3 * Arduino compatable (ish) Wiring library for the Raspberry Pi
4 * Copyright (c) 2012 Gordon Henderson
6 * Thanks to code samples from Gert Jan van Loo and the
7 * BCM2835 ARM Peripherals manual, however it's missing
8 * the clock section /grr/mutter/
9 ***********************************************************************
10 * This file is part of wiringPi:
11 * https://projects.drogon.net/raspberry-pi/wiringpi/
13 * wiringPi is free software: you can redistribute it and/or modify
14 * it under the terms of the GNU Lesser General Public License as
15 * published by the Free Software Foundation, either version 3 of the
16 * License, or (at your option) any later version.
18 * wiringPi is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU Lesser General Public License for more details.
23 * You should have received a copy of the GNU Lesser General Public
24 * License along with wiringPi.
25 * If not, see <http://www.gnu.org/licenses/>.
26 ***********************************************************************
32 // Added an abstraction layer to the main routines to save a tiny
33 // bit of run-time and make the clode a little cleaner (if a little
35 // Added waitForInterrupt code
39 // Added in support to use the /sys/class/gpio interface.
41 // Fixed a few more bugs to do with range-checking when in GPIO mode.
44 // Added c++ support for the .h file
45 // Added a new function to allow for using my "pin" numbers, or native
47 // Removed my busy-loop delay and replaced it with a call to delayMicroseconds
50 // Added in the 2 UART pins
51 // Change maxPins to numPins to more accurately reflect purpose
53 // Pad drive current fiddling
67 #include <sys/types.h>
74 void (*pinMode) (int pin, int mode) ;
75 void (*pullUpDnControl) (int pin, int pud) ;
76 void (*digitalWrite) (int pin, int value) ;
77 void (*pwmWrite) (int pin, int value) ;
78 void (*setPadDrive) (int group, int value) ;
79 int (*digitalRead) (int pin) ;
80 int (*waitForInterrupt) (int pin, int mS) ;
81 void (*delayMicroseconds) (unsigned int howLong) ;
91 #define BCM_PASSWORD 0x5A000000
94 // Port function select bits
96 #define FSEL_INPT 0b000
97 #define FSEL_OUTP 0b001
98 #define FSEL_ALT0 0b100
99 #define FSEL_ALT0 0b100
100 #define FSEL_ALT1 0b101
101 #define FSEL_ALT2 0b110
102 #define FSEL_ALT3 0b111
103 #define FSEL_ALT4 0b011
104 #define FSEL_ALT5 0b010
106 // Access from ARM Running Linux
107 // Take from Gert/Doms code. Some of this is not in the manual
108 // that I can find )-:
110 #define BCM2708_PERI_BASE 0x20000000
111 #define GPIO_PADS (BCM2708_PERI_BASE + 0x100000)
112 #define CLOCK_BASE (BCM2708_PERI_BASE + 0x101000)
113 #define GPIO_BASE (BCM2708_PERI_BASE + 0x200000)
114 #define GPIO_TIMER (BCM2708_PERI_BASE + 0x00B000)
115 #define GPIO_PWM (BCM2708_PERI_BASE + 0x20C000)
117 #define PAGE_SIZE (4*1024)
118 #define BLOCK_SIZE (4*1024)
122 #define PWM_CONTROL 0
129 #define PWMCLK_CNTL 40
130 #define PWMCLK_DIV 41
132 #define PWM1_MS_MODE 0x8000 // Run in MS mode
133 #define PWM1_USEFIFO 0x2000 // Data from FIFO
134 #define PWM1_REVPOLAR 0x1000 // Reverse polarity
135 #define PWM1_OFFSTATE 0x0800 // Ouput Off state
136 #define PWM1_REPEATFF 0x0400 // Repeat last value if FIFO empty
137 #define PWM1_SERIAL 0x0200 // Run in serial mode
138 #define PWM1_ENABLE 0x0100 // Channel Enable
140 #define PWM0_MS_MODE 0x0080 // Run in MS mode
141 #define PWM0_USEFIFO 0x0020 // Data from FIFO
142 #define PWM0_REVPOLAR 0x0010 // Reverse polarity
143 #define PWM0_OFFSTATE 0x0008 // Ouput Off state
144 #define PWM0_REPEATFF 0x0004 // Repeat last value if FIFO empty
145 #define PWM0_SERIAL 0x0002 // Run in serial mode
146 #define PWM0_ENABLE 0x0001 // Channel Enable
150 #define TIMER_LOAD (0x400 >> 2)
151 #define TIMER_VALUE (0x404 >> 2)
152 #define TIMER_CONTROL (0x408 >> 2)
153 #define TIMER_IRQ_CLR (0x40C >> 2)
154 #define TIMER_IRQ_RAW (0x410 >> 2)
155 #define TIMER_IRQ_MASK (0x414 >> 2)
156 #define TIMER_RELOAD (0x418 >> 2)
157 #define TIMER_PRE_DIV (0x41C >> 2)
158 #define TIMER_COUNTER (0x420 >> 2)
160 // Locals to hold pointers to the hardware
162 static volatile uint32_t *gpio ;
163 static volatile uint32_t *pwm ;
164 static volatile uint32_t *clk ;
165 static volatile uint32_t *pads ;
166 static volatile uint32_t *timer ;
168 static volatile uint32_t *timerIrqRaw ;
170 // The BCM2835 has 54 GPIO pins.
171 // BCM2835 data sheet, Page 90 onwards.
172 // There are 6 control registers, each control the functions of a block
174 // Each control register has 10 sets of 3 bits per GPIO pin:
176 // 000 = GPIO Pin X is an input
177 // 001 = GPIO Pin X is an output
178 // 100 = GPIO Pin X takes alternate function 0
179 // 101 = GPIO Pin X takes alternate function 1
180 // 110 = GPIO Pin X takes alternate function 2
181 // 111 = GPIO Pin X takes alternate function 3
182 // 011 = GPIO Pin X takes alternate function 4
183 // 010 = GPIO Pin X takes alternate function 5
185 // So the 3 bits for port X are:
186 // X / 10 + ((X % 10) * 3)
189 // Map a file descriptor from the /sys/class/gpio/gpioX/value
191 static int sysFds [64] ;
193 // Doing it the Arduino way with lookup tables...
194 // Yes, it's probably more innefficient than all the bit-twidling, but it
195 // does tend to make it all a bit clearer. At least to me!
198 // Take a Wiring pin (0 through X) and re-map it to the BCM_GPIO pin
200 static int pinToGpio [64] =
202 17, 18, 21, 22, 23, 24, 25, 4, // From the Original Wiki - GPIO 0 through 7
203 0, 1, // I2C - SDA0, SCL0
204 8, 7, // SPI - CE1, CE0
205 10, 9, 11, // SPI - MOSI, MISO, SCLK
206 14, 15, // UART - Tx, Rx
210 -1, -1, -1,-1,-1,-1,-1, -1, -1, -1, -1, -1, -1, -1, -1, // ... 31
211 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // ... 47
212 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // ... 63
216 // Map a BCM_GPIO pin to it's control port. (GPFSEL 0-5)
218 static uint8_t gpioToGPFSEL [] =
220 0,0,0,0,0,0,0,0,0,0,
221 1,1,1,1,1,1,1,1,1,1,
222 2,2,2,2,2,2,2,2,2,2,
223 3,3,3,3,3,3,3,3,3,3,
224 4,4,4,4,4,4,4,4,4,4,
225 5,5,5,5,5,5,5,5,5,5,
229 // Define the shift up for the 3 bits per pin in each GPFSEL port
231 static uint8_t gpioToShift [] =
233 0,3,6,9,12,15,18,21,24,27,
234 0,3,6,9,12,15,18,21,24,27,
235 0,3,6,9,12,15,18,21,24,27,
236 0,3,6,9,12,15,18,21,24,27,
237 0,3,6,9,12,15,18,21,24,27,
241 // (Word) offset to the GPIO Set registers for each GPIO pin
243 static uint8_t gpioToGPSET [] =
245 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,
246 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,
250 // (Word) offset to the GPIO Clear registers for each GPIO pin
252 static uint8_t gpioToGPCLR [] =
254 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,
255 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,
259 // (Word) offset to the GPIO Input level registers for each GPIO pin
261 static uint8_t gpioToGPLEV [] =
263 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,
264 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,
269 // (Word) offset to the Event Detect Status
271 static uint8_t gpioToEDS [] =
273 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,
274 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,
278 // (Word) offset to the Rising edgde ENable register
280 static uint8_t gpioToREN [] =
282 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,
283 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,
287 // (Word) offset to the Falling edgde ENable register
289 static uint8_t gpioToFEN [] =
291 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,
292 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,
297 // (Word) offset to the Pull Up Down Clock regsiter
301 static uint8_t gpioToPUDCLK [] =
303 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,
304 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,
308 // the ALT value to put a GPIO pin into PWM mode
310 static uint8_t gpioToPwmALT [] =
312 0, 0, 0, 0, 0, 0, 0, 0, // 0 -> 7
313 0, 0, 0, 0, FSEL_ALT0, FSEL_ALT0, 0, 0, // 8 -> 15
314 0, 0, FSEL_ALT5, FSEL_ALT5, 0, 0, 0, 0, // 16 -> 23
315 0, 0, 0, 0, 0, 0, 0, 0, // 24 -> 31
316 0, 0, 0, 0, 0, 0, 0, 0, // 32 -> 39
317 FSEL_ALT0, FSEL_ALT0, 0, 0, 0, FSEL_ALT0, 0, 0, // 40 -> 47
318 0, 0, 0, 0, 0, 0, 0, 0, // 48 -> 55
319 0, 0, 0, 0, 0, 0, 0, 0, // 56 -> 63
322 static uint8_t gpioToPwmPort [] =
324 0, 0, 0, 0, 0, 0, 0, 0, // 0 -> 7
325 0, 0, 0, 0, PWM0_DATA, PWM1_DATA, 0, 0, // 8 -> 15
326 0, 0, PWM0_DATA, PWM1_DATA, 0, 0, 0, 0, // 16 -> 23
327 0, 0, 0, 0, 0, 0, 0, 0, // 24 -> 31
328 0, 0, 0, 0, 0, 0, 0, 0, // 32 -> 39
329 PWM0_DATA, PWM1_DATA, 0, 0, 0, PWM1_DATA, 0, 0, // 40 -> 47
330 0, 0, 0, 0, 0, 0, 0, 0, // 48 -> 55
331 0, 0, 0, 0, 0, 0, 0, 0, // 56 -> 63
336 // Time for easy calculations
338 static unsigned long long epoch ;
340 //////////////////////////////////////////////////////////////////////////////////
345 * Sets the mode of a pin to be input, output or PWM output
346 *********************************************************************************
349 void pinModeGpio (int pin, int mode)
351 static int pwmRunning = FALSE ;
352 int fSel, shift, alt ;
356 fSel = gpioToGPFSEL [pin] ;
357 shift = gpioToShift [pin] ;
359 /**/ if (mode == INPUT)
360 *(gpio + fSel) = (*(gpio + fSel) & ~(7 << shift)) ; // Sets bits to zero = input
361 else if (mode == OUTPUT)
362 *(gpio + fSel) = (*(gpio + fSel) & ~(7 << shift)) | (1 << shift) ;
363 else if (mode == PWM_OUTPUT)
365 if ((alt = gpioToPwmALT [pin]) == 0) // Not a PWM pin
368 // Set pin to PWM mode
370 *(gpio + fSel) = (*(gpio + fSel) & ~(7 << shift)) | (alt << shift) ;
372 // We didn't initialise the PWM hardware at setup time - because it's possible that
373 // something else is using the PWM - e.g. the Audio systems! So if we use PWM
374 // here, then we're assuming that nothing else is, otherwise things are going
375 // to sound a bit funny...
381 *(clk + PWMCLK_DIV) = BCM_PASSWORD | (32<<12) ; // set pwm div to 32 (19.2/3 = 600KHz)
382 *(clk + PWMCLK_CNTL) = BCM_PASSWORD | 0x11 ; // Source=osc and enable
383 digitalWrite (pin, LOW) ;
384 *(pwm + PWM_CONTROL) = 0 ; // Disable PWM
385 delayMicroseconds (10) ;
386 *(pwm + PWM0_RANGE) = 0x400 ;
387 delayMicroseconds (10) ;
388 *(pwm + PWM1_RANGE) = 0x400 ;
389 delayMicroseconds (10) ;
393 *(pwm + PWM0_DATA) = 512 ;
394 *(pwm + PWM1_DATA) = 512 ;
396 *(pwm + PWM_CONTROL) = PWM0_ENABLE | PWM1_ENABLE ;
403 // When we change mode of any pin, we remove the pull up/downs
405 // delayMicroseconds (300) ;
406 // pullUpDnControl (pin, PUD_OFF) ;
409 void pinModeWPi (int pin, int mode)
411 pinModeGpio (pinToGpio [pin & 63], mode) ;
414 void pinModeSys (int pin, int mode)
424 * Enables edge-detect mode on a pin - from a 0 to a 1 or 1 to 0
425 * Pin must already be in input mode with appropriate pull up/downs set.
426 *********************************************************************************
429 void pinEnableED01Pi (int pin)
431 pin = pinToGpio [pin & 63] ;
440 *********************************************************************************
443 void digitalWriteWPi (int pin, int value)
445 pin = pinToGpio [pin & 63] ;
448 *(gpio + gpioToGPCLR [pin]) = 1 << (pin & 31) ;
450 *(gpio + gpioToGPSET [pin]) = 1 << (pin & 31) ;
453 void digitalWriteGpio (int pin, int value)
458 *(gpio + gpioToGPCLR [pin]) = 1 << (pin & 31) ;
460 *(gpio + gpioToGPSET [pin]) = 1 << (pin & 31) ;
463 void digitalWriteSys (int pin, int value)
467 if (sysFds [pin] != -1)
470 write (sysFds [pin], "0\n", 2) ;
472 write (sysFds [pin], "1\n", 2) ;
479 * Set an output PWM value
480 *********************************************************************************
483 void pwmWriteGpio (int pin, int value)
488 port = gpioToPwmPort [pin] ;
490 *(pwm + port) = value & 0x3FF ;
493 void pwmWriteWPi (int pin, int value)
495 pwmWriteGpio (pinToGpio [pin & 63], value) ;
498 void pwmWriteSys (int pin, int value)
506 * Set the PAD driver value
507 *********************************************************************************
510 void setPadDriveWPi (int group, int value)
514 if ((group < 0) || (group > 2))
517 wrVal = BCM_PASSWORD | 0x18 | (value & 7) ;
518 *(pads + group + 11) = wrVal ;
521 printf ("setPadDrive: Group: %d, value: %d (%08X)\n", group, value, wrVal) ;
522 printf ("Read : %08X\n", *(pads + group + 11)) ;
526 void setPadDriveGpio (int group, int value)
528 setPadDriveWPi (group, value) ;
531 void setPadDriveSys (int group, int value)
539 * Read the value of a given Pin, returning HIGH or LOW
540 *********************************************************************************
543 int digitalReadWPi (int pin)
545 pin = pinToGpio [pin & 63] ;
547 if ((*(gpio + gpioToGPLEV [pin]) & (1 << (pin & 31))) != 0)
553 int digitalReadGpio (int pin)
557 if ((*(gpio + gpioToGPLEV [pin]) & (1 << (pin & 31))) != 0)
563 int digitalReadSys (int pin)
569 if (sysFds [pin] == -1)
572 lseek (sysFds [pin], 0L, SEEK_SET) ;
573 read (sysFds [pin], &c, 1) ;
574 return (c == '0') ? 0 : 1 ;
580 * Control the internal pull-up/down resistors on a GPIO pin
581 * The Arduino only has pull-ups and these are enabled by writing 1
582 * to a port when in input mode - this paradigm doesn't quite apply
584 *********************************************************************************
587 void pullUpDnControlGpio (int pin, int pud)
592 *(gpio + GPPUD) = pud ; delayMicroseconds (5) ;
593 *(gpio + gpioToPUDCLK [pin]) = 1 << (pin & 31) ; delayMicroseconds (5) ;
595 *(gpio + GPPUD) = 0 ; delayMicroseconds (5) ;
596 *(gpio + gpioToPUDCLK [pin]) = 0 ; delayMicroseconds (5) ;
599 void pullUpDnControlWPi (int pin, int pud)
601 pullUpDnControlGpio (pinToGpio [pin & 63], pud) ;
604 void pullUpDnControlSys (int pin, int pud)
612 * Wait for Interrupt on a GPIO pin.
613 * This is actually done via the /sys/class/gpio interface regardless of
614 * the wiringPi access mode in-use. Maybe sometime it might get a better
615 * way for a bit more efficiency.
616 *********************************************************************************
619 int waitForInterruptSys (int pin, int mS)
623 struct pollfd polls ;
625 if ((fd = sysFds [pin & 63]) == -1)
630 x = read (fd, buf, 6) ;
636 lseek (fd, 0, SEEK_SET) ;
638 // Setup poll structure
641 polls.events = POLLPRI ; // Urgent data!
645 return poll (&polls, 1, mS) ;
648 int waitForInterruptWPi (int pin, int mS)
650 return waitForInterruptSys (pinToGpio [pin & 63], mS) ;
653 int waitForInterruptGpio (int pin, int mS)
655 return waitForInterruptSys (pin, mS) ;
663 * Wait for some number of milli seconds
664 *********************************************************************************
667 void delay (unsigned int howLong)
669 struct timespec sleeper, dummy ;
671 sleeper.tv_sec = (time_t)(howLong / 1000) ;
672 sleeper.tv_nsec = (long)(howLong % 1000) * 1000000 ;
674 nanosleep (&sleeper, &dummy) ;
680 * This is somewhat intersting. It seems that on the Pi, a single call
681 * to nanosleep takes some 80 to 130 microseconds anyway, so while
682 * obeying the standards (may take longer), it's not always what we
685 * So what I'll do now is if the delay is less than 100uS we'll do it
686 * in a hard loop, watching a built-in counter on the ARM chip. This is
687 * somewhat sub-optimal in that it uses 100% CPU, something not an issue
688 * in a microcontroller, but under a multi-tasking, multi-user OS, it's
689 * wastefull, however we've no real choice )-:
690 *********************************************************************************
693 void delayMicrosecondsSys (unsigned int howLong)
695 struct timespec sleeper, dummy ;
698 sleeper.tv_nsec = (long)(howLong * 1000) ;
700 nanosleep (&sleeper, &dummy) ;
703 void delayMicrosecondsHard (unsigned int howLong)
705 *(timer + TIMER_LOAD) = howLong ;
706 *(timer + TIMER_IRQ_CLR) = 0 ;
708 while (*timerIrqRaw == 0)
712 void delayMicrosecondsWPi (unsigned int howLong)
714 struct timespec sleeper, dummy ;
716 /**/ if (howLong == 0)
718 else if (howLong < 100)
719 delayMicrosecondsHard (howLong) ;
723 sleeper.tv_nsec = (long)(howLong * 1000) ;
724 nanosleep (&sleeper, &dummy) ;
731 * Return a number of milliseconds as an unsigned int.
732 *********************************************************************************
735 unsigned int millis (void)
738 unsigned long long t1 ;
740 gettimeofday (&tv, NULL) ;
742 t1 = (tv.tv_sec * 1000000 + tv.tv_usec) / 1000 ;
744 return (uint32_t)(t1 - epoch) ;
750 * Must be called once at the start of your program execution.
752 * Default setup: Initialises the system into wiringPi Pin mode and uses the
753 * memory mapped hardware directly.
754 *********************************************************************************
757 int wiringPiSetup (void)
760 uint8_t *gpioMem, *pwmMem, *clkMem, *padsMem, *timerMem ;
763 pinMode = pinModeWPi ;
764 pullUpDnControl = pullUpDnControlWPi ;
765 digitalWrite = digitalWriteWPi ;
766 pwmWrite = pwmWriteWPi ;
767 setPadDrive = setPadDriveWPi ;
768 digitalRead = digitalReadWPi ;
769 waitForInterrupt = waitForInterruptWPi ;
770 delayMicroseconds = delayMicrosecondsWPi ;
772 // Open the master /dev/memory device
774 if ((fd = open ("/dev/mem", O_RDWR | O_SYNC) ) < 0)
776 fprintf (stderr, "wiringPiSetup: Unable to open /dev/mem: %s\n", strerror (errno)) ;
782 // Allocate 2 pages - 1 ...
784 if ((gpioMem = malloc (BLOCK_SIZE + (PAGE_SIZE-1))) == NULL)
786 fprintf (stderr, "wiringPiSetup: malloc failed: %s\n", strerror (errno)) ;
790 // ... presumably to make sure we can round it up to a whole page size
792 if (((uint32_t)gpioMem % PAGE_SIZE) != 0)
793 gpioMem += PAGE_SIZE - ((uint32_t)gpioMem % PAGE_SIZE) ;
795 gpio = (uint32_t *)mmap((caddr_t)gpioMem, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, fd, GPIO_BASE) ;
797 if ((int32_t)gpio < 0)
799 fprintf (stderr, "wiringPiSetup: mmap failed: %s\n", strerror (errno)) ;
805 if ((pwmMem = malloc (BLOCK_SIZE + (PAGE_SIZE-1))) == NULL)
807 fprintf (stderr, "wiringPiSetup: pwmMem malloc failed: %s\n", strerror (errno)) ;
811 if (((uint32_t)pwmMem % PAGE_SIZE) != 0)
812 pwmMem += PAGE_SIZE - ((uint32_t)pwmMem % PAGE_SIZE) ;
814 pwm = (uint32_t *)mmap(pwmMem, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, fd, GPIO_PWM) ;
816 if ((int32_t)pwm < 0)
818 fprintf (stderr, "wiringPiSetup: mmap failed (pwm): %s\n", strerror (errno)) ;
822 // Clock control (needed for PWM)
824 if ((clkMem = malloc (BLOCK_SIZE + (PAGE_SIZE-1))) == NULL)
826 fprintf (stderr, "wiringPiSetup: clkMem malloc failed: %s\n", strerror (errno)) ;
830 if (((uint32_t)clkMem % PAGE_SIZE) != 0)
831 clkMem += PAGE_SIZE - ((uint32_t)clkMem % PAGE_SIZE) ;
833 clk = (uint32_t *)mmap(clkMem, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, fd, CLOCK_BASE) ;
835 if ((int32_t)clk < 0)
837 fprintf (stderr, "wiringPiSetup: mmap failed (clk): %s\n", strerror (errno)) ;
843 if ((padsMem = malloc (BLOCK_SIZE + (PAGE_SIZE-1))) == NULL)
845 fprintf (stderr, "wiringPiSetup: padsMem malloc failed: %s\n", strerror (errno)) ;
849 if (((uint32_t)padsMem % PAGE_SIZE) != 0)
850 padsMem += PAGE_SIZE - ((uint32_t)padsMem % PAGE_SIZE) ;
852 pads = (uint32_t *)mmap(padsMem, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, fd, GPIO_PADS) ;
854 if ((int32_t)pads < 0)
856 fprintf (stderr, "wiringPiSetup: mmap failed (pads): %s\n", strerror (errno)) ;
861 printf ("Checking pads @ 0x%08X\n", (unsigned int)pads) ;
862 printf (" -> %08X %08X %08X\n", *(pads + 11), *(pads + 12), *(pads + 13)) ;
867 if ((timerMem = malloc (BLOCK_SIZE + (PAGE_SIZE-1))) == NULL)
869 fprintf (stderr, "wiringPiSetup: timerMem malloc failed: %s\n", strerror (errno)) ;
873 if (((uint32_t)timerMem % PAGE_SIZE) != 0)
874 timerMem += PAGE_SIZE - ((uint32_t)timerMem % PAGE_SIZE) ;
876 timer = (uint32_t *)mmap(timerMem, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, fd, GPIO_TIMER) ;
878 if ((int32_t)timer < 0)
880 fprintf (stderr, "wiringPiSetup: mmap failed (timer): %s\n", strerror (errno)) ;
884 // Set the timer to free-running, 1MHz.
885 // 0xF9 is 249, the timer divide is base clock / (divide+1)
886 // so base clock is 250MHz / 250 = 1MHz.
888 *(timer + TIMER_CONTROL) = 0x0000280 ;
889 *(timer + TIMER_PRE_DIV) = 0x00000F9 ;
890 timerIrqRaw = timer + TIMER_IRQ_RAW ;
892 // Initialise our epoch for millis()
894 gettimeofday (&tv, NULL) ;
895 epoch = (tv.tv_sec * 1000000 + tv.tv_usec) / 1000 ;
903 * Must be called once at the start of your program execution.
905 * GPIO setup: Initialises the system into GPIO Pin mode and uses the
906 * memory mapped hardware directly.
907 *********************************************************************************
910 int wiringPiSetupGpio (void)
912 int x = wiringPiSetup () ;
917 pinMode = pinModeGpio ;
918 pullUpDnControl = pullUpDnControlGpio ;
919 digitalWrite = digitalWriteGpio ;
920 pwmWrite = pwmWriteGpio ;
921 setPadDrive = setPadDriveGpio ;
922 digitalRead = digitalReadGpio ;
923 waitForInterrupt = waitForInterruptGpio ;
924 delayMicroseconds = delayMicrosecondsWPi ; // Same
932 * Must be called once at the start of your program execution.
934 * Initialisation (again), however this time we are using the /sys/class/gpio
935 * interface to the GPIO systems - slightly slower, but always usable as
936 * a non-root user, assuming the devices are already exported and setup correctly.
939 int wiringPiSetupSys (void)
945 pinMode = pinModeSys ;
946 pullUpDnControl = pullUpDnControlSys ;
947 digitalWrite = digitalWriteSys ;
948 pwmWrite = pwmWriteSys ;
949 setPadDrive = setPadDriveSys ;
950 digitalRead = digitalReadSys ;
951 waitForInterrupt = waitForInterruptSys ;
952 delayMicroseconds = delayMicrosecondsSys ;
954 // Open and scan the directory, looking for exported GPIOs, and pre-open
955 // the 'value' interface to speed things up for later
957 for (pin = 0 ; pin < 64 ; ++pin)
959 sprintf (fName, "/sys/class/gpio/gpio%d/value", pin) ;
960 sysFds [pin] = open (fName, O_RDWR) ;
963 // Initialise the epoch for mills() ...
965 gettimeofday (&tv, NULL) ;
966 epoch = (tv.tv_sec * 1000000 + tv.tv_usec) / 1000 ;