/// +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=
/// <summary>
/// Constructor
/// </summary>
/// <param name="pwmPortIn">The PWM port we use</param>
/// <history>
/// 01 Dec 16 Cynic - Originally written
/// </history>
public PWMPortFS(PWMPortEnum pwmPortIn) : base(GpioEnum.GPIO_NONE)
{
pwmPort = pwmPortIn;
//Console.WriteLine("PWMPort Starts");
// open the port
OpenPort();
}
/// +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=
/// <summary>
/// The sysfs system requires a number to be used in order to
/// specify a specific PWM device on a EHRPWM chip This function
/// converts the PWMPortEnum value to that number
/// </summary>
/// <param name="pwmPortIn">The PWM port we use</param>
/// <returns>the export number</returns>
/// <history>
/// 07 Mar 19 Cynic - Originally written
/// 03 Mar 19 Cynic - Converted to new PWM Port Enum names
/// </history>
public uint ConvertPWMPortEnumToDeviceNumber(PWMPortEnum pwmPortIn)
{
if (pwmPortIn == PWMPortEnum.PWM0_A)
{
return(0); // 0 - EHRPWM0A
}
if (pwmPortIn == PWMPortEnum.PWM0_B)
{
return(1); // 1 - EHRPWM0B
}
if (pwmPortIn == PWMPortEnum.PWM1_A)
{
return(0); // 3 - EHRPWM1A
}
if (pwmPortIn == PWMPortEnum.PWM1_B)
{
return(1); // 4 - EHRPWM1B
}
if (pwmPortIn == PWMPortEnum.PWM2_A)
{
return(0); // 5 - EHRPWM2A
}
if (pwmPortIn == PWMPortEnum.PWM2_B)
{
return(1); // 6 - EHRPWM2B
}
throw new Exception("Unknown PWM Port: " + pwmPortIn.ToString());
}
/// +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=
/// <summary>
/// The sysfs system requires a number to be used in order to
/// export and manipulate the PWM device we wish to use. This function
/// converts the PWMPortEnum value to that number
/// </summary>
/// <param name="pwmPortIn">The PWM port we use</param>
/// <returns>the export number</returns>
/// <history>
/// 01 Dec 16 Cynic - Originally written
/// </history>
public uint ConvertPWMPortEnumToExportNumber(PWMPortEnum pwmPortIn)
{
if (pwmPortIn == PWMPortEnum.PWM_0)
{
return(0);
}
if (pwmPortIn == PWMPortEnum.PWM_1)
{
return(1);
}
throw new Exception("Unknown PWM Port: " + pwmPortIn.ToString());
}
/// +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=
/// <summary>
/// Gets the a fully qualified path for the FS files controlling the pwm
/// </summary>
/// <param name="subFileName">The name of the sub file</param>
/// <param name="pwmPortIn">The PWM port we use</param>
/// <history>
/// 01 Dec 16 Cynic - Originally written
/// </history>
private string GetFullPathToPWMFile(PWMPortEnum pwmPortIn, string subFileName)
{
StringBuilder chipFileName = new StringBuilder();
chipFileName.Append(RPIDefinitions.PWM_CHIPFILENAME_BASE);
if ((subFileName != null) && (subFileName.Length > 0))
{
chipFileName.Append(@"/");
chipFileName.Append(subFileName);
}
chipFileName.Replace("%chip%", ConvertPWMPortEnumToChipNumber(pwmPortIn).ToString());
chipFileName.Replace("%port%", ConvertPWMPortEnumToExportNumber(pwmPortIn).ToString());
return(chipFileName.ToString());
}
/// <summary> Prepares the PWM output for use. </summary>
private void Initialize()
{
PWMPortEnum Device = PWMBBB.PinToPWMID(this.Pins[0]);
// Final path will be: /sys/devices/platform/ocp/4830_000.epwmss/4830_200.pwm/pwm/pwmchip_/pwm_
// x x y z
// Where x refers to device #. dev 0 = 0, dev 1 = 2, dev 2 = 4.
// y is an arbitrary number.
// To me, it looks like this is assigned from 0 in steps of +2, in the order that the PWM devices were loaded into the device tree.
// Operationally, it seems to have no significance, and there only ever seems to be one in each *.epwmss/*.pwm/ folder.
// This is probably because at that point it is already narrowed to a single device (2 pins).
// z refers to output #. out A = 0, out B = 2.
// We need to write the pin number (z) into the "export" file, and a 1 into the "enable" file to prepare the pin for use.
// At that point, whatever needed to be set in memory is ready for BBBCSIO's PWMPortMM to take over and work.
// Why does Linux have to be so damn difficult with everything it does? :(
string Path = "/sys/devices/platform/ocp";
// Append the memory addresses.
byte ExportNum = 0;
switch (Device)
{
case PWMPortEnum.PWM0_A:
Path += "/48300000.epwmss/48300200.pwm/pwm/";
ExportNum = 0;
break;
case PWMPortEnum.PWM0_B:
Path += "/48300000.epwmss/48300200.pwm/pwm/";
ExportNum = 1;
break;
case PWMPortEnum.PWM1_A:
Path += "/48302000.epwmss/48302200.pwm/pwm/";
ExportNum = 0;
break;
case PWMPortEnum.PWM1_B:
Path += "/48302000.epwmss/48302200.pwm/pwm/";
ExportNum = 1;
break;
case PWMPortEnum.PWM2_A:
Path += "/48304000.epwmss/48304200.pwm/pwm/";
ExportNum = 0;
break;
case PWMPortEnum.PWM2_B:
Path += "/48304000.epwmss/48304200.pwm/pwm/";
ExportNum = 1;
break;
default: throw new Exception("Invalid PWM pin given.");
}
// Append the (arbitrary) pwmchip #, by using the first one we find.
string[] PWMChips = Directory.GetDirectories(Path);
Log.Output(Log.Severity.DEBUG, Log.Source.HARDWAREIO, "Attempting to find correct pwmchip number...");
bool FoundPWMChip = false;
foreach (string SubdirPath in PWMChips)
{
string Subdir = new DirectoryInfo(SubdirPath).Name;
if (Subdir.StartsWith("pwmchip"))
{
Path += Subdir;
FoundPWMChip = true;
Log.Output(Log.Severity.DEBUG, Log.Source.HARDWAREIO, "Found \"" + Subdir + "\", using.");
}
else
{
Log.Output(Log.Severity.DEBUG, Log.Source.HARDWAREIO, "Found \"" + Subdir + "\", no good.");
}
}
if (!FoundPWMChip)
{
throw new Exception("Could not find PWM chip number. Is your device tree set correctly?");
}
// Export and enable the pin.
if (!Directory.Exists(Path + "/pwm" + ExportNum))
{
StreamWriter Exporter = File.AppendText(Path + "/export");
Exporter.Write(ExportNum);
Exporter.Flush();
Exporter.Close();
}
Path += ("/pwm" + ExportNum);
StreamWriter Enabler = File.AppendText(Path + "/enable");
Enabler.Write("1");
Enabler.Flush();
Enabler.Close();
this.Port = new PWMPortMM(Device);
}
/// +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=
/// <summary>
/// The sysfs system requires a number to be used in order to
/// locate the appropriate pwmchip? file placed there by the
/// device driver
/// </summary>
/// <param name="pwmPortIn">The PWM port we use</param>
/// <returns>the chip number</returns>
/// <history>
/// 01 Dec 16 Cynic - Originally written
/// </history>
public uint ConvertPWMPortEnumToChipNumber(PWMPortEnum pwmPortIn)
{
// the drivers on the RPi2 only seem to support pwmchip0
// so we always return 0 here.
return(0);
}
