[PATCH] gxfb: Fixups for the AMD Geode GX framebuffer driver

We cannot assume that the BIOS will be correctly setting up the hardware, so
set some bits in various display registers to enable video output.  Allow an
advanced user to specify a frambuffer size, rather then probing the BIOS.  All
of these fixes were prompted by the OLPC effort.

[akpm@osdl.org: cleanups]
Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Acked-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 23 insertions, 1 deletions

diff --git a/drivers/video/geode/video_gx.c b/drivers/video/geode/video_gx.c
index 2b2a7880ea75..616ce339c5fa 100644
--- a/drivers/video/geode/video_gx.c
+++ b/drivers/video/geode/video_gx.c
@@ -178,7 +178,21 @@ static void gx_set_dclk_frequency(struct fb_info *info)
 static void gx_configure_display(struct fb_info *info)
 {
 	struct geodefb_par *par = info->par;
-	u32 dcfg, fp_pm;
+	u32 dcfg, fp_pm, misc;
+
+	/* Set up the MISC register */
+
+	misc = readl(par->vid_regs + GX_MISC);
+
+	/* Power up the DAC */
+	misc &= ~(GX_MISC_A_PWRDN | GX_MISC_DAC_PWRDN);
+
+	/* Disable gamma correction */
+	misc |= GX_MISC_GAM_EN;
+
+	writel(misc, par->vid_regs + GX_MISC);
+
+	/* Write the display configuration */
 
 	dcfg = readl(par->vid_regs + GX_DCFG);
 
@@ -199,9 +213,17 @@ static void gx_configure_display(struct fb_info *info)
 	if (info->var.sync & FB_SYNC_VERT_HIGH_ACT)
 		dcfg |= GX_DCFG_CRT_VSYNC_POL;
 
+	/* Enable the display logic */
+	/* Set up the DACS to blank normally */
+
+	dcfg |= GX_DCFG_CRT_EN | GX_DCFG_DAC_BL_EN;
+
+	/* Enable the external DAC VREF? */
+
 	writel(dcfg, par->vid_regs + GX_DCFG);
 
 	/* Power on flat panel. */
+
 	fp_pm = readl(par->vid_regs + GX_FP_PM);
 	fp_pm |= GX_FP_PM_P;
 	writel(fp_pm, par->vid_regs + GX_FP_PM);