[PATCH v14 00/10] cpuidle driver for QCOM SoCs: 8064, 8074, 8084

Lina Iyer
2014-12-02T17:39:08Z

Dependent patchsets -
https://lkml.org/lkml/2014/8/4/767
http://www.spinics.net/lists/linux-arm-msm/msg10799.html
http://www.spinics.net/lists/linux-arm-msm/msg10795.html

Changes since v13:
- Return values for idle states propagated back to the cpuidle driver.
- Remove static bool cpuidle_drv_init.
- Register cpuidle driver and cpuidle device separately.
- cpuidle device registered only when the SPM for the cpu is probed.
- Initialization changes to ensure dynamic cpuidle devices are registered only
after the cpuidle driver is registered.
- Removed wmb, replaced with a poll loop to ensure that the SPM registers are
written before executing wfi.
- Added spm_register_write_sync() for write guarantees.
- Removed irrelevant return value for spm_set_low_power_mode().
- Added comments, updated module description.
- Removed Reviewed-by and Acked-by on the spm and cpuidle-qcom patches.

Changes since v12:
- Minor fixes
- Added Reviewed-by

Changes since v11:
- Address review comments on spm.c
- Commenting style fixes
- Added Reviewed-by

Changes since v10:
[ https://www.mail-archive.com/devicetree at vger.kernel.org/msg51880.html ]
- Address review comments
- Added Acked-by and Reviewed-by

Changes since v9:
[ https://www.mail-archive.com/linux-arm-msm at vger.kernel.org/msg11714.html ]
- Address review comments on v9

Changes since v8:
[ https://www.mail-archive.com/linux-arm-msm at vger.kernel.org/msg11473.html ]
- Flatten out the file structure - merge pm.c into spm.c after discussions
- Add a new function to set warm boot address, in scm-boot.c
- Support for 8064 (New)
- Tested on 8074, 8084. 8064 was tested with a WIP tree
- Address review comments from v8
- Looking into possiblility of initializing the cpuidle device for a cpu,
only when the corresponding spm device is probed successfully.

Changes since v7:
[ https://www.mail-archive.com/linux-arm-msm at vger.kernel.org/msg11199.html ]
- Address review comments
- Tested on 8974 but not 8084
- WFI renamed to Standby
- Update commit text with original author and link to the downstream tree

Changes since v6:
[ https://www.mail-archive.com/linux-arm-msm at vger.kernel.org/msg11012.html ]
- SPM device nodes merged with existing SAW DT nodes
- SPM register information is handled within the driver
- Clean up from using 'msm' to 'qcom'
- Shorten some enumerations as well
- Review comments from v6 addressed
- New: Support for 8084 SoC
- Not tested. I do not have a board with this SoC, but the SPM
configuration should be identical for WFI and SPC

Changes since v5:
[ https://www.mail-archive.com/linux-arm-msm at vger.kernel.org/msg10559.html ]
- Merge spm-devices.c and spm.c into one file and one patch
- Simplify implementation of the driver.
- Update documentation mapping the DT properties with corresponding
SPM register information.
- Removed scm-boot changes for quad core warmboot, its has been pulled in.

Changes since v4:
[ https://www.mail-archive.com/linux-arm-msm at vger.kernel.org/msg10327.html ]
- Update to the v8 of ARM generic idle states patches
- Use platform device model for cpuidle-qcom
- Clean up msm-pm.c to remove unnecessary include files and functions
- Update commit text and documentation for all idle states
- Remove scm-boot relocate patch from this series, submitted earlier
[ https://www.mail-archive.com/linux-arm-msm at vger.kernel.org/msg10518.html ]

Changes since v3:
[ https://www.mail-archive.com/linux-arm-msm at vger.kernel.org/msg10288.html ]
- Fix CONFIG_QCOM_PM Kconfig as bool
- More clean ups in spm.c and spm-devices.c
- Removed and re-organized data structures to make initialization simple
- Remove export of sequence flush functions
- Updated commit text
- Comments for use of barriers.
- Rebase on top of 3.17-rc1

Changes since v2:
[ https://www.mail-archive.com/linux-arm-msm at vger.kernel.org/msg10148.html ]
- Prune all the drivers to support basic WFI and power down cpuidle
functionality. Remove debug code.
- Integrate KConfig changes into the drivers' patches.
- Use Lorenzo's ARM idle-states patches as the basis for reading cpuidle
c-states from DT.
[ http://marc.info/?l=linux-pm&m=140794514812383&w=2 ]
- Incorporate review comments
- Rebase on top of 3.16

Changes since v1/RFC:
[ https://www.mail-archive.com/linux-arm-msm at vger.kernel.org/msg10065.html ]
- Remove hotplug from the patch series. Will submit it separately.
- Fix SPM drivers per the review comments
- Modify patch sequence to compile SPM drivers independent of msm-pm, so as to
allow wfi() calls to use SPM even without SoC interface driver.

8074/8084/8064 like any ARM SoC can do architectural clock gating, that helps save
on power, but not enough of leakage power. Leakage power of the SoC can be
further reduced by turning off power to the core. To aid this, every core (cpu
and L2) is accompanied by a Sub-system Power Manager (SPM), that can be
configured to indicate the low power mode, the core would be put into and the
SPM programs the peripheral h/w accordingly to enter low power and turn off the
power rail to the core.

The idle invocation hierarchy -

CPUIDLE
|
cpuidle-qcom.c [CPUIdle driver]
|
------> spm.c [SPM driver]
|
------> scm-boot.c [SCM interface layer]
|
------------------------|--------------------------
(EL) Secure Monitor Code
|
|
wfi();
------------------------|--------------------------
(HW) [CPU] {clock gate}
|
-----> [SPM] {statemachine}

The patchset does the following -

- Introduce the SPM driver to control power to the core
- Add device bindings for 8974, 8084, 8064 CPU SPM devices
- Add cpuidle driver for QCOM cpus, using ARM generic idle state definitions.
- Add device bindings for 8974, 8084, 8064 idle-states - WFI and SPC

Thanks,
Lina

Lina Iyer (10):
qcom: scm: Move scm-boot files to drivers/soc/qcom/ and
include/soc/qcom
qcom: scm: Add SCM warmboot support for quad core SoCs
qcom: spm: Add Subsystem Power Manager driver
arm: dts: qcom: Add power-controller device node for 8074 Krait CPUs
arm: dts: qcom: Add power-controller device node for 8084 Krait CPUs
arm: dts: qcom: Update power-controller device node for 8064 Krait
CPUs
qcom: cpuidle: Add cpuidle driver for QCOM cpus
arm: dts: qcom: Add idle states device nodes for 8074
arm: dts: qcom: Add idle states device nodes for 8084
arm: dts: qcom: Add idle state device nodes for 8064

.../bindings/arm/msm/qcom,idle-state.txt | 81 +++++
.../devicetree/bindings/arm/msm/qcom,saw2.txt | 31 +-
arch/arm/boot/dts/qcom-apq8064.dtsi | 38 ++-
arch/arm/boot/dts/qcom-apq8084.dtsi | 48 ++-
arch/arm/boot/dts/qcom-msm8974.dtsi | 48 ++-
arch/arm/mach-qcom/Makefile | 1 -
arch/arm/mach-qcom/platsmp.c | 2 +-
drivers/cpuidle/Kconfig.arm | 7 +
drivers/cpuidle/Makefile | 1 +
drivers/cpuidle/cpuidle-qcom.c | 99 ++++++
drivers/soc/qcom/Kconfig | 8 +
drivers/soc/qcom/Makefile | 3 +-
.../arm/mach-qcom => drivers/soc/qcom}/scm-boot.c | 37 ++-
drivers/soc/qcom/spm.c | 338 +++++++++++++++++++++
include/soc/qcom/pm.h | 31 ++
.../arm/mach-qcom => include/soc/qcom}/scm-boot.h | 3 +-
16 files changed, 754 insertions(+), 22 deletions(-)
create mode 100644 Documentation/devicetree/bindings/arm/msm/qcom,idle-state.txt
create mode 100644 drivers/cpuidle/cpuidle-qcom.c
rename {arch/arm/mach-qcom => drivers/soc/qcom}/scm-boot.c (59%)
create mode 100644 drivers/soc/qcom/spm.c
create mode 100644 include/soc/qcom/pm.h
rename {arch/arm/mach-qcom => include/soc/qcom}/scm-boot.h (91%)

--
2.1.0