// SPDX-License-Identifier: GPL-2.0-only
/*
* ff-transaction.c - a part of driver for RME Fireface series
*
* Copyright (c) 2015-2017 Takashi Sakamoto
*/
#include "ff.h"
static void finish_transmit_midi_msg(struct snd_ff *ff, unsigned int port,
int rcode)
{
struct snd_rawmidi_substream *substream =
READ_ONCE(ff->rx_midi_substreams[port]);
if (rcode_is_permanent_error(rcode)) {
ff->rx_midi_error[port] = true;
return;
}
if (rcode != RCODE_COMPLETE) {
/* Transfer the message again, immediately. */
ff->next_ktime[port] = 0;
schedule_work(&ff->rx_midi_work[port]);
return;
}
snd_rawmidi_transmit_ack(substream, ff->rx_bytes[port]);
ff->rx_bytes[port] = 0;
if (!snd_rawmidi_transmit_empty(substream))
schedule_work(&ff->rx_midi_work[port]);
}
static void finish_transmit_midi0_msg(struct fw_card *card, int rcode,
void *data, size_t length,
void *callback_data)
{
struct snd_ff *ff =
container_of(callback_data, struct snd_ff, transactions[0]);
finish_transmit_midi_msg(ff, 0, rcode);
}
static void finish_transmit_midi1_msg(struct fw_card *card, int rcode,
void *data, size_t length,
void *callback_data)
{
struct snd_ff *ff =
container_of(callback_data, struct snd_ff, transactions[1]);
finish_transmit_midi_msg(ff, 1, rcode);
}
static void transmit_midi_msg(struct snd_ff *ff, unsigned int port)
{
struct snd_rawmidi_substream *substream =
READ_ONCE(ff->rx_midi_substreams[port]);
int quad_count;
struct fw_device *fw_dev = fw_parent_device(ff->unit);
unsigned long long addr;
int generation;
fw_transaction_callback_t callback;
int tcode;
if (substream == NULL || snd_rawmidi_transmit_empty(substream))
return;
if (ff->rx_bytes[port] > 0 || ff->rx_midi_error[port])
return;
/* Do it in next chance. */
if (ktime_after(ff->next_ktime[port], ktime_get())) {
schedule_work(&ff->rx_midi_work[port]);
return;
}
quad_count = ff->spec->protocol->fill_midi_msg(ff, substream, port);
if (quad_count <= 0)
return;
if (port == 0) {
addr = ff->spec->midi_rx_addrs[0];
callback = finish_transmit_midi0_msg;
} else {
addr = ff->spec->midi_rx_addrs[1];
callback = finish_transmit_midi1_msg;
}
/* Set interval to next transaction. */
ff->next_ktime[port] = ktime_add_ns(ktime_get(),
ff->rx_bytes[port] * 8 * (NSEC_PER_SEC / 31250));
if (quad_count == 1)
tcode = TCODE_WRITE_QUADLET_REQUEST;
else
tcode = TCODE_WRITE_BLOCK_REQUEST;
/*
* In Linux FireWire core, when generation is updated with memory
* barrier, node id has already been updated. In this module, After
* this smp_rmb(), load/store instructions to memory are completed.
* Thus, both of generation and node id are available with recent
* values. This is a light-serialization solution to handle bus reset
* events on IEEE 1394 bus.
*/
generation = fw_dev->generation;
smp_rmb();
fw_send_request(fw_dev->card, &ff->transactions[port], tcode,
fw_dev->node_id, generation, fw_dev->max_speed,
addr, &ff->msg_buf[port], quad_count * 4,
callback, &ff->transactions[port]);
}
static void transmit_midi0_msg(struct work_struct *work)
{
struct snd_ff *ff = container_of(work, struct snd_ff, rx_midi_work[0]);
transmit_midi_msg(ff, 0);
}
static void transmit_midi1_msg(struct work_struct *work)
{
struct snd_ff *ff = container_of(work, struct snd_ff, rx_midi_work[1]);
transmit_midi_msg(ff, 1);
}
static void handle_msg(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_ff *ff = callback_data;
__le32 *buf = data;
u32 tstamp = fw_request_get_timestamp(request);
unsigned long flag;
fw_send_response(card, request, RCODE_COMPLETE);
offset -= ff->async_handler.offset;
spin_lock_irqsave(&ff->lock, flag);
ff->spec->protocol->handle_msg(ff, (unsigned int)offset, buf, length, tstamp);
spin_unlock_irqrestore(&ff->lock, flag);
}
static int allocate_own_address(struct snd_ff *ff, int i)
{
struct fw_address_region midi_msg_region;
int err;
ff->async_handler.length = ff->spec->midi_addr_range;
ff->async_handler.address_callback = handle_msg;
ff->async_handler.callback_data = ff;
midi_msg_region.start = 0x000100000000ull * i;
midi_msg_region.end = midi_msg_region.start + ff->async_handler.length;
err = fw_core_add_address_handler(&ff->async_handler, &midi_msg_region);
if (err >= 0) {
/* Controllers are allowed to register this region. */
if (ff->async_handler.offset & 0x0000ffffffff) {
fw_core_remove_address_handler(&ff->async_handler);
err = -EAGAIN;
}
}
return err;
}
// Controllers are allowed to register higher 4 bytes of destination address to
// receive asynchronous transactions for MIDI messages, while the way to
// register lower 4 bytes of address is different depending on protocols. For
// details, please refer to comments in protocol implementations.
//
// This driver expects userspace applications to configure registers for the
// lower address because in most cases such registers has the other settings.
int snd_ff_transaction_reregister(struct snd_ff *ff)
{
struct fw_card *fw_card = fw_parent_device(ff->unit)->card;
u32 addr;
__le32 reg;
/*
* Controllers are allowed to register its node ID and upper 2 byte of
* local address to listen asynchronous transactions.
*/
addr = (fw_card->node_id << 16) | (ff->async_handler.offset >> 32);
reg = cpu_to_le32(addr);
return snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
ff->spec->midi_high_addr,
®, sizeof(reg), 0);
}
int snd_ff_transaction_register(struct snd_ff *ff)
{
int i, err;
/*
* Allocate in Memory Space of IEC 13213, but lower 4 byte in LSB should
* be zero due to device specification.
*/
for (i = 0; i < 0xffff; i++) {
err = allocate_own_address(ff, i);
if (err != -EBUSY && err != -EAGAIN)
break;
}
if (err < 0)
return err;
err = snd_ff_transaction_reregister(ff);
if (err < 0)
return err;
INIT_WORK(&ff->rx_midi_work[0], transmit_midi0_msg);
INIT_WORK(&ff->rx_midi_work[1], transmit_midi1_msg);
return 0;
}
void snd_ff_transaction_unregister(struct snd_ff *ff)
{
__le32 reg;
if (ff->async_handler.callback_data == NULL)
return;
ff->async_handler.callback_data = NULL;
/* Release higher 4 bytes of address. */
reg = cpu_to_le32(0x00000000);
snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
ff->spec->midi_high_addr,
®, sizeof(reg), 0);
fw_core_remove_address_handler(&ff->async_handler);
}
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