#define AMDTP_FDF_AM824 0x00
/*
+ * Nominally 3125 bytes/second, but the MIDI port's clock might be
+ * 1% too slow, and the bus clock 100 ppm too fast.
+ */
+#define MIDI_BYTES_PER_SECOND 3093
+
+/*
+ * Several devices look only at the first eight data blocks.
+ * In any case, this is more than enough for the MIDI data rate.
+ */
+#define MAX_MIDI_RX_BLOCKS 8
+
+/*
* The double-oh-three algorithm was discovered by Robin Gareus and Damien
* Zammit in 2012, with reverse-engineering for Digi 003 Rack.
*/
struct dot_state state;
unsigned int midi_ports;
+ /* 2 = MAX(DOT_MIDI_IN_PORTS, DOT_MIDI_OUT_PORTS) */
+ struct snd_rawmidi_substream *midi[2];
+ int midi_fifo_used[2];
+ int midi_fifo_limit;
void (*transfer_samples)(struct amdtp_stream *s,
struct snd_pcm_substream *pcm,
}
int amdtp_dot_set_parameters(struct amdtp_stream *s, unsigned int rate,
- unsigned int pcm_channels, unsigned int midi_ports)
+ unsigned int pcm_channels)
{
struct amdtp_dot *p = s->protocol;
int err;
s->fdf = AMDTP_FDF_AM824 | s->sfc;
p->pcm_channels = pcm_channels;
- p->midi_ports = midi_ports;
+
+ if (s->direction == AMDTP_IN_STREAM)
+ p->midi_ports = DOT_MIDI_IN_PORTS;
+ else
+ p->midi_ports = DOT_MIDI_OUT_PORTS;
+
+ /*
+ * We do not know the actual MIDI FIFO size of most devices. Just
+ * assume two bytes, i.e., one byte can be received over the bus while
+ * the previous one is transmitted over MIDI.
+ * (The value here is adjusted for midi_ratelimit_per_packet().)
+ */
+ p->midi_fifo_limit = rate - MIDI_BYTES_PER_SECOND * s->syt_interval + 1;
return 0;
}
}
}
+static bool midi_ratelimit_per_packet(struct amdtp_stream *s, unsigned int port)
+{
+ struct amdtp_dot *p = s->protocol;
+ int used;
+
+ used = p->midi_fifo_used[port];
+ if (used == 0)
+ return true;
+
+ used -= MIDI_BYTES_PER_SECOND * s->syt_interval;
+ used = max(used, 0);
+ p->midi_fifo_used[port] = used;
+
+ return used < p->midi_fifo_limit;
+}
+
+static inline void midi_use_bytes(struct amdtp_stream *s,
+ unsigned int port, unsigned int count)
+{
+ struct amdtp_dot *p = s->protocol;
+
+ p->midi_fifo_used[port] += amdtp_rate_table[s->sfc] * count;
+}
+
+static void write_midi_messages(struct amdtp_stream *s, __be32 *buffer,
+ unsigned int data_blocks)
+{
+ struct amdtp_dot *p = s->protocol;
+ unsigned int f, port;
+ int len;
+ u8 *b;
+
+ for (f = 0; f < data_blocks; f++) {
+ port = (s->data_block_counter + f) % 8;
+ b = (u8 *)&buffer[0];
+
+ len = 0;
+ if (port < p->midi_ports &&
+ midi_ratelimit_per_packet(s, port) &&
+ p->midi[port] != NULL)
+ len = snd_rawmidi_transmit(p->midi[port], b + 1, 2);
+
+ if (len > 0) {
+ b[3] = (0x10 << port) | len;
+ midi_use_bytes(s, port, len);
+ } else {
+ b[1] = 0;
+ b[2] = 0;
+ b[3] = 0;
+ }
+ b[0] = 0x80;
+
+ buffer += s->data_block_quadlets;
+ }
+}
+
+static void read_midi_messages(struct amdtp_stream *s, __be32 *buffer,
+ unsigned int data_blocks)
+{
+ struct amdtp_dot *p = s->protocol;
+ unsigned int f, port, len;
+ u8 *b;
+
+ for (f = 0; f < data_blocks; f++) {
+ b = (u8 *)&buffer[0];
+ port = b[3] >> 4;
+ len = b[3] & 0x0f;
+
+ if (port < p->midi_ports && p->midi[port] && len > 0)
+ snd_rawmidi_receive(p->midi[port], b + 1, len);
+
+ buffer += s->data_block_quadlets;
+ }
+}
+
int amdtp_dot_add_pcm_hw_constraints(struct amdtp_stream *s,
struct snd_pcm_runtime *runtime)
{
}
}
+void amdtp_dot_midi_trigger(struct amdtp_stream *s, unsigned int port,
+ struct snd_rawmidi_substream *midi)
+{
+ struct amdtp_dot *p = s->protocol;
+
+ if (port < p->midi_ports)
+ ACCESS_ONCE(p->midi[port]) = midi;
+}
+
static unsigned int process_tx_data_blocks(struct amdtp_stream *s,
__be32 *buffer,
unsigned int data_blocks,
pcm_frames = 0;
}
- /* A place holder for MIDI processing. */
+ read_midi_messages(s, buffer, data_blocks);
return pcm_frames;
}
pcm_frames = 0;
}
- /* A place holder for MIDI processing. */
+ write_midi_messages(s, buffer, data_blocks);
return pcm_frames;
}
#include <sound/pcm_params.h>
#include <sound/firewire.h>
#include <sound/hwdep.h>
+#include <sound/rawmidi.h>
#include "../lib.h"
#include "../iso-resources.h"
SND_DG00X_OPT_IFACE_MODE_COUNT,
};
+#define DOT_MIDI_IN_PORTS 1
+#define DOT_MIDI_OUT_PORTS 2
+
int amdtp_dot_init(struct amdtp_stream *s, struct fw_unit *unit,
enum amdtp_stream_direction dir);
int amdtp_dot_set_parameters(struct amdtp_stream *s, unsigned int rate,
- unsigned int pcm_channels,
- unsigned int midi_ports);
+ unsigned int pcm_channels);
void amdtp_dot_reset(struct amdtp_stream *s);
int amdtp_dot_add_pcm_hw_constraints(struct amdtp_stream *s,
struct snd_pcm_runtime *runtime);
void amdtp_dot_set_pcm_format(struct amdtp_stream *s, snd_pcm_format_t format);
+void amdtp_dot_midi_trigger(struct amdtp_stream *s, unsigned int port,
+ struct snd_rawmidi_substream *midi);
int snd_dg00x_transaction_register(struct snd_dg00x *dg00x);
int snd_dg00x_transaction_reregister(struct snd_dg00x *dg00x);