Use gpio event driver in gpio driver

interfaces/gpio_interface.h

@@ -10,11 +10,14 @@ class GpioInterface
     public:
         enum class direction {IN, OUT};
 
-        virtual void set_direction(direction) = 0;
+        virtual void set_direction(direction, bool) = 0;
         virtual uint32_t get() = 0;
         virtual void set() = 0;
         virtual void clear() = 0;
         virtual void toggle() = 0;
+
+        virtual void handle() = 0;
+        virtual uint32_t pin_number() = 0;
 };
 
 }

src/application/blinky/main.cc

@@ -7,6 +7,7 @@
 #include "platform/cm4/SystemTick.h"
 
 #include "platform/nrf52/gpio.h"
+#include "platform/nrf52/gpiote.h"
 #include "platform/nrf52/InterruptHandler.h"
 #include "platform/nrf52/InterruptGuardian.h"
 
@@ -15,6 +16,18 @@
 using namespace pinetime::platform;
 using namespace pinetime::virtual_timer;
 
+// IRQs
+nrf52::InterruptGuardian nrf52::InterruptGuardian::instance;
+cm4::InterruptGuardian cm4::InterruptGuardian::instance;
+
+// GPIO events
+nrf52::Gpiote gpiote;
+
+// Timer
+cm4::SystemTick system_tick;
+VirtualTimerDistributor virtual_timer_distributor(system_tick.instance());
+pinetime::Delay delay;
+
 enum {
     PIN_NUMBER_LED_1 = 17,
     PIN_NUMBER_LED_2 = 18,
@@ -29,15 +42,6 @@ nrf52::Gpio led_3(PIN_NUMBER_LED_3);
 nrf52::Gpio led_4(PIN_NUMBER_LED_4);
 std::array<nrf52::Gpio *, 4> leds = {&led_1, &led_2, &led_3, &led_4};
 
-// IRQs
-nrf52::InterruptGuardian nrf52::InterruptGuardian::instance;
-cm4::InterruptGuardian cm4::InterruptGuardian::instance;
-
-// Timer
-cm4::SystemTick system_tick;
-VirtualTimerDistributor virtual_timer_distributor(system_tick.instance());
-pinetime::Delay delay;
-
 int main(void)
 {
     cm4::InterruptGuardian::enable_interrupts();

src/platform/nrf52/gpio.cc

@@ -1,22 +1,33 @@
-#include "platform/nrf52/gpio.h"
-
 extern "C" {
     #include "nrf52.h"
     #include "nrf52_bitfields.h"
 
     NRF_GPIO_Type *const GPIO_REGS = reinterpret_cast<NRF_GPIO_Type *>(NRF_P0_BASE);
+    NRF_GPIOTE_Type *const GPIOTE_REGS = reinterpret_cast<NRF_GPIOTE_Type *>(NRF_GPIOTE_BASE);
 }
 
+#include "platform/nrf52/gpiote.h"
+#include "platform/nrf52/gpio.h"
+
 using namespace pinetime::platform::nrf52;
 
+Gpio::Gpio()
+    : pin(0)
+    , blocking(false)
+    , wait_for_event(false)
+{
+}
+
 Gpio::Gpio(uint32_t pin)
-    : pin_number(pin)
+    : pin(pin)
+    , blocking(false)
+    , wait_for_event(false)
 {
     this->set_direction(direction::OUT);
     this->clear();
 }
 
-void Gpio::set_direction(direction dir)
+void Gpio::set_direction(direction dir, bool blocking_read)
 {
     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;
@@ -33,36 +44,60 @@ void Gpio::set_direction(direction dir)
         // 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;
+        sense = GPIO_PIN_CNF_SENSE_Low << GPIO_PIN_CNF_SENSE_Pos;
+
+        gpiote.instance().register_handler(this);
+
+        this->blocking = blocking_read;
+
+        gpiote.instance().enable();
     }
-    GPIO_REGS->PIN_CNF[pin_number] = direct | input | pull | drive | sense;
+    GPIO_REGS->PIN_CNF[pin] = direct | input | pull | drive | sense;
 }
 
-void Gpio::set_pin_number(uint32_t pin)
+void Gpio::pin_number(uint32_t pin)
 {
-    this->pin_number = pin;
+    this->pin = pin;
+}
+
+uint32_t Gpio::pin_number()
+{
+    return this->pin;
 }
 
 uint32_t Gpio::get()
 {
-    uint32_t res = (GPIO_REGS->IN  >> pin_number) & 1UL;
+    if(this->blocking) {
+        this->wait_for_event = true;
+        while(this->wait_for_event == true) {
+            // FIXME: Low Power
+            asm volatile("nop");
+        }
+    }
+    uint32_t res = (GPIO_REGS->IN  >> pin) & 1UL;
+
     return res;
 }
 
 void Gpio::set()
 {
-    GPIO_REGS->OUTSET = 1UL << (this->pin_number);
+    GPIO_REGS->OUTSET = 1UL << (this->pin);
 }
 
 void Gpio::clear()
 {
-    GPIO_REGS->OUTCLR = 1UL << (this->pin_number);
+    GPIO_REGS->OUTCLR = 1UL << (this->pin);
 }
 
 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)));
+    GPIO_REGS->OUTSET = (~state & (1UL << (this->pin)));
+    GPIO_REGS->OUTCLR = (state & (1UL << (this->pin)));
+}
+
+void Gpio::handle()
+{
+    this->wait_for_event = false;
 }

src/platform/nrf52/gpio.h

@@ -3,22 +3,30 @@
 
 #include "gpio_interface.h"
 
+#include "platform/nrf52/InterruptHandler.h"
+
 namespace pinetime::platform::nrf52 {
 
 class Gpio : public pinetime::interfaces::GpioInterface
 {
-    public:
-        inline Gpio() {}
+public:
+    Gpio();
     Gpio(uint32_t);
-        void set_pin_number(uint32_t);
-        void set_direction(direction) override;
+    void pin_number(uint32_t);
+    uint32_t pin_number() override;
+
+    void set_direction(direction, bool blocking_read=false) override;
     uint32_t get() override;
     void set() override;
     void clear() override;
     void toggle() override;
 
-    private:
-        uint32_t pin_number;
+    void handle() override;
+
+private:
+    uint32_t pin;
+    bool blocking;
+    volatile bool wait_for_event;
 };
 
 }