drivers/dma/imx-dma.c

   1 /*
   2  * drivers/dma/imx-dma.c
   3  *
   4  * This file contains a driver for the Freescale i.MX DMA engine
   5  * found on i.MX1/21/27
   6  *
   7  * Copyright 2010 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
   8  *
   9  * The code contained herein is licensed under the GNU General Public
  10  * License. You may obtain a copy of the GNU General Public License
  11  * Version 2 or later at the following locations:
  12  *
  13  * http://www.opensource.org/licenses/gpl-license.html
  14  * http://www.gnu.org/copyleft/gpl.html
  15  */
  16 #include <linux/init.h>
  17 #include <linux/types.h>
  18 #include <linux/mm.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/device.h>
  22 #include <linux/dma-mapping.h>
  23 #include <linux/slab.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/dmaengine.h>
  26
  27 #include <asm/irq.h>
  28 #include <mach/dma-v1.h>
  29 #include <mach/hardware.h>
  30
  31 struct imxdma_channel {
  32         struct imxdma_engine            *imxdma;
  33         unsigned int                    channel;
  34         unsigned int                    imxdma_channel;
  35
  36         enum dma_slave_buswidth         word_size;
  37         dma_addr_t                      per_address;
  38         u32                             watermark_level;
  39         struct dma_chan                 chan;
  40         spinlock_t                      lock;
  41         struct dma_async_tx_descriptor  desc;
  42         dma_cookie_t                    last_completed;
  43         enum dma_status                 status;
  44         int                             dma_request;
  45         struct scatterlist              *sg_list;
  46 };
  47
  48 #define MAX_DMA_CHANNELS 8
  49
  50 struct imxdma_engine {
  51         struct device                   *dev;
  52         struct device_dma_parameters    dma_parms;
  53         struct dma_device               dma_device;
  54         struct imxdma_channel           channel[MAX_DMA_CHANNELS];
  55 };
  56
  57 static struct imxdma_channel *to_imxdma_chan(struct dma_chan *chan)
  58 {
  59         return container_of(chan, struct imxdma_channel, chan);
  60 }
  61
  62 static void imxdma_handle(struct imxdma_channel *imxdmac)
  63 {
  64         if (imxdmac->desc.callback)
  65                 imxdmac->desc.callback(imxdmac->desc.callback_param);
  66         imxdmac->last_completed = imxdmac->desc.cookie;
  67 }
  68
  69 static void imxdma_irq_handler(int channel, void *data)
  70 {
  71         struct imxdma_channel *imxdmac = data;
  72
  73         imxdmac->status = DMA_SUCCESS;
  74         imxdma_handle(imxdmac);
  75 }
  76
  77 static void imxdma_err_handler(int channel, void *data, int error)
  78 {
  79         struct imxdma_channel *imxdmac = data;
  80
  81         imxdmac->status = DMA_ERROR;
  82         imxdma_handle(imxdmac);
  83 }
  84
  85 static void imxdma_progression(int channel, void *data,
  86                 struct scatterlist *sg)
  87 {
  88         struct imxdma_channel *imxdmac = data;
  89
  90         imxdmac->status = DMA_SUCCESS;
  91         imxdma_handle(imxdmac);
  92 }
  93
  94 static int imxdma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
  95                 unsigned long arg)
  96 {
  97         struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
  98         struct dma_slave_config *dmaengine_cfg = (void *)arg;
  99         int ret;
 100         unsigned int mode = 0;
 101
 102         switch (cmd) {
 103         case DMA_TERMINATE_ALL:
 104                 imxdmac->status = DMA_ERROR;
 105                 imx_dma_disable(imxdmac->imxdma_channel);
 106                 return 0;
 107         case DMA_SLAVE_CONFIG:
 108                 if (dmaengine_cfg->direction == DMA_FROM_DEVICE) {
 109                         imxdmac->per_address = dmaengine_cfg->src_addr;
 110                         imxdmac->watermark_level = dmaengine_cfg->src_maxburst;
 111                         imxdmac->word_size = dmaengine_cfg->src_addr_width;
 112                 } else {
 113                         imxdmac->per_address = dmaengine_cfg->dst_addr;
 114                         imxdmac->watermark_level = dmaengine_cfg->dst_maxburst;
 115                         imxdmac->word_size = dmaengine_cfg->dst_addr_width;
 116                 }
 117
 118                 switch (imxdmac->word_size) {
 119                 case DMA_SLAVE_BUSWIDTH_1_BYTE:
 120                         mode = IMX_DMA_MEMSIZE_8;
 121                         break;
 122                 case DMA_SLAVE_BUSWIDTH_2_BYTES:
 123                         mode = IMX_DMA_MEMSIZE_16;
 124                         break;
 125                 default:
 126                 case DMA_SLAVE_BUSWIDTH_4_BYTES:
 127                         mode = IMX_DMA_MEMSIZE_32;
 128                         break;
 129                 }
 130                 ret = imx_dma_config_channel(imxdmac->imxdma_channel,
 131                                 mode | IMX_DMA_TYPE_FIFO,
 132                                 IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR,
 133                                 imxdmac->dma_request, 1);
 134
 135                 if (ret)
 136                         return ret;
 137
 138                 imx_dma_config_burstlen(imxdmac->imxdma_channel, imxdmac->watermark_level);
 139
 140                 return 0;
 141         default:
 142                 return -ENOSYS;
 143         }
 144
 145         return -EINVAL;
 146 }
 147
 148 static enum dma_status imxdma_tx_status(struct dma_chan *chan,
 149                                             dma_cookie_t cookie,
 150                                             struct dma_tx_state *txstate)
 151 {
 152         struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
 153         dma_cookie_t last_used;
 154         enum dma_status ret;
 155
 156         last_used = chan->cookie;
 157
 158         ret = dma_async_is_complete(cookie, imxdmac->last_completed, last_used);
 159         dma_set_tx_state(txstate, imxdmac->last_completed, last_used, 0);
 160
 161         return ret;
 162 }
 163
 164 static dma_cookie_t imxdma_assign_cookie(struct imxdma_channel *imxdma)
 165 {
 166         dma_cookie_t cookie = imxdma->chan.cookie;
 167
 168         if (++cookie < 0)
 169                 cookie = 1;
 170
 171         imxdma->chan.cookie = cookie;
 172         imxdma->desc.cookie = cookie;
 173
 174         return cookie;
 175 }
 176
 177 static dma_cookie_t imxdma_tx_submit(struct dma_async_tx_descriptor *tx)
 178 {
 179         struct imxdma_channel *imxdmac = to_imxdma_chan(tx->chan);
 180         dma_cookie_t cookie;
 181
 182         spin_lock_irq(&imxdmac->lock);
 183
 184         cookie = imxdma_assign_cookie(imxdmac);
 185
 186         imx_dma_enable(imxdmac->imxdma_channel);
 187
 188         spin_unlock_irq(&imxdmac->lock);
 189
 190         return cookie;
 191 }
 192
 193 static int imxdma_alloc_chan_resources(struct dma_chan *chan)
 194 {
 195         struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
 196         struct imx_dma_data *data = chan->private;
 197
 198         imxdmac->dma_request = data->dma_request;
 199
 200         dma_async_tx_descriptor_init(&imxdmac->desc, chan);
 201         imxdmac->desc.tx_submit = imxdma_tx_submit;
 202         /* txd.flags will be overwritten in prep funcs */
 203         imxdmac->desc.flags = DMA_CTRL_ACK;
 204
 205         imxdmac->status = DMA_SUCCESS;
 206
 207         return 0;
 208 }
 209
 210 static void imxdma_free_chan_resources(struct dma_chan *chan)
 211 {
 212         struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
 213
 214         imx_dma_disable(imxdmac->imxdma_channel);
 215
 216         if (imxdmac->sg_list) {
 217                 kfree(imxdmac->sg_list);
 218                 imxdmac->sg_list = NULL;
 219         }
 220 }
 221
 222 static struct dma_async_tx_descriptor *imxdma_prep_slave_sg(
 223                 struct dma_chan *chan, struct scatterlist *sgl,
 224                 unsigned int sg_len, enum dma_data_direction direction,
 225                 unsigned long flags)
 226 {
 227         struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
 228         struct scatterlist *sg;
 229         int i, ret, dma_length = 0;
 230         unsigned int dmamode;
 231
 232         if (imxdmac->status == DMA_IN_PROGRESS)
 233                 return NULL;
 234
 235         imxdmac->status = DMA_IN_PROGRESS;
 236
 237         for_each_sg(sgl, sg, sg_len, i) {
 238                 dma_length += sg->length;
 239         }
 240
 241         if (direction == DMA_FROM_DEVICE)
 242                 dmamode = DMA_MODE_READ;
 243         else
 244                 dmamode = DMA_MODE_WRITE;
 245
 246         switch (imxdmac->word_size) {
 247         case DMA_SLAVE_BUSWIDTH_4_BYTES:
 248                 if (sgl->length & 3 || sgl->dma_address & 3)
 249                         return NULL;
 250                 break;
 251         case DMA_SLAVE_BUSWIDTH_2_BYTES:
 252                 if (sgl->length & 1 || sgl->dma_address & 1)
 253                         return NULL;
 254                 break;
 255         case DMA_SLAVE_BUSWIDTH_1_BYTE:
 256                 break;
 257         default:
 258                 return NULL;
 259         }
 260
 261         ret = imx_dma_setup_sg(imxdmac->imxdma_channel, sgl, sg_len,
 262                  dma_length, imxdmac->per_address, dmamode);
 263         if (ret)
 264                 return NULL;
 265
 266         return &imxdmac->desc;
 267 }
 268
 269 static struct dma_async_tx_descriptor *imxdma_prep_dma_cyclic(
 270                 struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
 271                 size_t period_len, enum dma_data_direction direction)
 272 {
 273         struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
 274         struct imxdma_engine *imxdma = imxdmac->imxdma;
 275         int i, ret;
 276         unsigned int periods = buf_len / period_len;
 277         unsigned int dmamode;
 278
 279         dev_dbg(imxdma->dev, "%s channel: %d buf_len=%d period_len=%d\n",
 280                         __func__, imxdmac->channel, buf_len, period_len);
 281
 282         if (imxdmac->status == DMA_IN_PROGRESS)
 283                 return NULL;
 284         imxdmac->status = DMA_IN_PROGRESS;
 285
 286         ret = imx_dma_setup_progression_handler(imxdmac->imxdma_channel,
 287                         imxdma_progression);
 288         if (ret) {
 289                 dev_err(imxdma->dev, "Failed to setup the DMA handler\n");
 290                 return NULL;
 291         }
 292
 293         if (imxdmac->sg_list)
 294                 kfree(imxdmac->sg_list);
 295
 296         imxdmac->sg_list = kcalloc(periods + 1,
 297                         sizeof(struct scatterlist), GFP_KERNEL);
 298         if (!imxdmac->sg_list)
 299                 return NULL;
 300
 301         sg_init_table(imxdmac->sg_list, periods);
 302
 303         for (i = 0; i < periods; i++) {
 304                 imxdmac->sg_list[i].page_link = 0;
 305                 imxdmac->sg_list[i].offset = 0;
 306                 imxdmac->sg_list[i].dma_address = dma_addr;
 307                 imxdmac->sg_list[i].length = period_len;
 308                 dma_addr += period_len;
 309         }
 310
 311         /* close the loop */
 312         imxdmac->sg_list[periods].offset = 0;
 313         imxdmac->sg_list[periods].length = 0;
 314         imxdmac->sg_list[periods].page_link =
 315                 ((unsigned long)imxdmac->sg_list | 0x01) & ~0x02;
 316
 317         if (direction == DMA_FROM_DEVICE)
 318                 dmamode = DMA_MODE_READ;
 319         else
 320                 dmamode = DMA_MODE_WRITE;
 321
 322         ret = imx_dma_setup_sg(imxdmac->imxdma_channel, imxdmac->sg_list, periods,
 323                  IMX_DMA_LENGTH_LOOP, imxdmac->per_address, dmamode);
 324         if (ret)
 325                 return NULL;
 326
 327         return &imxdmac->desc;
 328 }
 329
 330 static void imxdma_issue_pending(struct dma_chan *chan)
 331 {
 332         /*
 333          * Nothing to do. We only have a single descriptor
 334          */
 335 }
 336
 337 static int __init imxdma_probe(struct platform_device *pdev)
 338 {
 339         struct imxdma_engine *imxdma;
 340         int ret, i;
 341
 342         imxdma = kzalloc(sizeof(*imxdma), GFP_KERNEL);
 343         if (!imxdma)
 344                 return -ENOMEM;
 345
 346         INIT_LIST_HEAD(&imxdma->dma_device.channels);
 347
 348         dma_cap_set(DMA_SLAVE, imxdma->dma_device.cap_mask);
 349         dma_cap_set(DMA_CYCLIC, imxdma->dma_device.cap_mask);
 350
 351         /* Initialize channel parameters */
 352         for (i = 0; i < MAX_DMA_CHANNELS; i++) {
 353                 struct imxdma_channel *imxdmac = &imxdma->channel[i];
 354
 355                 imxdmac->imxdma_channel = imx_dma_request_by_prio("dmaengine",
 356                                 DMA_PRIO_MEDIUM);
 357                 if ((int)imxdmac->channel < 0) {
 358                         ret = -ENODEV;
 359                         goto err_init;
 360                 }
 361
 362                 imx_dma_setup_handlers(imxdmac->imxdma_channel,
 363                        imxdma_irq_handler, imxdma_err_handler, imxdmac);
 364
 365                 imxdmac->imxdma = imxdma;
 366                 spin_lock_init(&imxdmac->lock);
 367
 368                 imxdmac->chan.device = &imxdma->dma_device;
 369                 imxdmac->channel = i;
 370
 371                 /* Add the channel to the DMAC list */
 372                 list_add_tail(&imxdmac->chan.device_node, &imxdma->dma_device.channels);
 373         }
 374
 375         imxdma->dev = &pdev->dev;
 376         imxdma->dma_device.dev = &pdev->dev;
 377
 378         imxdma->dma_device.device_alloc_chan_resources = imxdma_alloc_chan_resources;
 379         imxdma->dma_device.device_free_chan_resources = imxdma_free_chan_resources;
 380         imxdma->dma_device.device_tx_status = imxdma_tx_status;
 381         imxdma->dma_device.device_prep_slave_sg = imxdma_prep_slave_sg;
 382         imxdma->dma_device.device_prep_dma_cyclic = imxdma_prep_dma_cyclic;
 383         imxdma->dma_device.device_control = imxdma_control;
 384         imxdma->dma_device.device_issue_pending = imxdma_issue_pending;
 385
 386         platform_set_drvdata(pdev, imxdma);
 387
 388         imxdma->dma_device.dev->dma_parms = &imxdma->dma_parms;
 389         dma_set_max_seg_size(imxdma->dma_device.dev, 0xffffff);
 390
 391         ret = dma_async_device_register(&imxdma->dma_device);
 392         if (ret) {
 393                 dev_err(&pdev->dev, "unable to register\n");
 394                 goto err_init;
 395         }
 396
 397         return 0;
 398
 399 err_init:
 400         while (--i >= 0) {
 401                 struct imxdma_channel *imxdmac = &imxdma->channel[i];
 402                 imx_dma_free(imxdmac->imxdma_channel);
 403         }
 404
 405         kfree(imxdma);
 406         return ret;
 407 }
 408
 409 static int __exit imxdma_remove(struct platform_device *pdev)
 410 {
 411         struct imxdma_engine *imxdma = platform_get_drvdata(pdev);
 412         int i;
 413
 414         dma_async_device_unregister(&imxdma->dma_device);
 415
 416         for (i = 0; i < MAX_DMA_CHANNELS; i++) {
 417                 struct imxdma_channel *imxdmac = &imxdma->channel[i];
 418
 419                  imx_dma_free(imxdmac->imxdma_channel);
 420         }
 421
 422         kfree(imxdma);
 423
 424         return 0;
 425 }
 426
 427 static struct platform_driver imxdma_driver = {
 428         .driver         = {
 429                 .name   = "imx-dma",
 430         },
 431         .remove         = __exit_p(imxdma_remove),
 432 };
 433
 434 static int __init imxdma_module_init(void)
 435 {
 436         return platform_driver_probe(&imxdma_driver, imxdma_probe);
 437 }
 438 subsys_initcall(imxdma_module_init);
 439
 440 MODULE_AUTHOR("Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>");
 441 MODULE_DESCRIPTION("i.MX dma driver");
 442 MODULE_LICENSE("GPL");