1 files changed, 329 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/arm/raspberrypi/gpio/rpi-gpio.c b/c/src/lib/libbsp/arm/raspberrypi/gpio/rpi-gpio.c
new file mode 100644
index 0000000000..bd37e67765
--- /dev/null
+++ b/c/src/lib/libbsp/arm/raspberrypi/gpio/rpi-gpio.c
@@ -0,0 +1,329 @@
+/**
+ * @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;
+}
+
+uint8_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;
+}