From 8446be5d030c0d986cf90e0b395764f2c6ca443d Mon Sep 17 00:00:00 2001 From: Thomas Petazzoni Date: Fri, 21 Nov 2014 17:00:06 +0100 Subject: ARM: mvebu: implement suspend/resume support for Armada XP This commit implements the core of the platform code to enable suspend/resume on Armada XP. It registers the platform_suspend_ops structure, and implements the ->enter() hook of this structure. It is worth mentioning that this commit only provides the SoC-level part of suspend/resume, which calls into some board-specific code provided in a follow-up commit. The most important thing that this SoC-level code has to do is to build an in-memory structure that contains a magic number, the return address in the kernel after resume, and a set of address/value pairs. This structure is used by the bootloader to restore a certain number of registers (according to the set of address/value pairs) and then jump back into the kernel at the provided location. The code also puts the SDRAM into self-refresh mode, before calling into board-specific code to actually enter the suspend to RAM state. [ jac - add email exchange between Andrew Lunn and Thomas Petazzoni to better describe who consumes the address/value pairs ] > > Is this a well defined mechanism supported by mainline uboot, barebox > > etc. Or is it some Marvell extension to their uboot? > > As far as I know, it is a Marvell extension to their "binary header", > so it's done even before U-Boot starts. Since the hardware needs > assistance from the bootloader to do suspend/resume, there is > necessarily a certain amount of cooperation/agreement needed by what > the kernel does and what the bootloader expects. I'm not sure there's > any "standard" mechanism here. Do you know of any? > > I know the suspend/resume on the Blackfin architecture works the same > way (at least it used to work that way years ago when I did a bit of > Blackfin stuff). And here as well, there was some cooperation between > the kernel and the bootloader. See > arch/blackfin/mach-common/dpmc_modes.S, function do_hibernate() at the > end. > Signed-off-by: Thomas Petazzoni Link: https://lkml.kernel.org/r/1416585613-2113-10-git-send-email-thomas.petazzoni@free-electrons.com Signed-off-by: Jason Cooper --- arch/arm/mach-mvebu/common.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/arm/mach-mvebu/common.h') diff --git a/arch/arm/mach-mvebu/common.h b/arch/arm/mach-mvebu/common.h index 3ccb40c3bf94..3e0aca1f288a 100644 --- a/arch/arm/mach-mvebu/common.h +++ b/arch/arm/mach-mvebu/common.h @@ -25,4 +25,6 @@ int mvebu_system_controller_get_soc_id(u32 *dev, u32 *rev); void __iomem *mvebu_get_scu_base(void); +int mvebu_pm_init(void (*board_pm_enter)(void __iomem *sdram_reg, u32 srcmd)); + #endif -- cgit v1.2.3