From: Nuno Sá <nuno.sa@xxxxxxxxxx> The LTC4283 is a negative voltage hot swap controller that drives an external N-channel MOSFET to allow a board to be safely inserted and removed from a live backplane. Special note for the "adi,vpower-drns-enable" property. It allows to choose between the attenuated MOSFET drain voltage or the attenuated input voltage at the RTNS pin (effectively choosing between input or output power). This is a system level decision not really intended to change at runtime and hence is being added as a Firmware property. Signed-off-by: Nuno Sá <nuno.sa@xxxxxxxxxx> --- .../devicetree/bindings/hwmon/adi,ltc4283.yaml | 280 +++++++++++++++++++++ MAINTAINERS | 6 + 2 files changed, 286 insertions(+) diff --git a/Documentation/devicetree/bindings/hwmon/adi,ltc4283.yaml b/Documentation/devicetree/bindings/hwmon/adi,ltc4283.yaml new file mode 100644 index 0000000000000000000000000000000000000000..ec7768467e66f18f06d8a5258b3b115f23ea996d --- /dev/null +++ b/Documentation/devicetree/bindings/hwmon/adi,ltc4283.yaml @@ -0,0 +1,280 @@ +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/hwmon/adi,ltc4283.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: LTC4283 Negative Voltage Hot Swap Controller + +maintainers: + - Nuno Sá <nuno.sa@xxxxxxxxxx> + +description: | + The LTC4283 negative voltage hot swap controller drives an external N-channel + MOSFET to allow a board to be safely inserted and removed from a live + backplane. + + https://www.analog.com/media/en/technical-documentation/data-sheets/ltc4283.pdf + +properties: + compatible: + enum: + - adi,ltc4283 + + reg: + maxItems: 1 + + adi,rsense-nano-ohms: + description: Value of the sense resistor. + + adi,current-limit-sense-microvolt: + description: + The current limit sense voltage of the chip is adjustable between + 15mV and 30mV in 1mV steps. This effectively limits the current + on the load. + minimum: 15000 + maximum: 30000 + default: 15000 + + adi,current-limit-foldback-factor: + description: + Specifies the foldback factor for the current limit. The current limit + can be reduced (folded back) to one of four preset levels. The value + represents the percentage of the current limit sense voltage to use + during foldback. A value of 100 means no foldback. + $ref: /schemas/types.yaml#/definitions/uint32 + enum: [10, 20, 50, 100] + default: 100 + + adi,cooling-delay-ms: + description: + Cooling time to apply after an overcurrent fault, FET bad or + external fault. + enum: [512, 1002, 2005, 4100, 8190, 16400, 32800, 65600] + default: 512 + + adi,fet-bad-timer-delay-ms: + description: + FET bad timer delay. After a FET bad status condition is detected, + this timer is started. If the condition persists for the + specified time, the FET is turned off and a fault is logged. + enum: [256, 512, 1002, 2005] + default: 256 + + adi,power-good-reset-on-fet: + description: + If set, resets the power good status when the MOSFET is turned off. + Otherwise, it resets when a low output voltage is detected. + type: boolean + + adi,fet-turn-off-disable: + description: + If set, the MOSFET is turned off immediately when a FET fault is detected. + type: boolean + + adi,tmr-pull-down-disable: + description: Disables 2uA pull-down current on the TMR pin. + type: boolean + + adi,dvdt-inrush-control-disable: + description: + Enables dV/dt inrush control during startup. In dV/dt mode, the inrush + current is limited by controlling a constant output voltage ramp rate. + If not set, the inrush control mechanism is active current limiting. + type: boolean + + adi,fault-log-enable: + description: + If set, enables logging fault registers and ADC data into EEPROM upon a + fault. + type: boolean + + adi,vpower-drns-enable: + description: + If set, enables the attenuated MOSFET drain voltage to be monitored. This + effectively means that the MOSFET power is monitored. If not set, the + attenuated input voltage (and hence input power) is monitored. + type: boolean + + adi,external-fault-fet-off-enable: + description: Turns MOSFET off following an external fault. + type: boolean + + adi,undervoltage-retry-disable: + description: Do not retry to turn on the MOSFET after an undervoltage fault. + type: boolean + + adi,overvoltage-retry-disable: + description: Do not retry to turn on the MOSFET after an overvoltage fault. + type: boolean + + adi,external-fault-retry-enable: + description: Retry to turn on the MOSFET retry after an external fault. + type: boolean + + adi,overcurrent-retries: + description: Configures auto-retry following an Overcurrent fault. + $ref: /schemas/types.yaml#/definitions/string + enum: [latch-off, "1", "7", unlimited] + default: latch-off + + adi,fet-bad-retries: + description: + Configures auto-retry following a FET bad fault and a consequent MOSFET + turn off. + $ref: /schemas/types.yaml#/definitions/string + enum: [latch-off, "1", "7", unlimited] + default: latch-off + + adi,pgio1-func: + description: Configures the function of the PGIO1 pin. + $ref: /schemas/types.yaml#/definitions/string + enum: [inverted_power_good, power_good, gpio] + default: inverted_power_good + + adi,pgio2-func: + description: Configures the function of the PGIO2 pin. + $ref: /schemas/types.yaml#/definitions/string + enum: [inverted_power_good, power_good, gpio, active_current_limiting] + default: inverted_power_good + + adi,pgio3-func: + description: Configures the function of the PGIO3 pin. + $ref: /schemas/types.yaml#/definitions/string + enum: [inverted_power_good_input, power_good_input, gpio] + default: inverted_power_good_input + + adi,pgio4-func: + description: Configures the function of the PGIO4 pin. + $ref: /schemas/types.yaml#/definitions/string + enum: [inverted_external_fault, external_fault, gpio] + default: inverted_external_fault + + adi,gpio-on-adio1: + description: If set, the ADIO1 pin is used as a GPIO. + type: boolean + + adi,gpio-on-adio2: + description: If set, the ADIO2 pin is used as a GPIO. + type: boolean + + adi,gpio-on-adio3: + description: If set, the ADIO3 pin is used as a GPIO. + type: boolean + + adi,gpio-on-adio4: + description: If set, the ADIO4 pin is used as a GPIO. + type: boolean + + gpio-controller: true + + '#gpio-cells': + const: 2 + +dependencies: + adi,gpio-on-adio1: + - gpio-controller + - '#gpio-cells' + adi,gpio-on-adio2: + - gpio-controller + - '#gpio-cells' + adi,gpio-on-adio3: + - gpio-controller + - '#gpio-cells' + adi,gpio-on-adio4: + - gpio-controller + - '#gpio-cells' + adi,external-fault-retry-enable: + - adi,pgio4-func + adi,external-fault-fet-off-enable: + - adi,pgio4-func + +required: + - compatible + - reg + - adi,rsense-nano-ohms + +allOf: + - if: + required: + - adi,pgio1-func + then: + if: + properties: + adi,pgio1-func: + const: gpio + then: + required: + - gpio-controller + - '#gpio-cells' + + - if: + required: + - adi,pgio2-func + then: + if: + properties: + adi,pgio2-func: + const: gpio + then: + required: + - gpio-controller + - '#gpio-cells' + + - if: + required: + - adi,pgio3-func + then: + if: + properties: + adi,pgio3-func: + const: gpio + then: + required: + - gpio-controller + - '#gpio-cells' + + - if: + required: + - adi,pgio4-func + then: + if: + properties: + adi,pgio4-func: + const: gpio + then: + properties: + adi,external-fault-retry-enable: false + adi,external-fault-fet-off-enable: false + required: + - gpio-controller + - '#gpio-cells' + +additionalProperties: false + +examples: + - | + i2c { + #address-cells = <1>; + #size-cells = <0>; + + swap-controller@15 { + compatible = "adi,ltc4283"; + reg = <0x15>; + + adi,rsense-nano-ohms = <500>; + adi,current-limit-sense-microvolt = <25000>; + adi,current-limit-foldback-factor = <10>; + adi,cooling-delay-ms = <8190>; + adi,fet-bad-timer-delay-ms = <512>; + + adi,external-fault-fet-off-enable; + adi,pgio4-func = "external_fault"; + + adi,gpio-on-adio1; + adi,pgio1-func = "gpio"; + gpio-controller; + #gpio-cells = <2>; + }; + }; +... diff --git a/MAINTAINERS b/MAINTAINERS index e90710a9b40d7b32c151472a9ac3b02efd95f346..23a337246b99060161c620388c73829d9b98729d 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -14500,6 +14500,12 @@ F: Documentation/devicetree/bindings/hwmon/adi,ltc4282.yaml F: Documentation/hwmon/ltc4282.rst F: drivers/hwmon/ltc4282.c +LTC4283 HARDWARE MONITOR AND GPIO DRIVER +M: Nuno Sá <nuno.sa@xxxxxxxxxx> +L: linux-hwmon@xxxxxxxxxxxxxxx +S: Supported +F: Documentation/devicetree/bindings/hwmon/adi,ltc4283.yaml + LTC4286 HARDWARE MONITOR DRIVER M: Delphine CC Chiu <Delphine_CC_Chiu@xxxxxxxxxx> L: linux-hwmon@xxxxxxxxxxxxxxx -- 2.51.0
