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/pm_runtime.h>
  27#include <linux/regmap.h>
  28#include <linux/slab.h>
  29#include <linux/spinlock.h>
  30
  31#include "dmaengine.h"
  32#include "virt-dma.h"
  33
  34#define MDC_MAX_DMA_CHANNELS                    32
  35
  36#define MDC_GENERAL_CONFIG                      0x000
  37#define MDC_GENERAL_CONFIG_LIST_IEN             BIT(31)
  38#define MDC_GENERAL_CONFIG_IEN                  BIT(29)
  39#define MDC_GENERAL_CONFIG_LEVEL_INT            BIT(28)
  40#define MDC_GENERAL_CONFIG_INC_W                BIT(12)
  41#define MDC_GENERAL_CONFIG_INC_R                BIT(8)
  42#define MDC_GENERAL_CONFIG_PHYSICAL_W           BIT(7)
  43#define MDC_GENERAL_CONFIG_WIDTH_W_SHIFT        4
  44#define MDC_GENERAL_CONFIG_WIDTH_W_MASK         0x7
  45#define MDC_GENERAL_CONFIG_PHYSICAL_R           BIT(3)
  46#define MDC_GENERAL_CONFIG_WIDTH_R_SHIFT        0
  47#define MDC_GENERAL_CONFIG_WIDTH_R_MASK         0x7
  48
  49#define MDC_READ_PORT_CONFIG                    0x004
  50#define MDC_READ_PORT_CONFIG_STHREAD_SHIFT      28
  51#define MDC_READ_PORT_CONFIG_STHREAD_MASK       0xf
  52#define MDC_READ_PORT_CONFIG_RTHREAD_SHIFT      24
  53#define MDC_READ_PORT_CONFIG_RTHREAD_MASK       0xf
  54#define MDC_READ_PORT_CONFIG_WTHREAD_SHIFT      16
  55#define MDC_READ_PORT_CONFIG_WTHREAD_MASK       0xf
  56#define MDC_READ_PORT_CONFIG_BURST_SIZE_SHIFT   4
  57#define MDC_READ_PORT_CONFIG_BURST_SIZE_MASK    0xff
  58#define MDC_READ_PORT_CONFIG_DREQ_ENABLE        BIT(1)
  59
  60#define MDC_READ_ADDRESS                        0x008
  61
  62#define MDC_WRITE_ADDRESS                       0x00c
  63
  64#define MDC_TRANSFER_SIZE                       0x010
  65#define MDC_TRANSFER_SIZE_MASK                  0xffffff
  66
  67#define MDC_LIST_NODE_ADDRESS                   0x014
  68
  69#define MDC_CMDS_PROCESSED                      0x018
  70#define MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT 16
  71#define MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK  0x3f
  72#define MDC_CMDS_PROCESSED_INT_ACTIVE           BIT(8)
  73#define MDC_CMDS_PROCESSED_CMDS_DONE_SHIFT      0
  74#define MDC_CMDS_PROCESSED_CMDS_DONE_MASK       0x3f
  75
  76#define MDC_CONTROL_AND_STATUS                  0x01c
  77#define MDC_CONTROL_AND_STATUS_CANCEL           BIT(20)
  78#define MDC_CONTROL_AND_STATUS_LIST_EN          BIT(4)
  79#define MDC_CONTROL_AND_STATUS_EN               BIT(0)
  80
  81#define MDC_ACTIVE_TRANSFER_SIZE                0x030
  82
  83#define MDC_GLOBAL_CONFIG_A                             0x900
  84#define MDC_GLOBAL_CONFIG_A_THREAD_ID_WIDTH_SHIFT       16
  85#define MDC_GLOBAL_CONFIG_A_THREAD_ID_WIDTH_MASK        0xff
  86#define MDC_GLOBAL_CONFIG_A_DMA_CONTEXTS_SHIFT          8
  87#define MDC_GLOBAL_CONFIG_A_DMA_CONTEXTS_MASK           0xff
  88#define MDC_GLOBAL_CONFIG_A_SYS_DAT_WIDTH_SHIFT         0
  89#define MDC_GLOBAL_CONFIG_A_SYS_DAT_WIDTH_MASK          0xff
  90
  91struct mdc_hw_list_desc {
  92        u32 gen_conf;
  93        u32 readport_conf;
  94        u32 read_addr;
  95        u32 write_addr;
  96        u32 xfer_size;
  97        u32 node_addr;
  98        u32 cmds_done;
  99        u32 ctrl_status;
 100        /*
 101         * Not part of the list descriptor, but instead used by the CPU to
 102         * traverse the list.
 103         */
 104        struct mdc_hw_list_desc *next_desc;
 105};
 106
 107struct mdc_tx_desc {
 108        struct mdc_chan *chan;
 109        struct virt_dma_desc vd;
 110        dma_addr_t list_phys;
 111        struct mdc_hw_list_desc *list;
 112        bool cyclic;
 113        bool cmd_loaded;
 114        unsigned int list_len;
 115        unsigned int list_period_len;
 116        size_t list_xfer_size;
 117        unsigned int list_cmds_done;
 118};
 119
 120struct mdc_chan {
 121        struct mdc_dma *mdma;
 122        struct virt_dma_chan vc;
 123        struct dma_slave_config config;
 124        struct mdc_tx_desc *desc;
 125        int irq;
 126        unsigned int periph;
 127        unsigned int thread;
 128        unsigned int chan_nr;
 129};
 130
 131struct mdc_dma_soc_data {
 132        void (*enable_chan)(struct mdc_chan *mchan);
 133        void (*disable_chan)(struct mdc_chan *mchan);
 134};
 135
 136struct mdc_dma {
 137        struct dma_device dma_dev;
 138        void __iomem *regs;
 139        struct clk *clk;
 140        struct dma_pool *desc_pool;
 141        struct regmap *periph_regs;
 142        spinlock_t lock;
 143        unsigned int nr_threads;
 144        unsigned int nr_channels;
 145        unsigned int bus_width;
 146        unsigned int max_burst_mult;
 147        unsigned int max_xfer_size;
 148        const struct mdc_dma_soc_data *soc;
 149        struct mdc_chan channels[MDC_MAX_DMA_CHANNELS];
 150};
 151
 152static inline u32 mdc_readl(struct mdc_dma *mdma, u32 reg)
 153{
 154        return readl(mdma->regs + reg);
 155}
 156
 157static inline void mdc_writel(struct mdc_dma *mdma, u32 val, u32 reg)
 158{
 159        writel(val, mdma->regs + reg);
 160}
 161
 162static inline u32 mdc_chan_readl(struct mdc_chan *mchan, u32 reg)
 163{
 164        return mdc_readl(mchan->mdma, mchan->chan_nr * 0x040 + reg);
 165}
 166
 167static inline void mdc_chan_writel(struct mdc_chan *mchan, u32 val, u32 reg)
 168{
 169        mdc_writel(mchan->mdma, val, mchan->chan_nr * 0x040 + reg);
 170}
 171
 172static inline struct mdc_chan *to_mdc_chan(struct dma_chan *c)
 173{
 174        return container_of(to_virt_chan(c), struct mdc_chan, vc);
 175}
 176
 177static inline struct mdc_tx_desc *to_mdc_desc(struct dma_async_tx_descriptor *t)
 178{
 179        struct virt_dma_desc *vdesc = container_of(t, struct virt_dma_desc, tx);
 180
 181        return container_of(vdesc, struct mdc_tx_desc, vd);
 182}
 183
 184static inline struct device *mdma2dev(struct mdc_dma *mdma)
 185{
 186        return mdma->dma_dev.dev;
 187}
 188
 189static inline unsigned int to_mdc_width(unsigned int bytes)
 190{
 191        return ffs(bytes) - 1;
 192}
 193
 194static inline void mdc_set_read_width(struct mdc_hw_list_desc *ldesc,
 195                                      unsigned int bytes)
 196{
 197        ldesc->gen_conf |= to_mdc_width(bytes) <<
 198                MDC_GENERAL_CONFIG_WIDTH_R_SHIFT;
 199}
 200
 201static inline void mdc_set_write_width(struct mdc_hw_list_desc *ldesc,
 202                                       unsigned int bytes)
 203{
 204        ldesc->gen_conf |= to_mdc_width(bytes) <<
 205                MDC_GENERAL_CONFIG_WIDTH_W_SHIFT;
 206}
 207
 208static void mdc_list_desc_config(struct mdc_chan *mchan,
 209                                 struct mdc_hw_list_desc *ldesc,
 210                                 enum dma_transfer_direction dir,
 211                                 dma_addr_t src, dma_addr_t dst, size_t len)
 212{
 213        struct mdc_dma *mdma = mchan->mdma;
 214        unsigned int max_burst, burst_size;
 215
 216        ldesc->gen_conf = MDC_GENERAL_CONFIG_IEN | MDC_GENERAL_CONFIG_LIST_IEN |
 217                MDC_GENERAL_CONFIG_LEVEL_INT | MDC_GENERAL_CONFIG_PHYSICAL_W |
 218                MDC_GENERAL_CONFIG_PHYSICAL_R;
 219        ldesc->readport_conf =
 220                (mchan->thread << MDC_READ_PORT_CONFIG_STHREAD_SHIFT) |
 221                (mchan->thread << MDC_READ_PORT_CONFIG_RTHREAD_SHIFT) |
 222                (mchan->thread << MDC_READ_PORT_CONFIG_WTHREAD_SHIFT);
 223        ldesc->read_addr = src;
 224        ldesc->write_addr = dst;
 225        ldesc->xfer_size = len - 1;
 226        ldesc->node_addr = 0;
 227        ldesc->cmds_done = 0;
 228        ldesc->ctrl_status = MDC_CONTROL_AND_STATUS_LIST_EN |
 229                MDC_CONTROL_AND_STATUS_EN;
 230        ldesc->next_desc = NULL;
 231
 232        if (IS_ALIGNED(dst, mdma->bus_width) &&
 233            IS_ALIGNED(src, mdma->bus_width))
 234                max_burst = mdma->bus_width * mdma->max_burst_mult;
 235        else
 236                max_burst = mdma->bus_width * (mdma->max_burst_mult - 1);
 237
 238        if (dir == DMA_MEM_TO_DEV) {
 239                ldesc->gen_conf |= MDC_GENERAL_CONFIG_INC_R;
 240                ldesc->readport_conf |= MDC_READ_PORT_CONFIG_DREQ_ENABLE;
 241                mdc_set_read_width(ldesc, mdma->bus_width);
 242                mdc_set_write_width(ldesc, mchan->config.dst_addr_width);
 243                burst_size = min(max_burst, mchan->config.dst_maxburst *
 244                                 mchan->config.dst_addr_width);
 245        } else if (dir == DMA_DEV_TO_MEM) {
 246                ldesc->gen_conf |= MDC_GENERAL_CONFIG_INC_W;
 247                ldesc->readport_conf |= MDC_READ_PORT_CONFIG_DREQ_ENABLE;
 248                mdc_set_read_width(ldesc, mchan->config.src_addr_width);
 249                mdc_set_write_width(ldesc, mdma->bus_width);
 250                burst_size = min(max_burst, mchan->config.src_maxburst *
 251                                 mchan->config.src_addr_width);
 252        } else {
 253                ldesc->gen_conf |= MDC_GENERAL_CONFIG_INC_R |
 254                        MDC_GENERAL_CONFIG_INC_W;
 255                mdc_set_read_width(ldesc, mdma->bus_width);
 256                mdc_set_write_width(ldesc, mdma->bus_width);
 257                burst_size = max_burst;
 258        }
 259        ldesc->readport_conf |= (burst_size - 1) <<
 260                MDC_READ_PORT_CONFIG_BURST_SIZE_SHIFT;
 261}
 262
 263static void mdc_list_desc_free(struct mdc_tx_desc *mdesc)
 264{
 265        struct mdc_dma *mdma = mdesc->chan->mdma;
 266        struct mdc_hw_list_desc *curr, *next;
 267        dma_addr_t curr_phys, next_phys;
 268
 269        curr = mdesc->list;
 270        curr_phys = mdesc->list_phys;
 271        while (curr) {
 272                next = curr->next_desc;
 273                next_phys = curr->node_addr;
 274                dma_pool_free(mdma->desc_pool, curr, curr_phys);
 275                curr = next;
 276                curr_phys = next_phys;
 277        }
 278}
 279
 280static void mdc_desc_free(struct virt_dma_desc *vd)
 281{
 282        struct mdc_tx_desc *mdesc = to_mdc_desc(&vd->tx);
 283
 284        mdc_list_desc_free(mdesc);
 285        kfree(mdesc);
 286}
 287
 288static struct dma_async_tx_descriptor *mdc_prep_dma_memcpy(
 289        struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, size_t len,
 290        unsigned long flags)
 291{
 292        struct mdc_chan *mchan = to_mdc_chan(chan);
 293        struct mdc_dma *mdma = mchan->mdma;
 294        struct mdc_tx_desc *mdesc;
 295        struct mdc_hw_list_desc *curr, *prev = NULL;
 296        dma_addr_t curr_phys;
 297
 298        if (!len)
 299                return NULL;
 300
 301        mdesc = kzalloc(sizeof(*mdesc), GFP_NOWAIT);
 302        if (!mdesc)
 303                return NULL;
 304        mdesc->chan = mchan;
 305        mdesc->list_xfer_size = len;
 306
 307        while (len > 0) {
 308                size_t xfer_size;
 309
 310                curr = dma_pool_alloc(mdma->desc_pool, GFP_NOWAIT, &curr_phys);
 311                if (!curr)
 312                        goto free_desc;
 313
 314                if (prev) {
 315                        prev->node_addr = curr_phys;
 316                        prev->next_desc = curr;
 317                } else {
 318                        mdesc->list_phys = curr_phys;
 319                        mdesc->list = curr;
 320                }
 321
 322                xfer_size = min_t(size_t, mdma->max_xfer_size, len);
 323
 324                mdc_list_desc_config(mchan, curr, DMA_MEM_TO_MEM, src, dest,
 325                                     xfer_size);
 326
 327                prev = curr;
 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;
 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
 434                        mdesc->list_len++;
 435                        buf_addr += xfer_size;
 436                        buf_len -= xfer_size;
 437                        remainder -= xfer_size;
 438                }
 439        }
 440        prev->node_addr = mdesc->list_phys;
 441
 442        return vchan_tx_prep(&mchan->vc, &mdesc->vd, flags);
 443
 444free_desc:
 445        mdc_desc_free(&mdesc->vd);
 446
 447        return NULL;
 448}
 449
 450static struct dma_async_tx_descriptor *mdc_prep_slave_sg(
 451        struct dma_chan *chan, struct scatterlist *sgl,
 452        unsigned int sg_len, enum dma_transfer_direction dir,
 453        unsigned long flags, void *context)
 454{
 455        struct mdc_chan *mchan = to_mdc_chan(chan);
 456        struct mdc_dma *mdma = mchan->mdma;
 457        struct mdc_tx_desc *mdesc;
 458        struct scatterlist *sg;
 459        struct mdc_hw_list_desc *curr, *prev = NULL;
 460        dma_addr_t curr_phys;
 461        unsigned int i;
 462
 463        if (!sgl)
 464                return NULL;
 465
 466        if (!is_slave_direction(dir))
 467                return NULL;
 468
 469        if (mdc_check_slave_width(mchan, dir) < 0)
 470                return NULL;
 471
 472        mdesc = kzalloc(sizeof(*mdesc), GFP_NOWAIT);
 473        if (!mdesc)
 474                return NULL;
 475        mdesc->chan = mchan;
 476
 477        for_each_sg(sgl, sg, sg_len, i) {
 478                dma_addr_t buf = sg_dma_address(sg);
 479                size_t buf_len = sg_dma_len(sg);
 480
 481                while (buf_len > 0) {
 482                        size_t xfer_size;
 483
 484                        curr = dma_pool_alloc(mdma->desc_pool, GFP_NOWAIT,
 485                                              &curr_phys);
 486                        if (!curr)
 487                                goto free_desc;
 488
 489                        if (!prev) {
 490                                mdesc->list_phys = curr_phys;
 491                                mdesc->list = curr;
 492                        } else {
 493                                prev->node_addr = curr_phys;
 494                                prev->next_desc = curr;
 495                        }
 496
 497                        xfer_size = min_t(size_t, mdma->max_xfer_size,
 498                                          buf_len);
 499
 500                        if (dir == DMA_MEM_TO_DEV) {
 501                                mdc_list_desc_config(mchan, curr, dir, buf,
 502                                                     mchan->config.dst_addr,
 503                                                     xfer_size);
 504                        } else {
 505                                mdc_list_desc_config(mchan, curr, dir,
 506                                                     mchan->config.src_addr,
 507                                                     buf, xfer_size);
 508                        }
 509
 510                        prev = curr;
 511
 512                        mdesc->list_len++;
 513                        mdesc->list_xfer_size += xfer_size;
 514                        buf += xfer_size;
 515                        buf_len -= xfer_size;
 516                }
 517        }
 518
 519        return vchan_tx_prep(&mchan->vc, &mdesc->vd, flags);
 520
 521free_desc:
 522        mdc_desc_free(&mdesc->vd);
 523
 524        return NULL;
 525}
 526
 527static void mdc_issue_desc(struct mdc_chan *mchan)
 528{
 529        struct mdc_dma *mdma = mchan->mdma;
 530        struct virt_dma_desc *vd;
 531        struct mdc_tx_desc *mdesc;
 532        u32 val;
 533
 534        vd = vchan_next_desc(&mchan->vc);
 535        if (!vd)
 536                return;
 537
 538        list_del(&vd->node);
 539
 540        mdesc = to_mdc_desc(&vd->tx);
 541        mchan->desc = mdesc;
 542
 543        dev_dbg(mdma2dev(mdma), "Issuing descriptor on channel %d\n",
 544                mchan->chan_nr);
 545
 546        mdma->soc->enable_chan(mchan);
 547
 548        val = mdc_chan_readl(mchan, MDC_GENERAL_CONFIG);
 549        val |= MDC_GENERAL_CONFIG_LIST_IEN | MDC_GENERAL_CONFIG_IEN |
 550                MDC_GENERAL_CONFIG_LEVEL_INT | MDC_GENERAL_CONFIG_PHYSICAL_W |
 551                MDC_GENERAL_CONFIG_PHYSICAL_R;
 552        mdc_chan_writel(mchan, val, MDC_GENERAL_CONFIG);
 553        val = (mchan->thread << MDC_READ_PORT_CONFIG_STHREAD_SHIFT) |
 554                (mchan->thread << MDC_READ_PORT_CONFIG_RTHREAD_SHIFT) |
 555                (mchan->thread << MDC_READ_PORT_CONFIG_WTHREAD_SHIFT);
 556        mdc_chan_writel(mchan, val, MDC_READ_PORT_CONFIG);
 557        mdc_chan_writel(mchan, mdesc->list_phys, MDC_LIST_NODE_ADDRESS);
 558        val = mdc_chan_readl(mchan, MDC_CONTROL_AND_STATUS);
 559        val |= MDC_CONTROL_AND_STATUS_LIST_EN;
 560        mdc_chan_writel(mchan, val, MDC_CONTROL_AND_STATUS);
 561}
 562
 563static void mdc_issue_pending(struct dma_chan *chan)
 564{
 565        struct mdc_chan *mchan = to_mdc_chan(chan);
 566        unsigned long flags;
 567
 568        spin_lock_irqsave(&mchan->vc.lock, flags);
 569        if (vchan_issue_pending(&mchan->vc) && !mchan->desc)
 570                mdc_issue_desc(mchan);
 571        spin_unlock_irqrestore(&mchan->vc.lock, flags);
 572}
 573
 574static enum dma_status mdc_tx_status(struct dma_chan *chan,
 575        dma_cookie_t cookie, struct dma_tx_state *txstate)
 576{
 577        struct mdc_chan *mchan = to_mdc_chan(chan);
 578        struct mdc_tx_desc *mdesc;
 579        struct virt_dma_desc *vd;
 580        unsigned long flags;
 581        size_t bytes = 0;
 582        int ret;
 583
 584        ret = dma_cookie_status(chan, cookie, txstate);
 585        if (ret == DMA_COMPLETE)
 586                return ret;
 587
 588        if (!txstate)
 589                return ret;
 590
 591        spin_lock_irqsave(&mchan->vc.lock, flags);
 592        vd = vchan_find_desc(&mchan->vc, cookie);
 593        if (vd) {
 594                mdesc = to_mdc_desc(&vd->tx);
 595                bytes = mdesc->list_xfer_size;
 596        } else if (mchan->desc && mchan->desc->vd.tx.cookie == cookie) {
 597                struct mdc_hw_list_desc *ldesc;
 598                u32 val1, val2, done, processed, residue;
 599                int i, cmds;
 600
 601                mdesc = mchan->desc;
 602
 603                /*
 604                 * Determine the number of commands that haven't been
 605                 * processed (handled by the IRQ handler) yet.
 606                 */
 607                do {
 608                        val1 = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED) &
 609                                ~MDC_CMDS_PROCESSED_INT_ACTIVE;
 610                        residue = mdc_chan_readl(mchan,
 611                                                 MDC_ACTIVE_TRANSFER_SIZE);
 612                        val2 = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED) &
 613                                ~MDC_CMDS_PROCESSED_INT_ACTIVE;
 614                } while (val1 != val2);
 615
 616                done = (val1 >> MDC_CMDS_PROCESSED_CMDS_DONE_SHIFT) &
 617                        MDC_CMDS_PROCESSED_CMDS_DONE_MASK;
 618                processed = (val1 >> MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT) &
 619                        MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK;
 620                cmds = (done - processed) %
 621                        (MDC_CMDS_PROCESSED_CMDS_DONE_MASK + 1);
 622
 623                /*
 624                 * If the command loaded event hasn't been processed yet, then
 625                 * the difference above includes an extra command.
 626                 */
 627                if (!mdesc->cmd_loaded)
 628                        cmds--;
 629                else
 630                        cmds += mdesc->list_cmds_done;
 631
 632                bytes = mdesc->list_xfer_size;
 633                ldesc = mdesc->list;
 634                for (i = 0; i < cmds; i++) {
 635                        bytes -= ldesc->xfer_size + 1;
 636                        ldesc = ldesc->next_desc;
 637                }
 638                if (ldesc) {
 639                        if (residue != MDC_TRANSFER_SIZE_MASK)
 640                                bytes -= ldesc->xfer_size - residue;
 641                        else
 642                                bytes -= ldesc->xfer_size + 1;
 643                }
 644        }
 645        spin_unlock_irqrestore(&mchan->vc.lock, flags);
 646
 647        dma_set_residue(txstate, bytes);
 648
 649        return ret;
 650}
 651
 652static unsigned int mdc_get_new_events(struct mdc_chan *mchan)
 653{
 654        u32 val, processed, done1, done2;
 655        unsigned int ret;
 656
 657        val = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED);
 658        processed = (val >> MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT) &
 659                                MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK;
 660        /*
 661         * CMDS_DONE may have incremented between reading CMDS_PROCESSED
 662         * and clearing INT_ACTIVE.  Re-read CMDS_PROCESSED to ensure we
 663         * didn't miss a command completion.
 664         */
 665        do {
 666                val = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED);
 667
 668                done1 = (val >> MDC_CMDS_PROCESSED_CMDS_DONE_SHIFT) &
 669                        MDC_CMDS_PROCESSED_CMDS_DONE_MASK;
 670
 671                val &= ~((MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK <<
 672                          MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT) |
 673                         MDC_CMDS_PROCESSED_INT_ACTIVE);
 674
 675                val |= done1 << MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT;
 676
 677                mdc_chan_writel(mchan, val, MDC_CMDS_PROCESSED);
 678
 679                val = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED);
 680
 681                done2 = (val >> MDC_CMDS_PROCESSED_CMDS_DONE_SHIFT) &
 682                        MDC_CMDS_PROCESSED_CMDS_DONE_MASK;
 683        } while (done1 != done2);
 684
 685        if (done1 >= processed)
 686                ret = done1 - processed;
 687        else
 688                ret = ((MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK + 1) -
 689                        processed) + done1;
 690
 691        return ret;
 692}
 693
 694static int mdc_terminate_all(struct dma_chan *chan)
 695{
 696        struct mdc_chan *mchan = to_mdc_chan(chan);
 697        unsigned long flags;
 698        LIST_HEAD(head);
 699
 700        spin_lock_irqsave(&mchan->vc.lock, flags);
 701
 702        mdc_chan_writel(mchan, MDC_CONTROL_AND_STATUS_CANCEL,
 703                        MDC_CONTROL_AND_STATUS);
 704
 705        if (mchan->desc) {
 706                vchan_terminate_vdesc(&mchan->desc->vd);
 707                mchan->desc = NULL;
 708        }
 709        vchan_get_all_descriptors(&mchan->vc, &head);
 710
 711        mdc_get_new_events(mchan);
 712
 713        spin_unlock_irqrestore(&mchan->vc.lock, flags);
 714
 715        vchan_dma_desc_free_list(&mchan->vc, &head);
 716
 717        return 0;
 718}
 719
 720static void mdc_synchronize(struct dma_chan *chan)
 721{
 722        struct mdc_chan *mchan = to_mdc_chan(chan);
 723
 724        vchan_synchronize(&mchan->vc);
 725}
 726
 727static int mdc_slave_config(struct dma_chan *chan,
 728                            struct dma_slave_config *config)
 729{
 730        struct mdc_chan *mchan = to_mdc_chan(chan);
 731        unsigned long flags;
 732
 733        spin_lock_irqsave(&mchan->vc.lock, flags);
 734        mchan->config = *config;
 735        spin_unlock_irqrestore(&mchan->vc.lock, flags);
 736
 737        return 0;
 738}
 739
 740static int mdc_alloc_chan_resources(struct dma_chan *chan)
 741{
 742        struct mdc_chan *mchan = to_mdc_chan(chan);
 743        struct device *dev = mdma2dev(mchan->mdma);
 744
 745        return pm_runtime_get_sync(dev);
 746}
 747
 748static void mdc_free_chan_resources(struct dma_chan *chan)
 749{
 750        struct mdc_chan *mchan = to_mdc_chan(chan);
 751        struct mdc_dma *mdma = mchan->mdma;
 752        struct device *dev = mdma2dev(mdma);
 753
 754        mdc_terminate_all(chan);
 755        mdma->soc->disable_chan(mchan);
 756        pm_runtime_put(dev);
 757}
 758
 759static irqreturn_t mdc_chan_irq(int irq, void *dev_id)
 760{
 761        struct mdc_chan *mchan = (struct mdc_chan *)dev_id;
 762        struct mdc_tx_desc *mdesc;
 763        unsigned int i, new_events;
 764
 765        spin_lock(&mchan->vc.lock);
 766
 767        dev_dbg(mdma2dev(mchan->mdma), "IRQ on channel %d\n", mchan->chan_nr);
 768
 769        new_events = mdc_get_new_events(mchan);
 770
 771        if (!new_events)
 772                goto out;
 773
 774        mdesc = mchan->desc;
 775        if (!mdesc) {
 776                dev_warn(mdma2dev(mchan->mdma),
 777                         "IRQ with no active descriptor on channel %d\n",
 778                         mchan->chan_nr);
 779                goto out;
 780        }
 781
 782        for (i = 0; i < new_events; i++) {
 783                /*
 784                 * The first interrupt in a transfer indicates that the
 785                 * command list has been loaded, not that a command has
 786                 * been completed.
 787                 */
 788                if (!mdesc->cmd_loaded) {
 789                        mdesc->cmd_loaded = true;
 790                        continue;
 791                }
 792
 793                mdesc->list_cmds_done++;
 794                if (mdesc->cyclic) {
 795                        mdesc->list_cmds_done %= mdesc->list_len;
 796                        if (mdesc->list_cmds_done % mdesc->list_period_len == 0)
 797                                vchan_cyclic_callback(&mdesc->vd);
 798                } else if (mdesc->list_cmds_done == mdesc->list_len) {
 799                        mchan->desc = NULL;
 800                        vchan_cookie_complete(&mdesc->vd);
 801                        mdc_issue_desc(mchan);
 802                        break;
 803                }
 804        }
 805out:
 806        spin_unlock(&mchan->vc.lock);
 807
 808        return IRQ_HANDLED;
 809}
 810
 811static struct dma_chan *mdc_of_xlate(struct of_phandle_args *dma_spec,
 812                                     struct of_dma *ofdma)
 813{
 814        struct mdc_dma *mdma = ofdma->of_dma_data;
 815        struct dma_chan *chan;
 816
 817        if (dma_spec->args_count != 3)
 818                return NULL;
 819
 820        list_for_each_entry(chan, &mdma->dma_dev.channels, device_node) {
 821                struct mdc_chan *mchan = to_mdc_chan(chan);
 822
 823                if (!(dma_spec->args[1] & BIT(mchan->chan_nr)))
 824                        continue;
 825                if (dma_get_slave_channel(chan)) {
 826                        mchan->periph = dma_spec->args[0];
 827                        mchan->thread = dma_spec->args[2];
 828                        return chan;
 829                }
 830        }
 831
 832        return NULL;
 833}
 834
 835#define PISTACHIO_CR_PERIPH_DMA_ROUTE(ch)       (0x120 + 0x4 * ((ch) / 4))
 836#define PISTACHIO_CR_PERIPH_DMA_ROUTE_SHIFT(ch) (8 * ((ch) % 4))
 837#define PISTACHIO_CR_PERIPH_DMA_ROUTE_MASK      0x3f
 838
 839static void pistachio_mdc_enable_chan(struct mdc_chan *mchan)
 840{
 841        struct mdc_dma *mdma = mchan->mdma;
 842
 843        regmap_update_bits(mdma->periph_regs,
 844                           PISTACHIO_CR_PERIPH_DMA_ROUTE(mchan->chan_nr),
 845                           PISTACHIO_CR_PERIPH_DMA_ROUTE_MASK <<
 846                           PISTACHIO_CR_PERIPH_DMA_ROUTE_SHIFT(mchan->chan_nr),
 847                           mchan->periph <<
 848                           PISTACHIO_CR_PERIPH_DMA_ROUTE_SHIFT(mchan->chan_nr));
 849}
 850
 851static void pistachio_mdc_disable_chan(struct mdc_chan *mchan)
 852{
 853        struct mdc_dma *mdma = mchan->mdma;
 854
 855        regmap_update_bits(mdma->periph_regs,
 856                           PISTACHIO_CR_PERIPH_DMA_ROUTE(mchan->chan_nr),
 857                           PISTACHIO_CR_PERIPH_DMA_ROUTE_MASK <<
 858                           PISTACHIO_CR_PERIPH_DMA_ROUTE_SHIFT(mchan->chan_nr),
 859                           0);
 860}
 861
 862static const struct mdc_dma_soc_data pistachio_mdc_data = {
 863        .enable_chan = pistachio_mdc_enable_chan,
 864        .disable_chan = pistachio_mdc_disable_chan,
 865};
 866
 867static const struct of_device_id mdc_dma_of_match[] = {
 868        { .compatible = "img,pistachio-mdc-dma", .data = &pistachio_mdc_data, },
 869        { },
 870};
 871MODULE_DEVICE_TABLE(of, mdc_dma_of_match);
 872
 873static int img_mdc_runtime_suspend(struct device *dev)
 874{
 875        struct mdc_dma *mdma = dev_get_drvdata(dev);
 876
 877        clk_disable_unprepare(mdma->clk);
 878
 879        return 0;
 880}
 881
 882static int img_mdc_runtime_resume(struct device *dev)
 883{
 884        struct mdc_dma *mdma = dev_get_drvdata(dev);
 885
 886        return clk_prepare_enable(mdma->clk);
 887}
 888
 889static int mdc_dma_probe(struct platform_device *pdev)
 890{
 891        struct mdc_dma *mdma;
 892        struct resource *res;
 893        unsigned int i;
 894        u32 val;
 895        int ret;
 896
 897        mdma = devm_kzalloc(&pdev->dev, sizeof(*mdma), GFP_KERNEL);
 898        if (!mdma)
 899                return -ENOMEM;
 900        platform_set_drvdata(pdev, mdma);
 901
 902        mdma->soc = of_device_get_match_data(&pdev->dev);
 903
 904        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 905        mdma->regs = devm_ioremap_resource(&pdev->dev, res);
 906        if (IS_ERR(mdma->regs))
 907                return PTR_ERR(mdma->regs);
 908
 909        mdma->periph_regs = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
 910                                                            "img,cr-periph");
 911        if (IS_ERR(mdma->periph_regs))
 912                return PTR_ERR(mdma->periph_regs);
 913
 914        mdma->clk = devm_clk_get(&pdev->dev, "sys");
 915        if (IS_ERR(mdma->clk))
 916                return PTR_ERR(mdma->clk);
 917
 918        dma_cap_zero(mdma->dma_dev.cap_mask);
 919        dma_cap_set(DMA_SLAVE, mdma->dma_dev.cap_mask);
 920        dma_cap_set(DMA_PRIVATE, mdma->dma_dev.cap_mask);
 921        dma_cap_set(DMA_CYCLIC, mdma->dma_dev.cap_mask);
 922        dma_cap_set(DMA_MEMCPY, mdma->dma_dev.cap_mask);
 923
 924        val = mdc_readl(mdma, MDC_GLOBAL_CONFIG_A);
 925        mdma->nr_channels = (val >> MDC_GLOBAL_CONFIG_A_DMA_CONTEXTS_SHIFT) &
 926                MDC_GLOBAL_CONFIG_A_DMA_CONTEXTS_MASK;
 927        mdma->nr_threads =
 928                1 << ((val >> MDC_GLOBAL_CONFIG_A_THREAD_ID_WIDTH_SHIFT) &
 929                      MDC_GLOBAL_CONFIG_A_THREAD_ID_WIDTH_MASK);
 930        mdma->bus_width =
 931                (1 << ((val >> MDC_GLOBAL_CONFIG_A_SYS_DAT_WIDTH_SHIFT) &
 932                       MDC_GLOBAL_CONFIG_A_SYS_DAT_WIDTH_MASK)) / 8;
 933        /*
 934         * Although transfer sizes of up to MDC_TRANSFER_SIZE_MASK + 1 bytes
 935         * are supported, this makes it possible for the value reported in
 936         * MDC_ACTIVE_TRANSFER_SIZE to be ambiguous - an active transfer size
 937         * of MDC_TRANSFER_SIZE_MASK may indicate either that 0 bytes or
 938         * MDC_TRANSFER_SIZE_MASK + 1 bytes are remaining.  To eliminate this
 939         * ambiguity, restrict transfer sizes to one bus-width less than the
 940         * actual maximum.
 941         */
 942        mdma->max_xfer_size = MDC_TRANSFER_SIZE_MASK + 1 - mdma->bus_width;
 943
 944        of_property_read_u32(pdev->dev.of_node, "dma-channels",
 945                             &mdma->nr_channels);
 946        ret = of_property_read_u32(pdev->dev.of_node,
 947                                   "img,max-burst-multiplier",
 948                                   &mdma->max_burst_mult);
 949        if (ret)
 950                return ret;
 951
 952        mdma->dma_dev.dev = &pdev->dev;
 953        mdma->dma_dev.device_prep_slave_sg = mdc_prep_slave_sg;
 954        mdma->dma_dev.device_prep_dma_cyclic = mdc_prep_dma_cyclic;
 955        mdma->dma_dev.device_prep_dma_memcpy = mdc_prep_dma_memcpy;
 956        mdma->dma_dev.device_alloc_chan_resources = mdc_alloc_chan_resources;
 957        mdma->dma_dev.device_free_chan_resources = mdc_free_chan_resources;
 958        mdma->dma_dev.device_tx_status = mdc_tx_status;
 959        mdma->dma_dev.device_issue_pending = mdc_issue_pending;
 960        mdma->dma_dev.device_terminate_all = mdc_terminate_all;
 961        mdma->dma_dev.device_synchronize = mdc_synchronize;
 962        mdma->dma_dev.device_config = mdc_slave_config;
 963
 964        mdma->dma_dev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
 965        mdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
 966        for (i = 1; i <= mdma->bus_width; i <<= 1) {
 967                mdma->dma_dev.src_addr_widths |= BIT(i);
 968                mdma->dma_dev.dst_addr_widths |= BIT(i);
 969        }
 970
 971        INIT_LIST_HEAD(&mdma->dma_dev.channels);
 972        for (i = 0; i < mdma->nr_channels; i++) {
 973                struct mdc_chan *mchan = &mdma->channels[i];
 974
 975                mchan->mdma = mdma;
 976                mchan->chan_nr = i;
 977                mchan->irq = platform_get_irq(pdev, i);
 978                if (mchan->irq < 0)
 979                        return mchan->irq;
 980
 981                ret = devm_request_irq(&pdev->dev, mchan->irq, mdc_chan_irq,
 982                                       IRQ_TYPE_LEVEL_HIGH,
 983                                       dev_name(&pdev->dev), mchan);
 984                if (ret < 0)
 985                        return ret;
 986
 987                mchan->vc.desc_free = mdc_desc_free;
 988                vchan_init(&mchan->vc, &mdma->dma_dev);
 989        }
 990
 991        mdma->desc_pool = dmam_pool_create(dev_name(&pdev->dev), &pdev->dev,
 992                                           sizeof(struct mdc_hw_list_desc),
 993                                           4, 0);
 994        if (!mdma->desc_pool)
 995                return -ENOMEM;
 996
 997        pm_runtime_enable(&pdev->dev);
 998        if (!pm_runtime_enabled(&pdev->dev)) {
 999                ret = img_mdc_runtime_resume(&pdev->dev);
1000                if (ret)
1001                        return ret;
1002        }
1003
1004        ret = dma_async_device_register(&mdma->dma_dev);
1005        if (ret)
1006                goto suspend;
1007
1008        ret = of_dma_controller_register(pdev->dev.of_node, mdc_of_xlate, mdma);
1009        if (ret)
1010                goto unregister;
1011
1012        dev_info(&pdev->dev, "MDC with %u channels and %u threads\n",
1013                 mdma->nr_channels, mdma->nr_threads);
1014
1015        return 0;
1016
1017unregister:
1018        dma_async_device_unregister(&mdma->dma_dev);
1019suspend:
1020        if (!pm_runtime_enabled(&pdev->dev))
1021                img_mdc_runtime_suspend(&pdev->dev);
1022        pm_runtime_disable(&pdev->dev);
1023        return ret;
1024}
1025
1026static int mdc_dma_remove(struct platform_device *pdev)
1027{
1028        struct mdc_dma *mdma = platform_get_drvdata(pdev);
1029        struct mdc_chan *mchan, *next;
1030
1031        of_dma_controller_free(pdev->dev.of_node);
1032        dma_async_device_unregister(&mdma->dma_dev);
1033
1034        list_for_each_entry_safe(mchan, next, &mdma->dma_dev.channels,
1035                                 vc.chan.device_node) {
1036                list_del(&mchan->vc.chan.device_node);
1037
1038                devm_free_irq(&pdev->dev, mchan->irq, mchan);
1039
1040                tasklet_kill(&mchan->vc.task);
1041        }
1042
1043        pm_runtime_disable(&pdev->dev);
1044        if (!pm_runtime_status_suspended(&pdev->dev))
1045                img_mdc_runtime_suspend(&pdev->dev);
1046
1047        return 0;
1048}
1049
1050#ifdef CONFIG_PM_SLEEP
1051static int img_mdc_suspend_late(struct device *dev)
1052{
1053        struct mdc_dma *mdma = dev_get_drvdata(dev);
1054        int i;
1055
1056        /* Check that all channels are idle */
1057        for (i = 0; i < mdma->nr_channels; i++) {
1058                struct mdc_chan *mchan = &mdma->channels[i];
1059
1060                if (unlikely(mchan->desc))
1061                        return -EBUSY;
1062        }
1063
1064        return pm_runtime_force_suspend(dev);
1065}
1066
1067static int img_mdc_resume_early(struct device *dev)
1068{
1069        return pm_runtime_force_resume(dev);
1070}
1071#endif /* CONFIG_PM_SLEEP */
1072
1073static const struct dev_pm_ops img_mdc_pm_ops = {
1074        SET_RUNTIME_PM_OPS(img_mdc_runtime_suspend,
1075                           img_mdc_runtime_resume, NULL)
1076        SET_LATE_SYSTEM_SLEEP_PM_OPS(img_mdc_suspend_late,
1077                                     img_mdc_resume_early)
1078};
1079
1080static struct platform_driver mdc_dma_driver = {
1081        .driver = {
1082                .name = "img-mdc-dma",
1083                .pm = &img_mdc_pm_ops,
1084                .of_match_table = of_match_ptr(mdc_dma_of_match),
1085        },
1086        .probe = mdc_dma_probe,
1087        .remove = mdc_dma_remove,
1088};
1089module_platform_driver(mdc_dma_driver);
1090
1091MODULE_DESCRIPTION("IMG Multi-threaded DMA Controller (MDC) driver");
1092MODULE_AUTHOR("Andrew Bresticker <abrestic@chromium.org>");
1093MODULE_LICENSE("GPL v2");
1094