ati-vga: Add 30 bit palette access register

Radeon cards have a 30 bit DAC and corresponding palette register to
access it. We only use 8 bits but let the guests use 10 bit color
values for those that access it through this register.

Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-ID: <9fa19eec95d1563cc65853cf26912f230c702b32.1698871239.git.balaton@eik.bme.hu>

hw/display/ati.c

@@ -339,6 +339,9 @@ static uint64_t ati_mm_read(void *opaque, hwaddr addr, unsigned int size)
     case PALETTE_DATA:
         val = vga_ioport_read(&s->vga, VGA_PEL_D);
         break;
+    case PALETTE_30_DATA:
+        val = s->regs.palette[vga_ioport_read(&s->vga, VGA_PEL_IR)];
+        break;
     case CNFG_CNTL:
         val = s->regs.config_cntl;
         break;
@@ -673,6 +676,12 @@ static void ati_mm_write(void *opaque, hwaddr addr,
         data >>= 8;
         vga_ioport_write(&s->vga, VGA_PEL_D, data & 0xff);
         break;
+    case PALETTE_30_DATA:
+        s->regs.palette[vga_ioport_read(&s->vga, VGA_PEL_IW)] = data;
+        vga_ioport_write(&s->vga, VGA_PEL_D, (data >> 22) & 0xff);
+        vga_ioport_write(&s->vga, VGA_PEL_D, (data >> 12) & 0xff);
+        vga_ioport_write(&s->vga, VGA_PEL_D, (data >> 2) & 0xff);
+        break;
     case CNFG_CNTL:
         s->regs.config_cntl = data;
         break;

hw/display/ati_dbg.c

@@ -30,6 +30,7 @@ static struct ati_regdesc ati_reg_names[] = {
     {"AMCGPIO_EN_MIR", 0x00a8},
     {"PALETTE_INDEX", 0x00b0},
     {"PALETTE_DATA", 0x00b4},
+    {"PALETTE_30_DATA", 0x00b8},
     {"CNFG_CNTL", 0x00e0},
     {"GEN_RESET_CNTL", 0x00f0},
     {"CNFG_MEMSIZE", 0x00f8},

hw/display/ati_int.h

@@ -44,6 +44,7 @@ typedef struct ATIVGARegs {
     uint32_t gpio_dvi_ddc;
     uint32_t gpio_monid;
     uint32_t config_cntl;
+    uint32_t palette[256];
     uint32_t crtc_h_total_disp;
     uint32_t crtc_h_sync_strt_wid;
     uint32_t crtc_v_total_disp;

hw/display/ati_regs.h

@@ -48,6 +48,7 @@
 #define AMCGPIO_EN_MIR                          0x00a8
 #define PALETTE_INDEX                           0x00b0
 #define PALETTE_DATA                            0x00b4
+#define PALETTE_30_DATA                         0x00b8
 #define CNFG_CNTL                               0x00e0
 #define GEN_RESET_CNTL                          0x00f0
 #define CNFG_MEMSIZE                            0x00f8