Thanks. In the following line it has been chosen 0x00040000 to write in to the configuration register. pinconf[0x217c/4] = pinconf[0x217c/4] & 0x0000ffff | 0x00040000; // gpio_149
How to select that value? On Wednesday, 2 April 2014 18:19:19 UTC+5:30, Jacek Radzikowski wrote: > > The address is in bytes and pinconf is an array of integers, which are > 4 bytes long. > > j. > > > On Wed, Apr 2, 2014 at 8:02 AM, milkyway <muhamme...@gmail.com<javascript:>> > wrote: > > I am new to beagle baord. I have a doubt here. Please help. > > > > In the following line > > > > pinconf[0x217c/4] = pinconf[0x217c/4] & 0x0000ffff | 0x00040000; // > > gpio_149 > > > > Why do you need the division inside the pinconf array for indexing? > > > > > > On Wednesday, 7 December 2011 20:26:08 UTC+5:30, dl4mea wrote: > >> > >> Hello, > >> > >> My self given task was to get a LED blinking on the Beagleboard. > >> > >> After getting bored from "echo 0 > brightness" and puzzling together > >> some pieces of code that I found on the net, I finally got a piece of > >> plain C code that I can cross compile on a Linux machine and play on > >> the Beagleboard. The two user LEDs as well as one pin of the extension > >> connect flash in a 1sec clock with it. > >> > >> No guarantee for completeness, no guarantee for functionality, but > >> here it works. > >> > >> Enjoy! > >> > >> Günter (dl4mea) > >> > >> /* Blinking of user LEDs USR0 and USR1 and gpio_157 on Expansion > >> Connector P2 > >> NOTE: gpio_157 is 1.8V IO, possibly not sufficient for a LED > >> > >> disconnect user LEDs from Linux > >> echo none > /sys/class/leds/beagleboard::usr0/trigger; echo none > / > >> sys/class/leds/beagleboard::usr1/trigger; > >> > >> compile using > >> <path_to_cross>/arm-armv6-linux-gnueabi-g++ -static blink.c -o blink > >> > >> References: OMAP35x Applications Processor, Technical Reference Manual > >> spruf98u.pdf > >> */ > >> > >> #include <stdio.h> > >> #include <stdlib.h> > >> #include <sys/types.h> > >> #include <sys/stat.h> > >> #include <unistd.h> > >> #include <fcntl.h> > >> #include <sys/mman.h> > >> > >> int main(void) > >> { > >> > >> printf ("open file descriptor for PADCONFIG\n"); > >> int fd = open("/dev/mem", O_RDWR | O_SYNC); //O_SYNC makes the > >> memory uncacheable > >> if (fd < 0) { > >> printf("Could not open PADCONFIG memory fd\n"); > >> return 0; > >> } > >> > >> // Pad configuration > >> printf ("map PINCONFIG\n"); > >> volatile ulong *pinconf; > >> pinconf = (ulong*) mmap(NULL, 0x10000, PROT_READ | PROT_WRITE, > >> MAP_SHARED, fd, 0x48000000); > >> if (pinconf == MAP_FAILED) { > >> printf("Pinconf Mapping failed\n"); > >> close(fd); > >> return 0; > >> } > >> > >> printf ("set pinconfig GPIO\n"); > >> pinconf[0x217c/4] = pinconf[0x217c/4] & 0x0000ffff | > >> 0x00040000; // gpio_149 > >> pinconf[0x2180/4] = pinconf[0x2180/4] & 0xffff0000 | > >> 0x00000004; // gpio_150 > >> pinconf[0x218c/4] = pinconf[0x218c/4] & 0x0000ffff | > >> 0x00040000; // gpio_157 > >> close(fd); > >> > >> /* -------------------------------------- */ > >> > >> printf ("open file descriptor for GPIO\n"); > >> int gpio_fd = open("/dev/mem", O_RDWR | O_SYNC); > >> if (gpio_fd < 0) { > >> printf("Could not open GPIO memory fd\n"); > >> return 0; > >> } > >> > >> // GPIO configuration > >> printf ("map GPIO\n"); > >> volatile ulong *gpio; > >> gpio = (ulong*) mmap(NULL, 0x10000, PROT_READ | PROT_WRITE, > >> MAP_SHARED, gpio_fd, 0x49050000); > >> if (gpio == MAP_FAILED) { > >> printf ("GPIO Mapping failed\n"); > >> close(gpio_fd); > >> return 0; > >> } > >> > >> printf ("set GPIO config\n"); > >> > >> // Configure GPIO pins on bank 5 as output. > >> // GPIO 5 is at physical address 0x49056000 = 0x49050000+0x6000 > >> gpio[0x6034/4] &= ~0x20600000; // set low for output > >> // Also disable the wakeupenable and irqenable intertupts > >> // GPIO clear_Wakeupenable is offset by 0x80 for each bank > >> gpio[0x6080/4] = 0x20600000; // 0x1: Clear the corresponding > >> bit in the GPIO_WAKEUPENABLE register > >> // GPIO clear_irqenable1 is offset by 0x60 for each bank > >> gpio[0x6060/4] = 0x20600000; // 0x1: Clear the corresponding > >> bit in the GPIO_IRQENABLE1 register > >> // GPIO clear_irqenable2 is offset by 0x70 for each bank > >> gpio[0x6070/4] = 0x20600000; // 0x1: Clear the corresponding > >> bit in the GPIO_IRQENABLE2 register > >> > >> /* -------------------------------------- */ > >> > >> printf ("Toggle Pins\n"); > >> > >> int j=0; > >> for (j=0; j<10; j++) > >> { > >> printf ("j=%u\n", j); > >> //clear_data_out has offset 0x90 > >> gpio[0x6090/4]=0x20600000; > >> usleep(500000); > >> //set_data_out has offset 0x94 > >> gpio[0x6094/4]=0x20600000; > >> usleep(500000); > >> } > >> > >> close(gpio_fd); > >> } > > > > -- > > For more options, visit http://beagleboard.org/discuss > > --- > > You received this message because you are subscribed to the Google > Groups > > "BeagleBoard" group. > > To unsubscribe from this group and stop receiving emails from it, send > an > > email to beagleboard...@googlegroups.com <javascript:>. > > For more options, visit https://groups.google.com/d/optout. > > > > -- > Given a choice between two theories, take the one which is funnier > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. 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