edid: move timing generation into a separate function

The timing generation is currently performed inside the function that
fills in the DTD. The DisplayID generation needs it as well, so moving
it out to a separate function.

Based-on: <20210303152948.59943-2-akihiko.odaki@gmail.com>
Signed-off-by: Konstantin Nazarov <mail@knazarov.com>
Message-Id: <20210315114639.91953-1-mail@knazarov.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 20210427150824.638359-1-kraxel@redhat.com
Message-Id: <20210427150824.638359-7-kraxel@redhat.com>

hw/display/edid-generate.c

@@ -45,6 +45,35 @@ static const struct edid_mode {
     { .xres =  640,   .yres =  480,   .byte  = 35,   .bit = 5 },
 };
 
+typedef struct Timings {
+    uint32_t xfront;
+    uint32_t xsync;
+    uint32_t xblank;
+
+    uint32_t yfront;
+    uint32_t ysync;
+    uint32_t yblank;
+
+    uint64_t clock;
+} Timings;
+
+static void generate_timings(Timings *timings, uint32_t refresh_rate,
+                             uint32_t xres, uint32_t yres)
+{
+    /* pull some realistic looking timings out of thin air */
+    timings->xfront = xres * 25 / 100;
+    timings->xsync  = xres *  3 / 100;
+    timings->xblank = xres * 35 / 100;
+
+    timings->yfront = yres *  5 / 1000;
+    timings->ysync  = yres *  5 / 1000;
+    timings->yblank = yres * 35 / 1000;
+
+    timings->clock  = ((uint64_t)refresh_rate *
+                       (xres + timings->xblank) *
+                       (yres + timings->yblank)) / 10000000;
+}
+
 static void edid_ext_dta(uint8_t *dta)
 {
     dta[0] = 0x02;
@@ -227,38 +256,29 @@ static void edid_desc_timing(uint8_t *desc, uint32_t refresh_rate,
                              uint32_t xres, uint32_t yres,
                              uint32_t xmm, uint32_t ymm)
 {
-    /* pull some realistic looking timings out of thin air */
-    uint32_t xfront = xres * 25 / 100;
-    uint32_t xsync  = xres *  3 / 100;
-    uint32_t xblank = xres * 35 / 100;
-
-    uint32_t yfront = yres *  5 / 1000;
-    uint32_t ysync  = yres *  5 / 1000;
-    uint32_t yblank = yres * 35 / 1000;
-
-    uint64_t clock  = (uint64_t)refresh_rate * (xres + xblank) * (yres + yblank);
-
-    stl_le_p(desc, clock / 10000000);
+    Timings timings;
+    generate_timings(&timings, refresh_rate, xres, yres);
+    stl_le_p(desc, timings.clock);
 
     desc[2] = xres   & 0xff;
-    desc[3] = xblank & 0xff;
+    desc[3] = timings.xblank & 0xff;
     desc[4] = (((xres   & 0xf00) >> 4) |
-               ((xblank & 0xf00) >> 8));
+               ((timings.xblank & 0xf00) >> 8));
 
     desc[5] = yres   & 0xff;
-    desc[6] = yblank & 0xff;
+    desc[6] = timings.yblank & 0xff;
     desc[7] = (((yres   & 0xf00) >> 4) |
-               ((yblank & 0xf00) >> 8));
+               ((timings.yblank & 0xf00) >> 8));
 
-    desc[8] = xfront & 0xff;
-    desc[9] = xsync  & 0xff;
+    desc[8] = timings.xfront & 0xff;
+    desc[9] = timings.xsync  & 0xff;
 
-    desc[10] = (((yfront & 0x00f) << 4) |
-                ((ysync  & 0x00f) << 0));
-    desc[11] = (((xfront & 0x300) >> 2) |
-                ((xsync  & 0x300) >> 4) |
-                ((yfront & 0x030) >> 2) |
-                ((ysync  & 0x030) >> 4));
+    desc[10] = (((timings.yfront & 0x00f) << 4) |
+                ((timings.ysync  & 0x00f) << 0));
+    desc[11] = (((timings.xfront & 0x300) >> 2) |
+                ((timings.xsync  & 0x300) >> 4) |
+                ((timings.yfront & 0x030) >> 2) |
+                ((timings.ysync  & 0x030) >> 4));
 
     desc[12] = xmm & 0xff;
     desc[13] = ymm & 0xff;