motu-transaction.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));
}