Hey guys,
Thanks in getting back to me I have posted the code that I used to enable a
GPIO to act as input or an output below;
#include <stdlib.h>
#include <stdio.h>
#include <hw/inout.h>
#include <sys/mman.h>
#include <sys/neutrino.h>
#include <stdint.h>
#include <BeagleBoneIO.h>
uintptr_t MapIO(uintptr_t gpio_base, uint32_t BaseAddress)
{
gpio_base = mmap_device_io(AM335X_GPIO_SIZE, BaseAddress);
if(gpio_base == MAP_DEVICE_FAILED)
{
perror("Can't map device I/O for GPIO");
printf("Main Terminated...!\n");
return 0;
}
return gpio_base;
}
int WriteIO(uintptr_t gpio_base, int value, uint32_t BitsToModify)
{
uint32_t val = 0;
val = in32(gpio_base + GPIO_DATAOUT); // value that is currently on
the GPIO port
if (value==0)
{
val &= ~BitsToModify; // clear the bits
}
else
{
val |= BitsToModify; // set the bits
}
out32(gpio_base + GPIO_DATAOUT, val);
return 0;
}
int SetDDR(uintptr_t gpio_port, int Direction, uint32_t BitsToSet)
{
uint32_t val = 0;
// Read GPIO output enable register
// 0 The corresponding GPIO port is configured as an output.
// 1 The corresponding GPIO port is configured as an input.
val = in32(gpio_port + GPIO_OE);
printf("value of register output enable register= %#010x\n", val);
if(Direction== 0)
val &= ~(BitsToSet); // make sure they are 0
else
val |= BitsToSet; // make sure they are set to 1
out32(gpio_port + GPIO_OE, val); // write value to output enable
val = in32(gpio_port + GPIO_OE);
printf("Modified value of register output enable register= %#010x\n",
val);
return 0;
}
uint32_t ReadIO(uintptr_t gpio_base, uint32_t BitsToRead)
{
uint32_t val = 0;
val = in32(gpio_base + GPIO_DATAIN); // value that is currently on
the GPIO port
printf("\nvalue of data register = %#010x\n", val);
val &= BitsToRead; // mask bit
printf("value of data register after masking it = %#010x\n", val);
return val;
}
int main(int argc, char *argv[])
{
printf("Welcome to the QNX Momentics BeagleBone GPIO Reader\n");
uintptr_t gpio0_port = 0;
uintptr_t gpio1_port = 0;
uintptr_t gpio2_port = 0;
uintptr_t gpio3_port = 0;
uint32_t val = 0;
ThreadCtl(_NTO_TCTL_IO,NULL); // Request I/O privileges; let the
thread execute the I/O opcodes
// in, ins, out, outs, cli, sti on
architectures where it has the
// appropriate privilege, and let it
attach IRQ handlers. You need
// root permissions to use this
command. If a thread attempts to use
// faults with a SIGSEGV when the
opcode is attempted.
uintptr_t gpio_base;
gpio_base = mmap_device_io(0x08, 0x44e10844);
if(gpio_base == MAP_DEVICE_FAILED)
{
perror("Can't map Control Base Module");
printf("Main Terminated...!\n");
return 0;
}
printf("Device gpio_base\t = %#010x\n", gpio_base);
gpio1_port = MapIO(gpio1_port, AM335X_GPIO1_BASE);
// set the data direction
SetDDR(gpio1_port,1, GPIO1_28); // Main function of setting up pin 28
as an input
munmap_device_io(gpio1_port, AM335X_GPIO_SIZE);
printf("\nAll good - Main Terminated...!\n");
return EXIT_SUCCESS;
}
So what I've done above is, writing up a data direction register function
and writing to GPIO 28 to be an input(1). If I were to set GPIO 28 as an
output, I have to to just change SetDDR(gpio1_port, 0, GPIO1_28).
Hope it helps!
On Sat, Jul 4, 2015 at 4:35 AM, William Hermans <[email protected]> wrote:
> Salman, bear with me, as I know very little about QNX. If you could
> explain how you identified, and set the pin to input. That might help us
> better answer your question. WIth Debian, there are a few options, but no
> idea which of these options, if any are available with QNX.
>
> On Fri, Jul 3, 2015 at 10:57 AM, Max <[email protected]> wrote:
>
>> If the pin acts as the input then it should read an external state. I
>> would configure this pin as the output and then write 0/1 to a necessary
>> bit position
>>
>> Отправлено с iPad
>>
>> 3 июля 2015 г., в 19:02, Salman Feroze <[email protected]>
>> написал(а):
>>
>> Hey guys,
>>
>> I am relatively new in this forum, so please bear with me if the
>> questions I ask would sound unintelligent. I am currently working with the
>> Beagle Bone Black that is running QNX RTOS. I am trying to get my head
>> around this board by developing simple programs such as turning ON an
>> external LED that is connected to the board. So far, I have manage to
>> identify a GPIO pin and set it to be an input using the data direction
>> register (DDR) function. However, I am unable to move on from here.
>>
>> Since I have enabled the pin to act as input, how would I be able to use
>> it to turn ON an LED? What should be my next step be?
>>
>> Any input/suggestion would be much appreciated.
>>
>> --
>> For more options, visit http://beagleboard.org/discuss
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>
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