/**
* @file
*
* @ingroup RTEMSBSPsARMLPC176X
*
* @brief GPIO library for the lpc176x bsp.
*/
/*
* Copyright (c) 2014 Taller Technologies.
*
* @author Boretto Martin (martin.boretto@tallertechnologies.com)
* @author Diaz Marcos (marcos.diaz@tallertechnologies.com)
* @author Lenarduzzi Federico (federico.lenarduzzi@tallertechnologies.com)
* @author Daniel Chicco (daniel.chicco@tallertechnologies.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 <assert.h>
#include <bsp/irq.h>
#include <bsp/io.h>
#include <bsp/lpc-gpio.h>
#include <rtems/status-checks.h>
static uint32_t function_vector_size = 0u;
static lpc176x_registered_interrupt_function function_vector[
LPC176X_RESERVED_ISR_FUNCT_SIZE ];
static bool isr_installed = false;
rtems_status_code lpc176x_gpio_config(
const lpc176x_pin_number pin,
const lpc176x_gpio_direction dir
)
{
rtems_status_code status_code = RTEMS_INVALID_NUMBER;
if ( ( pin < LPC176X_MAX_PORT_NUMBER ) &&
( dir < LPC176X_GPIO_FUNCTION_COUNT ) ) {
const lpc176x_gpio_ports port = LPC176X_IO_PORT( pin );
const uint32_t pin_of_port = LPC176X_IO_PORT_BIT( pin );
lpc176x_pin_select( pin, LPC176X_PIN_FUNCTION_00 );
LPC176X_SET_BIT( LPC176X_FIO[ port ].dir, pin_of_port, dir );
status_code = RTEMS_SUCCESSFUL;
}
/* else implies that the pin or the egde are out of range. Also,
an invalid number is returned. */
return status_code;
}
/**
* @brief Check for a rising edge and call the interrupt function.
*
* @param statR Rising edge interrupt.
* @param pin The pin to check.
* @param registered_isr_function Interrupt to check.
* @return TRUE if is a rising edge. FALSE otherwise.
*/
static bool lpc176x_check_rising_edge_and_call(
const uint32_t statR,
const lpc176x_registered_interrupt_function registered_isr_function,
const uint32_t pin
)
{
bool is_rising = false;
if ( statR & LPC176X_PIN_BIT( pin ) ) {
registered_isr_function.function( registered_isr_function.pin,
LPC176X_GPIO_INTERRUPT_RISING );
is_rising = true;
}
/* else implies that the current interrupt is not STATR. Also,
there is nothing to do. */
return is_rising;
}
/**
* @brief Check for a falling edge and call the interrupt function.
*
* @param statR Falling edge interrupt.
* @param pin The pin to check.
* @param registered_isr_function Interrupt to check.
* @return TRUE if is a falling edge. FALSE otherwise.
*/
static bool lpc176x_check_falling_edge_and_call(
const uint32_t statF,
const lpc176x_registered_interrupt_function registered_isr_function,
const uint32_t pin
)
{
bool is_falling = false;
if ( statF & LPC176X_PIN_BIT( pin ) ) {
registered_isr_function.function( registered_isr_function.pin,
LPC176X_GPIO_INTERRUPT_FALLING );
is_falling = true;
}
/* else implies that the current interrupt is not STATF. Also,
there is nothing to do. */
return is_falling;
}
/**
* @brief Returns the interrupts base address according to the current port.
*
* @param port Input/Output port.
* @return Interrupt base address.
*/
static lpc176x_interrupt_control*lpc176x_get_interrupt_address(
const lpc176x_gpio_ports port )
{
lpc176x_interrupt_control *interrupt;
switch ( port ) {
case ( LPC176X_GPIO_PORT_0 ):
interrupt = (lpc176x_interrupt_control *) LPC176X_IO0_INT_BASE_ADDRESS;
break;
case ( LPC176X_GPIO_PORT_2 ):
interrupt = (lpc176x_interrupt_control *) LPC176X_IO2_INT_BASE_ADDRESS;
break;
case ( LPC176X_GPIO_PORT_1 ):
case ( LPC176X_GPIO_PORT_3 ):
case ( LPC176X_GPIO_PORT_4 ):
default:
interrupt = NULL;
}
return interrupt;
}
/**
* @brief Checks the type of the current interrupt.
*
* @param registered_isr_function Interrupt to check.
*/
static void check_for_interrupt(
const lpc176x_registered_interrupt_function registered_isr_function )
{
assert( registered_isr_function.pin < LPC176X_MAX_PORT_NUMBER );
const lpc176x_gpio_ports port = LPC176X_IO_PORT(
registered_isr_function.pin );
const uint32_t pin = LPC176X_IO_PORT_BIT( registered_isr_function.pin );
lpc176x_interrupt_control *interrupt = lpc176x_get_interrupt_address( port );
assert( interrupt != NULL );
bool is_rising_edge = lpc176x_check_rising_edge_and_call( interrupt->StatR,
registered_isr_function,
pin );
bool is_falling_edge = lpc176x_check_falling_edge_and_call( interrupt->StatF,
registered_isr_function,
pin );
if ( is_rising_edge || is_falling_edge ) {
interrupt->Clr = LPC176X_PIN_BIT( pin );
}
/* else implies that the current interrupt is not CLR. Also,
there is nothing to do. */
}
/**
* @brief Checks all interrupts types.
*
* @param arg Interrupt to check.
*/
static inline void lpc176x_gpio_isr( void *arg )
{
unsigned int i;
for ( i = 0; i < function_vector_size; ++i ) {
check_for_interrupt( function_vector[ i ] );
}
}
/**
* @brief Depending of the current edge sets rising/falling interrupt.
*
* @param edge Current edge.
* @param pin_of_port Pin of the port to set the interrupt.
* @param interrupt To enable the falling o rising edge.
*/
static void lpc176x_set_falling_or_rising_interrupt(
const lpc176x_gpio_interrupt edge,
const uint32_t pin_of_port,
lpc176x_interrupt_control *interrupt
)
{
if ( edge & LPC176X_GPIO_INTERRUPT_RISING ) {
LPC176X_SET_BIT( interrupt->EnR, pin_of_port, LPC176X_INT_ENABLE );
}
/* else implies that it should not install the interrupt for a RISING edge.
Also, there is nothing to do. */
if ( edge & LPC176X_GPIO_INTERRUPT_FALLING ) {
LPC176X_SET_BIT( interrupt->EnF, pin_of_port, LPC176X_INT_ENABLE );
}
/* else implies that it should not install the interrupt for a FALLING edge.
Also, there is nothing to do. */
}
/**
* @brief Registers the pin and the callbacks functions.
*
* @param edge Current edge.
* @param pin The pin to configure.
* @param isr_funct Callback function to set.
*/
static void lpc176x_register_pin_and_callback(
const lpc176x_gpio_interrupt edge,
const lpc176x_pin_number pin,
const lpc176x_gpio_interrupt_function isr_funct
)
{
if ( edge ) {
assert( function_vector_size < LPC176X_RESERVED_ISR_FUNCT_SIZE );
function_vector[ function_vector_size ].function = isr_funct;
function_vector[ function_vector_size ].pin = pin;
++function_vector_size;
}
/* else implies that the current interrupt is DISABLED or BOTH. Also,
there is nothing to do. */
}
/**
* @brief Installs the interrupt handler.
*
* @param edge Which edge enable.
* @return RTEMS_SUCCESSFUL if the installation was success.
*/
static rtems_status_code lpc176x_install_interrupt_handler(
const lpc176x_gpio_interrupt edge )
{
rtems_status_code status_code = RTEMS_SUCCESSFUL;
if ( !isr_installed && edge ) {
status_code = rtems_interrupt_handler_install( LPC176X_IRQ_EINT_3,
"gpio_interrupt",
RTEMS_INTERRUPT_UNIQUE,
lpc176x_gpio_isr,
NULL );
isr_installed = true;
}
/* else implies that the interrupts have been previously installed. Also,
there is nothing to do. */
return status_code;
}
/**
* @brief Configures the pin as input, enables interrupt for an
* edge/s and sets isrfunct as the function to call when that
* interrupt occurs.
*
* @param pin The pin to configure.
* @param edge Which edge or edges will activate the interrupt.
* @param isrfunct The function that is called when the interrupt occurs.
* @return RTEMS_SUCCESSFUL if the configuration was success.
*/
static rtems_status_code lpc176x_check_edge_and_set_gpio_interrupts(
const lpc176x_pin_number pin,
const lpc176x_gpio_interrupt edge,
const lpc176x_gpio_interrupt_function isr_funct
)
{
rtems_status_code status_code = RTEMS_SUCCESSFUL;
const lpc176x_gpio_ports port = LPC176X_IO_PORT( pin );
const uint32_t pin_of_port = LPC176X_IO_PORT_BIT( pin );
lpc176x_interrupt_control *interrupt = lpc176x_get_interrupt_address( port );
assert( interrupt != NULL );
lpc176x_gpio_config( pin, LPC176X_GPIO_FUNCTION_INPUT );
lpc176x_set_falling_or_rising_interrupt( edge, pin_of_port, interrupt );
lpc176x_register_pin_and_callback( edge, pin, isr_funct );
status_code = lpc176x_install_interrupt_handler( edge );
return status_code;
}
rtems_status_code lpc176x_gpio_config_input_with_interrupt(
const lpc176x_pin_number pin,
const lpc176x_gpio_interrupt edge,
const lpc176x_gpio_interrupt_function isr_funct
)
{
rtems_status_code status_code = RTEMS_INVALID_NUMBER;
if ( ( pin < LPC176X_MAX_PORT_NUMBER )
&& ( edge < LPC176X_GPIO_INTERRUPT_COUNT ) ) {
status_code = lpc176x_check_edge_and_set_gpio_interrupts( pin,
edge,
isr_funct );
}
/* else implies that the pin or the egde are out of range. Also,
an invalid number is returned. */
return status_code;
}
rtems_status_code lpc176x_gpio_set_pin( const lpc176x_pin_number pin )
{
rtems_status_code status_code = RTEMS_INVALID_NUMBER;
if ( pin < LPC176X_MAX_PORT_NUMBER ) {
const lpc176x_gpio_ports port = LPC176X_IO_PORT( pin );
const uint32_t pin_of_port = LPC176X_IO_PORT_BIT( pin );
LPC176X_FIO[ port ].set = LPC176X_PIN_BIT( pin_of_port );
status_code = RTEMS_SUCCESSFUL;
}
/* else implies that the pin or the egde are out of range. Also,
an invalid number is returned. */
return status_code;
}
rtems_status_code lpc176x_gpio_clear_pin( const lpc176x_pin_number pin )
{
rtems_status_code status_code = RTEMS_INVALID_NUMBER;
if ( pin < LPC176X_MAX_PORT_NUMBER ) {
const lpc176x_gpio_ports port = LPC176X_IO_PORT( pin );
const uint32_t pin_of_port = LPC176X_IO_PORT_BIT( pin );
LPC176X_FIO[ port ].clr = LPC176X_PIN_BIT( pin_of_port );
status_code = RTEMS_SUCCESSFUL;
}
/* else implies that the pin or the egde are out of range. Also,
an invalid number is returned. */
return status_code;
}
rtems_status_code lpc176x_gpio_write_pin(
const lpc176x_pin_number pin,
const bool value
)
{
rtems_status_code status_code;
if ( value ) {
status_code = lpc176x_gpio_set_pin( pin );
} else {
status_code = lpc176x_gpio_clear_pin( pin );
}
return status_code;
}
inline rtems_status_code lpc176x_gpio_get_pin_value(
const lpc176x_pin_number pin,
bool *pin_value
)
{
assert( pin < LPC176X_MAX_PORT_NUMBER );
rtems_status_code status_code = RTEMS_SUCCESSFUL;
const lpc176x_gpio_ports port = LPC176X_IO_PORT( pin );
const uint32_t pin_of_port = LPC176X_IO_PORT_BIT( pin );
*pin_value = ( LPC176X_FIO[ port ].pin & LPC176X_PIN_BIT( pin_of_port ) );
return status_code;
}
