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>
diff --git a/arch/arm/mach-at91/spl_atmel.c b/arch/arm/mach-at91/spl_atmel.c
index b75c2cc..ce16ef3 100644
--- a/arch/arm/mach-at91/spl_atmel.c
+++ b/arch/arm/mach-at91/spl_atmel.c
@@ -32,6 +32,20 @@
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);
@@ -47,11 +61,13 @@
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
-#ifndef CONFIG_SAMA5D4
+#if !defined(CONFIG_SAMA5D4) && !defined(CONFIG_SAMA5D2)
tmp = readl(&pmc->mor);
tmp &= ~AT91_PMC_MOR_MOSCRCEN;
tmp &= ~AT91_PMC_MOR_KEY(0xff);