drivers/dma/sf-pdma/sf-pdma.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * SiFive FU540 Platform DMA driver
   4  * Copyright (C) 2019 SiFive
   5  *
   6  * Based partially on:
   7  * - drivers/dma/fsl-edma.c
   8  * - drivers/dma/dw-edma/
   9  * - drivers/dma/pxa-dma.c
  10  *
  11  * See the following sources for further documentation:
  12  * - Chapter 12 "Platform DMA Engine (PDMA)" of
  13  *   SiFive FU540-C000 v1.0
  14  *   https://static.dev.sifive.com/FU540-C000-v1.0.pdf
  15  */
  16 #include <linux/module.h>
  17 #include <linux/device.h>
  18 #include <linux/kernel.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/mod_devicetable.h>
  21 #include <linux/dma-mapping.h>
  22 #include <linux/of.h>
  23 #include <linux/slab.h>
  24
  25 #include "sf-pdma.h"
  26
  27 #ifndef readq
  28 static inline unsigned long long readq(void __iomem *addr)
  29 {
  30         return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
  31 }
  32 #endif
  33
  34 #ifndef writeq
  35 static inline void writeq(unsigned long long v, void __iomem *addr)
  36 {
  37         writel(lower_32_bits(v), addr);
  38         writel(upper_32_bits(v), addr + 4);
  39 }
  40 #endif
  41
  42 static inline struct sf_pdma_chan *to_sf_pdma_chan(struct dma_chan *dchan)
  43 {
  44         return container_of(dchan, struct sf_pdma_chan, vchan.chan);
  45 }
  46
  47 static inline struct sf_pdma_desc *to_sf_pdma_desc(struct virt_dma_desc *vd)
  48 {
  49         return container_of(vd, struct sf_pdma_desc, vdesc);
  50 }
  51
  52 static struct sf_pdma_desc *sf_pdma_alloc_desc(struct sf_pdma_chan *chan)
  53 {
  54         struct sf_pdma_desc *desc;
  55         unsigned long flags;
  56
  57         spin_lock_irqsave(&chan->lock, flags);
  58
  59         if (chan->desc && !chan->desc->in_use) {
  60                 spin_unlock_irqrestore(&chan->lock, flags);
  61                 return chan->desc;
  62         }
  63
  64         spin_unlock_irqrestore(&chan->lock, flags);
  65
  66         desc = kzalloc(sizeof(*desc), GFP_NOWAIT);
  67         if (!desc)
  68                 return NULL;
  69
  70         desc->chan = chan;
  71
  72         return desc;
  73 }
  74
  75 static void sf_pdma_fill_desc(struct sf_pdma_desc *desc,
  76                               u64 dst, u64 src, u64 size)
  77 {
  78         desc->xfer_type = PDMA_FULL_SPEED;
  79         desc->xfer_size = size;
  80         desc->dst_addr = dst;
  81         desc->src_addr = src;
  82 }
  83
  84 static void sf_pdma_disclaim_chan(struct sf_pdma_chan *chan)
  85 {
  86         struct pdma_regs *regs = &chan->regs;
  87
  88         writel(PDMA_CLEAR_CTRL, regs->ctrl);
  89 }
  90
  91 static struct dma_async_tx_descriptor *
  92 sf_pdma_prep_dma_memcpy(struct dma_chan *dchan, dma_addr_t dest, dma_addr_t src,
  93                         size_t len, unsigned long flags)
  94 {
  95         struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
  96         struct sf_pdma_desc *desc;
  97         unsigned long iflags;
  98
  99         if (chan && (!len || !dest || !src)) {
 100                 dev_err(chan->pdma->dma_dev.dev,
 101                         "Please check dma len, dest, src!\n");
 102                 return NULL;
 103         }
 104
 105         desc = sf_pdma_alloc_desc(chan);
 106         if (!desc)
 107                 return NULL;
 108
 109         desc->in_use = true;
 110         desc->dirn = DMA_MEM_TO_MEM;
 111         desc->async_tx = vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
 112
 113         spin_lock_irqsave(&chan->vchan.lock, iflags);
 114         chan->desc = desc;
 115         sf_pdma_fill_desc(desc, dest, src, len);
 116         spin_unlock_irqrestore(&chan->vchan.lock, iflags);
 117
 118         return desc->async_tx;
 119 }
 120
 121 static int sf_pdma_slave_config(struct dma_chan *dchan,
 122                                 struct dma_slave_config *cfg)
 123 {
 124         struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
 125
 126         memcpy(&chan->cfg, cfg, sizeof(*cfg));
 127
 128         return 0;
 129 }
 130
 131 static int sf_pdma_alloc_chan_resources(struct dma_chan *dchan)
 132 {
 133         struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
 134         struct pdma_regs *regs = &chan->regs;
 135
 136         dma_cookie_init(dchan);
 137         writel(PDMA_CLAIM_MASK, regs->ctrl);
 138
 139         return 0;
 140 }
 141
 142 static void sf_pdma_disable_request(struct sf_pdma_chan *chan)
 143 {
 144         struct pdma_regs *regs = &chan->regs;
 145
 146         writel(readl(regs->ctrl) & ~PDMA_RUN_MASK, regs->ctrl);
 147 }
 148
 149 static void sf_pdma_free_chan_resources(struct dma_chan *dchan)
 150 {
 151         struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
 152         unsigned long flags;
 153         LIST_HEAD(head);
 154
 155         spin_lock_irqsave(&chan->vchan.lock, flags);
 156         sf_pdma_disable_request(chan);
 157         kfree(chan->desc);
 158         chan->desc = NULL;
 159         vchan_get_all_descriptors(&chan->vchan, &head);
 160         sf_pdma_disclaim_chan(chan);
 161         spin_unlock_irqrestore(&chan->vchan.lock, flags);
 162         vchan_dma_desc_free_list(&chan->vchan, &head);
 163 }
 164
 165 static size_t sf_pdma_desc_residue(struct sf_pdma_chan *chan,
 166                                    dma_cookie_t cookie)
 167 {
 168         struct virt_dma_desc *vd = NULL;
 169         struct pdma_regs *regs = &chan->regs;
 170         unsigned long flags;
 171         u64 residue = 0;
 172         struct sf_pdma_desc *desc;
 173         struct dma_async_tx_descriptor *tx;
 174
 175         spin_lock_irqsave(&chan->vchan.lock, flags);
 176
 177         tx = &chan->desc->vdesc.tx;
 178         if (cookie == tx->chan->completed_cookie)
 179                 goto out;
 180
 181         if (cookie == tx->cookie) {
 182                 residue = readq(regs->residue);
 183         } else {
 184                 vd = vchan_find_desc(&chan->vchan, cookie);
 185                 if (!vd)
 186                         goto out;
 187
 188                 desc = to_sf_pdma_desc(vd);
 189                 residue = desc->xfer_size;
 190         }
 191
 192 out:
 193         spin_unlock_irqrestore(&chan->vchan.lock, flags);
 194         return residue;
 195 }
 196
 197 static enum dma_status
 198 sf_pdma_tx_status(struct dma_chan *dchan,
 199                   dma_cookie_t cookie,
 200                   struct dma_tx_state *txstate)
 201 {
 202         struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
 203         enum dma_status status;
 204
 205         status = dma_cookie_status(dchan, cookie, txstate);
 206
 207         if (txstate && status != DMA_ERROR)
 208                 dma_set_residue(txstate, sf_pdma_desc_residue(chan, cookie));
 209
 210         return status;
 211 }
 212
 213 static int sf_pdma_terminate_all(struct dma_chan *dchan)
 214 {
 215         struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
 216         unsigned long flags;
 217         LIST_HEAD(head);
 218
 219         spin_lock_irqsave(&chan->vchan.lock, flags);
 220         sf_pdma_disable_request(chan);
 221         kfree(chan->desc);
 222         chan->desc = NULL;
 223         chan->xfer_err = false;
 224         vchan_get_all_descriptors(&chan->vchan, &head);
 225         spin_unlock_irqrestore(&chan->vchan.lock, flags);
 226         vchan_dma_desc_free_list(&chan->vchan, &head);
 227
 228         return 0;
 229 }
 230
 231 static void sf_pdma_enable_request(struct sf_pdma_chan *chan)
 232 {
 233         struct pdma_regs *regs = &chan->regs;
 234         u32 v;
 235
 236         v = PDMA_CLAIM_MASK |
 237                 PDMA_ENABLE_DONE_INT_MASK |
 238                 PDMA_ENABLE_ERR_INT_MASK |
 239                 PDMA_RUN_MASK;
 240
 241         writel(v, regs->ctrl);
 242 }
 243
 244 static void sf_pdma_xfer_desc(struct sf_pdma_chan *chan)
 245 {
 246         struct sf_pdma_desc *desc = chan->desc;
 247         struct pdma_regs *regs = &chan->regs;
 248
 249         if (!desc) {
 250                 dev_err(chan->pdma->dma_dev.dev, "NULL desc.\n");
 251                 return;
 252         }
 253
 254         writel(desc->xfer_type, regs->xfer_type);
 255         writeq(desc->xfer_size, regs->xfer_size);
 256         writeq(desc->dst_addr, regs->dst_addr);
 257         writeq(desc->src_addr, regs->src_addr);
 258
 259         chan->desc = desc;
 260         chan->status = DMA_IN_PROGRESS;
 261         sf_pdma_enable_request(chan);
 262 }
 263
 264 static void sf_pdma_issue_pending(struct dma_chan *dchan)
 265 {
 266         struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
 267         unsigned long flags;
 268
 269         spin_lock_irqsave(&chan->vchan.lock, flags);
 270
 271         if (vchan_issue_pending(&chan->vchan) && chan->desc)
 272                 sf_pdma_xfer_desc(chan);
 273
 274         spin_unlock_irqrestore(&chan->vchan.lock, flags);
 275 }
 276
 277 static void sf_pdma_free_desc(struct virt_dma_desc *vdesc)
 278 {
 279         struct sf_pdma_desc *desc;
 280
 281         desc = to_sf_pdma_desc(vdesc);
 282         desc->in_use = false;
 283 }
 284
 285 static void sf_pdma_donebh_tasklet(struct tasklet_struct *t)
 286 {
 287         struct sf_pdma_chan *chan = from_tasklet(chan, t, done_tasklet);
 288         unsigned long flags;
 289
 290         spin_lock_irqsave(&chan->lock, flags);
 291         if (chan->xfer_err) {
 292                 chan->retries = MAX_RETRY;
 293                 chan->status = DMA_COMPLETE;
 294                 chan->xfer_err = false;
 295         }
 296         spin_unlock_irqrestore(&chan->lock, flags);
 297
 298         spin_lock_irqsave(&chan->vchan.lock, flags);
 299         list_del(&chan->desc->vdesc.node);
 300         vchan_cookie_complete(&chan->desc->vdesc);
 301         spin_unlock_irqrestore(&chan->vchan.lock, flags);
 302 }
 303
 304 static void sf_pdma_errbh_tasklet(struct tasklet_struct *t)
 305 {
 306         struct sf_pdma_chan *chan = from_tasklet(chan, t, err_tasklet);
 307         struct sf_pdma_desc *desc = chan->desc;
 308         unsigned long flags;
 309
 310         spin_lock_irqsave(&chan->lock, flags);
 311         if (chan->retries <= 0) {
 312                 /* fail to recover */
 313                 spin_unlock_irqrestore(&chan->lock, flags);
 314                 dmaengine_desc_get_callback_invoke(desc->async_tx, NULL);
 315         } else {
 316                 /* retry */
 317                 chan->retries--;
 318                 chan->xfer_err = true;
 319                 chan->status = DMA_ERROR;
 320
 321                 sf_pdma_enable_request(chan);
 322                 spin_unlock_irqrestore(&chan->lock, flags);
 323         }
 324 }
 325
 326 static irqreturn_t sf_pdma_done_isr(int irq, void *dev_id)
 327 {
 328         struct sf_pdma_chan *chan = dev_id;
 329         struct pdma_regs *regs = &chan->regs;
 330         u64 residue;
 331
 332         spin_lock(&chan->vchan.lock);
 333         writel((readl(regs->ctrl)) & ~PDMA_DONE_STATUS_MASK, regs->ctrl);
 334         residue = readq(regs->residue);
 335
 336         if (!residue) {
 337                 tasklet_hi_schedule(&chan->done_tasklet);
 338         } else {
 339                 /* submit next trascatioin if possible */
 340                 struct sf_pdma_desc *desc = chan->desc;
 341
 342                 desc->src_addr += desc->xfer_size - residue;
 343                 desc->dst_addr += desc->xfer_size - residue;
 344                 desc->xfer_size = residue;
 345
 346                 sf_pdma_xfer_desc(chan);
 347         }
 348
 349         spin_unlock(&chan->vchan.lock);
 350
 351         return IRQ_HANDLED;
 352 }
 353
 354 static irqreturn_t sf_pdma_err_isr(int irq, void *dev_id)
 355 {
 356         struct sf_pdma_chan *chan = dev_id;
 357         struct pdma_regs *regs = &chan->regs;
 358
 359         spin_lock(&chan->lock);
 360         writel((readl(regs->ctrl)) & ~PDMA_ERR_STATUS_MASK, regs->ctrl);
 361         spin_unlock(&chan->lock);
 362
 363         tasklet_schedule(&chan->err_tasklet);
 364
 365         return IRQ_HANDLED;
 366 }
 367
 368 /**
 369  * sf_pdma_irq_init() - Init PDMA IRQ Handlers
 370  * @pdev: pointer of platform_device
 371  * @pdma: pointer of PDMA engine. Caller should check NULL
 372  *
 373  * Initialize DONE and ERROR interrupt handler for 4 channels. Caller should
 374  * make sure the pointer passed in are non-NULL. This function should be called
 375  * only one time during the device probe.
 376  *
 377  * Context: Any context.
 378  *
 379  * Return:
 380  * * 0          - OK to init all IRQ handlers
 381  * * -EINVAL    - Fail to request IRQ
 382  */
 383 static int sf_pdma_irq_init(struct platform_device *pdev, struct sf_pdma *pdma)
 384 {
 385         int irq, r, i;
 386         struct sf_pdma_chan *chan;
 387
 388         for (i = 0; i < pdma->n_chans; i++) {
 389                 chan = &pdma->chans[i];
 390
 391                 irq = platform_get_irq(pdev, i * 2);
 392                 if (irq < 0) {
 393                         dev_err(&pdev->dev, "ch(%d) Can't get done irq.\n", i);
 394                         return -EINVAL;
 395                 }
 396
 397                 r = devm_request_irq(&pdev->dev, irq, sf_pdma_done_isr, 0,
 398                                      dev_name(&pdev->dev), (void *)chan);
 399                 if (r) {
 400                         dev_err(&pdev->dev, "Fail to attach done ISR: %d\n", r);
 401                         return -EINVAL;
 402                 }
 403
 404                 chan->txirq = irq;
 405
 406                 irq = platform_get_irq(pdev, (i * 2) + 1);
 407                 if (irq < 0) {
 408                         dev_err(&pdev->dev, "ch(%d) Can't get err irq.\n", i);
 409                         return -EINVAL;
 410                 }
 411
 412                 r = devm_request_irq(&pdev->dev, irq, sf_pdma_err_isr, 0,
 413                                      dev_name(&pdev->dev), (void *)chan);
 414                 if (r) {
 415                         dev_err(&pdev->dev, "Fail to attach err ISR: %d\n", r);
 416                         return -EINVAL;
 417                 }
 418
 419                 chan->errirq = irq;
 420         }
 421
 422         return 0;
 423 }
 424
 425 /**
 426  * sf_pdma_setup_chans() - Init settings of each channel
 427  * @pdma: pointer of PDMA engine. Caller should check NULL
 428  *
 429  * Initialize all data structure and register base. Caller should make sure
 430  * the pointer passed in are non-NULL. This function should be called only
 431  * one time during the device probe.
 432  *
 433  * Context: Any context.
 434  *
 435  * Return: none
 436  */
 437 static void sf_pdma_setup_chans(struct sf_pdma *pdma)
 438 {
 439         int i;
 440         struct sf_pdma_chan *chan;
 441
 442         INIT_LIST_HEAD(&pdma->dma_dev.channels);
 443
 444         for (i = 0; i < pdma->n_chans; i++) {
 445                 chan = &pdma->chans[i];
 446
 447                 chan->regs.ctrl =
 448                         SF_PDMA_REG_BASE(i) + PDMA_CTRL;
 449                 chan->regs.xfer_type =
 450                         SF_PDMA_REG_BASE(i) + PDMA_XFER_TYPE;
 451                 chan->regs.xfer_size =
 452                         SF_PDMA_REG_BASE(i) + PDMA_XFER_SIZE;
 453                 chan->regs.dst_addr =
 454                         SF_PDMA_REG_BASE(i) + PDMA_DST_ADDR;
 455                 chan->regs.src_addr =
 456                         SF_PDMA_REG_BASE(i) + PDMA_SRC_ADDR;
 457                 chan->regs.act_type =
 458                         SF_PDMA_REG_BASE(i) + PDMA_ACT_TYPE;
 459                 chan->regs.residue =
 460                         SF_PDMA_REG_BASE(i) + PDMA_REMAINING_BYTE;
 461                 chan->regs.cur_dst_addr =
 462                         SF_PDMA_REG_BASE(i) + PDMA_CUR_DST_ADDR;
 463                 chan->regs.cur_src_addr =
 464                         SF_PDMA_REG_BASE(i) + PDMA_CUR_SRC_ADDR;
 465
 466                 chan->pdma = pdma;
 467                 chan->pm_state = RUNNING;
 468                 chan->slave_id = i;
 469                 chan->xfer_err = false;
 470                 spin_lock_init(&chan->lock);
 471
 472                 chan->vchan.desc_free = sf_pdma_free_desc;
 473                 vchan_init(&chan->vchan, &pdma->dma_dev);
 474
 475                 writel(PDMA_CLEAR_CTRL, chan->regs.ctrl);
 476
 477                 tasklet_setup(&chan->done_tasklet, sf_pdma_donebh_tasklet);
 478                 tasklet_setup(&chan->err_tasklet, sf_pdma_errbh_tasklet);
 479         }
 480 }
 481
 482 static int sf_pdma_probe(struct platform_device *pdev)
 483 {
 484         struct sf_pdma *pdma;
 485         struct sf_pdma_chan *chan;
 486         struct resource *res;
 487         int len, chans;
 488         int ret;
 489         const enum dma_slave_buswidth widths =
 490                 DMA_SLAVE_BUSWIDTH_1_BYTE | DMA_SLAVE_BUSWIDTH_2_BYTES |
 491                 DMA_SLAVE_BUSWIDTH_4_BYTES | DMA_SLAVE_BUSWIDTH_8_BYTES |
 492                 DMA_SLAVE_BUSWIDTH_16_BYTES | DMA_SLAVE_BUSWIDTH_32_BYTES |
 493                 DMA_SLAVE_BUSWIDTH_64_BYTES;
 494
 495         chans = PDMA_NR_CH;
 496         len = sizeof(*pdma) + sizeof(*chan) * chans;
 497         pdma = devm_kzalloc(&pdev->dev, len, GFP_KERNEL);
 498         if (!pdma)
 499                 return -ENOMEM;
 500
 501         pdma->n_chans = chans;
 502
 503         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 504         pdma->membase = devm_ioremap_resource(&pdev->dev, res);
 505         if (IS_ERR(pdma->membase))
 506                 return PTR_ERR(pdma->membase);
 507
 508         ret = sf_pdma_irq_init(pdev, pdma);
 509         if (ret)
 510                 return ret;
 511
 512         sf_pdma_setup_chans(pdma);
 513
 514         pdma->dma_dev.dev = &pdev->dev;
 515
 516         /* Setup capability */
 517         dma_cap_set(DMA_MEMCPY, pdma->dma_dev.cap_mask);
 518         pdma->dma_dev.copy_align = 2;
 519         pdma->dma_dev.src_addr_widths = widths;
 520         pdma->dma_dev.dst_addr_widths = widths;
 521         pdma->dma_dev.directions = BIT(DMA_MEM_TO_MEM);
 522         pdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
 523         pdma->dma_dev.descriptor_reuse = true;
 524
 525         /* Setup DMA APIs */
 526         pdma->dma_dev.device_alloc_chan_resources =
 527                 sf_pdma_alloc_chan_resources;
 528         pdma->dma_dev.device_free_chan_resources =
 529                 sf_pdma_free_chan_resources;
 530         pdma->dma_dev.device_tx_status = sf_pdma_tx_status;
 531         pdma->dma_dev.device_prep_dma_memcpy = sf_pdma_prep_dma_memcpy;
 532         pdma->dma_dev.device_config = sf_pdma_slave_config;
 533         pdma->dma_dev.device_terminate_all = sf_pdma_terminate_all;
 534         pdma->dma_dev.device_issue_pending = sf_pdma_issue_pending;
 535
 536         platform_set_drvdata(pdev, pdma);
 537
 538         ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
 539         if (ret)
 540                 dev_warn(&pdev->dev,
 541                          "Failed to set DMA mask. Fall back to default.\n");
 542
 543         ret = dma_async_device_register(&pdma->dma_dev);
 544         if (ret) {
 545                 dev_err(&pdev->dev,
 546                         "Can't register SiFive Platform DMA. (%d)\n", ret);
 547                 return ret;
 548         }
 549
 550         return 0;
 551 }
 552
 553 static int sf_pdma_remove(struct platform_device *pdev)
 554 {
 555         struct sf_pdma *pdma = platform_get_drvdata(pdev);
 556         struct sf_pdma_chan *ch;
 557         int i;
 558
 559         for (i = 0; i < PDMA_NR_CH; i++) {
 560                 ch = &pdma->chans[i];
 561
 562                 devm_free_irq(&pdev->dev, ch->txirq, ch);
 563                 devm_free_irq(&pdev->dev, ch->errirq, ch);
 564                 list_del(&ch->vchan.chan.device_node);
 565                 tasklet_kill(&ch->vchan.task);
 566                 tasklet_kill(&ch->done_tasklet);
 567                 tasklet_kill(&ch->err_tasklet);
 568         }
 569
 570         dma_async_device_unregister(&pdma->dma_dev);
 571
 572         return 0;
 573 }
 574
 575 static const struct of_device_id sf_pdma_dt_ids[] = {
 576         { .compatible = "sifive,fu540-c000-pdma" },
 577         {},
 578 };
 579 MODULE_DEVICE_TABLE(of, sf_pdma_dt_ids);
 580
 581 static struct platform_driver sf_pdma_driver = {
 582         .probe          = sf_pdma_probe,
 583         .remove         = sf_pdma_remove,
 584         .driver         = {
 585                 .name   = "sf-pdma",
 586                 .of_match_table = sf_pdma_dt_ids,
 587         },
 588 };
 589
 590 static int __init sf_pdma_init(void)
 591 {
 592         return platform_driver_register(&sf_pdma_driver);
 593 }
 594
 595 static void __exit sf_pdma_exit(void)
 596 {
 597         platform_driver_unregister(&sf_pdma_driver);
 598 }
 599
 600 /* do early init */
 601 subsys_initcall(sf_pdma_init);
 602 module_exit(sf_pdma_exit);
 603
 604 MODULE_LICENSE("GPL v2");
 605 MODULE_DESCRIPTION("SiFive Platform DMA driver");
 606 MODULE_AUTHOR("Green Wan <green.wan@sifive.com>");