sound/firewire/fireface/ff-transaction.c - pub/scm/linux/kernel/git/mkl/linux-can - Git at Google

 // 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);

 	fw_send_response(card, request, RCODE_COMPLETE);

 	offset -= ff->async_handler.offset;

 	guard(spinlock_irqsave)(&ff->lock);
 	ff->spec->protocol->handle_msg(ff, (unsigned int)offset, buf, length, tstamp);
 }

 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,
 				  &reg, 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,
 			   &reg, sizeof(reg), 0);

 	fw_core_remove_address_handler(&ff->async_handler);
 }
	// 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);

	fw_send_response(card, request, RCODE_COMPLETE);

	offset -= ff->async_handler.offset;

	guard(spinlock_irqsave)(&ff->lock);
	ff->spec->protocol->handle_msg(ff, (unsigned int)offset, buf, length, tstamp);
	}

	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,
	&reg, 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,
	&reg, sizeof(reg), 0);

	fw_core_remove_address_handler(&ff->async_handler);
	}