u-boot/cpu/i386/sc520/sc520.c
Graeme Russ 6d7f610b09 Factor out SC520 sub-features
Moved sub-features of the SC520 code which is currently selectively compiled
using #ifdef out of sc520.c into individual files selectively compiled via
the makefile

Signed-off-by: Graeme Russ <graeme.russ at gmail.com>
2009-03-20 22:39:13 +01:00

239 lines
5.9 KiB
C

/*
* (C) Copyright 2002
* Daniel Engström, Omicron Ceti AB <daniel@omicron.se>.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
/* stuff specific for the sc520,
* but idependent of implementation */
#include <common.h>
#include <asm/io.h>
#include <asm/ic/sc520.h>
DECLARE_GLOBAL_DATA_PTR;
/*
* utility functions for boards based on the AMD sc520
*
* void write_mmcr_byte(u16 mmcr, u8 data)
* void write_mmcr_word(u16 mmcr, u16 data)
* void write_mmcr_long(u16 mmcr, u32 data)
*
* u8 read_mmcr_byte(u16 mmcr)
* u16 read_mmcr_word(u16 mmcr)
* u32 read_mmcr_long(u16 mmcr)
*
* void init_sc520(void)
* unsigned long init_sc520_dram(void)
*/
static u32 mmcr_base= 0xfffef000;
void write_mmcr_byte(u16 mmcr, u8 data)
{
writeb(data, mmcr+mmcr_base);
}
void write_mmcr_word(u16 mmcr, u16 data)
{
writew(data, mmcr+mmcr_base);
}
void write_mmcr_long(u16 mmcr, u32 data)
{
writel(data, mmcr+mmcr_base);
}
u8 read_mmcr_byte(u16 mmcr)
{
return readb(mmcr+mmcr_base);
}
u16 read_mmcr_word(u16 mmcr)
{
return readw(mmcr+mmcr_base);
}
u32 read_mmcr_long(u16 mmcr)
{
return readl(mmcr+mmcr_base);
}
void init_sc520(void)
{
/* Set the UARTxCTL register at it's slower,
* baud clock giving us a 1.8432 MHz reference
*/
write_mmcr_byte(SC520_UART1CTL, 7);
write_mmcr_byte(SC520_UART2CTL, 7);
/* first set the timer pin mapping */
write_mmcr_byte(SC520_CLKSEL, 0x72); /* no clock frequency selected, use 1.1892MHz */
/* enable PCI bus arbitrer */
write_mmcr_byte(SC520_SYSARBCTL,0x02); /* enable concurrent mode */
write_mmcr_word(SC520_SYSARBMENB,0x1f); /* enable external grants */
write_mmcr_word(SC520_HBCTL,0x04); /* enable posted-writes */
if (CONFIG_SYS_SC520_HIGH_SPEED) {
write_mmcr_byte(SC520_CPUCTL, 0x2); /* set it to 133 MHz and write back */
gd->cpu_clk = 133000000;
printf("## CPU Speed set to 133MHz\n");
} else {
write_mmcr_byte(SC520_CPUCTL, 1); /* set CPU to 100 MHz and write back cache */
printf("## CPU Speed set to 100MHz\n");
gd->cpu_clk = 100000000;
}
/* wait at least one millisecond */
asm("movl $0x2000,%%ecx\n"
"wait_loop: pushl %%ecx\n"
"popl %%ecx\n"
"loop wait_loop\n": : : "ecx");
/* turn on the SDRAM write buffer */
write_mmcr_byte(SC520_DBCTL, 0x11);
/* turn on the cache and disable write through */
asm("movl %%cr0, %%eax\n"
"andl $0x9fffffff, %%eax\n"
"movl %%eax, %%cr0\n" : : : "eax");
}
unsigned long init_sc520_dram(void)
{
bd_t *bd = gd->bd;
u32 dram_present=0;
u32 dram_ctrl;
#ifdef CONFIG_SYS_SDRAM_DRCTMCTL
/* these memory control registers are set up in the assember part,
* in sc520_asm.S, during 'mem_init'. If we muck with them here,
* after we are running a stack in RAM, we have troubles. Besides,
* these refresh and delay values are better ? simply specified
* outright in the include/configs/{cfg} file since the HW designer
* simply dictates it.
*/
#else
int val;
int cas_precharge_delay = CONFIG_SYS_SDRAM_PRECHARGE_DELAY;
int refresh_rate = CONFIG_SYS_SDRAM_REFRESH_RATE;
int ras_cas_delay = CONFIG_SYS_SDRAM_RAS_CAS_DELAY;
/* set SDRAM speed here */
refresh_rate/=78;
if (refresh_rate<=1) {
val = 0; /* 7.8us */
} else if (refresh_rate==2) {
val = 1; /* 15.6us */
} else if (refresh_rate==3 || refresh_rate==4) {
val = 2; /* 31.2us */
} else {
val = 3; /* 62.4us */
}
write_mmcr_byte(SC520_DRCCTL, (read_mmcr_byte(SC520_DRCCTL) & 0xcf) | (val<<4));
val = read_mmcr_byte(SC520_DRCTMCTL);
val &= 0xf0;
if (cas_precharge_delay==3) {
val |= 0x04; /* 3T */
} else if (cas_precharge_delay==4) {
val |= 0x08; /* 4T */
} else if (cas_precharge_delay>4) {
val |= 0x0c;
}
if (ras_cas_delay > 3) {
val |= 2;
} else {
val |= 1;
}
write_mmcr_byte(SC520_DRCTMCTL, val);
#endif
/* We read-back the configuration of the dram
* controller that the assembly code wrote */
dram_ctrl = read_mmcr_long(SC520_DRCBENDADR);
bd->bi_dram[0].start = 0;
if (dram_ctrl & 0x80) {
/* bank 0 enabled */
dram_present = bd->bi_dram[1].start = (dram_ctrl & 0x7f) << 22;
bd->bi_dram[0].size = bd->bi_dram[1].start;
} else {
bd->bi_dram[0].size = 0;
bd->bi_dram[1].start = bd->bi_dram[0].start;
}
if (dram_ctrl & 0x8000) {
/* bank 1 enabled */
dram_present = bd->bi_dram[2].start = (dram_ctrl & 0x7f00) << 14;
bd->bi_dram[1].size = bd->bi_dram[2].start - bd->bi_dram[1].start;
} else {
bd->bi_dram[1].size = 0;
bd->bi_dram[2].start = bd->bi_dram[1].start;
}
if (dram_ctrl & 0x800000) {
/* bank 2 enabled */
dram_present = bd->bi_dram[3].start = (dram_ctrl & 0x7f0000) << 6;
bd->bi_dram[2].size = bd->bi_dram[3].start - bd->bi_dram[2].start;
} else {
bd->bi_dram[2].size = 0;
bd->bi_dram[3].start = bd->bi_dram[2].start;
}
if (dram_ctrl & 0x80000000) {
/* bank 3 enabled */
dram_present = (dram_ctrl & 0x7f000000) >> 2;
bd->bi_dram[3].size = dram_present - bd->bi_dram[3].start;
} else {
bd->bi_dram[3].size = 0;
}
#if 0
printf("Configured %d bytes of dram\n", dram_present);
#endif
gd->ram_size = dram_present;
return dram_present;
}
#ifdef CONFIG_SYS_SC520_RESET
void reset_cpu(ulong addr)
{
printf("Resetting using SC520 MMCR\n");
/* Write a '1' to the SYS_RST of the RESCFG MMCR */
write_mmcr_word(SC520_RESCFG, 0x0001);
/* NOTREACHED */
}
#endif