u-boot/cpu/at32ap/cpu.c
Haavard Skinnemoen df548d3c3e AVR32: Resource management rewrite
Rewrite the resource management code (i.e. I/O memory, clock gating,
gpio) so it doesn't depend on any global state. This is necessary
because this code is heavily used before relocation to RAM, so we
can't write to any global variables.

As an added bonus, this makes u-boot's memory footprint a bit smaller,
although some functionality has been left out; all clocks are enabled
all the time, and there's no checking for gpio line conflicts.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
2007-04-14 15:20:27 +02:00

130 lines
3.5 KiB
C

/*
* Copyright (C) 2005-2006 Atmel Corporation
*
* 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
*/
#include <common.h>
#include <command.h>
#include <asm/io.h>
#include <asm/sections.h>
#include <asm/sysreg.h>
#include <asm/arch/clk.h>
#include <asm/arch/memory-map.h>
#include "hsmc3.h"
#include "sm.h"
/* Sanity checks */
#if (CFG_CLKDIV_CPU > CFG_CLKDIV_HSB) \
|| (CFG_CLKDIV_HSB > CFG_CLKDIV_PBA) \
|| (CFG_CLKDIV_HSB > CFG_CLKDIV_PBB)
# error Constraint fCPU >= fHSB >= fPB{A,B} violated
#endif
#if defined(CONFIG_PLL) && ((CFG_PLL0_MUL < 1) || (CFG_PLL0_DIV < 1))
# error Invalid PLL multiplier and/or divider
#endif
DECLARE_GLOBAL_DATA_PTR;
static void pm_init(void)
{
uint32_t cksel;
#ifdef CONFIG_PLL
/* Initialize the PLL */
sm_writel(PM_PLL0, (SM_BF(PLLCOUNT, CFG_PLL0_SUPPRESS_CYCLES)
| SM_BF(PLLMUL, CFG_PLL0_MUL - 1)
| SM_BF(PLLDIV, CFG_PLL0_DIV - 1)
| SM_BF(PLLOPT, CFG_PLL0_OPT)
| SM_BF(PLLOSC, 0)
| SM_BIT(PLLEN)));
/* Wait for lock */
while (!(sm_readl(PM_ISR) & SM_BIT(LOCK0))) ;
#endif
/* Set up clocks for the CPU and all peripheral buses */
cksel = 0;
if (CFG_CLKDIV_CPU)
cksel |= SM_BIT(CPUDIV) | SM_BF(CPUSEL, CFG_CLKDIV_CPU - 1);
if (CFG_CLKDIV_HSB)
cksel |= SM_BIT(HSBDIV) | SM_BF(HSBSEL, CFG_CLKDIV_HSB - 1);
if (CFG_CLKDIV_PBA)
cksel |= SM_BIT(PBADIV) | SM_BF(PBASEL, CFG_CLKDIV_PBA - 1);
if (CFG_CLKDIV_PBB)
cksel |= SM_BIT(PBBDIV) | SM_BF(PBBSEL, CFG_CLKDIV_PBB - 1);
sm_writel(PM_CKSEL, cksel);
gd->cpu_hz = get_cpu_clk_rate();
#ifdef CONFIG_PLL
/* Use PLL0 as main clock */
sm_writel(PM_MCCTRL, SM_BIT(PLLSEL));
#endif
}
int cpu_init(void)
{
extern void _evba(void);
char *p;
gd->cpu_hz = CFG_OSC0_HZ;
/* TODO: Move somewhere else, but needs to be run before we
* increase the clock frequency. */
hsmc3_writel(MODE0, 0x00031103);
hsmc3_writel(CYCLE0, 0x000c000d);
hsmc3_writel(PULSE0, 0x0b0a0906);
hsmc3_writel(SETUP0, 0x00010002);
pm_init();
sysreg_write(EVBA, (unsigned long)&_evba);
asm volatile("csrf %0" : : "i"(SYSREG_EM_OFFSET));
/* Lock everything that mess with the flash in the icache */
for (p = __flashprog_start; p <= (__flashprog_end + CFG_ICACHE_LINESZ);
p += CFG_ICACHE_LINESZ)
asm volatile("cache %0, 0x02" : "=m"(*p) :: "memory");
return 0;
}
void prepare_to_boot(void)
{
/* Flush both caches and the write buffer */
asm volatile("cache %0[4], 010\n\t"
"cache %0[0], 000\n\t"
"sync 0" : : "r"(0) : "memory");
}
int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
{
/* This will reset the CPU core, caches, MMU and all internal busses */
__builtin_mtdr(8, 1 << 13); /* set DC:DBE */
__builtin_mtdr(8, 1 << 30); /* set DC:RES */
/* Flush the pipeline before we declare it a failure */
asm volatile("sub pc, pc, -4");
return -1;
}