projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 5955815e TS |
1 | /* |
| 2 | * AM824 format in Audio and Music Data Transmission Protocol (IEC 61883-6) | |
| 3 | * | |
| 4 | * Copyright (c) 2015 Takashi Sakamoto <o-takashi@sakamocchi.jp> | |
| 5 | * | |
| 6 | * Licensed under the terms of the GNU General Public License, version 2. | |
| 7 | */ | |
| 8 | ||
| 9 | #include "amdtp-am824.h" | |
| 10 | ||
| 11 | #define CIP_FMT_AM 0x10 | |
| 12 | ||
| 51c29fd2 TS |
13 | /* "Clock-based rate control mode" is just supported. */ |
| 14 | #define AMDTP_FDF_AM824 0x00 | |
| 15 | ||
| 16 | /** | |
| 17 | * amdtp_am824_set_parameters - set stream parameters | |
| 18 | * @s: the AMDTP stream to configure | |
| 19 | * @rate: the sample rate | |
| 20 | * @pcm_channels: the number of PCM samples in each data block, to be encoded | |
| 21 | * as AM824 multi-bit linear audio | |
| 22 | * @midi_ports: the number of MIDI ports (i.e., MPX-MIDI Data Channels) | |
| 23 | * @double_pcm_frames: one data block transfers two PCM frames | |
| 24 | * | |
| 25 | * The parameters must be set before the stream is started, and must not be | |
| 26 | * changed while the stream is running. | |
| 27 | */ | |
| 28 | int amdtp_am824_set_parameters(struct amdtp_stream *s, unsigned int rate, | |
| 29 | unsigned int pcm_channels, | |
| 30 | unsigned int midi_ports, | |
| 31 | bool double_pcm_frames) | |
| 32 | { | |
| 33 | int err; | |
| 34 | ||
| 35 | err = amdtp_stream_set_parameters(s, rate, pcm_channels, midi_ports); | |
| 36 | if (err < 0) | |
| 37 | return err; | |
| 38 | ||
| 39 | s->fdf = AMDTP_FDF_AM824 | s->sfc; | |
| 40 | ||
| 41 | /* | |
| 42 | * In IEC 61883-6, one data block represents one event. In ALSA, one | |
| 43 | * event equals to one PCM frame. But Dice has a quirk at higher | |
| 44 | * sampling rate to transfer two PCM frames in one data block. | |
| 45 | */ | |
| 46 | if (double_pcm_frames) | |
| 47 | s->frame_multiplier = 2; | |
| 48 | else | |
| 49 | s->frame_multiplier = 1; | |
| 50 | ||
| 51 | return 0; | |
| 52 | } | |
| 53 | EXPORT_SYMBOL_GPL(amdtp_am824_set_parameters); | |
| 54 | ||
| f65be911 TS |
55 | /** |
| 56 | * amdtp_am824_set_pcm_position - set an index of data channel for a channel | |
| 57 | * of PCM frame | |
| 58 | * @s: the AMDTP stream | |
| 59 | * @index: the index of data channel in an data block | |
| 60 | * @position: the channel of PCM frame | |
| 61 | */ | |
| 62 | void amdtp_am824_set_pcm_position(struct amdtp_stream *s, unsigned int index, | |
| 63 | unsigned int position) | |
| 64 | { | |
| 65 | if (index < s->pcm_channels) | |
| 66 | s->pcm_positions[index] = position; | |
| 67 | } | |
| 68 | EXPORT_SYMBOL_GPL(amdtp_am824_set_pcm_position); | |
| 69 | ||
| 70 | /** | |
| 71 | * amdtp_am824_set_midi_position - set a index of data channel for MIDI | |
| 72 | * conformant data channel | |
| 73 | * @s: the AMDTP stream | |
| 74 | * @position: the index of data channel in an data block | |
| 75 | */ | |
| 76 | void amdtp_am824_set_midi_position(struct amdtp_stream *s, | |
| 77 | unsigned int position) | |
| 78 | { | |
| 79 | s->midi_position = position; | |
| 80 | } | |
| 81 | EXPORT_SYMBOL_GPL(amdtp_am824_set_midi_position); | |
| 82 | ||
| bc8500da TS |
83 | /** |
| 84 | * amdtp_am824_add_pcm_hw_constraints - add hw constraints for PCM substream | |
| 85 | * @s: the AMDTP stream for AM824 data block, must be initialized. | |
| 86 | * @runtime: the PCM substream runtime | |
| 87 | * | |
| 88 | */ | |
| 89 | int amdtp_am824_add_pcm_hw_constraints(struct amdtp_stream *s, | |
| 90 | struct snd_pcm_runtime *runtime) | |
| 91 | { | |
| 92 | int err; | |
| 93 | ||
| 94 | err = amdtp_stream_add_pcm_hw_constraints(s, runtime); | |
| 95 | if (err < 0) | |
| 96 | return err; | |
| 97 | ||
| 98 | /* AM824 in IEC 61883-6 can deliver 24bit data. */ | |
| 99 | return snd_pcm_hw_constraint_msbits(runtime, 0, 32, 24); | |
| 100 | } | |
| 101 | EXPORT_SYMBOL_GPL(amdtp_am824_add_pcm_hw_constraints); | |
| 102 | ||
| 5955815e TS |
103 | /** |
| 104 | * amdtp_am824_init - initialize an AMDTP stream structure to handle AM824 | |
| 105 | * data block | |
| 106 | * @s: the AMDTP stream to initialize | |
| 107 | * @unit: the target of the stream | |
| 108 | * @dir: the direction of stream | |
| 109 | * @flags: the packet transmission method to use | |
| 110 | */ | |
| 111 | int amdtp_am824_init(struct amdtp_stream *s, struct fw_unit *unit, | |
| 112 | enum amdtp_stream_direction dir, enum cip_flags flags) | |
| 113 | { | |
| 114 | return amdtp_stream_init(s, unit, dir, flags, CIP_FMT_AM); | |
| 115 | } | |
| 116 | EXPORT_SYMBOL_GPL(amdtp_am824_init); |