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