viafb: Retain GEMODE reserved bits

Commit c3e25673843153ea75fda79a47cf12f10a25ca37 (viafb: 2D engine rewrite)
changed the setting of the GEMODE register so that the reserved bits are no
longer preserved.  Fix that; at the same time, move this code to its own
function and restore the use of symbolic constants.

Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: ScottFang@viatech.com.cn
Cc: JosephChan@via.com.tw
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

diff --git a/drivers/video/via/accel.c b/drivers/video/via/accel.c
index d5077df..a52147c 100644 (file)
--- a/drivers/video/via/accel.c
+++ b/drivers/video/via/accel.c
@@ -165,12 +165,42 @@ static int hw_bitblt_1(void __iomem *engine, u8 op, u32 width, u32 height,
        return 0;
 }
 
+/*
+ * Figure out an appropriate bytes-per-pixel setting.
+ */
+static int viafb_set_bpp(void __iomem *engine, u8 bpp)
+{
+       u32 gemode;
+
+       /* Preserve the reserved bits */
+       /* Lowest 2 bits to zero gives us no rotation */
+       gemode = readl(engine + VIA_REG_GEMODE) & 0xfffffcfc;
+       switch (bpp) {
+       case 8:
+               gemode |= VIA_GEM_8bpp;
+               break;
+       case 16:
+               gemode |= VIA_GEM_16bpp;
+               break;
+       case 32:
+               gemode |= VIA_GEM_32bpp;
+               break;
+       default:
+               printk(KERN_WARNING "hw_bitblt_2: Unsupported bpp %d\n", bpp);
+               return -EINVAL;
+       }
+       writel(gemode, engine + VIA_REG_GEMODE);
+       return 0;
+}
+
+
 static int hw_bitblt_2(void __iomem *engine, u8 op, u32 width, u32 height,
        u8 dst_bpp, u32 dst_addr, u32 dst_pitch, u32 dst_x, u32 dst_y,
        u32 *src_mem, u32 src_addr, u32 src_pitch, u32 src_x, u32 src_y,
        u32 fg_color, u32 bg_color, u8 fill_rop)
 {
        u32 ge_cmd = 0, tmp, i;
+       int ret;
 
        if (!op || op > 3) {
                printk(KERN_WARNING "hw_bitblt_2: Invalid operation: %d\n", op);
@@ -204,22 +234,9 @@ static int hw_bitblt_2(void __iomem *engine, u8 op, u32 width, u32 height,
                }
        }
 
-       switch (dst_bpp) {
-       case 8:
-               tmp = 0x00000000;
-               break;
-       case 16:
-               tmp = 0x00000100;
-               break;
-       case 32:
-               tmp = 0x00000300;
-               break;
-       default:
-               printk(KERN_WARNING "hw_bitblt_2: Unsupported bpp %d\n",
-                       dst_bpp);
-               return -EINVAL;
-       }
-       writel(tmp, engine + 0x04);
+       ret = viafb_set_bpp(engine, dst_bpp);
+       if (ret)
+               return ret;
 
        if (op == VIA_BITBLT_FILL)
                tmp = 0;