linux/sound/firewire/motu/motu-transaction.c
Takashi Sakamoto 5aaab1bf37 ALSA: firewire-motu: enable to read transaction cache via hwdep interface
MOTU FireWire series can transfer messages to registered address. These
messages are transferred for the status of internal clock synchronization
just after starting streams.

When the synchronization is stable, it's 0x01ffffff. Else, it's 0x05ffffff.

This commit adds a functionality for user space applications to receive
content of the message.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-03-28 12:34:06 +02:00

138 lines
3.5 KiB
C

/*
* motu-transaction.c - a part of driver for MOTU FireWire series
*
* Copyright (c) 2015-2017 Takashi Sakamoto <o-takashi@sakamocchi.jp>
*
* Licensed under the terms of the GNU General Public License, version 2.
*/
#include "motu.h"
#define SND_MOTU_ADDR_BASE 0xfffff0000000ULL
#define ASYNC_ADDR_HI 0x0b04
#define ASYNC_ADDR_LO 0x0b08
int snd_motu_transaction_read(struct snd_motu *motu, u32 offset, __be32 *reg,
size_t size)
{
int tcode;
if (size % sizeof(__be32) > 0 || size <= 0)
return -EINVAL;
if (size == sizeof(__be32))
tcode = TCODE_READ_QUADLET_REQUEST;
else
tcode = TCODE_READ_BLOCK_REQUEST;
return snd_fw_transaction(motu->unit, tcode,
SND_MOTU_ADDR_BASE + offset, reg, size, 0);
}
int snd_motu_transaction_write(struct snd_motu *motu, u32 offset, __be32 *reg,
size_t size)
{
int tcode;
if (size % sizeof(__be32) > 0 || size <= 0)
return -EINVAL;
if (size == sizeof(__be32))
tcode = TCODE_WRITE_QUADLET_REQUEST;
else
tcode = TCODE_WRITE_BLOCK_REQUEST;
return snd_fw_transaction(motu->unit, tcode,
SND_MOTU_ADDR_BASE + offset, reg, size, 0);
}
static void handle_message(struct fw_card *card, struct fw_request *request,
int tcode, int destination, int source,
int generation, unsigned long long offset,
void *data, size_t length, void *callback_data)
{
struct snd_motu *motu = callback_data;
__be32 *buf = (__be32 *)data;
unsigned long flags;
if (tcode != TCODE_WRITE_QUADLET_REQUEST) {
fw_send_response(card, request, RCODE_COMPLETE);
return;
}
if (offset != motu->async_handler.offset || length != 4) {
fw_send_response(card, request, RCODE_ADDRESS_ERROR);
return;
}
spin_lock_irqsave(&motu->lock, flags);
motu->msg = be32_to_cpu(*buf);
spin_unlock_irqrestore(&motu->lock, flags);
fw_send_response(card, request, RCODE_COMPLETE);
wake_up(&motu->hwdep_wait);
}
int snd_motu_transaction_reregister(struct snd_motu *motu)
{
struct fw_device *device = fw_parent_device(motu->unit);
__be32 data;
int err;
if (motu->async_handler.callback_data == NULL)
return -EINVAL;
/* Register messaging address. Block transaction is not allowed. */
data = cpu_to_be32((device->card->node_id << 16) |
(motu->async_handler.offset >> 32));
err = snd_motu_transaction_write(motu, ASYNC_ADDR_HI, &data,
sizeof(data));
if (err < 0)
return err;
data = cpu_to_be32(motu->async_handler.offset);
return snd_motu_transaction_write(motu, ASYNC_ADDR_LO, &data,
sizeof(data));
}
int snd_motu_transaction_register(struct snd_motu *motu)
{
static const struct fw_address_region resp_register_region = {
.start = 0xffffe0000000ull,
.end = 0xffffe000ffffull,
};
int err;
/* Perhaps, 4 byte messages are transferred. */
motu->async_handler.length = 4;
motu->async_handler.address_callback = handle_message;
motu->async_handler.callback_data = motu;
err = fw_core_add_address_handler(&motu->async_handler,
&resp_register_region);
if (err < 0)
return err;
err = snd_motu_transaction_reregister(motu);
if (err < 0) {
fw_core_remove_address_handler(&motu->async_handler);
motu->async_handler.address_callback = NULL;
}
return err;
}
void snd_motu_transaction_unregister(struct snd_motu *motu)
{
__be32 data;
if (motu->async_handler.address_callback != NULL)
fw_core_remove_address_handler(&motu->async_handler);
motu->async_handler.address_callback = NULL;
/* Unregister the address. */
data = cpu_to_be32(0x00000000);
snd_motu_transaction_write(motu, ASYNC_ADDR_HI, &data, sizeof(data));
snd_motu_transaction_write(motu, ASYNC_ADDR_LO, &data, sizeof(data));
}