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--- tutorials:common:gpio_on_lubuntu [2014/05/20 15:47]
allen [Using sunxi-gpio kernel module]
+++ tutorials:common:gpio_on_lubuntu [2014/07/01 20:03] (current)
allen [Cubieboard pin]
@@ Line 1: / Line 1: @@
+==== Cubieboard pin ====
+Cubietruck         [[http://docs.cubieboard.org/a20-cubietruck_gpio_pin]]
+Cubieboard 1 2 [[http://docs.cubieboard.org/cubieboard1_and_cubieboard2_gpio_pin]]
+Fex Guide   [[http://linux-sunxi.org/Fex_Guide]]
+A10 Datasheet  [[http://dl.linux-sunxi.org/A10/A10%20Datasheet%20-%20v1.21%20(2012-04-06).pdf|A10 Datasheet(For Pin multiplexing reference）]]
+A20 Datasheet  [[http://dl.cubieboard.org/software/ubuntuone/public/cubieboard/docs/A20_user manual V1.0 20130322.pdf|A20 user manual V1.0 20130322.pdf(datasheet)]]
 ====Using sunxi-gpio kernel module====
@@ Line 109: / Line 124: @@
 </code>
 Save as gpio.c,download [[http://dl.cubieboard.org/software/libs/gpio.tar|gpio_lib]],then<code>
-gcc gpio_lib.c -c
+$sudo apt-get install gcc build-essential
-gcc gpio.c -c
+$tar -xf gpio.tar
-gcc gpio.o gpio_lib.o -o gpio
+$cd gpio/
-./gpio
+$gcc gpio_lib.c -c
+$gcc gpio.c -c
+$gcc gpio.o gpio_lib.o -o gpio
+$./gpio
 </code>
 If you have used a led connect GND and PD01 port,the led is going to blink in cycle time.\\
 Of course you can define and use other port .\\
 Use above the method  like high-delay-low-delay  to simulate  PWM output .\\
+====Using  mmap mapping IO address====
+<code>
+	///////////////////////////////////////////////////////////////////////////////
+	#include <ctype.h>
+	#include <string.h>
+	#include <stdlib.h>
+	#include <stdio.h>
+	#include <math.h>
+	#include <time.h>
+	#include <signal.h>
+	#include <sys/types.h>
+	#include <sys/stat.h>
+	#include <fcntl.h>
+	#include <sys/mman.h>
+	#include <sys/select.h>
+	#include <pthread.h>
+	#include <unistd.h>
+	#include <sched.h>
+	#include <errno.h>
+	#define SW_PORTC_IO_BASE  0x01c20800
+	int main() {
+	   unsigned int * pc;
+	   int fd, i;
+	   char * ptr;
+	   unsigned int addr_start, addr_offset, PageSize, PageMask, data;
+	   PageSize = sysconf(_SC_PAGESIZE);
+	   PageMask = (~(PageSize-1));
+	   addr_start = SW_PORTC_IO_BASE & PageMask;
+	   addr_offset = SW_PORTC_IO_BASE & ~PageMask;
+	   fd = open("/dev/mem", O_RDWR);
+	   if(fd < 0) {
+	      perror("Unable to open /dev/mem");
+	      return(-1);
+	   }
+	   pc = mmap(0, PageSize*2, PROT_READ|PROT_WRITE, MAP_SHARED, fd, addr_start);
+	   if(pc == MAP_FAILED) {
+	      perror("Unable to mmap file");
+	      printf("pc:%lx\n", (unsigned long)pc);
+	      return(-1);
+	   }
+	   printf("PageSize:%8.8x\tPageMask:%8.8x\naddr_start:%8.8x\taddr_offset:%8.8x\n",PageSize,PageMask,addr_start,addr_offset);
+	   printf("pc:%8.8x\n", *(unsigned int *)pc);
+	   ptr = (char *)pc + addr_offset;
+	   data = *(unsigned int *)(ptr+0x10c);
+	   for(i=0;i<1000;i++){
+	      data |= 1<<20;                              //green led connect PH20
+	      *(unsigned int *)(ptr+0x10c) = data;
+	      usleep(100000);
+	      data &= ~(1<<20);
+	      *(unsigned int *)(ptr+0x10c) = data;
+	      usleep(500000);
+	   }
+	   return 0;
+	}
+</code>
+save as test.c,then
+<code>
+$sudo apt-get install gcc build-essential
+$gcc test.c -o test
+$./test &
+</code>
+The green LED is blinking  in cycle time.You can modify the ''data |= 1<<20;'' and ''data &= ~(1<<20);'' to use PH15 like ''data |= 1<<15;'' and ''data &= ~(1<<15);''.If you have used a led connect VCC and PH15 port,the led is going to blink in cycle time.\\

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