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WiringPi/wiringPi/wiringPi.c
Gordon Henderson 98bcb20d93 Slight change to the gpio program to fix SPI buffer size when loading 
the module.
Typo in gpio man page
Bug fixed in board revision detection (which would never happen
anyway, however)
2013-02-07 21:53:49 +00:00

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/*
* 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
#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 <pthread.h>
#include <sys/time.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <sys/ioctl.h>
#include "wiringPi.h"
// Function stubs
void (*pinMode) (int pin, int mode) ;
int (*getAlt) (int pin) ;
void (*pullUpDnControl) (int pin, int pud) ;
void (*digitalWrite) (int pin, int value) ;
void (*digitalWriteByte) (int value) ;
void (*pwmWrite) (int pin, int value) ;
void (*gpioClockSet) (int pin, int value) ;
void (*setPadDrive) (int group, int value) ;
int (*digitalRead) (int pin) ;
int (*waitForInterrupt) (int pin, int mS) ;
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
// 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 - the ALT values
//
// 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)
// 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
// Taken 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 + 0x00100000)
#define CLOCK_BASE (BCM2708_PERI_BASE + 0x00101000)
#define GPIO_BASE (BCM2708_PERI_BASE + 0x00200000)
#define GPIO_TIMER (BCM2708_PERI_BASE + 0x0000B000)
#define GPIO_PWM (BCM2708_PERI_BASE + 0x0020C000)
#define PAGE_SIZE (4*1024)
#define BLOCK_SIZE (4*1024)
// PWM
// Word offsets into the PWM control region
#define PWM_CONTROL 0
#define PWM_STATUS 1
#define PWM0_RANGE 4
#define PWM0_DATA 5
#define PWM1_RANGE 8
#define PWM1_DATA 9
// Clock regsiter offsets
#define PWMCLK_CNTL 40
#define PWMCLK_DIV 41
#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
#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
// Timer
// Word offsets
#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 ;
// Time for easy calculations
static uint64_t epochMilli, epochMicro ;
// Misc
static int wiringPiMode = WPI_MODE_UNINITIALISED ;
// Debugging
int wiringPiDebug = FALSE ;
// sysFds:
// Map a file descriptor from the /sys/class/gpio/gpioX/value
static int sysFds [64] ;
// ISR Data
static void (*isrFunctions [64])(void) ;
// 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
// GPPUD:
// GPIO Pin pull up/down register
#define GPPUD 37
// gpioToPUDCLK
// (Word) offset to the Pull Up Down Clock regsiter
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
} ;
// gpioToPwmPort
// The port value to put a GPIO pin into PWM mode
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
} ;
// gpioToGpClkALT:
// ALT value to put a GPIO pin into GP Clock mode.
// On the Pi we can really only use BCM_GPIO_4 and BCM_GPIO_21
// for clocks 0 and 1 respectivey, however I'll include the full
// list for completeness - maybe one day...
#define GPIO_CLOCK_SOURCE 1
// gpioToGpClkALT0:
static uint8_t gpioToGpClkALT0 [] =
{
0, 0, 0, 0, FSEL_ALT0, FSEL_ALT0, FSEL_ALT0, 0, // 0 -> 7
0, 0, 0, 0, 0, 0, 0, 0, // 8 -> 15
0, 0, 0, 0, FSEL_ALT5, FSEL_ALT5, 0, 0, // 16 -> 23
0, 0, 0, 0, 0, 0, 0, 0, // 24 -> 31
FSEL_ALT0, 0, FSEL_ALT0, 0, 0, 0, 0, 0, // 32 -> 39
0, 0, FSEL_ALT0, FSEL_ALT0, FSEL_ALT0, 0, 0, 0, // 40 -> 47
0, 0, 0, 0, 0, 0, 0, 0, // 48 -> 55
0, 0, 0, 0, 0, 0, 0, 0, // 56 -> 63
} ;
// gpioToClk:
// (word) Offsets to the clock Control and Divisor register
static uint8_t gpioToClkCon [] =
{
-1, -1, -1, -1, 28, 30, 32, -1, // 0 -> 7
-1, -1, -1, -1, -1, -1, -1, -1, // 8 -> 15
-1, -1, -1, -1, 28, 30, -1, -1, // 16 -> 23
-1, -1, -1, -1, -1, -1, -1, -1, // 24 -> 31
28, -1, 28, -1, -1, -1, -1, -1, // 32 -> 39
-1, -1, 28, 30, 28, -1, -1, -1, // 40 -> 47
-1, -1, -1, -1, -1, -1, -1, -1, // 48 -> 55
-1, -1, -1, -1, -1, -1, -1, -1, // 56 -> 63
} ;
static uint8_t gpioToClkDiv [] =
{
-1, -1, -1, -1, 29, 31, 33, -1, // 0 -> 7
-1, -1, -1, -1, -1, -1, -1, -1, // 8 -> 15
-1, -1, -1, -1, 29, 31, -1, -1, // 16 -> 23
-1, -1, -1, -1, -1, -1, -1, -1, // 24 -> 31
29, -1, 29, -1, -1, -1, -1, -1, // 32 -> 39
-1, -1, 29, 31, 29, -1, -1, -1, // 40 -> 47
-1, -1, -1, -1, -1, -1, -1, -1, // 48 -> 55
-1, -1, -1, -1, -1, -1, -1, -1, // 56 -> 63
} ;
/*
* 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 are some 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 (Early reports?
* 0005 - Rev 2 (but error?)
* 0006 - Rev 2
* 0008 - Rev 2 - Model A
* 000e - Rev 2 + 512MB
* 000f - Rev 2 + 512MB
*
* A small thorn is the olde style overvolting - that will add in
* 1000000
*
*********************************************************************************
*/
static void piBoardRevOops (char *why)
{
fprintf (stderr, "piBoardRev: Unable to determine board revision from /proc/cpuinfo\n") ;
fprintf (stderr, " -> %s\n", why) ;
fprintf (stderr, " -> You may want to check:\n") ;
fprintf (stderr, " -> http://www.raspberrypi.org/phpBB3/viewtopic.php?p=184410#p184410\n") ;
exit (EXIT_FAILURE) ;
}
int piBoardRev (void)
{
FILE *cpuFd ;
char line [120] ;
char *c, lastChar ;
static int boardRev = -1 ;
if (boardRev != -1) // No point checking twice
return boardRev ;
if ((cpuFd = fopen ("/proc/cpuinfo", "r")) == NULL)
piBoardRevOops ("Unable to open /proc/cpuinfo") ;
while (fgets (line, 120, cpuFd) != NULL)
if (strncmp (line, "Revision", 8) == 0)
break ;
fclose (cpuFd) ;
if (strncmp (line, "Revision", 8) != 0)
piBoardRevOops ("No \"Revision\" line") ;
for (c = &line [strlen (line) - 1] ; (*c == '\n') || (*c == '\r') ; --c)
*c = 0 ;
if (wiringPiDebug)
printf ("piboardRev: Revision string: %s\n", line) ;
for (c = line ; *c ; ++c)
if (isdigit (*c))
break ;
if (!isdigit (*c))
piBoardRevOops ("No numeric revision string") ;
// 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 = line [strlen (line) - 1] ;
if (wiringPiDebug)
printf ("piboardRev: lastChar is: '%c' (%d, 0x%02X)\n", lastChar, lastChar, lastChar) ;
/**/ if ((lastChar == '2') || (lastChar == '3'))
boardRev = 1 ;
else
boardRev = 2 ;
if (wiringPiDebug)
printf ("piBoardRev: Returning revision: %d\n", boardRev) ;
return boardRev ;
}
/*
* getAlt:
* Returns the ALT bits for a given port. Only really of-use
* for the gpio readall command (I think)
*********************************************************************************
*/
int getAltGpio (int pin)
{
int fSel, shift, alt ;
pin &= 63 ;
fSel = gpioToGPFSEL [pin] ;
shift = gpioToShift [pin] ;
alt = (*(gpio + fSel) >> shift) & 7 ;
return alt ;
}
int getAltWPi (int pin)
{
return getAltGpio (pinToGpio [pin & 63]) ;
}
int getAltSys (int pin)
{
return 0 ;
}
/*
* 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)
{
uint32_t 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 ((*(clk + PWMCLK_CNTL) & 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) ;
}
}
/*
* digitalWriteByte:
* Write an 8-bit byte to the first 8 GPIO pins - try to do it as
* fast as possible.
* However it still needs 2 operations to set the bits, so any external
* hardware must not rely on seeing a change as there will be a change
* to set the outputs bits to zero, then another change to set the 1's
*********************************************************************************
*/
void digitalWriteByteGpio (int value)
{
uint32_t pinSet = 0 ;
uint32_t pinClr = 0 ;
int mask = 1 ;
int pin ;
for (pin = 0 ; pin < 8 ; ++pin)
{
if ((value & mask) == 0)
pinClr |= (1 << pinToGpio [pin]) ;
else
pinSet |= (1 << pinToGpio [pin]) ;
mask <<= 1 ;
}
*(gpio + gpioToGPCLR [0]) = pinClr ;
*(gpio + gpioToGPSET [0]) = pinSet ;
}
void digitalWriteByteSys (int value)
{
int mask = 1 ;
int pin ;
for (pin = 0 ; pin < 8 ; ++pin)
{
digitalWriteSys (pinToGpio [pin], value & mask) ;
mask <<= 1 ;
}
}
/*
* 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 ;
}
/*
* gpioClockSet:
* Set the freuency on a GPIO clock pin
*********************************************************************************
*/
void gpioClockSetGpio (int pin, int freq)
{
int divi, divr, divf ;
pin &= 63 ;
divi = 19200000 / freq ;
divr = 19200000 % freq ;
divf = (int)((double)divr * 4096.0 / 19200000.0) ;
if (divi > 4095)
divi = 4095 ;
*(clk + gpioToClkCon [pin]) = BCM_PASSWORD | GPIO_CLOCK_SOURCE ; // Stop GPIO Clock
while ((*(clk + gpioToClkCon [pin]) & 0x80) != 0) // ... and wait
;
*(clk + gpioToClkDiv [pin]) = BCM_PASSWORD | (divi << 12) | divf ; // Set dividers
*(clk + gpioToClkCon [pin]) = BCM_PASSWORD | 0x10 | GPIO_CLOCK_SOURCE ; // Start Clock
}
void gpioClockSetWPi (int pin, int freq)
{
gpioClockSetGpio (pinToGpio [pin & 63], freq) ;
}
void gpioClockSetSys (int pin, int freq)
{
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 ;
if (wiringPiDebug)
{
printf ("setPadDrive: Group: %d, value: %d (%08X)\n", group, value, wrVal) ;
printf ("Read : %08X\n", *(pads + group + 11)) ;
}
}
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 ;
}
/*
* pinMode:
* Sets the mode of a pin to be input, output or PWM output
*********************************************************************************
*/
void pinModeGpio (int pin, int mode)
{
// register int barrier ;
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) ;
delayMicroseconds (110) ; // See comments in pwmSetClockWPi
pwmSetModeWPi (PWM_MODE_BAL) ; // Pi default mode
pwmSetRangeWPi (1024) ; // Default range of 1024
pwmSetClockWPi (32) ; // 19.2 / 32 = 600KHz - Also starts the PWM
}
else if (mode == GPIO_CLOCK)
{
if ((alt = gpioToGpClkALT0 [pin]) == 0) // Not a GPIO_CLOCK pin
return ;
// Set pin to GPIO_CLOCK mode and set the clock frequency to 100KHz
*(gpio + fSel) = (*(gpio + fSel) & ~(7 << shift)) | (alt << shift) ;
delayMicroseconds (110) ;
gpioClockSetGpio (pin, 100000) ;
}
}
void pinModeWPi (int pin, int mode)
{
pinModeGpio (pinToGpio [pin & 63], mode) ;
}
void pinModeSys (int pin, int mode)
{
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 ;
uint8_t c ;
struct pollfd polls ;
if ((fd = sysFds [pin & 63]) == -1)
return -2 ;
// Setup poll structure
polls.fd = fd ;
polls.events = POLLPRI ; // Urgent data!
// Wait for it ...
x = poll (&polls, 1, mS) ;
// Do a dummy read to clear the interrupt
// A one character read appars to be enough.
(void)read (fd, &c, 1) ;
return x ;
}
int waitForInterruptWPi (int pin, int mS)
{
return waitForInterruptSys (pinToGpio [pin & 63], mS) ;
}
int waitForInterruptGpio (int pin, int mS)
{
return waitForInterruptSys (pin, mS) ;
}
/*
* interruptHandler:
* This is a thread and gets started to wait for the interrupt we're
* hoping to catch. It will call the user-function when the interrupt
* fires.
*********************************************************************************
*/
static void *interruptHandler (void *arg)
{
int myPin = *(int *)arg ;
(void)piHiPri (55) ; // Only effective if we run as root
for (;;)
if (waitForInterruptSys (myPin, -1) > 0)
isrFunctions [myPin] () ;
return NULL ;
}
/*
* wiringPiISR:
* Take the details and create an interrupt handler that will do a call-
* back to the user supplied function.
*********************************************************************************
*/
int wiringPiISR (int pin, int mode, void (*function)(void))
{
pthread_t threadId ;
char fName [64] ;
char *modeS ;
char pinS [8] ;
pid_t pid ;
int count, i ;
uint8_t c ;
pin &= 63 ;
if (wiringPiMode == WPI_MODE_UNINITIALISED)
{
fprintf (stderr, "wiringPiISR: wiringPi has not been initialised. Unable to continue.\n") ;
exit (EXIT_FAILURE) ;
}
else if (wiringPiMode == WPI_MODE_PINS)
pin = pinToGpio [pin] ;
// Now export the pin and set the right edge
// We're going to use the gpio program to do this, so it assumes
// a full installation of wiringPi. It's a bit 'clunky', but it
// is a way that will work when we're running in "Sys" mode, as
// a non-root user. (without sudo)
if (mode != INT_EDGE_SETUP)
{
/**/ if (mode == INT_EDGE_FALLING)
modeS = "falling" ;
else if (mode == INT_EDGE_RISING)
modeS = "rising" ;
else
modeS = "both" ;
sprintf (pinS, "%d", pin) ;
if ((pid = fork ()) < 0) // Fail
return pid ;
if (pid == 0) // Child, exec
{
execl ("/usr/local/bin/gpio", "gpio", "edge", pinS, modeS, (char *)NULL) ;
return -1 ; // Failure ...
}
else // Parent, wait
wait (NULL) ;
}
// Now pre-open the /sys/class node - it may already be open if
// we are in Sys mode, but this will do no harm.
sprintf (fName, "/sys/class/gpio/gpio%d/value", pin) ;
if ((sysFds [pin] = open (fName, O_RDWR)) < 0)
return -1 ;
// Clear any initial pending interrupt
ioctl (sysFds [pin], FIONREAD, &count) ;
for (i = 0 ; i < count ; ++i)
read (sysFds [pin], &c, 1) ;
isrFunctions [pin] = function ;
pthread_create (&threadId, NULL, interruptHandler, &pin) ;
delay (1) ;
return 0 ;
}
/*
* initialiseEpoch:
* Initialise our start-of-time variable to be the current unix
* time in milliseconds.
*********************************************************************************
*/
static void initialiseEpoch (void)
{
struct timeval tv ;
gettimeofday (&tv, NULL) ;
epochMilli = (uint64_t)tv.tv_sec * (uint64_t)1000 + (uint64_t)(tv.tv_usec / 1000) ;
epochMicro = (uint64_t)tv.tv_sec * (uint64_t)1000000 + (uint64_t)(tv.tv_usec) ;
}
/*
* 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 )-:
*
* Plan B: It seems all might not be well with that plan, so changing it
* to use gettimeofday () and poll on that instead...
*********************************************************************************
*/
void delayMicrosecondsHard (unsigned int howLong)
{
struct timeval tNow, tLong, tEnd ;
gettimeofday (&tNow, NULL) ;
tLong.tv_sec = howLong / 1000000 ;
tLong.tv_usec = howLong % 1000000 ;
timeradd (&tNow, &tLong, &tEnd) ;
while (timercmp (&tNow, &tEnd, <))
gettimeofday (&tNow, NULL) ;
}
void delayMicroseconds (unsigned int howLong)
{
struct timespec sleeper ;
/**/ if (howLong == 0)
return ;
else if (howLong < 100)
delayMicrosecondsHard (howLong) ;
else
{
sleeper.tv_sec = 0 ;
sleeper.tv_nsec = (long)(howLong * 1000) ;
nanosleep (&sleeper, NULL) ;
}
}
/*
* millis:
* Return a number of milliseconds as an unsigned int.
*********************************************************************************
*/
unsigned int millis (void)
{
struct timeval tv ;
uint64_t now ;
gettimeofday (&tv, NULL) ;
now = (uint64_t)tv.tv_sec * (uint64_t)1000 + (uint64_t)(tv.tv_usec / 1000) ;
return (uint32_t)(now - epochMilli) ;
}
/*
* micros:
* Return a number of microseconds as an unsigned int.
*********************************************************************************
*/
unsigned int micros (void)
{
struct timeval tv ;
uint64_t now ;
gettimeofday (&tv, NULL) ;
now = (uint64_t)tv.tv_sec * (uint64_t)1000000 + (uint64_t)tv.tv_usec ;
return (uint32_t)(now - epochMicro) ;
}
/*
* 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 ;
if (geteuid () != 0)
{
fprintf (stderr, "wiringPi:\n Must be root to call wiringPiSetup().\n (Did you forget sudo?)\n") ;
exit (EXIT_FAILURE) ;
}
if (getenv ("WIRINGPI_DEBUG") != NULL)
{
printf ("wiringPi: Debug mode enabled\n") ;
wiringPiDebug = TRUE ;
}
if (wiringPiDebug)
printf ("wiringPi: wiringPiSetup called\n") ;
pinMode = pinModeWPi ;
getAlt = getAltWPi ;
pullUpDnControl = pullUpDnControlWPi ;
digitalWrite = digitalWriteWPi ;
digitalWriteByte = digitalWriteByteGpio ; // Same code
gpioClockSet = gpioClockSetWPi ;
pwmWrite = pwmWriteWPi ;
setPadDrive = setPadDriveWPi ;
digitalRead = digitalReadWPi ;
waitForInterrupt = waitForInterruptWPi ;
pwmSetMode = pwmSetModeWPi ;
pwmSetRange = pwmSetRangeWPi ;
pwmSetClock = pwmSetClockWPi ;
boardRev = piBoardRev () ;
if (boardRev == 1)
pinToGpio = pinToGpioR1 ;
else
pinToGpio = pinToGpioR2 ;
// Open the master /dev/memory device
if ((fd = open ("/dev/mem", O_RDWR | O_SYNC) ) < 0)
{
if (wiringPiDebug)
{
int serr = errno ;
fprintf (stderr, "wiringPiSetup: Unable to open /dev/mem: %s\n", strerror (errno)) ;
errno = serr ;
}
return -1 ;
}
// GPIO:
gpio = (uint32_t *)mmap(0, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, fd, GPIO_BASE) ;
if ((int32_t)gpio == -1)
{
if (wiringPiDebug)
{
int serr = errno ;
fprintf (stderr, "wiringPiSetup: mmap failed: %s\n", strerror (errno)) ;
errno = serr ;
}
return -1 ;
}
// PWM
pwm = (uint32_t *)mmap(0, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, fd, GPIO_PWM) ;
if ((int32_t)pwm == -1)
{
if (wiringPiDebug)
{
int serr = errno ;
fprintf (stderr, "wiringPiSetup: mmap failed (pwm): %s\n", strerror (errno)) ;
errno = serr ;
}
return -1 ;
}
// Clock control (needed for PWM)
clk = (uint32_t *)mmap(0, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, fd, CLOCK_BASE) ;
if ((int32_t)clk == -1)
{
if (wiringPiDebug)
{
int serr = errno ;
fprintf (stderr, "wiringPiSetup: mmap failed (clk): %s\n", strerror (errno)) ;
errno = serr ;
}
return -1 ;
}
// The drive pads
pads = (uint32_t *)mmap(0, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, fd, GPIO_PADS) ;
if ((int32_t)pads == -1)
{
if (wiringPiDebug)
{
int serr = errno ;
fprintf (stderr, "wiringPiSetup: mmap failed (pads): %s\n", strerror (errno)) ;
errno = serr ;
}
return -1 ;
}
// The system timer
timer = (uint32_t *)mmap(0, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, fd, GPIO_TIMER) ;
if ((int32_t)timer == -1)
{
if (wiringPiDebug)
{
int serr = errno ;
fprintf (stderr, "wiringPiSetup: mmap failed (timer): %s\n", strerror (errno)) ;
errno = serr ;
}
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 ;
initialiseEpoch () ;
wiringPiMode = WPI_MODE_PINS ;
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 (geteuid () != 0)
{
fprintf (stderr, "Must be root to call wiringPiSetupGpio(). (Did you forget sudo?)\n") ;
exit (EXIT_FAILURE) ;
}
if ((x = wiringPiSetup ()) < 0)
return x ;
if (wiringPiDebug)
printf ("wiringPi: wiringPiSetupGpio called\n") ;
pinMode = pinModeGpio ;
getAlt = getAltGpio ;
pullUpDnControl = pullUpDnControlGpio ;
digitalWrite = digitalWriteGpio ;
digitalWriteByte = digitalWriteByteGpio ;
gpioClockSet = gpioClockSetGpio ;
pwmWrite = pwmWriteGpio ;
setPadDrive = setPadDriveGpio ;
digitalRead = digitalReadGpio ;
waitForInterrupt = waitForInterruptGpio ;
pwmSetMode = pwmSetModeWPi ;
pwmSetRange = pwmSetRangeWPi ;
pwmSetClock = pwmSetClockWPi ;
wiringPiMode = WPI_MODE_GPIO ;
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 boardRev ;
int pin ;
char fName [128] ;
if (getenv ("WIRINGPI_DEBUG") != NULL)
wiringPiDebug = TRUE ;
if (wiringPiDebug)
printf ("wiringPi: wiringPiSetupSys called\n") ;
pinMode = pinModeSys ;
getAlt = getAltSys ;
pullUpDnControl = pullUpDnControlSys ;
digitalWrite = digitalWriteSys ;
digitalWriteByte = digitalWriteByteSys ;
gpioClockSet = gpioClockSetSys ;
pwmWrite = pwmWriteSys ;
setPadDrive = setPadDriveSys ;
digitalRead = digitalReadSys ;
waitForInterrupt = waitForInterruptSys ;
pwmSetMode = pwmSetModeSys ;
pwmSetRange = pwmSetRangeSys ;
pwmSetClock = pwmSetClockSys ;
boardRev = piBoardRev () ;
if (boardRev == 1)
pinToGpio = pinToGpioR1 ;
else
pinToGpio = pinToGpioR2 ;
// 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) ;
}
initialiseEpoch () ;
wiringPiMode = WPI_MODE_GPIO_SYS ;
return 0 ;
}
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