[PATCH 00/17] omap4: pm: suspend, hotplug and cpuilde support
Santosh Shilimkar
santosh.shilimkar at ti.com
Sat Feb 19 05:42:21 EST 2011
This series adds OMAP4 suspend and cpuidle support till MPU subsystem
(MPUSS) off-mode. The suspend on SMP machines uses cpu-hotplug
infrastructure to take down the non-boot CPUs. We put secondary
CPU(CPU1 in OMAP4) to OFF state via cpu-hotplug.
In cpuidle too, low power states are attempted only when the
CPU1 is put to OFF state via cpu-hotplug because of hardware
constraints.
Timer wakeup from suspend, debug pm counters and enable_off_mode
provisions are supported as well.
Special thanks to Kevin Hilman <khilman at ti.com> for doing detail
off-the list reviews.
The patches are generated against mainline 2.6.38-rc5 and tested with
OMAP4430 SDP and OMAP4 PANDA board. Any OMAP4 board with ES2.X silicon,
below features should work with this series. On ES1.0, these PM
features are not supported.
1. CPU hotplug (CPU is put into off-mode)
2. Suspend (Both CPUs put to off-mode and MPUSS to OFF/RET)
3. CPUILDE with below C-states.
C1 - CPU0 ON + CPU1 ON/OFF + MPU ON + CORE ON
C2 - CPU0 ON + CPU1 OFF + MPU ON + CORE ON
C3 - CPU0 OFF + CPU1 OFF + MPU CSWR + CORE ON
C4 - CPU0 OFF + CPU1 OFF + MPU OFF + CORE ON
In OMAP4 mpuss consist of dual Cortex-A9 with per-cpu local timers
GIC(Generic Interrupt Controller), SCU(Snoop Control Unit) and PL310
L2 cache controller and CPU0/CPU1 LPRM modules.
CPU0, CPU1 and MPUSS have there own power domain and hence multiple
low power state combinations are possible. The CPU10 and CPU1
Close switch Retention(CSWR) isn't supported by hardware.
Based on various studies, measurements, hardware constraints
and recommendations from hardware team, only below low power
modes are supported on OMAP4.
----------------------------------------
CPU0 CPU1 MPUSS
----------------------------------------
ON ON ON
OFF OFF CSWR
OFF OFF OSWR
OFF OFF OFF
-----------------------------------------
Note: CPU0 is the master core and it is the last CPU to go down
and first to wake-up when MPUSS low power states are attempted
OSWR(Open Switch Retention) is not added as part of this series
because it needs some power domain level support which isn't ready
yet.
http://www.mail-archive.com/linux-omap@vger.kernel.org/msg38667.html
Powerdomain INACTIVE support is also dropped because of its
inconsistency between OMAP4 and OMAP3.
More information on this thread -
http://www.spinics.net/lists/linux-omap/msg45370.html
This series has a dependency on few patches from below series which
are posted earlier.
- Clock domain split series [1] (Already in Paul's queue)
- Few power domain patches from [2] (Already in Paul's queue)
- GIC and SCU patches from [3]
- Local Timer patches from [4]
The cpu-hotplug and suspend works with omap2plus_defconfig. Not to damage
your file system with current omap2plus_defconfig, disable ARCH_OMAP2 so
that V6 and V7 support is not built together with SMP.
To tryout cpuidle, CONFIG_CPU_IDLE needs to be enabled in the build.
CPU-HOTPLUG commands :
offline : $echo 0 > /sys/devices/system/cpu/cpu1/online
online : $echo 1 > /sys/devices/system/cpu/cpu1/online
Suspend :$echo mem > /sys/power/state
cpuilde : To trigger cpuidle deeper C-states on OMAP4, CPU1 needs
to be offlied
$echo 0 > /sys/devices/system/cpu/cpu1/online
To see PM debug counters,
$mount -t debugfs debugfs /proc/sys/debug/
$cat /proc/sys/debug/pm_debug/count
off-mode debugfs control:
enable: $echo 1 > /proc/sys/debug/pm_debug/enable_off_mode
disable: $echo 0 > /proc/sys/debug/pm_debug/enable_off_mode
For testing, I have put together all these patches and dependencies
on below git branch.
git://dev.omapzoom.org/pub/scm/santosh/kernel-omap4-base.git omap4_pm_fornext
Rajendra Nayak (1):
omap4: cpuidle: Basic CPUidle support
Santosh Shilimkar (16):
omap4: pm: Add omap WakeupGen module support
omap4: pm: Add SAR RAM support
omap4: Export scu base address
omap4: pm: Add CPUx OFF mode support
omap4: pm: Initialise all the clockdomains to supported states
omap4: pm: Program CPU1 to hit OFF when off-lined
omap4: pm: CPU1 wakeup workaround form Low power modes
omap4: pm: Add GIC save/restore support
omap4: pm: Add WakeupGen save/restore support
omap4: pm: Add L2 cache lowpower support
omap4: suspend: Add MPUSS RET and OFF support
omap4: pm-debug: Add wakeup timer and debug counters
omap4: cpuidle: Add MPUSS RET OFF states
omap4: cpuidle: Switch to gptimer from twd in deeper C-states.
omap4: cpuidle: Allow debugfs control through enable_off_mode
omap4: Remove un-used do_wfi() macro.
arch/arm/mach-omap2/Makefile | 8 +-
arch/arm/mach-omap2/cpuidle44xx.c | 365 +++++++++++++++++
arch/arm/mach-omap2/include/mach/omap-wakeupgen.h | 41 ++
arch/arm/mach-omap2/include/mach/omap4-common.h | 56 +++-
arch/arm/mach-omap2/omap-hotplug.c | 31 ++-
arch/arm/mach-omap2/omap-smp.c | 29 ++-
arch/arm/mach-omap2/omap-wakeupgen.c | 287 +++++++++++++
arch/arm/mach-omap2/omap4-common.c | 28 ++-
arch/arm/mach-omap2/omap4-mpuss-lowpower.c | 442 +++++++++++++++++++++
arch/arm/mach-omap2/omap4-sar-layout.h | 71 ++++
arch/arm/mach-omap2/pm-debug.c | 8 +-
arch/arm/mach-omap2/pm.h | 3 +
arch/arm/mach-omap2/pm44xx.c | 125 ++++++-
arch/arm/mach-omap2/sleep44xx.S | 398 +++++++++++++++++++
arch/arm/plat-omap/include/plat/omap44xx.h | 1 +
15 files changed, 1870 insertions(+), 23 deletions(-)
create mode 100644 arch/arm/mach-omap2/cpuidle44xx.c
create mode 100644 arch/arm/mach-omap2/include/mach/omap-wakeupgen.h
create mode 100644 arch/arm/mach-omap2/omap-wakeupgen.c
create mode 100644 arch/arm/mach-omap2/omap4-mpuss-lowpower.c
create mode 100644 arch/arm/mach-omap2/omap4-sar-layout.h
create mode 100644 arch/arm/mach-omap2/sleep44xx.S
Regrads,
Santosh
[1] http://www.spinics.net/lists/linux-omap/msg44153.html
[2] http://www.mail-archive.com/linux-omap@vger.kernel.org/msg43257.html
[3] http://www.mail-archive.com/linux-omap@vger.kernel.org/msg42939.html
[4] http://www.spinics.net/lists/linux-omap/msg45710.html
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