avr32: Power Management support ("standby" and "mem" modes)

Implement Standby support. In this mode, we'll suspend all drivers,
put the SDRAM in self-refresh mode and switch off the HSB bus
("frozen" mode.)

Implement Suspend-to-mem support. In this mode, we suspend all
drivers, put the SDRAM into self-refresh mode and switch off all
internal clocks except the 32 kHz oscillator ("stop" mode.)

The lowest-level suspend code runs from a small portion of SRAM
allocated at startup time. This gets rid of a small potential race
with the SDRAM where we might try to enter self-refresh mode in the
middle of an icache burst. We also relocate all interrupt and
exception handlers to SRAM during the small window when we enter and
exit the low-power modes.

We don't need to do any special tricks to start and stop the PLL. The
main clock is automatically gated by hardware until the PLL is stable.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/arch/avr32/Kconfig b/arch/avr32/Kconfig
index e8ee5fa..45d63c9 100644
--- a/arch/avr32/Kconfig
+++ b/arch/avr32/Kconfig
@@ -205,6 +205,11 @@ endmenu
 
 menu "Power management options"
 
+source "kernel/power/Kconfig"
+
+config ARCH_SUSPEND_POSSIBLE
+	def_bool y
+
 menu "CPU Frequency scaling"
 
 source "drivers/cpufreq/Kconfig"