viafb: complete support for VX800/VX855 accelerated framebuffer

This patch is a painful merge of change
a90bab567ece3e915d0ccd55ab00c9bb333fa8c0 (viafb: Add support for 2D
accelerated framebuffer on VX800/VX855) in the OLPC tree, originally by
Harald Welte.  Harald's changelog read:

	The VX800/VX820 and the VX855/VX875 chipsets have a different 2D
    	acceleration engine called "M1".  The M1 engine has some subtle
    	(and some not-so-subtle) differences to the previous engines, so
    	support for accelerated framebuffer on those chipsets was disabled
    	so far.

This merge tries to preserve Harald's changes in the framework of the
much-changed 2.6.34 viafb code.

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, 9 deletions

diff --git a/drivers/video/via/accel.c b/drivers/video/via/accel.c
index 7c1d9c41623..0d90c859cc1 100644
--- a/drivers/video/via/accel.c
+++ b/drivers/video/via/accel.c
@@ -317,6 +317,7 @@ int viafb_init_engine(struct fb_info *info)
 {
         struct viafb_par *viapar = info->par;
         void __iomem *engine;
+        int highest_reg, i;
         u32 vq_start_addr, vq_end_addr, vq_start_low, vq_end_low, vq_high,
                 vq_len, chip_name = viapar->shared->chip_info.gfx_chip_name;
 
@@ -328,6 +329,18 @@ int viafb_init_engine(struct fb_info *info)
                 return -ENOMEM;
         }
 
+        /* Initialize registers to reset the 2D engine */
+        switch (viapar->shared->chip_info.twod_engine) {
+        case VIA_2D_ENG_M1:
+                highest_reg = 0x5c;
+                break;
+        default:
+                highest_reg = 0x40;
+                break;
+        }
+        for (i = 0; i <= highest_reg; i += 4)
+                writel(0x0, engine + i);
+
         switch (chip_name) {
         case UNICHROME_CLE266:
         case UNICHROME_K400:
@@ -357,13 +370,12 @@ int viafb_init_engine(struct fb_info *info)
         viapar->shared->vq_vram_addr = viapar->fbmem_free;
         viapar->fbmem_used += VQ_SIZE;
 
-        /* Init 2D engine reg to reset 2D engine */
-        writel(0x0, engine + VIA_REG_KEYCONTROL);
-
         /* Init AGP and VQ regs */
         switch (chip_name) {
         case UNICHROME_K8M890:
         case UNICHROME_P4M900:
+        case UNICHROME_VX800:
+        case UNICHROME_VX855:
                 writel(0x00100000, engine + VIA_REG_CR_TRANSET);
                 writel(0x680A0000, engine + VIA_REG_CR_TRANSPACE);
                 writel(0x02000000, engine + VIA_REG_CR_TRANSPACE);
@@ -398,6 +410,8 @@ int viafb_init_engine(struct fb_info *info)
         switch (chip_name) {
         case UNICHROME_K8M890:
         case UNICHROME_P4M900:
+        case UNICHROME_VX800:
+        case UNICHROME_VX855:
                 vq_start_low |= 0x20000000;
                 vq_end_low |= 0x20000000;
                 vq_high |= 0x20000000;
@@ -475,15 +489,25 @@ void viafb_wait_engine_idle(struct fb_info *info)
 {
         struct viafb_par *viapar = info->par;
         int loop = 0;
+        u32 mask;
 
-        while (!(readl(viapar->shared->engine_mmio + VIA_REG_STATUS) &
-                        VIA_VR_QUEUE_BUSY) && (loop < MAXLOOP)) {
-                loop++;
-                cpu_relax();
+        switch (viapar->shared->chip_info.twod_engine) {
+        case VIA_2D_ENG_H5:
+        case VIA_2D_ENG_M1:
+                mask = VIA_CMD_RGTR_BUSY_M1 | VIA_2D_ENG_BUSY_M1 |
+                              VIA_3D_ENG_BUSY_M1;
+                break;
+        default:
+                while (!(readl(viapar->shared->engine_mmio + VIA_REG_STATUS) &
+                                VIA_VR_QUEUE_BUSY) && (loop < MAXLOOP)) {
+                        loop++;
+                        cpu_relax();
+                }
+                mask = VIA_CMD_RGTR_BUSY | VIA_2D_ENG_BUSY | VIA_3D_ENG_BUSY;
+                break;
         }
 
-        while ((readl(viapar->shared->engine_mmio + VIA_REG_STATUS) &
-                    (VIA_CMD_RGTR_BUSY | VIA_2D_ENG_BUSY | VIA_3D_ENG_BUSY)) &&
+        while ((readl(viapar->shared->engine_mmio + VIA_REG_STATUS) & mask) &&
                     (loop < MAXLOOP)) {
                 loop++;
                 cpu_relax();