From ccbe6b7ab8649720da358bbf9922b70d8d03f27c Mon Sep 17 00:00:00 2001
From: Ken Van Hoeylandt <git@kenvanhoeylandt.net>
Date: Sat, 27 Jan 2024 12:34:02 +0100
Subject: [PATCH] LilyGo T-Deck keyboard support & display driver improvements
 (#19)

* LilyGo T-Deck keyboard support

* reverse logic

* docs and readability

* cleanup

* optimize driver buffer

* cleanup
---
 CODING_STYLE.md                               |  6 +-
 boards/lilygo_tdeck/bootstrap.c               | 54 ++++++++---
 boards/lilygo_tdeck/config.h                  |  7 ++
 boards/lilygo_tdeck/display.c                 | 14 +--
 boards/lilygo_tdeck/keyboard.c                | 95 +++++++++++++++++++
 boards/lilygo_tdeck/keyboard.h                | 18 ++++
 boards/lilygo_tdeck/lvgl.c                    |  6 +-
 boards/lilygo_tdeck/touch.c                   | 31 +-----
 docs/ideas.md                                 |  6 +-
 .../system/wifi_connect/wifi_connect_view.c   | 25 +++--
 .../system/wifi_connect/wifi_connect_view.h   |  1 +
 tactility/src/app.c                           |  1 -
 tactility/src/hardware.c                      |  6 +-
 tactility/src/services/gui/gui.c              | 13 ++-
 tactility/src/services/gui/gui.h              | 30 ++++++
 tactility/src/services/loader/loader.c        |  1 +
 tactility/src/tactility.c                     |  8 +-
 tactility/src/tactility.h                     |  8 +-
 tactility/src/tactility_config.h              |  6 ++
 tactility/src/ui/lvgl_keypad.c                | 23 +++++
 tactility/src/ui/lvgl_keypad.h                | 16 ++++
 21 files changed, 302 insertions(+), 73 deletions(-)
 create mode 100644 boards/lilygo_tdeck/config.h
 create mode 100644 boards/lilygo_tdeck/keyboard.c
 create mode 100644 boards/lilygo_tdeck/keyboard.h
 create mode 100644 tactility/src/tactility_config.h
 create mode 100644 tactility/src/ui/lvgl_keypad.c
 create mode 100644 tactility/src/ui/lvgl_keypad.h

diff --git a/CODING_STYLE.md b/CODING_STYLE.md
index 1dfb4311..11578c30 100644
--- a/CODING_STYLE.md
+++ b/CODING_STYLE.md
@@ -26,9 +26,11 @@ Like `some_feature_i.h`
 
 Names are snake-case.
 
-Public functions are prefixed with `tt_` for `tactility-core` and `tactility` projects.
+The `tt_` prefix is used for public functions that are part of `tactility/` or `tactility-core/`
 Internal/static functions don't have prefix requirements, but prefixes are allowed.
 
+The prefix is **not** used for drivers, services and apps.
+
 Public functions have the feature name after `tt_`.
 
 If a feature has setters or getters, it's added after the feature name part.
@@ -36,7 +38,7 @@ If a feature has setters or getters, it's added after the feature name part.
 Example:
 
 ```c
-void tt_feature_get_name() {
+void tt_counter_get_limit() {
     // ...
 }
 ```
diff --git a/boards/lilygo_tdeck/bootstrap.c b/boards/lilygo_tdeck/bootstrap.c
index 039599c3..c1577071 100644
--- a/boards/lilygo_tdeck/bootstrap.c
+++ b/boards/lilygo_tdeck/bootstrap.c
@@ -1,29 +1,61 @@
-#include "esp_log.h"
-#include "driver/gpio.h"
+#include "config.h"
+#include "keyboard.h"
 #include "kernel.h"
-#include "esp_lvgl_port.h"
+#include "log.h"
 
-#define TAG "lilygo_tdeck_bootstrap"
-#define TDECK_PERI_POWERON GPIO_NUM_10
+#define TAG "tdeck_bootstrap"
 
 lv_disp_t* lilygo_tdeck_init_display();
 
-static void tdeck_power_on() {
+static bool tdeck_power_on() {
     ESP_LOGI(TAG, "power on");
     gpio_config_t device_power_signal_config = {
-        .pin_bit_mask = BIT64(TDECK_PERI_POWERON),
+        .pin_bit_mask = BIT64(TDECK_POWERON_GPIO),
         .mode = GPIO_MODE_OUTPUT,
         .pull_up_en = GPIO_PULLUP_DISABLE,
         .pull_down_en = GPIO_PULLDOWN_DISABLE,
         .intr_type = GPIO_INTR_DISABLE,
     };
-    gpio_config(&device_power_signal_config);
-    gpio_set_level(TDECK_PERI_POWERON, 1);
+
+    if (gpio_config(&device_power_signal_config) != ESP_OK) {
+        return false;
+    }
+
+    if (gpio_set_level(TDECK_POWERON_GPIO, 1) != ESP_OK) {
+        return false;
+    }
+
+    return true;
 }
 
-void lilygo_tdeck_bootstrap() {
-    tdeck_power_on();
+static bool init_i2c() {
+    const i2c_config_t i2c_conf = {
+        .mode = I2C_MODE_MASTER,
+        .sda_io_num = GPIO_NUM_18,
+        .sda_pullup_en = GPIO_PULLUP_DISABLE,
+        .scl_io_num = GPIO_NUM_8,
+        .scl_pullup_en = GPIO_PULLUP_DISABLE,
+        .master.clk_speed = 400000
+    };
+
+    return i2c_param_config(TDECK_I2C_BUS_HANDLE, &i2c_conf) == ESP_OK
+        && i2c_driver_install(TDECK_I2C_BUS_HANDLE, i2c_conf.mode, 0, 0, 0) == ESP_OK;
+}
+
+bool lilygo_tdeck_bootstrap() {
+    if (!tdeck_power_on()) {
+        TT_LOG_E(TAG, "failed to power on device");
+    }
+
     // Give keyboard's ESP time to boot
     // It uses I2C and seems to interfere with the touch driver
     tt_delay_ms(500);
+
+    if (!init_i2c()) {
+        TT_LOG_E(TAG, "failed to init I2C");
+    }
+
+    keyboard_wait_for_response();
+
+    return true;
 }
diff --git a/boards/lilygo_tdeck/config.h b/boards/lilygo_tdeck/config.h
new file mode 100644
index 00000000..d99fec1b
--- /dev/null
+++ b/boards/lilygo_tdeck/config.h
@@ -0,0 +1,7 @@
+#pragma once
+
+#include "driver/i2c.h"
+#include "driver/gpio.h"
+
+#define TDECK_I2C_BUS_HANDLE (0)
+#define TDECK_POWERON_GPIO GPIO_NUM_10
diff --git a/boards/lilygo_tdeck/display.c b/boards/lilygo_tdeck/display.c
index e7086022..d83111e2 100644
--- a/boards/lilygo_tdeck/display.c
+++ b/boards/lilygo_tdeck/display.c
@@ -6,7 +6,7 @@
 #include "esp_log.h"
 #include "esp_lvgl_port.h"
 
-#define TAG "lilygo_tdeck_display"
+#define TAG "tdeck_display"
 
 #define LCD_SPI_HOST SPI2_HOST
 #define LCD_PIN_SCLK GPIO_NUM_40
@@ -21,6 +21,7 @@
 #define LCD_VERTICAL_RESOLUTION 240
 #define LCD_BITS_PER_PIXEL 16
 #define LCD_DRAW_BUFFER_HEIGHT (LCD_VERTICAL_RESOLUTION / 10)
+#define LCD_SPI_TRANSFER_HEIGHT (LCD_VERTICAL_RESOLUTION / 10)
 
 // Backlight PWM
 #define LCD_BACKLIGHT_LEDC_TIMER LEDC_TIMER_0
@@ -60,7 +61,7 @@ static void tdeck_backlight() {
 lv_disp_t* lilygo_tdeck_init_display() {
     ESP_LOGI(TAG, "creating display");
 
-    int draw_buffer_size = LCD_HORIZONTAL_RESOLUTION * LCD_DRAW_BUFFER_HEIGHT * (LCD_BITS_PER_PIXEL / 8);
+    int max_transfer_size = LCD_HORIZONTAL_RESOLUTION * LCD_SPI_TRANSFER_HEIGHT * (LCD_BITS_PER_PIXEL / 8);
 
     spi_bus_config_t bus_config = {
         .sclk_io_num = LCD_PIN_SCLK,
@@ -68,7 +69,7 @@ lv_disp_t* lilygo_tdeck_init_display() {
         .miso_io_num = LCD_PIN_MISO,
         .quadwp_io_num = -1, // Quad SPI LCD driver is not yet supported
         .quadhd_io_num = -1, // Quad SPI LCD driver is not yet supported
-        .max_transfer_sz = draw_buffer_size,
+        .max_transfer_sz = max_transfer_size,
     };
 
     if (spi_bus_initialize(LCD_SPI_HOST, &bus_config, SPI_DMA_CH_AUTO) != ESP_OK) {
@@ -154,17 +155,18 @@ lv_disp_t* lilygo_tdeck_init_display() {
         .io_handle = io_handle,
         .panel_handle = panel_handle,
         .buffer_size = LCD_HORIZONTAL_RESOLUTION * LCD_DRAW_BUFFER_HEIGHT * (LCD_BITS_PER_PIXEL / 8),
-        .double_buffer = false,
+        .double_buffer = true, // Disable to free up SPIRAM
         .hres = LCD_HORIZONTAL_RESOLUTION,
         .vres = LCD_VERTICAL_RESOLUTION,
         .monochrome = false,
         .rotation = {
-            .swap_xy = true, // TODO: check if code above is still needed
+            .swap_xy = true,
             .mirror_x = true,
             .mirror_y = false,
         },
         .flags = {
-            .buff_dma = true,
+            .buff_dma = false,
+            .buff_spiram = true,
         }
     };
 
diff --git a/boards/lilygo_tdeck/keyboard.c b/boards/lilygo_tdeck/keyboard.c
new file mode 100644
index 00000000..fa049a9d
--- /dev/null
+++ b/boards/lilygo_tdeck/keyboard.c
@@ -0,0 +1,95 @@
+#include "keyboard.h"
+#include "config.h"
+#include "hal/lv_hal.h"
+#include "tactility_core.h"
+#include "ui/lvgl_keypad.h"
+#include <driver/i2c.h>
+
+#define TAG "tdeck_keyboard"
+#define KEYBOARD_SLAVE_ADDRESS 0x55
+
+typedef struct {
+    lv_indev_drv_t* driver;
+    lv_indev_t* device;
+} KeyboardData;
+
+static inline esp_err_t keyboard_i2c_read(uint8_t* output) {
+    return i2c_master_read_from_device(
+        TDECK_I2C_BUS_HANDLE,
+        KEYBOARD_SLAVE_ADDRESS,
+        output,
+        1,
+        configTICK_RATE_HZ / 10
+    );
+}
+
+void keyboard_wait_for_response() {
+    TT_LOG_I(TAG, "wake await...");
+    bool awake = false;
+    uint8_t read_buffer = 0x00;
+    do {
+        awake = keyboard_i2c_read(&read_buffer) == ESP_OK;
+        if (!awake) {
+            tt_delay_ms(100);
+        }
+    } while (!awake);
+    TT_LOG_I(TAG, "awake");
+}
+
+/**
+ * The callback simulates press and release events, because the T-Deck
+ * keyboard only publishes press events on I2C.
+ * LVGL currently works without those extra release events, but they
+ * are implemented for correctness and future compatibility.
+ *
+ * @param indev_drv
+ * @param data
+ */
+static void keyboard_read_callback(TT_UNUSED struct _lv_indev_drv_t* indev_drv, lv_indev_data_t* data) {
+    static uint8_t last_buffer = 0x00;
+    uint8_t read_buffer = 0x00;
+
+    // Defaults
+    data->key = 0;
+    data->state = LV_INDEV_STATE_RELEASED;
+
+    if (keyboard_i2c_read(&read_buffer) == ESP_OK) {
+        if (read_buffer == 0 && read_buffer != last_buffer) {
+            TT_LOG_I(TAG, "released %d", last_buffer);
+            data->key = last_buffer;
+            data->state = LV_INDEV_STATE_RELEASED;
+        } else if (read_buffer != 0) {
+            TT_LOG_I(TAG, "pressed %d", read_buffer);
+            data->key = read_buffer;
+            data->state = LV_INDEV_STATE_PRESSED;
+        }
+    }
+
+    last_buffer = read_buffer;
+}
+
+Keyboard keyboard_alloc(_Nullable lv_disp_t* display) {
+    KeyboardData* data = malloc(sizeof(KeyboardData));
+
+    data->driver = malloc(sizeof(lv_indev_drv_t));
+    memset(data->driver, 0, sizeof(lv_indev_drv_t));
+    lv_indev_drv_init(data->driver);
+
+    data->driver->type = LV_INDEV_TYPE_KEYPAD;
+    data->driver->read_cb = &keyboard_read_callback;
+    data->driver->disp = display;
+
+    data->device = lv_indev_drv_register(data->driver);
+    tt_check(data->device != NULL);
+
+    tt_lvgl_keypad_set_indev(data->device);
+
+    return data;
+}
+
+void keyboard_free(Keyboard keyboard) {
+    KeyboardData* data = (KeyboardData*)keyboard;
+    lv_indev_delete(data->device);
+    free(data->driver);
+    free(data);
+}
diff --git a/boards/lilygo_tdeck/keyboard.h b/boards/lilygo_tdeck/keyboard.h
new file mode 100644
index 00000000..fda164f3
--- /dev/null
+++ b/boards/lilygo_tdeck/keyboard.h
@@ -0,0 +1,18 @@
+#pragma once
+
+#include "lvgl.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void keyboard_wait_for_response();
+
+typedef void* Keyboard;
+
+Keyboard keyboard_alloc(_Nullable lv_disp_t* display);
+void keyboard_free(Keyboard keyboard);
+
+#ifdef __cplusplus
+}
+#endif
\ No newline at end of file
diff --git a/boards/lilygo_tdeck/lvgl.c b/boards/lilygo_tdeck/lvgl.c
index 597f4210..18a8d8d4 100644
--- a/boards/lilygo_tdeck/lvgl.c
+++ b/boards/lilygo_tdeck/lvgl.c
@@ -1,9 +1,10 @@
 #include "esp_lvgl_port.h"
+#include "keyboard.h"
 #include "log.h"
 #include "ui/lvgl_sync.h"
 #include <thread.h>
 
-#define TAG "lilygo_tdeck_lvgl"
+#define TAG "tdeck_lvgl"
 
 lv_disp_t* lilygo_tdeck_init_display();
 bool lilygo_tdeck_init_touch(esp_lcd_panel_io_handle_t* io_handle, esp_lcd_touch_handle_t* touch_handle);
@@ -33,7 +34,6 @@ bool lilygo_init_lvgl() {
         return false;
     }
 
-
     // Add touch
     if (!lilygo_tdeck_init_touch(&touch_io_handle, &touch_handle)) {
         return false;
@@ -53,5 +53,7 @@ bool lilygo_init_lvgl() {
     // Set syncing functions
     tt_lvgl_sync_set(&lvgl_port_lock, &lvgl_port_unlock);
 
+    keyboard_alloc(display);
+
     return true;
 }
diff --git a/boards/lilygo_tdeck/touch.c b/boards/lilygo_tdeck/touch.c
index adeab833..89d304bf 100644
--- a/boards/lilygo_tdeck/touch.c
+++ b/boards/lilygo_tdeck/touch.c
@@ -1,37 +1,16 @@
+#include "config.h"
+#include "driver/i2c.h"
+#include "esp_err.h"
 #include "esp_lcd_touch_gt911.h"
 #include "esp_log.h"
-#include "esp_err.h"
-#include "driver/i2c.h"
 
-#define TOUCH_I2C_PORT 0
-
-#define TAG "lilygo_tdeck_touch"
+#define TAG "tdeck_touch"
 
 bool lilygo_tdeck_init_touch(esp_lcd_panel_io_handle_t* io_handle, esp_lcd_touch_handle_t* touch_handle) {
     ESP_LOGI(TAG, "creating touch");
 
-    const i2c_config_t i2c_conf = {
-        .mode = I2C_MODE_MASTER,
-        .sda_io_num = GPIO_NUM_18,
-        .sda_pullup_en = GPIO_PULLUP_DISABLE,
-        .scl_io_num = GPIO_NUM_8,
-        .scl_pullup_en = GPIO_PULLUP_DISABLE,
-        .master.clk_speed = 400000
-    };
-
-    if (i2c_param_config(TOUCH_I2C_PORT, &i2c_conf) != ESP_OK) {
-        ESP_LOGE(TAG, "i2c config failed");
-        return false;
-    }
-
-    if (i2c_driver_install(TOUCH_I2C_PORT, i2c_conf.mode, 0, 0, 0) != ESP_OK) {
-        ESP_LOGE(TAG, "i2c driver install failed");
-        return false;
-    }
-
     const esp_lcd_panel_io_i2c_config_t touch_io_config = ESP_LCD_TOUCH_IO_I2C_GT911_CONFIG();
-
-    if (esp_lcd_new_panel_io_i2c((esp_lcd_i2c_bus_handle_t)TOUCH_I2C_PORT, &touch_io_config, io_handle) != ESP_OK) {
+    if (esp_lcd_new_panel_io_i2c((esp_lcd_i2c_bus_handle_t)TDECK_I2C_BUS_HANDLE, &touch_io_config, io_handle) != ESP_OK) {
         ESP_LOGE(TAG, "touch io i2c creation failed");
         return false;
     }
diff --git a/docs/ideas.md b/docs/ideas.md
index 210d8fed..1c8560d8 100644
--- a/docs/ideas.md
+++ b/docs/ideas.md
@@ -4,6 +4,9 @@
 - Replace FreeRTOS semaphore from `Loader` with internal `Mutex`
 - Create unit tests for `tactility-core` and `tactility` (PC-only for now)
 - Have a way to deinit LVGL drivers that are created from `HardwareConfig`
+- Thread is broken: `tt_thread_join()` always hangs because `tt_thread_cleanup_tcb_event()`
+is not automatically called. This is normally done by a hook in `FreeRTOSConfig.h`
+but that seems to not work with ESP32. I should investigate task cleanup hooks further.
  
 # Core Ideas
 - Make a HAL? It would mainly be there to support PC development. It's a lot of effort for supporting what's effectively a dev-only feature.
@@ -15,4 +18,5 @@
 - BadUSB
 - IR transceiver app
 - GPIO status viewer
-- BlueTooth keyboard app
\ No newline at end of file
+- BlueTooth keyboard app
+- Investigate CSI https://stevenmhernandez.github.io/ESP32-CSI-Tool/
\ No newline at end of file
diff --git a/tactility-esp/src/apps/system/wifi_connect/wifi_connect_view.c b/tactility-esp/src/apps/system/wifi_connect/wifi_connect_view.c
index c574404c..fdc70a9a 100644
--- a/tactility-esp/src/apps/system/wifi_connect/wifi_connect_view.c
+++ b/tactility-esp/src/apps/system/wifi_connect/wifi_connect_view.c
@@ -4,6 +4,7 @@
 #include "lvgl.h"
 #include "services/gui/gui.h"
 #include "services/wifi/wifi_credentials.h"
+#include "ui/lvgl_keypad.h"
 #include "ui/spacer.h"
 #include "ui/style.h"
 #include "wifi_connect.h"
@@ -103,12 +104,14 @@ void wifi_connect_view_create(App app, void* wifi, lv_obj_t* parent) {
 
     wifi_connect_view_create_bottom_buttons(wifi, parent);
 
-    lv_obj_add_event_cb(view->ssid_textarea, show_keyboard, LV_EVENT_FOCUSED, NULL);
-    lv_obj_add_event_cb(view->ssid_textarea, hide_keyboard, LV_EVENT_DEFOCUSED, NULL);
-    lv_obj_add_event_cb(view->ssid_textarea, hide_keyboard, LV_EVENT_READY, NULL);
-    lv_obj_add_event_cb(view->password_textarea, show_keyboard, LV_EVENT_FOCUSED, NULL);
-    lv_obj_add_event_cb(view->password_textarea, hide_keyboard, LV_EVENT_DEFOCUSED, NULL);
-    lv_obj_add_event_cb(view->password_textarea, hide_keyboard, LV_EVENT_READY, NULL);
+    if (gui_keyboard_is_enabled()) {
+        lv_obj_add_event_cb(view->ssid_textarea, show_keyboard, LV_EVENT_FOCUSED, NULL);
+        lv_obj_add_event_cb(view->ssid_textarea, hide_keyboard, LV_EVENT_DEFOCUSED, NULL);
+        lv_obj_add_event_cb(view->ssid_textarea, hide_keyboard, LV_EVENT_READY, NULL);
+        lv_obj_add_event_cb(view->password_textarea, show_keyboard, LV_EVENT_FOCUSED, NULL);
+        lv_obj_add_event_cb(view->password_textarea, hide_keyboard, LV_EVENT_DEFOCUSED, NULL);
+        lv_obj_add_event_cb(view->password_textarea, hide_keyboard, LV_EVENT_READY, NULL);
+    }
 
     // Init from app parameters
     Bundle* _Nullable bundle = tt_app_get_parameters(app);
@@ -123,10 +126,18 @@ void wifi_connect_view_create(App app, void* wifi, lv_obj_t* parent) {
             lv_textarea_set_text(view->password_textarea, password);
         }
     }
+
+    // Hardware keyboard("keypad") requires a group
+    view->group = lv_group_create();
+    lv_group_add_obj(view->group, view->ssid_textarea);
+    lv_group_add_obj(view->group, view->password_textarea);
+    tt_lvgl_keypad_activate(view->group);
 }
 
 void wifi_connect_view_destroy(TT_UNUSED WifiConnectView* view) {
-    // NO-OP
+    // Cleanup keypad group
+    tt_lvgl_keypad_deactivate();
+    lv_group_del(view->group);
 }
 
 void wifi_connect_view_update(
diff --git a/tactility-esp/src/apps/system/wifi_connect/wifi_connect_view.h b/tactility-esp/src/apps/system/wifi_connect/wifi_connect_view.h
index b534c81d..432e9d5a 100644
--- a/tactility-esp/src/apps/system/wifi_connect/wifi_connect_view.h
+++ b/tactility-esp/src/apps/system/wifi_connect/wifi_connect_view.h
@@ -15,6 +15,7 @@ typedef struct {
     lv_obj_t* connect_button;
     lv_obj_t* cancel_button;
     lv_obj_t* remember_switch;
+    lv_group_t* group;
 } WifiConnectView;
 
 void wifi_connect_view_create(App app, void* wifi, lv_obj_t* parent);
diff --git a/tactility/src/app.c b/tactility/src/app.c
index b93473a6..7b675351 100644
--- a/tactility/src/app.c
+++ b/tactility/src/app.c
@@ -1,6 +1,5 @@
 #include "app_i.h"
 
-#include <stdio.h>
 #include <stdlib.h>
 
 static AppFlags tt_app_get_flags_default(AppType type);
diff --git a/tactility/src/hardware.c b/tactility/src/hardware.c
index 25c63d2d..256a4249 100644
--- a/tactility/src/hardware.c
+++ b/tactility/src/hardware.c
@@ -6,9 +6,9 @@
 void tt_hardware_init(const HardwareConfig* config) {
     if (config->bootstrap != NULL) {
         TT_LOG_I(TAG, "Bootstrapping");
-        config->bootstrap();
+        tt_check(config->bootstrap(), "bootstrap failed");
     }
 
-    tt_check(config->init_lvgl);
-    config->init_lvgl();
+    tt_check(config->init_lvgl, "lvlg init not set");
+    tt_check(config->init_lvgl(), "lvgl init failed");
 }
diff --git a/tactility/src/services/gui/gui.c b/tactility/src/services/gui/gui.c
index 47d502fd..2b317100 100644
--- a/tactility/src/services/gui/gui.c
+++ b/tactility/src/services/gui/gui.c
@@ -1,10 +1,8 @@
 #include "gui_i.h"
 
-#include "check.h"
-#include "core_extra_defines.h"
+#include "tactility.h"
 #include "ui/lvgl_sync.h"
-#include "kernel.h"
-#include "log.h"
+#include "ui/lvgl_keypad.h"
 
 #ifdef ESP_PLATFORM
 #include "freertos/FreeRTOS.h"
@@ -30,7 +28,7 @@ Gui* gui_alloc() {
         &gui_main,
         NULL
     );
-    instance->mutex = tt_mutex_alloc(MutexTypeNormal);
+    instance->mutex = tt_mutex_alloc(MutexTypeRecursive);
     instance->keyboard = NULL;
 
     tt_check(tt_lvgl_lock(1000 / portTICK_PERIOD_MS));
@@ -102,6 +100,10 @@ void gui_keyboard_hide() {
     }
 }
 
+bool gui_keyboard_is_enabled() {
+    return !tt_lvgl_keypad_is_available() || TT_CONFIG_FORCE_ONSCREEN_KEYBOARD;
+}
+
 void gui_hide_app() {
     gui_lock();
     ViewPort* view_port = gui->app_view_port;
@@ -158,6 +160,7 @@ static void gui_stop(TT_UNUSED Service service) {
     ThreadId thread_id = tt_thread_get_id(gui->thread);
     tt_thread_flags_set(thread_id, GUI_THREAD_FLAG_EXIT);
     tt_thread_join(gui->thread);
+    tt_thread_free(gui->thread);
 
     gui_unlock();
 
diff --git a/tactility/src/services/gui/gui.h b/tactility/src/services/gui/gui.h
index a3d1b2cd..f9ed7226 100644
--- a/tactility/src/services/gui/gui.h
+++ b/tactility/src/services/gui/gui.h
@@ -3,6 +3,7 @@
 #include "app.h"
 #include "service_manifest.h"
 #include "view_port.h"
+#include <stdbool.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -10,14 +11,43 @@ extern "C" {
 
 typedef struct Gui Gui;
 
+/**
+ * Set the app viewport in the gui state and request the gui to draw it.
+ *
+ * @param app
+ * @param on_show
+ * @param on_hide
+ */
 void gui_show_app(App app, ViewPortShowCallback on_show, ViewPortHideCallback on_hide);
 
+/**
+ * Hide the current app's viewport.
+ * Does not request a re-draw because after hiding the current app,
+ * we always show the previous app, and there is always at least 1 app running.
+ */
 void gui_hide_app();
 
+/**
+ * Show the on-screen keyboard.
+ * @param textarea the textarea to focus the input for
+ */
 void gui_keyboard_show(lv_obj_t* textarea);
 
+/**
+ * Hide the on-screen keyboard.
+ * Has no effect when the keyboard is not visible.
+ */
 void gui_keyboard_hide();
 
+/**
+ * This function is to facilitate hardware keyboards like the one on Lilygo T-Deck.
+ * The software keyboard is only shown when both of these conditions are true:
+ *  - there is no hardware keyboard
+ *  - TT_CONFIG_FORCE_ONSCREEN_KEYBOARD is set to true in tactility_config.h
+ * @return if we should show a keyboard for text input inside our apps
+ */
+bool gui_keyboard_is_enabled();
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/tactility/src/services/loader/loader.c b/tactility/src/services/loader/loader.c
index 9530496b..f518fe14 100644
--- a/tactility/src/services/loader/loader.c
+++ b/tactility/src/services/loader/loader.c
@@ -313,6 +313,7 @@ static void loader_stop(TT_UNUSED Service service) {
     };
     tt_message_queue_put(loader_singleton->queue, &message, TtWaitForever);
     tt_thread_join(loader_singleton->thread);
+    tt_thread_free(loader_singleton->thread);
 
     loader_free();
     loader_singleton = NULL;
diff --git a/tactility/src/tactility.c b/tactility/src/tactility.c
index 48a4e905..82367757 100644
--- a/tactility/src/tactility.c
+++ b/tactility/src/tactility.c
@@ -21,9 +21,9 @@ static void register_system_apps() {
     tt_app_manifest_registry_add(&system_info_app);
 }
 
-static void register_user_apps(const AppManifest* const apps[CONFIG_APPS_LIMIT]) {
+static void register_user_apps(const AppManifest* const apps[TT_CONFIG_APPS_LIMIT]) {
     TT_LOG_I(TAG, "Registering user apps");
-    for (size_t i = 0; i < CONFIG_APPS_LIMIT; i++) {
+    for (size_t i = 0; i < TT_CONFIG_APPS_LIMIT; i++) {
         const AppManifest* manifest = apps[i];
         if (manifest != NULL) {
             tt_app_manifest_registry_add(manifest);
@@ -46,9 +46,9 @@ static void start_system_services() {
     tt_service_registry_start(loader_service.id);
 }
 
-static void register_and_start_user_services(const ServiceManifest* const services[CONFIG_SERVICES_LIMIT]) {
+static void register_and_start_user_services(const ServiceManifest* const services[TT_CONFIG_SERVICES_LIMIT]) {
     TT_LOG_I(TAG, "Registering and starting user services");
-    for (size_t i = 0; i < CONFIG_SERVICES_LIMIT; i++) {
+    for (size_t i = 0; i < TT_CONFIG_SERVICES_LIMIT; i++) {
         const ServiceManifest* manifest = services[i];
         if (manifest != NULL) {
             tt_service_registry_add(manifest);
diff --git a/tactility/src/tactility.h b/tactility/src/tactility.h
index efd8c89b..311d08ee 100644
--- a/tactility/src/tactility.h
+++ b/tactility/src/tactility.h
@@ -3,19 +3,17 @@
 #include "app_manifest.h"
 #include "hardware_config.h"
 #include "service_manifest.h"
+#include "tactility_config.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-#define CONFIG_APPS_LIMIT 32
-#define CONFIG_SERVICES_LIMIT 32
-
 typedef struct {
     const HardwareConfig* hardware;
     // List of user applications
-    const AppManifest* const apps[CONFIG_APPS_LIMIT];
-    const ServiceManifest* const services[CONFIG_SERVICES_LIMIT];
+    const AppManifest* const apps[TT_CONFIG_APPS_LIMIT];
+    const ServiceManifest* const services[TT_CONFIG_SERVICES_LIMIT];
     const char* auto_start_app_id;
 } Config;
 
diff --git a/tactility/src/tactility_config.h b/tactility/src/tactility_config.h
new file mode 100644
index 00000000..41780321
--- /dev/null
+++ b/tactility/src/tactility_config.h
@@ -0,0 +1,6 @@
+#pragma once
+
+#define TT_CONFIG_APPS_LIMIT 32
+#define TT_CONFIG_SERVICES_LIMIT 32
+
+#define TT_CONFIG_FORCE_ONSCREEN_KEYBOARD false
\ No newline at end of file
diff --git a/tactility/src/ui/lvgl_keypad.c b/tactility/src/ui/lvgl_keypad.c
new file mode 100644
index 00000000..38d9d583
--- /dev/null
+++ b/tactility/src/ui/lvgl_keypad.c
@@ -0,0 +1,23 @@
+#include "lvgl_keypad.h"
+
+static lv_indev_t* keyboard_device = NULL;
+
+bool tt_lvgl_keypad_is_available() {
+    return keyboard_device != NULL;
+}
+
+void tt_lvgl_keypad_set_indev(lv_indev_t* device) {
+    keyboard_device = device;
+}
+
+void tt_lvgl_keypad_activate(lv_group_t* group) {
+    if (keyboard_device != NULL) {
+        lv_indev_set_group(keyboard_device, group);
+    }
+}
+
+void tt_lvgl_keypad_deactivate() {
+    if (keyboard_device != NULL) {
+        lv_indev_set_group(keyboard_device, NULL);
+    }
+}
diff --git a/tactility/src/ui/lvgl_keypad.h b/tactility/src/ui/lvgl_keypad.h
new file mode 100644
index 00000000..c531c4a4
--- /dev/null
+++ b/tactility/src/ui/lvgl_keypad.h
@@ -0,0 +1,16 @@
+#pragma once
+
+#include "lvgl.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+bool tt_lvgl_keypad_is_available();
+void tt_lvgl_keypad_set_indev(lv_indev_t* device);
+void tt_lvgl_keypad_activate(lv_group_t* group);
+void tt_lvgl_keypad_deactivate();
+
+#ifdef __cplusplus
+}
+#endif
\ No newline at end of file