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 #include <linux/genalloc.h>
  20
  21 #include <sound/core.h>
  22 #include <sound/pcm.h>
  23 #include <sound/pcm_params.h>
  24 #include <sound/soc.h>
  25
  26 #include <asm/dma.h>
  27
  28 #include "davinci-pcm.h"
  29
  30 #ifdef DEBUG
  31 static void print_buf_info(int slot, char *name)
  32 {
  33         struct edmacc_param p;
  34         if (slot < 0)
  35                 return;
  36         edma_read_slot(slot, &p);
  37         printk(KERN_DEBUG "%s: 0x%x, opt=%x, src=%x, a_b_cnt=%x dst=%x\n",
  38                         name, slot, p.opt, p.src, p.a_b_cnt, p.dst);
  39         printk(KERN_DEBUG "    src_dst_bidx=%x link_bcntrld=%x src_dst_cidx=%x ccnt=%x\n",
  40                         p.src_dst_bidx, p.link_bcntrld, p.src_dst_cidx, p.ccnt);
  41 }
  42 #else
  43 static void print_buf_info(int slot, char *name)
  44 {
  45 }
  46 #endif
  47
  48 #define DAVINCI_PCM_FMTBITS     (\
  49                                 SNDRV_PCM_FMTBIT_S8     |\
  50                                 SNDRV_PCM_FMTBIT_U8     |\
  51                                 SNDRV_PCM_FMTBIT_S16_LE |\
  52                                 SNDRV_PCM_FMTBIT_S16_BE |\
  53                                 SNDRV_PCM_FMTBIT_U16_LE |\
  54                                 SNDRV_PCM_FMTBIT_U16_BE |\
  55                                 SNDRV_PCM_FMTBIT_S24_LE |\
  56                                 SNDRV_PCM_FMTBIT_S24_BE |\
  57                                 SNDRV_PCM_FMTBIT_U24_LE |\
  58                                 SNDRV_PCM_FMTBIT_U24_BE |\
  59                                 SNDRV_PCM_FMTBIT_S32_LE |\
  60                                 SNDRV_PCM_FMTBIT_S32_BE |\
  61                                 SNDRV_PCM_FMTBIT_U32_LE |\
  62                                 SNDRV_PCM_FMTBIT_U32_BE)
  63
  64 static struct snd_pcm_hardware pcm_hardware_playback = {
  65         .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
  66                  SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
  67                  SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME|
  68                  SNDRV_PCM_INFO_BATCH),
  69         .formats = DAVINCI_PCM_FMTBITS,
  70         .rates = SNDRV_PCM_RATE_8000_192000 | SNDRV_PCM_RATE_KNOT,
  71         .rate_min = 8000,
  72         .rate_max = 192000,
  73         .channels_min = 2,
  74         .channels_max = 384,
  75         .buffer_bytes_max = 128 * 1024,
  76         .period_bytes_min = 32,
  77         .period_bytes_max = 8 * 1024,
  78         .periods_min = 16,
  79         .periods_max = 255,
  80         .fifo_size = 0,
  81 };
  82
  83 static struct snd_pcm_hardware pcm_hardware_capture = {
  84         .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
  85                  SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
  86                  SNDRV_PCM_INFO_PAUSE |
  87                  SNDRV_PCM_INFO_BATCH),
  88         .formats = DAVINCI_PCM_FMTBITS,
  89         .rates = SNDRV_PCM_RATE_8000_192000 | SNDRV_PCM_RATE_KNOT,
  90         .rate_min = 8000,
  91         .rate_max = 192000,
  92         .channels_min = 2,
  93         .channels_max = 384,
  94         .buffer_bytes_max = 128 * 1024,
  95         .period_bytes_min = 32,
  96         .period_bytes_max = 8 * 1024,
  97         .periods_min = 16,
  98         .periods_max = 255,
  99         .fifo_size = 0,
 100 };
 101
 102 /*
 103  * How ping/pong works....
 104  *
 105  * Playback:
 106  * ram_params - copys 2*ping_size from start of SDRAM to iram,
 107  *      links to ram_link2
 108  * ram_link2 - copys rest of SDRAM to iram in ping_size units,
 109  *      links to ram_link
 110  * ram_link - copys entire SDRAM to iram in ping_size uints,
 111  *      links to self
 112  *
 113  * asp_params - same as asp_link[0]
 114  * asp_link[0] - copys from lower half of iram to asp port
 115  *      links to asp_link[1], triggers iram copy event on completion
 116  * asp_link[1] - copys from upper half of iram to asp port
 117  *      links to asp_link[0], triggers iram copy event on completion
 118  *      triggers interrupt only needed to let upper SOC levels update position
 119  *      in stream on completion
 120  *
 121  * When playback is started:
 122  *      ram_params started
 123  *      asp_params started
 124  *
 125  * Capture:
 126  * ram_params - same as ram_link,
 127  *      links to ram_link
 128  * ram_link - same as playback
 129  *      links to self
 130  *
 131  * asp_params - same as playback
 132  * asp_link[0] - same as playback
 133  * asp_link[1] - same as playback
 134  *
 135  * When capture is started:
 136  *      asp_params started
 137  */
 138 struct davinci_runtime_data {
 139         spinlock_t lock;
 140         int period;             /* current DMA period */
 141         int asp_channel;        /* Master DMA channel */
 142         int asp_link[2];        /* asp parameter link channel, ping/pong */
 143         struct davinci_pcm_dma_params *params;  /* DMA params */
 144         int ram_channel;
 145         int ram_link;
 146         int ram_link2;
 147         struct edmacc_param asp_params;
 148         struct edmacc_param ram_params;
 149 };
 150
 151 static void davinci_pcm_period_elapsed(struct snd_pcm_substream *substream)
 152 {
 153         struct davinci_runtime_data *prtd = substream->runtime->private_data;
 154         struct snd_pcm_runtime *runtime = substream->runtime;
 155
 156         prtd->period++;
 157         if (unlikely(prtd->period >= runtime->periods))
 158                 prtd->period = 0;
 159 }
 160
 161 static void davinci_pcm_period_reset(struct snd_pcm_substream *substream)
 162 {
 163         struct davinci_runtime_data *prtd = substream->runtime->private_data;
 164
 165         prtd->period = 0;
 166 }
 167 /*
 168  * Not used with ping/pong
 169  */
 170 static void davinci_pcm_enqueue_dma(struct snd_pcm_substream *substream)
 171 {
 172         struct davinci_runtime_data *prtd = substream->runtime->private_data;
 173         struct snd_pcm_runtime *runtime = substream->runtime;
 174         unsigned int period_size;
 175         unsigned int dma_offset;
 176         dma_addr_t dma_pos;
 177         dma_addr_t src, dst;
 178         unsigned short src_bidx, dst_bidx;
 179         unsigned short src_cidx, dst_cidx;
 180         unsigned int data_type;
 181         unsigned short acnt;
 182         unsigned int count;
 183         unsigned int fifo_level;
 184
 185         period_size = snd_pcm_lib_period_bytes(substream);
 186         dma_offset = prtd->period * period_size;
 187         dma_pos = runtime->dma_addr + dma_offset;
 188         fifo_level = prtd->params->fifo_level;
 189
 190         pr_debug("davinci_pcm: audio_set_dma_params_play channel = %d "
 191                 "dma_ptr = %x period_size=%x\n", prtd->asp_link[0], dma_pos,
 192                 period_size);
 193
 194         data_type = prtd->params->data_type;
 195         count = period_size / data_type;
 196         if (fifo_level)
 197                 count /= fifo_level;
 198
 199         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 200                 src = dma_pos;
 201                 dst = prtd->params->dma_addr;
 202                 src_bidx = data_type;
 203                 dst_bidx = 0;
 204                 src_cidx = data_type * fifo_level;
 205                 dst_cidx = 0;
 206         } else {
 207                 src = prtd->params->dma_addr;
 208                 dst = dma_pos;
 209                 src_bidx = 0;
 210                 dst_bidx = data_type;
 211                 src_cidx = 0;
 212                 dst_cidx = data_type * fifo_level;
 213         }
 214
 215         acnt = prtd->params->acnt;
 216         edma_set_src(prtd->asp_link[0], src, INCR, W8BIT);
 217         edma_set_dest(prtd->asp_link[0], dst, INCR, W8BIT);
 218
 219         edma_set_src_index(prtd->asp_link[0], src_bidx, src_cidx);
 220         edma_set_dest_index(prtd->asp_link[0], dst_bidx, dst_cidx);
 221
 222         if (!fifo_level)
 223                 edma_set_transfer_params(prtd->asp_link[0], acnt, count, 1, 0,
 224                                                         ASYNC);
 225         else
 226                 edma_set_transfer_params(prtd->asp_link[0], acnt, fifo_level,
 227                                                         count, fifo_level,
 228                                                         ABSYNC);
 229 }
 230
 231 static void davinci_pcm_dma_irq(unsigned link, u16 ch_status, void *data)
 232 {
 233         struct snd_pcm_substream *substream = data;
 234         struct davinci_runtime_data *prtd = substream->runtime->private_data;
 235
 236         print_buf_info(prtd->ram_channel, "i ram_channel");
 237         pr_debug("davinci_pcm: link=%d, status=0x%x\n", link, ch_status);
 238
 239         if (unlikely(ch_status != DMA_COMPLETE))
 240                 return;
 241
 242         if (snd_pcm_running(substream)) {
 243                 spin_lock(&prtd->lock);
 244                 if (prtd->ram_channel < 0) {
 245                         /* No ping/pong must fix up link dma data*/
 246                         davinci_pcm_enqueue_dma(substream);
 247                 }
 248                 davinci_pcm_period_elapsed(substream);
 249                 spin_unlock(&prtd->lock);
 250                 snd_pcm_period_elapsed(substream);
 251         }
 252 }
 253
 254 #ifdef CONFIG_GENERIC_ALLOCATOR
 255 static int allocate_sram(struct snd_pcm_substream *substream,
 256                 struct gen_pool *sram_pool, unsigned size,
 257                 struct snd_pcm_hardware *ppcm)
 258 {
 259         struct snd_dma_buffer *buf = &substream->dma_buffer;
 260         struct snd_dma_buffer *iram_dma = NULL;
 261         dma_addr_t iram_phys = 0;
 262         void *iram_virt = NULL;
 263
 264         if (buf->private_data || !size)
 265                 return 0;
 266
 267         ppcm->period_bytes_max = size;
 268         iram_virt = (void *)gen_pool_alloc(sram_pool, size);
 269         if (!iram_virt)
 270                 goto exit1;
 271         iram_phys = gen_pool_virt_to_phys(sram_pool, (unsigned)iram_virt);
 272         iram_dma = kzalloc(sizeof(*iram_dma), GFP_KERNEL);
 273         if (!iram_dma)
 274                 goto exit2;
 275         iram_dma->area = iram_virt;
 276         iram_dma->addr = iram_phys;
 277         memset(iram_dma->area, 0, size);
 278         iram_dma->bytes = size;
 279         buf->private_data = iram_dma;
 280         return 0;
 281 exit2:
 282         if (iram_virt)
 283                 gen_pool_free(sram_pool, (unsigned)iram_virt, size);
 284 exit1:
 285         return -ENOMEM;
 286 }
 287
 288 static void davinci_free_sram(struct snd_pcm_substream *substream,
 289                               struct snd_dma_buffer *iram_dma)
 290 {
 291         struct davinci_runtime_data *prtd = substream->runtime->private_data;
 292         struct gen_pool *sram_pool = prtd->params->sram_pool;
 293
 294         gen_pool_free(sram_pool, (unsigned) iram_dma->area, iram_dma->bytes);
 295 }
 296 #else
 297 static int allocate_sram(struct snd_pcm_substream *substream,
 298                 struct gen_pool *sram_pool, unsigned size,
 299                 struct snd_pcm_hardware *ppcm)
 300 {
 301         return 0;
 302 }
 303
 304 static void davinci_free_sram(struct snd_pcm_substream *substream,
 305                               struct snd_dma_buffer *iram_dma)
 306 {
 307 }
 308 #endif
 309
 310 /*
 311  * Only used with ping/pong.
 312  * This is called after runtime->dma_addr, period_bytes and data_type are valid
 313  */
 314 static int ping_pong_dma_setup(struct snd_pcm_substream *substream)
 315 {
 316         unsigned short ram_src_cidx, ram_dst_cidx;
 317         struct snd_pcm_runtime *runtime = substream->runtime;
 318         struct davinci_runtime_data *prtd = runtime->private_data;
 319         struct snd_dma_buffer *iram_dma =
 320                 (struct snd_dma_buffer *)substream->dma_buffer.private_data;
 321         struct davinci_pcm_dma_params *params = prtd->params;
 322         unsigned int data_type = params->data_type;
 323         unsigned int acnt = params->acnt;
 324         /* divide by 2 for ping/pong */
 325         unsigned int ping_size = snd_pcm_lib_period_bytes(substream) >> 1;
 326         unsigned int fifo_level = prtd->params->fifo_level;
 327         unsigned int count;
 328         if ((data_type == 0) || (data_type > 4)) {
 329                 printk(KERN_ERR "%s: data_type=%i\n", __func__, data_type);
 330                 return -EINVAL;
 331         }
 332         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 333                 dma_addr_t asp_src_pong = iram_dma->addr + ping_size;
 334                 ram_src_cidx = ping_size;
 335                 ram_dst_cidx = -ping_size;
 336                 edma_set_src(prtd->asp_link[1], asp_src_pong, INCR, W8BIT);
 337
 338                 edma_set_src_index(prtd->asp_link[0], data_type,
 339                                 data_type * fifo_level);
 340                 edma_set_src_index(prtd->asp_link[1], data_type,
 341                                 data_type * fifo_level);
 342
 343                 edma_set_src(prtd->ram_link, runtime->dma_addr, INCR, W32BIT);
 344         } else {
 345                 dma_addr_t asp_dst_pong = iram_dma->addr + ping_size;
 346                 ram_src_cidx = -ping_size;
 347                 ram_dst_cidx = ping_size;
 348                 edma_set_dest(prtd->asp_link[1], asp_dst_pong, INCR, W8BIT);
 349
 350                 edma_set_dest_index(prtd->asp_link[0], data_type,
 351                                 data_type * fifo_level);
 352                 edma_set_dest_index(prtd->asp_link[1], data_type,
 353                                 data_type * fifo_level);
 354
 355                 edma_set_dest(prtd->ram_link, runtime->dma_addr, INCR, W32BIT);
 356         }
 357
 358         if (!fifo_level) {
 359                 count = ping_size / data_type;
 360                 edma_set_transfer_params(prtd->asp_link[0], acnt, count,
 361                                 1, 0, ASYNC);
 362                 edma_set_transfer_params(prtd->asp_link[1], acnt, count,
 363                                 1, 0, ASYNC);
 364         } else {
 365                 count = ping_size / (data_type * fifo_level);
 366                 edma_set_transfer_params(prtd->asp_link[0], acnt, fifo_level,
 367                                 count, fifo_level, ABSYNC);
 368                 edma_set_transfer_params(prtd->asp_link[1], acnt, fifo_level,
 369                                 count, fifo_level, ABSYNC);
 370         }
 371
 372         edma_set_src_index(prtd->ram_link, ping_size, ram_src_cidx);
 373         edma_set_dest_index(prtd->ram_link, ping_size, ram_dst_cidx);
 374         edma_set_transfer_params(prtd->ram_link, ping_size, 2,
 375                         runtime->periods, 2, ASYNC);
 376
 377         /* init master params */
 378         edma_read_slot(prtd->asp_link[0], &prtd->asp_params);
 379         edma_read_slot(prtd->ram_link, &prtd->ram_params);
 380         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 381                 struct edmacc_param p_ram;
 382                 /* Copy entire iram buffer before playback started */
 383                 prtd->ram_params.a_b_cnt = (1 << 16) | (ping_size << 1);
 384                 /* 0 dst_bidx */
 385                 prtd->ram_params.src_dst_bidx = (ping_size << 1);
 386                 /* 0 dst_cidx */
 387                 prtd->ram_params.src_dst_cidx = (ping_size << 1);
 388                 prtd->ram_params.ccnt = 1;
 389
 390                 /* Skip 1st period */
 391                 edma_read_slot(prtd->ram_link, &p_ram);
 392                 p_ram.src += (ping_size << 1);
 393                 p_ram.ccnt -= 1;
 394                 edma_write_slot(prtd->ram_link2, &p_ram);
 395                 /*
 396                  * When 1st started, ram -> iram dma channel will fill the
 397                  * entire iram.  Then, whenever a ping/pong asp buffer finishes,
 398                  * 1/2 iram will be filled.
 399                  */
 400                 prtd->ram_params.link_bcntrld =
 401                         EDMA_CHAN_SLOT(prtd->ram_link2) << 5;
 402         }
 403         return 0;
 404 }
 405
 406 /* 1 asp tx or rx channel using 2 parameter channels
 407  * 1 ram to/from iram channel using 1 parameter channel
 408  *
 409  * Playback
 410  * ram copy channel kicks off first,
 411  * 1st ram copy of entire iram buffer completion kicks off asp channel
 412  * asp tcc always kicks off ram copy of 1/2 iram buffer
 413  *
 414  * Record
 415  * asp channel starts, tcc kicks off ram copy
 416  */
 417 static int request_ping_pong(struct snd_pcm_substream *substream,
 418                 struct davinci_runtime_data *prtd,
 419                 struct snd_dma_buffer *iram_dma)
 420 {
 421         dma_addr_t asp_src_ping;
 422         dma_addr_t asp_dst_ping;
 423         int ret;
 424         struct davinci_pcm_dma_params *params = prtd->params;
 425
 426         /* Request ram master channel */
 427         ret = prtd->ram_channel = edma_alloc_channel(EDMA_CHANNEL_ANY,
 428                                   davinci_pcm_dma_irq, substream,
 429                                   prtd->params->ram_chan_q);
 430         if (ret < 0)
 431                 goto exit1;
 432
 433         /* Request ram link channel */
 434         ret = prtd->ram_link = edma_alloc_slot(
 435                         EDMA_CTLR(prtd->ram_channel), EDMA_SLOT_ANY);
 436         if (ret < 0)
 437                 goto exit2;
 438
 439         ret = prtd->asp_link[1] = edma_alloc_slot(
 440                         EDMA_CTLR(prtd->asp_channel), EDMA_SLOT_ANY);
 441         if (ret < 0)
 442                 goto exit3;
 443
 444         prtd->ram_link2 = -1;
 445         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 446                 ret = prtd->ram_link2 = edma_alloc_slot(
 447                         EDMA_CTLR(prtd->ram_channel), EDMA_SLOT_ANY);
 448                 if (ret < 0)
 449                         goto exit4;
 450         }
 451         /* circle ping-pong buffers */
 452         edma_link(prtd->asp_link[0], prtd->asp_link[1]);
 453         edma_link(prtd->asp_link[1], prtd->asp_link[0]);
 454         /* circle ram buffers */
 455         edma_link(prtd->ram_link, prtd->ram_link);
 456
 457         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 458                 asp_src_ping = iram_dma->addr;
 459                 asp_dst_ping = params->dma_addr;        /* fifo */
 460         } else {
 461                 asp_src_ping = params->dma_addr;        /* fifo */
 462                 asp_dst_ping = iram_dma->addr;
 463         }
 464         /* ping */
 465         edma_set_src(prtd->asp_link[0], asp_src_ping, INCR, W16BIT);
 466         edma_set_dest(prtd->asp_link[0], asp_dst_ping, INCR, W16BIT);
 467         edma_set_src_index(prtd->asp_link[0], 0, 0);
 468         edma_set_dest_index(prtd->asp_link[0], 0, 0);
 469
 470         edma_read_slot(prtd->asp_link[0], &prtd->asp_params);
 471         prtd->asp_params.opt &= ~(TCCMODE | EDMA_TCC(0x3f) | TCINTEN);
 472         prtd->asp_params.opt |= TCCHEN |
 473                 EDMA_TCC(prtd->ram_channel & 0x3f);
 474         edma_write_slot(prtd->asp_link[0], &prtd->asp_params);
 475
 476         /* pong */
 477         edma_set_src(prtd->asp_link[1], asp_src_ping, INCR, W16BIT);
 478         edma_set_dest(prtd->asp_link[1], asp_dst_ping, INCR, W16BIT);
 479         edma_set_src_index(prtd->asp_link[1], 0, 0);
 480         edma_set_dest_index(prtd->asp_link[1], 0, 0);
 481
 482         edma_read_slot(prtd->asp_link[1], &prtd->asp_params);
 483         prtd->asp_params.opt &= ~(TCCMODE | EDMA_TCC(0x3f));
 484         /* interrupt after every pong completion */
 485         prtd->asp_params.opt |= TCINTEN | TCCHEN |
 486                 EDMA_TCC(prtd->ram_channel & 0x3f);
 487         edma_write_slot(prtd->asp_link[1], &prtd->asp_params);
 488
 489         /* ram */
 490         edma_set_src(prtd->ram_link, iram_dma->addr, INCR, W32BIT);
 491         edma_set_dest(prtd->ram_link, iram_dma->addr, INCR, W32BIT);
 492         pr_debug("%s: audio dma channels/slots in use for ram:%u %u %u,"
 493                 "for asp:%u %u %u\n", __func__,
 494                 prtd->ram_channel, prtd->ram_link, prtd->ram_link2,
 495                 prtd->asp_channel, prtd->asp_link[0],
 496                 prtd->asp_link[1]);
 497         return 0;
 498 exit4:
 499         edma_free_channel(prtd->asp_link[1]);
 500         prtd->asp_link[1] = -1;
 501 exit3:
 502         edma_free_channel(prtd->ram_link);
 503         prtd->ram_link = -1;
 504 exit2:
 505         edma_free_channel(prtd->ram_channel);
 506         prtd->ram_channel = -1;
 507 exit1:
 508         return ret;
 509 }
 510
 511 static int davinci_pcm_dma_request(struct snd_pcm_substream *substream)
 512 {
 513         struct snd_dma_buffer *iram_dma;
 514         struct davinci_runtime_data *prtd = substream->runtime->private_data;
 515         struct davinci_pcm_dma_params *params = prtd->params;
 516         int ret;
 517
 518         if (!params)
 519                 return -ENODEV;
 520
 521         /* Request asp master DMA channel */
 522         ret = prtd->asp_channel = edma_alloc_channel(params->channel,
 523                         davinci_pcm_dma_irq, substream,
 524                         prtd->params->asp_chan_q);
 525         if (ret < 0)
 526                 goto exit1;
 527
 528         /* Request asp link channels */
 529         ret = prtd->asp_link[0] = edma_alloc_slot(
 530                         EDMA_CTLR(prtd->asp_channel), EDMA_SLOT_ANY);
 531         if (ret < 0)
 532                 goto exit2;
 533
 534         iram_dma = (struct snd_dma_buffer *)substream->dma_buffer.private_data;
 535         if (iram_dma) {
 536                 if (request_ping_pong(substream, prtd, iram_dma) == 0)
 537                         return 0;
 538                 printk(KERN_WARNING "%s: dma channel allocation failed,"
 539                                 "not using sram\n", __func__);
 540         }
 541
 542         /* Issue transfer completion IRQ when the channel completes a
 543          * transfer, then always reload from the same slot (by a kind
 544          * of loopback link).  The completion IRQ handler will update
 545          * the reload slot with a new buffer.
 546          *
 547          * REVISIT save p_ram here after setting up everything except
 548          * the buffer and its length (ccnt) ... use it as a template
 549          * so davinci_pcm_enqueue_dma() takes less time in IRQ.
 550          */
 551         edma_read_slot(prtd->asp_link[0], &prtd->asp_params);
 552         prtd->asp_params.opt |= TCINTEN |
 553                 EDMA_TCC(EDMA_CHAN_SLOT(prtd->asp_channel));
 554         prtd->asp_params.link_bcntrld = EDMA_CHAN_SLOT(prtd->asp_link[0]) << 5;
 555         edma_write_slot(prtd->asp_link[0], &prtd->asp_params);
 556         return 0;
 557 exit2:
 558         edma_free_channel(prtd->asp_channel);
 559         prtd->asp_channel = -1;
 560 exit1:
 561         return ret;
 562 }
 563
 564 static int davinci_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 565 {
 566         struct davinci_runtime_data *prtd = substream->runtime->private_data;
 567         int ret = 0;
 568
 569         spin_lock(&prtd->lock);
 570
 571         switch (cmd) {
 572         case SNDRV_PCM_TRIGGER_START:
 573                 edma_start(prtd->asp_channel);
 574                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
 575                     prtd->ram_channel >= 0) {
 576                         /* copy 1st iram buffer */
 577                         edma_start(prtd->ram_channel);
 578                 }
 579                 break;
 580         case SNDRV_PCM_TRIGGER_RESUME:
 581         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 582                 edma_resume(prtd->asp_channel);
 583                 break;
 584         case SNDRV_PCM_TRIGGER_STOP:
 585         case SNDRV_PCM_TRIGGER_SUSPEND:
 586         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 587                 edma_pause(prtd->asp_channel);
 588                 break;
 589         default:
 590                 ret = -EINVAL;
 591                 break;
 592         }
 593
 594         spin_unlock(&prtd->lock);
 595
 596         return ret;
 597 }
 598
 599 static int davinci_pcm_prepare(struct snd_pcm_substream *substream)
 600 {
 601         struct davinci_runtime_data *prtd = substream->runtime->private_data;
 602
 603         davinci_pcm_period_reset(substream);
 604         if (prtd->ram_channel >= 0) {
 605                 int ret = ping_pong_dma_setup(substream);
 606                 if (ret < 0)
 607                         return ret;
 608
 609                 edma_write_slot(prtd->ram_channel, &prtd->ram_params);
 610                 edma_write_slot(prtd->asp_channel, &prtd->asp_params);
 611
 612                 print_buf_info(prtd->ram_channel, "ram_channel");
 613                 print_buf_info(prtd->ram_link, "ram_link");
 614                 print_buf_info(prtd->ram_link2, "ram_link2");
 615                 print_buf_info(prtd->asp_channel, "asp_channel");
 616                 print_buf_info(prtd->asp_link[0], "asp_link[0]");
 617                 print_buf_info(prtd->asp_link[1], "asp_link[1]");
 618
 619                 /*
 620                  * There is a phase offset of 2 periods between the position
 621                  * used by dma setup and the position reported in the pointer
 622                  * function.
 623                  *
 624                  * The phase offset, when not using ping-pong buffers, is due to
 625                  * the two consecutive calls to davinci_pcm_enqueue_dma() below.
 626                  *
 627                  * Whereas here, with ping-pong buffers, the phase is due to
 628                  * there being an entire buffer transfer complete before the
 629                  * first dma completion event triggers davinci_pcm_dma_irq().
 630                  */
 631                 davinci_pcm_period_elapsed(substream);
 632                 davinci_pcm_period_elapsed(substream);
 633
 634                 return 0;
 635         }
 636         davinci_pcm_enqueue_dma(substream);
 637         davinci_pcm_period_elapsed(substream);
 638
 639         /* Copy self-linked parameter RAM entry into master channel */
 640         edma_read_slot(prtd->asp_link[0], &prtd->asp_params);
 641         edma_write_slot(prtd->asp_channel, &prtd->asp_params);
 642         davinci_pcm_enqueue_dma(substream);
 643         davinci_pcm_period_elapsed(substream);
 644
 645         return 0;
 646 }
 647
 648 static snd_pcm_uframes_t
 649 davinci_pcm_pointer(struct snd_pcm_substream *substream)
 650 {
 651         struct snd_pcm_runtime *runtime = substream->runtime;
 652         struct davinci_runtime_data *prtd = runtime->private_data;
 653         unsigned int offset;
 654         int asp_count;
 655         unsigned int period_size = snd_pcm_lib_period_bytes(substream);
 656
 657         /*
 658          * There is a phase offset of 2 periods between the position used by dma
 659          * setup and the position reported in the pointer function. Either +2 in
 660          * the dma setup or -2 here in the pointer function (with wrapping,
 661          * both) accounts for this offset -- choose the latter since it makes
 662          * the first-time setup clearer.
 663          */
 664         spin_lock(&prtd->lock);
 665         asp_count = prtd->period - 2;
 666         spin_unlock(&prtd->lock);
 667
 668         if (asp_count < 0)
 669                 asp_count += runtime->periods;
 670         asp_count *= period_size;
 671
 672         offset = bytes_to_frames(runtime, asp_count);
 673         if (offset >= runtime->buffer_size)
 674                 offset = 0;
 675
 676         return offset;
 677 }
 678
 679 static int davinci_pcm_open(struct snd_pcm_substream *substream)
 680 {
 681         struct snd_pcm_runtime *runtime = substream->runtime;
 682         struct davinci_runtime_data *prtd;
 683         struct snd_pcm_hardware *ppcm;
 684         int ret = 0;
 685         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 686         struct davinci_pcm_dma_params *pa;
 687         struct davinci_pcm_dma_params *params;
 688
 689         pa = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
 690         if (!pa)
 691                 return -ENODEV;
 692         params = &pa[substream->stream];
 693
 694         ppcm = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ?
 695                         &pcm_hardware_playback : &pcm_hardware_capture;
 696         allocate_sram(substream, params->sram_pool, params->sram_size, ppcm);
 697         snd_soc_set_runtime_hwparams(substream, ppcm);
 698         /* ensure that buffer size is a multiple of period size */
 699         ret = snd_pcm_hw_constraint_integer(runtime,
 700                                                 SNDRV_PCM_HW_PARAM_PERIODS);
 701         if (ret < 0)
 702                 return ret;
 703
 704         prtd = kzalloc(sizeof(struct davinci_runtime_data), GFP_KERNEL);
 705         if (prtd == NULL)
 706                 return -ENOMEM;
 707
 708         spin_lock_init(&prtd->lock);
 709         prtd->params = params;
 710         prtd->asp_channel = -1;
 711         prtd->asp_link[0] = prtd->asp_link[1] = -1;
 712         prtd->ram_channel = -1;
 713         prtd->ram_link = -1;
 714         prtd->ram_link2 = -1;
 715
 716         runtime->private_data = prtd;
 717
 718         ret = davinci_pcm_dma_request(substream);
 719         if (ret) {
 720                 printk(KERN_ERR "davinci_pcm: Failed to get dma channels\n");
 721                 kfree(prtd);
 722         }
 723
 724         return ret;
 725 }
 726
 727 static int davinci_pcm_close(struct snd_pcm_substream *substream)
 728 {
 729         struct snd_pcm_runtime *runtime = substream->runtime;
 730         struct davinci_runtime_data *prtd = runtime->private_data;
 731
 732         if (prtd->ram_channel >= 0)
 733                 edma_stop(prtd->ram_channel);
 734         if (prtd->asp_channel >= 0)
 735                 edma_stop(prtd->asp_channel);
 736         if (prtd->asp_link[0] >= 0)
 737                 edma_unlink(prtd->asp_link[0]);
 738         if (prtd->asp_link[1] >= 0)
 739                 edma_unlink(prtd->asp_link[1]);
 740         if (prtd->ram_link >= 0)
 741                 edma_unlink(prtd->ram_link);
 742
 743         if (prtd->asp_link[0] >= 0)
 744                 edma_free_slot(prtd->asp_link[0]);
 745         if (prtd->asp_link[1] >= 0)
 746                 edma_free_slot(prtd->asp_link[1]);
 747         if (prtd->asp_channel >= 0)
 748                 edma_free_channel(prtd->asp_channel);
 749         if (prtd->ram_link >= 0)
 750                 edma_free_slot(prtd->ram_link);
 751         if (prtd->ram_link2 >= 0)
 752                 edma_free_slot(prtd->ram_link2);
 753         if (prtd->ram_channel >= 0)
 754                 edma_free_channel(prtd->ram_channel);
 755
 756         kfree(prtd);
 757
 758         return 0;
 759 }
 760
 761 static int davinci_pcm_hw_params(struct snd_pcm_substream *substream,
 762                                  struct snd_pcm_hw_params *hw_params)
 763 {
 764         return snd_pcm_lib_malloc_pages(substream,
 765                                         params_buffer_bytes(hw_params));
 766 }
 767
 768 static int davinci_pcm_hw_free(struct snd_pcm_substream *substream)
 769 {
 770         return snd_pcm_lib_free_pages(substream);
 771 }
 772
 773 static int davinci_pcm_mmap(struct snd_pcm_substream *substream,
 774                             struct vm_area_struct *vma)
 775 {
 776         struct snd_pcm_runtime *runtime = substream->runtime;
 777
 778         return dma_mmap_writecombine(substream->pcm->card->dev, vma,
 779                                      runtime->dma_area,
 780                                      runtime->dma_addr,
 781                                      runtime->dma_bytes);
 782 }
 783
 784 static struct snd_pcm_ops davinci_pcm_ops = {
 785         .open =         davinci_pcm_open,
 786         .close =        davinci_pcm_close,
 787         .ioctl =        snd_pcm_lib_ioctl,
 788         .hw_params =    davinci_pcm_hw_params,
 789         .hw_free =      davinci_pcm_hw_free,
 790         .prepare =      davinci_pcm_prepare,
 791         .trigger =      davinci_pcm_trigger,
 792         .pointer =      davinci_pcm_pointer,
 793         .mmap =         davinci_pcm_mmap,
 794 };
 795
 796 static int davinci_pcm_preallocate_dma_buffer(struct snd_pcm *pcm, int stream,
 797                 size_t size)
 798 {
 799         struct snd_pcm_substream *substream = pcm->streams[stream].substream;
 800         struct snd_dma_buffer *buf = &substream->dma_buffer;
 801
 802         buf->dev.type = SNDRV_DMA_TYPE_DEV;
 803         buf->dev.dev = pcm->card->dev;
 804         buf->private_data = NULL;
 805         buf->area = dma_alloc_writecombine(pcm->card->dev, size,
 806                                            &buf->addr, GFP_KERNEL);
 807
 808         pr_debug("davinci_pcm: preallocate_dma_buffer: area=%p, addr=%p, "
 809                 "size=%d\n", (void *) buf->area, (void *) buf->addr, size);
 810
 811         if (!buf->area)
 812                 return -ENOMEM;
 813
 814         buf->bytes = size;
 815         return 0;
 816 }
 817
 818 static void davinci_pcm_free(struct snd_pcm *pcm)
 819 {
 820         struct snd_pcm_substream *substream;
 821         struct snd_dma_buffer *buf;
 822         int stream;
 823
 824         for (stream = 0; stream < 2; stream++) {
 825                 struct snd_dma_buffer *iram_dma;
 826                 substream = pcm->streams[stream].substream;
 827                 if (!substream)
 828                         continue;
 829
 830                 buf = &substream->dma_buffer;
 831                 if (!buf->area)
 832                         continue;
 833
 834                 dma_free_writecombine(pcm->card->dev, buf->bytes,
 835                                       buf->area, buf->addr);
 836                 buf->area = NULL;
 837                 iram_dma = buf->private_data;
 838                 if (iram_dma) {
 839                         davinci_free_sram(substream, iram_dma);
 840                         kfree(iram_dma);
 841                 }
 842         }
 843 }
 844
 845 static u64 davinci_pcm_dmamask = DMA_BIT_MASK(32);
 846
 847 static int davinci_pcm_new(struct snd_soc_pcm_runtime *rtd)
 848 {
 849         struct snd_card *card = rtd->card->snd_card;
 850         struct snd_pcm *pcm = rtd->pcm;
 851         int ret;
 852
 853         if (!card->dev->dma_mask)
 854                 card->dev->dma_mask = &davinci_pcm_dmamask;
 855         if (!card->dev->coherent_dma_mask)
 856                 card->dev->coherent_dma_mask = DMA_BIT_MASK(32);
 857
 858         if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
 859                 ret = davinci_pcm_preallocate_dma_buffer(pcm,
 860                         SNDRV_PCM_STREAM_PLAYBACK,
 861                         pcm_hardware_playback.buffer_bytes_max);
 862                 if (ret)
 863                         return ret;
 864         }
 865
 866         if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
 867                 ret = davinci_pcm_preallocate_dma_buffer(pcm,
 868                         SNDRV_PCM_STREAM_CAPTURE,
 869                         pcm_hardware_capture.buffer_bytes_max);
 870                 if (ret)
 871                         return ret;
 872         }
 873
 874         return 0;
 875 }
 876
 877 static struct snd_soc_platform_driver davinci_soc_platform = {
 878         .ops =          &davinci_pcm_ops,
 879         .pcm_new =      davinci_pcm_new,
 880         .pcm_free =     davinci_pcm_free,
 881 };
 882
 883 int davinci_soc_platform_register(struct device *dev)
 884 {
 885         return snd_soc_register_platform(dev, &davinci_soc_platform);
 886 }
 887 EXPORT_SYMBOL_GPL(davinci_soc_platform_register);
 888
 889 void davinci_soc_platform_unregister(struct device *dev)
 890 {
 891         snd_soc_unregister_platform(dev);
 892 }
 893 EXPORT_SYMBOL_GPL(davinci_soc_platform_unregister);
 894
 895 MODULE_AUTHOR("Vladimir Barinov");
 896 MODULE_DESCRIPTION("TI DAVINCI PCM DMA module");
 897 MODULE_LICENSE("GPL");