From: Jean Pihet <j-pihet@xxxxxx>
Implement OMAP PM layer omap_pm_set_max_dev_wakeup_lat API by
creating a unified API which calls omap_device_set_dev_constraint
for all classes of constraints (devices wake-up latency, devices
throughput...).
The implementation of the constraints framework is at the omap_device
level: management and storage of the constraints, dispatching of the
constraints to the appropriate low level layers.
NOTE: only works for devices which have been converted to use
omap_device/omap_hwmod.
Longer term, we could possibly remove this API from the OMAP PM layer,
and instead directly use the device level API.
For the devices wake-up latency constraints, the power domains get
the next power state programmed directly in the registers via
pwrdm_wakeuplat_update_pwrst.
Note about PM QOS: the MPU and CORE power domains get the next power
state via cpuidle, which get the strongest wake-up latency constraint
by querying PM QOS. The usage of PM QOS is temporary, until a generic
solution is in place.
The bus throughput constraints framework is supported by still is a
no-op for the moment.
For the wake-up latency constraints framework to have effect on the
power domains states, CONFIG_CPU_IDLE and CONFIG_OMAP_PM_CONSTRAINTS
must be enabled.
Based on Vibhore's original patch and completely reworked using
omap_device, omap_hwmod, powerdomain and PM QOS frameworks.
Cc: Vibhore Vardhan <vvardhan@xxxxxx>
Tested on OMAP3 Beagleboard in RET/OFF using wake-up latency constraints
on MPU, CORE and PER.
Based on khilman's pm-core branch
v4:
. updated after review comments on linux-omap mailing list,
. bug fix in the use of plist_first and plist_last if the list is empty.
v3:
. updated after review comments from Kevin,
. patches re-ordering for git bisect compliance,
. reworked the constraints storage and management:
- the omap_device layer stores all constraints in per-omap_device
constraints lists,
- the powerdomain layer manages the wake-up latency constraints in
per-pwrdm constraint list and applies the constraint to the
corresponding power domain.
. add the support for the INACTIVE power state,
. move the power domains state initialization from pwrdms_setup to an early init call.
v2:
. updated after review comments from Kevin and Paul,
. initial patch split according to the layering,
. added support for ascending or descending order of constraints values,
. added throughput constraints to the framework, although the tput implementation
currently is a no-op.
To Do:
. refine the wake-up latency figures by defining the conditions of measurements and by
measuring on actual OMAP3 hardware,
. define the effect of power domains states combinations,
. debug: add some control knobs for the wake-up latencies in /sysfs,
. add a user-space API to request and remove constraints,
. add OMAP4 support when low power modes code is merged in.
Jean Pihet (8):
OMAP PM: create a PM layer plugin for per-device constraints
OMAP2+: powerdomain: control power domains next state
OMAP3: powerdomain data: add wake-up latency figures
OMAP2+: omap_hwmod: manage the omap_devices the wake-up latency
constraints
OMAP: PM CONSTRAINTS: add an enum for the classes of constraint
OMAP2+: omap_device: implement the constraints management code
OMAP: PM CONSTRAINTS: implement wake-up latency constraints
OMAP PM: early init of the pwrdms states
arch/arm/mach-omap2/omap_hwmod.c | 26 ++-
arch/arm/mach-omap2/pm34xx.c | 2 +-
arch/arm/mach-omap2/pm44xx.c | 2 +-
arch/arm/mach-omap2/powerdomain.c | 213 ++++++++++++++
arch/arm/mach-omap2/powerdomain.h | 42 +++-
arch/arm/mach-omap2/powerdomains3xxx_data.c | 84 ++++++-
arch/arm/plat-omap/Kconfig | 7 +
arch/arm/plat-omap/Makefile | 1 +
arch/arm/plat-omap/include/plat/omap-pm.h | 4 +
arch/arm/plat-omap/include/plat/omap_device.h | 15 +-
arch/arm/plat-omap/include/plat/omap_hwmod.h | 2 +
arch/arm/plat-omap/omap-pm-constraints.c | 369 +++++++++++++++++++++++++
arch/arm/plat-omap/omap_device.c | 191 +++++++++++++
13 files changed, 950 insertions(+), 8 deletions(-)
create mode 100644 arch/arm/plat-omap/omap-pm-constraints.c
--
1.7.2.5
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