/*
* wiringPi:
* Arduino compatable (ish) Wiring library for the Raspberry Pi
* Copyright (c) 2012 Gordon Henderson
* Additional code for pwmSetClock by Chris Hall <chris@kchall.plus.com>
*
* Thanks to code samples from Gert Jan van Loo and the
* BCM2835 ARM Peripherals manual, however it's missing
* the clock section /grr/mutter/
***********************************************************************
* This file is part of wiringPi:
* https://projects.drogon.net/raspberry-pi/wiringpi/
*
* wiringPi is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* wiringPi 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with wiringPi.
* If not, see <http://www.gnu.org/licenses/>.
***********************************************************************
*/
// Revisions:
// 19 Jul 2012:
// Moved to the LGPL
// Added an abstraction layer to the main routines to save a tiny
// bit of run-time and make the clode a little cleaner (if a little
// larger)
// Added waitForInterrupt code
// Added piHiPri code
//
// 9 Jul 2012:
// Added in support to use the /sys/class/gpio interface.
// 2 Jul 2012:
// Fixed a few more bugs to do with range-checking when in GPIO mode.
// 11 Jun 2012:
// Fixed some typos.
// Added c++ support for the .h file
// Added a new function to allow for using my "pin" numbers, or native
// GPIO pin numbers.
// Removed my busy-loop delay and replaced it with a call to delayMicroseconds
//
// 02 May 2012:
// Added in the 2 UART pins
// Change maxPins to numPins to more accurately reflect purpose
// Pad drive current fiddling
#undef DEBUG_PADS
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <ctype.h>
#include <poll.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <time.h>
#include <fcntl.h>
#include <sys/time.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include "wiringPi.h"
// Function stubs
void (*pinMode) (int pin, int mode) ;
void (*pullUpDnControl) (int pin, int pud) ;
void (*digitalWrite) (int pin, int value) ;
void (*pwmWrite) (int pin, int value) ;
void (*setPadDrive) (int group, int value) ;
int (*digitalRead) (int pin) ;
int (*waitForInterrupt) (int pin, int mS) ;
void (*delayMicroseconds) (unsigned int howLong) ;
void (*pwmSetMode) (int mode) ;
void (*pwmSetRange) (unsigned int range) ;
void (*pwmSetClock) (int divisor) ;
#ifndef TRUE
#define TRUE (1==1)
#define FALSE (1==2)
#endif
// BCM Magic
#define BCM_PASSWORD 0x5A000000
// Port function select bits
#define FSEL_INPT 0b000
#define FSEL_OUTP 0b001
#define FSEL_ALT0 0b100
#define FSEL_ALT0 0b100
#define FSEL_ALT1 0b101
#define FSEL_ALT2 0b110
#define FSEL_ALT3 0b111
#define FSEL_ALT4 0b011
#define FSEL_ALT5 0b010
// Access from ARM Running Linux
// Take from Gert/Doms code. Some of this is not in the manual
// that I can find )-:
#define BCM2708_PERI_BASE 0x20000000
#define GPIO_PADS (BCM2708_PERI_BASE + 0x100000)
#define CLOCK_BASE (BCM2708_PERI_BASE + 0x101000)
#define GPIO_BASE (BCM2708_PERI_BASE + 0x200000)
#define GPIO_TIMER (BCM2708_PERI_BASE + 0x00B000)
#define GPIO_PWM (BCM2708_PERI_BASE + 0x20C000)
#define PAGE_SIZE (4*1024)
#define BLOCK_SIZE (4*1024)
// PWM
#define PWM_CONTROL 0
#define PWM_STATUS 1
#define PWM0_RANGE 4
#define PWM0_DATA 5
#define PWM1_RANGE 8
#define PWM1_DATA 9
#define PWMCLK_CNTL 40
#define PWMCLK_DIV 41
#define PWM1_MS_MODE 0x8000 // Run in MS mode
#define PWM1_USEFIFO 0x2000 // Data from FIFO
#define PWM1_REVPOLAR 0x1000 // Reverse polarity
#define PWM1_OFFSTATE 0x0800 // Ouput Off state
#define PWM1_REPEATFF 0x0400 // Repeat last value if FIFO empty
#define PWM1_SERIAL 0x0200 // Run in serial mode
#define PWM1_ENABLE 0x0100 // Channel Enable
#define PWM0_MS_MODE 0x0080 // Run in MS mode
#define PWM0_USEFIFO 0x0020 // Data from FIFO
#define PWM0_REVPOLAR 0x0010 // Reverse polarity
#define PWM0_OFFSTATE 0x0008 // Ouput Off state
#define PWM0_REPEATFF 0x0004 // Repeat last value if FIFO empty
#define PWM0_SERIAL 0x0002 // Run in serial mode
#define PWM0_ENABLE 0x0001 // Channel Enable
// Timer
#define TIMER_LOAD (0x400 >> 2)
#define TIMER_VALUE (0x404 >> 2)
#define TIMER_CONTROL (0x408 >> 2)
#define TIMER_IRQ_CLR (0x40C >> 2)
#define TIMER_IRQ_RAW (0x410 >> 2)
#define TIMER_IRQ_MASK (0x414 >> 2)
#define TIMER_RELOAD (0x418 >> 2)
#define TIMER_PRE_DIV (0x41C >> 2)
#define TIMER_COUNTER (0x420 >> 2)
// Locals to hold pointers to the hardware
static volatile uint32_t *gpio ;
static volatile uint32_t *pwm ;
static volatile uint32_t *clk ;
static volatile uint32_t *pads ;
static volatile uint32_t *timer ;
static volatile uint32_t *timerIrqRaw ;
// Debugging
static int wiringPiDebug = FALSE ;
// The BCM2835 has 54 GPIO pins.
// BCM2835 data sheet, Page 90 onwards.
// There are 6 control registers, each control the functions of a block
// of 10 pins.
// Each control register has 10 sets of 3 bits per GPIO pin:
//
// 000 = GPIO Pin X is an input
// 001 = GPIO Pin X is an output
// 100 = GPIO Pin X takes alternate function 0
// 101 = GPIO Pin X takes alternate function 1
// 110 = GPIO Pin X takes alternate function 2
// 111 = GPIO Pin X takes alternate function 3
// 011 = GPIO Pin X takes alternate function 4
// 010 = GPIO Pin X takes alternate function 5
//
// So the 3 bits for port X are:
// X / 10 + ((X % 10) * 3)
// sysFds:
// Map a file descriptor from the /sys/class/gpio/gpioX/value
static int sysFds [64] ;
// Doing it the Arduino way with lookup tables...
// Yes, it's probably more innefficient than all the bit-twidling, but it
// does tend to make it all a bit clearer. At least to me!
// pinToGpio:
// Take a Wiring pin (0 through X) and re-map it to the BCM_GPIO pin
// Cope for 2 different board revieions here
static int *pinToGpio ;
static int pinToGpioR1 [64] =
{
17, 18, 21, 22, 23, 24, 25, 4, // From the Original Wiki - GPIO 0 through 7
0, 1, // I2C - SDA0, SCL0
8, 7, // SPI - CE1, CE0
10, 9, 11, // SPI - MOSI, MISO, SCLK
14, 15, // UART - Tx, Rx
// Padding:
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // ... 31
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // ... 47
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // ... 63
} ;
static int pinToGpioR2 [64] =
{
17, 18, 27, 22, 23, 24, 25, 4, // From the Original Wiki - GPIO 0 through 7: wpi 0 - 7
2, 3, // I2C - SDA0, SCL0 wpi 8 - 9
8, 7, // SPI - CE1, CE0 wpi 10 - 11
10, 9, 11, // SPI - MOSI, MISO, SCLK wpi 12 - 14
14, 15, // UART - Tx, Rx wpi 15 - 16
28, 29, 30, 31, // New GPIOs 8 though 11 wpi 17 - 20
// Padding:
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // ... 31
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // ... 47
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // ... 63
} ;
// gpioToGPFSEL:
// Map a BCM_GPIO pin to it's control port. (GPFSEL 0-5)
static uint8_t gpioToGPFSEL [] =
{
0,0,0,0,0,0,0,0,0,0,
1,1,1,1,1,1,1,1,1,1,
2,2,2,2,2,2,2,2,2,2,
3,3,3,3,3,3,3,3,3,3,
4,4,4,4,4,4,4,4,4,4,
5,5,5,5,5,5,5,5,5,5,
} ;
// gpioToShift
// Define the shift up for the 3 bits per pin in each GPFSEL port
static uint8_t gpioToShift [] =
{
0,3,6,9,12,15,18,21,24,27,
0,3,6,9,12,15,18,21,24,27,
0,3,6,9,12,15,18,21,24,27,
0,3,6,9,12,15,18,21,24,27,
0,3,6,9,12,15,18,21,24,27,
} ;
// gpioToGPSET:
// (Word) offset to the GPIO Set registers for each GPIO pin
static uint8_t gpioToGPSET [] =
{
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
} ;
// gpioToGPCLR:
// (Word) offset to the GPIO Clear registers for each GPIO pin
static uint8_t gpioToGPCLR [] =
{
10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10,
11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,11,
} ;
// gpioToGPLEV:
// (Word) offset to the GPIO Input level registers for each GPIO pin
static uint8_t gpioToGPLEV [] =
{
13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,
14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,
} ;
#ifdef notYetReady
// gpioToEDS
// (Word) offset to the Event Detect Status
static uint8_t gpioToEDS [] =
{
16,16,16,16,16,16,16,16,16,16,16,16,16,16,16,16,16,16,16,16,16,16,16,16,16,16,16,16,16,16,16,16,
17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,17,
} ;
// gpioToREN
// (Word) offset to the Rising edgde ENable register
static uint8_t gpioToREN [] =
{
19,19,19,19,19,19,19,19,19,19,19,19,19,19,19,19,19,19,19,19,19,19,19,19,19,19,19,19,19,19,19,19,
20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,
} ;
// gpioToFEN
// (Word) offset to the Falling edgde ENable register
static uint8_t gpioToFEN [] =
{
22,22,22,22,22,22,22,22,22,22,22,22,22,22,22,22,22,22,22,22,22,22,22,22,22,22,22,22,22,22,22,22,
23,23,23,23,23,23,23,23,23,23,23,23,23,23,23,23,23,23,23,23,23,23,23,23,23,23,23,23,23,23,23,23,
} ;
#endif
// gpioToPUDCLK
// (Word) offset to the Pull Up Down Clock regsiter
#define GPPUD 37
static uint8_t gpioToPUDCLK [] =
{
38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,
39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,
} ;
// gpioToPwmALT
// the ALT value to put a GPIO pin into PWM mode
static uint8_t gpioToPwmALT [] =
{
0, 0, 0, 0, 0, 0, 0, 0, // 0 -> 7
0, 0, 0, 0, FSEL_ALT0, FSEL_ALT0, 0, 0, // 8 -> 15
0, 0, FSEL_ALT5, FSEL_ALT5, 0, 0, 0, 0, // 16 -> 23
0, 0, 0, 0, 0, 0, 0, 0, // 24 -> 31
0, 0, 0, 0, 0, 0, 0, 0, // 32 -> 39
FSEL_ALT0, FSEL_ALT0, 0, 0, 0, FSEL_ALT0, 0, 0, // 40 -> 47
0, 0, 0, 0, 0, 0, 0, 0, // 48 -> 55
0, 0, 0, 0, 0, 0, 0, 0, // 56 -> 63
} ;
static uint8_t gpioToPwmPort [] =
{
0, 0, 0, 0, 0, 0, 0, 0, // 0 -> 7
0, 0, 0, 0, PWM0_DATA, PWM1_DATA, 0, 0, // 8 -> 15
0, 0, PWM0_DATA, PWM1_DATA, 0, 0, 0, 0, // 16 -> 23
0, 0, 0, 0, 0, 0, 0, 0, // 24 -> 31
0, 0, 0, 0, 0, 0, 0, 0, // 32 -> 39
PWM0_DATA, PWM1_DATA, 0, 0, 0, PWM1_DATA, 0, 0, // 40 -> 47
0, 0, 0, 0, 0, 0, 0, 0, // 48 -> 55
0, 0, 0, 0, 0, 0, 0, 0, // 56 -> 63
} ;
// Time for easy calculations
static unsigned long long epoch ;
/*
* Functions
*********************************************************************************
*/
/*
* wpiPinToGpio:
* Translate a wiringPi Pin number to native GPIO pin number.
* (We don't use this here, prefering to just do the lookup directly,
* but it's been requested!)
*********************************************************************************
*/
int wpiPinToGpio (int wpiPin)
{
return pinToGpio [wpiPin & 63] ;
}
/*
* piBoardRev:
* Return a number representing the hardware revision of the board.
* Revision is currently 1 or 2. -1 is returned on error.
*
* Much confusion here )-:
* Seems there ar esome boards with 0000 in them (mistake in manufacture)
* and some board with 0005 in them (another mistake in manufacture).
* So the distinction between boards that I can see is:
* 0000 - Error
* 0001 - Not used
* 0002 - Rev 1
* 0003 - Rev 1
* 0004 - Rev 2
* 0005 - Rev 2
* 0006 - Rev 2
* 000f - Rev 2 + 512MB
*
* A small thorn is the olde style overvolting - that will add in
* 1000000
*
*********************************************************************************
*/
int piBoardRev (void)
{
FILE *cpuFd ;
char line [120] ;
char *c, lastChar ;
static int boardRev = -1 ;
// No point checking twice...
if (boardRev != -1)
return boardRev ;
if ((cpuFd = fopen ("/proc/cpuinfo", "r")) == NULL)
return -1 ;
while (fgets (line, 120, cpuFd) != NULL)
if (strncmp (line, "Revision", 8) == 0)
break ;
fclose (cpuFd) ;
if (line == NULL)
{
fprintf (stderr, "piBoardRev: Unable to determine board revision from /proc/cpuinfo\n") ;
fprintf (stderr, " (No \"Revision\" line)\n") ;
errno = 0 ;
return -1 ;
}
for (c = line ; *c ; ++c)
if (isdigit (*c))
break ;
if (!isdigit (*c))
{
fprintf (stderr, "piBoardRev: Unable to determine board revision from /proc/cpuinfo\n") ;
fprintf (stderr, " (No numeric revision string in: \"%s\"\n", line) ;
errno = 0 ;
return -1 ;
}
// If you have overvolted the Pi, then it appears that the revision
// has 100000 added to it!
if (wiringPiDebug)
if (strlen (c) != 4)
printf ("piboardRev: This Pi has/is overvolted!\n") ;
lastChar = c [strlen (c) - 2] ;
/**/ if ((lastChar == '2') || (lastChar == '3'))
boardRev = 1 ;
else
boardRev = 2 ;
#ifdef DO_WE_CARE_ABOUT_THIS_NOW
else
{
fprintf (stderr, "WARNING: wiringPi: Unable to determine board revision from \"%d\"\n", r) ;
fprintf (stderr, " -> You may want to check:\n") ;
fprintf (stderr, " -> http://www.raspberrypi.org/phpBB3/viewtopic.php?p=184410#p184410\n") ;
fprintf (stderr, " -> Assuming a Rev 1 board\n") ;
boardRev = 1 ;
}
#endif
if (wiringPiDebug)
printf ("piboardRev: Revision string: %s, board revision: %d\n", c, boardRev) ;
return boardRev ;
}
/*
* pinMode:
* Sets the mode of a pin to be input, output or PWM output
*********************************************************************************
*/
void pinModeGpio (int pin, int mode)
{
int fSel, shift, alt ;
pin &= 63 ;
fSel = gpioToGPFSEL [pin] ;
shift = gpioToShift [pin] ;
/**/ if (mode == INPUT)
*(gpio + fSel) = (*(gpio + fSel) & ~(7 << shift)) ; // Sets bits to zero = input
else if (mode == OUTPUT)
*(gpio + fSel) = (*(gpio + fSel) & ~(7 << shift)) | (1 << shift) ;
else if (mode == PWM_OUTPUT)
{
if ((alt = gpioToPwmALT [pin]) == 0) // Not a PWM pin
return ;
// Set pin to PWM mode
*(gpio + fSel) = (*(gpio + fSel) & ~(7 << shift)) | (alt << shift) ;
// Page 107 of the BCM Peripherals manual talks about the GPIO clocks,
// but I'm assuming (hoping!) that this applies to other clocks too.
*(pwm + PWM_CONTROL) = 0 ; // Stop PWM
*(clk + PWMCLK_CNTL) = BCM_PASSWORD | 0x01 ; // Stop PWM Clock
delayMicroseconds (110) ; // See comments in pwmSetClockWPi
(void)*(pwm + PWM_CONTROL) ;
while ((*(pwm + PWM_CONTROL) & 0x80) != 0) // Wait for clock to be !BUSY
delayMicroseconds (1) ;
*(clk + PWMCLK_DIV) = BCM_PASSWORD | (32 << 12) ; // set pwm div to 32 (19.2/32 = 600KHz)
*(clk + PWMCLK_CNTL) = BCM_PASSWORD | 0x11 ; // enable clk
// Default range regsiter of 1024
*(pwm + PWM0_DATA) = 0 ; *(pwm + PWM0_RANGE) = 1024 ;
*(pwm + PWM1_DATA) = 0 ; *(pwm + PWM1_RANGE) = 1024 ;
// Enable PWMs in balanced mode (default)
*(pwm + PWM_CONTROL) = PWM0_ENABLE | PWM1_ENABLE ;
}
// When we change mode of any pin, we remove the pull up/downs
// Or we used to... Hm. Commented out now because for some wieird reason,
// it seems to block subsequent attempts to set the pull up/downs and I've
// not quite gotten to the bottom of why this happens
// The down-side is that the pull up/downs are rememberd in the SoC between
// power cycles, so it's going to be a good idea to explicitly set them in
// any new code.
//
// pullUpDnControl (pin, PUD_OFF) ;
}
void pinModeWPi (int pin, int mode)
{
pinModeGpio (pinToGpio [pin & 63], mode) ;
}
void pinModeSys (int pin, int mode)
{
return ;
}
/*
* pwmControl:
* Allow the user to control some of the PWM functions
*********************************************************************************
*/
void pwmSetModeWPi (int mode)
{
if (mode == PWM_MODE_MS)
*(pwm + PWM_CONTROL) = PWM0_ENABLE | PWM1_ENABLE | PWM0_MS_MODE | PWM1_MS_MODE ;
else
*(pwm + PWM_CONTROL) = PWM0_ENABLE | PWM1_ENABLE ;
}
void pwmSetModeSys (int mode)
{
return ;
}
void pwmSetRangeWPi (unsigned int range)
{
*(pwm + PWM0_RANGE) = range ; delayMicroseconds (10) ;
*(pwm + PWM1_RANGE) = range ; delayMicroseconds (10) ;
}
void pwmSetRangeSys (unsigned int range)
{
return ;
}
/*
* pwmSetClockWPi:
* Set/Change the PWM clock. Originally my code, but changed
* (for the better!) by Chris Hall, <chris@kchall.plus.com>
* after further study of the manual and testing with a 'scope
*********************************************************************************
*/
void pwmSetClockWPi (int divisor)
{
unsigned int pwm_control ;
divisor &= 4095 ;
if (wiringPiDebug)
printf ("Setting to: %d. Current: 0x%08X\n", divisor, *(clk + PWMCLK_DIV)) ;
pwm_control = *(pwm + PWM_CONTROL) ; // preserve PWM_CONTROL
// We need to stop PWM prior to stopping PWM clock in MS mode otherwise BUSY
// stays high.
*(pwm + PWM_CONTROL) = 0 ; // Stop PWM
// Stop PWM clock before changing divisor. The delay after this does need to
// this big (95uS occasionally fails, 100uS OK), it's almost as though the BUSY
// flag is not working properly in balanced mode. Without the delay when DIV is
// adjusted the clock sometimes switches to very slow, once slow further DIV
// adjustments do nothing and it's difficult to get out of this mode.
*(clk + PWMCLK_CNTL) = BCM_PASSWORD | 0x01 ; // Stop PWM Clock
delayMicroseconds (110) ; // prevents clock going sloooow
while ((*(pwm + PWM_CONTROL) & 0x80) != 0) // Wait for clock to be !BUSY
delayMicroseconds (1) ;
*(clk + PWMCLK_DIV) = BCM_PASSWORD | (divisor << 12) ;
*(clk + PWMCLK_CNTL) = BCM_PASSWORD | 0x11 ; // Start PWM clock
*(pwm + PWM_CONTROL) = pwm_control ; // restore PWM_CONTROL
if (wiringPiDebug)
printf ("Set to: %d. Now : 0x%08X\n", divisor, *(clk + PWMCLK_DIV)) ;
}
void pwmSetClockSys (int divisor)
{
return ;
}
#ifdef notYetReady
/*
* pinED01:
* pinED10:
* Enables edge-detect mode on a pin - from a 0 to a 1 or 1 to 0
* Pin must already be in input mode with appropriate pull up/downs set.
*********************************************************************************
*/
void pinEnableED01Pi (int pin)
{
pin = pinToGpio [pin & 63] ;
}
#endif
/*
* digitalWrite:
* Set an output bit
*********************************************************************************
*/
void digitalWriteWPi (int pin, int value)
{
pin = pinToGpio [pin & 63] ;
if (value == LOW)
*(gpio + gpioToGPCLR [pin]) = 1 << (pin & 31) ;
else
*(gpio + gpioToGPSET [pin]) = 1 << (pin & 31) ;
}
void digitalWriteGpio (int pin, int value)
{
pin &= 63 ;
if (value == LOW)
*(gpio + gpioToGPCLR [pin]) = 1 << (pin & 31) ;
else
*(gpio + gpioToGPSET [pin]) = 1 << (pin & 31) ;
}
void digitalWriteSys (int pin, int value)
{
pin &= 63 ;
if (sysFds [pin] != -1)
{
if (value == LOW)
write (sysFds [pin], "0\n", 2) ;
else
write (sysFds [pin], "1\n", 2) ;
}
}
/*
* pwmWrite:
* Set an output PWM value
*********************************************************************************
*/
void pwmWriteGpio (int pin, int value)
{
int port ;
pin = pin & 63 ;
port = gpioToPwmPort [pin] ;
*(pwm + port) = value ;
}
void pwmWriteWPi (int pin, int value)
{
pwmWriteGpio (pinToGpio [pin & 63], value) ;
}
void pwmWriteSys (int pin, int value)
{
return ;
}
/*
* setPadDrive:
* Set the PAD driver value
*********************************************************************************
*/
void setPadDriveWPi (int group, int value)
{
uint32_t wrVal ;
if ((group < 0) || (group > 2))
return ;
wrVal = BCM_PASSWORD | 0x18 | (value & 7) ;
*(pads + group + 11) = wrVal ;
#ifdef DEBUG_PADS
printf ("setPadDrive: Group: %d, value: %d (%08X)\n", group, value, wrVal) ;
printf ("Read : %08X\n", *(pads + group + 11)) ;
#endif
}
void setPadDriveGpio (int group, int value)
{
setPadDriveWPi (group, value) ;
}
void setPadDriveSys (int group, int value)
{
return ;
}
/*
* digitalRead:
* Read the value of a given Pin, returning HIGH or LOW
*********************************************************************************
*/
int digitalReadWPi (int pin)
{
pin = pinToGpio [pin & 63] ;
if ((*(gpio + gpioToGPLEV [pin]) & (1 << (pin & 31))) != 0)
return HIGH ;
else
return LOW ;
}
int digitalReadGpio (int pin)
{
pin &= 63 ;
if ((*(gpio + gpioToGPLEV [pin]) & (1 << (pin & 31))) != 0)
return HIGH ;
else
return LOW ;
}
int digitalReadSys (int pin)
{
char c ;
pin &= 63 ;
if (sysFds [pin] == -1)
return 0 ;
lseek (sysFds [pin], 0L, SEEK_SET) ;
read (sysFds [pin], &c, 1) ;
return (c == '0') ? 0 : 1 ;
}
/*
* pullUpDownCtrl:
* Control the internal pull-up/down resistors on a GPIO pin
* The Arduino only has pull-ups and these are enabled by writing 1
* to a port when in input mode - this paradigm doesn't quite apply
* here though.
*********************************************************************************
*/
void pullUpDnControlGpio (int pin, int pud)
{
pin &= 63 ;
pud &= 3 ;
*(gpio + GPPUD) = pud ; delayMicroseconds (5) ;
*(gpio + gpioToPUDCLK [pin]) = 1 << (pin & 31) ; delayMicroseconds (5) ;
*(gpio + GPPUD) = 0 ; delayMicroseconds (5) ;
*(gpio + gpioToPUDCLK [pin]) = 0 ; delayMicroseconds (5) ;
}
void pullUpDnControlWPi (int pin, int pud)
{
pullUpDnControlGpio (pinToGpio [pin & 63], pud) ;
}
void pullUpDnControlSys (int pin, int pud)
{
return ;
}
/*
* waitForInterrupt:
* Wait for Interrupt on a GPIO pin.
* This is actually done via the /sys/class/gpio interface regardless of
* the wiringPi access mode in-use. Maybe sometime it might get a better
* way for a bit more efficiency.
*********************************************************************************
*/
int waitForInterruptSys (int pin, int mS)
{
int fd, x ;
char buf [8] ;
struct pollfd polls ;
if ((fd = sysFds [pin & 63]) == -1)
return -2 ;
// Do a dummy read
x = read (fd, buf, 6) ;
if (x < 0)
return x ;
// And seek
lseek (fd, 0, SEEK_SET) ;
// Setup poll structure
polls.fd = fd ;
polls.events = POLLPRI ; // Urgent data!
// Wait for it ...
return poll (&polls, 1, mS) ;
}
int waitForInterruptWPi (int pin, int mS)
{
return waitForInterruptSys (pinToGpio [pin & 63], mS) ;
}
int waitForInterruptGpio (int pin, int mS)
{
return waitForInterruptSys (pin, mS) ;
}
/*
* delay:
* Wait for some number of milli seconds
*********************************************************************************
*/
void delay (unsigned int howLong)
{
struct timespec sleeper, dummy ;
sleeper.tv_sec = (time_t)(howLong / 1000) ;
sleeper.tv_nsec = (long)(howLong % 1000) * 1000000 ;
nanosleep (&sleeper, &dummy) ;
}
/*
* delayMicroseconds:
* This is somewhat intersting. It seems that on the Pi, a single call
* to nanosleep takes some 80 to 130 microseconds anyway, so while
* obeying the standards (may take longer), it's not always what we
* want!
*
* So what I'll do now is if the delay is less than 100uS we'll do it
* in a hard loop, watching a built-in counter on the ARM chip. This is
* somewhat sub-optimal in that it uses 100% CPU, something not an issue
* in a microcontroller, but under a multi-tasking, multi-user OS, it's
* wastefull, however we've no real choice )-:
*********************************************************************************
*/
void delayMicrosecondsSys (unsigned int howLong)
{
struct timespec sleeper, dummy ;
sleeper.tv_sec = 0 ;
sleeper.tv_nsec = (long)(howLong * 1000) ;
nanosleep (&sleeper, &dummy) ;
}
void delayMicrosecondsHard (unsigned int howLong)
{
*(timer + TIMER_LOAD) = howLong ;
*(timer + TIMER_IRQ_CLR) = 0 ;
while (*timerIrqRaw == 0)
;
}
void delayMicrosecondsWPi (unsigned int howLong)
{
struct timespec sleeper, dummy ;
/**/ if (howLong == 0)
return ;
else if (howLong < 100)
delayMicrosecondsHard (howLong) ;
else
{
sleeper.tv_sec = 0 ;
sleeper.tv_nsec = (long)(howLong * 1000) ;
nanosleep (&sleeper, &dummy) ;
}
}
/*
* millis:
* Return a number of milliseconds as an unsigned int.
*********************************************************************************
*/
unsigned int millis (void)
{
struct timeval tv ;
unsigned long long t1 ;
gettimeofday (&tv, NULL) ;
t1 = (tv.tv_sec * 1000000 + tv.tv_usec) / 1000 ;
return (uint32_t)(t1 - epoch) ;
}
/*
* wiringPiSetup:
* Must be called once at the start of your program execution.
*
* Default setup: Initialises the system into wiringPi Pin mode and uses the
* memory mapped hardware directly.
*********************************************************************************
*/
int wiringPiSetup (void)
{
int fd ;
int boardRev ;
uint8_t *gpioMem, *pwmMem, *clkMem, *padsMem, *timerMem ;
struct timeval tv ;
if (getenv ("WIRINGPI_DEBUG") != NULL)
wiringPiDebug = TRUE ;
if (wiringPiDebug)
printf ("wiringPi: wiringPiSetup called\n") ;
pinMode = pinModeWPi ;
pullUpDnControl = pullUpDnControlWPi ;
digitalWrite = digitalWriteWPi ;
pwmWrite = pwmWriteWPi ;
setPadDrive = setPadDriveWPi ;
digitalRead = digitalReadWPi ;
waitForInterrupt = waitForInterruptWPi ;
delayMicroseconds = delayMicrosecondsWPi ;
pwmSetMode = pwmSetModeWPi ;
pwmSetRange = pwmSetRangeWPi ;
pwmSetClock = pwmSetClockWPi ;
if ((boardRev = piBoardRev ()) < 0)
return -1 ;
if (boardRev == 1)
pinToGpio = pinToGpioR1 ;
else
pinToGpio = pinToGpioR2 ;
// Open the master /dev/memory device
if ((fd = open ("/dev/mem", O_RDWR | O_SYNC) ) < 0)
{
fprintf (stderr, "wiringPiSetup: Unable to open /dev/mem: %s\n", strerror (errno)) ;
return -1 ;
}
// GPIO:
// Allocate 2 pages - 1 ...
if ((gpioMem = malloc (BLOCK_SIZE + (PAGE_SIZE-1))) == NULL)
{
fprintf (stderr, "wiringPiSetup: malloc failed: %s\n", strerror (errno)) ;
return -1 ;
}
// ... presumably to make sure we can round it up to a whole page size
if (((uint32_t)gpioMem % PAGE_SIZE) != 0)
gpioMem += PAGE_SIZE - ((uint32_t)gpioMem % PAGE_SIZE) ;
gpio = (uint32_t *)mmap((caddr_t)gpioMem, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, fd, GPIO_BASE) ;
if ((int32_t)gpio < 0)
{
fprintf (stderr, "wiringPiSetup: mmap failed: %s\n", strerror (errno)) ;
return -1 ;
}
// PWM
if ((pwmMem = malloc (BLOCK_SIZE + (PAGE_SIZE-1))) == NULL)
{
fprintf (stderr, "wiringPiSetup: pwmMem malloc failed: %s\n", strerror (errno)) ;
return -1 ;
}
if (((uint32_t)pwmMem % PAGE_SIZE) != 0)
pwmMem += PAGE_SIZE - ((uint32_t)pwmMem % PAGE_SIZE) ;
pwm = (uint32_t *)mmap(pwmMem, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, fd, GPIO_PWM) ;
if ((int32_t)pwm < 0)
{
fprintf (stderr, "wiringPiSetup: mmap failed (pwm): %s\n", strerror (errno)) ;
return -1 ;
}
// Clock control (needed for PWM)
if ((clkMem = malloc (BLOCK_SIZE + (PAGE_SIZE-1))) == NULL)
{
fprintf (stderr, "wiringPiSetup: clkMem malloc failed: %s\n", strerror (errno)) ;
return -1 ;
}
if (((uint32_t)clkMem % PAGE_SIZE) != 0)
clkMem += PAGE_SIZE - ((uint32_t)clkMem % PAGE_SIZE) ;
clk = (uint32_t *)mmap(clkMem, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, fd, CLOCK_BASE) ;
if ((int32_t)clk < 0)
{
fprintf (stderr, "wiringPiSetup: mmap failed (clk): %s\n", strerror (errno)) ;
return -1 ;
}
// The drive pads
if ((padsMem = malloc (BLOCK_SIZE + (PAGE_SIZE-1))) == NULL)
{
fprintf (stderr, "wiringPiSetup: padsMem malloc failed: %s\n", strerror (errno)) ;
return -1 ;
}
if (((uint32_t)padsMem % PAGE_SIZE) != 0)
padsMem += PAGE_SIZE - ((uint32_t)padsMem % PAGE_SIZE) ;
pads = (uint32_t *)mmap(padsMem, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, fd, GPIO_PADS) ;
if ((int32_t)pads < 0)
{
fprintf (stderr, "wiringPiSetup: mmap failed (pads): %s\n", strerror (errno)) ;
return -1 ;
}
#ifdef DEBUG_PADS
printf ("Checking pads @ 0x%08X\n", (unsigned int)pads) ;
printf (" -> %08X %08X %08X\n", *(pads + 11), *(pads + 12), *(pads + 13)) ;
#endif
// The system timer
if ((timerMem = malloc (BLOCK_SIZE + (PAGE_SIZE-1))) == NULL)
{
fprintf (stderr, "wiringPiSetup: timerMem malloc failed: %s\n", strerror (errno)) ;
return -1 ;
}
if (((uint32_t)timerMem % PAGE_SIZE) != 0)
timerMem += PAGE_SIZE - ((uint32_t)timerMem % PAGE_SIZE) ;
timer = (uint32_t *)mmap(timerMem, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, fd, GPIO_TIMER) ;
if ((int32_t)timer < 0)
{
fprintf (stderr, "wiringPiSetup: mmap failed (timer): %s\n", strerror (errno)) ;
return -1 ;
}
// Set the timer to free-running, 1MHz.
// 0xF9 is 249, the timer divide is base clock / (divide+1)
// so base clock is 250MHz / 250 = 1MHz.
*(timer + TIMER_CONTROL) = 0x0000280 ;
*(timer + TIMER_PRE_DIV) = 0x00000F9 ;
timerIrqRaw = timer + TIMER_IRQ_RAW ;
// Initialise our epoch for millis()
gettimeofday (&tv, NULL) ;
epoch = (tv.tv_sec * 1000000 + tv.tv_usec) / 1000 ;
return 0 ;
}
/*
* wiringPiSetupGpio:
* Must be called once at the start of your program execution.
*
* GPIO setup: Initialises the system into GPIO Pin mode and uses the
* memory mapped hardware directly.
*********************************************************************************
*/
int wiringPiSetupGpio (void)
{
int x ;
if (wiringPiDebug)
printf ("wiringPi: wiringPiSetupGpio called\n") ;
if ((x = wiringPiSetup ()) < 0)
return x ;
pinMode = pinModeGpio ;
pullUpDnControl = pullUpDnControlGpio ;
digitalWrite = digitalWriteGpio ;
pwmWrite = pwmWriteGpio ;
setPadDrive = setPadDriveGpio ;
digitalRead = digitalReadGpio ;
waitForInterrupt = waitForInterruptGpio ;
delayMicroseconds = delayMicrosecondsWPi ; // Same
pwmSetMode = pwmSetModeWPi ;
pwmSetRange = pwmSetRangeWPi ;
pwmSetClock = pwmSetClockWPi ;
return 0 ;
}
/*
* wiringPiSetupSys:
* Must be called once at the start of your program execution.
*
* Initialisation (again), however this time we are using the /sys/class/gpio
* interface to the GPIO systems - slightly slower, but always usable as
* a non-root user, assuming the devices are already exported and setup correctly.
*/
int wiringPiSetupSys (void)
{
int pin ;
struct timeval tv ;
char fName [128] ;
if (wiringPiDebug)
printf ("wiringPi: wiringPiSetupSys called\n") ;
pinMode = pinModeSys ;
pullUpDnControl = pullUpDnControlSys ;
digitalWrite = digitalWriteSys ;
pwmWrite = pwmWriteSys ;
setPadDrive = setPadDriveSys ;
digitalRead = digitalReadSys ;
waitForInterrupt = waitForInterruptSys ;
delayMicroseconds = delayMicrosecondsSys ;
pwmSetMode = pwmSetModeSys ;
pwmSetRange = pwmSetRangeSys ;
pwmSetClock = pwmSetClockSys ;
// Open and scan the directory, looking for exported GPIOs, and pre-open
// the 'value' interface to speed things up for later
for (pin = 0 ; pin < 64 ; ++pin)
{
sprintf (fName, "/sys/class/gpio/gpio%d/value", pin) ;
sysFds [pin] = open (fName, O_RDWR) ;
}
// Initialise the epoch for mills() ...
gettimeofday (&tv, NULL) ;
epoch = (tv.tv_sec * 1000000 + tv.tv_usec) / 1000 ;
return 0 ;
}
// ############################################################################