sound/soc/davinci/davinci-pcm.c

   1 /*
   2  * ALSA PCM interface for the TI DAVINCI processor
   3  *
   4  * Author:      Vladimir Barinov, <vbarinov@embeddedalley.com>
   5  * Copyright:   (C) 2007 MontaVista Software, Inc., <source@mvista.com>
   6  * added SRAM ping/pong (C) 2008 Troy Kisky <troy.kisky@boundarydevices.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/slab.h>
  17 #include <linux/dma-mapping.h>
  18 #include <linux/kernel.h>
  19
  20 #include <sound/core.h>
  21 #include <sound/pcm.h>
  22 #include <sound/pcm_params.h>
  23 #include <sound/soc.h>
  24
  25 #include <asm/dma.h>
  26 #include <mach/edma.h>
  27 #include <mach/sram.h>
  28
  29 #include "davinci-pcm.h"
  30
  31 #ifdef DEBUG
  32 static void print_buf_info(int slot, char *name)
  33 {
  34         struct edmacc_param p;
  35         if (slot < 0)
  36                 return;
  37         edma_read_slot(slot, &p);
  38         printk(KERN_DEBUG "%s: 0x%x, opt=%x, src=%x, a_b_cnt=%x dst=%x\n",
  39                         name, slot, p.opt, p.src, p.a_b_cnt, p.dst);
  40         printk(KERN_DEBUG "    src_dst_bidx=%x link_bcntrld=%x src_dst_cidx=%x ccnt=%x\n",
  41                         p.src_dst_bidx, p.link_bcntrld, p.src_dst_cidx, p.ccnt);
  42 }
  43 #else
  44 static void print_buf_info(int slot, char *name)
  45 {
  46 }
  47 #endif
  48
  49 #define DAVINCI_PCM_FMTBITS     (\
  50                                 SNDRV_PCM_FMTBIT_S8     |\
  51                                 SNDRV_PCM_FMTBIT_U8     |\
  52                                 SNDRV_PCM_FMTBIT_S16_LE |\
  53                                 SNDRV_PCM_FMTBIT_S16_BE |\
  54                                 SNDRV_PCM_FMTBIT_U16_LE |\
  55                                 SNDRV_PCM_FMTBIT_U16_BE |\
  56                                 SNDRV_PCM_FMTBIT_S24_LE |\
  57                                 SNDRV_PCM_FMTBIT_S24_BE |\
  58                                 SNDRV_PCM_FMTBIT_U24_LE |\
  59                                 SNDRV_PCM_FMTBIT_U24_BE |\
  60                                 SNDRV_PCM_FMTBIT_S32_LE |\
  61                                 SNDRV_PCM_FMTBIT_S32_BE |\
  62                                 SNDRV_PCM_FMTBIT_U32_LE |\
  63                                 SNDRV_PCM_FMTBIT_U32_BE)
  64
  65 static struct snd_pcm_hardware pcm_hardware_playback = {
  66         .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
  67                  SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
  68                  SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME|
  69                  SNDRV_PCM_INFO_BATCH),
  70         .formats = DAVINCI_PCM_FMTBITS,
  71         .rates = (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_16000 |
  72                   SNDRV_PCM_RATE_22050 | SNDRV_PCM_RATE_32000 |
  73                   SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000 |
  74                   SNDRV_PCM_RATE_88200 | SNDRV_PCM_RATE_96000 |
  75                   SNDRV_PCM_RATE_KNOT),
  76         .rate_min = 8000,
  77         .rate_max = 96000,
  78         .channels_min = 2,
  79         .channels_max = 384,
  80         .buffer_bytes_max = 128 * 1024,
  81         .period_bytes_min = 32,
  82         .period_bytes_max = 8 * 1024,
  83         .periods_min = 16,
  84         .periods_max = 255,
  85         .fifo_size = 0,
  86 };
  87
  88 static struct snd_pcm_hardware pcm_hardware_capture = {
  89         .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
  90                  SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
  91                  SNDRV_PCM_INFO_PAUSE |
  92                  SNDRV_PCM_INFO_BATCH),
  93         .formats = DAVINCI_PCM_FMTBITS,
  94         .rates = (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_16000 |
  95                   SNDRV_PCM_RATE_22050 | SNDRV_PCM_RATE_32000 |
  96                   SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000 |
  97                   SNDRV_PCM_RATE_88200 | SNDRV_PCM_RATE_96000 |
  98                   SNDRV_PCM_RATE_KNOT),
  99         .rate_min = 8000,
 100         .rate_max = 96000,
 101         .channels_min = 2,
 102         .channels_max = 384,
 103         .buffer_bytes_max = 128 * 1024,
 104         .period_bytes_min = 32,
 105         .period_bytes_max = 8 * 1024,
 106         .periods_min = 16,
 107         .periods_max = 255,
 108         .fifo_size = 0,
 109 };
 110
 111 /*
 112  * How ping/pong works....
 113  *
 114  * Playback:
 115  * ram_params - copys 2*ping_size from start of SDRAM to iram,
 116  *      links to ram_link2
 117  * ram_link2 - copys rest of SDRAM to iram in ping_size units,
 118  *      links to ram_link
 119  * ram_link - copys entire SDRAM to iram in ping_size uints,
 120  *      links to self
 121  *
 122  * asp_params - same as asp_link[0]
 123  * asp_link[0] - copys from lower half of iram to asp port
 124  *      links to asp_link[1], triggers iram copy event on completion
 125  * asp_link[1] - copys from upper half of iram to asp port
 126  *      links to asp_link[0], triggers iram copy event on completion
 127  *      triggers interrupt only needed to let upper SOC levels update position
 128  *      in stream on completion
 129  *
 130  * When playback is started:
 131  *      ram_params started
 132  *      asp_params started
 133  *
 134  * Capture:
 135  * ram_params - same as ram_link,
 136  *      links to ram_link
 137  * ram_link - same as playback
 138  *      links to self
 139  *
 140  * asp_params - same as playback
 141  * asp_link[0] - same as playback
 142  * asp_link[1] - same as playback
 143  *
 144  * When capture is started:
 145  *      asp_params started
 146  */
 147 struct davinci_runtime_data {
 148         spinlock_t lock;
 149         int period;             /* current DMA period */
 150         int asp_channel;        /* Master DMA channel */
 151         int asp_link[2];        /* asp parameter link channel, ping/pong */
 152         struct davinci_pcm_dma_params *params;  /* DMA params */
 153         int ram_channel;
 154         int ram_link;
 155         int ram_link2;
 156         struct edmacc_param asp_params;
 157         struct edmacc_param ram_params;
 158 };
 159
 160 static void davinci_pcm_period_elapsed(struct snd_pcm_substream *substream)
 161 {
 162         struct davinci_runtime_data *prtd = substream->runtime->private_data;
 163         struct snd_pcm_runtime *runtime = substream->runtime;
 164
 165         prtd->period++;
 166         if (unlikely(prtd->period >= runtime->periods))
 167                 prtd->period = 0;
 168 }
 169
 170 static void davinci_pcm_period_reset(struct snd_pcm_substream *substream)
 171 {
 172         struct davinci_runtime_data *prtd = substream->runtime->private_data;
 173
 174         prtd->period = 0;
 175 }
 176 /*
 177  * Not used with ping/pong
 178  */
 179 static void davinci_pcm_enqueue_dma(struct snd_pcm_substream *substream)
 180 {
 181         struct davinci_runtime_data *prtd = substream->runtime->private_data;
 182         struct snd_pcm_runtime *runtime = substream->runtime;
 183         unsigned int period_size;
 184         unsigned int dma_offset;
 185         dma_addr_t dma_pos;
 186         dma_addr_t src, dst;
 187         unsigned short src_bidx, dst_bidx;
 188         unsigned short src_cidx, dst_cidx;
 189         unsigned int data_type;
 190         unsigned short acnt;
 191         unsigned int count;
 192         unsigned int fifo_level;
 193
 194         period_size = snd_pcm_lib_period_bytes(substream);
 195         dma_offset = prtd->period * period_size;
 196         dma_pos = runtime->dma_addr + dma_offset;
 197         fifo_level = prtd->params->fifo_level;
 198
 199         pr_debug("davinci_pcm: audio_set_dma_params_play channel = %d "
 200                 "dma_ptr = %x period_size=%x\n", prtd->asp_link[0], dma_pos,
 201                 period_size);
 202
 203         data_type = prtd->params->data_type;
 204         count = period_size / data_type;
 205         if (fifo_level)
 206                 count /= fifo_level;
 207
 208         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 209                 src = dma_pos;
 210                 dst = prtd->params->dma_addr;
 211                 src_bidx = data_type;
 212                 dst_bidx = 0;
 213                 src_cidx = data_type * fifo_level;
 214                 dst_cidx = 0;
 215         } else {
 216                 src = prtd->params->dma_addr;
 217                 dst = dma_pos;
 218                 src_bidx = 0;
 219                 dst_bidx = data_type;
 220                 src_cidx = 0;
 221                 dst_cidx = data_type * fifo_level;
 222         }
 223
 224         acnt = prtd->params->acnt;
 225         edma_set_src(prtd->asp_link[0], src, INCR, W8BIT);
 226         edma_set_dest(prtd->asp_link[0], dst, INCR, W8BIT);
 227
 228         edma_set_src_index(prtd->asp_link[0], src_bidx, src_cidx);
 229         edma_set_dest_index(prtd->asp_link[0], dst_bidx, dst_cidx);
 230
 231         if (!fifo_level)
 232                 edma_set_transfer_params(prtd->asp_link[0], acnt, count, 1, 0,
 233                                                         ASYNC);
 234         else
 235                 edma_set_transfer_params(prtd->asp_link[0], acnt, fifo_level,
 236                                                         count, fifo_level,
 237                                                         ABSYNC);
 238 }
 239
 240 static void davinci_pcm_dma_irq(unsigned link, u16 ch_status, void *data)
 241 {
 242         struct snd_pcm_substream *substream = data;
 243         struct davinci_runtime_data *prtd = substream->runtime->private_data;
 244
 245         print_buf_info(prtd->ram_channel, "i ram_channel");
 246         pr_debug("davinci_pcm: link=%d, status=0x%x\n", link, ch_status);
 247
 248         if (unlikely(ch_status != DMA_COMPLETE))
 249                 return;
 250
 251         if (snd_pcm_running(substream)) {
 252                 spin_lock(&prtd->lock);
 253                 if (prtd->ram_channel < 0) {
 254                         /* No ping/pong must fix up link dma data*/
 255                         davinci_pcm_enqueue_dma(substream);
 256                 }
 257                 davinci_pcm_period_elapsed(substream);
 258                 spin_unlock(&prtd->lock);
 259                 snd_pcm_period_elapsed(substream);
 260         }
 261 }
 262
 263 static int allocate_sram(struct snd_pcm_substream *substream, unsigned size,
 264                 struct snd_pcm_hardware *ppcm)
 265 {
 266         struct snd_dma_buffer *buf = &substream->dma_buffer;
 267         struct snd_dma_buffer *iram_dma = NULL;
 268         dma_addr_t iram_phys = 0;
 269         void *iram_virt = NULL;
 270
 271         if (buf->private_data || !size)
 272                 return 0;
 273
 274         ppcm->period_bytes_max = size;
 275         iram_virt = sram_alloc(size, &iram_phys);
 276         if (!iram_virt)
 277                 goto exit1;
 278         iram_dma = kzalloc(sizeof(*iram_dma), GFP_KERNEL);
 279         if (!iram_dma)
 280                 goto exit2;
 281         iram_dma->area = iram_virt;
 282         iram_dma->addr = iram_phys;
 283         memset(iram_dma->area, 0, size);
 284         iram_dma->bytes = size;
 285         buf->private_data = iram_dma;
 286         return 0;
 287 exit2:
 288         if (iram_virt)
 289                 sram_free(iram_virt, size);
 290 exit1:
 291         return -ENOMEM;
 292 }
 293
 294 /*
 295  * Only used with ping/pong.
 296  * This is called after runtime->dma_addr, period_bytes and data_type are valid
 297  */
 298 static int ping_pong_dma_setup(struct snd_pcm_substream *substream)
 299 {
 300         unsigned short ram_src_cidx, ram_dst_cidx;
 301         struct snd_pcm_runtime *runtime = substream->runtime;
 302         struct davinci_runtime_data *prtd = runtime->private_data;
 303         struct snd_dma_buffer *iram_dma =
 304                 (struct snd_dma_buffer *)substream->dma_buffer.private_data;
 305         struct davinci_pcm_dma_params *params = prtd->params;
 306         unsigned int data_type = params->data_type;
 307         unsigned int acnt = params->acnt;
 308         /* divide by 2 for ping/pong */
 309         unsigned int ping_size = snd_pcm_lib_period_bytes(substream) >> 1;
 310         unsigned int fifo_level = prtd->params->fifo_level;
 311         unsigned int count;
 312         if ((data_type == 0) || (data_type > 4)) {
 313                 printk(KERN_ERR "%s: data_type=%i\n", __func__, data_type);
 314                 return -EINVAL;
 315         }
 316         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 317                 dma_addr_t asp_src_pong = iram_dma->addr + ping_size;
 318                 ram_src_cidx = ping_size;
 319                 ram_dst_cidx = -ping_size;
 320                 edma_set_src(prtd->asp_link[1], asp_src_pong, INCR, W8BIT);
 321
 322                 edma_set_src_index(prtd->asp_link[0], data_type,
 323                                 data_type * fifo_level);
 324                 edma_set_src_index(prtd->asp_link[1], data_type,
 325                                 data_type * fifo_level);
 326
 327                 edma_set_src(prtd->ram_link, runtime->dma_addr, INCR, W32BIT);
 328         } else {
 329                 dma_addr_t asp_dst_pong = iram_dma->addr + ping_size;
 330                 ram_src_cidx = -ping_size;
 331                 ram_dst_cidx = ping_size;
 332                 edma_set_dest(prtd->asp_link[1], asp_dst_pong, INCR, W8BIT);
 333
 334                 edma_set_dest_index(prtd->asp_link[0], data_type,
 335                                 data_type * fifo_level);
 336                 edma_set_dest_index(prtd->asp_link[1], data_type,
 337                                 data_type * fifo_level);
 338
 339                 edma_set_dest(prtd->ram_link, runtime->dma_addr, INCR, W32BIT);
 340         }
 341
 342         if (!fifo_level) {
 343                 count = ping_size / data_type;
 344                 edma_set_transfer_params(prtd->asp_link[0], acnt, count,
 345                                 1, 0, ASYNC);
 346                 edma_set_transfer_params(prtd->asp_link[1], acnt, count,
 347                                 1, 0, ASYNC);
 348         } else {
 349                 count = ping_size / (data_type * fifo_level);
 350                 edma_set_transfer_params(prtd->asp_link[0], acnt, fifo_level,
 351                                 count, fifo_level, ABSYNC);
 352                 edma_set_transfer_params(prtd->asp_link[1], acnt, fifo_level,
 353                                 count, fifo_level, ABSYNC);
 354         }
 355
 356         edma_set_src_index(prtd->ram_link, ping_size, ram_src_cidx);
 357         edma_set_dest_index(prtd->ram_link, ping_size, ram_dst_cidx);
 358         edma_set_transfer_params(prtd->ram_link, ping_size, 2,
 359                         runtime->periods, 2, ASYNC);
 360
 361         /* init master params */
 362         edma_read_slot(prtd->asp_link[0], &prtd->asp_params);
 363         edma_read_slot(prtd->ram_link, &prtd->ram_params);
 364         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 365                 struct edmacc_param p_ram;
 366                 /* Copy entire iram buffer before playback started */
 367                 prtd->ram_params.a_b_cnt = (1 << 16) | (ping_size << 1);
 368                 /* 0 dst_bidx */
 369                 prtd->ram_params.src_dst_bidx = (ping_size << 1);
 370                 /* 0 dst_cidx */
 371                 prtd->ram_params.src_dst_cidx = (ping_size << 1);
 372                 prtd->ram_params.ccnt = 1;
 373
 374                 /* Skip 1st period */
 375                 edma_read_slot(prtd->ram_link, &p_ram);
 376                 p_ram.src += (ping_size << 1);
 377                 p_ram.ccnt -= 1;
 378                 edma_write_slot(prtd->ram_link2, &p_ram);
 379                 /*
 380                  * When 1st started, ram -> iram dma channel will fill the
 381                  * entire iram.  Then, whenever a ping/pong asp buffer finishes,
 382                  * 1/2 iram will be filled.
 383                  */
 384                 prtd->ram_params.link_bcntrld =
 385                         EDMA_CHAN_SLOT(prtd->ram_link2) << 5;
 386         }
 387         return 0;
 388 }
 389
 390 /* 1 asp tx or rx channel using 2 parameter channels
 391  * 1 ram to/from iram channel using 1 parameter channel
 392  *
 393  * Playback
 394  * ram copy channel kicks off first,
 395  * 1st ram copy of entire iram buffer completion kicks off asp channel
 396  * asp tcc always kicks off ram copy of 1/2 iram buffer
 397  *
 398  * Record
 399  * asp channel starts, tcc kicks off ram copy
 400  */
 401 static int request_ping_pong(struct snd_pcm_substream *substream,
 402                 struct davinci_runtime_data *prtd,
 403                 struct snd_dma_buffer *iram_dma)
 404 {
 405         dma_addr_t asp_src_ping;
 406         dma_addr_t asp_dst_ping;
 407         int ret;
 408         struct davinci_pcm_dma_params *params = prtd->params;
 409
 410         /* Request ram master channel */
 411         ret = prtd->ram_channel = edma_alloc_channel(EDMA_CHANNEL_ANY,
 412                                   davinci_pcm_dma_irq, substream,
 413                                   prtd->params->ram_chan_q);
 414         if (ret < 0)
 415                 goto exit1;
 416
 417         /* Request ram link channel */
 418         ret = prtd->ram_link = edma_alloc_slot(
 419                         EDMA_CTLR(prtd->ram_channel), EDMA_SLOT_ANY);
 420         if (ret < 0)
 421                 goto exit2;
 422
 423         ret = prtd->asp_link[1] = edma_alloc_slot(
 424                         EDMA_CTLR(prtd->asp_channel), EDMA_SLOT_ANY);
 425         if (ret < 0)
 426                 goto exit3;
 427
 428         prtd->ram_link2 = -1;
 429         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 430                 ret = prtd->ram_link2 = edma_alloc_slot(
 431                         EDMA_CTLR(prtd->ram_channel), EDMA_SLOT_ANY);
 432                 if (ret < 0)
 433                         goto exit4;
 434         }
 435         /* circle ping-pong buffers */
 436         edma_link(prtd->asp_link[0], prtd->asp_link[1]);
 437         edma_link(prtd->asp_link[1], prtd->asp_link[0]);
 438         /* circle ram buffers */
 439         edma_link(prtd->ram_link, prtd->ram_link);
 440
 441         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 442                 asp_src_ping = iram_dma->addr;
 443                 asp_dst_ping = params->dma_addr;        /* fifo */
 444         } else {
 445                 asp_src_ping = params->dma_addr;        /* fifo */
 446                 asp_dst_ping = iram_dma->addr;
 447         }
 448         /* ping */
 449         edma_set_src(prtd->asp_link[0], asp_src_ping, INCR, W16BIT);
 450         edma_set_dest(prtd->asp_link[0], asp_dst_ping, INCR, W16BIT);
 451         edma_set_src_index(prtd->asp_link[0], 0, 0);
 452         edma_set_dest_index(prtd->asp_link[0], 0, 0);
 453
 454         edma_read_slot(prtd->asp_link[0], &prtd->asp_params);
 455         prtd->asp_params.opt &= ~(TCCMODE | EDMA_TCC(0x3f) | TCINTEN);
 456         prtd->asp_params.opt |= TCCHEN |
 457                 EDMA_TCC(prtd->ram_channel & 0x3f);
 458         edma_write_slot(prtd->asp_link[0], &prtd->asp_params);
 459
 460         /* pong */
 461         edma_set_src(prtd->asp_link[1], asp_src_ping, INCR, W16BIT);
 462         edma_set_dest(prtd->asp_link[1], asp_dst_ping, INCR, W16BIT);
 463         edma_set_src_index(prtd->asp_link[1], 0, 0);
 464         edma_set_dest_index(prtd->asp_link[1], 0, 0);
 465
 466         edma_read_slot(prtd->asp_link[1], &prtd->asp_params);
 467         prtd->asp_params.opt &= ~(TCCMODE | EDMA_TCC(0x3f));
 468         /* interrupt after every pong completion */
 469         prtd->asp_params.opt |= TCINTEN | TCCHEN |
 470                 EDMA_TCC(prtd->ram_channel & 0x3f);
 471         edma_write_slot(prtd->asp_link[1], &prtd->asp_params);
 472
 473         /* ram */
 474         edma_set_src(prtd->ram_link, iram_dma->addr, INCR, W32BIT);
 475         edma_set_dest(prtd->ram_link, iram_dma->addr, INCR, W32BIT);
 476         pr_debug("%s: audio dma channels/slots in use for ram:%u %u %u,"
 477                 "for asp:%u %u %u\n", __func__,
 478                 prtd->ram_channel, prtd->ram_link, prtd->ram_link2,
 479                 prtd->asp_channel, prtd->asp_link[0],
 480                 prtd->asp_link[1]);
 481         return 0;
 482 exit4:
 483         edma_free_channel(prtd->asp_link[1]);
 484         prtd->asp_link[1] = -1;
 485 exit3:
 486         edma_free_channel(prtd->ram_link);
 487         prtd->ram_link = -1;
 488 exit2:
 489         edma_free_channel(prtd->ram_channel);
 490         prtd->ram_channel = -1;
 491 exit1:
 492         return ret;
 493 }
 494
 495 static int davinci_pcm_dma_request(struct snd_pcm_substream *substream)
 496 {
 497         struct snd_dma_buffer *iram_dma;
 498         struct davinci_runtime_data *prtd = substream->runtime->private_data;
 499         struct davinci_pcm_dma_params *params = prtd->params;
 500         int ret;
 501
 502         if (!params)
 503                 return -ENODEV;
 504
 505         /* Request asp master DMA channel */
 506         ret = prtd->asp_channel = edma_alloc_channel(params->channel,
 507                         davinci_pcm_dma_irq, substream,
 508                         prtd->params->asp_chan_q);
 509         if (ret < 0)
 510                 goto exit1;
 511
 512         /* Request asp link channels */
 513         ret = prtd->asp_link[0] = edma_alloc_slot(
 514                         EDMA_CTLR(prtd->asp_channel), EDMA_SLOT_ANY);
 515         if (ret < 0)
 516                 goto exit2;
 517
 518         iram_dma = (struct snd_dma_buffer *)substream->dma_buffer.private_data;
 519         if (iram_dma) {
 520                 if (request_ping_pong(substream, prtd, iram_dma) == 0)
 521                         return 0;
 522                 printk(KERN_WARNING "%s: dma channel allocation failed,"
 523                                 "not using sram\n", __func__);
 524         }
 525
 526         /* Issue transfer completion IRQ when the channel completes a
 527          * transfer, then always reload from the same slot (by a kind
 528          * of loopback link).  The completion IRQ handler will update
 529          * the reload slot with a new buffer.
 530          *
 531          * REVISIT save p_ram here after setting up everything except
 532          * the buffer and its length (ccnt) ... use it as a template
 533          * so davinci_pcm_enqueue_dma() takes less time in IRQ.
 534          */
 535         edma_read_slot(prtd->asp_link[0], &prtd->asp_params);
 536         prtd->asp_params.opt |= TCINTEN |
 537                 EDMA_TCC(EDMA_CHAN_SLOT(prtd->asp_channel));
 538         prtd->asp_params.link_bcntrld = EDMA_CHAN_SLOT(prtd->asp_link[0]) << 5;
 539         edma_write_slot(prtd->asp_link[0], &prtd->asp_params);
 540         return 0;
 541 exit2:
 542         edma_free_channel(prtd->asp_channel);
 543         prtd->asp_channel = -1;
 544 exit1:
 545         return ret;
 546 }
 547
 548 static int davinci_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 549 {
 550         struct davinci_runtime_data *prtd = substream->runtime->private_data;
 551         int ret = 0;
 552
 553         spin_lock(&prtd->lock);
 554
 555         switch (cmd) {
 556         case SNDRV_PCM_TRIGGER_START:
 557                 edma_start(prtd->asp_channel);
 558                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
 559                     prtd->ram_channel >= 0) {
 560                         /* copy 1st iram buffer */
 561                         edma_start(prtd->ram_channel);
 562                 }
 563                 break;
 564         case SNDRV_PCM_TRIGGER_RESUME:
 565         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 566                 edma_resume(prtd->asp_channel);
 567                 break;
 568         case SNDRV_PCM_TRIGGER_STOP:
 569         case SNDRV_PCM_TRIGGER_SUSPEND:
 570         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 571                 edma_pause(prtd->asp_channel);
 572                 break;
 573         default:
 574                 ret = -EINVAL;
 575                 break;
 576         }
 577
 578         spin_unlock(&prtd->lock);
 579
 580         return ret;
 581 }
 582
 583 static int davinci_pcm_prepare(struct snd_pcm_substream *substream)
 584 {
 585         struct davinci_runtime_data *prtd = substream->runtime->private_data;
 586
 587         davinci_pcm_period_reset(substream);
 588         if (prtd->ram_channel >= 0) {
 589                 int ret = ping_pong_dma_setup(substream);
 590                 if (ret < 0)
 591                         return ret;
 592
 593                 edma_write_slot(prtd->ram_channel, &prtd->ram_params);
 594                 edma_write_slot(prtd->asp_channel, &prtd->asp_params);
 595
 596                 print_buf_info(prtd->ram_channel, "ram_channel");
 597                 print_buf_info(prtd->ram_link, "ram_link");
 598                 print_buf_info(prtd->ram_link2, "ram_link2");
 599                 print_buf_info(prtd->asp_channel, "asp_channel");
 600                 print_buf_info(prtd->asp_link[0], "asp_link[0]");
 601                 print_buf_info(prtd->asp_link[1], "asp_link[1]");
 602
 603                 /*
 604                  * There is a phase offset of 2 periods between the position
 605                  * used by dma setup and the position reported in the pointer
 606                  * function.
 607                  *
 608                  * The phase offset, when not using ping-pong buffers, is due to
 609                  * the two consecutive calls to davinci_pcm_enqueue_dma() below.
 610                  *
 611                  * Whereas here, with ping-pong buffers, the phase is due to
 612                  * there being an entire buffer transfer complete before the
 613                  * first dma completion event triggers davinci_pcm_dma_irq().
 614                  */
 615                 davinci_pcm_period_elapsed(substream);
 616                 davinci_pcm_period_elapsed(substream);
 617
 618                 return 0;
 619         }
 620         davinci_pcm_enqueue_dma(substream);
 621         davinci_pcm_period_elapsed(substream);
 622
 623         /* Copy self-linked parameter RAM entry into master channel */
 624         edma_read_slot(prtd->asp_link[0], &prtd->asp_params);
 625         edma_write_slot(prtd->asp_channel, &prtd->asp_params);
 626         davinci_pcm_enqueue_dma(substream);
 627         davinci_pcm_period_elapsed(substream);
 628
 629         return 0;
 630 }
 631
 632 static snd_pcm_uframes_t
 633 davinci_pcm_pointer(struct snd_pcm_substream *substream)
 634 {
 635         struct snd_pcm_runtime *runtime = substream->runtime;
 636         struct davinci_runtime_data *prtd = runtime->private_data;
 637         unsigned int offset;
 638         int asp_count;
 639         unsigned int period_size = snd_pcm_lib_period_bytes(substream);
 640
 641         /*
 642          * There is a phase offset of 2 periods between the position used by dma
 643          * setup and the position reported in the pointer function. Either +2 in
 644          * the dma setup or -2 here in the pointer function (with wrapping,
 645          * both) accounts for this offset -- choose the latter since it makes
 646          * the first-time setup clearer.
 647          */
 648         spin_lock(&prtd->lock);
 649         asp_count = prtd->period - 2;
 650         spin_unlock(&prtd->lock);
 651
 652         if (asp_count < 0)
 653                 asp_count += runtime->periods;
 654         asp_count *= period_size;
 655
 656         offset = bytes_to_frames(runtime, asp_count);
 657         if (offset >= runtime->buffer_size)
 658                 offset = 0;
 659
 660         return offset;
 661 }
 662
 663 static int davinci_pcm_open(struct snd_pcm_substream *substream)
 664 {
 665         struct snd_pcm_runtime *runtime = substream->runtime;
 666         struct davinci_runtime_data *prtd;
 667         struct snd_pcm_hardware *ppcm;
 668         int ret = 0;
 669         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 670         struct davinci_pcm_dma_params *pa;
 671         struct davinci_pcm_dma_params *params;
 672
 673         pa = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
 674         if (!pa)
 675                 return -ENODEV;
 676         params = &pa[substream->stream];
 677
 678         ppcm = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ?
 679                         &pcm_hardware_playback : &pcm_hardware_capture;
 680         allocate_sram(substream, params->sram_size, ppcm);
 681         snd_soc_set_runtime_hwparams(substream, ppcm);
 682         /* ensure that buffer size is a multiple of period size */
 683         ret = snd_pcm_hw_constraint_integer(runtime,
 684                                                 SNDRV_PCM_HW_PARAM_PERIODS);
 685         if (ret < 0)
 686                 return ret;
 687
 688         prtd = kzalloc(sizeof(struct davinci_runtime_data), GFP_KERNEL);
 689         if (prtd == NULL)
 690                 return -ENOMEM;
 691
 692         spin_lock_init(&prtd->lock);
 693         prtd->params = params;
 694         prtd->asp_channel = -1;
 695         prtd->asp_link[0] = prtd->asp_link[1] = -1;
 696         prtd->ram_channel = -1;
 697         prtd->ram_link = -1;
 698         prtd->ram_link2 = -1;
 699
 700         runtime->private_data = prtd;
 701
 702         ret = davinci_pcm_dma_request(substream);
 703         if (ret) {
 704                 printk(KERN_ERR "davinci_pcm: Failed to get dma channels\n");
 705                 kfree(prtd);
 706         }
 707
 708         return ret;
 709 }
 710
 711 static int davinci_pcm_close(struct snd_pcm_substream *substream)
 712 {
 713         struct snd_pcm_runtime *runtime = substream->runtime;
 714         struct davinci_runtime_data *prtd = runtime->private_data;
 715
 716         if (prtd->ram_channel >= 0)
 717                 edma_stop(prtd->ram_channel);
 718         if (prtd->asp_channel >= 0)
 719                 edma_stop(prtd->asp_channel);
 720         if (prtd->asp_link[0] >= 0)
 721                 edma_unlink(prtd->asp_link[0]);
 722         if (prtd->asp_link[1] >= 0)
 723                 edma_unlink(prtd->asp_link[1]);
 724         if (prtd->ram_link >= 0)
 725                 edma_unlink(prtd->ram_link);
 726
 727         if (prtd->asp_link[0] >= 0)
 728                 edma_free_slot(prtd->asp_link[0]);
 729         if (prtd->asp_link[1] >= 0)
 730                 edma_free_slot(prtd->asp_link[1]);
 731         if (prtd->asp_channel >= 0)
 732                 edma_free_channel(prtd->asp_channel);
 733         if (prtd->ram_link >= 0)
 734                 edma_free_slot(prtd->ram_link);
 735         if (prtd->ram_link2 >= 0)
 736                 edma_free_slot(prtd->ram_link2);
 737         if (prtd->ram_channel >= 0)
 738                 edma_free_channel(prtd->ram_channel);
 739
 740         kfree(prtd);
 741
 742         return 0;
 743 }
 744
 745 static int davinci_pcm_hw_params(struct snd_pcm_substream *substream,
 746                                  struct snd_pcm_hw_params *hw_params)
 747 {
 748         return snd_pcm_lib_malloc_pages(substream,
 749                                         params_buffer_bytes(hw_params));
 750 }
 751
 752 static int davinci_pcm_hw_free(struct snd_pcm_substream *substream)
 753 {
 754         return snd_pcm_lib_free_pages(substream);
 755 }
 756
 757 static int davinci_pcm_mmap(struct snd_pcm_substream *substream,
 758                             struct vm_area_struct *vma)
 759 {
 760         struct snd_pcm_runtime *runtime = substream->runtime;
 761
 762         return dma_mmap_writecombine(substream->pcm->card->dev, vma,
 763                                      runtime->dma_area,
 764                                      runtime->dma_addr,
 765                                      runtime->dma_bytes);
 766 }
 767
 768 static struct snd_pcm_ops davinci_pcm_ops = {
 769         .open =         davinci_pcm_open,
 770         .close =        davinci_pcm_close,
 771         .ioctl =        snd_pcm_lib_ioctl,
 772         .hw_params =    davinci_pcm_hw_params,
 773         .hw_free =      davinci_pcm_hw_free,
 774         .prepare =      davinci_pcm_prepare,
 775         .trigger =      davinci_pcm_trigger,
 776         .pointer =      davinci_pcm_pointer,
 777         .mmap =         davinci_pcm_mmap,
 778 };
 779
 780 static int davinci_pcm_preallocate_dma_buffer(struct snd_pcm *pcm, int stream,
 781                 size_t size)
 782 {
 783         struct snd_pcm_substream *substream = pcm->streams[stream].substream;
 784         struct snd_dma_buffer *buf = &substream->dma_buffer;
 785
 786         buf->dev.type = SNDRV_DMA_TYPE_DEV;
 787         buf->dev.dev = pcm->card->dev;
 788         buf->private_data = NULL;
 789         buf->area = dma_alloc_writecombine(pcm->card->dev, size,
 790                                            &buf->addr, GFP_KERNEL);
 791
 792         pr_debug("davinci_pcm: preallocate_dma_buffer: area=%p, addr=%p, "
 793                 "size=%d\n", (void *) buf->area, (void *) buf->addr, size);
 794
 795         if (!buf->area)
 796                 return -ENOMEM;
 797
 798         buf->bytes = size;
 799         return 0;
 800 }
 801
 802 static void davinci_pcm_free(struct snd_pcm *pcm)
 803 {
 804         struct snd_pcm_substream *substream;
 805         struct snd_dma_buffer *buf;
 806         int stream;
 807
 808         for (stream = 0; stream < 2; stream++) {
 809                 struct snd_dma_buffer *iram_dma;
 810                 substream = pcm->streams[stream].substream;
 811                 if (!substream)
 812                         continue;
 813
 814                 buf = &substream->dma_buffer;
 815                 if (!buf->area)
 816                         continue;
 817
 818                 dma_free_writecombine(pcm->card->dev, buf->bytes,
 819                                       buf->area, buf->addr);
 820                 buf->area = NULL;
 821                 iram_dma = buf->private_data;
 822                 if (iram_dma) {
 823                         sram_free(iram_dma->area, iram_dma->bytes);
 824                         kfree(iram_dma);
 825                 }
 826         }
 827 }
 828
 829 static u64 davinci_pcm_dmamask = 0xffffffff;
 830
 831 static int davinci_pcm_new(struct snd_soc_pcm_runtime *rtd)
 832 {
 833         struct snd_card *card = rtd->card->snd_card;
 834         struct snd_pcm *pcm = rtd->pcm;
 835         int ret;
 836
 837         if (!card->dev->dma_mask)
 838                 card->dev->dma_mask = &davinci_pcm_dmamask;
 839         if (!card->dev->coherent_dma_mask)
 840                 card->dev->coherent_dma_mask = 0xffffffff;
 841
 842         if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
 843                 ret = davinci_pcm_preallocate_dma_buffer(pcm,
 844                         SNDRV_PCM_STREAM_PLAYBACK,
 845                         pcm_hardware_playback.buffer_bytes_max);
 846                 if (ret)
 847                         return ret;
 848         }
 849
 850         if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
 851                 ret = davinci_pcm_preallocate_dma_buffer(pcm,
 852                         SNDRV_PCM_STREAM_CAPTURE,
 853                         pcm_hardware_capture.buffer_bytes_max);
 854                 if (ret)
 855                         return ret;
 856         }
 857
 858         return 0;
 859 }
 860
 861 static struct snd_soc_platform_driver davinci_soc_platform = {
 862         .ops =          &davinci_pcm_ops,
 863         .pcm_new =      davinci_pcm_new,
 864         .pcm_free =     davinci_pcm_free,
 865 };
 866
 867 static int __devinit davinci_soc_platform_probe(struct platform_device *pdev)
 868 {
 869         return snd_soc_register_platform(&pdev->dev, &davinci_soc_platform);
 870 }
 871
 872 static int __devexit davinci_soc_platform_remove(struct platform_device *pdev)
 873 {
 874         snd_soc_unregister_platform(&pdev->dev);
 875         return 0;
 876 }
 877
 878 static struct platform_driver davinci_pcm_driver = {
 879         .driver = {
 880                         .name = "davinci-pcm-audio",
 881                         .owner = THIS_MODULE,
 882         },
 883
 884         .probe = davinci_soc_platform_probe,
 885         .remove = __devexit_p(davinci_soc_platform_remove),
 886 };
 887
 888 module_platform_driver(davinci_pcm_driver);
 889
 890 MODULE_AUTHOR("Vladimir Barinov");
 891 MODULE_DESCRIPTION("TI DAVINCI PCM DMA module");
 892 MODULE_LICENSE("GPL");