linux/sound/firewire/amdtp.h
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   1#ifndef SOUND_FIREWIRE_AMDTP_H_INCLUDED
   2#define SOUND_FIREWIRE_AMDTP_H_INCLUDED
   3
   4#include <linux/mutex.h>
   5#include <linux/spinlock.h>
   6#include "packets-buffer.h"
   7
   8/**
   9 * enum cip_out_flags - describes details of the streaming protocol
  10 * @CIP_NONBLOCKING: In non-blocking mode, each packet contains
  11 *      sample_rate/8000 samples, with rounding up or down to adjust
  12 *      for clock skew and left-over fractional samples.  This should
  13 *      be used if supported by the device.
  14 */
  15enum cip_out_flags {
  16        CIP_NONBLOCKING = 0,
  17};
  18
  19/**
  20 * enum cip_sfc - a stream's sample rate
  21 */
  22enum cip_sfc {
  23        CIP_SFC_32000  = 0,
  24        CIP_SFC_44100  = 1,
  25        CIP_SFC_48000  = 2,
  26        CIP_SFC_88200  = 3,
  27        CIP_SFC_96000  = 4,
  28        CIP_SFC_176400 = 5,
  29        CIP_SFC_192000 = 6,
  30};
  31
  32#define AMDTP_OUT_PCM_FORMAT_BITS       (SNDRV_PCM_FMTBIT_S16 | \
  33                                         SNDRV_PCM_FMTBIT_S32)
  34
  35struct fw_unit;
  36struct fw_iso_context;
  37struct snd_pcm_substream;
  38
  39struct amdtp_out_stream {
  40        struct fw_unit *unit;
  41        enum cip_out_flags flags;
  42        struct fw_iso_context *context;
  43        struct mutex mutex;
  44
  45        enum cip_sfc sfc;
  46        unsigned int data_block_quadlets;
  47        unsigned int pcm_channels;
  48        unsigned int midi_ports;
  49        void (*transfer_samples)(struct amdtp_out_stream *s,
  50                                 struct snd_pcm_substream *pcm,
  51                                 __be32 *buffer, unsigned int frames);
  52
  53        unsigned int syt_interval;
  54        unsigned int source_node_id_field;
  55        struct iso_packets_buffer buffer;
  56
  57        struct snd_pcm_substream *pcm;
  58
  59        int packet_index;
  60        unsigned int data_block_counter;
  61
  62        unsigned int data_block_state;
  63
  64        unsigned int last_syt_offset;
  65        unsigned int syt_offset_state;
  66
  67        unsigned int pcm_buffer_pointer;
  68        unsigned int pcm_period_pointer;
  69};
  70
  71int amdtp_out_stream_init(struct amdtp_out_stream *s, struct fw_unit *unit,
  72                          enum cip_out_flags flags);
  73void amdtp_out_stream_destroy(struct amdtp_out_stream *s);
  74
  75void amdtp_out_stream_set_rate(struct amdtp_out_stream *s, unsigned int rate);
  76unsigned int amdtp_out_stream_get_max_payload(struct amdtp_out_stream *s);
  77
  78int amdtp_out_stream_start(struct amdtp_out_stream *s, int channel, int speed);
  79void amdtp_out_stream_update(struct amdtp_out_stream *s);
  80void amdtp_out_stream_stop(struct amdtp_out_stream *s);
  81
  82void amdtp_out_stream_set_pcm_format(struct amdtp_out_stream *s,
  83                                     snd_pcm_format_t format);
  84void amdtp_out_stream_pcm_abort(struct amdtp_out_stream *s);
  85
  86/**
  87 * amdtp_out_stream_set_pcm - configure format of PCM samples
  88 * @s: the AMDTP output stream to be configured
  89 * @pcm_channels: the number of PCM samples in each data block, to be encoded
  90 *                as AM824 multi-bit linear audio
  91 *
  92 * This function must not be called while the stream is running.
  93 */
  94static inline void amdtp_out_stream_set_pcm(struct amdtp_out_stream *s,
  95                                            unsigned int pcm_channels)
  96{
  97        s->pcm_channels = pcm_channels;
  98}
  99
 100/**
 101 * amdtp_out_stream_set_midi - configure format of MIDI data
 102 * @s: the AMDTP output stream to be configured
 103 * @midi_ports: the number of MIDI ports (i.e., MPX-MIDI Data Channels)
 104 *
 105 * This function must not be called while the stream is running.
 106 */
 107static inline void amdtp_out_stream_set_midi(struct amdtp_out_stream *s,
 108                                             unsigned int midi_ports)
 109{
 110        s->midi_ports = midi_ports;
 111}
 112
 113/**
 114 * amdtp_out_streaming_error - check for streaming error
 115 * @s: the AMDTP output stream
 116 *
 117 * If this function returns true, the stream's packet queue has stopped due to
 118 * an asynchronous error.
 119 */
 120static inline bool amdtp_out_streaming_error(struct amdtp_out_stream *s)
 121{
 122        return s->packet_index < 0;
 123}
 124
 125/**
 126 * amdtp_out_stream_pcm_prepare - prepare PCM device for running
 127 * @s: the AMDTP output stream
 128 *
 129 * This function should be called from the PCM device's .prepare callback.
 130 */
 131static inline void amdtp_out_stream_pcm_prepare(struct amdtp_out_stream *s)
 132{
 133        s->pcm_buffer_pointer = 0;
 134        s->pcm_period_pointer = 0;
 135}
 136
 137/**
 138 * amdtp_out_stream_pcm_trigger - start/stop playback from a PCM device
 139 * @s: the AMDTP output stream
 140 * @pcm: the PCM device to be started, or %NULL to stop the current device
 141 *
 142 * Call this function on a running isochronous stream to enable the actual
 143 * transmission of PCM data.  This function should be called from the PCM
 144 * device's .trigger callback.
 145 */
 146static inline void amdtp_out_stream_pcm_trigger(struct amdtp_out_stream *s,
 147                                                struct snd_pcm_substream *pcm)
 148{
 149        ACCESS_ONCE(s->pcm) = pcm;
 150}
 151
 152/**
 153 * amdtp_out_stream_pcm_pointer - get the PCM buffer position
 154 * @s: the AMDTP output stream that transports the PCM data
 155 *
 156 * Returns the current buffer position, in frames.
 157 */
 158static inline unsigned long
 159amdtp_out_stream_pcm_pointer(struct amdtp_out_stream *s)
 160{
 161        return ACCESS_ONCE(s->pcm_buffer_pointer);
 162}
 163
 164static inline bool cip_sfc_is_base_44100(enum cip_sfc sfc)
 165{
 166        return sfc & 1;
 167}
 168
 169#endif
 170
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