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.s...@atmel.com>
---
arch/arm/cpu/at91-common/spl.c | 39 +++++++++++++++++++++++++++++++
arch/arm/include/asm/arch-at91/at91_pmc.h | 4 ++++
2 files changed, 43 insertions(+)
diff --git a/arch/arm/cpu/at91-common/spl.c b/arch/arm/cpu/at91-common/spl.c
index 7f4debb..cbb5a52 100644
--- a/arch/arm/cpu/at91-common/spl.c
+++ b/arch/arm/cpu/at91-common/spl.c
@@ -20,6 +20,43 @@ static void at91_disable_wdt(void)
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;
@@ -76,6 +113,8 @@ u32 spl_boot_mode(void)
void s_init(void)
{
+ switch_to_main_crystal_osc();
+
/* disable watchdog */
at91_disable_wdt();
diff --git a/arch/arm/include/asm/arch-at91/at91_pmc.h
b/arch/arm/include/asm/arch-at91/at91_pmc.h
index 4535608..04f6239 100644
--- a/arch/arm/include/asm/arch-at91/at91_pmc.h
+++ b/arch/arm/include/asm/arch-at91/at91_pmc.h
@@ -70,7 +70,10 @@ typedef struct at91_pmc {
#define AT91_PMC_MOR_MOSCEN 0x01
#define AT91_PMC_MOR_OSCBYPASS 0x02
+#define AT91_PMC_MOR_MOSCRCEN 0x08
#define AT91_PMC_MOR_OSCOUNT(x) ((x & 0xff) << 8)
+#define AT91_PMC_MOR_KEY(x) ((x & 0xff) << 16)
+#define AT91_PMC_MOR_MOSCSEL (1 << 24)
#define AT91_PMC_PLLXR_DIV(x) (x & 0xFF)
#define AT91_PMC_PLLXR_PLLCOUNT(x) ((x & 0x3F) << 8)
@@ -142,6 +145,7 @@ typedef struct at91_pmc {
#define AT91_PMC_IXR_PCKRDY1 0x00000200
#define AT91_PMC_IXR_PCKRDY2 0x00000400
#define AT91_PMC_IXR_PCKRDY3 0x00000800
+#define AT91_PMC_IXR_MOSCSELS 0x00010000
#define AT91_PMC_PCK (1 << 0) /*
Processor Clock */
#define AT91RM9200_PMC_UDP (1 << 1) /* USB
Devcice Port Clock [AT91RM9200 only] */
--
1.8.5.2
_______________________________________________
U-Boot mailing list
U-Boot@lists.denx.de
http://lists.denx.de/mailman/listinfo/u-boot
