linux/drivers/dma/pch_dma.c
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   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
  64static unsigned int init_nr_desc_per_channel = 64;
  65module_param(init_nr_desc_per_channel, uint, 0644);
  66MODULE_PARM_DESC(init_nr_desc_per_channel,
  67                 "initial descriptors per channel (default: 64)");
  68
  69struct pch_dma_desc_regs {
  70        u32     dev_addr;
  71        u32     mem_addr;
  72        u32     size;
  73        u32     next;
  74};
  75
  76struct 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[0];
  86};
  87
  88struct 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
  95struct 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
 121struct 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[0];
 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
 141static 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
 146static 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
 151static inline struct pch_dma *to_pd(struct dma_device *ddev)
 152{
 153        return container_of(ddev, struct pch_dma, dma);
 154}
 155
 156static inline struct device *chan2dev(struct dma_chan *chan)
 157{
 158        return &chan->dev->device;
 159}
 160
 161static inline struct device *chan2parent(struct dma_chan *chan)
 162{
 163        return chan->dev->device.parent;
 164}
 165
 166static 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
 172static 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
 178static 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
 196static 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
 217static 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
 234static 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
 244static 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
 252static 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
 288static 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
 302static 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
 319static 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
 338static 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
 349static 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
 363static 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_bh(&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_bh(&pd_chan->lock);
 380        return 0;
 381}
 382
 383static 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, GFP_KERNEL, &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
 402static 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_bh(&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_bh(&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_bh(&pd_chan->lock);
 425                        pd_chan->descs_allocated++;
 426                        spin_unlock_bh(&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
 436static void pdc_desc_put(struct pch_dma_chan *pd_chan,
 437                         struct pch_dma_desc *desc)
 438{
 439        if (desc) {
 440                spin_lock_bh(&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_bh(&pd_chan->lock);
 444        }
 445}
 446
 447static 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
 486static 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
 508static 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
 528static 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_bh(&pd_chan->lock);
 534                pdc_advance_work(pd_chan);
 535                spin_unlock_bh(&pd_chan->lock);
 536        }
 537}
 538
 539static 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
 596                if (!first) {
 597                        first = desc;
 598                } else {
 599                        prev->regs.next |= desc->txd.phys;
 600                        list_add_tail(&desc->desc_node, &first->tx_list);
 601                }
 602
 603                prev = desc;
 604        }
 605
 606        if (flags & DMA_PREP_INTERRUPT)
 607                desc->regs.next = DMA_DESC_END_WITH_IRQ;
 608        else
 609                desc->regs.next = DMA_DESC_END_WITHOUT_IRQ;
 610
 611        first->txd.cookie = -EBUSY;
 612        desc->txd.flags = flags;
 613
 614        return &first->txd;
 615
 616err_desc_get:
 617        dev_err(chan2dev(chan), "failed to get desc or wrong parameters\n");
 618        pdc_desc_put(pd_chan, first);
 619        return NULL;
 620}
 621
 622static int pd_device_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
 623                             unsigned long arg)
 624{
 625        struct pch_dma_chan *pd_chan = to_pd_chan(chan);
 626        struct pch_dma_desc *desc, *_d;
 627        LIST_HEAD(list);
 628
 629        if (cmd != DMA_TERMINATE_ALL)
 630                return -ENXIO;
 631
 632        spin_lock_bh(&pd_chan->lock);
 633
 634        pdc_set_mode(&pd_chan->chan, DMA_CTL0_DISABLE);
 635
 636        list_splice_init(&pd_chan->active_list, &list);
 637        list_splice_init(&pd_chan->queue, &list);
 638
 639        list_for_each_entry_safe(desc, _d, &list, desc_node)
 640                pdc_chain_complete(pd_chan, desc);
 641
 642        spin_unlock_bh(&pd_chan->lock);
 643
 644
 645        return 0;
 646}
 647
 648static void pdc_tasklet(unsigned long data)
 649{
 650        struct pch_dma_chan *pd_chan = (struct pch_dma_chan *)data;
 651
 652        if (!pdc_is_idle(pd_chan)) {
 653                dev_err(chan2dev(&pd_chan->chan),
 654                        "BUG: handle non-idle channel in tasklet\n");
 655                return;
 656        }
 657
 658        spin_lock_bh(&pd_chan->lock);
 659        if (test_and_clear_bit(0, &pd_chan->err_status))
 660                pdc_handle_error(pd_chan);
 661        else
 662                pdc_advance_work(pd_chan);
 663        spin_unlock_bh(&pd_chan->lock);
 664}
 665
 666static irqreturn_t pd_irq(int irq, void *devid)
 667{
 668        struct pch_dma *pd = (struct pch_dma *)devid;
 669        struct pch_dma_chan *pd_chan;
 670        u32 sts0;
 671        int i;
 672        int ret = IRQ_NONE;
 673
 674        sts0 = dma_readl(pd, STS0);
 675
 676        dev_dbg(pd->dma.dev, "pd_irq sts0: %x\n", sts0);
 677
 678        for (i = 0; i < pd->dma.chancnt; i++) {
 679                pd_chan = &pd->channels[i];
 680
 681                if (sts0 & DMA_STATUS_IRQ(i)) {
 682                        if (sts0 & DMA_STATUS_ERR(i))
 683                                set_bit(0, &pd_chan->err_status);
 684
 685                        tasklet_schedule(&pd_chan->tasklet);
 686                        ret = IRQ_HANDLED;
 687                }
 688
 689        }
 690
 691        /* clear interrupt bits in status register */
 692        dma_writel(pd, STS0, sts0);
 693
 694        return ret;
 695}
 696
 697static void pch_dma_save_regs(struct pch_dma *pd)
 698{
 699        struct pch_dma_chan *pd_chan;
 700        struct dma_chan *chan, *_c;
 701        int i = 0;
 702
 703        pd->regs.dma_ctl0 = dma_readl(pd, CTL0);
 704        pd->regs.dma_ctl1 = dma_readl(pd, CTL1);
 705        pd->regs.dma_ctl2 = dma_readl(pd, CTL2);
 706
 707        list_for_each_entry_safe(chan, _c, &pd->dma.channels, device_node) {
 708                pd_chan = to_pd_chan(chan);
 709
 710                pd->ch_regs[i].dev_addr = channel_readl(pd_chan, DEV_ADDR);
 711                pd->ch_regs[i].mem_addr = channel_readl(pd_chan, MEM_ADDR);
 712                pd->ch_regs[i].size = channel_readl(pd_chan, SIZE);
 713                pd->ch_regs[i].next = channel_readl(pd_chan, NEXT);
 714
 715                i++;
 716        }
 717}
 718
 719static void pch_dma_restore_regs(struct pch_dma *pd)
 720{
 721        struct pch_dma_chan *pd_chan;
 722        struct dma_chan *chan, *_c;
 723        int i = 0;
 724
 725        dma_writel(pd, CTL0, pd->regs.dma_ctl0);
 726        dma_writel(pd, CTL1, pd->regs.dma_ctl1);
 727        dma_writel(pd, CTL2, pd->regs.dma_ctl2);
 728
 729        list_for_each_entry_safe(chan, _c, &pd->dma.channels, device_node) {
 730                pd_chan = to_pd_chan(chan);
 731
 732                channel_writel(pd_chan, DEV_ADDR, pd->ch_regs[i].dev_addr);
 733                channel_writel(pd_chan, MEM_ADDR, pd->ch_regs[i].mem_addr);
 734                channel_writel(pd_chan, SIZE, pd->ch_regs[i].size);
 735                channel_writel(pd_chan, NEXT, pd->ch_regs[i].next);
 736
 737                i++;
 738        }
 739}
 740
 741static int pch_dma_suspend(struct pci_dev *pdev, pm_message_t state)
 742{
 743        struct pch_dma *pd = pci_get_drvdata(pdev);
 744
 745        if (pd)
 746                pch_dma_save_regs(pd);
 747
 748        pci_save_state(pdev);
 749        pci_disable_device(pdev);
 750        pci_set_power_state(pdev, pci_choose_state(pdev, state));
 751
 752        return 0;
 753}
 754
 755static int pch_dma_resume(struct pci_dev *pdev)
 756{
 757        struct pch_dma *pd = pci_get_drvdata(pdev);
 758        int err;
 759
 760        pci_set_power_state(pdev, PCI_D0);
 761        pci_restore_state(pdev);
 762
 763        err = pci_enable_device(pdev);
 764        if (err) {
 765                dev_dbg(&pdev->dev, "failed to enable device\n");
 766                return err;
 767        }
 768
 769        if (pd)
 770                pch_dma_restore_regs(pd);
 771
 772        return 0;
 773}
 774
 775static int __devinit pch_dma_probe(struct pci_dev *pdev,
 776                                   const struct pci_device_id *id)
 777{
 778        struct pch_dma *pd;
 779        struct pch_dma_regs *regs;
 780        unsigned int nr_channels;
 781        int err;
 782        int i;
 783
 784        nr_channels = id->driver_data;
 785        pd = kzalloc(sizeof(struct pch_dma)+
 786                sizeof(struct pch_dma_chan) * nr_channels, GFP_KERNEL);
 787        if (!pd)
 788                return -ENOMEM;
 789
 790        pci_set_drvdata(pdev, pd);
 791
 792        err = pci_enable_device(pdev);
 793        if (err) {
 794                dev_err(&pdev->dev, "Cannot enable PCI device\n");
 795                goto err_free_mem;
 796        }
 797
 798        if (!(pci_resource_flags(pdev, 1) & IORESOURCE_MEM)) {
 799                dev_err(&pdev->dev, "Cannot find proper base address\n");
 800                goto err_disable_pdev;
 801        }
 802
 803        err = pci_request_regions(pdev, DRV_NAME);
 804        if (err) {
 805                dev_err(&pdev->dev, "Cannot obtain PCI resources\n");
 806                goto err_disable_pdev;
 807        }
 808
 809        err = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
 810        if (err) {
 811                dev_err(&pdev->dev, "Cannot set proper DMA config\n");
 812                goto err_free_res;
 813        }
 814
 815        regs = pd->membase = pci_iomap(pdev, 1, 0);
 816        if (!pd->membase) {
 817                dev_err(&pdev->dev, "Cannot map MMIO registers\n");
 818                err = -ENOMEM;
 819                goto err_free_res;
 820        }
 821
 822        pci_set_master(pdev);
 823
 824        err = request_irq(pdev->irq, pd_irq, IRQF_SHARED, DRV_NAME, pd);
 825        if (err) {
 826                dev_err(&pdev->dev, "Failed to request IRQ\n");
 827                goto err_iounmap;
 828        }
 829
 830        pd->pool = pci_pool_create("pch_dma_desc_pool", pdev,
 831                                   sizeof(struct pch_dma_desc), 4, 0);
 832        if (!pd->pool) {
 833                dev_err(&pdev->dev, "Failed to alloc DMA descriptors\n");
 834                err = -ENOMEM;
 835                goto err_free_irq;
 836        }
 837
 838        pd->dma.dev = &pdev->dev;
 839        pd->dma.chancnt = nr_channels;
 840
 841        INIT_LIST_HEAD(&pd->dma.channels);
 842
 843        for (i = 0; i < nr_channels; i++) {
 844                struct pch_dma_chan *pd_chan = &pd->channels[i];
 845
 846                pd_chan->chan.device = &pd->dma;
 847                pd_chan->chan.cookie = 1;
 848                pd_chan->chan.chan_id = i;
 849
 850                pd_chan->membase = &regs->desc[i];
 851
 852                pd_chan->dir = (i % 2) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
 853
 854                spin_lock_init(&pd_chan->lock);
 855
 856                INIT_LIST_HEAD(&pd_chan->active_list);
 857                INIT_LIST_HEAD(&pd_chan->queue);
 858                INIT_LIST_HEAD(&pd_chan->free_list);
 859
 860                tasklet_init(&pd_chan->tasklet, pdc_tasklet,
 861                             (unsigned long)pd_chan);
 862                list_add_tail(&pd_chan->chan.device_node, &pd->dma.channels);
 863        }
 864
 865        dma_cap_zero(pd->dma.cap_mask);
 866        dma_cap_set(DMA_PRIVATE, pd->dma.cap_mask);
 867        dma_cap_set(DMA_SLAVE, pd->dma.cap_mask);
 868
 869        pd->dma.device_alloc_chan_resources = pd_alloc_chan_resources;
 870        pd->dma.device_free_chan_resources = pd_free_chan_resources;
 871        pd->dma.device_tx_status = pd_tx_status;
 872        pd->dma.device_issue_pending = pd_issue_pending;
 873        pd->dma.device_prep_slave_sg = pd_prep_slave_sg;
 874        pd->dma.device_control = pd_device_control;
 875
 876        err = dma_async_device_register(&pd->dma);
 877        if (err) {
 878                dev_err(&pdev->dev, "Failed to register DMA device\n");
 879                goto err_free_pool;
 880        }
 881
 882        return 0;
 883
 884err_free_pool:
 885        pci_pool_destroy(pd->pool);
 886err_free_irq:
 887        free_irq(pdev->irq, pd);
 888err_iounmap:
 889        pci_iounmap(pdev, pd->membase);
 890err_free_res:
 891        pci_release_regions(pdev);
 892err_disable_pdev:
 893        pci_disable_device(pdev);
 894err_free_mem:
 895        return err;
 896}
 897
 898static void __devexit pch_dma_remove(struct pci_dev *pdev)
 899{
 900        struct pch_dma *pd = pci_get_drvdata(pdev);
 901        struct pch_dma_chan *pd_chan;
 902        struct dma_chan *chan, *_c;
 903
 904        if (pd) {
 905                dma_async_device_unregister(&pd->dma);
 906
 907                list_for_each_entry_safe(chan, _c, &pd->dma.channels,
 908                                         device_node) {
 909                        pd_chan = to_pd_chan(chan);
 910
 911                        tasklet_disable(&pd_chan->tasklet);
 912                        tasklet_kill(&pd_chan->tasklet);
 913                }
 914
 915                pci_pool_destroy(pd->pool);
 916                free_irq(pdev->irq, pd);
 917                pci_iounmap(pdev, pd->membase);
 918                pci_release_regions(pdev);
 919                pci_disable_device(pdev);
 920                kfree(pd);
 921        }
 922}
 923
 924/* PCI Device ID of DMA device */
 925#define PCI_VENDOR_ID_ROHM             0x10DB
 926#define PCI_DEVICE_ID_EG20T_PCH_DMA_8CH        0x8810
 927#define PCI_DEVICE_ID_EG20T_PCH_DMA_4CH        0x8815
 928#define PCI_DEVICE_ID_ML7213_DMA1_8CH   0x8026
 929#define PCI_DEVICE_ID_ML7213_DMA2_8CH   0x802B
 930#define PCI_DEVICE_ID_ML7213_DMA3_4CH   0x8034
 931
 932static const struct pci_device_id pch_dma_id_table[] = {
 933        { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_EG20T_PCH_DMA_8CH), 8 },
 934        { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_EG20T_PCH_DMA_4CH), 4 },
 935        { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA1_8CH), 8}, /* UART Video */
 936        { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA2_8CH), 8}, /* PCMIF SPI */
 937        { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA3_4CH), 4}, /* FPGA */
 938        { 0, },
 939};
 940
 941static struct pci_driver pch_dma_driver = {
 942        .name           = DRV_NAME,
 943        .id_table       = pch_dma_id_table,
 944        .probe          = pch_dma_probe,
 945        .remove         = __devexit_p(pch_dma_remove),
 946#ifdef CONFIG_PM
 947        .suspend        = pch_dma_suspend,
 948        .resume         = pch_dma_resume,
 949#endif
 950};
 951
 952static int __init pch_dma_init(void)
 953{
 954        return pci_register_driver(&pch_dma_driver);
 955}
 956
 957static void __exit pch_dma_exit(void)
 958{
 959        pci_unregister_driver(&pch_dma_driver);
 960}
 961
 962module_init(pch_dma_init);
 963module_exit(pch_dma_exit);
 964
 965MODULE_DESCRIPTION("Intel EG20T PCH / OKI SEMICONDUCTOR ML7213 IOH "
 966                   "DMA controller driver");
 967MODULE_AUTHOR("Yong Wang <yong.y.wang@intel.com>");
 968MODULE_LICENSE("GPL v2");
 969