u-boot/arch/arm/mach-at91/spl_atmel.c
Wenyou Yang 3ceb5118c6 ARM: at91: spl: Adjust switching to oscillator for SAMA5D2
As said in 29.5.7 section of SAMA5D2 datasheet, before switching to
the crystal oscillator, a check must be carried out to ensure that
the oscillator is present and that its freqency is valid.

Signed-off-by: Wenyou Yang <wenyou.yang@microchip.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-09-14 16:02:44 -04:00

131 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_pit.h>
#include <asm/arch/at91_pmc.h>
#include <asm/arch/at91_rstc.h>
#include <asm/arch/at91_wdt.h>
#include <asm/arch/clk.h>
#include <spl.h>
DECLARE_GLOBAL_DATA_PTR;
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))
;
#if defined(CONFIG_SAMA5D2)
/* Enable a measurement of the external oscillator */
tmp = readl(&pmc->mcfr);
tmp |= AT91_PMC_MCFR_CCSS_XTAL_OSC;
tmp |= AT91_PMC_MCFR_RCMEAS;
writel(tmp, &pmc->mcfr);
while (!(readl(&pmc->mcfr) & AT91_PMC_MCFR_MAINRDY))
;
if (!(readl(&pmc->mcfr) & AT91_PMC_MCFR_MAINF_MASK))
hang();
#endif
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))
;
#if !defined(CONFIG_SAMA5D2)
/* Wait until MAINRDY field is set to make sure main clock is stable */
while (!(readl(&pmc->mcfr) & AT91_PMC_MAINRDY))
;
#endif
#if !defined(CONFIG_SAMA5D4) && !defined(CONFIG_SAMA5D2)
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);
#endif
}
__weak void matrix_init(void)
{
/* This only be used for sama5d4 soc now */
}
__weak void redirect_int_from_saic_to_aic(void)
{
/* This only be used for sama5d4 soc now */
}
/* empty stub to satisfy current lowlevel_init, can be removed any time */
void s_init(void)
{
}
void board_init_f(ulong dummy)
{
int ret;
switch_to_main_crystal_osc();
#ifdef CONFIG_SAMA5D2
configure_2nd_sram_as_l2_cache();
#endif
/* disable watchdog */
at91_disable_wdt();
/* PMC configuration */
at91_pmc_init();
at91_clock_init(CONFIG_SYS_AT91_MAIN_CLOCK);
matrix_init();
redirect_int_from_saic_to_aic();
timer_init();
board_early_init_f();
mem_init();
ret = spl_init();
if (ret) {
debug("spl_init() failed: %d\n", ret);
hang();
}
preloader_console_init();
}