Refactor LVGL code into kernel module (#472)

* **New Features**
  * Added a standalone LVGL module and enabled LVGL support in the simulator for richer local UI testing.

* **Refactor**
  * HAL and LVGL split into distinct modules; startup and device attach/detach flows reorganized for clearer lifecycle management.
  * Public APIs tightened with clearer nullability/documentation.

* **Bug Fixes**
  * More consistent LVGL start/stop and device attach/detach behavior for improved stability.

TactilityKernel/Include/tactility/device.h

@@ -181,7 +181,7 @@ static inline void device_unlock(struct Device* device) {
 }
 
 static inline const struct DeviceType* device_get_type(struct Device* device) {
-    return device->internal.driver ? device->internal.driver->deviceType : NULL;
+    return device->internal.driver ? device->internal.driver->device_type : NULL;
 }
 /**
  * Iterate through all the known devices

TactilityKernel/Include/tactility/driver.h

@@ -20,13 +20,13 @@ struct Driver {
     /** Array of const char*, terminated by NULL */
     const char**compatible;
     /** Function to initialize the driver for a device */
-    error_t (*startDevice)(struct Device* dev);
+    error_t (*start_device)(struct Device* dev);
     /** Function to deinitialize the driver for a device */
-    error_t (*stopDevice)(struct Device* dev);
+    error_t (*stop_device)(struct Device* dev);
     /** Contains the driver's functions */
     const void* api;
     /** Which type of devices this driver creates (can be NULL) */
-    const struct DeviceType* deviceType;
+    const struct DeviceType* device_type;
     /** The module that owns this driver. When it is NULL, the system owns the driver and it cannot be removed from registration. */
     const struct Module* owner;
     /** Internal data */
@@ -54,7 +54,7 @@ bool driver_is_compatible(struct Driver* driver, const char* compatible);
 struct Driver* driver_find_compatible(const char* compatible);
 
 static inline const struct DeviceType* driver_get_device_type(struct Driver* driver) {
-    return driver->deviceType;
+    return driver->device_type;
 }
 
 #ifdef __cplusplus

TactilityKernel/Include/tactility/module.h

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: Apache-2.0
 #pragma once
 
 #ifdef __cplusplus

TactilityKernel/Include/tactility/time.h

@@ -5,6 +5,9 @@
  */
 #pragma once
 
+#ifndef __cplusplus
+#include <assert.h>
+#endif
 #include <stdint.h>
 
 #include "defines.h"
@@ -17,8 +20,16 @@
 #include <time.h>
 #endif
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 // Projects that include this header must align with Tactility's frequency (e.g. apps)
+#ifdef __cplusplus
 static_assert(configTICK_RATE_HZ == 1000);
+#else
+static_assert(configTICK_RATE_HZ == 1000, "configTICK_RATE_HZ must be 1000");
+#endif
 
 static inline uint32_t get_tick_frequency() {
     return configTICK_RATE_HZ;
@@ -54,26 +65,30 @@ static inline int64_t get_micros_since_boot() {
 #ifdef ESP_PLATFORM
     return esp_timer_get_time();
 #else
-    timespec ts;
+    struct timespec ts;
     if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0) {
-        return (static_cast<int64_t>(ts.tv_sec) * 1000000LL) + (ts.tv_nsec / 1000);
+        return ((int64_t)ts.tv_sec * 1000000LL) + (ts.tv_nsec / 1000);
     }
-    timeval tv;
-    gettimeofday(&tv, nullptr);
-    return (static_cast<int64_t>(tv.tv_sec) * 1000000LL) + tv.tv_usec;
+    struct timeval tv;
+    gettimeofday(&tv, NULL);
+    return ((int64_t)tv.tv_sec * 1000000LL) + tv.tv_usec;
 #endif
 }
 
 /** Convert seconds to ticks */
 static inline TickType_t seconds_to_ticks(uint32_t seconds) {
-    return static_cast<uint64_t>(seconds) * 1000U / portTICK_PERIOD_MS;
+    return (uint64_t)seconds * 1000U / portTICK_PERIOD_MS;
 }
 
 /** Convert milliseconds to ticks */
 static inline TickType_t millis_to_ticks(uint32_t milliSeconds) {
 #if configTICK_RATE_HZ == 1000
-    return static_cast<TickType_t>(milliSeconds);
+    return (TickType_t)milliSeconds;
 #else
     return static_cast<TickType_t>(((float)configTICK_RATE_HZ) / 1000.0f * (float)milliSeconds);
 #endif
 }
+
+#ifdef __cplusplus
+}
+#endif