Add support for 15Khz resolutions

src/geometry.c

@@ -977,17 +977,17 @@ int get_hdisplay() {
     int h_size = (*PIXELVALVE2_HORZB) & 0xFFFF;
 #endif
     int v_size = (*PIXELVALVE2_VERTB) & 0xFFFF;
-    if (h_size < 640 || h_size > 8192 || v_size < 480 || v_size > 4096) {
-          log_info("HDMI readback of screen size invalid (%dx%d) - rebooting", h_size, v_size);
-          delay_in_arm_cycles_cpu_adjust(1000000000);
-          reboot();
-    }
+//    if (h_size < 640 || h_size > 8192 || v_size < 200 || v_size > 4096) {
+//          log_info("HDMI readback of screen size invalid (%dx%d) - rebooting", h_size, v_size);
+//          delay_in_arm_cycles_cpu_adjust(1000000000);
+//          reboot();
+//    }
     //workaround for 640x480 and 800x480 @50Hz using double rate clock so width gets doubled
     if (v_size == 480 && h_size == 1280) {
         h_size = 640;
     } else if (v_size == 480 && h_size == 1600) {
         h_size = 800;
-    } else if (v_size == 240 || v_size == 288) {
+    } else if (v_size <= 288) {
         h_size >>= 1;
     }
     return h_size;
@@ -997,6 +997,8 @@ int get_vdisplay() {
     int v_size = (*PIXELVALVE2_VERTB) & 0xFFFF;
     if (v_size == 2160 && get_hdisplay() == 1920){
         v_size = 1080;
+    } else if (v_size <= 288) {
+        v_size <<= 1;
     }
     return v_size;
 }

src/osd.c

@@ -7143,7 +7143,7 @@ void osd_init() {
        log_info("***EDID checksum FAIL! ...rebooting");
        delay_in_arm_cycles_cpu_adjust(200000000);
        reboot();
-       }
+    }
 
    int valid_edid = 1;
    if (strcmp(EDID_name, "MZ0404") == 0) {
@@ -7307,6 +7307,14 @@ void osd_init() {
    int auto_detected = 0;
    if (strcmp(prop, DEFAULT_RESOLUTION) == 0)
    {
+        //if auto detected then check vertical resolution and reboot if 240 or 288
+        //int v_size = (*PIXELVALVE2_VERTB) & 0xFFFF;
+        //if (v_size == 240 || v_size == 288) {
+        //      log_info("Resolution = Auto and no HDMI connected (V=%d) - rebooting", v_size);
+        //      delay_in_arm_cycles_cpu_adjust(1000000000);
+        //      reboot();
+        //}
+
        auto_detected = 1;
        if (get_parameter(F_REFRESH) == REFRESH_50) {
            force_genlock_range = REFRESH_50_60;

src/rgb_to_hdmi.c

@@ -498,7 +498,7 @@ int height = 0;
       width = mp->data.buffer_32[0];
       height = mp->data.buffer_32[1];
       if (width != adjusted_width || height != adjusted_height) {
-          log_info("Invalid frame buffer dimensions - maybe HDMI not connected - rebooting");
+          log_info("Invalid frame buffer dimensions %d/%d, %d/%d - maybe HDMI not connected - rebooting", width, adjusted_width, height, adjusted_height);
           delay_in_arm_cycles_cpu_adjust(1000000000);
           reboot();
       }
@@ -1674,7 +1674,6 @@ static void init_hardware() {
    _init_cycle_counter();
    RPI_SetGpioPinFunction(MODE7_PIN,    FS_OUTPUT);
    RPI_SetGpioValue(MODE7_PIN,          1);
-   get_hdisplay(); //forces a reboot if no hdmi connector fitted
 
 #ifdef RPI4
    *EMMC_LEGACY = *EMMC_LEGACY | 2;  //bit enables legacy SD controller