From df0e302bf81e359902ab19ef7d35e2c017c48131 Mon Sep 17 00:00:00 2001
From: Thomas Klaehn <thomas.klaehn@perinet.io>
Date: Sun, 26 Apr 2020 08:55:44 +0200
Subject: [PATCH] Add gpio event driver

---
 src/platform/nrf52/gpiote.cc              | 77 +++++++++++++++++++++++
 src/platform/nrf52/gpiote.h               | 44 +++++++++++++
 src/platform/nrf52/low_level_interrupt.cc | 10 +++
 3 files changed, 131 insertions(+)
 create mode 100644 src/platform/nrf52/gpiote.cc
 create mode 100644 src/platform/nrf52/gpiote.h

diff --git a/src/platform/nrf52/gpiote.cc b/src/platform/nrf52/gpiote.cc
new file mode 100644
index 0000000..dcc729f
--- /dev/null
+++ b/src/platform/nrf52/gpiote.cc
@@ -0,0 +1,77 @@
+#include <cassert>
+
+#include "platform/nrf52/InterruptHandler.h"
+#include "platform/nrf52/InterruptGuardian.h"
+
+#include "platform/nrf52/gpiote.h"
+
+extern "C" {
+    #include "nrf52.h"
+    #include "nrf52_bitfields.h"
+
+    NRF_GPIOTE_Type *const GPIOTE_REGS = reinterpret_cast<NRF_GPIOTE_Type *>(NRF_GPIOTE_BASE);
+}
+
+using namespace pinetime::platform::nrf52;
+
+Gpiote::Gpiote()
+    : InterruptHandler(InterruptGuardian::Nrf52IrqN::GPIOTE_IRQ)
+    , num_registered(0)
+{
+    for(auto it = this->gpiote_channels.begin(); it != this->gpiote_channels.end(); ++it) {
+        *it = nullptr;
+    }
+}
+
+void Gpiote::enable()
+{
+    NVIC_SetPriority(GPIOTE_IRQn, 7);
+    NVIC_EnableIRQ(GPIOTE_IRQn);
+}
+
+void Gpiote::disable()
+{
+    NVIC_DisableIRQ(GPIOTE_IRQn);
+}
+
+void Gpiote::register_handler(pinetime::interfaces::GpioInterface *gpio)
+{
+    if(num_registered == GPIOTE_CHANNELS) {
+        //FIXME: Error notification
+        return;
+    }
+
+    if(num_registered == 0) {
+        this->enable();
+    } else {
+        //check if gpio already registered
+        for(auto it = this->gpiote_channels.begin(); it != this->gpiote_channels.end(); ++it) {
+            if(*it == gpio) {
+                return;
+            }
+        }
+    }
+    uint32_t i = 0;
+    for(auto it = this->gpiote_channels.begin(); it != this->gpiote_channels.end(); ++it) {
+        if(*it == nullptr) {
+            *it = gpio;
+            GPIOTE_REGS->INTENSET = GPIOTE_INTENSET_IN0_Msk;
+            GPIOTE_REGS->CONFIG[i] = (GPIOTE_CONFIG_POLARITY_Toggle << GPIOTE_CONFIG_POLARITY_Pos)
+                                   | ((gpio->pin_number()) << GPIOTE_CONFIG_PSEL_Pos)
+                                   | (GPIOTE_CONFIG_MODE_Event << GPIOTE_CONFIG_MODE_Pos);
+        }
+        i++;
+    }
+}
+
+void Gpiote::handle()
+{
+    for(uint32_t i = 0; i < GPIOTE_CHANNELS; ++i) {
+        if(GPIOTE_REGS->EVENTS_IN[i] != 0) {
+            GPIOTE_REGS->EVENTS_IN[i] = 0;
+            pinetime::interfaces::GpioInterface *h = this->gpiote_channels[i];
+            assert(h != nullptr);
+            h->handle();
+        }
+    }
+}
diff --git a/src/platform/nrf52/gpiote.h b/src/platform/nrf52/gpiote.h
new file mode 100644
index 0000000..6b7408c
--- /dev/null
+++ b/src/platform/nrf52/gpiote.h
@@ -0,0 +1,44 @@
+#ifndef __PLATFORM_NRF52_GPIOTE_H__
+#define __PLATFORM_NRF52_GPIOTE_H__
+
+#include <array>
+
+#include "gpio_interface.h"
+#include "platform/nrf52/InterruptHandler.h"
+
+namespace pinetime::platform::nrf52
+{
+class Gpiote;
+}
+extern pinetime::platform::nrf52::Gpiote gpiote;
+
+namespace pinetime::platform::nrf52
+{
+
+class Gpiote
+    : public pinetime::platform::nrf52::InterruptHandler
+{
+public:
+    Gpiote();
+
+    static inline Gpiote & instance() { return gpiote; }
+
+    void enable() override;
+    void disable() override;
+
+    void register_handler(pinetime::interfaces::GpioInterface *);
+
+private:
+    void handle() override;
+
+    enum {
+        GPIOTE_CHANNELS = 8,
+    };
+
+    std::array<pinetime::interfaces::GpioInterface *, GPIOTE_CHANNELS> gpiote_channels;
+    uint32_t num_registered;
+};
+
+}
+
+#endif
diff --git a/src/platform/nrf52/low_level_interrupt.cc b/src/platform/nrf52/low_level_interrupt.cc
index 35807ab..c185c90 100644
--- a/src/platform/nrf52/low_level_interrupt.cc
+++ b/src/platform/nrf52/low_level_interrupt.cc
@@ -54,3 +54,13 @@ void SPIM0_SPIS0_TWIM0_TWIS0_SPI0_TWI0_IRQHandler(void)
 
     h->handle();
 }
+
+void GPIOTE_IRQHandler(void)
+{
+    uint32_t irq_nr = InterruptGuardian::Nrf52IrqN::GPIOTE_IRQ;
+    InterruptHandler *h = InterruptGuardian::instance.nrf52_vector[irq_nr];
+
+    assert(h != nullptr);
+
+    h->handle();
+}