#include <sound/asound.h>
#include <sound/memalloc.h>
#include <linux/poll.h>
+#include <linux/mm.h>
#include <linux/bitops.h>
#define snd_pcm_substream_chip(substream) ((substream)->private_data)
int number;
char name[32]; /* substream name */
int stream; /* stream (direction) */
+ char latency_id[20]; /* latency identifier */
size_t buffer_bytes_max; /* limit ring buffer size */
struct snd_dma_buffer dma_buffer;
unsigned int dma_buf_id;