drivers/dma/pl330.c

   1 /* linux/drivers/dma/pl330.c
   2  *
   3  * Copyright (C) 2010 Samsung Electronics Co. Ltd.
   4  *      Jaswinder Singh <jassi.brar@samsung.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  */
  11
  12 #include <linux/io.h>
  13 #include <linux/init.h>
  14 #include <linux/slab.h>
  15 #include <linux/module.h>
  16 #include <linux/dmaengine.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/amba/bus.h>
  19 #include <linux/amba/pl330.h>
  20 #include <linux/pm_runtime.h>
  21 #include <linux/scatterlist.h>
  22
  23 #define NR_DEFAULT_DESC 16
  24
  25 enum desc_status {
  26         /* In the DMAC pool */
  27         FREE,
  28         /*
  29          * Allocted to some channel during prep_xxx
  30          * Also may be sitting on the work_list.
  31          */
  32         PREP,
  33         /*
  34          * Sitting on the work_list and already submitted
  35          * to the PL330 core. Not more than two descriptors
  36          * of a channel can be BUSY at any time.
  37          */
  38         BUSY,
  39         /*
  40          * Sitting on the channel work_list but xfer done
  41          * by PL330 core
  42          */
  43         DONE,
  44 };
  45
  46 struct dma_pl330_chan {
  47         /* Schedule desc completion */
  48         struct tasklet_struct task;
  49
  50         /* DMA-Engine Channel */
  51         struct dma_chan chan;
  52
  53         /* Last completed cookie */
  54         dma_cookie_t completed;
  55
  56         /* List of to be xfered descriptors */
  57         struct list_head work_list;
  58
  59         /* Pointer to the DMAC that manages this channel,
  60          * NULL if the channel is available to be acquired.
  61          * As the parent, this DMAC also provides descriptors
  62          * to the channel.
  63          */
  64         struct dma_pl330_dmac *dmac;
  65
  66         /* To protect channel manipulation */
  67         spinlock_t lock;
  68
  69         /* Token of a hardware channel thread of PL330 DMAC
  70          * NULL if the channel is available to be acquired.
  71          */
  72         void *pl330_chid;
  73
  74         /* For D-to-M and M-to-D channels */
  75         int burst_sz; /* the peripheral fifo width */
  76         int burst_len; /* the number of burst */
  77         dma_addr_t fifo_addr;
  78
  79         /* for cyclic capability */
  80         bool cyclic;
  81 };
  82
  83 struct dma_pl330_dmac {
  84         struct pl330_info pif;
  85
  86         /* DMA-Engine Device */
  87         struct dma_device ddma;
  88
  89         /* Pool of descriptors available for the DMAC's channels */
  90         struct list_head desc_pool;
  91         /* To protect desc_pool manipulation */
  92         spinlock_t pool_lock;
  93
  94         /* Peripheral channels connected to this DMAC */
  95         struct dma_pl330_chan *peripherals; /* keep at end */
  96
  97         struct clk *clk;
  98 };
  99
 100 struct dma_pl330_desc {
 101         /* To attach to a queue as child */
 102         struct list_head node;
 103
 104         /* Descriptor for the DMA Engine API */
 105         struct dma_async_tx_descriptor txd;
 106
 107         /* Xfer for PL330 core */
 108         struct pl330_xfer px;
 109
 110         struct pl330_reqcfg rqcfg;
 111         struct pl330_req req;
 112
 113         enum desc_status status;
 114
 115         /* The channel which currently holds this desc */
 116         struct dma_pl330_chan *pchan;
 117 };
 118
 119 static inline struct dma_pl330_chan *
 120 to_pchan(struct dma_chan *ch)
 121 {
 122         if (!ch)
 123                 return NULL;
 124
 125         return container_of(ch, struct dma_pl330_chan, chan);
 126 }
 127
 128 static inline struct dma_pl330_desc *
 129 to_desc(struct dma_async_tx_descriptor *tx)
 130 {
 131         return container_of(tx, struct dma_pl330_desc, txd);
 132 }
 133
 134 static inline void free_desc_list(struct list_head *list)
 135 {
 136         struct dma_pl330_dmac *pdmac;
 137         struct dma_pl330_desc *desc;
 138         struct dma_pl330_chan *pch;
 139         unsigned long flags;
 140
 141         if (list_empty(list))
 142                 return;
 143
 144         /* Finish off the work list */
 145         list_for_each_entry(desc, list, node) {
 146                 dma_async_tx_callback callback;
 147                 void *param;
 148
 149                 /* All desc in a list belong to same channel */
 150                 pch = desc->pchan;
 151                 callback = desc->txd.callback;
 152                 param = desc->txd.callback_param;
 153
 154                 if (callback)
 155                         callback(param);
 156
 157                 desc->pchan = NULL;
 158         }
 159
 160         pdmac = pch->dmac;
 161
 162         spin_lock_irqsave(&pdmac->pool_lock, flags);
 163         list_splice_tail_init(list, &pdmac->desc_pool);
 164         spin_unlock_irqrestore(&pdmac->pool_lock, flags);
 165 }
 166
 167 static inline void handle_cyclic_desc_list(struct list_head *list)
 168 {
 169         struct dma_pl330_desc *desc;
 170         struct dma_pl330_chan *pch;
 171         unsigned long flags;
 172
 173         if (list_empty(list))
 174                 return;
 175
 176         list_for_each_entry(desc, list, node) {
 177                 dma_async_tx_callback callback;
 178
 179                 /* Change status to reload it */
 180                 desc->status = PREP;
 181                 pch = desc->pchan;
 182                 callback = desc->txd.callback;
 183                 if (callback)
 184                         callback(desc->txd.callback_param);
 185         }
 186
 187         spin_lock_irqsave(&pch->lock, flags);
 188         list_splice_tail_init(list, &pch->work_list);
 189         spin_unlock_irqrestore(&pch->lock, flags);
 190 }
 191
 192 static inline void fill_queue(struct dma_pl330_chan *pch)
 193 {
 194         struct dma_pl330_desc *desc;
 195         int ret;
 196
 197         list_for_each_entry(desc, &pch->work_list, node) {
 198
 199                 /* If already submitted */
 200                 if (desc->status == BUSY)
 201                         break;
 202
 203                 ret = pl330_submit_req(pch->pl330_chid,
 204                                                 &desc->req);
 205                 if (!ret) {
 206                         desc->status = BUSY;
 207                         break;
 208                 } else if (ret == -EAGAIN) {
 209                         /* QFull or DMAC Dying */
 210                         break;
 211                 } else {
 212                         /* Unacceptable request */
 213                         desc->status = DONE;
 214                         dev_err(pch->dmac->pif.dev, "%s:%d Bad Desc(%d)\n",
 215                                         __func__, __LINE__, desc->txd.cookie);
 216                         tasklet_schedule(&pch->task);
 217                 }
 218         }
 219 }
 220
 221 static void pl330_tasklet(unsigned long data)
 222 {
 223         struct dma_pl330_chan *pch = (struct dma_pl330_chan *)data;
 224         struct dma_pl330_desc *desc, *_dt;
 225         unsigned long flags;
 226         LIST_HEAD(list);
 227
 228         spin_lock_irqsave(&pch->lock, flags);
 229
 230         /* Pick up ripe tomatoes */
 231         list_for_each_entry_safe(desc, _dt, &pch->work_list, node)
 232                 if (desc->status == DONE) {
 233                         pch->completed = desc->txd.cookie;
 234                         list_move_tail(&desc->node, &list);
 235                 }
 236
 237         /* Try to submit a req imm. next to the last completed cookie */
 238         fill_queue(pch);
 239
 240         /* Make sure the PL330 Channel thread is active */
 241         pl330_chan_ctrl(pch->pl330_chid, PL330_OP_START);
 242
 243         spin_unlock_irqrestore(&pch->lock, flags);
 244
 245         if (pch->cyclic)
 246                 handle_cyclic_desc_list(&list);
 247         else
 248                 free_desc_list(&list);
 249 }
 250
 251 static void dma_pl330_rqcb(void *token, enum pl330_op_err err)
 252 {
 253         struct dma_pl330_desc *desc = token;
 254         struct dma_pl330_chan *pch = desc->pchan;
 255         unsigned long flags;
 256
 257         /* If desc aborted */
 258         if (!pch)
 259                 return;
 260
 261         spin_lock_irqsave(&pch->lock, flags);
 262
 263         desc->status = DONE;
 264
 265         spin_unlock_irqrestore(&pch->lock, flags);
 266
 267         tasklet_schedule(&pch->task);
 268 }
 269
 270 static int pl330_alloc_chan_resources(struct dma_chan *chan)
 271 {
 272         struct dma_pl330_chan *pch = to_pchan(chan);
 273         struct dma_pl330_dmac *pdmac = pch->dmac;
 274         unsigned long flags;
 275
 276         spin_lock_irqsave(&pch->lock, flags);
 277
 278         pch->completed = chan->cookie = 1;
 279         pch->cyclic = false;
 280
 281         pch->pl330_chid = pl330_request_channel(&pdmac->pif);
 282         if (!pch->pl330_chid) {
 283                 spin_unlock_irqrestore(&pch->lock, flags);
 284                 return 0;
 285         }
 286
 287         tasklet_init(&pch->task, pl330_tasklet, (unsigned long) pch);
 288
 289         spin_unlock_irqrestore(&pch->lock, flags);
 290
 291         return 1;
 292 }
 293
 294 static int pl330_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, unsigned long arg)
 295 {
 296         struct dma_pl330_chan *pch = to_pchan(chan);
 297         struct dma_pl330_desc *desc, *_dt;
 298         unsigned long flags;
 299         struct dma_pl330_dmac *pdmac = pch->dmac;
 300         struct dma_slave_config *slave_config;
 301         LIST_HEAD(list);
 302
 303         switch (cmd) {
 304         case DMA_TERMINATE_ALL:
 305                 spin_lock_irqsave(&pch->lock, flags);
 306
 307                 /* FLUSH the PL330 Channel thread */
 308                 pl330_chan_ctrl(pch->pl330_chid, PL330_OP_FLUSH);
 309
 310                 /* Mark all desc done */
 311                 list_for_each_entry_safe(desc, _dt, &pch->work_list , node) {
 312                         desc->status = DONE;
 313                         pch->completed = desc->txd.cookie;
 314                         list_move_tail(&desc->node, &list);
 315                 }
 316
 317                 list_splice_tail_init(&list, &pdmac->desc_pool);
 318                 spin_unlock_irqrestore(&pch->lock, flags);
 319                 break;
 320         case DMA_SLAVE_CONFIG:
 321                 slave_config = (struct dma_slave_config *)arg;
 322
 323                 if (slave_config->direction == DMA_TO_DEVICE) {
 324                         if (slave_config->dst_addr)
 325                                 pch->fifo_addr = slave_config->dst_addr;
 326                         if (slave_config->dst_addr_width)
 327                                 pch->burst_sz = __ffs(slave_config->dst_addr_width);
 328                         if (slave_config->dst_maxburst)
 329                                 pch->burst_len = slave_config->dst_maxburst;
 330                 } else if (slave_config->direction == DMA_FROM_DEVICE) {
 331                         if (slave_config->src_addr)
 332                                 pch->fifo_addr = slave_config->src_addr;
 333                         if (slave_config->src_addr_width)
 334                                 pch->burst_sz = __ffs(slave_config->src_addr_width);
 335                         if (slave_config->src_maxburst)
 336                                 pch->burst_len = slave_config->src_maxburst;
 337                 }
 338                 break;
 339         default:
 340                 dev_err(pch->dmac->pif.dev, "Not supported command.\n");
 341                 return -ENXIO;
 342         }
 343
 344         return 0;
 345 }
 346
 347 static void pl330_free_chan_resources(struct dma_chan *chan)
 348 {
 349         struct dma_pl330_chan *pch = to_pchan(chan);
 350         unsigned long flags;
 351
 352         spin_lock_irqsave(&pch->lock, flags);
 353
 354         tasklet_kill(&pch->task);
 355
 356         pl330_release_channel(pch->pl330_chid);
 357         pch->pl330_chid = NULL;
 358
 359         if (pch->cyclic)
 360                 list_splice_tail_init(&pch->work_list, &pch->dmac->desc_pool);
 361
 362         spin_unlock_irqrestore(&pch->lock, flags);
 363 }
 364
 365 static enum dma_status
 366 pl330_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
 367                  struct dma_tx_state *txstate)
 368 {
 369         struct dma_pl330_chan *pch = to_pchan(chan);
 370         dma_cookie_t last_done, last_used;
 371         int ret;
 372
 373         last_done = pch->completed;
 374         last_used = chan->cookie;
 375
 376         ret = dma_async_is_complete(cookie, last_done, last_used);
 377
 378         dma_set_tx_state(txstate, last_done, last_used, 0);
 379
 380         return ret;
 381 }
 382
 383 static void pl330_issue_pending(struct dma_chan *chan)
 384 {
 385         pl330_tasklet((unsigned long) to_pchan(chan));
 386 }
 387
 388 /*
 389  * We returned the last one of the circular list of descriptor(s)
 390  * from prep_xxx, so the argument to submit corresponds to the last
 391  * descriptor of the list.
 392  */
 393 static dma_cookie_t pl330_tx_submit(struct dma_async_tx_descriptor *tx)
 394 {
 395         struct dma_pl330_desc *desc, *last = to_desc(tx);
 396         struct dma_pl330_chan *pch = to_pchan(tx->chan);
 397         dma_cookie_t cookie;
 398         unsigned long flags;
 399
 400         spin_lock_irqsave(&pch->lock, flags);
 401
 402         /* Assign cookies to all nodes */
 403         cookie = tx->chan->cookie;
 404
 405         while (!list_empty(&last->node)) {
 406                 desc = list_entry(last->node.next, struct dma_pl330_desc, node);
 407
 408                 if (++cookie < 0)
 409                         cookie = 1;
 410                 desc->txd.cookie = cookie;
 411
 412                 list_move_tail(&desc->node, &pch->work_list);
 413         }
 414
 415         if (++cookie < 0)
 416                 cookie = 1;
 417         last->txd.cookie = cookie;
 418
 419         list_add_tail(&last->node, &pch->work_list);
 420
 421         tx->chan->cookie = cookie;
 422
 423         spin_unlock_irqrestore(&pch->lock, flags);
 424
 425         return cookie;
 426 }
 427
 428 static inline void _init_desc(struct dma_pl330_desc *desc)
 429 {
 430         desc->pchan = NULL;
 431         desc->req.x = &desc->px;
 432         desc->req.token = desc;
 433         desc->rqcfg.swap = SWAP_NO;
 434         desc->rqcfg.privileged = 0;
 435         desc->rqcfg.insnaccess = 0;
 436         desc->rqcfg.scctl = SCCTRL0;
 437         desc->rqcfg.dcctl = DCCTRL0;
 438         desc->req.cfg = &desc->rqcfg;
 439         desc->req.xfer_cb = dma_pl330_rqcb;
 440         desc->txd.tx_submit = pl330_tx_submit;
 441
 442         INIT_LIST_HEAD(&desc->node);
 443 }
 444
 445 /* Returns the number of descriptors added to the DMAC pool */
 446 int add_desc(struct dma_pl330_dmac *pdmac, gfp_t flg, int count)
 447 {
 448         struct dma_pl330_desc *desc;
 449         unsigned long flags;
 450         int i;
 451
 452         if (!pdmac)
 453                 return 0;
 454
 455         desc = kmalloc(count * sizeof(*desc), flg);
 456         if (!desc)
 457                 return 0;
 458
 459         spin_lock_irqsave(&pdmac->pool_lock, flags);
 460
 461         for (i = 0; i < count; i++) {
 462                 _init_desc(&desc[i]);
 463                 list_add_tail(&desc[i].node, &pdmac->desc_pool);
 464         }
 465
 466         spin_unlock_irqrestore(&pdmac->pool_lock, flags);
 467
 468         return count;
 469 }
 470
 471 static struct dma_pl330_desc *
 472 pluck_desc(struct dma_pl330_dmac *pdmac)
 473 {
 474         struct dma_pl330_desc *desc = NULL;
 475         unsigned long flags;
 476
 477         if (!pdmac)
 478                 return NULL;
 479
 480         spin_lock_irqsave(&pdmac->pool_lock, flags);
 481
 482         if (!list_empty(&pdmac->desc_pool)) {
 483                 desc = list_entry(pdmac->desc_pool.next,
 484                                 struct dma_pl330_desc, node);
 485
 486                 list_del_init(&desc->node);
 487
 488                 desc->status = PREP;
 489                 desc->txd.callback = NULL;
 490         }
 491
 492         spin_unlock_irqrestore(&pdmac->pool_lock, flags);
 493
 494         return desc;
 495 }
 496
 497 static struct dma_pl330_desc *pl330_get_desc(struct dma_pl330_chan *pch)
 498 {
 499         struct dma_pl330_dmac *pdmac = pch->dmac;
 500         struct dma_pl330_peri *peri = pch->chan.private;
 501         struct dma_pl330_desc *desc;
 502
 503         /* Pluck one desc from the pool of DMAC */
 504         desc = pluck_desc(pdmac);
 505
 506         /* If the DMAC pool is empty, alloc new */
 507         if (!desc) {
 508                 if (!add_desc(pdmac, GFP_ATOMIC, 1))
 509                         return NULL;
 510
 511                 /* Try again */
 512                 desc = pluck_desc(pdmac);
 513                 if (!desc) {
 514                         dev_err(pch->dmac->pif.dev,
 515                                 "%s:%d ALERT!\n", __func__, __LINE__);
 516                         return NULL;
 517                 }
 518         }
 519
 520         /* Initialize the descriptor */
 521         desc->pchan = pch;
 522         desc->txd.cookie = 0;
 523         async_tx_ack(&desc->txd);
 524
 525         if (peri) {
 526                 desc->req.rqtype = peri->rqtype;
 527                 desc->req.peri = pch->chan.chan_id;
 528         } else {
 529                 desc->req.rqtype = MEMTOMEM;
 530                 desc->req.peri = 0;
 531         }
 532
 533         dma_async_tx_descriptor_init(&desc->txd, &pch->chan);
 534
 535         return desc;
 536 }
 537
 538 static inline void fill_px(struct pl330_xfer *px,
 539                 dma_addr_t dst, dma_addr_t src, size_t len)
 540 {
 541         px->next = NULL;
 542         px->bytes = len;
 543         px->dst_addr = dst;
 544         px->src_addr = src;
 545 }
 546
 547 static struct dma_pl330_desc *
 548 __pl330_prep_dma_memcpy(struct dma_pl330_chan *pch, dma_addr_t dst,
 549                 dma_addr_t src, size_t len)
 550 {
 551         struct dma_pl330_desc *desc = pl330_get_desc(pch);
 552
 553         if (!desc) {
 554                 dev_err(pch->dmac->pif.dev, "%s:%d Unable to fetch desc\n",
 555                         __func__, __LINE__);
 556                 return NULL;
 557         }
 558
 559         /*
 560          * Ideally we should lookout for reqs bigger than
 561          * those that can be programmed with 256 bytes of
 562          * MC buffer, but considering a req size is seldom
 563          * going to be word-unaligned and more than 200MB,
 564          * we take it easy.
 565          * Also, should the limit is reached we'd rather
 566          * have the platform increase MC buffer size than
 567          * complicating this API driver.
 568          */
 569         fill_px(&desc->px, dst, src, len);
 570
 571         return desc;
 572 }
 573
 574 /* Call after fixing burst size */
 575 static inline int get_burst_len(struct dma_pl330_desc *desc, size_t len)
 576 {
 577         struct dma_pl330_chan *pch = desc->pchan;
 578         struct pl330_info *pi = &pch->dmac->pif;
 579         int burst_len;
 580
 581         burst_len = pi->pcfg.data_bus_width / 8;
 582         burst_len *= pi->pcfg.data_buf_dep;
 583         burst_len >>= desc->rqcfg.brst_size;
 584
 585         /* src/dst_burst_len can't be more than 16 */
 586         if (burst_len > 16)
 587                 burst_len = 16;
 588
 589         while (burst_len > 1) {
 590                 if (!(len % (burst_len << desc->rqcfg.brst_size)))
 591                         break;
 592                 burst_len--;
 593         }
 594
 595         return burst_len;
 596 }
 597
 598 static struct dma_async_tx_descriptor *pl330_prep_dma_cyclic(
 599                 struct dma_chan *chan, dma_addr_t dma_addr, size_t len,
 600                 size_t period_len, enum dma_data_direction direction)
 601 {
 602         struct dma_pl330_desc *desc;
 603         struct dma_pl330_chan *pch = to_pchan(chan);
 604         dma_addr_t dst;
 605         dma_addr_t src;
 606
 607         desc = pl330_get_desc(pch);
 608         if (!desc) {
 609                 dev_err(pch->dmac->pif.dev, "%s:%d Unable to fetch desc\n",
 610                         __func__, __LINE__);
 611                 return NULL;
 612         }
 613
 614         switch (direction) {
 615         case DMA_TO_DEVICE:
 616                 desc->rqcfg.src_inc = 1;
 617                 desc->rqcfg.dst_inc = 0;
 618                 src = dma_addr;
 619                 dst = pch->fifo_addr;
 620                 break;
 621         case DMA_FROM_DEVICE:
 622                 desc->rqcfg.src_inc = 0;
 623                 desc->rqcfg.dst_inc = 1;
 624                 src = pch->fifo_addr;
 625                 dst = dma_addr;
 626                 break;
 627         default:
 628                 dev_err(pch->dmac->pif.dev, "%s:%d Invalid dma direction\n",
 629                 __func__, __LINE__);
 630                 return NULL;
 631         }
 632
 633         desc->rqcfg.brst_size = pch->burst_sz;
 634         desc->rqcfg.brst_len = 1;
 635
 636         pch->cyclic = true;
 637
 638         fill_px(&desc->px, dst, src, period_len);
 639
 640         return &desc->txd;
 641 }
 642
 643 static struct dma_async_tx_descriptor *
 644 pl330_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dst,
 645                 dma_addr_t src, size_t len, unsigned long flags)
 646 {
 647         struct dma_pl330_desc *desc;
 648         struct dma_pl330_chan *pch = to_pchan(chan);
 649         struct dma_pl330_peri *peri = chan->private;
 650         struct pl330_info *pi;
 651         int burst;
 652
 653         if (unlikely(!pch || !len))
 654                 return NULL;
 655
 656         if (peri && peri->rqtype != MEMTOMEM)
 657                 return NULL;
 658
 659         pi = &pch->dmac->pif;
 660
 661         desc = __pl330_prep_dma_memcpy(pch, dst, src, len);
 662         if (!desc)
 663                 return NULL;
 664
 665         desc->rqcfg.src_inc = 1;
 666         desc->rqcfg.dst_inc = 1;
 667
 668         /* Select max possible burst size */
 669         burst = pi->pcfg.data_bus_width / 8;
 670
 671         while (burst > 1) {
 672                 if (!(len % burst))
 673                         break;
 674                 burst /= 2;
 675         }
 676
 677         desc->rqcfg.brst_size = 0;
 678         while (burst != (1 << desc->rqcfg.brst_size))
 679                 desc->rqcfg.brst_size++;
 680
 681         desc->rqcfg.brst_len = get_burst_len(desc, len);
 682
 683         desc->txd.flags = flags;
 684
 685         return &desc->txd;
 686 }
 687
 688 static struct dma_async_tx_descriptor *
 689 pl330_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 690                 unsigned int sg_len, enum dma_data_direction direction,
 691                 unsigned long flg)
 692 {
 693         struct dma_pl330_desc *first, *desc = NULL;
 694         struct dma_pl330_chan *pch = to_pchan(chan);
 695         struct dma_pl330_peri *peri = chan->private;
 696         struct scatterlist *sg;
 697         unsigned long flags;
 698         int i;
 699         dma_addr_t addr;
 700
 701         if (unlikely(!pch || !sgl || !sg_len || !peri))
 702                 return NULL;
 703
 704         /* Make sure the direction is consistent */
 705         if ((direction == DMA_TO_DEVICE &&
 706                                 peri->rqtype != MEMTODEV) ||
 707                         (direction == DMA_FROM_DEVICE &&
 708                                 peri->rqtype != DEVTOMEM)) {
 709                 dev_err(pch->dmac->pif.dev, "%s:%d Invalid Direction\n",
 710                                 __func__, __LINE__);
 711                 return NULL;
 712         }
 713
 714         addr = pch->fifo_addr;
 715
 716         first = NULL;
 717
 718         for_each_sg(sgl, sg, sg_len, i) {
 719
 720                 desc = pl330_get_desc(pch);
 721                 if (!desc) {
 722                         struct dma_pl330_dmac *pdmac = pch->dmac;
 723
 724                         dev_err(pch->dmac->pif.dev,
 725                                 "%s:%d Unable to fetch desc\n",
 726                                 __func__, __LINE__);
 727                         if (!first)
 728                                 return NULL;
 729
 730                         spin_lock_irqsave(&pdmac->pool_lock, flags);
 731
 732                         while (!list_empty(&first->node)) {
 733                                 desc = list_entry(first->node.next,
 734                                                 struct dma_pl330_desc, node);
 735                                 list_move_tail(&desc->node, &pdmac->desc_pool);
 736                         }
 737
 738                         list_move_tail(&first->node, &pdmac->desc_pool);
 739
 740                         spin_unlock_irqrestore(&pdmac->pool_lock, flags);
 741
 742                         return NULL;
 743                 }
 744
 745                 if (!first)
 746                         first = desc;
 747                 else
 748                         list_add_tail(&desc->node, &first->node);
 749
 750                 if (direction == DMA_TO_DEVICE) {
 751                         desc->rqcfg.src_inc = 1;
 752                         desc->rqcfg.dst_inc = 0;
 753                         fill_px(&desc->px,
 754                                 addr, sg_dma_address(sg), sg_dma_len(sg));
 755                 } else {
 756                         desc->rqcfg.src_inc = 0;
 757                         desc->rqcfg.dst_inc = 1;
 758                         fill_px(&desc->px,
 759                                 sg_dma_address(sg), addr, sg_dma_len(sg));
 760                 }
 761
 762                 desc->rqcfg.brst_size = pch->burst_sz;
 763                 desc->rqcfg.brst_len = 1;
 764         }
 765
 766         /* Return the last desc in the chain */
 767         desc->txd.flags = flg;
 768         return &desc->txd;
 769 }
 770
 771 static irqreturn_t pl330_irq_handler(int irq, void *data)
 772 {
 773         if (pl330_update(data))
 774                 return IRQ_HANDLED;
 775         else
 776                 return IRQ_NONE;
 777 }
 778
 779 static int __devinit
 780 pl330_probe(struct amba_device *adev, const struct amba_id *id)
 781 {
 782         struct dma_pl330_platdata *pdat;
 783         struct dma_pl330_dmac *pdmac;
 784         struct dma_pl330_chan *pch;
 785         struct pl330_info *pi;
 786         struct dma_device *pd;
 787         struct resource *res;
 788         int i, ret, irq;
 789         int num_chan;
 790
 791         pdat = adev->dev.platform_data;
 792
 793         /* Allocate a new DMAC and its Channels */
 794         pdmac = kzalloc(sizeof(*pdmac), GFP_KERNEL);
 795         if (!pdmac) {
 796                 dev_err(&adev->dev, "unable to allocate mem\n");
 797                 return -ENOMEM;
 798         }
 799
 800         pi = &pdmac->pif;
 801         pi->dev = &adev->dev;
 802         pi->pl330_data = NULL;
 803         pi->mcbufsz = pdat ? pdat->mcbuf_sz : 0;
 804
 805         res = &adev->res;
 806         request_mem_region(res->start, resource_size(res), "dma-pl330");
 807
 808         pi->base = ioremap(res->start, resource_size(res));
 809         if (!pi->base) {
 810                 ret = -ENXIO;
 811                 goto probe_err1;
 812         }
 813
 814         pdmac->clk = clk_get(&adev->dev, "dma");
 815         if (IS_ERR(pdmac->clk)) {
 816                 dev_err(&adev->dev, "Cannot get operation clock.\n");
 817                 ret = -EINVAL;
 818                 goto probe_err1;
 819         }
 820
 821         amba_set_drvdata(adev, pdmac);
 822
 823 #ifdef CONFIG_PM_RUNTIME
 824         /* to use the runtime PM helper functions */
 825         pm_runtime_enable(&adev->dev);
 826
 827         /* enable the power domain */
 828         if (pm_runtime_get_sync(&adev->dev)) {
 829                 dev_err(&adev->dev, "failed to get runtime pm\n");
 830                 ret = -ENODEV;
 831                 goto probe_err1;
 832         }
 833 #else
 834         /* enable dma clk */
 835         clk_enable(pdmac->clk);
 836 #endif
 837
 838         irq = adev->irq[0];
 839         ret = request_irq(irq, pl330_irq_handler, 0,
 840                         dev_name(&adev->dev), pi);
 841         if (ret)
 842                 goto probe_err2;
 843
 844         ret = pl330_add(pi);
 845         if (ret)
 846                 goto probe_err3;
 847
 848         INIT_LIST_HEAD(&pdmac->desc_pool);
 849         spin_lock_init(&pdmac->pool_lock);
 850
 851         /* Create a descriptor pool of default size */
 852         if (!add_desc(pdmac, GFP_KERNEL, NR_DEFAULT_DESC))
 853                 dev_warn(&adev->dev, "unable to allocate desc\n");
 854
 855         pd = &pdmac->ddma;
 856         INIT_LIST_HEAD(&pd->channels);
 857
 858         /* Initialize channel parameters */
 859         num_chan = max(pdat ? pdat->nr_valid_peri : 0, (u8)pi->pcfg.num_chan);
 860         pdmac->peripherals = kzalloc(num_chan * sizeof(*pch), GFP_KERNEL);
 861         if (!pdmac->peripherals) {
 862                 ret = -ENOMEM;
 863                 dev_err(&adev->dev, "unable to allocate pdmac->peripherals\n");
 864                 goto probe_err4;
 865         }
 866
 867         for (i = 0; i < num_chan; i++) {
 868                 pch = &pdmac->peripherals[i];
 869                 if (pdat) {
 870                         struct dma_pl330_peri *peri = &pdat->peri[i];
 871
 872                         switch (peri->rqtype) {
 873                         case MEMTOMEM:
 874                                 dma_cap_set(DMA_MEMCPY, pd->cap_mask);
 875                                 break;
 876                         case MEMTODEV:
 877                         case DEVTOMEM:
 878                                 dma_cap_set(DMA_SLAVE, pd->cap_mask);
 879                                 dma_cap_set(DMA_CYCLIC, pd->cap_mask);
 880                                 break;
 881                         default:
 882                                 dev_err(&adev->dev, "DEVTODEV Not Supported\n");
 883                                 continue;
 884                         }
 885                         pch->chan.private = peri;
 886                 } else {
 887                         dma_cap_set(DMA_MEMCPY, pd->cap_mask);
 888                         pch->chan.private = NULL;
 889                 }
 890
 891                 INIT_LIST_HEAD(&pch->work_list);
 892                 spin_lock_init(&pch->lock);
 893                 pch->pl330_chid = NULL;
 894                 pch->chan.device = pd;
 895                 pch->dmac = pdmac;
 896
 897                 /* Add the channel to the DMAC list */
 898                 list_add_tail(&pch->chan.device_node, &pd->channels);
 899         }
 900
 901         pd->dev = &adev->dev;
 902
 903         pd->device_alloc_chan_resources = pl330_alloc_chan_resources;
 904         pd->device_free_chan_resources = pl330_free_chan_resources;
 905         pd->device_prep_dma_memcpy = pl330_prep_dma_memcpy;
 906         pd->device_prep_dma_cyclic = pl330_prep_dma_cyclic;
 907         pd->device_tx_status = pl330_tx_status;
 908         pd->device_prep_slave_sg = pl330_prep_slave_sg;
 909         pd->device_control = pl330_control;
 910         pd->device_issue_pending = pl330_issue_pending;
 911
 912         ret = dma_async_device_register(pd);
 913         if (ret) {
 914                 dev_err(&adev->dev, "unable to register DMAC\n");
 915                 goto probe_err4;
 916         }
 917
 918         dev_info(&adev->dev,
 919                 "Loaded driver for PL330 DMAC-%d\n", adev->periphid);
 920         dev_info(&adev->dev,
 921                 "\tDBUFF-%ux%ubytes Num_Chans-%u Num_Peri-%u Num_Events-%u\n",
 922                 pi->pcfg.data_buf_dep,
 923                 pi->pcfg.data_bus_width / 8, pi->pcfg.num_chan,
 924                 pi->pcfg.num_peri, pi->pcfg.num_events);
 925
 926         return 0;
 927
 928 probe_err4:
 929         pl330_del(pi);
 930 probe_err3:
 931         free_irq(irq, pi);
 932 probe_err2:
 933         iounmap(pi->base);
 934 probe_err1:
 935         release_mem_region(res->start, resource_size(res));
 936         kfree(pdmac);
 937
 938         return ret;
 939 }
 940
 941 static int __devexit pl330_remove(struct amba_device *adev)
 942 {
 943         struct dma_pl330_dmac *pdmac = amba_get_drvdata(adev);
 944         struct dma_pl330_chan *pch, *_p;
 945         struct pl330_info *pi;
 946         struct resource *res;
 947         int irq;
 948
 949         if (!pdmac)
 950                 return 0;
 951
 952         amba_set_drvdata(adev, NULL);
 953
 954         /* Idle the DMAC */
 955         list_for_each_entry_safe(pch, _p, &pdmac->ddma.channels,
 956                         chan.device_node) {
 957
 958                 /* Remove the channel */
 959                 list_del(&pch->chan.device_node);
 960
 961                 /* Flush the channel */
 962                 pl330_control(&pch->chan, DMA_TERMINATE_ALL, 0);
 963                 pl330_free_chan_resources(&pch->chan);
 964         }
 965
 966         pi = &pdmac->pif;
 967
 968         pl330_del(pi);
 969
 970         irq = adev->irq[0];
 971         free_irq(irq, pi);
 972
 973         iounmap(pi->base);
 974
 975         res = &adev->res;
 976         release_mem_region(res->start, resource_size(res));
 977
 978 #ifdef CONFIG_PM_RUNTIME
 979         pm_runtime_put(&adev->dev);
 980         pm_runtime_disable(&adev->dev);
 981 #else
 982         clk_disable(pdmac->clk);
 983 #endif
 984
 985         kfree(pdmac);
 986
 987         return 0;
 988 }
 989
 990 static struct amba_id pl330_ids[] = {
 991         {
 992                 .id     = 0x00041330,
 993                 .mask   = 0x000fffff,
 994         },
 995         { 0, 0 },
 996 };
 997
 998 #ifdef CONFIG_PM_RUNTIME
 999 static int pl330_runtime_suspend(struct device *dev)
1000 {
1001         struct dma_pl330_dmac *pdmac = dev_get_drvdata(dev);
1002
1003         if (!pdmac) {
1004                 dev_err(dev, "failed to get dmac\n");
1005                 return -ENODEV;
1006         }
1007
1008         clk_disable(pdmac->clk);
1009
1010         return 0;
1011 }
1012
1013 static int pl330_runtime_resume(struct device *dev)
1014 {
1015         struct dma_pl330_dmac *pdmac = dev_get_drvdata(dev);
1016
1017         if (!pdmac) {
1018                 dev_err(dev, "failed to get dmac\n");
1019                 return -ENODEV;
1020         }
1021
1022         clk_enable(pdmac->clk);
1023
1024         return 0;
1025 }
1026 #else
1027 #define pl330_runtime_suspend   NULL
1028 #define pl330_runtime_resume    NULL
1029 #endif /* CONFIG_PM_RUNTIME */
1030
1031 static const struct dev_pm_ops pl330_pm_ops = {
1032         .runtime_suspend = pl330_runtime_suspend,
1033         .runtime_resume = pl330_runtime_resume,
1034 };
1035
1036 static struct amba_driver pl330_driver = {
1037         .drv = {
1038                 .owner = THIS_MODULE,
1039                 .name = "dma-pl330",
1040                 .pm = &pl330_pm_ops,
1041         },
1042         .id_table = pl330_ids,
1043         .probe = pl330_probe,
1044         .remove = pl330_remove,
1045 };
1046
1047 static int __init pl330_init(void)
1048 {
1049         return amba_driver_register(&pl330_driver);
1050 }
1051 module_init(pl330_init);
1052
1053 static void __exit pl330_exit(void)
1054 {
1055         amba_driver_unregister(&pl330_driver);
1056         return;
1057 }
1058 module_exit(pl330_exit);
1059
1060 MODULE_AUTHOR("Jaswinder Singh <jassi.brar@samsung.com>");
1061 MODULE_DESCRIPTION("API Driver for PL330 DMAC");
1062 MODULE_LICENSE("GPL");