blob: 8cc7607356999b0dd921deb75a33090b4e90884a [file] [log] [blame]
/*
* This file is part of the coreboot project.
*
* Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.com>
* Copyright (C) 2018 Lubomir Rintel <lkundrak@v3.sk>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#define __SIMPLE_DEVICE__
#include "vx900.h"
#include <device/pci.h>
#include <cbmem.h>
#define MCU PCI_DEV(0, 0, 3)
#define CHROME_9_HD_MIN_FB_SIZE 8
#define CHROME_9_HD_MAX_FB_SIZE 512
/* Helper to determine the framebuffer size */
void vx900_set_chrome9hd_fb_size(u32 size_mb)
{
u8 reg8, ranksize;
u32 tom_mb, max_size_mb;
int i;
/* The minimum framebuffer size is 8MB. */
size_mb = MAX(size_mb, CHROME_9_HD_MIN_FB_SIZE);
/*
* We have two limitations on the maximum framebuffer size:
* 1) (Sanity) No more that 1/4 of system RAM
* 2) (Hardware limitation) No larger than DRAM in last rank
* Check both of these limitations and apply them to our framebuffer */
tom_mb = (pci_read_config16(MCU, 0x88) & 0x07ff) << (24 - 20);
max_size_mb = tom_mb >> 2;
if (size_mb > max_size_mb) {
printk(BIOS_ALERT, "The framebuffer size of %dMB is larger"
" than 1/4 of available memory.\n"
" Limiting framebuffer to %dMB\n", size_mb, max_size_mb);
size_mb = max_size_mb;
}
/* Now handle limitation #2
* Look at the ending address of the memory ranks, from last to first,
* until we find one that is not zero. That is our last rank, and its
* size is the limit of our framebuffer. */
/* FIXME: This has a bug. If we remap memory above 4G, we consider the
* memory hole as part of our RAM. Thus if we install 3G, with a TOLM of
* 2.5G, our TOM will be at 5G and we'll assume we have 5G RAM instead
* of the actual 3.5G */
for (i = VX900_MAX_MEM_RANKS - 1; i > -1; i--) {
reg8 = pci_read_config8(MCU, 0x40 + i);
if (reg8 == 0)
continue;
/* We've reached the last populated rank */
ranksize = reg8 - pci_read_config8(MCU, 0x48 + i);
max_size_mb = ranksize << 6;
/* That's it. We got what we needed. */
break;
}
if (size_mb > max_size_mb) {
printk(BIOS_ALERT, "The framebuffer size of %dMB is larger"
" than size of the last DRAM rank.\n"
" Limiting framebuffer to %dMB\n", size_mb, max_size_mb);
size_mb = max_size_mb;
}
/* Now round the framebuffer size to the closest power of 2 */
u8 fb_pow = 0;
while (size_mb >> fb_pow)
fb_pow++;
fb_pow--;
size_mb = (1 << fb_pow);
pci_mod_config8(MCU, 0xa1, 7 << 4, (fb_pow - 2) << 4);
}
/* Gets the configured framebuffer size as a power of 2 */
u8 vx900_get_chrome9hd_fb_pow(void)
{
u8 fb_pow = (pci_read_config8(MCU, 0xa1) >> 4) & 7;
if (fb_pow > 0)
fb_pow += 2;
return fb_pow;
}
/* Gets the configured framebuffer size in MB */
u32 vx900_get_chrome9hd_fb_size(void)
{
u8 size = vx900_get_chrome9hd_fb_pow();
if (size == 0)
return 0;
return 1 << size;
}
u32 vx900_get_tolm(void)
{
return (pci_read_config16(MCU, 0x84) & 0xfff0) >> 4;
}
void *cbmem_top(void)
{
uintptr_t tolm;
uintptr_t fb_size;
tolm = vx900_get_tolm ();
fb_size = vx900_get_chrome9hd_fb_size ();
if (tolm > 0xfc0 || tolm <= 0x3ff || fb_size == 0x0)
return NULL;
return (void *)((tolm - fb_size) << 20);
}