搞定了2.6.24.4上的uda1341的驱动，共享源码

younger0

最近做了博创2410开发板上uda1341的驱动，从网上下了一些源代码，直接拿过来在2.6.24上行不通。然后就自己去看内核中和dma相关的代码，最终把驱动弄好了，能顺利播放音乐了。把移植过程介绍一下，供大家参考。 遇到的第一个问题是dma通道的映射问题。通道映射不正确的话，uda1341就没有输出。这个问题我觉得是移植过程中解决的主要问题。关于2.6.24中dma的基本建立过程在我的另一篇文章中有介绍，大家可以看一下：
http://blog.chinaunix.net/u1/57747/showart_718784.html
 然后直接介绍移植过程中需要修改的地方。首先还是dma通道的问题。在内核的arch/arm/plat-s3c24xx/dma.c的s3c2410_dma_map_channel函数中修改如下：static struct s3c2410_dma_chan *s3c2410_dma_map_channel(int channel){ struct s3c24xx_dma_order_ch *ord = NULL; struct s3c24xx_dma_map *ch_map; struct s3c2410_dma_chan *dmach; int ch; if (dma_sel.map == NULL || channel > dma_sel.map_size)  return NULL; ch_map = dma_sel.map + channel; /* first, try the board mapping */#if 0                                            //这里 if (dma_order) {  ord = &dma_order->channels[channel];  for (ch = 0; ch    if (!is_channel_valid(ord->list[ch]))    continue;   if (s3c2410_chans[ord->list[ch]].in_use == 0) {    ch = ord->list[ch] & ~DMA_CH_VALID;    goto found;   }  }  if (ord->flags & DMA_CH_NEVER)   return NULL; }#endif                                           //这里 /* second, search the channel map for first free */就是注释掉一段代码就行了。然后，还是同一个文件中，修改这个函数：s3c2410_dma_enqueue这个函数的结尾： } else if (chan->state == S3C2410_DMA_IDLE) {  if (chan->flags & S3C2410_DMAF_AUTOSTART) {   s3c2410_dma_ctrl(channel, S3C2410_DMAOP_START); //修改的只有这一行  } } local_irq_restore(flags); return 0;} 上面注释的那行，把第一个参数chan->number，换成了现在的channel。 ok，这个文件就改这些。下面贴出uda1341.c这个文件：#include  #include  #include  #include  #include  #include  #include  #include  #include  #include  #include  #include  #include  #include  #include #include #include  #include  #include  #include  #include  #include  #include  #include  #include  #include  #include  #include  #include  #include  #include #define DMA_BUF_WR 1 #define DMA_BUF_RD 0#define DMA_CH1 DMACH_I2S_IN#define DMA_CH2 DMACH_I2S_OUTstatic struct clk *iis_clock; static void __iomem *iis_base;static struct s3c2410_dma_client s3c2410iis_dma_out= {  .name = "I2SSDO", };static struct s3c2410_dma_client s3c2410iis_dma_in = {  .name = "I2SSDI", };static void init_s3c2410_iis_bus(void);#define DEF_VOLUME 65/* UDA1341 Register bits */ #define UDA1341_ADDR 0x14#define UDA1341_REG_DATA0 (UDA1341_ADDR + 0) #define UDA1341_REG_STATUS (UDA1341_ADDR + 2)/* status control */ #define STAT0 (0x00) #define STAT0_RST (1 #define STAT0_SC_MASK (3 #define STAT0_SC_512FS (0 #define STAT0_SC_384FS (1 #define STAT0_SC_256FS (2 #define STAT0_IF_MASK (7 #define STAT0_IF_I2S (0 #define STAT0_IF_LSB16 (1 #define STAT0_IF_LSB18 (2 #define STAT0_IF_LSB20 (3 #define STAT0_IF_MSB (4 #define STAT0_IF_LSB16MSB (5 #define STAT0_IF_LSB18MSB (6 #define STAT0_IF_LSB20MSB (7 #define STAT0_DC_FILTER (1 #define STAT0_DC_NO_FILTER (0 #define STAT1 (0x80) #define STAT1_DAC_GAIN (1 #define STAT1_ADC_GAIN (1 #define STAT1_ADC_POL (1 #define STAT1_DAC_POL (1 #define STAT1_DBL_SPD (1 #define STAT1_ADC_ON (1 #define STAT1_DAC_ON (1 /* data0 direct control */ #define DATA0 (0x00) #define DATA0_VOLUME_MASK (0x3f) #define DATA0_VOLUME(x) (x)#define DATA1 (0x40) #define DATA1_BASS(x) ((x) #define DATA1_BASS_MASK (15 #define DATA1_TREBLE(x) ((x)) #define DATA1_TREBLE_MASK (3)#define DATA2 (0x80) #define DATA2_PEAKAFTER (0x1 #define DATA2_DEEMP_NONE (0x0 #define DATA2_DEEMP_32KHz (0x1 #define DATA2_DEEMP_44KHz (0x2 #define DATA2_DEEMP_48KHz (0x3 #define DATA2_MUTE (0x1 #define DATA2_FILTER_FLAT (0x0 #define DATA2_FILTER_MIN (0x1 #define DATA2_FILTER_MAX (0x3 /* data0 extend control */ #define EXTADDR(n) (0xc0 | (n)) #define EXTDATA(d) (0xe0 | (d))#define EXT0 0 #define EXT0_CH1_GAIN(x) (x) #define EXT1 1 #define EXT1_CH2_GAIN(x) (x) #define EXT2 2 #define EXT2_MIC_GAIN_MASK (7 #define EXT2_MIC_GAIN(x) ((x) #define EXT2_MIXMODE_DOUBLEDIFF (0) #define EXT2_MIXMODE_CH1 (1) #define EXT2_MIXMODE_CH2 (2) #define EXT2_MIXMODE_MIX (3) #define EXT4 4 #define EXT4_AGC_ENABLE (1 #define EXT4_INPUT_GAIN_MASK (3) #define EXT4_INPUT_GAIN(x) ((x) & 3) #define EXT5 5 #define EXT5_INPUT_GAIN(x) ((x) >> 2) #define EXT6 6 #define EXT6_AGC_CONSTANT_MASK (7 #define EXT6_AGC_CONSTANT(x) ((x) #define EXT6_AGC_LEVEL_MASK (3) #define EXT6_AGC_LEVEL(x) (x)#define AUDIO_NAME "UDA1341" #define AUDIO_NAME_VERBOSE "UDA1341 audio driver"#define AUDIO_FMT_MASK (AFMT_S16_LE) #define AUDIO_FMT_DEFAULT (AFMT_S16_LE)#define AUDIO_CHANNELS_DEFAULT 2 #define AUDIO_RATE_DEFAULT 8000#define AUDIO_NBFRAGS_DEFAULT 8 #define AUDIO_FRAGSIZE_DEFAULT 8192#define S_CLOCK_FREQ 384typedef struct {  int size; /* buffer size */  char *start; /* point to actual buffer */  dma_addr_t dma_addr; /* physical buffer address */  struct semaphore sem; /* down before touching the buffer */  int master; /* owner for buffer allocation, contain size when true */ } audio_buf_t;typedef struct {  audio_buf_t *buffers; /* pointer to audio buffer structures */  audio_buf_t *buf; /* current buffer used by read/write */  u_int buf_idx; /* index for the pointer above */  u_int fragsize; /* fragment i.e. buffer size */  u_int nbfrags; /* nbr of fragments */         enum dma_ch dmach; } audio_stream_t;static audio_stream_t output_stream; static audio_stream_t input_stream;#define NEXT_BUF(_s_,_b_) { \        (_s_)->_b_##_idx++; \        (_s_)->_b_##_idx %= (_s_)->nbfrags; \        (_s_)->_b_ = (_s_)->buffers + (_s_)->_b_##_idx; } static u_int audio_rate; static int audio_channels; static int audio_fmt; static u_int audio_fragsize; static u_int audio_nbfrags;static int audio_rd_refcount; static int audio_wr_refcount; #define audio_active (audio_rd_refcount | audio_wr_refcount)static int audio_dev_dsp; static int audio_dev_mixer; static int audio_mix_modcnt;static int uda1341_volume; static u8 uda_sampling; static int uda1341_boost; static int mixer_igain=0x4; /* -6db*/static void uda1341_l3_address(u8 data) {  int i;  unsigned long flags;   local_irq_save(flags);   s3c2410_gpio_setpin(S3C2410_GPG9,1); s3c2410_gpio_setpin(S3C2410_GPG0,0); udelay(10); s3c2410_gpio_setpin(S3C2410_GPG8,0); udelay(5);  for (i = 0; i   if (data & 0x1) {    s3c2410_gpio_setpin(S3C2410_GPG9,0);   s3c2410_gpio_setpin(S3C2410_GPG0,1);    udelay(1);    s3c2410_gpio_setpin(S3C2410_GPG9,1);   udelay(1);  } else {    s3c2410_gpio_setpin(S3C2410_GPG9,0);   s3c2410_gpio_setpin(S3C2410_GPG0,0);    udelay(1);    s3c2410_gpio_setpin(S3C2410_GPG9,1);   udelay(1);  }   data >>= 1;  }  udelay(5); s3c2410_gpio_setpin(S3C2410_GPG8,1);  udelay(1); local_irq_restore(flags); }static void uda1341_l3_data(u8 data) {  int i;  unsigned long flags; local_irq_save(flags); s3c2410_gpio_setpin(S3C2410_GPG8,1); udelay(5);  for (i = 0; i   if (data & 0x1) {    s3c2410_gpio_setpin(S3C2410_GPG9,0);   s3c2410_gpio_setpin(S3C2410_GPG0,1);    udelay(1);    s3c2410_gpio_setpin(S3C2410_GPG9,1);   udelay(1);  } else {    s3c2410_gpio_setpin(S3C2410_GPG9,0);   s3c2410_gpio_setpin(S3C2410_GPG0,0);    udelay(1);    s3c2410_gpio_setpin(S3C2410_GPG9,1);   udelay(1);  }     data >>= 1;  }  udelay(1); s3c2410_gpio_setpin(S3C2410_GPG8, 0); udelay(2); s3c2410_gpio_setpin(S3C2410_GPG8, 1);        local_irq_restore(flags); }static void audio_clear_buf(audio_stream_t * s) {    s3c2410_dma_ctrl(s->dmach, S3C2410_DMAOP_FLUSH);   if (s->buffers) {   int frag;     for (frag = 0; frag nbfrags; frag++) {    if (!s->buffers[frag].master)     continue;    dma_free_coherent(NULL,     s->buffers[frag].master,     s->buffers[frag].start,     s->buffers[frag].dma_addr);   }   kfree(s->buffers);   s->buffers = NULL;  }   s->buf_idx = 0;  s->buf = NULL; }static int audio_setup_buf(audio_stream_t * s) {  int frag;  int dmasize = 0;  char *dmabuf = 0;  dma_addr_t dmaphys = 0;   if (s->buffers)   return -EBUSY;   s->nbfrags = audio_nbfrags;  s->fragsize = audio_fragsize;   s->buffers = (audio_buf_t *)   kmalloc(sizeof(audio_buf_t) * s->nbfrags, GFP_KERNEL);  if (!s->buffers)   goto err;  memset(s->buffers, 0, sizeof(audio_buf_t) * s->nbfrags);   for (frag = 0; frag nbfrags; frag++) {   audio_buf_t *b = &s->buffers[frag];     if (!dmasize) {    dmasize = (s->nbfrags - frag) * s->fragsize;    do {     dmabuf = dma_alloc_coherent(NULL, dmasize, &dmaphys, GFP_KERNEL|GFP_DMA);     if (!dmabuf)      dmasize -= s->fragsize;    } while (!dmabuf && dmasize);    if (!dmabuf)     goto err;    b->master = dmasize;   }     b->start = dmabuf;   b->dma_addr = dmaphys;   sema_init(&b->sem, 1);     dmabuf += s->fragsize;   dmaphys += s->fragsize;   dmasize -= s->fragsize;  }   s->buf_idx = 0;  s->buf = &s->buffers[0];  return 0;  err:  printk(AUDIO_NAME ": unable to allocate audio memory\n ");  audio_clear_buf(s);  return -ENOMEM; }static void audio_dmaout_done_callback(struct s3c2410_dma_chan *ch, void *buf, int size,enum s3c2410_dma_buffresult result) {  audio_buf_t *b = (audio_buf_t *) buf;  up(&b->sem);  wake_up(&b->sem.wait); }static void audio_dmain_done_callback(struct s3c2410_dma_chan *ch, void *buf, int size,enum s3c2410_dma_buffresult result) {  audio_buf_t *b = (audio_buf_t *) buf;  b->size = size;  up(&b->sem);  wake_up(&b->sem.wait); } /* using when write */ static int audio_sync(struct file *file) {  audio_stream_t *s = &output_stream;  audio_buf_t *b = s->buf;   printk("audio_sync\n");  if (!s->buffers)   return 0;   if (b->size != 0) {   down(&b->sem);   s3c2410_dma_enqueue(s->dmach, (void *) b, b->dma_addr, b->size);   b->size = 0;   NEXT_BUF(s, buf);  }   b = s->buffers + ((s->nbfrags + s->buf_idx - 1) % s->nbfrags);  if (down_interruptible(&b->sem))   return -EINTR;  up(&b->sem);   return 0; }static inline int copy_from_user_mono_stereo(char *to, const char *from, int count) {  u_int *dst = (u_int *)to;  const char *end = from + count;   if (!access_ok(VERIFY_READ, from, count))   return -EFAULT;   if ((int)from & 0x2) {   u_int v;   __get_user(v, (const u_short *)from); from += 2;   *dst++ = v | (v  }   while (from   u_int v, x, y;   __get_user(v, (const u_int *)from); from += 4;   x = v   x |= x >> 16;   y = v >> 16;   y |= y   *dst++ = x;   *dst++ = y;  }   if (from   u_int v;   __get_user(v, (const u_short *)from);   *dst = v | (v  }   return 0; }static ssize_t smdk2410_audio_write(struct file *file, const char *buffer,size_t count, loff_t * ppos){ const char *buffer0 = buffer; audio_stream_t *s = &output_stream; int chunksize, ret = 0; switch (file->f_flags & O_ACCMODE) {  case O_WRONLY:  case O_RDWR:  break;  default:   return -EPERM; } if (!s->buffers && audio_setup_buf(s))  return -ENOMEM; count &= ~0x03; while (count > 0) {  audio_buf_t *b = s->buf;  if (file->f_flags & O_NONBLOCK) {   ret = -EAGAIN;   if (down_trylock(&b->sem))    break;  } else {   ret = -ERESTARTSYS;   if (down_interruptible(&b->sem))   break;  }  if (audio_channels == 2) {   chunksize = s->fragsize - b->size;   if (chunksize > count)   chunksize = count;   if (copy_from_user(b->start + b->size, buffer, chunksize)) {    up(&b->sem);    return -EFAULT;   }   b->size += chunksize;  } else {   chunksize = (s->fragsize - b->size) >> 1;   if (chunksize > count)   chunksize = count;   if (copy_from_user_mono_stereo(b->start + b->size,buffer, chunksize)) {   up(&b->sem);   return -EFAULT;   }   b->size += chunksize*2;  }  buffer += chunksize;  count -= chunksize;  if (b->size fragsize) {  up(&b->sem);  break;  }                ret = s3c2410_dma_enqueue(s->dmach, (void *)b, b->dma_addr, b->size);  if(ret) {   printk("dma enqueue failed.\n");   return ret;  }  b->size = 0;  NEXT_BUF(s, buf); } if ((buffer - buffer0)) ret = buffer - buffer0; return ret;}static ssize_t smdk2410_audio_read(struct file *file, char *buffer,            size_t count, loff_t * ppos) {  const char *buffer0 = buffer;  audio_stream_t *s = &input_stream;  int chunksize, ret = 0;   printk("audio_read: count=%d\n", count);  if (ppos != &file->f_pos)   return -ESPIPE;   if (!s->buffers) {   int i;     if (audio_setup_buf(s))    return -ENOMEM;     for (i = 0; i nbfrags; i++) {    audio_buf_t *b = s->buf;    down(&b->sem);    s3c2410_dma_enqueue(s->dmach, (void *) b, b->dma_addr, s->fragsize);    NEXT_BUF(s, buf);   }  }   while (count > 0) {   audio_buf_t *b = s->buf;     /* Wait for a buffer to become full */   if (file->f_flags & O_NONBLOCK) {    ret = -EAGAIN;    if (down_trylock(&b->sem))     break;   } else {    ret = -ERESTARTSYS;    if (down_interruptible(&b->sem))     break;   }     chunksize = b->size;   if (chunksize > count)    chunksize = count;     if (copy_to_user(buffer, b->start + s->fragsize - b->size,    chunksize)) {    up(&b->sem);    return -EFAULT;   }     b->size -= chunksize;     buffer += chunksize;   count -= chunksize;   if (b->size > 0) {    up(&b->sem);    break;   }     /* Make current buffer available for DMA again */   s3c2410_dma_enqueue(s->dmach, (void *) b, b->dma_addr, s->fragsize);     NEXT_BUF(s, buf);  }   if ((buffer - buffer0))   ret = buffer - buffer0;   printk("audio_read: return=%d\n", ret);  return ret; }static unsigned int smdk2410_audio_poll(struct file *file,           struct poll_table_struct *wait) {  unsigned int mask = 0;  int i;   printk("audio_poll(): mode=%s\n",  (file->f_mode & FMODE_WRITE) ? "w" : "");    if (file->f_mode & FMODE_READ) {   if (!input_stream.buffers && audio_setup_buf(&input_stream))    return -ENOMEM;   poll_wait(file, &input_stream.buf->sem.wait, wait);     for (i = 0; i    if (atomic_read(&input_stream.buffers.sem.count) > 0)     mask |= POLLIN | POLLWRNORM;    break;   }  }    if (file->f_mode & FMODE_WRITE) {   if (!output_stream.buffers && audio_setup_buf(&output_stream))    return -ENOMEM;   poll_wait(file, &output_stream.buf->sem.wait, wait);     for (i = 0; i    if (atomic_read(&output_stream.buffers.sem.count) > 0)     mask |= POLLOUT | POLLWRNORM;    break;   }  }   return mask; }static loff_t smdk2410_audio_llseek(struct file *file, loff_t offset,          int origin) {  return -ESPIPE; }static int smdk2410_mixer_ioctl(struct inode *inode, struct file *file,         unsigned int cmd, unsigned long arg) {  int ret;  long val = 0;   switch (cmd) {  case SOUND_MIXER_INFO:   {    mixer_info info;    strncpy(info.id, "UDA1341", sizeof(info.id));    strncpy(info.name,"Philips UDA1341", sizeof(info.name));    info.modify_counter = audio_mix_modcnt;    return copy_to_user((void *)arg, &info, sizeof(info));   }    case SOUND_OLD_MIXER_INFO:   {    _old_mixer_info info;    strncpy(info.id, "UDA1341", sizeof(info.id));    strncpy(info.name,"Philips UDA1341", sizeof(info.name));    return copy_to_user((void *)arg, &info, sizeof(info));   }    case SOUND_MIXER_READ_STEREODEVS:   return put_user(0, (long *) arg);    case SOUND_MIXER_READ_CAPS:   val = SOUND_CAP_EXCL_INPUT;   return put_user(val, (long *) arg);    case SOUND_MIXER_WRITE_VOLUME:   ret = get_user(val, (long *) arg);   if (ret)    return ret;   uda1341_volume = 63 - (((val & 0xff) + 1) * 63) / 100;   uda1341_l3_address(UDA1341_REG_DATA0);   uda1341_l3_data(uda1341_volume);   break;    case SOUND_MIXER_READ_VOLUME:   val = ((63 - uda1341_volume) * 100) / 63;   val |= val   return put_user(val, (long *) arg);    case SOUND_MIXER_READ_IGAIN:   val = ((31- mixer_igain) * 100) / 31;   return put_user(val, (int *) arg);    case SOUND_MIXER_WRITE_IGAIN:   ret = get_user(val, (int *) arg);   if (ret)    return ret;   mixer_igain = 31 - (val * 31 / 100);   /* use mixer gain channel 1*/   uda1341_l3_address(UDA1341_REG_DATA0);   uda1341_l3_data(EXTADDR(EXT0));   uda1341_l3_data(EXTDATA(EXT0_CH1_GAIN(mixer_igain)));   break;    default:      return -ENOSYS;  }   audio_mix_modcnt++;  return 0; } static int iispsr_value(int s_bit_clock, int sample_rate){ unsigned int i,j,prescaler = 0; i = s_bit_clock*sample_rate; prescaler = clk_get_rate(iis_clock)/i; j = clk_get_rate(iis_clock)%i; if(j   return (prescaler - 1); return prescaler;}static int audio_set_dsp_speed(long val) {   unsigned long iispsr = 0;  unsigned long value = 0;  value = iispsr_value(S_CLOCK_FREQ, val);  iispsr = (value      writel(iispsr, iis_base + S3C2410_IISPSR);  iispsr = readl(iis_base + S3C2410_IISPSR);  return (audio_rate = val);}static int smdk2410_audio_ioctl(struct inode *inode, struct file *file,    uint cmd, ulong arg){ long val; switch (cmd) {  case SNDCTL_DSP_SETFMT:   get_user(val, (long *) arg);   if (val & AUDIO_FMT_MASK) {    audio_fmt = val;    break;   } else    return -EINVAL;  case SNDCTL_DSP_CHANNELS:  case SNDCTL_DSP_STEREO:   get_user(val, (long *) arg);   if (cmd == SNDCTL_DSP_STEREO)    val = val ? 2 : 1;   if (val != 1 && val != 2)    return -EINVAL;   audio_channels = val;   break;  case SOUND_PCM_READ_CHANNELS:   put_user(audio_channels, (long *) arg);   break;  case SNDCTL_DSP_SPEED:   get_user(val, (long *) arg);   val = audio_set_dsp_speed(val);   if (val     return -EINVAL;   put_user(val, (long *) arg);   break;  case SOUND_PCM_READ_RATE:   put_user(audio_rate, (long *) arg);   break;  case SNDCTL_DSP_GETFMTS:   put_user(AUDIO_FMT_MASK, (long *) arg);   break;  case SNDCTL_DSP_GETBLKSIZE:   if(file->f_mode & FMODE_WRITE)    return put_user(audio_fragsize, (long *) arg);   else    return put_user(audio_fragsize, (int *) arg);  case SNDCTL_DSP_SETFRAGMENT:   if (file->f_mode & FMODE_WRITE) {    if (output_stream.buffers)     return -EBUSY;    get_user(val, (long *) arg);    audio_fragsize = 1     if (audio_fragsize      audio_fragsize = 16;    if (audio_fragsize > 16384)     audio_fragsize = 16384;    audio_nbfrags = (val >> 16) & 0x7FFF;    if (audio_nbfrags      audio_nbfrags = 2;    if (audio_nbfrags * audio_fragsize > 128 * 1024)     audio_nbfrags = 128 * 1024 / audio_fragsize;    if (audio_setup_buf(&output_stream))     return -ENOMEM;   }   if (file->f_mode & FMODE_READ) {    if (input_stream.buffers)     return -EBUSY;    get_user(val, (int *) arg);    audio_fragsize = 1     if (audio_fragsize      audio_fragsize = 16;    if (audio_fragsize > 16384)     audio_fragsize = 16384;    audio_nbfrags = (val >> 16) & 0x7FFF;    if (audio_nbfrags      audio_nbfrags = 2;    if (audio_nbfrags * audio_fragsize > 128 * 1024)     audio_nbfrags = 128 * 1024 / audio_fragsize;    if (audio_setup_buf(&input_stream))     return -ENOMEM;   }   break;  case SNDCTL_DSP_SYNC:   return audio_sync(file);  case SNDCTL_DSP_GETOSPACE:  {   audio_stream_t *s = &output_stream;   audio_buf_info *inf = (audio_buf_info *) arg;   int err = access_ok(VERIFY_WRITE, inf, sizeof(*inf));   int i;   int frags = 0, bytes = 0;   if (err)    return err;   for (i = 0; i nbfrags; i++) {    if (atomic_read(&s->buffers.sem.count) > 0) {     if (s->buffers.size == 0) frags++;     bytes += s->fragsize - s->buffers.size;    }   }   put_user(frags, &inf->fragments);   put_user(s->nbfrags, &inf->fragstotal);   put_user(s->fragsize, &inf->fragsize);   put_user(bytes, &inf->bytes);   break;  }  case SNDCTL_DSP_GETISPACE:  {   audio_stream_t *s = &input_stream;   audio_buf_info *inf = (audio_buf_info *) arg;   int err = access_ok(VERIFY_WRITE, inf, sizeof(*inf));   int i;   int frags = 0, bytes = 0;   if (!(file->f_mode & FMODE_READ))    return -EINVAL;   if (err)    return err;   for(i = 0; i nbfrags; i++){    if (atomic_read(&s->buffers.sem.count) > 0)    {     if (s->buffers.size == s->fragsize)      frags++;     bytes += s->buffers.size;    }   }   put_user(frags, &inf->fragments);   put_user(s->nbfrags, &inf->fragstotal);   put_user(s->fragsize, &inf->fragsize);   put_user(bytes, &inf->bytes);   break;  }  case SNDCTL_DSP_RESET:   if (file->f_mode & FMODE_READ) {    audio_clear_buf(&input_stream);   }   if (file->f_mode & FMODE_WRITE) {    audio_clear_buf(&output_stream);   }   return 0;  case SNDCTL_DSP_NONBLOCK:   file->f_flags |= O_NONBLOCK;   return 0;  case SNDCTL_DSP_POST:  case SNDCTL_DSP_SUBDIVIDE:  case SNDCTL_DSP_GETCAPS:  case SNDCTL_DSP_GETTRIGGER:  case SNDCTL_DSP_SETTRIGGER:  case SNDCTL_DSP_GETIPTR:  case SNDCTL_DSP_GETOPTR:  case SNDCTL_DSP_MAPINBUF:  case SNDCTL_DSP_MAPOUTBUF:  case SNDCTL_DSP_SETSYNCRO:  case SNDCTL_DSP_SETDUPLEX:   return -ENOSYS;  default:   return smdk2410_mixer_ioctl(inode, file, cmd, arg); } return 0;}static int smdk2410_audio_open(struct inode *inode, struct file *file) {  int cold = !audio_active;  printk("audio open\n"); if ((file->f_flags & O_ACCMODE) == O_RDONLY) {   if (audio_rd_refcount || audio_wr_refcount)    return -EBUSY;   audio_rd_refcount++;  } else if ((file->f_flags & O_ACCMODE) == O_WRONLY) {   if (audio_wr_refcount)    return -EBUSY;   audio_wr_refcount++;  } else if ((file->f_flags & O_ACCMODE) == O_RDWR) {   if (audio_rd_refcount || audio_wr_refcount)    return -EBUSY;   audio_rd_refcount++;   audio_wr_refcount++;  } else   return -EINVAL;   if (cold) {   audio_rate = AUDIO_RATE_DEFAULT;   audio_channels = AUDIO_CHANNELS_DEFAULT;   audio_fragsize = AUDIO_FRAGSIZE_DEFAULT;   audio_nbfrags = AUDIO_NBFRAGS_DEFAULT;   init_s3c2410_iis_bus();   if ((file->f_mode & FMODE_WRITE)){    audio_clear_buf(&output_stream);  }   if ((file->f_mode & FMODE_READ))     audio_clear_buf(&input_stream);   }  return 0; }static int smdk2410_mixer_open(struct inode *inode, struct file *file) {  return 0; }static int smdk2410_audio_release(struct inode *inode, struct file *file) { if (file->f_mode & FMODE_READ) {   if (audio_rd_refcount == 1)    audio_clear_buf(&input_stream);   audio_rd_refcount = 0;  }   if(file->f_mode & FMODE_WRITE) {   if (audio_wr_refcount == 1) {    audio_sync(file);    audio_clear_buf(&output_stream);    audio_wr_refcount = 0;   }  }   return 0; }static int smdk2410_mixer_release(struct inode *inode, struct file *file) {  return 0; }static struct file_operations smdk2410_audio_fops = {  .llseek = smdk2410_audio_llseek,  .write = smdk2410_audio_write,  .read = smdk2410_audio_read,  .poll = smdk2410_audio_poll,  .ioctl = smdk2410_audio_ioctl,  .open = smdk2410_audio_open,  .release = smdk2410_audio_release };static struct file_operations smdk2410_mixer_fops = {  .ioctl = smdk2410_mixer_ioctl,  .open =  smdk2410_mixer_open,  .release = smdk2410_mixer_release };static void init_uda1341(void) {         unsigned long flags; uda1341_volume = 62 - ((DEF_VOLUME * 61) / 100);  uda1341_boost = 0;  uda_sampling = DATA2_DEEMP_NONE;  uda_sampling &= ~(DATA2_MUTE); local_irq_save(flags); s3c2410_gpio_setpin(S3C2410_GPG9, 1); s3c2410_gpio_setpin(S3C2410_GPG8, 1); local_irq_restore(flags); uda1341_l3_address(UDA1341_REG_STATUS); uda1341_l3_data(STAT0_RST);      uda1341_l3_address(UDA1341_REG_STATUS); uda1341_l3_data(STAT0_SC_384FS | STAT0_IF_MSB | STAT0_DC_FILTER);     uda1341_l3_data(STAT1 | STAT1_DAC_GAIN | STAT1_ADC_GAIN | STAT1_ADC_ON | STAT1_DAC_ON); uda1341_l3_address(UDA1341_REG_DATA0); uda1341_l3_data(DATA0 |DATA0_VOLUME(uda1341_volume));   uda1341_l3_data(DATA1 |DATA1_BASS(uda1341_boost)| DATA1_TREBLE(0)); uda1341_l3_data(DATA2 |uda_sampling); uda1341_l3_data(EXTADDR(EXT2)); uda1341_l3_data(EXTDATA(EXT2_MIC_GAIN(0x6)| EXT2_MIXMODE_CH2)); uda1341_l3_data(EXTADDR(EXT5)); uda1341_l3_data(EXTDATA(0x7)); local_irq_save(flags); s3c2410_gpio_setpin(S3C2410_GPG9, 1); s3c2410_gpio_setpin(S3C2410_GPG8, 0); local_irq_restore(flags);}static void init_s3c2410_iis_bus(void){  unsigned long iiscon, iismod, iisfcon;   clk_enable(iis_clock);   iiscon = iismod = iisfcon = 0;   iiscon |= S3C2410_IISCON_PSCEN; // Enable prescaler  iiscon |= S3C2410_IISCON_IISEN; // Enable interface iiscon |= S3C2410_IISCON_RXDMAEN; //Enable RX DMA service request  iiscon |= S3C2410_IISCON_TXDMAEN; //Enable TX DMA service request   iismod |= S3C2410_IISMOD_LR_LLOW; // Low for left channel  iismod |= S3C2410_IISMOD_MSB; iismod |= S3C2410_IISMOD_16BIT; // Serial data bit/channel is 16 bit  iismod |= S3C2410_IISMOD_384FS; // Master clock freq = 384 fs  iismod |= S3C2410_IISMOD_TXRXMODE; //Set RX Mode  iismod |= S3C2410_IISMOD_32FS; // 32 fs   iisfcon|= S3C2410_IISFCON_RXDMA; //Set RX FIFO acces mode to DMA  iisfcon|= S3C2410_IISFCON_RXENABLE; //Enable RX Fifo  iisfcon|= S3C2410_IISFCON_TXDMA; //Set RX FIFO acces mode to DMA  iisfcon|= S3C2410_IISFCON_TXENABLE; audio_set_dsp_speed(44100);   writel(iismod, iis_base + S3C2410_IISMOD);  writel(iisfcon, iis_base + S3C2410_IISFCON);  writel(iiscon, iis_base + S3C2410_IISCON);}static int __init audio_init_dma(audio_stream_t * s, char *desc) {  int ret ;  enum s3c2410_dmasrc source;  int hwcfg;  unsigned long devaddr;  int dcon;  unsigned int flags = 0;   if(s->dmach == DMA_CH2){   source = S3C2410_DMASRC_MEM;   hwcfg = 3;   devaddr = 0x55000010;   dcon = 0xa0800000;   flags = S3C2410_DMAF_AUTOSTART;     ret = s3c2410_dma_request(s->dmach, &s3c2410iis_dma_out, NULL);  s3c2410_dma_devconfig(s->dmach, source, hwcfg, devaddr);   s3c2410_dma_config(s->dmach, 2, dcon);   s3c2410_dma_set_buffdone_fn(s->dmach, audio_dmaout_done_callback);   s3c2410_dma_setflags(s->dmach, flags);  return ret;  }  else if(s->dmach == DMA_CH1){   source =S3C2410_DMASRC_HW;  hwcfg =3;  devaddr = 0x55000010;  dcon = 0xa2900000;  flags = S3C2410_DMAF_AUTOSTART;    ret = s3c2410_dma_request(s->dmach, &s3c2410iis_dma_in, NULL);  s3c2410_dma_devconfig(s->dmach, source, hwcfg, devaddr);  s3c2410_dma_config(s->dmach, 2, dcon);  s3c2410_dma_set_buffdone_fn(s->dmach, audio_dmain_done_callback);  s3c2410_dma_setflags(s->dmach, flags);  return ret ; }  else   return 1; }static int audio_clear_dma(audio_stream_t * s,struct s3c2410_dma_client *client) {  s3c2410_dma_set_buffdone_fn(s->dmach, NULL);  s3c2410_dma_free(s->dmach, client);  return 0; }static int __init s3c2410iis_probe(struct platform_device *pdev) {  struct resource *res; int size;        unsigned long flags; res = platform_get_resource(pdev, IORESOURCE_MEM, 0);  if (res == NULL) {   printk(KERN_INFO "failed to get memory region resouce\n");   return -ENOENT;  }  if (!request_mem_region(res->start, 0x20, pdev->name)) {   printk(KERN_INFO "failed to get memory region\n");           return -EBUSY;         }  size = (res->end - res->start) + 1; iis_base = ioremap(res->start, size);  if (iis_base == NULL) {   printk(KERN_INFO "failed to ioremap() region\n");   return -EINVAL;  }   iis_clock = clk_get(&pdev->dev, "iis");  if (iis_clock == NULL) {   printk(KERN_INFO "failed to find clock source\n");   return -ENOENT;  }   clk_enable(iis_clock);   local_irq_save(flags);   /* GPB 4: L3CLOCK, OUTPUT */  s3c2410_gpio_cfgpin(S3C2410_GPG9, S3C2410_GPG9_OUTP); s3c2410_gpio_pullup(S3C2410_GPG9, 1); /* GPB 3: L3DATA, OUTPUT */  s3c2410_gpio_cfgpin(S3C2410_GPG0,S3C2410_GPG0_OUTP); s3c2410_gpio_pullup(S3C2410_GPG0, 1); /* GPB 2: L3MODE, OUTPUT */  s3c2410_gpio_cfgpin(S3C2410_GPG8,S3C2410_GPG8_OUTP); s3c2410_gpio_pullup(S3C2410_GPG8, 1); /* GPE 3: I2SSDI */  s3c2410_gpio_cfgpin(S3C2410_GPE3,S3C2410_GPE3_I2SSDI); s3c2410_gpio_pullup(S3C2410_GPE3, 0); /* GPE 0: I2SLRCK */  s3c2410_gpio_cfgpin(S3C2410_GPE0,S3C2410_GPE0_I2SLRCK);  s3c2410_gpio_pullup(S3C2410_GPE0, 0); /* GPE 1: I2SSCLK */  s3c2410_gpio_cfgpin(S3C2410_GPE1,S3C2410_GPE1_I2SSCLK); s3c2410_gpio_pullup(S3C2410_GPE1, 0); /* GPE 2: CDCLK */  s3c2410_gpio_cfgpin(S3C2410_GPE2,S3C2410_GPE2_CDCLK); s3c2410_gpio_pullup(S3C2410_GPE2, 0);  /* GPE 4: I2SSDO */  s3c2410_gpio_cfgpin(S3C2410_GPE4,S3C2410_GPE4_I2SSDO); s3c2410_gpio_pullup(S3C2410_GPE4, 0);  local_irq_restore(flags);  init_uda1341();   output_stream.dmach = DMA_CH2;   if (audio_init_dma(&output_stream, "UDA1341 out")) {   audio_clear_dma(&output_stream,&s3c2410iis_dma_out);   printk( KERN_WARNING AUDIO_NAME_VERBOSE    ": unable to get DMA channels\n" );   return -EBUSY;  }  input_stream.dmach = DMA_CH1;  if (audio_init_dma(&input_stream, "UDA1341 in")) {   audio_clear_dma(&input_stream,&s3c2410iis_dma_in);   printk( KERN_WARNING AUDIO_NAME_VERBOSE    ": unable to get DMA channels\n" );   return -EBUSY;  }  audio_dev_dsp = register_sound_dsp(&smdk2410_audio_fops, -1);  audio_dev_mixer = register_sound_mixer(&smdk2410_mixer_fops, -1);   printk(AUDIO_NAME_VERBOSE " initialized\n");   return 0; }static int s3c2410iis_remove(struct platform_device *dev) {  unregister_sound_dsp(audio_dev_dsp);  unregister_sound_mixer(audio_dev_mixer);  audio_clear_dma(&output_stream,&s3c2410iis_dma_out);  audio_clear_dma(&input_stream,&s3c2410iis_dma_in); /* input */  printk(AUDIO_NAME_VERBOSE " unloaded\n");  return 0; }static struct platform_driver s3c2410iis_driver = {   .probe = s3c2410iis_probe,   .remove = s3c2410iis_remove,  .driver = {    .name = "s3c2410-iis",    .owner = THIS_MODULE,  },};static int __init s3c2410_uda1341_init(void) {  memzero(&input_stream, sizeof(audio_stream_t));  memzero(&output_stream, sizeof(audio_stream_t));  return platform_driver_register(&s3c2410iis_driver); }static void __exit s3c2410_uda1341_exit(void) {  platform_driver_unregister(&s3c2410iis_driver); }module_init(s3c2410_uda1341_init); module_exit(s3c2410_uda1341_exit);MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("S3C2410 uda1341 sound driver"); 把上面的文件保存到sound/oss中，然后修改sound/oss中的kconfig和makefile，使内核加入该文件，然后编译就可以了。 值得注意的地方是，在驱动程序中DMA_CH1和DMA_CH2我是定义成DMACH_I2S_IN和DMACH_I2S_OUT，与其他人的程序中有一定的区别。上面两个量是枚举类型，大家可以查看include/asm-arm/plat-s3c24xx/dma.h文件，里面有它们的定义。
               
               
               
               

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