/**
* @file rpi-gpio.c
*
* @ingroup raspberrypi_gpio
*
* @brief Support for the Raspberry PI GPIO.
*/
/*
* Copyright (c) 2014-2015 Andre Marques <andre.lousa.marques 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/raspberrypi.h>
#include <bsp/irq-generic.h>
#include <bsp/gpio.h>
#include <bsp/rpi-gpio.h>
#include <stdlib.h>
/* Calculates a bitmask to assign an alternate function to a given pin. */
#define SELECT_PIN_FUNCTION(fn, pn) (fn << ((pn % 10) * 3))
rtems_gpio_specific_data alt_func_def[] = {
{.io_function = RPI_ALT_FUNC_0, .pin_data = NULL},
{.io_function = RPI_ALT_FUNC_1, .pin_data = NULL},
{.io_function = RPI_ALT_FUNC_2, .pin_data = NULL},
{.io_function = RPI_ALT_FUNC_3, .pin_data = NULL},
{.io_function = RPI_ALT_FUNC_4, .pin_data = NULL},
{.io_function = RPI_ALT_FUNC_5, .pin_data = NULL}
};
/* Raspberry Pi 1 Revision 2 gpio interface definitions. */
#include "gpio-interfaces-pi1-rev2.c"
/* Waits a number of CPU cycles. */
static void arm_delay(uint8_t cycles)
{
uint8_t i;
for ( i = 0; i < cycles; ++i ) {
asm volatile("nop");
}
}
static rtems_status_code rpi_select_pin_function(
uint32_t bank,
uint32_t pin,
uint32_t type
) {
/* Calculate the pin function select register address. */
volatile unsigned int *pin_addr = (unsigned int *) BCM2835_GPIO_REGS_BASE +
(pin / 10);
if ( type == RPI_DIGITAL_IN ) {
*(pin_addr) &= ~SELECT_PIN_FUNCTION(RPI_DIGITAL_IN, pin);
}
else {
*(pin_addr) |= SELECT_PIN_FUNCTION(type, pin);
}
return RTEMS_SUCCESSFUL;
}
rtems_status_code rtems_gpio_bsp_multi_set(uint32_t bank, uint32_t bitmask)
{
BCM2835_REG(BCM2835_GPIO_GPSET0) = bitmask;
return RTEMS_SUCCESSFUL;
}
rtems_status_code rtems_gpio_bsp_multi_clear(uint32_t bank, uint32_t bitmask)
{
BCM2835_REG(BCM2835_GPIO_GPCLR0) = bitmask;
return RTEMS_SUCCESSFUL;
}
uint32_t rtems_gpio_bsp_multi_read(uint32_t bank, uint32_t bitmask)
{
return (BCM2835_REG(BCM2835_GPIO_GPLEV0) & bitmask);
}
rtems_status_code rtems_gpio_bsp_set(uint32_t bank, uint32_t pin)
{
BCM2835_REG(BCM2835_GPIO_GPSET0) = (1 << pin);
return RTEMS_SUCCESSFUL;
}
rtems_status_code rtems_gpio_bsp_clear(uint32_t bank, uint32_t pin)
{
BCM2835_REG(BCM2835_GPIO_GPCLR0) = (1 << pin);
return RTEMS_SUCCESSFUL;
}
uint32_t rtems_gpio_bsp_get_value(uint32_t bank, uint32_t pin)
{
return (BCM2835_REG(BCM2835_GPIO_GPLEV0) & (1 << pin));
}
rtems_status_code rtems_gpio_bsp_select_input(
uint32_t bank,
uint32_t pin,
void *bsp_specific
) {
return rpi_select_pin_function(bank, pin, RPI_DIGITAL_IN);
}
rtems_status_code rtems_gpio_bsp_select_output(
uint32_t bank,
uint32_t pin,
void *bsp_specific
) {
return rpi_select_pin_function(bank, pin, RPI_DIGITAL_OUT);
}
rtems_status_code rtems_bsp_select_specific_io(
uint32_t bank,
uint32_t pin,
uint32_t function,
void *pin_data
) {
return rpi_select_pin_function(bank, pin, function);
}
rtems_status_code rtems_gpio_bsp_set_resistor_mode(
uint32_t bank,
uint32_t pin,
rtems_gpio_pull_mode mode
) {
/* Set control signal. */
switch ( mode ) {
case PULL_UP:
BCM2835_REG(BCM2835_GPIO_GPPUD) = (1 << 1);
break;
case PULL_DOWN:
BCM2835_REG(BCM2835_GPIO_GPPUD) = (1 << 0);
break;
case NO_PULL_RESISTOR:
BCM2835_REG(BCM2835_GPIO_GPPUD) = 0;
break;
default:
return RTEMS_UNSATISFIED;
}
/* Wait 150 cyles, as per BCM2835 documentation. */
arm_delay(150);
/* Setup clock for the control signal. */
BCM2835_REG(BCM2835_GPIO_GPPUDCLK0) = (1 << pin);
arm_delay(150);
/* Remove the control signal. */
BCM2835_REG(BCM2835_GPIO_GPPUD) = 0;
/* Remove the clock. */
BCM2835_REG(BCM2835_GPIO_GPPUDCLK0) = 0;
return RTEMS_SUCCESSFUL;
}
rtems_vector_number rtems_gpio_bsp_get_vector(uint32_t bank)
{
return BCM2835_IRQ_ID_GPIO_0;
}
uint32_t rtems_gpio_bsp_interrupt_line(rtems_vector_number vector)
{
uint32_t event_status;
/* Retrieve the interrupt event status. */
event_status = BCM2835_REG(BCM2835_GPIO_GPEDS0);
/* Clear the interrupt line. */
BCM2835_REG(BCM2835_GPIO_GPEDS0) = event_status;
return event_status;
}
rtems_status_code rtems_bsp_enable_interrupt(
uint32_t bank,
uint32_t pin,
rtems_gpio_interrupt interrupt
) {
switch ( interrupt ) {
case FALLING_EDGE:
/* Enables asynchronous falling edge detection. */
BCM2835_REG(BCM2835_GPIO_GPAFEN0) |= (1 << pin);
break;
case RISING_EDGE:
/* Enables asynchronous rising edge detection. */
BCM2835_REG(BCM2835_GPIO_GPAREN0) |= (1 << pin);
break;
case BOTH_EDGES:
/* Enables asynchronous falling edge detection. */
BCM2835_REG(BCM2835_GPIO_GPAFEN0) |= (1 << pin);
/* Enables asynchronous rising edge detection. */
BCM2835_REG(BCM2835_GPIO_GPAREN0) |= (1 << pin);
break;
case LOW_LEVEL:
/* Enables pin low level detection. */
BCM2835_REG(BCM2835_GPIO_GPLEN0) |= (1 << pin);
break;
case HIGH_LEVEL:
/* Enables pin high level detection. */
BCM2835_REG(BCM2835_GPIO_GPHEN0) |= (1 << pin);
break;
case BOTH_LEVELS:
/* Enables pin low level detection. */
BCM2835_REG(BCM2835_GPIO_GPLEN0) |= (1 << pin);
/* Enables pin high level detection. */
BCM2835_REG(BCM2835_GPIO_GPHEN0) |= (1 << pin);
break;
case NONE:
default:
return RTEMS_UNSATISFIED;
}
return RTEMS_SUCCESSFUL;
}
rtems_status_code rtems_bsp_disable_interrupt(
uint32_t bank,
uint32_t pin,
rtems_gpio_interrupt interrupt
) {
switch ( interrupt ) {
case FALLING_EDGE:
/* Disables asynchronous falling edge detection. */
BCM2835_REG(BCM2835_GPIO_GPAFEN0) &= ~(1 << pin);
break;
case RISING_EDGE:
/* Disables asynchronous rising edge detection. */
BCM2835_REG(BCM2835_GPIO_GPAREN0) &= ~(1 << pin);
break;
case BOTH_EDGES:
/* Disables asynchronous falling edge detection. */
BCM2835_REG(BCM2835_GPIO_GPAFEN0) &= ~(1 << pin);
/* Disables asynchronous rising edge detection. */
BCM2835_REG(BCM2835_GPIO_GPAREN0) &= ~(1 << pin);
break;
case LOW_LEVEL:
/* Disables pin low level detection. */
BCM2835_REG(BCM2835_GPIO_GPLEN0) &= ~(1 << pin);
break;
case HIGH_LEVEL:
/* Disables pin high level detection. */
BCM2835_REG(BCM2835_GPIO_GPHEN0) &= ~(1 << pin);
break;
case BOTH_LEVELS:
/* Disables pin low level detection. */
BCM2835_REG(BCM2835_GPIO_GPLEN0) &= ~(1 << pin);
/* Disables pin high level detection. */
BCM2835_REG(BCM2835_GPIO_GPHEN0) &= ~(1 << pin);
break;
case NONE:
default:
return RTEMS_UNSATISFIED;
}
return RTEMS_SUCCESSFUL;
}
rtems_status_code rpi_gpio_select_jtag(void)
{
return rtems_gpio_multi_select(jtag_config, JTAG_PIN_COUNT);
}
rtems_status_code rpi_gpio_select_spi(void)
{
return rtems_gpio_multi_select(spi_config, SPI_PIN_COUNT);
}
rtems_status_code rpi_gpio_select_i2c(void)
{
return rtems_gpio_multi_select(i2c_config, I2C_PIN_COUNT);
}
rtems_status_code rtems_gpio_bsp_multi_select(
rtems_gpio_multiple_pin_select *pins,
uint32_t pin_count,
uint32_t select_bank
) {
uint32_t register_address;
uint32_t select_register;
uint8_t i;
register_address = BCM2835_GPIO_REGS_BASE + (select_bank * 0x04);
select_register = BCM2835_REG(register_address);
for ( i = 0; i < pin_count; ++i ) {
if ( pins[i].function == DIGITAL_INPUT ) {
select_register &=
~SELECT_PIN_FUNCTION(RPI_DIGITAL_IN, pins[i].pin_number);
}
else if ( pins[i].function == DIGITAL_OUTPUT ) {
select_register |=
SELECT_PIN_FUNCTION(RPI_DIGITAL_OUT, pins[i].pin_number);
}
else { /* BSP_SPECIFIC function. */
select_register |=
SELECT_PIN_FUNCTION(pins[i].io_function, pins[i].pin_number);
}
}
BCM2835_REG(register_address) = select_register;
return RTEMS_SUCCESSFUL;
}
rtems_status_code rtems_gpio_bsp_specific_group_operation(
uint32_t bank,
uint32_t *pins,
uint32_t pin_count,
void *arg
) {
return RTEMS_NOT_DEFINED;
}
