video: xilinxfb: Add support for little endian accesses

Dynamically detect endianess on IP and use
ioread/iowrite functions instead of powerpc and microblaze
specific out_be32.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

1 files changed, 28 insertions, 2 deletions

diff --git a/drivers/video/xilinxfb.c b/drivers/video/xilinxfb.c
index bd3b85d890d4..f3d4a69e1e4e 100644
--- a/drivers/video/xilinxfb.c
+++ b/drivers/video/xilinxfb.c
@@ -117,6 +117,7 @@ static struct fb_var_screeninfo xilinx_fb_var = {
 
 
 #define BUS_ACCESS_FLAG         0x1 /* 1 = BUS, 0 = DCR */
+#define LITTLE_ENDIAN_ACCESS    0x2 /* LITTLE ENDIAN IO functions */
 
 struct xilinxfb_drvdata {
 
@@ -153,14 +154,33 @@ struct xilinxfb_drvdata {
 static void xilinx_fb_out32(struct xilinxfb_drvdata *drvdata, u32 offset,
                                 u32 val)
 {
-        if (drvdata->flags & BUS_ACCESS_FLAG)
-                out_be32(drvdata->regs + (offset << 2), val);
+        if (drvdata->flags & BUS_ACCESS_FLAG) {
+                if (drvdata->flags & LITTLE_ENDIAN_ACCESS)
+                        iowrite32(val, drvdata->regs + (offset << 2));
+                else
+                        iowrite32be(val, drvdata->regs + (offset << 2));
+        }
 #ifdef CONFIG_PPC_DCR
         else
                 dcr_write(drvdata->dcr_host, offset, val);
 #endif
 }
 
+static u32 xilinx_fb_in32(struct xilinxfb_drvdata *drvdata, u32 offset)
+{
+        if (drvdata->flags & BUS_ACCESS_FLAG) {
+                if (drvdata->flags & LITTLE_ENDIAN_ACCESS)
+                        return ioread32(drvdata->regs + (offset << 2));
+                else
+                        return ioread32be(drvdata->regs + (offset << 2));
+        }
+#ifdef CONFIG_PPC_DCR
+        else
+                return dcr_read(drvdata->dcr_host, offset);
+#endif
+        return 0;
+}
+
 static int
 xilinx_fb_setcolreg(unsigned regno, unsigned red, unsigned green, unsigned blue,
         unsigned transp, struct fb_info *fbi)
@@ -271,6 +291,12 @@ static int xilinxfb_assign(struct platform_device *pdev,
 
         /* Tell the hardware where the frame buffer is */
         xilinx_fb_out32(drvdata, REG_FB_ADDR, drvdata->fb_phys);
+        rc = xilinx_fb_in32(drvdata, REG_FB_ADDR);
+        /* Endianess detection */
+        if (rc != drvdata->fb_phys) {
+                drvdata->flags |= LITTLE_ENDIAN_ACCESS;
+                xilinx_fb_out32(drvdata, REG_FB_ADDR, drvdata->fb_phys);
+        }
 
         /* Turn on the display */
         drvdata->reg_ctrl_default = REG_CTRL_ENABLE;