Papers3 improvements (#611)

- And Tab5 keyboard improvements
- Usb host keyboard improvements
- Symbols
- Requires the device.py change from CL-32 PR but that only affects visuals and not build breaking

TactilityKernel/include/tactility/drivers/display.h

@@ -23,7 +23,13 @@ enum DisplayCapability {
     DISPLAY_CAPABILITY_SLEEP = 1 << 6,
     DISPLAY_CAPABILITY_REQUIRES_FULL_FRAME = 1 << 7,
     /** Can be used by e-paper with pointer devices for long click timing changes. */
-    DISPLAY_CAPABILITY_SLOW_REFRESH = 1 << 8
+    DISPLAY_CAPABILITY_SLOW_REFRESH = 1 << 8,
+    /**
+     * Promise that draw_bitmap() never DMAs directly from the color_data pointer it's given (e.g.
+     * it copies/converts into its own buffer first). Lets the LVGL bridge allocate this display's
+     * draw buffer(s) from non-DMA-capable memory instead of forcing scarce internal RAM.
+     */
+    DISPLAY_CAPABILITY_PREFER_EXTERNAL_RAM = 1 << 9
 };
 
 /**
@@ -36,6 +42,11 @@ enum DisplayColorFormat {
     DISPLAY_COLOR_FORMAT_RGB565 = 0x3,
     DISPLAY_COLOR_FORMAT_RGB565_SWAPPED = 0x4,
     DISPLAY_COLOR_FORMAT_RGB888 = 0x5,
+    // 8 bpp luminance, 0x00 = black, 0xFF = white (matches LVGL's LV_COLOR_FORMAT_L8). Unlike
+    // MONOCHROME, the LVGL bridge does not force full-frame rendering for this format, so drivers
+    // that want real partial/tile updates (e.g. grayscale e-paper panels) should report this
+    // instead of MONOCHROME even if they intend to threshold down to black/white themselves.
+    DISPLAY_COLOR_FORMAT_GRAYSCALE8 = 0x6,
 };
 
 /**

TactilityKernel/include/tactility/drivers/keyboard.h

@@ -24,6 +24,25 @@ struct KeyboardKeyData {
      * immediately to drain it. False if this was the last pending event.
      */
     bool continue_reading;
+    /**
+     * @brief True if Ctrl was held when this key was pressed.
+     *
+     * Reported separately rather than folded into `key` because the two encodings collide: the C0
+     * control codes a terminal expects for Ctrl chords (Ctrl+C is 0x03, Ctrl+K is 0x0B, ...) overlap
+     * the LVGL key constants drivers emit in the same field (LV_KEY_END is 3, LV_KEY_PREV is 11,
+     * LV_KEY_UP is 17, ...), so a single uint32_t cannot express both. Consumers that want control
+     * codes derive them here, e.g.
+     * `((key >= 'a' && key <= 'z') || (key >= 'A' && key <= 'Z')) ? (key & 0x1F) : key`
+     * when ctrl is set.
+     *
+     * Drivers whose hardware cannot report Ctrl leave this false.
+     */
+    bool ctrl;
+    /**
+     * @brief True if Alt was held when this key was pressed. See ctrl for why modifiers are reported
+     * separately. Drivers whose hardware cannot report Alt leave this false.
+     */
+    bool alt;
 };
 
 /**

TactilityKernel/include/tactility/drivers/usb_host_hid.h

@@ -43,7 +43,18 @@ typedef enum {
 typedef struct {
     UsbHidEventType type;
     union {
-        struct { uint32_t key_code; bool pressed; } key;
+        /**
+         * @brief A key press or release.
+         *
+         * `ctrl` and `alt` report the modifiers separately rather than folding them into
+         * `key_code`, because the two encodings collide: the C0 control codes a terminal expects
+         * for Ctrl chords (Ctrl+C is 0x03, Ctrl+K is 0x0B) overlap the UsbHidKey constants above
+         * (USB_HID_KEY_END is 3, USB_HID_KEY_PREV is 11). A consumer wanting control codes derives
+         * them here, e.g.
+         * `((key_code >= 'a' && key_code <= 'z') || (key_code >= 'A' && key_code <= 'Z')) ?
+         * (key_code & 0x1F) : key_code`.
+         */
+        struct { uint32_t key_code; bool pressed; bool ctrl; bool alt; } key;
         struct { int32_t dx; int32_t dy; }         mouse_move;
         struct { bool button1; bool button2; }     mouse_btn;
         struct { int32_t delta; }                  scroll;

TactilityKernel/source/drivers/keyboard.cpp

@@ -9,6 +9,12 @@ extern "C" {
 
 error_t keyboard_read_key(Device* device, KeyboardKeyData* data) {
     const auto* driver = device_get_driver(device);
+
+    // Default the modifier fields here rather than in each driver: only drivers whose hardware can
+    // report modifiers set them, and the rest would otherwise leave whatever the caller's stack held.
+    data->ctrl = false;
+    data->alt = false;
+
     return KEYBOARD_DRIVER_API(driver)->read_key(device, data);
 }
 

TactilityKernel/source/symbols.c

@@ -171,6 +171,7 @@ const struct ModuleSymbol KERNEL_SYMBOLS[] = {
     DEFINE_MODULE_SYMBOL(file_system_unmount),
     DEFINE_MODULE_SYMBOL(file_system_is_mounted),
     DEFINE_MODULE_SYMBOL(file_system_get_path),
+    DEFINE_MODULE_SYMBOL(file_system_for_each),
     // memory
     DEFINE_MODULE_SYMBOL(MEMORY_POLICY_DEFAULT),
     DEFINE_MODULE_SYMBOL(memory_print_stats),