177 | * Call the driver-provided buffer initialization |
| 178 | * callback, if given. An error in initialization |
| 179 | * results in queue setup failure. |
| 180 | */ |
| 181 | ret = call_qop(q, buf_init, vb); |
| 182 | if (ret) { |
| 183 | dprintk(1, "Buffer %d %p initialization" |
| 184 | " failed\n", buffer, vb); |
| 185 | __vb2_buf_mem_free(vb); |
| 186 | kfree(vb); |
| 187 | break; |
| 188 | } |
| 189 | } |
| 190 | |
| 191 | q->bufs[buffer] = vb; |
| 192 | } |
| 193 | |
| 194 | q->num_buffers = buffer; |
| 195 | |
| 196 | __setup_offsets(q); |
| 197 | |
| 198 | dprintk(1, "Allocated %d buffers, %d plane(s) each\n", |
| 199 | q->num_buffers, num_planes); |
| 200 | |
| 201 | return buffer; |
| 202 | } |
| 203 | |
| 204 | /** |
| 205 | * __vb2_free_mem() - release all video buffer memory for a given queue |
| 206 | */ |
| 207 | static void __vb2_free_mem(struct vb2_queue *q) |
| 208 | { |
| 209 | unsigned int buffer; |
| 210 | struct vb2_buffer *vb; |
| 211 | |
| 212 | for (buffer = 0; buffer < q->num_buffers; ++buffer) { |
| 213 | vb = q->bufs[buffer]; |
| 214 | if (!vb) |
| 215 | continue; |
| 216 | |
| 217 | /* Free MMAP buffers or release USERPTR buffers */ |
| 218 | if (q->memory == V4L2_MEMORY_MMAP) |
| 219 | __vb2_buf_mem_free(vb); |
| 220 | else |
| 221 | __vb2_buf_userptr_put(vb); |
| 222 | } |
| 223 | } |
| 224 | |
| 225 | /** |
| 226 | * __vb2_queue_free() - free the queue - video memory and related information |
| 227 | * and return the queue to an uninitialized state. Might be called even if the |
| 228 | * queue has already been freed. |
| 229 | */ |
| 230 | static int __vb2_queue_free(struct vb2_queue *q) |
| 231 | { |
| 232 | unsigned int buffer; |
| 233 | |
| 234 | /* Call driver-provided cleanup function for each buffer, if provided */ |
| 235 | if (q->ops->buf_cleanup) { |
| 236 | for (buffer = 0; buffer < q->num_buffers; ++buffer) { |
| 237 | if (NULL == q->bufs[buffer]) |
| 238 | continue; |
| 239 | q->ops->buf_cleanup(q->bufs[buffer]); |
| 240 | } |
| 241 | } |
| 242 | |
| 243 | /* Release video buffer memory */ |
| 244 | __vb2_free_mem(q); |
| 245 | |
| 246 | /* Free videobuf buffers */ |
| 247 | for (buffer = 0; buffer < q->num_buffers; ++buffer) { |
| 248 | kfree(q->bufs[buffer]); |
| 249 | q->bufs[buffer] = NULL; |
| 250 | } |
| 251 | |
| 252 | q->num_buffers = 0; |
| 253 | q->memory = 0; |
| 254 | |
| 255 | return 0; |
| 256 | } |
| 257 | |
| 258 | /** |
| 259 | * __verify_planes_array() - verify that the planes array passed in struct |
| 260 | * v4l2_buffer from userspace can be safely used |
| 261 | */ |
| 262 | static int __verify_planes_array(struct vb2_buffer *vb, struct v4l2_buffer *b) |
| 263 | { |
| 264 | /* Is memory for copying plane information present? */ |
| 265 | if (NULL == b->m.planes) { |
| 266 | dprintk(1, "Multi-planar buffer passed but " |
| 267 | "planes array not provided\n"); |
| 268 | return -EINVAL; |
| 269 | } |
| 270 | |
| 271 | if (b->length < vb->num_planes || b->length > VIDEO_MAX_PLANES) { |
| 272 | dprintk(1, "Incorrect planes array length, " |
| 273 | "expected %d, got %d\n", vb->num_planes, b->length); |
| 274 | return -EINVAL; |
| 275 | } |
| 276 | |
| 277 | return 0; |
| 278 | } |
| 279 | |
| 280 | /** |
| 281 | * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be |
| 282 | * returned to userspace |
| 283 | */ |
| 284 | static int __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b) |
| 285 | { |
| 286 | struct vb2_queue *q = vb->vb2_queue; |
| 287 | int ret = 0; |
| 288 | |
| 289 | /* Copy back data such as timestamp, input, etc. */ |
| 290 | memcpy(b, &vb->v4l2_buf, offsetof(struct v4l2_buffer, m)); |
| 291 | b->input = vb->v4l2_buf.input; |
| 292 | b->reserved = vb->v4l2_buf.reserved; |
| 293 | |
| 294 | if (V4L2_TYPE_IS_MULTIPLANAR(q->type)) { |
| 295 | ret = __verify_planes_array(vb, b); |
| 296 | if (ret) |
| 297 | return ret; |
| 298 | |
| 299 | /* |
| 300 | * Fill in plane-related data if userspace provided an array |
| 301 | * for it. The memory and size is verified above. |
| 302 | */ |
| 303 | memcpy(b->m.planes, vb->v4l2_planes, |
| 304 | b->length * sizeof(struct v4l2_plane)); |
| 305 | } else { |
| 306 | /* |
| 307 | * We use length and offset in v4l2_planes array even for |
| 308 | * single-planar buffers, but userspace does not. |
| 309 | */ |
| 310 | b->length = vb->v4l2_planes[0].length; |
| 311 | b->bytesused = vb->v4l2_planes[0].bytesused; |
| 312 | if (q->memory == V4L2_MEMORY_MMAP) |
| 313 | b->m.offset = vb->v4l2_planes[0].m.mem_offset; |
| 314 | else if (q->memory == V4L2_MEMORY_USERPTR) |
| 315 | b->m.userptr = vb->v4l2_planes[0].m.userptr; |
| 316 | } |
| 317 | |
| 318 | b->flags = 0; |
| 319 | |
| 320 | switch (vb->state) { |
| 321 | case VB2_BUF_STATE_QUEUED: |
| 322 | case VB2_BUF_STATE_ACTIVE: |
| 323 | b->flags |= V4L2_BUF_FLAG_QUEUED; |
| 324 | break; |
| 325 | case VB2_BUF_STATE_ERROR: |
| 326 | b->flags |= V4L2_BUF_FLAG_ERROR; |
| 327 | /* fall through */ |
| 328 | case VB2_BUF_STATE_DONE: |
| 329 | b->flags |= V4L2_BUF_FLAG_DONE; |
| 330 | break; |
| 331 | case VB2_BUF_STATE_DEQUEUED: |
| 332 | /* nothing */ |
| 333 | break; |
| 334 | } |
| 335 | |
| 336 | if (vb->num_planes_mapped == vb->num_planes) |
| 337 | b->flags |= V4L2_BUF_FLAG_MAPPED; |
| 338 | |
| 339 | return ret; |
| 340 | } |
| 341 | |
| 342 | /** |
| 343 | * vb2_querybuf() - query video buffer information |
| 344 | * @q: videobuf queue |
| 345 | * @b: buffer struct passed from userspace to vidioc_querybuf handler |
| 346 | * in driver |
| 347 | * |
| 348 | * Should be called from vidioc_querybuf ioctl handler in driver. |
| 349 | * This function will verify the passed v4l2_buffer structure and fill the |
| 350 | * relevant information for the userspace. |
| 351 | * |
| 352 | * The return values from this function are intended to be directly returned |
| 353 | * from vidioc_querybuf handler in driver. |
| 354 | */ |
| 355 | int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b) |
| 356 | { |
| 357 | struct vb2_buffer *vb; |
| 358 | |
| 359 | if (b->type != q->type) { |
| 360 | dprintk(1, "querybuf: wrong buffer type\n"); |
| 361 | return -EINVAL; |
| 362 | } |
| 363 | |
| 364 | if (b->index >= q->num_buffers) { |
| 365 | dprintk(1, "querybuf: buffer index out of range\n"); |
| 366 | return -EINVAL; |
| 367 | } |
| 368 | vb = q->bufs[b->index]; |
| 369 | |
| 370 | return __fill_v4l2_buffer(vb, b); |
| 371 | } |
| 372 | EXPORT_SYMBOL(vb2_querybuf); |
| 373 | |
| 374 | /** |
| 375 | * __verify_userptr_ops() - verify that all memory operations required for |
| 376 | * USERPTR queue type have been provided |
| 377 | */ |
| 378 | static int __verify_userptr_ops(struct vb2_queue *q) |
| 379 | { |
| 380 | if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr || |
| 381 | !q->mem_ops->put_userptr) |
| 382 | return -EINVAL; |
| 383 | |
| 384 | return 0; |
| 385 | } |
| 386 | |
| 387 | /** |
| 388 | * __verify_mmap_ops() - verify that all memory operations required for |
| 389 | * MMAP queue type have been provided |
| 390 | */ |
| 391 | static int __verify_mmap_ops(struct vb2_queue *q) |
| 392 | { |
| 393 | if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc || |
| 394 | !q->mem_ops->put || !q->mem_ops->mmap) |
| 395 | return -EINVAL; |
| 396 | |
| 397 | return 0; |
| 398 | } |
| 399 | |
| 400 | /** |
| 401 | * __buffers_in_use() - return true if any buffers on the queue are in use and |
| 402 | * the queue cannot be freed (by the means of REQBUFS(0)) call |
| 403 | */ |
| 404 | static bool __buffers_in_use(struct vb2_queue *q) |
| 405 | { |
| 406 | unsigned int buffer, plane; |
| 407 | struct vb2_buffer *vb; |
| 408 | |
| 409 | for (buffer = 0; buffer < q->num_buffers; ++buffer) { |
| 410 | vb = q->bufs[buffer]; |
| 411 | for (plane = 0; plane < vb->num_planes; ++plane) { |
| 412 | /* |
| 413 | * If num_users() has not been provided, call_memop |
| 414 | * will return 0, apparently nobody cares about this |
| 415 | * case anyway. If num_users() returns more than 1, |
| 416 | * we are not the only user of the plane's memory. |
| 417 | */ |
| 418 | if (call_memop(q, plane, num_users, |
| 419 | vb->planes[plane].mem_priv) > 1) |
| 420 | return true; |
| 421 | } |
| 422 | } |
| 423 | |
| 424 | return false; |
| 425 | } |
| 426 | |
| 427 | /** |
| 428 | * vb2_reqbufs() - Initiate streaming |
| 429 | * @q: videobuf2 queue |
| 430 | * @req: struct passed from userspace to vidioc_reqbufs handler in driver |
| 431 | * |
| 432 | * Should be called from vidioc_reqbufs ioctl handler of a driver. |
| 433 | * This function: |
| 434 | * 1) verifies streaming parameters passed from the userspace, |
| 435 | * 2) sets up the queue, |
| 436 | * 3) negotiates number of buffers and planes per buffer with the driver |
| 437 | * to be used during streaming, |
| 438 | * 4) allocates internal buffer structures (struct vb2_buffer), according to |
| 439 | * the agreed parameters, |
| 440 | * 5) for MMAP memory type, allocates actual video memory, using the |
| 441 | * memory handling/allocation routines provided during queue initialization |
| 442 | * |
| 443 | * If req->count is 0, all the memory will be freed instead. |
| 444 | * If the queue has been allocated previously (by a previous vb2_reqbufs) call |
| 445 | * and the queue is not busy, memory will be reallocated. |
| 446 | * |
| 447 | * The return values from this function are intended to be directly returned |
| 448 | * from vidioc_reqbufs handler in driver. |
| 449 | */ |
| 450 | int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req) |
| 451 | { |
| 452 | unsigned int num_buffers, num_planes; |
| 453 | unsigned long plane_sizes[VIDEO_MAX_PLANES]; |
| 454 | int ret = 0; |
| 455 | |
| 456 | if (req->memory != V4L2_MEMORY_MMAP |
| 457 | && req->memory != V4L2_MEMORY_USERPTR) { |
| 458 | dprintk(1, "reqbufs: unsupported memory type\n"); |
| 459 | return -EINVAL; |
| 460 | } |
| 461 | |
| 462 | if (req->type != q->type) { |
| 463 | dprintk(1, "reqbufs: requested type is incorrect\n"); |
| 464 | return -EINVAL; |
| 465 | } |
| 466 | |
| 467 | if (q->streaming) { |
| 468 | dprintk(1, "reqbufs: streaming active\n"); |
| 469 | return -EBUSY; |
| 470 | } |
| 471 | |
| 472 | /* |
| 473 | * Make sure all the required memory ops for given memory type |
| 474 | * are available. |
| 475 | */ |
| 476 | if (req->memory == V4L2_MEMORY_MMAP && __verify_mmap_ops(q)) { |
| 477 | dprintk(1, "reqbufs: MMAP for current setup unsupported\n"); |
| 478 | return -EINVAL; |
| 479 | } |
| 480 | |
| 481 | if (req->memory == V4L2_MEMORY_USERPTR && __verify_userptr_ops(q)) { |
| 482 | dprintk(1, "reqbufs: USERPTR for current setup unsupported\n"); |
| 483 | return -EINVAL; |
| 484 | } |
| 485 | |
| 486 | if (req->count == 0 || q->num_buffers != 0) { |
| 487 | /* |
| 488 | * We already have buffers allocated, so first check if they |
| 489 | * are not in use and can be freed. |
| 490 | */ |
| 491 | if (q->memory == V4L2_MEMORY_MMAP && __buffers_in_use(q)) { |
| 492 | dprintk(1, "reqbufs: memory in use, cannot free\n"); |
| 493 | return -EBUSY; |
| 494 | } |
| 495 | |
| 496 | ret = __vb2_queue_free(q); |
| 497 | if (ret != 0) |
| 498 | return ret; |
| 499 | } |
| 500 | |
| 501 | /* |
| 502 | * Make sure the requested values and current defaults are sane. |
| 503 | */ |
| 504 | num_buffers = min_t(unsigned int, req->count, VIDEO_MAX_FRAME); |
| 505 | memset(plane_sizes, 0, sizeof(plane_sizes)); |
| 506 | memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx)); |
| 507 | |
| 508 | /* |
| 509 | * Ask the driver how many buffers and planes per buffer it requires. |
| 510 | * Driver also sets the size and allocator context for each plane. |
| 511 | */ |
| 512 | ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes, |
| 513 | plane_sizes, q->alloc_ctx); |
| 514 | if (ret) |
| 515 | return ret; |
| 516 | |
| 517 | /* Finally, allocate buffers and video memory */ |
| 518 | ret = __vb2_queue_alloc(q, req->memory, num_buffers, num_planes, |
| 519 | plane_sizes); |
| 520 | if (ret < 0) { |
| 521 | dprintk(1, "Memory allocation failed with error: %d\n", ret); |
| 522 | return ret; |
| 523 | } |
| 524 | |
| 525 | /* |
| 526 | * Check if driver can handle the allocated number of buffers. |
| 527 | */ |
| 528 | if (ret < num_buffers) { |
| 529 | unsigned int orig_num_buffers; |
| 530 | |
| 531 | orig_num_buffers = num_buffers = ret; |
| 532 | ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes, |
| 533 | plane_sizes, q->alloc_ctx); |
| 534 | if (ret) |
| 535 | goto free_mem; |
| 536 | |
| 537 | if (orig_num_buffers < num_buffers) { |
| 538 | ret = -ENOMEM; |
| 539 | goto free_mem; |
| 540 | } |
| 541 | |
| 542 | /* |
| 543 | * Ok, driver accepted smaller number of buffers. |
| 544 | */ |
| 545 | ret = num_buffers; |
| 546 | } |
| 547 | |
| 548 | q->memory = req->memory; |
| 549 | |
| 550 | /* |
| 551 | * Return the number of successfully allocated buffers |
| 552 | * to the userspace. |
| 553 | */ |
| 554 | req->count = ret; |
| 555 | |
| 556 | return 0; |
| 557 | |
| 558 | free_mem: |
| 559 | __vb2_queue_free(q); |
| 560 | return ret; |
| 561 | } |
| 562 | EXPORT_SYMBOL_GPL(vb2_reqbufs); |
| 563 | |
| 564 | /** |
| 565 | * vb2_plane_vaddr() - Return a kernel virtual address of a given plane |
| 566 | * @vb: vb2_buffer to which the plane in question belongs to |
| 567 | * @plane_no: plane number for which the address is to be returned |
| 568 | * |
| 569 | * This function returns a kernel virtual address of a given plane if |
| 570 | * such a mapping exist, NULL otherwise. |
| 571 | */ |
| 572 | void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no) |
| 573 | { |
| 574 | struct vb2_queue *q = vb->vb2_queue; |
| 575 | |
| 576 | if (plane_no > vb->num_planes) |
| 577 | return NULL; |
| 578 | |
| 579 | return call_memop(q, plane_no, vaddr, vb->planes[plane_no].mem_priv); |
| 580 | |
| 581 | } |
| 582 | EXPORT_SYMBOL_GPL(vb2_plane_vaddr); |
| 583 | |
| 584 | /** |
| 585 | * vb2_plane_cookie() - Return allocator specific cookie for the given plane |
| 586 | * @vb: vb2_buffer to which the plane in question belongs to |
| 587 | * @plane_no: plane number for which the cookie is to be returned |
| 588 | * |
| 589 | * This function returns an allocator specific cookie for a given plane if |
| 590 | * available, NULL otherwise. The allocator should provide some simple static |
| 591 | * inline function, which would convert this cookie to the allocator specific |
| 592 | * type that can be used directly by the driver to access the buffer. This can |
| 593 | * be for example physical address, pointer to scatter list or IOMMU mapping. |
| 594 | */ |
| 595 | void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no) |
| 596 | { |
| 597 | struct vb2_queue *q = vb->vb2_queue; |
| 598 | |
| 599 | if (plane_no > vb->num_planes) |
| 600 | return NULL; |
| 601 | |
| 602 | return call_memop(q, plane_no, cookie, vb->planes[plane_no].mem_priv); |
| 603 | } |
| 604 | EXPORT_SYMBOL_GPL(vb2_plane_cookie); |
| 605 | |
| 606 | /** |
| 607 | * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished |
| 608 | * @vb: vb2_buffer returned from the driver |
| 609 | * @state: either VB2_BUF_STATE_DONE if the operation finished successfully |
| 610 | * or VB2_BUF_STATE_ERROR if the operation finished with an error |
| 611 | * |
| 612 | * This function should be called by the driver after a hardware operation on |
| 613 | * a buffer is finished and the buffer may be returned to userspace. The driver |
| 614 | * cannot use this buffer anymore until it is queued back to it by videobuf |
| 615 | * by the means of buf_queue callback. Only buffers previously queued to the |
| 616 | * driver by buf_queue can be passed to this function. |
| 617 | */ |
| 618 | void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state) |
| 619 | { |
| 620 | struct vb2_queue *q = vb->vb2_queue; |
| 621 | unsigned long flags; |
| 622 | |
| 623 | if (vb->state != VB2_BUF_STATE_ACTIVE) |
| 624 | return; |
| 625 | |
| 626 | if (state != VB2_BUF_STATE_DONE && state != VB2_BUF_STATE_ERROR) |
| 627 | return; |
| 628 | |
| 629 | dprintk(4, "Done processing on buffer %d, state: %d\n", |
| 630 | vb->v4l2_buf.index, vb->state); |
| 631 | |
| 632 | /* Add the buffer to the done buffers list */ |
| 633 | spin_lock_irqsave(&q->done_lock, flags); |
| 634 | vb->state = state; |
| 635 | list_add_tail(&vb->done_entry, &q->done_list); |
| 636 | atomic_dec(&q->queued_count); |
| 637 | spin_unlock_irqrestore(&q->done_lock, flags); |
| 638 | |
| 639 | /* Inform any processes that may be waiting for buffers */ |
| 640 | wake_up(&q->done_wq); |
| 641 | } |
| 642 | EXPORT_SYMBOL_GPL(vb2_buffer_done); |
| 643 | |
| 644 | /** |
| 645 | * __fill_vb2_buffer() - fill a vb2_buffer with information provided in |
| 646 | * a v4l2_buffer by the userspace |
| 647 | */ |
| 648 | static int __fill_vb2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b, |
| 649 | struct v4l2_plane *v4l2_planes) |
| 650 | { |
| 651 | unsigned int plane; |
| 652 | int ret; |
| 653 | |
| 654 | if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) { |
| 655 | /* |
| 656 | * Verify that the userspace gave us a valid array for |
| 657 | * plane information. |
| 658 | */ |
| 659 | ret = __verify_planes_array(vb, b); |
| 660 | if (ret) |
| 661 | return ret; |
| 662 | |
| 663 | /* Fill in driver-provided information for OUTPUT types */ |
| 664 | if (V4L2_TYPE_IS_OUTPUT(b->type)) { |
| 665 | /* |
| 666 | * Will have to go up to b->length when API starts |
| 667 | * accepting variable number of planes. |
| 668 | */ |
| 669 | for (plane = 0; plane < vb->num_planes; ++plane) { |
| 670 | v4l2_planes[plane].bytesused = |
| 671 | b->m.planes[plane].bytesused; |
| 672 | v4l2_planes[plane].data_offset = |
| 673 | b->m.planes[plane].data_offset; |
| 674 | } |
| 675 | } |
| 676 | |
| 677 | if (b->memory == V4L2_MEMORY_USERPTR) { |
| 678 | for (plane = 0; plane < vb->num_planes; ++plane) { |
| 679 | v4l2_planes[plane].m.userptr = |
| 680 | b->m.planes[plane].m.userptr; |
| 681 | v4l2_planes[plane].length = |
| 682 | b->m.planes[plane].length; |
| 683 | } |
| 684 | } |
| 685 | } else { |
| 686 | /* |
| 687 | * Single-planar buffers do not use planes array, |
| 688 | * so fill in relevant v4l2_buffer struct fields instead. |
| 689 | * In videobuf we use our internal V4l2_planes struct for |
| 690 | * single-planar buffers as well, for simplicity. |
| 691 | */ |
| 692 | if (V4L2_TYPE_IS_OUTPUT(b->type)) |
| 693 | v4l2_planes[0].bytesused = b->bytesused; |
| 694 | |
| 695 | if (b->memory == V4L2_MEMORY_USERPTR) { |
| 696 | v4l2_planes[0].m.userptr = b->m.userptr; |
| 697 | v4l2_planes[0].length = b->length; |
| 698 | } |
| 699 | } |
| 700 | |
| 701 | vb->v4l2_buf.field = b->field; |
| 702 | vb->v4l2_buf.timestamp = b->timestamp; |
| 703 | |
| 704 | return 0; |
| 705 | } |
| 706 | |
| 707 | /** |
| 708 | * __qbuf_userptr() - handle qbuf of a USERPTR buffer |
| 709 | */ |
| 710 | static int __qbuf_userptr(struct vb2_buffer *vb, struct v4l2_buffer *b) |
| 711 | { |
| 712 | struct v4l2_plane planes[VIDEO_MAX_PLANES]; |
| 713 | struct vb2_queue *q = vb->vb2_queue; |
| 714 | void *mem_priv; |
| 715 | unsigned int plane; |
| 716 | int ret; |
| 717 | int write = !V4L2_TYPE_IS_OUTPUT(q->type); |
| 718 | |
| 719 | /* Verify and copy relevant information provided by the userspace */ |
| 720 | ret = __fill_vb2_buffer(vb, b, planes); |
| 721 | if (ret) |
| 722 | return ret; |
| 723 | |
| 724 | for (plane = 0; plane < vb->num_planes; ++plane) { |
| 725 | /* Skip the plane if already verified */ |
| 726 | if (vb->v4l2_planes[plane].m.userptr == planes[plane].m.userptr |
| 727 | && vb->v4l2_planes[plane].length == planes[plane].length) |
| 728 | continue; |
| 729 | |
| 730 | dprintk(3, "qbuf: userspace address for plane %d changed, " |
| 731 | "reacquiring memory\n", plane); |
| 732 | |
| 733 | /* Release previously acquired memory if present */ |
| 734 | if (vb->planes[plane].mem_priv) |
| 735 | call_memop(q, plane, put_userptr, |
| 736 | vb->planes[plane].mem_priv); |
| 737 | |
| 738 | vb->planes[plane].mem_priv = NULL; |
| 739 | |
| 740 | /* Acquire each plane's memory */ |
| 741 | if (q->mem_ops->get_userptr) { |
| 742 | mem_priv = q->mem_ops->get_userptr(q->alloc_ctx[plane], |
| 743 | planes[plane].m.userptr, |
| 744 | planes[plane].length, |
| 745 | write); |
| 746 | if (IS_ERR(mem_priv)) { |
| 747 | dprintk(1, "qbuf: failed acquiring userspace " |
| 748 | "memory for plane %d\n", plane); |
| 749 | ret = PTR_ERR(mem_priv); |
| 750 | goto err; |
| 751 | } |
| 752 | vb->planes[plane].mem_priv = mem_priv; |
| 753 | } |
| 754 | } |
| 755 | |
| 756 | /* |
| 757 | * Call driver-specific initialization on the newly acquired buffer, |
| 758 | * if provided. |
| 759 | */ |
| 760 | ret = call_qop(q, buf_init, vb); |
| 761 | if (ret) { |
| 762 | dprintk(1, "qbuf: buffer initialization failed\n"); |
| 763 | goto err; |
| 764 | } |
| 765 | |
| 766 | /* |
| 767 | * Now that everything is in order, copy relevant information |
| 768 | * provided by userspace. |
| 769 | */ |
| 770 | for (plane = 0; plane < vb->num_planes; ++plane) |
| 771 | vb->v4l2_planes[plane] = planes[plane]; |
| 772 | |
| 773 | return 0; |
| 774 | err: |
| 775 | /* In case of errors, release planes that were already acquired */ |
| 776 | for (; plane > 0; --plane) { |
| 777 | call_memop(q, plane, put_userptr, |
| 778 | vb->planes[plane - 1].mem_priv); |
| 779 | vb->planes[plane - 1].mem_priv = NULL; |
| 780 | } |
| 781 | |
| 782 | return ret; |
| 783 | } |
| 784 | |
| 785 | /** |
| 786 | * __qbuf_mmap() - handle qbuf of an MMAP buffer |
| 787 | */ |
| 788 | static int __qbuf_mmap(struct vb2_buffer *vb, struct v4l2_buffer *b) |
| 789 | { |
| 790 | return __fill_vb2_buffer(vb, b, vb->v4l2_planes); |
| 791 | } |
| 792 | |
| 793 | /** |
| 794 | * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing |
| 795 | */ |
| 796 | static void __enqueue_in_driver(struct vb2_buffer *vb) |
| 797 | { |
| 798 | struct vb2_queue *q = vb->vb2_queue; |
| 799 | |
| 800 | vb->state = VB2_BUF_STATE_ACTIVE; |
| 801 | atomic_inc(&q->queued_count); |
| 802 | q->ops->buf_queue(vb); |
| 803 | } |
| 804 | |
| 805 | /** |
| 806 | * vb2_qbuf() - Queue a buffer from userspace |
| 807 | * @q: videobuf2 queue |
| 808 | * @b: buffer structure passed from userspace to vidioc_qbuf handler |
| 809 | * in driver |
| 810 | * |
| 811 | * Should be called from vidioc_qbuf ioctl handler of a driver. |
| 812 | * This function: |
| 813 | * 1) verifies the passed buffer, |
| 814 | * 2) calls buf_prepare callback in the driver (if provided), in which |
| 815 | * driver-specific buffer initialization can be performed, |
| 816 | * 3) if streaming is on, queues the buffer in driver by the means of buf_queue |
| 817 | * callback for processing. |
| 818 | * |
| 819 | * The return values from this function are intended to be directly returned |
| 820 | * from vidioc_qbuf handler in driver. |
| 821 | */ |
| 822 | int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b) |
| 823 | { |
| 824 | struct vb2_buffer *vb; |
| 825 | int ret = 0; |
| 826 | |
| 827 | if (b->type != q->type) { |
| 828 | dprintk(1, "qbuf: invalid buffer type\n"); |
| 829 | return -EINVAL; |
| 830 | } |
| 831 | |
| 832 | if (b->index >= q->num_buffers) { |
| 833 | dprintk(1, "qbuf: buffer index out of range\n"); |
| 834 | return -EINVAL; |
| 835 | } |
| 836 | |
| 837 | vb = q->bufs[b->index]; |
| 838 | if (NULL == vb) { |
| 839 | /* Should never happen */ |
| 840 | dprintk(1, "qbuf: buffer is NULL\n"); |
| 841 | return -EINVAL; |
| 842 | } |
| 843 | |
| 844 | if (b->memory != q->memory) { |
| 845 | dprintk(1, "qbuf: invalid memory type\n"); |
| 846 | return -EINVAL; |
| 847 | } |
| 848 | |
| 849 | if (vb->state != VB2_BUF_STATE_DEQUEUED) { |
| 850 | dprintk(1, "qbuf: buffer already in use\n"); |
| 851 | return -EINVAL; |
| 852 | } |
| 853 | |
| 854 | if (q->memory == V4L2_MEMORY_MMAP) |
| 855 | ret = __qbuf_mmap(vb, b); |
| 856 | else if (q->memory == V4L2_MEMORY_USERPTR) |
| 857 | ret = __qbuf_userptr(vb, b); |
| 858 | else { |
| 859 | WARN(1, "Invalid queue type\n"); |
| 860 | return -EINVAL; |
| 861 | } |
| 862 | |
| 863 | if (ret) |
| 864 | return ret; |
| 865 | |
| 866 | ret = call_qop(q, buf_prepare, vb); |
| 867 | if (ret) { |
| 868 | dprintk(1, "qbuf: buffer preparation failed\n"); |
| 869 | return ret; |
| 870 | } |
| 871 | |
| 872 | /* |
| 873 | * Add to the queued buffers list, a buffer will stay on it until |
| 874 | * dequeued in dqbuf. |
| 875 | */ |
| 876 | list_add_tail(&vb->queued_entry, &q->queued_list); |
| 877 | vb->state = VB2_BUF_STATE_QUEUED; |
| 878 | |
| 879 | /* |
| 880 | * If already streaming, give the buffer to driver for processing. |
| 881 | * If not, the buffer will be given to driver on next streamon. |
| 882 | */ |
| 883 | if (q->streaming) |
| 884 | __enqueue_in_driver(vb); |
| 885 | |
| 886 | dprintk(1, "qbuf of buffer %d succeeded\n", vb->v4l2_buf.index); |
| 887 | return 0; |
| 888 | } |
| 889 | EXPORT_SYMBOL_GPL(vb2_qbuf); |
| 890 | |
| 891 | /** |
| 892 | * __vb2_wait_for_done_vb() - wait for a buffer to become available |
| 893 | * for dequeuing |
| 894 | * |
| 895 | * Will sleep if required for nonblocking == false. |
| 896 | */ |
| 897 | static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking) |
| 898 | { |
| 899 | /* |
| 900 | * All operations on vb_done_list are performed under done_lock |
| 901 | * spinlock protection. However, buffers may be removed from |
| 902 | * it and returned to userspace only while holding both driver's |
| 903 | * lock and the done_lock spinlock. Thus we can be sure that as |
| 904 | * long as we hold the driver's lock, the list will remain not |
| 905 | * empty if list_empty() check succeeds. |
| 906 | */ |
| 907 | |
| 908 | for (;;) { |
| 909 | int ret; |
| 910 | |
| 911 | if (!q->streaming) { |
| 912 | dprintk(1, "Streaming off, will not wait for buffers\n"); |
| 913 | return -EINVAL; |
| 914 | } |
| 915 | |
| 916 | if (!list_empty(&q->done_list)) { |
| 917 | /* |
| 918 | * Found a buffer that we were waiting for. |
| 919 | */ |
| 920 | break; |
| 921 | } |
| 922 | |
| 923 | if (nonblocking) { |
| 924 | dprintk(1, "Nonblocking and no buffers to dequeue, " |
| 925 | "will not wait\n"); |
| 926 | return -EAGAIN; |
| 927 | } |
| 928 | |
| 929 | /* |
| 930 | * We are streaming and blocking, wait for another buffer to |
| 931 | * become ready or for streamoff. Driver's lock is released to |
| 932 | * allow streamoff or qbuf to be called while waiting. |
| 933 | */ |
| 934 | call_qop(q, wait_prepare, q); |
| 935 | |
| 936 | /* |
| 937 | * All locks have been released, it is safe to sleep now. |
| 938 | */ |
| 939 | dprintk(3, "Will sleep waiting for buffers\n"); |
| 940 | ret = wait_event_interruptible(q->done_wq, |
| 941 | !list_empty(&q->done_list) || !q->streaming); |
| 942 | |
| 943 | /* |
| 944 | * We need to reevaluate both conditions again after reacquiring |
| 945 | * the locks or return an error if one occurred. |
| 946 | */ |
| 947 | call_qop(q, wait_finish, q); |
| 948 | if (ret) |
| 949 | return ret; |
| 950 | } |
| 951 | return 0; |
| 952 | } |
| 953 | |
| 954 | /** |
| 955 | * __vb2_get_done_vb() - get a buffer ready for dequeuing |
| 956 | * |
| 957 | * Will sleep if required for nonblocking == false. |
| 958 | */ |
| 959 | static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb, |
| 960 | int nonblocking) |
| 961 | { |
| 962 | unsigned long flags; |
| 963 | int ret; |
| 964 | |
| 965 | /* |
| 966 | * Wait for at least one buffer to become available on the done_list. |
| 967 | */ |
| 968 | ret = __vb2_wait_for_done_vb(q, nonblocking); |
| 969 | if (ret) |
| 970 | return ret; |
| 971 | |
| 972 | /* |
| 973 | * Driver's lock has been held since we last verified that done_list |
| 974 | * is not empty, so no need for another list_empty(done_list) check. |
| 975 | */ |
| 976 | spin_lock_irqsave(&q->done_lock, flags); |
| 977 | *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry); |
| 978 | list_del(&(*vb)->done_entry); |
| 979 | spin_unlock_irqrestore(&q->done_lock, flags); |
| 980 | |
| 981 | return 0; |
| 982 | } |
| 983 | |
| 984 | /** |
| 985 | * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2 |
| 986 | * @q: videobuf2 queue |
| 987 | * |
| 988 | * This function will wait until all buffers that have been given to the driver |
| 989 | * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call |
| 990 | * wait_prepare, wait_finish pair. It is intended to be called with all locks |
| 991 | * taken, for example from stop_streaming() callback. |
| 992 | */ |
| 993 | int vb2_wait_for_all_buffers(struct vb2_queue *q) |
| 994 | { |
| 995 | if (!q->streaming) { |
| 996 | dprintk(1, "Streaming off, will not wait for buffers\n"); |
| 997 | return -EINVAL; |
| 998 | } |
| 999 | |
| 1000 | wait_event(q->done_wq, !atomic_read(&q->queued_count)); |
| 1001 | return 0; |
| 1002 | } |
| 1003 | EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers); |
| 1004 | |
| 1005 | /** |
| 1006 | * vb2_dqbuf() - Dequeue a buffer to the userspace |
| 1007 | * @q: videobuf2 queue |
| 1008 | * @b: buffer structure passed from userspace to vidioc_dqbuf handler |
| 1009 | * in driver |
| 1010 | * @nonblocking: if true, this call will not sleep waiting for a buffer if no |
| 1011 | * buffers ready for dequeuing are present. Normally the driver |
| 1012 | * would be passing (file->f_flags & O_NONBLOCK) here |
| 1013 | * |
| 1014 | * Should be called from vidioc_dqbuf ioctl handler of a driver. |
| 1015 | * This function: |
| 1016 | * 1) verifies the passed buffer, |
| 1017 | * 2) calls buf_finish callback in the driver (if provided), in which |
| 1018 | * driver can perform any additional operations that may be required before |
| 1019 | * returning the buffer to userspace, such as cache sync, |
| 1020 | * 3) the buffer struct members are filled with relevant information for |
| 1021 | * the userspace. |
| 1022 | * |
| 1023 | * The return values from this function are intended to be directly returned |
| 1024 | * from vidioc_dqbuf handler in driver. |
| 1025 | */ |
| 1026 | int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking) |
| 1027 | { |
| 1028 | struct vb2_buffer *vb = NULL; |
| 1029 | int ret; |
| 1030 | |
| 1031 | if (b->type != q->type) { |
| 1032 | dprintk(1, "dqbuf: invalid buffer type\n"); |
| 1033 | return -EINVAL; |
| 1034 | } |
| 1035 | |
| 1036 | ret = __vb2_get_done_vb(q, &vb, nonblocking); |
| 1037 | if (ret < 0) { |
| 1038 | dprintk(1, "dqbuf: error getting next done buffer\n"); |
| 1039 | return ret; |
| 1040 | } |
| 1041 | |
| 1042 | ret = call_qop(q, buf_finish, vb); |
| 1043 | if (ret) { |
| 1044 | dprintk(1, "dqbuf: buffer finish failed\n"); |
| 1045 | return ret; |
| 1046 | } |
| 1047 | |
| 1048 | switch (vb->state) { |
| 1049 | case VB2_BUF_STATE_DONE: |
| 1050 | dprintk(3, "dqbuf: Returning done buffer\n"); |
| 1051 | break; |
| 1052 | case VB2_BUF_STATE_ERROR: |
| 1053 | dprintk(3, "dqbuf: Returning done buffer with errors\n"); |
| 1054 | break; |
| 1055 | default: |
| 1056 | dprintk(1, "dqbuf: Invalid buffer state\n"); |
| 1057 | return -EINVAL; |
| 1058 | } |
| 1059 | |
| 1060 | /* Fill buffer information for the userspace */ |
| 1061 | __fill_v4l2_buffer(vb, b); |
| 1062 | /* Remove from videobuf queue */ |
| 1063 | list_del(&vb->queued_entry); |
| 1064 | |
| 1065 | dprintk(1, "dqbuf of buffer %d, with state %d\n", |
| 1066 | vb->v4l2_buf.index, vb->state); |
| 1067 | |
| 1068 | vb->state = VB2_BUF_STATE_DEQUEUED; |
| 1069 | return 0; |
| 1070 | } |
| 1071 | EXPORT_SYMBOL_GPL(vb2_dqbuf); |
| 1072 | |
| 1073 | /** |
| 1074 | * vb2_streamon - start streaming |
| 1075 | * @q: videobuf2 queue |
| 1076 | * @type: type argument passed from userspace to vidioc_streamon handler |
| 1077 | * |
| 1078 | * Should be called from vidioc_streamon handler of a driver. |
| 1079 | * This function: |
| 1080 | * 1) verifies current state |
| 1081 | * 2) starts streaming and passes any previously queued buffers to the driver |
| 1082 | * |
| 1083 | * The return values from this function are intended to be directly returned |
| 1084 | * from vidioc_streamon handler in the driver. |
| 1085 | */ |
| 1086 | int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type) |
| 1087 | { |
| 1088 | struct vb2_buffer *vb; |
| 1089 | |
| 1090 | if (type != q->type) { |
| 1091 | dprintk(1, "streamon: invalid stream type\n"); |
| 1092 | return -EINVAL; |
| 1093 | } |
| 1094 | |
| 1095 | if (q->streaming) { |
| 1096 | dprintk(1, "streamon: already streaming\n"); |
| 1097 | return -EBUSY; |
| 1098 | } |
| 1099 | |
| 1100 | /* |
| 1101 | * Cannot start streaming on an OUTPUT device if no buffers have |
| 1102 | * been queued yet. |
| 1103 | */ |
| 1104 | if (V4L2_TYPE_IS_OUTPUT(q->type)) { |
| 1105 | if (list_empty(&q->queued_list)) { |
| 1106 | dprintk(1, "streamon: no output buffers queued\n"); |
| 1107 | return -EINVAL; |
| 1108 | } |
| 1109 | } |
| 1110 | |
| 1111 | q->streaming = 1; |
| 1112 | |
| 1113 | /* |
| 1114 | * Let driver notice that streaming state has been enabled. |
| 1115 | */ |
| 1116 | call_qop(q, start_streaming, q); |
| 1117 | |
| 1118 | /* |
| 1119 | * If any buffers were queued before streamon, |
| 1120 | * we can now pass them to driver for processing. |
| 1121 | */ |
| 1122 | list_for_each_entry(vb, &q->queued_list, queued_entry) |
| 1123 | __enqueue_in_driver(vb); |
| 1124 | |
| 1125 | dprintk(3, "Streamon successful\n"); |
| 1126 | return 0; |
| 1127 | } |
| 1128 | EXPORT_SYMBOL_GPL(vb2_streamon); |
| 1129 | |
| 1130 | /** |
| 1131 | * __vb2_queue_cancel() - cancel and stop (pause) streaming |
| 1132 | * |
| 1133 | * Removes all queued buffers from driver's queue and all buffers queued by |
| 1134 | * userspace from videobuf's queue. Returns to state after reqbufs. |
| 1135 | */ |
| 1136 | static void __vb2_queue_cancel(struct vb2_queue *q) |
| 1137 | { |
| 1138 | unsigned int i; |
| 1139 | |
| 1140 | /* |
| 1141 | * Tell driver to stop all transactions and release all queued |
| 1142 | * buffers. |
| 1143 | */ |
| 1144 | if (q->streaming) |
| 1145 | call_qop(q, stop_streaming, q); |
| 1146 | q->streaming = 0; |
| 1147 | |
| 1148 | /* |
| 1149 | * Remove all buffers from videobuf's list... |
| 1150 | */ |
| 1151 | INIT_LIST_HEAD(&q->queued_list); |
| 1152 | /* |
| 1153 | * ...and done list; userspace will not receive any buffers it |
| 1154 | * has not already dequeued before initiating cancel. |
| 1155 | */ |
| 1156 | INIT_LIST_HEAD(&q->done_list); |
| 1157 | wake_up_all(&q->done_wq); |
| 1158 | |
| 1159 | /* |
| 1160 | * Reinitialize all buffers for next use. |
| 1161 | */ |
| 1162 | for (i = 0; i < q->num_buffers; ++i) |
| 1163 | q->bufs[i]->state = VB2_BUF_STATE_DEQUEUED; |
| 1164 | } |
| 1165 | |
| 1166 | /** |
| 1167 | * vb2_streamoff - stop streaming |
| 1168 | * @q: videobuf2 queue |
| 1169 | * @type: type argument passed from userspace to vidioc_streamoff handler |
| 1170 | * |
| 1171 | * Should be called from vidioc_streamoff handler of a driver. |
| 1172 | * This function: |
| 1173 | * 1) verifies current state, |
| 1174 | * 2) stop streaming and dequeues any queued buffers, including those previously |
| 1175 | * passed to the driver (after waiting for the driver to finish). |
| 1176 | * |
| 1177 | * This call can be used for pausing playback. |
| 1178 | * The return values from this function are intended to be directly returned |
| 1179 | * from vidioc_streamoff handler in the driver |
| 1180 | */ |
| 1181 | int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type) |
| 1182 | { |
| 1183 | if (type != q->type) { |
| 1184 | dprintk(1, "streamoff: invalid stream type\n"); |
| 1185 | return -EINVAL; |
| 1186 | } |
| 1187 | |
| 1188 | if (!q->streaming) { |
| 1189 | dprintk(1, "streamoff: not streaming\n"); |
| 1190 | return -EINVAL; |
| 1191 | } |
| 1192 | |
| 1193 | /* |
| 1194 | * Cancel will pause streaming and remove all buffers from the driver |
| 1195 | * and videobuf, effectively returning control over them to userspace. |
| 1196 | */ |
| 1197 | __vb2_queue_cancel(q); |
| 1198 | |
| 1199 | dprintk(3, "Streamoff successful\n"); |
| 1200 | return 0; |
| 1201 | } |
| 1202 | EXPORT_SYMBOL_GPL(vb2_streamoff); |
| 1203 | |
| 1204 | /** |
| 1205 | * __find_plane_by_offset() - find plane associated with the given offset off |
| 1206 | */ |
| 1207 | static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off, |
| 1208 | unsigned int *_buffer, unsigned int *_plane) |
| 1209 | { |
| 1210 | struct vb2_buffer *vb; |
| 1211 | unsigned int buffer, plane; |
| 1212 | |
| 1213 | /* |
| 1214 | * Go over all buffers and their planes, comparing the given offset |
| 1215 | * with an offset assigned to each plane. If a match is found, |
| 1216 | * return its buffer and plane numbers. |
| 1217 | */ |
| 1218 | for (buffer = 0; buffer < q->num_buffers; ++buffer) { |
| 1219 | vb = q->bufs[buffer]; |
| 1220 | |
| 1221 | for (plane = 0; plane < vb->num_planes; ++plane) { |
| 1222 | if (vb->v4l2_planes[plane].m.mem_offset == off) { |
| 1223 | *_buffer = buffer; |
| 1224 | *_plane = plane; |
| 1225 | return 0; |
| 1226 | } |
| 1227 | } |
| 1228 | } |
| 1229 | |
| 1230 | return -EINVAL; |
| 1231 | } |
| 1232 | |
| 1233 | /** |
| 1234 | * vb2_mmap() - map video buffers into application address space |
| 1235 | * @q: videobuf2 queue |
| 1236 | * @vma: vma passed to the mmap file operation handler in the driver |
| 1237 | * |
| 1238 | * Should be called from mmap file operation handler of a driver. |
| 1239 | * This function maps one plane of one of the available video buffers to |
| 1240 | * userspace. To map whole video memory allocated on reqbufs, this function |
| 1241 | * has to be called once per each plane per each buffer previously allocated. |
| 1242 | * |
| 1243 | * When the userspace application calls mmap, it passes to it an offset returned |
| 1244 | * to it earlier by the means of vidioc_querybuf handler. That offset acts as |
| 1245 | * a "cookie", which is then used to identify the plane to be mapped. |
| 1246 | * This function finds a plane with a matching offset and a mapping is performed |
| 1247 | * by the means of a provided memory operation. |
| 1248 | * |
| 1249 | * The return values from this function are intended to be directly returned |
| 1250 | * from the mmap handler in driver. |
| 1251 | */ |
| 1252 | int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma) |
| 1253 | { |
| 1254 | unsigned long off = vma->vm_pgoff << PAGE_SHIFT; |
| 1255 | struct vb2_plane *vb_plane; |
| 1256 | struct vb2_buffer *vb; |
| 1257 | unsigned int buffer, plane; |
| 1258 | int ret; |
| 1259 | |
| 1260 | if (q->memory != V4L2_MEMORY_MMAP) { |
| 1261 | dprintk(1, "Queue is not currently set up for mmap\n"); |
| 1262 | return -EINVAL; |
| 1263 | } |
| 1264 | |
| 1265 | /* |
| 1266 | * Check memory area access mode. |
| 1267 | */ |
| 1268 | if (!(vma->vm_flags & VM_SHARED)) { |
| 1269 | dprintk(1, "Invalid vma flags, VM_SHARED needed\n"); |
| 1270 | return -EINVAL; |
| 1271 | } |
| 1272 | if (V4L2_TYPE_IS_OUTPUT(q->type)) { |
| 1273 | if (!(vma->vm_flags & VM_WRITE)) { |
| 1274 | dprintk(1, "Invalid vma flags, VM_WRITE needed\n"); |
| 1275 | return -EINVAL; |
| 1276 | } |
| 1277 | } else { |
| 1278 | if (!(vma->vm_flags & VM_READ)) { |
| 1279 | dprintk(1, "Invalid vma flags, VM_READ needed\n"); |
| 1280 | return -EINVAL; |
| 1281 | } |
| 1282 | } |
| 1283 | |
| 1284 | /* |
| 1285 | * Find the plane corresponding to the offset passed by userspace. |
| 1286 | */ |
| 1287 | ret = __find_plane_by_offset(q, off, &buffer, &plane); |
| 1288 | if (ret) |
| 1289 | return ret; |
| 1290 | |
| 1291 | vb = q->bufs[buffer]; |
| 1292 | vb_plane = &vb->planes[plane]; |
| 1293 | |
| 1294 | ret = q->mem_ops->mmap(vb_plane->mem_priv, vma); |
| 1295 | if (ret) |
| 1296 | return ret; |
| 1297 | |
| 1298 | vb_plane->mapped = 1; |
| 1299 | vb->num_planes_mapped++; |
| 1300 | |
| 1301 | dprintk(3, "Buffer %d, plane %d successfully mapped\n", buffer, plane); |
| 1302 | return 0; |
| 1303 | } |
| 1304 | EXPORT_SYMBOL_GPL(vb2_mmap); |
| 1305 | |
| 1306 | |
| 1307 | /** |
| 1308 | * vb2_poll() - implements poll userspace operation |
| 1309 | * @q: videobuf2 queue |
| 1310 | * @file: file argument passed to the poll file operation handler |
| 1311 | * @wait: wait argument passed to the poll file operation handler |
| 1312 | * |
| 1313 | * This function implements poll file operation handler for a driver. |
| 1314 | * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will |
| 1315 | * be informed that the file descriptor of a video device is available for |
| 1316 | * reading. |
| 1317 | * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor |
| 1318 | * will be reported as available for writing. |
| 1319 | * |
| 1320 | * The return values from this function are intended to be directly returned |
| 1321 | * from poll handler in driver. |
| 1322 | */ |
| 1323 | unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait) |
| 1324 | { |
| 1325 | unsigned long flags; |
| 1326 | struct vb2_buffer *vb = NULL; |
| 1327 | |
| 1328 | /* |
| 1329 | * There is nothing to wait for if no buffers have already been queued. |
| 1330 | */ |
| 1331 | if (list_empty(&q->queued_list)) |
| 1332 | return POLLERR; |
| 1333 | |
| 1334 | poll_wait(file, &q->done_wq, wait); |
| 1335 | |
| 1336 | /* |
| 1337 | * Take first buffer available for dequeuing. |
| 1338 | */ |
| 1339 | spin_lock_irqsave(&q->done_lock, flags); |
| 1340 | if (!list_empty(&q->done_list)) |
| 1341 | vb = list_first_entry(&q->done_list, struct vb2_buffer, |
| 1342 | done_entry); |
| 1343 | spin_unlock_irqrestore(&q->done_lock, flags); |
| 1344 | |
| 1345 | if (vb && (vb->state == VB2_BUF_STATE_DONE |
| 1346 | || vb->state == VB2_BUF_STATE_ERROR)) { |
| 1347 | return (V4L2_TYPE_IS_OUTPUT(q->type)) ? POLLOUT | POLLWRNORM : |
| 1348 | POLLIN | POLLRDNORM; |
| 1349 | } |
| 1350 | return 0; |
| 1351 | } |
| 1352 | EXPORT_SYMBOL_GPL(vb2_poll); |
| 1353 | |
| 1354 | /** |
| 1355 | * vb2_queue_init() - initialize a videobuf2 queue |
| 1356 | * @q: videobuf2 queue; this structure should be allocated in driver |
| 1357 | * |
| 1358 | * The vb2_queue structure should be allocated by the driver. The driver is |
| 1359 | * responsible of clearing it's content and setting initial values for some |
| 1360 | * required entries before calling this function. |
| 1361 | * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer |
| 1362 | * to the struct vb2_queue description in include/media/videobuf2-core.h |
| 1363 | * for more information. |
| 1364 | */ |
| 1365 | int vb2_queue_init(struct vb2_queue *q) |
| 1366 | { |
| 1367 | BUG_ON(!q); |
| 1368 | BUG_ON(!q->ops); |
| 1369 | BUG_ON(!q->mem_ops); |
| 1370 | BUG_ON(!q->type); |
| 1371 | BUG_ON(!q->io_modes); |
| 1372 | |
| 1373 | BUG_ON(!q->ops->queue_setup); |
| 1374 | BUG_ON(!q->ops->buf_queue); |
| 1375 | |
| 1376 | INIT_LIST_HEAD(&q->queued_list); |
| 1377 | INIT_LIST_HEAD(&q->done_list); |
| 1378 | spin_lock_init(&q->done_lock); |
| 1379 | init_waitqueue_head(&q->done_wq); |
| 1380 | |
| 1381 | if (q->buf_struct_size == 0) |
| 1382 | q->buf_struct_size = sizeof(struct vb2_buffer); |
| 1383 | |
| 1384 | return 0; |
| 1385 | } |
| 1386 | EXPORT_SYMBOL_GPL(vb2_queue_init); |
| 1387 | |
| 1388 | /** |
| 1389 | * vb2_queue_release() - stop streaming, release the queue and free memory |
| 1390 | * @q: videobuf2 queue |
| 1391 | * |
| 1392 | * This function stops streaming and performs necessary clean ups, including |
| 1393 | * freeing video buffer memory. The driver is responsible for freeing |
| 1394 | * the vb2_queue structure itself. |
| 1395 | */ |
| 1396 | void vb2_queue_release(struct vb2_queue *q) |
| 1397 | { |
| 1398 | __vb2_queue_cancel(q); |
| 1399 | __vb2_queue_free(q); |
| 1400 | } |
| 1401 | EXPORT_SYMBOL_GPL(vb2_queue_release); |
| 1402 | |
| 1403 | MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2"); |
| 1404 | MODULE_AUTHOR("Pawel Osciak, Marek Szyprowski"); |
| 1405 | MODULE_LICENSE("GPL"); |