drivers/net/ethernet/ti/davinci_cpdma.c

   1 /*
   2  * Texas Instruments CPDMA Driver
   3  *
   4  * Copyright (C) 2010 Texas Instruments
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as
   8  * published by the Free Software Foundation version 2.
   9  *
  10  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  11  * kind, whether express or implied; without even the implied warranty
  12  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15 #include <linux/kernel.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/device.h>
  18 #include <linux/module.h>
  19 #include <linux/slab.h>
  20 #include <linux/err.h>
  21 #include <linux/dma-mapping.h>
  22 #include <linux/io.h>
  23 #include <linux/delay.h>
  24 #include <linux/genalloc.h>
  25 #include "davinci_cpdma.h"
  26
  27 /* DMA Registers */
  28 #define CPDMA_TXIDVER           0x00
  29 #define CPDMA_TXCONTROL         0x04
  30 #define CPDMA_TXTEARDOWN        0x08
  31 #define CPDMA_RXIDVER           0x10
  32 #define CPDMA_RXCONTROL         0x14
  33 #define CPDMA_SOFTRESET         0x1c
  34 #define CPDMA_RXTEARDOWN        0x18
  35 #define CPDMA_TXINTSTATRAW      0x80
  36 #define CPDMA_TXINTSTATMASKED   0x84
  37 #define CPDMA_TXINTMASKSET      0x88
  38 #define CPDMA_TXINTMASKCLEAR    0x8c
  39 #define CPDMA_MACINVECTOR       0x90
  40 #define CPDMA_MACEOIVECTOR      0x94
  41 #define CPDMA_RXINTSTATRAW      0xa0
  42 #define CPDMA_RXINTSTATMASKED   0xa4
  43 #define CPDMA_RXINTMASKSET      0xa8
  44 #define CPDMA_RXINTMASKCLEAR    0xac
  45 #define CPDMA_DMAINTSTATRAW     0xb0
  46 #define CPDMA_DMAINTSTATMASKED  0xb4
  47 #define CPDMA_DMAINTMASKSET     0xb8
  48 #define CPDMA_DMAINTMASKCLEAR   0xbc
  49 #define CPDMA_DMAINT_HOSTERR    BIT(1)
  50
  51 /* the following exist only if has_ext_regs is set */
  52 #define CPDMA_DMACONTROL        0x20
  53 #define CPDMA_DMASTATUS         0x24
  54 #define CPDMA_RXBUFFOFS         0x28
  55 #define CPDMA_EM_CONTROL        0x2c
  56
  57 /* Descriptor mode bits */
  58 #define CPDMA_DESC_SOP          BIT(31)
  59 #define CPDMA_DESC_EOP          BIT(30)
  60 #define CPDMA_DESC_OWNER        BIT(29)
  61 #define CPDMA_DESC_EOQ          BIT(28)
  62 #define CPDMA_DESC_TD_COMPLETE  BIT(27)
  63 #define CPDMA_DESC_PASS_CRC     BIT(26)
  64 #define CPDMA_DESC_TO_PORT_EN   BIT(20)
  65 #define CPDMA_TO_PORT_SHIFT     16
  66 #define CPDMA_DESC_PORT_MASK    (BIT(18) | BIT(17) | BIT(16))
  67 #define CPDMA_DESC_CRC_LEN      4
  68
  69 #define CPDMA_TEARDOWN_VALUE    0xfffffffc
  70
  71 struct cpdma_desc {
  72         /* hardware fields */
  73         u32                     hw_next;
  74         u32                     hw_buffer;
  75         u32                     hw_len;
  76         u32                     hw_mode;
  77         /* software fields */
  78         void                    *sw_token;
  79         u32                     sw_buffer;
  80         u32                     sw_len;
  81 };
  82
  83 struct cpdma_desc_pool {
  84         phys_addr_t             phys;
  85         dma_addr_t              hw_addr;
  86         void __iomem            *iomap;         /* ioremap map */
  87         void                    *cpumap;        /* dma_alloc map */
  88         int                     desc_size, mem_size;
  89         int                     num_desc, used_desc;
  90         struct device           *dev;
  91         struct gen_pool         *gen_pool;
  92 };
  93
  94 enum cpdma_state {
  95         CPDMA_STATE_IDLE,
  96         CPDMA_STATE_ACTIVE,
  97         CPDMA_STATE_TEARDOWN,
  98 };
  99
 100 struct cpdma_ctlr {
 101         enum cpdma_state        state;
 102         struct cpdma_params     params;
 103         struct device           *dev;
 104         struct cpdma_desc_pool  *pool;
 105         spinlock_t              lock;
 106         struct cpdma_chan       *channels[2 * CPDMA_MAX_CHANNELS];
 107 };
 108
 109 struct cpdma_chan {
 110         struct cpdma_desc __iomem       *head, *tail;
 111         void __iomem                    *hdp, *cp, *rxfree;
 112         enum cpdma_state                state;
 113         struct cpdma_ctlr               *ctlr;
 114         int                             chan_num;
 115         spinlock_t                      lock;
 116         int                             count;
 117         u32                             desc_num;
 118         u32                             mask;
 119         cpdma_handler_fn                handler;
 120         enum dma_data_direction         dir;
 121         struct cpdma_chan_stats         stats;
 122         /* offsets into dmaregs */
 123         int     int_set, int_clear, td;
 124 };
 125
 126 /* The following make access to common cpdma_ctlr params more readable */
 127 #define dmaregs         params.dmaregs
 128 #define num_chan        params.num_chan
 129
 130 /* various accessors */
 131 #define dma_reg_read(ctlr, ofs)         __raw_readl((ctlr)->dmaregs + (ofs))
 132 #define chan_read(chan, fld)            __raw_readl((chan)->fld)
 133 #define desc_read(desc, fld)            __raw_readl(&(desc)->fld)
 134 #define dma_reg_write(ctlr, ofs, v)     __raw_writel(v, (ctlr)->dmaregs + (ofs))
 135 #define chan_write(chan, fld, v)        __raw_writel(v, (chan)->fld)
 136 #define desc_write(desc, fld, v)        __raw_writel((u32)(v), &(desc)->fld)
 137
 138 #define cpdma_desc_to_port(chan, mode, directed)                        \
 139         do {                                                            \
 140                 if (!is_rx_chan(chan) && ((directed == 1) ||            \
 141                                           (directed == 2)))             \
 142                         mode |= (CPDMA_DESC_TO_PORT_EN |                \
 143                                  (directed << CPDMA_TO_PORT_SHIFT));    \
 144         } while (0)
 145
 146 static void cpdma_desc_pool_destroy(struct cpdma_desc_pool *pool)
 147 {
 148         if (!pool)
 149                 return;
 150
 151         WARN_ON(pool->used_desc);
 152         if (pool->cpumap)
 153                 dma_free_coherent(pool->dev, pool->mem_size, pool->cpumap,
 154                                   pool->phys);
 155         else
 156                 iounmap(pool->iomap);
 157 }
 158
 159 /*
 160  * Utility constructs for a cpdma descriptor pool.  Some devices (e.g. davinci
 161  * emac) have dedicated on-chip memory for these descriptors.  Some other
 162  * devices (e.g. cpsw switches) use plain old memory.  Descriptor pools
 163  * abstract out these details
 164  */
 165 static struct cpdma_desc_pool *
 166 cpdma_desc_pool_create(struct device *dev, u32 phys, dma_addr_t hw_addr,
 167                                 int size, int align)
 168 {
 169         struct cpdma_desc_pool *pool;
 170         int ret;
 171
 172         pool = devm_kzalloc(dev, sizeof(*pool), GFP_KERNEL);
 173         if (!pool)
 174                 goto gen_pool_create_fail;
 175
 176         pool->dev       = dev;
 177         pool->mem_size  = size;
 178         pool->desc_size = ALIGN(sizeof(struct cpdma_desc), align);
 179         pool->num_desc  = size / pool->desc_size;
 180
 181         pool->gen_pool = devm_gen_pool_create(dev, ilog2(pool->desc_size), -1,
 182                                               "cpdma");
 183         if (IS_ERR(pool->gen_pool)) {
 184                 dev_err(dev, "pool create failed %ld\n",
 185                         PTR_ERR(pool->gen_pool));
 186                 goto gen_pool_create_fail;
 187         }
 188
 189         if (phys) {
 190                 pool->phys  = phys;
 191                 pool->iomap = ioremap(phys, size); /* should be memremap? */
 192                 pool->hw_addr = hw_addr;
 193         } else {
 194                 pool->cpumap = dma_alloc_coherent(dev, size, &pool->hw_addr,
 195                                                   GFP_KERNEL);
 196                 pool->iomap = (void __iomem __force *)pool->cpumap;
 197                 pool->phys = pool->hw_addr; /* assumes no IOMMU, don't use this value */
 198         }
 199
 200         if (!pool->iomap)
 201                 goto gen_pool_create_fail;
 202
 203         ret = gen_pool_add_virt(pool->gen_pool, (unsigned long)pool->iomap,
 204                                 pool->phys, pool->mem_size, -1);
 205         if (ret < 0) {
 206                 dev_err(dev, "pool add failed %d\n", ret);
 207                 goto gen_pool_add_virt_fail;
 208         }
 209
 210         return pool;
 211
 212 gen_pool_add_virt_fail:
 213         cpdma_desc_pool_destroy(pool);
 214 gen_pool_create_fail:
 215         return NULL;
 216 }
 217
 218 static inline dma_addr_t desc_phys(struct cpdma_desc_pool *pool,
 219                   struct cpdma_desc __iomem *desc)
 220 {
 221         if (!desc)
 222                 return 0;
 223         return pool->hw_addr + (__force long)desc - (__force long)pool->iomap;
 224 }
 225
 226 static inline struct cpdma_desc __iomem *
 227 desc_from_phys(struct cpdma_desc_pool *pool, dma_addr_t dma)
 228 {
 229         return dma ? pool->iomap + dma - pool->hw_addr : NULL;
 230 }
 231
 232 static struct cpdma_desc __iomem *
 233 cpdma_desc_alloc(struct cpdma_desc_pool *pool)
 234 {
 235         struct cpdma_desc __iomem *desc = NULL;
 236
 237         desc = (struct cpdma_desc __iomem *)gen_pool_alloc(pool->gen_pool,
 238                                                            pool->desc_size);
 239         if (desc)
 240                 pool->used_desc++;
 241
 242         return desc;
 243 }
 244
 245 static void cpdma_desc_free(struct cpdma_desc_pool *pool,
 246                             struct cpdma_desc __iomem *desc, int num_desc)
 247 {
 248         gen_pool_free(pool->gen_pool, (unsigned long)desc, pool->desc_size);
 249         pool->used_desc--;
 250 }
 251
 252 struct cpdma_ctlr *cpdma_ctlr_create(struct cpdma_params *params)
 253 {
 254         struct cpdma_ctlr *ctlr;
 255
 256         ctlr = devm_kzalloc(params->dev, sizeof(*ctlr), GFP_KERNEL);
 257         if (!ctlr)
 258                 return NULL;
 259
 260         ctlr->state = CPDMA_STATE_IDLE;
 261         ctlr->params = *params;
 262         ctlr->dev = params->dev;
 263         spin_lock_init(&ctlr->lock);
 264
 265         ctlr->pool = cpdma_desc_pool_create(ctlr->dev,
 266                                             ctlr->params.desc_mem_phys,
 267                                             ctlr->params.desc_hw_addr,
 268                                             ctlr->params.desc_mem_size,
 269                                             ctlr->params.desc_align);
 270         if (!ctlr->pool)
 271                 return NULL;
 272
 273         if (WARN_ON(ctlr->num_chan > CPDMA_MAX_CHANNELS))
 274                 ctlr->num_chan = CPDMA_MAX_CHANNELS;
 275         return ctlr;
 276 }
 277 EXPORT_SYMBOL_GPL(cpdma_ctlr_create);
 278
 279 int cpdma_ctlr_start(struct cpdma_ctlr *ctlr)
 280 {
 281         unsigned long flags;
 282         int i;
 283
 284         spin_lock_irqsave(&ctlr->lock, flags);
 285         if (ctlr->state != CPDMA_STATE_IDLE) {
 286                 spin_unlock_irqrestore(&ctlr->lock, flags);
 287                 return -EBUSY;
 288         }
 289
 290         if (ctlr->params.has_soft_reset) {
 291                 unsigned timeout = 10 * 100;
 292
 293                 dma_reg_write(ctlr, CPDMA_SOFTRESET, 1);
 294                 while (timeout) {
 295                         if (dma_reg_read(ctlr, CPDMA_SOFTRESET) == 0)
 296                                 break;
 297                         udelay(10);
 298                         timeout--;
 299                 }
 300                 WARN_ON(!timeout);
 301         }
 302
 303         for (i = 0; i < ctlr->num_chan; i++) {
 304                 __raw_writel(0, ctlr->params.txhdp + 4 * i);
 305                 __raw_writel(0, ctlr->params.rxhdp + 4 * i);
 306                 __raw_writel(0, ctlr->params.txcp + 4 * i);
 307                 __raw_writel(0, ctlr->params.rxcp + 4 * i);
 308         }
 309
 310         dma_reg_write(ctlr, CPDMA_RXINTMASKCLEAR, 0xffffffff);
 311         dma_reg_write(ctlr, CPDMA_TXINTMASKCLEAR, 0xffffffff);
 312
 313         dma_reg_write(ctlr, CPDMA_TXCONTROL, 1);
 314         dma_reg_write(ctlr, CPDMA_RXCONTROL, 1);
 315
 316         ctlr->state = CPDMA_STATE_ACTIVE;
 317
 318         for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
 319                 if (ctlr->channels[i])
 320                         cpdma_chan_start(ctlr->channels[i]);
 321         }
 322         spin_unlock_irqrestore(&ctlr->lock, flags);
 323         return 0;
 324 }
 325 EXPORT_SYMBOL_GPL(cpdma_ctlr_start);
 326
 327 int cpdma_ctlr_stop(struct cpdma_ctlr *ctlr)
 328 {
 329         unsigned long flags;
 330         int i;
 331
 332         spin_lock_irqsave(&ctlr->lock, flags);
 333         if (ctlr->state == CPDMA_STATE_TEARDOWN) {
 334                 spin_unlock_irqrestore(&ctlr->lock, flags);
 335                 return -EINVAL;
 336         }
 337
 338         ctlr->state = CPDMA_STATE_TEARDOWN;
 339
 340         for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
 341                 if (ctlr->channels[i])
 342                         cpdma_chan_stop(ctlr->channels[i]);
 343         }
 344
 345         dma_reg_write(ctlr, CPDMA_RXINTMASKCLEAR, 0xffffffff);
 346         dma_reg_write(ctlr, CPDMA_TXINTMASKCLEAR, 0xffffffff);
 347
 348         dma_reg_write(ctlr, CPDMA_TXCONTROL, 0);
 349         dma_reg_write(ctlr, CPDMA_RXCONTROL, 0);
 350
 351         ctlr->state = CPDMA_STATE_IDLE;
 352
 353         spin_unlock_irqrestore(&ctlr->lock, flags);
 354         return 0;
 355 }
 356 EXPORT_SYMBOL_GPL(cpdma_ctlr_stop);
 357
 358 int cpdma_ctlr_destroy(struct cpdma_ctlr *ctlr)
 359 {
 360         int ret = 0, i;
 361
 362         if (!ctlr)
 363                 return -EINVAL;
 364
 365         if (ctlr->state != CPDMA_STATE_IDLE)
 366                 cpdma_ctlr_stop(ctlr);
 367
 368         for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++)
 369                 cpdma_chan_destroy(ctlr->channels[i]);
 370
 371         cpdma_desc_pool_destroy(ctlr->pool);
 372         return ret;
 373 }
 374 EXPORT_SYMBOL_GPL(cpdma_ctlr_destroy);
 375
 376 int cpdma_ctlr_int_ctrl(struct cpdma_ctlr *ctlr, bool enable)
 377 {
 378         unsigned long flags;
 379         int i, reg;
 380
 381         spin_lock_irqsave(&ctlr->lock, flags);
 382         if (ctlr->state != CPDMA_STATE_ACTIVE) {
 383                 spin_unlock_irqrestore(&ctlr->lock, flags);
 384                 return -EINVAL;
 385         }
 386
 387         reg = enable ? CPDMA_DMAINTMASKSET : CPDMA_DMAINTMASKCLEAR;
 388         dma_reg_write(ctlr, reg, CPDMA_DMAINT_HOSTERR);
 389
 390         for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
 391                 if (ctlr->channels[i])
 392                         cpdma_chan_int_ctrl(ctlr->channels[i], enable);
 393         }
 394
 395         spin_unlock_irqrestore(&ctlr->lock, flags);
 396         return 0;
 397 }
 398 EXPORT_SYMBOL_GPL(cpdma_ctlr_int_ctrl);
 399
 400 void cpdma_ctlr_eoi(struct cpdma_ctlr *ctlr, u32 value)
 401 {
 402         dma_reg_write(ctlr, CPDMA_MACEOIVECTOR, value);
 403 }
 404 EXPORT_SYMBOL_GPL(cpdma_ctlr_eoi);
 405
 406 struct cpdma_chan *cpdma_chan_create(struct cpdma_ctlr *ctlr, int chan_num,
 407                                      cpdma_handler_fn handler)
 408 {
 409         struct cpdma_chan *chan;
 410         int offset = (chan_num % CPDMA_MAX_CHANNELS) * 4;
 411         unsigned long flags;
 412
 413         if (__chan_linear(chan_num) >= ctlr->num_chan)
 414                 return NULL;
 415
 416         chan = devm_kzalloc(ctlr->dev, sizeof(*chan), GFP_KERNEL);
 417         if (!chan)
 418                 return ERR_PTR(-ENOMEM);
 419
 420         spin_lock_irqsave(&ctlr->lock, flags);
 421         if (ctlr->channels[chan_num]) {
 422                 spin_unlock_irqrestore(&ctlr->lock, flags);
 423                 devm_kfree(ctlr->dev, chan);
 424                 return ERR_PTR(-EBUSY);
 425         }
 426
 427         chan->ctlr      = ctlr;
 428         chan->state     = CPDMA_STATE_IDLE;
 429         chan->chan_num  = chan_num;
 430         chan->handler   = handler;
 431         chan->desc_num = ctlr->pool->num_desc / 2;
 432
 433         if (is_rx_chan(chan)) {
 434                 chan->hdp       = ctlr->params.rxhdp + offset;
 435                 chan->cp        = ctlr->params.rxcp + offset;
 436                 chan->rxfree    = ctlr->params.rxfree + offset;
 437                 chan->int_set   = CPDMA_RXINTMASKSET;
 438                 chan->int_clear = CPDMA_RXINTMASKCLEAR;
 439                 chan->td        = CPDMA_RXTEARDOWN;
 440                 chan->dir       = DMA_FROM_DEVICE;
 441         } else {
 442                 chan->hdp       = ctlr->params.txhdp + offset;
 443                 chan->cp        = ctlr->params.txcp + offset;
 444                 chan->int_set   = CPDMA_TXINTMASKSET;
 445                 chan->int_clear = CPDMA_TXINTMASKCLEAR;
 446                 chan->td        = CPDMA_TXTEARDOWN;
 447                 chan->dir       = DMA_TO_DEVICE;
 448         }
 449         chan->mask = BIT(chan_linear(chan));
 450
 451         spin_lock_init(&chan->lock);
 452
 453         ctlr->channels[chan_num] = chan;
 454         spin_unlock_irqrestore(&ctlr->lock, flags);
 455         return chan;
 456 }
 457 EXPORT_SYMBOL_GPL(cpdma_chan_create);
 458
 459 int cpdma_chan_get_rx_buf_num(struct cpdma_ctlr *ctlr)
 460 {
 461         return ctlr->pool->num_desc / 2;
 462 }
 463 EXPORT_SYMBOL_GPL(cpdma_chan_get_rx_buf_num);
 464
 465 int cpdma_chan_destroy(struct cpdma_chan *chan)
 466 {
 467         struct cpdma_ctlr *ctlr;
 468         unsigned long flags;
 469
 470         if (!chan)
 471                 return -EINVAL;
 472         ctlr = chan->ctlr;
 473
 474         spin_lock_irqsave(&ctlr->lock, flags);
 475         if (chan->state != CPDMA_STATE_IDLE)
 476                 cpdma_chan_stop(chan);
 477         ctlr->channels[chan->chan_num] = NULL;
 478         spin_unlock_irqrestore(&ctlr->lock, flags);
 479         return 0;
 480 }
 481 EXPORT_SYMBOL_GPL(cpdma_chan_destroy);
 482
 483 int cpdma_chan_get_stats(struct cpdma_chan *chan,
 484                          struct cpdma_chan_stats *stats)
 485 {
 486         unsigned long flags;
 487         if (!chan)
 488                 return -EINVAL;
 489         spin_lock_irqsave(&chan->lock, flags);
 490         memcpy(stats, &chan->stats, sizeof(*stats));
 491         spin_unlock_irqrestore(&chan->lock, flags);
 492         return 0;
 493 }
 494 EXPORT_SYMBOL_GPL(cpdma_chan_get_stats);
 495
 496 static void __cpdma_chan_submit(struct cpdma_chan *chan,
 497                                 struct cpdma_desc __iomem *desc)
 498 {
 499         struct cpdma_ctlr               *ctlr = chan->ctlr;
 500         struct cpdma_desc __iomem       *prev = chan->tail;
 501         struct cpdma_desc_pool          *pool = ctlr->pool;
 502         dma_addr_t                      desc_dma;
 503         u32                             mode;
 504
 505         desc_dma = desc_phys(pool, desc);
 506
 507         /* simple case - idle channel */
 508         if (!chan->head) {
 509                 chan->stats.head_enqueue++;
 510                 chan->head = desc;
 511                 chan->tail = desc;
 512                 if (chan->state == CPDMA_STATE_ACTIVE)
 513                         chan_write(chan, hdp, desc_dma);
 514                 return;
 515         }
 516
 517         /* first chain the descriptor at the tail of the list */
 518         desc_write(prev, hw_next, desc_dma);
 519         chan->tail = desc;
 520         chan->stats.tail_enqueue++;
 521
 522         /* next check if EOQ has been triggered already */
 523         mode = desc_read(prev, hw_mode);
 524         if (((mode & (CPDMA_DESC_EOQ | CPDMA_DESC_OWNER)) == CPDMA_DESC_EOQ) &&
 525             (chan->state == CPDMA_STATE_ACTIVE)) {
 526                 desc_write(prev, hw_mode, mode & ~CPDMA_DESC_EOQ);
 527                 chan_write(chan, hdp, desc_dma);
 528                 chan->stats.misqueued++;
 529         }
 530 }
 531
 532 int cpdma_chan_submit(struct cpdma_chan *chan, void *token, void *data,
 533                       int len, int directed)
 534 {
 535         struct cpdma_ctlr               *ctlr = chan->ctlr;
 536         struct cpdma_desc __iomem       *desc;
 537         dma_addr_t                      buffer;
 538         unsigned long                   flags;
 539         u32                             mode;
 540         int                             ret = 0;
 541
 542         spin_lock_irqsave(&chan->lock, flags);
 543
 544         if (chan->state == CPDMA_STATE_TEARDOWN) {
 545                 ret = -EINVAL;
 546                 goto unlock_ret;
 547         }
 548
 549         if (chan->count >= chan->desc_num)      {
 550                 chan->stats.desc_alloc_fail++;
 551                 ret = -ENOMEM;
 552                 goto unlock_ret;
 553         }
 554
 555         desc = cpdma_desc_alloc(ctlr->pool);
 556         if (!desc) {
 557                 chan->stats.desc_alloc_fail++;
 558                 ret = -ENOMEM;
 559                 goto unlock_ret;
 560         }
 561
 562         if (len < ctlr->params.min_packet_size) {
 563                 len = ctlr->params.min_packet_size;
 564                 chan->stats.runt_transmit_buff++;
 565         }
 566
 567         buffer = dma_map_single(ctlr->dev, data, len, chan->dir);
 568         ret = dma_mapping_error(ctlr->dev, buffer);
 569         if (ret) {
 570                 cpdma_desc_free(ctlr->pool, desc, 1);
 571                 ret = -EINVAL;
 572                 goto unlock_ret;
 573         }
 574
 575         mode = CPDMA_DESC_OWNER | CPDMA_DESC_SOP | CPDMA_DESC_EOP;
 576         cpdma_desc_to_port(chan, mode, directed);
 577
 578         desc_write(desc, hw_next,   0);
 579         desc_write(desc, hw_buffer, buffer);
 580         desc_write(desc, hw_len,    len);
 581         desc_write(desc, hw_mode,   mode | len);
 582         desc_write(desc, sw_token,  token);
 583         desc_write(desc, sw_buffer, buffer);
 584         desc_write(desc, sw_len,    len);
 585
 586         __cpdma_chan_submit(chan, desc);
 587
 588         if (chan->state == CPDMA_STATE_ACTIVE && chan->rxfree)
 589                 chan_write(chan, rxfree, 1);
 590
 591         chan->count++;
 592
 593 unlock_ret:
 594         spin_unlock_irqrestore(&chan->lock, flags);
 595         return ret;
 596 }
 597 EXPORT_SYMBOL_GPL(cpdma_chan_submit);
 598
 599 bool cpdma_check_free_tx_desc(struct cpdma_chan *chan)
 600 {
 601         struct cpdma_ctlr       *ctlr = chan->ctlr;
 602         struct cpdma_desc_pool  *pool = ctlr->pool;
 603         bool                    free_tx_desc;
 604         unsigned long           flags;
 605
 606         spin_lock_irqsave(&chan->lock, flags);
 607         free_tx_desc = (chan->count < chan->desc_num) &&
 608                          gen_pool_avail(pool->gen_pool);
 609         spin_unlock_irqrestore(&chan->lock, flags);
 610         return free_tx_desc;
 611 }
 612 EXPORT_SYMBOL_GPL(cpdma_check_free_tx_desc);
 613
 614 static void __cpdma_chan_free(struct cpdma_chan *chan,
 615                               struct cpdma_desc __iomem *desc,
 616                               int outlen, int status)
 617 {
 618         struct cpdma_ctlr               *ctlr = chan->ctlr;
 619         struct cpdma_desc_pool          *pool = ctlr->pool;
 620         dma_addr_t                      buff_dma;
 621         int                             origlen;
 622         void                            *token;
 623
 624         token      = (void *)desc_read(desc, sw_token);
 625         buff_dma   = desc_read(desc, sw_buffer);
 626         origlen    = desc_read(desc, sw_len);
 627
 628         dma_unmap_single(ctlr->dev, buff_dma, origlen, chan->dir);
 629         cpdma_desc_free(pool, desc, 1);
 630         (*chan->handler)(token, outlen, status);
 631 }
 632
 633 static int __cpdma_chan_process(struct cpdma_chan *chan)
 634 {
 635         struct cpdma_ctlr               *ctlr = chan->ctlr;
 636         struct cpdma_desc __iomem       *desc;
 637         int                             status, outlen;
 638         int                             cb_status = 0;
 639         struct cpdma_desc_pool          *pool = ctlr->pool;
 640         dma_addr_t                      desc_dma;
 641         unsigned long                   flags;
 642
 643         spin_lock_irqsave(&chan->lock, flags);
 644
 645         desc = chan->head;
 646         if (!desc) {
 647                 chan->stats.empty_dequeue++;
 648                 status = -ENOENT;
 649                 goto unlock_ret;
 650         }
 651         desc_dma = desc_phys(pool, desc);
 652
 653         status  = __raw_readl(&desc->hw_mode);
 654         outlen  = status & 0x7ff;
 655         if (status & CPDMA_DESC_OWNER) {
 656                 chan->stats.busy_dequeue++;
 657                 status = -EBUSY;
 658                 goto unlock_ret;
 659         }
 660
 661         if (status & CPDMA_DESC_PASS_CRC)
 662                 outlen -= CPDMA_DESC_CRC_LEN;
 663
 664         status  = status & (CPDMA_DESC_EOQ | CPDMA_DESC_TD_COMPLETE |
 665                             CPDMA_DESC_PORT_MASK);
 666
 667         chan->head = desc_from_phys(pool, desc_read(desc, hw_next));
 668         chan_write(chan, cp, desc_dma);
 669         chan->count--;
 670         chan->stats.good_dequeue++;
 671
 672         if (status & CPDMA_DESC_EOQ) {
 673                 chan->stats.requeue++;
 674                 chan_write(chan, hdp, desc_phys(pool, chan->head));
 675         }
 676
 677         spin_unlock_irqrestore(&chan->lock, flags);
 678         if (unlikely(status & CPDMA_DESC_TD_COMPLETE))
 679                 cb_status = -ENOSYS;
 680         else
 681                 cb_status = status;
 682
 683         __cpdma_chan_free(chan, desc, outlen, cb_status);
 684         return status;
 685
 686 unlock_ret:
 687         spin_unlock_irqrestore(&chan->lock, flags);
 688         return status;
 689 }
 690
 691 int cpdma_chan_process(struct cpdma_chan *chan, int quota)
 692 {
 693         int used = 0, ret = 0;
 694
 695         if (chan->state != CPDMA_STATE_ACTIVE)
 696                 return -EINVAL;
 697
 698         while (used < quota) {
 699                 ret = __cpdma_chan_process(chan);
 700                 if (ret < 0)
 701                         break;
 702                 used++;
 703         }
 704         return used;
 705 }
 706 EXPORT_SYMBOL_GPL(cpdma_chan_process);
 707
 708 int cpdma_chan_start(struct cpdma_chan *chan)
 709 {
 710         struct cpdma_ctlr       *ctlr = chan->ctlr;
 711         struct cpdma_desc_pool  *pool = ctlr->pool;
 712         unsigned long           flags;
 713
 714         spin_lock_irqsave(&chan->lock, flags);
 715         if (chan->state != CPDMA_STATE_IDLE) {
 716                 spin_unlock_irqrestore(&chan->lock, flags);
 717                 return -EBUSY;
 718         }
 719         if (ctlr->state != CPDMA_STATE_ACTIVE) {
 720                 spin_unlock_irqrestore(&chan->lock, flags);
 721                 return -EINVAL;
 722         }
 723         dma_reg_write(ctlr, chan->int_set, chan->mask);
 724         chan->state = CPDMA_STATE_ACTIVE;
 725         if (chan->head) {
 726                 chan_write(chan, hdp, desc_phys(pool, chan->head));
 727                 if (chan->rxfree)
 728                         chan_write(chan, rxfree, chan->count);
 729         }
 730
 731         spin_unlock_irqrestore(&chan->lock, flags);
 732         return 0;
 733 }
 734 EXPORT_SYMBOL_GPL(cpdma_chan_start);
 735
 736 int cpdma_chan_stop(struct cpdma_chan *chan)
 737 {
 738         struct cpdma_ctlr       *ctlr = chan->ctlr;
 739         struct cpdma_desc_pool  *pool = ctlr->pool;
 740         unsigned long           flags;
 741         int                     ret;
 742         unsigned                timeout;
 743
 744         spin_lock_irqsave(&chan->lock, flags);
 745         if (chan->state == CPDMA_STATE_TEARDOWN) {
 746                 spin_unlock_irqrestore(&chan->lock, flags);
 747                 return -EINVAL;
 748         }
 749
 750         chan->state = CPDMA_STATE_TEARDOWN;
 751         dma_reg_write(ctlr, chan->int_clear, chan->mask);
 752
 753         /* trigger teardown */
 754         dma_reg_write(ctlr, chan->td, chan_linear(chan));
 755
 756         /* wait for teardown complete */
 757         timeout = 100 * 100; /* 100 ms */
 758         while (timeout) {
 759                 u32 cp = chan_read(chan, cp);
 760                 if ((cp & CPDMA_TEARDOWN_VALUE) == CPDMA_TEARDOWN_VALUE)
 761                         break;
 762                 udelay(10);
 763                 timeout--;
 764         }
 765         WARN_ON(!timeout);
 766         chan_write(chan, cp, CPDMA_TEARDOWN_VALUE);
 767
 768         /* handle completed packets */
 769         spin_unlock_irqrestore(&chan->lock, flags);
 770         do {
 771                 ret = __cpdma_chan_process(chan);
 772                 if (ret < 0)
 773                         break;
 774         } while ((ret & CPDMA_DESC_TD_COMPLETE) == 0);
 775         spin_lock_irqsave(&chan->lock, flags);
 776
 777         /* remaining packets haven't been tx/rx'ed, clean them up */
 778         while (chan->head) {
 779                 struct cpdma_desc __iomem *desc = chan->head;
 780                 dma_addr_t next_dma;
 781
 782                 next_dma = desc_read(desc, hw_next);
 783                 chan->head = desc_from_phys(pool, next_dma);
 784                 chan->count--;
 785                 chan->stats.teardown_dequeue++;
 786
 787                 /* issue callback without locks held */
 788                 spin_unlock_irqrestore(&chan->lock, flags);
 789                 __cpdma_chan_free(chan, desc, 0, -ENOSYS);
 790                 spin_lock_irqsave(&chan->lock, flags);
 791         }
 792
 793         chan->state = CPDMA_STATE_IDLE;
 794         spin_unlock_irqrestore(&chan->lock, flags);
 795         return 0;
 796 }
 797 EXPORT_SYMBOL_GPL(cpdma_chan_stop);
 798
 799 int cpdma_chan_int_ctrl(struct cpdma_chan *chan, bool enable)
 800 {
 801         unsigned long flags;
 802
 803         spin_lock_irqsave(&chan->lock, flags);
 804         if (chan->state != CPDMA_STATE_ACTIVE) {
 805                 spin_unlock_irqrestore(&chan->lock, flags);
 806                 return -EINVAL;
 807         }
 808
 809         dma_reg_write(chan->ctlr, enable ? chan->int_set : chan->int_clear,
 810                       chan->mask);
 811         spin_unlock_irqrestore(&chan->lock, flags);
 812
 813         return 0;
 814 }
 815
 816 struct cpdma_control_info {
 817         u32             reg;
 818         u32             shift, mask;
 819         int             access;
 820 #define ACCESS_RO       BIT(0)
 821 #define ACCESS_WO       BIT(1)
 822 #define ACCESS_RW       (ACCESS_RO | ACCESS_WO)
 823 };
 824
 825 static struct cpdma_control_info controls[] = {
 826         [CPDMA_CMD_IDLE]          = {CPDMA_DMACONTROL,  3,  1,      ACCESS_WO},
 827         [CPDMA_COPY_ERROR_FRAMES] = {CPDMA_DMACONTROL,  4,  1,      ACCESS_RW},
 828         [CPDMA_RX_OFF_LEN_UPDATE] = {CPDMA_DMACONTROL,  2,  1,      ACCESS_RW},
 829         [CPDMA_RX_OWNERSHIP_FLIP] = {CPDMA_DMACONTROL,  1,  1,      ACCESS_RW},
 830         [CPDMA_TX_PRIO_FIXED]     = {CPDMA_DMACONTROL,  0,  1,      ACCESS_RW},
 831         [CPDMA_STAT_IDLE]         = {CPDMA_DMASTATUS,   31, 1,      ACCESS_RO},
 832         [CPDMA_STAT_TX_ERR_CODE]  = {CPDMA_DMASTATUS,   20, 0xf,    ACCESS_RW},
 833         [CPDMA_STAT_TX_ERR_CHAN]  = {CPDMA_DMASTATUS,   16, 0x7,    ACCESS_RW},
 834         [CPDMA_STAT_RX_ERR_CODE]  = {CPDMA_DMASTATUS,   12, 0xf,    ACCESS_RW},
 835         [CPDMA_STAT_RX_ERR_CHAN]  = {CPDMA_DMASTATUS,   8,  0x7,    ACCESS_RW},
 836         [CPDMA_RX_BUFFER_OFFSET]  = {CPDMA_RXBUFFOFS,   0,  0xffff, ACCESS_RW},
 837 };
 838
 839 int cpdma_control_get(struct cpdma_ctlr *ctlr, int control)
 840 {
 841         unsigned long flags;
 842         struct cpdma_control_info *info = &controls[control];
 843         int ret;
 844
 845         spin_lock_irqsave(&ctlr->lock, flags);
 846
 847         ret = -ENOTSUPP;
 848         if (!ctlr->params.has_ext_regs)
 849                 goto unlock_ret;
 850
 851         ret = -EINVAL;
 852         if (ctlr->state != CPDMA_STATE_ACTIVE)
 853                 goto unlock_ret;
 854
 855         ret = -ENOENT;
 856         if (control < 0 || control >= ARRAY_SIZE(controls))
 857                 goto unlock_ret;
 858
 859         ret = -EPERM;
 860         if ((info->access & ACCESS_RO) != ACCESS_RO)
 861                 goto unlock_ret;
 862
 863         ret = (dma_reg_read(ctlr, info->reg) >> info->shift) & info->mask;
 864
 865 unlock_ret:
 866         spin_unlock_irqrestore(&ctlr->lock, flags);
 867         return ret;
 868 }
 869
 870 int cpdma_control_set(struct cpdma_ctlr *ctlr, int control, int value)
 871 {
 872         unsigned long flags;
 873         struct cpdma_control_info *info = &controls[control];
 874         int ret;
 875         u32 val;
 876
 877         spin_lock_irqsave(&ctlr->lock, flags);
 878
 879         ret = -ENOTSUPP;
 880         if (!ctlr->params.has_ext_regs)
 881                 goto unlock_ret;
 882
 883         ret = -EINVAL;
 884         if (ctlr->state != CPDMA_STATE_ACTIVE)
 885                 goto unlock_ret;
 886
 887         ret = -ENOENT;
 888         if (control < 0 || control >= ARRAY_SIZE(controls))
 889                 goto unlock_ret;
 890
 891         ret = -EPERM;
 892         if ((info->access & ACCESS_WO) != ACCESS_WO)
 893                 goto unlock_ret;
 894
 895         val  = dma_reg_read(ctlr, info->reg);
 896         val &= ~(info->mask << info->shift);
 897         val |= (value & info->mask) << info->shift;
 898         dma_reg_write(ctlr, info->reg, val);
 899         ret = 0;
 900
 901 unlock_ret:
 902         spin_unlock_irqrestore(&ctlr->lock, flags);
 903         return ret;
 904 }
 905 EXPORT_SYMBOL_GPL(cpdma_control_set);
 906
 907 MODULE_LICENSE("GPL");