drivers/dma/pch_dma.c

   1 /*
   2  * Topcliff PCH DMA controller driver
   3  * Copyright (c) 2010 Intel Corporation
   4  * Copyright (C) 2011 LAPIS 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 #include "dmaengine.h"
  29
  30 #define DRV_NAME "pch-dma"
  31
  32 #define DMA_CTL0_DISABLE                0x0
  33 #define DMA_CTL0_SG                     0x1
  34 #define DMA_CTL0_ONESHOT                0x2
  35 #define DMA_CTL0_MODE_MASK_BITS         0x3
  36 #define DMA_CTL0_DIR_SHIFT_BITS         2
  37 #define DMA_CTL0_BITS_PER_CH            4
  38
  39 #define DMA_CTL2_START_SHIFT_BITS       8
  40 #define DMA_CTL2_IRQ_ENABLE_MASK        ((1UL << DMA_CTL2_START_SHIFT_BITS) - 1)
  41
  42 #define DMA_STATUS_IDLE                 0x0
  43 #define DMA_STATUS_DESC_READ            0x1
  44 #define DMA_STATUS_WAIT                 0x2
  45 #define DMA_STATUS_ACCESS               0x3
  46 #define DMA_STATUS_BITS_PER_CH          2
  47 #define DMA_STATUS_MASK_BITS            0x3
  48 #define DMA_STATUS_SHIFT_BITS           16
  49 #define DMA_STATUS_IRQ(x)               (0x1 << (x))
  50 #define DMA_STATUS0_ERR(x)              (0x1 << ((x) + 8))
  51 #define DMA_STATUS2_ERR(x)              (0x1 << (x))
  52
  53 #define DMA_DESC_WIDTH_SHIFT_BITS       12
  54 #define DMA_DESC_WIDTH_1_BYTE           (0x3 << DMA_DESC_WIDTH_SHIFT_BITS)
  55 #define DMA_DESC_WIDTH_2_BYTES          (0x2 << DMA_DESC_WIDTH_SHIFT_BITS)
  56 #define DMA_DESC_WIDTH_4_BYTES          (0x0 << DMA_DESC_WIDTH_SHIFT_BITS)
  57 #define DMA_DESC_MAX_COUNT_1_BYTE       0x3FF
  58 #define DMA_DESC_MAX_COUNT_2_BYTES      0x3FF
  59 #define DMA_DESC_MAX_COUNT_4_BYTES      0x7FF
  60 #define DMA_DESC_END_WITHOUT_IRQ        0x0
  61 #define DMA_DESC_END_WITH_IRQ           0x1
  62 #define DMA_DESC_FOLLOW_WITHOUT_IRQ     0x2
  63 #define DMA_DESC_FOLLOW_WITH_IRQ        0x3
  64
  65 #define MAX_CHAN_NR                     12
  66
  67 #define DMA_MASK_CTL0_MODE      0x33333333
  68 #define DMA_MASK_CTL2_MODE      0x00003333
  69
  70 static unsigned int init_nr_desc_per_channel = 64;
  71 module_param(init_nr_desc_per_channel, uint, 0644);
  72 MODULE_PARM_DESC(init_nr_desc_per_channel,
  73                  "initial descriptors per channel (default: 64)");
  74
  75 struct pch_dma_desc_regs {
  76         u32     dev_addr;
  77         u32     mem_addr;
  78         u32     size;
  79         u32     next;
  80 };
  81
  82 struct pch_dma_regs {
  83         u32     dma_ctl0;
  84         u32     dma_ctl1;
  85         u32     dma_ctl2;
  86         u32     dma_ctl3;
  87         u32     dma_sts0;
  88         u32     dma_sts1;
  89         u32     dma_sts2;
  90         u32     reserved3;
  91         struct pch_dma_desc_regs desc[MAX_CHAN_NR];
  92 };
  93
  94 struct pch_dma_desc {
  95         struct pch_dma_desc_regs regs;
  96         struct dma_async_tx_descriptor txd;
  97         struct list_head        desc_node;
  98         struct list_head        tx_list;
  99 };
 100
 101 struct pch_dma_chan {
 102         struct dma_chan         chan;
 103         void __iomem *membase;
 104         enum dma_transfer_direction dir;
 105         struct tasklet_struct   tasklet;
 106         unsigned long           err_status;
 107
 108         spinlock_t              lock;
 109
 110         struct list_head        active_list;
 111         struct list_head        queue;
 112         struct list_head        free_list;
 113         unsigned int            descs_allocated;
 114 };
 115
 116 #define PDC_DEV_ADDR    0x00
 117 #define PDC_MEM_ADDR    0x04
 118 #define PDC_SIZE        0x08
 119 #define PDC_NEXT        0x0C
 120
 121 #define channel_readl(pdc, name) \
 122         readl((pdc)->membase + PDC_##name)
 123 #define channel_writel(pdc, name, val) \
 124         writel((val), (pdc)->membase + PDC_##name)
 125
 126 struct pch_dma {
 127         struct dma_device       dma;
 128         void __iomem *membase;
 129         struct pci_pool         *pool;
 130         struct pch_dma_regs     regs;
 131         struct pch_dma_desc_regs ch_regs[MAX_CHAN_NR];
 132         struct pch_dma_chan     channels[MAX_CHAN_NR];
 133 };
 134
 135 #define PCH_DMA_CTL0    0x00
 136 #define PCH_DMA_CTL1    0x04
 137 #define PCH_DMA_CTL2    0x08
 138 #define PCH_DMA_CTL3    0x0C
 139 #define PCH_DMA_STS0    0x10
 140 #define PCH_DMA_STS1    0x14
 141 #define PCH_DMA_STS2    0x18
 142
 143 #define dma_readl(pd, name) \
 144         readl((pd)->membase + PCH_DMA_##name)
 145 #define dma_writel(pd, name, val) \
 146         writel((val), (pd)->membase + PCH_DMA_##name)
 147
 148 static inline
 149 struct pch_dma_desc *to_pd_desc(struct dma_async_tx_descriptor *txd)
 150 {
 151         return container_of(txd, struct pch_dma_desc, txd);
 152 }
 153
 154 static inline struct pch_dma_chan *to_pd_chan(struct dma_chan *chan)
 155 {
 156         return container_of(chan, struct pch_dma_chan, chan);
 157 }
 158
 159 static inline struct pch_dma *to_pd(struct dma_device *ddev)
 160 {
 161         return container_of(ddev, struct pch_dma, dma);
 162 }
 163
 164 static inline struct device *chan2dev(struct dma_chan *chan)
 165 {
 166         return &chan->dev->device;
 167 }
 168
 169 static inline struct device *chan2parent(struct dma_chan *chan)
 170 {
 171         return chan->dev->device.parent;
 172 }
 173
 174 static inline
 175 struct pch_dma_desc *pdc_first_active(struct pch_dma_chan *pd_chan)
 176 {
 177         return list_first_entry(&pd_chan->active_list,
 178                                 struct pch_dma_desc, desc_node);
 179 }
 180
 181 static inline
 182 struct pch_dma_desc *pdc_first_queued(struct pch_dma_chan *pd_chan)
 183 {
 184         return list_first_entry(&pd_chan->queue,
 185                                 struct pch_dma_desc, desc_node);
 186 }
 187
 188 static void pdc_enable_irq(struct dma_chan *chan, int enable)
 189 {
 190         struct pch_dma *pd = to_pd(chan->device);
 191         u32 val;
 192         int pos;
 193
 194         if (chan->chan_id < 8)
 195                 pos = chan->chan_id;
 196         else
 197                 pos = chan->chan_id + 8;
 198
 199         val = dma_readl(pd, CTL2);
 200
 201         if (enable)
 202                 val |= 0x1 << pos;
 203         else
 204                 val &= ~(0x1 << pos);
 205
 206         dma_writel(pd, CTL2, val);
 207
 208         dev_dbg(chan2dev(chan), "pdc_enable_irq: chan %d -> %x\n",
 209                 chan->chan_id, val);
 210 }
 211
 212 static void pdc_set_dir(struct dma_chan *chan)
 213 {
 214         struct pch_dma_chan *pd_chan = to_pd_chan(chan);
 215         struct pch_dma *pd = to_pd(chan->device);
 216         u32 val;
 217         u32 mask_mode;
 218         u32 mask_ctl;
 219
 220         if (chan->chan_id < 8) {
 221                 val = dma_readl(pd, CTL0);
 222
 223                 mask_mode = DMA_CTL0_MODE_MASK_BITS <<
 224                                         (DMA_CTL0_BITS_PER_CH * chan->chan_id);
 225                 mask_ctl = DMA_MASK_CTL0_MODE & ~(DMA_CTL0_MODE_MASK_BITS <<
 226                                        (DMA_CTL0_BITS_PER_CH * chan->chan_id));
 227                 val &= mask_mode;
 228                 if (pd_chan->dir == DMA_MEM_TO_DEV)
 229                         val |= 0x1 << (DMA_CTL0_BITS_PER_CH * chan->chan_id +
 230                                        DMA_CTL0_DIR_SHIFT_BITS);
 231                 else
 232                         val &= ~(0x1 << (DMA_CTL0_BITS_PER_CH * chan->chan_id +
 233                                          DMA_CTL0_DIR_SHIFT_BITS));
 234
 235                 val |= mask_ctl;
 236                 dma_writel(pd, CTL0, val);
 237         } else {
 238                 int ch = chan->chan_id - 8; /* ch8-->0 ch9-->1 ... ch11->3 */
 239                 val = dma_readl(pd, CTL3);
 240
 241                 mask_mode = DMA_CTL0_MODE_MASK_BITS <<
 242                                                 (DMA_CTL0_BITS_PER_CH * ch);
 243                 mask_ctl = DMA_MASK_CTL2_MODE & ~(DMA_CTL0_MODE_MASK_BITS <<
 244                                                  (DMA_CTL0_BITS_PER_CH * ch));
 245                 val &= mask_mode;
 246                 if (pd_chan->dir == DMA_MEM_TO_DEV)
 247                         val |= 0x1 << (DMA_CTL0_BITS_PER_CH * ch +
 248                                        DMA_CTL0_DIR_SHIFT_BITS);
 249                 else
 250                         val &= ~(0x1 << (DMA_CTL0_BITS_PER_CH * ch +
 251                                          DMA_CTL0_DIR_SHIFT_BITS));
 252                 val |= mask_ctl;
 253                 dma_writel(pd, CTL3, val);
 254         }
 255
 256         dev_dbg(chan2dev(chan), "pdc_set_dir: chan %d -> %x\n",
 257                 chan->chan_id, val);
 258 }
 259
 260 static void pdc_set_mode(struct dma_chan *chan, u32 mode)
 261 {
 262         struct pch_dma *pd = to_pd(chan->device);
 263         u32 val;
 264         u32 mask_ctl;
 265         u32 mask_dir;
 266
 267         if (chan->chan_id < 8) {
 268                 mask_ctl = DMA_MASK_CTL0_MODE & ~(DMA_CTL0_MODE_MASK_BITS <<
 269                            (DMA_CTL0_BITS_PER_CH * chan->chan_id));
 270                 mask_dir = 1 << (DMA_CTL0_BITS_PER_CH * chan->chan_id +\
 271                                  DMA_CTL0_DIR_SHIFT_BITS);
 272                 val = dma_readl(pd, CTL0);
 273                 val &= mask_dir;
 274                 val |= mode << (DMA_CTL0_BITS_PER_CH * chan->chan_id);
 275                 val |= mask_ctl;
 276                 dma_writel(pd, CTL0, val);
 277         } else {
 278                 int ch = chan->chan_id - 8; /* ch8-->0 ch9-->1 ... ch11->3 */
 279                 mask_ctl = DMA_MASK_CTL2_MODE & ~(DMA_CTL0_MODE_MASK_BITS <<
 280                                                  (DMA_CTL0_BITS_PER_CH * ch));
 281                 mask_dir = 1 << (DMA_CTL0_BITS_PER_CH * ch +\
 282                                  DMA_CTL0_DIR_SHIFT_BITS);
 283                 val = dma_readl(pd, CTL3);
 284                 val &= mask_dir;
 285                 val |= mode << (DMA_CTL0_BITS_PER_CH * ch);
 286                 val |= mask_ctl;
 287                 dma_writel(pd, CTL3, val);
 288         }
 289
 290         dev_dbg(chan2dev(chan), "pdc_set_mode: chan %d -> %x\n",
 291                 chan->chan_id, val);
 292 }
 293
 294 static u32 pdc_get_status0(struct pch_dma_chan *pd_chan)
 295 {
 296         struct pch_dma *pd = to_pd(pd_chan->chan.device);
 297         u32 val;
 298
 299         val = dma_readl(pd, STS0);
 300         return DMA_STATUS_MASK_BITS & (val >> (DMA_STATUS_SHIFT_BITS +
 301                         DMA_STATUS_BITS_PER_CH * pd_chan->chan.chan_id));
 302 }
 303
 304 static u32 pdc_get_status2(struct pch_dma_chan *pd_chan)
 305 {
 306         struct pch_dma *pd = to_pd(pd_chan->chan.device);
 307         u32 val;
 308
 309         val = dma_readl(pd, STS2);
 310         return DMA_STATUS_MASK_BITS & (val >> (DMA_STATUS_SHIFT_BITS +
 311                         DMA_STATUS_BITS_PER_CH * (pd_chan->chan.chan_id - 8)));
 312 }
 313
 314 static bool pdc_is_idle(struct pch_dma_chan *pd_chan)
 315 {
 316         u32 sts;
 317
 318         if (pd_chan->chan.chan_id < 8)
 319                 sts = pdc_get_status0(pd_chan);
 320         else
 321                 sts = pdc_get_status2(pd_chan);
 322
 323
 324         if (sts == DMA_STATUS_IDLE)
 325                 return true;
 326         else
 327                 return false;
 328 }
 329
 330 static void pdc_dostart(struct pch_dma_chan *pd_chan, struct pch_dma_desc* desc)
 331 {
 332         if (!pdc_is_idle(pd_chan)) {
 333                 dev_err(chan2dev(&pd_chan->chan),
 334                         "BUG: Attempt to start non-idle channel\n");
 335                 return;
 336         }
 337
 338         dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> dev_addr: %x\n",
 339                 pd_chan->chan.chan_id, desc->regs.dev_addr);
 340         dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> mem_addr: %x\n",
 341                 pd_chan->chan.chan_id, desc->regs.mem_addr);
 342         dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> size: %x\n",
 343                 pd_chan->chan.chan_id, desc->regs.size);
 344         dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> next: %x\n",
 345                 pd_chan->chan.chan_id, desc->regs.next);
 346
 347         if (list_empty(&desc->tx_list)) {
 348                 channel_writel(pd_chan, DEV_ADDR, desc->regs.dev_addr);
 349                 channel_writel(pd_chan, MEM_ADDR, desc->regs.mem_addr);
 350                 channel_writel(pd_chan, SIZE, desc->regs.size);
 351                 channel_writel(pd_chan, NEXT, desc->regs.next);
 352                 pdc_set_mode(&pd_chan->chan, DMA_CTL0_ONESHOT);
 353         } else {
 354                 channel_writel(pd_chan, NEXT, desc->txd.phys);
 355                 pdc_set_mode(&pd_chan->chan, DMA_CTL0_SG);
 356         }
 357 }
 358
 359 static void pdc_chain_complete(struct pch_dma_chan *pd_chan,
 360                                struct pch_dma_desc *desc)
 361 {
 362         struct dma_async_tx_descriptor *txd = &desc->txd;
 363         dma_async_tx_callback callback = txd->callback;
 364         void *param = txd->callback_param;
 365
 366         list_splice_init(&desc->tx_list, &pd_chan->free_list);
 367         list_move(&desc->desc_node, &pd_chan->free_list);
 368
 369         if (callback)
 370                 callback(param);
 371 }
 372
 373 static void pdc_complete_all(struct pch_dma_chan *pd_chan)
 374 {
 375         struct pch_dma_desc *desc, *_d;
 376         LIST_HEAD(list);
 377
 378         BUG_ON(!pdc_is_idle(pd_chan));
 379
 380         if (!list_empty(&pd_chan->queue))
 381                 pdc_dostart(pd_chan, pdc_first_queued(pd_chan));
 382
 383         list_splice_init(&pd_chan->active_list, &list);
 384         list_splice_init(&pd_chan->queue, &pd_chan->active_list);
 385
 386         list_for_each_entry_safe(desc, _d, &list, desc_node)
 387                 pdc_chain_complete(pd_chan, desc);
 388 }
 389
 390 static void pdc_handle_error(struct pch_dma_chan *pd_chan)
 391 {
 392         struct pch_dma_desc *bad_desc;
 393
 394         bad_desc = pdc_first_active(pd_chan);
 395         list_del(&bad_desc->desc_node);
 396
 397         list_splice_init(&pd_chan->queue, pd_chan->active_list.prev);
 398
 399         if (!list_empty(&pd_chan->active_list))
 400                 pdc_dostart(pd_chan, pdc_first_active(pd_chan));
 401
 402         dev_crit(chan2dev(&pd_chan->chan), "Bad descriptor submitted\n");
 403         dev_crit(chan2dev(&pd_chan->chan), "descriptor cookie: %d\n",
 404                  bad_desc->txd.cookie);
 405
 406         pdc_chain_complete(pd_chan, bad_desc);
 407 }
 408
 409 static void pdc_advance_work(struct pch_dma_chan *pd_chan)
 410 {
 411         if (list_empty(&pd_chan->active_list) ||
 412                 list_is_singular(&pd_chan->active_list)) {
 413                 pdc_complete_all(pd_chan);
 414         } else {
 415                 pdc_chain_complete(pd_chan, pdc_first_active(pd_chan));
 416                 pdc_dostart(pd_chan, pdc_first_active(pd_chan));
 417         }
 418 }
 419
 420 static dma_cookie_t pd_tx_submit(struct dma_async_tx_descriptor *txd)
 421 {
 422         struct pch_dma_desc *desc = to_pd_desc(txd);
 423         struct pch_dma_chan *pd_chan = to_pd_chan(txd->chan);
 424         dma_cookie_t cookie;
 425
 426         spin_lock(&pd_chan->lock);
 427         cookie = dma_cookie_assign(txd);
 428
 429         if (list_empty(&pd_chan->active_list)) {
 430                 list_add_tail(&desc->desc_node, &pd_chan->active_list);
 431                 pdc_dostart(pd_chan, desc);
 432         } else {
 433                 list_add_tail(&desc->desc_node, &pd_chan->queue);
 434         }
 435
 436         spin_unlock(&pd_chan->lock);
 437         return 0;
 438 }
 439
 440 static struct pch_dma_desc *pdc_alloc_desc(struct dma_chan *chan, gfp_t flags)
 441 {
 442         struct pch_dma_desc *desc = NULL;
 443         struct pch_dma *pd = to_pd(chan->device);
 444         dma_addr_t addr;
 445
 446         desc = pci_pool_alloc(pd->pool, flags, &addr);
 447         if (desc) {
 448                 memset(desc, 0, sizeof(struct pch_dma_desc));
 449                 INIT_LIST_HEAD(&desc->tx_list);
 450                 dma_async_tx_descriptor_init(&desc->txd, chan);
 451                 desc->txd.tx_submit = pd_tx_submit;
 452                 desc->txd.flags = DMA_CTRL_ACK;
 453                 desc->txd.phys = addr;
 454         }
 455
 456         return desc;
 457 }
 458
 459 static struct pch_dma_desc *pdc_desc_get(struct pch_dma_chan *pd_chan)
 460 {
 461         struct pch_dma_desc *desc, *_d;
 462         struct pch_dma_desc *ret = NULL;
 463         int i = 0;
 464
 465         spin_lock(&pd_chan->lock);
 466         list_for_each_entry_safe(desc, _d, &pd_chan->free_list, desc_node) {
 467                 i++;
 468                 if (async_tx_test_ack(&desc->txd)) {
 469                         list_del(&desc->desc_node);
 470                         ret = desc;
 471                         break;
 472                 }
 473                 dev_dbg(chan2dev(&pd_chan->chan), "desc %p not ACKed\n", desc);
 474         }
 475         spin_unlock(&pd_chan->lock);
 476         dev_dbg(chan2dev(&pd_chan->chan), "scanned %d descriptors\n", i);
 477
 478         if (!ret) {
 479                 ret = pdc_alloc_desc(&pd_chan->chan, GFP_NOIO);
 480                 if (ret) {
 481                         spin_lock(&pd_chan->lock);
 482                         pd_chan->descs_allocated++;
 483                         spin_unlock(&pd_chan->lock);
 484                 } else {
 485                         dev_err(chan2dev(&pd_chan->chan),
 486                                 "failed to alloc desc\n");
 487                 }
 488         }
 489
 490         return ret;
 491 }
 492
 493 static void pdc_desc_put(struct pch_dma_chan *pd_chan,
 494                          struct pch_dma_desc *desc)
 495 {
 496         if (desc) {
 497                 spin_lock(&pd_chan->lock);
 498                 list_splice_init(&desc->tx_list, &pd_chan->free_list);
 499                 list_add(&desc->desc_node, &pd_chan->free_list);
 500                 spin_unlock(&pd_chan->lock);
 501         }
 502 }
 503
 504 static int pd_alloc_chan_resources(struct dma_chan *chan)
 505 {
 506         struct pch_dma_chan *pd_chan = to_pd_chan(chan);
 507         struct pch_dma_desc *desc;
 508         LIST_HEAD(tmp_list);
 509         int i;
 510
 511         if (!pdc_is_idle(pd_chan)) {
 512                 dev_dbg(chan2dev(chan), "DMA channel not idle ?\n");
 513                 return -EIO;
 514         }
 515
 516         if (!list_empty(&pd_chan->free_list))
 517                 return pd_chan->descs_allocated;
 518
 519         for (i = 0; i < init_nr_desc_per_channel; i++) {
 520                 desc = pdc_alloc_desc(chan, GFP_KERNEL);
 521
 522                 if (!desc) {
 523                         dev_warn(chan2dev(chan),
 524                                 "Only allocated %d initial descriptors\n", i);
 525                         break;
 526                 }
 527
 528                 list_add_tail(&desc->desc_node, &tmp_list);
 529         }
 530
 531         spin_lock_irq(&pd_chan->lock);
 532         list_splice(&tmp_list, &pd_chan->free_list);
 533         pd_chan->descs_allocated = i;
 534         dma_cookie_init(chan);
 535         spin_unlock_irq(&pd_chan->lock);
 536
 537         pdc_enable_irq(chan, 1);
 538
 539         return pd_chan->descs_allocated;
 540 }
 541
 542 static void pd_free_chan_resources(struct dma_chan *chan)
 543 {
 544         struct pch_dma_chan *pd_chan = to_pd_chan(chan);
 545         struct pch_dma *pd = to_pd(chan->device);
 546         struct pch_dma_desc *desc, *_d;
 547         LIST_HEAD(tmp_list);
 548
 549         BUG_ON(!pdc_is_idle(pd_chan));
 550         BUG_ON(!list_empty(&pd_chan->active_list));
 551         BUG_ON(!list_empty(&pd_chan->queue));
 552
 553         spin_lock_irq(&pd_chan->lock);
 554         list_splice_init(&pd_chan->free_list, &tmp_list);
 555         pd_chan->descs_allocated = 0;
 556         spin_unlock_irq(&pd_chan->lock);
 557
 558         list_for_each_entry_safe(desc, _d, &tmp_list, desc_node)
 559                 pci_pool_free(pd->pool, desc, desc->txd.phys);
 560
 561         pdc_enable_irq(chan, 0);
 562 }
 563
 564 static enum dma_status pd_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
 565                                     struct dma_tx_state *txstate)
 566 {
 567         struct pch_dma_chan *pd_chan = to_pd_chan(chan);
 568         enum dma_status ret;
 569
 570         spin_lock_irq(&pd_chan->lock);
 571         ret = dma_cookie_status(chan, cookie, txstate);
 572         spin_unlock_irq(&pd_chan->lock);
 573
 574         return ret;
 575 }
 576
 577 static void pd_issue_pending(struct dma_chan *chan)
 578 {
 579         struct pch_dma_chan *pd_chan = to_pd_chan(chan);
 580
 581         if (pdc_is_idle(pd_chan)) {
 582                 spin_lock(&pd_chan->lock);
 583                 pdc_advance_work(pd_chan);
 584                 spin_unlock(&pd_chan->lock);
 585         }
 586 }
 587
 588 static struct dma_async_tx_descriptor *pd_prep_slave_sg(struct dma_chan *chan,
 589                         struct scatterlist *sgl, unsigned int sg_len,
 590                         enum dma_transfer_direction direction, unsigned long flags,
 591                         void *context)
 592 {
 593         struct pch_dma_chan *pd_chan = to_pd_chan(chan);
 594         struct pch_dma_slave *pd_slave = chan->private;
 595         struct pch_dma_desc *first = NULL;
 596         struct pch_dma_desc *prev = NULL;
 597         struct pch_dma_desc *desc = NULL;
 598         struct scatterlist *sg;
 599         dma_addr_t reg;
 600         int i;
 601
 602         if (unlikely(!sg_len)) {
 603                 dev_info(chan2dev(chan), "prep_slave_sg: length is zero!\n");
 604                 return NULL;
 605         }
 606
 607         if (direction == DMA_DEV_TO_MEM)
 608                 reg = pd_slave->rx_reg;
 609         else if (direction == DMA_MEM_TO_DEV)
 610                 reg = pd_slave->tx_reg;
 611         else
 612                 return NULL;
 613
 614         pd_chan->dir = direction;
 615         pdc_set_dir(chan);
 616
 617         for_each_sg(sgl, sg, sg_len, i) {
 618                 desc = pdc_desc_get(pd_chan);
 619
 620                 if (!desc)
 621                         goto err_desc_get;
 622
 623                 desc->regs.dev_addr = reg;
 624                 desc->regs.mem_addr = sg_dma_address(sg);
 625                 desc->regs.size = sg_dma_len(sg);
 626                 desc->regs.next = DMA_DESC_FOLLOW_WITHOUT_IRQ;
 627
 628                 switch (pd_slave->width) {
 629                 case PCH_DMA_WIDTH_1_BYTE:
 630                         if (desc->regs.size > DMA_DESC_MAX_COUNT_1_BYTE)
 631                                 goto err_desc_get;
 632                         desc->regs.size |= DMA_DESC_WIDTH_1_BYTE;
 633                         break;
 634                 case PCH_DMA_WIDTH_2_BYTES:
 635                         if (desc->regs.size > DMA_DESC_MAX_COUNT_2_BYTES)
 636                                 goto err_desc_get;
 637                         desc->regs.size |= DMA_DESC_WIDTH_2_BYTES;
 638                         break;
 639                 case PCH_DMA_WIDTH_4_BYTES:
 640                         if (desc->regs.size > DMA_DESC_MAX_COUNT_4_BYTES)
 641                                 goto err_desc_get;
 642                         desc->regs.size |= DMA_DESC_WIDTH_4_BYTES;
 643                         break;
 644                 default:
 645                         goto err_desc_get;
 646                 }
 647
 648                 if (!first) {
 649                         first = desc;
 650                 } else {
 651                         prev->regs.next |= desc->txd.phys;
 652                         list_add_tail(&desc->desc_node, &first->tx_list);
 653                 }
 654
 655                 prev = desc;
 656         }
 657
 658         if (flags & DMA_PREP_INTERRUPT)
 659                 desc->regs.next = DMA_DESC_END_WITH_IRQ;
 660         else
 661                 desc->regs.next = DMA_DESC_END_WITHOUT_IRQ;
 662
 663         first->txd.cookie = -EBUSY;
 664         desc->txd.flags = flags;
 665
 666         return &first->txd;
 667
 668 err_desc_get:
 669         dev_err(chan2dev(chan), "failed to get desc or wrong parameters\n");
 670         pdc_desc_put(pd_chan, first);
 671         return NULL;
 672 }
 673
 674 static int pd_device_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
 675                              unsigned long arg)
 676 {
 677         struct pch_dma_chan *pd_chan = to_pd_chan(chan);
 678         struct pch_dma_desc *desc, *_d;
 679         LIST_HEAD(list);
 680
 681         if (cmd != DMA_TERMINATE_ALL)
 682                 return -ENXIO;
 683
 684         spin_lock_irq(&pd_chan->lock);
 685
 686         pdc_set_mode(&pd_chan->chan, DMA_CTL0_DISABLE);
 687
 688         list_splice_init(&pd_chan->active_list, &list);
 689         list_splice_init(&pd_chan->queue, &list);
 690
 691         list_for_each_entry_safe(desc, _d, &list, desc_node)
 692                 pdc_chain_complete(pd_chan, desc);
 693
 694         spin_unlock_irq(&pd_chan->lock);
 695
 696         return 0;
 697 }
 698
 699 static void pdc_tasklet(unsigned long data)
 700 {
 701         struct pch_dma_chan *pd_chan = (struct pch_dma_chan *)data;
 702         unsigned long flags;
 703
 704         if (!pdc_is_idle(pd_chan)) {
 705                 dev_err(chan2dev(&pd_chan->chan),
 706                         "BUG: handle non-idle channel in tasklet\n");
 707                 return;
 708         }
 709
 710         spin_lock_irqsave(&pd_chan->lock, flags);
 711         if (test_and_clear_bit(0, &pd_chan->err_status))
 712                 pdc_handle_error(pd_chan);
 713         else
 714                 pdc_advance_work(pd_chan);
 715         spin_unlock_irqrestore(&pd_chan->lock, flags);
 716 }
 717
 718 static irqreturn_t pd_irq(int irq, void *devid)
 719 {
 720         struct pch_dma *pd = (struct pch_dma *)devid;
 721         struct pch_dma_chan *pd_chan;
 722         u32 sts0;
 723         u32 sts2;
 724         int i;
 725         int ret0 = IRQ_NONE;
 726         int ret2 = IRQ_NONE;
 727
 728         sts0 = dma_readl(pd, STS0);
 729         sts2 = dma_readl(pd, STS2);
 730
 731         dev_dbg(pd->dma.dev, "pd_irq sts0: %x\n", sts0);
 732
 733         for (i = 0; i < pd->dma.chancnt; i++) {
 734                 pd_chan = &pd->channels[i];
 735
 736                 if (i < 8) {
 737                         if (sts0 & DMA_STATUS_IRQ(i)) {
 738                                 if (sts0 & DMA_STATUS0_ERR(i))
 739                                         set_bit(0, &pd_chan->err_status);
 740
 741                                 tasklet_schedule(&pd_chan->tasklet);
 742                                 ret0 = IRQ_HANDLED;
 743                         }
 744                 } else {
 745                         if (sts2 & DMA_STATUS_IRQ(i - 8)) {
 746                                 if (sts2 & DMA_STATUS2_ERR(i))
 747                                         set_bit(0, &pd_chan->err_status);
 748
 749                                 tasklet_schedule(&pd_chan->tasklet);
 750                                 ret2 = IRQ_HANDLED;
 751                         }
 752                 }
 753         }
 754
 755         /* clear interrupt bits in status register */
 756         if (ret0)
 757                 dma_writel(pd, STS0, sts0);
 758         if (ret2)
 759                 dma_writel(pd, STS2, sts2);
 760
 761         return ret0 | ret2;
 762 }
 763
 764 #ifdef  CONFIG_PM
 765 static void pch_dma_save_regs(struct pch_dma *pd)
 766 {
 767         struct pch_dma_chan *pd_chan;
 768         struct dma_chan *chan, *_c;
 769         int i = 0;
 770
 771         pd->regs.dma_ctl0 = dma_readl(pd, CTL0);
 772         pd->regs.dma_ctl1 = dma_readl(pd, CTL1);
 773         pd->regs.dma_ctl2 = dma_readl(pd, CTL2);
 774         pd->regs.dma_ctl3 = dma_readl(pd, CTL3);
 775
 776         list_for_each_entry_safe(chan, _c, &pd->dma.channels, device_node) {
 777                 pd_chan = to_pd_chan(chan);
 778
 779                 pd->ch_regs[i].dev_addr = channel_readl(pd_chan, DEV_ADDR);
 780                 pd->ch_regs[i].mem_addr = channel_readl(pd_chan, MEM_ADDR);
 781                 pd->ch_regs[i].size = channel_readl(pd_chan, SIZE);
 782                 pd->ch_regs[i].next = channel_readl(pd_chan, NEXT);
 783
 784                 i++;
 785         }
 786 }
 787
 788 static void pch_dma_restore_regs(struct pch_dma *pd)
 789 {
 790         struct pch_dma_chan *pd_chan;
 791         struct dma_chan *chan, *_c;
 792         int i = 0;
 793
 794         dma_writel(pd, CTL0, pd->regs.dma_ctl0);
 795         dma_writel(pd, CTL1, pd->regs.dma_ctl1);
 796         dma_writel(pd, CTL2, pd->regs.dma_ctl2);
 797         dma_writel(pd, CTL3, pd->regs.dma_ctl3);
 798
 799         list_for_each_entry_safe(chan, _c, &pd->dma.channels, device_node) {
 800                 pd_chan = to_pd_chan(chan);
 801
 802                 channel_writel(pd_chan, DEV_ADDR, pd->ch_regs[i].dev_addr);
 803                 channel_writel(pd_chan, MEM_ADDR, pd->ch_regs[i].mem_addr);
 804                 channel_writel(pd_chan, SIZE, pd->ch_regs[i].size);
 805                 channel_writel(pd_chan, NEXT, pd->ch_regs[i].next);
 806
 807                 i++;
 808         }
 809 }
 810
 811 static int pch_dma_suspend(struct pci_dev *pdev, pm_message_t state)
 812 {
 813         struct pch_dma *pd = pci_get_drvdata(pdev);
 814
 815         if (pd)
 816                 pch_dma_save_regs(pd);
 817
 818         pci_save_state(pdev);
 819         pci_disable_device(pdev);
 820         pci_set_power_state(pdev, pci_choose_state(pdev, state));
 821
 822         return 0;
 823 }
 824
 825 static int pch_dma_resume(struct pci_dev *pdev)
 826 {
 827         struct pch_dma *pd = pci_get_drvdata(pdev);
 828         int err;
 829
 830         pci_set_power_state(pdev, PCI_D0);
 831         pci_restore_state(pdev);
 832
 833         err = pci_enable_device(pdev);
 834         if (err) {
 835                 dev_dbg(&pdev->dev, "failed to enable device\n");
 836                 return err;
 837         }
 838
 839         if (pd)
 840                 pch_dma_restore_regs(pd);
 841
 842         return 0;
 843 }
 844 #endif
 845
 846 static int pch_dma_probe(struct pci_dev *pdev,
 847                                    const struct pci_device_id *id)
 848 {
 849         struct pch_dma *pd;
 850         struct pch_dma_regs *regs;
 851         unsigned int nr_channels;
 852         int err;
 853         int i;
 854
 855         nr_channels = id->driver_data;
 856         pd = kzalloc(sizeof(*pd), GFP_KERNEL);
 857         if (!pd)
 858                 return -ENOMEM;
 859
 860         pci_set_drvdata(pdev, pd);
 861
 862         err = pci_enable_device(pdev);
 863         if (err) {
 864                 dev_err(&pdev->dev, "Cannot enable PCI device\n");
 865                 goto err_free_mem;
 866         }
 867
 868         if (!(pci_resource_flags(pdev, 1) & IORESOURCE_MEM)) {
 869                 dev_err(&pdev->dev, "Cannot find proper base address\n");
 870                 goto err_disable_pdev;
 871         }
 872
 873         err = pci_request_regions(pdev, DRV_NAME);
 874         if (err) {
 875                 dev_err(&pdev->dev, "Cannot obtain PCI resources\n");
 876                 goto err_disable_pdev;
 877         }
 878
 879         err = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
 880         if (err) {
 881                 dev_err(&pdev->dev, "Cannot set proper DMA config\n");
 882                 goto err_free_res;
 883         }
 884
 885         regs = pd->membase = pci_iomap(pdev, 1, 0);
 886         if (!pd->membase) {
 887                 dev_err(&pdev->dev, "Cannot map MMIO registers\n");
 888                 err = -ENOMEM;
 889                 goto err_free_res;
 890         }
 891
 892         pci_set_master(pdev);
 893
 894         err = request_irq(pdev->irq, pd_irq, IRQF_SHARED, DRV_NAME, pd);
 895         if (err) {
 896                 dev_err(&pdev->dev, "Failed to request IRQ\n");
 897                 goto err_iounmap;
 898         }
 899
 900         pd->pool = pci_pool_create("pch_dma_desc_pool", pdev,
 901                                    sizeof(struct pch_dma_desc), 4, 0);
 902         if (!pd->pool) {
 903                 dev_err(&pdev->dev, "Failed to alloc DMA descriptors\n");
 904                 err = -ENOMEM;
 905                 goto err_free_irq;
 906         }
 907
 908         pd->dma.dev = &pdev->dev;
 909
 910         INIT_LIST_HEAD(&pd->dma.channels);
 911
 912         for (i = 0; i < nr_channels; i++) {
 913                 struct pch_dma_chan *pd_chan = &pd->channels[i];
 914
 915                 pd_chan->chan.device = &pd->dma;
 916                 dma_cookie_init(&pd_chan->chan);
 917
 918                 pd_chan->membase = &regs->desc[i];
 919
 920                 spin_lock_init(&pd_chan->lock);
 921
 922                 INIT_LIST_HEAD(&pd_chan->active_list);
 923                 INIT_LIST_HEAD(&pd_chan->queue);
 924                 INIT_LIST_HEAD(&pd_chan->free_list);
 925
 926                 tasklet_init(&pd_chan->tasklet, pdc_tasklet,
 927                              (unsigned long)pd_chan);
 928                 list_add_tail(&pd_chan->chan.device_node, &pd->dma.channels);
 929         }
 930
 931         dma_cap_zero(pd->dma.cap_mask);
 932         dma_cap_set(DMA_PRIVATE, pd->dma.cap_mask);
 933         dma_cap_set(DMA_SLAVE, pd->dma.cap_mask);
 934
 935         pd->dma.device_alloc_chan_resources = pd_alloc_chan_resources;
 936         pd->dma.device_free_chan_resources = pd_free_chan_resources;
 937         pd->dma.device_tx_status = pd_tx_status;
 938         pd->dma.device_issue_pending = pd_issue_pending;
 939         pd->dma.device_prep_slave_sg = pd_prep_slave_sg;
 940         pd->dma.device_control = pd_device_control;
 941
 942         err = dma_async_device_register(&pd->dma);
 943         if (err) {
 944                 dev_err(&pdev->dev, "Failed to register DMA device\n");
 945                 goto err_free_pool;
 946         }
 947
 948         return 0;
 949
 950 err_free_pool:
 951         pci_pool_destroy(pd->pool);
 952 err_free_irq:
 953         free_irq(pdev->irq, pd);
 954 err_iounmap:
 955         pci_iounmap(pdev, pd->membase);
 956 err_free_res:
 957         pci_release_regions(pdev);
 958 err_disable_pdev:
 959         pci_disable_device(pdev);
 960 err_free_mem:
 961         return err;
 962 }
 963
 964 static void pch_dma_remove(struct pci_dev *pdev)
 965 {
 966         struct pch_dma *pd = pci_get_drvdata(pdev);
 967         struct pch_dma_chan *pd_chan;
 968         struct dma_chan *chan, *_c;
 969
 970         if (pd) {
 971                 dma_async_device_unregister(&pd->dma);
 972
 973                 list_for_each_entry_safe(chan, _c, &pd->dma.channels,
 974                                          device_node) {
 975                         pd_chan = to_pd_chan(chan);
 976
 977                         tasklet_disable(&pd_chan->tasklet);
 978                         tasklet_kill(&pd_chan->tasklet);
 979                 }
 980
 981                 pci_pool_destroy(pd->pool);
 982                 free_irq(pdev->irq, pd);
 983                 pci_iounmap(pdev, pd->membase);
 984                 pci_release_regions(pdev);
 985                 pci_disable_device(pdev);
 986                 kfree(pd);
 987         }
 988 }
 989
 990 /* PCI Device ID of DMA device */
 991 #define PCI_VENDOR_ID_ROHM             0x10DB
 992 #define PCI_DEVICE_ID_EG20T_PCH_DMA_8CH        0x8810
 993 #define PCI_DEVICE_ID_EG20T_PCH_DMA_4CH        0x8815
 994 #define PCI_DEVICE_ID_ML7213_DMA1_8CH   0x8026
 995 #define PCI_DEVICE_ID_ML7213_DMA2_8CH   0x802B
 996 #define PCI_DEVICE_ID_ML7213_DMA3_4CH   0x8034
 997 #define PCI_DEVICE_ID_ML7213_DMA4_12CH  0x8032
 998 #define PCI_DEVICE_ID_ML7223_DMA1_4CH   0x800B
 999 #define PCI_DEVICE_ID_ML7223_DMA2_4CH   0x800E
1000 #define PCI_DEVICE_ID_ML7223_DMA3_4CH   0x8017
1001 #define PCI_DEVICE_ID_ML7223_DMA4_4CH   0x803B
1002 #define PCI_DEVICE_ID_ML7831_DMA1_8CH   0x8810
1003 #define PCI_DEVICE_ID_ML7831_DMA2_4CH   0x8815
1004
1005 DEFINE_PCI_DEVICE_TABLE(pch_dma_id_table) = {
1006         { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_EG20T_PCH_DMA_8CH), 8 },
1007         { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_EG20T_PCH_DMA_4CH), 4 },
1008         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA1_8CH), 8}, /* UART Video */
1009         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA2_8CH), 8}, /* PCMIF SPI */
1010         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA3_4CH), 4}, /* FPGA */
1011         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA4_12CH), 12}, /* I2S */
1012         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_DMA1_4CH), 4}, /* UART */
1013         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_DMA2_4CH), 4}, /* Video SPI */
1014         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_DMA3_4CH), 4}, /* Security */
1015         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_DMA4_4CH), 4}, /* FPGA */
1016         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7831_DMA1_8CH), 8}, /* UART */
1017         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7831_DMA2_4CH), 4}, /* SPI */
1018         { 0, },
1019 };
1020
1021 static struct pci_driver pch_dma_driver = {
1022         .name           = DRV_NAME,
1023         .id_table       = pch_dma_id_table,
1024         .probe          = pch_dma_probe,
1025         .remove         = pch_dma_remove,
1026 #ifdef CONFIG_PM
1027         .suspend        = pch_dma_suspend,
1028         .resume         = pch_dma_resume,
1029 #endif
1030 };
1031
1032 static int __init pch_dma_init(void)
1033 {
1034         return pci_register_driver(&pch_dma_driver);
1035 }
1036
1037 static void __exit pch_dma_exit(void)
1038 {
1039         pci_unregister_driver(&pch_dma_driver);
1040 }
1041
1042 module_init(pch_dma_init);
1043 module_exit(pch_dma_exit);
1044
1045 MODULE_DESCRIPTION("Intel EG20T PCH / LAPIS Semicon ML7213/ML7223/ML7831 IOH "
1046                    "DMA controller driver");
1047 MODULE_AUTHOR("Yong Wang <yong.y.wang@intel.com>");
1048 MODULE_LICENSE("GPL v2");