[PATCH v5 0/7] QCOM 8074 cpuidle driver

[Pramod Gurav]

Hi Lina,

With your patchset on top of 3.17-rc4 with v9 of ARM generic idle states
patches from Lorenzo I have tested cpuidle on dragonboard8974 with
Linaro test suites. All testcases report pass. Also verified manually
through sysfs to see changes in usage count and other details about each
state on all cpus.

So,
Tested-by:  Pramod Gurav <pramod.gurav at smartplayin.com>

I have a comment/observation only on name entry for each state which
reflects only "cpu-idle-state-" as Lorenzo dt-idle driver limits
CPUIDLE_NAME_LEN to 16.

Thanks
Pramod.
On Friday 05 September 2014 04:05 AM, Lina Iyer wrote:
> 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 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]
> 	|
> 	------>	msm-pm.c [SoC Interface layer for QCOM chipsets]
> 		|
> 		------> spm-devices.c [SPM devices manager]
> 		|	|
> 		|	------>	spm.c [SPM h/w driver]
> 		|
> 		------> scm-boot.c [SCM interface layer]		
> 			|
> ------------------------|--------------------------
> (EL)			Secure Monitor Code
> 			|
> 			|
> 			wfi(); 
> ------------------------|--------------------------
> (HW)			[CPU] {clock gate}
> 			|
> 			-----> [SPM] {statemachine}
> 			
> 
> The patchset does the following -
> 
> - Add new Secure Monitor flags to support warmboot of a quad core system.
> 
> - Introduce the SPM driver to control power to the core. The SPM h/w IP works
> in conjunction with the Krait CPU/L2. When the core executes WFI instruction,
> the core is clockgated and the SPM state machine takes over and powers the core
> down. An interrupt from GIC, resumes the SPM state machine which brings the cpu
> out of the low power mode.
> 
> - Add a SPM device manager to configure multiple SPM devices.
> 
> - Add the device tree configuration for each of the SPM nodes. There is one for
> each cpu. There is one for each cpu.
> 
> - Introduce the SoC driver interface layer to configure SPM per the core's idle
>  state. To power down the cpu core, the SPM h/w needs to be set up correctly
> to power down the core, when the core executes WFI. Linux is expected to call
> into Secure Monitor to power down the core. At reset, the core will start in
> seure mode and will be returned back to Linux. 
> 
> - Add CPUIDLE driver for QCOM cpus. The cpuidle driver uses the SoC interface
> layer to configure the SPM to allow Krait to be powered down. The cpuidle driver
> is based on ARM idle-state framework for cpuidle drivers.
> 
> - Provide device configuration for 8074 SoC. Current support is for WFI and
> standalone power collapse, which powers only the core independent of the
> other cores and caches.
> 
> Thanks,
> Lina
> 
> 
> 
> Lina Iyer (7):
>   msm: scm: Add SCM warmboot flags for quad core targets.
>   qcom: spm: Add Subsystem Power Manager driver (SAW2)
>   qcom: spm-devices: Add SPM device manager for the SoC
>   arm: dts: qcom: Add SPM device bindings for 8974
>   qcom: msm-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
> 
>  .../bindings/arm/msm/qcom,idle-state.txt           |  72 ++++++++
>  Documentation/devicetree/bindings/arm/msm/spm.txt  |  47 +++++
>  arch/arm/boot/dts/qcom-msm8974-pm.dtsi             |  69 +++++++
>  arch/arm/boot/dts/qcom-msm8974.dtsi                |  30 +++-
>  drivers/cpuidle/Kconfig.arm                        |   7 +
>  drivers/cpuidle/Makefile                           |   1 +
>  drivers/cpuidle/cpuidle-qcom.c                     |  87 +++++++++
>  drivers/soc/qcom/Kconfig                           |   8 +
>  drivers/soc/qcom/Makefile                          |   1 +
>  drivers/soc/qcom/msm-pm.c                          | 106 +++++++++++
>  drivers/soc/qcom/spm-devices.c                     | 198 +++++++++++++++++++++
>  drivers/soc/qcom/spm-drv.h                         |  69 +++++++
>  drivers/soc/qcom/spm.c                             | 192 ++++++++++++++++++++
>  include/soc/qcom/pm.h                              |  31 ++++
>  include/soc/qcom/scm-boot.h                        |   2 +
>  include/soc/qcom/spm.h                             |  38 ++++
>  16 files changed, 954 insertions(+), 4 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/arm/msm/qcom,idle-state.txt
>  create mode 100644 Documentation/devicetree/bindings/arm/msm/spm.txt
>  create mode 100644 arch/arm/boot/dts/qcom-msm8974-pm.dtsi
>  create mode 100644 drivers/cpuidle/cpuidle-qcom.c
>  create mode 100644 drivers/soc/qcom/msm-pm.c
>  create mode 100644 drivers/soc/qcom/spm-devices.c
>  create mode 100644 drivers/soc/qcom/spm-drv.h
>  create mode 100644 drivers/soc/qcom/spm.c
>  create mode 100644 include/soc/qcom/pm.h
>  create mode 100644 include/soc/qcom/spm.h
>