kernel/drivers/dma/img-mdc-dma.c

   1 /*
   2  * IMG Multi-threaded DMA Controller (MDC)
   3  *
   4  * Copyright (C) 2009,2012,2013 Imagination Technologies Ltd.
   5  * Copyright (C) 2014 Google, Inc.
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms and conditions of the GNU General Public License,
   9  * version 2, as published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/clk.h>
  13 #include <linux/dma-mapping.h>
  14 #include <linux/dmaengine.h>
  15 #include <linux/dmapool.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/io.h>
  18 #include <linux/irq.h>
  19 #include <linux/kernel.h>
  20 #include <linux/mfd/syscon.h>
  21 #include <linux/module.h>
  22 #include <linux/of.h>
  23 #include <linux/of_device.h>
  24 #include <linux/of_dma.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/regmap.h>
  27 #include <linux/slab.h>
  28 #include <linux/spinlock.h>
  29
  30 #include "dmaengine.h"
  31 #include "virt-dma.h"
  32
  33 #define MDC_MAX_DMA_CHANNELS                    32
  34
  35 #define MDC_GENERAL_CONFIG                      0x000
  36 #define MDC_GENERAL_CONFIG_LIST_IEN             BIT(31)
  37 #define MDC_GENERAL_CONFIG_IEN                  BIT(29)
  38 #define MDC_GENERAL_CONFIG_LEVEL_INT            BIT(28)
  39 #define MDC_GENERAL_CONFIG_INC_W                BIT(12)
  40 #define MDC_GENERAL_CONFIG_INC_R                BIT(8)
  41 #define MDC_GENERAL_CONFIG_PHYSICAL_W           BIT(7)
  42 #define MDC_GENERAL_CONFIG_WIDTH_W_SHIFT        4
  43 #define MDC_GENERAL_CONFIG_WIDTH_W_MASK         0x7
  44 #define MDC_GENERAL_CONFIG_PHYSICAL_R           BIT(3)
  45 #define MDC_GENERAL_CONFIG_WIDTH_R_SHIFT        0
  46 #define MDC_GENERAL_CONFIG_WIDTH_R_MASK         0x7
  47
  48 #define MDC_READ_PORT_CONFIG                    0x004
  49 #define MDC_READ_PORT_CONFIG_STHREAD_SHIFT      28
  50 #define MDC_READ_PORT_CONFIG_STHREAD_MASK       0xf
  51 #define MDC_READ_PORT_CONFIG_RTHREAD_SHIFT      24
  52 #define MDC_READ_PORT_CONFIG_RTHREAD_MASK       0xf
  53 #define MDC_READ_PORT_CONFIG_WTHREAD_SHIFT      16
  54 #define MDC_READ_PORT_CONFIG_WTHREAD_MASK       0xf
  55 #define MDC_READ_PORT_CONFIG_BURST_SIZE_SHIFT   4
  56 #define MDC_READ_PORT_CONFIG_BURST_SIZE_MASK    0xff
  57 #define MDC_READ_PORT_CONFIG_DREQ_ENABLE        BIT(1)
  58
  59 #define MDC_READ_ADDRESS                        0x008
  60
  61 #define MDC_WRITE_ADDRESS                       0x00c
  62
  63 #define MDC_TRANSFER_SIZE                       0x010
  64 #define MDC_TRANSFER_SIZE_MASK                  0xffffff
  65
  66 #define MDC_LIST_NODE_ADDRESS                   0x014
  67
  68 #define MDC_CMDS_PROCESSED                      0x018
  69 #define MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT 16
  70 #define MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK  0x3f
  71 #define MDC_CMDS_PROCESSED_INT_ACTIVE           BIT(8)
  72 #define MDC_CMDS_PROCESSED_CMDS_DONE_SHIFT      0
  73 #define MDC_CMDS_PROCESSED_CMDS_DONE_MASK       0x3f
  74
  75 #define MDC_CONTROL_AND_STATUS                  0x01c
  76 #define MDC_CONTROL_AND_STATUS_CANCEL           BIT(20)
  77 #define MDC_CONTROL_AND_STATUS_LIST_EN          BIT(4)
  78 #define MDC_CONTROL_AND_STATUS_EN               BIT(0)
  79
  80 #define MDC_ACTIVE_TRANSFER_SIZE                0x030
  81
  82 #define MDC_GLOBAL_CONFIG_A                             0x900
  83 #define MDC_GLOBAL_CONFIG_A_THREAD_ID_WIDTH_SHIFT       16
  84 #define MDC_GLOBAL_CONFIG_A_THREAD_ID_WIDTH_MASK        0xff
  85 #define MDC_GLOBAL_CONFIG_A_DMA_CONTEXTS_SHIFT          8
  86 #define MDC_GLOBAL_CONFIG_A_DMA_CONTEXTS_MASK           0xff
  87 #define MDC_GLOBAL_CONFIG_A_SYS_DAT_WIDTH_SHIFT         0
  88 #define MDC_GLOBAL_CONFIG_A_SYS_DAT_WIDTH_MASK          0xff
  89
  90 struct mdc_hw_list_desc {
  91         u32 gen_conf;
  92         u32 readport_conf;
  93         u32 read_addr;
  94         u32 write_addr;
  95         u32 xfer_size;
  96         u32 node_addr;
  97         u32 cmds_done;
  98         u32 ctrl_status;
  99         /*
 100          * Not part of the list descriptor, but instead used by the CPU to
 101          * traverse the list.
 102          */
 103         struct mdc_hw_list_desc *next_desc;
 104 };
 105
 106 struct mdc_tx_desc {
 107         struct mdc_chan *chan;
 108         struct virt_dma_desc vd;
 109         dma_addr_t list_phys;
 110         struct mdc_hw_list_desc *list;
 111         bool cyclic;
 112         bool cmd_loaded;
 113         unsigned int list_len;
 114         unsigned int list_period_len;
 115         size_t list_xfer_size;
 116         unsigned int list_cmds_done;
 117 };
 118
 119 struct mdc_chan {
 120         struct mdc_dma *mdma;
 121         struct virt_dma_chan vc;
 122         struct dma_slave_config config;
 123         struct mdc_tx_desc *desc;
 124         int irq;
 125         unsigned int periph;
 126         unsigned int thread;
 127         unsigned int chan_nr;
 128 };
 129
 130 struct mdc_dma_soc_data {
 131         void (*enable_chan)(struct mdc_chan *mchan);
 132         void (*disable_chan)(struct mdc_chan *mchan);
 133 };
 134
 135 struct mdc_dma {
 136         struct dma_device dma_dev;
 137         void __iomem *regs;
 138         struct clk *clk;
 139         struct dma_pool *desc_pool;
 140         struct regmap *periph_regs;
 141         spinlock_t lock;
 142         unsigned int nr_threads;
 143         unsigned int nr_channels;
 144         unsigned int bus_width;
 145         unsigned int max_burst_mult;
 146         unsigned int max_xfer_size;
 147         const struct mdc_dma_soc_data *soc;
 148         struct mdc_chan channels[MDC_MAX_DMA_CHANNELS];
 149 };
 150
 151 static inline u32 mdc_readl(struct mdc_dma *mdma, u32 reg)
 152 {
 153         return readl(mdma->regs + reg);
 154 }
 155
 156 static inline void mdc_writel(struct mdc_dma *mdma, u32 val, u32 reg)
 157 {
 158         writel(val, mdma->regs + reg);
 159 }
 160
 161 static inline u32 mdc_chan_readl(struct mdc_chan *mchan, u32 reg)
 162 {
 163         return mdc_readl(mchan->mdma, mchan->chan_nr * 0x040 + reg);
 164 }
 165
 166 static inline void mdc_chan_writel(struct mdc_chan *mchan, u32 val, u32 reg)
 167 {
 168         mdc_writel(mchan->mdma, val, mchan->chan_nr * 0x040 + reg);
 169 }
 170
 171 static inline struct mdc_chan *to_mdc_chan(struct dma_chan *c)
 172 {
 173         return container_of(to_virt_chan(c), struct mdc_chan, vc);
 174 }
 175
 176 static inline struct mdc_tx_desc *to_mdc_desc(struct dma_async_tx_descriptor *t)
 177 {
 178         struct virt_dma_desc *vdesc = container_of(t, struct virt_dma_desc, tx);
 179
 180         return container_of(vdesc, struct mdc_tx_desc, vd);
 181 }
 182
 183 static inline struct device *mdma2dev(struct mdc_dma *mdma)
 184 {
 185         return mdma->dma_dev.dev;
 186 }
 187
 188 static inline unsigned int to_mdc_width(unsigned int bytes)
 189 {
 190         return ffs(bytes) - 1;
 191 }
 192
 193 static inline void mdc_set_read_width(struct mdc_hw_list_desc *ldesc,
 194                                       unsigned int bytes)
 195 {
 196         ldesc->gen_conf |= to_mdc_width(bytes) <<
 197                 MDC_GENERAL_CONFIG_WIDTH_R_SHIFT;
 198 }
 199
 200 static inline void mdc_set_write_width(struct mdc_hw_list_desc *ldesc,
 201                                        unsigned int bytes)
 202 {
 203         ldesc->gen_conf |= to_mdc_width(bytes) <<
 204                 MDC_GENERAL_CONFIG_WIDTH_W_SHIFT;
 205 }
 206
 207 static void mdc_list_desc_config(struct mdc_chan *mchan,
 208                                  struct mdc_hw_list_desc *ldesc,
 209                                  enum dma_transfer_direction dir,
 210                                  dma_addr_t src, dma_addr_t dst, size_t len)
 211 {
 212         struct mdc_dma *mdma = mchan->mdma;
 213         unsigned int max_burst, burst_size;
 214
 215         ldesc->gen_conf = MDC_GENERAL_CONFIG_IEN | MDC_GENERAL_CONFIG_LIST_IEN |
 216                 MDC_GENERAL_CONFIG_LEVEL_INT | MDC_GENERAL_CONFIG_PHYSICAL_W |
 217                 MDC_GENERAL_CONFIG_PHYSICAL_R;
 218         ldesc->readport_conf =
 219                 (mchan->thread << MDC_READ_PORT_CONFIG_STHREAD_SHIFT) |
 220                 (mchan->thread << MDC_READ_PORT_CONFIG_RTHREAD_SHIFT) |
 221                 (mchan->thread << MDC_READ_PORT_CONFIG_WTHREAD_SHIFT);
 222         ldesc->read_addr = src;
 223         ldesc->write_addr = dst;
 224         ldesc->xfer_size = len - 1;
 225         ldesc->node_addr = 0;
 226         ldesc->cmds_done = 0;
 227         ldesc->ctrl_status = MDC_CONTROL_AND_STATUS_LIST_EN |
 228                 MDC_CONTROL_AND_STATUS_EN;
 229         ldesc->next_desc = NULL;
 230
 231         if (IS_ALIGNED(dst, mdma->bus_width) &&
 232             IS_ALIGNED(src, mdma->bus_width))
 233                 max_burst = mdma->bus_width * mdma->max_burst_mult;
 234         else
 235                 max_burst = mdma->bus_width * (mdma->max_burst_mult - 1);
 236
 237         if (dir == DMA_MEM_TO_DEV) {
 238                 ldesc->gen_conf |= MDC_GENERAL_CONFIG_INC_R;
 239                 ldesc->readport_conf |= MDC_READ_PORT_CONFIG_DREQ_ENABLE;
 240                 mdc_set_read_width(ldesc, mdma->bus_width);
 241                 mdc_set_write_width(ldesc, mchan->config.dst_addr_width);
 242                 burst_size = min(max_burst, mchan->config.dst_maxburst *
 243                                  mchan->config.dst_addr_width);
 244         } else if (dir == DMA_DEV_TO_MEM) {
 245                 ldesc->gen_conf |= MDC_GENERAL_CONFIG_INC_W;
 246                 ldesc->readport_conf |= MDC_READ_PORT_CONFIG_DREQ_ENABLE;
 247                 mdc_set_read_width(ldesc, mchan->config.src_addr_width);
 248                 mdc_set_write_width(ldesc, mdma->bus_width);
 249                 burst_size = min(max_burst, mchan->config.src_maxburst *
 250                                  mchan->config.src_addr_width);
 251         } else {
 252                 ldesc->gen_conf |= MDC_GENERAL_CONFIG_INC_R |
 253                         MDC_GENERAL_CONFIG_INC_W;
 254                 mdc_set_read_width(ldesc, mdma->bus_width);
 255                 mdc_set_write_width(ldesc, mdma->bus_width);
 256                 burst_size = max_burst;
 257         }
 258         ldesc->readport_conf |= (burst_size - 1) <<
 259                 MDC_READ_PORT_CONFIG_BURST_SIZE_SHIFT;
 260 }
 261
 262 static void mdc_list_desc_free(struct mdc_tx_desc *mdesc)
 263 {
 264         struct mdc_dma *mdma = mdesc->chan->mdma;
 265         struct mdc_hw_list_desc *curr, *next;
 266         dma_addr_t curr_phys, next_phys;
 267
 268         curr = mdesc->list;
 269         curr_phys = mdesc->list_phys;
 270         while (curr) {
 271                 next = curr->next_desc;
 272                 next_phys = curr->node_addr;
 273                 dma_pool_free(mdma->desc_pool, curr, curr_phys);
 274                 curr = next;
 275                 curr_phys = next_phys;
 276         }
 277 }
 278
 279 static void mdc_desc_free(struct virt_dma_desc *vd)
 280 {
 281         struct mdc_tx_desc *mdesc = to_mdc_desc(&vd->tx);
 282
 283         mdc_list_desc_free(mdesc);
 284         kfree(mdesc);
 285 }
 286
 287 static struct dma_async_tx_descriptor *mdc_prep_dma_memcpy(
 288         struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, size_t len,
 289         unsigned long flags)
 290 {
 291         struct mdc_chan *mchan = to_mdc_chan(chan);
 292         struct mdc_dma *mdma = mchan->mdma;
 293         struct mdc_tx_desc *mdesc;
 294         struct mdc_hw_list_desc *curr, *prev = NULL;
 295         dma_addr_t curr_phys, prev_phys;
 296
 297         if (!len)
 298                 return NULL;
 299
 300         mdesc = kzalloc(sizeof(*mdesc), GFP_NOWAIT);
 301         if (!mdesc)
 302                 return NULL;
 303         mdesc->chan = mchan;
 304         mdesc->list_xfer_size = len;
 305
 306         while (len > 0) {
 307                 size_t xfer_size;
 308
 309                 curr = dma_pool_alloc(mdma->desc_pool, GFP_NOWAIT, &curr_phys);
 310                 if (!curr)
 311                         goto free_desc;
 312
 313                 if (prev) {
 314                         prev->node_addr = curr_phys;
 315                         prev->next_desc = curr;
 316                 } else {
 317                         mdesc->list_phys = curr_phys;
 318                         mdesc->list = curr;
 319                 }
 320
 321                 xfer_size = min_t(size_t, mdma->max_xfer_size, len);
 322
 323                 mdc_list_desc_config(mchan, curr, DMA_MEM_TO_MEM, src, dest,
 324                                      xfer_size);
 325
 326                 prev = curr;
 327                 prev_phys = curr_phys;
 328
 329                 mdesc->list_len++;
 330                 src += xfer_size;
 331                 dest += xfer_size;
 332                 len -= xfer_size;
 333         }
 334
 335         return vchan_tx_prep(&mchan->vc, &mdesc->vd, flags);
 336
 337 free_desc:
 338         mdc_desc_free(&mdesc->vd);
 339
 340         return NULL;
 341 }
 342
 343 static int mdc_check_slave_width(struct mdc_chan *mchan,
 344                                  enum dma_transfer_direction dir)
 345 {
 346         enum dma_slave_buswidth width;
 347
 348         if (dir == DMA_MEM_TO_DEV)
 349                 width = mchan->config.dst_addr_width;
 350         else
 351                 width = mchan->config.src_addr_width;
 352
 353         switch (width) {
 354         case DMA_SLAVE_BUSWIDTH_1_BYTE:
 355         case DMA_SLAVE_BUSWIDTH_2_BYTES:
 356         case DMA_SLAVE_BUSWIDTH_4_BYTES:
 357         case DMA_SLAVE_BUSWIDTH_8_BYTES:
 358                 break;
 359         default:
 360                 return -EINVAL;
 361         }
 362
 363         if (width > mchan->mdma->bus_width)
 364                 return -EINVAL;
 365
 366         return 0;
 367 }
 368
 369 static struct dma_async_tx_descriptor *mdc_prep_dma_cyclic(
 370         struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
 371         size_t period_len, enum dma_transfer_direction dir,
 372         unsigned long flags)
 373 {
 374         struct mdc_chan *mchan = to_mdc_chan(chan);
 375         struct mdc_dma *mdma = mchan->mdma;
 376         struct mdc_tx_desc *mdesc;
 377         struct mdc_hw_list_desc *curr, *prev = NULL;
 378         dma_addr_t curr_phys, prev_phys;
 379
 380         if (!buf_len && !period_len)
 381                 return NULL;
 382
 383         if (!is_slave_direction(dir))
 384                 return NULL;
 385
 386         if (mdc_check_slave_width(mchan, dir) < 0)
 387                 return NULL;
 388
 389         mdesc = kzalloc(sizeof(*mdesc), GFP_NOWAIT);
 390         if (!mdesc)
 391                 return NULL;
 392         mdesc->chan = mchan;
 393         mdesc->cyclic = true;
 394         mdesc->list_xfer_size = buf_len;
 395         mdesc->list_period_len = DIV_ROUND_UP(period_len,
 396                                               mdma->max_xfer_size);
 397
 398         while (buf_len > 0) {
 399                 size_t remainder = min(period_len, buf_len);
 400
 401                 while (remainder > 0) {
 402                         size_t xfer_size;
 403
 404                         curr = dma_pool_alloc(mdma->desc_pool, GFP_NOWAIT,
 405                                               &curr_phys);
 406                         if (!curr)
 407                                 goto free_desc;
 408
 409                         if (!prev) {
 410                                 mdesc->list_phys = curr_phys;
 411                                 mdesc->list = curr;
 412                         } else {
 413                                 prev->node_addr = curr_phys;
 414                                 prev->next_desc = curr;
 415                         }
 416
 417                         xfer_size = min_t(size_t, mdma->max_xfer_size,
 418                                           remainder);
 419
 420                         if (dir == DMA_MEM_TO_DEV) {
 421                                 mdc_list_desc_config(mchan, curr, dir,
 422                                                      buf_addr,
 423                                                      mchan->config.dst_addr,
 424                                                      xfer_size);
 425                         } else {
 426                                 mdc_list_desc_config(mchan, curr, dir,
 427                                                      mchan->config.src_addr,
 428                                                      buf_addr,
 429                                                      xfer_size);
 430                         }
 431
 432                         prev = curr;
 433                         prev_phys = curr_phys;
 434
 435                         mdesc->list_len++;
 436                         buf_addr += xfer_size;
 437                         buf_len -= xfer_size;
 438                         remainder -= xfer_size;
 439                 }
 440         }
 441         prev->node_addr = mdesc->list_phys;
 442
 443         return vchan_tx_prep(&mchan->vc, &mdesc->vd, flags);
 444
 445 free_desc:
 446         mdc_desc_free(&mdesc->vd);
 447
 448         return NULL;
 449 }
 450
 451 static struct dma_async_tx_descriptor *mdc_prep_slave_sg(
 452         struct dma_chan *chan, struct scatterlist *sgl,
 453         unsigned int sg_len, enum dma_transfer_direction dir,
 454         unsigned long flags, void *context)
 455 {
 456         struct mdc_chan *mchan = to_mdc_chan(chan);
 457         struct mdc_dma *mdma = mchan->mdma;
 458         struct mdc_tx_desc *mdesc;
 459         struct scatterlist *sg;
 460         struct mdc_hw_list_desc *curr, *prev = NULL;
 461         dma_addr_t curr_phys, prev_phys;
 462         unsigned int i;
 463
 464         if (!sgl)
 465                 return NULL;
 466
 467         if (!is_slave_direction(dir))
 468                 return NULL;
 469
 470         if (mdc_check_slave_width(mchan, dir) < 0)
 471                 return NULL;
 472
 473         mdesc = kzalloc(sizeof(*mdesc), GFP_NOWAIT);
 474         if (!mdesc)
 475                 return NULL;
 476         mdesc->chan = mchan;
 477
 478         for_each_sg(sgl, sg, sg_len, i) {
 479                 dma_addr_t buf = sg_dma_address(sg);
 480                 size_t buf_len = sg_dma_len(sg);
 481
 482                 while (buf_len > 0) {
 483                         size_t xfer_size;
 484
 485                         curr = dma_pool_alloc(mdma->desc_pool, GFP_NOWAIT,
 486                                               &curr_phys);
 487                         if (!curr)
 488                                 goto free_desc;
 489
 490                         if (!prev) {
 491                                 mdesc->list_phys = curr_phys;
 492                                 mdesc->list = curr;
 493                         } else {
 494                                 prev->node_addr = curr_phys;
 495                                 prev->next_desc = curr;
 496                         }
 497
 498                         xfer_size = min_t(size_t, mdma->max_xfer_size,
 499                                           buf_len);
 500
 501                         if (dir == DMA_MEM_TO_DEV) {
 502                                 mdc_list_desc_config(mchan, curr, dir, buf,
 503                                                      mchan->config.dst_addr,
 504                                                      xfer_size);
 505                         } else {
 506                                 mdc_list_desc_config(mchan, curr, dir,
 507                                                      mchan->config.src_addr,
 508                                                      buf, xfer_size);
 509                         }
 510
 511                         prev = curr;
 512                         prev_phys = curr_phys;
 513
 514                         mdesc->list_len++;
 515                         mdesc->list_xfer_size += xfer_size;
 516                         buf += xfer_size;
 517                         buf_len -= xfer_size;
 518                 }
 519         }
 520
 521         return vchan_tx_prep(&mchan->vc, &mdesc->vd, flags);
 522
 523 free_desc:
 524         mdc_desc_free(&mdesc->vd);
 525
 526         return NULL;
 527 }
 528
 529 static void mdc_issue_desc(struct mdc_chan *mchan)
 530 {
 531         struct mdc_dma *mdma = mchan->mdma;
 532         struct virt_dma_desc *vd;
 533         struct mdc_tx_desc *mdesc;
 534         u32 val;
 535
 536         vd = vchan_next_desc(&mchan->vc);
 537         if (!vd)
 538                 return;
 539
 540         list_del(&vd->node);
 541
 542         mdesc = to_mdc_desc(&vd->tx);
 543         mchan->desc = mdesc;
 544
 545         dev_dbg(mdma2dev(mdma), "Issuing descriptor on channel %d\n",
 546                 mchan->chan_nr);
 547
 548         mdma->soc->enable_chan(mchan);
 549
 550         val = mdc_chan_readl(mchan, MDC_GENERAL_CONFIG);
 551         val |= MDC_GENERAL_CONFIG_LIST_IEN | MDC_GENERAL_CONFIG_IEN |
 552                 MDC_GENERAL_CONFIG_LEVEL_INT | MDC_GENERAL_CONFIG_PHYSICAL_W |
 553                 MDC_GENERAL_CONFIG_PHYSICAL_R;
 554         mdc_chan_writel(mchan, val, MDC_GENERAL_CONFIG);
 555         val = (mchan->thread << MDC_READ_PORT_CONFIG_STHREAD_SHIFT) |
 556                 (mchan->thread << MDC_READ_PORT_CONFIG_RTHREAD_SHIFT) |
 557                 (mchan->thread << MDC_READ_PORT_CONFIG_WTHREAD_SHIFT);
 558         mdc_chan_writel(mchan, val, MDC_READ_PORT_CONFIG);
 559         mdc_chan_writel(mchan, mdesc->list_phys, MDC_LIST_NODE_ADDRESS);
 560         val = mdc_chan_readl(mchan, MDC_CONTROL_AND_STATUS);
 561         val |= MDC_CONTROL_AND_STATUS_LIST_EN;
 562         mdc_chan_writel(mchan, val, MDC_CONTROL_AND_STATUS);
 563 }
 564
 565 static void mdc_issue_pending(struct dma_chan *chan)
 566 {
 567         struct mdc_chan *mchan = to_mdc_chan(chan);
 568         unsigned long flags;
 569
 570         spin_lock_irqsave(&mchan->vc.lock, flags);
 571         if (vchan_issue_pending(&mchan->vc) && !mchan->desc)
 572                 mdc_issue_desc(mchan);
 573         spin_unlock_irqrestore(&mchan->vc.lock, flags);
 574 }
 575
 576 static enum dma_status mdc_tx_status(struct dma_chan *chan,
 577         dma_cookie_t cookie, struct dma_tx_state *txstate)
 578 {
 579         struct mdc_chan *mchan = to_mdc_chan(chan);
 580         struct mdc_tx_desc *mdesc;
 581         struct virt_dma_desc *vd;
 582         unsigned long flags;
 583         size_t bytes = 0;
 584         int ret;
 585
 586         ret = dma_cookie_status(chan, cookie, txstate);
 587         if (ret == DMA_COMPLETE)
 588                 return ret;
 589
 590         if (!txstate)
 591                 return ret;
 592
 593         spin_lock_irqsave(&mchan->vc.lock, flags);
 594         vd = vchan_find_desc(&mchan->vc, cookie);
 595         if (vd) {
 596                 mdesc = to_mdc_desc(&vd->tx);
 597                 bytes = mdesc->list_xfer_size;
 598         } else if (mchan->desc && mchan->desc->vd.tx.cookie == cookie) {
 599                 struct mdc_hw_list_desc *ldesc;
 600                 u32 val1, val2, done, processed, residue;
 601                 int i, cmds;
 602
 603                 mdesc = mchan->desc;
 604
 605                 /*
 606                  * Determine the number of commands that haven't been
 607                  * processed (handled by the IRQ handler) yet.
 608                  */
 609                 do {
 610                         val1 = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED) &
 611                                 ~MDC_CMDS_PROCESSED_INT_ACTIVE;
 612                         residue = mdc_chan_readl(mchan,
 613                                                  MDC_ACTIVE_TRANSFER_SIZE);
 614                         val2 = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED) &
 615                                 ~MDC_CMDS_PROCESSED_INT_ACTIVE;
 616                 } while (val1 != val2);
 617
 618                 done = (val1 >> MDC_CMDS_PROCESSED_CMDS_DONE_SHIFT) &
 619                         MDC_CMDS_PROCESSED_CMDS_DONE_MASK;
 620                 processed = (val1 >> MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT) &
 621                         MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK;
 622                 cmds = (done - processed) %
 623                         (MDC_CMDS_PROCESSED_CMDS_DONE_MASK + 1);
 624
 625                 /*
 626                  * If the command loaded event hasn't been processed yet, then
 627                  * the difference above includes an extra command.
 628                  */
 629                 if (!mdesc->cmd_loaded)
 630                         cmds--;
 631                 else
 632                         cmds += mdesc->list_cmds_done;
 633
 634                 bytes = mdesc->list_xfer_size;
 635                 ldesc = mdesc->list;
 636                 for (i = 0; i < cmds; i++) {
 637                         bytes -= ldesc->xfer_size + 1;
 638                         ldesc = ldesc->next_desc;
 639                 }
 640                 if (ldesc) {
 641                         if (residue != MDC_TRANSFER_SIZE_MASK)
 642                                 bytes -= ldesc->xfer_size - residue;
 643                         else
 644                                 bytes -= ldesc->xfer_size + 1;
 645                 }
 646         }
 647         spin_unlock_irqrestore(&mchan->vc.lock, flags);
 648
 649         dma_set_residue(txstate, bytes);
 650
 651         return ret;
 652 }
 653
 654 static int mdc_terminate_all(struct dma_chan *chan)
 655 {
 656         struct mdc_chan *mchan = to_mdc_chan(chan);
 657         struct mdc_tx_desc *mdesc;
 658         unsigned long flags;
 659         LIST_HEAD(head);
 660
 661         spin_lock_irqsave(&mchan->vc.lock, flags);
 662
 663         mdc_chan_writel(mchan, MDC_CONTROL_AND_STATUS_CANCEL,
 664                         MDC_CONTROL_AND_STATUS);
 665
 666         mdesc = mchan->desc;
 667         mchan->desc = NULL;
 668         vchan_get_all_descriptors(&mchan->vc, &head);
 669
 670         spin_unlock_irqrestore(&mchan->vc.lock, flags);
 671
 672         if (mdesc)
 673                 mdc_desc_free(&mdesc->vd);
 674         vchan_dma_desc_free_list(&mchan->vc, &head);
 675
 676         return 0;
 677 }
 678
 679 static int mdc_slave_config(struct dma_chan *chan,
 680                             struct dma_slave_config *config)
 681 {
 682         struct mdc_chan *mchan = to_mdc_chan(chan);
 683         unsigned long flags;
 684
 685         spin_lock_irqsave(&mchan->vc.lock, flags);
 686         mchan->config = *config;
 687         spin_unlock_irqrestore(&mchan->vc.lock, flags);
 688
 689         return 0;
 690 }
 691
 692 static void mdc_free_chan_resources(struct dma_chan *chan)
 693 {
 694         struct mdc_chan *mchan = to_mdc_chan(chan);
 695         struct mdc_dma *mdma = mchan->mdma;
 696
 697         mdc_terminate_all(chan);
 698
 699         mdma->soc->disable_chan(mchan);
 700 }
 701
 702 static irqreturn_t mdc_chan_irq(int irq, void *dev_id)
 703 {
 704         struct mdc_chan *mchan = (struct mdc_chan *)dev_id;
 705         struct mdc_tx_desc *mdesc;
 706         u32 val, processed, done1, done2;
 707         unsigned int i;
 708
 709         spin_lock(&mchan->vc.lock);
 710
 711         val = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED);
 712         processed = (val >> MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT) &
 713                 MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK;
 714         /*
 715          * CMDS_DONE may have incremented between reading CMDS_PROCESSED
 716          * and clearing INT_ACTIVE.  Re-read CMDS_PROCESSED to ensure we
 717          * didn't miss a command completion.
 718          */
 719         do {
 720                 val = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED);
 721                 done1 = (val >> MDC_CMDS_PROCESSED_CMDS_DONE_SHIFT) &
 722                         MDC_CMDS_PROCESSED_CMDS_DONE_MASK;
 723                 val &= ~((MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK <<
 724                           MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT) |
 725                          MDC_CMDS_PROCESSED_INT_ACTIVE);
 726                 val |= done1 << MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT;
 727                 mdc_chan_writel(mchan, val, MDC_CMDS_PROCESSED);
 728                 val = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED);
 729                 done2 = (val >> MDC_CMDS_PROCESSED_CMDS_DONE_SHIFT) &
 730                         MDC_CMDS_PROCESSED_CMDS_DONE_MASK;
 731         } while (done1 != done2);
 732
 733         dev_dbg(mdma2dev(mchan->mdma), "IRQ on channel %d\n", mchan->chan_nr);
 734
 735         mdesc = mchan->desc;
 736         if (!mdesc) {
 737                 dev_warn(mdma2dev(mchan->mdma),
 738                          "IRQ with no active descriptor on channel %d\n",
 739                          mchan->chan_nr);
 740                 goto out;
 741         }
 742
 743         for (i = processed; i != done1;
 744              i = (i + 1) % (MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK + 1)) {
 745                 /*
 746                  * The first interrupt in a transfer indicates that the
 747                  * command list has been loaded, not that a command has
 748                  * been completed.
 749                  */
 750                 if (!mdesc->cmd_loaded) {
 751                         mdesc->cmd_loaded = true;
 752                         continue;
 753                 }
 754
 755                 mdesc->list_cmds_done++;
 756                 if (mdesc->cyclic) {
 757                         mdesc->list_cmds_done %= mdesc->list_len;
 758                         if (mdesc->list_cmds_done % mdesc->list_period_len == 0)
 759                                 vchan_cyclic_callback(&mdesc->vd);
 760                 } else if (mdesc->list_cmds_done == mdesc->list_len) {
 761                         mchan->desc = NULL;
 762                         vchan_cookie_complete(&mdesc->vd);
 763                         mdc_issue_desc(mchan);
 764                         break;
 765                 }
 766         }
 767 out:
 768         spin_unlock(&mchan->vc.lock);
 769
 770         return IRQ_HANDLED;
 771 }
 772
 773 static struct dma_chan *mdc_of_xlate(struct of_phandle_args *dma_spec,
 774                                      struct of_dma *ofdma)
 775 {
 776         struct mdc_dma *mdma = ofdma->of_dma_data;
 777         struct dma_chan *chan;
 778
 779         if (dma_spec->args_count != 3)
 780                 return NULL;
 781
 782         list_for_each_entry(chan, &mdma->dma_dev.channels, device_node) {
 783                 struct mdc_chan *mchan = to_mdc_chan(chan);
 784
 785                 if (!(dma_spec->args[1] & BIT(mchan->chan_nr)))
 786                         continue;
 787                 if (dma_get_slave_channel(chan)) {
 788                         mchan->periph = dma_spec->args[0];
 789                         mchan->thread = dma_spec->args[2];
 790                         return chan;
 791                 }
 792         }
 793
 794         return NULL;
 795 }
 796
 797 #define PISTACHIO_CR_PERIPH_DMA_ROUTE(ch)       (0x120 + 0x4 * ((ch) / 4))
 798 #define PISTACHIO_CR_PERIPH_DMA_ROUTE_SHIFT(ch) (8 * ((ch) % 4))
 799 #define PISTACHIO_CR_PERIPH_DMA_ROUTE_MASK      0x3f
 800
 801 static void pistachio_mdc_enable_chan(struct mdc_chan *mchan)
 802 {
 803         struct mdc_dma *mdma = mchan->mdma;
 804
 805         regmap_update_bits(mdma->periph_regs,
 806                            PISTACHIO_CR_PERIPH_DMA_ROUTE(mchan->chan_nr),
 807                            PISTACHIO_CR_PERIPH_DMA_ROUTE_MASK <<
 808                            PISTACHIO_CR_PERIPH_DMA_ROUTE_SHIFT(mchan->chan_nr),
 809                            mchan->periph <<
 810                            PISTACHIO_CR_PERIPH_DMA_ROUTE_SHIFT(mchan->chan_nr));
 811 }
 812
 813 static void pistachio_mdc_disable_chan(struct mdc_chan *mchan)
 814 {
 815         struct mdc_dma *mdma = mchan->mdma;
 816
 817         regmap_update_bits(mdma->periph_regs,
 818                            PISTACHIO_CR_PERIPH_DMA_ROUTE(mchan->chan_nr),
 819                            PISTACHIO_CR_PERIPH_DMA_ROUTE_MASK <<
 820                            PISTACHIO_CR_PERIPH_DMA_ROUTE_SHIFT(mchan->chan_nr),
 821                            0);
 822 }
 823
 824 static const struct mdc_dma_soc_data pistachio_mdc_data = {
 825         .enable_chan = pistachio_mdc_enable_chan,
 826         .disable_chan = pistachio_mdc_disable_chan,
 827 };
 828
 829 static const struct of_device_id mdc_dma_of_match[] = {
 830         { .compatible = "img,pistachio-mdc-dma", .data = &pistachio_mdc_data, },
 831         { },
 832 };
 833 MODULE_DEVICE_TABLE(of, mdc_dma_of_match);
 834
 835 static int mdc_dma_probe(struct platform_device *pdev)
 836 {
 837         struct mdc_dma *mdma;
 838         struct resource *res;
 839         const struct of_device_id *match;
 840         unsigned int i;
 841         u32 val;
 842         int ret;
 843
 844         mdma = devm_kzalloc(&pdev->dev, sizeof(*mdma), GFP_KERNEL);
 845         if (!mdma)
 846                 return -ENOMEM;
 847         platform_set_drvdata(pdev, mdma);
 848
 849         match = of_match_device(mdc_dma_of_match, &pdev->dev);
 850         mdma->soc = match->data;
 851
 852         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 853         mdma->regs = devm_ioremap_resource(&pdev->dev, res);
 854         if (IS_ERR(mdma->regs))
 855                 return PTR_ERR(mdma->regs);
 856
 857         mdma->periph_regs = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
 858                                                             "img,cr-periph");
 859         if (IS_ERR(mdma->periph_regs))
 860                 return PTR_ERR(mdma->periph_regs);
 861
 862         mdma->clk = devm_clk_get(&pdev->dev, "sys");
 863         if (IS_ERR(mdma->clk))
 864                 return PTR_ERR(mdma->clk);
 865
 866         ret = clk_prepare_enable(mdma->clk);
 867         if (ret)
 868                 return ret;
 869
 870         dma_cap_zero(mdma->dma_dev.cap_mask);
 871         dma_cap_set(DMA_SLAVE, mdma->dma_dev.cap_mask);
 872         dma_cap_set(DMA_PRIVATE, mdma->dma_dev.cap_mask);
 873         dma_cap_set(DMA_CYCLIC, mdma->dma_dev.cap_mask);
 874         dma_cap_set(DMA_MEMCPY, mdma->dma_dev.cap_mask);
 875
 876         val = mdc_readl(mdma, MDC_GLOBAL_CONFIG_A);
 877         mdma->nr_channels = (val >> MDC_GLOBAL_CONFIG_A_DMA_CONTEXTS_SHIFT) &
 878                 MDC_GLOBAL_CONFIG_A_DMA_CONTEXTS_MASK;
 879         mdma->nr_threads =
 880                 1 << ((val >> MDC_GLOBAL_CONFIG_A_THREAD_ID_WIDTH_SHIFT) &
 881                       MDC_GLOBAL_CONFIG_A_THREAD_ID_WIDTH_MASK);
 882         mdma->bus_width =
 883                 (1 << ((val >> MDC_GLOBAL_CONFIG_A_SYS_DAT_WIDTH_SHIFT) &
 884                        MDC_GLOBAL_CONFIG_A_SYS_DAT_WIDTH_MASK)) / 8;
 885         /*
 886          * Although transfer sizes of up to MDC_TRANSFER_SIZE_MASK + 1 bytes
 887          * are supported, this makes it possible for the value reported in
 888          * MDC_ACTIVE_TRANSFER_SIZE to be ambiguous - an active transfer size
 889          * of MDC_TRANSFER_SIZE_MASK may indicate either that 0 bytes or
 890          * MDC_TRANSFER_SIZE_MASK + 1 bytes are remaining.  To eliminate this
 891          * ambiguity, restrict transfer sizes to one bus-width less than the
 892          * actual maximum.
 893          */
 894         mdma->max_xfer_size = MDC_TRANSFER_SIZE_MASK + 1 - mdma->bus_width;
 895
 896         of_property_read_u32(pdev->dev.of_node, "dma-channels",
 897                              &mdma->nr_channels);
 898         ret = of_property_read_u32(pdev->dev.of_node,
 899                                    "img,max-burst-multiplier",
 900                                    &mdma->max_burst_mult);
 901         if (ret)
 902                 goto disable_clk;
 903
 904         mdma->dma_dev.dev = &pdev->dev;
 905         mdma->dma_dev.device_prep_slave_sg = mdc_prep_slave_sg;
 906         mdma->dma_dev.device_prep_dma_cyclic = mdc_prep_dma_cyclic;
 907         mdma->dma_dev.device_prep_dma_memcpy = mdc_prep_dma_memcpy;
 908         mdma->dma_dev.device_free_chan_resources = mdc_free_chan_resources;
 909         mdma->dma_dev.device_tx_status = mdc_tx_status;
 910         mdma->dma_dev.device_issue_pending = mdc_issue_pending;
 911         mdma->dma_dev.device_terminate_all = mdc_terminate_all;
 912         mdma->dma_dev.device_config = mdc_slave_config;
 913
 914         mdma->dma_dev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
 915         mdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
 916         for (i = 1; i <= mdma->bus_width; i <<= 1) {
 917                 mdma->dma_dev.src_addr_widths |= BIT(i);
 918                 mdma->dma_dev.dst_addr_widths |= BIT(i);
 919         }
 920
 921         INIT_LIST_HEAD(&mdma->dma_dev.channels);
 922         for (i = 0; i < mdma->nr_channels; i++) {
 923                 struct mdc_chan *mchan = &mdma->channels[i];
 924
 925                 mchan->mdma = mdma;
 926                 mchan->chan_nr = i;
 927                 mchan->irq = platform_get_irq(pdev, i);
 928                 if (mchan->irq < 0) {
 929                         ret = mchan->irq;
 930                         goto disable_clk;
 931                 }
 932                 ret = devm_request_irq(&pdev->dev, mchan->irq, mdc_chan_irq,
 933                                        IRQ_TYPE_LEVEL_HIGH,
 934                                        dev_name(&pdev->dev), mchan);
 935                 if (ret < 0)
 936                         goto disable_clk;
 937
 938                 mchan->vc.desc_free = mdc_desc_free;
 939                 vchan_init(&mchan->vc, &mdma->dma_dev);
 940         }
 941
 942         mdma->desc_pool = dmam_pool_create(dev_name(&pdev->dev), &pdev->dev,
 943                                            sizeof(struct mdc_hw_list_desc),
 944                                            4, 0);
 945         if (!mdma->desc_pool) {
 946                 ret = -ENOMEM;
 947                 goto disable_clk;
 948         }
 949
 950         ret = dma_async_device_register(&mdma->dma_dev);
 951         if (ret)
 952                 goto disable_clk;
 953
 954         ret = of_dma_controller_register(pdev->dev.of_node, mdc_of_xlate, mdma);
 955         if (ret)
 956                 goto unregister;
 957
 958         dev_info(&pdev->dev, "MDC with %u channels and %u threads\n",
 959                  mdma->nr_channels, mdma->nr_threads);
 960
 961         return 0;
 962
 963 unregister:
 964         dma_async_device_unregister(&mdma->dma_dev);
 965 disable_clk:
 966         clk_disable_unprepare(mdma->clk);
 967         return ret;
 968 }
 969
 970 static int mdc_dma_remove(struct platform_device *pdev)
 971 {
 972         struct mdc_dma *mdma = platform_get_drvdata(pdev);
 973         struct mdc_chan *mchan, *next;
 974
 975         of_dma_controller_free(pdev->dev.of_node);
 976         dma_async_device_unregister(&mdma->dma_dev);
 977
 978         list_for_each_entry_safe(mchan, next, &mdma->dma_dev.channels,
 979                                  vc.chan.device_node) {
 980                 list_del(&mchan->vc.chan.device_node);
 981
 982                 synchronize_irq(mchan->irq);
 983                 devm_free_irq(&pdev->dev, mchan->irq, mchan);
 984
 985                 tasklet_kill(&mchan->vc.task);
 986         }
 987
 988         clk_disable_unprepare(mdma->clk);
 989
 990         return 0;
 991 }
 992
 993 static struct platform_driver mdc_dma_driver = {
 994         .driver = {
 995                 .name = "img-mdc-dma",
 996                 .of_match_table = of_match_ptr(mdc_dma_of_match),
 997         },
 998         .probe = mdc_dma_probe,
 999         .remove = mdc_dma_remove,
1000 };
1001 module_platform_driver(mdc_dma_driver);
1002
1003 MODULE_DESCRIPTION("IMG Multi-threaded DMA Controller (MDC) driver");
1004 MODULE_AUTHOR("Andrew Bresticker <abrestic@chromium.org>");
1005 MODULE_LICENSE("GPL v2");