drivers/dma/fsldma.c

   1 /*
   2  * Freescale MPC85xx, MPC83xx DMA Engine support
   3  *
   4  * Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved.
   5  *
   6  * Author:
   7  *   Zhang Wei <wei.zhang@freescale.com>, Jul 2007
   8  *   Ebony Zhu <ebony.zhu@freescale.com>, May 2007
   9  *
  10  * Description:
  11  *   DMA engine driver for Freescale MPC8540 DMA controller, which is
  12  *   also fit for MPC8560, MPC8555, MPC8548, MPC8641, and etc.
  13  *   The support for MPC8349 DMA contorller is also added.
  14  *
  15  * This is free software; you can redistribute it and/or modify
  16  * it under the terms of the GNU General Public License as published by
  17  * the Free Software Foundation; either version 2 of the License, or
  18  * (at your option) any later version.
  19  *
  20  */
  21
  22 #include <linux/init.h>
  23 #include <linux/module.h>
  24 #include <linux/pci.h>
  25 #include <linux/interrupt.h>
  26 #include <linux/dmaengine.h>
  27 #include <linux/delay.h>
  28 #include <linux/dma-mapping.h>
  29 #include <linux/dmapool.h>
  30 #include <linux/of_platform.h>
  31
  32 #include "fsldma.h"
  33
  34 static void dma_init(struct fsl_dma_chan *fsl_chan)
  35 {
  36         /* Reset the channel */
  37         DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr, 0, 32);
  38
  39         switch (fsl_chan->feature & FSL_DMA_IP_MASK) {
  40         case FSL_DMA_IP_85XX:
  41                 /* Set the channel to below modes:
  42                  * EIE - Error interrupt enable
  43                  * EOSIE - End of segments interrupt enable (basic mode)
  44                  * EOLNIE - End of links interrupt enable
  45                  */
  46                 DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr, FSL_DMA_MR_EIE
  47                                 | FSL_DMA_MR_EOLNIE | FSL_DMA_MR_EOSIE, 32);
  48                 break;
  49         case FSL_DMA_IP_83XX:
  50                 /* Set the channel to below modes:
  51                  * EOTIE - End-of-transfer interrupt enable
  52                  */
  53                 DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr, FSL_DMA_MR_EOTIE,
  54                                 32);
  55                 break;
  56         }
  57
  58 }
  59
  60 static void set_sr(struct fsl_dma_chan *fsl_chan, u32 val)
  61 {
  62         DMA_OUT(fsl_chan, &fsl_chan->reg_base->sr, val, 32);
  63 }
  64
  65 static u32 get_sr(struct fsl_dma_chan *fsl_chan)
  66 {
  67         return DMA_IN(fsl_chan, &fsl_chan->reg_base->sr, 32);
  68 }
  69
  70 static void set_desc_cnt(struct fsl_dma_chan *fsl_chan,
  71                                 struct fsl_dma_ld_hw *hw, u32 count)
  72 {
  73         hw->count = CPU_TO_DMA(fsl_chan, count, 32);
  74 }
  75
  76 static void set_desc_src(struct fsl_dma_chan *fsl_chan,
  77                                 struct fsl_dma_ld_hw *hw, dma_addr_t src)
  78 {
  79         u64 snoop_bits;
  80
  81         snoop_bits = ((fsl_chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
  82                 ? ((u64)FSL_DMA_SATR_SREADTYPE_SNOOP_READ << 32) : 0;
  83         hw->src_addr = CPU_TO_DMA(fsl_chan, snoop_bits | src, 64);
  84 }
  85
  86 static void set_desc_dest(struct fsl_dma_chan *fsl_chan,
  87                                 struct fsl_dma_ld_hw *hw, dma_addr_t dest)
  88 {
  89         u64 snoop_bits;
  90
  91         snoop_bits = ((fsl_chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
  92                 ? ((u64)FSL_DMA_DATR_DWRITETYPE_SNOOP_WRITE << 32) : 0;
  93         hw->dst_addr = CPU_TO_DMA(fsl_chan, snoop_bits | dest, 64);
  94 }
  95
  96 static void set_desc_next(struct fsl_dma_chan *fsl_chan,
  97                                 struct fsl_dma_ld_hw *hw, dma_addr_t next)
  98 {
  99         u64 snoop_bits;
 100
 101         snoop_bits = ((fsl_chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
 102                 ? FSL_DMA_SNEN : 0;
 103         hw->next_ln_addr = CPU_TO_DMA(fsl_chan, snoop_bits | next, 64);
 104 }
 105
 106 static void set_cdar(struct fsl_dma_chan *fsl_chan, dma_addr_t addr)
 107 {
 108         DMA_OUT(fsl_chan, &fsl_chan->reg_base->cdar, addr | FSL_DMA_SNEN, 64);
 109 }
 110
 111 static dma_addr_t get_cdar(struct fsl_dma_chan *fsl_chan)
 112 {
 113         return DMA_IN(fsl_chan, &fsl_chan->reg_base->cdar, 64) & ~FSL_DMA_SNEN;
 114 }
 115
 116 static void set_ndar(struct fsl_dma_chan *fsl_chan, dma_addr_t addr)
 117 {
 118         DMA_OUT(fsl_chan, &fsl_chan->reg_base->ndar, addr, 64);
 119 }
 120
 121 static dma_addr_t get_ndar(struct fsl_dma_chan *fsl_chan)
 122 {
 123         return DMA_IN(fsl_chan, &fsl_chan->reg_base->ndar, 64);
 124 }
 125
 126 static u32 get_bcr(struct fsl_dma_chan *fsl_chan)
 127 {
 128         return DMA_IN(fsl_chan, &fsl_chan->reg_base->bcr, 32);
 129 }
 130
 131 static int dma_is_idle(struct fsl_dma_chan *fsl_chan)
 132 {
 133         u32 sr = get_sr(fsl_chan);
 134         return (!(sr & FSL_DMA_SR_CB)) || (sr & FSL_DMA_SR_CH);
 135 }
 136
 137 static void dma_start(struct fsl_dma_chan *fsl_chan)
 138 {
 139         u32 mr_set = 0;;
 140
 141         if (fsl_chan->feature & FSL_DMA_CHAN_PAUSE_EXT) {
 142                 DMA_OUT(fsl_chan, &fsl_chan->reg_base->bcr, 0, 32);
 143                 mr_set |= FSL_DMA_MR_EMP_EN;
 144         } else
 145                 DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
 146                         DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32)
 147                                 & ~FSL_DMA_MR_EMP_EN, 32);
 148
 149         if (fsl_chan->feature & FSL_DMA_CHAN_START_EXT)
 150                 mr_set |= FSL_DMA_MR_EMS_EN;
 151         else
 152                 mr_set |= FSL_DMA_MR_CS;
 153
 154         DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
 155                         DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32)
 156                         | mr_set, 32);
 157 }
 158
 159 static void dma_halt(struct fsl_dma_chan *fsl_chan)
 160 {
 161         int i;
 162
 163         DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
 164                 DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32) | FSL_DMA_MR_CA,
 165                 32);
 166         DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
 167                 DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32) & ~(FSL_DMA_MR_CS
 168                 | FSL_DMA_MR_EMS_EN | FSL_DMA_MR_CA), 32);
 169
 170         for (i = 0; i < 100; i++) {
 171                 if (dma_is_idle(fsl_chan))
 172                         break;
 173                 udelay(10);
 174         }
 175         if (i >= 100 && !dma_is_idle(fsl_chan))
 176                 dev_err(fsl_chan->dev, "DMA halt timeout!\n");
 177 }
 178
 179 static void set_ld_eol(struct fsl_dma_chan *fsl_chan,
 180                         struct fsl_desc_sw *desc)
 181 {
 182         u64 snoop_bits;
 183
 184         snoop_bits = ((fsl_chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
 185                 ? FSL_DMA_SNEN : 0;
 186
 187         desc->hw.next_ln_addr = CPU_TO_DMA(fsl_chan,
 188                 DMA_TO_CPU(fsl_chan, desc->hw.next_ln_addr, 64) | FSL_DMA_EOL
 189                         | snoop_bits, 64);
 190 }
 191
 192 static void append_ld_queue(struct fsl_dma_chan *fsl_chan,
 193                 struct fsl_desc_sw *new_desc)
 194 {
 195         struct fsl_desc_sw *queue_tail = to_fsl_desc(fsl_chan->ld_queue.prev);
 196
 197         if (list_empty(&fsl_chan->ld_queue))
 198                 return;
 199
 200         /* Link to the new descriptor physical address and
 201          * Enable End-of-segment interrupt for
 202          * the last link descriptor.
 203          * (the previous node's next link descriptor)
 204          *
 205          * For FSL_DMA_IP_83xx, the snoop enable bit need be set.
 206          */
 207         queue_tail->hw.next_ln_addr = CPU_TO_DMA(fsl_chan,
 208                         new_desc->async_tx.phys | FSL_DMA_EOSIE |
 209                         (((fsl_chan->feature & FSL_DMA_IP_MASK)
 210                                 == FSL_DMA_IP_83XX) ? FSL_DMA_SNEN : 0), 64);
 211 }
 212
 213 /**
 214  * fsl_chan_set_src_loop_size - Set source address hold transfer size
 215  * @fsl_chan : Freescale DMA channel
 216  * @size     : Address loop size, 0 for disable loop
 217  *
 218  * The set source address hold transfer size. The source
 219  * address hold or loop transfer size is when the DMA transfer
 220  * data from source address (SA), if the loop size is 4, the DMA will
 221  * read data from SA, SA + 1, SA + 2, SA + 3, then loop back to SA,
 222  * SA + 1 ... and so on.
 223  */
 224 static void fsl_chan_set_src_loop_size(struct fsl_dma_chan *fsl_chan, int size)
 225 {
 226         switch (size) {
 227         case 0:
 228                 DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
 229                         DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32) &
 230                         (~FSL_DMA_MR_SAHE), 32);
 231                 break;
 232         case 1:
 233         case 2:
 234         case 4:
 235         case 8:
 236                 DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
 237                         DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32) |
 238                         FSL_DMA_MR_SAHE | (__ilog2(size) << 14),
 239                         32);
 240                 break;
 241         }
 242 }
 243
 244 /**
 245  * fsl_chan_set_dest_loop_size - Set destination address hold transfer size
 246  * @fsl_chan : Freescale DMA channel
 247  * @size     : Address loop size, 0 for disable loop
 248  *
 249  * The set destination address hold transfer size. The destination
 250  * address hold or loop transfer size is when the DMA transfer
 251  * data to destination address (TA), if the loop size is 4, the DMA will
 252  * write data to TA, TA + 1, TA + 2, TA + 3, then loop back to TA,
 253  * TA + 1 ... and so on.
 254  */
 255 static void fsl_chan_set_dest_loop_size(struct fsl_dma_chan *fsl_chan, int size)
 256 {
 257         switch (size) {
 258         case 0:
 259                 DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
 260                         DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32) &
 261                         (~FSL_DMA_MR_DAHE), 32);
 262                 break;
 263         case 1:
 264         case 2:
 265         case 4:
 266         case 8:
 267                 DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
 268                         DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32) |
 269                         FSL_DMA_MR_DAHE | (__ilog2(size) << 16),
 270                         32);
 271                 break;
 272         }
 273 }
 274
 275 /**
 276  * fsl_chan_toggle_ext_pause - Toggle channel external pause status
 277  * @fsl_chan : Freescale DMA channel
 278  * @size     : Pause control size, 0 for disable external pause control.
 279  *             The maximum is 1024.
 280  *
 281  * The Freescale DMA channel can be controlled by the external
 282  * signal DREQ#. The pause control size is how many bytes are allowed
 283  * to transfer before pausing the channel, after which a new assertion
 284  * of DREQ# resumes channel operation.
 285  */
 286 static void fsl_chan_toggle_ext_pause(struct fsl_dma_chan *fsl_chan, int size)
 287 {
 288         if (size > 1024)
 289                 return;
 290
 291         if (size) {
 292                 DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
 293                         DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32)
 294                                 | ((__ilog2(size) << 24) & 0x0f000000),
 295                         32);
 296                 fsl_chan->feature |= FSL_DMA_CHAN_PAUSE_EXT;
 297         } else
 298                 fsl_chan->feature &= ~FSL_DMA_CHAN_PAUSE_EXT;
 299 }
 300
 301 /**
 302  * fsl_chan_toggle_ext_start - Toggle channel external start status
 303  * @fsl_chan : Freescale DMA channel
 304  * @enable   : 0 is disabled, 1 is enabled.
 305  *
 306  * If enable the external start, the channel can be started by an
 307  * external DMA start pin. So the dma_start() does not start the
 308  * transfer immediately. The DMA channel will wait for the
 309  * control pin asserted.
 310  */
 311 static void fsl_chan_toggle_ext_start(struct fsl_dma_chan *fsl_chan, int enable)
 312 {
 313         if (enable)
 314                 fsl_chan->feature |= FSL_DMA_CHAN_START_EXT;
 315         else
 316                 fsl_chan->feature &= ~FSL_DMA_CHAN_START_EXT;
 317 }
 318
 319 static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx)
 320 {
 321         struct fsl_dma_chan *fsl_chan = to_fsl_chan(tx->chan);
 322         struct fsl_desc_sw *desc;
 323         unsigned long flags;
 324         dma_cookie_t cookie;
 325
 326         /* cookie increment and adding to ld_queue must be atomic */
 327         spin_lock_irqsave(&fsl_chan->desc_lock, flags);
 328
 329         cookie = fsl_chan->common.cookie;
 330         list_for_each_entry(desc, &tx->tx_list, node) {
 331                 cookie++;
 332                 if (cookie < 0)
 333                         cookie = 1;
 334
 335                 desc->async_tx.cookie = cookie;
 336         }
 337
 338         fsl_chan->common.cookie = cookie;
 339         append_ld_queue(fsl_chan, tx_to_fsl_desc(tx));
 340         list_splice_init(&tx->tx_list, fsl_chan->ld_queue.prev);
 341
 342         spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
 343
 344         return cookie;
 345 }
 346
 347 /**
 348  * fsl_dma_alloc_descriptor - Allocate descriptor from channel's DMA pool.
 349  * @fsl_chan : Freescale DMA channel
 350  *
 351  * Return - The descriptor allocated. NULL for failed.
 352  */
 353 static struct fsl_desc_sw *fsl_dma_alloc_descriptor(
 354                                         struct fsl_dma_chan *fsl_chan)
 355 {
 356         dma_addr_t pdesc;
 357         struct fsl_desc_sw *desc_sw;
 358
 359         desc_sw = dma_pool_alloc(fsl_chan->desc_pool, GFP_ATOMIC, &pdesc);
 360         if (desc_sw) {
 361                 memset(desc_sw, 0, sizeof(struct fsl_desc_sw));
 362                 dma_async_tx_descriptor_init(&desc_sw->async_tx,
 363                                                 &fsl_chan->common);
 364                 desc_sw->async_tx.tx_submit = fsl_dma_tx_submit;
 365                 desc_sw->async_tx.phys = pdesc;
 366         }
 367
 368         return desc_sw;
 369 }
 370
 371
 372 /**
 373  * fsl_dma_alloc_chan_resources - Allocate resources for DMA channel.
 374  * @fsl_chan : Freescale DMA channel
 375  *
 376  * This function will create a dma pool for descriptor allocation.
 377  *
 378  * Return - The number of descriptors allocated.
 379  */
 380 static int fsl_dma_alloc_chan_resources(struct dma_chan *chan)
 381 {
 382         struct fsl_dma_chan *fsl_chan = to_fsl_chan(chan);
 383
 384         /* Has this channel already been allocated? */
 385         if (fsl_chan->desc_pool)
 386                 return 1;
 387
 388         /* We need the descriptor to be aligned to 32bytes
 389          * for meeting FSL DMA specification requirement.
 390          */
 391         fsl_chan->desc_pool = dma_pool_create("fsl_dma_engine_desc_pool",
 392                         fsl_chan->dev, sizeof(struct fsl_desc_sw),
 393                         32, 0);
 394         if (!fsl_chan->desc_pool) {
 395                 dev_err(fsl_chan->dev, "No memory for channel %d "
 396                         "descriptor dma pool.\n", fsl_chan->id);
 397                 return 0;
 398         }
 399
 400         return 1;
 401 }
 402
 403 /**
 404  * fsl_dma_free_chan_resources - Free all resources of the channel.
 405  * @fsl_chan : Freescale DMA channel
 406  */
 407 static void fsl_dma_free_chan_resources(struct dma_chan *chan)
 408 {
 409         struct fsl_dma_chan *fsl_chan = to_fsl_chan(chan);
 410         struct fsl_desc_sw *desc, *_desc;
 411         unsigned long flags;
 412
 413         dev_dbg(fsl_chan->dev, "Free all channel resources.\n");
 414         spin_lock_irqsave(&fsl_chan->desc_lock, flags);
 415         list_for_each_entry_safe(desc, _desc, &fsl_chan->ld_queue, node) {
 416 #ifdef FSL_DMA_LD_DEBUG
 417                 dev_dbg(fsl_chan->dev,
 418                                 "LD %p will be released.\n", desc);
 419 #endif
 420                 list_del(&desc->node);
 421                 /* free link descriptor */
 422                 dma_pool_free(fsl_chan->desc_pool, desc, desc->async_tx.phys);
 423         }
 424         spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
 425         dma_pool_destroy(fsl_chan->desc_pool);
 426
 427         fsl_chan->desc_pool = NULL;
 428 }
 429
 430 static struct dma_async_tx_descriptor *
 431 fsl_dma_prep_interrupt(struct dma_chan *chan, unsigned long flags)
 432 {
 433         struct fsl_dma_chan *fsl_chan;
 434         struct fsl_desc_sw *new;
 435
 436         if (!chan)
 437                 return NULL;
 438
 439         fsl_chan = to_fsl_chan(chan);
 440
 441         new = fsl_dma_alloc_descriptor(fsl_chan);
 442         if (!new) {
 443                 dev_err(fsl_chan->dev, "No free memory for link descriptor\n");
 444                 return NULL;
 445         }
 446
 447         new->async_tx.cookie = -EBUSY;
 448         new->async_tx.flags = flags;
 449
 450         /* Insert the link descriptor to the LD ring */
 451         list_add_tail(&new->node, &new->async_tx.tx_list);
 452
 453         /* Set End-of-link to the last link descriptor of new list*/
 454         set_ld_eol(fsl_chan, new);
 455
 456         return &new->async_tx;
 457 }
 458
 459 static struct dma_async_tx_descriptor *fsl_dma_prep_memcpy(
 460         struct dma_chan *chan, dma_addr_t dma_dest, dma_addr_t dma_src,
 461         size_t len, unsigned long flags)
 462 {
 463         struct fsl_dma_chan *fsl_chan;
 464         struct fsl_desc_sw *first = NULL, *prev = NULL, *new;
 465         struct list_head *list;
 466         size_t copy;
 467
 468         if (!chan)
 469                 return NULL;
 470
 471         if (!len)
 472                 return NULL;
 473
 474         fsl_chan = to_fsl_chan(chan);
 475
 476         do {
 477
 478                 /* Allocate the link descriptor from DMA pool */
 479                 new = fsl_dma_alloc_descriptor(fsl_chan);
 480                 if (!new) {
 481                         dev_err(fsl_chan->dev,
 482                                         "No free memory for link descriptor\n");
 483                         goto fail;
 484                 }
 485 #ifdef FSL_DMA_LD_DEBUG
 486                 dev_dbg(fsl_chan->dev, "new link desc alloc %p\n", new);
 487 #endif
 488
 489                 copy = min(len, (size_t)FSL_DMA_BCR_MAX_CNT);
 490
 491                 set_desc_cnt(fsl_chan, &new->hw, copy);
 492                 set_desc_src(fsl_chan, &new->hw, dma_src);
 493                 set_desc_dest(fsl_chan, &new->hw, dma_dest);
 494
 495                 if (!first)
 496                         first = new;
 497                 else
 498                         set_desc_next(fsl_chan, &prev->hw, new->async_tx.phys);
 499
 500                 new->async_tx.cookie = 0;
 501                 async_tx_ack(&new->async_tx);
 502
 503                 prev = new;
 504                 len -= copy;
 505                 dma_src += copy;
 506                 dma_dest += copy;
 507
 508                 /* Insert the link descriptor to the LD ring */
 509                 list_add_tail(&new->node, &first->async_tx.tx_list);
 510         } while (len);
 511
 512         new->async_tx.flags = flags; /* client is in control of this ack */
 513         new->async_tx.cookie = -EBUSY;
 514
 515         /* Set End-of-link to the last link descriptor of new list*/
 516         set_ld_eol(fsl_chan, new);
 517
 518         return &first->async_tx;
 519
 520 fail:
 521         if (!first)
 522                 return NULL;
 523
 524         list = &first->async_tx.tx_list;
 525         list_for_each_entry_safe_reverse(new, prev, list, node) {
 526                 list_del(&new->node);
 527                 dma_pool_free(fsl_chan->desc_pool, new, new->async_tx.phys);
 528         }
 529
 530         return NULL;
 531 }
 532
 533 /**
 534  * fsl_dma_update_completed_cookie - Update the completed cookie.
 535  * @fsl_chan : Freescale DMA channel
 536  */
 537 static void fsl_dma_update_completed_cookie(struct fsl_dma_chan *fsl_chan)
 538 {
 539         struct fsl_desc_sw *cur_desc, *desc;
 540         dma_addr_t ld_phy;
 541
 542         ld_phy = get_cdar(fsl_chan) & FSL_DMA_NLDA_MASK;
 543
 544         if (ld_phy) {
 545                 cur_desc = NULL;
 546                 list_for_each_entry(desc, &fsl_chan->ld_queue, node)
 547                         if (desc->async_tx.phys == ld_phy) {
 548                                 cur_desc = desc;
 549                                 break;
 550                         }
 551
 552                 if (cur_desc && cur_desc->async_tx.cookie) {
 553                         if (dma_is_idle(fsl_chan))
 554                                 fsl_chan->completed_cookie =
 555                                         cur_desc->async_tx.cookie;
 556                         else
 557                                 fsl_chan->completed_cookie =
 558                                         cur_desc->async_tx.cookie - 1;
 559                 }
 560         }
 561 }
 562
 563 /**
 564  * fsl_chan_ld_cleanup - Clean up link descriptors
 565  * @fsl_chan : Freescale DMA channel
 566  *
 567  * This function clean up the ld_queue of DMA channel.
 568  * If 'in_intr' is set, the function will move the link descriptor to
 569  * the recycle list. Otherwise, free it directly.
 570  */
 571 static void fsl_chan_ld_cleanup(struct fsl_dma_chan *fsl_chan)
 572 {
 573         struct fsl_desc_sw *desc, *_desc;
 574         unsigned long flags;
 575
 576         spin_lock_irqsave(&fsl_chan->desc_lock, flags);
 577
 578         dev_dbg(fsl_chan->dev, "chan completed_cookie = %d\n",
 579                         fsl_chan->completed_cookie);
 580         list_for_each_entry_safe(desc, _desc, &fsl_chan->ld_queue, node) {
 581                 dma_async_tx_callback callback;
 582                 void *callback_param;
 583
 584                 if (dma_async_is_complete(desc->async_tx.cookie,
 585                             fsl_chan->completed_cookie, fsl_chan->common.cookie)
 586                                 == DMA_IN_PROGRESS)
 587                         break;
 588
 589                 callback = desc->async_tx.callback;
 590                 callback_param = desc->async_tx.callback_param;
 591
 592                 /* Remove from ld_queue list */
 593                 list_del(&desc->node);
 594
 595                 dev_dbg(fsl_chan->dev, "link descriptor %p will be recycle.\n",
 596                                 desc);
 597                 dma_pool_free(fsl_chan->desc_pool, desc, desc->async_tx.phys);
 598
 599                 /* Run the link descriptor callback function */
 600                 if (callback) {
 601                         spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
 602                         dev_dbg(fsl_chan->dev, "link descriptor %p callback\n",
 603                                         desc);
 604                         callback(callback_param);
 605                         spin_lock_irqsave(&fsl_chan->desc_lock, flags);
 606                 }
 607         }
 608         spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
 609 }
 610
 611 /**
 612  * fsl_chan_xfer_ld_queue - Transfer link descriptors in channel ld_queue.
 613  * @fsl_chan : Freescale DMA channel
 614  */
 615 static void fsl_chan_xfer_ld_queue(struct fsl_dma_chan *fsl_chan)
 616 {
 617         struct list_head *ld_node;
 618         dma_addr_t next_dest_addr;
 619         unsigned long flags;
 620
 621         spin_lock_irqsave(&fsl_chan->desc_lock, flags);
 622
 623         if (!dma_is_idle(fsl_chan))
 624                 goto out_unlock;
 625
 626         dma_halt(fsl_chan);
 627
 628         /* If there are some link descriptors
 629          * not transfered in queue. We need to start it.
 630          */
 631
 632         /* Find the first un-transfer desciptor */
 633         for (ld_node = fsl_chan->ld_queue.next;
 634                 (ld_node != &fsl_chan->ld_queue)
 635                         && (dma_async_is_complete(
 636                                 to_fsl_desc(ld_node)->async_tx.cookie,
 637                                 fsl_chan->completed_cookie,
 638                                 fsl_chan->common.cookie) == DMA_SUCCESS);
 639                 ld_node = ld_node->next);
 640
 641         if (ld_node != &fsl_chan->ld_queue) {
 642                 /* Get the ld start address from ld_queue */
 643                 next_dest_addr = to_fsl_desc(ld_node)->async_tx.phys;
 644                 dev_dbg(fsl_chan->dev, "xfer LDs staring from 0x%llx\n",
 645                                 (unsigned long long)next_dest_addr);
 646                 set_cdar(fsl_chan, next_dest_addr);
 647                 dma_start(fsl_chan);
 648         } else {
 649                 set_cdar(fsl_chan, 0);
 650                 set_ndar(fsl_chan, 0);
 651         }
 652
 653 out_unlock:
 654         spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
 655 }
 656
 657 /**
 658  * fsl_dma_memcpy_issue_pending - Issue the DMA start command
 659  * @fsl_chan : Freescale DMA channel
 660  */
 661 static void fsl_dma_memcpy_issue_pending(struct dma_chan *chan)
 662 {
 663         struct fsl_dma_chan *fsl_chan = to_fsl_chan(chan);
 664
 665 #ifdef FSL_DMA_LD_DEBUG
 666         struct fsl_desc_sw *ld;
 667         unsigned long flags;
 668
 669         spin_lock_irqsave(&fsl_chan->desc_lock, flags);
 670         if (list_empty(&fsl_chan->ld_queue)) {
 671                 spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
 672                 return;
 673         }
 674
 675         dev_dbg(fsl_chan->dev, "--memcpy issue--\n");
 676         list_for_each_entry(ld, &fsl_chan->ld_queue, node) {
 677                 int i;
 678                 dev_dbg(fsl_chan->dev, "Ch %d, LD %08x\n",
 679                                 fsl_chan->id, ld->async_tx.phys);
 680                 for (i = 0; i < 8; i++)
 681                         dev_dbg(fsl_chan->dev, "LD offset %d: %08x\n",
 682                                         i, *(((u32 *)&ld->hw) + i));
 683         }
 684         dev_dbg(fsl_chan->dev, "----------------\n");
 685         spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
 686 #endif
 687
 688         fsl_chan_xfer_ld_queue(fsl_chan);
 689 }
 690
 691 /**
 692  * fsl_dma_is_complete - Determine the DMA status
 693  * @fsl_chan : Freescale DMA channel
 694  */
 695 static enum dma_status fsl_dma_is_complete(struct dma_chan *chan,
 696                                         dma_cookie_t cookie,
 697                                         dma_cookie_t *done,
 698                                         dma_cookie_t *used)
 699 {
 700         struct fsl_dma_chan *fsl_chan = to_fsl_chan(chan);
 701         dma_cookie_t last_used;
 702         dma_cookie_t last_complete;
 703
 704         fsl_chan_ld_cleanup(fsl_chan);
 705
 706         last_used = chan->cookie;
 707         last_complete = fsl_chan->completed_cookie;
 708
 709         if (done)
 710                 *done = last_complete;
 711
 712         if (used)
 713                 *used = last_used;
 714
 715         return dma_async_is_complete(cookie, last_complete, last_used);
 716 }
 717
 718 static irqreturn_t fsl_dma_chan_do_interrupt(int irq, void *data)
 719 {
 720         struct fsl_dma_chan *fsl_chan = (struct fsl_dma_chan *)data;
 721         u32 stat;
 722         int update_cookie = 0;
 723         int xfer_ld_q = 0;
 724
 725         stat = get_sr(fsl_chan);
 726         dev_dbg(fsl_chan->dev, "event: channel %d, stat = 0x%x\n",
 727                                                 fsl_chan->id, stat);
 728         set_sr(fsl_chan, stat);         /* Clear the event register */
 729
 730         stat &= ~(FSL_DMA_SR_CB | FSL_DMA_SR_CH);
 731         if (!stat)
 732                 return IRQ_NONE;
 733
 734         if (stat & FSL_DMA_SR_TE)
 735                 dev_err(fsl_chan->dev, "Transfer Error!\n");
 736
 737         /* Programming Error
 738          * The DMA_INTERRUPT async_tx is a NULL transfer, which will
 739          * triger a PE interrupt.
 740          */
 741         if (stat & FSL_DMA_SR_PE) {
 742                 dev_dbg(fsl_chan->dev, "event: Programming Error INT\n");
 743                 if (get_bcr(fsl_chan) == 0) {
 744                         /* BCR register is 0, this is a DMA_INTERRUPT async_tx.
 745                          * Now, update the completed cookie, and continue the
 746                          * next uncompleted transfer.
 747                          */
 748                         update_cookie = 1;
 749                         xfer_ld_q = 1;
 750                 }
 751                 stat &= ~FSL_DMA_SR_PE;
 752         }
 753
 754         /* If the link descriptor segment transfer finishes,
 755          * we will recycle the used descriptor.
 756          */
 757         if (stat & FSL_DMA_SR_EOSI) {
 758                 dev_dbg(fsl_chan->dev, "event: End-of-segments INT\n");
 759                 dev_dbg(fsl_chan->dev, "event: clndar 0x%llx, nlndar 0x%llx\n",
 760                         (unsigned long long)get_cdar(fsl_chan),
 761                         (unsigned long long)get_ndar(fsl_chan));
 762                 stat &= ~FSL_DMA_SR_EOSI;
 763                 update_cookie = 1;
 764         }
 765
 766         /* For MPC8349, EOCDI event need to update cookie
 767          * and start the next transfer if it exist.
 768          */
 769         if (stat & FSL_DMA_SR_EOCDI) {
 770                 dev_dbg(fsl_chan->dev, "event: End-of-Chain link INT\n");
 771                 stat &= ~FSL_DMA_SR_EOCDI;
 772                 update_cookie = 1;
 773                 xfer_ld_q = 1;
 774         }
 775
 776         /* If it current transfer is the end-of-transfer,
 777          * we should clear the Channel Start bit for
 778          * prepare next transfer.
 779          */
 780         if (stat & FSL_DMA_SR_EOLNI) {
 781                 dev_dbg(fsl_chan->dev, "event: End-of-link INT\n");
 782                 stat &= ~FSL_DMA_SR_EOLNI;
 783                 xfer_ld_q = 1;
 784         }
 785
 786         if (update_cookie)
 787                 fsl_dma_update_completed_cookie(fsl_chan);
 788         if (xfer_ld_q)
 789                 fsl_chan_xfer_ld_queue(fsl_chan);
 790         if (stat)
 791                 dev_dbg(fsl_chan->dev, "event: unhandled sr 0x%02x\n",
 792                                         stat);
 793
 794         dev_dbg(fsl_chan->dev, "event: Exit\n");
 795         tasklet_schedule(&fsl_chan->tasklet);
 796         return IRQ_HANDLED;
 797 }
 798
 799 static irqreturn_t fsl_dma_do_interrupt(int irq, void *data)
 800 {
 801         struct fsl_dma_device *fdev = (struct fsl_dma_device *)data;
 802         u32 gsr;
 803         int ch_nr;
 804
 805         gsr = (fdev->feature & FSL_DMA_BIG_ENDIAN) ? in_be32(fdev->reg_base)
 806                         : in_le32(fdev->reg_base);
 807         ch_nr = (32 - ffs(gsr)) / 8;
 808
 809         return fdev->chan[ch_nr] ? fsl_dma_chan_do_interrupt(irq,
 810                         fdev->chan[ch_nr]) : IRQ_NONE;
 811 }
 812
 813 static void dma_do_tasklet(unsigned long data)
 814 {
 815         struct fsl_dma_chan *fsl_chan = (struct fsl_dma_chan *)data;
 816         fsl_chan_ld_cleanup(fsl_chan);
 817 }
 818
 819 static int __devinit fsl_dma_chan_probe(struct fsl_dma_device *fdev,
 820         struct device_node *node, u32 feature, const char *compatible)
 821 {
 822         struct fsl_dma_chan *new_fsl_chan;
 823         int err;
 824
 825         /* alloc channel */
 826         new_fsl_chan = kzalloc(sizeof(struct fsl_dma_chan), GFP_KERNEL);
 827         if (!new_fsl_chan) {
 828                 dev_err(fdev->dev, "No free memory for allocating "
 829                                 "dma channels!\n");
 830                 return -ENOMEM;
 831         }
 832
 833         /* get dma channel register base */
 834         err = of_address_to_resource(node, 0, &new_fsl_chan->reg);
 835         if (err) {
 836                 dev_err(fdev->dev, "Can't get %s property 'reg'\n",
 837                                 node->full_name);
 838                 goto err_no_reg;
 839         }
 840
 841         new_fsl_chan->feature = feature;
 842
 843         if (!fdev->feature)
 844                 fdev->feature = new_fsl_chan->feature;
 845
 846         /* If the DMA device's feature is different than its channels',
 847          * report the bug.
 848          */
 849         WARN_ON(fdev->feature != new_fsl_chan->feature);
 850
 851         new_fsl_chan->dev = fdev->dev;
 852         new_fsl_chan->reg_base = ioremap(new_fsl_chan->reg.start,
 853                         new_fsl_chan->reg.end - new_fsl_chan->reg.start + 1);
 854
 855         new_fsl_chan->id = ((new_fsl_chan->reg.start - 0x100) & 0xfff) >> 7;
 856         if (new_fsl_chan->id >= FSL_DMA_MAX_CHANS_PER_DEVICE) {
 857                 dev_err(fdev->dev, "There is no %d channel!\n",
 858                                 new_fsl_chan->id);
 859                 err = -EINVAL;
 860                 goto err_no_chan;
 861         }
 862         fdev->chan[new_fsl_chan->id] = new_fsl_chan;
 863         tasklet_init(&new_fsl_chan->tasklet, dma_do_tasklet,
 864                         (unsigned long)new_fsl_chan);
 865
 866         /* Init the channel */
 867         dma_init(new_fsl_chan);
 868
 869         /* Clear cdar registers */
 870         set_cdar(new_fsl_chan, 0);
 871
 872         switch (new_fsl_chan->feature & FSL_DMA_IP_MASK) {
 873         case FSL_DMA_IP_85XX:
 874                 new_fsl_chan->toggle_ext_start = fsl_chan_toggle_ext_start;
 875                 new_fsl_chan->toggle_ext_pause = fsl_chan_toggle_ext_pause;
 876         case FSL_DMA_IP_83XX:
 877                 new_fsl_chan->set_src_loop_size = fsl_chan_set_src_loop_size;
 878                 new_fsl_chan->set_dest_loop_size = fsl_chan_set_dest_loop_size;
 879         }
 880
 881         spin_lock_init(&new_fsl_chan->desc_lock);
 882         INIT_LIST_HEAD(&new_fsl_chan->ld_queue);
 883
 884         new_fsl_chan->common.device = &fdev->common;
 885
 886         /* Add the channel to DMA device channel list */
 887         list_add_tail(&new_fsl_chan->common.device_node,
 888                         &fdev->common.channels);
 889         fdev->common.chancnt++;
 890
 891         new_fsl_chan->irq = irq_of_parse_and_map(node, 0);
 892         if (new_fsl_chan->irq != NO_IRQ) {
 893                 err = request_irq(new_fsl_chan->irq,
 894                                         &fsl_dma_chan_do_interrupt, IRQF_SHARED,
 895                                         "fsldma-channel", new_fsl_chan);
 896                 if (err) {
 897                         dev_err(fdev->dev, "DMA channel %s request_irq error "
 898                                 "with return %d\n", node->full_name, err);
 899                         goto err_no_irq;
 900                 }
 901         }
 902
 903         dev_info(fdev->dev, "#%d (%s), irq %d\n", new_fsl_chan->id,
 904                  compatible,
 905                  new_fsl_chan->irq != NO_IRQ ? new_fsl_chan->irq : fdev->irq);
 906
 907         return 0;
 908
 909 err_no_irq:
 910         list_del(&new_fsl_chan->common.device_node);
 911 err_no_chan:
 912         iounmap(new_fsl_chan->reg_base);
 913 err_no_reg:
 914         kfree(new_fsl_chan);
 915         return err;
 916 }
 917
 918 static void fsl_dma_chan_remove(struct fsl_dma_chan *fchan)
 919 {
 920         if (fchan->irq != NO_IRQ)
 921                 free_irq(fchan->irq, fchan);
 922         list_del(&fchan->common.device_node);
 923         iounmap(fchan->reg_base);
 924         kfree(fchan);
 925 }
 926
 927 static int __devinit of_fsl_dma_probe(struct of_device *dev,
 928                         const struct of_device_id *match)
 929 {
 930         int err;
 931         struct fsl_dma_device *fdev;
 932         struct device_node *child;
 933
 934         fdev = kzalloc(sizeof(struct fsl_dma_device), GFP_KERNEL);
 935         if (!fdev) {
 936                 dev_err(&dev->dev, "No enough memory for 'priv'\n");
 937                 return -ENOMEM;
 938         }
 939         fdev->dev = &dev->dev;
 940         INIT_LIST_HEAD(&fdev->common.channels);
 941
 942         /* get DMA controller register base */
 943         err = of_address_to_resource(dev->node, 0, &fdev->reg);
 944         if (err) {
 945                 dev_err(&dev->dev, "Can't get %s property 'reg'\n",
 946                                 dev->node->full_name);
 947                 goto err_no_reg;
 948         }
 949
 950         dev_info(&dev->dev, "Probe the Freescale DMA driver for %s "
 951                         "controller at 0x%llx...\n",
 952                         match->compatible, (unsigned long long)fdev->reg.start);
 953         fdev->reg_base = ioremap(fdev->reg.start, fdev->reg.end
 954                                                 - fdev->reg.start + 1);
 955
 956         dma_cap_set(DMA_MEMCPY, fdev->common.cap_mask);
 957         dma_cap_set(DMA_INTERRUPT, fdev->common.cap_mask);
 958         fdev->common.device_alloc_chan_resources = fsl_dma_alloc_chan_resources;
 959         fdev->common.device_free_chan_resources = fsl_dma_free_chan_resources;
 960         fdev->common.device_prep_dma_interrupt = fsl_dma_prep_interrupt;
 961         fdev->common.device_prep_dma_memcpy = fsl_dma_prep_memcpy;
 962         fdev->common.device_is_tx_complete = fsl_dma_is_complete;
 963         fdev->common.device_issue_pending = fsl_dma_memcpy_issue_pending;
 964         fdev->common.dev = &dev->dev;
 965
 966         fdev->irq = irq_of_parse_and_map(dev->node, 0);
 967         if (fdev->irq != NO_IRQ) {
 968                 err = request_irq(fdev->irq, &fsl_dma_do_interrupt, IRQF_SHARED,
 969                                         "fsldma-device", fdev);
 970                 if (err) {
 971                         dev_err(&dev->dev, "DMA device request_irq error "
 972                                 "with return %d\n", err);
 973                         goto err;
 974                 }
 975         }
 976
 977         dev_set_drvdata(&(dev->dev), fdev);
 978
 979         /* We cannot use of_platform_bus_probe() because there is no
 980          * of_platform_bus_remove.  Instead, we manually instantiate every DMA
 981          * channel object.
 982          */
 983         for_each_child_of_node(dev->node, child) {
 984                 if (of_device_is_compatible(child, "fsl,eloplus-dma-channel"))
 985                         fsl_dma_chan_probe(fdev, child,
 986                                 FSL_DMA_IP_85XX | FSL_DMA_BIG_ENDIAN,
 987                                 "fsl,eloplus-dma-channel");
 988                 if (of_device_is_compatible(child, "fsl,elo-dma-channel"))
 989                         fsl_dma_chan_probe(fdev, child,
 990                                 FSL_DMA_IP_83XX | FSL_DMA_LITTLE_ENDIAN,
 991                                 "fsl,elo-dma-channel");
 992         }
 993
 994         dma_async_device_register(&fdev->common);
 995         return 0;
 996
 997 err:
 998         iounmap(fdev->reg_base);
 999 err_no_reg:
1000         kfree(fdev);
1001         return err;
1002 }
1003
1004 static int of_fsl_dma_remove(struct of_device *of_dev)
1005 {
1006         struct fsl_dma_device *fdev;
1007         unsigned int i;
1008
1009         fdev = dev_get_drvdata(&of_dev->dev);
1010
1011         dma_async_device_unregister(&fdev->common);
1012
1013         for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++)
1014                 if (fdev->chan[i])
1015                         fsl_dma_chan_remove(fdev->chan[i]);
1016
1017         if (fdev->irq != NO_IRQ)
1018                 free_irq(fdev->irq, fdev);
1019
1020         iounmap(fdev->reg_base);
1021
1022         kfree(fdev);
1023         dev_set_drvdata(&of_dev->dev, NULL);
1024
1025         return 0;
1026 }
1027
1028 static struct of_device_id of_fsl_dma_ids[] = {
1029         { .compatible = "fsl,eloplus-dma", },
1030         { .compatible = "fsl,elo-dma", },
1031         {}
1032 };
1033
1034 static struct of_platform_driver of_fsl_dma_driver = {
1035         .name = "fsl-elo-dma",
1036         .match_table = of_fsl_dma_ids,
1037         .probe = of_fsl_dma_probe,
1038         .remove = of_fsl_dma_remove,
1039 };
1040
1041 static __init int of_fsl_dma_init(void)
1042 {
1043         int ret;
1044
1045         pr_info("Freescale Elo / Elo Plus DMA driver\n");
1046
1047         ret = of_register_platform_driver(&of_fsl_dma_driver);
1048         if (ret)
1049                 pr_err("fsldma: failed to register platform driver\n");
1050
1051         return ret;
1052 }
1053
1054 static void __exit of_fsl_dma_exit(void)
1055 {
1056         of_unregister_platform_driver(&of_fsl_dma_driver);
1057 }
1058
1059 subsys_initcall(of_fsl_dma_init);
1060 module_exit(of_fsl_dma_exit);
1061
1062 MODULE_DESCRIPTION("Freescale Elo / Elo Plus DMA driver");
1063 MODULE_LICENSE("GPL");