gxfb: Get the frambuffer size from the BIOS
This works for me but the board I have can only have 16 MiB available for the framebuffer so I've not tested any other sizes.
David Vrabel
Signature · 4 lines
David Vrabel, Design Engineer Arcom, Clifton Road Tel: +44 (0)1223 411200 ext. 3233 Cambridge CB1 7EA, UK Web: http://www.arcom.com/
gxfb: Get the frambuffer size from the BIOS
From: Jordan Crouse <[email protected]>
Use the Geode GX BIOS virtual registers to get the actual size of the framebuffer.
Signed-off-by Jordan Crouse <[email protected]>
Signed-off-by David Vrabel <[email protected]>
---
drivers/video/geode/display_gx.c | 15 ++++++++++++--- drivers/video/geode/display_gx.h | 2 +- 2 files changed, 13 insertions(+), 4 deletions(-)
drivers/video/geode/display_gx.c +12 -3
@@ -21,10 +21,19 @@#include "geodefb.h" #include "display_gx.h" -int gx_frame_buffer_size (void ) +unsigned int gx_frame_buffer_size (void ) { -/* Assuming 16 MiB. */ -return 16 *1024 *1024 ; +unsigned int val; + +/* FB size is reported by a virtual register */ +/* Virtual register class = 0x02 */ +/* VG_MEM_SIZE(512Kb units) = 0x00 */ + +outw (0XFC53 ,0xAC1C ); +outw (0x0200 ,0xAC1C ); + + val = (unsigned int )(inw (0xAC1E )) &0xFFl ; +return (val <<19 ); }int gx_line_delta (int xres,int bpp)
drivers/video/geode/display_gx.h +1 -1
@@ -11,7 +11,7 @@#ifndef __DISPLAY_GX_H__#define __DISPLAY_GX_H__ -int gx_frame_buffer_size (void ); +unsigned int gx_frame_buffer_size (void );int gx_line_delta (int xres,int bpp);extern struct geode_dc_ops gx_dc_ops;