root/jack2/trunk/jackmp/linux/firewire/JackFFADODriver.cpp

/*
Copyright (C) 2001 Paul Davis
Copyright (C) 2004 Grame
Copyright (C) 2007 Pieter Palmers
Copyright (C) 2009 Devin Anderson

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#include <iostream>
#include <unistd.h>
#include <math.h>
#include <stdio.h>
#include <memory.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <stdarg.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/time.h>
#include <regex.h>
#include <string.h>

#include "JackFFADODriver.h"
#include "JackFFADOMidiInputPort.h"
#include "JackFFADOMidiOutputPort.h"
#include "JackEngineControl.h"
#include "JackClientControl.h"
#include "JackPort.h"
#include "JackGraphManager.h"
#include "JackCompilerDeps.h"
#include "JackLockedEngine.h"

namespace Jack
{

#define FIREWIRE_REQUIRED_FFADO_API_VERSION 8

#define jack_get_microseconds GetMicroSeconds

int
JackFFADODriver::ffado_driver_read (ffado_driver_t * driver, jack_nframes_t nframes)
{
    channel_t chn;
    jack_default_audio_sample_t* buf = NULL;

    printEnter();
    for (chn = 0; chn < driver->capture_nchannels; chn++) {
        // if nothing connected, don't process
        if (fGraphManager->GetConnectionsNum(fCapturePortList[chn]) == 0) {
            buf = (jack_default_audio_sample_t*)driver->scratchbuffer;
            // we always have to specify a valid buffer
            ffado_streaming_set_capture_stream_buffer(driver->dev, chn, (char *)(buf));
            // notify the streaming system that it can (but doesn't have to) skip
            // this channel
            ffado_streaming_capture_stream_onoff(driver->dev, chn, 0);
        } else {
            if (driver->capture_channels[chn].stream_type == ffado_stream_type_audio) {
                buf = (jack_default_audio_sample_t*)fGraphManager->GetBuffer(fCapturePortList[chn],  nframes);

                /* if the returned buffer is invalid, use the dummy buffer */
                if (!buf) buf = (jack_default_audio_sample_t*)driver->scratchbuffer;

                ffado_streaming_set_capture_stream_buffer(driver->dev, chn, (char *)(buf));
                ffado_streaming_capture_stream_onoff(driver->dev, chn, 1);
            } else if (driver->capture_channels[chn].stream_type == ffado_stream_type_midi) {
                ffado_streaming_set_capture_stream_buffer(driver->dev, chn,
                        (char *)(driver->capture_channels[chn].midi_buffer));
                ffado_streaming_capture_stream_onoff(driver->dev, chn, 1);
            } else { // always have a valid buffer
                ffado_streaming_set_capture_stream_buffer(driver->dev, chn, (char *)(driver->scratchbuffer));
                // don't process what we don't use
                ffado_streaming_capture_stream_onoff(driver->dev, chn, 0);
            }
        }
    }

    /* now transfer the buffers */
    ffado_streaming_transfer_capture_buffers(driver->dev);

    /* process the midi data */
    for (chn = 0; chn < driver->capture_nchannels; chn++) {
        if (driver->capture_channels[chn].stream_type == ffado_stream_type_midi) {
            JackFFADOMidiInputPort *midi_input = (JackFFADOMidiInputPort *) driver->capture_channels[chn].midi_input;
            JackMidiBuffer *buffer = (JackMidiBuffer *) fGraphManager->GetBuffer(fCapturePortList[chn], nframes);
            midi_input->Process(buffer, driver->capture_channels[chn].midi_buffer, nframes);
        }
    }

    printExit();
    return 0;
}

int
JackFFADODriver::ffado_driver_write (ffado_driver_t * driver, jack_nframes_t nframes)
{
    channel_t chn;
    jack_default_audio_sample_t* buf;
    printEnter();

    driver->process_count++;

    for (chn = 0; chn < driver->playback_nchannels; chn++) {
        if (fGraphManager->GetConnectionsNum(fPlaybackPortList[chn]) == 0) {
            buf = (jack_default_audio_sample_t*)driver->nullbuffer;
            // we always have to specify a valid buffer
            ffado_streaming_set_playback_stream_buffer(driver->dev, chn, (char *)(buf));
            // notify the streaming system that it can (but doesn't have to) skip
            // this channel
            ffado_streaming_playback_stream_onoff(driver->dev, chn, 0);
        } else {
            if (driver->playback_channels[chn].stream_type == ffado_stream_type_audio) {
                buf = (jack_default_audio_sample_t*)fGraphManager->GetBuffer(fPlaybackPortList[chn], nframes);
                /* use the silent buffer if there is no valid jack buffer */
                if (!buf) buf = (jack_default_audio_sample_t*)driver->nullbuffer;
                ffado_streaming_set_playback_stream_buffer(driver->dev, chn, (char *)(buf));
                ffado_streaming_playback_stream_onoff(driver->dev, chn, 1);
            } else if (driver->playback_channels[chn].stream_type == ffado_stream_type_midi) {
                uint32_t *midi_buffer = driver->playback_channels[chn].midi_buffer;
                memset(midi_buffer, 0, nframes * sizeof(uint32_t));
                buf = (jack_default_audio_sample_t *) fGraphManager->GetBuffer(fPlaybackPortList[chn], nframes);
                ffado_streaming_set_playback_stream_buffer(driver->dev, chn, (char *)(midi_buffer));
                ffado_streaming_playback_stream_onoff(driver->dev, chn, buf ? 1 : 0);
                JackFFADOMidiOutputPort *midi_output = (JackFFADOMidiOutputPort *) driver->playback_channels[chn].midi_output;
                midi_output->Process((JackMidiBuffer *) buf, midi_buffer, nframes);

            } else { // always have a valid buffer
                ffado_streaming_set_playback_stream_buffer(driver->dev, chn, (char *)(driver->nullbuffer));
                ffado_streaming_playback_stream_onoff(driver->dev, chn, 0);
            }
        }
    }
    ffado_streaming_transfer_playback_buffers(driver->dev);
    printExit();
    return 0;
}

jack_nframes_t
JackFFADODriver::ffado_driver_wait (ffado_driver_t *driver, int extra_fd, int *status,
                                    float *delayed_usecs)
{
    jack_time_t wait_enter;
    jack_time_t wait_ret;
    ffado_wait_response response;

    printEnter();

    wait_enter = jack_get_microseconds ();
    if (wait_enter > driver->wait_next) {
        /*
                * This processing cycle was delayed past the
                * next due interrupt!  Do not account this as
                * a wakeup delay:
                */
        driver->wait_next = 0;
        driver->wait_late++;
    }
// *status = -2; interrupt
// *status = -3; timeout
// *status = -4; extra FD

    response = ffado_streaming_wait(driver->dev);

    wait_ret = jack_get_microseconds ();

    if (driver->wait_next && wait_ret > driver->wait_next) {
        *delayed_usecs = wait_ret - driver->wait_next;
    }
    driver->wait_last = wait_ret;
    driver->wait_next = wait_ret + driver->period_usecs;
//         driver->engine->transport_cycle_start (driver->engine, wait_ret);

    if(response == ffado_wait_ok) {
       // all good
       *status = 0;
    } else if (response == ffado_wait_xrun) {
        // xrun happened, but it's handled
        *status = 0;
        return 0;
    } else if (response == ffado_wait_error) {
        // an error happened (unhandled xrun)
        // this should be fatal
        jack_error("JackFFADODriver::ffado_driver_wait - unhandled xrun");
        *status = -1;
        return 0;
    } else if (response == ffado_wait_shutdown) {
        // ffado requested shutdown (e.g. device unplugged)
        // this should be fatal
        jack_error("JackFFADODriver::ffado_driver_wait - shutdown requested "
                   "(device unplugged?)");
        *status = -1;
        return 0;
    } else {
        // unknown response code. should be fatal
        // this should be fatal
        jack_error("JackFFADODriver::ffado_driver_wait - unexpected error "
                   "code '%d' returned from 'ffado_streaming_wait'", response);
        *status = -1;
        return 0;
    }

    fBeginDateUst = wait_ret;

    printExit();
    return driver->period_size;
}

int
JackFFADODriver::ffado_driver_start (ffado_driver_t *driver)
{
    int retval = 0;

    if ((retval = ffado_streaming_start(driver->dev))) {
        printError("Could not start streaming threads");

        return retval;
    }
    return 0;
}

int
JackFFADODriver::ffado_driver_stop (ffado_driver_t *driver)
{
    int retval = 0;

    if ((retval = ffado_streaming_stop(driver->dev))) {
        printError("Could not stop streaming threads");
        return retval;
    }

    return 0;
}

int
JackFFADODriver::ffado_driver_restart (ffado_driver_t *driver)
{
    if (Stop())
        return -1;
    return Start();
}

int
JackFFADODriver::SetBufferSize (jack_nframes_t nframes)
{
    printError("Buffer size change requested but not supported!!!");

    /*
    driver->period_size = nframes;
    driver->period_usecs =
            (jack_time_t) floor ((((float) nframes) / driver->sample_rate)
                                 * 1000000.0f);
    */

    /* tell the engine to change its buffer size */
    //driver->engine->set_buffer_size (driver->engine, nframes);

    return -1; // unsupported
}

typedef void (*JackDriverFinishFunction) (jack_driver_t *);

ffado_driver_t *
JackFFADODriver::ffado_driver_new (const char *name,
                                   ffado_jack_settings_t *params)
{
    ffado_driver_t *driver;

    assert(params);

    if (ffado_get_api_version() != FIREWIRE_REQUIRED_FFADO_API_VERSION) {
        printError("Incompatible libffado version! (%s)", ffado_get_version());
        return NULL;
    }

    printMessage("Starting FFADO backend (%s)", ffado_get_version());

    driver = (ffado_driver_t*)calloc (1, sizeof (ffado_driver_t));

    /* Setup the jack interfaces */
    jack_driver_nt_init ((jack_driver_nt_t *) driver);

    /*        driver->nt_attach    = (JackDriverNTAttachFunction)   ffado_driver_attach;
            driver->nt_detach    = (JackDriverNTDetachFunction)   ffado_driver_detach;
            driver->nt_start     = (JackDriverNTStartFunction)    ffado_driver_start;
            driver->nt_stop      = (JackDriverNTStopFunction)     ffado_driver_stop;
            driver->nt_run_cycle = (JackDriverNTRunCycleFunction) ffado_driver_run_cycle;
            driver->null_cycle   = (JackDriverNullCycleFunction)  ffado_driver_null_cycle;
            driver->write        = (JackDriverReadFunction)       ffado_driver_write;
            driver->read         = (JackDriverReadFunction)       ffado_driver_read;
            driver->nt_bufsize   = (JackDriverNTBufSizeFunction)  ffado_driver_bufsize;
            */

    /* copy command line parameter contents to the driver structure */
    memcpy(&driver->settings, params, sizeof(ffado_jack_settings_t));

    /* prepare all parameters */
    driver->sample_rate = params->sample_rate;
    driver->period_size = params->period_size;
    fBeginDateUst = 0;

    driver->period_usecs =
        (jack_time_t) floor ((((float) driver->period_size) * 1000000.0f) / driver->sample_rate);

//         driver->client = client;
    driver->engine = NULL;

    memset(&driver->device_options, 0, sizeof(driver->device_options));
    driver->device_options.sample_rate = params->sample_rate;
    driver->device_options.period_size = params->period_size;
    driver->device_options.nb_buffers = params->buffer_size;
    driver->device_options.verbose = params->verbose_level;
    driver->capture_frame_latency = params->capture_frame_latency;
    driver->playback_frame_latency = params->playback_frame_latency;
    driver->device_options.snoop_mode = params->snoop_mode;

    debugPrint(DEBUG_LEVEL_STARTUP, " Driver compiled on %s %s", __DATE__, __TIME__);
    debugPrint(DEBUG_LEVEL_STARTUP, " Created driver %s", name);
    debugPrint(DEBUG_LEVEL_STARTUP, "            period_size:   %d", driver->device_options.period_size);
    debugPrint(DEBUG_LEVEL_STARTUP, "            period_usecs:  %d", driver->period_usecs);
    debugPrint(DEBUG_LEVEL_STARTUP, "            sample rate:   %d", driver->device_options.sample_rate);
    debugPrint(DEBUG_LEVEL_STARTUP, "            verbose level: %d", driver->device_options.verbose);

    return (ffado_driver_t *) driver;
}

void
JackFFADODriver::ffado_driver_delete (ffado_driver_t *driver)
{
    free (driver);
}

int JackFFADODriver::Attach()
{
    JackPort* port;
    jack_port_id_t port_index;
    char buf[REAL_JACK_PORT_NAME_SIZE];
    char portname[REAL_JACK_PORT_NAME_SIZE];
    jack_latency_range_t range;

    ffado_driver_t* driver = (ffado_driver_t*)fDriver;

    jack_log("JackFFADODriver::Attach fBufferSize %ld fSampleRate %ld", fEngineControl->fBufferSize, fEngineControl->fSampleRate);

    g_verbose = (fEngineControl->fVerbose ? 1 : 0);

    /* preallocate some buffers such that they don't have to be allocated
       in RT context (or from the stack)
     */
    /* the null buffer is a buffer that contains one period of silence */
    driver->nullbuffer = (ffado_sample_t *)calloc(driver->period_size, sizeof(ffado_sample_t));
    if (driver->nullbuffer == NULL) {
        printError("could not allocate memory for null buffer");
        return -1;
    }
    /* calloc should do this, but it can't hurt to be sure */
    memset(driver->nullbuffer, 0, driver->period_size*sizeof(ffado_sample_t));

    /* the scratch buffer is a buffer of one period that can be used as dummy memory */
    driver->scratchbuffer = (ffado_sample_t *)calloc(driver->period_size, sizeof(ffado_sample_t));
    if (driver->scratchbuffer == NULL) {
        printError("could not allocate memory for scratch buffer");
        return -1;
    }

    /* packetizer thread options */
    driver->device_options.realtime = (fEngineControl->fRealTime ? 1 : 0);

    driver->device_options.packetizer_priority = fEngineControl->fServerPriority +
            FFADO_RT_PRIORITY_PACKETIZER_RELATIVE;
    if (driver->device_options.packetizer_priority > 98) {
        driver->device_options.packetizer_priority = 98;
    }

    // initialize the thread
    driver->dev = ffado_streaming_init(driver->device_info, driver->device_options);

    if (!driver->dev) {
        printError("FFADO: Error creating virtual device");
        return -1;
    }

    if (driver->device_options.realtime) {
        printMessage("Streaming thread running with Realtime scheduling, priority %d",
                     driver->device_options.packetizer_priority);
    } else {
        printMessage("Streaming thread running without Realtime scheduling");
    }

    ffado_streaming_set_audio_datatype(driver->dev, ffado_audio_datatype_float);

    /* ports */

    // capture
    driver->capture_nchannels = ffado_streaming_get_nb_capture_streams(driver->dev);
    driver->capture_channels = (ffado_capture_channel_t *)calloc(driver->capture_nchannels, sizeof(ffado_capture_channel_t));
    if (driver->capture_channels == NULL) {
        printError("could not allocate memory for capture channel list");
        return -1;
    }

    fCaptureChannels = 0;
    for (channel_t chn = 0; chn < driver->capture_nchannels; chn++) {
        ffado_streaming_get_capture_stream_name(driver->dev, chn, portname, sizeof(portname));

        driver->capture_channels[chn].stream_type = ffado_streaming_get_capture_stream_type(driver->dev, chn);
        if (driver->capture_channels[chn].stream_type == ffado_stream_type_audio) {
            snprintf(buf, sizeof(buf), "firewire_pcm:%s_in", portname);
            printMessage ("Registering audio capture port %s", buf);
            if (fEngine->PortRegister(fClientControl.fRefNum, buf,
                              JACK_DEFAULT_AUDIO_TYPE,
                              CaptureDriverFlags,
                              fEngineControl->fBufferSize, &port_index) < 0) {
                jack_error("driver: cannot register port for %s", buf);
                return -1;
            }

            // setup port parameters
            if (ffado_streaming_set_capture_stream_buffer(driver->dev, chn, NULL)) {
                printError(" cannot configure initial port buffer for %s", buf);
            }
            ffado_streaming_capture_stream_onoff(driver->dev, chn, 0);

            port = fGraphManager->GetPort(port_index);
            range.min = range.max = driver->period_size + driver->capture_frame_latency;
            port->SetLatencyRange(JackCaptureLatency, &range);
            // capture port aliases (jackd1 style port names)
            snprintf(buf, sizeof(buf), "%s:capture_%i", fClientControl.fName, (int) chn + 1);
            port->SetAlias(buf);
            fCapturePortList[chn] = port_index;
            jack_log("JackFFADODriver::Attach fCapturePortList[i] %ld ", port_index);
            fCaptureChannels++;
        } else if (driver->capture_channels[chn].stream_type == ffado_stream_type_midi) {
            snprintf(buf, sizeof(buf), "firewire_pcm:%s_in", portname);
            printMessage ("Registering midi capture port %s", buf);
            if (fEngine->PortRegister(fClientControl.fRefNum, buf,
                              JACK_DEFAULT_MIDI_TYPE,
                              CaptureDriverFlags,
                              fEngineControl->fBufferSize, &port_index) < 0) {
                jack_error("driver: cannot register port for %s", buf);
                return -1;
            }

            // setup port parameters
            if (ffado_streaming_set_capture_stream_buffer(driver->dev, chn, NULL)) {
                printError(" cannot configure initial port buffer for %s", buf);
            }
            if (ffado_streaming_capture_stream_onoff(driver->dev, chn, 0)) {
                printError(" cannot enable port %s", buf);
            }

            driver->capture_channels[chn].midi_input = new JackFFADOMidiInputPort();
            // setup the midi buffer
            driver->capture_channels[chn].midi_buffer = (uint32_t *)calloc(driver->period_size, sizeof(uint32_t));

            port = fGraphManager->GetPort(port_index);
            range.min = range.max = driver->period_size + driver->capture_frame_latency;
            port->SetLatencyRange(JackCaptureLatency, &range);
            fCapturePortList[chn] = port_index;
            jack_log("JackFFADODriver::Attach fCapturePortList[i] %ld ", port_index);
            fCaptureChannels++;
        } else {
            printMessage ("Don't register capture port %s", portname);
        }
    }

    // playback
    driver->playback_nchannels = ffado_streaming_get_nb_playback_streams(driver->dev);
    driver->playback_channels = (ffado_playback_channel_t *)calloc(driver->playback_nchannels, sizeof(ffado_playback_channel_t));
    if (driver->playback_channels == NULL) {
        printError("could not allocate memory for playback channel list");
        return -1;
    }

    fPlaybackChannels = 0;
    for (channel_t chn = 0; chn < driver->playback_nchannels; chn++) {
        ffado_streaming_get_playback_stream_name(driver->dev, chn, portname, sizeof(portname));

        driver->playback_channels[chn].stream_type = ffado_streaming_get_playback_stream_type(driver->dev, chn);

        if (driver->playback_channels[chn].stream_type == ffado_stream_type_audio) {
            snprintf(buf, sizeof(buf), "firewire_pcm:%s_out", portname);
            printMessage ("Registering audio playback port %s", buf);
            if (fEngine->PortRegister(fClientControl.fRefNum, buf,
                              JACK_DEFAULT_AUDIO_TYPE,
                              PlaybackDriverFlags,
                              fEngineControl->fBufferSize, &port_index) < 0) {
                jack_error("driver: cannot register port for %s", buf);
                return -1;
            }

            // setup port parameters
            if (ffado_streaming_set_playback_stream_buffer(driver->dev, chn, NULL)) {
                printError(" cannot configure initial port buffer for %s", buf);
            }
            if (ffado_streaming_playback_stream_onoff(driver->dev, chn, 0)) {
                printError(" cannot enable port %s", buf);
            }

            port = fGraphManager->GetPort(port_index);
            // Add one buffer more latency if "async" mode is used...
            range.min = range.max = (driver->period_size * (driver->device_options.nb_buffers - 1)) + ((fEngineControl->fSyncMode) ? 0 : fEngineControl->fBufferSize) + driver->playback_frame_latency;
            port->SetLatencyRange(JackPlaybackLatency, &range);
            // playback port aliases (jackd1 style port names)
            snprintf(buf, sizeof(buf), "%s:playback_%i", fClientControl.fName, (int) chn + 1);
            port->SetAlias(buf);
            fPlaybackPortList[chn] = port_index;
            jack_log("JackFFADODriver::Attach fPlaybackPortList[i] %ld ", port_index);
            fPlaybackChannels++;
        } else if (driver->playback_channels[chn].stream_type == ffado_stream_type_midi) {
            snprintf(buf, sizeof(buf), "firewire_pcm:%s_out", portname);
            printMessage ("Registering midi playback port %s", buf);

            if (fEngine->PortRegister(fClientControl.fRefNum, buf,
                              JACK_DEFAULT_MIDI_TYPE,
                              PlaybackDriverFlags,
                              fEngineControl->fBufferSize, &port_index) < 0) {
                jack_error("driver: cannot register port for %s", buf);
                return -1;
            }

            // setup port parameters
            if (ffado_streaming_set_playback_stream_buffer(driver->dev, chn, NULL)) {
                printError(" cannot configure initial port buffer for %s", buf);
            }
            if (ffado_streaming_playback_stream_onoff(driver->dev, chn, 0)) {
                printError(" cannot enable port %s", buf);
            }
            // setup the midi buffer

            // This constructor optionally accepts arguments for the
            // non-realtime buffer size and the realtime buffer size.  Ideally,
            // these would become command-line options for the FFADO driver.
            driver->playback_channels[chn].midi_output = new JackFFADOMidiOutputPort();

            driver->playback_channels[chn].midi_buffer = (uint32_t *)calloc(driver->period_size, sizeof(uint32_t));

            port = fGraphManager->GetPort(port_index);
            range.min = range.max = (driver->period_size * (driver->device_options.nb_buffers - 1)) + ((fEngineControl->fSyncMode) ? 0 : fEngineControl->fBufferSize) + driver->playback_frame_latency;
            port->SetLatencyRange(JackPlaybackLatency, &range);
            fPlaybackPortList[chn] = port_index;
            jack_log("JackFFADODriver::Attach fPlaybackPortList[i] %ld ", port_index);
            fPlaybackChannels++;
        } else {
            printMessage ("Don't register playback port %s", portname);
        }
    }

    assert(fCaptureChannels < DRIVER_PORT_NUM);
    assert(fPlaybackChannels < DRIVER_PORT_NUM);

    if (ffado_streaming_prepare(driver->dev)) {
        printError("Could not prepare streaming device!");
        return -1;
    }

    // this makes no sense...
    assert(fCaptureChannels + fPlaybackChannels > 0);
    return 0;
}

int JackFFADODriver::Detach()
{
    channel_t chn;
    ffado_driver_t* driver = (ffado_driver_t*)fDriver;
    jack_log("JackFFADODriver::Detach");

    // finish the libfreebob streaming
    ffado_streaming_finish(driver->dev);
    driver->dev = NULL;

    // free all internal buffers
    for (chn = 0; chn < driver->capture_nchannels; chn++) {
        if (driver->capture_channels[chn].midi_buffer)
            free(driver->capture_channels[chn].midi_buffer);
        if (driver->capture_channels[chn].midi_input)
            delete ((JackFFADOMidiInputPort *) (driver->capture_channels[chn].midi_input));
    }
    free(driver->capture_channels);

    for (chn = 0; chn < driver->playback_nchannels; chn++) {
        if (driver->playback_channels[chn].midi_buffer)
            free(driver->playback_channels[chn].midi_buffer);
        if (driver->playback_channels[chn].midi_output)
            delete ((JackFFADOMidiOutputPort *) (driver->playback_channels[chn].midi_output));
    }
    free(driver->playback_channels);

    free(driver->nullbuffer);
    free(driver->scratchbuffer);

    return JackAudioDriver::Detach();  // Generic JackAudioDriver Detach
}

int JackFFADODriver::Open(ffado_jack_settings_t *params)
{
    // Generic JackAudioDriver Open
    if (JackAudioDriver::Open(
                params->period_size, params->sample_rate,
                params->playback_ports, params->playback_ports,
                0, 0, 0, "", "",
                params->capture_frame_latency, params->playback_frame_latency) != 0) {
        return -1;
    }

    fDriver = (jack_driver_t *)ffado_driver_new ("ffado_pcm", params);

    if (fDriver) {
        // FFADO driver may have changed the in/out values
        //fCaptureChannels = ((ffado_driver_t *)fDriver)->capture_nchannels_audio;
        //fPlaybackChannels = ((ffado_driver_t *)fDriver)->playback_nchannels_audio;
        return 0;
    } else {
        JackAudioDriver::Close();
        return -1;
    }
}

int JackFFADODriver::Close()
{
    // Generic audio driver close
    int res = JackAudioDriver::Close();

    ffado_driver_delete((ffado_driver_t*)fDriver);
    return res;
}

int JackFFADODriver::Start()
{
    int res = JackAudioDriver::Start();
    if (res >= 0) {
        res = ffado_driver_start((ffado_driver_t *)fDriver);
        if (res < 0) {
            JackAudioDriver::Stop();
        }
    }
    return res;
}

int JackFFADODriver::Stop()
{
    int res = ffado_driver_stop((ffado_driver_t *)fDriver);
    if (JackAudioDriver::Stop() < 0) {
        res = -1;
    }
    return res;
}

int JackFFADODriver::Read()
{
    printEnter();

    /* Taken from ffado_driver_run_cycle */
    ffado_driver_t* driver = (ffado_driver_t*)fDriver;
    int wait_status = 0;
    fDelayedUsecs = 0.f;

retry:

    jack_nframes_t nframes = ffado_driver_wait(driver, -1, &wait_status,
                             &fDelayedUsecs);

    if ((wait_status < 0)) {
        printError( "wait status < 0! (= %d)", wait_status);
        return -1;
    }

    if (nframes == 0) {
        /* we detected an xrun and restarted: notify
         * clients about the delay.
         */
        jack_log("FFADO XRun");
        NotifyXRun(fBeginDateUst, fDelayedUsecs);
        goto retry; /* recoverable error*/
    }

    if (nframes != fEngineControl->fBufferSize)
        jack_log("JackFFADODriver::Read warning nframes = %ld", nframes);

    // Has to be done before read
    JackDriver::CycleIncTime();

    printExit();
    return ffado_driver_read((ffado_driver_t *)fDriver, fEngineControl->fBufferSize);
}

int JackFFADODriver::Write()
{
    printEnter();
    int res = ffado_driver_write((ffado_driver_t *)fDriver, fEngineControl->fBufferSize);
    printExit();
    return res;
}

void
JackFFADODriver::jack_driver_init (jack_driver_t *driver)
{
    memset (driver, 0, sizeof (*driver));

    driver->attach = 0;
    driver->detach = 0;
    driver->write = 0;
    driver->read = 0;
    driver->null_cycle = 0;
    driver->bufsize = 0;
    driver->start = 0;
    driver->stop = 0;
}

void
JackFFADODriver::jack_driver_nt_init (jack_driver_nt_t * driver)
{
    memset (driver, 0, sizeof (*driver));

    jack_driver_init ((jack_driver_t *) driver);

    driver->attach = 0;
    driver->detach = 0;
    driver->bufsize = 0;
    driver->stop = 0;
    driver->start = 0;

    driver->nt_bufsize = 0;
    driver->nt_start = 0;
    driver->nt_stop = 0;
    driver->nt_attach = 0;
    driver->nt_detach = 0;
    driver->nt_run_cycle = 0;
}

} // end of namespace


#ifdef __cplusplus
extern "C"
{
#endif

    SERVER_EXPORT const jack_driver_desc_t *
    driver_get_descriptor () {
        jack_driver_desc_t * desc;
        jack_driver_desc_filler_t filler;
        jack_driver_param_value_t value;

        desc = jack_driver_descriptor_construct("firewire", JackDriverMaster, "Linux FFADO API based audio backend", &filler);

        strcpy(value.str, "hw:0");
        jack_driver_descriptor_add_parameter(
            desc,
            &filler,
            "device",
            'd',
            JackDriverParamString,
            &value,
            NULL,
            "The FireWire device to use.",
            "The FireWire device to use. Please consult the FFADO documentation for more info.");

        value.ui = 1024;
        jack_driver_descriptor_add_parameter(desc, &filler, "period", 'p', JackDriverParamUInt, &value, NULL, "Frames per period", NULL);

        value.ui = 3;
        jack_driver_descriptor_add_parameter(desc, &filler, "nperiods", 'n', JackDriverParamUInt, &value, NULL, "Number of periods of playback latency", NULL);

        value.ui = 48000U;
        jack_driver_descriptor_add_parameter(desc, &filler, "rate", 'r', JackDriverParamUInt, &value, NULL, "Sample rate", NULL);

        value.i = 0;
        jack_driver_descriptor_add_parameter(desc, &filler, "capture", 'C', JackDriverParamBool, &value, NULL, "Provide capture ports.", NULL);
        jack_driver_descriptor_add_parameter(desc, &filler, "playback", 'P', JackDriverParamBool, &value, NULL, "Provide playback ports.", NULL);

        value.i = 1;
        jack_driver_descriptor_add_parameter(desc, &filler, "duplex", 'D', JackDriverParamBool, &value, NULL, "Provide both capture and playback ports.", NULL);

        value.ui = 0;
        jack_driver_descriptor_add_parameter(desc, &filler, "input-latency", 'I', JackDriverParamUInt, &value, NULL, "Extra input latency (frames)", NULL);
        jack_driver_descriptor_add_parameter(desc, &filler, "output-latency", 'O', JackDriverParamUInt, &value, NULL, "Extra output latency (frames)", NULL);

        value.ui = 0;
        jack_driver_descriptor_add_parameter(desc, &filler, "inchannels", 'i', JackDriverParamUInt, &value, NULL, "Number of input channels to provide (note: currently ignored)", NULL);
        jack_driver_descriptor_add_parameter(desc, &filler, "outchannels", 'o', JackDriverParamUInt, &value, NULL, "Number of output channels to provide (note: currently ignored)", NULL);

        value.ui = 3;
        jack_driver_descriptor_add_parameter(desc, &filler, "verbose", 'v', JackDriverParamUInt, &value, NULL, "libffado verbose level", NULL);

        value.i = 0;
        jack_driver_descriptor_add_parameter(desc, &filler, "snoop", 'X', JackDriverParamBool, &value, NULL, "Snoop firewire traffic", NULL);

        return desc;
    }

    SERVER_EXPORT Jack::JackDriverClientInterface* driver_initialize(Jack::JackLockedEngine* engine, Jack::JackSynchro* table, const JSList* params) {
        const JSList * node;
        const jack_driver_param_t * param;

        ffado_jack_settings_t cmlparams;

        char *device_name=(char*)"hw:0";

        cmlparams.period_size_set = 0;
        cmlparams.sample_rate_set = 0;
        cmlparams.buffer_size_set = 0;

        /* default values */
        cmlparams.period_size = 1024;
        cmlparams.sample_rate = 48000;
        cmlparams.buffer_size = 3;
        cmlparams.playback_ports = 0;
        cmlparams.capture_ports = 0;
        cmlparams.playback_frame_latency = 0;
        cmlparams.capture_frame_latency = 0;

        cmlparams.verbose_level = 0;

        cmlparams.slave_mode = 0;
        cmlparams.snoop_mode = 0;
        cmlparams.device_info = NULL;

        for (node = params; node; node = jack_slist_next (node)) {
            param = (jack_driver_param_t *) node->data;

            switch (param->character) {
                case 'd':
                    device_name = const_cast<char*>(param->value.str);
                    break;
                case 'p':
                    cmlparams.period_size = param->value.ui;
                    cmlparams.period_size_set = 1;
                    break;
                case 'n':
                    cmlparams.buffer_size = param->value.ui;
                    cmlparams.buffer_size_set = 1;
                    break;
                case 'r':
                    cmlparams.sample_rate = param->value.ui;
                    cmlparams.sample_rate_set = 1;
                    break;
                case 'i':
                    cmlparams.capture_ports = param->value.ui;
                    break;
                case 'o':
                    cmlparams.playback_ports = param->value.ui;
                    break;
                case 'I':
                    cmlparams.capture_frame_latency = param->value.ui;
                    break;
                case 'O':
                    cmlparams.playback_frame_latency = param->value.ui;
                    break;
                case 'x':
                    cmlparams.slave_mode = param->value.ui;
                    break;
                case 'X':
                    cmlparams.snoop_mode = param->value.i;
                    break;
                case 'v':
                    cmlparams.verbose_level = param->value.ui;
            }
        }

        /* duplex is the default */
        if (!cmlparams.playback_ports && !cmlparams.capture_ports) {
            cmlparams.playback_ports = 1;
            cmlparams.capture_ports = 1;
        }

        // temporary
        cmlparams.device_info = device_name;

        Jack::JackFFADODriver* ffado_driver = new Jack::JackFFADODriver("system", "firewire_pcm", engine, table);
        Jack::JackDriverClientInterface* threaded_driver = new Jack::JackThreadedDriver(ffado_driver);
        // Special open for FFADO driver...
        if (ffado_driver->Open(&cmlparams) == 0) {
            return threaded_driver;
        } else {
            delete threaded_driver; // Delete the decorated driver
            return NULL;
        }
    }

#ifdef __cplusplus
}
#endif