drivers/dma/milbeaut-hdmac.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 //
   3 // Copyright (C) 2019 Linaro Ltd.
   4 // Copyright (C) 2019 Socionext Inc.
   5
   6 #include <linux/bits.h>
   7 #include <linux/clk.h>
   8 #include <linux/dma-mapping.h>
   9 #include <linux/interrupt.h>
  10 #include <linux/iopoll.h>
  11 #include <linux/list.h>
  12 #include <linux/module.h>
  13 #include <linux/of_dma.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/slab.h>
  16 #include <linux/types.h>
  17 #include <linux/bitfield.h>
  18
  19 #include "virt-dma.h"
  20
  21 #define MLB_HDMAC_DMACR         0x0     /* global */
  22 #define MLB_HDMAC_DE            BIT(31)
  23 #define MLB_HDMAC_DS            BIT(30)
  24 #define MLB_HDMAC_PR            BIT(28)
  25 #define MLB_HDMAC_DH            GENMASK(27, 24)
  26
  27 #define MLB_HDMAC_CH_STRIDE     0x10
  28
  29 #define MLB_HDMAC_DMACA         0x0     /* channel */
  30 #define MLB_HDMAC_EB            BIT(31)
  31 #define MLB_HDMAC_PB            BIT(30)
  32 #define MLB_HDMAC_ST            BIT(29)
  33 #define MLB_HDMAC_IS            GENMASK(28, 24)
  34 #define MLB_HDMAC_BT            GENMASK(23, 20)
  35 #define MLB_HDMAC_BC            GENMASK(19, 16)
  36 #define MLB_HDMAC_TC            GENMASK(15, 0)
  37 #define MLB_HDMAC_DMACB         0x4
  38 #define MLB_HDMAC_TT            GENMASK(31, 30)
  39 #define MLB_HDMAC_MS            GENMASK(29, 28)
  40 #define MLB_HDMAC_TW            GENMASK(27, 26)
  41 #define MLB_HDMAC_FS            BIT(25)
  42 #define MLB_HDMAC_FD            BIT(24)
  43 #define MLB_HDMAC_RC            BIT(23)
  44 #define MLB_HDMAC_RS            BIT(22)
  45 #define MLB_HDMAC_RD            BIT(21)
  46 #define MLB_HDMAC_EI            BIT(20)
  47 #define MLB_HDMAC_CI            BIT(19)
  48 #define HDMAC_PAUSE             0x7
  49 #define MLB_HDMAC_SS            GENMASK(18, 16)
  50 #define MLB_HDMAC_SP            GENMASK(15, 12)
  51 #define MLB_HDMAC_DP            GENMASK(11, 8)
  52 #define MLB_HDMAC_DMACSA        0x8
  53 #define MLB_HDMAC_DMACDA        0xc
  54
  55 #define MLB_HDMAC_BUSWIDTHS             (BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
  56                                         BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
  57                                         BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))
  58
  59 struct milbeaut_hdmac_desc {
  60         struct virt_dma_desc vd;
  61         struct scatterlist *sgl;
  62         unsigned int sg_len;
  63         unsigned int sg_cur;
  64         enum dma_transfer_direction dir;
  65 };
  66
  67 struct milbeaut_hdmac_chan {
  68         struct virt_dma_chan vc;
  69         struct milbeaut_hdmac_device *mdev;
  70         struct milbeaut_hdmac_desc *md;
  71         void __iomem *reg_ch_base;
  72         unsigned int slave_id;
  73         struct dma_slave_config cfg;
  74 };
  75
  76 struct milbeaut_hdmac_device {
  77         struct dma_device ddev;
  78         struct clk *clk;
  79         void __iomem *reg_base;
  80         struct milbeaut_hdmac_chan channels[0];
  81 };
  82
  83 static struct milbeaut_hdmac_chan *
  84 to_milbeaut_hdmac_chan(struct virt_dma_chan *vc)
  85 {
  86         return container_of(vc, struct milbeaut_hdmac_chan, vc);
  87 }
  88
  89 static struct milbeaut_hdmac_desc *
  90 to_milbeaut_hdmac_desc(struct virt_dma_desc *vd)
  91 {
  92         return container_of(vd, struct milbeaut_hdmac_desc, vd);
  93 }
  94
  95 /* mc->vc.lock must be held by caller */
  96 static struct milbeaut_hdmac_desc *
  97 milbeaut_hdmac_next_desc(struct milbeaut_hdmac_chan *mc)
  98 {
  99         struct virt_dma_desc *vd;
 100
 101         vd = vchan_next_desc(&mc->vc);
 102         if (!vd) {
 103                 mc->md = NULL;
 104                 return NULL;
 105         }
 106
 107         list_del(&vd->node);
 108
 109         mc->md = to_milbeaut_hdmac_desc(vd);
 110
 111         return mc->md;
 112 }
 113
 114 /* mc->vc.lock must be held by caller */
 115 static void milbeaut_chan_start(struct milbeaut_hdmac_chan *mc,
 116                                 struct milbeaut_hdmac_desc *md)
 117 {
 118         struct scatterlist *sg;
 119         u32 cb, ca, src_addr, dest_addr, len;
 120         u32 width, burst;
 121
 122         sg = &md->sgl[md->sg_cur];
 123         len = sg_dma_len(sg);
 124
 125         cb = MLB_HDMAC_CI | MLB_HDMAC_EI;
 126         if (md->dir == DMA_MEM_TO_DEV) {
 127                 cb |= MLB_HDMAC_FD;
 128                 width = mc->cfg.dst_addr_width;
 129                 burst = mc->cfg.dst_maxburst;
 130                 src_addr = sg_dma_address(sg);
 131                 dest_addr = mc->cfg.dst_addr;
 132         } else {
 133                 cb |= MLB_HDMAC_FS;
 134                 width = mc->cfg.src_addr_width;
 135                 burst = mc->cfg.src_maxburst;
 136                 src_addr = mc->cfg.src_addr;
 137                 dest_addr = sg_dma_address(sg);
 138         }
 139         cb |= FIELD_PREP(MLB_HDMAC_TW, (width >> 1));
 140         cb |= FIELD_PREP(MLB_HDMAC_MS, 2);
 141
 142         writel_relaxed(MLB_HDMAC_DE, mc->mdev->reg_base + MLB_HDMAC_DMACR);
 143         writel_relaxed(src_addr, mc->reg_ch_base + MLB_HDMAC_DMACSA);
 144         writel_relaxed(dest_addr, mc->reg_ch_base + MLB_HDMAC_DMACDA);
 145         writel_relaxed(cb, mc->reg_ch_base + MLB_HDMAC_DMACB);
 146
 147         ca = FIELD_PREP(MLB_HDMAC_IS, mc->slave_id);
 148         if (burst == 16)
 149                 ca |= FIELD_PREP(MLB_HDMAC_BT, 0xf);
 150         else if (burst == 8)
 151                 ca |= FIELD_PREP(MLB_HDMAC_BT, 0xd);
 152         else if (burst == 4)
 153                 ca |= FIELD_PREP(MLB_HDMAC_BT, 0xb);
 154         burst *= width;
 155         ca |= FIELD_PREP(MLB_HDMAC_TC, (len / burst - 1));
 156         writel_relaxed(ca, mc->reg_ch_base + MLB_HDMAC_DMACA);
 157         ca |= MLB_HDMAC_EB;
 158         writel_relaxed(ca, mc->reg_ch_base + MLB_HDMAC_DMACA);
 159 }
 160
 161 /* mc->vc.lock must be held by caller */
 162 static void milbeaut_hdmac_start(struct milbeaut_hdmac_chan *mc)
 163 {
 164         struct milbeaut_hdmac_desc *md;
 165
 166         md = milbeaut_hdmac_next_desc(mc);
 167         if (md)
 168                 milbeaut_chan_start(mc, md);
 169 }
 170
 171 static irqreturn_t milbeaut_hdmac_interrupt(int irq, void *dev_id)
 172 {
 173         struct milbeaut_hdmac_chan *mc = dev_id;
 174         struct milbeaut_hdmac_desc *md;
 175         u32 val;
 176
 177         spin_lock(&mc->vc.lock);
 178
 179         /* Ack and Disable irqs */
 180         val = readl_relaxed(mc->reg_ch_base + MLB_HDMAC_DMACB);
 181         val &= ~(FIELD_PREP(MLB_HDMAC_SS, HDMAC_PAUSE));
 182         writel_relaxed(val, mc->reg_ch_base + MLB_HDMAC_DMACB);
 183         val &= ~MLB_HDMAC_EI;
 184         val &= ~MLB_HDMAC_CI;
 185         writel_relaxed(val, mc->reg_ch_base + MLB_HDMAC_DMACB);
 186
 187         md = mc->md;
 188         if (!md)
 189                 goto out;
 190
 191         md->sg_cur++;
 192
 193         if (md->sg_cur >= md->sg_len) {
 194                 vchan_cookie_complete(&md->vd);
 195                 md = milbeaut_hdmac_next_desc(mc);
 196                 if (!md)
 197                         goto out;
 198         }
 199
 200         milbeaut_chan_start(mc, md);
 201
 202 out:
 203         spin_unlock(&mc->vc.lock);
 204         return IRQ_HANDLED;
 205 }
 206
 207 static void milbeaut_hdmac_free_chan_resources(struct dma_chan *chan)
 208 {
 209         vchan_free_chan_resources(to_virt_chan(chan));
 210 }
 211
 212 static int
 213 milbeaut_hdmac_chan_config(struct dma_chan *chan, struct dma_slave_config *cfg)
 214 {
 215         struct virt_dma_chan *vc = to_virt_chan(chan);
 216         struct milbeaut_hdmac_chan *mc = to_milbeaut_hdmac_chan(vc);
 217
 218         spin_lock(&mc->vc.lock);
 219         mc->cfg = *cfg;
 220         spin_unlock(&mc->vc.lock);
 221
 222         return 0;
 223 }
 224
 225 static int milbeaut_hdmac_chan_pause(struct dma_chan *chan)
 226 {
 227         struct virt_dma_chan *vc = to_virt_chan(chan);
 228         struct milbeaut_hdmac_chan *mc = to_milbeaut_hdmac_chan(vc);
 229         u32 val;
 230
 231         spin_lock(&mc->vc.lock);
 232         val = readl_relaxed(mc->reg_ch_base + MLB_HDMAC_DMACA);
 233         val |= MLB_HDMAC_PB;
 234         writel_relaxed(val, mc->reg_ch_base + MLB_HDMAC_DMACA);
 235         spin_unlock(&mc->vc.lock);
 236
 237         return 0;
 238 }
 239
 240 static int milbeaut_hdmac_chan_resume(struct dma_chan *chan)
 241 {
 242         struct virt_dma_chan *vc = to_virt_chan(chan);
 243         struct milbeaut_hdmac_chan *mc = to_milbeaut_hdmac_chan(vc);
 244         u32 val;
 245
 246         spin_lock(&mc->vc.lock);
 247         val = readl_relaxed(mc->reg_ch_base + MLB_HDMAC_DMACA);
 248         val &= ~MLB_HDMAC_PB;
 249         writel_relaxed(val, mc->reg_ch_base + MLB_HDMAC_DMACA);
 250         spin_unlock(&mc->vc.lock);
 251
 252         return 0;
 253 }
 254
 255 static struct dma_async_tx_descriptor *
 256 milbeaut_hdmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 257                              unsigned int sg_len,
 258                              enum dma_transfer_direction direction,
 259                              unsigned long flags, void *context)
 260 {
 261         struct virt_dma_chan *vc = to_virt_chan(chan);
 262         struct milbeaut_hdmac_desc *md;
 263         int i;
 264
 265         if (!is_slave_direction(direction))
 266                 return NULL;
 267
 268         md = kzalloc(sizeof(*md), GFP_NOWAIT);
 269         if (!md)
 270                 return NULL;
 271
 272         md->sgl = kzalloc(sizeof(*sgl) * sg_len, GFP_NOWAIT);
 273         if (!md->sgl) {
 274                 kfree(md);
 275                 return NULL;
 276         }
 277
 278         for (i = 0; i < sg_len; i++)
 279                 md->sgl[i] = sgl[i];
 280
 281         md->sg_len = sg_len;
 282         md->dir = direction;
 283
 284         return vchan_tx_prep(vc, &md->vd, flags);
 285 }
 286
 287 static int milbeaut_hdmac_terminate_all(struct dma_chan *chan)
 288 {
 289         struct virt_dma_chan *vc = to_virt_chan(chan);
 290         struct milbeaut_hdmac_chan *mc = to_milbeaut_hdmac_chan(vc);
 291         unsigned long flags;
 292         u32 val;
 293
 294         LIST_HEAD(head);
 295
 296         spin_lock_irqsave(&vc->lock, flags);
 297
 298         val = readl_relaxed(mc->reg_ch_base + MLB_HDMAC_DMACA);
 299         val &= ~MLB_HDMAC_EB; /* disable the channel */
 300         writel_relaxed(val, mc->reg_ch_base + MLB_HDMAC_DMACA);
 301
 302         if (mc->md) {
 303                 vchan_terminate_vdesc(&mc->md->vd);
 304                 mc->md = NULL;
 305         }
 306
 307         vchan_get_all_descriptors(vc, &head);
 308
 309         spin_unlock_irqrestore(&vc->lock, flags);
 310
 311         vchan_dma_desc_free_list(vc, &head);
 312
 313         return 0;
 314 }
 315
 316 static void milbeaut_hdmac_synchronize(struct dma_chan *chan)
 317 {
 318         vchan_synchronize(to_virt_chan(chan));
 319 }
 320
 321 static enum dma_status milbeaut_hdmac_tx_status(struct dma_chan *chan,
 322                                                 dma_cookie_t cookie,
 323                                                 struct dma_tx_state *txstate)
 324 {
 325         struct virt_dma_chan *vc;
 326         struct virt_dma_desc *vd;
 327         struct milbeaut_hdmac_chan *mc;
 328         struct milbeaut_hdmac_desc *md = NULL;
 329         enum dma_status stat;
 330         unsigned long flags;
 331         int i;
 332
 333         stat = dma_cookie_status(chan, cookie, txstate);
 334         /* Return immediately if we do not need to compute the residue. */
 335         if (stat == DMA_COMPLETE || !txstate)
 336                 return stat;
 337
 338         vc = to_virt_chan(chan);
 339
 340         spin_lock_irqsave(&vc->lock, flags);
 341
 342         mc = to_milbeaut_hdmac_chan(vc);
 343
 344         /* residue from the on-flight chunk */
 345         if (mc->md && mc->md->vd.tx.cookie == cookie) {
 346                 struct scatterlist *sg;
 347                 u32 done;
 348
 349                 md = mc->md;
 350                 sg = &md->sgl[md->sg_cur];
 351
 352                 if (md->dir == DMA_DEV_TO_MEM)
 353                         done = readl_relaxed(mc->reg_ch_base
 354                                              + MLB_HDMAC_DMACDA);
 355                 else
 356                         done = readl_relaxed(mc->reg_ch_base
 357                                              + MLB_HDMAC_DMACSA);
 358                 done -= sg_dma_address(sg);
 359
 360                 txstate->residue = -done;
 361         }
 362
 363         if (!md) {
 364                 vd = vchan_find_desc(vc, cookie);
 365                 if (vd)
 366                         md = to_milbeaut_hdmac_desc(vd);
 367         }
 368
 369         if (md) {
 370                 /* residue from the queued chunks */
 371                 for (i = md->sg_cur; i < md->sg_len; i++)
 372                         txstate->residue += sg_dma_len(&md->sgl[i]);
 373         }
 374
 375         spin_unlock_irqrestore(&vc->lock, flags);
 376
 377         return stat;
 378 }
 379
 380 static void milbeaut_hdmac_issue_pending(struct dma_chan *chan)
 381 {
 382         struct virt_dma_chan *vc = to_virt_chan(chan);
 383         struct milbeaut_hdmac_chan *mc = to_milbeaut_hdmac_chan(vc);
 384         unsigned long flags;
 385
 386         spin_lock_irqsave(&vc->lock, flags);
 387
 388         if (vchan_issue_pending(vc) && !mc->md)
 389                 milbeaut_hdmac_start(mc);
 390
 391         spin_unlock_irqrestore(&vc->lock, flags);
 392 }
 393
 394 static void milbeaut_hdmac_desc_free(struct virt_dma_desc *vd)
 395 {
 396         struct milbeaut_hdmac_desc *md = to_milbeaut_hdmac_desc(vd);
 397
 398         kfree(md->sgl);
 399         kfree(md);
 400 }
 401
 402 static struct dma_chan *
 403 milbeaut_hdmac_xlate(struct of_phandle_args *dma_spec, struct of_dma *of_dma)
 404 {
 405         struct milbeaut_hdmac_device *mdev = of_dma->of_dma_data;
 406         struct milbeaut_hdmac_chan *mc;
 407         struct virt_dma_chan *vc;
 408         struct dma_chan *chan;
 409
 410         if (dma_spec->args_count != 1)
 411                 return NULL;
 412
 413         chan = dma_get_any_slave_channel(&mdev->ddev);
 414         if (!chan)
 415                 return NULL;
 416
 417         vc = to_virt_chan(chan);
 418         mc = to_milbeaut_hdmac_chan(vc);
 419         mc->slave_id = dma_spec->args[0];
 420
 421         return chan;
 422 }
 423
 424 static int milbeaut_hdmac_chan_init(struct platform_device *pdev,
 425                                     struct milbeaut_hdmac_device *mdev,
 426                                     int chan_id)
 427 {
 428         struct device *dev = &pdev->dev;
 429         struct milbeaut_hdmac_chan *mc = &mdev->channels[chan_id];
 430         char *irq_name;
 431         int irq, ret;
 432
 433         irq = platform_get_irq(pdev, chan_id);
 434         if (irq < 0)
 435                 return irq;
 436
 437         irq_name = devm_kasprintf(dev, GFP_KERNEL, "milbeaut-hdmac-%d",
 438                                   chan_id);
 439         if (!irq_name)
 440                 return -ENOMEM;
 441
 442         ret = devm_request_irq(dev, irq, milbeaut_hdmac_interrupt,
 443                                IRQF_SHARED, irq_name, mc);
 444         if (ret)
 445                 return ret;
 446
 447         mc->mdev = mdev;
 448         mc->reg_ch_base = mdev->reg_base + MLB_HDMAC_CH_STRIDE * (chan_id + 1);
 449         mc->vc.desc_free = milbeaut_hdmac_desc_free;
 450         vchan_init(&mc->vc, &mdev->ddev);
 451
 452         return 0;
 453 }
 454
 455 static int milbeaut_hdmac_probe(struct platform_device *pdev)
 456 {
 457         struct device *dev = &pdev->dev;
 458         struct milbeaut_hdmac_device *mdev;
 459         struct dma_device *ddev;
 460         int nr_chans, ret, i;
 461
 462         nr_chans = platform_irq_count(pdev);
 463         if (nr_chans < 0)
 464                 return nr_chans;
 465
 466         ret = dma_set_mask(dev, DMA_BIT_MASK(32));
 467         if (ret)
 468                 return ret;
 469
 470         mdev = devm_kzalloc(dev, struct_size(mdev, channels, nr_chans),
 471                             GFP_KERNEL);
 472         if (!mdev)
 473                 return -ENOMEM;
 474
 475         mdev->reg_base = devm_platform_ioremap_resource(pdev, 0);
 476         if (IS_ERR(mdev->reg_base))
 477                 return PTR_ERR(mdev->reg_base);
 478
 479         mdev->clk = devm_clk_get(dev, NULL);
 480         if (IS_ERR(mdev->clk)) {
 481                 dev_err(dev, "failed to get clock\n");
 482                 return PTR_ERR(mdev->clk);
 483         }
 484
 485         ret = clk_prepare_enable(mdev->clk);
 486         if (ret)
 487                 return ret;
 488
 489         ddev = &mdev->ddev;
 490         ddev->dev = dev;
 491         dma_cap_set(DMA_SLAVE, ddev->cap_mask);
 492         dma_cap_set(DMA_PRIVATE, ddev->cap_mask);
 493         ddev->src_addr_widths = MLB_HDMAC_BUSWIDTHS;
 494         ddev->dst_addr_widths = MLB_HDMAC_BUSWIDTHS;
 495         ddev->directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM);
 496         ddev->device_free_chan_resources = milbeaut_hdmac_free_chan_resources;
 497         ddev->device_config = milbeaut_hdmac_chan_config;
 498         ddev->device_pause = milbeaut_hdmac_chan_pause;
 499         ddev->device_resume = milbeaut_hdmac_chan_resume;
 500         ddev->device_prep_slave_sg = milbeaut_hdmac_prep_slave_sg;
 501         ddev->device_terminate_all = milbeaut_hdmac_terminate_all;
 502         ddev->device_synchronize = milbeaut_hdmac_synchronize;
 503         ddev->device_tx_status = milbeaut_hdmac_tx_status;
 504         ddev->device_issue_pending = milbeaut_hdmac_issue_pending;
 505         INIT_LIST_HEAD(&ddev->channels);
 506
 507         for (i = 0; i < nr_chans; i++) {
 508                 ret = milbeaut_hdmac_chan_init(pdev, mdev, i);
 509                 if (ret)
 510                         goto disable_clk;
 511         }
 512
 513         ret = dma_async_device_register(ddev);
 514         if (ret)
 515                 goto disable_clk;
 516
 517         ret = of_dma_controller_register(dev->of_node,
 518                                          milbeaut_hdmac_xlate, mdev);
 519         if (ret)
 520                 goto unregister_dmac;
 521
 522         platform_set_drvdata(pdev, mdev);
 523
 524         return 0;
 525
 526 unregister_dmac:
 527         dma_async_device_unregister(ddev);
 528 disable_clk:
 529         clk_disable_unprepare(mdev->clk);
 530
 531         return ret;
 532 }
 533
 534 static int milbeaut_hdmac_remove(struct platform_device *pdev)
 535 {
 536         struct milbeaut_hdmac_device *mdev = platform_get_drvdata(pdev);
 537         struct dma_chan *chan;
 538         int ret;
 539
 540         /*
 541          * Before reaching here, almost all descriptors have been freed by the
 542          * ->device_free_chan_resources() hook. However, each channel might
 543          * be still holding one descriptor that was on-flight at that moment.
 544          * Terminate it to make sure this hardware is no longer running. Then,
 545          * free the channel resources once again to avoid memory leak.
 546          */
 547         list_for_each_entry(chan, &mdev->ddev.channels, device_node) {
 548                 ret = dmaengine_terminate_sync(chan);
 549                 if (ret)
 550                         return ret;
 551                 milbeaut_hdmac_free_chan_resources(chan);
 552         }
 553
 554         of_dma_controller_free(pdev->dev.of_node);
 555         dma_async_device_unregister(&mdev->ddev);
 556         clk_disable_unprepare(mdev->clk);
 557
 558         return 0;
 559 }
 560
 561 static const struct of_device_id milbeaut_hdmac_match[] = {
 562         { .compatible = "socionext,milbeaut-m10v-hdmac" },
 563         { /* sentinel */ }
 564 };
 565 MODULE_DEVICE_TABLE(of, milbeaut_hdmac_match);
 566
 567 static struct platform_driver milbeaut_hdmac_driver = {
 568         .probe = milbeaut_hdmac_probe,
 569         .remove = milbeaut_hdmac_remove,
 570         .driver = {
 571                 .name = "milbeaut-m10v-hdmac",
 572                 .of_match_table = milbeaut_hdmac_match,
 573         },
 574 };
 575 module_platform_driver(milbeaut_hdmac_driver);
 576
 577 MODULE_DESCRIPTION("Milbeaut HDMAC DmaEngine driver");
 578 MODULE_LICENSE("GPL v2");