arch/powerpc/platforms/pasemi/dma_lib.c

   1 /*
   2  * Copyright (C) 2006-2007 PA Semi, Inc
   3  *
   4  * Common functions for DMA access on PA Semi PWRficient
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  18  */
  19
  20 #include <linux/kernel.h>
  21 #include <linux/init.h>
  22 #include <linux/module.h>
  23 #include <linux/pci.h>
  24 #include <linux/of.h>
  25
  26 #include <asm/pasemi_dma.h>
  27
  28 #define MAX_TXCH 64
  29 #define MAX_RXCH 64
  30 #define MAX_FLAGS 64
  31 #define MAX_FUN 8
  32
  33 static struct pasdma_status *dma_status;
  34
  35 static void __iomem *iob_regs;
  36 static void __iomem *mac_regs[6];
  37 static void __iomem *dma_regs;
  38
  39 static int base_hw_irq;
  40
  41 static int num_txch, num_rxch;
  42
  43 static struct pci_dev *dma_pdev;
  44
  45 /* Bitmaps to handle allocation of channels */
  46
  47 static DECLARE_BITMAP(txch_free, MAX_TXCH);
  48 static DECLARE_BITMAP(rxch_free, MAX_RXCH);
  49 static DECLARE_BITMAP(flags_free, MAX_FLAGS);
  50 static DECLARE_BITMAP(fun_free, MAX_FUN);
  51
  52 /* pasemi_read_iob_reg - read IOB register
  53  * @reg: Register to read (offset into PCI CFG space)
  54  */
  55 unsigned int pasemi_read_iob_reg(unsigned int reg)
  56 {
  57         return in_le32(iob_regs+reg);
  58 }
  59 EXPORT_SYMBOL(pasemi_read_iob_reg);
  60
  61 /* pasemi_write_iob_reg - write IOB register
  62  * @reg: Register to write to (offset into PCI CFG space)
  63  * @val: Value to write
  64  */
  65 void pasemi_write_iob_reg(unsigned int reg, unsigned int val)
  66 {
  67         out_le32(iob_regs+reg, val);
  68 }
  69 EXPORT_SYMBOL(pasemi_write_iob_reg);
  70
  71 /* pasemi_read_mac_reg - read MAC register
  72  * @intf: MAC interface
  73  * @reg: Register to read (offset into PCI CFG space)
  74  */
  75 unsigned int pasemi_read_mac_reg(int intf, unsigned int reg)
  76 {
  77         return in_le32(mac_regs[intf]+reg);
  78 }
  79 EXPORT_SYMBOL(pasemi_read_mac_reg);
  80
  81 /* pasemi_write_mac_reg - write MAC register
  82  * @intf: MAC interface
  83  * @reg: Register to write to (offset into PCI CFG space)
  84  * @val: Value to write
  85  */
  86 void pasemi_write_mac_reg(int intf, unsigned int reg, unsigned int val)
  87 {
  88         out_le32(mac_regs[intf]+reg, val);
  89 }
  90 EXPORT_SYMBOL(pasemi_write_mac_reg);
  91
  92 /* pasemi_read_dma_reg - read DMA register
  93  * @reg: Register to read (offset into PCI CFG space)
  94  */
  95 unsigned int pasemi_read_dma_reg(unsigned int reg)
  96 {
  97         return in_le32(dma_regs+reg);
  98 }
  99 EXPORT_SYMBOL(pasemi_read_dma_reg);
 100
 101 /* pasemi_write_dma_reg - write DMA register
 102  * @reg: Register to write to (offset into PCI CFG space)
 103  * @val: Value to write
 104  */
 105 void pasemi_write_dma_reg(unsigned int reg, unsigned int val)
 106 {
 107         out_le32(dma_regs+reg, val);
 108 }
 109 EXPORT_SYMBOL(pasemi_write_dma_reg);
 110
 111 static int pasemi_alloc_tx_chan(enum pasemi_dmachan_type type)
 112 {
 113         int bit;
 114         int start, limit;
 115
 116         switch (type & (TXCHAN_EVT0|TXCHAN_EVT1)) {
 117         case TXCHAN_EVT0:
 118                 start = 0;
 119                 limit = 10;
 120                 break;
 121         case TXCHAN_EVT1:
 122                 start = 10;
 123                 limit = MAX_TXCH;
 124                 break;
 125         default:
 126                 start = 0;
 127                 limit = MAX_TXCH;
 128                 break;
 129         }
 130 retry:
 131         bit = find_next_bit(txch_free, MAX_TXCH, start);
 132         if (bit >= limit)
 133                 return -ENOSPC;
 134         if (!test_and_clear_bit(bit, txch_free))
 135                 goto retry;
 136
 137         return bit;
 138 }
 139
 140 static void pasemi_free_tx_chan(int chan)
 141 {
 142         BUG_ON(test_bit(chan, txch_free));
 143         set_bit(chan, txch_free);
 144 }
 145
 146 static int pasemi_alloc_rx_chan(void)
 147 {
 148         int bit;
 149 retry:
 150         bit = find_first_bit(rxch_free, MAX_RXCH);
 151         if (bit >= MAX_TXCH)
 152                 return -ENOSPC;
 153         if (!test_and_clear_bit(bit, rxch_free))
 154                 goto retry;
 155
 156         return bit;
 157 }
 158
 159 static void pasemi_free_rx_chan(int chan)
 160 {
 161         BUG_ON(test_bit(chan, rxch_free));
 162         set_bit(chan, rxch_free);
 163 }
 164
 165 /* pasemi_dma_alloc_chan - Allocate a DMA channel
 166  * @type: Type of channel to allocate
 167  * @total_size: Total size of structure to allocate (to allow for more
 168  *              room behind the structure to be used by the client)
 169  * @offset: Offset in bytes from start of the total structure to the beginning
 170  *          of struct pasemi_dmachan. Needed when struct pasemi_dmachan is
 171  *          not the first member of the client structure.
 172  *
 173  * pasemi_dma_alloc_chan allocates a DMA channel for use by a client. The
 174  * type argument specifies whether it's a RX or TX channel, and in the case
 175  * of TX channels which group it needs to belong to (if any).
 176  *
 177  * Returns a pointer to the total structure allocated on success, NULL
 178  * on failure.
 179  */
 180 void *pasemi_dma_alloc_chan(enum pasemi_dmachan_type type,
 181                             int total_size, int offset)
 182 {
 183         void *buf;
 184         struct pasemi_dmachan *chan;
 185         int chno;
 186
 187         BUG_ON(total_size < sizeof(struct pasemi_dmachan));
 188
 189         buf = kzalloc(total_size, GFP_KERNEL);
 190
 191         if (!buf)
 192                 return NULL;
 193         chan = buf + offset;
 194
 195         chan->priv = buf;
 196
 197         switch (type & (TXCHAN|RXCHAN)) {
 198         case RXCHAN:
 199                 chno = pasemi_alloc_rx_chan();
 200                 chan->chno = chno;
 201                 chan->irq = irq_create_mapping(NULL,
 202                                                base_hw_irq + num_txch + chno);
 203                 chan->status = &dma_status->rx_sta[chno];
 204                 break;
 205         case TXCHAN:
 206                 chno = pasemi_alloc_tx_chan(type);
 207                 chan->chno = chno;
 208                 chan->irq = irq_create_mapping(NULL, base_hw_irq + chno);
 209                 chan->status = &dma_status->tx_sta[chno];
 210                 break;
 211         }
 212
 213         chan->chan_type = type;
 214
 215         return chan;
 216 }
 217 EXPORT_SYMBOL(pasemi_dma_alloc_chan);
 218
 219 /* pasemi_dma_free_chan - Free a previously allocated channel
 220  * @chan: Channel to free
 221  *
 222  * Frees a previously allocated channel. It will also deallocate any
 223  * descriptor ring associated with the channel, if allocated.
 224  */
 225 void pasemi_dma_free_chan(struct pasemi_dmachan *chan)
 226 {
 227         if (chan->ring_virt)
 228                 pasemi_dma_free_ring(chan);
 229
 230         switch (chan->chan_type & (RXCHAN|TXCHAN)) {
 231         case RXCHAN:
 232                 pasemi_free_rx_chan(chan->chno);
 233                 break;
 234         case TXCHAN:
 235                 pasemi_free_tx_chan(chan->chno);
 236                 break;
 237         }
 238
 239         kfree(chan->priv);
 240 }
 241 EXPORT_SYMBOL(pasemi_dma_free_chan);
 242
 243 /* pasemi_dma_alloc_ring - Allocate descriptor ring for a channel
 244  * @chan: Channel for which to allocate
 245  * @ring_size: Ring size in 64-bit (8-byte) words
 246  *
 247  * Allocate a descriptor ring for a channel. Returns 0 on success, errno
 248  * on failure. The passed in struct pasemi_dmachan is updated with the
 249  * virtual and DMA addresses of the ring.
 250  */
 251 int pasemi_dma_alloc_ring(struct pasemi_dmachan *chan, int ring_size)
 252 {
 253         BUG_ON(chan->ring_virt);
 254
 255         chan->ring_size = ring_size;
 256
 257         chan->ring_virt = dma_alloc_coherent(&dma_pdev->dev,
 258                                              ring_size * sizeof(u64),
 259                                              &chan->ring_dma, GFP_KERNEL);
 260
 261         if (!chan->ring_virt)
 262                 return -ENOMEM;
 263
 264         memset(chan->ring_virt, 0, ring_size * sizeof(u64));
 265
 266         return 0;
 267 }
 268 EXPORT_SYMBOL(pasemi_dma_alloc_ring);
 269
 270 /* pasemi_dma_free_ring - Free an allocated descriptor ring for a channel
 271  * @chan: Channel for which to free the descriptor ring
 272  *
 273  * Frees a previously allocated descriptor ring for a channel.
 274  */
 275 void pasemi_dma_free_ring(struct pasemi_dmachan *chan)
 276 {
 277         BUG_ON(!chan->ring_virt);
 278
 279         dma_free_coherent(&dma_pdev->dev, chan->ring_size * sizeof(u64),
 280                           chan->ring_virt, chan->ring_dma);
 281         chan->ring_virt = NULL;
 282         chan->ring_size = 0;
 283         chan->ring_dma = 0;
 284 }
 285 EXPORT_SYMBOL(pasemi_dma_free_ring);
 286
 287 /* pasemi_dma_start_chan - Start a DMA channel
 288  * @chan: Channel to start
 289  * @cmdsta: Additional CCMDSTA/TCMDSTA bits to write
 290  *
 291  * Enables (starts) a DMA channel with optional additional arguments.
 292  */
 293 void pasemi_dma_start_chan(const struct pasemi_dmachan *chan, const u32 cmdsta)
 294 {
 295         if (chan->chan_type == RXCHAN)
 296                 pasemi_write_dma_reg(PAS_DMA_RXCHAN_CCMDSTA(chan->chno),
 297                                      cmdsta | PAS_DMA_RXCHAN_CCMDSTA_EN);
 298         else
 299                 pasemi_write_dma_reg(PAS_DMA_TXCHAN_TCMDSTA(chan->chno),
 300                                      cmdsta | PAS_DMA_TXCHAN_TCMDSTA_EN);
 301 }
 302 EXPORT_SYMBOL(pasemi_dma_start_chan);
 303
 304 /* pasemi_dma_stop_chan - Stop a DMA channel
 305  * @chan: Channel to stop
 306  *
 307  * Stops (disables) a DMA channel. This is done by setting the ST bit in the
 308  * CMDSTA register and waiting on the ACT (active) bit to clear, then
 309  * finally disabling the whole channel.
 310  *
 311  * This function will only try for a short while for the channel to stop, if
 312  * it doesn't it will return failure.
 313  *
 314  * Returns 1 on success, 0 on failure.
 315  */
 316 #define MAX_RETRIES 5000
 317 int pasemi_dma_stop_chan(const struct pasemi_dmachan *chan)
 318 {
 319         int reg, retries;
 320         u32 sta;
 321
 322         if (chan->chan_type == RXCHAN) {
 323                 reg = PAS_DMA_RXCHAN_CCMDSTA(chan->chno);
 324                 pasemi_write_dma_reg(reg, PAS_DMA_RXCHAN_CCMDSTA_ST);
 325                 for (retries = 0; retries < MAX_RETRIES; retries++) {
 326                         sta = pasemi_read_dma_reg(reg);
 327                         if (!(sta & PAS_DMA_RXCHAN_CCMDSTA_ACT)) {
 328                                 pasemi_write_dma_reg(reg, 0);
 329                                 return 1;
 330                         }
 331                         cond_resched();
 332                 }
 333         } else {
 334                 reg = PAS_DMA_TXCHAN_TCMDSTA(chan->chno);
 335                 pasemi_write_dma_reg(reg, PAS_DMA_TXCHAN_TCMDSTA_ST);
 336                 for (retries = 0; retries < MAX_RETRIES; retries++) {
 337                         sta = pasemi_read_dma_reg(reg);
 338                         if (!(sta & PAS_DMA_TXCHAN_TCMDSTA_ACT)) {
 339                                 pasemi_write_dma_reg(reg, 0);
 340                                 return 1;
 341                         }
 342                         cond_resched();
 343                 }
 344         }
 345
 346         return 0;
 347 }
 348 EXPORT_SYMBOL(pasemi_dma_stop_chan);
 349
 350 /* pasemi_dma_alloc_buf - Allocate a buffer to use for DMA
 351  * @chan: Channel to allocate for
 352  * @size: Size of buffer in bytes
 353  * @handle: DMA handle
 354  *
 355  * Allocate a buffer to be used by the DMA engine for read/write,
 356  * similar to dma_alloc_coherent().
 357  *
 358  * Returns the virtual address of the buffer, or NULL in case of failure.
 359  */
 360 void *pasemi_dma_alloc_buf(struct pasemi_dmachan *chan, int size,
 361                            dma_addr_t *handle)
 362 {
 363         return dma_alloc_coherent(&dma_pdev->dev, size, handle, GFP_KERNEL);
 364 }
 365 EXPORT_SYMBOL(pasemi_dma_alloc_buf);
 366
 367 /* pasemi_dma_free_buf - Free a buffer used for DMA
 368  * @chan: Channel the buffer was allocated for
 369  * @size: Size of buffer in bytes
 370  * @handle: DMA handle
 371  *
 372  * Frees a previously allocated buffer.
 373  */
 374 void pasemi_dma_free_buf(struct pasemi_dmachan *chan, int size,
 375                          dma_addr_t *handle)
 376 {
 377         dma_free_coherent(&dma_pdev->dev, size, handle, GFP_KERNEL);
 378 }
 379 EXPORT_SYMBOL(pasemi_dma_free_buf);
 380
 381 /* pasemi_dma_alloc_flag - Allocate a flag (event) for channel syncronization
 382  *
 383  * Allocates a flag for use with channel syncronization (event descriptors).
 384  * Returns allocated flag (0-63), < 0 on error.
 385  */
 386 int pasemi_dma_alloc_flag(void)
 387 {
 388         int bit;
 389
 390 retry:
 391         bit = find_next_bit(flags_free, MAX_FLAGS, 0);
 392         if (bit >= MAX_FLAGS)
 393                 return -ENOSPC;
 394         if (!test_and_clear_bit(bit, flags_free))
 395                 goto retry;
 396
 397         return bit;
 398 }
 399 EXPORT_SYMBOL(pasemi_dma_alloc_flag);
 400
 401
 402 /* pasemi_dma_free_flag - Deallocates a flag (event)
 403  * @flag: Flag number to deallocate
 404  *
 405  * Frees up a flag so it can be reused for other purposes.
 406  */
 407 void pasemi_dma_free_flag(int flag)
 408 {
 409         BUG_ON(test_bit(flag, flags_free));
 410         BUG_ON(flag >= MAX_FLAGS);
 411         set_bit(flag, flags_free);
 412 }
 413 EXPORT_SYMBOL(pasemi_dma_free_flag);
 414
 415
 416 /* pasemi_dma_set_flag - Sets a flag (event) to 1
 417  * @flag: Flag number to set active
 418  *
 419  * Sets the flag provided to 1.
 420  */
 421 void pasemi_dma_set_flag(int flag)
 422 {
 423         BUG_ON(flag >= MAX_FLAGS);
 424         if (flag < 32)
 425                 pasemi_write_dma_reg(PAS_DMA_TXF_SFLG0, 1 << flag);
 426         else
 427                 pasemi_write_dma_reg(PAS_DMA_TXF_SFLG1, 1 << flag);
 428 }
 429 EXPORT_SYMBOL(pasemi_dma_set_flag);
 430
 431 /* pasemi_dma_clear_flag - Sets a flag (event) to 0
 432  * @flag: Flag number to set inactive
 433  *
 434  * Sets the flag provided to 0.
 435  */
 436 void pasemi_dma_clear_flag(int flag)
 437 {
 438         BUG_ON(flag >= MAX_FLAGS);
 439         if (flag < 32)
 440                 pasemi_write_dma_reg(PAS_DMA_TXF_CFLG0, 1 << flag);
 441         else
 442                 pasemi_write_dma_reg(PAS_DMA_TXF_CFLG1, 1 << flag);
 443 }
 444 EXPORT_SYMBOL(pasemi_dma_clear_flag);
 445
 446 /* pasemi_dma_alloc_fun - Allocate a function engine
 447  *
 448  * Allocates a function engine to use for crypto/checksum offload
 449  * Returns allocated engine (0-8), < 0 on error.
 450  */
 451 int pasemi_dma_alloc_fun(void)
 452 {
 453         int bit;
 454
 455 retry:
 456         bit = find_next_bit(fun_free, MAX_FLAGS, 0);
 457         if (bit >= MAX_FLAGS)
 458                 return -ENOSPC;
 459         if (!test_and_clear_bit(bit, fun_free))
 460                 goto retry;
 461
 462         return bit;
 463 }
 464 EXPORT_SYMBOL(pasemi_dma_alloc_fun);
 465
 466
 467 /* pasemi_dma_free_fun - Deallocates a function engine
 468  * @flag: Engine number to deallocate
 469  *
 470  * Frees up a function engine so it can be used for other purposes.
 471  */
 472 void pasemi_dma_free_fun(int fun)
 473 {
 474         BUG_ON(test_bit(fun, fun_free));
 475         BUG_ON(fun >= MAX_FLAGS);
 476         set_bit(fun, fun_free);
 477 }
 478 EXPORT_SYMBOL(pasemi_dma_free_fun);
 479
 480
 481 static void *map_onedev(struct pci_dev *p, int index)
 482 {
 483         struct device_node *dn;
 484         void __iomem *ret;
 485
 486         dn = pci_device_to_OF_node(p);
 487         if (!dn)
 488                 goto fallback;
 489
 490         ret = of_iomap(dn, index);
 491         if (!ret)
 492                 goto fallback;
 493
 494         return ret;
 495 fallback:
 496         /* This is hardcoded and ugly, but we have some firmware versions
 497          * that don't provide the register space in the device tree. Luckily
 498          * they are at well-known locations so we can just do the math here.
 499          */
 500         return ioremap(0xe0000000 + (p->devfn << 12), 0x2000);
 501 }
 502
 503 /* pasemi_dma_init - Initialize the PA Semi DMA library
 504  *
 505  * This function initializes the DMA library. It must be called before
 506  * any other function in the library.
 507  *
 508  * Returns 0 on success, errno on failure.
 509  */
 510 int pasemi_dma_init(void)
 511 {
 512         static DEFINE_SPINLOCK(init_lock);
 513         struct pci_dev *iob_pdev;
 514         struct pci_dev *pdev;
 515         struct resource res;
 516         struct device_node *dn;
 517         int i, intf, err = 0;
 518         unsigned long timeout;
 519         u32 tmp;
 520
 521         if (!machine_is(pasemi))
 522                 return -ENODEV;
 523
 524         spin_lock(&init_lock);
 525
 526         /* Make sure we haven't already initialized */
 527         if (dma_pdev)
 528                 goto out;
 529
 530         iob_pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa001, NULL);
 531         if (!iob_pdev) {
 532                 BUG();
 533                 printk(KERN_WARNING "Can't find I/O Bridge\n");
 534                 err = -ENODEV;
 535                 goto out;
 536         }
 537         iob_regs = map_onedev(iob_pdev, 0);
 538
 539         dma_pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa007, NULL);
 540         if (!dma_pdev) {
 541                 BUG();
 542                 printk(KERN_WARNING "Can't find DMA controller\n");
 543                 err = -ENODEV;
 544                 goto out;
 545         }
 546         dma_regs = map_onedev(dma_pdev, 0);
 547         base_hw_irq = virq_to_hw(dma_pdev->irq);
 548
 549         pci_read_config_dword(dma_pdev, PAS_DMA_CAP_TXCH, &tmp);
 550         num_txch = (tmp & PAS_DMA_CAP_TXCH_TCHN_M) >> PAS_DMA_CAP_TXCH_TCHN_S;
 551
 552         pci_read_config_dword(dma_pdev, PAS_DMA_CAP_RXCH, &tmp);
 553         num_rxch = (tmp & PAS_DMA_CAP_RXCH_RCHN_M) >> PAS_DMA_CAP_RXCH_RCHN_S;
 554
 555         intf = 0;
 556         for (pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa006, NULL);
 557              pdev;
 558              pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa006, pdev))
 559                 mac_regs[intf++] = map_onedev(pdev, 0);
 560
 561         pci_dev_put(pdev);
 562
 563         for (pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa005, NULL);
 564              pdev;
 565              pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa005, pdev))
 566                 mac_regs[intf++] = map_onedev(pdev, 0);
 567
 568         pci_dev_put(pdev);
 569
 570         dn = pci_device_to_OF_node(iob_pdev);
 571         if (dn)
 572                 err = of_address_to_resource(dn, 1, &res);
 573         if (!dn || err) {
 574                 /* Fallback for old firmware */
 575                 res.start = 0xfd800000;
 576                 res.end = res.start + 0x1000;
 577         }
 578         dma_status = __ioremap(res.start, res.end-res.start, 0);
 579         pci_dev_put(iob_pdev);
 580
 581         for (i = 0; i < MAX_TXCH; i++)
 582                 __set_bit(i, txch_free);
 583
 584         for (i = 0; i < MAX_RXCH; i++)
 585                 __set_bit(i, rxch_free);
 586
 587         timeout = jiffies + HZ;
 588         pasemi_write_dma_reg(PAS_DMA_COM_RXCMD, 0);
 589         while (pasemi_read_dma_reg(PAS_DMA_COM_RXSTA) & 1) {
 590                 if (time_after(jiffies, timeout)) {
 591                         pr_warning("Warning: Could not disable RX section\n");
 592                         break;
 593                 }
 594         }
 595
 596         timeout = jiffies + HZ;
 597         pasemi_write_dma_reg(PAS_DMA_COM_TXCMD, 0);
 598         while (pasemi_read_dma_reg(PAS_DMA_COM_TXSTA) & 1) {
 599                 if (time_after(jiffies, timeout)) {
 600                         pr_warning("Warning: Could not disable TX section\n");
 601                         break;
 602                 }
 603         }
 604
 605         /* setup resource allocations for the different DMA sections */
 606         tmp = pasemi_read_dma_reg(PAS_DMA_COM_CFG);
 607         pasemi_write_dma_reg(PAS_DMA_COM_CFG, tmp | 0x18000000);
 608
 609         /* enable tx section */
 610         pasemi_write_dma_reg(PAS_DMA_COM_TXCMD, PAS_DMA_COM_TXCMD_EN);
 611
 612         /* enable rx section */
 613         pasemi_write_dma_reg(PAS_DMA_COM_RXCMD, PAS_DMA_COM_RXCMD_EN);
 614
 615         for (i = 0; i < MAX_FLAGS; i++)
 616                 __set_bit(i, flags_free);
 617
 618         for (i = 0; i < MAX_FUN; i++)
 619                 __set_bit(i, fun_free);
 620
 621         /* clear all status flags */
 622         pasemi_write_dma_reg(PAS_DMA_TXF_CFLG0, 0xffffffff);
 623         pasemi_write_dma_reg(PAS_DMA_TXF_CFLG1, 0xffffffff);
 624
 625         printk(KERN_INFO "PA Semi PWRficient DMA library initialized "
 626                 "(%d tx, %d rx channels)\n", num_txch, num_rxch);
 627
 628 out:
 629         spin_unlock(&init_lock);
 630         return err;
 631 }
 632 EXPORT_SYMBOL(pasemi_dma_init);