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Diffstat (limited to 'Documentation')
5 files changed, 215 insertions, 6 deletions
diff --git a/Documentation/devicetree/bindings/arm/msm/qcom,idle-state.txt b/Documentation/devicetree/bindings/arm/msm/qcom,idle-state.txt new file mode 100644 index 000000000000..ae1b07f852c6 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/msm/qcom,idle-state.txt @@ -0,0 +1,81 @@ +QCOM Idle States for cpuidle driver + +ARM provides idle-state node to define the cpuidle states, as defined in [1]. +cpuidle-qcom is the cpuidle driver for Qualcomm SoCs and uses these idle +states. Idle states have different enter/exit latency and residency values. +The idle states supported by the QCOM SoC are defined as - + + * Standby + * Retention + * Standalone Power Collapse (Standalone PC or SPC) + * Power Collapse (PC) + +Standby: Standby does a little more in addition to architectural clock gating. +When the WFI instruction is executed the ARM core would gate its internal +clocks. In addition to gating the clocks, QCOM cpus use this instruction as a +trigger to execute the SPM state machine. The SPM state machine waits for the +interrupt to trigger the core back in to active. This triggers the cache +hierarchy to enter standby states, when all cpus are idle. An interrupt brings +the SPM state machine out of its wait, the next step is to ensure that the +cache hierarchy is also out of standby, and then the cpu is allowed to resume +execution. + +Retention: Retention is a low power state where the core is clock gated and +the memory and the registers associated with the core are retained. The +voltage may be reduced to the minimum value needed to keep the processor +registers active. The SPM should be configured to execute the retention +sequence and would wait for interrupt, before restoring the cpu to execution +state. Retention may have a slightly higher latency than Standby. + +Standalone PC: A cpu can power down and warmboot if there is a sufficient time +between the time it enters idle and the next known wake up. SPC mode is used +to indicate a core entering a power down state without consulting any other +cpu or the system resources. This helps save power only on that core. The SPM +sequence for this idle state is programmed to power down the supply to the +core, wait for the interrupt, restore power to the core, and ensure the +system state including cache hierarchy is ready before allowing core to +resume. Applying power and resetting the core causes the core to warmboot +back into Elevation Level (EL) which trampolines the control back to the +kernel. Entering a power down state for the cpu, needs to be done by trapping +into a EL. Failing to do so, would result in a crash enforced by the warm boot +code in the EL for the SoC. On SoCs with write-back L1 cache, the cache has to +be flushed in s/w, before powering down the core. + +Power Collapse: This state is similar to the SPC mode, but distinguishes +itself in that the cpu acknowledges and permits the SoC to enter deeper sleep +modes. In a hierarchical power domain SoC, this means L2 and other caches can +be flushed, system bus, clocks - lowered, and SoC main XO clock gated and +voltages reduced, provided all cpus enter this state. Since the span of low +power modes possible at this state is vast, the exit latency and the residency +of this low power mode would be considered high even though at a cpu level, +this essentially is cpu power down. The SPM in this state also may handshake +with the Resource power manager processor in the SoC to indicate a complete +application processor subsystem shut down. + +The idle-state for QCOM SoCs are distinguished by the compatible property of +the idle-states device node. +The devicetree representation of the idle state should be - + +Required properties: + +- compatible: Must be one of - + "qcom,idle-state-stby", + "qcom,idle-state-ret", + "qcom,idle-state-spc", + "qcom,idle-state-pc", + and "arm,idle-state". + +Other required and optional properties are specified in [1]. + +Example: + + idle-states { + CPU_SPC: spc { + compatible = "qcom,idle-state-spc", "arm,idle-state"; + entry-latency-us = <150>; + exit-latency-us = <200>; + min-residency-us = <2000>; + }; + }; + +[1]. Documentation/devicetree/bindings/arm/idle-states.txt diff --git a/Documentation/devicetree/bindings/arm/msm/qcom,saw2.txt b/Documentation/devicetree/bindings/arm/msm/qcom,saw2.txt index 1505fb8e131a..690c3c002ad2 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" - 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; }; diff --git a/Documentation/devicetree/bindings/mfd/qcom-rpm.txt b/Documentation/devicetree/bindings/mfd/qcom-rpm.txt new file mode 100644 index 000000000000..85e31980017a --- /dev/null +++ b/Documentation/devicetree/bindings/mfd/qcom-rpm.txt @@ -0,0 +1,70 @@ +Qualcomm Resource Power Manager (RPM) + +This driver is used to interface with the Resource Power Manager (RPM) found in +various Qualcomm platforms. The RPM allows each component in the system to vote +for state of the system resources, such as clocks, regulators and bus +frequencies. + +- compatible: + Usage: required + Value type: <string> + Definition: must be one of: + "qcom,rpm-apq8064" + "qcom,rpm-msm8660" + "qcom,rpm-msm8960" + +- reg: + Usage: required + Value type: <prop-encoded-array> + Definition: base address and size of the RPM's message ram + +- interrupts: + Usage: required + Value type: <prop-encoded-array> + Definition: three entries specifying the RPM's: + 1. acknowledgement interrupt + 2. error interrupt + 3. wakeup interrupt + +- interrupt-names: + Usage: required + Value type: <string-array> + Definition: must be the three strings "ack", "err" and "wakeup", in order + +- #address-cells: + Usage: required + Value type: <u32> + Definition: must be 1 + +- #size-cells: + Usage: required + Value type: <u32> + Definition: must be 0 + +- qcom,ipc: + Usage: required + Value type: <prop-encoded-array> + + Definition: three entries specifying the outgoing ipc bit used for + signaling the RPM: + - phandle to a syscon node representing the apcs registers + - u32 representing offset to the register within the syscon + - u32 representing the ipc bit within the register + + += EXAMPLE + + #include <dt-bindings/mfd/qcom-rpm.h> + + rpm@108000 { + compatible = "qcom,rpm-msm8960"; + reg = <0x108000 0x1000>; + qcom,ipc = <&apcs 0x8 2>; + + interrupts = <0 19 0>, <0 21 0>, <0 22 0>; + interrupt-names = "ack", "err", "wakeup"; + + #address-cells = <1>; + #size-cells = <0>; + }; + diff --git a/Documentation/devicetree/bindings/mmc/mmc-pwrseq-simple.txt b/Documentation/devicetree/bindings/mmc/mmc-pwrseq-simple.txt new file mode 100644 index 000000000000..a462c50f19a8 --- /dev/null +++ b/Documentation/devicetree/bindings/mmc/mmc-pwrseq-simple.txt @@ -0,0 +1,25 @@ +* The simple MMC power sequence provider + +The purpose of the simple MMC power sequence provider is to supports a set of +common properties between various SOC designs. It thus enables us to use the +same provider for several SOC designs. + +Required properties: +- compatible : contains "mmc-pwrseq-simple". + +Optional properties: +- reset-gpios : contains a list of GPIO specifiers. The reset GPIOs are asserted + at initialization and prior we start the power up procedure of the card. + They will be de-asserted right after the power has been provided to the + card. +- clocks : Must contain an entry for the entry in clock-names. + See ../clocks/clock-bindings.txt for details. +- clock-names : Must include the following entry: + "ext_clock" (External clock provided to the card). + +Example: + + sdhci0_pwrseq { + compatible = "mmc-pwrseq-simple"; + reset-gpios = <&gpio1 12 0>; + } diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt b/Documentation/devicetree/bindings/mmc/mmc.txt index b52628b18a53..86a9677618d2 100644 --- a/Documentation/devicetree/bindings/mmc/mmc.txt +++ b/Documentation/devicetree/bindings/mmc/mmc.txt @@ -64,6 +64,19 @@ Optional SDIO properties: - keep-power-in-suspend: Preserves card power during a suspend/resume cycle - enable-sdio-wakeup: Enables wake up of host system on SDIO IRQ assertion +MMC power sequences: +-------------------- + +System on chip designs may specify a specific MMC power sequence. To +successfully detect an (e)MMC/SD/SDIO card, that power sequence must be +maintained while initializing the card. + +Optional property: +- mmc-pwrseq: phandle to the MMC power sequence node. See "mmc-pwrseq-*" + for documentation of MMC power sequence bindings. + + + Example: sdhci@ab000000 { @@ -77,4 +90,5 @@ sdhci@ab000000 { max-frequency = <50000000>; keep-power-in-suspend; enable-sdio-wakeup; + mmc-pwrseq = <&sdhci0_pwrseq> } |