]> git.baikalelectronics.ru Git - kernel.git/commit
ARM: imx53: Set DDR pins to high impedance when in suspend to RAM.
authorMartin Fuzzey <mfuzzey@parkeon.com>
Tue, 12 May 2015 13:31:03 +0000 (15:31 +0200)
committerShawn Guo <shawn.guo@linaro.org>
Wed, 3 Jun 2015 06:49:36 +0000 (14:49 +0800)
commita3e0cf716b6d0f394f5993b8be3a51e72b5b7622
tree6b528f14bfcfcd9ff3b6526694cfab2e637e2b51
parentbc57393cb76b05265771dfb92143e65c6ea5281b
ARM: imx53: Set DDR pins to high impedance when in suspend to RAM.

In order to save power the DDR pins should be put into high
impedance when in suspend to RAM.

This requires manually requesting self refresh (rather than using the
automatic mode implemented by the CCM / ESDCTL), followed by
reconfiguring the IOMUXC.

Of course the code to do this cannot itself run from DDR so the
code is copied to and executed from internal memory.

In my tests using a custom i.MX53 board with LPDDR2 RAM
this reduced the suspend power consumption from 200mW to 60mW.

Signed-off-by: Martin Fuzzey <mfuzzey@parkeon.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
arch/arm/mach-imx/Makefile
arch/arm/mach-imx/common.h
arch/arm/mach-imx/pm-imx5.c
arch/arm/mach-imx/suspend-imx53.S [new file with mode: 0644]