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>

2 files changed, 4 insertions, 0 deletions

diff --git a/include/asm-avr32/arch-at32ap/pm.h b/include/asm-avr32/arch-at32ap/pm.h
index 356e43064903..979b355b77b6 100644
--- a/include/asm-avr32/arch-at32ap/pm.h
+++ b/include/asm-avr32/arch-at32ap/pm.h
@@ -19,6 +19,7 @@
 
 #ifndef __ASSEMBLY__
 extern void cpu_enter_idle(void);
+extern void cpu_enter_standby(unsigned long sdramc_base);
 
 extern bool disable_idle_sleep;
 
@@ -43,6 +44,8 @@ static inline void cpu_idle_sleep(void)
         else
                 cpu_enter_idle();
 }
+
+void intc_set_suspend_handler(unsigned long offset);
 #endif
 
 #endif /* __ASM_AVR32_ARCH_PM_H */
diff --git a/include/asm-avr32/thread_info.h b/include/asm-avr32/thread_info.h
index 07049f6c0d41..df68631b7b27 100644
--- a/include/asm-avr32/thread_info.h
+++ b/include/asm-avr32/thread_info.h
@@ -88,6 +88,7 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_MEMDIE              6
 #define TIF_RESTORE_SIGMASK     7       /* restore signal mask in do_signal */
 #define TIF_CPU_GOING_TO_SLEEP  8       /* CPU is entering sleep 0 mode */
+#define TIF_FREEZE              29
 #define TIF_DEBUG               30      /* debugging enabled */
 #define TIF_USERSPACE           31      /* true if FS sets userspace */