[PATCH v8 0/7] QCOM 8974 and 8084 cpuidle driver

[Lina Iyer]

Hi,

This v8 revision of the cpuidle driver is available at
git.linaro.org:/people/lina.iyer/linux-next cpuidle-v8


Changes since v7:
[ https://www.mail-archive.com/linux-arm-msm@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@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@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@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@vger.kernel.org/msg10518.html ]

Changes since v3:
[ https://www.mail-archive.com/linux-arm-msm@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@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@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 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]
	|
	------>	pm.c [SoC Interface layer for QCOM chipsets]
		|
		------> 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 CPU SPM devices 

- Add device bindings for 8084 CPU SPM devices

- Introduce the SoC interface layer to configure SPM per the core's idle state.

- Add CPUIDLE driver for QCOM cpus, using ARM generic idle state definitions.

- Add device bindings for 8974 idle-states - WFI and SPC

- Add device bindings for 8084 idle-states - WFI and SPC

Thanks,
Lina


Lina Iyer (7):
  qcom: spm: Add Subsystem Power Manager driver
  arm: dts: qcom: Add power-controller device node for 8974 Krait CPUs
  arm: dts: qcom: Add power-controller device node for 8084 Krait CPUs
  qcom: pm: Add cpu low power mode functions
  qcom: cpuidle: Add cpuidle driver for QCOM cpus
  arm: dts: qcom: Add idle states device nodes for 8974
  arm: dts: qcom: Add idle states device nodes for 8084

 .../bindings/arm/msm/qcom,idle-state.txt           |  81 ++++++++
 .../devicetree/bindings/arm/msm/qcom,saw2.txt      |  31 ++-
 arch/arm/boot/dts/qcom-apq8084.dtsi                |  46 ++++-
 arch/arm/boot/dts/qcom-msm8974.dtsi                |  46 ++++-
 drivers/cpuidle/Kconfig.arm                        |   7 +
 drivers/cpuidle/Makefile                           |   1 +
 drivers/cpuidle/cpuidle-qcom.c                     |  79 ++++++++
 drivers/soc/qcom/Kconfig                           |   8 +
 drivers/soc/qcom/Makefile                          |   1 +
 drivers/soc/qcom/pm.c                              | 115 +++++++++++
 drivers/soc/qcom/spm.c                             | 223 +++++++++++++++++++++
 include/soc/qcom/pm.h                              |  28 +++
 12 files changed, 658 insertions(+), 8 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/arm/msm/qcom,idle-state.txt
 create mode 100644 drivers/cpuidle/cpuidle-qcom.c
 create mode 100644 drivers/soc/qcom/pm.c
 create mode 100644 drivers/soc/qcom/spm.c
 create mode 100644 include/soc/qcom/pm.h

-- 
1.9.1