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
404 // Or we used to... Hm. Commented out now because for some wieird reason,
405 // it seems to block subsequent attempts to set the pull up/downs and I've
406 // not quite gotten to the bottom of why this happens
407 // The down-side is that the pull up/downs are rememberd in the SoC between
408 // power cycles, so it's going to be a good idea to explicitly set them in
411 // pullUpDnControl (pin, PUD_OFF) ;
415 void pinModeWPi (int pin, int mode)
417 pinModeGpio (pinToGpio [pin & 63], mode) ;
420 void pinModeSys (int pin, int mode)
430 * Enables edge-detect mode on a pin - from a 0 to a 1 or 1 to 0
431 * Pin must already be in input mode with appropriate pull up/downs set.
432 *********************************************************************************
435 void pinEnableED01Pi (int pin)
437 pin = pinToGpio [pin & 63] ;
446 *********************************************************************************
449 void digitalWriteWPi (int pin, int value)
451 pin = pinToGpio [pin & 63] ;
454 *(gpio + gpioToGPCLR [pin]) = 1 << (pin & 31) ;
456 *(gpio + gpioToGPSET [pin]) = 1 << (pin & 31) ;
459 void digitalWriteGpio (int pin, int value)
464 *(gpio + gpioToGPCLR [pin]) = 1 << (pin & 31) ;
466 *(gpio + gpioToGPSET [pin]) = 1 << (pin & 31) ;
469 void digitalWriteSys (int pin, int value)
473 if (sysFds [pin] != -1)
476 write (sysFds [pin], "0\n", 2) ;
478 write (sysFds [pin], "1\n", 2) ;
485 * Set an output PWM value
486 *********************************************************************************
489 void pwmWriteGpio (int pin, int value)
494 port = gpioToPwmPort [pin] ;
496 *(pwm + port) = value & 0x3FF ;
499 void pwmWriteWPi (int pin, int value)
501 pwmWriteGpio (pinToGpio [pin & 63], value) ;
504 void pwmWriteSys (int pin, int value)
512 * Set the PAD driver value
513 *********************************************************************************
516 void setPadDriveWPi (int group, int value)
520 if ((group < 0) || (group > 2))
523 wrVal = BCM_PASSWORD | 0x18 | (value & 7) ;
524 *(pads + group + 11) = wrVal ;
527 printf ("setPadDrive: Group: %d, value: %d (%08X)\n", group, value, wrVal) ;
528 printf ("Read : %08X\n", *(pads + group + 11)) ;
532 void setPadDriveGpio (int group, int value)
534 setPadDriveWPi (group, value) ;
537 void setPadDriveSys (int group, int value)
545 * Read the value of a given Pin, returning HIGH or LOW
546 *********************************************************************************
549 int digitalReadWPi (int pin)
551 pin = pinToGpio [pin & 63] ;
553 if ((*(gpio + gpioToGPLEV [pin]) & (1 << (pin & 31))) != 0)
559 int digitalReadGpio (int pin)
563 if ((*(gpio + gpioToGPLEV [pin]) & (1 << (pin & 31))) != 0)
569 int digitalReadSys (int pin)
575 if (sysFds [pin] == -1)
578 lseek (sysFds [pin], 0L, SEEK_SET) ;
579 read (sysFds [pin], &c, 1) ;
580 return (c == '0') ? 0 : 1 ;
586 * Control the internal pull-up/down resistors on a GPIO pin
587 * The Arduino only has pull-ups and these are enabled by writing 1
588 * to a port when in input mode - this paradigm doesn't quite apply
590 *********************************************************************************
593 void pullUpDnControlGpio (int pin, int pud)
598 *(gpio + GPPUD) = pud ; delayMicroseconds (5) ;
599 *(gpio + gpioToPUDCLK [pin]) = 1 << (pin & 31) ; delayMicroseconds (5) ;
601 *(gpio + GPPUD) = 0 ; delayMicroseconds (5) ;
602 *(gpio + gpioToPUDCLK [pin]) = 0 ; delayMicroseconds (5) ;
605 void pullUpDnControlWPi (int pin, int pud)
607 pullUpDnControlGpio (pinToGpio [pin & 63], pud) ;
610 void pullUpDnControlSys (int pin, int pud)
618 * Wait for Interrupt on a GPIO pin.
619 * This is actually done via the /sys/class/gpio interface regardless of
620 * the wiringPi access mode in-use. Maybe sometime it might get a better
621 * way for a bit more efficiency.
622 *********************************************************************************
625 int waitForInterruptSys (int pin, int mS)
629 struct pollfd polls ;
631 if ((fd = sysFds [pin & 63]) == -1)
636 x = read (fd, buf, 6) ;
642 lseek (fd, 0, SEEK_SET) ;
644 // Setup poll structure
647 polls.events = POLLPRI ; // Urgent data!
651 return poll (&polls, 1, mS) ;
654 int waitForInterruptWPi (int pin, int mS)
656 return waitForInterruptSys (pinToGpio [pin & 63], mS) ;
659 int waitForInterruptGpio (int pin, int mS)
661 return waitForInterruptSys (pin, mS) ;
669 * Wait for some number of milli seconds
670 *********************************************************************************
673 void delay (unsigned int howLong)
675 struct timespec sleeper, dummy ;
677 sleeper.tv_sec = (time_t)(howLong / 1000) ;
678 sleeper.tv_nsec = (long)(howLong % 1000) * 1000000 ;
680 nanosleep (&sleeper, &dummy) ;
686 * This is somewhat intersting. It seems that on the Pi, a single call
687 * to nanosleep takes some 80 to 130 microseconds anyway, so while
688 * obeying the standards (may take longer), it's not always what we
691 * So what I'll do now is if the delay is less than 100uS we'll do it
692 * in a hard loop, watching a built-in counter on the ARM chip. This is
693 * somewhat sub-optimal in that it uses 100% CPU, something not an issue
694 * in a microcontroller, but under a multi-tasking, multi-user OS, it's
695 * wastefull, however we've no real choice )-:
696 *********************************************************************************
699 void delayMicrosecondsSys (unsigned int howLong)
701 struct timespec sleeper, dummy ;
704 sleeper.tv_nsec = (long)(howLong * 1000) ;
706 nanosleep (&sleeper, &dummy) ;
709 void delayMicrosecondsHard (unsigned int howLong)
711 *(timer + TIMER_LOAD) = howLong ;
712 *(timer + TIMER_IRQ_CLR) = 0 ;
714 while (*timerIrqRaw == 0)
718 void delayMicrosecondsWPi (unsigned int howLong)
720 struct timespec sleeper, dummy ;
722 /**/ if (howLong == 0)
724 else if (howLong < 100)
725 delayMicrosecondsHard (howLong) ;
729 sleeper.tv_nsec = (long)(howLong * 1000) ;
730 nanosleep (&sleeper, &dummy) ;
737 * Return a number of milliseconds as an unsigned int.
738 *********************************************************************************
741 unsigned int millis (void)
744 unsigned long long t1 ;
746 gettimeofday (&tv, NULL) ;
748 t1 = (tv.tv_sec * 1000000 + tv.tv_usec) / 1000 ;
750 return (uint32_t)(t1 - epoch) ;
756 * Must be called once at the start of your program execution.
758 * Default setup: Initialises the system into wiringPi Pin mode and uses the
759 * memory mapped hardware directly.
760 *********************************************************************************
763 int wiringPiSetup (void)
766 uint8_t *gpioMem, *pwmMem, *clkMem, *padsMem, *timerMem ;
769 pinMode = pinModeWPi ;
770 pullUpDnControl = pullUpDnControlWPi ;
771 digitalWrite = digitalWriteWPi ;
772 pwmWrite = pwmWriteWPi ;
773 setPadDrive = setPadDriveWPi ;
774 digitalRead = digitalReadWPi ;
775 waitForInterrupt = waitForInterruptWPi ;
776 delayMicroseconds = delayMicrosecondsWPi ;
778 // Open the master /dev/memory device
780 if ((fd = open ("/dev/mem", O_RDWR | O_SYNC) ) < 0)
782 fprintf (stderr, "wiringPiSetup: Unable to open /dev/mem: %s\n", strerror (errno)) ;
788 // Allocate 2 pages - 1 ...
790 if ((gpioMem = malloc (BLOCK_SIZE + (PAGE_SIZE-1))) == NULL)
792 fprintf (stderr, "wiringPiSetup: malloc failed: %s\n", strerror (errno)) ;
796 // ... presumably to make sure we can round it up to a whole page size
798 if (((uint32_t)gpioMem % PAGE_SIZE) != 0)
799 gpioMem += PAGE_SIZE - ((uint32_t)gpioMem % PAGE_SIZE) ;
801 gpio = (uint32_t *)mmap((caddr_t)gpioMem, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, fd, GPIO_BASE) ;
803 if ((int32_t)gpio < 0)
805 fprintf (stderr, "wiringPiSetup: mmap failed: %s\n", strerror (errno)) ;
811 if ((pwmMem = malloc (BLOCK_SIZE + (PAGE_SIZE-1))) == NULL)
813 fprintf (stderr, "wiringPiSetup: pwmMem malloc failed: %s\n", strerror (errno)) ;
817 if (((uint32_t)pwmMem % PAGE_SIZE) != 0)
818 pwmMem += PAGE_SIZE - ((uint32_t)pwmMem % PAGE_SIZE) ;
820 pwm = (uint32_t *)mmap(pwmMem, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, fd, GPIO_PWM) ;
822 if ((int32_t)pwm < 0)
824 fprintf (stderr, "wiringPiSetup: mmap failed (pwm): %s\n", strerror (errno)) ;
828 // Clock control (needed for PWM)
830 if ((clkMem = malloc (BLOCK_SIZE + (PAGE_SIZE-1))) == NULL)
832 fprintf (stderr, "wiringPiSetup: clkMem malloc failed: %s\n", strerror (errno)) ;
836 if (((uint32_t)clkMem % PAGE_SIZE) != 0)
837 clkMem += PAGE_SIZE - ((uint32_t)clkMem % PAGE_SIZE) ;
839 clk = (uint32_t *)mmap(clkMem, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, fd, CLOCK_BASE) ;
841 if ((int32_t)clk < 0)
843 fprintf (stderr, "wiringPiSetup: mmap failed (clk): %s\n", strerror (errno)) ;
849 if ((padsMem = malloc (BLOCK_SIZE + (PAGE_SIZE-1))) == NULL)
851 fprintf (stderr, "wiringPiSetup: padsMem malloc failed: %s\n", strerror (errno)) ;
855 if (((uint32_t)padsMem % PAGE_SIZE) != 0)
856 padsMem += PAGE_SIZE - ((uint32_t)padsMem % PAGE_SIZE) ;
858 pads = (uint32_t *)mmap(padsMem, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, fd, GPIO_PADS) ;
860 if ((int32_t)pads < 0)
862 fprintf (stderr, "wiringPiSetup: mmap failed (pads): %s\n", strerror (errno)) ;
867 printf ("Checking pads @ 0x%08X\n", (unsigned int)pads) ;
868 printf (" -> %08X %08X %08X\n", *(pads + 11), *(pads + 12), *(pads + 13)) ;
873 if ((timerMem = malloc (BLOCK_SIZE + (PAGE_SIZE-1))) == NULL)
875 fprintf (stderr, "wiringPiSetup: timerMem malloc failed: %s\n", strerror (errno)) ;
879 if (((uint32_t)timerMem % PAGE_SIZE) != 0)
880 timerMem += PAGE_SIZE - ((uint32_t)timerMem % PAGE_SIZE) ;
882 timer = (uint32_t *)mmap(timerMem, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, fd, GPIO_TIMER) ;
884 if ((int32_t)timer < 0)
886 fprintf (stderr, "wiringPiSetup: mmap failed (timer): %s\n", strerror (errno)) ;
890 // Set the timer to free-running, 1MHz.
891 // 0xF9 is 249, the timer divide is base clock / (divide+1)
892 // so base clock is 250MHz / 250 = 1MHz.
894 *(timer + TIMER_CONTROL) = 0x0000280 ;
895 *(timer + TIMER_PRE_DIV) = 0x00000F9 ;
896 timerIrqRaw = timer + TIMER_IRQ_RAW ;
898 // Initialise our epoch for millis()
900 gettimeofday (&tv, NULL) ;
901 epoch = (tv.tv_sec * 1000000 + tv.tv_usec) / 1000 ;
909 * Must be called once at the start of your program execution.
911 * GPIO setup: Initialises the system into GPIO Pin mode and uses the
912 * memory mapped hardware directly.
913 *********************************************************************************
916 int wiringPiSetupGpio (void)
918 int x = wiringPiSetup () ;
923 pinMode = pinModeGpio ;
924 pullUpDnControl = pullUpDnControlGpio ;
925 digitalWrite = digitalWriteGpio ;
926 pwmWrite = pwmWriteGpio ;
927 setPadDrive = setPadDriveGpio ;
928 digitalRead = digitalReadGpio ;
929 waitForInterrupt = waitForInterruptGpio ;
930 delayMicroseconds = delayMicrosecondsWPi ; // Same
938 * Must be called once at the start of your program execution.
940 * Initialisation (again), however this time we are using the /sys/class/gpio
941 * interface to the GPIO systems - slightly slower, but always usable as
942 * a non-root user, assuming the devices are already exported and setup correctly.
945 int wiringPiSetupSys (void)
951 pinMode = pinModeSys ;
952 pullUpDnControl = pullUpDnControlSys ;
953 digitalWrite = digitalWriteSys ;
954 pwmWrite = pwmWriteSys ;
955 setPadDrive = setPadDriveSys ;
956 digitalRead = digitalReadSys ;
957 waitForInterrupt = waitForInterruptSys ;
958 delayMicroseconds = delayMicrosecondsSys ;
960 // Open and scan the directory, looking for exported GPIOs, and pre-open
961 // the 'value' interface to speed things up for later
963 for (pin = 0 ; pin < 64 ; ++pin)
965 sprintf (fName, "/sys/class/gpio/gpio%d/value", pin) ;
966 sysFds [pin] = open (fName, O_RDWR) ;
969 // Initialise the epoch for mills() ...
971 gettimeofday (&tv, NULL) ;
972 epoch = (tv.tv_sec * 1000000 + tv.tv_usec) / 1000 ;