drm: mxsfb: fix pixel clock polarity
[linux-2.6-microblaze.git] / drivers / gpu / drm / mxsfb / mxsfb_crtc.c
index 259f71b..165abd2 100644 (file)
@@ -196,9 +196,16 @@ static void mxsfb_crtc_mode_set_nofb(struct mxsfb_drm_private *mxsfb)
                vdctrl0 |= VDCTRL0_HSYNC_ACT_HIGH;
        if (m->flags & DRM_MODE_FLAG_PVSYNC)
                vdctrl0 |= VDCTRL0_VSYNC_ACT_HIGH;
-       if (bus_flags & DRM_BUS_FLAG_DE_HIGH)
+       /* Make sure Data Enable is high active by default */
+       if (!(bus_flags & DRM_BUS_FLAG_DE_LOW))
                vdctrl0 |= VDCTRL0_ENABLE_ACT_HIGH;
-       if (bus_flags & DRM_BUS_FLAG_PIXDATA_NEGEDGE)
+       /*
+        * DRM_BUS_FLAG_PIXDATA_ defines are controller centric,
+        * controllers VDCTRL0_DOTCLK is display centric.
+        * Drive on positive edge       -> display samples on falling edge
+        * DRM_BUS_FLAG_PIXDATA_POSEDGE -> VDCTRL0_DOTCLK_ACT_FALLING
+        */
+       if (bus_flags & DRM_BUS_FLAG_PIXDATA_POSEDGE)
                vdctrl0 |= VDCTRL0_DOTCLK_ACT_FALLING;
 
        writel(vdctrl0, mxsfb->base + LCDC_VDCTRL0);