gxfb: replace FBSIZE config option with a module parameter

Use a command line option (vram) rather than hardcoding the vram size.  LxFB
already does this; it's useful for machines that can't query the BIOS for fb
size.  This patch originated from David Woodhouse, was modified by Jordan
Crouse, and was then modified further by me.

This also adds some gxfb documentation in Documentation/fb.

Signed-off-by: Andres Salomon <dilinger@debian.org>
Cc: Jordan Crouse <jordan.crouse@amd.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 6 deletions

diff --git a/drivers/video/geode/gxfb_core.c b/drivers/video/geode/gxfb_core.c
index 546e53038fa..8021bcb9ab6 100644
--- a/drivers/video/geode/gxfb_core.c
+++ b/drivers/video/geode/gxfb_core.c
@@ -37,6 +37,7 @@
 #include "video_gx.h"
 
 static char *mode_option;
+static int vram;
 
 /* Modes relevant to the GX (taken from modedb.c) */
 static const struct fb_videomode gx_modedb[] __initdata = {
@@ -208,7 +209,6 @@ static int gxfb_blank(int blank_mode, struct fb_info *info)
 static int __init gxfb_map_video_memory(struct fb_info *info, struct pci_dev *dev)
 {
 	struct geodefb_par *par = info->par;
-	int fb_len;
 	int ret;
 
 	ret = pci_enable_device(dev);
@@ -233,21 +233,20 @@ static int __init gxfb_map_video_memory(struct fb_info *info, struct pci_dev *de
 	ret = pci_request_region(dev, 0, "gxfb (framebuffer)");
 	if (ret < 0)
 		return ret;
-	if ((fb_len = gx_frame_buffer_size()) < 0)
-		return -ENOMEM;
+
 	info->fix.smem_start = pci_resource_start(dev, 0);
-	info->fix.smem_len = fb_len;
+	info->fix.smem_len = vram ? vram : gx_frame_buffer_size();
 	info->screen_base = ioremap(info->fix.smem_start, info->fix.smem_len);
 	if (!info->screen_base)
 		return -ENOMEM;
 
-	/* Set the 16MB aligned base address of the graphics memory region
+	/* Set the 16MiB aligned base address of the graphics memory region
 	 * in the display controller */
 
 	writel(info->fix.smem_start & 0xFF000000,
 			par->dc_regs + DC_GLIU0_MEM_OFFSET);
 
-	dev_info(&dev->dev, "%d Kibyte of video memory at 0x%lx\n",
+	dev_info(&dev->dev, "%d KiB of video memory at 0x%lx\n",
 		 info->fix.smem_len / 1024, info->fix.smem_start);
 
 	return 0;
@@ -455,5 +454,8 @@ module_exit(gxfb_cleanup);
 module_param(mode_option, charp, 0);
 MODULE_PARM_DESC(mode_option, "video mode (<x>x<y>[-<bpp>][@<refr>])");
 
+module_param(vram, int, 0);
+MODULE_PARM_DESC(vram, "video memory size");
+
 MODULE_DESCRIPTION("Framebuffer driver for the AMD Geode GX");
 MODULE_LICENSE("GPL");