GPIO Driver development on BeagleBone Black with RTEMS

beagleboard.h

/**
 * @file
 *
 * @ingroup arm_beagle
 *
 * @brief Global BSP definitions.
 */

/*
 * Copyright (c) 2015 Ketul Shah <ketulshah1993 at gmail.com>

 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://www.rtems.org/license/LICENSE.
 */

#ifndef LIBBSP_ARM_BEAGLE_H
#define LIBBSP_ARM_BEAGLE_H

#include <stdint.h>
#include <bsp/utility.h>

/* GPIO Memory Registers */

#if IS_AM335X
#define AM335X_GPIO0_BASE        (0x44E07000)
#define AM335X_GPIO1_BASE        (0x4804C000)
#define AM335X_GPIO2_BASE        (0x481AC000)
#define AM335X_GPIO3_BASE        (0x481AE000)
#define AM335X_GPIO_OE           (0x134)
#define AM335X_GPIO_DATAOUT      (0x13C)
#define AM335X_GPIO_DATAIN       (0x138)
#define AM335X_GPIO_CLEARDATAOUT (0x190)
#define AM335X_GPIO_SETDATAOUT   (0x194)
#endif

#if IS_DM3730
#define DM37XX_GPIO1_BASE        (0x48310000)
#define DM37XX_GPIO2_BASE        (0x49050000)
#define DM37XX_GPIO3_BASE        (0x49052000)
#define DM37XX_GPIO4_BASE        (0x49054000)
#define DM37XX_GPIO5_BASE        (0x49056000)
#define DM37XX_GPIO6_BASE        (0x49058000)
#define DM37XX_GPIO_OE           (0x34)
#define DM37XX_GPIO_DATAOUT      (0x3c)
#define DM37XX_GPIO_DATAIN       (0x38)
#define DM37XX_GPIO_CLEARDATAOUT (0x90)
#define DM37XX_GPIO_SETDATAOUT   (0x94)
#endif

gpio.c

/**
 * @file
 *
 * @ingroup arm_beagle
 *
 * @brief Global BSP definitions.
 */

/*
 * Copyright (c) 2015 Ketul Shah <ketulshah1993 at gmail.com>

 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://www.rtems.org/license/LICENSE.
 */

#include <bsp/beagleboard.h>
#include <bsp/irq.h>
#include <bsp/gpio.h>
#include <bsp.h>

#include <stdlib.h>
#include <stdint.h>

bool is_initialized = flase;

void gpio_initialize(void)
{	
   if ( is_initialized )
    return;

  is_initialized = true;
/*Enabling GPIO1 pins as OUTPUT PINs*/
  write32(AM335X_GPIO1_BASE +GPIO_OE,0x00000000);
}

void gpio_set_value(unsigned gpio, int value)
{

   if (value)
	{
	   uint8_t tmp = readb(AM335X_GPIO1_BASE + gpio/8+GPIO_SETDATAOUT);
           tmp |= (1 << gpio%8);
	   writeb(tmp, AM335X_GPIO1_BASE + gpio/8+GPIO_SETDATAOUT);
	}
   else
	{
           uint8_t tmp = readb(AM335X_GPIO1_BASE + gpio/8+GPIO_CLEARDATAOUT);
	   tmp |= (1 << gpio%8);
	   writeb(tmp, AM335X_GPIO1_BASE + gpio/8+GPIO_CLEARDATAOUT);

	}

}

void allgpioset(void)
{
printf("Setting all gpio1\n");
write32(AM335X_GPIO1_BASE +GPIO_SETDATAOUT,0xFFFFFFFF);
}

void allgpioclr(void)
{
printf("Clearing all gpio1\n");
write32(AM335X_GPIO1_BASE+GPIO_CLEARDATAOUT,0xFFFFFFFF);
}

gpio.h

/**
 * @file
 *
 * @ingroup arm_beagle
 *
 * @brief Global BSP definitions.
 */

/*
 * Copyright (c) 2015 Ketul Shah <ketulshah1993 at gmail.com>

 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://www.rtems.org/license/LICENSE.
 */

#ifndef LIBBSP_ARM_BEAGLE_GPIO_H
#define LIBBSP_ARM_BEAGLE_GPIO_H

#include <rtems.h>
#include "beagleboard.h"

#include <rtems.h>

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

extern void gpio_initialize(void);

extern void allgpioset(void);

extern void allgpioclr(void);
extern void gpio_set_value(unsigned gpio, int value);

#endif /* LIBBSP_ARM_BEAGLE_GPIO_H */

init.c

/**
 * @file
 *
 * @ingroup arm_beagle
 *
 * @brief Global BSP definitions.
 */
 
/*
 * Copyright (c) 2015 Ketul Shah <ketulshah1993 at gmail.com>

 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://www.rtems.org/license/LICENSE.
 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <rtems.h>
#include <rtems/test.h>

#include <bsp/gpio.h> /* Calls the BSP gpio library */
#include <rtems/status-checks.h>

#include <stdio.h>
#include <stdlib.h>

void inline delaysec(float sec)
{
rtems_task_wake_after(sec*rtems_clock_get_ticks_per_second());
}

/*Function for USR LEDs demo.*/

void inline gpio_auto()
{
/*Generating some patterns*/
allgpioset();
delaysec(1);
allgpioclr();
gpio_set_value(22,1);gpio_set_value(24,1);
delaysec(0.4);
gpio_set_value(22,1);gpio_set_value(24,0);
delaysec(0.3);
gpio_set_value(21,1);gpio_set_value(23,1);
delaysec(0.5);
gpio_set_value(22,0);gpio_set_value(24,0);
delaysec(0.2);
gpio_set_value(22,1);
delaysec(0.2);
allgpioclr();
delaysec(0.1);
}

rtems_task Init(rtems_task_argument argument);

const char rtems_test_name[] = "GPIO TEST";

rtems_task Init(
  rtems_task_argument ignored
)
{
  rtems_test_begin();
  printf("GPIO Testing started\n");
  gpio_initialize();
  allgpioclr();
  gpio_auto();
  printf( "GPIO TEST by Ketul\n" );
  rtems_test_end();
  exit( 0 );
}


/* Clock driver module is enabled*/
#define CONFIGURE_APPLICATION_NEEDS_CLOCK_DRIVER

#define CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER

#define CONFIGURE_MAXIMUM_TASKS            1
#define CONFIGURE_USE_DEVFS_AS_BASE_FILESYSTEM

#define CONFIGURE_RTEMS_INIT_TASKS_TABLE

#define CONFIGURE_INITIAL_EXTENSIONS RTEMS_TEST_INITIAL_EXTENSION

#define CONFIGURE_INIT
#include <rtems/confdefs.h>