The ULP1 (Ultra Low-power mode 1) is introduced by SAMA5D2. In order to achieve the lowest power consumption, in the ULP1 mode, all the clocks are shut off, inclusive the embedded 12MHz RC oscillator. The fast startup signal is used as a wake up source for ULP1 mode. As soon as the wake up event is asserted, the embedded 12MHz RC oscillator restarts automatically, which fast startup signal to trigger the PMC to wake up the system from the ULP1 mode can be configured via DT. It is based on the following patch set: http://lists.infradead.org/pipermail/linux-arm-kernel/2015-December/390954.html Wenyou Yang (4): ARM: at91: pm: create a separate procedure for the ULP0 mode ARM: at91: pm: add ULP1 mode support ARM: at91: pm: configure PMC fast startup signals Documentation: atmel-at91: add DT bindings for fast startup .../devicetree/bindings/arm/atmel-pmc.txt | 74 +++++++++ arch/arm/mach-at91/pm.c | 112 +++++++++++++- arch/arm/mach-at91/pm.h | 7 + arch/arm/mach-at91/pm_suspend.S | 158 +++++++++++++++++--- include/linux/clk/at91_pmc.h | 36 +++++ 5 files changed, 362 insertions(+), 25 deletions(-) -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
