drivers/video/via/iface.c

   1 /*
   2  * Copyright 1998-2008 VIA Technologies, Inc. All Rights Reserved.
   3  * Copyright 2001-2008 S3 Graphics, Inc. All Rights Reserved.
   4
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public
   7  * License as published by the Free Software Foundation;
   8  * either version 2, or (at your option) any later version.
   9
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTIES OR REPRESENTATIONS; without even
  12  * the implied warranty of MERCHANTABILITY or FITNESS FOR
  13  * A PARTICULAR PURPOSE.See the GNU General Public License
  14  * for more details.
  15
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc.,
  19  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  20  */
  21
  22 #include "global.h"
  23
  24 /* Get frame buffer size from VGA BIOS */
  25
  26 unsigned int viafb_get_memsize(void)
  27 {
  28         unsigned int m;
  29
  30         /* If memory size provided by user */
  31         if (viafb_memsize)
  32                 m = viafb_memsize * Mb;
  33         else {
  34                 m = (unsigned int)viafb_read_reg(VIASR, SR39);
  35                 m = m * (4 * Mb);
  36
  37                 if ((m < (16 * Mb)) || (m > (64 * Mb)))
  38                         m = 16 * Mb;
  39         }
  40         DEBUG_MSG(KERN_INFO "framebuffer size = %d Mb\n", m / Mb);
  41         return m;
  42 }
  43
  44 /* Get Video Buffer Starting Physical Address(back door)*/
  45
  46 unsigned long viafb_get_videobuf_addr(void)
  47 {
  48         struct pci_dev *pdev = NULL;
  49         unsigned char sys_mem;
  50         unsigned char video_mem;
  51         unsigned long sys_mem_size;
  52         unsigned long video_mem_size;
  53         /*system memory = 256 MB, video memory 64 MB */
  54         unsigned long vmem_starting_adr = 0x0C000000;
  55
  56         pdev =
  57             (struct pci_dev *)pci_get_device(VIA_K800_BRIDGE_VID,
  58                                              VIA_K800_BRIDGE_DID, NULL);
  59         if (pdev != NULL) {
  60                 pci_read_config_byte(pdev, VIA_K800_SYSTEM_MEMORY_REG,
  61                                      &sys_mem);
  62                 pci_read_config_byte(pdev, VIA_K800_VIDEO_MEMORY_REG,
  63                                      &video_mem);
  64                 video_mem = (video_mem & 0x70) >> 4;
  65                 sys_mem_size = ((unsigned long)sys_mem) << 24;
  66                 if (video_mem != 0)
  67                         video_mem_size = (1 << (video_mem)) * 1024 * 1024;
  68                 else
  69                         video_mem_size = 0;
  70
  71                 vmem_starting_adr = sys_mem_size - video_mem_size;
  72                 pci_dev_put(pdev);
  73         }
  74
  75         DEBUG_MSG(KERN_INFO "Video Memory Starting Address = %lx \n",
  76                   vmem_starting_adr);
  77         return vmem_starting_adr;
  78 }