arch/arm/mach-s3c64xx/dma.c

   1 /* linux/arch/arm/plat-s3c64xx/dma.c
   2  *
   3  * Copyright 2009 Openmoko, Inc.
   4  * Copyright 2009 Simtec Electronics
   5  *      Ben Dooks <ben@simtec.co.uk>
   6  *      http://armlinux.simtec.co.uk/
   7  *
   8  * S3C64XX DMA core
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13 */
  14
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/dmapool.h>
  19 #include <linux/sysdev.h>
  20 #include <linux/errno.h>
  21 #include <linux/slab.h>
  22 #include <linux/delay.h>
  23 #include <linux/clk.h>
  24 #include <linux/err.h>
  25 #include <linux/io.h>
  26
  27 #include <mach/dma.h>
  28 #include <mach/map.h>
  29 #include <mach/irqs.h>
  30
  31 #include <mach/regs-sys.h>
  32
  33 #include <asm/hardware/pl080.h>
  34
  35 /* dma channel state information */
  36
  37 struct s3c64xx_dmac {
  38         struct sys_device        sysdev;
  39         struct clk              *clk;
  40         void __iomem            *regs;
  41         struct s3c2410_dma_chan *channels;
  42         enum dma_ch              chanbase;
  43 };
  44
  45 /* pool to provide LLI buffers */
  46 static struct dma_pool *dma_pool;
  47
  48 /* Debug configuration and code */
  49
  50 static unsigned char debug_show_buffs = 0;
  51
  52 static void dbg_showchan(struct s3c2410_dma_chan *chan)
  53 {
  54         pr_debug("DMA%d: %08x->%08x L %08x C %08x,%08x S %08x\n",
  55                  chan->number,
  56                  readl(chan->regs + PL080_CH_SRC_ADDR),
  57                  readl(chan->regs + PL080_CH_DST_ADDR),
  58                  readl(chan->regs + PL080_CH_LLI),
  59                  readl(chan->regs + PL080_CH_CONTROL),
  60                  readl(chan->regs + PL080S_CH_CONTROL2),
  61                  readl(chan->regs + PL080S_CH_CONFIG));
  62 }
  63
  64 static void show_lli(struct pl080s_lli *lli)
  65 {
  66         pr_debug("LLI[%p] %08x->%08x, NL %08x C %08x,%08x\n",
  67                  lli, lli->src_addr, lli->dst_addr, lli->next_lli,
  68                  lli->control0, lli->control1);
  69 }
  70
  71 static void dbg_showbuffs(struct s3c2410_dma_chan *chan)
  72 {
  73         struct s3c64xx_dma_buff *ptr;
  74         struct s3c64xx_dma_buff *end;
  75
  76         pr_debug("DMA%d: buffs next %p, curr %p, end %p\n",
  77                  chan->number, chan->next, chan->curr, chan->end);
  78
  79         ptr = chan->next;
  80         end = chan->end;
  81
  82         if (debug_show_buffs) {
  83                 for (; ptr != NULL; ptr = ptr->next) {
  84                         pr_debug("DMA%d: %08x ",
  85                                  chan->number, ptr->lli_dma);
  86                         show_lli(ptr->lli);
  87                 }
  88         }
  89 }
  90
  91 /* End of Debug */
  92
  93 static struct s3c2410_dma_chan *s3c64xx_dma_map_channel(unsigned int channel)
  94 {
  95         struct s3c2410_dma_chan *chan;
  96         unsigned int start, offs;
  97
  98         start = 0;
  99
 100         if (channel >= DMACH_PCM1_TX)
 101                 start = 8;
 102
 103         for (offs = 0; offs < 8; offs++) {
 104                 chan = &s3c2410_chans[start + offs];
 105                 if (!chan->in_use)
 106                         goto found;
 107         }
 108
 109         return NULL;
 110
 111 found:
 112         s3c_dma_chan_map[channel] = chan;
 113         return chan;
 114 }
 115
 116 int s3c2410_dma_config(enum dma_ch channel, int xferunit)
 117 {
 118         struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
 119
 120         if (chan == NULL)
 121                 return -EINVAL;
 122
 123         switch (xferunit) {
 124         case 1:
 125                 chan->hw_width = 0;
 126                 break;
 127         case 2:
 128                 chan->hw_width = 1;
 129                 break;
 130         case 4:
 131                 chan->hw_width = 2;
 132                 break;
 133         default:
 134                 printk(KERN_ERR "%s: illegal width %d\n", __func__, xferunit);
 135                 return -EINVAL;
 136         }
 137
 138         return 0;
 139 }
 140 EXPORT_SYMBOL(s3c2410_dma_config);
 141
 142 static void s3c64xx_dma_fill_lli(struct s3c2410_dma_chan *chan,
 143                                  struct pl080s_lli *lli,
 144                                  dma_addr_t data, int size)
 145 {
 146         dma_addr_t src, dst;
 147         u32 control0, control1;
 148
 149         switch (chan->source) {
 150         case S3C2410_DMASRC_HW:
 151                 src = chan->dev_addr;
 152                 dst = data;
 153                 control0 = PL080_CONTROL_SRC_AHB2;
 154                 control0 |= PL080_CONTROL_DST_INCR;
 155                 break;
 156
 157         case S3C2410_DMASRC_MEM:
 158                 src = data;
 159                 dst = chan->dev_addr;
 160                 control0 = PL080_CONTROL_DST_AHB2;
 161                 control0 |= PL080_CONTROL_SRC_INCR;
 162                 break;
 163         default:
 164                 BUG();
 165         }
 166
 167         /* note, we do not currently setup any of the burst controls */
 168
 169         control1 = size >> chan->hw_width;      /* size in no of xfers */
 170         control0 |= PL080_CONTROL_PROT_SYS;     /* always in priv. mode */
 171         control0 |= PL080_CONTROL_TC_IRQ_EN;    /* always fire IRQ */
 172         control0 |= (u32)chan->hw_width << PL080_CONTROL_DWIDTH_SHIFT;
 173         control0 |= (u32)chan->hw_width << PL080_CONTROL_SWIDTH_SHIFT;
 174
 175         lli->src_addr = src;
 176         lli->dst_addr = dst;
 177         lli->next_lli = 0;
 178         lli->control0 = control0;
 179         lli->control1 = control1;
 180 }
 181
 182 static void s3c64xx_lli_to_regs(struct s3c2410_dma_chan *chan,
 183                                 struct pl080s_lli *lli)
 184 {
 185         void __iomem *regs = chan->regs;
 186
 187         pr_debug("%s: LLI %p => regs\n", __func__, lli);
 188         show_lli(lli);
 189
 190         writel(lli->src_addr, regs + PL080_CH_SRC_ADDR);
 191         writel(lli->dst_addr, regs + PL080_CH_DST_ADDR);
 192         writel(lli->next_lli, regs + PL080_CH_LLI);
 193         writel(lli->control0, regs + PL080_CH_CONTROL);
 194         writel(lli->control1, regs + PL080S_CH_CONTROL2);
 195 }
 196
 197 static int s3c64xx_dma_start(struct s3c2410_dma_chan *chan)
 198 {
 199         struct s3c64xx_dmac *dmac = chan->dmac;
 200         u32 config;
 201         u32 bit = chan->bit;
 202
 203         dbg_showchan(chan);
 204
 205         pr_debug("%s: clearing interrupts\n", __func__);
 206
 207         /* clear interrupts */
 208         writel(bit, dmac->regs + PL080_TC_CLEAR);
 209         writel(bit, dmac->regs + PL080_ERR_CLEAR);
 210
 211         pr_debug("%s: starting channel\n", __func__);
 212
 213         config = readl(chan->regs + PL080S_CH_CONFIG);
 214         config |= PL080_CONFIG_ENABLE;
 215         config &= ~PL080_CONFIG_HALT;
 216
 217         pr_debug("%s: writing config %08x\n", __func__, config);
 218         writel(config, chan->regs + PL080S_CH_CONFIG);
 219
 220         return 0;
 221 }
 222
 223 static int s3c64xx_dma_stop(struct s3c2410_dma_chan *chan)
 224 {
 225         u32 config;
 226         int timeout;
 227
 228         pr_debug("%s: stopping channel\n", __func__);
 229
 230         dbg_showchan(chan);
 231
 232         config = readl(chan->regs + PL080S_CH_CONFIG);
 233         config |= PL080_CONFIG_HALT;
 234         writel(config, chan->regs + PL080S_CH_CONFIG);
 235
 236         timeout = 1000;
 237         do {
 238                 config = readl(chan->regs + PL080S_CH_CONFIG);
 239                 pr_debug("%s: %d - config %08x\n", __func__, timeout, config);
 240                 if (config & PL080_CONFIG_ACTIVE)
 241                         udelay(10);
 242                 else
 243                         break;
 244                 } while (--timeout > 0);
 245
 246         if (config & PL080_CONFIG_ACTIVE) {
 247                 printk(KERN_ERR "%s: channel still active\n", __func__);
 248                 return -EFAULT;
 249         }
 250
 251         config = readl(chan->regs + PL080S_CH_CONFIG);
 252         config &= ~PL080_CONFIG_ENABLE;
 253         writel(config, chan->regs + PL080S_CH_CONFIG);
 254
 255         return 0;
 256 }
 257
 258 static inline void s3c64xx_dma_bufffdone(struct s3c2410_dma_chan *chan,
 259                                          struct s3c64xx_dma_buff *buf,
 260                                          enum s3c2410_dma_buffresult result)
 261 {
 262         if (chan->callback_fn != NULL)
 263                 (chan->callback_fn)(chan, buf->pw, 0, result);
 264 }
 265
 266 static void s3c64xx_dma_freebuff(struct s3c64xx_dma_buff *buff)
 267 {
 268         dma_pool_free(dma_pool, buff->lli, buff->lli_dma);
 269         kfree(buff);
 270 }
 271
 272 static int s3c64xx_dma_flush(struct s3c2410_dma_chan *chan)
 273 {
 274         struct s3c64xx_dma_buff *buff, *next;
 275         u32 config;
 276
 277         dbg_showchan(chan);
 278
 279         pr_debug("%s: flushing channel\n", __func__);
 280
 281         config = readl(chan->regs + PL080S_CH_CONFIG);
 282         config &= ~PL080_CONFIG_ENABLE;
 283         writel(config, chan->regs + PL080S_CH_CONFIG);
 284
 285         /* dump all the buffers associated with this channel */
 286
 287         for (buff = chan->curr; buff != NULL; buff = next) {
 288                 next = buff->next;
 289                 pr_debug("%s: buff %p (next %p)\n", __func__, buff, buff->next);
 290
 291                 s3c64xx_dma_bufffdone(chan, buff, S3C2410_RES_ABORT);
 292                 s3c64xx_dma_freebuff(buff);
 293         }
 294
 295         chan->curr = chan->next = chan->end = NULL;
 296
 297         return 0;
 298 }
 299
 300 int s3c2410_dma_ctrl(enum dma_ch channel, enum s3c2410_chan_op op)
 301 {
 302         struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
 303
 304         WARN_ON(!chan);
 305         if (!chan)
 306                 return -EINVAL;
 307
 308         switch (op) {
 309         case S3C2410_DMAOP_START:
 310                 return s3c64xx_dma_start(chan);
 311
 312         case S3C2410_DMAOP_STOP:
 313                 return s3c64xx_dma_stop(chan);
 314
 315         case S3C2410_DMAOP_FLUSH:
 316                 return s3c64xx_dma_flush(chan);
 317
 318         /* believe PAUSE/RESUME are no-ops */
 319         case S3C2410_DMAOP_PAUSE:
 320         case S3C2410_DMAOP_RESUME:
 321         case S3C2410_DMAOP_STARTED:
 322         case S3C2410_DMAOP_TIMEOUT:
 323                 return 0;
 324         }
 325
 326         return -ENOENT;
 327 }
 328 EXPORT_SYMBOL(s3c2410_dma_ctrl);
 329
 330 /* s3c2410_dma_enque
 331  *
 332  */
 333
 334 int s3c2410_dma_enqueue(enum dma_ch channel, void *id,
 335                         dma_addr_t data, int size)
 336 {
 337         struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
 338         struct s3c64xx_dma_buff *next;
 339         struct s3c64xx_dma_buff *buff;
 340         struct pl080s_lli *lli;
 341         unsigned long flags;
 342         int ret;
 343
 344         WARN_ON(!chan);
 345         if (!chan)
 346                 return -EINVAL;
 347
 348         buff = kzalloc(sizeof(struct s3c64xx_dma_buff), GFP_ATOMIC);
 349         if (!buff) {
 350                 printk(KERN_ERR "%s: no memory for buffer\n", __func__);
 351                 return -ENOMEM;
 352         }
 353
 354         lli = dma_pool_alloc(dma_pool, GFP_ATOMIC, &buff->lli_dma);
 355         if (!lli) {
 356                 printk(KERN_ERR "%s: no memory for lli\n", __func__);
 357                 ret = -ENOMEM;
 358                 goto err_buff;
 359         }
 360
 361         pr_debug("%s: buff %p, dp %08x lli (%p, %08x) %d\n",
 362                  __func__, buff, data, lli, (u32)buff->lli_dma, size);
 363
 364         buff->lli = lli;
 365         buff->pw = id;
 366
 367         s3c64xx_dma_fill_lli(chan, lli, data, size);
 368
 369         local_irq_save(flags);
 370
 371         if ((next = chan->next) != NULL) {
 372                 struct s3c64xx_dma_buff *end = chan->end;
 373                 struct pl080s_lli *endlli = end->lli;
 374
 375                 pr_debug("enquing onto channel\n");
 376
 377                 end->next = buff;
 378                 endlli->next_lli = buff->lli_dma;
 379
 380                 if (chan->flags & S3C2410_DMAF_CIRCULAR) {
 381                         struct s3c64xx_dma_buff *curr = chan->curr;
 382                         lli->next_lli = curr->lli_dma;
 383                 }
 384
 385                 if (next == chan->curr) {
 386                         writel(buff->lli_dma, chan->regs + PL080_CH_LLI);
 387                         chan->next = buff;
 388                 }
 389
 390                 show_lli(endlli);
 391                 chan->end = buff;
 392         } else {
 393                 pr_debug("enquing onto empty channel\n");
 394
 395                 chan->curr = buff;
 396                 chan->next = buff;
 397                 chan->end = buff;
 398
 399                 s3c64xx_lli_to_regs(chan, lli);
 400         }
 401
 402         local_irq_restore(flags);
 403
 404         show_lli(lli);
 405
 406         dbg_showchan(chan);
 407         dbg_showbuffs(chan);
 408         return 0;
 409
 410 err_buff:
 411         kfree(buff);
 412         return ret;
 413 }
 414
 415 EXPORT_SYMBOL(s3c2410_dma_enqueue);
 416
 417
 418 int s3c2410_dma_devconfig(enum dma_ch channel,
 419                           enum s3c2410_dmasrc source,
 420                           unsigned long devaddr)
 421 {
 422         struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
 423         u32 peripheral;
 424         u32 config = 0;
 425
 426         pr_debug("%s: channel %d, source %d, dev %08lx, chan %p\n",
 427                  __func__, channel, source, devaddr, chan);
 428
 429         WARN_ON(!chan);
 430         if (!chan)
 431                 return -EINVAL;
 432
 433         peripheral = (chan->peripheral & 0xf);
 434         chan->source = source;
 435         chan->dev_addr = devaddr;
 436
 437         pr_debug("%s: peripheral %d\n", __func__, peripheral);
 438
 439         switch (source) {
 440         case S3C2410_DMASRC_HW:
 441                 config = 2 << PL080_CONFIG_FLOW_CONTROL_SHIFT;
 442                 config |= peripheral << PL080_CONFIG_SRC_SEL_SHIFT;
 443                 break;
 444         case S3C2410_DMASRC_MEM:
 445                 config = 1 << PL080_CONFIG_FLOW_CONTROL_SHIFT;
 446                 config |= peripheral << PL080_CONFIG_DST_SEL_SHIFT;
 447                 break;
 448         default:
 449                 printk(KERN_ERR "%s: bad source\n", __func__);
 450                 return -EINVAL;
 451         }
 452
 453         /* allow TC and ERR interrupts */
 454         config |= PL080_CONFIG_TC_IRQ_MASK;
 455         config |= PL080_CONFIG_ERR_IRQ_MASK;
 456
 457         pr_debug("%s: config %08x\n", __func__, config);
 458
 459         writel(config, chan->regs + PL080S_CH_CONFIG);
 460
 461         return 0;
 462 }
 463 EXPORT_SYMBOL(s3c2410_dma_devconfig);
 464
 465
 466 int s3c2410_dma_getposition(enum dma_ch channel,
 467                             dma_addr_t *src, dma_addr_t *dst)
 468 {
 469         struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
 470
 471         WARN_ON(!chan);
 472         if (!chan)
 473                 return -EINVAL;
 474
 475         if (src != NULL)
 476                 *src = readl(chan->regs + PL080_CH_SRC_ADDR);
 477
 478         if (dst != NULL)
 479                 *dst = readl(chan->regs + PL080_CH_DST_ADDR);
 480
 481         return 0;
 482 }
 483 EXPORT_SYMBOL(s3c2410_dma_getposition);
 484
 485 /* s3c2410_request_dma
 486  *
 487  * get control of an dma channel
 488 */
 489
 490 int s3c2410_dma_request(enum dma_ch channel,
 491                         struct s3c2410_dma_client *client,
 492                         void *dev)
 493 {
 494         struct s3c2410_dma_chan *chan;
 495         unsigned long flags;
 496
 497         pr_debug("dma%d: s3c2410_request_dma: client=%s, dev=%p\n",
 498                  channel, client->name, dev);
 499
 500         local_irq_save(flags);
 501
 502         chan = s3c64xx_dma_map_channel(channel);
 503         if (chan == NULL) {
 504                 local_irq_restore(flags);
 505                 return -EBUSY;
 506         }
 507
 508         dbg_showchan(chan);
 509
 510         chan->client = client;
 511         chan->in_use = 1;
 512         chan->peripheral = channel;
 513
 514         local_irq_restore(flags);
 515
 516         /* need to setup */
 517
 518         pr_debug("%s: channel initialised, %p\n", __func__, chan);
 519
 520         return chan->number | DMACH_LOW_LEVEL;
 521 }
 522
 523 EXPORT_SYMBOL(s3c2410_dma_request);
 524
 525 /* s3c2410_dma_free
 526  *
 527  * release the given channel back to the system, will stop and flush
 528  * any outstanding transfers, and ensure the channel is ready for the
 529  * next claimant.
 530  *
 531  * Note, although a warning is currently printed if the freeing client
 532  * info is not the same as the registrant's client info, the free is still
 533  * allowed to go through.
 534 */
 535
 536 int s3c2410_dma_free(enum dma_ch channel, struct s3c2410_dma_client *client)
 537 {
 538         struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
 539         unsigned long flags;
 540
 541         if (chan == NULL)
 542                 return -EINVAL;
 543
 544         local_irq_save(flags);
 545
 546         if (chan->client != client) {
 547                 printk(KERN_WARNING "dma%d: possible free from different client (channel %p, passed %p)\n",
 548                        channel, chan->client, client);
 549         }
 550
 551         /* sort out stopping and freeing the channel */
 552
 553
 554         chan->client = NULL;
 555         chan->in_use = 0;
 556
 557         if (!(channel & DMACH_LOW_LEVEL))
 558                 s3c_dma_chan_map[channel] = NULL;
 559
 560         local_irq_restore(flags);
 561
 562         return 0;
 563 }
 564
 565 EXPORT_SYMBOL(s3c2410_dma_free);
 566
 567 static irqreturn_t s3c64xx_dma_irq(int irq, void *pw)
 568 {
 569         struct s3c64xx_dmac *dmac = pw;
 570         struct s3c2410_dma_chan *chan;
 571         enum s3c2410_dma_buffresult res;
 572         u32 tcstat, errstat;
 573         u32 bit;
 574         int offs;
 575
 576         tcstat = readl(dmac->regs + PL080_TC_STATUS);
 577         errstat = readl(dmac->regs + PL080_ERR_STATUS);
 578
 579         for (offs = 0, bit = 1; offs < 8; offs++, bit <<= 1) {
 580                 struct s3c64xx_dma_buff *buff;
 581
 582                 if (!(errstat & bit) && !(tcstat & bit))
 583                         continue;
 584
 585                 chan = dmac->channels + offs;
 586                 res = S3C2410_RES_ERR;
 587
 588                 if (tcstat & bit) {
 589                         writel(bit, dmac->regs + PL080_TC_CLEAR);
 590                         res = S3C2410_RES_OK;
 591                 }
 592
 593                 if (errstat & bit)
 594                         writel(bit, dmac->regs + PL080_ERR_CLEAR);
 595
 596                 /* 'next' points to the buffer that is next to the
 597                  * currently active buffer.
 598                  * For CIRCULAR queues, 'next' will be same as 'curr'
 599                  * when 'end' is the active buffer.
 600                  */
 601                 buff = chan->curr;
 602                 while (buff && buff != chan->next
 603                                 && buff->next != chan->next)
 604                         buff = buff->next;
 605
 606                 if (!buff)
 607                         BUG();
 608
 609                 if (buff == chan->next)
 610                         buff = chan->end;
 611
 612                 s3c64xx_dma_bufffdone(chan, buff, res);
 613
 614                 /* Free the node and update curr, if non-circular queue */
 615                 if (!(chan->flags & S3C2410_DMAF_CIRCULAR)) {
 616                         chan->curr = buff->next;
 617                         s3c64xx_dma_freebuff(buff);
 618                 }
 619
 620                 /* Update 'next' */
 621                 buff = chan->next;
 622                 if (chan->next == chan->end) {
 623                         chan->next = chan->curr;
 624                         if (!(chan->flags & S3C2410_DMAF_CIRCULAR))
 625                                 chan->end = NULL;
 626                 } else {
 627                         chan->next = buff->next;
 628                 }
 629         }
 630
 631         return IRQ_HANDLED;
 632 }
 633
 634 static struct sysdev_class dma_sysclass = {
 635         .name           = "s3c64xx-dma",
 636 };
 637
 638 static int s3c64xx_dma_init1(int chno, enum dma_ch chbase,
 639                              int irq, unsigned int base)
 640 {
 641         struct s3c2410_dma_chan *chptr = &s3c2410_chans[chno];
 642         struct s3c64xx_dmac *dmac;
 643         char clkname[16];
 644         void __iomem *regs;
 645         void __iomem *regptr;
 646         int err, ch;
 647
 648         dmac = kzalloc(sizeof(struct s3c64xx_dmac), GFP_KERNEL);
 649         if (!dmac) {
 650                 printk(KERN_ERR "%s: failed to alloc mem\n", __func__);
 651                 return -ENOMEM;
 652         }
 653
 654         dmac->sysdev.id = chno / 8;
 655         dmac->sysdev.cls = &dma_sysclass;
 656
 657         err = sysdev_register(&dmac->sysdev);
 658         if (err) {
 659                 printk(KERN_ERR "%s: failed to register sysdevice\n", __func__);
 660                 goto err_alloc;
 661         }
 662
 663         regs = ioremap(base, 0x200);
 664         if (!regs) {
 665                 printk(KERN_ERR "%s: failed to ioremap()\n", __func__);
 666                 err = -ENXIO;
 667                 goto err_dev;
 668         }
 669
 670         snprintf(clkname, sizeof(clkname), "dma%d", dmac->sysdev.id);
 671
 672         dmac->clk = clk_get(NULL, clkname);
 673         if (IS_ERR(dmac->clk)) {
 674                 printk(KERN_ERR "%s: failed to get clock %s\n", __func__, clkname);
 675                 err = PTR_ERR(dmac->clk);
 676                 goto err_map;
 677         }
 678
 679         clk_enable(dmac->clk);
 680
 681         dmac->regs = regs;
 682         dmac->chanbase = chbase;
 683         dmac->channels = chptr;
 684
 685         err = request_irq(irq, s3c64xx_dma_irq, 0, "DMA", dmac);
 686         if (err < 0) {
 687                 printk(KERN_ERR "%s: failed to get irq\n", __func__);
 688                 goto err_clk;
 689         }
 690
 691         regptr = regs + PL080_Cx_BASE(0);
 692
 693         for (ch = 0; ch < 8; ch++, chptr++) {
 694                 pr_debug("%s: registering DMA %d (%p)\n",
 695                          __func__, chno + ch, regptr);
 696
 697                 chptr->bit = 1 << ch;
 698                 chptr->number = chno + ch;
 699                 chptr->dmac = dmac;
 700                 chptr->regs = regptr;
 701                 regptr += PL080_Cx_STRIDE;
 702         }
 703
 704         /* for the moment, permanently enable the controller */
 705         writel(PL080_CONFIG_ENABLE, regs + PL080_CONFIG);
 706
 707         printk(KERN_INFO "PL080: IRQ %d, at %p, channels %d..%d\n",
 708                irq, regs, chno, chno+8);
 709
 710         return 0;
 711
 712 err_clk:
 713         clk_disable(dmac->clk);
 714         clk_put(dmac->clk);
 715 err_map:
 716         iounmap(regs);
 717 err_dev:
 718         sysdev_unregister(&dmac->sysdev);
 719 err_alloc:
 720         kfree(dmac);
 721         return err;
 722 }
 723
 724 static int __init s3c64xx_dma_init(void)
 725 {
 726         int ret;
 727
 728         printk(KERN_INFO "%s: Registering DMA channels\n", __func__);
 729
 730         dma_pool = dma_pool_create("DMA-LLI", NULL, sizeof(struct pl080s_lli), 16, 0);
 731         if (!dma_pool) {
 732                 printk(KERN_ERR "%s: failed to create pool\n", __func__);
 733                 return -ENOMEM;
 734         }
 735
 736         ret = sysdev_class_register(&dma_sysclass);
 737         if (ret) {
 738                 printk(KERN_ERR "%s: failed to create sysclass\n", __func__);
 739                 return -ENOMEM;
 740         }
 741
 742         /* Set all DMA configuration to be DMA, not SDMA */
 743         writel(0xffffff, S3C64XX_SDMA_SEL);
 744
 745         /* Register standard DMA controllers */
 746         s3c64xx_dma_init1(0, DMACH_UART0, IRQ_DMA0, 0x75000000);
 747         s3c64xx_dma_init1(8, DMACH_PCM1_TX, IRQ_DMA1, 0x75100000);
 748
 749         return 0;
 750 }
 751
 752 arch_initcall(s3c64xx_dma_init);