u-boot/arch/arm/cpu/at91-common/spl.c
Bo Shen 12bbc0ba81 ARM: atmel: switch to main crystal osc for SPL boot
If without switch to main crystal oscillator, the sama5d3 SoC will
use internal on chip RC oscillator.
In order to get better accuracy, switch to main crystal oscillator.

Signed-off-by: Bo Shen <voice.shen@atmel.com>
Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
2014-05-27 00:10:40 +02:00

133 lines
2.6 KiB
C

/*
* Copyright (C) 2013 Atmel Corporation
* Bo Shen <voice.shen@atmel.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <asm/io.h>
#include <asm/arch/at91_common.h>
#include <asm/arch/at91_pmc.h>
#include <asm/arch/at91_wdt.h>
#include <asm/arch/clk.h>
#include <spl.h>
static void at91_disable_wdt(void)
{
struct at91_wdt *wdt = (struct at91_wdt *)ATMEL_BASE_WDT;
writel(AT91_WDT_MR_WDDIS, &wdt->mr);
}
static void switch_to_main_crystal_osc(void)
{
struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC;
u32 tmp;
tmp = readl(&pmc->mor);
tmp &= ~AT91_PMC_MOR_OSCOUNT(0xff);
tmp &= ~AT91_PMC_MOR_KEY(0xff);
tmp |= AT91_PMC_MOR_MOSCEN;
tmp |= AT91_PMC_MOR_OSCOUNT(8);
tmp |= AT91_PMC_MOR_KEY(0x37);
writel(tmp, &pmc->mor);
while (!(readl(&pmc->sr) & AT91_PMC_IXR_MOSCS))
;
tmp = readl(&pmc->mor);
tmp &= ~AT91_PMC_MOR_OSCBYPASS;
tmp &= ~AT91_PMC_MOR_KEY(0xff);
tmp |= AT91_PMC_MOR_KEY(0x37);
writel(tmp, &pmc->mor);
tmp = readl(&pmc->mor);
tmp |= AT91_PMC_MOR_MOSCSEL;
tmp &= ~AT91_PMC_MOR_KEY(0xff);
tmp |= AT91_PMC_MOR_KEY(0x37);
writel(tmp, &pmc->mor);
while (!(readl(&pmc->sr) & AT91_PMC_IXR_MOSCSELS))
;
tmp = readl(&pmc->mor);
tmp &= ~AT91_PMC_MOR_MOSCRCEN;
tmp &= ~AT91_PMC_MOR_KEY(0xff);
tmp |= AT91_PMC_MOR_KEY(0x37);
writel(tmp, &pmc->mor);
}
void at91_plla_init(u32 pllar)
{
struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC;
writel(pllar, &pmc->pllar);
while (!(readl(&pmc->sr) & (AT91_PMC_LOCKA | AT91_PMC_MCKRDY)))
;
}
void at91_mck_init(u32 mckr)
{
struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC;
u32 tmp;
tmp = readl(&pmc->mckr);
tmp &= ~(AT91_PMC_MCKR_PRES_MASK |
AT91_PMC_MCKR_MDIV_MASK |
AT91_PMC_MCKR_PLLADIV_2);
tmp |= mckr & (AT91_PMC_MCKR_PRES_MASK |
AT91_PMC_MCKR_MDIV_MASK |
AT91_PMC_MCKR_PLLADIV_2);
writel(tmp, &pmc->mckr);
while (!(readl(&pmc->sr) & AT91_PMC_MCKRDY))
;
}
u32 spl_boot_device(void)
{
#ifdef CONFIG_SYS_USE_MMC
return BOOT_DEVICE_MMC1;
#elif CONFIG_SYS_USE_NANDFLASH
return BOOT_DEVICE_NAND;
#elif CONFIG_SYS_USE_SERIALFLASH
return BOOT_DEVICE_SPI;
#endif
return BOOT_DEVICE_NONE;
}
u32 spl_boot_mode(void)
{
switch (spl_boot_device()) {
#ifdef CONFIG_SYS_USE_MMC
case BOOT_DEVICE_MMC1:
return MMCSD_MODE_FAT;
break;
#endif
case BOOT_DEVICE_NONE:
default:
hang();
}
}
void s_init(void)
{
switch_to_main_crystal_osc();
/* disable watchdog */
at91_disable_wdt();
/* PMC configuration */
at91_pmc_init();
at91_clock_init(CONFIG_SYS_AT91_MAIN_CLOCK);
timer_init();
board_early_init_f();
preloader_console_init();
mem_init();
}