drivers/dma/mv_xor.c

   1 /*
   2  * offload engine driver for the Marvell XOR engine
   3  * Copyright (C) 2007, 2008, Marvell International Ltd.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  */
  14
  15 #include <linux/init.h>
  16 #include <linux/slab.h>
  17 #include <linux/delay.h>
  18 #include <linux/dma-mapping.h>
  19 #include <linux/spinlock.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/of_device.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/memory.h>
  24 #include <linux/clk.h>
  25 #include <linux/of.h>
  26 #include <linux/of_irq.h>
  27 #include <linux/irqdomain.h>
  28 #include <linux/cpumask.h>
  29 #include <linux/platform_data/dma-mv_xor.h>
  30
  31 #include "dmaengine.h"
  32 #include "mv_xor.h"
  33
  34 enum mv_xor_mode {
  35         XOR_MODE_IN_REG,
  36         XOR_MODE_IN_DESC,
  37 };
  38
  39 static void mv_xor_issue_pending(struct dma_chan *chan);
  40
  41 #define to_mv_xor_chan(chan)            \
  42         container_of(chan, struct mv_xor_chan, dmachan)
  43
  44 #define to_mv_xor_slot(tx)              \
  45         container_of(tx, struct mv_xor_desc_slot, async_tx)
  46
  47 #define mv_chan_to_devp(chan)           \
  48         ((chan)->dmadev.dev)
  49
  50 static void mv_desc_init(struct mv_xor_desc_slot *desc,
  51                          dma_addr_t addr, u32 byte_count,
  52                          enum dma_ctrl_flags flags)
  53 {
  54         struct mv_xor_desc *hw_desc = desc->hw_desc;
  55
  56         hw_desc->status = XOR_DESC_DMA_OWNED;
  57         hw_desc->phy_next_desc = 0;
  58         /* Enable end-of-descriptor interrupts only for DMA_PREP_INTERRUPT */
  59         hw_desc->desc_command = (flags & DMA_PREP_INTERRUPT) ?
  60                                 XOR_DESC_EOD_INT_EN : 0;
  61         hw_desc->phy_dest_addr = addr;
  62         hw_desc->byte_count = byte_count;
  63 }
  64
  65 static void mv_desc_set_mode(struct mv_xor_desc_slot *desc)
  66 {
  67         struct mv_xor_desc *hw_desc = desc->hw_desc;
  68
  69         switch (desc->type) {
  70         case DMA_XOR:
  71         case DMA_INTERRUPT:
  72                 hw_desc->desc_command |= XOR_DESC_OPERATION_XOR;
  73                 break;
  74         case DMA_MEMCPY:
  75                 hw_desc->desc_command |= XOR_DESC_OPERATION_MEMCPY;
  76                 break;
  77         default:
  78                 BUG();
  79                 return;
  80         }
  81 }
  82
  83 static void mv_desc_set_next_desc(struct mv_xor_desc_slot *desc,
  84                                   u32 next_desc_addr)
  85 {
  86         struct mv_xor_desc *hw_desc = desc->hw_desc;
  87         BUG_ON(hw_desc->phy_next_desc);
  88         hw_desc->phy_next_desc = next_desc_addr;
  89 }
  90
  91 static void mv_desc_set_src_addr(struct mv_xor_desc_slot *desc,
  92                                  int index, dma_addr_t addr)
  93 {
  94         struct mv_xor_desc *hw_desc = desc->hw_desc;
  95         hw_desc->phy_src_addr[mv_phy_src_idx(index)] = addr;
  96         if (desc->type == DMA_XOR)
  97                 hw_desc->desc_command |= (1 << index);
  98 }
  99
 100 static u32 mv_chan_get_current_desc(struct mv_xor_chan *chan)
 101 {
 102         return readl_relaxed(XOR_CURR_DESC(chan));
 103 }
 104
 105 static void mv_chan_set_next_descriptor(struct mv_xor_chan *chan,
 106                                         u32 next_desc_addr)
 107 {
 108         writel_relaxed(next_desc_addr, XOR_NEXT_DESC(chan));
 109 }
 110
 111 static void mv_chan_unmask_interrupts(struct mv_xor_chan *chan)
 112 {
 113         u32 val = readl_relaxed(XOR_INTR_MASK(chan));
 114         val |= XOR_INTR_MASK_VALUE << (chan->idx * 16);
 115         writel_relaxed(val, XOR_INTR_MASK(chan));
 116 }
 117
 118 static u32 mv_chan_get_intr_cause(struct mv_xor_chan *chan)
 119 {
 120         u32 intr_cause = readl_relaxed(XOR_INTR_CAUSE(chan));
 121         intr_cause = (intr_cause >> (chan->idx * 16)) & 0xFFFF;
 122         return intr_cause;
 123 }
 124
 125 static void mv_chan_clear_eoc_cause(struct mv_xor_chan *chan)
 126 {
 127         u32 val;
 128
 129         val = XOR_INT_END_OF_DESC | XOR_INT_END_OF_CHAIN | XOR_INT_STOPPED;
 130         val = ~(val << (chan->idx * 16));
 131         dev_dbg(mv_chan_to_devp(chan), "%s, val 0x%08x\n", __func__, val);
 132         writel_relaxed(val, XOR_INTR_CAUSE(chan));
 133 }
 134
 135 static void mv_chan_clear_err_status(struct mv_xor_chan *chan)
 136 {
 137         u32 val = 0xFFFF0000 >> (chan->idx * 16);
 138         writel_relaxed(val, XOR_INTR_CAUSE(chan));
 139 }
 140
 141 static void mv_chan_set_mode(struct mv_xor_chan *chan,
 142                              u32 op_mode)
 143 {
 144         u32 config = readl_relaxed(XOR_CONFIG(chan));
 145
 146         config &= ~0x7;
 147         config |= op_mode;
 148
 149 #if defined(__BIG_ENDIAN)
 150         config |= XOR_DESCRIPTOR_SWAP;
 151 #else
 152         config &= ~XOR_DESCRIPTOR_SWAP;
 153 #endif
 154
 155         writel_relaxed(config, XOR_CONFIG(chan));
 156 }
 157
 158 static void mv_chan_activate(struct mv_xor_chan *chan)
 159 {
 160         dev_dbg(mv_chan_to_devp(chan), " activate chan.\n");
 161
 162         /* writel ensures all descriptors are flushed before activation */
 163         writel(BIT(0), XOR_ACTIVATION(chan));
 164 }
 165
 166 static char mv_chan_is_busy(struct mv_xor_chan *chan)
 167 {
 168         u32 state = readl_relaxed(XOR_ACTIVATION(chan));
 169
 170         state = (state >> 4) & 0x3;
 171
 172         return (state == 1) ? 1 : 0;
 173 }
 174
 175 /*
 176  * mv_chan_start_new_chain - program the engine to operate on new
 177  * chain headed by sw_desc
 178  * Caller must hold &mv_chan->lock while calling this function
 179  */
 180 static void mv_chan_start_new_chain(struct mv_xor_chan *mv_chan,
 181                                     struct mv_xor_desc_slot *sw_desc)
 182 {
 183         dev_dbg(mv_chan_to_devp(mv_chan), "%s %d: sw_desc %p\n",
 184                 __func__, __LINE__, sw_desc);
 185
 186         /* set the hardware chain */
 187         mv_chan_set_next_descriptor(mv_chan, sw_desc->async_tx.phys);
 188
 189         mv_chan->pending++;
 190         mv_xor_issue_pending(&mv_chan->dmachan);
 191 }
 192
 193 static dma_cookie_t
 194 mv_desc_run_tx_complete_actions(struct mv_xor_desc_slot *desc,
 195                                 struct mv_xor_chan *mv_chan,
 196                                 dma_cookie_t cookie)
 197 {
 198         BUG_ON(desc->async_tx.cookie < 0);
 199
 200         if (desc->async_tx.cookie > 0) {
 201                 cookie = desc->async_tx.cookie;
 202
 203                 /* call the callback (must not sleep or submit new
 204                  * operations to this channel)
 205                  */
 206                 if (desc->async_tx.callback)
 207                         desc->async_tx.callback(
 208                                 desc->async_tx.callback_param);
 209
 210                 dma_descriptor_unmap(&desc->async_tx);
 211         }
 212
 213         /* run dependent operations */
 214         dma_run_dependencies(&desc->async_tx);
 215
 216         return cookie;
 217 }
 218
 219 static int
 220 mv_chan_clean_completed_slots(struct mv_xor_chan *mv_chan)
 221 {
 222         struct mv_xor_desc_slot *iter, *_iter;
 223
 224         dev_dbg(mv_chan_to_devp(mv_chan), "%s %d\n", __func__, __LINE__);
 225         list_for_each_entry_safe(iter, _iter, &mv_chan->completed_slots,
 226                                  node) {
 227
 228                 if (async_tx_test_ack(&iter->async_tx))
 229                         list_move_tail(&iter->node, &mv_chan->free_slots);
 230         }
 231         return 0;
 232 }
 233
 234 static int
 235 mv_desc_clean_slot(struct mv_xor_desc_slot *desc,
 236                    struct mv_xor_chan *mv_chan)
 237 {
 238         dev_dbg(mv_chan_to_devp(mv_chan), "%s %d: desc %p flags %d\n",
 239                 __func__, __LINE__, desc, desc->async_tx.flags);
 240
 241         /* the client is allowed to attach dependent operations
 242          * until 'ack' is set
 243          */
 244         if (!async_tx_test_ack(&desc->async_tx))
 245                 /* move this slot to the completed_slots */
 246                 list_move_tail(&desc->node, &mv_chan->completed_slots);
 247         else
 248                 list_move_tail(&desc->node, &mv_chan->free_slots);
 249
 250         return 0;
 251 }
 252
 253 /* This function must be called with the mv_xor_chan spinlock held */
 254 static void mv_chan_slot_cleanup(struct mv_xor_chan *mv_chan)
 255 {
 256         struct mv_xor_desc_slot *iter, *_iter;
 257         dma_cookie_t cookie = 0;
 258         int busy = mv_chan_is_busy(mv_chan);
 259         u32 current_desc = mv_chan_get_current_desc(mv_chan);
 260         int current_cleaned = 0;
 261         struct mv_xor_desc *hw_desc;
 262
 263         dev_dbg(mv_chan_to_devp(mv_chan), "%s %d\n", __func__, __LINE__);
 264         dev_dbg(mv_chan_to_devp(mv_chan), "current_desc %x\n", current_desc);
 265         mv_chan_clean_completed_slots(mv_chan);
 266
 267         /* free completed slots from the chain starting with
 268          * the oldest descriptor
 269          */
 270
 271         list_for_each_entry_safe(iter, _iter, &mv_chan->chain,
 272                                  node) {
 273
 274                 /* clean finished descriptors */
 275                 hw_desc = iter->hw_desc;
 276                 if (hw_desc->status & XOR_DESC_SUCCESS) {
 277                         cookie = mv_desc_run_tx_complete_actions(iter, mv_chan,
 278                                                                  cookie);
 279
 280                         /* done processing desc, clean slot */
 281                         mv_desc_clean_slot(iter, mv_chan);
 282
 283                         /* break if we did cleaned the current */
 284                         if (iter->async_tx.phys == current_desc) {
 285                                 current_cleaned = 1;
 286                                 break;
 287                         }
 288                 } else {
 289                         if (iter->async_tx.phys == current_desc) {
 290                                 current_cleaned = 0;
 291                                 break;
 292                         }
 293                 }
 294         }
 295
 296         if ((busy == 0) && !list_empty(&mv_chan->chain)) {
 297                 if (current_cleaned) {
 298                         /*
 299                          * current descriptor cleaned and removed, run
 300                          * from list head
 301                          */
 302                         iter = list_entry(mv_chan->chain.next,
 303                                           struct mv_xor_desc_slot,
 304                                           node);
 305                         mv_chan_start_new_chain(mv_chan, iter);
 306                 } else {
 307                         if (!list_is_last(&iter->node, &mv_chan->chain)) {
 308                                 /*
 309                                  * descriptors are still waiting after
 310                                  * current, trigger them
 311                                  */
 312                                 iter = list_entry(iter->node.next,
 313                                                   struct mv_xor_desc_slot,
 314                                                   node);
 315                                 mv_chan_start_new_chain(mv_chan, iter);
 316                         } else {
 317                                 /*
 318                                  * some descriptors are still waiting
 319                                  * to be cleaned
 320                                  */
 321                                 tasklet_schedule(&mv_chan->irq_tasklet);
 322                         }
 323                 }
 324         }
 325
 326         if (cookie > 0)
 327                 mv_chan->dmachan.completed_cookie = cookie;
 328 }
 329
 330 static void mv_xor_tasklet(unsigned long data)
 331 {
 332         struct mv_xor_chan *chan = (struct mv_xor_chan *) data;
 333
 334         spin_lock_bh(&chan->lock);
 335         mv_chan_slot_cleanup(chan);
 336         spin_unlock_bh(&chan->lock);
 337 }
 338
 339 static struct mv_xor_desc_slot *
 340 mv_chan_alloc_slot(struct mv_xor_chan *mv_chan)
 341 {
 342         struct mv_xor_desc_slot *iter;
 343
 344         spin_lock_bh(&mv_chan->lock);
 345
 346         if (!list_empty(&mv_chan->free_slots)) {
 347                 iter = list_first_entry(&mv_chan->free_slots,
 348                                         struct mv_xor_desc_slot,
 349                                         node);
 350
 351                 list_move_tail(&iter->node, &mv_chan->allocated_slots);
 352
 353                 spin_unlock_bh(&mv_chan->lock);
 354
 355                 /* pre-ack descriptor */
 356                 async_tx_ack(&iter->async_tx);
 357                 iter->async_tx.cookie = -EBUSY;
 358
 359                 return iter;
 360
 361         }
 362
 363         spin_unlock_bh(&mv_chan->lock);
 364
 365         /* try to free some slots if the allocation fails */
 366         tasklet_schedule(&mv_chan->irq_tasklet);
 367
 368         return NULL;
 369 }
 370
 371 /************************ DMA engine API functions ****************************/
 372 static dma_cookie_t
 373 mv_xor_tx_submit(struct dma_async_tx_descriptor *tx)
 374 {
 375         struct mv_xor_desc_slot *sw_desc = to_mv_xor_slot(tx);
 376         struct mv_xor_chan *mv_chan = to_mv_xor_chan(tx->chan);
 377         struct mv_xor_desc_slot *old_chain_tail;
 378         dma_cookie_t cookie;
 379         int new_hw_chain = 1;
 380
 381         dev_dbg(mv_chan_to_devp(mv_chan),
 382                 "%s sw_desc %p: async_tx %p\n",
 383                 __func__, sw_desc, &sw_desc->async_tx);
 384
 385         spin_lock_bh(&mv_chan->lock);
 386         cookie = dma_cookie_assign(tx);
 387
 388         if (list_empty(&mv_chan->chain))
 389                 list_move_tail(&sw_desc->node, &mv_chan->chain);
 390         else {
 391                 new_hw_chain = 0;
 392
 393                 old_chain_tail = list_entry(mv_chan->chain.prev,
 394                                             struct mv_xor_desc_slot,
 395                                             node);
 396                 list_move_tail(&sw_desc->node, &mv_chan->chain);
 397
 398                 dev_dbg(mv_chan_to_devp(mv_chan), "Append to last desc %pa\n",
 399                         &old_chain_tail->async_tx.phys);
 400
 401                 /* fix up the hardware chain */
 402                 mv_desc_set_next_desc(old_chain_tail, sw_desc->async_tx.phys);
 403
 404                 /* if the channel is not busy */
 405                 if (!mv_chan_is_busy(mv_chan)) {
 406                         u32 current_desc = mv_chan_get_current_desc(mv_chan);
 407                         /*
 408                          * and the curren desc is the end of the chain before
 409                          * the append, then we need to start the channel
 410                          */
 411                         if (current_desc == old_chain_tail->async_tx.phys)
 412                                 new_hw_chain = 1;
 413                 }
 414         }
 415
 416         if (new_hw_chain)
 417                 mv_chan_start_new_chain(mv_chan, sw_desc);
 418
 419         spin_unlock_bh(&mv_chan->lock);
 420
 421         return cookie;
 422 }
 423
 424 /* returns the number of allocated descriptors */
 425 static int mv_xor_alloc_chan_resources(struct dma_chan *chan)
 426 {
 427         void *virt_desc;
 428         dma_addr_t dma_desc;
 429         int idx;
 430         struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);
 431         struct mv_xor_desc_slot *slot = NULL;
 432         int num_descs_in_pool = MV_XOR_POOL_SIZE/MV_XOR_SLOT_SIZE;
 433
 434         /* Allocate descriptor slots */
 435         idx = mv_chan->slots_allocated;
 436         while (idx < num_descs_in_pool) {
 437                 slot = kzalloc(sizeof(*slot), GFP_KERNEL);
 438                 if (!slot) {
 439                         dev_info(mv_chan_to_devp(mv_chan),
 440                                  "channel only initialized %d descriptor slots",
 441                                  idx);
 442                         break;
 443                 }
 444                 virt_desc = mv_chan->dma_desc_pool_virt;
 445                 slot->hw_desc = virt_desc + idx * MV_XOR_SLOT_SIZE;
 446
 447                 dma_async_tx_descriptor_init(&slot->async_tx, chan);
 448                 slot->async_tx.tx_submit = mv_xor_tx_submit;
 449                 INIT_LIST_HEAD(&slot->node);
 450                 dma_desc = mv_chan->dma_desc_pool;
 451                 slot->async_tx.phys = dma_desc + idx * MV_XOR_SLOT_SIZE;
 452                 slot->idx = idx++;
 453
 454                 spin_lock_bh(&mv_chan->lock);
 455                 mv_chan->slots_allocated = idx;
 456                 list_add_tail(&slot->node, &mv_chan->free_slots);
 457                 spin_unlock_bh(&mv_chan->lock);
 458         }
 459
 460         dev_dbg(mv_chan_to_devp(mv_chan),
 461                 "allocated %d descriptor slots\n",
 462                 mv_chan->slots_allocated);
 463
 464         return mv_chan->slots_allocated ? : -ENOMEM;
 465 }
 466
 467 static struct dma_async_tx_descriptor *
 468 mv_xor_prep_dma_xor(struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src,
 469                     unsigned int src_cnt, size_t len, unsigned long flags)
 470 {
 471         struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);
 472         struct mv_xor_desc_slot *sw_desc;
 473
 474         if (unlikely(len < MV_XOR_MIN_BYTE_COUNT))
 475                 return NULL;
 476
 477         BUG_ON(len > MV_XOR_MAX_BYTE_COUNT);
 478
 479         dev_dbg(mv_chan_to_devp(mv_chan),
 480                 "%s src_cnt: %d len: %u dest %pad flags: %ld\n",
 481                 __func__, src_cnt, len, &dest, flags);
 482
 483         sw_desc = mv_chan_alloc_slot(mv_chan);
 484         if (sw_desc) {
 485                 sw_desc->type = DMA_XOR;
 486                 sw_desc->async_tx.flags = flags;
 487                 mv_desc_init(sw_desc, dest, len, flags);
 488                 if (mv_chan->op_in_desc == XOR_MODE_IN_DESC)
 489                         mv_desc_set_mode(sw_desc);
 490                 while (src_cnt--)
 491                         mv_desc_set_src_addr(sw_desc, src_cnt, src[src_cnt]);
 492         }
 493
 494         dev_dbg(mv_chan_to_devp(mv_chan),
 495                 "%s sw_desc %p async_tx %p \n",
 496                 __func__, sw_desc, &sw_desc->async_tx);
 497         return sw_desc ? &sw_desc->async_tx : NULL;
 498 }
 499
 500 static struct dma_async_tx_descriptor *
 501 mv_xor_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 502                 size_t len, unsigned long flags)
 503 {
 504         /*
 505          * A MEMCPY operation is identical to an XOR operation with only
 506          * a single source address.
 507          */
 508         return mv_xor_prep_dma_xor(chan, dest, &src, 1, len, flags);
 509 }
 510
 511 static struct dma_async_tx_descriptor *
 512 mv_xor_prep_dma_interrupt(struct dma_chan *chan, unsigned long flags)
 513 {
 514         struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);
 515         dma_addr_t src, dest;
 516         size_t len;
 517
 518         src = mv_chan->dummy_src_addr;
 519         dest = mv_chan->dummy_dst_addr;
 520         len = MV_XOR_MIN_BYTE_COUNT;
 521
 522         /*
 523          * We implement the DMA_INTERRUPT operation as a minimum sized
 524          * XOR operation with a single dummy source address.
 525          */
 526         return mv_xor_prep_dma_xor(chan, dest, &src, 1, len, flags);
 527 }
 528
 529 static void mv_xor_free_chan_resources(struct dma_chan *chan)
 530 {
 531         struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);
 532         struct mv_xor_desc_slot *iter, *_iter;
 533         int in_use_descs = 0;
 534
 535         spin_lock_bh(&mv_chan->lock);
 536
 537         mv_chan_slot_cleanup(mv_chan);
 538
 539         list_for_each_entry_safe(iter, _iter, &mv_chan->chain,
 540                                         node) {
 541                 in_use_descs++;
 542                 list_move_tail(&iter->node, &mv_chan->free_slots);
 543         }
 544         list_for_each_entry_safe(iter, _iter, &mv_chan->completed_slots,
 545                                  node) {
 546                 in_use_descs++;
 547                 list_move_tail(&iter->node, &mv_chan->free_slots);
 548         }
 549         list_for_each_entry_safe(iter, _iter, &mv_chan->allocated_slots,
 550                                  node) {
 551                 in_use_descs++;
 552                 list_move_tail(&iter->node, &mv_chan->free_slots);
 553         }
 554         list_for_each_entry_safe_reverse(
 555                 iter, _iter, &mv_chan->free_slots, node) {
 556                 list_del(&iter->node);
 557                 kfree(iter);
 558                 mv_chan->slots_allocated--;
 559         }
 560
 561         dev_dbg(mv_chan_to_devp(mv_chan), "%s slots_allocated %d\n",
 562                 __func__, mv_chan->slots_allocated);
 563         spin_unlock_bh(&mv_chan->lock);
 564
 565         if (in_use_descs)
 566                 dev_err(mv_chan_to_devp(mv_chan),
 567                         "freeing %d in use descriptors!\n", in_use_descs);
 568 }
 569
 570 /**
 571  * mv_xor_status - poll the status of an XOR transaction
 572  * @chan: XOR channel handle
 573  * @cookie: XOR transaction identifier
 574  * @txstate: XOR transactions state holder (or NULL)
 575  */
 576 static enum dma_status mv_xor_status(struct dma_chan *chan,
 577                                           dma_cookie_t cookie,
 578                                           struct dma_tx_state *txstate)
 579 {
 580         struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);
 581         enum dma_status ret;
 582
 583         ret = dma_cookie_status(chan, cookie, txstate);
 584         if (ret == DMA_COMPLETE)
 585                 return ret;
 586
 587         spin_lock_bh(&mv_chan->lock);
 588         mv_chan_slot_cleanup(mv_chan);
 589         spin_unlock_bh(&mv_chan->lock);
 590
 591         return dma_cookie_status(chan, cookie, txstate);
 592 }
 593
 594 static void mv_chan_dump_regs(struct mv_xor_chan *chan)
 595 {
 596         u32 val;
 597
 598         val = readl_relaxed(XOR_CONFIG(chan));
 599         dev_err(mv_chan_to_devp(chan), "config       0x%08x\n", val);
 600
 601         val = readl_relaxed(XOR_ACTIVATION(chan));
 602         dev_err(mv_chan_to_devp(chan), "activation   0x%08x\n", val);
 603
 604         val = readl_relaxed(XOR_INTR_CAUSE(chan));
 605         dev_err(mv_chan_to_devp(chan), "intr cause   0x%08x\n", val);
 606
 607         val = readl_relaxed(XOR_INTR_MASK(chan));
 608         dev_err(mv_chan_to_devp(chan), "intr mask    0x%08x\n", val);
 609
 610         val = readl_relaxed(XOR_ERROR_CAUSE(chan));
 611         dev_err(mv_chan_to_devp(chan), "error cause  0x%08x\n", val);
 612
 613         val = readl_relaxed(XOR_ERROR_ADDR(chan));
 614         dev_err(mv_chan_to_devp(chan), "error addr   0x%08x\n", val);
 615 }
 616
 617 static void mv_chan_err_interrupt_handler(struct mv_xor_chan *chan,
 618                                           u32 intr_cause)
 619 {
 620         if (intr_cause & XOR_INT_ERR_DECODE) {
 621                 dev_dbg(mv_chan_to_devp(chan), "ignoring address decode error\n");
 622                 return;
 623         }
 624
 625         dev_err(mv_chan_to_devp(chan), "error on chan %d. intr cause 0x%08x\n",
 626                 chan->idx, intr_cause);
 627
 628         mv_chan_dump_regs(chan);
 629         WARN_ON(1);
 630 }
 631
 632 static irqreturn_t mv_xor_interrupt_handler(int irq, void *data)
 633 {
 634         struct mv_xor_chan *chan = data;
 635         u32 intr_cause = mv_chan_get_intr_cause(chan);
 636
 637         dev_dbg(mv_chan_to_devp(chan), "intr cause %x\n", intr_cause);
 638
 639         if (intr_cause & XOR_INTR_ERRORS)
 640                 mv_chan_err_interrupt_handler(chan, intr_cause);
 641
 642         tasklet_schedule(&chan->irq_tasklet);
 643
 644         mv_chan_clear_eoc_cause(chan);
 645
 646         return IRQ_HANDLED;
 647 }
 648
 649 static void mv_xor_issue_pending(struct dma_chan *chan)
 650 {
 651         struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);
 652
 653         if (mv_chan->pending >= MV_XOR_THRESHOLD) {
 654                 mv_chan->pending = 0;
 655                 mv_chan_activate(mv_chan);
 656         }
 657 }
 658
 659 /*
 660  * Perform a transaction to verify the HW works.
 661  */
 662
 663 static int mv_chan_memcpy_self_test(struct mv_xor_chan *mv_chan)
 664 {
 665         int i, ret;
 666         void *src, *dest;
 667         dma_addr_t src_dma, dest_dma;
 668         struct dma_chan *dma_chan;
 669         dma_cookie_t cookie;
 670         struct dma_async_tx_descriptor *tx;
 671         struct dmaengine_unmap_data *unmap;
 672         int err = 0;
 673
 674         src = kmalloc(sizeof(u8) * PAGE_SIZE, GFP_KERNEL);
 675         if (!src)
 676                 return -ENOMEM;
 677
 678         dest = kzalloc(sizeof(u8) * PAGE_SIZE, GFP_KERNEL);
 679         if (!dest) {
 680                 kfree(src);
 681                 return -ENOMEM;
 682         }
 683
 684         /* Fill in src buffer */
 685         for (i = 0; i < PAGE_SIZE; i++)
 686                 ((u8 *) src)[i] = (u8)i;
 687
 688         dma_chan = &mv_chan->dmachan;
 689         if (mv_xor_alloc_chan_resources(dma_chan) < 1) {
 690                 err = -ENODEV;
 691                 goto out;
 692         }
 693
 694         unmap = dmaengine_get_unmap_data(dma_chan->device->dev, 2, GFP_KERNEL);
 695         if (!unmap) {
 696                 err = -ENOMEM;
 697                 goto free_resources;
 698         }
 699
 700         src_dma = dma_map_page(dma_chan->device->dev, virt_to_page(src), 0,
 701                                  PAGE_SIZE, DMA_TO_DEVICE);
 702         unmap->addr[0] = src_dma;
 703
 704         ret = dma_mapping_error(dma_chan->device->dev, src_dma);
 705         if (ret) {
 706                 err = -ENOMEM;
 707                 goto free_resources;
 708         }
 709         unmap->to_cnt = 1;
 710
 711         dest_dma = dma_map_page(dma_chan->device->dev, virt_to_page(dest), 0,
 712                                   PAGE_SIZE, DMA_FROM_DEVICE);
 713         unmap->addr[1] = dest_dma;
 714
 715         ret = dma_mapping_error(dma_chan->device->dev, dest_dma);
 716         if (ret) {
 717                 err = -ENOMEM;
 718                 goto free_resources;
 719         }
 720         unmap->from_cnt = 1;
 721         unmap->len = PAGE_SIZE;
 722
 723         tx = mv_xor_prep_dma_memcpy(dma_chan, dest_dma, src_dma,
 724                                     PAGE_SIZE, 0);
 725         if (!tx) {
 726                 dev_err(dma_chan->device->dev,
 727                         "Self-test cannot prepare operation, disabling\n");
 728                 err = -ENODEV;
 729                 goto free_resources;
 730         }
 731
 732         cookie = mv_xor_tx_submit(tx);
 733         if (dma_submit_error(cookie)) {
 734                 dev_err(dma_chan->device->dev,
 735                         "Self-test submit error, disabling\n");
 736                 err = -ENODEV;
 737                 goto free_resources;
 738         }
 739
 740         mv_xor_issue_pending(dma_chan);
 741         async_tx_ack(tx);
 742         msleep(1);
 743
 744         if (mv_xor_status(dma_chan, cookie, NULL) !=
 745             DMA_COMPLETE) {
 746                 dev_err(dma_chan->device->dev,
 747                         "Self-test copy timed out, disabling\n");
 748                 err = -ENODEV;
 749                 goto free_resources;
 750         }
 751
 752         dma_sync_single_for_cpu(dma_chan->device->dev, dest_dma,
 753                                 PAGE_SIZE, DMA_FROM_DEVICE);
 754         if (memcmp(src, dest, PAGE_SIZE)) {
 755                 dev_err(dma_chan->device->dev,
 756                         "Self-test copy failed compare, disabling\n");
 757                 err = -ENODEV;
 758                 goto free_resources;
 759         }
 760
 761 free_resources:
 762         dmaengine_unmap_put(unmap);
 763         mv_xor_free_chan_resources(dma_chan);
 764 out:
 765         kfree(src);
 766         kfree(dest);
 767         return err;
 768 }
 769
 770 #define MV_XOR_NUM_SRC_TEST 4 /* must be <= 15 */
 771 static int
 772 mv_chan_xor_self_test(struct mv_xor_chan *mv_chan)
 773 {
 774         int i, src_idx, ret;
 775         struct page *dest;
 776         struct page *xor_srcs[MV_XOR_NUM_SRC_TEST];
 777         dma_addr_t dma_srcs[MV_XOR_NUM_SRC_TEST];
 778         dma_addr_t dest_dma;
 779         struct dma_async_tx_descriptor *tx;
 780         struct dmaengine_unmap_data *unmap;
 781         struct dma_chan *dma_chan;
 782         dma_cookie_t cookie;
 783         u8 cmp_byte = 0;
 784         u32 cmp_word;
 785         int err = 0;
 786         int src_count = MV_XOR_NUM_SRC_TEST;
 787
 788         for (src_idx = 0; src_idx < src_count; src_idx++) {
 789                 xor_srcs[src_idx] = alloc_page(GFP_KERNEL);
 790                 if (!xor_srcs[src_idx]) {
 791                         while (src_idx--)
 792                                 __free_page(xor_srcs[src_idx]);
 793                         return -ENOMEM;
 794                 }
 795         }
 796
 797         dest = alloc_page(GFP_KERNEL);
 798         if (!dest) {
 799                 while (src_idx--)
 800                         __free_page(xor_srcs[src_idx]);
 801                 return -ENOMEM;
 802         }
 803
 804         /* Fill in src buffers */
 805         for (src_idx = 0; src_idx < src_count; src_idx++) {
 806                 u8 *ptr = page_address(xor_srcs[src_idx]);
 807                 for (i = 0; i < PAGE_SIZE; i++)
 808                         ptr[i] = (1 << src_idx);
 809         }
 810
 811         for (src_idx = 0; src_idx < src_count; src_idx++)
 812                 cmp_byte ^= (u8) (1 << src_idx);
 813
 814         cmp_word = (cmp_byte << 24) | (cmp_byte << 16) |
 815                 (cmp_byte << 8) | cmp_byte;
 816
 817         memset(page_address(dest), 0, PAGE_SIZE);
 818
 819         dma_chan = &mv_chan->dmachan;
 820         if (mv_xor_alloc_chan_resources(dma_chan) < 1) {
 821                 err = -ENODEV;
 822                 goto out;
 823         }
 824
 825         unmap = dmaengine_get_unmap_data(dma_chan->device->dev, src_count + 1,
 826                                          GFP_KERNEL);
 827         if (!unmap) {
 828                 err = -ENOMEM;
 829                 goto free_resources;
 830         }
 831
 832         /* test xor */
 833         for (i = 0; i < src_count; i++) {
 834                 unmap->addr[i] = dma_map_page(dma_chan->device->dev, xor_srcs[i],
 835                                               0, PAGE_SIZE, DMA_TO_DEVICE);
 836                 dma_srcs[i] = unmap->addr[i];
 837                 ret = dma_mapping_error(dma_chan->device->dev, unmap->addr[i]);
 838                 if (ret) {
 839                         err = -ENOMEM;
 840                         goto free_resources;
 841                 }
 842                 unmap->to_cnt++;
 843         }
 844
 845         unmap->addr[src_count] = dma_map_page(dma_chan->device->dev, dest, 0, PAGE_SIZE,
 846                                       DMA_FROM_DEVICE);
 847         dest_dma = unmap->addr[src_count];
 848         ret = dma_mapping_error(dma_chan->device->dev, unmap->addr[src_count]);
 849         if (ret) {
 850                 err = -ENOMEM;
 851                 goto free_resources;
 852         }
 853         unmap->from_cnt = 1;
 854         unmap->len = PAGE_SIZE;
 855
 856         tx = mv_xor_prep_dma_xor(dma_chan, dest_dma, dma_srcs,
 857                                  src_count, PAGE_SIZE, 0);
 858         if (!tx) {
 859                 dev_err(dma_chan->device->dev,
 860                         "Self-test cannot prepare operation, disabling\n");
 861                 err = -ENODEV;
 862                 goto free_resources;
 863         }
 864
 865         cookie = mv_xor_tx_submit(tx);
 866         if (dma_submit_error(cookie)) {
 867                 dev_err(dma_chan->device->dev,
 868                         "Self-test submit error, disabling\n");
 869                 err = -ENODEV;
 870                 goto free_resources;
 871         }
 872
 873         mv_xor_issue_pending(dma_chan);
 874         async_tx_ack(tx);
 875         msleep(8);
 876
 877         if (mv_xor_status(dma_chan, cookie, NULL) !=
 878             DMA_COMPLETE) {
 879                 dev_err(dma_chan->device->dev,
 880                         "Self-test xor timed out, disabling\n");
 881                 err = -ENODEV;
 882                 goto free_resources;
 883         }
 884
 885         dma_sync_single_for_cpu(dma_chan->device->dev, dest_dma,
 886                                 PAGE_SIZE, DMA_FROM_DEVICE);
 887         for (i = 0; i < (PAGE_SIZE / sizeof(u32)); i++) {
 888                 u32 *ptr = page_address(dest);
 889                 if (ptr[i] != cmp_word) {
 890                         dev_err(dma_chan->device->dev,
 891                                 "Self-test xor failed compare, disabling. index %d, data %x, expected %x\n",
 892                                 i, ptr[i], cmp_word);
 893                         err = -ENODEV;
 894                         goto free_resources;
 895                 }
 896         }
 897
 898 free_resources:
 899         dmaengine_unmap_put(unmap);
 900         mv_xor_free_chan_resources(dma_chan);
 901 out:
 902         src_idx = src_count;
 903         while (src_idx--)
 904                 __free_page(xor_srcs[src_idx]);
 905         __free_page(dest);
 906         return err;
 907 }
 908
 909 static int mv_xor_channel_remove(struct mv_xor_chan *mv_chan)
 910 {
 911         struct dma_chan *chan, *_chan;
 912         struct device *dev = mv_chan->dmadev.dev;
 913
 914         dma_async_device_unregister(&mv_chan->dmadev);
 915
 916         dma_free_coherent(dev, MV_XOR_POOL_SIZE,
 917                           mv_chan->dma_desc_pool_virt, mv_chan->dma_desc_pool);
 918         dma_unmap_single(dev, mv_chan->dummy_src_addr,
 919                          MV_XOR_MIN_BYTE_COUNT, DMA_FROM_DEVICE);
 920         dma_unmap_single(dev, mv_chan->dummy_dst_addr,
 921                          MV_XOR_MIN_BYTE_COUNT, DMA_TO_DEVICE);
 922
 923         list_for_each_entry_safe(chan, _chan, &mv_chan->dmadev.channels,
 924                                  device_node) {
 925                 list_del(&chan->device_node);
 926         }
 927
 928         free_irq(mv_chan->irq, mv_chan);
 929
 930         return 0;
 931 }
 932
 933 static struct mv_xor_chan *
 934 mv_xor_channel_add(struct mv_xor_device *xordev,
 935                    struct platform_device *pdev,
 936                    int idx, dma_cap_mask_t cap_mask, int irq, int op_in_desc)
 937 {
 938         int ret = 0;
 939         struct mv_xor_chan *mv_chan;
 940         struct dma_device *dma_dev;
 941
 942         mv_chan = devm_kzalloc(&pdev->dev, sizeof(*mv_chan), GFP_KERNEL);
 943         if (!mv_chan)
 944                 return ERR_PTR(-ENOMEM);
 945
 946         mv_chan->idx = idx;
 947         mv_chan->irq = irq;
 948         mv_chan->op_in_desc = op_in_desc;
 949
 950         dma_dev = &mv_chan->dmadev;
 951
 952         /*
 953          * These source and destination dummy buffers are used to implement
 954          * a DMA_INTERRUPT operation as a minimum-sized XOR operation.
 955          * Hence, we only need to map the buffers at initialization-time.
 956          */
 957         mv_chan->dummy_src_addr = dma_map_single(dma_dev->dev,
 958                 mv_chan->dummy_src, MV_XOR_MIN_BYTE_COUNT, DMA_FROM_DEVICE);
 959         mv_chan->dummy_dst_addr = dma_map_single(dma_dev->dev,
 960                 mv_chan->dummy_dst, MV_XOR_MIN_BYTE_COUNT, DMA_TO_DEVICE);
 961
 962         /* allocate coherent memory for hardware descriptors
 963          * note: writecombine gives slightly better performance, but
 964          * requires that we explicitly flush the writes
 965          */
 966         mv_chan->dma_desc_pool_virt =
 967           dma_alloc_wc(&pdev->dev, MV_XOR_POOL_SIZE, &mv_chan->dma_desc_pool,
 968                        GFP_KERNEL);
 969         if (!mv_chan->dma_desc_pool_virt)
 970                 return ERR_PTR(-ENOMEM);
 971
 972         /* discover transaction capabilites from the platform data */
 973         dma_dev->cap_mask = cap_mask;
 974
 975         INIT_LIST_HEAD(&dma_dev->channels);
 976
 977         /* set base routines */
 978         dma_dev->device_alloc_chan_resources = mv_xor_alloc_chan_resources;
 979         dma_dev->device_free_chan_resources = mv_xor_free_chan_resources;
 980         dma_dev->device_tx_status = mv_xor_status;
 981         dma_dev->device_issue_pending = mv_xor_issue_pending;
 982         dma_dev->dev = &pdev->dev;
 983
 984         /* set prep routines based on capability */
 985         if (dma_has_cap(DMA_INTERRUPT, dma_dev->cap_mask))
 986                 dma_dev->device_prep_dma_interrupt = mv_xor_prep_dma_interrupt;
 987         if (dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask))
 988                 dma_dev->device_prep_dma_memcpy = mv_xor_prep_dma_memcpy;
 989         if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
 990                 dma_dev->max_xor = 8;
 991                 dma_dev->device_prep_dma_xor = mv_xor_prep_dma_xor;
 992         }
 993
 994         mv_chan->mmr_base = xordev->xor_base;
 995         mv_chan->mmr_high_base = xordev->xor_high_base;
 996         tasklet_init(&mv_chan->irq_tasklet, mv_xor_tasklet, (unsigned long)
 997                      mv_chan);
 998
 999         /* clear errors before enabling interrupts */
1000         mv_chan_clear_err_status(mv_chan);
1001
1002         ret = request_irq(mv_chan->irq, mv_xor_interrupt_handler,
1003                           0, dev_name(&pdev->dev), mv_chan);
1004         if (ret)
1005                 goto err_free_dma;
1006
1007         mv_chan_unmask_interrupts(mv_chan);
1008
1009         if (mv_chan->op_in_desc == XOR_MODE_IN_DESC)
1010                 mv_chan_set_mode(mv_chan, XOR_OPERATION_MODE_IN_DESC);
1011         else
1012                 mv_chan_set_mode(mv_chan, XOR_OPERATION_MODE_XOR);
1013
1014         spin_lock_init(&mv_chan->lock);
1015         INIT_LIST_HEAD(&mv_chan->chain);
1016         INIT_LIST_HEAD(&mv_chan->completed_slots);
1017         INIT_LIST_HEAD(&mv_chan->free_slots);
1018         INIT_LIST_HEAD(&mv_chan->allocated_slots);
1019         mv_chan->dmachan.device = dma_dev;
1020         dma_cookie_init(&mv_chan->dmachan);
1021
1022         list_add_tail(&mv_chan->dmachan.device_node, &dma_dev->channels);
1023
1024         if (dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask)) {
1025                 ret = mv_chan_memcpy_self_test(mv_chan);
1026                 dev_dbg(&pdev->dev, "memcpy self test returned %d\n", ret);
1027                 if (ret)
1028                         goto err_free_irq;
1029         }
1030
1031         if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
1032                 ret = mv_chan_xor_self_test(mv_chan);
1033                 dev_dbg(&pdev->dev, "xor self test returned %d\n", ret);
1034                 if (ret)
1035                         goto err_free_irq;
1036         }
1037
1038         dev_info(&pdev->dev, "Marvell XOR (%s): ( %s%s%s)\n",
1039                  mv_chan->op_in_desc ? "Descriptor Mode" : "Registers Mode",
1040                  dma_has_cap(DMA_XOR, dma_dev->cap_mask) ? "xor " : "",
1041                  dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask) ? "cpy " : "",
1042                  dma_has_cap(DMA_INTERRUPT, dma_dev->cap_mask) ? "intr " : "");
1043
1044         dma_async_device_register(dma_dev);
1045         return mv_chan;
1046
1047 err_free_irq:
1048         free_irq(mv_chan->irq, mv_chan);
1049  err_free_dma:
1050         dma_free_coherent(&pdev->dev, MV_XOR_POOL_SIZE,
1051                           mv_chan->dma_desc_pool_virt, mv_chan->dma_desc_pool);
1052         return ERR_PTR(ret);
1053 }
1054
1055 static void
1056 mv_xor_conf_mbus_windows(struct mv_xor_device *xordev,
1057                          const struct mbus_dram_target_info *dram)
1058 {
1059         void __iomem *base = xordev->xor_high_base;
1060         u32 win_enable = 0;
1061         int i;
1062
1063         for (i = 0; i < 8; i++) {
1064                 writel(0, base + WINDOW_BASE(i));
1065                 writel(0, base + WINDOW_SIZE(i));
1066                 if (i < 4)
1067                         writel(0, base + WINDOW_REMAP_HIGH(i));
1068         }
1069
1070         for (i = 0; i < dram->num_cs; i++) {
1071                 const struct mbus_dram_window *cs = dram->cs + i;
1072
1073                 writel((cs->base & 0xffff0000) |
1074                        (cs->mbus_attr << 8) |
1075                        dram->mbus_dram_target_id, base + WINDOW_BASE(i));
1076                 writel((cs->size - 1) & 0xffff0000, base + WINDOW_SIZE(i));
1077
1078                 win_enable |= (1 << i);
1079                 win_enable |= 3 << (16 + (2 * i));
1080         }
1081
1082         writel(win_enable, base + WINDOW_BAR_ENABLE(0));
1083         writel(win_enable, base + WINDOW_BAR_ENABLE(1));
1084         writel(0, base + WINDOW_OVERRIDE_CTRL(0));
1085         writel(0, base + WINDOW_OVERRIDE_CTRL(1));
1086 }
1087
1088 /*
1089  * Since this XOR driver is basically used only for RAID5, we don't
1090  * need to care about synchronizing ->suspend with DMA activity,
1091  * because the DMA engine will naturally be quiet due to the block
1092  * devices being suspended.
1093  */
1094 static int mv_xor_suspend(struct platform_device *pdev, pm_message_t state)
1095 {
1096         struct mv_xor_device *xordev = platform_get_drvdata(pdev);
1097         int i;
1098
1099         for (i = 0; i < MV_XOR_MAX_CHANNELS; i++) {
1100                 struct mv_xor_chan *mv_chan = xordev->channels[i];
1101
1102                 if (!mv_chan)
1103                         continue;
1104
1105                 mv_chan->saved_config_reg =
1106                         readl_relaxed(XOR_CONFIG(mv_chan));
1107                 mv_chan->saved_int_mask_reg =
1108                         readl_relaxed(XOR_INTR_MASK(mv_chan));
1109         }
1110
1111         return 0;
1112 }
1113
1114 static int mv_xor_resume(struct platform_device *dev)
1115 {
1116         struct mv_xor_device *xordev = platform_get_drvdata(dev);
1117         const struct mbus_dram_target_info *dram;
1118         int i;
1119
1120         for (i = 0; i < MV_XOR_MAX_CHANNELS; i++) {
1121                 struct mv_xor_chan *mv_chan = xordev->channels[i];
1122
1123                 if (!mv_chan)
1124                         continue;
1125
1126                 writel_relaxed(mv_chan->saved_config_reg,
1127                                XOR_CONFIG(mv_chan));
1128                 writel_relaxed(mv_chan->saved_int_mask_reg,
1129                                XOR_INTR_MASK(mv_chan));
1130         }
1131
1132         dram = mv_mbus_dram_info();
1133         if (dram)
1134                 mv_xor_conf_mbus_windows(xordev, dram);
1135
1136         return 0;
1137 }
1138
1139 static const struct of_device_id mv_xor_dt_ids[] = {
1140         { .compatible = "marvell,orion-xor", .data = (void *)XOR_MODE_IN_REG },
1141         { .compatible = "marvell,armada-380-xor", .data = (void *)XOR_MODE_IN_DESC },
1142         {},
1143 };
1144
1145 static unsigned int mv_xor_engine_count;
1146
1147 static int mv_xor_probe(struct platform_device *pdev)
1148 {
1149         const struct mbus_dram_target_info *dram;
1150         struct mv_xor_device *xordev;
1151         struct mv_xor_platform_data *pdata = dev_get_platdata(&pdev->dev);
1152         struct resource *res;
1153         unsigned int max_engines, max_channels;
1154         int i, ret;
1155         int op_in_desc;
1156
1157         dev_notice(&pdev->dev, "Marvell shared XOR driver\n");
1158
1159         xordev = devm_kzalloc(&pdev->dev, sizeof(*xordev), GFP_KERNEL);
1160         if (!xordev)
1161                 return -ENOMEM;
1162
1163         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1164         if (!res)
1165                 return -ENODEV;
1166
1167         xordev->xor_base = devm_ioremap(&pdev->dev, res->start,
1168                                         resource_size(res));
1169         if (!xordev->xor_base)
1170                 return -EBUSY;
1171
1172         res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1173         if (!res)
1174                 return -ENODEV;
1175
1176         xordev->xor_high_base = devm_ioremap(&pdev->dev, res->start,
1177                                              resource_size(res));
1178         if (!xordev->xor_high_base)
1179                 return -EBUSY;
1180
1181         platform_set_drvdata(pdev, xordev);
1182
1183         /*
1184          * (Re-)program MBUS remapping windows if we are asked to.
1185          */
1186         dram = mv_mbus_dram_info();
1187         if (dram)
1188                 mv_xor_conf_mbus_windows(xordev, dram);
1189
1190         /* Not all platforms can gate the clock, so it is not
1191          * an error if the clock does not exists.
1192          */
1193         xordev->clk = clk_get(&pdev->dev, NULL);
1194         if (!IS_ERR(xordev->clk))
1195                 clk_prepare_enable(xordev->clk);
1196
1197         /*
1198          * We don't want to have more than one channel per CPU in
1199          * order for async_tx to perform well. So we limit the number
1200          * of engines and channels so that we take into account this
1201          * constraint. Note that we also want to use channels from
1202          * separate engines when possible.
1203          */
1204         max_engines = num_present_cpus();
1205         max_channels = min_t(unsigned int,
1206                              MV_XOR_MAX_CHANNELS,
1207                              DIV_ROUND_UP(num_present_cpus(), 2));
1208
1209         if (mv_xor_engine_count >= max_engines)
1210                 return 0;
1211
1212         if (pdev->dev.of_node) {
1213                 struct device_node *np;
1214                 int i = 0;
1215                 const struct of_device_id *of_id =
1216                         of_match_device(mv_xor_dt_ids,
1217                                         &pdev->dev);
1218
1219                 for_each_child_of_node(pdev->dev.of_node, np) {
1220                         struct mv_xor_chan *chan;
1221                         dma_cap_mask_t cap_mask;
1222                         int irq;
1223                         op_in_desc = (int)of_id->data;
1224
1225                         if (i >= max_channels)
1226                                 continue;
1227
1228                         dma_cap_zero(cap_mask);
1229                         dma_cap_set(DMA_MEMCPY, cap_mask);
1230                         dma_cap_set(DMA_XOR, cap_mask);
1231                         dma_cap_set(DMA_INTERRUPT, cap_mask);
1232
1233                         irq = irq_of_parse_and_map(np, 0);
1234                         if (!irq) {
1235                                 ret = -ENODEV;
1236                                 goto err_channel_add;
1237                         }
1238
1239                         chan = mv_xor_channel_add(xordev, pdev, i,
1240                                                   cap_mask, irq, op_in_desc);
1241                         if (IS_ERR(chan)) {
1242                                 ret = PTR_ERR(chan);
1243                                 irq_dispose_mapping(irq);
1244                                 goto err_channel_add;
1245                         }
1246
1247                         xordev->channels[i] = chan;
1248                         i++;
1249                 }
1250         } else if (pdata && pdata->channels) {
1251                 for (i = 0; i < max_channels; i++) {
1252                         struct mv_xor_channel_data *cd;
1253                         struct mv_xor_chan *chan;
1254                         int irq;
1255
1256                         cd = &pdata->channels[i];
1257                         if (!cd) {
1258                                 ret = -ENODEV;
1259                                 goto err_channel_add;
1260                         }
1261
1262                         irq = platform_get_irq(pdev, i);
1263                         if (irq < 0) {
1264                                 ret = irq;
1265                                 goto err_channel_add;
1266                         }
1267
1268                         chan = mv_xor_channel_add(xordev, pdev, i,
1269                                                   cd->cap_mask, irq,
1270                                                   XOR_MODE_IN_REG);
1271                         if (IS_ERR(chan)) {
1272                                 ret = PTR_ERR(chan);
1273                                 goto err_channel_add;
1274                         }
1275
1276                         xordev->channels[i] = chan;
1277                 }
1278         }
1279
1280         return 0;
1281
1282 err_channel_add:
1283         for (i = 0; i < MV_XOR_MAX_CHANNELS; i++)
1284                 if (xordev->channels[i]) {
1285                         mv_xor_channel_remove(xordev->channels[i]);
1286                         if (pdev->dev.of_node)
1287                                 irq_dispose_mapping(xordev->channels[i]->irq);
1288                 }
1289
1290         if (!IS_ERR(xordev->clk)) {
1291                 clk_disable_unprepare(xordev->clk);
1292                 clk_put(xordev->clk);
1293         }
1294
1295         return ret;
1296 }
1297
1298 static struct platform_driver mv_xor_driver = {
1299         .probe          = mv_xor_probe,
1300         .suspend        = mv_xor_suspend,
1301         .resume         = mv_xor_resume,
1302         .driver         = {
1303                 .name           = MV_XOR_NAME,
1304                 .of_match_table = of_match_ptr(mv_xor_dt_ids),
1305         },
1306 };
1307
1308
1309 static int __init mv_xor_init(void)
1310 {
1311         return platform_driver_register(&mv_xor_driver);
1312 }
1313 device_initcall(mv_xor_init);
1314
1315 /*
1316 MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");
1317 MODULE_DESCRIPTION("DMA engine driver for Marvell's XOR engine");
1318 MODULE_LICENSE("GPL");
1319 */