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path: root/arch/avr32/mach-at32ap/sdramc.h
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2008-07-02avr32: Power Management support ("standby" and "mem" modes)Haavard Skinnemoen
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>