Qualcomm RPM Regulators rpm-regulator-smd is a regulator driver which supports regulators inside of PMICs which are controlled by the RPM processor. Communication with the RPM processor takes place over SMD. Required structure: - RPM regulators must be described in two levels of devices nodes. The first level describes the interface with the RPM. The second level describes properties of one regulator framework interface (of potentially many) to the regulator. [First Level Nodes] Required properties: - compatible: Must be "qcom,rpm-regulator-smd-resource" - qcom,resource-name: Resource name string for this regulator to be used in RPM transactions. Length is 4 characters max. - qcom,resource-id: Resource instance ID for this regulator to be used in RPM transactions. - qcom,regulator-type: Type of this regulator. Supported values are: 0 = LDO 1 = SMPS 2 = VS 3 = NCP Optional properties: - qcom,allow-atomic: Flag specifying if atomic access is allowed for this regulator. Supported values are: 0 or not present = mutex locks used 1 = spinlocks used - qcom,enable-time: Time in us to delay after enabling the regulator - qcom,hpm-min-load: Load current in uA which corresponds to the minimum load which requires the regulator to be in high power mode. [Second Level Nodes] Required properties: - compatible: Must be "qcom,rpm-regulator-smd" - regulator-name: A string used as a descriptive name for regulator outputs - qcom,set: Specifies which sets that requests made with this regulator interface should be sent to. Regulator requests sent in the active set take effect immediately. Requests sent in the sleep set take effect when the Apps processor transitions into RPM assisted power collapse. Supported values are: 1 = Active set only 2 = Sleep set only 3 = Both active and sleep sets Optional properties: - parent-supply: phandle to the parent supply/regulator node - qcom,system-load: Load in uA present on regulator that is not captured by any consumer request - qcom,use-voltage-corner: Flag that signifies if regulator_set_voltage calls should modify the corner parameter instead of the voltage parameter. When used, voltages specified inside of the regulator framework represent corners that have been incremented by 1. This value shift is necessary to work around limitations in the regulator framework which treat 0 uV as an error. - qcom,use-voltage-floor-corner: Flag that signifies if regulator_set_voltage calls should modify the floor corner parameter instead of the voltage parameter. When used, voltages specified inside of the regulator framework represent corners that have been incremented by 1. The properties qcom,use-voltage-corner and qcom,use-voltage-floor-corner are mutually exclusive. Only one may be specified for a given regulator. - qcom,always-send-voltage: Flag which indicates that updates to the voltage or voltage corner set point should always be sent immediately to the RPM. If this flag is not specified, then voltage set point updates are only sent if the given regulator has also been enabled by a Linux consumer. - qcom,always-send-current: Flag which indicates that updates to the load current should always be sent immediately to the RPM. If this flag is not specified, then load current updates are only sent if the given regulator has also been enabled by a Linux consumer. The following properties specify initial values for parameters to be sent to the RPM in regulator requests. - qcom,init-enable: 0 = regulator disabled 1 = regulator enabled - qcom,init-voltage: Voltage in uV - qcom,init-current: Current in mA - qcom,init-ldo-mode: Operating mode to be used with LDO regulators Supported values are: 0 = mode determined by current requests 1 = force HPM (NPM) - qcom,init-smps-mode: Operating mode to be used with SMPS regulators Supported values are: 0 = auto; hardware determines mode 1 = mode determined by current requests 2 = force HPM (PWM) - qcom,init-pin-ctrl-enable: Bit mask specifying which hardware pins should be used to enable the regulator, if any; supported bits are: 0 = ignore all hardware enable signals BIT(0) = follow HW0_EN signal BIT(1) = follow HW1_EN signal BIT(2) = follow HW2_EN signal BIT(3) = follow HW3_EN signal - qcom,init-pin-ctrl-mode: Bit mask specifying which hardware pins should be used to force the regulator into high power mode, if any. Supported bits are: 0 = ignore all hardware enable signals BIT(0) = follow HW0_EN signal BIT(1) = follow HW1_EN signal BIT(2) = follow HW2_EN signal BIT(3) = follow HW3_EN signal BIT(4) = follow PMIC awake state - qcom,init-frequency: Switching frequency divisor for SMPS regulators. Supported values are n = 0 to 31 where freq = 19.2 MHz / (n + 1). - qcom,init-head-room: Voltage head room in mV required for the regulator. This head room value should be used in situations where the device connected to the output of the regulator has low noise tolerance. Note that the RPM independently enforces a safety head room value for subregulated LDOs which is sufficient to account for LDO drop-out voltage. - qcom,init-quiet-mode: Specify that quiet mode is needed for an SMPS regulator in order to have lower output noise. Supported values are: 0 = No quiet mode 1 = Quiet mode 2 = Super quiet mode - qcom,init-freq-reason: Consumer requiring specified frequency for an SMPS regulator. Supported values are: 0 = None 1 = Bluetooth 2 = GPS 4 = WLAN 8 = WAN - qcom,init-voltage-corner: Performance corner to use in order to determine voltage set point. This value corresponds to the actual value that will be sent and is not incremented by 1 like the values used inside of the regulator framework. The meaning of corner values is set by the RPM. It is possible that different regulators on a given platform or similar regulators on different platforms will utilize different corner values. These are corner values supported on MSM8974 for PMIC PM8841 SMPS 2 (VDD_Dig); nominal voltages for these corners are also shown: 0 = None (don't care) 1 = Retention (0.5000 V) 2 = SVS Krait (0.7250 V) 3 = SVS SOC (0.8125 V) 4 = Normal (0.9000 V) 5 = Turbo (0.9875 V) 6 = Super Turbo (1.0500 V) - qcom,init-disallow-bypass: Specify that bypass mode should not be used for a given LDO regulator. When in bypass mode, an LDO performs no regulation and acts as a simple switch. The RPM can utilize this mode for an LDO that is subregulated from an SMPS when it is possible to reduce the SMPS voltage to the desired LDO output level. Bypass mode may be disallowed if lower LDO output noise is required. Supported values are: 0 = Allow RPM to utilize LDO bypass mode if possible 1 = Disallow LDO bypass mode - qcom,init-voltage-floor-corner: Minimum performance corner to use if any processor in the system is awake. This property supports the same values as qcom,init-voltage-corner. All properties specified within the core regulator framework can also be used in second level nodes. These bindings can be found in: Documentation/devicetree/bindings/regulator/regulator.txt. Example: rpm-regulator-smpb1 { qcom,resource-name = "smpb"; qcom,resource-id = <1>; qcom,regulator-type = <1>; qcom,hpm-min-load = <100000>; compatible = "qcom,rpm-regulator-smd-resource"; status = "disabled"; pm8841_s1: regulator-s1 { regulator-name = "8841_s1"; qcom,set = <3>; regulator-min-microvolt = <900000>; regulator-max-microvolt = <1150000>; qcom,init-voltage = <1150000>; compatible = "qcom,rpm-regulator-smd"; }; pm8841_s1_ao: regulator-s1-ao { regulator-name = "8841_s1_ao"; qcom,set = <1>; regulator-min-microvolt = <900000>; regulator-max-microvolt = <1150000>; compatible = "qcom,rpm-regulator-smd"; }; pm8841_s1_corner: regulator-s1-corner { regulator-name = "8841_s1_corner"; qcom,set = <3>; regulator-min-microvolt = <1>; regulator-max-microvolt = <6>; qcom,init-voltage-corner = <3>; qcom,use-voltage-corner; compatible = "qcom,rpm-regulator-smd"; }; };