Implement device management (#199)

- Added `tt::hal::Device` and functions (de)register devices and search for them.
- Refactored apps: `Power` and `Display` settings apps now use the device API to find devices.
- Implemented the new API for all existing drivers for all devices, including the simulator.
- Updated HAL Configuration to return `std::shared_ptr` instead of raw pointers.
- Added test project for headless tests and implemented tests for the new code.

TactilityHeadless/Include/Tactility/hal/Configuration.h

@@ -12,8 +12,8 @@ typedef bool (*InitLvgl)();
 
 class Display;
 class Keyboard;
-typedef Display* (*CreateDisplay)();
-typedef Keyboard* (*CreateKeyboard)();
+typedef std::shared_ptr<Display> (*CreateDisplay)();
+typedef std::shared_ptr<Keyboard> (*CreateKeyboard)();
 typedef std::shared_ptr<Power> (*CreatePower)();
 
 struct Configuration {

TactilityHeadless/Include/Tactility/hal/Device.h

@@ -0,0 +1,83 @@
+#pragma once
+
+#include <memory>
+#include <string>
+#include <vector>
+
+namespace tt::hal {
+
+/**
+ * Base class for HAL-related devices.
+ */
+class Device {
+
+public:
+
+    enum class Type {
+        I2c,
+        Display,
+        Touch,
+        SdCard,
+        Keyboard,
+        Power
+    };
+
+    typedef uint32_t Id;
+
+private:
+
+    Id id;
+
+public:
+
+    Device();
+    virtual ~Device() = default;
+
+    Id getId() const { return id; }
+
+    /** The type of device. */
+    virtual Type getType() const = 0;
+
+    /** The part number or hardware name e.g. TdeckTouch, TdeckDisplay, BQ24295, etc. */
+    virtual std::string getName() const = 0;
+
+    /** A short description of what this device does.
+     * e.g. "USB charging controller with I2C interface."
+     */
+    virtual std::string getDescription() const = 0;
+};
+
+
+/**
+ * Adds a device to the registry.
+ * @warning This will leak memory if you want to destroy a device and don't call deregisterDevice()!
+ */
+void registerDevice(const std::shared_ptr<Device>& device);
+
+/** Remove a device from the registry. */
+void deregisterDevice(const std::shared_ptr<Device>& device);
+
+/** Find a device in the registry by its name. */
+std::shared_ptr<Device> _Nullable findDevice(std::string name);
+
+/** Find a device in the registry by its identifier. */
+std::shared_ptr<Device> _Nullable findDevice(Device::Id id);
+
+/** Find 0, 1 or more devices in the registry by type. */
+std::vector<std::shared_ptr<Device>> findDevices(Device::Type type);
+
+/** Get a copy of the entire device registry in its current state. */
+std::vector<std::shared_ptr<Device>> getDevices();
+
+template<class DeviceType>
+std::shared_ptr<DeviceType> findFirstDevice(Device::Type type) {
+    auto devices = findDevices(type);
+    if (devices.empty()) {
+        return {};
+    } else {
+        auto& first = devices[0];
+        return std::static_pointer_cast<DeviceType>(first);
+    }
+}
+
+}

TactilityHeadless/Include/Tactility/hal/Display.h

@@ -1,13 +1,19 @@
 #pragma once
 
-#include "lvgl.h"
+#include "Device.h"
+
+#include <lvgl.h>
 
 namespace tt::hal {
 
 class Touch;
 
-class Display {
+class Display : public Device {
+
 public:
+
+    Type getType() const override { return Type::Display; }
+
     virtual bool start() = 0;
     virtual bool stop() = 0;
 
@@ -15,7 +21,7 @@ public:
     virtual bool isPoweredOn() const { return true; }
     virtual bool supportsPowerControl() const { return false; }
 
-    virtual Touch* _Nullable createTouch() = 0;
+    virtual std::shared_ptr<Touch> _Nullable createTouch() = 0;
 
     /** Set a value in the range [0, 255] */
     virtual void setBacklightDuty(uint8_t backlightDuty) { /* NO-OP */ }

TactilityHeadless/Include/Tactility/hal/Keyboard.h

@@ -1,13 +1,19 @@
 #pragma once
 
-#include "lvgl.h"
+#include "Device.h"
+
+#include <lvgl.h>
 
 namespace tt::hal {
 
 class Display;
 
-class Keyboard {
+class Keyboard : public Device {
+
 public:
+
+    Type getType() const override { return Type::Keyboard; }
+
     virtual bool start(lv_display_t* display) = 0;
     virtual bool stop() = 0;
     virtual bool isAttached() const = 0;

TactilityHeadless/Include/Tactility/hal/Power.h

@@ -1,15 +1,18 @@
 #pragma once
 
+#include "Device.h"
 #include <cstdint>
 
 namespace tt::hal {
 
-class Power{
+class Power : public Device {
 
 public:
 
     Power() = default;
-    virtual ~Power() = default;
+    ~Power() override = default;
+
+    Type getType() const override { return Type::Power; }
 
     enum class MetricType {
         IsCharging, // bool

TactilityHeadless/Include/Tactility/hal/SdCard.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include "Device.h"
+
 #include <Tactility/TactilityCore.h>
 
 namespace tt::hal {
@@ -7,8 +9,10 @@ namespace tt::hal {
 #define TT_SDCARD_MOUNT_NAME "sdcard"
 #define TT_SDCARD_MOUNT_POINT "/sdcard"
 
-class SdCard {
+class SdCard : public Device {
+
 public:
+
     enum class State {
         Mounted,
         Unmounted,
@@ -22,11 +26,15 @@ public:
     };
 
 private:
+
     MountBehaviour mountBehaviour;
 
 public:
+
     explicit SdCard(MountBehaviour mountBehaviour) : mountBehaviour(mountBehaviour) {}
-    virtual ~SdCard() = default;
+    virtual ~SdCard() override = default;
+
+    Type getType() const final { return Type::SdCard; };
 
     virtual bool mount(const char* mountPath) = 0;
     virtual bool unmount() = 0;

TactilityHeadless/Include/Tactility/hal/SpiSdCard.h

@@ -70,6 +70,9 @@ public:
         config(std::move(config))
     {}
 
+    std::string getName() const final { return "SD Card"; }
+    std::string getDescription() const final { return "SD card via SPI interface"; }
+
     bool mount(const char* mountPath) override;
     bool unmount() override;
     State getState() const override;

TactilityHeadless/Include/Tactility/hal/Touch.h

@@ -1,14 +1,19 @@
 #pragma once
 
-#include "lvgl.h"
+#include "Device.h"
+
+#include <lvgl.h>
 
 namespace tt::hal {
 
 class Display;
 
-class Touch {
+class Touch : public Device {
 
 public:
+
+    Type getType() const override { return Type::SdCard; }
+
     virtual bool start(lv_display_t* display) = 0;
     virtual bool stop() = 0;
 

TactilityHeadless/Include/Tactility/hal/i2c/I2cDevice.h

@@ -1,6 +1,9 @@
 #pragma once
 
-#include "./I2c.h"
+#include "I2c.h"
+#include "../Device.h"
+
+namespace tt::hal::i2c {
 
 /**
  * Represents an I2C peripheral at a specific port and address.
@@ -8,7 +11,7 @@
  *
  * All read and write calls are thread-safe.
  */
-class I2cDevice {
+class I2cDevice : public Device {
 
 protected:
 
@@ -17,6 +20,8 @@ protected:
 
     static constexpr TickType_t DEFAULT_TIMEOUT = 1000 / portTICK_PERIOD_MS;
 
+    Type getType() const override { return Type::I2c; }
+
     bool readRegister8(uint8_t reg, uint8_t& result) const;
     bool writeRegister8(uint8_t reg, uint8_t value) const;
     bool readRegister12(uint8_t reg, float& out) const;
@@ -26,7 +31,10 @@ protected:
     bool bitOff(uint8_t reg, uint8_t bitmask) const;
     bool bitOnByIndex(uint8_t reg, uint8_t index) const { return bitOn(reg, 1 << index); }
     bool bitOffByIndex(uint8_t reg, uint8_t index) const { return bitOff(reg, 1 << index); }
+
 public:
 
     explicit I2cDevice(i2c_port_t port, uint32_t address) : port(port), address(address) {}
 };
+
+}