Makefile

@@ -34,6 +34,8 @@ TARGET_HEX = $(patsubst %.elf,%.hex,$(TARGET))
 TARGET_PACKAGE = $(patsubst %.hex,%.zip,$(TARGET_HEX))
 THIS_MAKEFILE := $(lastword $(MAKEFILE_LIST))
 
+INCLUDES += src/
+INCLUDES += interfaces/
 INCLUDES += include/
 INCLUDES += include/application/$(APPLICATION)
 

interfaces/gpio_interface.h

@@ -0,0 +1,21 @@
+#ifndef __INTERFACES_GPIO_INTERFACE_H__
+#define __INTERFACES_GPIO_INTERFACE_H__
+
+#include <cstdint>
+
+namespace interfaces {
+
+class GpioInterface
+{
+    public:
+        enum class direction {IN, OUT};
+
+        virtual void set_direction(direction) = 0;
+        virtual uint32_t get() = 0;
+        virtual void set() = 0;
+        virtual void clear() = 0;
+        virtual void toggle() = 0;
+};
+
+}
+#endif

src/application/blinky/main.cc

@@ -1,24 +1,14 @@
-extern "C" {
-    #include <stdbool.h>
-    #include <stdint.h>
+#include "delay.h"
+#include "platform/gpio.h"
 
-    #include "delay.h"
-    #include "board.h"
-}
+using namespace hal;
 
 int main(void)
 {
-    unsigned int cnt[4] = {0, 0, 0, 0};
-    const struct driver *leds[4] = {&led_1, &led_2, &led_3, &led_4};
-    for(unsigned int i = 0; i < 4; i++) {
-        drv_open(leds[i]);
-    }
+    Gpio led_1(17);
     while(true) {
-        for(unsigned int i = 0; i < 4; i++) {
-            char c = (cnt[i]++ % 2) + 0x30;
-            drv_write(leds[i], &c, 1);
-            delay_ms(500);
-        }
+        delay_ms(200);
+        led_1.toggle();
     }
     return 0;
 }

src/platform/gpio.h

@@ -0,0 +1,10 @@
+#ifndef __PLATFORM_GPIO_H__
+#define __PLATFORM_GPIO_H__
+
+#if defined(PLATFORM_nrf52)
+    #include "platform/nrf52/gpio.h"
+
+    namespace hal = platform::nrf52;
+#endif
+
+#endif

src/platform/nrf52/gpio.c

@@ -1,63 +0,0 @@
-#include <assert.h>
-#include <stdint.h>
-#include <stddef.h>
-
-#include "gpio.h"
-
-#include "nrf_gpio.h"
-
-int gpio_open(const struct driver *drv)
-{
-    assert(NULL != drv);
-
-    struct gpio *this = (struct gpio *)(drv->dev);
-
-    if(this->dir == OUT) {
-        nrf_gpio_cfg_output((uint32_t)(this->pin));
-    nrf_gpio_pin_clear(this->pin);
-    }
-    // FIXME: implement input configuration
-
-    return 0;
-}
-
-int gpio_close(const struct driver *drv)
-{
-    assert(NULL != drv);
-
-    struct gpio *this = (struct gpio *)(drv->dev);
-    nrf_gpio_pin_clear(this->pin);
-
-    return 0;
-}
-
-int gpio_read(const struct driver *drv, char *buffer, unsigned int len)
-{
-    assert(NULL != drv);
-
-    if(len == 0) {
-        return 0;
-    }
-
-    struct gpio *this = (struct gpio *)(drv->dev);
-
-    uint32_t value = nrf_gpio_pin_read(this->pin);
-    buffer[0] = value + 0x30;   // ascii convert
-
-    return 1;
-}
-
-int gpio_write(const struct driver *drv, const char *buffer, unsigned int len)
-{
-    assert((NULL != drv) && (NULL != buffer));
-
-    if(len == 0) {
-        return 0;
-    }
-
-    struct gpio *this = (struct gpio *)(drv->dev);
-
-    nrf_gpio_pin_write(this->pin, buffer[0] - 0x30);
-
-    return 1;
-}

src/platform/nrf52/gpio.cc

@@ -0,0 +1,62 @@
+#include "platform/nrf52/gpio.h"
+
+extern "C" {
+    #include "nrf.h"
+
+    NRF_GPIO_Type *const GPIO_REGS = reinterpret_cast<NRF_GPIO_Type *>(NRF_P0_BASE);
+}
+
+using namespace platform::nrf52;
+
+Gpio::Gpio(uint32_t pin)
+    : pin_number(pin)
+{
+    this->set_direction(direction::OUT);
+    this->clear();
+}
+
+void Gpio::set_direction(direction dir)
+{
+    uint32_t direct = GPIO_PIN_CNF_DIR_Output << GPIO_PIN_CNF_DIR_Pos;
+    uint32_t input = GPIO_PIN_CNF_INPUT_Disconnect << GPIO_PIN_CNF_INPUT_Pos;
+    uint32_t pull = GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos;
+    uint32_t drive = GPIO_PIN_CNF_DRIVE_S0S1 << GPIO_PIN_CNF_DRIVE_Pos;
+    uint32_t sense = GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos;
+    if(dir == direction::IN) {
+        direct = GPIO_PIN_CNF_DIR_Input << GPIO_PIN_CNF_DIR_Pos;
+        input = GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos;
+
+        // FIXME: Make this configurable
+        // GPIO_PIN_CNF_PULL_Disabled, ///<  Pin pull-up resistor disabled.
+        // GPIO_PIN_CNF_PULL_Pulldown, ///<  Pin pull-down resistor enabled.
+        // GPIO_PIN_CNF_PULL_Pullup,   ///<  Pin pull-up resistor enabled.
+        pull = GPIO_PIN_CNF_PULL_Pullup  << GPIO_PIN_CNF_PULL_Pos;
+        drive = GPIO_PIN_CNF_DRIVE_S0S1 << GPIO_PIN_CNF_DRIVE_Pos;
+        sense = GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos;
+    }
+    GPIO_REGS->PIN_CNF[pin_number] = direct | input | pull | drive | sense;
+}
+
+uint32_t Gpio::get()
+{
+    uint32_t res = (GPIO_REGS->IN  >> pin_number) & 1UL;
+    return res;
+}
+
+void Gpio::set()
+{
+    GPIO_REGS->OUTSET = 1UL << (this->pin_number);
+}
+
+void Gpio::clear()
+{
+    GPIO_REGS->OUTCLR = 1UL << (this->pin_number);
+}
+
+void Gpio::toggle()
+{
+    uint32_t state = GPIO_REGS->OUT;
+
+    GPIO_REGS->OUTSET = (~state & (1UL << (this->pin_number)));
+    GPIO_REGS->OUTCLR = (state & (1UL << (this->pin_number)));
+}

src/platform/nrf52/gpio.h

@@ -0,0 +1,24 @@
+#ifndef __PLATFORM_NRF52_GPIO_H__
+#define __PLATFORM_NRF52_GPIO_H__
+
+#include "gpio_interface.h"
+
+namespace platform::nrf52 {
+
+class Gpio : public interfaces::GpioInterface
+{
+    public:
+        explicit Gpio(uint32_t);
+        void set_direction(direction) override;
+        uint32_t get() override;
+        void set() override;
+        void clear() override;
+        void toggle() override;
+
+    private:
+        uint32_t pin_number;
+};
+
+}
+
+#endif