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Subject[PATCH 7/8] ARM: at91: pm: disable RC oscillator in ULP0
Date
From: Claudiu Beznea <claudiu.beznea@microchip.com>

Disable RC oscillator in ULP0 as datasheet specifies.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
arch/arm/mach-at91/pm_suspend.S | 39 +++++++++++++++++++++++++++++++++++++--
1 file changed, 37 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mach-at91/pm_suspend.S b/arch/arm/mach-at91/pm_suspend.S
index 8b18cad1dcf5..5c33023f9129 100644
--- a/arch/arm/mach-at91/pm_suspend.S
+++ b/arch/arm/mach-at91/pm_suspend.S
@@ -178,11 +178,46 @@ ENDPROC(at91_backup_mode)
orr tmp1, tmp1, #AT91_PMC_KEY
str tmp1, [pmc, #AT91_CKGR_MOR]

+ /* Save RC oscillator state */
+ ldr tmp1, [pmc, #AT91_PMC_SR]
+ str tmp1, .saved_osc_status
+ tst tmp1, #AT91_PMC_MOSCRCS
+ bne 1f
+
+ /* Turn off RC oscillator */
+ ldr tmp1, [pmc, #AT91_CKGR_MOR]
+ bic tmp1, tmp1, #AT91_PMC_MOSCRCEN
+ bic tmp1, tmp1, #AT91_PMC_KEY_MASK
+ orr tmp1, tmp1, #AT91_PMC_KEY
+ str tmp1, [pmc, #AT91_CKGR_MOR]
+
+ /* Wait main RC disabled done */
+2: ldr tmp1, [pmc, #AT91_PMC_SR]
+ tst tmp1, #AT91_PMC_MOSCRCS
+ bne 2b
+
/* Wait for interrupt */
- at91_cpu_idle
+1: at91_cpu_idle

- /* Turn on the crystal oscillator */
+ /* Restore RC oscillator state */
+ ldr tmp1, .saved_osc_status
+ tst tmp1, #AT91_PMC_MOSCRCS
+ beq 4f
+
+ /* Turn on RC oscillator */
ldr tmp1, [pmc, #AT91_CKGR_MOR]
+ orr tmp1, tmp1, #AT91_PMC_MOSCRCEN
+ bic tmp1, tmp1, #AT91_PMC_KEY_MASK
+ orr tmp1, tmp1, #AT91_PMC_KEY
+ str tmp1, [pmc, #AT91_CKGR_MOR]
+
+ /* Wait main RC stabilization */
+3: ldr tmp1, [pmc, #AT91_PMC_SR]
+ tst tmp1, #AT91_PMC_MOSCRCS
+ beq 3b
+
+ /* Turn on the crystal oscillator */
+4: ldr tmp1, [pmc, #AT91_CKGR_MOR]
orr tmp1, tmp1, #AT91_PMC_MOSCEN
orr tmp1, tmp1, #AT91_PMC_KEY
str tmp1, [pmc, #AT91_CKGR_MOR]
--
2.7.4
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