sound/soc/sh/dma-sh7760.c

   1 /*
   2  * SH7760 ("camelot") DMABRG audio DMA unit support
   3  *
   4  * Copyright (C) 2007 Manuel Lauss <mano@roarinelk.homelinux.net>
   5  *  licensed under the terms outlined in the file COPYING at the root
   6  *  of the linux kernel sources.
   7  *
   8  * The SH7760 DMABRG provides 4 dma channels (2x rec, 2x play), which
   9  * trigger an interrupt when one half of the programmed transfer size
  10  * has been xmitted.
  11  *
  12  * FIXME: little-endian only for now
  13  */
  14
  15 #include <linux/module.h>
  16 #include <linux/gfp.h>
  17 #include <linux/init.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/dma-mapping.h>
  20 #include <sound/core.h>
  21 #include <sound/pcm.h>
  22 #include <sound/pcm_params.h>
  23 #include <sound/soc.h>
  24 #include <asm/dmabrg.h>
  25
  26
  27 /* registers and bits */
  28 #define BRGATXSAR       0x00
  29 #define BRGARXDAR       0x04
  30 #define BRGATXTCR       0x08
  31 #define BRGARXTCR       0x0C
  32 #define BRGACR          0x10
  33 #define BRGATXTCNT      0x14
  34 #define BRGARXTCNT      0x18
  35
  36 #define ACR_RAR         (1 << 18)
  37 #define ACR_RDS         (1 << 17)
  38 #define ACR_RDE         (1 << 16)
  39 #define ACR_TAR         (1 << 2)
  40 #define ACR_TDS         (1 << 1)
  41 #define ACR_TDE         (1 << 0)
  42
  43 /* receiver/transmitter data alignment */
  44 #define ACR_RAM_NONE    (0 << 24)
  45 #define ACR_RAM_4BYTE   (1 << 24)
  46 #define ACR_RAM_2WORD   (2 << 24)
  47 #define ACR_TAM_NONE    (0 << 8)
  48 #define ACR_TAM_4BYTE   (1 << 8)
  49 #define ACR_TAM_2WORD   (2 << 8)
  50
  51
  52 struct camelot_pcm {
  53         unsigned long mmio;  /* DMABRG audio channel control reg MMIO */
  54         unsigned int txid;    /* ID of first DMABRG IRQ for this unit */
  55
  56         struct snd_pcm_substream *tx_ss;
  57         unsigned long tx_period_size;
  58         unsigned int  tx_period;
  59
  60         struct snd_pcm_substream *rx_ss;
  61         unsigned long rx_period_size;
  62         unsigned int  rx_period;
  63
  64 } cam_pcm_data[2] = {
  65         {
  66                 .mmio   =       0xFE3C0040,
  67                 .txid   =       DMABRGIRQ_A0TXF,
  68         },
  69         {
  70                 .mmio   =       0xFE3C0060,
  71                 .txid   =       DMABRGIRQ_A1TXF,
  72         },
  73 };
  74
  75 #define BRGREG(x)       (*(unsigned long *)(cam->mmio + (x)))
  76
  77 /*
  78  * set a minimum of 16kb per period, to avoid interrupt-"storm" and
  79  * resulting skipping. In general, the bigger the minimum size, the
  80  * better for overall system performance. (The SH7760 is a puny CPU
  81  * with a slow SDRAM interface and poor internal bus bandwidth,
  82  * *especially* when the LCDC is active).  The minimum for the DMAC
  83  * is 8 bytes; 16kbytes are enough to get skip-free playback of a
  84  * 44kHz/16bit/stereo MP3 on a lightly loaded system, and maintain
  85  * reasonable responsiveness in MPlayer.
  86  */
  87 #define DMABRG_PERIOD_MIN               16 * 1024
  88 #define DMABRG_PERIOD_MAX               0x03fffffc
  89 #define DMABRG_PREALLOC_BUFFER          32 * 1024
  90 #define DMABRG_PREALLOC_BUFFER_MAX      32 * 1024
  91
  92 /* support everything the SSI supports */
  93 #define DMABRG_RATES    \
  94         SNDRV_PCM_RATE_8000_192000
  95
  96 #define DMABRG_FMTS     \
  97         (SNDRV_PCM_FMTBIT_S8      | SNDRV_PCM_FMTBIT_U8      |  \
  98          SNDRV_PCM_FMTBIT_S16_LE  | SNDRV_PCM_FMTBIT_U16_LE  |  \
  99          SNDRV_PCM_FMTBIT_S20_3LE | SNDRV_PCM_FMTBIT_U20_3LE |  \
 100          SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_U24_3LE |  \
 101          SNDRV_PCM_FMTBIT_S32_LE  | SNDRV_PCM_FMTBIT_U32_LE)
 102
 103 static struct snd_pcm_hardware camelot_pcm_hardware = {
 104         .info = (SNDRV_PCM_INFO_MMAP |
 105                 SNDRV_PCM_INFO_INTERLEAVED |
 106                 SNDRV_PCM_INFO_BLOCK_TRANSFER |
 107                 SNDRV_PCM_INFO_MMAP_VALID |
 108                 SNDRV_PCM_INFO_BATCH),
 109         .formats =      DMABRG_FMTS,
 110         .rates =        DMABRG_RATES,
 111         .rate_min =             8000,
 112         .rate_max =             192000,
 113         .channels_min =         2,
 114         .channels_max =         8,              /* max of the SSI */
 115         .buffer_bytes_max =     DMABRG_PERIOD_MAX,
 116         .period_bytes_min =     DMABRG_PERIOD_MIN,
 117         .period_bytes_max =     DMABRG_PERIOD_MAX / 2,
 118         .periods_min =          2,
 119         .periods_max =          2,
 120         .fifo_size =            128,
 121 };
 122
 123 static void camelot_txdma(void *data)
 124 {
 125         struct camelot_pcm *cam = data;
 126         cam->tx_period ^= 1;
 127         snd_pcm_period_elapsed(cam->tx_ss);
 128 }
 129
 130 static void camelot_rxdma(void *data)
 131 {
 132         struct camelot_pcm *cam = data;
 133         cam->rx_period ^= 1;
 134         snd_pcm_period_elapsed(cam->rx_ss);
 135 }
 136
 137 static int camelot_pcm_open(struct snd_pcm_substream *substream)
 138 {
 139         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 140         struct camelot_pcm *cam = &cam_pcm_data[rtd->dai->cpu_dai->id];
 141         int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1;
 142         int ret, dmairq;
 143
 144         snd_soc_set_runtime_hwparams(substream, &camelot_pcm_hardware);
 145
 146         /* DMABRG buffer half/full events */
 147         dmairq = (recv) ? cam->txid + 2 : cam->txid;
 148         if (recv) {
 149                 cam->rx_ss = substream;
 150                 ret = dmabrg_request_irq(dmairq, camelot_rxdma, cam);
 151                 if (unlikely(ret)) {
 152                         pr_debug("audio unit %d irqs already taken!\n",
 153                              rtd->dai->cpu_dai->id);
 154                         return -EBUSY;
 155                 }
 156                 (void)dmabrg_request_irq(dmairq + 1,camelot_rxdma, cam);
 157         } else {
 158                 cam->tx_ss = substream;
 159                 ret = dmabrg_request_irq(dmairq, camelot_txdma, cam);
 160                 if (unlikely(ret)) {
 161                         pr_debug("audio unit %d irqs already taken!\n",
 162                              rtd->dai->cpu_dai->id);
 163                         return -EBUSY;
 164                 }
 165                 (void)dmabrg_request_irq(dmairq + 1, camelot_txdma, cam);
 166         }
 167         return 0;
 168 }
 169
 170 static int camelot_pcm_close(struct snd_pcm_substream *substream)
 171 {
 172         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 173         struct camelot_pcm *cam = &cam_pcm_data[rtd->dai->cpu_dai->id];
 174         int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1;
 175         int dmairq;
 176
 177         dmairq = (recv) ? cam->txid + 2 : cam->txid;
 178
 179         if (recv)
 180                 cam->rx_ss = NULL;
 181         else
 182                 cam->tx_ss = NULL;
 183
 184         dmabrg_free_irq(dmairq + 1);
 185         dmabrg_free_irq(dmairq);
 186
 187         return 0;
 188 }
 189
 190 static int camelot_hw_params(struct snd_pcm_substream *substream,
 191                              struct snd_pcm_hw_params *hw_params)
 192 {
 193         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 194         struct camelot_pcm *cam = &cam_pcm_data[rtd->dai->cpu_dai->id];
 195         int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1;
 196         int ret;
 197
 198         ret = snd_pcm_lib_malloc_pages(substream,
 199                                        params_buffer_bytes(hw_params));
 200         if (ret < 0)
 201                 return ret;
 202
 203         if (recv) {
 204                 cam->rx_period_size = params_period_bytes(hw_params);
 205                 cam->rx_period = 0;
 206         } else {
 207                 cam->tx_period_size = params_period_bytes(hw_params);
 208                 cam->tx_period = 0;
 209         }
 210         return 0;
 211 }
 212
 213 static int camelot_hw_free(struct snd_pcm_substream *substream)
 214 {
 215         return snd_pcm_lib_free_pages(substream);
 216 }
 217
 218 static int camelot_prepare(struct snd_pcm_substream *substream)
 219 {
 220         struct snd_pcm_runtime *runtime = substream->runtime;
 221         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 222         struct camelot_pcm *cam = &cam_pcm_data[rtd->dai->cpu_dai->id];
 223
 224         pr_debug("PCM data: addr 0x%08ulx len %d\n",
 225                  (u32)runtime->dma_addr, runtime->dma_bytes);
 226
 227         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 228                 BRGREG(BRGATXSAR) = (unsigned long)runtime->dma_area;
 229                 BRGREG(BRGATXTCR) = runtime->dma_bytes;
 230         } else {
 231                 BRGREG(BRGARXDAR) = (unsigned long)runtime->dma_area;
 232                 BRGREG(BRGARXTCR) = runtime->dma_bytes;
 233         }
 234
 235         return 0;
 236 }
 237
 238 static inline void dmabrg_play_dma_start(struct camelot_pcm *cam)
 239 {
 240         unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS);
 241         /* start DMABRG engine: XFER start, auto-addr-reload */
 242         BRGREG(BRGACR) = acr | ACR_TDE | ACR_TAR | ACR_TAM_2WORD;
 243 }
 244
 245 static inline void dmabrg_play_dma_stop(struct camelot_pcm *cam)
 246 {
 247         unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS);
 248         /* forcibly terminate data transmission */
 249         BRGREG(BRGACR) = acr | ACR_TDS;
 250 }
 251
 252 static inline void dmabrg_rec_dma_start(struct camelot_pcm *cam)
 253 {
 254         unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS);
 255         /* start DMABRG engine: recv start, auto-reload */
 256         BRGREG(BRGACR) = acr | ACR_RDE | ACR_RAR | ACR_RAM_2WORD;
 257 }
 258
 259 static inline void dmabrg_rec_dma_stop(struct camelot_pcm *cam)
 260 {
 261         unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS);
 262         /* forcibly terminate data receiver */
 263         BRGREG(BRGACR) = acr | ACR_RDS;
 264 }
 265
 266 static int camelot_trigger(struct snd_pcm_substream *substream, int cmd)
 267 {
 268         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 269         struct camelot_pcm *cam = &cam_pcm_data[rtd->dai->cpu_dai->id];
 270         int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1;
 271
 272         switch (cmd) {
 273         case SNDRV_PCM_TRIGGER_START:
 274                 if (recv)
 275                         dmabrg_rec_dma_start(cam);
 276                 else
 277                         dmabrg_play_dma_start(cam);
 278                 break;
 279         case SNDRV_PCM_TRIGGER_STOP:
 280                 if (recv)
 281                         dmabrg_rec_dma_stop(cam);
 282                 else
 283                         dmabrg_play_dma_stop(cam);
 284                 break;
 285         default:
 286                 return -EINVAL;
 287         }
 288
 289         return 0;
 290 }
 291
 292 static snd_pcm_uframes_t camelot_pos(struct snd_pcm_substream *substream)
 293 {
 294         struct snd_pcm_runtime *runtime = substream->runtime;
 295         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 296         struct camelot_pcm *cam = &cam_pcm_data[rtd->dai->cpu_dai->id];
 297         int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1;
 298         unsigned long pos;
 299
 300         /* cannot use the DMABRG pointer register: under load, by the
 301          * time ALSA comes around to read the register, it is already
 302          * far ahead (or worse, already done with the fragment) of the
 303          * position at the time the IRQ was triggered, which results in
 304          * fast-playback sound in my test application (ScummVM)
 305          */
 306         if (recv)
 307                 pos = cam->rx_period ? cam->rx_period_size : 0;
 308         else
 309                 pos = cam->tx_period ? cam->tx_period_size : 0;
 310
 311         return bytes_to_frames(runtime, pos);
 312 }
 313
 314 static struct snd_pcm_ops camelot_pcm_ops = {
 315         .open           = camelot_pcm_open,
 316         .close          = camelot_pcm_close,
 317         .ioctl          = snd_pcm_lib_ioctl,
 318         .hw_params      = camelot_hw_params,
 319         .hw_free        = camelot_hw_free,
 320         .prepare        = camelot_prepare,
 321         .trigger        = camelot_trigger,
 322         .pointer        = camelot_pos,
 323 };
 324
 325 static void camelot_pcm_free(struct snd_pcm *pcm)
 326 {
 327         snd_pcm_lib_preallocate_free_for_all(pcm);
 328 }
 329
 330 static int camelot_pcm_new(struct snd_card *card,
 331                            struct snd_soc_dai *dai,
 332                            struct snd_pcm *pcm)
 333 {
 334         /* dont use SNDRV_DMA_TYPE_DEV, since it will oops the SH kernel
 335          * in MMAP mode (i.e. aplay -M)
 336          */
 337         snd_pcm_lib_preallocate_pages_for_all(pcm,
 338                 SNDRV_DMA_TYPE_CONTINUOUS,
 339                 snd_dma_continuous_data(GFP_KERNEL),
 340                 DMABRG_PREALLOC_BUFFER, DMABRG_PREALLOC_BUFFER_MAX);
 341
 342         return 0;
 343 }
 344
 345 struct snd_soc_platform sh7760_soc_platform = {
 346         .name           = "sh7760-pcm",
 347         .pcm_ops        = &camelot_pcm_ops,
 348         .pcm_new        = camelot_pcm_new,
 349         .pcm_free       = camelot_pcm_free,
 350 };
 351 EXPORT_SYMBOL_GPL(sh7760_soc_platform);
 352
 353 static int __init sh7760_soc_platform_init(void)
 354 {
 355         return snd_soc_register_platform(&sh7760_soc_platform);
 356 }
 357 module_init(sh7760_soc_platform_init);
 358
 359 static void __exit sh7760_soc_platform_exit(void)
 360 {
 361         snd_soc_unregister_platform(&sh7760_soc_platform);
 362 }
 363 module_exit(sh7760_soc_platform_exit);
 364
 365 MODULE_LICENSE("GPL");
 366 MODULE_DESCRIPTION("SH7760 Audio DMA (DMABRG) driver");
 367 MODULE_AUTHOR("Manuel Lauss <mano@roarinelk.homelinux.net>");