arch/arm/plat-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/delay.h>
  22 #include <linux/clk.h>
  23 #include <linux/err.h>
  24 #include <linux/io.h>
  25
  26 #include <mach/dma.h>
  27 #include <mach/map.h>
  28 #include <mach/irqs.h>
  29
  30 #include <plat/dma-plat.h>
  31 #include <plat/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(unsigned int 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 |= (u32)chan->hw_width << PL080_CONTROL_SWIDTH_SHIFT;
 155                 control0 |= 2 << PL080_CONTROL_DWIDTH_SHIFT;
 156                 control0 |= PL080_CONTROL_DST_INCR;
 157                 break;
 158
 159         case S3C2410_DMASRC_MEM:
 160                 src = data;
 161                 dst = chan->dev_addr;
 162                 control0 = PL080_CONTROL_DST_AHB2;
 163                 control0 |= (u32)chan->hw_width << PL080_CONTROL_DWIDTH_SHIFT;
 164                 control0 |= 2 << PL080_CONTROL_SWIDTH_SHIFT;
 165                 control0 |= PL080_CONTROL_SRC_INCR;
 166                 break;
 167         default:
 168                 BUG();
 169         }
 170
 171         /* note, we do not currently setup any of the burst controls */
 172
 173         control1 = size >> chan->hw_width;      /* size in no of xfers */
 174         control0 |= PL080_CONTROL_PROT_SYS;     /* always in priv. mode */
 175         control0 |= PL080_CONTROL_TC_IRQ_EN;    /* always fire IRQ */
 176
 177         lli->src_addr = src;
 178         lli->dst_addr = dst;
 179         lli->next_lli = 0;
 180         lli->control0 = control0;
 181         lli->control1 = control1;
 182 }
 183
 184 static void s3c64xx_lli_to_regs(struct s3c2410_dma_chan *chan,
 185                                 struct pl080s_lli *lli)
 186 {
 187         void __iomem *regs = chan->regs;
 188
 189         pr_debug("%s: LLI %p => regs\n", __func__, lli);
 190         show_lli(lli);
 191
 192         writel(lli->src_addr, regs + PL080_CH_SRC_ADDR);
 193         writel(lli->dst_addr, regs + PL080_CH_DST_ADDR);
 194         writel(lli->next_lli, regs + PL080_CH_LLI);
 195         writel(lli->control0, regs + PL080_CH_CONTROL);
 196         writel(lli->control1, regs + PL080S_CH_CONTROL2);
 197 }
 198
 199 static int s3c64xx_dma_start(struct s3c2410_dma_chan *chan)
 200 {
 201         struct s3c64xx_dmac *dmac = chan->dmac;
 202         u32 config;
 203         u32 bit = chan->bit;
 204
 205         dbg_showchan(chan);
 206
 207         pr_debug("%s: clearing interrupts\n", __func__);
 208
 209         /* clear interrupts */
 210         writel(bit, dmac->regs + PL080_TC_CLEAR);
 211         writel(bit, dmac->regs + PL080_ERR_CLEAR);
 212
 213         pr_debug("%s: starting channel\n", __func__);
 214
 215         config = readl(chan->regs + PL080S_CH_CONFIG);
 216         config |= PL080_CONFIG_ENABLE;
 217
 218         pr_debug("%s: writing config %08x\n", __func__, config);
 219         writel(config, chan->regs + PL080S_CH_CONFIG);
 220
 221         return 0;
 222 }
 223
 224 static int s3c64xx_dma_stop(struct s3c2410_dma_chan *chan)
 225 {
 226         u32 config;
 227         int timeout;
 228
 229         pr_debug("%s: stopping channel\n", __func__);
 230
 231         dbg_showchan(chan);
 232
 233         config = readl(chan->regs + PL080S_CH_CONFIG);
 234         config |= PL080_CONFIG_HALT;
 235         writel(config, chan->regs + PL080S_CH_CONFIG);
 236
 237         timeout = 1000;
 238         do {
 239                 config = readl(chan->regs + PL080S_CH_CONFIG);
 240                 pr_debug("%s: %d - config %08x\n", __func__, timeout, config);
 241                 if (config & PL080_CONFIG_ACTIVE)
 242                         udelay(10);
 243                 else
 244                         break;
 245                 } while (--timeout > 0);
 246
 247         if (config & PL080_CONFIG_ACTIVE) {
 248                 printk(KERN_ERR "%s: channel still active\n", __func__);
 249                 return -EFAULT;
 250         }
 251
 252         config = readl(chan->regs + PL080S_CH_CONFIG);
 253         config &= ~PL080_CONFIG_ENABLE;
 254         writel(config, chan->regs + PL080S_CH_CONFIG);
 255
 256         return 0;
 257 }
 258
 259 static inline void s3c64xx_dma_bufffdone(struct s3c2410_dma_chan *chan,
 260                                          struct s3c64xx_dma_buff *buf,
 261                                          enum s3c2410_dma_buffresult result)
 262 {
 263         if (chan->callback_fn != NULL)
 264                 (chan->callback_fn)(chan, buf->pw, 0, result);
 265 }
 266
 267 static void s3c64xx_dma_freebuff(struct s3c64xx_dma_buff *buff)
 268 {
 269         dma_pool_free(dma_pool, buff->lli, buff->lli_dma);
 270         kfree(buff);
 271 }
 272
 273 static int s3c64xx_dma_flush(struct s3c2410_dma_chan *chan)
 274 {
 275         struct s3c64xx_dma_buff *buff, *next;
 276         u32 config;
 277
 278         dbg_showchan(chan);
 279
 280         pr_debug("%s: flushing channel\n", __func__);
 281
 282         config = readl(chan->regs + PL080S_CH_CONFIG);
 283         config &= ~PL080_CONFIG_ENABLE;
 284         writel(config, chan->regs + PL080S_CH_CONFIG);
 285
 286         /* dump all the buffers associated with this channel */
 287
 288         for (buff = chan->curr; buff != NULL; buff = next) {
 289                 next = buff->next;
 290                 pr_debug("%s: buff %p (next %p)\n", __func__, buff, buff->next);
 291
 292                 s3c64xx_dma_bufffdone(chan, buff, S3C2410_RES_ABORT);
 293                 s3c64xx_dma_freebuff(buff);
 294         }
 295
 296         chan->curr = chan->next = chan->end = NULL;
 297
 298         return 0;
 299 }
 300
 301 int s3c2410_dma_ctrl(unsigned int channel, enum s3c2410_chan_op op)
 302 {
 303         struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
 304
 305         WARN_ON(!chan);
 306         if (!chan)
 307                 return -EINVAL;
 308
 309         switch (op) {
 310         case S3C2410_DMAOP_START:
 311                 return s3c64xx_dma_start(chan);
 312
 313         case S3C2410_DMAOP_STOP:
 314                 return s3c64xx_dma_stop(chan);
 315
 316         case S3C2410_DMAOP_FLUSH:
 317                 return s3c64xx_dma_flush(chan);
 318
 319         /* belive PAUSE/RESUME are no-ops */
 320         case S3C2410_DMAOP_PAUSE:
 321         case S3C2410_DMAOP_RESUME:
 322         case S3C2410_DMAOP_STARTED:
 323         case S3C2410_DMAOP_TIMEOUT:
 324                 return 0;
 325         }
 326
 327         return -ENOENT;
 328 }
 329 EXPORT_SYMBOL(s3c2410_dma_ctrl);
 330
 331 /* s3c2410_dma_enque
 332  *
 333  */
 334
 335 int s3c2410_dma_enqueue(unsigned int channel, void *id,
 336                         dma_addr_t data, int size)
 337 {
 338         struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
 339         struct s3c64xx_dma_buff *next;
 340         struct s3c64xx_dma_buff *buff;
 341         struct pl080s_lli *lli;
 342         int ret;
 343
 344         WARN_ON(!chan);
 345         if (!chan)
 346                 return -EINVAL;
 347
 348         buff = kzalloc(sizeof(struct s3c64xx_dma_buff), GFP_KERNEL);
 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_KERNEL, &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         if ((next = chan->next) != NULL) {
 370                 struct s3c64xx_dma_buff *end = chan->end;
 371                 struct pl080s_lli *endlli = end->lli;
 372
 373                 pr_debug("enquing onto channel\n");
 374
 375                 end->next = buff;
 376                 endlli->next_lli = buff->lli_dma;
 377
 378                 if (chan->flags & S3C2410_DMAF_CIRCULAR) {
 379                         struct s3c64xx_dma_buff *curr = chan->curr;
 380                         lli->next_lli = curr->lli_dma;
 381                 }
 382
 383                 if (next == chan->curr) {
 384                         writel(buff->lli_dma, chan->regs + PL080_CH_LLI);
 385                         chan->next = buff;
 386                 }
 387
 388                 show_lli(endlli);
 389                 chan->end = buff;
 390         } else {
 391                 pr_debug("enquing onto empty channel\n");
 392
 393                 chan->curr = buff;
 394                 chan->next = buff;
 395                 chan->end = buff;
 396
 397                 s3c64xx_lli_to_regs(chan, lli);
 398         }
 399
 400         show_lli(lli);
 401
 402         dbg_showchan(chan);
 403         dbg_showbuffs(chan);
 404         return 0;
 405
 406 err_buff:
 407         kfree(buff);
 408         return ret;
 409 }
 410
 411 EXPORT_SYMBOL(s3c2410_dma_enqueue);
 412
 413
 414 int s3c2410_dma_devconfig(int channel,
 415                           enum s3c2410_dmasrc source,
 416                           unsigned long devaddr)
 417 {
 418         struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
 419         u32 peripheral;
 420         u32 config = 0;
 421
 422         pr_debug("%s: channel %d, source %d, dev %08lx, chan %p\n",
 423                  __func__, channel, source, devaddr, chan);
 424
 425         WARN_ON(!chan);
 426         if (!chan)
 427                 return -EINVAL;
 428
 429         peripheral = (chan->peripheral & 0xf);
 430         chan->source = source;
 431         chan->dev_addr = devaddr;
 432
 433         pr_debug("%s: peripheral %d\n", __func__, peripheral);
 434
 435         switch (source) {
 436         case S3C2410_DMASRC_HW:
 437                 config = 2 << PL080_CONFIG_FLOW_CONTROL_SHIFT;
 438                 config |= peripheral << PL080_CONFIG_SRC_SEL_SHIFT;
 439                 break;
 440         case S3C2410_DMASRC_MEM:
 441                 config = 1 << PL080_CONFIG_FLOW_CONTROL_SHIFT;
 442                 config |= peripheral << PL080_CONFIG_DST_SEL_SHIFT;
 443                 break;
 444         default:
 445                 printk(KERN_ERR "%s: bad source\n", __func__);
 446                 return -EINVAL;
 447         }
 448
 449         /* allow TC and ERR interrupts */
 450         config |= PL080_CONFIG_TC_IRQ_MASK;
 451         config |= PL080_CONFIG_ERR_IRQ_MASK;
 452
 453         pr_debug("%s: config %08x\n", __func__, config);
 454
 455         writel(config, chan->regs + PL080S_CH_CONFIG);
 456
 457         return 0;
 458 }
 459 EXPORT_SYMBOL(s3c2410_dma_devconfig);
 460
 461
 462 int s3c2410_dma_getposition(unsigned int channel,
 463                             dma_addr_t *src, dma_addr_t *dst)
 464 {
 465         struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
 466
 467         WARN_ON(!chan);
 468         if (!chan)
 469                 return -EINVAL;
 470
 471         if (src != NULL)
 472                 *src = readl(chan->regs + PL080_CH_SRC_ADDR);
 473
 474         if (dst != NULL)
 475                 *dst = readl(chan->regs + PL080_CH_DST_ADDR);
 476
 477         return 0;
 478 }
 479 EXPORT_SYMBOL(s3c2410_dma_getposition);
 480
 481 /* s3c2410_request_dma
 482  *
 483  * get control of an dma channel
 484 */
 485
 486 int s3c2410_dma_request(unsigned int channel,
 487                         struct s3c2410_dma_client *client,
 488                         void *dev)
 489 {
 490         struct s3c2410_dma_chan *chan;
 491         unsigned long flags;
 492
 493         pr_debug("dma%d: s3c2410_request_dma: client=%s, dev=%p\n",
 494                  channel, client->name, dev);
 495
 496         local_irq_save(flags);
 497
 498         chan = s3c64xx_dma_map_channel(channel);
 499         if (chan == NULL) {
 500                 local_irq_restore(flags);
 501                 return -EBUSY;
 502         }
 503
 504         dbg_showchan(chan);
 505
 506         chan->client = client;
 507         chan->in_use = 1;
 508         chan->peripheral = channel;
 509
 510         local_irq_restore(flags);
 511
 512         /* need to setup */
 513
 514         pr_debug("%s: channel initialised, %p\n", __func__, chan);
 515
 516         return chan->number | DMACH_LOW_LEVEL;
 517 }
 518
 519 EXPORT_SYMBOL(s3c2410_dma_request);
 520
 521 /* s3c2410_dma_free
 522  *
 523  * release the given channel back to the system, will stop and flush
 524  * any outstanding transfers, and ensure the channel is ready for the
 525  * next claimant.
 526  *
 527  * Note, although a warning is currently printed if the freeing client
 528  * info is not the same as the registrant's client info, the free is still
 529  * allowed to go through.
 530 */
 531
 532 int s3c2410_dma_free(unsigned int channel, struct s3c2410_dma_client *client)
 533 {
 534         struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
 535         unsigned long flags;
 536
 537         if (chan == NULL)
 538                 return -EINVAL;
 539
 540         local_irq_save(flags);
 541
 542         if (chan->client != client) {
 543                 printk(KERN_WARNING "dma%d: possible free from different client (channel %p, passed %p)\n",
 544                        channel, chan->client, client);
 545         }
 546
 547         /* sort out stopping and freeing the channel */
 548
 549
 550         chan->client = NULL;
 551         chan->in_use = 0;
 552
 553         if (!(channel & DMACH_LOW_LEVEL))
 554                 s3c_dma_chan_map[channel] = NULL;
 555
 556         local_irq_restore(flags);
 557
 558         return 0;
 559 }
 560
 561 EXPORT_SYMBOL(s3c2410_dma_free);
 562
 563
 564 static void s3c64xx_dma_tcirq(struct s3c64xx_dmac *dmac, int offs)
 565 {
 566         struct s3c2410_dma_chan *chan = dmac->channels + offs;
 567
 568         /* note, we currently do not bother to work out which buffer
 569          * or buffers have been completed since the last tc-irq. */
 570
 571         if (chan->callback_fn)
 572                 (chan->callback_fn)(chan, chan->curr->pw, 0, S3C2410_RES_OK);
 573 }
 574
 575 static void s3c64xx_dma_errirq(struct s3c64xx_dmac *dmac, int offs)
 576 {
 577         printk(KERN_DEBUG "%s: offs %d\n", __func__, offs);
 578 }
 579
 580 static irqreturn_t s3c64xx_dma_irq(int irq, void *pw)
 581 {
 582         struct s3c64xx_dmac *dmac = pw;
 583         u32 tcstat, errstat;
 584         u32 bit;
 585         int offs;
 586
 587         tcstat = readl(dmac->regs + PL080_TC_STATUS);
 588         errstat = readl(dmac->regs + PL080_ERR_STATUS);
 589
 590         for (offs = 0, bit = 1; offs < 8; offs++, bit <<= 1) {
 591                 if (tcstat & bit) {
 592                         writel(bit, dmac->regs + PL080_TC_CLEAR);
 593                         s3c64xx_dma_tcirq(dmac, offs);
 594                 }
 595
 596                 if (errstat & bit) {
 597                         s3c64xx_dma_errirq(dmac, offs);
 598                         writel(bit, dmac->regs + PL080_ERR_CLEAR);
 599                 }
 600         }
 601
 602         return IRQ_HANDLED;
 603 }
 604
 605 static struct sysdev_class dma_sysclass = {
 606         .name           = "s3c64xx-dma",
 607 };
 608
 609 static int s3c64xx_dma_init1(int chno, enum dma_ch chbase,
 610                              int irq, unsigned int base)
 611 {
 612         struct s3c2410_dma_chan *chptr = &s3c2410_chans[chno];
 613         struct s3c64xx_dmac *dmac;
 614         char clkname[16];
 615         void __iomem *regs;
 616         void __iomem *regptr;
 617         int err, ch;
 618
 619         dmac = kzalloc(sizeof(struct s3c64xx_dmac), GFP_KERNEL);
 620         if (!dmac) {
 621                 printk(KERN_ERR "%s: failed to alloc mem\n", __func__);
 622                 return -ENOMEM;
 623         }
 624
 625         dmac->sysdev.id = chno / 8;
 626         dmac->sysdev.cls = &dma_sysclass;
 627
 628         err = sysdev_register(&dmac->sysdev);
 629         if (err) {
 630                 printk(KERN_ERR "%s: failed to register sysdevice\n", __func__);
 631                 goto err_alloc;
 632         }
 633
 634         regs = ioremap(base, 0x200);
 635         if (!regs) {
 636                 printk(KERN_ERR "%s: failed to ioremap()\n", __func__);
 637                 err = -ENXIO;
 638                 goto err_dev;
 639         }
 640
 641         snprintf(clkname, sizeof(clkname), "dma%d", dmac->sysdev.id);
 642
 643         dmac->clk = clk_get(NULL, clkname);
 644         if (IS_ERR(dmac->clk)) {
 645                 printk(KERN_ERR "%s: failed to get clock %s\n", __func__, clkname);
 646                 err = PTR_ERR(dmac->clk);
 647                 goto err_map;
 648         }
 649
 650         clk_enable(dmac->clk);
 651
 652         dmac->regs = regs;
 653         dmac->chanbase = chbase;
 654         dmac->channels = chptr;
 655
 656         err = request_irq(irq, s3c64xx_dma_irq, 0, "DMA", dmac);
 657         if (err < 0) {
 658                 printk(KERN_ERR "%s: failed to get irq\n", __func__);
 659                 goto err_clk;
 660         }
 661
 662         regptr = regs + PL080_Cx_BASE(0);
 663
 664         for (ch = 0; ch < 8; ch++, chno++, chptr++) {
 665                 printk(KERN_INFO "%s: registering DMA %d (%p)\n",
 666                        __func__, chno, regptr);
 667
 668                 chptr->bit = 1 << ch;
 669                 chptr->number = chno;
 670                 chptr->dmac = dmac;
 671                 chptr->regs = regptr;
 672                 regptr += PL008_Cx_STRIDE;
 673         }
 674
 675         /* for the moment, permanently enable the controller */
 676         writel(PL080_CONFIG_ENABLE, regs + PL080_CONFIG);
 677
 678         printk(KERN_INFO "PL080: IRQ %d, at %p\n", irq, regs);
 679
 680         return 0;
 681
 682 err_clk:
 683         clk_disable(dmac->clk);
 684         clk_put(dmac->clk);
 685 err_map:
 686         iounmap(regs);
 687 err_dev:
 688         sysdev_unregister(&dmac->sysdev);
 689 err_alloc:
 690         kfree(dmac);
 691         return err;
 692 }
 693
 694 static int __init s3c64xx_dma_init(void)
 695 {
 696         int ret;
 697
 698         printk(KERN_INFO "%s: Registering DMA channels\n", __func__);
 699
 700         dma_pool = dma_pool_create("DMA-LLI", NULL, 32, 16, 0);
 701         if (!dma_pool) {
 702                 printk(KERN_ERR "%s: failed to create pool\n", __func__);
 703                 return -ENOMEM;
 704         }
 705
 706         ret = sysdev_class_register(&dma_sysclass);
 707         if (ret) {
 708                 printk(KERN_ERR "%s: failed to create sysclass\n", __func__);
 709                 return -ENOMEM;
 710         }
 711
 712         /* Set all DMA configuration to be DMA, not SDMA */
 713         writel(0xffffff, S3C_SYSREG(0x110));
 714
 715         /* Register standard DMA controlers */
 716         s3c64xx_dma_init1(0, DMACH_UART0, IRQ_DMA0, 0x75000000);
 717         s3c64xx_dma_init1(8, DMACH_PCM1_TX, IRQ_DMA1, 0x75100000);
 718
 719         return 0;
 720 }
 721
 722 arch_initcall(s3c64xx_dma_init);