New kernel drivers, filesystem API, and more (#513)

* **New Features**
  * BMI270 6-axis IMU driver added; new unified filesystem abstraction for mounted filesystems.
  * Public Wi‑Fi API surface (no implementation yet)
  * SDMMC driver added (kernel drive$)
  * expanded GPIO interrupt/callback support
* **Improvements**
  * M5Stack Tab5: revamped GPIO/power initialization and IMU integration.
  * LVGL updates including device fontSize configuration.
  * Updated all code related to SD card device/fs handling
  * Rename LilyGO T-HMI S3 to LilyGO T-HMI
* **Bug Fixes**
  * Simplified and consolidated SD card handling and mount discovery.

TactilityKernel/source/drivers/gpio_controller.cpp

@@ -14,22 +14,25 @@
 extern "C" {
 
 struct GpioControllerData {
-    struct Mutex mutex {};
+    Mutex mutex {};
     uint32_t pin_count;
-    struct GpioDescriptor* descriptors = nullptr;
+    GpioDescriptor* descriptors = nullptr;
+    void* controller_context;
 
-    explicit GpioControllerData(uint32_t pin_count) : pin_count(pin_count) {
+    explicit GpioControllerData(
+        uint32_t pin_count, void* controller_context
+    ) : pin_count(pin_count), controller_context(controller_context) {
         mutex_construct(&mutex);
     }
 
-    error_t init_descriptors(Device* device, void* controller_context) {
-        descriptors = (struct GpioDescriptor*)calloc(pin_count, sizeof(struct GpioDescriptor));
+    error_t init_descriptors(Device* device) {
+        descriptors = static_cast<GpioDescriptor*>(calloc(pin_count, sizeof(GpioDescriptor)));
         if (!descriptors) return ERROR_OUT_OF_MEMORY;
         for (uint32_t i = 0; i < pin_count; ++i) {
             descriptors[i].controller = device;
-            descriptors[i].pin = (gpio_pin_t)i;
+            descriptors[i].pin = static_cast<gpio_pin_t>(i);
             descriptors[i].owner_type = GPIO_OWNER_NONE;
-            descriptors[i].controller_context = controller_context;
+            descriptors[i].controller_context = this->controller_context;
         }
         return ERROR_NONE;
     }
@@ -42,14 +45,14 @@ struct GpioControllerData {
     }
 };
 
-struct GpioDescriptor* gpio_descriptor_acquire(
-    struct Device* controller,
+GpioDescriptor* gpio_descriptor_acquire(
+    Device* controller,
     gpio_pin_t pin_number,
-    enum GpioOwnerType owner
+    GpioOwnerType owner
 ) {
     check(owner != GPIO_OWNER_NONE);
 
-    auto* data = (struct GpioControllerData*)device_get_driver_data(controller);
+    auto* data = static_cast<struct GpioControllerData*>(device_get_driver_data(controller));
 
     mutex_lock(&data->mutex);
     if (pin_number >= data->pin_count) {
@@ -57,7 +60,7 @@ struct GpioDescriptor* gpio_descriptor_acquire(
         return nullptr;
     }
 
-    struct GpioDescriptor* desc = &data->descriptors[pin_number];
+    GpioDescriptor* desc = &data->descriptors[pin_number];
     if (desc->owner_type != GPIO_OWNER_NONE) {
         mutex_unlock(&data->mutex);
         return nullptr;
@@ -69,22 +72,27 @@ struct GpioDescriptor* gpio_descriptor_acquire(
     return desc;
 }
 
-error_t gpio_descriptor_release(struct GpioDescriptor* descriptor) {
+error_t gpio_descriptor_release(GpioDescriptor* descriptor) {
+    auto* data = static_cast<struct GpioControllerData*>(device_get_driver_data(descriptor->controller));
+    mutex_lock(&data->mutex);
     descriptor->owner_type = GPIO_OWNER_NONE;
+    mutex_unlock(&data->mutex);
     return ERROR_NONE;
 }
 
-error_t gpio_controller_get_pin_count(struct Device* device, uint32_t* count) {
-    auto* data = (struct GpioControllerData*)device_get_driver_data(device);
+error_t gpio_controller_get_pin_count(Device* device, uint32_t* count) {
+    auto* data = static_cast<struct GpioControllerData*>(device_get_driver_data(device));
+    mutex_lock(&data->mutex);
     *count = data->pin_count;
+    mutex_unlock(&data->mutex);
     return ERROR_NONE;
 }
 
-error_t gpio_controller_init_descriptors(struct Device* device, uint32_t pin_count, void* controller_context) {
-    auto* data = new(std::nothrow) GpioControllerData(pin_count);
+error_t gpio_controller_init_descriptors(Device* device, uint32_t pin_count, void* controller_context) {
+    auto* data = new(std::nothrow) GpioControllerData(pin_count, controller_context);
     if (!data) return ERROR_OUT_OF_MEMORY;
 
-    if (data->init_descriptors(device, controller_context) != ERROR_NONE) {
+    if (data->init_descriptors(device) != ERROR_NONE) {
         delete data;
         return ERROR_OUT_OF_MEMORY;
     }
@@ -93,49 +101,82 @@ error_t gpio_controller_init_descriptors(struct Device* device, uint32_t pin_cou
     return ERROR_NONE;
 }
 
-error_t gpio_controller_deinit_descriptors(struct Device* device) {
+error_t gpio_controller_deinit_descriptors(Device* device) {
     auto* data = static_cast<struct GpioControllerData*>(device_get_driver_data(device));
-    delete data;
     device_set_driver_data(device, nullptr);
+    delete data;
     return ERROR_NONE;
 }
 
-error_t gpio_descriptor_set_level(struct GpioDescriptor* descriptor, bool high) {
+void* gpio_controller_get_controller_context(Device* device) {
+    auto* data = static_cast<struct GpioControllerData*>(device_get_driver_data(device));
+    return data->controller_context;
+}
+
+error_t gpio_descriptor_set_level(GpioDescriptor* descriptor, bool high) {
     const auto* driver = device_get_driver(descriptor->controller);
     return GPIO_INTERNAL_API(driver)->set_level(descriptor, high);
 }
 
-error_t gpio_descriptor_get_level(struct GpioDescriptor* descriptor, bool* high) {
+error_t gpio_descriptor_get_level(GpioDescriptor* descriptor, bool* high) {
     const auto* driver = device_get_driver(descriptor->controller);
     return GPIO_INTERNAL_API(driver)->get_level(descriptor, high);
 }
 
-error_t gpio_descriptor_set_flags(struct GpioDescriptor* descriptor, gpio_flags_t flags) {
+error_t gpio_descriptor_set_flags(GpioDescriptor* descriptor, gpio_flags_t flags) {
     const auto* driver = device_get_driver(descriptor->controller);
     return GPIO_INTERNAL_API(driver)->set_flags(descriptor, flags);
 }
 
-error_t gpio_descriptor_get_flags(struct GpioDescriptor* descriptor, gpio_flags_t* flags) {
+error_t gpio_descriptor_get_flags(GpioDescriptor* descriptor, gpio_flags_t* flags) {
     const auto* driver = device_get_driver(descriptor->controller);
     return GPIO_INTERNAL_API(driver)->get_flags(descriptor, flags);
 }
 
-error_t gpio_descriptor_get_pin_number(struct GpioDescriptor* descriptor, gpio_pin_t* pin) {
+error_t gpio_descriptor_get_pin_number(GpioDescriptor* descriptor, gpio_pin_t* pin) {
     *pin = descriptor->pin;
     return ERROR_NONE;
 }
 
-error_t gpio_descriptor_get_native_pin_number(struct GpioDescriptor* descriptor, void* pin_number) {
+error_t gpio_descriptor_get_native_pin_number(GpioDescriptor* descriptor, void* pin_number) {
     const auto* driver = device_get_driver(descriptor->controller);
     return GPIO_INTERNAL_API(driver)->get_native_pin_number(descriptor, pin_number);
 }
 
-error_t gpio_descriptor_get_owner_type(struct GpioDescriptor* descriptor, GpioOwnerType* owner_type) {
+error_t gpio_descriptor_add_callback(GpioDescriptor* descriptor, void (*callback)(void*), void* arg) {
+    const auto* driver = device_get_driver(descriptor->controller);
+    auto* api = GPIO_INTERNAL_API(driver);
+    if (!api->add_callback) return ERROR_NOT_SUPPORTED;
+    return api->add_callback(descriptor, callback, arg);
+}
+
+error_t gpio_descriptor_remove_callback(GpioDescriptor* descriptor) {
+    const auto* driver = device_get_driver(descriptor->controller);
+    auto* api = GPIO_INTERNAL_API(driver);
+    if (!api->remove_callback) return ERROR_NOT_SUPPORTED;
+    return api->remove_callback(descriptor);
+}
+
+error_t gpio_descriptor_enable_interrupt(GpioDescriptor* descriptor) {
+    const auto* driver = device_get_driver(descriptor->controller);
+    auto* api = GPIO_INTERNAL_API(driver);
+    if (!api->enable_interrupt) return ERROR_NOT_SUPPORTED;
+    return api->enable_interrupt(descriptor);
+}
+
+error_t gpio_descriptor_disable_interrupt(GpioDescriptor* descriptor) {
+    const auto* driver = device_get_driver(descriptor->controller);
+    auto* api = GPIO_INTERNAL_API(driver);
+    if (!api->disable_interrupt) return ERROR_NOT_SUPPORTED;
+    return api->disable_interrupt(descriptor);
+}
+
+error_t gpio_descriptor_get_owner_type(GpioDescriptor* descriptor, GpioOwnerType* owner_type) {
     *owner_type = descriptor->owner_type;
     return ERROR_NONE;
 }
 
-const struct DeviceType GPIO_CONTROLLER_TYPE {
+const DeviceType GPIO_CONTROLLER_TYPE {
     .name = "gpio-controller"
 };
 

TactilityKernel/source/filesystem/file_system.cpp

@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: Apache-2.0
+
+#include <algorithm>
+#include <tactility/concurrent/mutex.h>
+#include <tactility/concurrent/recursive_mutex.h>
+#include <tactility/filesystem/file_system.h>
+#include <vector>
+
+// Define the internal FileSystem structure
+struct FileSystem {
+    const FileSystemApi* api;
+    void* data;
+};
+
+// Global list of file systems and its mutex
+struct FileSystemsLedger {
+    std::vector<FileSystem*> file_systems;
+    // Use recursive mutex so that file_system_for_each() can lock within the callback
+    RecursiveMutex mutex {};
+
+    FileSystemsLedger() { recursive_mutex_construct(&mutex); }
+    ~FileSystemsLedger() { recursive_mutex_destruct(&mutex); }
+
+    void lock() { recursive_mutex_lock(&mutex); }
+    bool is_locked() { return recursive_mutex_is_locked(&mutex); }
+    void unlock() { recursive_mutex_unlock(&mutex); }
+};
+
+static FileSystemsLedger& get_ledger() {
+    static FileSystemsLedger ledger;
+    return ledger;
+}
+
+extern "C" {
+
+FileSystem* file_system_add(const FileSystemApi* fs_api, void* data) {
+    auto& ledger = get_ledger();
+    check(!ledger.is_locked()); // ensure file_system_for_each() doesn't add a filesystem while iterating
+    ledger.lock();
+    
+    auto* fs = new(std::nothrow) struct FileSystem();
+    check(fs != nullptr);
+    fs->api = fs_api;
+    fs->data = data;
+    ledger.file_systems.push_back(fs);
+    
+    ledger.unlock();
+    return fs;
+}
+
+void file_system_remove(FileSystem* fs) {
+    check(!file_system_is_mounted(fs));
+    auto& ledger = get_ledger();
+    check(!ledger.is_locked()); // ensure file_system_for_each() doesn't remove a filesystem while iterating
+    ledger.lock();
+    
+    auto it = std::ranges::find(ledger.file_systems, fs);
+    if (it != ledger.file_systems.end()) {
+        ledger.file_systems.erase(it);
+        delete fs;
+    }
+    
+    ledger.unlock();
+}
+
+void file_system_for_each(void* callback_context, bool (*callback)(FileSystem* fs, void* context)) {
+    auto& ledger = get_ledger();
+    ledger.lock();
+    for (auto* fs : ledger.file_systems) {
+        if (!callback(fs, callback_context)) break;
+    }
+    ledger.unlock();
+}
+
+error_t file_system_mount(FileSystem* fs) {
+    // Assuming 'device' is accessible or passed via a different mechanism
+    // as it's required by the FileSystemApi signatures.
+    return fs->api->mount(fs->data);
+}
+
+error_t file_system_unmount(FileSystem* fs) {
+    return fs->api->unmount(fs->data);
+}
+
+bool file_system_is_mounted(FileSystem* fs) {
+    return fs->api->is_mounted(fs->data);
+}
+
+error_t file_system_get_path(FileSystem* fs, char* out_path, size_t out_path_size) {
+    return fs->api->get_path(fs->data, out_path, out_path_size);
+}
+
+}

TactilityKernel/source/kernel_symbols.c

@@ -1,3 +1,7 @@
+#include <tactility/concurrent/dispatcher.h>
+#include <tactility/concurrent/event_group.h>
+#include <tactility/concurrent/thread.h>
+#include <tactility/concurrent/timer.h>
 #include <tactility/device.h>
 #include <tactility/driver.h>
 #include <tactility/drivers/gpio_controller.h>
@@ -6,14 +10,14 @@
 #include <tactility/drivers/root.h>
 #include <tactility/drivers/spi_controller.h>
 #include <tactility/drivers/uart_controller.h>
-#include <tactility/concurrent/dispatcher.h>
-#include <tactility/concurrent/event_group.h>
-#include <tactility/concurrent/thread.h>
-#include <tactility/concurrent/timer.h>
 #include <tactility/error.h>
-#include <tactility/log.h>
+#include <tactility/filesystem/file_system.h>
 #include <tactility/module.h>
 
+#ifndef ESP_PLATFORM
+#include <tactility/log.h>
+#endif
+
 /**
  * This file is a C file instead of C++, so we can import all headers as C code.
  * The intent is to catch errors that only show up when compiling as C and not as C++.
@@ -153,6 +157,11 @@ const struct ModuleSymbol KERNEL_SYMBOLS[] = {
     DEFINE_MODULE_SYMBOL(timer_set_callback_priority),
     // error
     DEFINE_MODULE_SYMBOL(error_to_string),
+    // file system
+    DEFINE_MODULE_SYMBOL(file_system_mount),
+    DEFINE_MODULE_SYMBOL(file_system_unmount),
+    DEFINE_MODULE_SYMBOL(file_system_is_mounted),
+    DEFINE_MODULE_SYMBOL(file_system_get_path),
     // log
 #ifndef ESP_PLATFORM
     DEFINE_MODULE_SYMBOL(log_generic),

TactilityKernel/source/module.cpp

@@ -12,8 +12,8 @@ struct ModuleInternal {
 };
 
 struct ModuleLedger {
-    std::vector<struct Module*> modules;
-    struct Mutex mutex {};
+    std::vector<Module*> modules;
+    Mutex mutex {};
 
     ModuleLedger() { mutex_construct(&mutex); }
     ~ModuleLedger() { mutex_destruct(&mutex); }
@@ -23,36 +23,37 @@ static ModuleLedger ledger;
 
 extern "C" {
 
-error_t module_construct(struct Module* module) {
+error_t module_construct(Module* module) {
     module->internal = new (std::nothrow) ModuleInternal();
     if (module->internal == nullptr) return ERROR_OUT_OF_MEMORY;
     return ERROR_NONE;
 }
 
-error_t module_destruct(struct Module* module) {
+error_t module_destruct(Module* module) {
     delete static_cast<ModuleInternal*>(module->internal);
     module->internal = nullptr;
     return ERROR_NONE;
 }
 
-error_t module_add(struct Module* module) {
+error_t module_add(Module* module) {
     mutex_lock(&ledger.mutex);
     ledger.modules.push_back(module);
     mutex_unlock(&ledger.mutex);
     return ERROR_NONE;
 }
 
-error_t module_remove(struct Module* module) {
+error_t module_remove(Module* module) {
     mutex_lock(&ledger.mutex);
     ledger.modules.erase(std::remove(ledger.modules.begin(), ledger.modules.end(), module), ledger.modules.end());
     mutex_unlock(&ledger.mutex);
     return ERROR_NONE;
 }
 
-error_t module_start(struct Module* module) {
+error_t module_start(Module* module) {
     LOG_I(TAG, "start %s", module->name);
 
-    auto* internal = static_cast<ModuleInternal*>(module->internal);
+    auto* internal = module->internal;
+    if (internal == nullptr) return ERROR_INVALID_STATE;
     if (internal->started) return ERROR_NONE;
 
     error_t error = module->start();
@@ -61,13 +62,15 @@ error_t module_start(struct Module* module) {
 }
 
 bool module_is_started(struct Module* module) {
-    return static_cast<ModuleInternal*>(module->internal)->started;
+    auto* internal = module->internal;
+    return internal != nullptr && internal->started;
 }
 
 error_t module_stop(struct Module* module) {
     LOG_I(TAG, "stop %s", module->name);
 
-    auto* internal = static_cast<ModuleInternal*>(module->internal);
+    auto* internal = module->internal;
+    if (internal == nullptr) return ERROR_INVALID_STATE;
     if (!internal->started) return ERROR_NONE;
 
     error_t error = module->stop();