[PATCH V8 1/3] ARM: imx: add suspend in ocram support for i.mx6q
Shawn Guo
shawn.guo at linaro.org
Sat Jan 18 21:49:50 EST 2014
On Fri, Jan 17, 2014 at 11:39:05AM +0800, Anson Huang wrote:
> When system enter suspend, we can set the DDR IO to
> high-Z state to save DDR IOs' power consumption, this
> operation can save many power(from ~26mA at 1.5V to ~15mA at 1.5V,
> measured on i.MX6Q SabreSD board, R25) of DDR IOs. To
> achieve that, we need to copy the suspend code to ocram
> and run the low level hardware related code(set DDR IOs
> to high-Z state) in ocram.
>
> If there is no ocram space available, then system will
> still do suspend in external DDR, hence no DDR IOs will
> be set to high-Z.
>
> The OCRAM usage layout is as below,
>
> ocram suspend region(4K currently):
> ======================== high address ======================
> .
> .
> .
> ^
> ^
> ^
> imx6_suspend code
> PM_INFO structure(imx6_cpu_pm_info)
> ======================== low address =======================
>
> Reviewed-by: Sascha Hauer <s.hauer at pengutronix.de>
> Signed-off-by: Anson Huang <b20788 at freescale.com>
Thanks for the work. Applied all 3, thanks.
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