From 4b4a8a35f3f90f1af75cdf5d9c26b47d4b8dcabb Mon Sep 17 00:00:00 2001
From: Pete Johanson <peter@peterjohanson.com>
Date: Fri, 7 Feb 2025 00:05:21 -0700
Subject: [PATCH] fix(display): POSIX lvgl fixes (#2812)

fix(display): Do LVGL task processing in main on POSIX.

An SDL/Zephyr bug prevents proper display when SDL calls are
made from anything but the main thread, so add task handling
in our simple main function when on POSIX.

fix(usb): Compilation fix for 64-bit targets

Properly handle differences in the size of `size_t` on 64-bit
architectures.

fix(display): Imply, but don't force, LVGL mono theme

Some targets may be using color displays, so instead of forcing
on the mono theme, merely imply it to default it
---
 app/src/display/Kconfig |  2 +-
 app/src/display/main.c  |  8 ++++++++
 app/src/main.c          | 15 +++++++++++++++
 app/src/usb_hid.c       |  4 +++-
 4 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/app/src/display/Kconfig b/app/src/display/Kconfig
index 14a380b92..64e12b73e 100644
--- a/app/src/display/Kconfig
+++ b/app/src/display/Kconfig
@@ -5,7 +5,7 @@ menuconfig ZMK_DISPLAY
     bool "Enable ZMK Display"
     select DISPLAY
     select LVGL
-    select LV_CONF_MINIMAL
+    imply LV_CONF_MINIMAL
 
 if ZMK_DISPLAY
 
diff --git a/app/src/display/main.c b/app/src/display/main.c
index e15e2de0c..361f1fcaf 100644
--- a/app/src/display/main.c
+++ b/app/src/display/main.c
@@ -56,13 +56,17 @@ K_TIMER_DEFINE(display_timer, display_timer_cb, NULL);
 
 void unblank_display_cb(struct k_work *work) {
     display_blanking_off(display);
+#if !IS_ENABLED(CONFIG_ARCH_POSIX)
     k_timer_start(&display_timer, K_MSEC(TICK_MS), K_MSEC(TICK_MS));
+#endif // !IS_ENABLED(CONFIG_ARCH_POSIX)
 }
 
 #if IS_ENABLED(CONFIG_ZMK_DISPLAY_BLANK_ON_IDLE)
 
 void blank_display_cb(struct k_work *work) {
+#if !IS_ENABLED(CONFIG_ARCH_POSIX)
     k_timer_stop(&display_timer);
+#endif // !IS_ENABLED(CONFIG_ARCH_POSIX)
     display_blanking_on(display);
 }
 K_WORK_DEFINE(blank_display_work, blank_display_cb);
@@ -132,7 +136,11 @@ int zmk_display_init() {
                        CONFIG_ZMK_DISPLAY_DEDICATED_THREAD_PRIORITY, NULL);
 #endif
 
+#if IS_ENABLED(CONFIG_ARCH_POSIX)
+    initialize_display(NULL);
+#else
     k_work_submit_to_queue(zmk_display_work_q(), &init_work);
+#endif
 
     LOG_DBG("");
     return 0;
diff --git a/app/src/main.c b/app/src/main.c
index 60df1a45d..0f77382ad 100644
--- a/app/src/main.c
+++ b/app/src/main.c
@@ -12,7 +12,12 @@
 #include <zephyr/logging/log.h>
 LOG_MODULE_REGISTER(zmk, CONFIG_ZMK_LOG_LEVEL);
 
+#if IS_ENABLED(CONFIG_ZMK_DISPLAY)
+
 #include <zmk/display.h>
+#include <lvgl.h>
+
+#endif
 
 int main(void) {
     LOG_INF("Welcome to ZMK!\n");
@@ -24,6 +29,16 @@ int main(void) {
 
 #ifdef CONFIG_ZMK_DISPLAY
     zmk_display_init();
+
+#if IS_ENABLED(CONFIG_ARCH_POSIX)
+    // Workaround for an SDL display issue:
+    // https://github.com/zephyrproject-rtos/zephyr/issues/71410
+    while (1) {
+        lv_task_handler();
+        k_sleep(K_MSEC(10));
+    }
+#endif
+
 #endif /* CONFIG_ZMK_DISPLAY */
 
     return 0;
diff --git a/app/src/usb_hid.c b/app/src/usb_hid.c
index 945ae9890..9adc7db80 100644
--- a/app/src/usb_hid.c
+++ b/app/src/usb_hid.c
@@ -89,7 +89,9 @@ static int get_report_cb(const struct device *dev, struct usb_setup_packet *setu
     case HID_REPORT_TYPE_INPUT:
         switch (setup->wValue & HID_GET_REPORT_ID_MASK) {
         case ZMK_HID_REPORT_ID_KEYBOARD: {
-            *data = get_keyboard_report(len);
+            size_t size;
+            *data = get_keyboard_report(&size);
+            *len = (int32_t)size;
             break;
         }
         case ZMK_HID_REPORT_ID_CONSUMER: {