linux/sound/firewire/amdtp.h
Clemens Ladisch 25ca917c0f ALSA: firewire-lib: limit the MIDI data rate
Do no send MIDI bytes at the full rate at which FireWire packets happen
to be sent, but restrict them to the actual rate of a real MIDI port.
This is required by the specification, and prevents data loss when the
device's buffer overruns.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Tested-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-01-16 22:51:23 +01:00

293 lines
8.9 KiB
C

#ifndef SOUND_FIREWIRE_AMDTP_H_INCLUDED
#define SOUND_FIREWIRE_AMDTP_H_INCLUDED
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/mutex.h>
#include <sound/asound.h>
#include "packets-buffer.h"
/**
* enum cip_flags - describes details of the streaming protocol
* @CIP_NONBLOCKING: In non-blocking mode, each packet contains
* sample_rate/8000 samples, with rounding up or down to adjust
* for clock skew and left-over fractional samples. This should
* be used if supported by the device.
* @CIP_BLOCKING: In blocking mode, each packet contains either zero or
* SYT_INTERVAL samples, with these two types alternating so that
* the overall sample rate comes out right.
* @CIP_SYNC_TO_DEVICE: In sync to device mode, time stamp in out packets is
* generated by in packets. Defaultly this driver generates timestamp.
* @CIP_EMPTY_WITH_TAG0: Only for in-stream. Empty in-packets have TAG0.
* @CIP_DBC_IS_END_EVENT: Only for in-stream. The value of dbc in an in-packet
* corresponds to the end of event in the packet. Out of IEC 61883.
* @CIP_WRONG_DBS: Only for in-stream. The value of dbs is wrong in in-packets.
* The value of data_block_quadlets is used instead of reported value.
* @CIP_SKIP_DBC_ZERO_CHECK: Only for in-stream. Packets with zero in dbc is
* skipped for detecting discontinuity.
* @CIP_SKIP_INIT_DBC_CHECK: Only for in-stream. The value of dbc in first
* packet is not continuous from an initial value.
* @CIP_EMPTY_HAS_WRONG_DBC: Only for in-stream. The value of dbc in empty
* packet is wrong but the others are correct.
*/
enum cip_flags {
CIP_NONBLOCKING = 0x00,
CIP_BLOCKING = 0x01,
CIP_SYNC_TO_DEVICE = 0x02,
CIP_EMPTY_WITH_TAG0 = 0x04,
CIP_DBC_IS_END_EVENT = 0x08,
CIP_WRONG_DBS = 0x10,
CIP_SKIP_DBC_ZERO_CHECK = 0x20,
CIP_SKIP_INIT_DBC_CHECK = 0x40,
CIP_EMPTY_HAS_WRONG_DBC = 0x80,
};
/**
* enum cip_sfc - supported Sampling Frequency Codes (SFCs)
* @CIP_SFC_32000: 32,000 data blocks
* @CIP_SFC_44100: 44,100 data blocks
* @CIP_SFC_48000: 48,000 data blocks
* @CIP_SFC_88200: 88,200 data blocks
* @CIP_SFC_96000: 96,000 data blocks
* @CIP_SFC_176400: 176,400 data blocks
* @CIP_SFC_192000: 192,000 data blocks
* @CIP_SFC_COUNT: the number of supported SFCs
*
* These values are used to show nominal Sampling Frequency Code in
* Format Dependent Field (FDF) of AMDTP packet header. In IEC 61883-6:2002,
* this code means the number of events per second. Actually the code
* represents the number of data blocks transferred per second in an AMDTP
* stream.
*
* In IEC 61883-6:2005, some extensions were added to support more types of
* data such as 'One Bit LInear Audio', therefore the meaning of SFC became
* different depending on the types.
*
* Currently our implementation is compatible with IEC 61883-6:2002.
*/
enum cip_sfc {
CIP_SFC_32000 = 0,
CIP_SFC_44100 = 1,
CIP_SFC_48000 = 2,
CIP_SFC_88200 = 3,
CIP_SFC_96000 = 4,
CIP_SFC_176400 = 5,
CIP_SFC_192000 = 6,
CIP_SFC_COUNT
};
#define AMDTP_IN_PCM_FORMAT_BITS SNDRV_PCM_FMTBIT_S32
#define AMDTP_OUT_PCM_FORMAT_BITS (SNDRV_PCM_FMTBIT_S16 | \
SNDRV_PCM_FMTBIT_S32)
/*
* This module supports maximum 64 PCM channels for one PCM stream
* This is for our convenience.
*/
#define AMDTP_MAX_CHANNELS_FOR_PCM 64
/*
* AMDTP packet can include channels for MIDI conformant data.
* Each MIDI conformant data channel includes 8 MPX-MIDI data stream.
* Each MPX-MIDI data stream includes one data stream from/to MIDI ports.
*
* This module supports maximum 1 MIDI conformant data channels.
* Then this AMDTP packets can transfer maximum 8 MIDI data streams.
*/
#define AMDTP_MAX_CHANNELS_FOR_MIDI 1
struct fw_unit;
struct fw_iso_context;
struct snd_pcm_substream;
struct snd_pcm_runtime;
struct snd_rawmidi_substream;
enum amdtp_stream_direction {
AMDTP_OUT_STREAM = 0,
AMDTP_IN_STREAM
};
struct amdtp_stream {
struct fw_unit *unit;
enum cip_flags flags;
enum amdtp_stream_direction direction;
struct fw_iso_context *context;
struct mutex mutex;
enum cip_sfc sfc;
unsigned int data_block_quadlets;
unsigned int pcm_channels;
unsigned int midi_ports;
void (*transfer_samples)(struct amdtp_stream *s,
struct snd_pcm_substream *pcm,
__be32 *buffer, unsigned int frames);
u8 pcm_positions[AMDTP_MAX_CHANNELS_FOR_PCM];
u8 midi_position;
unsigned int syt_interval;
unsigned int transfer_delay;
unsigned int source_node_id_field;
struct iso_packets_buffer buffer;
struct snd_pcm_substream *pcm;
struct tasklet_struct period_tasklet;
int packet_index;
unsigned int data_block_counter;
unsigned int data_block_state;
unsigned int last_syt_offset;
unsigned int syt_offset_state;
unsigned int pcm_buffer_pointer;
unsigned int pcm_period_pointer;
bool pointer_flush;
bool double_pcm_frames;
struct snd_rawmidi_substream *midi[AMDTP_MAX_CHANNELS_FOR_MIDI * 8];
int midi_fifo_limit;
int midi_fifo_used[AMDTP_MAX_CHANNELS_FOR_MIDI * 8];
/* quirk: fixed interval of dbc between previos/current packets. */
unsigned int tx_dbc_interval;
bool callbacked;
wait_queue_head_t callback_wait;
struct amdtp_stream *sync_slave;
};
int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit,
enum amdtp_stream_direction dir,
enum cip_flags flags);
void amdtp_stream_destroy(struct amdtp_stream *s);
void amdtp_stream_set_parameters(struct amdtp_stream *s,
unsigned int rate,
unsigned int pcm_channels,
unsigned int midi_ports);
unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s);
int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed);
void amdtp_stream_update(struct amdtp_stream *s);
void amdtp_stream_stop(struct amdtp_stream *s);
int amdtp_stream_add_pcm_hw_constraints(struct amdtp_stream *s,
struct snd_pcm_runtime *runtime);
void amdtp_stream_set_pcm_format(struct amdtp_stream *s,
snd_pcm_format_t format);
void amdtp_stream_pcm_prepare(struct amdtp_stream *s);
unsigned long amdtp_stream_pcm_pointer(struct amdtp_stream *s);
void amdtp_stream_pcm_abort(struct amdtp_stream *s);
extern const unsigned int amdtp_syt_intervals[CIP_SFC_COUNT];
extern const unsigned int amdtp_rate_table[CIP_SFC_COUNT];
/**
* amdtp_stream_running - check stream is running or not
* @s: the AMDTP stream
*
* If this function returns true, the stream is running.
*/
static inline bool amdtp_stream_running(struct amdtp_stream *s)
{
return !IS_ERR(s->context);
}
/**
* amdtp_streaming_error - check for streaming error
* @s: the AMDTP stream
*
* If this function returns true, the stream's packet queue has stopped due to
* an asynchronous error.
*/
static inline bool amdtp_streaming_error(struct amdtp_stream *s)
{
return s->packet_index < 0;
}
/**
* amdtp_stream_pcm_running - check PCM substream is running or not
* @s: the AMDTP stream
*
* If this function returns true, PCM substream in the AMDTP stream is running.
*/
static inline bool amdtp_stream_pcm_running(struct amdtp_stream *s)
{
return !!s->pcm;
}
/**
* amdtp_stream_pcm_trigger - start/stop playback from a PCM device
* @s: the AMDTP stream
* @pcm: the PCM device to be started, or %NULL to stop the current device
*
* Call this function on a running isochronous stream to enable the actual
* transmission of PCM data. This function should be called from the PCM
* device's .trigger callback.
*/
static inline void amdtp_stream_pcm_trigger(struct amdtp_stream *s,
struct snd_pcm_substream *pcm)
{
ACCESS_ONCE(s->pcm) = pcm;
}
/**
* amdtp_stream_midi_trigger - start/stop playback/capture with a MIDI device
* @s: the AMDTP stream
* @port: index of MIDI port
* @midi: the MIDI device to be started, or %NULL to stop the current device
*
* Call this function on a running isochronous stream to enable the actual
* transmission of MIDI data. This function should be called from the MIDI
* device's .trigger callback.
*/
static inline void amdtp_stream_midi_trigger(struct amdtp_stream *s,
unsigned int port,
struct snd_rawmidi_substream *midi)
{
if (port < s->midi_ports)
ACCESS_ONCE(s->midi[port]) = midi;
}
static inline bool cip_sfc_is_base_44100(enum cip_sfc sfc)
{
return sfc & 1;
}
static inline void amdtp_stream_set_sync(enum cip_flags sync_mode,
struct amdtp_stream *master,
struct amdtp_stream *slave)
{
if (sync_mode == CIP_SYNC_TO_DEVICE) {
master->flags |= CIP_SYNC_TO_DEVICE;
slave->flags |= CIP_SYNC_TO_DEVICE;
master->sync_slave = slave;
} else {
master->flags &= ~CIP_SYNC_TO_DEVICE;
slave->flags &= ~CIP_SYNC_TO_DEVICE;
master->sync_slave = NULL;
}
slave->sync_slave = NULL;
}
/**
* amdtp_stream_wait_callback - sleep till callbacked or timeout
* @s: the AMDTP stream
* @timeout: msec till timeout
*
* If this function return false, the AMDTP stream should be stopped.
*/
static inline bool amdtp_stream_wait_callback(struct amdtp_stream *s,
unsigned int timeout)
{
return wait_event_timeout(s->callback_wait,
s->callbacked == true,
msecs_to_jiffies(timeout)) > 0;
}
#endif