Russell King | 7bedaa5 | 2012-04-13 12:10:24 +0100 | [diff] [blame^] | 1 | /* |
| 2 | * OMAP DMAengine support |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License version 2 as |
| 6 | * published by the Free Software Foundation. |
| 7 | */ |
| 8 | #include <linux/dmaengine.h> |
| 9 | #include <linux/dma-mapping.h> |
| 10 | #include <linux/err.h> |
| 11 | #include <linux/init.h> |
| 12 | #include <linux/interrupt.h> |
| 13 | #include <linux/list.h> |
| 14 | #include <linux/module.h> |
| 15 | #include <linux/omap-dma.h> |
| 16 | #include <linux/platform_device.h> |
| 17 | #include <linux/slab.h> |
| 18 | #include <linux/spinlock.h> |
| 19 | |
| 20 | #include "virt-dma.h" |
| 21 | #include <plat/dma.h> |
| 22 | |
| 23 | struct omap_dmadev { |
| 24 | struct dma_device ddev; |
| 25 | spinlock_t lock; |
| 26 | struct tasklet_struct task; |
| 27 | struct list_head pending; |
| 28 | }; |
| 29 | |
| 30 | struct omap_chan { |
| 31 | struct virt_dma_chan vc; |
| 32 | struct list_head node; |
| 33 | |
| 34 | struct dma_slave_config cfg; |
| 35 | unsigned dma_sig; |
| 36 | |
| 37 | int dma_ch; |
| 38 | struct omap_desc *desc; |
| 39 | unsigned sgidx; |
| 40 | }; |
| 41 | |
| 42 | struct omap_sg { |
| 43 | dma_addr_t addr; |
| 44 | uint32_t en; /* number of elements (24-bit) */ |
| 45 | uint32_t fn; /* number of frames (16-bit) */ |
| 46 | }; |
| 47 | |
| 48 | struct omap_desc { |
| 49 | struct virt_dma_desc vd; |
| 50 | enum dma_transfer_direction dir; |
| 51 | dma_addr_t dev_addr; |
| 52 | |
| 53 | uint8_t es; /* OMAP_DMA_DATA_TYPE_xxx */ |
| 54 | uint8_t sync_mode; /* OMAP_DMA_SYNC_xxx */ |
| 55 | uint8_t sync_type; /* OMAP_DMA_xxx_SYNC* */ |
| 56 | uint8_t periph_port; /* Peripheral port */ |
| 57 | |
| 58 | unsigned sglen; |
| 59 | struct omap_sg sg[0]; |
| 60 | }; |
| 61 | |
| 62 | static const unsigned es_bytes[] = { |
| 63 | [OMAP_DMA_DATA_TYPE_S8] = 1, |
| 64 | [OMAP_DMA_DATA_TYPE_S16] = 2, |
| 65 | [OMAP_DMA_DATA_TYPE_S32] = 4, |
| 66 | }; |
| 67 | |
| 68 | static inline struct omap_dmadev *to_omap_dma_dev(struct dma_device *d) |
| 69 | { |
| 70 | return container_of(d, struct omap_dmadev, ddev); |
| 71 | } |
| 72 | |
| 73 | static inline struct omap_chan *to_omap_dma_chan(struct dma_chan *c) |
| 74 | { |
| 75 | return container_of(c, struct omap_chan, vc.chan); |
| 76 | } |
| 77 | |
| 78 | static inline struct omap_desc *to_omap_dma_desc(struct dma_async_tx_descriptor *t) |
| 79 | { |
| 80 | return container_of(t, struct omap_desc, vd.tx); |
| 81 | } |
| 82 | |
| 83 | static void omap_dma_desc_free(struct virt_dma_desc *vd) |
| 84 | { |
| 85 | kfree(container_of(vd, struct omap_desc, vd)); |
| 86 | } |
| 87 | |
| 88 | static void omap_dma_start_sg(struct omap_chan *c, struct omap_desc *d, |
| 89 | unsigned idx) |
| 90 | { |
| 91 | struct omap_sg *sg = d->sg + idx; |
| 92 | |
| 93 | if (d->dir == DMA_DEV_TO_MEM) |
| 94 | omap_set_dma_dest_params(c->dma_ch, OMAP_DMA_PORT_EMIFF, |
| 95 | OMAP_DMA_AMODE_POST_INC, sg->addr, 0, 0); |
| 96 | else |
| 97 | omap_set_dma_src_params(c->dma_ch, OMAP_DMA_PORT_EMIFF, |
| 98 | OMAP_DMA_AMODE_POST_INC, sg->addr, 0, 0); |
| 99 | |
| 100 | omap_set_dma_transfer_params(c->dma_ch, d->es, sg->en, sg->fn, |
| 101 | d->sync_mode, c->dma_sig, d->sync_type); |
| 102 | |
| 103 | omap_start_dma(c->dma_ch); |
| 104 | } |
| 105 | |
| 106 | static void omap_dma_start_desc(struct omap_chan *c) |
| 107 | { |
| 108 | struct virt_dma_desc *vd = vchan_next_desc(&c->vc); |
| 109 | struct omap_desc *d; |
| 110 | |
| 111 | if (!vd) { |
| 112 | c->desc = NULL; |
| 113 | return; |
| 114 | } |
| 115 | |
| 116 | list_del(&vd->node); |
| 117 | |
| 118 | c->desc = d = to_omap_dma_desc(&vd->tx); |
| 119 | c->sgidx = 0; |
| 120 | |
| 121 | if (d->dir == DMA_DEV_TO_MEM) |
| 122 | omap_set_dma_src_params(c->dma_ch, d->periph_port, |
| 123 | OMAP_DMA_AMODE_CONSTANT, d->dev_addr, 0, 0); |
| 124 | else |
| 125 | omap_set_dma_dest_params(c->dma_ch, d->periph_port, |
| 126 | OMAP_DMA_AMODE_CONSTANT, d->dev_addr, 0, 0); |
| 127 | |
| 128 | omap_dma_start_sg(c, d, 0); |
| 129 | } |
| 130 | |
| 131 | static void omap_dma_callback(int ch, u16 status, void *data) |
| 132 | { |
| 133 | struct omap_chan *c = data; |
| 134 | struct omap_desc *d; |
| 135 | unsigned long flags; |
| 136 | |
| 137 | spin_lock_irqsave(&c->vc.lock, flags); |
| 138 | d = c->desc; |
| 139 | if (d) { |
| 140 | if (++c->sgidx < d->sglen) { |
| 141 | omap_dma_start_sg(c, d, c->sgidx); |
| 142 | } else { |
| 143 | omap_dma_start_desc(c); |
| 144 | vchan_cookie_complete(&d->vd); |
| 145 | } |
| 146 | } |
| 147 | spin_unlock_irqrestore(&c->vc.lock, flags); |
| 148 | } |
| 149 | |
| 150 | /* |
| 151 | * This callback schedules all pending channels. We could be more |
| 152 | * clever here by postponing allocation of the real DMA channels to |
| 153 | * this point, and freeing them when our virtual channel becomes idle. |
| 154 | * |
| 155 | * We would then need to deal with 'all channels in-use' |
| 156 | */ |
| 157 | static void omap_dma_sched(unsigned long data) |
| 158 | { |
| 159 | struct omap_dmadev *d = (struct omap_dmadev *)data; |
| 160 | LIST_HEAD(head); |
| 161 | |
| 162 | spin_lock_irq(&d->lock); |
| 163 | list_splice_tail_init(&d->pending, &head); |
| 164 | spin_unlock_irq(&d->lock); |
| 165 | |
| 166 | while (!list_empty(&head)) { |
| 167 | struct omap_chan *c = list_first_entry(&head, |
| 168 | struct omap_chan, node); |
| 169 | |
| 170 | spin_lock_irq(&c->vc.lock); |
| 171 | list_del_init(&c->node); |
| 172 | omap_dma_start_desc(c); |
| 173 | spin_unlock_irq(&c->vc.lock); |
| 174 | } |
| 175 | } |
| 176 | |
| 177 | static int omap_dma_alloc_chan_resources(struct dma_chan *chan) |
| 178 | { |
| 179 | struct omap_chan *c = to_omap_dma_chan(chan); |
| 180 | |
| 181 | dev_info(c->vc.chan.device->dev, "allocating channel for %u\n", c->dma_sig); |
| 182 | |
| 183 | return omap_request_dma(c->dma_sig, "DMA engine", |
| 184 | omap_dma_callback, c, &c->dma_ch); |
| 185 | } |
| 186 | |
| 187 | static void omap_dma_free_chan_resources(struct dma_chan *chan) |
| 188 | { |
| 189 | struct omap_chan *c = to_omap_dma_chan(chan); |
| 190 | |
| 191 | vchan_free_chan_resources(&c->vc); |
| 192 | omap_free_dma(c->dma_ch); |
| 193 | |
| 194 | dev_info(c->vc.chan.device->dev, "freeing channel for %u\n", c->dma_sig); |
| 195 | } |
| 196 | |
| 197 | static enum dma_status omap_dma_tx_status(struct dma_chan *chan, |
| 198 | dma_cookie_t cookie, struct dma_tx_state *txstate) |
| 199 | { |
| 200 | /* |
| 201 | * FIXME: do we need to return pending bytes? |
| 202 | * We have no users of that info at the moment... |
| 203 | */ |
| 204 | return dma_cookie_status(chan, cookie, txstate); |
| 205 | } |
| 206 | |
| 207 | static void omap_dma_issue_pending(struct dma_chan *chan) |
| 208 | { |
| 209 | struct omap_chan *c = to_omap_dma_chan(chan); |
| 210 | unsigned long flags; |
| 211 | |
| 212 | spin_lock_irqsave(&c->vc.lock, flags); |
| 213 | if (vchan_issue_pending(&c->vc) && !c->desc) { |
| 214 | struct omap_dmadev *d = to_omap_dma_dev(chan->device); |
| 215 | spin_lock(&d->lock); |
| 216 | if (list_empty(&c->node)) |
| 217 | list_add_tail(&c->node, &d->pending); |
| 218 | spin_unlock(&d->lock); |
| 219 | tasklet_schedule(&d->task); |
| 220 | } |
| 221 | spin_unlock_irqrestore(&c->vc.lock, flags); |
| 222 | } |
| 223 | |
| 224 | static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg( |
| 225 | struct dma_chan *chan, struct scatterlist *sgl, unsigned sglen, |
| 226 | enum dma_transfer_direction dir, unsigned long tx_flags, void *context) |
| 227 | { |
| 228 | struct omap_chan *c = to_omap_dma_chan(chan); |
| 229 | enum dma_slave_buswidth dev_width; |
| 230 | struct scatterlist *sgent; |
| 231 | struct omap_desc *d; |
| 232 | dma_addr_t dev_addr; |
| 233 | unsigned i, j = 0, es, en, frame_bytes, sync_type; |
| 234 | u32 burst; |
| 235 | |
| 236 | if (dir == DMA_DEV_TO_MEM) { |
| 237 | dev_addr = c->cfg.src_addr; |
| 238 | dev_width = c->cfg.src_addr_width; |
| 239 | burst = c->cfg.src_maxburst; |
| 240 | sync_type = OMAP_DMA_SRC_SYNC; |
| 241 | } else if (dir == DMA_MEM_TO_DEV) { |
| 242 | dev_addr = c->cfg.dst_addr; |
| 243 | dev_width = c->cfg.dst_addr_width; |
| 244 | burst = c->cfg.dst_maxburst; |
| 245 | sync_type = OMAP_DMA_DST_SYNC; |
| 246 | } else { |
| 247 | dev_err(chan->device->dev, "%s: bad direction?\n", __func__); |
| 248 | return NULL; |
| 249 | } |
| 250 | |
| 251 | /* Bus width translates to the element size (ES) */ |
| 252 | switch (dev_width) { |
| 253 | case DMA_SLAVE_BUSWIDTH_1_BYTE: |
| 254 | es = OMAP_DMA_DATA_TYPE_S8; |
| 255 | break; |
| 256 | case DMA_SLAVE_BUSWIDTH_2_BYTES: |
| 257 | es = OMAP_DMA_DATA_TYPE_S16; |
| 258 | break; |
| 259 | case DMA_SLAVE_BUSWIDTH_4_BYTES: |
| 260 | es = OMAP_DMA_DATA_TYPE_S32; |
| 261 | break; |
| 262 | default: /* not reached */ |
| 263 | return NULL; |
| 264 | } |
| 265 | |
| 266 | /* Now allocate and setup the descriptor. */ |
| 267 | d = kzalloc(sizeof(*d) + sglen * sizeof(d->sg[0]), GFP_ATOMIC); |
| 268 | if (!d) |
| 269 | return NULL; |
| 270 | |
| 271 | d->dir = dir; |
| 272 | d->dev_addr = dev_addr; |
| 273 | d->es = es; |
| 274 | d->sync_mode = OMAP_DMA_SYNC_FRAME; |
| 275 | d->sync_type = sync_type; |
| 276 | d->periph_port = OMAP_DMA_PORT_TIPB; |
| 277 | |
| 278 | /* |
| 279 | * Build our scatterlist entries: each contains the address, |
| 280 | * the number of elements (EN) in each frame, and the number of |
| 281 | * frames (FN). Number of bytes for this entry = ES * EN * FN. |
| 282 | * |
| 283 | * Burst size translates to number of elements with frame sync. |
| 284 | * Note: DMA engine defines burst to be the number of dev-width |
| 285 | * transfers. |
| 286 | */ |
| 287 | en = burst; |
| 288 | frame_bytes = es_bytes[es] * en; |
| 289 | for_each_sg(sgl, sgent, sglen, i) { |
| 290 | d->sg[j].addr = sg_dma_address(sgent); |
| 291 | d->sg[j].en = en; |
| 292 | d->sg[j].fn = sg_dma_len(sgent) / frame_bytes; |
| 293 | j++; |
| 294 | } |
| 295 | |
| 296 | d->sglen = j; |
| 297 | |
| 298 | return vchan_tx_prep(&c->vc, &d->vd, tx_flags); |
| 299 | } |
| 300 | |
| 301 | static int omap_dma_slave_config(struct omap_chan *c, struct dma_slave_config *cfg) |
| 302 | { |
| 303 | if (cfg->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES || |
| 304 | cfg->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES) |
| 305 | return -EINVAL; |
| 306 | |
| 307 | memcpy(&c->cfg, cfg, sizeof(c->cfg)); |
| 308 | |
| 309 | return 0; |
| 310 | } |
| 311 | |
| 312 | static int omap_dma_terminate_all(struct omap_chan *c) |
| 313 | { |
| 314 | struct omap_dmadev *d = to_omap_dma_dev(c->vc.chan.device); |
| 315 | unsigned long flags; |
| 316 | LIST_HEAD(head); |
| 317 | |
| 318 | spin_lock_irqsave(&c->vc.lock, flags); |
| 319 | |
| 320 | /* Prevent this channel being scheduled */ |
| 321 | spin_lock(&d->lock); |
| 322 | list_del_init(&c->node); |
| 323 | spin_unlock(&d->lock); |
| 324 | |
| 325 | /* |
| 326 | * Stop DMA activity: we assume the callback will not be called |
| 327 | * after omap_stop_dma() returns (even if it does, it will see |
| 328 | * c->desc is NULL and exit.) |
| 329 | */ |
| 330 | if (c->desc) { |
| 331 | c->desc = NULL; |
| 332 | omap_stop_dma(c->dma_ch); |
| 333 | } |
| 334 | |
| 335 | vchan_get_all_descriptors(&c->vc, &head); |
| 336 | spin_unlock_irqrestore(&c->vc.lock, flags); |
| 337 | vchan_dma_desc_free_list(&c->vc, &head); |
| 338 | |
| 339 | return 0; |
| 340 | } |
| 341 | |
| 342 | static int omap_dma_pause(struct omap_chan *c) |
| 343 | { |
| 344 | /* FIXME: not supported by platform private API */ |
| 345 | return -EINVAL; |
| 346 | } |
| 347 | |
| 348 | static int omap_dma_resume(struct omap_chan *c) |
| 349 | { |
| 350 | /* FIXME: not supported by platform private API */ |
| 351 | return -EINVAL; |
| 352 | } |
| 353 | |
| 354 | static int omap_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, |
| 355 | unsigned long arg) |
| 356 | { |
| 357 | struct omap_chan *c = to_omap_dma_chan(chan); |
| 358 | int ret; |
| 359 | |
| 360 | switch (cmd) { |
| 361 | case DMA_SLAVE_CONFIG: |
| 362 | ret = omap_dma_slave_config(c, (struct dma_slave_config *)arg); |
| 363 | break; |
| 364 | |
| 365 | case DMA_TERMINATE_ALL: |
| 366 | ret = omap_dma_terminate_all(c); |
| 367 | break; |
| 368 | |
| 369 | case DMA_PAUSE: |
| 370 | ret = omap_dma_pause(c); |
| 371 | break; |
| 372 | |
| 373 | case DMA_RESUME: |
| 374 | ret = omap_dma_resume(c); |
| 375 | break; |
| 376 | |
| 377 | default: |
| 378 | ret = -ENXIO; |
| 379 | break; |
| 380 | } |
| 381 | |
| 382 | return ret; |
| 383 | } |
| 384 | |
| 385 | static int omap_dma_chan_init(struct omap_dmadev *od, int dma_sig) |
| 386 | { |
| 387 | struct omap_chan *c; |
| 388 | |
| 389 | c = kzalloc(sizeof(*c), GFP_KERNEL); |
| 390 | if (!c) |
| 391 | return -ENOMEM; |
| 392 | |
| 393 | c->dma_sig = dma_sig; |
| 394 | c->vc.desc_free = omap_dma_desc_free; |
| 395 | vchan_init(&c->vc, &od->ddev); |
| 396 | INIT_LIST_HEAD(&c->node); |
| 397 | |
| 398 | od->ddev.chancnt++; |
| 399 | |
| 400 | return 0; |
| 401 | } |
| 402 | |
| 403 | static void omap_dma_free(struct omap_dmadev *od) |
| 404 | { |
| 405 | tasklet_kill(&od->task); |
| 406 | while (!list_empty(&od->ddev.channels)) { |
| 407 | struct omap_chan *c = list_first_entry(&od->ddev.channels, |
| 408 | struct omap_chan, vc.chan.device_node); |
| 409 | |
| 410 | list_del(&c->vc.chan.device_node); |
| 411 | tasklet_kill(&c->vc.task); |
| 412 | kfree(c); |
| 413 | } |
| 414 | kfree(od); |
| 415 | } |
| 416 | |
| 417 | static int omap_dma_probe(struct platform_device *pdev) |
| 418 | { |
| 419 | struct omap_dmadev *od; |
| 420 | int rc, i; |
| 421 | |
| 422 | od = kzalloc(sizeof(*od), GFP_KERNEL); |
| 423 | if (!od) |
| 424 | return -ENOMEM; |
| 425 | |
| 426 | dma_cap_set(DMA_SLAVE, od->ddev.cap_mask); |
| 427 | od->ddev.device_alloc_chan_resources = omap_dma_alloc_chan_resources; |
| 428 | od->ddev.device_free_chan_resources = omap_dma_free_chan_resources; |
| 429 | od->ddev.device_tx_status = omap_dma_tx_status; |
| 430 | od->ddev.device_issue_pending = omap_dma_issue_pending; |
| 431 | od->ddev.device_prep_slave_sg = omap_dma_prep_slave_sg; |
| 432 | od->ddev.device_control = omap_dma_control; |
| 433 | od->ddev.dev = &pdev->dev; |
| 434 | INIT_LIST_HEAD(&od->ddev.channels); |
| 435 | INIT_LIST_HEAD(&od->pending); |
| 436 | spin_lock_init(&od->lock); |
| 437 | |
| 438 | tasklet_init(&od->task, omap_dma_sched, (unsigned long)od); |
| 439 | |
| 440 | for (i = 0; i < 127; i++) { |
| 441 | rc = omap_dma_chan_init(od, i); |
| 442 | if (rc) { |
| 443 | omap_dma_free(od); |
| 444 | return rc; |
| 445 | } |
| 446 | } |
| 447 | |
| 448 | rc = dma_async_device_register(&od->ddev); |
| 449 | if (rc) { |
| 450 | pr_warn("OMAP-DMA: failed to register slave DMA engine device: %d\n", |
| 451 | rc); |
| 452 | omap_dma_free(od); |
| 453 | } else { |
| 454 | platform_set_drvdata(pdev, od); |
| 455 | } |
| 456 | |
| 457 | dev_info(&pdev->dev, "OMAP DMA engine driver\n"); |
| 458 | |
| 459 | return rc; |
| 460 | } |
| 461 | |
| 462 | static int omap_dma_remove(struct platform_device *pdev) |
| 463 | { |
| 464 | struct omap_dmadev *od = platform_get_drvdata(pdev); |
| 465 | |
| 466 | dma_async_device_unregister(&od->ddev); |
| 467 | omap_dma_free(od); |
| 468 | |
| 469 | return 0; |
| 470 | } |
| 471 | |
| 472 | static struct platform_driver omap_dma_driver = { |
| 473 | .probe = omap_dma_probe, |
| 474 | .remove = omap_dma_remove, |
| 475 | .driver = { |
| 476 | .name = "omap-dma-engine", |
| 477 | .owner = THIS_MODULE, |
| 478 | }, |
| 479 | }; |
| 480 | |
| 481 | bool omap_dma_filter_fn(struct dma_chan *chan, void *param) |
| 482 | { |
| 483 | if (chan->device->dev->driver == &omap_dma_driver.driver) { |
| 484 | struct omap_chan *c = to_omap_dma_chan(chan); |
| 485 | unsigned req = *(unsigned *)param; |
| 486 | |
| 487 | return req == c->dma_sig; |
| 488 | } |
| 489 | return false; |
| 490 | } |
| 491 | EXPORT_SYMBOL_GPL(omap_dma_filter_fn); |
| 492 | |
| 493 | static struct platform_device *pdev; |
| 494 | |
| 495 | static const struct platform_device_info omap_dma_dev_info = { |
| 496 | .name = "omap-dma-engine", |
| 497 | .id = -1, |
| 498 | .dma_mask = DMA_BIT_MASK(32), |
| 499 | }; |
| 500 | |
| 501 | static int omap_dma_init(void) |
| 502 | { |
| 503 | int rc = platform_driver_register(&omap_dma_driver); |
| 504 | |
| 505 | if (rc == 0) { |
| 506 | pdev = platform_device_register_full(&omap_dma_dev_info); |
| 507 | if (IS_ERR(pdev)) { |
| 508 | platform_driver_unregister(&omap_dma_driver); |
| 509 | rc = PTR_ERR(pdev); |
| 510 | } |
| 511 | } |
| 512 | return rc; |
| 513 | } |
| 514 | subsys_initcall(omap_dma_init); |
| 515 | |
| 516 | static void __exit omap_dma_exit(void) |
| 517 | { |
| 518 | platform_device_unregister(pdev); |
| 519 | platform_driver_unregister(&omap_dma_driver); |
| 520 | } |
| 521 | module_exit(omap_dma_exit); |
| 522 | |
| 523 | MODULE_AUTHOR("Russell King"); |
| 524 | MODULE_LICENSE("GPL"); |