Add IIO driver

This commit is based on Matt Flax's commits, just slightly polished and
split into logical blocks.

I did not review the code itself, since Stephane has already accepted
Matt's sequence into the codebase, thus indicating he's fine with the
changes.

linux/iio/JackIIODriver.cpp

@@ -0,0 +1,233 @@
+/*
+Copyright (C) 2013 Matt Flax <flatmax@flatmax.org>
+
+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 "JackIIODriver.h"
+#include "driver_interface.h"
+#include "JackEngineControl.h"
+#include "JackGraphManager.h"
+
+#include <values.h>
+
+#define IIO_DEFAULT_CHIP "AD7476A" ///< The default IIO recording chip to look for.
+#define IIO_DEFAULT_READ_FS 1.e6 ///< The default IIO sample rate for the default chip.
+#define IIO_DEFAULT_PERIOD_SIZE 2048 ///< The default period size is in the ms range
+#define IIO_DEFAULT_PERIOD_COUNT 2 ///< The default number of periods
+#define IIO_DEFAULT_CAPUTURE_PORT_COUNT MAXINT ///< The default number of capture ports is exceedingly big, trimmed down to a realistic size in driver_initialize
+//#define IIO_SAFETY_FACTOR 2./3. ///< The default safety factor, allow consumption of this fraction of the available DMA buffer before we don't allow the driver to continue.
+#define IIO_SAFETY_FACTOR 1. ///< The default safety factor, allow consumption of this fraction of the available DMA buffer before we don't allow the driver to continue.
+
+namespace Jack {
+
+int JackIIODriver::Attach() {
+    //cout<<"JackIIODriver::Attach\n";
+    JackAudioDriver::SetSampleRate((jack_nframes_t)IIO_DEFAULT_READ_FS);
+
+    int ret;
+    if ((ret=iio.enable(true))!=NO_ERROR) { // start the DMA
+        iio.close();
+        return ret;
+    }
+    return JackAudioDriver::Attach();
+}
+
+int JackIIODriver::Detach() {
+    //cout<<"JackIIODriver::Detach\n";
+    iio.enable(false); // stop the DMA
+    return JackAudioDriver::Detach();
+}
+
+int JackIIODriver::Read() {
+    //cout<<"JackIIODriver::Read\n";
+
+    if (iio.getDeviceCnt()<1) {
+        jack_error("JackIIODriver:: No IIO devices are present ");
+        return -1;
+    }
+    uint devChCnt=iio[0].getChCnt(); // the number of channels per device
+
+    jack_nframes_t nframes=data.rows()/devChCnt;
+    if (nframes != fEngineControl->fBufferSize)
+        jack_error("JackIIODriver::Read warning : Jack period size = %ld IIO period size = %ld", fEngineControl->fBufferSize, nframes);
+
+//    cout<<"processing buffer size : "<<fEngineControl->fBufferSize<<endl;
+//    cout<<"processing channel count : "<<fCaptureChannels<<endl;
+
+    int ret=iio.read(nframes, data); // read the data from the IIO subsystem
+    if (ret!=NO_ERROR)
+        return -1;
+
+
+    // Keep begin cycle time
+    JackDriver::CycleTakeBeginTime(); // is this necessary ?
+
+    int maxAvailChCnt=data.cols()*devChCnt;
+    jack_default_audio_sample_t scaleFactor=1./32768.;
+
+    if (fCaptureChannels>maxAvailChCnt)
+        jack_error("JackIIODriver::Read warning : Jack period size = %ld IIO period size = %ld", fEngineControl->fBufferSize, nframes);
+
+    for (int i = 0; i < fCaptureChannels; i++) {
+        int col=i/devChCnt; // find the column and offset to read from
+        int rowOffset=i%devChCnt;
+        if (fGraphManager->GetConnectionsNum(fCapturePortList[i]) > 0) {
+            jack_default_audio_sample_t *dest=GetInputBuffer(i);
+
+            for (jack_nframes_t j=0; j<nframes; j++){
+//                dest[j]=(float)j/(float)nframes;
+                dest[j]=(jack_default_audio_sample_t)(data(j*devChCnt+rowOffset, col))*scaleFactor;
+//                cout<<dest[j]<<'\t'<<data(j*devChCnt+rowOffset, col)<<"\t\t";
+            }
+        }
+    }
+
+    return 0;
+}
+
+int JackIIODriver::Write() {
+    //        cout<<"JackIIODriver::Write\n";
+    JackDriver::CycleTakeEndTime(); // is this necessary ?
+    return 0;
+}
+
+} // end namespace Jack
+
+
+#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("iio", JackDriverMaster, "Linux Industrial IO backend", &filler);
+
+    strcpy(value.str, IIO_DEFAULT_CHIP);
+    jack_driver_descriptor_add_parameter(desc, &filler, "chip", 'C', JackDriverParamString, &value, NULL, "The name of the chip to search for in the IIO devices", NULL);
+
+    value.ui = IIO_DEFAULT_CAPUTURE_PORT_COUNT;
+    jack_driver_descriptor_add_parameter(desc, &filler, "capture", 'i', JackDriverParamUInt, &value, NULL, "Provide capture count (block size).", NULL);
+
+    value.ui = IIO_DEFAULT_PERIOD_SIZE;
+    jack_driver_descriptor_add_parameter(desc, &filler, "period", 'p', JackDriverParamUInt, &value, NULL, "Frames (samples per channel) per period", NULL);
+
+    value.ui = IIO_DEFAULT_PERIOD_COUNT;
+    jack_driver_descriptor_add_parameter(desc, &filler, "nperiods", 'n', JackDriverParamUInt, &value, NULL, "Number of available periods (block count)", NULL);
+
+    return desc;
+}
+
+SERVER_EXPORT Jack::JackDriverClientInterface* driver_initialize(Jack::JackLockedEngine* engine, Jack::JackSynchro* table, const JSList* params) {
+
+    // As of this implementation the IIO driver is only capture... to be expanded.
+
+    string chipName(IIO_DEFAULT_CHIP); // the default chip name to search for in the IIO devices.
+    float fs = IIO_DEFAULT_READ_FS; // IIO sample rate is fixed.
+    jack_nframes_t periodSize = IIO_DEFAULT_PERIOD_SIZE; // default block size
+    jack_nframes_t periodCount    = IIO_DEFAULT_PERIOD_COUNT; // default block count
+    uint inChCnt = IIO_DEFAULT_CAPUTURE_PORT_COUNT; // The default number of physical input channels - a very large number, to be reduced.
+
+    for (const JSList *node = params; node; node = jack_slist_next (node)) {
+        jack_driver_param_t *param = (jack_driver_param_t *) node->data;
+
+        switch (param->character) {
+        case 'C': // we are specifying a new chip name
+            chipName = param->value.str;
+            break;
+        case 'i': // we are specifying the number of capture channels
+            inChCnt = param->value.ui;
+            break;
+        case 'p':
+            periodSize = param->value.ui;
+            break;
+        case 'n':
+            periodCount = param->value.ui;
+            break;
+        }
+    }
+
+    // create the driver which contains the IIO class
+    Jack::JackIIODriver* iio_driver = new Jack::JackIIODriver("system", "iio_pcm", engine, table);
+    if (!iio_driver) {
+        jack_error("\nHave you run out of memory ? I tried to create the IIO driver in memory but failed!\n");
+        return NULL;
+    }
+
+    // interrogate the available iio devices searching for the chip name
+    if (iio_driver->iio.findDevicesByChipName(chipName)!=NO_ERROR) { // find all devices with a particular chip which are present.
+        jack_error("\nThe iio driver found no devices by the name %s\n", chipName.c_str());
+        delete iio_driver;
+        return NULL;
+    }
+
+    if (iio_driver->iio.getDeviceCnt()<1) { // If there are no devices found by that chip name, then indicate.
+        jack_error("\nThe iio driver found no devices by the name %s\n", chipName.c_str());
+        delete iio_driver;
+        return NULL;
+    }
+
+    iio_driver->iio.printInfo(); // print out detail about the devices which were found ...
+
+    // if the available number of ports is less then the requested number, then restrict to the number of physical ports.
+    if (iio_driver->iio.getChCnt()<inChCnt)
+        inChCnt=iio_driver->iio.getChCnt();
+
+    // resize the data buffer column count to match the device count
+    int colCnt=(int)ceil((float)inChCnt/(float)iio_driver->iio[0].getChCnt()); // check whether we require less then the available number of channels
+    int ret=iio_driver->iio.getReadArray(periodSize, iio_driver->data); // resize the array to be able to read enough memory
+    if (ret!=NO_ERROR) {
+        jack_error("iio::getReadArray couldn't create the data buffer, indicating the problem.");
+        delete iio_driver;
+        return NULL;
+    }
+    if (iio_driver->data.cols()>colCnt) // resize the data columns to match the specified number of columns (channels / channels per device)
+        iio_driver->data.resize(iio_driver->data.rows(), colCnt);
+
+    ret=iio_driver->iio.open(periodCount, periodSize); // try to open all IIO devices
+    if (ret!=NO_ERROR)
+        delete iio_driver;
+        return NULL;
+
+    Jack::JackDriverClientInterface* threaded_driver = new Jack::JackThreadedDriver(iio_driver);
+    if (threaded_driver) {
+        bool capture=true, playback=false, monitor=false;
+        int outChCnt=0;
+        jack_nframes_t inputLatency = periodSize*periodCount, outputLatency=0;
+        // Special open for OSS driver...
+        if (iio_driver->Open(periodSize, periodCount, capture, playback, inChCnt, outChCnt, monitor, "iio:device", "iio:device", inputLatency, outputLatency)!=0) {
+            delete threaded_driver;
+            threaded_driver=NULL;
+        }
+    } else
+        jack_error("\nHave you run out of memory ? I tried to create Jack's standard threaded driver in memory but failed! The good news is that you had enough memory to create the IIO driver.\n");
+
+    if (!threaded_driver) { // handle the case that the threaded_driver was not created succ.
+        delete iio_driver;
+        iio_driver=NULL;
+    }
+
+    return threaded_driver;
+}
+
+#ifdef __cplusplus
+}
+#endif

linux/iio/JackIIODriver.h

@@ -0,0 +1,69 @@
+/*
+Copyright (C) 2013 Matt Flax <flatmax@flatmax.org>
+
+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.
+
+*/
+
+#ifndef JACKIIODRIVER_H
+#define JACKIIODRIVER_H
+
+#include "JackAudioDriver.h"
+#include "JackThreadedDriver.h"
+
+#include <IIO/IIOMMap.H>
+
+namespace Jack {
+
+/** The Linux Industrial IO (IIO) subsystem driver for Jack.
+Currently this driver only supports capture.
+*/
+class JackIIODriver : public JackAudioDriver {
+
+public:
+    IIOMMap iio; ///< The actual IIO devices
+    Eigen::Array<unsigned short int, Eigen::Dynamic, Eigen::Dynamic> data; ///< When we grab a mmapped buffer, store it here.
+
+    /** Constructor
+    */
+    JackIIODriver(const char* name, const char* alias, JackLockedEngine* engine, JackSynchro* table) : JackAudioDriver(name, alias, engine, table) {
+    }
+
+    /** Destructor
+    */
+    virtual ~JackIIODriver() {
+    }
+
+//    virtual int Process(){
+////        cout<<"JackIIODriver::Process\n";
+//        return JackAudioDriver::Process();
+//    }
+//
+    virtual int Attach(); ///< Enables the IIO system.
+
+    virtual int Detach(); ///< Disables the IIO system.
+
+    virtual int Read(); ///< Read from the IIO sysetm and load the jack buffers
+
+    virtual int Write(); ///< Not implemented.
+
+    virtual int SetBufferSize(jack_nframes_t buffer_size){
+        cout<<"JackIIODriver::SetBufferSize("<<buffer_size<<")\n";
+        return JackAudioDriver::SetBufferSize(buffer_size);
+    }
+};
+
+} // end of Jack namespace
+#endif // JACKIIODRIVER_H