feat(xteink): expose the panel frame generation over QOM

The wasm front end already tracked panel refreshes; make the counter
unconditional and alias it onto the machine so native front ends can
redraw on refresh instead of on a timer.

hw/display/xteink_x3_eink.c

@@ -11,11 +11,21 @@
 #include "hw/irq.h"
 #include "hw/display/xteink_x3_eink.h"
 
+/* Frame Counter - Both the wasm front end and the QMP web UI poll this to redraw only on a real
+ * panel refresh. Only one panel is instantiated per machine, so a single counter suffices. */
+static uint32_t xteink_frame_generation;
+
+static void xteink_frame_generation_init(Object *obj)
+{
+    object_property_add_uint32_ptr(obj, "frame-generation",
+                                   &xteink_frame_generation,
+                                   OBJ_PROP_FLAG_READ);
+}
+
 #ifdef __EMSCRIPTEN__
 #include <emscripten/emscripten.h>
 
 static QemuConsole *xteink_wasm_console;
-static uint32_t xteink_wasm_generation;
 
 EMSCRIPTEN_KEEPALIVE uintptr_t xteink_wasm_framebuffer(void)
 {
@@ -51,17 +61,18 @@ EMSCRIPTEN_KEEPALIVE int xteink_wasm_stride(void)
 
 EMSCRIPTEN_KEEPALIVE uint32_t xteink_wasm_frame_generation(void)
 {
-    return qatomic_read(&xteink_wasm_generation);
+    return qatomic_read(&xteink_frame_generation);
 }
 
-static void xteink_wasm_frame_updated(QemuConsole *console)
+static void xteink_frame_updated(QemuConsole *console)
 {
     xteink_wasm_console = console;
-    qatomic_inc(&xteink_wasm_generation);
+    qatomic_inc(&xteink_frame_generation);
 }
 #else
-static void xteink_wasm_frame_updated(QemuConsole *console)
+static void xteink_frame_updated(QemuConsole *console)
 {
+    qatomic_inc(&xteink_frame_generation);
 }
 #endif
 
@@ -73,7 +84,8 @@ static void xteink_wasm_frame_updated(QemuConsole *console)
 #define CMD_LUT_FIRST 0x20
 #define CMD_LUT_LAST 0x24
 
-#define BUSY_TIME_NS (5 * SCALE_MS)
+/* Mirror a real panel refresh (~1 s): shorter pulses let the completion edge pass before the firmware arms its ISR, costing a 30 s timeout. */
+#define BUSY_TIME_NS (1000 * SCALE_MS)
 
 #define XTEINK_X3_LUT_PREFIX_SIZE 13
 
@@ -220,7 +232,7 @@ static void xteink_x3_eink_render(XteinkX3EinkState *s)
         }
     }
 
-    xteink_wasm_frame_updated(s->console);
+    xteink_frame_updated(s->console);
     dpy_gfx_update(s->console, 0, 0, XTEINK_X3_HEIGHT, XTEINK_X3_WIDTH);
 }
 
@@ -326,6 +338,7 @@ static void xteink_x3_eink_init(Object *obj)
 {
     XteinkX3EinkState *s = XTEINK_X3_EINK(obj);
 
+    xteink_frame_generation_init(obj);
     s->console = graphic_console_init(DEVICE(s), 0,
                                       &xteink_x3_eink_graphics_ops, s);
     dpy_gfx_replace_surface(s->console,
@@ -378,7 +391,7 @@ static void xteink_x4_eink_render(XteinkX4EinkState *s)
     DisplaySurface *surface = qemu_console_surface(s->console);
     memset(surface_data(surface), 0xff,
            surface_stride(surface) * surface_height(surface));
-    xteink_wasm_frame_updated(s->console);
+    xteink_frame_updated(s->console);
     dpy_gfx_update(s->console, 0, 0, 480, 800);
 }
 
@@ -412,6 +425,7 @@ static void xteink_x4_eink_init(Object *obj)
 {
     XteinkX4EinkState *s = XTEINK_X4_EINK(obj);
 
+    xteink_frame_generation_init(obj);
     s->console = graphic_console_init(DEVICE(s), 0,
                                       &xteink_x4_eink_graphics_ops, s);
     dpy_gfx_replace_surface(s->console, qemu_create_displaysurface(480, 800));

hw/riscv/esp32c3.c

@@ -868,6 +868,8 @@ static void xteink_machine_init(MachineState *machine)
     DeviceState *panel = ssi_create_peripheral(ms->spi2.bus,
         ms->x4 ? TYPE_XTEINK_X4_EINK : TYPE_XTEINK_X3_EINK);
     qemu_input_handler_register(panel, &xteink_key_handler);
+    object_property_add_alias(OBJECT(machine), "frame-generation",
+                              OBJECT(panel), "frame-generation");
     qdev_connect_gpio_out_named(DEVICE(&ms->gpio), ESP32_GPIO_OUTPUT, 21,
         qdev_get_gpio_in_named(panel, SSI_GPIO_CS, 0));
     qdev_connect_gpio_out_named(DEVICE(&ms->gpio), ESP32_GPIO_OUTPUT, 4,