linux/drivers/dma/img-mdc-dma.c
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   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
  90struct 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
 106struct 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
 119struct 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
 130struct mdc_dma_soc_data {
 131        void (*enable_chan)(struct mdc_chan *mchan);
 132        void (*disable_chan)(struct mdc_chan *mchan);
 133};
 134
 135struct 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
 151static inline u32 mdc_readl(struct mdc_dma *mdma, u32 reg)
 152{
 153        return readl(mdma->regs + reg);
 154}
 155
 156static inline void mdc_writel(struct mdc_dma *mdma, u32 val, u32 reg)
 157{
 158        writel(val, mdma->regs + reg);
 159}
 160
 161static 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
 166static 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
 171static 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
 176static 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
 183static inline struct device *mdma2dev(struct mdc_dma *mdma)
 184{
 185        return mdma->dma_dev.dev;
 186}
 187
 188static inline unsigned int to_mdc_width(unsigned int bytes)
 189{
 190        return ffs(bytes) - 1;
 191}
 192
 193static 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
 200static 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
 207static 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
 262static 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
 279static 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
 287static 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
 337free_desc:
 338        mdc_desc_free(&mdesc->vd);
 339
 340        return NULL;
 341}
 342
 343static 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
 369static 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
 445free_desc:
 446        mdc_desc_free(&mdesc->vd);
 447
 448        return NULL;
 449}
 450
 451static 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
 523free_desc:
 524        mdc_desc_free(&mdesc->vd);
 525
 526        return NULL;
 527}
 528
 529static 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
 565static 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
 576static 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
 654static 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
 679static 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
 692static 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
 702static 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        }
 767out:
 768        spin_unlock(&mchan->vc.lock);
 769
 770        return IRQ_HANDLED;
 771}
 772
 773static 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
 801static 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
 813static 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
 824static 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
 829static const struct of_device_id mdc_dma_of_match[] = {
 830        { .compatible = "img,pistachio-mdc-dma", .data = &pistachio_mdc_data, },
 831        { },
 832};
 833MODULE_DEVICE_TABLE(of, mdc_dma_of_match);
 834
 835static 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
 963unregister:
 964        dma_async_device_unregister(&mdma->dma_dev);
 965disable_clk:
 966        clk_disable_unprepare(mdma->clk);
 967        return ret;
 968}
 969
 970static 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
 993static 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};
1001module_platform_driver(mdc_dma_driver);
1002
1003MODULE_DESCRIPTION("IMG Multi-threaded DMA Controller (MDC) driver");
1004MODULE_AUTHOR("Andrew Bresticker <abrestic@chromium.org>");
1005MODULE_LICENSE("GPL v2");
1006