git.oblomov.eu Git - linux-2.6/blob - 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 = 0;
 162         DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
 163                 DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32) | FSL_DMA_MR_CA,
 164                 32);
 165         DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
 166                 DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32) & ~(FSL_DMA_MR_CS
 167                 | FSL_DMA_MR_EMS_EN | FSL_DMA_MR_CA), 32);
 168
 169         while (!dma_is_idle(fsl_chan) && (i++ < 100))
 170                 udelay(10);
 171         if (i >= 100 && !dma_is_idle(fsl_chan))
 172                 dev_err(fsl_chan->dev, "DMA halt timeout!\n");
 173 }
 174
 175 static void set_ld_eol(struct fsl_dma_chan *fsl_chan,
 176                         struct fsl_desc_sw *desc)
 177 {
 178         desc->hw.next_ln_addr = CPU_TO_DMA(fsl_chan,
 179                 DMA_TO_CPU(fsl_chan, desc->hw.next_ln_addr, 64) | FSL_DMA_EOL,
 180                 64);
 181 }
 182
 183 static void append_ld_queue(struct fsl_dma_chan *fsl_chan,
 184                 struct fsl_desc_sw *new_desc)
 185 {
 186         struct fsl_desc_sw *queue_tail = to_fsl_desc(fsl_chan->ld_queue.prev);
 187
 188         if (list_empty(&fsl_chan->ld_queue))
 189                 return;
 190
 191         /* Link to the new descriptor physical address and
 192          * Enable End-of-segment interrupt for
 193          * the last link descriptor.
 194          * (the previous node's next link descriptor)
 195          *
 196          * For FSL_DMA_IP_83xx, the snoop enable bit need be set.
 197          */
 198         queue_tail->hw.next_ln_addr = CPU_TO_DMA(fsl_chan,
 199                         new_desc->async_tx.phys | FSL_DMA_EOSIE |
 200                         (((fsl_chan->feature & FSL_DMA_IP_MASK)
 201                                 == FSL_DMA_IP_83XX) ? FSL_DMA_SNEN : 0), 64);
 202 }
 203
 204 /**
 205  * fsl_chan_set_src_loop_size - Set source address hold transfer size
 206  * @fsl_chan : Freescale DMA channel
 207  * @size     : Address loop size, 0 for disable loop
 208  *
 209  * The set source address hold transfer size. The source
 210  * address hold or loop transfer size is when the DMA transfer
 211  * data from source address (SA), if the loop size is 4, the DMA will
 212  * read data from SA, SA + 1, SA + 2, SA + 3, then loop back to SA,
 213  * SA + 1 ... and so on.
 214  */
 215 static void fsl_chan_set_src_loop_size(struct fsl_dma_chan *fsl_chan, int size)
 216 {
 217         switch (size) {
 218         case 0:
 219                 DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
 220                         DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32) &
 221                         (~FSL_DMA_MR_SAHE), 32);
 222                 break;
 223         case 1:
 224         case 2:
 225         case 4:
 226         case 8:
 227                 DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
 228                         DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32) |
 229                         FSL_DMA_MR_SAHE | (__ilog2(size) << 14),
 230                         32);
 231                 break;
 232         }
 233 }
 234
 235 /**
 236  * fsl_chan_set_dest_loop_size - Set destination address hold transfer size
 237  * @fsl_chan : Freescale DMA channel
 238  * @size     : Address loop size, 0 for disable loop
 239  *
 240  * The set destination address hold transfer size. The destination
 241  * address hold or loop transfer size is when the DMA transfer
 242  * data to destination address (TA), if the loop size is 4, the DMA will
 243  * write data to TA, TA + 1, TA + 2, TA + 3, then loop back to TA,
 244  * TA + 1 ... and so on.
 245  */
 246 static void fsl_chan_set_dest_loop_size(struct fsl_dma_chan *fsl_chan, int size)
 247 {
 248         switch (size) {
 249         case 0:
 250                 DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
 251                         DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32) &
 252                         (~FSL_DMA_MR_DAHE), 32);
 253                 break;
 254         case 1:
 255         case 2:
 256         case 4:
 257         case 8:
 258                 DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
 259                         DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32) |
 260                         FSL_DMA_MR_DAHE | (__ilog2(size) << 16),
 261                         32);
 262                 break;
 263         }
 264 }
 265
 266 /**
 267  * fsl_chan_toggle_ext_pause - Toggle channel external pause status
 268  * @fsl_chan : Freescale DMA channel
 269  * @size     : Pause control size, 0 for disable external pause control.
 270  *             The maximum is 1024.
 271  *
 272  * The Freescale DMA channel can be controlled by the external
 273  * signal DREQ#. The pause control size is how many bytes are allowed
 274  * to transfer before pausing the channel, after which a new assertion
 275  * of DREQ# resumes channel operation.
 276  */
 277 static void fsl_chan_toggle_ext_pause(struct fsl_dma_chan *fsl_chan, int size)
 278 {
 279         if (size > 1024)
 280                 return;
 281
 282         if (size) {
 283                 DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
 284                         DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32)
 285                                 | ((__ilog2(size) << 24) & 0x0f000000),
 286                         32);
 287                 fsl_chan->feature |= FSL_DMA_CHAN_PAUSE_EXT;
 288         } else
 289                 fsl_chan->feature &= ~FSL_DMA_CHAN_PAUSE_EXT;
 290 }
 291
 292 /**
 293  * fsl_chan_toggle_ext_start - Toggle channel external start status
 294  * @fsl_chan : Freescale DMA channel
 295  * @enable   : 0 is disabled, 1 is enabled.
 296  *
 297  * If enable the external start, the channel can be started by an
 298  * external DMA start pin. So the dma_start() does not start the
 299  * transfer immediately. The DMA channel will wait for the
 300  * control pin asserted.
 301  */
 302 static void fsl_chan_toggle_ext_start(struct fsl_dma_chan *fsl_chan, int enable)
 303 {
 304         if (enable)
 305                 fsl_chan->feature |= FSL_DMA_CHAN_START_EXT;
 306         else
 307                 fsl_chan->feature &= ~FSL_DMA_CHAN_START_EXT;
 308 }
 309
 310 static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx)
 311 {
 312         struct fsl_desc_sw *desc = tx_to_fsl_desc(tx);
 313         struct fsl_dma_chan *fsl_chan = to_fsl_chan(tx->chan);
 314         unsigned long flags;
 315         dma_cookie_t cookie;
 316
 317         /* cookie increment and adding to ld_queue must be atomic */
 318         spin_lock_irqsave(&fsl_chan->desc_lock, flags);
 319
 320         cookie = fsl_chan->common.cookie;
 321         cookie++;
 322         if (cookie < 0)
 323                 cookie = 1;
 324         desc->async_tx.cookie = cookie;
 325         fsl_chan->common.cookie = desc->async_tx.cookie;
 326
 327         append_ld_queue(fsl_chan, desc);
 328         list_splice_init(&desc->async_tx.tx_list, fsl_chan->ld_queue.prev);
 329
 330         spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
 331
 332         return cookie;
 333 }
 334
 335 /**
 336  * fsl_dma_alloc_descriptor - Allocate descriptor from channel's DMA pool.
 337  * @fsl_chan : Freescale DMA channel
 338  *
 339  * Return - The descriptor allocated. NULL for failed.
 340  */
 341 static struct fsl_desc_sw *fsl_dma_alloc_descriptor(
 342                                         struct fsl_dma_chan *fsl_chan)
 343 {
 344         dma_addr_t pdesc;
 345         struct fsl_desc_sw *desc_sw;
 346
 347         desc_sw = dma_pool_alloc(fsl_chan->desc_pool, GFP_ATOMIC, &pdesc);
 348         if (desc_sw) {
 349                 memset(desc_sw, 0, sizeof(struct fsl_desc_sw));
 350                 dma_async_tx_descriptor_init(&desc_sw->async_tx,
 351                                                 &fsl_chan->common);
 352                 desc_sw->async_tx.tx_submit = fsl_dma_tx_submit;
 353                 INIT_LIST_HEAD(&desc_sw->async_tx.tx_list);
 354                 desc_sw->async_tx.phys = pdesc;
 355         }
 356
 357         return desc_sw;
 358 }
 359
 360
 361 /**
 362  * fsl_dma_alloc_chan_resources - Allocate resources for DMA channel.
 363  * @fsl_chan : Freescale DMA channel
 364  *
 365  * This function will create a dma pool for descriptor allocation.
 366  *
 367  * Return - The number of descriptors allocated.
 368  */
 369 static int fsl_dma_alloc_chan_resources(struct dma_chan *chan)
 370 {
 371         struct fsl_dma_chan *fsl_chan = to_fsl_chan(chan);
 372
 373         /* Has this channel already been allocated? */
 374         if (fsl_chan->desc_pool)
 375                 return 1;
 376
 377         /* We need the descriptor to be aligned to 32bytes
 378          * for meeting FSL DMA specification requirement.
 379          */
 380         fsl_chan->desc_pool = dma_pool_create("fsl_dma_engine_desc_pool",
 381                         fsl_chan->dev, sizeof(struct fsl_desc_sw),
 382                         32, 0);
 383         if (!fsl_chan->desc_pool) {
 384                 dev_err(fsl_chan->dev, "No memory for channel %d "
 385                         "descriptor dma pool.\n", fsl_chan->id);
 386                 return 0;
 387         }
 388
 389         return 1;
 390 }
 391
 392 /**
 393  * fsl_dma_free_chan_resources - Free all resources of the channel.
 394  * @fsl_chan : Freescale DMA channel
 395  */
 396 static void fsl_dma_free_chan_resources(struct dma_chan *chan)
 397 {
 398         struct fsl_dma_chan *fsl_chan = to_fsl_chan(chan);
 399         struct fsl_desc_sw *desc, *_desc;
 400         unsigned long flags;
 401
 402         dev_dbg(fsl_chan->dev, "Free all channel resources.\n");
 403         spin_lock_irqsave(&fsl_chan->desc_lock, flags);
 404         list_for_each_entry_safe(desc, _desc, &fsl_chan->ld_queue, node) {
 405 #ifdef FSL_DMA_LD_DEBUG
 406                 dev_dbg(fsl_chan->dev,
 407                                 "LD %p will be released.\n", desc);
 408 #endif
 409                 list_del(&desc->node);
 410                 /* free link descriptor */
 411                 dma_pool_free(fsl_chan->desc_pool, desc, desc->async_tx.phys);
 412         }
 413         spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
 414         dma_pool_destroy(fsl_chan->desc_pool);
 415
 416         fsl_chan->desc_pool = NULL;
 417 }
 418
 419 static struct dma_async_tx_descriptor *
 420 fsl_dma_prep_interrupt(struct dma_chan *chan, unsigned long flags)
 421 {
 422         struct fsl_dma_chan *fsl_chan;
 423         struct fsl_desc_sw *new;
 424
 425         if (!chan)
 426                 return NULL;
 427
 428         fsl_chan = to_fsl_chan(chan);
 429
 430         new = fsl_dma_alloc_descriptor(fsl_chan);
 431         if (!new) {
 432                 dev_err(fsl_chan->dev, "No free memory for link descriptor\n");
 433                 return NULL;
 434         }
 435
 436         new->async_tx.cookie = -EBUSY;
 437         new->async_tx.flags = flags;
 438
 439         /* Insert the link descriptor to the LD ring */
 440         list_add_tail(&new->node, &new->async_tx.tx_list);
 441
 442         /* Set End-of-link to the last link descriptor of new list*/
 443         set_ld_eol(fsl_chan, new);
 444
 445         return &new->async_tx;
 446 }
 447
 448 static struct dma_async_tx_descriptor *fsl_dma_prep_memcpy(
 449         struct dma_chan *chan, dma_addr_t dma_dest, dma_addr_t dma_src,
 450         size_t len, unsigned long flags)
 451 {
 452         struct fsl_dma_chan *fsl_chan;
 453         struct fsl_desc_sw *first = NULL, *prev = NULL, *new;
 454         size_t copy;
 455         LIST_HEAD(link_chain);
 456
 457         if (!chan)
 458                 return NULL;
 459
 460         if (!len)
 461                 return NULL;
 462
 463         fsl_chan = to_fsl_chan(chan);
 464
 465         do {
 466
 467                 /* Allocate the link descriptor from DMA pool */
 468                 new = fsl_dma_alloc_descriptor(fsl_chan);
 469                 if (!new) {
 470                         dev_err(fsl_chan->dev,
 471                                         "No free memory for link descriptor\n");
 472                         return NULL;
 473                 }
 474 #ifdef FSL_DMA_LD_DEBUG
 475                 dev_dbg(fsl_chan->dev, "new link desc alloc %p\n", new);
 476 #endif
 477
 478                 copy = min(len, (size_t)FSL_DMA_BCR_MAX_CNT);
 479
 480                 set_desc_cnt(fsl_chan, &new->hw, copy);
 481                 set_desc_src(fsl_chan, &new->hw, dma_src);
 482                 set_desc_dest(fsl_chan, &new->hw, dma_dest);
 483
 484                 if (!first)
 485                         first = new;
 486                 else
 487                         set_desc_next(fsl_chan, &prev->hw, new->async_tx.phys);
 488
 489                 new->async_tx.cookie = 0;
 490                 async_tx_ack(&new->async_tx);
 491
 492                 prev = new;
 493                 len -= copy;
 494                 dma_src += copy;
 495                 dma_dest += copy;
 496
 497                 /* Insert the link descriptor to the LD ring */
 498                 list_add_tail(&new->node, &first->async_tx.tx_list);
 499         } while (len);
 500
 501         new->async_tx.flags = flags; /* client is in control of this ack */
 502         new->async_tx.cookie = -EBUSY;
 503
 504         /* Set End-of-link to the last link descriptor of new list*/
 505         set_ld_eol(fsl_chan, new);
 506
 507         return first ? &first->async_tx : NULL;
 508 }
 509
 510 /**
 511  * fsl_dma_update_completed_cookie - Update the completed cookie.
 512  * @fsl_chan : Freescale DMA channel
 513  */
 514 static void fsl_dma_update_completed_cookie(struct fsl_dma_chan *fsl_chan)
 515 {
 516         struct fsl_desc_sw *cur_desc, *desc;
 517         dma_addr_t ld_phy;
 518
 519         ld_phy = get_cdar(fsl_chan) & FSL_DMA_NLDA_MASK;
 520
 521         if (ld_phy) {
 522                 cur_desc = NULL;
 523                 list_for_each_entry(desc, &fsl_chan->ld_queue, node)
 524                         if (desc->async_tx.phys == ld_phy) {
 525                                 cur_desc = desc;
 526                                 break;
 527                         }
 528
 529                 if (cur_desc && cur_desc->async_tx.cookie) {
 530                         if (dma_is_idle(fsl_chan))
 531                                 fsl_chan->completed_cookie =
 532                                         cur_desc->async_tx.cookie;
 533                         else
 534                                 fsl_chan->completed_cookie =
 535                                         cur_desc->async_tx.cookie - 1;
 536                 }
 537         }
 538 }
 539
 540 /**
 541  * fsl_chan_ld_cleanup - Clean up link descriptors
 542  * @fsl_chan : Freescale DMA channel
 543  *
 544  * This function clean up the ld_queue of DMA channel.
 545  * If 'in_intr' is set, the function will move the link descriptor to
 546  * the recycle list. Otherwise, free it directly.
 547  */
 548 static void fsl_chan_ld_cleanup(struct fsl_dma_chan *fsl_chan)
 549 {
 550         struct fsl_desc_sw *desc, *_desc;
 551         unsigned long flags;
 552
 553         spin_lock_irqsave(&fsl_chan->desc_lock, flags);
 554
 555         dev_dbg(fsl_chan->dev, "chan completed_cookie = %d\n",
 556                         fsl_chan->completed_cookie);
 557         list_for_each_entry_safe(desc, _desc, &fsl_chan->ld_queue, node) {
 558                 dma_async_tx_callback callback;
 559                 void *callback_param;
 560
 561                 if (dma_async_is_complete(desc->async_tx.cookie,
 562                             fsl_chan->completed_cookie, fsl_chan->common.cookie)
 563                                 == DMA_IN_PROGRESS)
 564                         break;
 565
 566                 callback = desc->async_tx.callback;
 567                 callback_param = desc->async_tx.callback_param;
 568
 569                 /* Remove from ld_queue list */
 570                 list_del(&desc->node);
 571
 572                 dev_dbg(fsl_chan->dev, "link descriptor %p will be recycle.\n",
 573                                 desc);
 574                 dma_pool_free(fsl_chan->desc_pool, desc, desc->async_tx.phys);
 575
 576                 /* Run the link descriptor callback function */
 577                 if (callback) {
 578                         spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
 579                         dev_dbg(fsl_chan->dev, "link descriptor %p callback\n",
 580                                         desc);
 581                         callback(callback_param);
 582                         spin_lock_irqsave(&fsl_chan->desc_lock, flags);
 583                 }
 584         }
 585         spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
 586 }
 587
 588 /**
 589  * fsl_chan_xfer_ld_queue - Transfer link descriptors in channel ld_queue.
 590  * @fsl_chan : Freescale DMA channel
 591  */
 592 static void fsl_chan_xfer_ld_queue(struct fsl_dma_chan *fsl_chan)
 593 {
 594         struct list_head *ld_node;
 595         dma_addr_t next_dest_addr;
 596         unsigned long flags;
 597
 598         if (!dma_is_idle(fsl_chan))
 599                 return;
 600
 601         dma_halt(fsl_chan);
 602
 603         /* If there are some link descriptors
 604          * not transfered in queue. We need to start it.
 605          */
 606         spin_lock_irqsave(&fsl_chan->desc_lock, flags);
 607
 608         /* Find the first un-transfer desciptor */
 609         for (ld_node = fsl_chan->ld_queue.next;
 610                 (ld_node != &fsl_chan->ld_queue)
 611                         && (dma_async_is_complete(
 612                                 to_fsl_desc(ld_node)->async_tx.cookie,
 613                                 fsl_chan->completed_cookie,
 614                                 fsl_chan->common.cookie) == DMA_SUCCESS);
 615                 ld_node = ld_node->next);
 616
 617         spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
 618
 619         if (ld_node != &fsl_chan->ld_queue) {
 620                 /* Get the ld start address from ld_queue */
 621                 next_dest_addr = to_fsl_desc(ld_node)->async_tx.phys;
 622                 dev_dbg(fsl_chan->dev, "xfer LDs staring from %p\n",
 623                                 (void *)next_dest_addr);
 624                 set_cdar(fsl_chan, next_dest_addr);
 625                 dma_start(fsl_chan);
 626         } else {
 627                 set_cdar(fsl_chan, 0);
 628                 set_ndar(fsl_chan, 0);
 629         }
 630 }
 631
 632 /**
 633  * fsl_dma_memcpy_issue_pending - Issue the DMA start command
 634  * @fsl_chan : Freescale DMA channel
 635  */
 636 static void fsl_dma_memcpy_issue_pending(struct dma_chan *chan)
 637 {
 638         struct fsl_dma_chan *fsl_chan = to_fsl_chan(chan);
 639
 640 #ifdef FSL_DMA_LD_DEBUG
 641         struct fsl_desc_sw *ld;
 642         unsigned long flags;
 643
 644         spin_lock_irqsave(&fsl_chan->desc_lock, flags);
 645         if (list_empty(&fsl_chan->ld_queue)) {
 646                 spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
 647                 return;
 648         }
 649
 650         dev_dbg(fsl_chan->dev, "--memcpy issue--\n");
 651         list_for_each_entry(ld, &fsl_chan->ld_queue, node) {
 652                 int i;
 653                 dev_dbg(fsl_chan->dev, "Ch %d, LD %08x\n",
 654                                 fsl_chan->id, ld->async_tx.phys);
 655                 for (i = 0; i < 8; i++)
 656                         dev_dbg(fsl_chan->dev, "LD offset %d: %08x\n",
 657                                         i, *(((u32 *)&ld->hw) + i));
 658         }
 659         dev_dbg(fsl_chan->dev, "----------------\n");
 660         spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
 661 #endif
 662
 663         fsl_chan_xfer_ld_queue(fsl_chan);
 664 }
 665
 666 /**
 667  * fsl_dma_is_complete - Determine the DMA status
 668  * @fsl_chan : Freescale DMA channel
 669  */
 670 static enum dma_status fsl_dma_is_complete(struct dma_chan *chan,
 671                                         dma_cookie_t cookie,
 672                                         dma_cookie_t *done,
 673                                         dma_cookie_t *used)
 674 {
 675         struct fsl_dma_chan *fsl_chan = to_fsl_chan(chan);
 676         dma_cookie_t last_used;
 677         dma_cookie_t last_complete;
 678
 679         fsl_chan_ld_cleanup(fsl_chan);
 680
 681         last_used = chan->cookie;
 682         last_complete = fsl_chan->completed_cookie;
 683
 684         if (done)
 685                 *done = last_complete;
 686
 687         if (used)
 688                 *used = last_used;
 689
 690         return dma_async_is_complete(cookie, last_complete, last_used);
 691 }
 692
 693 static irqreturn_t fsl_dma_chan_do_interrupt(int irq, void *data)
 694 {
 695         struct fsl_dma_chan *fsl_chan = (struct fsl_dma_chan *)data;
 696         u32 stat;
 697         int update_cookie = 0;
 698         int xfer_ld_q = 0;
 699
 700         stat = get_sr(fsl_chan);
 701         dev_dbg(fsl_chan->dev, "event: channel %d, stat = 0x%x\n",
 702                                                 fsl_chan->id, stat);
 703         set_sr(fsl_chan, stat);         /* Clear the event register */
 704
 705         stat &= ~(FSL_DMA_SR_CB | FSL_DMA_SR_CH);
 706         if (!stat)
 707                 return IRQ_NONE;
 708
 709         if (stat & FSL_DMA_SR_TE)
 710                 dev_err(fsl_chan->dev, "Transfer Error!\n");
 711
 712         /* Programming Error
 713          * The DMA_INTERRUPT async_tx is a NULL transfer, which will
 714          * triger a PE interrupt.
 715          */
 716         if (stat & FSL_DMA_SR_PE) {
 717                 dev_dbg(fsl_chan->dev, "event: Programming Error INT\n");
 718                 if (get_bcr(fsl_chan) == 0) {
 719                         /* BCR register is 0, this is a DMA_INTERRUPT async_tx.
 720                          * Now, update the completed cookie, and continue the
 721                          * next uncompleted transfer.
 722                          */
 723                         update_cookie = 1;
 724                         xfer_ld_q = 1;
 725                 }
 726                 stat &= ~FSL_DMA_SR_PE;
 727         }
 728
 729         /* If the link descriptor segment transfer finishes,
 730          * we will recycle the used descriptor.
 731          */
 732         if (stat & FSL_DMA_SR_EOSI) {
 733                 dev_dbg(fsl_chan->dev, "event: End-of-segments INT\n");
 734                 dev_dbg(fsl_chan->dev, "event: clndar %p, nlndar %p\n",
 735                         (void *)get_cdar(fsl_chan), (void *)get_ndar(fsl_chan));
 736                 stat &= ~FSL_DMA_SR_EOSI;
 737                 update_cookie = 1;
 738         }
 739
 740         /* For MPC8349, EOCDI event need to update cookie
 741          * and start the next transfer if it exist.
 742          */
 743         if (stat & FSL_DMA_SR_EOCDI) {
 744                 dev_dbg(fsl_chan->dev, "event: End-of-Chain link INT\n");
 745                 stat &= ~FSL_DMA_SR_EOCDI;
 746                 update_cookie = 1;
 747                 xfer_ld_q = 1;
 748         }
 749
 750         /* If it current transfer is the end-of-transfer,
 751          * we should clear the Channel Start bit for
 752          * prepare next transfer.
 753          */
 754         if (stat & FSL_DMA_SR_EOLNI) {
 755                 dev_dbg(fsl_chan->dev, "event: End-of-link INT\n");
 756                 stat &= ~FSL_DMA_SR_EOLNI;
 757                 xfer_ld_q = 1;
 758         }
 759
 760         if (update_cookie)
 761                 fsl_dma_update_completed_cookie(fsl_chan);
 762         if (xfer_ld_q)
 763                 fsl_chan_xfer_ld_queue(fsl_chan);
 764         if (stat)
 765                 dev_dbg(fsl_chan->dev, "event: unhandled sr 0x%02x\n",
 766                                         stat);
 767
 768         dev_dbg(fsl_chan->dev, "event: Exit\n");
 769         tasklet_schedule(&fsl_chan->tasklet);
 770         return IRQ_HANDLED;
 771 }
 772
 773 static irqreturn_t fsl_dma_do_interrupt(int irq, void *data)
 774 {
 775         struct fsl_dma_device *fdev = (struct fsl_dma_device *)data;
 776         u32 gsr;
 777         int ch_nr;
 778
 779         gsr = (fdev->feature & FSL_DMA_BIG_ENDIAN) ? in_be32(fdev->reg_base)
 780                         : in_le32(fdev->reg_base);
 781         ch_nr = (32 - ffs(gsr)) / 8;
 782
 783         return fdev->chan[ch_nr] ? fsl_dma_chan_do_interrupt(irq,
 784                         fdev->chan[ch_nr]) : IRQ_NONE;
 785 }
 786
 787 static void dma_do_tasklet(unsigned long data)
 788 {
 789         struct fsl_dma_chan *fsl_chan = (struct fsl_dma_chan *)data;
 790         fsl_chan_ld_cleanup(fsl_chan);
 791 }
 792
 793 static int __devinit fsl_dma_chan_probe(struct fsl_dma_device *fdev,
 794         struct device_node *node, u32 feature, const char *compatible)
 795 {
 796         struct fsl_dma_chan *new_fsl_chan;
 797         int err;
 798
 799         /* alloc channel */
 800         new_fsl_chan = kzalloc(sizeof(struct fsl_dma_chan), GFP_KERNEL);
 801         if (!new_fsl_chan) {
 802                 dev_err(fdev->dev, "No free memory for allocating "
 803                                 "dma channels!\n");
 804                 return -ENOMEM;
 805         }
 806
 807         /* get dma channel register base */
 808         err = of_address_to_resource(node, 0, &new_fsl_chan->reg);
 809         if (err) {
 810                 dev_err(fdev->dev, "Can't get %s property 'reg'\n",
 811                                 node->full_name);
 812                 goto err_no_reg;
 813         }
 814
 815         new_fsl_chan->feature = feature;
 816
 817         if (!fdev->feature)
 818                 fdev->feature = new_fsl_chan->feature;
 819
 820         /* If the DMA device's feature is different than its channels',
 821          * report the bug.
 822          */
 823         WARN_ON(fdev->feature != new_fsl_chan->feature);
 824
 825         new_fsl_chan->dev = &new_fsl_chan->common.dev->device;
 826         new_fsl_chan->reg_base = ioremap(new_fsl_chan->reg.start,
 827                         new_fsl_chan->reg.end - new_fsl_chan->reg.start + 1);
 828
 829         new_fsl_chan->id = ((new_fsl_chan->reg.start - 0x100) & 0xfff) >> 7;
 830         if (new_fsl_chan->id > FSL_DMA_MAX_CHANS_PER_DEVICE) {
 831                 dev_err(fdev->dev, "There is no %d channel!\n",
 832                                 new_fsl_chan->id);
 833                 err = -EINVAL;
 834                 goto err_no_chan;
 835         }
 836         fdev->chan[new_fsl_chan->id] = new_fsl_chan;
 837         tasklet_init(&new_fsl_chan->tasklet, dma_do_tasklet,
 838                         (unsigned long)new_fsl_chan);
 839
 840         /* Init the channel */
 841         dma_init(new_fsl_chan);
 842
 843         /* Clear cdar registers */
 844         set_cdar(new_fsl_chan, 0);
 845
 846         switch (new_fsl_chan->feature & FSL_DMA_IP_MASK) {
 847         case FSL_DMA_IP_85XX:
 848                 new_fsl_chan->toggle_ext_start = fsl_chan_toggle_ext_start;
 849                 new_fsl_chan->toggle_ext_pause = fsl_chan_toggle_ext_pause;
 850         case FSL_DMA_IP_83XX:
 851                 new_fsl_chan->set_src_loop_size = fsl_chan_set_src_loop_size;
 852                 new_fsl_chan->set_dest_loop_size = fsl_chan_set_dest_loop_size;
 853         }
 854
 855         spin_lock_init(&new_fsl_chan->desc_lock);
 856         INIT_LIST_HEAD(&new_fsl_chan->ld_queue);
 857
 858         new_fsl_chan->common.device = &fdev->common;
 859
 860         /* Add the channel to DMA device channel list */
 861         list_add_tail(&new_fsl_chan->common.device_node,
 862                         &fdev->common.channels);
 863         fdev->common.chancnt++;
 864
 865         new_fsl_chan->irq = irq_of_parse_and_map(node, 0);
 866         if (new_fsl_chan->irq != NO_IRQ) {
 867                 err = request_irq(new_fsl_chan->irq,
 868                                         &fsl_dma_chan_do_interrupt, IRQF_SHARED,
 869                                         "fsldma-channel", new_fsl_chan);
 870                 if (err) {
 871                         dev_err(fdev->dev, "DMA channel %s request_irq error "
 872                                 "with return %d\n", node->full_name, err);
 873                         goto err_no_irq;
 874                 }
 875         }
 876
 877         dev_info(fdev->dev, "#%d (%s), irq %d\n", new_fsl_chan->id,
 878                                 compatible, new_fsl_chan->irq);
 879
 880         return 0;
 881
 882 err_no_irq:
 883         list_del(&new_fsl_chan->common.device_node);
 884 err_no_chan:
 885         iounmap(new_fsl_chan->reg_base);
 886 err_no_reg:
 887         kfree(new_fsl_chan);
 888         return err;
 889 }
 890
 891 static void fsl_dma_chan_remove(struct fsl_dma_chan *fchan)
 892 {
 893         free_irq(fchan->irq, fchan);
 894         list_del(&fchan->common.device_node);
 895         iounmap(fchan->reg_base);
 896         kfree(fchan);
 897 }
 898
 899 static int __devinit of_fsl_dma_probe(struct of_device *dev,
 900                         const struct of_device_id *match)
 901 {
 902         int err;
 903         struct fsl_dma_device *fdev;
 904         struct device_node *child;
 905
 906         fdev = kzalloc(sizeof(struct fsl_dma_device), GFP_KERNEL);
 907         if (!fdev) {
 908                 dev_err(&dev->dev, "No enough memory for 'priv'\n");
 909                 return -ENOMEM;
 910         }
 911         fdev->dev = &dev->dev;
 912         INIT_LIST_HEAD(&fdev->common.channels);
 913
 914         /* get DMA controller register base */
 915         err = of_address_to_resource(dev->node, 0, &fdev->reg);
 916         if (err) {
 917                 dev_err(&dev->dev, "Can't get %s property 'reg'\n",
 918                                 dev->node->full_name);
 919                 goto err_no_reg;
 920         }
 921
 922         dev_info(&dev->dev, "Probe the Freescale DMA driver for %s "
 923                         "controller at %p...\n",
 924                         match->compatible, (void *)fdev->reg.start);
 925         fdev->reg_base = ioremap(fdev->reg.start, fdev->reg.end
 926                                                 - fdev->reg.start + 1);
 927
 928         dma_cap_set(DMA_MEMCPY, fdev->common.cap_mask);
 929         dma_cap_set(DMA_INTERRUPT, fdev->common.cap_mask);
 930         fdev->common.device_alloc_chan_resources = fsl_dma_alloc_chan_resources;
 931         fdev->common.device_free_chan_resources = fsl_dma_free_chan_resources;
 932         fdev->common.device_prep_dma_interrupt = fsl_dma_prep_interrupt;
 933         fdev->common.device_prep_dma_memcpy = fsl_dma_prep_memcpy;
 934         fdev->common.device_is_tx_complete = fsl_dma_is_complete;
 935         fdev->common.device_issue_pending = fsl_dma_memcpy_issue_pending;
 936         fdev->common.dev = &dev->dev;
 937
 938         fdev->irq = irq_of_parse_and_map(dev->node, 0);
 939         if (fdev->irq != NO_IRQ) {
 940                 err = request_irq(fdev->irq, &fsl_dma_do_interrupt, IRQF_SHARED,
 941                                         "fsldma-device", fdev);
 942                 if (err) {
 943                         dev_err(&dev->dev, "DMA device request_irq error "
 944                                 "with return %d\n", err);
 945                         goto err;
 946                 }
 947         }
 948
 949         dev_set_drvdata(&(dev->dev), fdev);
 950
 951         /* We cannot use of_platform_bus_probe() because there is no
 952          * of_platform_bus_remove.  Instead, we manually instantiate every DMA
 953          * channel object.
 954          */
 955         for_each_child_of_node(dev->node, child) {
 956                 if (of_device_is_compatible(child, "fsl,eloplus-dma-channel"))
 957                         fsl_dma_chan_probe(fdev, child,
 958                                 FSL_DMA_IP_85XX | FSL_DMA_BIG_ENDIAN,
 959                                 "fsl,eloplus-dma-channel");
 960                 if (of_device_is_compatible(child, "fsl,elo-dma-channel"))
 961                         fsl_dma_chan_probe(fdev, child,
 962                                 FSL_DMA_IP_83XX | FSL_DMA_LITTLE_ENDIAN,
 963                                 "fsl,elo-dma-channel");
 964         }
 965
 966         dma_async_device_register(&fdev->common);
 967         return 0;
 968
 969 err:
 970         iounmap(fdev->reg_base);
 971 err_no_reg:
 972         kfree(fdev);
 973         return err;
 974 }
 975
 976 static int of_fsl_dma_remove(struct of_device *of_dev)
 977 {
 978         struct fsl_dma_device *fdev;
 979         unsigned int i;
 980
 981         fdev = dev_get_drvdata(&of_dev->dev);
 982
 983         dma_async_device_unregister(&fdev->common);
 984
 985         for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++)
 986                 if (fdev->chan[i])
 987                         fsl_dma_chan_remove(fdev->chan[i]);
 988
 989         if (fdev->irq != NO_IRQ)
 990                 free_irq(fdev->irq, fdev);
 991
 992         iounmap(fdev->reg_base);
 993
 994         kfree(fdev);
 995         dev_set_drvdata(&of_dev->dev, NULL);
 996
 997         return 0;
 998 }
 999
1000 static struct of_device_id of_fsl_dma_ids[] = {
1001         { .compatible = "fsl,eloplus-dma", },
1002         { .compatible = "fsl,elo-dma", },
1003         {}
1004 };
1005
1006 static struct of_platform_driver of_fsl_dma_driver = {
1007         .name = "fsl-elo-dma",
1008         .match_table = of_fsl_dma_ids,
1009         .probe = of_fsl_dma_probe,
1010         .remove = of_fsl_dma_remove,
1011 };
1012
1013 static __init int of_fsl_dma_init(void)
1014 {
1015         int ret;
1016
1017         pr_info("Freescale Elo / Elo Plus DMA driver\n");
1018
1019         ret = of_register_platform_driver(&of_fsl_dma_driver);
1020         if (ret)
1021                 pr_err("fsldma: failed to register platform driver\n");
1022
1023         return ret;
1024 }
1025
1026 static void __exit of_fsl_dma_exit(void)
1027 {
1028         of_unregister_platform_driver(&of_fsl_dma_driver);
1029 }
1030
1031 subsys_initcall(of_fsl_dma_init);
1032 module_exit(of_fsl_dma_exit);
1033
1034 MODULE_DESCRIPTION("Freescale Elo / Elo Plus DMA driver");
1035 MODULE_LICENSE("GPL");