From: Claudiu Beznea <[email protected]> Disable RC oscillator in ULP0 as datasheet specifies.
Signed-off-by: Claudiu Beznea <[email protected]> --- 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
