This patch adds suspend function for i.MX6UL, it supports
"standby" and "mem" mode, for "standby" mode, SoC will
enter STOP mode only, while for "mem" mode, SoC will
enter STOP mode and DDR IO will be set to low power
mode.
As i.MX6UL contains a "Cortex-A7" ARM core which has no
PL310, so we need to avoid any PL310 operations during
suspend/resume, also, we need to flush Cortex-A7's inernal
L2 cache before suspend.
Signed-off-by: Anson Huang <b20788@freescale.com>
As the DDR/IO and MMDC setting are different on LPDDR2 and DDR3,
we used cpu type to decide how to do these settings in suspend
before which is NOT flexible, take i.MX6SL for example, although
it has LPDDR2 on EVK board, but users can also use DDR3 on other
boards, so it is better to read the DDR type from MMDC then decide
how to do related settings.
Signed-off-by: Anson Huang <b20788@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
After the suspend routine running in OCRAM puts DDR into self-refresh,
it will access IOMUXC block to float DDR IO for power saving. A TLB
missing of IOMUXC base address may happen in this case, and triggers an
access to DDR, and thus hangs the system.
The failure is discovered by running suspend/resume on a Cubox-i board.
Though the issue is not Cubox-i specific, it can be hit the on the board
quite easily with the 3.15 or 3.16 kernel.
Fix the issue with a dummy access to IOMUXC block at the beginning of
suspend routine, so that the address translation can be filled into TLB
before DDR is put into self-refresh.
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Cc: <stable@vger.kernel.org>
Acked-by: Anson Huang <Anson.Huang@freescale.com>
ARMv6 and greater introduced a new instruction ("bx") which can be used
to return from function calls. Recent CPUs perform better when the
"bx lr" instruction is used rather than the "mov pc, lr" instruction,
and this sequence is strongly recommended to be used by the ARM
architecture manual (section A.4.1.1).
We provide a new macro "ret" with all its variants for the condition
code which will resolve to the appropriate instruction.
Rather than doing this piecemeal, and miss some instances, change all
the "mov pc" instances to use the new macro, with the exception of
the "movs" instruction and the kprobes code. This allows us to detect
the "mov pc, lr" case and fix it up - and also gives us the possibility
of deploying this for other registers depending on the CPU selection.
Reported-by: Will Deacon <will.deacon@arm.com>
Tested-by: Stephen Warren <swarren@nvidia.com> # Tegra Jetson TK1
Tested-by: Robert Jarzmik <robert.jarzmik@free.fr> # mioa701_bootresume.S
Tested-by: Andrew Lunn <andrew@lunn.ch> # Kirkwood
Tested-by: Shawn Guo <shawn.guo@freescale.com>
Tested-by: Tony Lindgren <tony@atomide.com> # OMAPs
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com> # Armada XP, 375, 385
Acked-by: Sekhar Nori <nsekhar@ti.com> # DaVinci
Acked-by: Christoffer Dall <christoffer.dall@linaro.org> # kvm/hyp
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com> # PXA3xx
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> # Xen
Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> # ARMv7M
Tested-by: Simon Horman <horms+renesas@verge.net.au> # Shmobile
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The suspend-imx6.S is introduced recently for suspend low-level assembly
code. Since function v7_cpu_resume() is only used by suspend support,
it makes sense to move the function into suspend-imx6.S, and control the
build of the file with CONFIG_SUSPEND option.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
i.MX6SL's suspend in ocram function is derived from i.MX6Q,
it can lower the DDR IO power from ~10mA@1.2V to ~1mA@1.2V,
measured on i.MX6SL EVK board, SH5.
Signed-off-by: Anson Huang <b20788@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
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@1.5V to ~15mA@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@pengutronix.de>
Signed-off-by: Anson Huang <b20788@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
