drivers/dma/pch_dma.c

   1 /*
   2  * Topcliff PCH DMA controller driver
   3  * Copyright (c) 2010 Intel Corporation
   4  * Copyright (C) 2011 OKI SEMICONDUCTOR CO., LTD.
   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., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19
  20 #include <linux/dmaengine.h>
  21 #include <linux/dma-mapping.h>
  22 #include <linux/init.h>
  23 #include <linux/pci.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/module.h>
  26 #include <linux/pch_dma.h>
  27
  28 #define DRV_NAME "pch-dma"
  29
  30 #define DMA_CTL0_DISABLE                0x0
  31 #define DMA_CTL0_SG                     0x1
  32 #define DMA_CTL0_ONESHOT                0x2
  33 #define DMA_CTL0_MODE_MASK_BITS         0x3
  34 #define DMA_CTL0_DIR_SHIFT_BITS         2
  35 #define DMA_CTL0_BITS_PER_CH            4
  36
  37 #define DMA_CTL2_START_SHIFT_BITS       8
  38 #define DMA_CTL2_IRQ_ENABLE_MASK        ((1UL << DMA_CTL2_START_SHIFT_BITS) - 1)
  39
  40 #define DMA_STATUS_IDLE                 0x0
  41 #define DMA_STATUS_DESC_READ            0x1
  42 #define DMA_STATUS_WAIT                 0x2
  43 #define DMA_STATUS_ACCESS               0x3
  44 #define DMA_STATUS_BITS_PER_CH          2
  45 #define DMA_STATUS_MASK_BITS            0x3
  46 #define DMA_STATUS_SHIFT_BITS           16
  47 #define DMA_STATUS_IRQ(x)               (0x1 << (x))
  48 #define DMA_STATUS_ERR(x)               (0x1 << ((x) + 8))
  49
  50 #define DMA_DESC_WIDTH_SHIFT_BITS       12
  51 #define DMA_DESC_WIDTH_1_BYTE           (0x3 << DMA_DESC_WIDTH_SHIFT_BITS)
  52 #define DMA_DESC_WIDTH_2_BYTES          (0x2 << DMA_DESC_WIDTH_SHIFT_BITS)
  53 #define DMA_DESC_WIDTH_4_BYTES          (0x0 << DMA_DESC_WIDTH_SHIFT_BITS)
  54 #define DMA_DESC_MAX_COUNT_1_BYTE       0x3FF
  55 #define DMA_DESC_MAX_COUNT_2_BYTES      0x3FF
  56 #define DMA_DESC_MAX_COUNT_4_BYTES      0x7FF
  57 #define DMA_DESC_END_WITHOUT_IRQ        0x0
  58 #define DMA_DESC_END_WITH_IRQ           0x1
  59 #define DMA_DESC_FOLLOW_WITHOUT_IRQ     0x2
  60 #define DMA_DESC_FOLLOW_WITH_IRQ        0x3
  61
  62 #define MAX_CHAN_NR                     8
  63
  64 static unsigned int init_nr_desc_per_channel = 64;
  65 module_param(init_nr_desc_per_channel, uint, 0644);
  66 MODULE_PARM_DESC(init_nr_desc_per_channel,
  67                  "initial descriptors per channel (default: 64)");
  68
  69 struct pch_dma_desc_regs {
  70         u32     dev_addr;
  71         u32     mem_addr;
  72         u32     size;
  73         u32     next;
  74 };
  75
  76 struct pch_dma_regs {
  77         u32     dma_ctl0;
  78         u32     dma_ctl1;
  79         u32     dma_ctl2;
  80         u32     reserved1;
  81         u32     dma_sts0;
  82         u32     dma_sts1;
  83         u32     reserved2;
  84         u32     reserved3;
  85         struct pch_dma_desc_regs desc[MAX_CHAN_NR];
  86 };
  87
  88 struct pch_dma_desc {
  89         struct pch_dma_desc_regs regs;
  90         struct dma_async_tx_descriptor txd;
  91         struct list_head        desc_node;
  92         struct list_head        tx_list;
  93 };
  94
  95 struct pch_dma_chan {
  96         struct dma_chan         chan;
  97         void __iomem *membase;
  98         enum dma_data_direction dir;
  99         struct tasklet_struct   tasklet;
 100         unsigned long           err_status;
 101
 102         spinlock_t              lock;
 103
 104         dma_cookie_t            completed_cookie;
 105         struct list_head        active_list;
 106         struct list_head        queue;
 107         struct list_head        free_list;
 108         unsigned int            descs_allocated;
 109 };
 110
 111 #define PDC_DEV_ADDR    0x00
 112 #define PDC_MEM_ADDR    0x04
 113 #define PDC_SIZE        0x08
 114 #define PDC_NEXT        0x0C
 115
 116 #define channel_readl(pdc, name) \
 117         readl((pdc)->membase + PDC_##name)
 118 #define channel_writel(pdc, name, val) \
 119         writel((val), (pdc)->membase + PDC_##name)
 120
 121 struct pch_dma {
 122         struct dma_device       dma;
 123         void __iomem *membase;
 124         struct pci_pool         *pool;
 125         struct pch_dma_regs     regs;
 126         struct pch_dma_desc_regs ch_regs[MAX_CHAN_NR];
 127         struct pch_dma_chan     channels[MAX_CHAN_NR];
 128 };
 129
 130 #define PCH_DMA_CTL0    0x00
 131 #define PCH_DMA_CTL1    0x04
 132 #define PCH_DMA_CTL2    0x08
 133 #define PCH_DMA_STS0    0x10
 134 #define PCH_DMA_STS1    0x14
 135
 136 #define dma_readl(pd, name) \
 137         readl((pd)->membase + PCH_DMA_##name)
 138 #define dma_writel(pd, name, val) \
 139         writel((val), (pd)->membase + PCH_DMA_##name)
 140
 141 static inline struct pch_dma_desc *to_pd_desc(struct dma_async_tx_descriptor *txd)
 142 {
 143         return container_of(txd, struct pch_dma_desc, txd);
 144 }
 145
 146 static inline struct pch_dma_chan *to_pd_chan(struct dma_chan *chan)
 147 {
 148         return container_of(chan, struct pch_dma_chan, chan);
 149 }
 150
 151 static inline struct pch_dma *to_pd(struct dma_device *ddev)
 152 {
 153         return container_of(ddev, struct pch_dma, dma);
 154 }
 155
 156 static inline struct device *chan2dev(struct dma_chan *chan)
 157 {
 158         return &chan->dev->device;
 159 }
 160
 161 static inline struct device *chan2parent(struct dma_chan *chan)
 162 {
 163         return chan->dev->device.parent;
 164 }
 165
 166 static inline struct pch_dma_desc *pdc_first_active(struct pch_dma_chan *pd_chan)
 167 {
 168         return list_first_entry(&pd_chan->active_list,
 169                                 struct pch_dma_desc, desc_node);
 170 }
 171
 172 static inline struct pch_dma_desc *pdc_first_queued(struct pch_dma_chan *pd_chan)
 173 {
 174         return list_first_entry(&pd_chan->queue,
 175                                 struct pch_dma_desc, desc_node);
 176 }
 177
 178 static void pdc_enable_irq(struct dma_chan *chan, int enable)
 179 {
 180         struct pch_dma *pd = to_pd(chan->device);
 181         u32 val;
 182
 183         val = dma_readl(pd, CTL2);
 184
 185         if (enable)
 186                 val |= 0x1 << chan->chan_id;
 187         else
 188                 val &= ~(0x1 << chan->chan_id);
 189
 190         dma_writel(pd, CTL2, val);
 191
 192         dev_dbg(chan2dev(chan), "pdc_enable_irq: chan %d -> %x\n",
 193                 chan->chan_id, val);
 194 }
 195
 196 static void pdc_set_dir(struct dma_chan *chan)
 197 {
 198         struct pch_dma_chan *pd_chan = to_pd_chan(chan);
 199         struct pch_dma *pd = to_pd(chan->device);
 200         u32 val;
 201
 202         val = dma_readl(pd, CTL0);
 203
 204         if (pd_chan->dir == DMA_TO_DEVICE)
 205                 val |= 0x1 << (DMA_CTL0_BITS_PER_CH * chan->chan_id +
 206                                DMA_CTL0_DIR_SHIFT_BITS);
 207         else
 208                 val &= ~(0x1 << (DMA_CTL0_BITS_PER_CH * chan->chan_id +
 209                                  DMA_CTL0_DIR_SHIFT_BITS));
 210
 211         dma_writel(pd, CTL0, val);
 212
 213         dev_dbg(chan2dev(chan), "pdc_set_dir: chan %d -> %x\n",
 214                 chan->chan_id, val);
 215 }
 216
 217 static void pdc_set_mode(struct dma_chan *chan, u32 mode)
 218 {
 219         struct pch_dma *pd = to_pd(chan->device);
 220         u32 val;
 221
 222         val = dma_readl(pd, CTL0);
 223
 224         val &= ~(DMA_CTL0_MODE_MASK_BITS <<
 225                 (DMA_CTL0_BITS_PER_CH * chan->chan_id));
 226         val |= mode << (DMA_CTL0_BITS_PER_CH * chan->chan_id);
 227
 228         dma_writel(pd, CTL0, val);
 229
 230         dev_dbg(chan2dev(chan), "pdc_set_mode: chan %d -> %x\n",
 231                 chan->chan_id, val);
 232 }
 233
 234 static u32 pdc_get_status(struct pch_dma_chan *pd_chan)
 235 {
 236         struct pch_dma *pd = to_pd(pd_chan->chan.device);
 237         u32 val;
 238
 239         val = dma_readl(pd, STS0);
 240         return DMA_STATUS_MASK_BITS & (val >> (DMA_STATUS_SHIFT_BITS +
 241                         DMA_STATUS_BITS_PER_CH * pd_chan->chan.chan_id));
 242 }
 243
 244 static bool pdc_is_idle(struct pch_dma_chan *pd_chan)
 245 {
 246         if (pdc_get_status(pd_chan) == DMA_STATUS_IDLE)
 247                 return true;
 248         else
 249                 return false;
 250 }
 251
 252 static void pdc_dostart(struct pch_dma_chan *pd_chan, struct pch_dma_desc* desc)
 253 {
 254         struct pch_dma *pd = to_pd(pd_chan->chan.device);
 255         u32 val;
 256
 257         if (!pdc_is_idle(pd_chan)) {
 258                 dev_err(chan2dev(&pd_chan->chan),
 259                         "BUG: Attempt to start non-idle channel\n");
 260                 return;
 261         }
 262
 263         dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> dev_addr: %x\n",
 264                 pd_chan->chan.chan_id, desc->regs.dev_addr);
 265         dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> mem_addr: %x\n",
 266                 pd_chan->chan.chan_id, desc->regs.mem_addr);
 267         dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> size: %x\n",
 268                 pd_chan->chan.chan_id, desc->regs.size);
 269         dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> next: %x\n",
 270                 pd_chan->chan.chan_id, desc->regs.next);
 271
 272         if (list_empty(&desc->tx_list)) {
 273                 channel_writel(pd_chan, DEV_ADDR, desc->regs.dev_addr);
 274                 channel_writel(pd_chan, MEM_ADDR, desc->regs.mem_addr);
 275                 channel_writel(pd_chan, SIZE, desc->regs.size);
 276                 channel_writel(pd_chan, NEXT, desc->regs.next);
 277                 pdc_set_mode(&pd_chan->chan, DMA_CTL0_ONESHOT);
 278         } else {
 279                 channel_writel(pd_chan, NEXT, desc->txd.phys);
 280                 pdc_set_mode(&pd_chan->chan, DMA_CTL0_SG);
 281         }
 282
 283         val = dma_readl(pd, CTL2);
 284         val |= 1 << (DMA_CTL2_START_SHIFT_BITS + pd_chan->chan.chan_id);
 285         dma_writel(pd, CTL2, val);
 286 }
 287
 288 static void pdc_chain_complete(struct pch_dma_chan *pd_chan,
 289                                struct pch_dma_desc *desc)
 290 {
 291         struct dma_async_tx_descriptor *txd = &desc->txd;
 292         dma_async_tx_callback callback = txd->callback;
 293         void *param = txd->callback_param;
 294
 295         list_splice_init(&desc->tx_list, &pd_chan->free_list);
 296         list_move(&desc->desc_node, &pd_chan->free_list);
 297
 298         if (callback)
 299                 callback(param);
 300 }
 301
 302 static void pdc_complete_all(struct pch_dma_chan *pd_chan)
 303 {
 304         struct pch_dma_desc *desc, *_d;
 305         LIST_HEAD(list);
 306
 307         BUG_ON(!pdc_is_idle(pd_chan));
 308
 309         if (!list_empty(&pd_chan->queue))
 310                 pdc_dostart(pd_chan, pdc_first_queued(pd_chan));
 311
 312         list_splice_init(&pd_chan->active_list, &list);
 313         list_splice_init(&pd_chan->queue, &pd_chan->active_list);
 314
 315         list_for_each_entry_safe(desc, _d, &list, desc_node)
 316                 pdc_chain_complete(pd_chan, desc);
 317 }
 318
 319 static void pdc_handle_error(struct pch_dma_chan *pd_chan)
 320 {
 321         struct pch_dma_desc *bad_desc;
 322
 323         bad_desc = pdc_first_active(pd_chan);
 324         list_del(&bad_desc->desc_node);
 325
 326         list_splice_init(&pd_chan->queue, pd_chan->active_list.prev);
 327
 328         if (!list_empty(&pd_chan->active_list))
 329                 pdc_dostart(pd_chan, pdc_first_active(pd_chan));
 330
 331         dev_crit(chan2dev(&pd_chan->chan), "Bad descriptor submitted\n");
 332         dev_crit(chan2dev(&pd_chan->chan), "descriptor cookie: %d\n",
 333                  bad_desc->txd.cookie);
 334
 335         pdc_chain_complete(pd_chan, bad_desc);
 336 }
 337
 338 static void pdc_advance_work(struct pch_dma_chan *pd_chan)
 339 {
 340         if (list_empty(&pd_chan->active_list) ||
 341                 list_is_singular(&pd_chan->active_list)) {
 342                 pdc_complete_all(pd_chan);
 343         } else {
 344                 pdc_chain_complete(pd_chan, pdc_first_active(pd_chan));
 345                 pdc_dostart(pd_chan, pdc_first_active(pd_chan));
 346         }
 347 }
 348
 349 static dma_cookie_t pdc_assign_cookie(struct pch_dma_chan *pd_chan,
 350                                       struct pch_dma_desc *desc)
 351 {
 352         dma_cookie_t cookie = pd_chan->chan.cookie;
 353
 354         if (++cookie < 0)
 355                 cookie = 1;
 356
 357         pd_chan->chan.cookie = cookie;
 358         desc->txd.cookie = cookie;
 359
 360         return cookie;
 361 }
 362
 363 static dma_cookie_t pd_tx_submit(struct dma_async_tx_descriptor *txd)
 364 {
 365         struct pch_dma_desc *desc = to_pd_desc(txd);
 366         struct pch_dma_chan *pd_chan = to_pd_chan(txd->chan);
 367         dma_cookie_t cookie;
 368
 369         spin_lock(&pd_chan->lock);
 370         cookie = pdc_assign_cookie(pd_chan, desc);
 371
 372         if (list_empty(&pd_chan->active_list)) {
 373                 list_add_tail(&desc->desc_node, &pd_chan->active_list);
 374                 pdc_dostart(pd_chan, desc);
 375         } else {
 376                 list_add_tail(&desc->desc_node, &pd_chan->queue);
 377         }
 378
 379         spin_unlock(&pd_chan->lock);
 380         return 0;
 381 }
 382
 383 static struct pch_dma_desc *pdc_alloc_desc(struct dma_chan *chan, gfp_t flags)
 384 {
 385         struct pch_dma_desc *desc = NULL;
 386         struct pch_dma *pd = to_pd(chan->device);
 387         dma_addr_t addr;
 388
 389         desc = pci_pool_alloc(pd->pool, flags, &addr);
 390         if (desc) {
 391                 memset(desc, 0, sizeof(struct pch_dma_desc));
 392                 INIT_LIST_HEAD(&desc->tx_list);
 393                 dma_async_tx_descriptor_init(&desc->txd, chan);
 394                 desc->txd.tx_submit = pd_tx_submit;
 395                 desc->txd.flags = DMA_CTRL_ACK;
 396                 desc->txd.phys = addr;
 397         }
 398
 399         return desc;
 400 }
 401
 402 static struct pch_dma_desc *pdc_desc_get(struct pch_dma_chan *pd_chan)
 403 {
 404         struct pch_dma_desc *desc, *_d;
 405         struct pch_dma_desc *ret = NULL;
 406         int i;
 407
 408         spin_lock(&pd_chan->lock);
 409         list_for_each_entry_safe(desc, _d, &pd_chan->free_list, desc_node) {
 410                 i++;
 411                 if (async_tx_test_ack(&desc->txd)) {
 412                         list_del(&desc->desc_node);
 413                         ret = desc;
 414                         break;
 415                 }
 416                 dev_dbg(chan2dev(&pd_chan->chan), "desc %p not ACKed\n", desc);
 417         }
 418         spin_unlock(&pd_chan->lock);
 419         dev_dbg(chan2dev(&pd_chan->chan), "scanned %d descriptors\n", i);
 420
 421         if (!ret) {
 422                 ret = pdc_alloc_desc(&pd_chan->chan, GFP_NOIO);
 423                 if (ret) {
 424                         spin_lock(&pd_chan->lock);
 425                         pd_chan->descs_allocated++;
 426                         spin_unlock(&pd_chan->lock);
 427                 } else {
 428                         dev_err(chan2dev(&pd_chan->chan),
 429                                 "failed to alloc desc\n");
 430                 }
 431         }
 432
 433         return ret;
 434 }
 435
 436 static void pdc_desc_put(struct pch_dma_chan *pd_chan,
 437                          struct pch_dma_desc *desc)
 438 {
 439         if (desc) {
 440                 spin_lock(&pd_chan->lock);
 441                 list_splice_init(&desc->tx_list, &pd_chan->free_list);
 442                 list_add(&desc->desc_node, &pd_chan->free_list);
 443                 spin_unlock(&pd_chan->lock);
 444         }
 445 }
 446
 447 static int pd_alloc_chan_resources(struct dma_chan *chan)
 448 {
 449         struct pch_dma_chan *pd_chan = to_pd_chan(chan);
 450         struct pch_dma_desc *desc;
 451         LIST_HEAD(tmp_list);
 452         int i;
 453
 454         if (!pdc_is_idle(pd_chan)) {
 455                 dev_dbg(chan2dev(chan), "DMA channel not idle ?\n");
 456                 return -EIO;
 457         }
 458
 459         if (!list_empty(&pd_chan->free_list))
 460                 return pd_chan->descs_allocated;
 461
 462         for (i = 0; i < init_nr_desc_per_channel; i++) {
 463                 desc = pdc_alloc_desc(chan, GFP_KERNEL);
 464
 465                 if (!desc) {
 466                         dev_warn(chan2dev(chan),
 467                                 "Only allocated %d initial descriptors\n", i);
 468                         break;
 469                 }
 470
 471                 list_add_tail(&desc->desc_node, &tmp_list);
 472         }
 473
 474         spin_lock_bh(&pd_chan->lock);
 475         list_splice(&tmp_list, &pd_chan->free_list);
 476         pd_chan->descs_allocated = i;
 477         pd_chan->completed_cookie = chan->cookie = 1;
 478         spin_unlock_bh(&pd_chan->lock);
 479
 480         pdc_enable_irq(chan, 1);
 481         pdc_set_dir(chan);
 482
 483         return pd_chan->descs_allocated;
 484 }
 485
 486 static void pd_free_chan_resources(struct dma_chan *chan)
 487 {
 488         struct pch_dma_chan *pd_chan = to_pd_chan(chan);
 489         struct pch_dma *pd = to_pd(chan->device);
 490         struct pch_dma_desc *desc, *_d;
 491         LIST_HEAD(tmp_list);
 492
 493         BUG_ON(!pdc_is_idle(pd_chan));
 494         BUG_ON(!list_empty(&pd_chan->active_list));
 495         BUG_ON(!list_empty(&pd_chan->queue));
 496
 497         spin_lock_bh(&pd_chan->lock);
 498         list_splice_init(&pd_chan->free_list, &tmp_list);
 499         pd_chan->descs_allocated = 0;
 500         spin_unlock_bh(&pd_chan->lock);
 501
 502         list_for_each_entry_safe(desc, _d, &tmp_list, desc_node)
 503                 pci_pool_free(pd->pool, desc, desc->txd.phys);
 504
 505         pdc_enable_irq(chan, 0);
 506 }
 507
 508 static enum dma_status pd_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
 509                                     struct dma_tx_state *txstate)
 510 {
 511         struct pch_dma_chan *pd_chan = to_pd_chan(chan);
 512         dma_cookie_t last_used;
 513         dma_cookie_t last_completed;
 514         int ret;
 515
 516         spin_lock_bh(&pd_chan->lock);
 517         last_completed = pd_chan->completed_cookie;
 518         last_used = chan->cookie;
 519         spin_unlock_bh(&pd_chan->lock);
 520
 521         ret = dma_async_is_complete(cookie, last_completed, last_used);
 522
 523         dma_set_tx_state(txstate, last_completed, last_used, 0);
 524
 525         return ret;
 526 }
 527
 528 static void pd_issue_pending(struct dma_chan *chan)
 529 {
 530         struct pch_dma_chan *pd_chan = to_pd_chan(chan);
 531
 532         if (pdc_is_idle(pd_chan)) {
 533                 spin_lock(&pd_chan->lock);
 534                 pdc_advance_work(pd_chan);
 535                 spin_unlock(&pd_chan->lock);
 536         }
 537 }
 538
 539 static struct dma_async_tx_descriptor *pd_prep_slave_sg(struct dma_chan *chan,
 540                         struct scatterlist *sgl, unsigned int sg_len,
 541                         enum dma_data_direction direction, unsigned long flags)
 542 {
 543         struct pch_dma_chan *pd_chan = to_pd_chan(chan);
 544         struct pch_dma_slave *pd_slave = chan->private;
 545         struct pch_dma_desc *first = NULL;
 546         struct pch_dma_desc *prev = NULL;
 547         struct pch_dma_desc *desc = NULL;
 548         struct scatterlist *sg;
 549         dma_addr_t reg;
 550         int i;
 551
 552         if (unlikely(!sg_len)) {
 553                 dev_info(chan2dev(chan), "prep_slave_sg: length is zero!\n");
 554                 return NULL;
 555         }
 556
 557         if (direction == DMA_FROM_DEVICE)
 558                 reg = pd_slave->rx_reg;
 559         else if (direction == DMA_TO_DEVICE)
 560                 reg = pd_slave->tx_reg;
 561         else
 562                 return NULL;
 563
 564         for_each_sg(sgl, sg, sg_len, i) {
 565                 desc = pdc_desc_get(pd_chan);
 566
 567                 if (!desc)
 568                         goto err_desc_get;
 569
 570                 desc->regs.dev_addr = reg;
 571                 desc->regs.mem_addr = sg_phys(sg);
 572                 desc->regs.size = sg_dma_len(sg);
 573                 desc->regs.next = DMA_DESC_FOLLOW_WITHOUT_IRQ;
 574
 575                 switch (pd_slave->width) {
 576                 case PCH_DMA_WIDTH_1_BYTE:
 577                         if (desc->regs.size > DMA_DESC_MAX_COUNT_1_BYTE)
 578                                 goto err_desc_get;
 579                         desc->regs.size |= DMA_DESC_WIDTH_1_BYTE;
 580                         break;
 581                 case PCH_DMA_WIDTH_2_BYTES:
 582                         if (desc->regs.size > DMA_DESC_MAX_COUNT_2_BYTES)
 583                                 goto err_desc_get;
 584                         desc->regs.size |= DMA_DESC_WIDTH_2_BYTES;
 585                         break;
 586                 case PCH_DMA_WIDTH_4_BYTES:
 587                         if (desc->regs.size > DMA_DESC_MAX_COUNT_4_BYTES)
 588                                 goto err_desc_get;
 589                         desc->regs.size |= DMA_DESC_WIDTH_4_BYTES;
 590                         break;
 591                 default:
 592                         goto err_desc_get;
 593                 }
 594
 595                 if (!first) {
 596                         first = desc;
 597                 } else {
 598                         prev->regs.next |= desc->txd.phys;
 599                         list_add_tail(&desc->desc_node, &first->tx_list);
 600                 }
 601
 602                 prev = desc;
 603         }
 604
 605         if (flags & DMA_PREP_INTERRUPT)
 606                 desc->regs.next = DMA_DESC_END_WITH_IRQ;
 607         else
 608                 desc->regs.next = DMA_DESC_END_WITHOUT_IRQ;
 609
 610         first->txd.cookie = -EBUSY;
 611         desc->txd.flags = flags;
 612
 613         return &first->txd;
 614
 615 err_desc_get:
 616         dev_err(chan2dev(chan), "failed to get desc or wrong parameters\n");
 617         pdc_desc_put(pd_chan, first);
 618         return NULL;
 619 }
 620
 621 static int pd_device_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
 622                              unsigned long arg)
 623 {
 624         struct pch_dma_chan *pd_chan = to_pd_chan(chan);
 625         struct pch_dma_desc *desc, *_d;
 626         LIST_HEAD(list);
 627
 628         if (cmd != DMA_TERMINATE_ALL)
 629                 return -ENXIO;
 630
 631         spin_lock_bh(&pd_chan->lock);
 632
 633         pdc_set_mode(&pd_chan->chan, DMA_CTL0_DISABLE);
 634
 635         list_splice_init(&pd_chan->active_list, &list);
 636         list_splice_init(&pd_chan->queue, &list);
 637
 638         list_for_each_entry_safe(desc, _d, &list, desc_node)
 639                 pdc_chain_complete(pd_chan, desc);
 640
 641         spin_unlock_bh(&pd_chan->lock);
 642
 643         return 0;
 644 }
 645
 646 static void pdc_tasklet(unsigned long data)
 647 {
 648         struct pch_dma_chan *pd_chan = (struct pch_dma_chan *)data;
 649         unsigned long flags;
 650
 651         if (!pdc_is_idle(pd_chan)) {
 652                 dev_err(chan2dev(&pd_chan->chan),
 653                         "BUG: handle non-idle channel in tasklet\n");
 654                 return;
 655         }
 656
 657         spin_lock_irqsave(&pd_chan->lock, flags);
 658         if (test_and_clear_bit(0, &pd_chan->err_status))
 659                 pdc_handle_error(pd_chan);
 660         else
 661                 pdc_advance_work(pd_chan);
 662         spin_unlock_irqrestore(&pd_chan->lock, flags);
 663 }
 664
 665 static irqreturn_t pd_irq(int irq, void *devid)
 666 {
 667         struct pch_dma *pd = (struct pch_dma *)devid;
 668         struct pch_dma_chan *pd_chan;
 669         u32 sts0;
 670         int i;
 671         int ret = IRQ_NONE;
 672
 673         sts0 = dma_readl(pd, STS0);
 674
 675         dev_dbg(pd->dma.dev, "pd_irq sts0: %x\n", sts0);
 676
 677         for (i = 0; i < pd->dma.chancnt; i++) {
 678                 pd_chan = &pd->channels[i];
 679
 680                 if (sts0 & DMA_STATUS_IRQ(i)) {
 681                         if (sts0 & DMA_STATUS_ERR(i))
 682                                 set_bit(0, &pd_chan->err_status);
 683
 684                         tasklet_schedule(&pd_chan->tasklet);
 685                         ret = IRQ_HANDLED;
 686                 }
 687
 688         }
 689
 690         /* clear interrupt bits in status register */
 691         dma_writel(pd, STS0, sts0);
 692
 693         return ret;
 694 }
 695
 696 static void pch_dma_save_regs(struct pch_dma *pd)
 697 {
 698         struct pch_dma_chan *pd_chan;
 699         struct dma_chan *chan, *_c;
 700         int i = 0;
 701
 702         pd->regs.dma_ctl0 = dma_readl(pd, CTL0);
 703         pd->regs.dma_ctl1 = dma_readl(pd, CTL1);
 704         pd->regs.dma_ctl2 = dma_readl(pd, CTL2);
 705
 706         list_for_each_entry_safe(chan, _c, &pd->dma.channels, device_node) {
 707                 pd_chan = to_pd_chan(chan);
 708
 709                 pd->ch_regs[i].dev_addr = channel_readl(pd_chan, DEV_ADDR);
 710                 pd->ch_regs[i].mem_addr = channel_readl(pd_chan, MEM_ADDR);
 711                 pd->ch_regs[i].size = channel_readl(pd_chan, SIZE);
 712                 pd->ch_regs[i].next = channel_readl(pd_chan, NEXT);
 713
 714                 i++;
 715         }
 716 }
 717
 718 static void pch_dma_restore_regs(struct pch_dma *pd)
 719 {
 720         struct pch_dma_chan *pd_chan;
 721         struct dma_chan *chan, *_c;
 722         int i = 0;
 723
 724         dma_writel(pd, CTL0, pd->regs.dma_ctl0);
 725         dma_writel(pd, CTL1, pd->regs.dma_ctl1);
 726         dma_writel(pd, CTL2, pd->regs.dma_ctl2);
 727
 728         list_for_each_entry_safe(chan, _c, &pd->dma.channels, device_node) {
 729                 pd_chan = to_pd_chan(chan);
 730
 731                 channel_writel(pd_chan, DEV_ADDR, pd->ch_regs[i].dev_addr);
 732                 channel_writel(pd_chan, MEM_ADDR, pd->ch_regs[i].mem_addr);
 733                 channel_writel(pd_chan, SIZE, pd->ch_regs[i].size);
 734                 channel_writel(pd_chan, NEXT, pd->ch_regs[i].next);
 735
 736                 i++;
 737         }
 738 }
 739
 740 static int pch_dma_suspend(struct pci_dev *pdev, pm_message_t state)
 741 {
 742         struct pch_dma *pd = pci_get_drvdata(pdev);
 743
 744         if (pd)
 745                 pch_dma_save_regs(pd);
 746
 747         pci_save_state(pdev);
 748         pci_disable_device(pdev);
 749         pci_set_power_state(pdev, pci_choose_state(pdev, state));
 750
 751         return 0;
 752 }
 753
 754 static int pch_dma_resume(struct pci_dev *pdev)
 755 {
 756         struct pch_dma *pd = pci_get_drvdata(pdev);
 757         int err;
 758
 759         pci_set_power_state(pdev, PCI_D0);
 760         pci_restore_state(pdev);
 761
 762         err = pci_enable_device(pdev);
 763         if (err) {
 764                 dev_dbg(&pdev->dev, "failed to enable device\n");
 765                 return err;
 766         }
 767
 768         if (pd)
 769                 pch_dma_restore_regs(pd);
 770
 771         return 0;
 772 }
 773
 774 static int __devinit pch_dma_probe(struct pci_dev *pdev,
 775                                    const struct pci_device_id *id)
 776 {
 777         struct pch_dma *pd;
 778         struct pch_dma_regs *regs;
 779         unsigned int nr_channels;
 780         int err;
 781         int i;
 782
 783         nr_channels = id->driver_data;
 784         pd = kzalloc(sizeof(struct pch_dma)+
 785                 sizeof(struct pch_dma_chan) * nr_channels, GFP_KERNEL);
 786         if (!pd)
 787                 return -ENOMEM;
 788
 789         pci_set_drvdata(pdev, pd);
 790
 791         err = pci_enable_device(pdev);
 792         if (err) {
 793                 dev_err(&pdev->dev, "Cannot enable PCI device\n");
 794                 goto err_free_mem;
 795         }
 796
 797         if (!(pci_resource_flags(pdev, 1) & IORESOURCE_MEM)) {
 798                 dev_err(&pdev->dev, "Cannot find proper base address\n");
 799                 goto err_disable_pdev;
 800         }
 801
 802         err = pci_request_regions(pdev, DRV_NAME);
 803         if (err) {
 804                 dev_err(&pdev->dev, "Cannot obtain PCI resources\n");
 805                 goto err_disable_pdev;
 806         }
 807
 808         err = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
 809         if (err) {
 810                 dev_err(&pdev->dev, "Cannot set proper DMA config\n");
 811                 goto err_free_res;
 812         }
 813
 814         regs = pd->membase = pci_iomap(pdev, 1, 0);
 815         if (!pd->membase) {
 816                 dev_err(&pdev->dev, "Cannot map MMIO registers\n");
 817                 err = -ENOMEM;
 818                 goto err_free_res;
 819         }
 820
 821         pci_set_master(pdev);
 822
 823         err = request_irq(pdev->irq, pd_irq, IRQF_SHARED, DRV_NAME, pd);
 824         if (err) {
 825                 dev_err(&pdev->dev, "Failed to request IRQ\n");
 826                 goto err_iounmap;
 827         }
 828
 829         pd->pool = pci_pool_create("pch_dma_desc_pool", pdev,
 830                                    sizeof(struct pch_dma_desc), 4, 0);
 831         if (!pd->pool) {
 832                 dev_err(&pdev->dev, "Failed to alloc DMA descriptors\n");
 833                 err = -ENOMEM;
 834                 goto err_free_irq;
 835         }
 836
 837         pd->dma.dev = &pdev->dev;
 838         pd->dma.chancnt = nr_channels;
 839
 840         INIT_LIST_HEAD(&pd->dma.channels);
 841
 842         for (i = 0; i < nr_channels; i++) {
 843                 struct pch_dma_chan *pd_chan = &pd->channels[i];
 844
 845                 pd_chan->chan.device = &pd->dma;
 846                 pd_chan->chan.cookie = 1;
 847                 pd_chan->chan.chan_id = i;
 848
 849                 pd_chan->membase = &regs->desc[i];
 850
 851                 pd_chan->dir = (i % 2) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
 852
 853                 spin_lock_init(&pd_chan->lock);
 854
 855                 INIT_LIST_HEAD(&pd_chan->active_list);
 856                 INIT_LIST_HEAD(&pd_chan->queue);
 857                 INIT_LIST_HEAD(&pd_chan->free_list);
 858
 859                 tasklet_init(&pd_chan->tasklet, pdc_tasklet,
 860                              (unsigned long)pd_chan);
 861                 list_add_tail(&pd_chan->chan.device_node, &pd->dma.channels);
 862         }
 863
 864         dma_cap_zero(pd->dma.cap_mask);
 865         dma_cap_set(DMA_PRIVATE, pd->dma.cap_mask);
 866         dma_cap_set(DMA_SLAVE, pd->dma.cap_mask);
 867
 868         pd->dma.device_alloc_chan_resources = pd_alloc_chan_resources;
 869         pd->dma.device_free_chan_resources = pd_free_chan_resources;
 870         pd->dma.device_tx_status = pd_tx_status;
 871         pd->dma.device_issue_pending = pd_issue_pending;
 872         pd->dma.device_prep_slave_sg = pd_prep_slave_sg;
 873         pd->dma.device_control = pd_device_control;
 874
 875         err = dma_async_device_register(&pd->dma);
 876         if (err) {
 877                 dev_err(&pdev->dev, "Failed to register DMA device\n");
 878                 goto err_free_pool;
 879         }
 880
 881         return 0;
 882
 883 err_free_pool:
 884         pci_pool_destroy(pd->pool);
 885 err_free_irq:
 886         free_irq(pdev->irq, pd);
 887 err_iounmap:
 888         pci_iounmap(pdev, pd->membase);
 889 err_free_res:
 890         pci_release_regions(pdev);
 891 err_disable_pdev:
 892         pci_disable_device(pdev);
 893 err_free_mem:
 894         return err;
 895 }
 896
 897 static void __devexit pch_dma_remove(struct pci_dev *pdev)
 898 {
 899         struct pch_dma *pd = pci_get_drvdata(pdev);
 900         struct pch_dma_chan *pd_chan;
 901         struct dma_chan *chan, *_c;
 902
 903         if (pd) {
 904                 dma_async_device_unregister(&pd->dma);
 905
 906                 list_for_each_entry_safe(chan, _c, &pd->dma.channels,
 907                                          device_node) {
 908                         pd_chan = to_pd_chan(chan);
 909
 910                         tasklet_disable(&pd_chan->tasklet);
 911                         tasklet_kill(&pd_chan->tasklet);
 912                 }
 913
 914                 pci_pool_destroy(pd->pool);
 915                 free_irq(pdev->irq, pd);
 916                 pci_iounmap(pdev, pd->membase);
 917                 pci_release_regions(pdev);
 918                 pci_disable_device(pdev);
 919                 kfree(pd);
 920         }
 921 }
 922
 923 /* PCI Device ID of DMA device */
 924 #define PCI_VENDOR_ID_ROHM             0x10DB
 925 #define PCI_DEVICE_ID_EG20T_PCH_DMA_8CH        0x8810
 926 #define PCI_DEVICE_ID_EG20T_PCH_DMA_4CH        0x8815
 927 #define PCI_DEVICE_ID_ML7213_DMA1_8CH   0x8026
 928 #define PCI_DEVICE_ID_ML7213_DMA2_8CH   0x802B
 929 #define PCI_DEVICE_ID_ML7213_DMA3_4CH   0x8034
 930
 931 static const struct pci_device_id pch_dma_id_table[] = {
 932         { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_EG20T_PCH_DMA_8CH), 8 },
 933         { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_EG20T_PCH_DMA_4CH), 4 },
 934         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA1_8CH), 8}, /* UART Video */
 935         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA2_8CH), 8}, /* PCMIF SPI */
 936         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA3_4CH), 4}, /* FPGA */
 937         { 0, },
 938 };
 939
 940 static struct pci_driver pch_dma_driver = {
 941         .name           = DRV_NAME,
 942         .id_table       = pch_dma_id_table,
 943         .probe          = pch_dma_probe,
 944         .remove         = __devexit_p(pch_dma_remove),
 945 #ifdef CONFIG_PM
 946         .suspend        = pch_dma_suspend,
 947         .resume         = pch_dma_resume,
 948 #endif
 949 };
 950
 951 static int __init pch_dma_init(void)
 952 {
 953         return pci_register_driver(&pch_dma_driver);
 954 }
 955
 956 static void __exit pch_dma_exit(void)
 957 {
 958         pci_unregister_driver(&pch_dma_driver);
 959 }
 960
 961 module_init(pch_dma_init);
 962 module_exit(pch_dma_exit);
 963
 964 MODULE_DESCRIPTION("Intel EG20T PCH / OKI SEMICONDUCTOR ML7213 IOH "
 965                    "DMA controller driver");
 966 MODULE_AUTHOR("Yong Wang <yong.y.wang@intel.com>");
 967 MODULE_LICENSE("GPL v2");