On Mar 9, 2015, at 10:16 AM, Lina Iyer <[email protected]> wrote:
> SPM is a hardware block that controls the peripheral logic surrounding > the application cores (cpu/l$). When the core executes WFI instruction, > the SPM takes over the putting the core in low power state as > configured. The wake up for the SPM is an interrupt at the GIC, which > then completes the rest of low power mode sequence and brings the core > out of low power mode. > > The SPM has a set of control registers that configure the SPMs > individually based on the type of the core and the runtime conditions. > SPM is a finite state machine block to which a sequence is provided and > it interprets the bytes and executes them in sequence. Each low power > mode that the core can enter into is provided to the SPM as a sequence. > > Configure the SPM to set the core (cpu or L2) into its low power mode, > the index of the first command in the sequence is set in the SPM_CTL > register. When the core executes ARM wfi instruction, it triggers the > SPM state machine to start executing from that index. The SPM state > machine waits until the interrupt occurs and starts executing the rest > of the sequence until it hits the end of the sequence. The end of the > sequence jumps the core out of its low power mode. > > Add support for an idle driver to set up the SPM to place the core in > Standby or Standalone power collapse mode when the core is idle. > > Based on work by: Mahesh Sivasubramanian <[email protected]>, > Ai Li <[email protected]>, Praveen Chidambaram <[email protected]> > Original tree available at - > git://codeaurora.org/quic/la/kernel/msm-3.10.git > > Cc: Stephen Boyd <[email protected]> > Cc: Arnd Bergmann <[email protected]> > Cc: Kevin Hilman <[email protected]> > Cc: Daniel Lezcano <[email protected]> > Signed-off-by: Lina Iyer <[email protected]> > --- > .../devicetree/bindings/arm/msm/qcom,saw2.txt | 31 +- > drivers/soc/qcom/Kconfig | 7 + > drivers/soc/qcom/Makefile | 1 + > drivers/soc/qcom/spm.c | 422 +++++++++++++++++++++ > 4 files changed, 455 insertions(+), 6 deletions(-) > create mode 100644 drivers/soc/qcom/spm.c > > diff --git a/Documentation/devicetree/bindings/arm/msm/qcom,saw2.txt > b/Documentation/devicetree/bindings/arm/msm/qcom,saw2.txt > index 1505fb8..690c3c0 100644 > --- a/Documentation/devicetree/bindings/arm/msm/qcom,saw2.txt > +++ b/Documentation/devicetree/bindings/arm/msm/qcom,saw2.txt > @@ -2,11 +2,20 @@ SPM AVS Wrapper 2 (SAW2) > > The SAW2 is a wrapper around the Subsystem Power Manager (SPM) and the > Adaptive Voltage Scaling (AVS) hardware. The SPM is a programmable > -micro-controller that transitions a piece of hardware (like a processor or > +power-controller that transitions a piece of hardware (like a processor or > subsystem) into and out of low power modes via a direct connection to > the PMIC. It can also be wired up to interact with other processors in the > system, notifying them when a low power state is entered or exited. > > +Multiple revisions of the SAW hardware are supported using these Device > Nodes. > +SAW2 revisions differ in the register offset and configuration data. Also, > the > +same revision of the SAW in different SoCs may have different configuration > +data due the the differences in hardware capabilities. Hence the SoC name, > the > +version of the SAW hardware in that SoC and the distinction between cpu (big > +or Little) or cache, may be needed to uniquely identify the SAW register > +configuration and initialization data. The compatible string is used to > +indicate this parameter. > + > PROPERTIES > > - compatible: > @@ -14,10 +23,13 @@ PROPERTIES > Value type: <string> > Definition: shall contain "qcom,saw2". A more specific value should be > one of: > - "qcom,saw2-v1" > - "qcom,saw2-v1.1" > - "qcom,saw2-v2" > - "qcom,saw2-v2.1" > + "qcom,saw2-v1" > + "qcom,saw2-v1.1" > + "qcom,saw2-v2" > + "qcom,saw2-v2.1" > + "qcom,apq8064-saw2-v1.1-cpu" > + "qcom,msm8974-saw2-v2.1-cpu" > + "qcom,apq8084-saw2-v2.1-cpu” > We don’t seem to use the "qcom,saw2-v1*” variants so should we just drop them? > - reg: > Usage: required > @@ -26,10 +38,17 @@ PROPERTIES > the register region. An optional second element specifies > the base address and size of the alias register region. > > +- regulator: > + Usage: optional > + Value type: boolean > + Definition: Indicates that this SPM device acts as a regulator device > + device for the core (CPU or Cache) the SPM is attached > + to. > > Example: > > - regulator@2099000 { > + power-controller@2099000 { > compatible = "qcom,saw2"; > reg = <0x02099000 0x1000>, <0x02009000 0x1000>; > + regulator; > }; - k -- Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
