ALSA firewire-motu driver has some magic numbers from IEC 61883-1 to operates source packet header (SPH). This commit replaces them with macros.
Signed-off-by: Takashi Sakamoto o-takashi@sakamocchi.jp --- sound/firewire/motu/amdtp-motu.c | 40 +++++++++++++++++++++----------- 1 file changed, 26 insertions(+), 14 deletions(-)
diff --git a/sound/firewire/motu/amdtp-motu.c b/sound/firewire/motu/amdtp-motu.c index 18bf433f43b6..89638e1fbb69 100644 --- a/sound/firewire/motu/amdtp-motu.c +++ b/sound/firewire/motu/amdtp-motu.c @@ -16,6 +16,18 @@ #define CIP_FMT_MOTU_TX_V3 0x22 #define MOTU_FDF_AM824 0x22
+#define TICKS_PER_CYCLE 3072 +#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 + /* * Nominally 3125 bytes/second, but the MIDI port's clock might be * 1% too slow, and the bus clock 100 ppm too fast. @@ -97,17 +109,16 @@ 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;
- /* IEEE 1394 bus requires. */ - delay = 0x2e00; + delay = TRANSFER_DELAY_TICKS;
- /* For no-data or empty packets to adjust PCM sampling frequency. */ - delay += 8000 * 3072 * s->syt_interval / rate; + // 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 / 3072; + 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 % 3072; + p->next_ticks = delay % TICKS_PER_CYCLE; p->next_accumulated = 0;
return 0; @@ -363,18 +374,18 @@ static inline void compute_next_elapse_from_start(struct amdtp_motu *p) }
p->next_ticks += p->quotient_ticks_per_event; - if (p->next_ticks >= 3072) { - p->next_ticks -= 3072; + if (p->next_ticks >= TICKS_PER_CYCLE) { + p->next_ticks -= TICKS_PER_CYCLE; p->next_cycles++; }
- if (p->next_cycles >= 8000) { - p->next_cycles -= 8000; + if (p->next_cycles >= CYCLES_PER_SECOND) { + p->next_cycles -= CYCLES_PER_SECOND; p->next_seconds++; }
- if (p->next_seconds >= 128) - p->next_seconds -= 128; + 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, @@ -386,8 +397,9 @@ static void write_sph(struct amdtp_stream *s, __be32 *buffer, unsigned int data_ u32 sph;
for (i = 0; i < data_blocks; i++) { - next_cycles = (rx_start_cycle + p->next_cycles) % 8000; - sph = ((next_cycles << 12) | p->next_ticks) & 0x01ffffff; + 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); *buffer = cpu_to_be32(sph);
compute_next_elapse_from_start(p);