This commit takes ALSA firewire-motu driver to perform sequence replay for
media clock recovery.
Unlike the other types of device, the devices in MOTU FireWire series
require two levels of sequence replay; the sequence of the number of
data blocks per packet and the sequence of source packet header per data
block. The former is already cached by ALSA IEC 61883-1/6 packet streaming
engine and ready to be replayed. The latter is also cached by ALSA
firewire-motu driver itself with a previous patch. This commit takes
the driver to replay both of them from the caches.
The sequence replay is tested with below models:
* 828 mkII
* Traveler
* UltraLite
* 828 mk3 FireWire
* 828 mk3 Hybrid (except for high sampling transfer frequency
* UltraLite mk3 FireWire
* 4pre
* AudioExpress
Unfortunately, below models still don't generate better sound, requires
more work:
* 8pre
* 828 mk3 Hybrid at high sampling transfer frequency
As long as I know, MOTU protocol version 1 requires extra care of the
format of data block, thus below models are not supported yet in this
time:
* 828
* 896
Signed-off-by: Takashi Sakamoto <o-takashi@xxxxxxxxxxxxx>
---
sound/firewire/motu/amdtp-motu.c | 91 ++++++-------------------------
sound/firewire/motu/motu-stream.c | 7 ++-
sound/firewire/motu/motu.h | 2 +
3 files changed, 26 insertions(+), 74 deletions(-)
diff --git a/sound/firewire/motu/amdtp-motu.c b/sound/firewire/motu/amdtp-motu.c
index 1741ceb381c7..5388b85fb60e 100644
--- a/sound/firewire/motu/amdtp-motu.c
+++ b/sound/firewire/motu/amdtp-motu.c
@@ -20,10 +20,6 @@
#define CYCLES_PER_SECOND 8000
#define TICKS_PER_SECOND (TICKS_PER_CYCLE * CYCLES_PER_SECOND)
-#define IEEE1394_SEC_MODULUS 128
-
-#define TRANSFER_DELAY_TICKS 0x2e00 /* 479.17 microseconds */
-
#define CIP_SPH_CYCLE_SHIFT 12
#define CIP_SPH_CYCLE_MASK 0x01fff000
#define CIP_SPH_OFFSET_MASK 0x00000fff
@@ -35,14 +31,6 @@
#define MIDI_BYTES_PER_SECOND 3093
struct amdtp_motu {
- /* For timestamp processing. */
- unsigned int quotient_ticks_per_event;
- unsigned int remainder_ticks_per_event;
- unsigned int next_ticks;
- unsigned int next_accumulated;
- unsigned int next_cycles;
- unsigned int next_seconds;
-
unsigned int pcm_chunks;
unsigned int pcm_byte_offset;
@@ -61,20 +49,8 @@ int amdtp_motu_set_parameters(struct amdtp_stream *s, unsigned int rate,
unsigned int midi_ports,
struct snd_motu_packet_format *formats)
{
- static const struct {
- unsigned int quotient_ticks_per_event;
- unsigned int remainder_ticks_per_event;
- } params[] = {
- [CIP_SFC_44100] = { 557, 123 },
- [CIP_SFC_48000] = { 512, 0 },
- [CIP_SFC_88200] = { 278, 282 },
- [CIP_SFC_96000] = { 256, 0 },
- [CIP_SFC_176400] = { 139, 141 },
- [CIP_SFC_192000] = { 128, 0 },
- };
struct amdtp_motu *p = s->protocol;
unsigned int pcm_chunks, data_chunks, data_block_quadlets;
- unsigned int delay;
unsigned int mode;
int i, err;
@@ -111,18 +87,6 @@ int amdtp_motu_set_parameters(struct amdtp_stream *s, unsigned int rate,
p->midi_db_count = 0;
p->midi_db_interval = rate / MIDI_BYTES_PER_SECOND;
- delay = TRANSFER_DELAY_TICKS;
-
- // For no-data or empty packets to adjust PCM sampling frequency.
- delay += TICKS_PER_SECOND * s->syt_interval / rate;
-
- p->next_seconds = 0;
- p->next_cycles = delay / TICKS_PER_CYCLE;
- p->quotient_ticks_per_event = params[s->sfc].quotient_ticks_per_event;
- p->remainder_ticks_per_event = params[s->sfc].remainder_ticks_per_event;
- p->next_ticks = delay % TICKS_PER_CYCLE;
- p->next_accumulated = 0;
-
return 0;
}
@@ -400,47 +364,26 @@ static unsigned int process_ir_ctx_payloads(struct amdtp_stream *s,
return pcm_frames;
}
-static inline void compute_next_elapse_from_start(struct amdtp_motu *p)
+static void write_sph(struct amdtp_motu_cache *cache, __be32 *buffer, unsigned int data_blocks,
+ unsigned int data_block_quadlets)
{
- p->next_accumulated += p->remainder_ticks_per_event;
- if (p->next_accumulated >= 441) {
- p->next_accumulated -= 441;
- p->next_ticks++;
- }
-
- p->next_ticks += p->quotient_ticks_per_event;
- if (p->next_ticks >= TICKS_PER_CYCLE) {
- p->next_ticks -= TICKS_PER_CYCLE;
- p->next_cycles++;
- }
-
- if (p->next_cycles >= CYCLES_PER_SECOND) {
- p->next_cycles -= CYCLES_PER_SECOND;
- p->next_seconds++;
- }
-
- if (p->next_seconds >= IEEE1394_SEC_MODULUS)
- p->next_seconds -= IEEE1394_SEC_MODULUS;
-}
-
-static void write_sph(struct amdtp_stream *s, __be32 *buffer, unsigned int data_blocks,
- const unsigned int rx_start_cycle)
-{
- struct amdtp_motu *p = s->protocol;
- unsigned int next_cycles;
- unsigned int i;
- u32 sph;
+ unsigned int *event_offsets = cache->event_offsets;
+ const unsigned int cache_size = cache->size;
+ unsigned int cache_head = cache->head;
+ unsigned int base_tick = cache->rx_cycle_count * TICKS_PER_CYCLE;
+ int i;
for (i = 0; i < data_blocks; i++) {
- next_cycles = (rx_start_cycle + p->next_cycles) % CYCLES_PER_SECOND;
- sph = ((next_cycles << CIP_SPH_CYCLE_SHIFT) | p->next_ticks) &
- (CIP_SPH_CYCLE_MASK | CIP_SPH_OFFSET_MASK);
+ unsigned int tick = (base_tick + event_offsets[cache_head]) % TICKS_PER_SECOND;
+ u32 sph = ((tick / TICKS_PER_CYCLE) << CIP_SPH_CYCLE_SHIFT) | (tick % TICKS_PER_CYCLE);
*buffer = cpu_to_be32(sph);
- compute_next_elapse_from_start(p);
-
- buffer += s->data_block_quadlets;
+ cache_head = (cache_head + 1) % cache_size;
+ buffer += data_block_quadlets;
}
+
+ cache->head = cache_head;
+ cache->rx_cycle_count = (cache->rx_cycle_count + 1) % CYCLES_PER_SECOND;
}
static unsigned int process_it_ctx_payloads(struct amdtp_stream *s,
@@ -448,11 +391,13 @@ static unsigned int process_it_ctx_payloads(struct amdtp_stream *s,
unsigned int packets,
struct snd_pcm_substream *pcm)
{
- const unsigned int rx_start_cycle = s->domain->processing_cycle.rx_start;
struct amdtp_motu *p = s->protocol;
unsigned int pcm_frames = 0;
int i;
+ if (p->cache->rx_cycle_count == UINT_MAX)
+ p->cache->rx_cycle_count = (s->domain->processing_cycle.rx_start % CYCLES_PER_SECOND);
+
// For data block processing.
for (i = 0; i < packets; ++i) {
const struct pkt_desc *desc = descs + i;
@@ -471,7 +416,7 @@ static unsigned int process_it_ctx_payloads(struct amdtp_stream *s,
// TODO: how to interact control messages between userspace?
- write_sph(s, buf, data_blocks, rx_start_cycle);
+ write_sph(p->cache, buf, data_blocks, s->data_block_quadlets);
}
// For tracepoints.
diff --git a/sound/firewire/motu/motu-stream.c b/sound/firewire/motu/motu-stream.c
index 369002568b2d..43ff5be32b15 100644
--- a/sound/firewire/motu/motu-stream.c
+++ b/sound/firewire/motu/motu-stream.c
@@ -274,8 +274,13 @@ int snd_motu_stream_start_duplex(struct snd_motu *motu)
motu->cache.tail = 0;
motu->cache.tx_cycle_count = UINT_MAX;
+ motu->cache.head = 0;
+ motu->cache.rx_cycle_count = UINT_MAX;
- err = amdtp_domain_start(&motu->domain, 0, false, false);
+ // NOTE: The device requires both of replay; the sequence of the number of data
+ // blocks per packet, and the sequence of source packet header per data block as
+ // presentation time.
+ err = amdtp_domain_start(&motu->domain, 0, true, false);
if (err < 0)
goto stop_streams;
diff --git a/sound/firewire/motu/motu.h b/sound/firewire/motu/motu.h
index 10ba87062e81..674e3dc4e45d 100644
--- a/sound/firewire/motu/motu.h
+++ b/sound/firewire/motu/motu.h
@@ -44,6 +44,8 @@ struct amdtp_motu_cache {
unsigned int size;
unsigned int tail;
unsigned int tx_cycle_count;
+ unsigned int head;
+ unsigned int rx_cycle_count;
};
struct snd_motu {
--
2.27.0
