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>

1 files changed, 33 insertions, 16 deletions

diff --git a/drivers/video/via/accel.c b/drivers/video/via/accel.c
index d5077dfa9e00..a52147cf7f09 100644
--- 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;