1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
|
/*
* AM824 format in Audio and Music Data Transmission Protocol (IEC 61883-6)
*
* Copyright (c) 2015 Takashi Sakamoto <o-takashi@sakamocchi.jp>
*
* Licensed under the terms of the GNU General Public License, version 2.
*/
#include "amdtp-am824.h"
#define CIP_FMT_AM 0x10
/* "Clock-based rate control mode" is just supported. */
#define AMDTP_FDF_AM824 0x00
/**
* amdtp_am824_set_parameters - set stream parameters
* @s: the AMDTP stream to configure
* @rate: the sample rate
* @pcm_channels: the number of PCM samples in each data block, to be encoded
* as AM824 multi-bit linear audio
* @midi_ports: the number of MIDI ports (i.e., MPX-MIDI Data Channels)
* @double_pcm_frames: one data block transfers two PCM frames
*
* The parameters must be set before the stream is started, and must not be
* changed while the stream is running.
*/
int amdtp_am824_set_parameters(struct amdtp_stream *s, unsigned int rate,
unsigned int pcm_channels,
unsigned int midi_ports,
bool double_pcm_frames)
{
int err;
err = amdtp_stream_set_parameters(s, rate, pcm_channels, midi_ports);
if (err < 0)
return err;
s->fdf = AMDTP_FDF_AM824 | s->sfc;
/*
* In IEC 61883-6, one data block represents one event. In ALSA, one
* event equals to one PCM frame. But Dice has a quirk at higher
* sampling rate to transfer two PCM frames in one data block.
*/
if (double_pcm_frames)
s->frame_multiplier = 2;
else
s->frame_multiplier = 1;
return 0;
}
EXPORT_SYMBOL_GPL(amdtp_am824_set_parameters);
/**
* amdtp_am824_set_pcm_position - set an index of data channel for a channel
* of PCM frame
* @s: the AMDTP stream
* @index: the index of data channel in an data block
* @position: the channel of PCM frame
*/
void amdtp_am824_set_pcm_position(struct amdtp_stream *s, unsigned int index,
unsigned int position)
{
if (index < s->pcm_channels)
s->pcm_positions[index] = position;
}
EXPORT_SYMBOL_GPL(amdtp_am824_set_pcm_position);
/**
* amdtp_am824_set_midi_position - set a index of data channel for MIDI
* conformant data channel
* @s: the AMDTP stream
* @position: the index of data channel in an data block
*/
void amdtp_am824_set_midi_position(struct amdtp_stream *s,
unsigned int position)
{
s->midi_position = position;
}
EXPORT_SYMBOL_GPL(amdtp_am824_set_midi_position);
/**
* amdtp_am824_add_pcm_hw_constraints - add hw constraints for PCM substream
* @s: the AMDTP stream for AM824 data block, must be initialized.
* @runtime: the PCM substream runtime
*
*/
int amdtp_am824_add_pcm_hw_constraints(struct amdtp_stream *s,
struct snd_pcm_runtime *runtime)
{
int err;
err = amdtp_stream_add_pcm_hw_constraints(s, runtime);
if (err < 0)
return err;
/* AM824 in IEC 61883-6 can deliver 24bit data. */
return snd_pcm_hw_constraint_msbits(runtime, 0, 32, 24);
}
EXPORT_SYMBOL_GPL(amdtp_am824_add_pcm_hw_constraints);
/**
* amdtp_am824_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.
*/
void amdtp_am824_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;
}
EXPORT_SYMBOL_GPL(amdtp_am824_midi_trigger);
/**
* amdtp_am824_init - initialize an AMDTP stream structure to handle AM824
* data block
* @s: the AMDTP stream to initialize
* @unit: the target of the stream
* @dir: the direction of stream
* @flags: the packet transmission method to use
*/
int amdtp_am824_init(struct amdtp_stream *s, struct fw_unit *unit,
enum amdtp_stream_direction dir, enum cip_flags flags)
{
return amdtp_stream_init(s, unit, dir, flags, CIP_FMT_AM);
}
EXPORT_SYMBOL_GPL(amdtp_am824_init);
|
