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 remaining registers are separated into:
- <mach/regs-ost.h>
- <mach/regs-rtc.h>
- <mach/regs-intc.h>
and then we can remove pxa-regs.h completely. Instead of #include this
file, let's:
1. include the specific <mach/regs-*.h> with care (if that's absolutely
necessary)
2. define the registers in the driver, make cleanly defined API to expose
the register access to external with sufficient reason
Signed-off-by: Eric Miao <eric.miao@marvell.com>
Remove includes of asm/hardware.h in addition to asm/arch/hardware.h.
Then, since asm/hardware.h only exists to include asm/arch/hardware.h,
update everything to directly include asm/arch/hardware.h and remove
asm/hardware.h.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The power manager and core clock registers aren't present in PXA3
CPUs. Move them out of pxa-regs.h into pxa2xx-regs.h, and include
pxa2xx-regs.h where necessary.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
standby.S contains both PXA2 and PXA3 specific code. The PXA3
specific constants clash with the PXA2 ones, so give them a prefix.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Wakeup sources on PXA3 are enabled at two levels. First, the MFP
configuration has to be set to enable which edges a specific pin
will trigger a wakeup. The pin also has to be routed to a functional
unit. Lastly, the functional unit must be enabled as a wakeup source
in the appropriate AD*ER registers (AD2D0ER for standby resume.)
This doesn't fit well with the IRQ wake scheme - we currently do a
best effort conversion from IRQ numbers to functional unit wake enable
bits. For instance, there's several USB client related enable bits but
there's no corresponding IRQs to determine which you'd want. Conversely,
there's a single enable bit covering several functional units.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Todd Poynor
Add symbols for PXA2xx PWRMODE register M field that selects low-power
mode, replace unadorned constants. Honor power mode parameter of
pxa_cpu_suspend(mode), no longer force to 3 (sleep). Full Deep Sleep
low-power mode support for PXA27x is pending generic PM interfaces to
select more than 2 suspend-to-RAM-style power modes, but this is
expected soon. This can be hardcoded in the meantime by replacing the
pxa_cpu_suspend() parameter value. From David Burrage and Todd Poynor.
Try #2 removes one of the register copies and moves the code to save the
pxa_cpu_suspend parameter to immediately surround the call that requires
the parameter value be preserved.
Signed-off-by: Todd Poynor <tpoynor@mvista.com>
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Todd Poynor
Add support for PXA27x Standby mode, a low-power mode that retains CPU
and some peripheral state (the existing "sleep" mode is a power-power
mode that retains less state). Activated via:
echo -n standby > /sys/power/state
From: David Burrage and Todd Poynor
Signed-off-by: Todd Poynor <tpoynor@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Russell King