--- /dev/null
+/*
+ * ff-transaction.c - a part of driver for RME Fireface series
+ *
+ * Copyright (c) 2015-2017 Takashi Sakamoto
+ *
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+#include "ff.h"
+
+static void finish_transmit_midi_msg(struct snd_ff *ff, unsigned int port,
+ int rcode)
+{
+ struct snd_rawmidi_substream *substream =
+ ACCESS_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] = ktime_set(0, 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 inline void fill_midi_buf(struct snd_ff *ff, unsigned int port,
+ unsigned int index, u8 byte)
+{
+ ff->msg_buf[port][index] = cpu_to_le32(byte);
+}
+
+static void transmit_midi_msg(struct snd_ff *ff, unsigned int port)
+{
+ struct snd_rawmidi_substream *substream =
+ ACCESS_ONCE(ff->rx_midi_substreams[port]);
+ u8 *buf = (u8 *)ff->msg_buf[port];
+ int i, len;
+
+ struct fw_device *fw_dev = fw_parent_device(ff->unit);
+ unsigned long long addr;
+ int generation;
+ fw_transaction_callback_t callback;
+
+ 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;
+ }
+
+ len = snd_rawmidi_transmit_peek(substream, buf,
+ SND_FF_MAXIMIM_MIDI_QUADS);
+ if (len <= 0)
+ return;
+
+ for (i = len - 1; i >= 0; i--)
+ fill_midi_buf(ff, port, i, buf[i]);
+
+ if (port == 0) {
+ addr = ff->spec->protocol->midi_rx_port_0_reg;
+ callback = finish_transmit_midi0_msg;
+ } else {
+ addr = ff->spec->protocol->midi_rx_port_1_reg;
+ callback = finish_transmit_midi1_msg;
+ }
+
+ /* Set interval to next transaction. */
+ ff->next_ktime[port] = ktime_add_ns(ktime_get(),
+ len * 8 * NSEC_PER_SEC / 31250);
+ ff->rx_bytes[port] = len;
+
+ /*
+ * 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_WRITE_BLOCK_REQUEST,
+ fw_dev->node_id, generation, fw_dev->max_speed,
+ addr, &ff->msg_buf[port], len * 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_midi_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 quad;
+ u8 byte;
+ unsigned int index;
+ struct snd_rawmidi_substream *substream;
+ int i;
+
+ fw_send_response(card, request, RCODE_COMPLETE);
+
+ for (i = 0; i < length / 4; i++) {
+ quad = le32_to_cpu(buf[i]);
+
+ /* Message in first port. */
+ /*
+ * This value may represent the index of this unit when the same
+ * units are on the same IEEE 1394 bus. This driver doesn't use
+ * it.
+ */
+ index = (quad >> 8) & 0xff;
+ if (index > 0) {
+ substream = ACCESS_ONCE(ff->tx_midi_substreams[0]);
+ if (substream != NULL) {
+ byte = quad & 0xff;
+ snd_rawmidi_receive(substream, &byte, 1);
+ }
+ }
+
+ /* Message in second port. */
+ index = (quad >> 24) & 0xff;
+ if (index > 0) {
+ substream = ACCESS_ONCE(ff->tx_midi_substreams[1]);
+ if (substream != NULL) {
+ byte = (quad >> 16) & 0xff;
+ snd_rawmidi_receive(substream, &byte, 1);
+ }
+ }
+ }
+}
+
+static int allocate_own_address(struct snd_ff *ff, int i)
+{
+ struct fw_address_region midi_msg_region;
+ int err;
+
+ ff->async_handler.length = SND_FF_MAXIMIM_MIDI_QUADS * 4;
+ ff->async_handler.address_callback = handle_midi_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;
+}
+
+/*
+ * The configuration to start asynchronous transactions for MIDI messages is in
+ * 0x'0000'8010'051c. This register includes the other options, thus this driver
+ * doesn't touch it and leaves the decision to userspace. The userspace MUST add
+ * 0x04000000 to write transactions to the register to receive any MIDI
+ * messages.
+ *
+ * Here, I just describe MIDI-related offsets of the register, in little-endian
+ * order.
+ *
+ * Controllers are allowed to register higher 4 bytes of address to receive
+ * the transactions. The register is 0x'0000'8010'03f4. On the other hand, the
+ * controllers are not allowed to register lower 4 bytes of the address. They
+ * are forced to select from 4 options by writing corresponding bits to
+ * 0x'0000'8010'051c.
+ *
+ * The 3rd-6th bits in MSB of this register are used to indicate lower 4 bytes
+ * of address to which the device transferrs the transactions.
+ * - 6th: 0x'....'....'0000'0180
+ * - 5th: 0x'....'....'0000'0100
+ * - 4th: 0x'....'....'0000'0080
+ * - 3rd: 0x'....'....'0000'0000
+ *
+ * This driver configure 0x'....'....'0000'0000 for units to receive MIDI
+ * messages. 3rd bit of the register should be configured, however this driver
+ * deligates this task to user space applications due to a restriction that
+ * this register is write-only and the other bits have own effects.
+ *
+ * The 1st and 2nd bits in LSB of this register are used to cancel transferring
+ * asynchronous transactions. These two bits have the same effect.
+ * - 1st/2nd: cancel transferring
+ */
+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->protocol->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->protocol->midi_high_addr_reg,
+ ®, sizeof(reg), 0);
+
+ fw_core_remove_address_handler(&ff->async_handler);
+}
projects / GitHub / moto-9609 / android_kernel_motorola_exynos9610.git / commitdiff