drivers/dma/fsl-edma.c

   1 /*
   2  * drivers/dma/fsl-edma.c
   3  *
   4  * Copyright 2013-2014 Freescale Semiconductor, Inc.
   5  *
   6  * Driver for the Freescale eDMA engine with flexible channel multiplexing
   7  * capability for DMA request sources. The eDMA block can be found on some
   8  * Vybrid and Layerscape SoCs.
   9  *
  10  * This program is free software; you can redistribute  it and/or modify it
  11  * under  the terms of  the GNU General  Public License as published by the
  12  * Free Software Foundation;  either version 2 of the  License, or (at your
  13  * option) any later version.
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/clk.h>
  19 #include <linux/of.h>
  20 #include <linux/of_device.h>
  21 #include <linux/of_address.h>
  22 #include <linux/of_irq.h>
  23 #include <linux/of_dma.h>
  24
  25 #include "fsl-edma-common.h"
  26
  27 static irqreturn_t fsl_edma_tx_handler(int irq, void *dev_id)
  28 {
  29         struct fsl_edma_engine *fsl_edma = dev_id;
  30         unsigned int intr, ch;
  31         struct edma_regs *regs = &fsl_edma->regs;
  32         struct fsl_edma_chan *fsl_chan;
  33
  34         intr = edma_readl(fsl_edma, regs->intl);
  35         if (!intr)
  36                 return IRQ_NONE;
  37
  38         for (ch = 0; ch < fsl_edma->n_chans; ch++) {
  39                 if (intr & (0x1 << ch)) {
  40                         edma_writeb(fsl_edma, EDMA_CINT_CINT(ch), regs->cint);
  41
  42                         fsl_chan = &fsl_edma->chans[ch];
  43
  44                         spin_lock(&fsl_chan->vchan.lock);
  45                         if (!fsl_chan->edesc->iscyclic) {
  46                                 list_del(&fsl_chan->edesc->vdesc.node);
  47                                 vchan_cookie_complete(&fsl_chan->edesc->vdesc);
  48                                 fsl_chan->edesc = NULL;
  49                                 fsl_chan->status = DMA_COMPLETE;
  50                                 fsl_chan->idle = true;
  51                         } else {
  52                                 vchan_cyclic_callback(&fsl_chan->edesc->vdesc);
  53                         }
  54
  55                         if (!fsl_chan->edesc)
  56                                 fsl_edma_xfer_desc(fsl_chan);
  57
  58                         spin_unlock(&fsl_chan->vchan.lock);
  59                 }
  60         }
  61         return IRQ_HANDLED;
  62 }
  63
  64 static irqreturn_t fsl_edma_err_handler(int irq, void *dev_id)
  65 {
  66         struct fsl_edma_engine *fsl_edma = dev_id;
  67         unsigned int err, ch;
  68         struct edma_regs *regs = &fsl_edma->regs;
  69
  70         err = edma_readl(fsl_edma, regs->errl);
  71         if (!err)
  72                 return IRQ_NONE;
  73
  74         for (ch = 0; ch < fsl_edma->n_chans; ch++) {
  75                 if (err & (0x1 << ch)) {
  76                         fsl_edma_disable_request(&fsl_edma->chans[ch]);
  77                         edma_writeb(fsl_edma, EDMA_CERR_CERR(ch), regs->cerr);
  78                         fsl_edma->chans[ch].status = DMA_ERROR;
  79                         fsl_edma->chans[ch].idle = true;
  80                 }
  81         }
  82         return IRQ_HANDLED;
  83 }
  84
  85 static irqreturn_t fsl_edma_irq_handler(int irq, void *dev_id)
  86 {
  87         if (fsl_edma_tx_handler(irq, dev_id) == IRQ_HANDLED)
  88                 return IRQ_HANDLED;
  89
  90         return fsl_edma_err_handler(irq, dev_id);
  91 }
  92
  93 static struct dma_chan *fsl_edma_xlate(struct of_phandle_args *dma_spec,
  94                 struct of_dma *ofdma)
  95 {
  96         struct fsl_edma_engine *fsl_edma = ofdma->of_dma_data;
  97         struct dma_chan *chan, *_chan;
  98         struct fsl_edma_chan *fsl_chan;
  99         unsigned long chans_per_mux = fsl_edma->n_chans / DMAMUX_NR;
 100
 101         if (dma_spec->args_count != 2)
 102                 return NULL;
 103
 104         mutex_lock(&fsl_edma->fsl_edma_mutex);
 105         list_for_each_entry_safe(chan, _chan, &fsl_edma->dma_dev.channels, device_node) {
 106                 if (chan->client_count)
 107                         continue;
 108                 if ((chan->chan_id / chans_per_mux) == dma_spec->args[0]) {
 109                         chan = dma_get_slave_channel(chan);
 110                         if (chan) {
 111                                 chan->device->privatecnt++;
 112                                 fsl_chan = to_fsl_edma_chan(chan);
 113                                 fsl_chan->slave_id = dma_spec->args[1];
 114                                 fsl_edma_chan_mux(fsl_chan, fsl_chan->slave_id,
 115                                                 true);
 116                                 mutex_unlock(&fsl_edma->fsl_edma_mutex);
 117                                 return chan;
 118                         }
 119                 }
 120         }
 121         mutex_unlock(&fsl_edma->fsl_edma_mutex);
 122         return NULL;
 123 }
 124
 125 static int
 126 fsl_edma_irq_init(struct platform_device *pdev, struct fsl_edma_engine *fsl_edma)
 127 {
 128         int ret;
 129
 130         fsl_edma->txirq = platform_get_irq_byname(pdev, "edma-tx");
 131         if (fsl_edma->txirq < 0) {
 132                 dev_err(&pdev->dev, "Can't get edma-tx irq.\n");
 133                 return fsl_edma->txirq;
 134         }
 135
 136         fsl_edma->errirq = platform_get_irq_byname(pdev, "edma-err");
 137         if (fsl_edma->errirq < 0) {
 138                 dev_err(&pdev->dev, "Can't get edma-err irq.\n");
 139                 return fsl_edma->errirq;
 140         }
 141
 142         if (fsl_edma->txirq == fsl_edma->errirq) {
 143                 ret = devm_request_irq(&pdev->dev, fsl_edma->txirq,
 144                                 fsl_edma_irq_handler, 0, "eDMA", fsl_edma);
 145                 if (ret) {
 146                         dev_err(&pdev->dev, "Can't register eDMA IRQ.\n");
 147                          return  ret;
 148                 }
 149         } else {
 150                 ret = devm_request_irq(&pdev->dev, fsl_edma->txirq,
 151                                 fsl_edma_tx_handler, 0, "eDMA tx", fsl_edma);
 152                 if (ret) {
 153                         dev_err(&pdev->dev, "Can't register eDMA tx IRQ.\n");
 154                         return  ret;
 155                 }
 156
 157                 ret = devm_request_irq(&pdev->dev, fsl_edma->errirq,
 158                                 fsl_edma_err_handler, 0, "eDMA err", fsl_edma);
 159                 if (ret) {
 160                         dev_err(&pdev->dev, "Can't register eDMA err IRQ.\n");
 161                         return  ret;
 162                 }
 163         }
 164
 165         return 0;
 166 }
 167
 168 static void fsl_edma_irq_exit(
 169                 struct platform_device *pdev, struct fsl_edma_engine *fsl_edma)
 170 {
 171         if (fsl_edma->txirq == fsl_edma->errirq) {
 172                 devm_free_irq(&pdev->dev, fsl_edma->txirq, fsl_edma);
 173         } else {
 174                 devm_free_irq(&pdev->dev, fsl_edma->txirq, fsl_edma);
 175                 devm_free_irq(&pdev->dev, fsl_edma->errirq, fsl_edma);
 176         }
 177 }
 178
 179 static void fsl_disable_clocks(struct fsl_edma_engine *fsl_edma, int nr_clocks)
 180 {
 181         int i;
 182
 183         for (i = 0; i < nr_clocks; i++)
 184                 clk_disable_unprepare(fsl_edma->muxclk[i]);
 185 }
 186
 187 static int fsl_edma_probe(struct platform_device *pdev)
 188 {
 189         struct device_node *np = pdev->dev.of_node;
 190         struct fsl_edma_engine *fsl_edma;
 191         struct fsl_edma_chan *fsl_chan;
 192         struct edma_regs *regs;
 193         struct resource *res;
 194         int len, chans;
 195         int ret, i;
 196
 197         ret = of_property_read_u32(np, "dma-channels", &chans);
 198         if (ret) {
 199                 dev_err(&pdev->dev, "Can't get dma-channels.\n");
 200                 return ret;
 201         }
 202
 203         len = sizeof(*fsl_edma) + sizeof(*fsl_chan) * chans;
 204         fsl_edma = devm_kzalloc(&pdev->dev, len, GFP_KERNEL);
 205         if (!fsl_edma)
 206                 return -ENOMEM;
 207
 208         fsl_edma->version = v1;
 209         fsl_edma->n_chans = chans;
 210         mutex_init(&fsl_edma->fsl_edma_mutex);
 211
 212         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 213         fsl_edma->membase = devm_ioremap_resource(&pdev->dev, res);
 214         if (IS_ERR(fsl_edma->membase))
 215                 return PTR_ERR(fsl_edma->membase);
 216
 217         fsl_edma_setup_regs(fsl_edma);
 218         regs = &fsl_edma->regs;
 219
 220         for (i = 0; i < DMAMUX_NR; i++) {
 221                 char clkname[32];
 222
 223                 res = platform_get_resource(pdev, IORESOURCE_MEM, 1 + i);
 224                 fsl_edma->muxbase[i] = devm_ioremap_resource(&pdev->dev, res);
 225                 if (IS_ERR(fsl_edma->muxbase[i])) {
 226                         /* on error: disable all previously enabled clks */
 227                         fsl_disable_clocks(fsl_edma, i);
 228                         return PTR_ERR(fsl_edma->muxbase[i]);
 229                 }
 230
 231                 sprintf(clkname, "dmamux%d", i);
 232                 fsl_edma->muxclk[i] = devm_clk_get(&pdev->dev, clkname);
 233                 if (IS_ERR(fsl_edma->muxclk[i])) {
 234                         dev_err(&pdev->dev, "Missing DMAMUX block clock.\n");
 235                         /* on error: disable all previously enabled clks */
 236                         fsl_disable_clocks(fsl_edma, i);
 237                         return PTR_ERR(fsl_edma->muxclk[i]);
 238                 }
 239
 240                 ret = clk_prepare_enable(fsl_edma->muxclk[i]);
 241                 if (ret)
 242                         /* on error: disable all previously enabled clks */
 243                         fsl_disable_clocks(fsl_edma, i);
 244
 245         }
 246
 247         fsl_edma->big_endian = of_property_read_bool(np, "big-endian");
 248
 249         INIT_LIST_HEAD(&fsl_edma->dma_dev.channels);
 250         for (i = 0; i < fsl_edma->n_chans; i++) {
 251                 struct fsl_edma_chan *fsl_chan = &fsl_edma->chans[i];
 252
 253                 fsl_chan->edma = fsl_edma;
 254                 fsl_chan->pm_state = RUNNING;
 255                 fsl_chan->slave_id = 0;
 256                 fsl_chan->idle = true;
 257                 fsl_chan->vchan.desc_free = fsl_edma_free_desc;
 258                 vchan_init(&fsl_chan->vchan, &fsl_edma->dma_dev);
 259
 260                 edma_writew(fsl_edma, 0x0, &regs->tcd[i].csr);
 261                 fsl_edma_chan_mux(fsl_chan, 0, false);
 262         }
 263
 264         edma_writel(fsl_edma, ~0, regs->intl);
 265         ret = fsl_edma_irq_init(pdev, fsl_edma);
 266         if (ret)
 267                 return ret;
 268
 269         dma_cap_set(DMA_PRIVATE, fsl_edma->dma_dev.cap_mask);
 270         dma_cap_set(DMA_SLAVE, fsl_edma->dma_dev.cap_mask);
 271         dma_cap_set(DMA_CYCLIC, fsl_edma->dma_dev.cap_mask);
 272
 273         fsl_edma->dma_dev.dev = &pdev->dev;
 274         fsl_edma->dma_dev.device_alloc_chan_resources
 275                 = fsl_edma_alloc_chan_resources;
 276         fsl_edma->dma_dev.device_free_chan_resources
 277                 = fsl_edma_free_chan_resources;
 278         fsl_edma->dma_dev.device_tx_status = fsl_edma_tx_status;
 279         fsl_edma->dma_dev.device_prep_slave_sg = fsl_edma_prep_slave_sg;
 280         fsl_edma->dma_dev.device_prep_dma_cyclic = fsl_edma_prep_dma_cyclic;
 281         fsl_edma->dma_dev.device_config = fsl_edma_slave_config;
 282         fsl_edma->dma_dev.device_pause = fsl_edma_pause;
 283         fsl_edma->dma_dev.device_resume = fsl_edma_resume;
 284         fsl_edma->dma_dev.device_terminate_all = fsl_edma_terminate_all;
 285         fsl_edma->dma_dev.device_issue_pending = fsl_edma_issue_pending;
 286
 287         fsl_edma->dma_dev.src_addr_widths = FSL_EDMA_BUSWIDTHS;
 288         fsl_edma->dma_dev.dst_addr_widths = FSL_EDMA_BUSWIDTHS;
 289         fsl_edma->dma_dev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
 290
 291         platform_set_drvdata(pdev, fsl_edma);
 292
 293         ret = dma_async_device_register(&fsl_edma->dma_dev);
 294         if (ret) {
 295                 dev_err(&pdev->dev,
 296                         "Can't register Freescale eDMA engine. (%d)\n", ret);
 297                 fsl_disable_clocks(fsl_edma, DMAMUX_NR);
 298                 return ret;
 299         }
 300
 301         ret = of_dma_controller_register(np, fsl_edma_xlate, fsl_edma);
 302         if (ret) {
 303                 dev_err(&pdev->dev,
 304                         "Can't register Freescale eDMA of_dma. (%d)\n", ret);
 305                 dma_async_device_unregister(&fsl_edma->dma_dev);
 306                 fsl_disable_clocks(fsl_edma, DMAMUX_NR);
 307                 return ret;
 308         }
 309
 310         /* enable round robin arbitration */
 311         edma_writel(fsl_edma, EDMA_CR_ERGA | EDMA_CR_ERCA, regs->cr);
 312
 313         return 0;
 314 }
 315
 316 static int fsl_edma_remove(struct platform_device *pdev)
 317 {
 318         struct device_node *np = pdev->dev.of_node;
 319         struct fsl_edma_engine *fsl_edma = platform_get_drvdata(pdev);
 320
 321         fsl_edma_irq_exit(pdev, fsl_edma);
 322         fsl_edma_cleanup_vchan(&fsl_edma->dma_dev);
 323         of_dma_controller_free(np);
 324         dma_async_device_unregister(&fsl_edma->dma_dev);
 325         fsl_disable_clocks(fsl_edma, DMAMUX_NR);
 326
 327         return 0;
 328 }
 329
 330 static int fsl_edma_suspend_late(struct device *dev)
 331 {
 332         struct fsl_edma_engine *fsl_edma = dev_get_drvdata(dev);
 333         struct fsl_edma_chan *fsl_chan;
 334         unsigned long flags;
 335         int i;
 336
 337         for (i = 0; i < fsl_edma->n_chans; i++) {
 338                 fsl_chan = &fsl_edma->chans[i];
 339                 spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
 340                 /* Make sure chan is idle or will force disable. */
 341                 if (unlikely(!fsl_chan->idle)) {
 342                         dev_warn(dev, "WARN: There is non-idle channel.");
 343                         fsl_edma_disable_request(fsl_chan);
 344                         fsl_edma_chan_mux(fsl_chan, 0, false);
 345                 }
 346
 347                 fsl_chan->pm_state = SUSPENDED;
 348                 spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
 349         }
 350
 351         return 0;
 352 }
 353
 354 static int fsl_edma_resume_early(struct device *dev)
 355 {
 356         struct fsl_edma_engine *fsl_edma = dev_get_drvdata(dev);
 357         struct fsl_edma_chan *fsl_chan;
 358         struct edma_regs *regs = &fsl_edma->regs;
 359         int i;
 360
 361         for (i = 0; i < fsl_edma->n_chans; i++) {
 362                 fsl_chan = &fsl_edma->chans[i];
 363                 fsl_chan->pm_state = RUNNING;
 364                 edma_writew(fsl_edma, 0x0, &regs->tcd[i].csr);
 365                 if (fsl_chan->slave_id != 0)
 366                         fsl_edma_chan_mux(fsl_chan, fsl_chan->slave_id, true);
 367         }
 368
 369         edma_writel(fsl_edma, EDMA_CR_ERGA | EDMA_CR_ERCA, regs->cr);
 370
 371         return 0;
 372 }
 373
 374 /*
 375  * eDMA provides the service to others, so it should be suspend late
 376  * and resume early. When eDMA suspend, all of the clients should stop
 377  * the DMA data transmission and let the channel idle.
 378  */
 379 static const struct dev_pm_ops fsl_edma_pm_ops = {
 380         .suspend_late   = fsl_edma_suspend_late,
 381         .resume_early   = fsl_edma_resume_early,
 382 };
 383
 384 static const struct of_device_id fsl_edma_dt_ids[] = {
 385         { .compatible = "fsl,vf610-edma", },
 386         { /* sentinel */ }
 387 };
 388 MODULE_DEVICE_TABLE(of, fsl_edma_dt_ids);
 389
 390 static struct platform_driver fsl_edma_driver = {
 391         .driver         = {
 392                 .name   = "fsl-edma",
 393                 .of_match_table = fsl_edma_dt_ids,
 394                 .pm     = &fsl_edma_pm_ops,
 395         },
 396         .probe          = fsl_edma_probe,
 397         .remove         = fsl_edma_remove,
 398 };
 399
 400 static int __init fsl_edma_init(void)
 401 {
 402         return platform_driver_register(&fsl_edma_driver);
 403 }
 404 subsys_initcall(fsl_edma_init);
 405
 406 static void __exit fsl_edma_exit(void)
 407 {
 408         platform_driver_unregister(&fsl_edma_driver);
 409 }
 410 module_exit(fsl_edma_exit);
 411
 412 MODULE_ALIAS("platform:fsl-edma");
 413 MODULE_DESCRIPTION("Freescale eDMA engine driver");
 414 MODULE_LICENSE("GPL v2");