@@ -53,6 +53,12 @@ struct snd_firewire_event_motu_notification {
__u32 message; /* MOTU-specific bits. */
};
+struct snd_firewire_tascam_change {
+ unsigned int index;
+ __be32 before;
+ __be32 after;
+};
+
union snd_firewire_event {
struct snd_firewire_event_common common;
struct snd_firewire_event_lock_status lock_status;
@@ -121,13 +121,45 @@ static void read_status_messages(struct amdtp_stream *s,
__be32 *buffer, unsigned int data_blocks)
{
struct snd_tscm *tscm = container_of(s, struct snd_tscm, tx_stream);
+ bool used = READ_ONCE(tscm->hwdep->used);
int i;
for (i = 0; i < data_blocks; i++) {
unsigned int index;
+ __be32 before;
+ __be32 after;
index = be32_to_cpu(buffer[0]) % SNDRV_FIREWIRE_TASCAM_STATE_COUNT;
- tscm->state[index] = buffer[s->data_block_quadlets - 1];
+ before = tscm->state[index];
+ after = buffer[s->data_block_quadlets - 1];
+
+ if (used && index > 4 && index < 16) {
+ __be32 mask;
+
+ if (index == 5)
+ mask = cpu_to_be32(~0x0000ffff);
+ else if (index == 6)
+ mask = cpu_to_be32(~0x0000ffff);
+ else if (index == 8)
+ mask = cpu_to_be32(~0x000f0f00);
+ else
+ mask = cpu_to_be32(~0x00000000);
+
+ if ((before ^ after) & mask) {
+ struct snd_firewire_tascam_change *entry =
+ &tscm->queue[tscm->push_pos];
+
+ spin_lock_irq(&tscm->lock);
+ entry->index = index;
+ entry->before = before;
+ entry->after = after;
+ if (++tscm->push_pos >= SND_TSCM_QUEUE_COUNT)
+ tscm->push_pos = 0;
+ spin_unlock_irq(&tscm->lock);
+ }
+ }
+
+ tscm->state[index] = after;
buffer += s->data_block_quadlets;
}
}
@@ -195,5 +195,7 @@ int snd_tscm_create_hwdep_device(struct snd_tscm *tscm)
hwdep->private_data = tscm;
hwdep->exclusive = true;
+ tscm->hwdep = hwdep;
+
return err;
}
@@ -62,6 +62,8 @@ struct snd_fw_async_midi_port {
int consume_bytes;
};
+#define SND_TSCM_QUEUE_COUNT 16
+
struct snd_tscm {
struct snd_card *card;
struct fw_unit *unit;
@@ -92,6 +94,10 @@ struct snd_tscm {
// A cache of status information in tx isoc packets.
__be32 state[SNDRV_FIREWIRE_TASCAM_STATE_COUNT];
+ struct snd_hwdep *hwdep;
+ struct snd_firewire_tascam_change queue[SND_TSCM_QUEUE_COUNT];
+ unsigned int pull_pos;
+ unsigned int push_pos;
};
#define TSCM_ADDR_BASE 0xffff00000000ull
Units of TASCAM FireWire series transfer image of states of the unit in tx isochronous packets. Demultiplexing of the states from the packets is done in software interrupt context regardless of any process context. In a view of userspace applications, it needs to have notification mechanism to catch change of the states. This commit implements a queue to store events for the notification. The image of states includes fluctuating data such as level of gain/volume for physical input/output and position of knobs. Therefore the events are queued corresponding to some control features only. Furthermore, the queued events are planned to be consumed by userspace applications via ALSA hwdep interface. This commit suppresses event queueing when no applications open the hwdep interface. However, the queue is maintained in an optimistic scenario, thus without any care against overrrun. This is reasonable because target events are useless just to handle PCM frames. It starts queueing when an usespace application opens hwdep interface, thus it's expected to read the queued events steadily. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> --- include/uapi/sound/firewire.h | 6 +++++ sound/firewire/tascam/amdtp-tascam.c | 34 +++++++++++++++++++++++++++- sound/firewire/tascam/tascam-hwdep.c | 2 ++ sound/firewire/tascam/tascam.h | 6 +++++ 4 files changed, 47 insertions(+), 1 deletion(-)