1 files changed, 392 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/arm/lpc176x/gpio/gpio.c b/c/src/lib/libbsp/arm/lpc176x/gpio/gpio.c
new file mode 100644
index 0000000000..2fe69d4ea8
--- /dev/null
+++ b/c/src/lib/libbsp/arm/lpc176x/gpio/gpio.c
@@ -0,0 +1,392 @@
+/**
+ * @file gpio.c
+ *
+ * @ingroup lpc176x
+ *
+ * @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.com/license/LICENSE.
+ */
+
+#include <assert.h>
+#include <bsp/irq.h>
+#include <bsp/io.h>
+#include <bsp/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;
+}