linux-imx

/*

 * Audio and Music Data Transmission Protocol (IEC 61883-6) streams

 * with Common Isochronous Packet (IEC 61883-1) headers

 *

 * Copyright (c) Clemens Ladisch <clemens@ladisch.de>

 * Licensed under the terms of the GNU General Public License, version 2.

 */

​

#include <linux/device.h>

#include <linux/err.h>

#include <linux/firewire.h>

#include <linux/module.h>

#include <linux/slab.h>

#include <sound/pcm.h>

#include <sound/pcm_params.h>

#include "amdtp-stream.h"

​

#define TICKS_PER_CYCLE     3072

#define CYCLES_PER_SECOND   8000

#define TICKS_PER_SECOND    (TICKS_PER_CYCLE * CYCLES_PER_SECOND)

​

/* Always support Linux tracing subsystem. */

#define CREATE_TRACE_POINTS

#include "amdtp-stream-trace.h"

​

#define TRANSFER_DELAY_TICKS    0x2e00 /* 479.17 microseconds */

​

/* isochronous header parameters */

#define ISO_DATA_LENGTH_SHIFT   16

#define TAG_NO_CIP_HEADER   0

#define TAG_CIP         1

​

/* common isochronous packet header parameters */

#define CIP_EOH_SHIFT       31

#define CIP_EOH         (1u << CIP_EOH_SHIFT)

#define CIP_EOH_MASK        0x80000000

#define CIP_SID_SHIFT       24

#define CIP_SID_MASK        0x3f000000

#define CIP_DBS_MASK        0x00ff0000

#define CIP_DBS_SHIFT       16

#define CIP_SPH_MASK        0x00000400

#define CIP_SPH_SHIFT       10

#define CIP_DBC_MASK        0x000000ff

#define CIP_FMT_SHIFT       24

#define CIP_FMT_MASK        0x3f000000

#define CIP_FDF_MASK        0x00ff0000

#define CIP_FDF_SHIFT       16

#define CIP_SYT_MASK        0x0000ffff

#define CIP_SYT_NO_INFO     0xffff

​

/* Audio and Music transfer protocol specific parameters */

#define CIP_FMT_AM      0x10

#define AMDTP_FDF_NO_DATA   0xff

​

/* TODO: make these configurable */

#define INTERRUPT_INTERVAL  16

#define QUEUE_LENGTH        48

​

#define IN_PACKET_HEADER_SIZE   4

#define OUT_PACKET_HEADER_SIZE  0

​

static void pcm_period_tasklet(unsigned long data);

​