gpiobitbang

Macros
#define	APP_EC_OK   0
	success exit code
#define	APP_EC_ARGS   2
	command-line options/arguments error exit code
#define	APP_EC_EXEC   4
	execution exit code

Functions
static int	strToInt (const string &str, int &val)
static int	strToBits (const string &str, byte_t *p)
static void	mainInit (int argc, char *argv[])
	Main initialization. More...
static int	sysfsBitBang ()
	Bit bang bit pattern. More...
int	main (int argc, char *argv[])
	Main. More...

Variables
static char *	Argv0
	the command
static char *	OptsMethod = (char *)"sysfs"
	system file system
static int	OptsIbd = 1000
	inter-bit delay
static int	ArgsGpio
	gpio number
static byte_t *	ArgsPattern
	bit pattern to write
static size_t	PatByteCount
	pattern byte count
static size_t	PatBitCount
	pattern bit count
static OptsPgmInfo_T	PgmInfo
	Program information. More...
static OptsInfo_T	OptsInfo []
	Command line options information.

Detailed Description

Function Documentation

int main	(	int	argc,
		char *	argv[]
	)

Main.

Parameters

argc	Command-line argument count.
argv	Command-line argument list.

Returns

Returns 0 on succes, non-zero on failure.

Definition at line 308 of file gpiobitbang.cxx.

References APP_EC_ARGS, ArgsGpio, ArgsPattern, mainInit(), OptsIbd, OptsMethod, PatByteCount, and sysfsBitBang().

Referenced by mainInit().

{
  int   pin;
  int   ec;

  mainInit(argc, argv);


  printf("Bit banging pattern to GPIO %d.\n", ArgsGpio);
  printf("  Pattern: ");
  for(size_t i=0; i<PatByteCount; ++i)
  {
    printf("%02x ", ArgsPattern[i]);
  }
  printf("\n");
  printf("  Ibd:     %u usec\n", OptsIbd);

  if( !strcmp(OptsMethod, "sysfs") )
  {
    ec = sysfsBitBang();
  }
#ifdef MMAP_GPIO
  else if( !strcmp(OptsMethod, "mmap") )
  {
    ec = mmapBitBang();
  }
#endif // MMAP_GPIO
  else
  {
    fprintf(stderr,"%s: Unknown GPIO access method.", OptsMethod);
    ec = APP_EC_ARGS;
  }

  return ec;
}

static void mainInit ( int  argc, char *  argv[]  )

static

Main initialization.

Parameters

argc	Command-line argument count.
argv	Command-line argument list.

Exits:

Program terminates on conversion error.

Definition at line 190 of file gpiobitbang.cxx.

References APP_EC_ARGS, ArgsGpio, ArgsPattern, Argv0, OptsInfo, PatBitCount, PatByteCount, PgmInfo, and PkgInfo.

Referenced by main().

{
  int     i;
  byte_t *p;

  // name of this process
  Argv0 = basename(argv[0]);

  // parse input options
  argv = OptsGet(Argv0, &PkgInfo, &PgmInfo, OptsInfo, true, &argc, argv);

  if( argc == 0 )
  {
    fprintf(stderr, "%s: No GPIO pin number <gpio> specified.\n", Argv0);
    fprintf(stderr, "Try '%s --help' for more information.\n", Argv0);
    exit(APP_EC_ARGS);
  }

  else if( strToInt(argv[0], ArgsGpio) < 0 )
  {
    fprintf(stderr, "%s: '%s': Bad GPIO number.\n", Argv0, argv[0]);
    fprintf(stderr, "Try '%s --help' for more information.\n", Argv0);
    exit(APP_EC_ARGS);
  }

  if( argc == 1 )
  {
    fprintf(stderr, "%s: No bit pattern specified.\n", Argv0);
    fprintf(stderr, "Try '%s --help' for more information.\n", Argv0);
    exit(APP_EC_ARGS);
  }

  PatByteCount  = argc - 1;
  PatBitCount   = 8 * PatByteCount;
  ArgsPattern   = (byte_t *)malloc(sizeof(byte_t) * PatByteCount);

  for(i=1, p=ArgsPattern; i<argc; ++i, ++p)
  {
    if( strToBits(argv[i], p) < 0 )
    {
      fprintf(stderr, "%s: '%s': Bad bit pattern %d.\n", Argv0, argv[i], i);
      fprintf(stderr, "Try '%s --help' for more information.\n", Argv0);
      exit(APP_EC_ARGS);
    }
  }
}

static int sysfsBitBang ( )

static

Bit bang bit pattern.

Method: sysfs

Returns

Application exit code.

Definition at line 244 of file gpiobitbang.cxx.

References APP_EC_EXEC, APP_EC_OK, ArgsGpio, ArgsPattern, gpioBitBang(), gpioClose(), gpioOpen(), OptsIbd, and PatBitCount.

Referenced by main().

{
  int   fd;
  int   ec;

  if( (fd = gpioOpen(ArgsGpio)) < 0 )
  {
    return APP_EC_EXEC;
  }

  if( gpioBitBang(fd, ArgsPattern, PatBitCount, OptsIbd) < 0 )
  {
    ec = APP_EC_EXEC;
  }
  else
  {
    ec = APP_EC_OK;
  }

  gpioClose(fd);

  return ec;
}

Variable Documentation

OptsPgmInfo_T PgmInfo

static

Initial value:

=
{
  
  "<gpio> byte [byte...]",

  
  "Bit-bang bit pattern out GPIO pin.",

  
  "The %P command writes the specified bit pattern to the GPIO at the given "
  "exported number. "
  "A bit value of 0 sets the pin low. "
  "A bit value of 1 set the pin high."
  "The byte pattern is specified as a series of byte arguments of any of the "
  "format:\n"
  "  0xH[H]     hexidecimal      examples: 0x5        0x3C     0xff\n"
  "  0bB[B...]  binary           examples: 0b00000101 0b001111 0b11111111\n"
  "  D[D...]    unsigned integer examples: 5          60       255",

  
  NULL
}

Program information.

Definition at line 69 of file gpiobitbang.cxx.

Referenced by mainInit().