* [PATCH v6 0/3] hwmon: Add support for the LTC4283 Hot Swap Controller
@ 2026-03-03 17:00 Nuno Sá via B4 Relay
2026-03-03 17:00 ` [PATCH v6 1/3] dt-bindings: hwmon: Document the LTC4283 " Nuno Sá via B4 Relay
` (2 more replies)
0 siblings, 3 replies; 8+ messages in thread
From: Nuno Sá via B4 Relay @ 2026-03-03 17:00 UTC (permalink / raw)
To: linux-gpio, linux-hwmon, devicetree, linux-doc
Cc: Guenter Roeck, Rob Herring, Krzysztof Kozlowski, Conor Dooley,
Jonathan Corbet, Linus Walleij, Bartosz Golaszewski,
Bartosz Golaszewski
This is v6 for the LTC4283 how swap controller. Main change is that I'm
now using the auxiliary bus for adding the GPIO device (done depending
on FW properties).
Similar to the LTC4282 device, we're clearing some fault logs in the
reset_history attributes.
---
Changes in v6:
- Patch 2:
* Rework regmap to use single regmap with custom regmap_bus
(lm75-style);
* Add explicit i2c func checks;
* Make sure page support is enabled for energy reads;
* Fix MODULE_DESCRIPTION: "How Swap" -> "Hot Swap";
* Remove #include <linux/hwmon-sysfs.h> (unused);
* Fix commit message: "How Swap Controller" -> "Hot Swap Controller";
* Fix "Addresses scanned" section in docs (no .detect() supported).
- Patch 3:
* Fix typo: LTC42823_ADIO_CONFIG -> LTC4283_ADIO_CONFIG.
- Link to v5: https://lore.kernel.org/linux-hwmon/20251223-ltc4283-support-v5-0-1152bff59a61@analog.com/
---
---
Nuno Sá (3):
dt-bindings: hwmon: Document the LTC4283 Swap Controller
hwmon: ltc4283: Add support for the LTC4283 Swap Controller
gpio: gpio-ltc4283: Add support for the LTC4283 Swap Controller
.../devicetree/bindings/hwmon/adi,ltc4283.yaml | 272 +++
Documentation/hwmon/index.rst | 1 +
Documentation/hwmon/ltc4283.rst | 265 +++
MAINTAINERS | 9 +
drivers/gpio/Kconfig | 15 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-ltc4283.c | 218 +++
drivers/hwmon/Kconfig | 12 +
drivers/hwmon/Makefile | 1 +
drivers/hwmon/ltc4283.c | 1780 ++++++++++++++++++++
10 files changed, 2574 insertions(+)
---
base-commit: 78558965440b27814592ec82d8f3668395953b1b
change-id: 20260303-ltc4283-support-063f78acc5a4
--
Thanks!
- Nuno Sá
^ permalink raw reply [flat|nested] 8+ messages in thread* [PATCH v6 1/3] dt-bindings: hwmon: Document the LTC4283 Swap Controller 2026-03-03 17:00 [PATCH v6 0/3] hwmon: Add support for the LTC4283 Hot Swap Controller Nuno Sá via B4 Relay @ 2026-03-03 17:00 ` Nuno Sá via B4 Relay 2026-03-03 17:00 ` [PATCH v6 2/3] hwmon: ltc4283: Add support for " Nuno Sá via B4 Relay 2026-03-03 17:00 ` [PATCH v6 3/3] gpio: gpio-ltc4283: " Nuno Sá via B4 Relay 2 siblings, 0 replies; 8+ messages in thread From: Nuno Sá via B4 Relay @ 2026-03-03 17:00 UTC (permalink / raw) To: linux-gpio, linux-hwmon, devicetree, linux-doc Cc: Guenter Roeck, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Jonathan Corbet, Linus Walleij, Bartosz Golaszewski From: Nuno Sá <nuno.sa@analog.com> 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. Reviewed-by: Rob Herring (Arm) <robh@kernel.org> Signed-off-by: Nuno Sá <nuno.sa@analog.com> --- .../devicetree/bindings/hwmon/adi,ltc4283.yaml | 272 +++++++++++++++++++++ MAINTAINERS | 6 + 2 files changed, 278 insertions(+) diff --git a/Documentation/devicetree/bindings/hwmon/adi,ltc4283.yaml b/Documentation/devicetree/bindings/hwmon/adi,ltc4283.yaml new file mode 100644 index 000000000000..f82fff1ec7e4 --- /dev/null +++ b/Documentation/devicetree/bindings/hwmon/adi,ltc4283.yaml @@ -0,0 +1,272 @@ +# 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@analog.com> + +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: + properties: + adi,pgio1-func: + const: gpio + required: + - adi,pgio1-func + then: + required: + - gpio-controller + - '#gpio-cells' + + - if: + properties: + adi,pgio2-func: + const: gpio + required: + - adi,pgio2-func + then: + required: + - gpio-controller + - '#gpio-cells' + + - if: + properties: + adi,pgio3-func: + const: gpio + required: + - adi,pgio3-func + then: + required: + - gpio-controller + - '#gpio-cells' + + - if: + properties: + adi,pgio4-func: + const: gpio + required: + - adi,pgio4-func + 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 830c6f076b00..13ae2f3db449 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -15141,6 +15141,12 @@ 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@analog.com> +L: linux-hwmon@vger.kernel.org +S: Supported +F: Documentation/devicetree/bindings/hwmon/adi,ltc4283.yaml + LTC4286 HARDWARE MONITOR DRIVER M: Delphine CC Chiu <Delphine_CC_Chiu@Wiwynn.com> L: linux-hwmon@vger.kernel.org -- 2.53.0 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH v6 2/3] hwmon: ltc4283: Add support for the LTC4283 Swap Controller 2026-03-03 17:00 [PATCH v6 0/3] hwmon: Add support for the LTC4283 Hot Swap Controller Nuno Sá via B4 Relay 2026-03-03 17:00 ` [PATCH v6 1/3] dt-bindings: hwmon: Document the LTC4283 " Nuno Sá via B4 Relay @ 2026-03-03 17:00 ` Nuno Sá via B4 Relay 2026-03-04 11:05 ` kernel test robot 2026-03-06 17:41 ` Guenter Roeck 2026-03-03 17:00 ` [PATCH v6 3/3] gpio: gpio-ltc4283: " Nuno Sá via B4 Relay 2 siblings, 2 replies; 8+ messages in thread From: Nuno Sá via B4 Relay @ 2026-03-03 17:00 UTC (permalink / raw) To: linux-gpio, linux-hwmon, devicetree, linux-doc Cc: Guenter Roeck, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Jonathan Corbet, Linus Walleij, Bartosz Golaszewski From: Nuno Sá <nuno.sa@analog.com> Support the LTC4283 Hot Swap Controller. The device features programmable current limit with foldback and independently adjustable inrush current to optimize the MOSFET safe operating area (SOA). The SOA timer limits MOSFET temperature rise for reliable protection against overstresses. An I2C interface and onboard ADC allow monitoring of board current, voltage, power, energy, and fault status. Signed-off-by: Nuno Sá <nuno.sa@analog.com> --- Documentation/hwmon/index.rst | 1 + Documentation/hwmon/ltc4283.rst | 265 ++++++ MAINTAINERS | 1 + drivers/hwmon/Kconfig | 12 + drivers/hwmon/Makefile | 1 + drivers/hwmon/ltc4283.c | 1780 +++++++++++++++++++++++++++++++++++++++ 6 files changed, 2060 insertions(+) diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst index 559c32344cd3..eab95152abee 100644 --- a/Documentation/hwmon/index.rst +++ b/Documentation/hwmon/index.rst @@ -144,6 +144,7 @@ Hardware Monitoring Kernel Drivers ltc4260 ltc4261 ltc4282 + ltc4283 ltc4286 macsmc-hwmon max127 diff --git a/Documentation/hwmon/ltc4283.rst b/Documentation/hwmon/ltc4283.rst new file mode 100644 index 000000000000..225ba886531d --- /dev/null +++ b/Documentation/hwmon/ltc4283.rst @@ -0,0 +1,265 @@ +.. SPDX-License-Identifier: GPL-2.0-only + +Kernel drivers ltc4283 +========================================== + +Supported chips: + + * Analog Devices LTC4283 + + Prefix: 'ltc4283' + + Addresses scanned: - + + Datasheet: + + https://www.analog.com/media/en/technical-documentation/data-sheets/ltc4283.pdf + +Author: Nuno Sá <nuno.sa@analog.com> + +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. +The device features programmable current limit with foldback and independently +adjustable inrush current to optimize the MOSFET safe operating area (SOA). The +SOA timer limits MOSFET temperature rise for reliable protection against +overstresses. An I2C interface and onboard gear-shift ADC allow monitoring of +board current, voltage, power, energy, and fault status. Additional features +respond to input UV/OV, interrupt the host when a fault has occurred, notify +when output power is good, detect insertion of a board, turn off the MOSFET +if an external supply monitor fails to indicate power good within a timeout +period, and auto-reboot after a programmable delay following a host commanded +turn-off. + +Sysfs entries +_____________ + +The following attributes are supported. Limits are read-write and all the other +attributes are read-only. Note that the VADIOx channels might not be available +if the ADIO pins are used as GPIOs (naturally also affects the respective +differential channels). + +======================= ========================================== +in0_lcrit_alarm Critical Undervoltage alarm +in0_crit_alarm Critical Overvoltage alarm +in0_label Channel label (VIN) + +in1_input Output voltage (mV). +in1_min Undervoltage threshold +in1_max Overvoltage threshold +in1_lowest Lowest measured voltage +in1_highest Highest measured voltage +in1_reset_history Write 1 to reset history. +in1_min_alarm Undervoltage alarm +in1_max_alarm Overvoltage alarm +in1_label Channel label (VPWR) + +in2_input Output voltage (mV). +in2_min Undervoltage threshold +in2_max Overvoltage threshold +in2_lowest Lowest measured voltage +in2_highest Highest measured voltage +in2_reset_history Write 1 to reset history. +in2_min_alarm Undervoltage alarm +in2_max_alarm Overvoltage alarm +in2_enable Enable/Disable monitoring. +in2_label Channel label (VADI1) + +in3_input Output voltage (mV). +in3_min Undervoltage threshold +in3_max Overvoltage threshold +in3_lowest Lowest measured voltage +in3_highest Highest measured voltage +in3_reset_history Write 1 to reset history. +in3_min_alarm Undervoltage alarm +in3_max_alarm Overvoltage alarm +in3_enable Enable/Disable monitoring. +in3_label Channel label (VADI2) + +in4_input Output voltage (mV). +in4_min Undervoltage threshold +in4_max Overvoltage threshold +in4_lowest Lowest measured voltage +in4_highest Highest measured voltage +in4_reset_history Write 1 to reset history. +in4_min_alarm Undervoltage alarm +in4_max_alarm Overvoltage alarm +in4_enable Enable/Disable monitoring. +in4_label Channel label (VADI3) + +in5_input Output voltage (mV). +in5_min Undervoltage threshold +in5_max Overvoltage threshold +in5_lowest Lowest measured voltage +in5_highest Highest measured voltage +in5_reset_history Write 1 to reset history. +in5_min_alarm Undervoltage alarm +in5_max_alarm Overvoltage alarm +in5_enable Enable/Disable monitoring. +in5_label Channel label (VADI4) + +in6_input Output voltage (mV). +in6_min Undervoltage threshold +in6_max Overvoltage threshold +in6_lowest Lowest measured voltage +in6_highest Highest measured voltage +in6_reset_history Write 1 to reset history. +in6_min_alarm Undervoltage alarm +in6_max_alarm Overvoltage alarm +in6_enable Enable/Disable monitoring. +in6_label Channel label (VADIO1) + +in7_input Output voltage (mV). +in7_min Undervoltage threshold +in7_max Overvoltage threshold +in7_lowest Lowest measured voltage +in7_highest Highest measured voltage +in7_reset_history Write 1 to reset history. +in7_min_alarm Undervoltage alarm +in7_max_alarm Overvoltage alarm +in7_enable Enable/Disable monitoring. +in7_label Channel label (VADIO2) + +in8_input Output voltage (mV). +in8_min Undervoltage threshold +in8_max Overvoltage threshold +in8_lowest Lowest measured voltage +in8_highest Highest measured voltage +in8_reset_history Write 1 to reset history. +in8_min_alarm Undervoltage alarm +in8_max_alarm Overvoltage alarm +in8_enable Enable/Disable monitoring. +in8_label Channel label (VADIO3) + +in9_input Output voltage (mV). +in9_min Undervoltage threshold +in9_max Overvoltage threshold +in9_lowest Lowest measured voltage +in9_highest Highest measured voltage +in9_reset_history Write 1 to reset history. +in9_min_alarm Undervoltage alarm +in9_max_alarm Overvoltage alarm +in9_enable Enable/Disable monitoring. +in9_label Channel label (VADIO4) + +in10_input Output voltage (mV). +in10_min Undervoltage threshold +in10_max Overvoltage threshold +in10_lowest Lowest measured voltage +in10_highest Highest measured voltage +in10_reset_history Write 1 to reset history. +in10_min_alarm Undervoltage alarm +in10_max_alarm Overvoltage alarm +in10_enable Enable/Disable monitoring. +in10_label Channel label (DRNS) + +in11_input Output voltage (mV). +in11_min Undervoltage threshold +in11_max Overvoltage threshold +in11_lowest Lowest measured voltage +in11_highest Highest measured voltage +in11_reset_history Write 1 to reset history. + Also clears fet bad and short fault logs. +in11_min_alarm Undervoltage alarm +in11_max_alarm Overvoltage alarm +in11_enable Enable/Disable monitoring +in11_fault Failure in the MOSFET. Either bad or shorted FET. +in11_label Channel label (DRAIN) + +in12_input Output voltage (mV). +in12_min Undervoltage threshold +in12_max Overvoltage threshold +in12_lowest Lowest measured voltage +in12_highest Highest measured voltage +in12_reset_history Write 1 to reset history. +in12_min_alarm Undervoltage alarm +in12_max_alarm Overvoltage alarm +in12_enable Enable/Disable monitoring. +in12_label Channel label (ADIN2-ADIN1) + +in13_input Output voltage (mV). +in13_min Undervoltage threshold +in13_max Overvoltage threshold +in13_lowest Lowest measured voltage +in13_highest Highest measured voltage +in13_reset_history Write 1 to reset history. +in13_min_alarm Undervoltage alarm +in13_max_alarm Overvoltage alarm +in13_enable Enable/Disable monitoring. +in13_label Channel label (ADIN4-ADIN3) + +in14_input Output voltage (mV). +in14_min Undervoltage threshold +in14_max Overvoltage threshold +in14_lowest Lowest measured voltage +in14_highest Highest measured voltage +in14_reset_history Write 1 to reset history. +in14_min_alarm Undervoltage alarm +in14_max_alarm Overvoltage alarm +in14_enable Enable/Disable monitoring. +in14_label Channel label (ADIO2-ADIO1) + +in15_input Output voltage (mV). +in15_min Undervoltage threshold +in15_max Overvoltage threshold +in15_lowest Lowest measured voltage +in15_highest Highest measured voltage +in15_reset_history Write 1 to reset history. +in15_min_alarm Undervoltage alarm +in15_max_alarm Overvoltage alarm +in15_enable Enable/Disable monitoring. +in15_label Channel label (ADIO4-ADIO3) + +curr1_input Sense current (mA) +curr1_min Undercurrent threshold +curr1_max Overcurrent threshold +curr1_lowest Lowest measured current +curr1_highest Highest measured current +curr1_reset_history Write 1 to reset curr1 history. + Also clears overcurrent fault logs. +curr1_min_alarm Undercurrent alarm +curr1_max_alarm Overcurrent alarm +curr1_crit_alarm Critical Overcurrent alarm +curr1_label Channel label (ISENSE) + +power1_input Power (in uW) +power1_min Low power threshold +power1_max High power threshold +power1_input_lowest Historical minimum power use +power1_input_highest Historical maximum power use +power1_reset_history Write 1 to reset power1 history. + Also clears power fault logs. +power1_min_alarm Low power alarm +power1_max_alarm High power alarm +power1_label Channel label (Power) + +energy1_input Measured energy over time (in microJoule) +energy1_enable Enable/Disable Energy accumulation + +DebugFs entries +_______________ + +The chip also has a fault log register where failures can be logged. Hence, +as these are logging events, we give access to them in debugfs. Note that +even if some failure is detected in these logs, it does necessarily mean +that the failure is still present. As mentioned in the proper Sysfs entries, +these logs can be cleared by writing in the proper reset_history attribute. + +.. warning:: The debugfs interface is subject to change without notice + and is only available when the kernel is compiled with + ``CONFIG_DEBUG_FS`` defined. + +``/sys/kernel/debug/i2c/i2c-[X]/[X]-addr/`` +contains the following attributes: + +======================= ========================================== +power1_failed_fault_log Set to 1 by a power1 fault occurring. +power1_good_input_fault_log Set to 1 by a power1 good input fault occurring at PGIO3. +in11_fet_short_fault_log Set to 1 when a FET-short fault occurs. +in11_fet_bad_fault_log Set to 1 when a FET-BAD fault occurs. +in0_lcrit_fault_log Set to 1 by a VIN undervoltage fault occurring. +in0_crit_fault_log Set to 1 by a VIN overvoltage fault occurring. +curr1_crit_fault_log Set to 1 by an overcurrent fault occurring. +======================= ========================================== diff --git a/MAINTAINERS b/MAINTAINERS index 13ae2f3db449..38d22cf622b7 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -15146,6 +15146,7 @@ M: Nuno Sá <nuno.sa@analog.com> L: linux-hwmon@vger.kernel.org S: Supported F: Documentation/devicetree/bindings/hwmon/adi,ltc4283.yaml +F: drivers/hwmon/ltc4283.c LTC4286 HARDWARE MONITOR DRIVER M: Delphine CC Chiu <Delphine_CC_Chiu@Wiwynn.com> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 8f7ce66ae3a2..c529f622c2b8 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -1158,6 +1158,18 @@ config SENSORS_LTC4282 This driver can also be built as a module. If so, the module will be called ltc4282. +config SENSORS_LTC4283 + tristate "Analog Devices LTC4283" + depends on I2C + select REGMAP_I2C + select AUXILIARY_BUS + help + If you say yes here you get support for Analog Devices LTC4283 + Negative Voltage Hot Swap Controller I2C interface. + + This driver can also be built as a module. If so, the module will + be called ltc4283. + config SENSORS_LTQ_CPUTEMP bool "Lantiq cpu temperature sensor driver" depends on SOC_XWAY diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile index 556e86d277b1..cb77938dbe07 100644 --- a/drivers/hwmon/Makefile +++ b/drivers/hwmon/Makefile @@ -147,6 +147,7 @@ obj-$(CONFIG_SENSORS_LTC4245) += ltc4245.o obj-$(CONFIG_SENSORS_LTC4260) += ltc4260.o obj-$(CONFIG_SENSORS_LTC4261) += ltc4261.o obj-$(CONFIG_SENSORS_LTC4282) += ltc4282.o +obj-$(CONFIG_SENSORS_LTC4283) += ltc4283.o obj-$(CONFIG_SENSORS_LTQ_CPUTEMP) += ltq-cputemp.o obj-$(CONFIG_SENSORS_MACSMC_HWMON) += macsmc-hwmon.o obj-$(CONFIG_SENSORS_MAX1111) += max1111.o diff --git a/drivers/hwmon/ltc4283.c b/drivers/hwmon/ltc4283.c new file mode 100644 index 000000000000..83f1f741abac --- /dev/null +++ b/drivers/hwmon/ltc4283.c @@ -0,0 +1,1780 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Analog Devices LTC4283 I2C Negative Voltage Hot Swap Controller (HWMON) + * + * Copyright 2025 Analog Devices Inc. + */ +#include <linux/auxiliary_bus.h> +#include <linux/bitfield.h> +#include <linux/bitmap.h> +#include <linux/bitops.h> +#include <linux/bits.h> + +#include <linux/debugfs.h> +#include <linux/device.h> +#include <linux/device/devres.h> +#include <linux/hwmon.h> +#include <linux/i2c.h> +#include <linux/math.h> +#include <linux/math64.h> +#include <linux/minmax.h> +#include <linux/module.h> + +#include <linux/mod_devicetable.h> +#include <linux/overflow.h> +#include <linux/property.h> +#include <linux/regmap.h> +#include <linux/unaligned.h> +#include <linux/units.h> + +#define LTC4283_SYSTEM_STATUS 0x00 +#define LTC4283_FAULT_STATUS 0x03 +#define LTC4283_OV_MASK BIT(0) +#define LTC4283_UV_MASK BIT(1) +#define LTC4283_OC_MASK BIT(2) +#define LTC4283_FET_BAD_MASK BIT(3) +#define LTC4283_FET_SHORT_MASK BIT(6) +#define LTC4283_FAULT_LOG 0x04 +#define LTC4283_OV_FAULT_MASK BIT(0) +#define LTC4283_UV_FAULT_MASK BIT(1) +#define LTC4283_OC_FAULT_MASK BIT(2) +#define LTC4283_FET_BAD_FAULT_MASK BIT(3) +#define LTC4283_PGI_FAULT_MASK BIT(4) +#define LTC4283_PWR_FAIL_FAULT_MASK BIT(5) +#define LTC4283_FET_SHORT_FAULT_MASK BIT(6) +#define LTC4283_ADC_ALM_LOG_1 0x05 +#define LTC4283_POWER_LOW_ALM BIT(0) +#define LTC4283_POWER_HIGH_ALM BIT(1) +#define LTC4283_SENSE_LOW_ALM BIT(4) +#define LTC4283_SENSE_HIGH_ALM BIT(5) +#define LTC4283_ADC_ALM_LOG_2 0x06 +#define LTC4283_ADC_ALM_LOG_3 0x07 +#define LTC4283_ADC_ALM_LOG_4 0x08 +#define LTC4283_ADC_ALM_LOG_5 0x09 +#define LTC4283_CONTROL_1 0x0a +#define LTC4283_RW_PAGE_MASK BIT(0) +#define LTC4283_PIGIO2_ACLB_MASK BIT(2) +#define LTC4283_PWRGD_RST_CTRL_MASK BIT(3) +#define LTC4283_FET_BAD_OFF_MASK BIT(4) +#define LTC4283_THERM_TMR_MASK BIT(5) +#define LTC4283_DVDT_MASK BIT(6) +#define LTC4283_CONTROL_2 0x0b +#define LTC4283_OV_RETRY_MASK BIT(0) +#define LTC4283_UV_RETRY_MASK BIT(1) +#define LTC4283_OC_RETRY_MASK GENMASK(3, 2) +#define LTC4283_FET_BAD_RETRY_MASK GENMASK(5, 4) +#define LTC4283_EXT_FAULT_RETRY_MASK BIT(7) +#define LTC4283_RESERVED_OC 0x0c +#define LTC4283_CONFIG_1 0x0d +#define LTC4283_FB_MASK GENMASK(3, 2) +#define LTC4283_ILIM_MASK GENMASK(7, 4) +#define LTC4283_CONFIG_2 0x0e +#define LTC4283_COOLING_DL_MASK GENMASK(3, 1) +#define LTC4283_FTBD_DL_MASK GENMASK(5, 4) +#define LTC4283_CONFIG_3 0x0f +#define LTC4283_VPWR_DRNS_MASK BIT(6) +#define LTC4283_EXTFLT_TURN_OFF_MASK BIT(7) +#define LTC4283_PGIO_CONFIG 0x10 +#define LTC4283_PGIO1_CFG_MASK GENMASK(1, 0) +#define LTC4283_PGIO2_CFG_MASK GENMASK(3, 2) +#define LTC4283_PGIO3_CFG_MASK GENMASK(5, 4) +#define LTC4283_PGIO4_CFG_MASK GENMASK(7, 6) +#define LTC4283_PGIO_CONFIG_2 0x11 +#define LTC4283_ADC_MASK GENMASK(2, 0) +#define LTC4283_ADC_SELECT(c) (0x13 + (c) / 8) +#define LTC4283_ADC_SELECT_MASK(c) BIT((c) % 8) +#define LTC4283_SENSE_MIN_TH 0x1b +#define LTC4283_SENSE_MAX_TH 0x1c +#define LTC4283_VPWR_MIN_TH 0x1d +#define LTC4283_VPWR_MAX_TH 0x1e +#define LTC4283_POWER_MIN_TH 0x1f +#define LTC4283_POWER_MAX_TH 0x20 +#define LTC4283_ADC_2_MIN_TH(c) (0x21 + (c) * 2) +#define LTC4283_ADC_2_MAX_TH(c) (0x22 + (c) * 2) +#define LTC4283_ADC_2_MIN_TH_DIFF(c) (0x39 + (c) * 2) +#define LTC4283_ADC_2_MAX_TH_DIFF(c) (0x3a + (c) * 2) +#define LTC4283_SENSE 0x41 +#define LTC4283_SENSE_MIN 0x42 +#define LTC4283_SENSE_MAX 0x43 +#define LTC4283_VPWR 0x44 +#define LTC4283_VPWR_MIN 0x45 +#define LTC4283_VPWR_MAX 0x46 +#define LTC4283_POWER 0x47 +#define LTC4283_POWER_MIN 0x48 +#define LTC4283_POWER_MAX 0x49 +#define LTC4283_RESERVED_68 0x68 +#define LTC4283_RESERVED_6D 0x6D +/* get channels from ADC 2 */ +#define LTC4283_ADC_2(c) (0x4a + (c) * 3) +#define LTC4283_ADC_2_MIN(c) (0x4b + (c) * 3) +#define LTC4283_ADC_2_MAX(c) (0x4c + (c) * 3) +#define LTC4283_ADC_2_DIFF(c) (0x6e + (c) * 3) +#define LTC4283_ADC_2_MIN_DIFF(c) (0x6f + (c) * 3) +#define LTC4283_ADC_2_MAX_DIFF(c) (0x70 + (c) * 3) +#define LTC4283_ENERGY 0x7a +#define LTC4283_METER_CONTROL 0x84 +#define LTC4283_INTEGRATE_I_MASK BIT(0) +#define LTC4283_METER_HALT_MASK BIT(6) +#define LTC4283_RESERVED_86 0x86 +#define LTC4283_RESERVED_8F 0x8F +#define LTC4283_FAULT_LOG_CTRL 0x90 +#define LTC4283_FAULT_LOG_EN_MASK BIT(7) +#define LTC4283_RESERVED_91 0x91 +#define LTC4283_RESERVED_A1 0xA1 +#define LTC4283_RESERVED_A3 0xA3 +#define LTC4283_RESERVED_AC 0xAC +#define LTC4283_POWER_PLAY_MSB 0xE7 +#define LTC4283_POWER_PLAY_LSB 0xE8 +#define LTC4283_RESERVED_F1 0xF1 +#define LTC4283_RESERVED_FF 0xFF + +/* also applies for differential channels */ +#define LTC4283_ADC1_FS_uV 32768 +#define LTC4283_ADC2_FS_mV 2048 +#define LTC4283_TCONV_uS 64103 +#define LTC4283_VILIM_MIN_uV 15000 +#define LTC4283_VILIM_MAX_uV 30000 +#define LTC4283_VILIM_RANGE \ + (LTC4283_VILIM_MAX_uV - LTC4283_VILIM_MIN_uV + 1) + +#define LTC4283_PGIO_FUNC_GPIO 2 +#define LTC4283_PGIO2_FUNC_ACLB 3 + +/* voltage channels */ +enum { + LTC4283_CHAN_VIN, + LTC4283_CHAN_VPWR, + LTC4283_CHAN_ADI_1, + LTC4283_CHAN_ADI_2, + LTC4283_CHAN_ADI_3, + LTC4283_CHAN_ADI_4, + LTC4283_CHAN_ADIO_1, + LTC4283_CHAN_ADIO_2, + LTC4283_CHAN_ADIO_3, + LTC4283_CHAN_ADIO_4, + LTC4283_CHAN_DRNS, + LTC4283_CHAN_DRAIN, + /* differential channels */ + LTC4283_CHAN_ADIN12, + LTC4283_CHAN_ADIN34, + LTC4283_CHAN_ADIO12, + LTC4283_CHAN_ADIO34, + LTC4283_CHAN_MAX +}; + +/* Just for ease of use on the regmap */ +#define LTC4283_ADIO34_MAX \ + LTC4283_ADC_2_MAX_DIFF(LTC4283_CHAN_ADIO34 - LTC4283_CHAN_ADIN12) + +struct ltc4283_hwmon { + struct regmap *map; + struct i2c_client *client; + unsigned long gpio_mask; + unsigned long ch_enable_mask; + /* in microwatt */ + long power_max; + /* in millivolt */ + u32 vsense_max; + /* in tenths of microohm*/ + u32 rsense; + bool energy_en; + bool ext_fault; +}; + +static int ltc4283_read_voltage_word(const struct ltc4283_hwmon *st, + u32 reg, u32 fs, long *val) +{ + unsigned int __raw; + int ret; + + ret = regmap_read(st->map, reg, &__raw); + if (ret) + return ret; + + *val = DIV_ROUND_CLOSEST(__raw * fs, BIT(16)); + return 0; +} + +static int ltc4283_read_voltage_byte(const struct ltc4283_hwmon *st, + u32 reg, u32 fs, long *val) +{ + int ret; + u32 in; + + ret = regmap_read(st->map, reg, &in); + if (ret) + return ret; + + *val = DIV_ROUND_CLOSEST(in * fs, BIT(8)); + return 0; +} + +static u32 ltc4283_in_reg(u32 attr, u32 channel) +{ + switch (attr) { + case hwmon_in_input: + if (channel == LTC4283_CHAN_VPWR) + return LTC4283_VPWR; + if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN) + return LTC4283_ADC_2(channel - LTC4283_CHAN_ADI_1); + return LTC4283_ADC_2_DIFF(channel - LTC4283_CHAN_ADIN12); + case hwmon_in_highest: + if (channel == LTC4283_CHAN_VPWR) + return LTC4283_VPWR_MAX; + if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN) + return LTC4283_ADC_2_MAX(channel - LTC4283_CHAN_ADI_1); + return LTC4283_ADC_2_MAX_DIFF(channel - LTC4283_CHAN_ADIN12); + case hwmon_in_lowest: + if (channel == LTC4283_CHAN_VPWR) + return LTC4283_VPWR_MIN; + if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN) + return LTC4283_ADC_2_MIN(channel - LTC4283_CHAN_ADI_1); + return LTC4283_ADC_2_MIN_DIFF(channel - LTC4283_CHAN_ADIN12); + case hwmon_in_max: + if (channel == LTC4283_CHAN_VPWR) + return LTC4283_VPWR_MAX_TH; + if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN) + return LTC4283_ADC_2_MAX_TH(channel - LTC4283_CHAN_ADI_1); + return LTC4283_ADC_2_MAX_TH_DIFF(channel - LTC4283_CHAN_ADIN12); + default: + if (channel == LTC4283_CHAN_VPWR) + return LTC4283_VPWR_MIN_TH; + if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN) + return LTC4283_ADC_2_MIN_TH(channel - LTC4283_CHAN_ADI_1); + return LTC4283_ADC_2_MIN_TH_DIFF(channel - LTC4283_CHAN_ADIN12); + } +} + +static int ltc4283_read_in_vals(const struct ltc4283_hwmon *st, + u32 attr, u32 channel, long *val) +{ + u32 reg = ltc4283_in_reg(attr, channel); + int ret; + + if (channel < LTC4283_CHAN_ADIN12) { + if (attr != hwmon_in_max && attr != hwmon_in_min) + return ltc4283_read_voltage_word(st, reg, + LTC4283_ADC2_FS_mV, + val); + + return ltc4283_read_voltage_byte(st, reg, + LTC4283_ADC2_FS_mV, val); + } + + if (attr != hwmon_in_max && attr != hwmon_in_min) + ret = ltc4283_read_voltage_word(st, reg, + LTC4283_ADC1_FS_uV, val); + else + ret = ltc4283_read_voltage_byte(st, reg, + LTC4283_ADC1_FS_uV, val); + if (ret) + return ret; + + *val = DIV_ROUND_CLOSEST(*val, MILLI); + return 0; +} + +static int ltc4283_read_alarm(struct ltc4283_hwmon *st, u32 reg, + u32 mask, long *val) +{ + u32 alarm; + int ret; + + ret = regmap_read(st->map, reg, &alarm); + if (ret) + return ret; + + *val = !!(alarm & mask); + + /* If not status/fault logs, clear the alarm after reading it. */ + if (reg != LTC4283_FAULT_STATUS && reg != LTC4283_FAULT_LOG) + return regmap_clear_bits(st->map, reg, mask); + + return 0; +} + +static int ltc4283_read_in_alarm(struct ltc4283_hwmon *st, u32 channel, + bool max_alm, long *val) +{ + if (channel == LTC4283_VPWR) + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_1, + BIT(2 + max_alm), val); + + if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_ADI_4) { + u32 bit = (channel - LTC4283_CHAN_ADI_1) * 2; + /* + * Lower channels go to higher bits. We also want to go +1 down + * in the min_alarm case. + */ + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_2, + BIT(7 - bit - !max_alm), val); + } + + if (channel >= LTC4283_CHAN_ADIO_1 && channel <= LTC4283_CHAN_ADIO_4) { + u32 bit = (channel - LTC4283_CHAN_ADIO_1) * 2; + + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_3, + BIT(7 - bit - !max_alm), val); + } + + if (channel >= LTC4283_CHAN_ADIN12 && channel <= LTC4283_CHAN_ADIN34) { + u32 bit = (channel - LTC4283_CHAN_ADIN12) * 2; + + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_5, + BIT(7 - bit - !max_alm), val); + } + + if (channel == LTC4283_CHAN_DRNS) + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_4, + BIT(6 + max_alm), val); + + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_4, BIT(4 + max_alm), + val); +} + +static int ltc4283_read_in(struct ltc4283_hwmon *st, u32 attr, u32 channel, + long *val) +{ + switch (attr) { + case hwmon_in_input: + if (!test_bit(channel, &st->ch_enable_mask)) + return -ENODATA; + + return ltc4283_read_in_vals(st, attr, channel, val); + case hwmon_in_highest: + case hwmon_in_lowest: + case hwmon_in_max: + case hwmon_in_min: + return ltc4283_read_in_vals(st, attr, channel, val); + case hwmon_in_max_alarm: + return ltc4283_read_in_alarm(st, channel, true, val); + case hwmon_in_min_alarm: + return ltc4283_read_in_alarm(st, channel, false, val); + case hwmon_in_crit_alarm: + return ltc4283_read_alarm(st, LTC4283_FAULT_STATUS, + LTC4283_OV_MASK, val); + case hwmon_in_lcrit_alarm: + return ltc4283_read_alarm(st, LTC4283_FAULT_STATUS, + LTC4283_UV_MASK, val); + case hwmon_in_fault: + /* + * We report failure if we detect either a fer_bad or a + * fet_short in the status register. + */ + return ltc4283_read_alarm(st, LTC4283_FAULT_STATUS, + LTC4283_FET_BAD_MASK | LTC4283_FET_SHORT_MASK, val); + case hwmon_in_enable: + *val = test_bit(channel, &st->ch_enable_mask); + return 0; + default: + return -EOPNOTSUPP; + } + return 0; +} + +static int ltc4283_read_current_word(const struct ltc4283_hwmon *st, u32 reg, + long *val) +{ + u64 temp = (u64)LTC4283_ADC1_FS_uV * DECA * MILLI; + unsigned int __raw; + int ret; + + ret = regmap_read(st->map, reg, &__raw); + if (ret) + return ret; + + *val = DIV64_U64_ROUND_CLOSEST(__raw * temp, + BIT_ULL(16) * st->rsense); + + return 0; +} + +static int ltc4283_read_current_byte(const struct ltc4283_hwmon *st, u32 reg, + long *val) +{ + u64 temp = (u64)LTC4283_ADC1_FS_uV * DECA * MILLI; + u32 curr; + int ret; + + ret = regmap_read(st->map, reg, &curr); + if (ret) + return ret; + + *val = DIV_ROUND_CLOSEST_ULL(curr * temp, BIT(8) * st->rsense); + return 0; +} + +static int ltc4283_read_curr(struct ltc4283_hwmon *st, u32 attr, long *val) +{ + switch (attr) { + case hwmon_curr_input: + return ltc4283_read_current_word(st, LTC4283_SENSE, val); + case hwmon_curr_highest: + return ltc4283_read_current_word(st, LTC4283_SENSE_MAX, val); + case hwmon_curr_lowest: + return ltc4283_read_current_word(st, LTC4283_SENSE_MIN, val); + case hwmon_curr_max: + return ltc4283_read_current_byte(st, LTC4283_SENSE_MAX_TH, val); + case hwmon_curr_min: + return ltc4283_read_current_byte(st, LTC4283_SENSE_MIN_TH, val); + case hwmon_curr_max_alarm: + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_1, + LTC4283_SENSE_HIGH_ALM, val); + case hwmon_curr_min_alarm: + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_1, + LTC4283_SENSE_LOW_ALM, val); + case hwmon_curr_crit_alarm: + return ltc4283_read_alarm(st, LTC4283_FAULT_STATUS, + LTC4283_OC_MASK, val); + default: + return -EOPNOTSUPP; + } +} + +static int ltc4283_read_power_word(const struct ltc4283_hwmon *st, + u32 reg, long *val) +{ + u64 temp = (u64)LTC4283_ADC1_FS_uV * LTC4283_ADC2_FS_mV * DECA * MILLI; + unsigned int __raw; + int ret; + + ret = regmap_read(st->map, reg, &__raw); + if (ret) + return ret; + + /* + * Power is given by: + * P = CODE(16b) * 32.768mV * 2.048V / (2^16 * Rsense) + */ + *val = DIV64_U64_ROUND_CLOSEST(temp * __raw, BIT_ULL(16) * st->rsense); + + return 0; +} + +static int ltc4283_read_power_byte(const struct ltc4283_hwmon *st, + u32 reg, long *val) +{ + u64 temp = (u64)LTC4283_ADC1_FS_uV * LTC4283_ADC2_FS_mV * DECA * MILLI; + u32 power; + int ret; + + ret = regmap_read(st->map, reg, &power); + if (ret) + return ret; + + *val = DIV_ROUND_CLOSEST_ULL(power * temp, BIT(8) * st->rsense); + + return 0; +} + +static int ltc4283_read_power(struct ltc4283_hwmon *st, u32 attr, long *val) +{ + switch (attr) { + case hwmon_power_input: + return ltc4283_read_power_word(st, LTC4283_POWER, val); + case hwmon_power_input_highest: + return ltc4283_read_power_word(st, LTC4283_POWER_MAX, val); + case hwmon_power_input_lowest: + return ltc4283_read_power_word(st, LTC4283_POWER_MIN, val); + case hwmon_power_max_alarm: + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_1, + LTC4283_POWER_HIGH_ALM, val); + case hwmon_power_min_alarm: + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_1, + LTC4283_POWER_LOW_ALM, val); + case hwmon_power_max: + return ltc4283_read_power_byte(st, LTC4283_POWER_MAX_TH, val); + case hwmon_power_min: + return ltc4283_read_power_byte(st, LTC4283_POWER_MIN_TH, val); + default: + return -EOPNOTSUPP; + } +} + +static int ltc4283_read_energy(struct ltc4283_hwmon *st, u32 attr, s64 *val) +{ + u64 temp = LTC4283_ADC1_FS_uV * LTC4283_ADC2_FS_mV, energy, temp_2; + u8 raw[8]; + int ret; + + if (!st->energy_en) + return -ENODATA; + + ret = i2c_smbus_read_i2c_block_data(st->client, LTC4283_ENERGY, 6, raw); + if (ret < 0) + return ret; + if (ret != 6) + return -EIO; + + energy = get_unaligned_be64(raw) >> 16; + + /* + * The formula for energy is given by: + * E = CODE(48b) * 32.768mV * 2.048V * Tconv / 2^24 * Rsense + * + * As Rsense can have tenths of micro-ohm resolution, we need to + * multiply by DECA to get microjoule. + */ + if (check_mul_overflow(temp * LTC4283_TCONV_uS, energy, &temp_2)) { + /* + * We multiply again by 1000 to make sure that we don't get 0 + * in the following division which could happen for big rsense + * values. OTOH, we then divide energy first by 1000 so that + * we do not overflow u64 again for very small rsense values. + * We add 100 factor for proper conversion to microjoule. + */ + temp_2 = DIV64_U64_ROUND_CLOSEST(temp * LTC4283_TCONV_uS * MILLI, + BIT_ULL(24) * st->rsense); + energy = DIV_ROUND_CLOSEST_ULL(energy, MILLI * CENTI) * temp_2; + } else { + /* Put rsense back into nanoohm so we get microjoule. */ + energy = DIV64_U64_ROUND_CLOSEST(temp_2, BIT_ULL(24) * st->rsense * CENTI); + } + + *val = energy; + return 0; +} + +static int ltc4283_read(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long *val) +{ + struct ltc4283_hwmon *st = dev_get_drvdata(dev); + + switch (type) { + case hwmon_in: + return ltc4283_read_in(st, attr, channel, val); + case hwmon_curr: + return ltc4283_read_curr(st, attr, val); + case hwmon_power: + return ltc4283_read_power(st, attr, val); + case hwmon_energy: + *val = st->energy_en; + return 0; + case hwmon_energy64: + return ltc4283_read_energy(st, attr, (s64 *)val); + default: + return -EOPNOTSUPP; + } +} + +static int ltc4283_write_power_byte(const struct ltc4283_hwmon *st, u32 reg, + long val) +{ + u64 temp = (u64)LTC4283_ADC1_FS_uV * LTC4283_ADC2_FS_mV * DECA * MILLI; + u32 __raw; + + if (val > st->power_max) + val = st->power_max; + + __raw = DIV64_U64_ROUND_CLOSEST(val * BIT_ULL(8) * st->rsense, temp); + + return regmap_write(st->map, reg, __raw); +} + +static int ltc4283_write_power_word(const struct ltc4283_hwmon *st, + u32 reg, long val) +{ + u64 temp = st->rsense * BIT_ULL(16), temp_2; + u16 __raw; + + if (check_mul_overflow(val, temp, &temp_2)) { + temp = DIV_ROUND_CLOSEST_ULL(temp, DECA * MILLI); + __raw = DIV_ROUND_CLOSEST_ULL(temp * val, LTC4283_ADC1_FS_uV * LTC4283_ADC2_FS_mV); + } else { + temp = (u64)LTC4283_ADC1_FS_uV * LTC4283_ADC2_FS_mV * DECA * MILLI; + __raw = DIV64_U64_ROUND_CLOSEST(temp_2, temp); + } + + return regmap_write(st->map, reg, __raw); +} + +static int ltc4283_reset_power_hist(struct ltc4283_hwmon *st) +{ + int ret; + + ret = ltc4283_write_power_word(st, LTC4283_POWER_MIN, st->power_max); + if (ret) + return ret; + + ret = ltc4283_write_power_word(st, LTC4283_POWER_MAX, 0); + if (ret) + return ret; + + /* Clear possible power faults. */ + return regmap_clear_bits(st->map, LTC4283_FAULT_LOG, + LTC4283_PWR_FAIL_FAULT_MASK | LTC4283_PGI_FAULT_MASK); +} + +static int ltc4283_write_power(struct ltc4283_hwmon *st, u32 attr, long val) +{ + switch (attr) { + case hwmon_power_max: + return ltc4283_write_power_byte(st, LTC4283_POWER_MAX_TH, val); + case hwmon_power_min: + return ltc4283_write_power_byte(st, LTC4283_POWER_MIN_TH, val); + case hwmon_power_reset_history: + return ltc4283_reset_power_hist(st); + default: + return -EOPNOTSUPP; + } +} + +static int ltc4283_write_in_history(struct ltc4283_hwmon *st, u32 reg, + long lowest, u32 fs) +{ + u32 __raw; + int ret; + + __raw = DIV_ROUND_CLOSEST(BIT(16) * lowest, fs); + if (__raw == BIT(16)) + __raw = U16_MAX; + + ret = regmap_write(st->map, reg, __raw); + if (ret) + return ret; + + return regmap_write(st->map, reg + 1, 0); +} + +static int ltc4283_write_in_byte(const struct ltc4283_hwmon *st, + u32 reg, u32 fs, long val) +{ + u32 __raw; + + val = clamp_val(val, 0, fs); + __raw = DIV_ROUND_CLOSEST(val * BIT(8), fs); + + return regmap_write(st->map, reg, __raw); +} + +static int ltc4283_reset_in_hist(struct ltc4283_hwmon *st, u32 channel) +{ + u32 reg, fs; + int ret; + + /* + * Make sure to clear possible under/over voltage faults. Otherwise the + * chip won't latch on again. + */ + if (channel == LTC4283_CHAN_VIN) + return regmap_clear_bits(st->map, LTC4283_FAULT_LOG, + LTC4283_OV_FAULT_MASK | LTC4283_UV_FAULT_MASK); + + if (channel == LTC4283_CHAN_VPWR) + return ltc4283_write_in_history(st, LTC4283_VPWR_MIN, + LTC4283_ADC2_FS_mV, + LTC4283_ADC2_FS_mV); + + if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN) { + fs = LTC4283_ADC2_FS_mV; + reg = LTC4283_ADC_2_MIN(channel - LTC4283_CHAN_ADI_1); + } else { + fs = LTC4283_ADC1_FS_uV; + reg = LTC4283_ADC_2_MIN_DIFF(channel - LTC4283_CHAN_ADIN12); + } + + ret = ltc4283_write_in_history(st, reg, fs, fs); + if (ret) + return ret; + if (channel != LTC4283_CHAN_DRAIN) + return 0; + + /* Then, let's also clear possible fet faults. Same as above. */ + return regmap_clear_bits(st->map, LTC4283_FAULT_LOG, + LTC4283_FET_BAD_FAULT_MASK | LTC4283_FET_SHORT_FAULT_MASK); +} + +static int ltc4283_write_in_en(struct ltc4283_hwmon *st, u32 channel, bool en) +{ + unsigned int bit, adc_idx = channel - LTC4283_CHAN_ADI_1; + unsigned int reg = LTC4283_ADC_SELECT(adc_idx); + int ret; + + bit = LTC4283_ADC_SELECT_MASK(adc_idx); + if (channel > LTC4283_CHAN_DRAIN) + /* Account for two reserved fields after DRAIN. */ + bit <<= 2; + + if (en) + ret = regmap_set_bits(st->map, reg, bit); + else + ret = regmap_clear_bits(st->map, reg, bit); + if (ret) + return ret; + + __assign_bit(channel, &st->ch_enable_mask, en); + return 0; +} + +static int ltc4283_write_minmax(struct ltc4283_hwmon *st, long val, + u32 channel, bool is_max) +{ + u32 reg; + + if (channel == LTC4283_CHAN_VPWR) { + if (is_max) + return ltc4283_write_in_byte(st, LTC4283_VPWR_MAX_TH, + LTC4283_ADC2_FS_mV, val); + + return ltc4283_write_in_byte(st, LTC4283_VPWR_MIN_TH, + LTC4283_ADC2_FS_mV, val); + } + + if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN) { + if (is_max) { + reg = LTC4283_ADC_2_MAX_TH(channel - LTC4283_CHAN_ADI_1); + return ltc4283_write_in_byte(st, reg, + LTC4283_ADC2_FS_mV, val); + } + + reg = LTC4283_ADC_2_MIN_TH(channel - LTC4283_CHAN_ADI_1); + return ltc4283_write_in_byte(st, reg, LTC4283_ADC2_FS_mV, val); + } + + if (is_max) { + reg = LTC4283_ADC_2_MAX_TH_DIFF(channel - LTC4283_CHAN_ADIN12); + return ltc4283_write_in_byte(st, reg, LTC4283_ADC1_FS_uV, + val * MILLI); + } + + reg = LTC4283_ADC_2_MIN_TH_DIFF(channel - LTC4283_CHAN_ADIN12); + return ltc4283_write_in_byte(st, reg, LTC4283_ADC1_FS_uV, val * MILLI); +} + +static int ltc4283_write_in(struct ltc4283_hwmon *st, u32 attr, long val, + int channel) +{ + switch (attr) { + case hwmon_in_max: + return ltc4283_write_minmax(st, val, channel, true); + case hwmon_in_min: + return ltc4283_write_minmax(st, val, channel, false); + case hwmon_in_reset_history: + return ltc4283_reset_in_hist(st, channel); + case hwmon_in_enable: + return ltc4283_write_in_en(st, channel, !!val); + default: + return -EOPNOTSUPP; + } +} + +static int ltc4283_write_curr_byte(const struct ltc4283_hwmon *st, + u32 reg, long val) +{ + u32 temp = LTC4283_ADC1_FS_uV * DECA * MILLI; + u32 reg_val; + + reg_val = DIV_ROUND_CLOSEST_ULL(val * BIT_ULL(8) * st->rsense, temp); + return regmap_write(st->map, reg, reg_val); +} + +static int ltc4283_write_curr_history(struct ltc4283_hwmon *st) +{ + int ret; + + ret = ltc4283_write_in_history(st, LTC4283_SENSE_MIN, st->vsense_max, + LTC4283_ADC1_FS_uV); + if (ret) + return ret; + + /* Now, let's also clear possible overcurrent logs. */ + return regmap_clear_bits(st->map, LTC4283_FAULT_LOG, + LTC4283_OC_FAULT_MASK); +} + +static int ltc4283_write_curr(struct ltc4283_hwmon *st, u32 attr, long val) +{ + switch (attr) { + case hwmon_curr_max: + return ltc4283_write_curr_byte(st, LTC4283_SENSE_MAX_TH, val); + case hwmon_curr_min: + return ltc4283_write_curr_byte(st, LTC4283_SENSE_MIN_TH, val); + case hwmon_curr_reset_history: + return ltc4283_write_curr_history(st); + default: + return -EOPNOTSUPP; + } +} + +static int ltc4283_energy_enable_set(struct ltc4283_hwmon *st, long val) +{ + int ret; + + /* Setting the bit halts the meter. */ + val = !!val; + ret = regmap_update_bits(st->map, LTC4283_METER_CONTROL, + LTC4283_METER_HALT_MASK, + FIELD_PREP(LTC4283_METER_HALT_MASK, !val)); + if (ret) + return ret; + + st->energy_en = val; + + return 0; +} + +static int ltc4283_write(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long val) +{ + struct ltc4283_hwmon *st = dev_get_drvdata(dev); + + switch (type) { + case hwmon_power: + return ltc4283_write_power(st, attr, val); + case hwmon_in: + return ltc4283_write_in(st, attr, val, channel); + case hwmon_curr: + return ltc4283_write_curr(st, attr, val); + case hwmon_energy: + return ltc4283_energy_enable_set(st, val); + default: + return -EOPNOTSUPP; + } +} + +static umode_t ltc4283_in_is_visible(const struct ltc4283_hwmon *st, + u32 attr, int channel) +{ + /* If ADIO is set as a GPIO, don´t make it visible. */ + if (channel >= LTC4283_CHAN_ADIO_1 && channel <= LTC4283_CHAN_ADIO_4) { + /* ADIOX pins come at index 0 in the gpio mask. */ + channel -= LTC4283_CHAN_ADIO_1; + if (test_bit(channel, &st->gpio_mask)) + return 0; + } + + /* Also take care of differential channels. */ + if (channel >= LTC4283_CHAN_ADIO12 && channel <= LTC4283_CHAN_ADIO34) { + channel -= LTC4283_CHAN_ADIO12; + /* If one channel in the pair is used, make it invisible. */ + if (test_bit(channel * 2, &st->gpio_mask) || + test_bit(channel * 2 + 1, &st->gpio_mask)) + return 0; + } + + switch (attr) { + case hwmon_in_input: + case hwmon_in_highest: + case hwmon_in_lowest: + case hwmon_in_max_alarm: + case hwmon_in_min_alarm: + case hwmon_in_label: + case hwmon_in_lcrit_alarm: + case hwmon_in_crit_alarm: + case hwmon_in_fault: + return 0444; + case hwmon_in_max: + case hwmon_in_min: + case hwmon_in_enable: + return 0644; + case hwmon_in_reset_history: + return 0200; + default: + return 0; + } +} + +static umode_t ltc4283_curr_is_visible(u32 attr) +{ + switch (attr) { + case hwmon_curr_input: + case hwmon_curr_highest: + case hwmon_curr_lowest: + case hwmon_curr_max_alarm: + case hwmon_curr_min_alarm: + case hwmon_curr_crit_alarm: + case hwmon_curr_label: + return 0444; + case hwmon_curr_max: + case hwmon_curr_min: + return 0644; + case hwmon_curr_reset_history: + return 0200; + default: + return 0; + } +} + +static umode_t ltc4283_power_is_visible(u32 attr) +{ + switch (attr) { + case hwmon_power_input: + case hwmon_power_input_highest: + case hwmon_power_input_lowest: + case hwmon_power_label: + case hwmon_power_max_alarm: + case hwmon_power_min_alarm: + return 0444; + case hwmon_power_max: + case hwmon_power_min: + return 0644; + case hwmon_power_reset_history: + return 0200; + default: + return 0; + } +} + +static umode_t ltc4283_is_visible(const void *data, + enum hwmon_sensor_types type, + u32 attr, int channel) +{ + switch (type) { + case hwmon_in: + return ltc4283_in_is_visible(data, attr, channel); + case hwmon_curr: + return ltc4283_curr_is_visible(attr); + case hwmon_power: + return ltc4283_power_is_visible(attr); + case hwmon_energy: + /* hwmon_energy_enable */ + return 0644; + case hwmon_energy64: + /* hwmon_energy_input */ + return 0444; + default: + return 0; + } +} + +static const char * const ltc4283_in_strs[] = { + "VIN", "VPWR", "VADI1", "VADI2", "VADI3", "VADI4", "VADIO1", "VADIO2", + "VADIO3", "VADIO4", "DRNS", "DRAIN", "ADIN2-ADIN1", "ADIN4-ADIN3", + "ADIO2-ADIO1", "ADIO4-ADIO3" +}; + +static int ltc4283_read_labels(struct device *dev, + enum hwmon_sensor_types type, + u32 attr, int channel, const char **str) +{ + switch (type) { + case hwmon_in: + *str = ltc4283_in_strs[channel]; + return 0; + case hwmon_curr: + *str = "ISENSE"; + return 0; + case hwmon_power: + *str = "Power"; + return 0; + default: + return -EOPNOTSUPP; + } +} + +/* + * Set max limits for ISENSE and Power as that depends on the max voltage on + * rsense that is defined in ILIM_ADJUST. This is specially important for power + * because for some rsense and vfsout values, if we allow the default raw 255 + * value, that would overflow long in 32bit archs when reading back the max + * power limit. + */ +static int ltc4283_set_max_limits(struct ltc4283_hwmon *st, struct device *dev) +{ + u32 temp = st->vsense_max * DECA * MICRO; + int ret; + + ret = ltc4283_write_in_byte(st, LTC4283_SENSE_MAX_TH, LTC4283_ADC1_FS_uV, + st->vsense_max * MILLI); + if (ret) + return ret; + + /* Power is given by ISENSE * Vout. */ + st->power_max = DIV_ROUND_CLOSEST(temp, st->rsense) * LTC4283_ADC2_FS_mV; + return ltc4283_write_power_byte(st, LTC4283_POWER_MAX_TH, st->power_max); +} + +static int ltc4283_parse_array_prop(const struct ltc4283_hwmon *st, + struct device *dev, const char *prop, + const u32 *vals, u32 n_vals) +{ + u32 prop_val; + int ret; + u32 i; + + ret = device_property_read_u32(dev, prop, &prop_val); + if (ret) + return n_vals; + + for (i = 0; i < n_vals; i++) { + if (prop_val != vals[i]) + continue; + + return i; + } + + return dev_err_probe(dev, -EINVAL, + "Invalid %s property value %u, expected one of: %*ph\n", + prop, prop_val, n_vals, vals); +} + +static int ltc4283_get_defaults(struct ltc4283_hwmon *st) +{ + u32 reg_val, ilm_adjust, c; + int ret; + + ret = regmap_read(st->map, LTC4283_METER_CONTROL, ®_val); + if (ret) + return ret; + + st->energy_en = !FIELD_GET(LTC4283_METER_HALT_MASK, reg_val); + + ret = regmap_read(st->map, LTC4283_CONFIG_1, ®_val); + if (ret) + return ret; + + ilm_adjust = FIELD_GET(LTC4283_ILIM_MASK, reg_val); + st->vsense_max = LTC4283_VILIM_MIN_uV / MILLI + ilm_adjust; + + /* VPWR and VIN are always enabled */ + __set_bit(LTC4283_CHAN_VIN, &st->ch_enable_mask); + __set_bit(LTC4283_CHAN_VPWR, &st->ch_enable_mask); + for (c = LTC4283_CHAN_ADI_1; c < LTC4283_CHAN_MAX; c++) { + u32 chan = c - LTC4283_CHAN_ADI_1, bit; + + ret = regmap_read(st->map, LTC4283_ADC_SELECT(chan), ®_val); + if (ret) + return ret; + + bit = LTC4283_ADC_SELECT_MASK(chan); + if (c > LTC4283_CHAN_DRAIN) + /* account for two reserved fields after DRAIN */ + bit <<= 2; + + if (!(bit & reg_val)) + continue; + + __set_bit(c, &st->ch_enable_mask); + } + + return 0; +} + +static const char * const ltc4283_pgio1_funcs[] = { + "inverted_power_good", "power_good", "gpio" +}; + +static const char * const ltc4283_pgio2_funcs[] = { + "inverted_power_good", "power_good", "gpio", "active_current_limiting" +}; + +static const char * const ltc4283_pgio3_funcs[] = { + "inverted_power_good_input", "power_good_input", "gpio" +}; + +static const char * const ltc4283_pgio4_funcs[] = { + "inverted_external_fault", "external_fault", "gpio" +}; + +enum { + LTC4283_PIN_ADIO1, + LTC4283_PIN_ADIO2, + LTC4283_PIN_ADIO3, + LTC4283_PIN_ADIO4, + LTC4283_PIN_PGIO1, + LTC4283_PIN_PGIO2, + LTC4283_PIN_PGIO3, + LTC4283_PIN_PGIO4, +}; + +static int ltc4283_pgio_config(struct ltc4283_hwmon *st, struct device *dev) +{ + int ret, func; + + func = device_property_match_property_string(dev, "adi,pgio1-func", + ltc4283_pgio1_funcs, + ARRAY_SIZE(ltc4283_pgio1_funcs)); + if (func < 0 && func != -EINVAL) + return dev_err_probe(dev, func, + "Invalid adi,pgio1-func property\n"); + if (func >= 0) { + if (func == LTC4283_PGIO_FUNC_GPIO) { + __set_bit(LTC4283_PIN_PGIO1, &st->gpio_mask); + /* If GPIO, default to an input pin. */ + func++; + } + + ret = regmap_update_bits(st->map, LTC4283_PGIO_CONFIG, + LTC4283_PGIO1_CFG_MASK, + FIELD_PREP(LTC4283_PGIO1_CFG_MASK, func)); + if (ret) + return ret; + } + + func = device_property_match_property_string(dev, "adi,pgio2-func", + ltc4283_pgio2_funcs, + ARRAY_SIZE(ltc4283_pgio2_funcs)); + + if (func < 0 && func != -EINVAL) + return dev_err_probe(dev, func, + "Invalid adi,pgio2-func property\n"); + if (func >= 0) { + if (func != LTC4283_PGIO2_FUNC_ACLB) { + if (func == LTC4283_PGIO_FUNC_GPIO) { + __set_bit(LTC4283_PIN_PGIO2, &st->gpio_mask); + func++; + } + + ret = regmap_update_bits(st->map, LTC4283_PGIO_CONFIG, + LTC4283_PGIO2_CFG_MASK, + FIELD_PREP(LTC4283_PGIO2_CFG_MASK, func)); + } else { + ret = regmap_set_bits(st->map, LTC4283_CONTROL_1, + LTC4283_PIGIO2_ACLB_MASK); + } + + if (ret) + return ret; + } + + func = device_property_match_property_string(dev, "adi,pgio3-func", + ltc4283_pgio3_funcs, + ARRAY_SIZE(ltc4283_pgio3_funcs)); + + if (func < 0 && func != -EINVAL) + return dev_err_probe(dev, func, + "Invalid adi,pgio3-func property\n"); + if (func >= 0) { + if (func == LTC4283_PGIO_FUNC_GPIO) { + __set_bit(LTC4283_PIN_PGIO3, &st->gpio_mask); + func++; + } + + ret = regmap_update_bits(st->map, LTC4283_PGIO_CONFIG, + LTC4283_PGIO3_CFG_MASK, + FIELD_PREP(LTC4283_PGIO3_CFG_MASK, func)); + if (ret) + return ret; + } + + func = device_property_match_property_string(dev, "adi,pgio4-func", + ltc4283_pgio4_funcs, + ARRAY_SIZE(ltc4283_pgio4_funcs)); + + if (func < 0 && func != -EINVAL) + return dev_err_probe(dev, func, + "Invalid adi,pgio4-func property\n"); + if (func >= 0) { + if (func == LTC4283_PGIO_FUNC_GPIO) { + __set_bit(LTC4283_PIN_PGIO4, &st->gpio_mask); + func++; + } else { + st->ext_fault = true; + } + + ret = regmap_update_bits(st->map, LTC4283_PGIO_CONFIG, + LTC4283_PGIO4_CFG_MASK, + FIELD_PREP(LTC4283_PGIO4_CFG_MASK, func)); + if (ret) + return ret; + } + + return 0; +} + +static int ltc4283_adio_config(struct ltc4283_hwmon *st, struct device *dev, + const char *prop, u32 pin) +{ + u32 adc_idx; + int ret; + + if (!device_property_read_bool(dev, prop)) + return 0; + + adc_idx = LTC4283_CHAN_ADIO_1 - LTC4283_CHAN_ADI_1 + pin; + ret = regmap_clear_bits(st->map, LTC4283_ADC_SELECT(adc_idx), + LTC4283_ADC_SELECT_MASK(adc_idx)); + if (ret) + return ret; + + __set_bit(pin, &st->gpio_mask); + return 0; +} + +static int ltc4283_pin_config(struct ltc4283_hwmon *st, struct device *dev) +{ + int ret; + + ret = ltc4283_pgio_config(st, dev); + if (ret) + return ret; + + ret = ltc4283_adio_config(st, dev, "adi,gpio-on-adio1", LTC4283_PIN_ADIO1); + if (ret) + return ret; + + ret = ltc4283_adio_config(st, dev, "adi,gpio-on-adio2", LTC4283_PIN_ADIO2); + if (ret) + return ret; + + ret = ltc4283_adio_config(st, dev, "adi,gpio-on-adio3", LTC4283_PIN_ADIO3); + if (ret) + return ret; + + return ltc4283_adio_config(st, dev, "adi,gpio-on-adio4", LTC4283_PIN_ADIO4); +} + +static const char * const ltc4283_oc_fet_retry[] = { + "latch-off", "1", "7", "unlimited" +}; + +static const u32 ltc4283_fb_factor[] = { + 100, 50, 20, 10 +}; + +static const u32 ltc4283_cooling_dl[] = { + 512, 1002, 2005, 4100, 8190, 16400, 32800, 65600 +}; + +static const u32 ltc4283_fet_bad_delay[] = { + 256, 512, 1002, 2005 +}; + +static int ltc4283_setup(struct ltc4283_hwmon *st, struct device *dev) +{ + u32 val, chan; + int ret; + + /* The part has an eeprom so let's get the needed defaults from it */ + ret = ltc4283_get_defaults(st); + if (ret) + return ret; + + /* default to 1 micro ohm so we can probe without FW properties */ + st->rsense = 1 * MICRO; + ret = device_property_read_u32(dev, "adi,rsense-nano-ohms", + &st->rsense); + if (!ret) { + if (st->rsense < CENTI) + return dev_err_probe(dev, -EINVAL, + "adi,rsense-nano-ohms too small (< %lu)\n", + CENTI); + } + + /* + * The resolution for rsense is tenths of micro (eg: 62.5 uOhm) which + * means we need nano in the bindings. However, to make things easier to + * handle (with respect to overflows) we divide it by 100 as we don't + * really need the last two digits. + */ + st->rsense /= CENTI; + + ret = device_property_read_u32(dev, "adi,current-limit-sense-microvolt", + &st->vsense_max); + if (!ret) { + u32 reg_val; + + if (!in_range(st->vsense_max, LTC4283_VILIM_MIN_uV, + LTC4283_VILIM_RANGE)) { + return dev_err_probe(dev, -EINVAL, + "adi,current-limit-sense-microvolt (%u) out of range [%u %u]\n", + st->vsense_max, LTC4283_VILIM_MIN_uV, + LTC4283_VILIM_MAX_uV); + } + + st->vsense_max /= MILLI; + reg_val = FIELD_PREP(LTC4283_ILIM_MASK, + st->vsense_max - LTC4283_VILIM_MIN_uV / MILLI); + ret = regmap_update_bits(st->map, LTC4283_CONFIG_1, + LTC4283_ILIM_MASK, reg_val); + if (ret) + return ret; + } + + ret = ltc4283_parse_array_prop(st, dev, "adi,current-limit-foldback-factor", + ltc4283_fb_factor, ARRAY_SIZE(ltc4283_fb_factor)); + if (ret < 0) + return ret; + if (ret < ARRAY_SIZE(ltc4283_fb_factor)) { + ret = regmap_update_bits(st->map, LTC4283_CONFIG_1, LTC4283_FB_MASK, + FIELD_PREP(LTC4283_FB_MASK, ret)); + if (ret) + return ret; + } + + ret = ltc4283_parse_array_prop(st, dev, "adi,cooling-delay-ms", + ltc4283_cooling_dl, ARRAY_SIZE(ltc4283_cooling_dl)); + if (ret < 0) + return ret; + if (ret < ARRAY_SIZE(ltc4283_cooling_dl)) { + ret = regmap_update_bits(st->map, LTC4283_CONFIG_2, LTC4283_COOLING_DL_MASK, + FIELD_PREP(LTC4283_COOLING_DL_MASK, ret)); + if (ret) + return ret; + } + + ret = ltc4283_parse_array_prop(st, dev, "adi,fet-bad-timer-delay-ms", + ltc4283_fet_bad_delay, ARRAY_SIZE(ltc4283_fet_bad_delay)); + if (ret < 0) + return ret; + if (ret < ARRAY_SIZE(ltc4283_fet_bad_delay)) { + ret = regmap_update_bits(st->map, LTC4283_CONFIG_2, LTC4283_FTBD_DL_MASK, + FIELD_PREP(LTC4283_FTBD_DL_MASK, ret)); + if (ret) + return ret; + } + + ret = ltc4283_set_max_limits(st, dev); + if (ret) + return ret; + + ret = ltc4283_pin_config(st, dev); + if (ret) + return ret; + + if (device_property_read_bool(dev, "adi,power-good-reset-on-fet")) { + ret = regmap_clear_bits(st->map, LTC4283_CONTROL_1, + LTC4283_PWRGD_RST_CTRL_MASK); + if (ret) + return ret; + } + + if (device_property_read_bool(dev, "adi,fet-turn-off-disable")) { + ret = regmap_clear_bits(st->map, LTC4283_CONTROL_1, + LTC4283_FET_BAD_OFF_MASK); + if (ret) + return ret; + } + + if (device_property_read_bool(dev, "adi,tmr-pull-down-disable")) { + ret = regmap_set_bits(st->map, LTC4283_CONTROL_1, + LTC4283_THERM_TMR_MASK); + if (ret) + return ret; + } + + if (device_property_read_bool(dev, "adi,dvdt-inrush-control-disable")) { + ret = regmap_clear_bits(st->map, LTC4283_CONTROL_1, + LTC4283_DVDT_MASK); + if (ret) + return ret; + } + + if (device_property_read_bool(dev, "adi,undervoltage-retry-disable")) { + ret = regmap_clear_bits(st->map, LTC4283_CONTROL_2, + LTC4283_UV_RETRY_MASK); + if (ret) + return ret; + } + + if (device_property_read_bool(dev, "adi,overvoltage-retry-disable")) { + ret = regmap_clear_bits(st->map, LTC4283_CONTROL_2, + LTC4283_OV_RETRY_MASK); + if (ret) + return ret; + } + + if (device_property_read_bool(dev, "adi,external-fault-retry-enable")) { + if (!st->ext_fault) + return dev_err_probe(dev, -EINVAL, + "adi,external-fault-retry-enable set but PGIO4 not configured\n"); + ret = regmap_set_bits(st->map, LTC4283_CONTROL_2, + LTC4283_EXT_FAULT_RETRY_MASK); + if (ret) + return ret; + } + + if (device_property_read_bool(dev, "adi,fault-log-enable")) { + ret = regmap_set_bits(st->map, LTC4283_FAULT_LOG_CTRL, + LTC4283_FAULT_LOG_EN_MASK); + if (ret) + return ret; + } + + ret = device_property_match_property_string(dev, "adi,overcurrent-retries", + ltc4283_oc_fet_retry, + ARRAY_SIZE(ltc4283_oc_fet_retry)); + /* We still want to catch when an invalid string is given. */ + if (ret != -EINVAL) + return dev_err_probe(dev, ret, + "adi,overcurrent-retries invalid value\n"); + if (ret >= 0) { + ret = regmap_update_bits(st->map, LTC4283_CONTROL_2, + LTC4283_OC_RETRY_MASK, + FIELD_PREP(LTC4283_OC_RETRY_MASK, ret)); + if (ret) + return ret; + } + + ret = device_property_match_property_string(dev, "adi,fet-bad-retries", + ltc4283_oc_fet_retry, + ARRAY_SIZE(ltc4283_oc_fet_retry)); + if (ret != -EINVAL) + return dev_err_probe(dev, ret, + "adi,fet-bad-retries invalid value\n"); + if (ret >= 0) { + ret = regmap_update_bits(st->map, LTC4283_CONTROL_2, + LTC4283_FET_BAD_RETRY_MASK, + FIELD_PREP(LTC4283_FET_BAD_RETRY_MASK, ret)); + if (ret) + return ret; + } + + if (device_property_read_bool(dev, "adi,external-fault-fet-off-enable")) { + if (!st->ext_fault) + return dev_err_probe(dev, -EINVAL, + "adi,external-fault-fet-off-enable set but PGIO4 not configured\n"); + ret = regmap_set_bits(st->map, LTC4283_CONFIG_3, + LTC4283_EXTFLT_TURN_OFF_MASK); + if (ret) + return ret; + } + + if (device_property_read_bool(dev, "adi,vpower-drns-enable")) { + __clear_bit(LTC4283_CHAN_DRAIN, &st->ch_enable_mask); + chan = LTC4283_CHAN_DRAIN - LTC4283_CHAN_ADI_1; + val = 1; + } else { + __clear_bit(LTC4283_CHAN_DRNS, &st->ch_enable_mask); + chan = LTC4283_CHAN_DRNS - LTC4283_CHAN_ADI_1; + val = 0; + } + /* + * Then, let's by default disable the channel from the ADC2 that is + * already being monitored by the VPWR channel. One can still enable it + * later on if needed. + */ + ret = regmap_clear_bits(st->map, LTC4283_ADC_SELECT(chan), + LTC4283_ADC_SELECT_MASK(chan)); + if (ret) + return ret; + + ret = regmap_update_bits(st->map, LTC4283_CONFIG_3, + LTC4283_VPWR_DRNS_MASK, + FIELD_PREP(LTC4283_VPWR_DRNS_MASK, val)); + if (ret) + return ret; + + /* Make sure the ADC has 12bit resolution since we're assuming that. */ + ret = regmap_update_bits(st->map, LTC4283_PGIO_CONFIG_2, + LTC4283_ADC_MASK, + FIELD_PREP(LTC4283_ADC_MASK, 3)); + if (ret) + return ret; + + /* Energy reads (which are 6 byte block reads) rely on page access */ + ret = regmap_set_bits(st->map, LTC4283_CONTROL_1, LTC4283_RW_PAGE_MASK); + if (ret) + return ret; + + /* + * Make sure we are integrating power as we only support reporting + * consumed energy. + */ + return regmap_clear_bits(st->map, LTC4283_METER_CONTROL, + LTC4283_INTEGRATE_I_MASK); +} + +static const struct hwmon_channel_info * const ltc4283_info[] = { + HWMON_CHANNEL_INFO(in, + HWMON_I_LCRIT_ALARM | HWMON_I_CRIT_ALARM | + HWMON_I_RESET_HISTORY | HWMON_I_LABEL, + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | + HWMON_I_MAX_ALARM | HWMON_I_RESET_HISTORY | + HWMON_I_LABEL, + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | + HWMON_I_ENABLE | HWMON_I_LABEL, + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | + HWMON_I_ENABLE | HWMON_I_LABEL, + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | + HWMON_I_ENABLE | HWMON_I_LABEL, + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | + HWMON_I_ENABLE | HWMON_I_LABEL, + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | + HWMON_I_ENABLE | HWMON_I_LABEL, + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | + HWMON_I_ENABLE | HWMON_I_LABEL, + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | + HWMON_I_ENABLE | HWMON_I_LABEL, + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | + HWMON_I_ENABLE | HWMON_I_LABEL, + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | + HWMON_I_ENABLE | HWMON_I_LABEL, + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | + HWMON_I_FAULT | HWMON_I_ENABLE | HWMON_I_LABEL, + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | + HWMON_I_ENABLE | HWMON_I_LABEL, + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | + HWMON_I_ENABLE | HWMON_I_LABEL, + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | + HWMON_I_ENABLE | HWMON_I_LABEL, + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | + HWMON_I_ENABLE | HWMON_I_LABEL), + HWMON_CHANNEL_INFO(curr, + HWMON_C_INPUT | HWMON_C_LOWEST | HWMON_C_HIGHEST | + HWMON_C_MAX | HWMON_C_MIN | HWMON_C_MIN_ALARM | + HWMON_C_MAX_ALARM | HWMON_C_CRIT_ALARM | + HWMON_C_RESET_HISTORY | HWMON_C_LABEL), + HWMON_CHANNEL_INFO(power, + HWMON_P_INPUT | HWMON_P_INPUT_LOWEST | + HWMON_P_INPUT_HIGHEST | HWMON_P_MAX | HWMON_P_MIN | + HWMON_P_MAX_ALARM | HWMON_P_MIN_ALARM | + HWMON_P_RESET_HISTORY | HWMON_P_LABEL), + HWMON_CHANNEL_INFO(energy, + HWMON_E_ENABLE), + HWMON_CHANNEL_INFO(energy64, + HWMON_E_INPUT), + NULL +}; + +static const struct hwmon_ops ltc4283_ops = { + .read = ltc4283_read, + .write = ltc4283_write, + .is_visible = ltc4283_is_visible, + .read_string = ltc4283_read_labels, +}; + +static const struct hwmon_chip_info ltc4283_chip_info = { + .ops = <c4283_ops, + .info = ltc4283_info, +}; + +static int ltc4283_show_fault_log(void *arg, u64 *val, u32 mask) +{ + struct ltc4283_hwmon *st = arg; + long alarm; + int ret; + + ret = ltc4283_read_alarm(st, LTC4283_FAULT_LOG, mask, &alarm); + if (ret) + return ret; + + *val = alarm; + + return 0; +} + +static int ltc4283_show_in0_lcrit_fault_log(void *arg, u64 *val) +{ + return ltc4283_show_fault_log(arg, val, LTC4283_UV_FAULT_MASK); +} +DEFINE_DEBUGFS_ATTRIBUTE(ltc4283_in0_lcrit_fault_log, + ltc4283_show_in0_lcrit_fault_log, NULL, "%llu\n"); + +static int ltc4283_show_in0_crit_fault_log(void *arg, u64 *val) +{ + return ltc4283_show_fault_log(arg, val, LTC4283_OV_FAULT_MASK); +} +DEFINE_DEBUGFS_ATTRIBUTE(ltc4283_in0_crit_fault_log, + ltc4283_show_in0_crit_fault_log, NULL, "%llu\n"); + +static int ltc4283_show_fet_bad_fault_log(void *arg, u64 *val) +{ + return ltc4283_show_fault_log(arg, val, LTC4283_FET_BAD_FAULT_MASK); +} +DEFINE_DEBUGFS_ATTRIBUTE(ltc4283_fet_bad_fault_log, + ltc4283_show_fet_bad_fault_log, NULL, "%llu\n"); + +static int ltc4283_show_fet_short_fault_log(void *arg, u64 *val) +{ + return ltc4283_show_fault_log(arg, val, LTC4283_FET_SHORT_FAULT_MASK); +} +DEFINE_DEBUGFS_ATTRIBUTE(ltc4283_fet_short_fault_log, + ltc4283_show_fet_short_fault_log, NULL, "%llu\n"); + +static int ltc4283_show_curr1_crit_fault_log(void *arg, u64 *val) +{ + return ltc4283_show_fault_log(arg, val, LTC4283_OC_FAULT_MASK); +} +DEFINE_DEBUGFS_ATTRIBUTE(ltc4283_curr1_crit_fault_log, + ltc4283_show_curr1_crit_fault_log, NULL, "%llu\n"); + +static int ltc4283_show_power1_failed_fault_log(void *arg, u64 *val) +{ + return ltc4283_show_fault_log(arg, val, LTC4283_PWR_FAIL_FAULT_MASK); +} +DEFINE_DEBUGFS_ATTRIBUTE(ltc4283_power1_failed_fault_log, + ltc4283_show_power1_failed_fault_log, NULL, "%llu\n"); + +static int ltc4283_show_power1_good_input_fault_log(void *arg, u64 *val) +{ + return ltc4283_show_fault_log(arg, val, LTC4283_PGI_FAULT_MASK); +} +DEFINE_DEBUGFS_ATTRIBUTE(ltc4283_power1_good_input_fault_log, + ltc4283_show_power1_good_input_fault_log, NULL, "%llu\n"); + +static void ltc4283_debugfs_init(struct ltc4283_hwmon *st, struct i2c_client *i2c) +{ + debugfs_create_file_unsafe("in0_crit_fault_log", 0400, i2c->debugfs, st, + <c4283_in0_crit_fault_log); + debugfs_create_file_unsafe("in0_lcrit_fault_log", 0400, i2c->debugfs, st, + <c4283_in0_lcrit_fault_log); + debugfs_create_file_unsafe("in0_fet_bad_fault_log", 0400, i2c->debugfs, st, + <c4283_fet_bad_fault_log); + debugfs_create_file_unsafe("in0_fet_short_fault_log", 0400, i2c->debugfs, st, + <c4283_fet_short_fault_log); + debugfs_create_file_unsafe("curr1_crit_fault_log", 0400, i2c->debugfs, st, + <c4283_curr1_crit_fault_log); + debugfs_create_file_unsafe("power1_failed_fault_log", 0400, i2c->debugfs, st, + <c4283_power1_failed_fault_log); + debugfs_create_file_unsafe("power1_good_input_fault_log", 0400, i2c->debugfs, + st, <c4283_power1_good_input_fault_log); +} + +static bool ltc4283_is_word_reg(unsigned int reg) +{ + return reg >= LTC4283_SENSE && reg <= LTC4283_ADIO34_MAX; +} + +static int ltc4283_reg_read(void *context, unsigned int reg, unsigned int *val) +{ + struct i2c_client *client = context; + int ret; + + if (ltc4283_is_word_reg(reg)) + ret = i2c_smbus_read_word_swapped(client, reg); + else + ret = i2c_smbus_read_byte_data(client, reg); + + if (ret < 0) + return ret; + + *val = ret; + return 0; +} + +static int ltc4283_reg_write(void *context, unsigned int reg, unsigned int val) +{ + struct i2c_client *client = context; + + if (ltc4283_is_word_reg(reg)) + return i2c_smbus_write_word_swapped(client, reg, val); + + return i2c_smbus_write_byte_data(client, reg, val); +} + +static const struct regmap_bus ltc4283_regmap_bus = { + .reg_read = ltc4283_reg_read, + .reg_write = ltc4283_reg_write, +}; + +static bool ltc4283_writable_reg(struct device *dev, unsigned int reg) +{ + switch (reg) { + case LTC4283_SYSTEM_STATUS ... LTC4283_FAULT_STATUS: + return false; + case LTC4283_RESERVED_OC: + return false; + case LTC4283_RESERVED_86 ... LTC4283_RESERVED_8F: + return false; + case LTC4283_RESERVED_91 ... LTC4283_RESERVED_A1: + return false; + case LTC4283_RESERVED_A3: + return false; + case LTC4283_RESERVED_AC: + return false; + case LTC4283_POWER_PLAY_MSB ... LTC4283_POWER_PLAY_LSB: + return false; + case LTC4283_RESERVED_F1 ... LTC4283_RESERVED_FF: + return false; + default: + return true; + } +} + +static const struct regmap_config ltc4283_regmap_config = { + .reg_bits = 8, + .val_bits = 16, + .max_register = 0xFF, + .writeable_reg = ltc4283_writable_reg, +}; + +static int ltc4283_probe(struct i2c_client *client) +{ + struct device *dev = &client->dev, *hwmon; + struct auxiliary_device *adev; + struct ltc4283_hwmon *st; + int ret; + + st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL); + if (!st) + return -ENOMEM; + + if (!i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_BYTE_DATA | + I2C_FUNC_SMBUS_WORD_DATA | + I2C_FUNC_SMBUS_READ_I2C_BLOCK)) + return -EOPNOTSUPP; + + st->client = client; + st->map = devm_regmap_init(dev, <c4283_regmap_bus, client, + <c4283_regmap_config); + if (IS_ERR(st->map)) + return dev_err_probe(dev, PTR_ERR(st->map), + "Failed to create regmap\n"); + + ret = ltc4283_setup(st, dev); + if (ret) + return ret; + + hwmon = devm_hwmon_device_register_with_info(dev, "ltc4283", st, + <c4283_chip_info, NULL); + + if (IS_ERR(hwmon)) + return PTR_ERR(hwmon); + + ltc4283_debugfs_init(st, client); + + if (!st->gpio_mask) + return 0; + + adev = devm_auxiliary_device_create(dev, "gpio", &st->gpio_mask); + if (!adev) + return dev_err_probe(dev, -ENODEV, "Failed to add GPIO device\n"); + + return 0; +} + +static const struct of_device_id ltc4283_of_match[] = { + { .compatible = "adi,ltc4283" }, + { } +}; + +static const struct i2c_device_id ltc4283_i2c_id[] = { + { "ltc4283" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, ltc4283_i2c_id); + +static struct i2c_driver ltc4283_driver = { + .driver = { + .name = "ltc4283", + .of_match_table = ltc4283_of_match, + }, + .probe = ltc4283_probe, + .id_table = ltc4283_i2c_id, +}; +module_i2c_driver(ltc4283_driver); + +MODULE_AUTHOR("Nuno Sá <nuno.sa@analog.com>"); +MODULE_DESCRIPTION("LTC4283 Hot Swap Controller driver"); +MODULE_LICENSE("GPL"); -- 2.53.0 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH v6 2/3] hwmon: ltc4283: Add support for the LTC4283 Swap Controller 2026-03-03 17:00 ` [PATCH v6 2/3] hwmon: ltc4283: Add support for " Nuno Sá via B4 Relay @ 2026-03-04 11:05 ` kernel test robot 2026-03-04 12:20 ` Nuno Sá 2026-03-06 17:41 ` Guenter Roeck 1 sibling, 1 reply; 8+ messages in thread From: kernel test robot @ 2026-03-04 11:05 UTC (permalink / raw) To: Nuno Sá via B4 Relay, linux-gpio, linux-hwmon, devicetree, linux-doc Cc: oe-kbuild-all, Guenter Roeck, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Jonathan Corbet, Linus Walleij, Bartosz Golaszewski Hi Nuno, kernel test robot noticed the following build warnings: [auto build test WARNING on 78558965440b27814592ec82d8f3668395953b1b] url: https://github.com/intel-lab-lkp/linux/commits/Nuno-S-via-B4-Relay/dt-bindings-hwmon-Document-the-LTC4283-Swap-Controller/20260304-010255 base: 78558965440b27814592ec82d8f3668395953b1b patch link: https://lore.kernel.org/r/20260303-ltc4283-support-v6-2-efe11502fad2%40analog.com patch subject: [PATCH v6 2/3] hwmon: ltc4283: Add support for the LTC4283 Swap Controller compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261) docutils: docutils (Docutils 0.21.2, Python 3.13.5, on linux) reproduce: (https://download.01.org/0day-ci/archive/20260304/202603041109.HFnPWnj8-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202603041109.HFnPWnj8-lkp@intel.com/ All warnings (new ones prefixed by >>): ======================= ========================================== [docutils] >> Documentation/hwmon/ltc4283.rst:258: WARNING: Blank line required after table. [docutils] Documentation/mm/memfd_preservation:7: ./mm/memfd_luo.c:13: ERROR: Unexpected section title. vim +258 Documentation/hwmon/ltc4283.rst 256 257 ======================= ========================================== > 258 power1_failed_fault_log Set to 1 by a power1 fault occurring. -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v6 2/3] hwmon: ltc4283: Add support for the LTC4283 Swap Controller 2026-03-04 11:05 ` kernel test robot @ 2026-03-04 12:20 ` Nuno Sá 0 siblings, 0 replies; 8+ messages in thread From: Nuno Sá @ 2026-03-04 12:20 UTC (permalink / raw) To: kernel test robot, Nuno Sá via B4 Relay, linux-gpio, linux-hwmon, devicetree, linux-doc Cc: oe-kbuild-all, Guenter Roeck, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Jonathan Corbet, Linus Walleij, Bartosz Golaszewski On Wed, 2026-03-04 at 12:05 +0100, kernel test robot wrote: > Hi Nuno, > > kernel test robot noticed the following build warnings: > > [auto build test WARNING on 78558965440b27814592ec82d8f3668395953b1b] > > url: > https://github.com/intel-lab-lkp/linux/commits/Nuno-S-via-B4-Relay/dt-bindings-hwmon-Document-the-LTC4283-Swap-Controller/20260304-010255 > base: 78558965440b27814592ec82d8f3668395953b1b > patch link: https://lore.kernel.org/r/20260303-ltc4283-support-v6-2-efe11502fad2%40analog.com > patch subject: [PATCH v6 2/3] hwmon: ltc4283: Add support for the LTC4283 Swap Controller > compiler: clang version 20.1.8 > (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261) > docutils: docutils (Docutils 0.21.2, Python 3.13.5, on linux) > reproduce: > (https://download.01.org/0day-ci/archive/20260304/202603041109.HFnPWnj8-lkp@intel.com/reproduce) > > If you fix the issue in a separate patch/commit (i.e. not just a new version of > the same patch/commit), kindly add following tags > > Reported-by: kernel test robot <lkp@intel.com> > > Closes: https://lore.kernel.org/oe-kbuild-all/202603041109.HFnPWnj8-lkp@intel.com/ > > All warnings (new ones prefixed by >>): > > ======================= ========================================== [docutils] > > > Documentation/hwmon/ltc4283.rst:258: WARNING: Blank line required after table. [docutils] > Documentation/mm/memfd_preservation:7: ./mm/memfd_luo.c:13: ERROR: Unexpected section title. > > > vim +258 Documentation/hwmon/ltc4283.rst > > 256 > 257 ======================= ========================================== > > 258 power1_failed_fault_log Set to 1 by a power1 fault occurring. Arggh, will wait for more feedback before spinning a new version. - Nuno Sá ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v6 2/3] hwmon: ltc4283: Add support for the LTC4283 Swap Controller 2026-03-03 17:00 ` [PATCH v6 2/3] hwmon: ltc4283: Add support for " Nuno Sá via B4 Relay 2026-03-04 11:05 ` kernel test robot @ 2026-03-06 17:41 ` Guenter Roeck 2026-03-11 10:32 ` Nuno Sá 1 sibling, 1 reply; 8+ messages in thread From: Guenter Roeck @ 2026-03-06 17:41 UTC (permalink / raw) To: Nuno Sá Cc: linux-gpio, linux-hwmon, devicetree, linux-doc, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Jonathan Corbet, Linus Walleij, Bartosz Golaszewski Hi, On Tue, Mar 03, 2026 at 05:00:41PM +0000, Nuno Sá wrote: > From: Nuno Sá <nuno.sa@analog.com> > > Support the LTC4283 Hot Swap Controller. The device features programmable > current limit with foldback and independently adjustable inrush current to > optimize the MOSFET safe operating area (SOA). The SOA timer limits MOSFET > temperature rise for reliable protection against overstresses. > > An I2C interface and onboard ADC allow monitoring of board current, > voltage, power, energy, and fault status. > > Signed-off-by: Nuno Sá <nuno.sa@analog.com> > --- Feedback from AI review below. As far as I can see, the concerns are valid. My own comments are in [ ]. > Documentation/hwmon/index.rst | 1 + > Documentation/hwmon/ltc4283.rst | 265 ++++++ > MAINTAINERS | 1 + > drivers/hwmon/Kconfig | 12 + > drivers/hwmon/Makefile | 1 + > drivers/hwmon/ltc4283.c | 1780 +++++++++++++++++++++++++++++++++++++++ > 6 files changed, 2060 insertions(+) > > diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst > index 559c32344cd3..eab95152abee 100644 > --- a/Documentation/hwmon/index.rst > +++ b/Documentation/hwmon/index.rst > @@ -144,6 +144,7 @@ Hardware Monitoring Kernel Drivers > ltc4260 > ltc4261 > ltc4282 > + ltc4283 > ltc4286 > macsmc-hwmon > max127 > diff --git a/Documentation/hwmon/ltc4283.rst b/Documentation/hwmon/ltc4283.rst > new file mode 100644 > index 000000000000..225ba886531d > --- /dev/null > +++ b/Documentation/hwmon/ltc4283.rst > @@ -0,0 +1,265 @@ > +.. SPDX-License-Identifier: GPL-2.0-only > + > +Kernel drivers ltc4283 > +========================================== > + > +Supported chips: > + > + * Analog Devices LTC4283 > + > + Prefix: 'ltc4283' > + > + Addresses scanned: - > + > + Datasheet: > + > + https://www.analog.com/media/en/technical-documentation/data-sheets/ltc4283.pdf > + > +Author: Nuno Sá <nuno.sa@analog.com> > + > +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. > +The device features programmable current limit with foldback and independently > +adjustable inrush current to optimize the MOSFET safe operating area (SOA). The > +SOA timer limits MOSFET temperature rise for reliable protection against > +overstresses. An I2C interface and onboard gear-shift ADC allow monitoring of > +board current, voltage, power, energy, and fault status. Additional features > +respond to input UV/OV, interrupt the host when a fault has occurred, notify > +when output power is good, detect insertion of a board, turn off the MOSFET > +if an external supply monitor fails to indicate power good within a timeout > +period, and auto-reboot after a programmable delay following a host commanded > +turn-off. > + > +Sysfs entries > +_____________ > + > +The following attributes are supported. Limits are read-write and all the other > +attributes are read-only. Note that the VADIOx channels might not be available > +if the ADIO pins are used as GPIOs (naturally also affects the respective > +differential channels). > + > +======================= ========================================== > +in0_lcrit_alarm Critical Undervoltage alarm > +in0_crit_alarm Critical Overvoltage alarm > +in0_label Channel label (VIN) > + > +in1_input Output voltage (mV). > +in1_min Undervoltage threshold > +in1_max Overvoltage threshold > +in1_lowest Lowest measured voltage > +in1_highest Highest measured voltage > +in1_reset_history Write 1 to reset history. > +in1_min_alarm Undervoltage alarm > +in1_max_alarm Overvoltage alarm > +in1_label Channel label (VPWR) > + > +in2_input Output voltage (mV). > +in2_min Undervoltage threshold > +in2_max Overvoltage threshold > +in2_lowest Lowest measured voltage > +in2_highest Highest measured voltage > +in2_reset_history Write 1 to reset history. > +in2_min_alarm Undervoltage alarm > +in2_max_alarm Overvoltage alarm > +in2_enable Enable/Disable monitoring. > +in2_label Channel label (VADI1) > + > +in3_input Output voltage (mV). > +in3_min Undervoltage threshold > +in3_max Overvoltage threshold > +in3_lowest Lowest measured voltage > +in3_highest Highest measured voltage > +in3_reset_history Write 1 to reset history. > +in3_min_alarm Undervoltage alarm > +in3_max_alarm Overvoltage alarm > +in3_enable Enable/Disable monitoring. > +in3_label Channel label (VADI2) > + > +in4_input Output voltage (mV). > +in4_min Undervoltage threshold > +in4_max Overvoltage threshold > +in4_lowest Lowest measured voltage > +in4_highest Highest measured voltage > +in4_reset_history Write 1 to reset history. > +in4_min_alarm Undervoltage alarm > +in4_max_alarm Overvoltage alarm > +in4_enable Enable/Disable monitoring. > +in4_label Channel label (VADI3) > + > +in5_input Output voltage (mV). > +in5_min Undervoltage threshold > +in5_max Overvoltage threshold > +in5_lowest Lowest measured voltage > +in5_highest Highest measured voltage > +in5_reset_history Write 1 to reset history. > +in5_min_alarm Undervoltage alarm > +in5_max_alarm Overvoltage alarm > +in5_enable Enable/Disable monitoring. > +in5_label Channel label (VADI4) > + > +in6_input Output voltage (mV). > +in6_min Undervoltage threshold > +in6_max Overvoltage threshold > +in6_lowest Lowest measured voltage > +in6_highest Highest measured voltage > +in6_reset_history Write 1 to reset history. > +in6_min_alarm Undervoltage alarm > +in6_max_alarm Overvoltage alarm > +in6_enable Enable/Disable monitoring. > +in6_label Channel label (VADIO1) > + > +in7_input Output voltage (mV). > +in7_min Undervoltage threshold > +in7_max Overvoltage threshold > +in7_lowest Lowest measured voltage > +in7_highest Highest measured voltage > +in7_reset_history Write 1 to reset history. > +in7_min_alarm Undervoltage alarm > +in7_max_alarm Overvoltage alarm > +in7_enable Enable/Disable monitoring. > +in7_label Channel label (VADIO2) > + > +in8_input Output voltage (mV). > +in8_min Undervoltage threshold > +in8_max Overvoltage threshold > +in8_lowest Lowest measured voltage > +in8_highest Highest measured voltage > +in8_reset_history Write 1 to reset history. > +in8_min_alarm Undervoltage alarm > +in8_max_alarm Overvoltage alarm > +in8_enable Enable/Disable monitoring. > +in8_label Channel label (VADIO3) > + > +in9_input Output voltage (mV). > +in9_min Undervoltage threshold > +in9_max Overvoltage threshold > +in9_lowest Lowest measured voltage > +in9_highest Highest measured voltage > +in9_reset_history Write 1 to reset history. > +in9_min_alarm Undervoltage alarm > +in9_max_alarm Overvoltage alarm > +in9_enable Enable/Disable monitoring. > +in9_label Channel label (VADIO4) > + > +in10_input Output voltage (mV). > +in10_min Undervoltage threshold > +in10_max Overvoltage threshold > +in10_lowest Lowest measured voltage > +in10_highest Highest measured voltage > +in10_reset_history Write 1 to reset history. > +in10_min_alarm Undervoltage alarm > +in10_max_alarm Overvoltage alarm > +in10_enable Enable/Disable monitoring. > +in10_label Channel label (DRNS) > + > +in11_input Output voltage (mV). > +in11_min Undervoltage threshold > +in11_max Overvoltage threshold > +in11_lowest Lowest measured voltage > +in11_highest Highest measured voltage > +in11_reset_history Write 1 to reset history. > + Also clears fet bad and short fault logs. > +in11_min_alarm Undervoltage alarm > +in11_max_alarm Overvoltage alarm > +in11_enable Enable/Disable monitoring > +in11_fault Failure in the MOSFET. Either bad or shorted FET. > +in11_label Channel label (DRAIN) > + > +in12_input Output voltage (mV). > +in12_min Undervoltage threshold > +in12_max Overvoltage threshold > +in12_lowest Lowest measured voltage > +in12_highest Highest measured voltage > +in12_reset_history Write 1 to reset history. > +in12_min_alarm Undervoltage alarm > +in12_max_alarm Overvoltage alarm > +in12_enable Enable/Disable monitoring. > +in12_label Channel label (ADIN2-ADIN1) > + > +in13_input Output voltage (mV). > +in13_min Undervoltage threshold > +in13_max Overvoltage threshold > +in13_lowest Lowest measured voltage > +in13_highest Highest measured voltage > +in13_reset_history Write 1 to reset history. > +in13_min_alarm Undervoltage alarm > +in13_max_alarm Overvoltage alarm > +in13_enable Enable/Disable monitoring. > +in13_label Channel label (ADIN4-ADIN3) > + > +in14_input Output voltage (mV). > +in14_min Undervoltage threshold > +in14_max Overvoltage threshold > +in14_lowest Lowest measured voltage > +in14_highest Highest measured voltage > +in14_reset_history Write 1 to reset history. > +in14_min_alarm Undervoltage alarm > +in14_max_alarm Overvoltage alarm > +in14_enable Enable/Disable monitoring. > +in14_label Channel label (ADIO2-ADIO1) > + > +in15_input Output voltage (mV). > +in15_min Undervoltage threshold > +in15_max Overvoltage threshold > +in15_lowest Lowest measured voltage > +in15_highest Highest measured voltage > +in15_reset_history Write 1 to reset history. > +in15_min_alarm Undervoltage alarm > +in15_max_alarm Overvoltage alarm > +in15_enable Enable/Disable monitoring. > +in15_label Channel label (ADIO4-ADIO3) > + > +curr1_input Sense current (mA) > +curr1_min Undercurrent threshold > +curr1_max Overcurrent threshold > +curr1_lowest Lowest measured current > +curr1_highest Highest measured current > +curr1_reset_history Write 1 to reset curr1 history. > + Also clears overcurrent fault logs. > +curr1_min_alarm Undercurrent alarm > +curr1_max_alarm Overcurrent alarm > +curr1_crit_alarm Critical Overcurrent alarm > +curr1_label Channel label (ISENSE) > + > +power1_input Power (in uW) > +power1_min Low power threshold > +power1_max High power threshold > +power1_input_lowest Historical minimum power use > +power1_input_highest Historical maximum power use > +power1_reset_history Write 1 to reset power1 history. > + Also clears power fault logs. > +power1_min_alarm Low power alarm > +power1_max_alarm High power alarm > +power1_label Channel label (Power) > + > +energy1_input Measured energy over time (in microJoule) > +energy1_enable Enable/Disable Energy accumulation > + > +DebugFs entries > +_______________ > + > +The chip also has a fault log register where failures can be logged. Hence, > +as these are logging events, we give access to them in debugfs. Note that > +even if some failure is detected in these logs, it does necessarily mean > +that the failure is still present. As mentioned in the proper Sysfs entries, > +these logs can be cleared by writing in the proper reset_history attribute. > + > +.. warning:: The debugfs interface is subject to change without notice > + and is only available when the kernel is compiled with > + ``CONFIG_DEBUG_FS`` defined. > + > +``/sys/kernel/debug/i2c/i2c-[X]/[X]-addr/`` > +contains the following attributes: > + > +======================= ========================================== > +power1_failed_fault_log Set to 1 by a power1 fault occurring. > +power1_good_input_fault_log Set to 1 by a power1 good input fault occurring at PGIO3. > +in11_fet_short_fault_log Set to 1 when a FET-short fault occurs. > +in11_fet_bad_fault_log Set to 1 when a FET-BAD fault occurs. > +in0_lcrit_fault_log Set to 1 by a VIN undervoltage fault occurring. > +in0_crit_fault_log Set to 1 by a VIN overvoltage fault occurring. > +curr1_crit_fault_log Set to 1 by an overcurrent fault occurring. > +======================= ========================================== > diff --git a/MAINTAINERS b/MAINTAINERS > index 13ae2f3db449..38d22cf622b7 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -15146,6 +15146,7 @@ M: Nuno Sá <nuno.sa@analog.com> > L: linux-hwmon@vger.kernel.org > S: Supported > F: Documentation/devicetree/bindings/hwmon/adi,ltc4283.yaml > +F: drivers/hwmon/ltc4283.c > > LTC4286 HARDWARE MONITOR DRIVER > M: Delphine CC Chiu <Delphine_CC_Chiu@Wiwynn.com> > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig > index 8f7ce66ae3a2..c529f622c2b8 100644 > --- a/drivers/hwmon/Kconfig > +++ b/drivers/hwmon/Kconfig > @@ -1158,6 +1158,18 @@ config SENSORS_LTC4282 > This driver can also be built as a module. If so, the module will > be called ltc4282. > > +config SENSORS_LTC4283 > + tristate "Analog Devices LTC4283" > + depends on I2C > + select REGMAP_I2C > + select AUXILIARY_BUS > + help > + If you say yes here you get support for Analog Devices LTC4283 > + Negative Voltage Hot Swap Controller I2C interface. > + > + This driver can also be built as a module. If so, the module will > + be called ltc4283. > + > config SENSORS_LTQ_CPUTEMP > bool "Lantiq cpu temperature sensor driver" > depends on SOC_XWAY > diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile > index 556e86d277b1..cb77938dbe07 100644 > --- a/drivers/hwmon/Makefile > +++ b/drivers/hwmon/Makefile > @@ -147,6 +147,7 @@ obj-$(CONFIG_SENSORS_LTC4245) += ltc4245.o > obj-$(CONFIG_SENSORS_LTC4260) += ltc4260.o > obj-$(CONFIG_SENSORS_LTC4261) += ltc4261.o > obj-$(CONFIG_SENSORS_LTC4282) += ltc4282.o > +obj-$(CONFIG_SENSORS_LTC4283) += ltc4283.o > obj-$(CONFIG_SENSORS_LTQ_CPUTEMP) += ltq-cputemp.o > obj-$(CONFIG_SENSORS_MACSMC_HWMON) += macsmc-hwmon.o > obj-$(CONFIG_SENSORS_MAX1111) += max1111.o > diff --git a/drivers/hwmon/ltc4283.c b/drivers/hwmon/ltc4283.c > new file mode 100644 > index 000000000000..83f1f741abac > --- /dev/null > +++ b/drivers/hwmon/ltc4283.c > @@ -0,0 +1,1780 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Analog Devices LTC4283 I2C Negative Voltage Hot Swap Controller (HWMON) > + * > + * Copyright 2025 Analog Devices Inc. > + */ > +#include <linux/auxiliary_bus.h> > +#include <linux/bitfield.h> > +#include <linux/bitmap.h> > +#include <linux/bitops.h> > +#include <linux/bits.h> > + > +#include <linux/debugfs.h> > +#include <linux/device.h> > +#include <linux/device/devres.h> > +#include <linux/hwmon.h> > +#include <linux/i2c.h> > +#include <linux/math.h> > +#include <linux/math64.h> > +#include <linux/minmax.h> > +#include <linux/module.h> > + > +#include <linux/mod_devicetable.h> > +#include <linux/overflow.h> > +#include <linux/property.h> > +#include <linux/regmap.h> > +#include <linux/unaligned.h> > +#include <linux/units.h> > + > +#define LTC4283_SYSTEM_STATUS 0x00 > +#define LTC4283_FAULT_STATUS 0x03 > +#define LTC4283_OV_MASK BIT(0) > +#define LTC4283_UV_MASK BIT(1) > +#define LTC4283_OC_MASK BIT(2) > +#define LTC4283_FET_BAD_MASK BIT(3) > +#define LTC4283_FET_SHORT_MASK BIT(6) > +#define LTC4283_FAULT_LOG 0x04 > +#define LTC4283_OV_FAULT_MASK BIT(0) > +#define LTC4283_UV_FAULT_MASK BIT(1) > +#define LTC4283_OC_FAULT_MASK BIT(2) > +#define LTC4283_FET_BAD_FAULT_MASK BIT(3) > +#define LTC4283_PGI_FAULT_MASK BIT(4) > +#define LTC4283_PWR_FAIL_FAULT_MASK BIT(5) > +#define LTC4283_FET_SHORT_FAULT_MASK BIT(6) > +#define LTC4283_ADC_ALM_LOG_1 0x05 > +#define LTC4283_POWER_LOW_ALM BIT(0) > +#define LTC4283_POWER_HIGH_ALM BIT(1) > +#define LTC4283_SENSE_LOW_ALM BIT(4) > +#define LTC4283_SENSE_HIGH_ALM BIT(5) > +#define LTC4283_ADC_ALM_LOG_2 0x06 > +#define LTC4283_ADC_ALM_LOG_3 0x07 > +#define LTC4283_ADC_ALM_LOG_4 0x08 > +#define LTC4283_ADC_ALM_LOG_5 0x09 > +#define LTC4283_CONTROL_1 0x0a > +#define LTC4283_RW_PAGE_MASK BIT(0) > +#define LTC4283_PIGIO2_ACLB_MASK BIT(2) > +#define LTC4283_PWRGD_RST_CTRL_MASK BIT(3) > +#define LTC4283_FET_BAD_OFF_MASK BIT(4) > +#define LTC4283_THERM_TMR_MASK BIT(5) > +#define LTC4283_DVDT_MASK BIT(6) > +#define LTC4283_CONTROL_2 0x0b > +#define LTC4283_OV_RETRY_MASK BIT(0) > +#define LTC4283_UV_RETRY_MASK BIT(1) > +#define LTC4283_OC_RETRY_MASK GENMASK(3, 2) > +#define LTC4283_FET_BAD_RETRY_MASK GENMASK(5, 4) > +#define LTC4283_EXT_FAULT_RETRY_MASK BIT(7) > +#define LTC4283_RESERVED_OC 0x0c > +#define LTC4283_CONFIG_1 0x0d > +#define LTC4283_FB_MASK GENMASK(3, 2) > +#define LTC4283_ILIM_MASK GENMASK(7, 4) > +#define LTC4283_CONFIG_2 0x0e > +#define LTC4283_COOLING_DL_MASK GENMASK(3, 1) > +#define LTC4283_FTBD_DL_MASK GENMASK(5, 4) > +#define LTC4283_CONFIG_3 0x0f > +#define LTC4283_VPWR_DRNS_MASK BIT(6) > +#define LTC4283_EXTFLT_TURN_OFF_MASK BIT(7) > +#define LTC4283_PGIO_CONFIG 0x10 > +#define LTC4283_PGIO1_CFG_MASK GENMASK(1, 0) > +#define LTC4283_PGIO2_CFG_MASK GENMASK(3, 2) > +#define LTC4283_PGIO3_CFG_MASK GENMASK(5, 4) > +#define LTC4283_PGIO4_CFG_MASK GENMASK(7, 6) > +#define LTC4283_PGIO_CONFIG_2 0x11 > +#define LTC4283_ADC_MASK GENMASK(2, 0) > +#define LTC4283_ADC_SELECT(c) (0x13 + (c) / 8) > +#define LTC4283_ADC_SELECT_MASK(c) BIT((c) % 8) > +#define LTC4283_SENSE_MIN_TH 0x1b > +#define LTC4283_SENSE_MAX_TH 0x1c > +#define LTC4283_VPWR_MIN_TH 0x1d > +#define LTC4283_VPWR_MAX_TH 0x1e > +#define LTC4283_POWER_MIN_TH 0x1f > +#define LTC4283_POWER_MAX_TH 0x20 > +#define LTC4283_ADC_2_MIN_TH(c) (0x21 + (c) * 2) > +#define LTC4283_ADC_2_MAX_TH(c) (0x22 + (c) * 2) > +#define LTC4283_ADC_2_MIN_TH_DIFF(c) (0x39 + (c) * 2) > +#define LTC4283_ADC_2_MAX_TH_DIFF(c) (0x3a + (c) * 2) > +#define LTC4283_SENSE 0x41 > +#define LTC4283_SENSE_MIN 0x42 > +#define LTC4283_SENSE_MAX 0x43 > +#define LTC4283_VPWR 0x44 > +#define LTC4283_VPWR_MIN 0x45 > +#define LTC4283_VPWR_MAX 0x46 > +#define LTC4283_POWER 0x47 > +#define LTC4283_POWER_MIN 0x48 > +#define LTC4283_POWER_MAX 0x49 > +#define LTC4283_RESERVED_68 0x68 > +#define LTC4283_RESERVED_6D 0x6D > +/* get channels from ADC 2 */ > +#define LTC4283_ADC_2(c) (0x4a + (c) * 3) > +#define LTC4283_ADC_2_MIN(c) (0x4b + (c) * 3) > +#define LTC4283_ADC_2_MAX(c) (0x4c + (c) * 3) > +#define LTC4283_ADC_2_DIFF(c) (0x6e + (c) * 3) > +#define LTC4283_ADC_2_MIN_DIFF(c) (0x6f + (c) * 3) > +#define LTC4283_ADC_2_MAX_DIFF(c) (0x70 + (c) * 3) > +#define LTC4283_ENERGY 0x7a > +#define LTC4283_METER_CONTROL 0x84 > +#define LTC4283_INTEGRATE_I_MASK BIT(0) > +#define LTC4283_METER_HALT_MASK BIT(6) > +#define LTC4283_RESERVED_86 0x86 > +#define LTC4283_RESERVED_8F 0x8F > +#define LTC4283_FAULT_LOG_CTRL 0x90 > +#define LTC4283_FAULT_LOG_EN_MASK BIT(7) > +#define LTC4283_RESERVED_91 0x91 > +#define LTC4283_RESERVED_A1 0xA1 > +#define LTC4283_RESERVED_A3 0xA3 > +#define LTC4283_RESERVED_AC 0xAC > +#define LTC4283_POWER_PLAY_MSB 0xE7 > +#define LTC4283_POWER_PLAY_LSB 0xE8 > +#define LTC4283_RESERVED_F1 0xF1 > +#define LTC4283_RESERVED_FF 0xFF > + > +/* also applies for differential channels */ > +#define LTC4283_ADC1_FS_uV 32768 > +#define LTC4283_ADC2_FS_mV 2048 > +#define LTC4283_TCONV_uS 64103 > +#define LTC4283_VILIM_MIN_uV 15000 > +#define LTC4283_VILIM_MAX_uV 30000 > +#define LTC4283_VILIM_RANGE \ > + (LTC4283_VILIM_MAX_uV - LTC4283_VILIM_MIN_uV + 1) > + > +#define LTC4283_PGIO_FUNC_GPIO 2 > +#define LTC4283_PGIO2_FUNC_ACLB 3 > + > +/* voltage channels */ > +enum { > + LTC4283_CHAN_VIN, > + LTC4283_CHAN_VPWR, > + LTC4283_CHAN_ADI_1, > + LTC4283_CHAN_ADI_2, > + LTC4283_CHAN_ADI_3, > + LTC4283_CHAN_ADI_4, > + LTC4283_CHAN_ADIO_1, > + LTC4283_CHAN_ADIO_2, > + LTC4283_CHAN_ADIO_3, > + LTC4283_CHAN_ADIO_4, > + LTC4283_CHAN_DRNS, > + LTC4283_CHAN_DRAIN, > + /* differential channels */ > + LTC4283_CHAN_ADIN12, > + LTC4283_CHAN_ADIN34, > + LTC4283_CHAN_ADIO12, > + LTC4283_CHAN_ADIO34, > + LTC4283_CHAN_MAX > +}; > + > +/* Just for ease of use on the regmap */ > +#define LTC4283_ADIO34_MAX \ > + LTC4283_ADC_2_MAX_DIFF(LTC4283_CHAN_ADIO34 - LTC4283_CHAN_ADIN12) > + > +struct ltc4283_hwmon { > + struct regmap *map; > + struct i2c_client *client; > + unsigned long gpio_mask; > + unsigned long ch_enable_mask; > + /* in microwatt */ > + long power_max; > + /* in millivolt */ > + u32 vsense_max; > + /* in tenths of microohm*/ > + u32 rsense; > + bool energy_en; > + bool ext_fault; > +}; > + > +static int ltc4283_read_voltage_word(const struct ltc4283_hwmon *st, > + u32 reg, u32 fs, long *val) > +{ > + unsigned int __raw; > + int ret; > + > + ret = regmap_read(st->map, reg, &__raw); > + if (ret) > + return ret; > + > + *val = DIV_ROUND_CLOSEST(__raw * fs, BIT(16)); > + return 0; > +} > + > +static int ltc4283_read_voltage_byte(const struct ltc4283_hwmon *st, > + u32 reg, u32 fs, long *val) > +{ > + int ret; > + u32 in; > + > + ret = regmap_read(st->map, reg, &in); > + if (ret) > + return ret; > + > + *val = DIV_ROUND_CLOSEST(in * fs, BIT(8)); > + return 0; > +} > + > +static u32 ltc4283_in_reg(u32 attr, u32 channel) > +{ > + switch (attr) { > + case hwmon_in_input: > + if (channel == LTC4283_CHAN_VPWR) > + return LTC4283_VPWR; > + if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN) > + return LTC4283_ADC_2(channel - LTC4283_CHAN_ADI_1); > + return LTC4283_ADC_2_DIFF(channel - LTC4283_CHAN_ADIN12); > + case hwmon_in_highest: > + if (channel == LTC4283_CHAN_VPWR) > + return LTC4283_VPWR_MAX; > + if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN) > + return LTC4283_ADC_2_MAX(channel - LTC4283_CHAN_ADI_1); > + return LTC4283_ADC_2_MAX_DIFF(channel - LTC4283_CHAN_ADIN12); > + case hwmon_in_lowest: > + if (channel == LTC4283_CHAN_VPWR) > + return LTC4283_VPWR_MIN; > + if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN) > + return LTC4283_ADC_2_MIN(channel - LTC4283_CHAN_ADI_1); > + return LTC4283_ADC_2_MIN_DIFF(channel - LTC4283_CHAN_ADIN12); > + case hwmon_in_max: > + if (channel == LTC4283_CHAN_VPWR) > + return LTC4283_VPWR_MAX_TH; > + if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN) > + return LTC4283_ADC_2_MAX_TH(channel - LTC4283_CHAN_ADI_1); > + return LTC4283_ADC_2_MAX_TH_DIFF(channel - LTC4283_CHAN_ADIN12); > + default: > + if (channel == LTC4283_CHAN_VPWR) > + return LTC4283_VPWR_MIN_TH; > + if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN) > + return LTC4283_ADC_2_MIN_TH(channel - LTC4283_CHAN_ADI_1); > + return LTC4283_ADC_2_MIN_TH_DIFF(channel - LTC4283_CHAN_ADIN12); > + } > +} > + > +static int ltc4283_read_in_vals(const struct ltc4283_hwmon *st, > + u32 attr, u32 channel, long *val) > +{ > + u32 reg = ltc4283_in_reg(attr, channel); > + int ret; > + > + if (channel < LTC4283_CHAN_ADIN12) { > + if (attr != hwmon_in_max && attr != hwmon_in_min) > + return ltc4283_read_voltage_word(st, reg, > + LTC4283_ADC2_FS_mV, > + val); > + > + return ltc4283_read_voltage_byte(st, reg, > + LTC4283_ADC2_FS_mV, val); > + } > + > + if (attr != hwmon_in_max && attr != hwmon_in_min) > + ret = ltc4283_read_voltage_word(st, reg, > + LTC4283_ADC1_FS_uV, val); > + else > + ret = ltc4283_read_voltage_byte(st, reg, > + LTC4283_ADC1_FS_uV, val); > + if (ret) > + return ret; > + > + *val = DIV_ROUND_CLOSEST(*val, MILLI); > + return 0; > +} > + > +static int ltc4283_read_alarm(struct ltc4283_hwmon *st, u32 reg, > + u32 mask, long *val) > +{ > + u32 alarm; > + int ret; > + > + ret = regmap_read(st->map, reg, &alarm); > + if (ret) > + return ret; > + > + *val = !!(alarm & mask); > + > + /* If not status/fault logs, clear the alarm after reading it. */ > + if (reg != LTC4283_FAULT_STATUS && reg != LTC4283_FAULT_LOG) > + return regmap_clear_bits(st->map, reg, mask); > + > + return 0; > +} > + > +static int ltc4283_read_in_alarm(struct ltc4283_hwmon *st, u32 channel, > + bool max_alm, long *val) > +{ > + if (channel == LTC4283_VPWR) > + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_1, > + BIT(2 + max_alm), val); > + > + if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_ADI_4) { > + u32 bit = (channel - LTC4283_CHAN_ADI_1) * 2; > + /* > + * Lower channels go to higher bits. We also want to go +1 down > + * in the min_alarm case. > + */ > + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_2, > + BIT(7 - bit - !max_alm), val); > + } > + > + if (channel >= LTC4283_CHAN_ADIO_1 && channel <= LTC4283_CHAN_ADIO_4) { > + u32 bit = (channel - LTC4283_CHAN_ADIO_1) * 2; > + > + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_3, > + BIT(7 - bit - !max_alm), val); > + } > + > + if (channel >= LTC4283_CHAN_ADIN12 && channel <= LTC4283_CHAN_ADIN34) { > + u32 bit = (channel - LTC4283_CHAN_ADIN12) * 2; > + > + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_5, > + BIT(7 - bit - !max_alm), val); > + } > + > + if (channel == LTC4283_CHAN_DRNS) > + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_4, > + BIT(6 + max_alm), val); > + > + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_4, BIT(4 + max_alm), > + val); > +} > + > +static int ltc4283_read_in(struct ltc4283_hwmon *st, u32 attr, u32 channel, > + long *val) > +{ > + switch (attr) { > + case hwmon_in_input: > + if (!test_bit(channel, &st->ch_enable_mask)) > + return -ENODATA; > + > + return ltc4283_read_in_vals(st, attr, channel, val); > + case hwmon_in_highest: > + case hwmon_in_lowest: > + case hwmon_in_max: > + case hwmon_in_min: > + return ltc4283_read_in_vals(st, attr, channel, val); > + case hwmon_in_max_alarm: > + return ltc4283_read_in_alarm(st, channel, true, val); > + case hwmon_in_min_alarm: > + return ltc4283_read_in_alarm(st, channel, false, val); > + case hwmon_in_crit_alarm: > + return ltc4283_read_alarm(st, LTC4283_FAULT_STATUS, > + LTC4283_OV_MASK, val); > + case hwmon_in_lcrit_alarm: > + return ltc4283_read_alarm(st, LTC4283_FAULT_STATUS, > + LTC4283_UV_MASK, val); > + case hwmon_in_fault: > + /* > + * We report failure if we detect either a fer_bad or a > + * fet_short in the status register. > + */ > + return ltc4283_read_alarm(st, LTC4283_FAULT_STATUS, > + LTC4283_FET_BAD_MASK | LTC4283_FET_SHORT_MASK, val); > + case hwmon_in_enable: > + *val = test_bit(channel, &st->ch_enable_mask); > + return 0; > + default: > + return -EOPNOTSUPP; > + } > + return 0; > +} > + > +static int ltc4283_read_current_word(const struct ltc4283_hwmon *st, u32 reg, > + long *val) > +{ > + u64 temp = (u64)LTC4283_ADC1_FS_uV * DECA * MILLI; > + unsigned int __raw; > + int ret; > + > + ret = regmap_read(st->map, reg, &__raw); > + if (ret) > + return ret; > + > + *val = DIV64_U64_ROUND_CLOSEST(__raw * temp, > + BIT_ULL(16) * st->rsense); > + > + return 0; > +} > + > +static int ltc4283_read_current_byte(const struct ltc4283_hwmon *st, u32 reg, > + long *val) > +{ > + u64 temp = (u64)LTC4283_ADC1_FS_uV * DECA * MILLI; > + u32 curr; > + int ret; > + > + ret = regmap_read(st->map, reg, &curr); > + if (ret) > + return ret; > + > + *val = DIV_ROUND_CLOSEST_ULL(curr * temp, BIT(8) * st->rsense); > + return 0; > +} > + > +static int ltc4283_read_curr(struct ltc4283_hwmon *st, u32 attr, long *val) > +{ > + switch (attr) { > + case hwmon_curr_input: > + return ltc4283_read_current_word(st, LTC4283_SENSE, val); > + case hwmon_curr_highest: > + return ltc4283_read_current_word(st, LTC4283_SENSE_MAX, val); > + case hwmon_curr_lowest: > + return ltc4283_read_current_word(st, LTC4283_SENSE_MIN, val); > + case hwmon_curr_max: > + return ltc4283_read_current_byte(st, LTC4283_SENSE_MAX_TH, val); > + case hwmon_curr_min: > + return ltc4283_read_current_byte(st, LTC4283_SENSE_MIN_TH, val); > + case hwmon_curr_max_alarm: > + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_1, > + LTC4283_SENSE_HIGH_ALM, val); > + case hwmon_curr_min_alarm: > + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_1, > + LTC4283_SENSE_LOW_ALM, val); > + case hwmon_curr_crit_alarm: > + return ltc4283_read_alarm(st, LTC4283_FAULT_STATUS, > + LTC4283_OC_MASK, val); > + default: > + return -EOPNOTSUPP; > + } > +} > + > +static int ltc4283_read_power_word(const struct ltc4283_hwmon *st, > + u32 reg, long *val) > +{ > + u64 temp = (u64)LTC4283_ADC1_FS_uV * LTC4283_ADC2_FS_mV * DECA * MILLI; > + unsigned int __raw; > + int ret; > + > + ret = regmap_read(st->map, reg, &__raw); > + if (ret) > + return ret; > + > + /* > + * Power is given by: > + * P = CODE(16b) * 32.768mV * 2.048V / (2^16 * Rsense) > + */ > + *val = DIV64_U64_ROUND_CLOSEST(temp * __raw, BIT_ULL(16) * st->rsense); > + > + return 0; > +} > + > +static int ltc4283_read_power_byte(const struct ltc4283_hwmon *st, > + u32 reg, long *val) > +{ > + u64 temp = (u64)LTC4283_ADC1_FS_uV * LTC4283_ADC2_FS_mV * DECA * MILLI; > + u32 power; > + int ret; > + > + ret = regmap_read(st->map, reg, &power); > + if (ret) > + return ret; > + > + *val = DIV_ROUND_CLOSEST_ULL(power * temp, BIT(8) * st->rsense); > + > + return 0; > +} > + > +static int ltc4283_read_power(struct ltc4283_hwmon *st, u32 attr, long *val) > +{ > + switch (attr) { > + case hwmon_power_input: > + return ltc4283_read_power_word(st, LTC4283_POWER, val); > + case hwmon_power_input_highest: > + return ltc4283_read_power_word(st, LTC4283_POWER_MAX, val); > + case hwmon_power_input_lowest: > + return ltc4283_read_power_word(st, LTC4283_POWER_MIN, val); > + case hwmon_power_max_alarm: > + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_1, > + LTC4283_POWER_HIGH_ALM, val); > + case hwmon_power_min_alarm: > + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_1, > + LTC4283_POWER_LOW_ALM, val); > + case hwmon_power_max: > + return ltc4283_read_power_byte(st, LTC4283_POWER_MAX_TH, val); > + case hwmon_power_min: > + return ltc4283_read_power_byte(st, LTC4283_POWER_MIN_TH, val); > + default: > + return -EOPNOTSUPP; > + } > +} > + > +static int ltc4283_read_energy(struct ltc4283_hwmon *st, u32 attr, s64 *val) > +{ > + u64 temp = LTC4283_ADC1_FS_uV * LTC4283_ADC2_FS_mV, energy, temp_2; > + u8 raw[8]; > + int ret; > + > + if (!st->energy_en) > + return -ENODATA; > + > + ret = i2c_smbus_read_i2c_block_data(st->client, LTC4283_ENERGY, 6, raw); > + if (ret < 0) > + return ret; > + if (ret != 6) > + return -EIO; > + > + energy = get_unaligned_be64(raw) >> 16; This reads 8 bytes from `raw` which is only partially initialized, as the block data read is 6 bytes. This accesses uninitialized stack memory (`raw[6]` and `raw[7]`), which can trigger KMSAN warnings. Could we initialize `raw` to zero? [ Yes, the uninitialized data is then shifted out, but KMSAN won't know that. ] > + > + /* > + * The formula for energy is given by: > + * E = CODE(48b) * 32.768mV * 2.048V * Tconv / 2^24 * Rsense > + * > + * As Rsense can have tenths of micro-ohm resolution, we need to > + * multiply by DECA to get microjoule. > + */ > + if (check_mul_overflow(temp * LTC4283_TCONV_uS, energy, &temp_2)) { > + /* > + * We multiply again by 1000 to make sure that we don't get 0 > + * in the following division which could happen for big rsense > + * values. OTOH, we then divide energy first by 1000 so that > + * we do not overflow u64 again for very small rsense values. > + * We add 100 factor for proper conversion to microjoule. > + */ > + temp_2 = DIV64_U64_ROUND_CLOSEST(temp * LTC4283_TCONV_uS * MILLI, > + BIT_ULL(24) * st->rsense); > + energy = DIV_ROUND_CLOSEST_ULL(energy, MILLI * CENTI) * temp_2; > + } else { > + /* Put rsense back into nanoohm so we get microjoule. */ > + energy = DIV64_U64_ROUND_CLOSEST(temp_2, BIT_ULL(24) * st->rsense * CENTI); > + } > + > + *val = energy; > + return 0; > +} > + > +static int ltc4283_read(struct device *dev, enum hwmon_sensor_types type, > + u32 attr, int channel, long *val) > +{ > + struct ltc4283_hwmon *st = dev_get_drvdata(dev); > + > + switch (type) { > + case hwmon_in: > + return ltc4283_read_in(st, attr, channel, val); > + case hwmon_curr: > + return ltc4283_read_curr(st, attr, val); > + case hwmon_power: > + return ltc4283_read_power(st, attr, val); > + case hwmon_energy: > + *val = st->energy_en; > + return 0; > + case hwmon_energy64: > + return ltc4283_read_energy(st, attr, (s64 *)val); > + default: > + return -EOPNOTSUPP; > + } > +} > + > +static int ltc4283_write_power_byte(const struct ltc4283_hwmon *st, u32 reg, > + long val) > +{ > + u64 temp = (u64)LTC4283_ADC1_FS_uV * LTC4283_ADC2_FS_mV * DECA * MILLI; > + u32 __raw; > + > + if (val > st->power_max) > + val = st->power_max; > + If `val` is negative, the signed comparison works correctly, but `val` is then passed to the multiplication below. > + __raw = DIV64_U64_ROUND_CLOSEST(val * BIT_ULL(8) * st->rsense, temp); > + Here, `val` is implicitly cast to `u64`. A negative `val` will become a huge positive number and write a garbage 8-bit value. Could we clamp `val` to 0 as well using `clamp_val()`? > + return regmap_write(st->map, reg, __raw); > +} > + > +static int ltc4283_write_power_word(const struct ltc4283_hwmon *st, > + u32 reg, long val) > +{ > + u64 temp = st->rsense * BIT_ULL(16), temp_2; > + u16 __raw; > + > + if (check_mul_overflow(val, temp, &temp_2)) { > + temp = DIV_ROUND_CLOSEST_ULL(temp, DECA * MILLI); > + __raw = DIV_ROUND_CLOSEST_ULL(temp * val, LTC4283_ADC1_FS_uV * LTC4283_ADC2_FS_mV); > + } else { > + temp = (u64)LTC4283_ADC1_FS_uV * LTC4283_ADC2_FS_mV * DECA * MILLI; > + __raw = DIV64_U64_ROUND_CLOSEST(temp_2, temp); > + } > + > + return regmap_write(st->map, reg, __raw); > +} > + > +static int ltc4283_reset_power_hist(struct ltc4283_hwmon *st) > +{ > + int ret; > + > + ret = ltc4283_write_power_word(st, LTC4283_POWER_MIN, st->power_max); > + if (ret) > + return ret; > + > + ret = ltc4283_write_power_word(st, LTC4283_POWER_MAX, 0); > + if (ret) > + return ret; > + > + /* Clear possible power faults. */ > + return regmap_clear_bits(st->map, LTC4283_FAULT_LOG, > + LTC4283_PWR_FAIL_FAULT_MASK | LTC4283_PGI_FAULT_MASK); > +} > + > +static int ltc4283_write_power(struct ltc4283_hwmon *st, u32 attr, long val) > +{ > + switch (attr) { > + case hwmon_power_max: > + return ltc4283_write_power_byte(st, LTC4283_POWER_MAX_TH, val); > + case hwmon_power_min: > + return ltc4283_write_power_byte(st, LTC4283_POWER_MIN_TH, val); > + case hwmon_power_reset_history: > + return ltc4283_reset_power_hist(st); > + default: > + return -EOPNOTSUPP; > + } > +} > + > +static int ltc4283_write_in_history(struct ltc4283_hwmon *st, u32 reg, > + long lowest, u32 fs) > +{ > + u32 __raw; > + int ret; > + > + __raw = DIV_ROUND_CLOSEST(BIT(16) * lowest, fs); > + if (__raw == BIT(16)) > + __raw = U16_MAX; > + > + ret = regmap_write(st->map, reg, __raw); > + if (ret) > + return ret; > + > + return regmap_write(st->map, reg + 1, 0); > +} > + > +static int ltc4283_write_in_byte(const struct ltc4283_hwmon *st, > + u32 reg, u32 fs, long val) > +{ > + u32 __raw; > + > + val = clamp_val(val, 0, fs); > + __raw = DIV_ROUND_CLOSEST(val * BIT(8), fs); > + If `val` is equal to `fs`, `__raw` will be exactly 256. Since this value is later written to an 8-bit register via `i2c_smbus_write_byte_data()`, the value 256 wraps around to 0. Writing the maximum value to the threshold will thus inadvertently set it to the minimum. Should `__raw` be clamped to 255? > + return regmap_write(st->map, reg, __raw); > +} > + > +static int ltc4283_reset_in_hist(struct ltc4283_hwmon *st, u32 channel) > +{ > + u32 reg, fs; > + int ret; > + > + /* > + * Make sure to clear possible under/over voltage faults. Otherwise the > + * chip won't latch on again. > + */ > + if (channel == LTC4283_CHAN_VIN) > + return regmap_clear_bits(st->map, LTC4283_FAULT_LOG, > + LTC4283_OV_FAULT_MASK | LTC4283_UV_FAULT_MASK); > + > + if (channel == LTC4283_CHAN_VPWR) > + return ltc4283_write_in_history(st, LTC4283_VPWR_MIN, > + LTC4283_ADC2_FS_mV, > + LTC4283_ADC2_FS_mV); > + > + if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN) { > + fs = LTC4283_ADC2_FS_mV; > + reg = LTC4283_ADC_2_MIN(channel - LTC4283_CHAN_ADI_1); > + } else { > + fs = LTC4283_ADC1_FS_uV; > + reg = LTC4283_ADC_2_MIN_DIFF(channel - LTC4283_CHAN_ADIN12); > + } > + > + ret = ltc4283_write_in_history(st, reg, fs, fs); > + if (ret) > + return ret; > + if (channel != LTC4283_CHAN_DRAIN) > + return 0; > + > + /* Then, let's also clear possible fet faults. Same as above. */ > + return regmap_clear_bits(st->map, LTC4283_FAULT_LOG, > + LTC4283_FET_BAD_FAULT_MASK | LTC4283_FET_SHORT_FAULT_MASK); > +} > + > +static int ltc4283_write_in_en(struct ltc4283_hwmon *st, u32 channel, bool en) > +{ > + unsigned int bit, adc_idx = channel - LTC4283_CHAN_ADI_1; > + unsigned int reg = LTC4283_ADC_SELECT(adc_idx); > + int ret; > + > + bit = LTC4283_ADC_SELECT_MASK(adc_idx); > + if (channel > LTC4283_CHAN_DRAIN) > + /* Account for two reserved fields after DRAIN. */ > + bit <<= 2; > + > + if (en) > + ret = regmap_set_bits(st->map, reg, bit); > + else > + ret = regmap_clear_bits(st->map, reg, bit); > + if (ret) > + return ret; > + > + __assign_bit(channel, &st->ch_enable_mask, en); > + return 0; > +} > + > +static int ltc4283_write_minmax(struct ltc4283_hwmon *st, long val, > + u32 channel, bool is_max) > +{ > + u32 reg; > + > + if (channel == LTC4283_CHAN_VPWR) { > + if (is_max) > + return ltc4283_write_in_byte(st, LTC4283_VPWR_MAX_TH, > + LTC4283_ADC2_FS_mV, val); > + > + return ltc4283_write_in_byte(st, LTC4283_VPWR_MIN_TH, > + LTC4283_ADC2_FS_mV, val); > + } > + > + if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN) { > + if (is_max) { > + reg = LTC4283_ADC_2_MAX_TH(channel - LTC4283_CHAN_ADI_1); > + return ltc4283_write_in_byte(st, reg, > + LTC4283_ADC2_FS_mV, val); > + } > + > + reg = LTC4283_ADC_2_MIN_TH(channel - LTC4283_CHAN_ADI_1); > + return ltc4283_write_in_byte(st, reg, LTC4283_ADC2_FS_mV, val); > + } > + > + if (is_max) { > + reg = LTC4283_ADC_2_MAX_TH_DIFF(channel - LTC4283_CHAN_ADIN12); > + return ltc4283_write_in_byte(st, reg, LTC4283_ADC1_FS_uV, > + val * MILLI); > + } > + > + reg = LTC4283_ADC_2_MIN_TH_DIFF(channel - LTC4283_CHAN_ADIN12); > + return ltc4283_write_in_byte(st, reg, LTC4283_ADC1_FS_uV, val * MILLI); > +} > + > +static int ltc4283_write_in(struct ltc4283_hwmon *st, u32 attr, long val, > + int channel) > +{ > + switch (attr) { > + case hwmon_in_max: > + return ltc4283_write_minmax(st, val, channel, true); > + case hwmon_in_min: > + return ltc4283_write_minmax(st, val, channel, false); > + case hwmon_in_reset_history: > + return ltc4283_reset_in_hist(st, channel); > + case hwmon_in_enable: > + return ltc4283_write_in_en(st, channel, !!val); > + default: > + return -EOPNOTSUPP; > + } > +} > + > +static int ltc4283_write_curr_byte(const struct ltc4283_hwmon *st, > + u32 reg, long val) > +{ > + u32 temp = LTC4283_ADC1_FS_uV * DECA * MILLI; > + u32 reg_val; > + > + reg_val = DIV_ROUND_CLOSEST_ULL(val * BIT_ULL(8) * st->rsense, temp); `val` is not clamped here. A negative user input will be implicitly cast to `u64` and produce a massive value. Also, a very large user input will cause `reg_val` to exceed 255 and wrap around in the 8-bit register. Should `val` be clamped at the lower end, and `reg_val` at the upper end? > + return regmap_write(st->map, reg, reg_val); > +} > + > +static int ltc4283_write_curr_history(struct ltc4283_hwmon *st) > +{ > + int ret; > + > + ret = ltc4283_write_in_history(st, LTC4283_SENSE_MIN, st->vsense_max, > + LTC4283_ADC1_FS_uV); > + if (ret) > + return ret; Is this missing a multiplication by `MILLI`? `st->vsense_max` is in millivolts, while `LTC4283_ADC1_FS_uV` is in microvolts. Since `ltc4283_write_in_history` divides the value by the full scale, using `st->vsense_max` directly results in a raw value ~1000 times smaller than intended (e.g. 60 instead of 60000). This prevents SENSE_MIN from accurately tracking the lowest historical current. > + > + /* Now, let's also clear possible overcurrent logs. */ > + return regmap_clear_bits(st->map, LTC4283_FAULT_LOG, > + LTC4283_OC_FAULT_MASK); > +} > + > +static int ltc4283_write_curr(struct ltc4283_hwmon *st, u32 attr, long val) > +{ > + switch (attr) { > + case hwmon_curr_max: > + return ltc4283_write_curr_byte(st, LTC4283_SENSE_MAX_TH, val); > + case hwmon_curr_min: > + return ltc4283_write_curr_byte(st, LTC4283_SENSE_MIN_TH, val); > + case hwmon_curr_reset_history: > + return ltc4283_write_curr_history(st); > + default: > + return -EOPNOTSUPP; > + } > +} > + > +static int ltc4283_energy_enable_set(struct ltc4283_hwmon *st, long val) > +{ > + int ret; > + > + /* Setting the bit halts the meter. */ > + val = !!val; > + ret = regmap_update_bits(st->map, LTC4283_METER_CONTROL, > + LTC4283_METER_HALT_MASK, > + FIELD_PREP(LTC4283_METER_HALT_MASK, !val)); > + if (ret) > + return ret; > + > + st->energy_en = val; > + > + return 0; > +} > + > +static int ltc4283_write(struct device *dev, enum hwmon_sensor_types type, > + u32 attr, int channel, long val) > +{ > + struct ltc4283_hwmon *st = dev_get_drvdata(dev); > + > + switch (type) { > + case hwmon_power: > + return ltc4283_write_power(st, attr, val); > + case hwmon_in: > + return ltc4283_write_in(st, attr, val, channel); > + case hwmon_curr: > + return ltc4283_write_curr(st, attr, val); > + case hwmon_energy: > + return ltc4283_energy_enable_set(st, val); > + default: > + return -EOPNOTSUPP; > + } > +} > + > +static umode_t ltc4283_in_is_visible(const struct ltc4283_hwmon *st, > + u32 attr, int channel) > +{ > + /* If ADIO is set as a GPIO, don´t make it visible. */ > + if (channel >= LTC4283_CHAN_ADIO_1 && channel <= LTC4283_CHAN_ADIO_4) { > + /* ADIOX pins come at index 0 in the gpio mask. */ > + channel -= LTC4283_CHAN_ADIO_1; > + if (test_bit(channel, &st->gpio_mask)) > + return 0; > + } > + > + /* Also take care of differential channels. */ > + if (channel >= LTC4283_CHAN_ADIO12 && channel <= LTC4283_CHAN_ADIO34) { > + channel -= LTC4283_CHAN_ADIO12; > + /* If one channel in the pair is used, make it invisible. */ > + if (test_bit(channel * 2, &st->gpio_mask) || > + test_bit(channel * 2 + 1, &st->gpio_mask)) > + return 0; > + } > + > + switch (attr) { > + case hwmon_in_input: > + case hwmon_in_highest: > + case hwmon_in_lowest: > + case hwmon_in_max_alarm: > + case hwmon_in_min_alarm: > + case hwmon_in_label: > + case hwmon_in_lcrit_alarm: > + case hwmon_in_crit_alarm: > + case hwmon_in_fault: > + return 0444; > + case hwmon_in_max: > + case hwmon_in_min: > + case hwmon_in_enable: > + return 0644; > + case hwmon_in_reset_history: > + return 0200; > + default: > + return 0; > + } > +} > + > +static umode_t ltc4283_curr_is_visible(u32 attr) > +{ > + switch (attr) { > + case hwmon_curr_input: > + case hwmon_curr_highest: > + case hwmon_curr_lowest: > + case hwmon_curr_max_alarm: > + case hwmon_curr_min_alarm: > + case hwmon_curr_crit_alarm: > + case hwmon_curr_label: > + return 0444; > + case hwmon_curr_max: > + case hwmon_curr_min: > + return 0644; > + case hwmon_curr_reset_history: > + return 0200; > + default: > + return 0; > + } > +} > + > +static umode_t ltc4283_power_is_visible(u32 attr) > +{ > + switch (attr) { > + case hwmon_power_input: > + case hwmon_power_input_highest: > + case hwmon_power_input_lowest: > + case hwmon_power_label: > + case hwmon_power_max_alarm: > + case hwmon_power_min_alarm: > + return 0444; > + case hwmon_power_max: > + case hwmon_power_min: > + return 0644; > + case hwmon_power_reset_history: > + return 0200; > + default: > + return 0; > + } > +} > + > +static umode_t ltc4283_is_visible(const void *data, > + enum hwmon_sensor_types type, > + u32 attr, int channel) > +{ > + switch (type) { > + case hwmon_in: > + return ltc4283_in_is_visible(data, attr, channel); > + case hwmon_curr: > + return ltc4283_curr_is_visible(attr); > + case hwmon_power: > + return ltc4283_power_is_visible(attr); > + case hwmon_energy: > + /* hwmon_energy_enable */ > + return 0644; > + case hwmon_energy64: > + /* hwmon_energy_input */ > + return 0444; > + default: > + return 0; > + } > +} > + > +static const char * const ltc4283_in_strs[] = { > + "VIN", "VPWR", "VADI1", "VADI2", "VADI3", "VADI4", "VADIO1", "VADIO2", > + "VADIO3", "VADIO4", "DRNS", "DRAIN", "ADIN2-ADIN1", "ADIN4-ADIN3", > + "ADIO2-ADIO1", "ADIO4-ADIO3" > +}; > + > +static int ltc4283_read_labels(struct device *dev, > + enum hwmon_sensor_types type, > + u32 attr, int channel, const char **str) > +{ > + switch (type) { > + case hwmon_in: > + *str = ltc4283_in_strs[channel]; > + return 0; > + case hwmon_curr: > + *str = "ISENSE"; > + return 0; > + case hwmon_power: > + *str = "Power"; > + return 0; > + default: > + return -EOPNOTSUPP; > + } > +} > + > +/* > + * Set max limits for ISENSE and Power as that depends on the max voltage on > + * rsense that is defined in ILIM_ADJUST. This is specially important for power > + * because for some rsense and vfsout values, if we allow the default raw 255 > + * value, that would overflow long in 32bit archs when reading back the max > + * power limit. > + */ > +static int ltc4283_set_max_limits(struct ltc4283_hwmon *st, struct device *dev) > +{ > + u32 temp = st->vsense_max * DECA * MICRO; > + int ret; > + > + ret = ltc4283_write_in_byte(st, LTC4283_SENSE_MAX_TH, LTC4283_ADC1_FS_uV, > + st->vsense_max * MILLI); > + if (ret) > + return ret; > + > + /* Power is given by ISENSE * Vout. */ > + st->power_max = DIV_ROUND_CLOSEST(temp, st->rsense) * LTC4283_ADC2_FS_mV; > + return ltc4283_write_power_byte(st, LTC4283_POWER_MAX_TH, st->power_max); > +} > + > +static int ltc4283_parse_array_prop(const struct ltc4283_hwmon *st, > + struct device *dev, const char *prop, > + const u32 *vals, u32 n_vals) > +{ > + u32 prop_val; > + int ret; > + u32 i; > + > + ret = device_property_read_u32(dev, prop, &prop_val); > + if (ret) > + return n_vals; > + > + for (i = 0; i < n_vals; i++) { > + if (prop_val != vals[i]) > + continue; > + > + return i; > + } > + > + return dev_err_probe(dev, -EINVAL, > + "Invalid %s property value %u, expected one of: %*ph\n", > + prop, prop_val, n_vals, vals); > +} > + > +static int ltc4283_get_defaults(struct ltc4283_hwmon *st) > +{ > + u32 reg_val, ilm_adjust, c; > + int ret; > + > + ret = regmap_read(st->map, LTC4283_METER_CONTROL, ®_val); > + if (ret) > + return ret; > + > + st->energy_en = !FIELD_GET(LTC4283_METER_HALT_MASK, reg_val); > + > + ret = regmap_read(st->map, LTC4283_CONFIG_1, ®_val); > + if (ret) > + return ret; > + > + ilm_adjust = FIELD_GET(LTC4283_ILIM_MASK, reg_val); > + st->vsense_max = LTC4283_VILIM_MIN_uV / MILLI + ilm_adjust; > + > + /* VPWR and VIN are always enabled */ > + __set_bit(LTC4283_CHAN_VIN, &st->ch_enable_mask); > + __set_bit(LTC4283_CHAN_VPWR, &st->ch_enable_mask); > + for (c = LTC4283_CHAN_ADI_1; c < LTC4283_CHAN_MAX; c++) { > + u32 chan = c - LTC4283_CHAN_ADI_1, bit; > + > + ret = regmap_read(st->map, LTC4283_ADC_SELECT(chan), ®_val); > + if (ret) > + return ret; > + > + bit = LTC4283_ADC_SELECT_MASK(chan); > + if (c > LTC4283_CHAN_DRAIN) > + /* account for two reserved fields after DRAIN */ > + bit <<= 2; > + > + if (!(bit & reg_val)) > + continue; > + > + __set_bit(c, &st->ch_enable_mask); > + } > + > + return 0; > +} > + > +static const char * const ltc4283_pgio1_funcs[] = { > + "inverted_power_good", "power_good", "gpio" > +}; > + > +static const char * const ltc4283_pgio2_funcs[] = { > + "inverted_power_good", "power_good", "gpio", "active_current_limiting" > +}; > + > +static const char * const ltc4283_pgio3_funcs[] = { > + "inverted_power_good_input", "power_good_input", "gpio" > +}; > + > +static const char * const ltc4283_pgio4_funcs[] = { > + "inverted_external_fault", "external_fault", "gpio" > +}; > + > +enum { > + LTC4283_PIN_ADIO1, > + LTC4283_PIN_ADIO2, > + LTC4283_PIN_ADIO3, > + LTC4283_PIN_ADIO4, > + LTC4283_PIN_PGIO1, > + LTC4283_PIN_PGIO2, > + LTC4283_PIN_PGIO3, > + LTC4283_PIN_PGIO4, > +}; > + > +static int ltc4283_pgio_config(struct ltc4283_hwmon *st, struct device *dev) > +{ > + int ret, func; > + > + func = device_property_match_property_string(dev, "adi,pgio1-func", > + ltc4283_pgio1_funcs, > + ARRAY_SIZE(ltc4283_pgio1_funcs)); > + if (func < 0 && func != -EINVAL) > + return dev_err_probe(dev, func, > + "Invalid adi,pgio1-func property\n"); > + if (func >= 0) { > + if (func == LTC4283_PGIO_FUNC_GPIO) { > + __set_bit(LTC4283_PIN_PGIO1, &st->gpio_mask); > + /* If GPIO, default to an input pin. */ > + func++; > + } > + > + ret = regmap_update_bits(st->map, LTC4283_PGIO_CONFIG, > + LTC4283_PGIO1_CFG_MASK, > + FIELD_PREP(LTC4283_PGIO1_CFG_MASK, func)); > + if (ret) > + return ret; > + } > + > + func = device_property_match_property_string(dev, "adi,pgio2-func", > + ltc4283_pgio2_funcs, > + ARRAY_SIZE(ltc4283_pgio2_funcs)); > + > + if (func < 0 && func != -EINVAL) > + return dev_err_probe(dev, func, > + "Invalid adi,pgio2-func property\n"); > + if (func >= 0) { > + if (func != LTC4283_PGIO2_FUNC_ACLB) { > + if (func == LTC4283_PGIO_FUNC_GPIO) { > + __set_bit(LTC4283_PIN_PGIO2, &st->gpio_mask); > + func++; > + } > + > + ret = regmap_update_bits(st->map, LTC4283_PGIO_CONFIG, > + LTC4283_PGIO2_CFG_MASK, > + FIELD_PREP(LTC4283_PGIO2_CFG_MASK, func)); > + } else { > + ret = regmap_set_bits(st->map, LTC4283_CONTROL_1, > + LTC4283_PIGIO2_ACLB_MASK); > + } > + > + if (ret) > + return ret; > + } > + > + func = device_property_match_property_string(dev, "adi,pgio3-func", > + ltc4283_pgio3_funcs, > + ARRAY_SIZE(ltc4283_pgio3_funcs)); > + > + if (func < 0 && func != -EINVAL) > + return dev_err_probe(dev, func, > + "Invalid adi,pgio3-func property\n"); > + if (func >= 0) { > + if (func == LTC4283_PGIO_FUNC_GPIO) { > + __set_bit(LTC4283_PIN_PGIO3, &st->gpio_mask); > + func++; > + } > + > + ret = regmap_update_bits(st->map, LTC4283_PGIO_CONFIG, > + LTC4283_PGIO3_CFG_MASK, > + FIELD_PREP(LTC4283_PGIO3_CFG_MASK, func)); > + if (ret) > + return ret; > + } > + > + func = device_property_match_property_string(dev, "adi,pgio4-func", > + ltc4283_pgio4_funcs, > + ARRAY_SIZE(ltc4283_pgio4_funcs)); > + > + if (func < 0 && func != -EINVAL) > + return dev_err_probe(dev, func, > + "Invalid adi,pgio4-func property\n"); > + if (func >= 0) { > + if (func == LTC4283_PGIO_FUNC_GPIO) { > + __set_bit(LTC4283_PIN_PGIO4, &st->gpio_mask); > + func++; > + } else { > + st->ext_fault = true; > + } > + > + ret = regmap_update_bits(st->map, LTC4283_PGIO_CONFIG, > + LTC4283_PGIO4_CFG_MASK, > + FIELD_PREP(LTC4283_PGIO4_CFG_MASK, func)); > + if (ret) > + return ret; > + } > + > + return 0; > +} > + > +static int ltc4283_adio_config(struct ltc4283_hwmon *st, struct device *dev, > + const char *prop, u32 pin) > +{ > + u32 adc_idx; > + int ret; > + > + if (!device_property_read_bool(dev, prop)) > + return 0; > + > + adc_idx = LTC4283_CHAN_ADIO_1 - LTC4283_CHAN_ADI_1 + pin; > + ret = regmap_clear_bits(st->map, LTC4283_ADC_SELECT(adc_idx), > + LTC4283_ADC_SELECT_MASK(adc_idx)); > + if (ret) > + return ret; > + > + __set_bit(pin, &st->gpio_mask); > + return 0; > +} > + > +static int ltc4283_pin_config(struct ltc4283_hwmon *st, struct device *dev) > +{ > + int ret; > + > + ret = ltc4283_pgio_config(st, dev); > + if (ret) > + return ret; > + > + ret = ltc4283_adio_config(st, dev, "adi,gpio-on-adio1", LTC4283_PIN_ADIO1); > + if (ret) > + return ret; > + > + ret = ltc4283_adio_config(st, dev, "adi,gpio-on-adio2", LTC4283_PIN_ADIO2); > + if (ret) > + return ret; > + > + ret = ltc4283_adio_config(st, dev, "adi,gpio-on-adio3", LTC4283_PIN_ADIO3); > + if (ret) > + return ret; > + > + return ltc4283_adio_config(st, dev, "adi,gpio-on-adio4", LTC4283_PIN_ADIO4); > +} > + > +static const char * const ltc4283_oc_fet_retry[] = { > + "latch-off", "1", "7", "unlimited" > +}; > + > +static const u32 ltc4283_fb_factor[] = { > + 100, 50, 20, 10 > +}; > + > +static const u32 ltc4283_cooling_dl[] = { > + 512, 1002, 2005, 4100, 8190, 16400, 32800, 65600 > +}; > + > +static const u32 ltc4283_fet_bad_delay[] = { > + 256, 512, 1002, 2005 > +}; > + > +static int ltc4283_setup(struct ltc4283_hwmon *st, struct device *dev) > +{ > + u32 val, chan; > + int ret; > + > + /* The part has an eeprom so let's get the needed defaults from it */ > + ret = ltc4283_get_defaults(st); > + if (ret) > + return ret; > + > + /* default to 1 micro ohm so we can probe without FW properties */ > + st->rsense = 1 * MICRO; > + ret = device_property_read_u32(dev, "adi,rsense-nano-ohms", > + &st->rsense); > + if (!ret) { > + if (st->rsense < CENTI) > + return dev_err_probe(dev, -EINVAL, > + "adi,rsense-nano-ohms too small (< %lu)\n", > + CENTI); > + } > + > + /* > + * The resolution for rsense is tenths of micro (eg: 62.5 uOhm) which > + * means we need nano in the bindings. However, to make things easier to > + * handle (with respect to overflows) we divide it by 100 as we don't > + * really need the last two digits. > + */ > + st->rsense /= CENTI; > + > + ret = device_property_read_u32(dev, "adi,current-limit-sense-microvolt", > + &st->vsense_max); > + if (!ret) { > + u32 reg_val; > + > + if (!in_range(st->vsense_max, LTC4283_VILIM_MIN_uV, > + LTC4283_VILIM_RANGE)) { > + return dev_err_probe(dev, -EINVAL, > + "adi,current-limit-sense-microvolt (%u) out of range [%u %u]\n", > + st->vsense_max, LTC4283_VILIM_MIN_uV, > + LTC4283_VILIM_MAX_uV); > + } > + > + st->vsense_max /= MILLI; > + reg_val = FIELD_PREP(LTC4283_ILIM_MASK, > + st->vsense_max - LTC4283_VILIM_MIN_uV / MILLI); > + ret = regmap_update_bits(st->map, LTC4283_CONFIG_1, > + LTC4283_ILIM_MASK, reg_val); > + if (ret) > + return ret; > + } > + > + ret = ltc4283_parse_array_prop(st, dev, "adi,current-limit-foldback-factor", > + ltc4283_fb_factor, ARRAY_SIZE(ltc4283_fb_factor)); > + if (ret < 0) > + return ret; > + if (ret < ARRAY_SIZE(ltc4283_fb_factor)) { > + ret = regmap_update_bits(st->map, LTC4283_CONFIG_1, LTC4283_FB_MASK, > + FIELD_PREP(LTC4283_FB_MASK, ret)); > + if (ret) > + return ret; > + } > + > + ret = ltc4283_parse_array_prop(st, dev, "adi,cooling-delay-ms", > + ltc4283_cooling_dl, ARRAY_SIZE(ltc4283_cooling_dl)); > + if (ret < 0) > + return ret; > + if (ret < ARRAY_SIZE(ltc4283_cooling_dl)) { > + ret = regmap_update_bits(st->map, LTC4283_CONFIG_2, LTC4283_COOLING_DL_MASK, > + FIELD_PREP(LTC4283_COOLING_DL_MASK, ret)); > + if (ret) > + return ret; > + } > + > + ret = ltc4283_parse_array_prop(st, dev, "adi,fet-bad-timer-delay-ms", > + ltc4283_fet_bad_delay, ARRAY_SIZE(ltc4283_fet_bad_delay)); > + if (ret < 0) > + return ret; > + if (ret < ARRAY_SIZE(ltc4283_fet_bad_delay)) { > + ret = regmap_update_bits(st->map, LTC4283_CONFIG_2, LTC4283_FTBD_DL_MASK, > + FIELD_PREP(LTC4283_FTBD_DL_MASK, ret)); > + if (ret) > + return ret; > + } > + > + ret = ltc4283_set_max_limits(st, dev); > + if (ret) > + return ret; > + > + ret = ltc4283_pin_config(st, dev); > + if (ret) > + return ret; > + > + if (device_property_read_bool(dev, "adi,power-good-reset-on-fet")) { > + ret = regmap_clear_bits(st->map, LTC4283_CONTROL_1, > + LTC4283_PWRGD_RST_CTRL_MASK); > + if (ret) > + return ret; > + } > + > + if (device_property_read_bool(dev, "adi,fet-turn-off-disable")) { > + ret = regmap_clear_bits(st->map, LTC4283_CONTROL_1, > + LTC4283_FET_BAD_OFF_MASK); > + if (ret) > + return ret; > + } > + > + if (device_property_read_bool(dev, "adi,tmr-pull-down-disable")) { > + ret = regmap_set_bits(st->map, LTC4283_CONTROL_1, > + LTC4283_THERM_TMR_MASK); > + if (ret) > + return ret; > + } > + > + if (device_property_read_bool(dev, "adi,dvdt-inrush-control-disable")) { > + ret = regmap_clear_bits(st->map, LTC4283_CONTROL_1, > + LTC4283_DVDT_MASK); > + if (ret) > + return ret; > + } > + > + if (device_property_read_bool(dev, "adi,undervoltage-retry-disable")) { > + ret = regmap_clear_bits(st->map, LTC4283_CONTROL_2, > + LTC4283_UV_RETRY_MASK); > + if (ret) > + return ret; > + } > + > + if (device_property_read_bool(dev, "adi,overvoltage-retry-disable")) { > + ret = regmap_clear_bits(st->map, LTC4283_CONTROL_2, > + LTC4283_OV_RETRY_MASK); > + if (ret) > + return ret; > + } > + > + if (device_property_read_bool(dev, "adi,external-fault-retry-enable")) { > + if (!st->ext_fault) > + return dev_err_probe(dev, -EINVAL, > + "adi,external-fault-retry-enable set but PGIO4 not configured\n"); > + ret = regmap_set_bits(st->map, LTC4283_CONTROL_2, > + LTC4283_EXT_FAULT_RETRY_MASK); > + if (ret) > + return ret; > + } > + > + if (device_property_read_bool(dev, "adi,fault-log-enable")) { > + ret = regmap_set_bits(st->map, LTC4283_FAULT_LOG_CTRL, > + LTC4283_FAULT_LOG_EN_MASK); > + if (ret) > + return ret; > + } > + > + ret = device_property_match_property_string(dev, "adi,overcurrent-retries", > + ltc4283_oc_fet_retry, > + ARRAY_SIZE(ltc4283_oc_fet_retry)); > + /* We still want to catch when an invalid string is given. */ > + if (ret != -EINVAL) > + return dev_err_probe(dev, ret, > + "adi,overcurrent-retries invalid value\n"); > + if (ret >= 0) { > + ret = regmap_update_bits(st->map, LTC4283_CONTROL_2, > + LTC4283_OC_RETRY_MASK, > + FIELD_PREP(LTC4283_OC_RETRY_MASK, ret)); > + if (ret) > + return ret; > + } > + > + ret = device_property_match_property_string(dev, "adi,fet-bad-retries", > + ltc4283_oc_fet_retry, > + ARRAY_SIZE(ltc4283_oc_fet_retry)); > + if (ret != -EINVAL) > + return dev_err_probe(dev, ret, > + "adi,fet-bad-retries invalid value\n"); > + if (ret >= 0) { > + ret = regmap_update_bits(st->map, LTC4283_CONTROL_2, > + LTC4283_FET_BAD_RETRY_MASK, > + FIELD_PREP(LTC4283_FET_BAD_RETRY_MASK, ret)); > + if (ret) > + return ret; > + } > + > + if (device_property_read_bool(dev, "adi,external-fault-fet-off-enable")) { > + if (!st->ext_fault) > + return dev_err_probe(dev, -EINVAL, > + "adi,external-fault-fet-off-enable set but PGIO4 not configured\n"); > + ret = regmap_set_bits(st->map, LTC4283_CONFIG_3, > + LTC4283_EXTFLT_TURN_OFF_MASK); > + if (ret) > + return ret; > + } > + > + if (device_property_read_bool(dev, "adi,vpower-drns-enable")) { > + __clear_bit(LTC4283_CHAN_DRAIN, &st->ch_enable_mask); > + chan = LTC4283_CHAN_DRAIN - LTC4283_CHAN_ADI_1; > + val = 1; > + } else { > + __clear_bit(LTC4283_CHAN_DRNS, &st->ch_enable_mask); > + chan = LTC4283_CHAN_DRNS - LTC4283_CHAN_ADI_1; > + val = 0; > + } > + /* > + * Then, let's by default disable the channel from the ADC2 that is > + * already being monitored by the VPWR channel. One can still enable it > + * later on if needed. > + */ > + ret = regmap_clear_bits(st->map, LTC4283_ADC_SELECT(chan), > + LTC4283_ADC_SELECT_MASK(chan)); > + if (ret) > + return ret; > + > + ret = regmap_update_bits(st->map, LTC4283_CONFIG_3, > + LTC4283_VPWR_DRNS_MASK, > + FIELD_PREP(LTC4283_VPWR_DRNS_MASK, val)); > + if (ret) > + return ret; > + > + /* Make sure the ADC has 12bit resolution since we're assuming that. */ > + ret = regmap_update_bits(st->map, LTC4283_PGIO_CONFIG_2, > + LTC4283_ADC_MASK, > + FIELD_PREP(LTC4283_ADC_MASK, 3)); > + if (ret) > + return ret; > + > + /* Energy reads (which are 6 byte block reads) rely on page access */ > + ret = regmap_set_bits(st->map, LTC4283_CONTROL_1, LTC4283_RW_PAGE_MASK); > + if (ret) > + return ret; > + > + /* > + * Make sure we are integrating power as we only support reporting > + * consumed energy. > + */ > + return regmap_clear_bits(st->map, LTC4283_METER_CONTROL, > + LTC4283_INTEGRATE_I_MASK); > +} > + > +static const struct hwmon_channel_info * const ltc4283_info[] = { > + HWMON_CHANNEL_INFO(in, > + HWMON_I_LCRIT_ALARM | HWMON_I_CRIT_ALARM | > + HWMON_I_RESET_HISTORY | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | > + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | > + HWMON_I_MAX_ALARM | HWMON_I_RESET_HISTORY | > + HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | > + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | > + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | > + HWMON_I_ENABLE | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | > + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | > + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | > + HWMON_I_ENABLE | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | > + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | > + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | > + HWMON_I_ENABLE | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | > + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | > + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | > + HWMON_I_ENABLE | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | > + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | > + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | > + HWMON_I_ENABLE | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | > + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | > + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | > + HWMON_I_ENABLE | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | > + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | > + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | > + HWMON_I_ENABLE | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | > + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | > + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | > + HWMON_I_ENABLE | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | > + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | > + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | > + HWMON_I_ENABLE | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | > + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | > + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | > + HWMON_I_FAULT | HWMON_I_ENABLE | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | > + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | > + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | > + HWMON_I_ENABLE | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | > + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | > + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | > + HWMON_I_ENABLE | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | > + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | > + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | > + HWMON_I_ENABLE | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST | > + HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM | > + HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM | > + HWMON_I_ENABLE | HWMON_I_LABEL), > + HWMON_CHANNEL_INFO(curr, > + HWMON_C_INPUT | HWMON_C_LOWEST | HWMON_C_HIGHEST | > + HWMON_C_MAX | HWMON_C_MIN | HWMON_C_MIN_ALARM | > + HWMON_C_MAX_ALARM | HWMON_C_CRIT_ALARM | > + HWMON_C_RESET_HISTORY | HWMON_C_LABEL), > + HWMON_CHANNEL_INFO(power, > + HWMON_P_INPUT | HWMON_P_INPUT_LOWEST | > + HWMON_P_INPUT_HIGHEST | HWMON_P_MAX | HWMON_P_MIN | > + HWMON_P_MAX_ALARM | HWMON_P_MIN_ALARM | > + HWMON_P_RESET_HISTORY | HWMON_P_LABEL), > + HWMON_CHANNEL_INFO(energy, > + HWMON_E_ENABLE), > + HWMON_CHANNEL_INFO(energy64, > + HWMON_E_INPUT), > + NULL > +}; > + > +static const struct hwmon_ops ltc4283_ops = { > + .read = ltc4283_read, > + .write = ltc4283_write, > + .is_visible = ltc4283_is_visible, > + .read_string = ltc4283_read_labels, > +}; > + > +static const struct hwmon_chip_info ltc4283_chip_info = { > + .ops = <c4283_ops, > + .info = ltc4283_info, > +}; > + > +static int ltc4283_show_fault_log(void *arg, u64 *val, u32 mask) > +{ > + struct ltc4283_hwmon *st = arg; > + long alarm; > + int ret; > + > + ret = ltc4283_read_alarm(st, LTC4283_FAULT_LOG, mask, &alarm); > + if (ret) > + return ret; > + > + *val = alarm; > + > + return 0; > +} > + > +static int ltc4283_show_in0_lcrit_fault_log(void *arg, u64 *val) > +{ > + return ltc4283_show_fault_log(arg, val, LTC4283_UV_FAULT_MASK); > +} > +DEFINE_DEBUGFS_ATTRIBUTE(ltc4283_in0_lcrit_fault_log, > + ltc4283_show_in0_lcrit_fault_log, NULL, "%llu\n"); > + > +static int ltc4283_show_in0_crit_fault_log(void *arg, u64 *val) > +{ > + return ltc4283_show_fault_log(arg, val, LTC4283_OV_FAULT_MASK); > +} > +DEFINE_DEBUGFS_ATTRIBUTE(ltc4283_in0_crit_fault_log, > + ltc4283_show_in0_crit_fault_log, NULL, "%llu\n"); > + > +static int ltc4283_show_fet_bad_fault_log(void *arg, u64 *val) > +{ > + return ltc4283_show_fault_log(arg, val, LTC4283_FET_BAD_FAULT_MASK); > +} > +DEFINE_DEBUGFS_ATTRIBUTE(ltc4283_fet_bad_fault_log, > + ltc4283_show_fet_bad_fault_log, NULL, "%llu\n"); > + > +static int ltc4283_show_fet_short_fault_log(void *arg, u64 *val) > +{ > + return ltc4283_show_fault_log(arg, val, LTC4283_FET_SHORT_FAULT_MASK); > +} > +DEFINE_DEBUGFS_ATTRIBUTE(ltc4283_fet_short_fault_log, > + ltc4283_show_fet_short_fault_log, NULL, "%llu\n"); > + > +static int ltc4283_show_curr1_crit_fault_log(void *arg, u64 *val) > +{ > + return ltc4283_show_fault_log(arg, val, LTC4283_OC_FAULT_MASK); > +} > +DEFINE_DEBUGFS_ATTRIBUTE(ltc4283_curr1_crit_fault_log, > + ltc4283_show_curr1_crit_fault_log, NULL, "%llu\n"); > + > +static int ltc4283_show_power1_failed_fault_log(void *arg, u64 *val) > +{ > + return ltc4283_show_fault_log(arg, val, LTC4283_PWR_FAIL_FAULT_MASK); > +} > +DEFINE_DEBUGFS_ATTRIBUTE(ltc4283_power1_failed_fault_log, > + ltc4283_show_power1_failed_fault_log, NULL, "%llu\n"); > + > +static int ltc4283_show_power1_good_input_fault_log(void *arg, u64 *val) > +{ > + return ltc4283_show_fault_log(arg, val, LTC4283_PGI_FAULT_MASK); > +} > +DEFINE_DEBUGFS_ATTRIBUTE(ltc4283_power1_good_input_fault_log, > + ltc4283_show_power1_good_input_fault_log, NULL, "%llu\n"); > + > +static void ltc4283_debugfs_init(struct ltc4283_hwmon *st, struct i2c_client *i2c) > +{ > + debugfs_create_file_unsafe("in0_crit_fault_log", 0400, i2c->debugfs, st, > + <c4283_in0_crit_fault_log); > + debugfs_create_file_unsafe("in0_lcrit_fault_log", 0400, i2c->debugfs, st, > + <c4283_in0_lcrit_fault_log); > + debugfs_create_file_unsafe("in0_fet_bad_fault_log", 0400, i2c->debugfs, st, > + <c4283_fet_bad_fault_log); > + debugfs_create_file_unsafe("in0_fet_short_fault_log", 0400, i2c->debugfs, st, > + <c4283_fet_short_fault_log); > + debugfs_create_file_unsafe("curr1_crit_fault_log", 0400, i2c->debugfs, st, > + <c4283_curr1_crit_fault_log); > + debugfs_create_file_unsafe("power1_failed_fault_log", 0400, i2c->debugfs, st, > + <c4283_power1_failed_fault_log); > + debugfs_create_file_unsafe("power1_good_input_fault_log", 0400, i2c->debugfs, > + st, <c4283_power1_good_input_fault_log); > +} > + > +static bool ltc4283_is_word_reg(unsigned int reg) > +{ > + return reg >= LTC4283_SENSE && reg <= LTC4283_ADIO34_MAX; > +} > + > +static int ltc4283_reg_read(void *context, unsigned int reg, unsigned int *val) > +{ > + struct i2c_client *client = context; > + int ret; > + > + if (ltc4283_is_word_reg(reg)) > + ret = i2c_smbus_read_word_swapped(client, reg); > + else > + ret = i2c_smbus_read_byte_data(client, reg); > + > + if (ret < 0) > + return ret; > + > + *val = ret; > + return 0; > +} > + > +static int ltc4283_reg_write(void *context, unsigned int reg, unsigned int val) > +{ > + struct i2c_client *client = context; > + > + if (ltc4283_is_word_reg(reg)) > + return i2c_smbus_write_word_swapped(client, reg, val); > + > + return i2c_smbus_write_byte_data(client, reg, val); > +} > + > +static const struct regmap_bus ltc4283_regmap_bus = { > + .reg_read = ltc4283_reg_read, > + .reg_write = ltc4283_reg_write, > +}; > + > +static bool ltc4283_writable_reg(struct device *dev, unsigned int reg) > +{ > + switch (reg) { > + case LTC4283_SYSTEM_STATUS ... LTC4283_FAULT_STATUS: > + return false; > + case LTC4283_RESERVED_OC: > + return false; > + case LTC4283_RESERVED_86 ... LTC4283_RESERVED_8F: > + return false; > + case LTC4283_RESERVED_91 ... LTC4283_RESERVED_A1: > + return false; > + case LTC4283_RESERVED_A3: > + return false; > + case LTC4283_RESERVED_AC: > + return false; > + case LTC4283_POWER_PLAY_MSB ... LTC4283_POWER_PLAY_LSB: > + return false; > + case LTC4283_RESERVED_F1 ... LTC4283_RESERVED_FF: > + return false; > + default: > + return true; > + } > +} > + > +static const struct regmap_config ltc4283_regmap_config = { > + .reg_bits = 8, > + .val_bits = 16, > + .max_register = 0xFF, > + .writeable_reg = ltc4283_writable_reg, > +}; > + > +static int ltc4283_probe(struct i2c_client *client) > +{ > + struct device *dev = &client->dev, *hwmon; > + struct auxiliary_device *adev; > + struct ltc4283_hwmon *st; > + int ret; > + > + st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL); > + if (!st) > + return -ENOMEM; > + > + if (!i2c_check_functionality(client->adapter, > + I2C_FUNC_SMBUS_BYTE_DATA | > + I2C_FUNC_SMBUS_WORD_DATA | > + I2C_FUNC_SMBUS_READ_I2C_BLOCK)) > + return -EOPNOTSUPP; > + > + st->client = client; > + st->map = devm_regmap_init(dev, <c4283_regmap_bus, client, > + <c4283_regmap_config); > + if (IS_ERR(st->map)) > + return dev_err_probe(dev, PTR_ERR(st->map), > + "Failed to create regmap\n"); > + > + ret = ltc4283_setup(st, dev); > + if (ret) > + return ret; > + > + hwmon = devm_hwmon_device_register_with_info(dev, "ltc4283", st, > + <c4283_chip_info, NULL); > + > + if (IS_ERR(hwmon)) > + return PTR_ERR(hwmon); > + > + ltc4283_debugfs_init(st, client); > + > + if (!st->gpio_mask) > + return 0; > + > + adev = devm_auxiliary_device_create(dev, "gpio", &st->gpio_mask); > + if (!adev) > + return dev_err_probe(dev, -ENODEV, "Failed to add GPIO device\n"); > + > + return 0; > +} > + > +static const struct of_device_id ltc4283_of_match[] = { > + { .compatible = "adi,ltc4283" }, > + { } > +}; > + > +static const struct i2c_device_id ltc4283_i2c_id[] = { > + { "ltc4283" }, > + { } > +}; > +MODULE_DEVICE_TABLE(i2c, ltc4283_i2c_id); > + > +static struct i2c_driver ltc4283_driver = { > + .driver = { > + .name = "ltc4283", > + .of_match_table = ltc4283_of_match, > + }, > + .probe = ltc4283_probe, > + .id_table = ltc4283_i2c_id, > +}; > +module_i2c_driver(ltc4283_driver); > + > +MODULE_AUTHOR("Nuno Sá <nuno.sa@analog.com>"); > +MODULE_DESCRIPTION("LTC4283 Hot Swap Controller driver"); > +MODULE_LICENSE("GPL"); ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v6 2/3] hwmon: ltc4283: Add support for the LTC4283 Swap Controller 2026-03-06 17:41 ` Guenter Roeck @ 2026-03-11 10:32 ` Nuno Sá 0 siblings, 0 replies; 8+ messages in thread From: Nuno Sá @ 2026-03-11 10:32 UTC (permalink / raw) To: Guenter Roeck, Nuno Sá Cc: linux-gpio, linux-hwmon, devicetree, linux-doc, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Jonathan Corbet, Linus Walleij, Bartosz Golaszewski On Fri, 2026-03-06 at 09:41 -0800, Guenter Roeck wrote: > Hi, > > On Tue, Mar 03, 2026 at 05:00:41PM +0000, Nuno Sá wrote: > > From: Nuno Sá <nuno.sa@analog.com> > > > > Support the LTC4283 Hot Swap Controller. The device features programmable > > current limit with foldback and independently adjustable inrush current to > > optimize the MOSFET safe operating area (SOA). The SOA timer limits MOSFET > > temperature rise for reliable protection against overstresses. > > > > An I2C interface and onboard ADC allow monitoring of board current, > > voltage, power, energy, and fault status. > > > > Signed-off-by: Nuno Sá <nuno.sa@analog.com> > > --- > > Feedback from AI review below. As far as I can see, the concerns are valid. > My own comments are in [ ]. > > > Documentation/hwmon/index.rst | 1 + > > Documentation/hwmon/ltc4283.rst | 265 ++++++ > > MAINTAINERS | 1 + > > drivers/hwmon/Kconfig | 12 + > > drivers/hwmon/Makefile | 1 + > > drivers/hwmon/ltc4283.c | 1780 +++++++++++++++++++++++++++++++++++++++ > > 6 files changed, 2060 insertions(+) > > > > diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst > > index 559c32344cd3..eab95152abee 100644 > > --- a/Documentation/hwmon/index.rst > > +++ b/Documentation/hwmon/index.rst > > @@ -144,6 +144,7 @@ Hardware Monitoring Kernel Drivers > > ltc4260 > > ltc4261 > > ltc4282 > > + ltc4283 > > ltc4286 > > macsmc-hwmon > > max127 > > diff --git a/Documentation/hwmon/ltc4283.rst b/Documentation/hwmon/ltc4283.rst > > new file mode 100644 > > index 000000000000..225ba886531d > > --- /dev/null > > +++ b/Documentation/hwmon/ltc4283.rst > > @@ -0,0 +1,265 @@ > > +.. SPDX-License-Identifier: GPL-2.0-only > > + > > +Kernel drivers ltc4283 > > +========================================== > > + > > +Supported chips: > > + > > + * Analog Devices LTC4283 > > + > > + Prefix: 'ltc4283' > > + > > + Addresses scanned: - > > + > > + Datasheet: > > + > > + https://www.analog.com/media/en/technical-documentation/data-sheets/ltc4283.pdf > > + > > +Author: Nuno Sá <nuno.sa@analog.com> > > + > > +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. > > +The device features programmable current limit with foldback and independently > > +adjustable inrush current to optimize the MOSFET safe operating area (SOA). The > > +SOA timer limits MOSFET temperature rise for reliable protection against > > +overstresses. An I2C interface and onboard gear-shift ADC allow monitoring of > > +board current, voltage, power, energy, and fault status. Additional features > > +respond to input UV/OV, interrupt the host when a fault has occurred, notify > > +when output power is good, detect insertion of a board, turn off the MOSFET > > +if an external supply monitor fails to indicate power good within a timeout > > +period, and auto-reboot after a programmable delay following a host commanded > > +turn-off. > > + > > +Sysfs entries > > +_____________ > > + > > +The following attributes are supported. Limits are read-write and all the other > > +attributes are read-only. Note that the VADIOx channels might not be available > > +if the ADIO pins are used as GPIOs (naturally also affects the respective > > +differential channels). > > + > > +======================= ========================================== > > +in0_lcrit_alarm Critical Undervoltage alarm > > +in0_crit_alarm Critical Overvoltage alarm > > +in0_label Channel label (VIN) > > + > > +in1_input Output voltage (mV). > > +in1_min Undervoltage threshold > > +in1_max Overvoltage threshold > > +in1_lowest Lowest measured voltage > > +in1_highest Highest measured voltage > > +in1_reset_history Write 1 to reset history. > > +in1_min_alarm Undervoltage alarm > > +in1_max_alarm Overvoltage alarm > > +in1_label Channel label (VPWR) > > + > > +in2_input Output voltage (mV). > > +in2_min Undervoltage threshold > > +in2_max Overvoltage threshold > > +in2_lowest Lowest measured voltage > > +in2_highest Highest measured voltage > > +in2_reset_history Write 1 to reset history. > > +in2_min_alarm Undervoltage alarm > > +in2_max_alarm Overvoltage alarm > > +in2_enable Enable/Disable monitoring. > > +in2_label Channel label (VADI1) > > + > > +in3_input Output voltage (mV). > > +in3_min Undervoltage threshold > > +in3_max Overvoltage threshold > > +in3_lowest Lowest measured voltage > > +in3_highest Highest measured voltage > > +in3_reset_history Write 1 to reset history. > > +in3_min_alarm Undervoltage alarm > > +in3_max_alarm Overvoltage alarm > > +in3_enable Enable/Disable monitoring. > > +in3_label Channel label (VADI2) > > + > > +in4_input Output voltage (mV). > > +in4_min Undervoltage threshold > > +in4_max Overvoltage threshold > > +in4_lowest Lowest measured voltage > > +in4_highest Highest measured voltage > > +in4_reset_history Write 1 to reset history. > > +in4_min_alarm Undervoltage alarm > > +in4_max_alarm Overvoltage alarm > > +in4_enable Enable/Disable monitoring. > > +in4_label Channel label (VADI3) > > + > > +in5_input Output voltage (mV). > > +in5_min Undervoltage threshold > > +in5_max Overvoltage threshold > > +in5_lowest Lowest measured voltage > > +in5_highest Highest measured voltage > > +in5_reset_history Write 1 to reset history. > > +in5_min_alarm Undervoltage alarm > > +in5_max_alarm Overvoltage alarm > > +in5_enable Enable/Disable monitoring. > > +in5_label Channel label (VADI4) > > + > > +in6_input Output voltage (mV). > > +in6_min Undervoltage threshold > > +in6_max Overvoltage threshold > > +in6_lowest Lowest measured voltage > > +in6_highest Highest measured voltage > > +in6_reset_history Write 1 to reset history. > > +in6_min_alarm Undervoltage alarm > > +in6_max_alarm Overvoltage alarm > > +in6_enable Enable/Disable monitoring. > > +in6_label Channel label (VADIO1) > > + > > +in7_input Output voltage (mV). > > +in7_min Undervoltage threshold > > +in7_max Overvoltage threshold > > +in7_lowest Lowest measured voltage > > +in7_highest Highest measured voltage > > +in7_reset_history Write 1 to reset history. > > +in7_min_alarm Undervoltage alarm > > +in7_max_alarm Overvoltage alarm > > +in7_enable Enable/Disable monitoring. > > +in7_label Channel label (VADIO2) > > + > > +in8_input Output voltage (mV). > > +in8_min Undervoltage threshold > > +in8_max Overvoltage threshold > > +in8_lowest Lowest measured voltage > > +in8_highest Highest measured voltage > > +in8_reset_history Write 1 to reset history. > > +in8_min_alarm Undervoltage alarm > > +in8_max_alarm Overvoltage alarm > > +in8_enable Enable/Disable monitoring. > > +in8_label Channel label (VADIO3) > > + > > +in9_input Output voltage (mV). > > +in9_min Undervoltage threshold > > +in9_max Overvoltage threshold > > +in9_lowest Lowest measured voltage > > +in9_highest Highest measured voltage > > +in9_reset_history Write 1 to reset history. > > +in9_min_alarm Undervoltage alarm > > +in9_max_alarm Overvoltage alarm > > +in9_enable Enable/Disable monitoring. > > +in9_label Channel label (VADIO4) > > + > > +in10_input Output voltage (mV). > > +in10_min Undervoltage threshold > > +in10_max Overvoltage threshold > > +in10_lowest Lowest measured voltage > > +in10_highest Highest measured voltage > > +in10_reset_history Write 1 to reset history. > > +in10_min_alarm Undervoltage alarm > > +in10_max_alarm Overvoltage alarm > > +in10_enable Enable/Disable monitoring. > > +in10_label Channel label (DRNS) > > + > > +in11_input Output voltage (mV). > > +in11_min Undervoltage threshold > > +in11_max Overvoltage threshold > > +in11_lowest Lowest measured voltage > > +in11_highest Highest measured voltage > > +in11_reset_history Write 1 to reset history. > > + Also clears fet bad and short fault logs. > > +in11_min_alarm Undervoltage alarm > > +in11_max_alarm Overvoltage alarm > > +in11_enable Enable/Disable monitoring > > +in11_fault Failure in the MOSFET. Either bad or shorted FET. > > +in11_label Channel label (DRAIN) > > + > > +in12_input Output voltage (mV). > > +in12_min Undervoltage threshold > > +in12_max Overvoltage threshold > > +in12_lowest Lowest measured voltage > > +in12_highest Highest measured voltage > > +in12_reset_history Write 1 to reset history. > > +in12_min_alarm Undervoltage alarm > > +in12_max_alarm Overvoltage alarm > > +in12_enable Enable/Disable monitoring. > > +in12_label Channel label (ADIN2-ADIN1) > > + > > +in13_input Output voltage (mV). > > +in13_min Undervoltage threshold > > +in13_max Overvoltage threshold > > +in13_lowest Lowest measured voltage > > +in13_highest Highest measured voltage > > +in13_reset_history Write 1 to reset history. > > +in13_min_alarm Undervoltage alarm > > +in13_max_alarm Overvoltage alarm > > +in13_enable Enable/Disable monitoring. > > +in13_label Channel label (ADIN4-ADIN3) > > + > > +in14_input Output voltage (mV). > > +in14_min Undervoltage threshold > > +in14_max Overvoltage threshold > > +in14_lowest Lowest measured voltage > > +in14_highest Highest measured voltage > > +in14_reset_history Write 1 to reset history. > > +in14_min_alarm Undervoltage alarm > > +in14_max_alarm Overvoltage alarm > > +in14_enable Enable/Disable monitoring. > > +in14_label Channel label (ADIO2-ADIO1) > > + > > +in15_input Output voltage (mV). > > +in15_min Undervoltage threshold > > +in15_max Overvoltage threshold > > +in15_lowest Lowest measured voltage > > +in15_highest Highest measured voltage > > +in15_reset_history Write 1 to reset history. > > +in15_min_alarm Undervoltage alarm > > +in15_max_alarm Overvoltage alarm > > +in15_enable Enable/Disable monitoring. > > +in15_label Channel label (ADIO4-ADIO3) > > + > > +curr1_input Sense current (mA) > > +curr1_min Undercurrent threshold > > +curr1_max Overcurrent threshold > > +curr1_lowest Lowest measured current > > +curr1_highest Highest measured current > > +curr1_reset_history Write 1 to reset curr1 history. > > + Also clears overcurrent fault logs. > > +curr1_min_alarm Undercurrent alarm > > +curr1_max_alarm Overcurrent alarm > > +curr1_crit_alarm Critical Overcurrent alarm > > +curr1_label Channel label (ISENSE) > > + > > +power1_input Power (in uW) > > +power1_min Low power threshold > > +power1_max High power threshold > > +power1_input_lowest Historical minimum power use > > +power1_input_highest Historical maximum power use > > +power1_reset_history Write 1 to reset power1 history. > > + Also clears power fault logs. > > +power1_min_alarm Low power alarm > > +power1_max_alarm High power alarm > > +power1_label Channel label (Power) > > + > > +energy1_input Measured energy over time (in microJoule) > > +energy1_enable Enable/Disable Energy accumulation > > + > > +DebugFs entries > > +_______________ > > + > > +The chip also has a fault log register where failures can be logged. Hence, > > +as these are logging events, we give access to them in debugfs. Note that > > +even if some failure is detected in these logs, it does necessarily mean > > +that the failure is still present. As mentioned in the proper Sysfs entries, > > +these logs can be cleared by writing in the proper reset_history attribute. > > + > > +.. warning:: The debugfs interface is subject to change without notice > > + and is only available when the kernel is compiled with > > + ``CONFIG_DEBUG_FS`` defined. > > + > > +``/sys/kernel/debug/i2c/i2c-[X]/[X]-addr/`` > > +contains the following attributes: > > + > > +======================= ========================================== > > +power1_failed_fault_log Set to 1 by a power1 fault occurring. > > +power1_good_input_fault_log Set to 1 by a power1 good input fault occurring at PGIO3. > > +in11_fet_short_fault_log Set to 1 when a FET-short fault occurs. > > +in11_fet_bad_fault_log Set to 1 when a FET-BAD fault occurs. > > +in0_lcrit_fault_log Set to 1 by a VIN undervoltage fault occurring. > > +in0_crit_fault_log Set to 1 by a VIN overvoltage fault occurring. > > +curr1_crit_fault_log Set to 1 by an overcurrent fault occurring. > > +======================= ========================================== > > diff --git a/MAINTAINERS b/MAINTAINERS > > index 13ae2f3db449..38d22cf622b7 100644 > > --- a/MAINTAINERS > > +++ b/MAINTAINERS > > @@ -15146,6 +15146,7 @@ M: Nuno Sá <nuno.sa@analog.com> > > L: linux-hwmon@vger.kernel.org > > S: Supported > > F: Documentation/devicetree/bindings/hwmon/adi,ltc4283.yaml > > +F: drivers/hwmon/ltc4283.c > > > > LTC4286 HARDWARE MONITOR DRIVER > > M: Delphine CC Chiu <Delphine_CC_Chiu@Wiwynn.com> > > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig > > index 8f7ce66ae3a2..c529f622c2b8 100644 > > --- a/drivers/hwmon/Kconfig > > +++ b/drivers/hwmon/Kconfig > > @@ -1158,6 +1158,18 @@ config SENSORS_LTC4282 > > This driver can also be built as a module. If so, the module will > > be called ltc4282. > > > > +config SENSORS_LTC4283 > > + tristate "Analog Devices LTC4283" > > + depends on I2C > > + select REGMAP_I2C > > + select AUXILIARY_BUS > > + help > > + If you say yes here you get support for Analog Devices LTC4283 > > + Negative Voltage Hot Swap Controller I2C interface. > > + > > + This driver can also be built as a module. If so, the module will > > + be called ltc4283. > > + > > config SENSORS_LTQ_CPUTEMP > > bool "Lantiq cpu temperature sensor driver" > > depends on SOC_XWAY > > diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile > > index 556e86d277b1..cb77938dbe07 100644 > > --- a/drivers/hwmon/Makefile > > +++ b/drivers/hwmon/Makefile > > @@ -147,6 +147,7 @@ obj-$(CONFIG_SENSORS_LTC4245) += ltc4245.o > > obj-$(CONFIG_SENSORS_LTC4260) += ltc4260.o > > obj-$(CONFIG_SENSORS_LTC4261) += ltc4261.o > > obj-$(CONFIG_SENSORS_LTC4282) += ltc4282.o > > +obj-$(CONFIG_SENSORS_LTC4283) += ltc4283.o > > obj-$(CONFIG_SENSORS_LTQ_CPUTEMP) += ltq-cputemp.o > > obj-$(CONFIG_SENSORS_MACSMC_HWMON) += macsmc-hwmon.o > > obj-$(CONFIG_SENSORS_MAX1111) += max1111.o > > diff --git a/drivers/hwmon/ltc4283.c b/drivers/hwmon/ltc4283.c > > new file mode 100644 > > index 000000000000..83f1f741abac > > --- /dev/null > > +++ b/drivers/hwmon/ltc4283.c > > @@ -0,0 +1,1780 @@ > > +// SPDX-License-Identifier: GPL-2.0-only > > +/* > > + * Analog Devices LTC4283 I2C Negative Voltage Hot Swap Controller (HWMON) > > + * > > + * Copyright 2025 Analog Devices Inc. > > + */ > > +#include <linux/auxiliary_bus.h> > > +#include <linux/bitfield.h> > > +#include <linux/bitmap.h> > > +#include <linux/bitops.h> > > +#include <linux/bits.h> > > + > > +#include <linux/debugfs.h> > > +#include <linux/device.h> > > +#include <linux/device/devres.h> > > +#include <linux/hwmon.h> > > +#include <linux/i2c.h> > > +#include <linux/math.h> > > +#include <linux/math64.h> > > +#include <linux/minmax.h> > > +#include <linux/module.h> > > + > > +#include <linux/mod_devicetable.h> > > +#include <linux/overflow.h> > > +#include <linux/property.h> > > +#include <linux/regmap.h> > > +#include <linux/unaligned.h> > > +#include <linux/units.h> > > + > > +#define LTC4283_SYSTEM_STATUS 0x00 > > +#define LTC4283_FAULT_STATUS 0x03 > > +#define LTC4283_OV_MASK BIT(0) > > +#define LTC4283_UV_MASK BIT(1) > > +#define LTC4283_OC_MASK BIT(2) > > +#define LTC4283_FET_BAD_MASK BIT(3) > > +#define LTC4283_FET_SHORT_MASK BIT(6) > > +#define LTC4283_FAULT_LOG 0x04 > > +#define LTC4283_OV_FAULT_MASK BIT(0) > > +#define LTC4283_UV_FAULT_MASK BIT(1) > > +#define LTC4283_OC_FAULT_MASK BIT(2) > > +#define LTC4283_FET_BAD_FAULT_MASK BIT(3) > > +#define LTC4283_PGI_FAULT_MASK BIT(4) > > +#define LTC4283_PWR_FAIL_FAULT_MASK BIT(5) > > +#define LTC4283_FET_SHORT_FAULT_MASK BIT(6) > > +#define LTC4283_ADC_ALM_LOG_1 0x05 > > +#define LTC4283_POWER_LOW_ALM BIT(0) > > +#define LTC4283_POWER_HIGH_ALM BIT(1) > > +#define LTC4283_SENSE_LOW_ALM BIT(4) > > +#define LTC4283_SENSE_HIGH_ALM BIT(5) > > +#define LTC4283_ADC_ALM_LOG_2 0x06 > > +#define LTC4283_ADC_ALM_LOG_3 0x07 > > +#define LTC4283_ADC_ALM_LOG_4 0x08 > > +#define LTC4283_ADC_ALM_LOG_5 0x09 > > +#define LTC4283_CONTROL_1 0x0a > > +#define LTC4283_RW_PAGE_MASK BIT(0) > > +#define LTC4283_PIGIO2_ACLB_MASK BIT(2) > > +#define LTC4283_PWRGD_RST_CTRL_MASK BIT(3) > > +#define LTC4283_FET_BAD_OFF_MASK BIT(4) > > +#define LTC4283_THERM_TMR_MASK BIT(5) > > +#define LTC4283_DVDT_MASK BIT(6) > > +#define LTC4283_CONTROL_2 0x0b > > +#define LTC4283_OV_RETRY_MASK BIT(0) > > +#define LTC4283_UV_RETRY_MASK BIT(1) > > +#define LTC4283_OC_RETRY_MASK GENMASK(3, 2) > > +#define LTC4283_FET_BAD_RETRY_MASK GENMASK(5, 4) > > +#define LTC4283_EXT_FAULT_RETRY_MASK BIT(7) > > +#define LTC4283_RESERVED_OC 0x0c > > +#define LTC4283_CONFIG_1 0x0d > > +#define LTC4283_FB_MASK GENMASK(3, 2) > > +#define LTC4283_ILIM_MASK GENMASK(7, 4) > > +#define LTC4283_CONFIG_2 0x0e > > +#define LTC4283_COOLING_DL_MASK GENMASK(3, 1) > > +#define LTC4283_FTBD_DL_MASK GENMASK(5, 4) > > +#define LTC4283_CONFIG_3 0x0f > > +#define LTC4283_VPWR_DRNS_MASK BIT(6) > > +#define LTC4283_EXTFLT_TURN_OFF_MASK BIT(7) > > +#define LTC4283_PGIO_CONFIG 0x10 > > +#define LTC4283_PGIO1_CFG_MASK GENMASK(1, 0) > > +#define LTC4283_PGIO2_CFG_MASK GENMASK(3, 2) > > +#define LTC4283_PGIO3_CFG_MASK GENMASK(5, 4) > > +#define LTC4283_PGIO4_CFG_MASK GENMASK(7, 6) > > +#define LTC4283_PGIO_CONFIG_2 0x11 > > +#define LTC4283_ADC_MASK GENMASK(2, 0) > > +#define LTC4283_ADC_SELECT(c) (0x13 + (c) / 8) > > +#define LTC4283_ADC_SELECT_MASK(c) BIT((c) % 8) > > +#define LTC4283_SENSE_MIN_TH 0x1b > > +#define LTC4283_SENSE_MAX_TH 0x1c > > +#define LTC4283_VPWR_MIN_TH 0x1d > > +#define LTC4283_VPWR_MAX_TH 0x1e > > +#define LTC4283_POWER_MIN_TH 0x1f > > +#define LTC4283_POWER_MAX_TH 0x20 > > +#define LTC4283_ADC_2_MIN_TH(c) (0x21 + (c) * 2) > > +#define LTC4283_ADC_2_MAX_TH(c) (0x22 + (c) * 2) > > +#define LTC4283_ADC_2_MIN_TH_DIFF(c) (0x39 + (c) * 2) > > +#define LTC4283_ADC_2_MAX_TH_DIFF(c) (0x3a + (c) * 2) > > +#define LTC4283_SENSE 0x41 > > +#define LTC4283_SENSE_MIN 0x42 > > +#define LTC4283_SENSE_MAX 0x43 > > +#define LTC4283_VPWR 0x44 > > +#define LTC4283_VPWR_MIN 0x45 > > +#define LTC4283_VPWR_MAX 0x46 > > +#define LTC4283_POWER 0x47 > > +#define LTC4283_POWER_MIN 0x48 > > +#define LTC4283_POWER_MAX 0x49 > > +#define LTC4283_RESERVED_68 0x68 > > +#define LTC4283_RESERVED_6D 0x6D > > +/* get channels from ADC 2 */ > > +#define LTC4283_ADC_2(c) (0x4a + (c) * 3) > > +#define LTC4283_ADC_2_MIN(c) (0x4b + (c) * 3) > > +#define LTC4283_ADC_2_MAX(c) (0x4c + (c) * 3) > > +#define LTC4283_ADC_2_DIFF(c) (0x6e + (c) * 3) > > +#define LTC4283_ADC_2_MIN_DIFF(c) (0x6f + (c) * 3) > > +#define LTC4283_ADC_2_MAX_DIFF(c) (0x70 + (c) * 3) > > +#define LTC4283_ENERGY 0x7a > > +#define LTC4283_METER_CONTROL 0x84 > > +#define LTC4283_INTEGRATE_I_MASK BIT(0) > > +#define LTC4283_METER_HALT_MASK BIT(6) > > +#define LTC4283_RESERVED_86 0x86 > > +#define LTC4283_RESERVED_8F 0x8F > > +#define LTC4283_FAULT_LOG_CTRL 0x90 > > +#define LTC4283_FAULT_LOG_EN_MASK BIT(7) > > +#define LTC4283_RESERVED_91 0x91 > > +#define LTC4283_RESERVED_A1 0xA1 > > +#define LTC4283_RESERVED_A3 0xA3 > > +#define LTC4283_RESERVED_AC 0xAC > > +#define LTC4283_POWER_PLAY_MSB 0xE7 > > +#define LTC4283_POWER_PLAY_LSB 0xE8 > > +#define LTC4283_RESERVED_F1 0xF1 > > +#define LTC4283_RESERVED_FF 0xFF > > + > > +/* also applies for differential channels */ > > +#define LTC4283_ADC1_FS_uV 32768 > > +#define LTC4283_ADC2_FS_mV 2048 > > +#define LTC4283_TCONV_uS 64103 > > +#define LTC4283_VILIM_MIN_uV 15000 > > +#define LTC4283_VILIM_MAX_uV 30000 > > +#define LTC4283_VILIM_RANGE \ > > + (LTC4283_VILIM_MAX_uV - LTC4283_VILIM_MIN_uV + 1) > > + > > +#define LTC4283_PGIO_FUNC_GPIO 2 > > +#define LTC4283_PGIO2_FUNC_ACLB 3 > > + > > +/* voltage channels */ > > +enum { > > + LTC4283_CHAN_VIN, > > + LTC4283_CHAN_VPWR, > > + LTC4283_CHAN_ADI_1, > > + LTC4283_CHAN_ADI_2, > > + LTC4283_CHAN_ADI_3, > > + LTC4283_CHAN_ADI_4, > > + LTC4283_CHAN_ADIO_1, > > + LTC4283_CHAN_ADIO_2, > > + LTC4283_CHAN_ADIO_3, > > + LTC4283_CHAN_ADIO_4, > > + LTC4283_CHAN_DRNS, > > + LTC4283_CHAN_DRAIN, > > + /* differential channels */ > > + LTC4283_CHAN_ADIN12, > > + LTC4283_CHAN_ADIN34, > > + LTC4283_CHAN_ADIO12, > > + LTC4283_CHAN_ADIO34, > > + LTC4283_CHAN_MAX > > +}; > > + > > +/* Just for ease of use on the regmap */ > > +#define LTC4283_ADIO34_MAX \ > > + LTC4283_ADC_2_MAX_DIFF(LTC4283_CHAN_ADIO34 - LTC4283_CHAN_ADIN12) > > + > > +struct ltc4283_hwmon { > > + struct regmap *map; > > + struct i2c_client *client; > > + unsigned long gpio_mask; > > + unsigned long ch_enable_mask; > > + /* in microwatt */ > > + long power_max; > > + /* in millivolt */ > > + u32 vsense_max; > > + /* in tenths of microohm*/ > > + u32 rsense; > > + bool energy_en; > > + bool ext_fault; > > +}; > > + > > +static int ltc4283_read_voltage_word(const struct ltc4283_hwmon *st, > > + u32 reg, u32 fs, long *val) > > +{ > > + unsigned int __raw; > > + int ret; > > + > > + ret = regmap_read(st->map, reg, &__raw); > > + if (ret) > > + return ret; > > + > > + *val = DIV_ROUND_CLOSEST(__raw * fs, BIT(16)); > > + return 0; > > +} > > + > > +static int ltc4283_read_voltage_byte(const struct ltc4283_hwmon *st, > > + u32 reg, u32 fs, long *val) > > +{ > > + int ret; > > + u32 in; > > + > > + ret = regmap_read(st->map, reg, &in); > > + if (ret) > > + return ret; > > + > > + *val = DIV_ROUND_CLOSEST(in * fs, BIT(8)); > > + return 0; > > +} > > + > > +static u32 ltc4283_in_reg(u32 attr, u32 channel) > > +{ > > + switch (attr) { > > + case hwmon_in_input: > > + if (channel == LTC4283_CHAN_VPWR) > > + return LTC4283_VPWR; > > + if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN) > > + return LTC4283_ADC_2(channel - LTC4283_CHAN_ADI_1); > > + return LTC4283_ADC_2_DIFF(channel - LTC4283_CHAN_ADIN12); > > + case hwmon_in_highest: > > + if (channel == LTC4283_CHAN_VPWR) > > + return LTC4283_VPWR_MAX; > > + if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN) > > + return LTC4283_ADC_2_MAX(channel - LTC4283_CHAN_ADI_1); > > + return LTC4283_ADC_2_MAX_DIFF(channel - LTC4283_CHAN_ADIN12); > > + case hwmon_in_lowest: > > + if (channel == LTC4283_CHAN_VPWR) > > + return LTC4283_VPWR_MIN; > > + if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN) > > + return LTC4283_ADC_2_MIN(channel - LTC4283_CHAN_ADI_1); > > + return LTC4283_ADC_2_MIN_DIFF(channel - LTC4283_CHAN_ADIN12); > > + case hwmon_in_max: > > + if (channel == LTC4283_CHAN_VPWR) > > + return LTC4283_VPWR_MAX_TH; > > + if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN) > > + return LTC4283_ADC_2_MAX_TH(channel - LTC4283_CHAN_ADI_1); > > + return LTC4283_ADC_2_MAX_TH_DIFF(channel - LTC4283_CHAN_ADIN12); > > + default: > > + if (channel == LTC4283_CHAN_VPWR) > > + return LTC4283_VPWR_MIN_TH; > > + if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN) > > + return LTC4283_ADC_2_MIN_TH(channel - LTC4283_CHAN_ADI_1); > > + return LTC4283_ADC_2_MIN_TH_DIFF(channel - LTC4283_CHAN_ADIN12); > > + } > > +} > > + > > +static int ltc4283_read_in_vals(const struct ltc4283_hwmon *st, > > + u32 attr, u32 channel, long *val) > > +{ > > + u32 reg = ltc4283_in_reg(attr, channel); > > + int ret; > > + > > + if (channel < LTC4283_CHAN_ADIN12) { > > + if (attr != hwmon_in_max && attr != hwmon_in_min) > > + return ltc4283_read_voltage_word(st, reg, > > + LTC4283_ADC2_FS_mV, > > + val); > > + > > + return ltc4283_read_voltage_byte(st, reg, > > + LTC4283_ADC2_FS_mV, val); > > + } > > + > > + if (attr != hwmon_in_max && attr != hwmon_in_min) > > + ret = ltc4283_read_voltage_word(st, reg, > > + LTC4283_ADC1_FS_uV, val); > > + else > > + ret = ltc4283_read_voltage_byte(st, reg, > > + LTC4283_ADC1_FS_uV, val); > > + if (ret) > > + return ret; > > + > > + *val = DIV_ROUND_CLOSEST(*val, MILLI); > > + return 0; > > +} > > + > > +static int ltc4283_read_alarm(struct ltc4283_hwmon *st, u32 reg, > > + u32 mask, long *val) > > +{ > > + u32 alarm; > > + int ret; > > + > > + ret = regmap_read(st->map, reg, &alarm); > > + if (ret) > > + return ret; > > + > > + *val = !!(alarm & mask); > > + > > + /* If not status/fault logs, clear the alarm after reading it. */ > > + if (reg != LTC4283_FAULT_STATUS && reg != LTC4283_FAULT_LOG) > > + return regmap_clear_bits(st->map, reg, mask); > > + > > + return 0; > > +} > > + > > +static int ltc4283_read_in_alarm(struct ltc4283_hwmon *st, u32 channel, > > + bool max_alm, long *val) > > +{ > > + if (channel == LTC4283_VPWR) > > + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_1, > > + BIT(2 + max_alm), val); > > + > > + if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_ADI_4) { > > + u32 bit = (channel - LTC4283_CHAN_ADI_1) * 2; > > + /* > > + * Lower channels go to higher bits. We also want to go +1 down > > + * in the min_alarm case. > > + */ > > + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_2, > > + BIT(7 - bit - !max_alm), val); > > + } > > + > > + if (channel >= LTC4283_CHAN_ADIO_1 && channel <= LTC4283_CHAN_ADIO_4) { > > + u32 bit = (channel - LTC4283_CHAN_ADIO_1) * 2; > > + > > + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_3, > > + BIT(7 - bit - !max_alm), val); > > + } > > + > > + if (channel >= LTC4283_CHAN_ADIN12 && channel <= LTC4283_CHAN_ADIN34) { > > + u32 bit = (channel - LTC4283_CHAN_ADIN12) * 2; > > + > > + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_5, > > + BIT(7 - bit - !max_alm), val); > > + } > > + > > + if (channel == LTC4283_CHAN_DRNS) > > + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_4, > > + BIT(6 + max_alm), val); > > + > > + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_4, BIT(4 + max_alm), > > + val); > > +} > > + > > +static int ltc4283_read_in(struct ltc4283_hwmon *st, u32 attr, u32 channel, > > + long *val) > > +{ > > + switch (attr) { > > + case hwmon_in_input: > > + if (!test_bit(channel, &st->ch_enable_mask)) > > + return -ENODATA; > > + > > + return ltc4283_read_in_vals(st, attr, channel, val); > > + case hwmon_in_highest: > > + case hwmon_in_lowest: > > + case hwmon_in_max: > > + case hwmon_in_min: > > + return ltc4283_read_in_vals(st, attr, channel, val); > > + case hwmon_in_max_alarm: > > + return ltc4283_read_in_alarm(st, channel, true, val); > > + case hwmon_in_min_alarm: > > + return ltc4283_read_in_alarm(st, channel, false, val); > > + case hwmon_in_crit_alarm: > > + return ltc4283_read_alarm(st, LTC4283_FAULT_STATUS, > > + LTC4283_OV_MASK, val); > > + case hwmon_in_lcrit_alarm: > > + return ltc4283_read_alarm(st, LTC4283_FAULT_STATUS, > > + LTC4283_UV_MASK, val); > > + case hwmon_in_fault: > > + /* > > + * We report failure if we detect either a fer_bad or a > > + * fet_short in the status register. > > + */ > > + return ltc4283_read_alarm(st, LTC4283_FAULT_STATUS, > > + LTC4283_FET_BAD_MASK | LTC4283_FET_SHORT_MASK, val); > > + case hwmon_in_enable: > > + *val = test_bit(channel, &st->ch_enable_mask); > > + return 0; > > + default: > > + return -EOPNOTSUPP; > > + } > > + return 0; > > +} > > + > > +static int ltc4283_read_current_word(const struct ltc4283_hwmon *st, u32 reg, > > + long *val) > > +{ > > + u64 temp = (u64)LTC4283_ADC1_FS_uV * DECA * MILLI; > > + unsigned int __raw; > > + int ret; > > + > > + ret = regmap_read(st->map, reg, &__raw); > > + if (ret) > > + return ret; > > + > > + *val = DIV64_U64_ROUND_CLOSEST(__raw * temp, > > + BIT_ULL(16) * st->rsense); > > + > > + return 0; > > +} > > + > > +static int ltc4283_read_current_byte(const struct ltc4283_hwmon *st, u32 reg, > > + long *val) > > +{ > > + u64 temp = (u64)LTC4283_ADC1_FS_uV * DECA * MILLI; > > + u32 curr; > > + int ret; > > + > > + ret = regmap_read(st->map, reg, &curr); > > + if (ret) > > + return ret; > > + > > + *val = DIV_ROUND_CLOSEST_ULL(curr * temp, BIT(8) * st->rsense); > > + return 0; > > +} > > + > > +static int ltc4283_read_curr(struct ltc4283_hwmon *st, u32 attr, long *val) > > +{ > > + switch (attr) { > > + case hwmon_curr_input: > > + return ltc4283_read_current_word(st, LTC4283_SENSE, val); > > + case hwmon_curr_highest: > > + return ltc4283_read_current_word(st, LTC4283_SENSE_MAX, val); > > + case hwmon_curr_lowest: > > + return ltc4283_read_current_word(st, LTC4283_SENSE_MIN, val); > > + case hwmon_curr_max: > > + return ltc4283_read_current_byte(st, LTC4283_SENSE_MAX_TH, val); > > + case hwmon_curr_min: > > + return ltc4283_read_current_byte(st, LTC4283_SENSE_MIN_TH, val); > > + case hwmon_curr_max_alarm: > > + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_1, > > + LTC4283_SENSE_HIGH_ALM, val); > > + case hwmon_curr_min_alarm: > > + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_1, > > + LTC4283_SENSE_LOW_ALM, val); > > + case hwmon_curr_crit_alarm: > > + return ltc4283_read_alarm(st, LTC4283_FAULT_STATUS, > > + LTC4283_OC_MASK, val); > > + default: > > + return -EOPNOTSUPP; > > + } > > +} > > + > > +static int ltc4283_read_power_word(const struct ltc4283_hwmon *st, > > + u32 reg, long *val) > > +{ > > + u64 temp = (u64)LTC4283_ADC1_FS_uV * LTC4283_ADC2_FS_mV * DECA * MILLI; > > + unsigned int __raw; > > + int ret; > > + > > + ret = regmap_read(st->map, reg, &__raw); > > + if (ret) > > + return ret; > > + > > + /* > > + * Power is given by: > > + * P = CODE(16b) * 32.768mV * 2.048V / (2^16 * Rsense) > > + */ > > + *val = DIV64_U64_ROUND_CLOSEST(temp * __raw, BIT_ULL(16) * st->rsense); > > + > > + return 0; > > +} > > + > > +static int ltc4283_read_power_byte(const struct ltc4283_hwmon *st, > > + u32 reg, long *val) > > +{ > > + u64 temp = (u64)LTC4283_ADC1_FS_uV * LTC4283_ADC2_FS_mV * DECA * MILLI; > > + u32 power; > > + int ret; > > + > > + ret = regmap_read(st->map, reg, &power); > > + if (ret) > > + return ret; > > + > > + *val = DIV_ROUND_CLOSEST_ULL(power * temp, BIT(8) * st->rsense); > > + > > + return 0; > > +} > > + > > +static int ltc4283_read_power(struct ltc4283_hwmon *st, u32 attr, long *val) > > +{ > > + switch (attr) { > > + case hwmon_power_input: > > + return ltc4283_read_power_word(st, LTC4283_POWER, val); > > + case hwmon_power_input_highest: > > + return ltc4283_read_power_word(st, LTC4283_POWER_MAX, val); > > + case hwmon_power_input_lowest: > > + return ltc4283_read_power_word(st, LTC4283_POWER_MIN, val); > > + case hwmon_power_max_alarm: > > + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_1, > > + LTC4283_POWER_HIGH_ALM, val); > > + case hwmon_power_min_alarm: > > + return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_1, > > + LTC4283_POWER_LOW_ALM, val); > > + case hwmon_power_max: > > + return ltc4283_read_power_byte(st, LTC4283_POWER_MAX_TH, val); > > + case hwmon_power_min: > > + return ltc4283_read_power_byte(st, LTC4283_POWER_MIN_TH, val); > > + default: > > + return -EOPNOTSUPP; > > + } > > +} > > + > > +static int ltc4283_read_energy(struct ltc4283_hwmon *st, u32 attr, s64 *val) > > +{ > > + u64 temp = LTC4283_ADC1_FS_uV * LTC4283_ADC2_FS_mV, energy, temp_2; > > + u8 raw[8]; > > + int ret; > > + > > + if (!st->energy_en) > > + return -ENODATA; > > + > > + ret = i2c_smbus_read_i2c_block_data(st->client, LTC4283_ENERGY, 6, raw); > > + if (ret < 0) > > + return ret; > > + if (ret != 6) > > + return -EIO; > > + > > + energy = get_unaligned_be64(raw) >> 16; > > This reads 8 bytes from `raw` which is only partially initialized, as the block > data read is 6 bytes. This accesses uninitialized stack memory (`raw[6]` and > `raw[7]`), which can trigger KMSAN warnings. Could we initialize `raw` to zero? > > [ Yes, the uninitialized data is then shifted out, but KMSAN won't know that. ] Yeah, that was my reasoning but ok. I'll initialize it to 0. > > > + > > + /* > > + * The formula for energy is given by: > > + * E = CODE(48b) * 32.768mV * 2.048V * Tconv / 2^24 * Rsense > > + * > > + * As Rsense can have tenths of micro-ohm resolution, we need to > > + * multiply by DECA to get microjoule. > > + */ > > + if (check_mul_overflow(temp * LTC4283_TCONV_uS, energy, &temp_2)) { > > + /* > > + * We multiply again by 1000 to make sure that we don't get 0 > > + * in the following division which could happen for big rsense > > + * values. OTOH, we then divide energy first by 1000 so that > > + * we do not overflow u64 again for very small rsense values. > > + * We add 100 factor for proper conversion to microjoule. > > + */ > > + temp_2 = DIV64_U64_ROUND_CLOSEST(temp * LTC4283_TCONV_uS * MILLI, > > + BIT_ULL(24) * st->rsense); > > + energy = DIV_ROUND_CLOSEST_ULL(energy, MILLI * CENTI) * temp_2; > > + } else { > > + /* Put rsense back into nanoohm so we get microjoule. */ > > + energy = DIV64_U64_ROUND_CLOSEST(temp_2, BIT_ULL(24) * st->rsense * CENTI); > > + } > > + > > + *val = energy; > > + return 0; > > +} > > + > > +static int ltc4283_read(struct device *dev, enum hwmon_sensor_types type, > > + u32 attr, int channel, long *val) > > +{ > > + struct ltc4283_hwmon *st = dev_get_drvdata(dev); > > + > > + switch (type) { > > + case hwmon_in: > > + return ltc4283_read_in(st, attr, channel, val); > > + case hwmon_curr: > > + return ltc4283_read_curr(st, attr, val); > > + case hwmon_power: > > + return ltc4283_read_power(st, attr, val); > > + case hwmon_energy: > > + *val = st->energy_en; > > + return 0; > > + case hwmon_energy64: > > + return ltc4283_read_energy(st, attr, (s64 *)val); > > + default: > > + return -EOPNOTSUPP; > > + } > > +} > > + > > +static int ltc4283_write_power_byte(const struct ltc4283_hwmon *st, u32 reg, > > + long val) > > +{ > > + u64 temp = (u64)LTC4283_ADC1_FS_uV * LTC4283_ADC2_FS_mV * DECA * MILLI; > > + u32 __raw; > > + > > + if (val > st->power_max) > > + val = st->power_max; > > + > If `val` is negative, the signed comparison works correctly, but `val` is > then passed to the multiplication below. > > > + __raw = DIV64_U64_ROUND_CLOSEST(val * BIT_ULL(8) * st->rsense, temp); > > + > Here, `val` is implicitly cast to `u64`. A negative `val` will become a huge > positive number and write a garbage 8-bit value. > Could we clamp `val` to 0 as well using `clamp_val()`? Alright, clamp() it is. > > > + return regmap_write(st->map, reg, __raw); > > +} > > + > > +static int ltc4283_write_power_word(const struct ltc4283_hwmon *st, > > + u32 reg, long val) > > +{ > > + u64 temp = st->rsense * BIT_ULL(16), temp_2; > > + u16 __raw; > > + > > + if (check_mul_overflow(val, temp, &temp_2)) { > > + temp = DIV_ROUND_CLOSEST_ULL(temp, DECA * MILLI); > > + __raw = DIV_ROUND_CLOSEST_ULL(temp * val, LTC4283_ADC1_FS_uV * > > LTC4283_ADC2_FS_mV); > > + } else { > > + temp = (u64)LTC4283_ADC1_FS_uV * LTC4283_ADC2_FS_mV * DECA * MILLI; > > + __raw = DIV64_U64_ROUND_CLOSEST(temp_2, temp); > > + } > > + > > + return regmap_write(st->map, reg, __raw); > > +} > > + > > +static int ltc4283_reset_power_hist(struct ltc4283_hwmon *st) > > +{ > > + int ret; > > + > > + ret = ltc4283_write_power_word(st, LTC4283_POWER_MIN, st->power_max); > > + if (ret) > > + return ret; > > + > > + ret = ltc4283_write_power_word(st, LTC4283_POWER_MAX, 0); > > + if (ret) > > + return ret; > > + > > + /* Clear possible power faults. */ > > + return regmap_clear_bits(st->map, LTC4283_FAULT_LOG, > > + LTC4283_PWR_FAIL_FAULT_MASK | LTC4283_PGI_FAULT_MASK); > > +} > > + > > +static int ltc4283_write_power(struct ltc4283_hwmon *st, u32 attr, long val) > > +{ > > + switch (attr) { > > + case hwmon_power_max: > > + return ltc4283_write_power_byte(st, LTC4283_POWER_MAX_TH, val); > > + case hwmon_power_min: > > + return ltc4283_write_power_byte(st, LTC4283_POWER_MIN_TH, val); > > + case hwmon_power_reset_history: > > + return ltc4283_reset_power_hist(st); > > + default: > > + return -EOPNOTSUPP; > > + } > > +} > > + > > +static int ltc4283_write_in_history(struct ltc4283_hwmon *st, u32 reg, > > + long lowest, u32 fs) > > +{ > > + u32 __raw; > > + int ret; > > + > > + __raw = DIV_ROUND_CLOSEST(BIT(16) * lowest, fs); > > + if (__raw == BIT(16)) > > + __raw = U16_MAX; > > + > > + ret = regmap_write(st->map, reg, __raw); > > + if (ret) > > + return ret; > > + > > + return regmap_write(st->map, reg + 1, 0); > > +} > > + > > +static int ltc4283_write_in_byte(const struct ltc4283_hwmon *st, > > + u32 reg, u32 fs, long val) > > +{ > > + u32 __raw; > > + > > + val = clamp_val(val, 0, fs); > > + __raw = DIV_ROUND_CLOSEST(val * BIT(8), fs); > > + > If `val` is equal to `fs`, `__raw` will be exactly 256. Since this value is > later written to an 8-bit register via `i2c_smbus_write_byte_data()`, the > value 256 wraps around to 0. Writing the maximum value to the threshold > will thus inadvertently set it to the minimum. > > Should `__raw` be clamped to 255? Don't think so. Will do the same as in ltc4283_write_in_history() for the edge case. > > > + return regmap_write(st->map, reg, __raw); > > +} > > + > > +static int ltc4283_reset_in_hist(struct ltc4283_hwmon *st, u32 channel) > > +{ > > + u32 reg, fs; > > + int ret; > > + > > + /* > > + * Make sure to clear possible under/over voltage faults. Otherwise the > > + * chip won't latch on again. > > + */ > > + if (channel == LTC4283_CHAN_VIN) > > + return regmap_clear_bits(st->map, LTC4283_FAULT_LOG, > > + LTC4283_OV_FAULT_MASK | LTC4283_UV_FAULT_MASK); > > + > > + if (channel == LTC4283_CHAN_VPWR) > > + return ltc4283_write_in_history(st, LTC4283_VPWR_MIN, > > + LTC4283_ADC2_FS_mV, > > + LTC4283_ADC2_FS_mV); > > + > > + if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN) { > > + fs = LTC4283_ADC2_FS_mV; > > + reg = LTC4283_ADC_2_MIN(channel - LTC4283_CHAN_ADI_1); > > + } else { > > + fs = LTC4283_ADC1_FS_uV; > > + reg = LTC4283_ADC_2_MIN_DIFF(channel - LTC4283_CHAN_ADIN12); > > + } > > + > > + ret = ltc4283_write_in_history(st, reg, fs, fs); > > + if (ret) > > + return ret; > > + if (channel != LTC4283_CHAN_DRAIN) > > + return 0; > > + > > + /* Then, let's also clear possible fet faults. Same as above. */ > > + return regmap_clear_bits(st->map, LTC4283_FAULT_LOG, > > + LTC4283_FET_BAD_FAULT_MASK | LTC4283_FET_SHORT_FAULT_MASK); > > +} > > + > > +static int ltc4283_write_in_en(struct ltc4283_hwmon *st, u32 channel, bool en) > > +{ > > + unsigned int bit, adc_idx = channel - LTC4283_CHAN_ADI_1; > > + unsigned int reg = LTC4283_ADC_SELECT(adc_idx); > > + int ret; > > + > > + bit = LTC4283_ADC_SELECT_MASK(adc_idx); > > + if (channel > LTC4283_CHAN_DRAIN) > > + /* Account for two reserved fields after DRAIN. */ > > + bit <<= 2; > > + > > + if (en) > > + ret = regmap_set_bits(st->map, reg, bit); > > + else > > + ret = regmap_clear_bits(st->map, reg, bit); > > + if (ret) > > + return ret; > > + > > + __assign_bit(channel, &st->ch_enable_mask, en); > > + return 0; > > +} > > + > > +static int ltc4283_write_minmax(struct ltc4283_hwmon *st, long val, > > + u32 channel, bool is_max) > > +{ > > + u32 reg; > > + > > + if (channel == LTC4283_CHAN_VPWR) { > > + if (is_max) > > + return ltc4283_write_in_byte(st, LTC4283_VPWR_MAX_TH, > > + LTC4283_ADC2_FS_mV, val); > > + > > + return ltc4283_write_in_byte(st, LTC4283_VPWR_MIN_TH, > > + LTC4283_ADC2_FS_mV, val); > > + } > > + > > + if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN) { > > + if (is_max) { > > + reg = LTC4283_ADC_2_MAX_TH(channel - LTC4283_CHAN_ADI_1); > > + return ltc4283_write_in_byte(st, reg, > > + LTC4283_ADC2_FS_mV, val); > > + } > > + > > + reg = LTC4283_ADC_2_MIN_TH(channel - LTC4283_CHAN_ADI_1); > > + return ltc4283_write_in_byte(st, reg, LTC4283_ADC2_FS_mV, val); > > + } > > + > > + if (is_max) { > > + reg = LTC4283_ADC_2_MAX_TH_DIFF(channel - LTC4283_CHAN_ADIN12); > > + return ltc4283_write_in_byte(st, reg, LTC4283_ADC1_FS_uV, > > + val * MILLI); > > + } > > + > > + reg = LTC4283_ADC_2_MIN_TH_DIFF(channel - LTC4283_CHAN_ADIN12); > > + return ltc4283_write_in_byte(st, reg, LTC4283_ADC1_FS_uV, val * MILLI); > > +} > > + > > +static int ltc4283_write_in(struct ltc4283_hwmon *st, u32 attr, long val, > > + int channel) > > +{ > > + switch (attr) { > > + case hwmon_in_max: > > + return ltc4283_write_minmax(st, val, channel, true); > > + case hwmon_in_min: > > + return ltc4283_write_minmax(st, val, channel, false); > > + case hwmon_in_reset_history: > > + return ltc4283_reset_in_hist(st, channel); > > + case hwmon_in_enable: > > + return ltc4283_write_in_en(st, channel, !!val); > > + default: > > + return -EOPNOTSUPP; > > + } > > +} > > + > > +static int ltc4283_write_curr_byte(const struct ltc4283_hwmon *st, > > + u32 reg, long val) > > +{ > > + u32 temp = LTC4283_ADC1_FS_uV * DECA * MILLI; > > + u32 reg_val; > > + > > + reg_val = DIV_ROUND_CLOSEST_ULL(val * BIT_ULL(8) * st->rsense, temp); > > `val` is not clamped here. A negative user input will be implicitly cast to `u64` > and produce a massive value. Also, a very large user input will cause `reg_val` > to exceed 255 and wrap around in the 8-bit register. > Should `val` be clamped at the lower end, and `reg_val` at the upper end? I guess we should clamp to vsense_max. So, val * rsense <= vsense_max > > > + return regmap_write(st->map, reg, reg_val); > > +} > > + > > +static int ltc4283_write_curr_history(struct ltc4283_hwmon *st) > > +{ > > + int ret; > > + > > + ret = ltc4283_write_in_history(st, LTC4283_SENSE_MIN, st->vsense_max, > > + LTC4283_ADC1_FS_uV); > > + if (ret) > > + return ret; > > Is this missing a multiplication by `MILLI`? > `st->vsense_max` is in millivolts, while `LTC4283_ADC1_FS_uV` is in > microvolts. Since `ltc4283_write_in_history` divides the value by the full > scale, using `st->vsense_max` directly results in a raw value ~1000 times > smaller than intended (e.g. 60 instead of 60000). This prevents SENSE_MIN > from accurately tracking the lowest historical current. good catch! - Nuno Sá > > ^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH v6 3/3] gpio: gpio-ltc4283: Add support for the LTC4283 Swap Controller 2026-03-03 17:00 [PATCH v6 0/3] hwmon: Add support for the LTC4283 Hot Swap Controller Nuno Sá via B4 Relay 2026-03-03 17:00 ` [PATCH v6 1/3] dt-bindings: hwmon: Document the LTC4283 " Nuno Sá via B4 Relay 2026-03-03 17:00 ` [PATCH v6 2/3] hwmon: ltc4283: Add support for " Nuno Sá via B4 Relay @ 2026-03-03 17:00 ` Nuno Sá via B4 Relay 2 siblings, 0 replies; 8+ messages in thread From: Nuno Sá via B4 Relay @ 2026-03-03 17:00 UTC (permalink / raw) To: linux-gpio, linux-hwmon, devicetree, linux-doc Cc: Guenter Roeck, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Jonathan Corbet, Linus Walleij, Bartosz Golaszewski, Bartosz Golaszewski From: Nuno Sá <nuno.sa@analog.com> The LTC4283 device has up to 8 pins that can be configured as GPIOs. Note that PGIO pins are not set as GPIOs by default so if they are configured to be used as GPIOs we need to make sure to initialize them to a sane default. They are set as inputs by default. Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Linus Walleij <linusw@kernel.org> Signed-off-by: Nuno Sá <nuno.sa@analog.com> --- MAINTAINERS | 2 + drivers/gpio/Kconfig | 15 +++ drivers/gpio/Makefile | 1 + drivers/gpio/gpio-ltc4283.c | 218 ++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 236 insertions(+) diff --git a/MAINTAINERS b/MAINTAINERS index 38d22cf622b7..0f4fc6c189f6 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -15143,9 +15143,11 @@ F: drivers/hwmon/ltc4282.c LTC4283 HARDWARE MONITOR AND GPIO DRIVER M: Nuno Sá <nuno.sa@analog.com> +L: linux-gpio@vger.kernel.org L: linux-hwmon@vger.kernel.org S: Supported F: Documentation/devicetree/bindings/hwmon/adi,ltc4283.yaml +F: drivers/gpio/gpio-ltc4283.c F: drivers/hwmon/ltc4283.c LTC4286 HARDWARE MONITOR DRIVER diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index b45fb799e36c..ba2621024598 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -1758,6 +1758,21 @@ config GPIO_WM8994 endmenu +menu "Auxiliary Bus GPIO drivers" + depends on AUXILIARY_BUS + +config GPIO_LTC4283 + tristate "Analog Devices LTC4283 GPIO support" + depends on SENSORS_LTC4283 + help + If you say yes here you want the GPIO function available in Analog + Devices LTC4283 Negative Voltage Hot Swap Controller. + + This driver can also be built as a module. If so, the module will + be called gpio-ltc4283. + +endmenu + menu "PCI GPIO expanders" depends on PCI diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index c05f7d795c43..ff37aca5029c 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -102,6 +102,7 @@ obj-$(CONFIG_GPIO_LP873X) += gpio-lp873x.o obj-$(CONFIG_GPIO_LP87565) += gpio-lp87565.o obj-$(CONFIG_GPIO_LPC18XX) += gpio-lpc18xx.o obj-$(CONFIG_GPIO_LPC32XX) += gpio-lpc32xx.o +obj-$(CONFIG_GPIO_LTC4283) += gpio-ltc4283.o obj-$(CONFIG_GPIO_MACSMC) += gpio-macsmc.o obj-$(CONFIG_GPIO_MADERA) += gpio-madera.o obj-$(CONFIG_GPIO_MAX3191X) += gpio-max3191x.o diff --git a/drivers/gpio/gpio-ltc4283.c b/drivers/gpio/gpio-ltc4283.c new file mode 100644 index 000000000000..6609443c5d62 --- /dev/null +++ b/drivers/gpio/gpio-ltc4283.c @@ -0,0 +1,218 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Analog Devices LTC4283 GPIO driver + * + * Copyright 2025 Analog Devices Inc. + */ + +#include <linux/auxiliary_bus.h> +#include <linux/bitfield.h> +#include <linux/bitmap.h> +#include <linux/bits.h> +#include <linux/device.h> +#include <linux/gpio/driver.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/regmap.h> + +#define LTC4283_PINS_MAX 8 +#define LTC4283_PGIOX_START_NR 4 +#define LTC4283_INPUT_STATUS 0x02 +#define LTC4283_PGIO_CONFIG 0x10 +#define LTC4283_PGIO_CFG_MASK(pin) \ + GENMASK(((pin) - LTC4283_PGIOX_START_NR) * 2 + 1, (((pin) - LTC4283_PGIOX_START_NR) * 2)) +#define LTC4283_PGIO_CONFIG_2 0x11 + +#define LTC4283_ADIO_CONFIG 0x12 +/* starts at bit 4 */ +#define LTC4283_ADIOX_CONFIG_MASK(pin) BIT((pin) + 4) +#define LTC4283_PGIO_DIR_IN 3 +#define LTC4283_PGIO_DIR_OUT 2 + +struct ltc4283_gpio { + struct gpio_chip gpio_chip; + struct regmap *regmap; +}; + +static int ltc4283_pgio_get_direction(const struct ltc4283_gpio *st, unsigned int off) +{ + unsigned int val; + int ret; + + ret = regmap_read(st->regmap, LTC4283_PGIO_CONFIG, &val); + if (ret) + return ret; + + val = field_get(LTC4283_PGIO_CFG_MASK(off), val); + if (val == LTC4283_PGIO_DIR_IN) + return GPIO_LINE_DIRECTION_IN; + + return GPIO_LINE_DIRECTION_OUT; +} + +static int ltc4283_gpio_get_direction(struct gpio_chip *gc, unsigned int off) +{ + struct ltc4283_gpio *st = gpiochip_get_data(gc); + unsigned int val; + int ret; + + if (off >= LTC4283_PGIOX_START_NR) + return ltc4283_pgio_get_direction(st, off); + + ret = regmap_read(st->regmap, LTC4283_ADIO_CONFIG, &val); + if (ret) + return ret; + + if (val & LTC4283_ADIOX_CONFIG_MASK(off)) + return GPIO_LINE_DIRECTION_IN; + + return GPIO_LINE_DIRECTION_OUT; +} + +static int ltc4283_gpio_direction_set(const struct ltc4283_gpio *st, + unsigned int off, bool input) +{ + if (off >= LTC4283_PGIOX_START_NR) { + unsigned int val = LTC4283_PGIO_DIR_OUT; + + if (input) + val = LTC4283_PGIO_DIR_IN; + + val = field_prep(LTC4283_PGIO_CFG_MASK(off), val); + return regmap_update_bits(st->regmap, LTC4283_PGIO_CONFIG, + LTC4283_PGIO_CFG_MASK(off), val); + } + + return regmap_update_bits(st->regmap, LTC4283_ADIO_CONFIG, + LTC4283_ADIOX_CONFIG_MASK(off), + field_prep(LTC4283_ADIOX_CONFIG_MASK(off), input)); +} + +static int __ltc4283_gpio_set_value(const struct ltc4283_gpio *st, + unsigned int off, int val) +{ + u32 reg = off < LTC4283_PGIOX_START_NR ? LTC4283_ADIO_CONFIG : LTC4283_PGIO_CONFIG_2; + + return regmap_update_bits(st->regmap, reg, BIT(off), + field_prep(BIT(off), !!val)); +} + +static int ltc4283_gpio_direction_input(struct gpio_chip *gc, unsigned int off) +{ + struct ltc4283_gpio *st = gpiochip_get_data(gc); + + return ltc4283_gpio_direction_set(st, off, true); +} + +static int ltc4283_gpio_direction_output(struct gpio_chip *gc, unsigned int off, int val) +{ + struct ltc4283_gpio *st = gpiochip_get_data(gc); + int ret; + + ret = ltc4283_gpio_direction_set(st, off, false); + if (ret) + return ret; + + return __ltc4283_gpio_set_value(st, off, val); +} + +static int ltc4283_gpio_get_value(struct gpio_chip *gc, unsigned int off) +{ + struct ltc4283_gpio *st = gpiochip_get_data(gc); + unsigned int val, reg; + int ret, dir; + + dir = ltc4283_gpio_get_direction(gc, off); + if (dir < 0) + return dir; + + if (dir == GPIO_LINE_DIRECTION_IN) { + ret = regmap_read(st->regmap, LTC4283_INPUT_STATUS, &val); + if (ret) + return ret; + + /* ADIO1 is at bit 3. */ + if (off < LTC4283_PGIOX_START_NR) + return !!(val & BIT(3 - off)); + + /* PGIO1 is at bit 7. */ + return !!(val & BIT(7 - (off - LTC4283_PGIOX_START_NR))); + } + + if (off < LTC4283_PGIOX_START_NR) + reg = LTC4283_ADIO_CONFIG; + else + reg = LTC4283_PGIO_CONFIG_2; + + ret = regmap_read(st->regmap, reg, &val); + if (ret) + return ret; + + return !!(val & BIT(off)); +} + +static int ltc4283_gpio_set_value(struct gpio_chip *gc, unsigned int off, int val) +{ + struct ltc4283_gpio *st = gpiochip_get_data(gc); + + return __ltc4283_gpio_set_value(st, off, val); +} + +static int ltc4283_init_valid_mask(struct gpio_chip *gc, unsigned long *valid_mask, + unsigned int ngpios) +{ + unsigned long *mask = dev_get_platdata(gc->parent); + + bitmap_copy(valid_mask, mask, ngpios); + return 0; +} + +static int ltc4283_gpio_probe(struct auxiliary_device *adev, + const struct auxiliary_device_id *id) +{ + struct device *dev = &adev->dev; + struct ltc4283_gpio *st; + struct gpio_chip *gc; + + st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL); + if (!st) + return -ENOMEM; + + st->regmap = dev_get_regmap(dev->parent, NULL); + if (!st->regmap) + return dev_err_probe(dev, -ENODEV, + "Failed to get regmap\n"); + + gc = &st->gpio_chip; + gc->parent = dev; + gc->get_direction = ltc4283_gpio_get_direction; + gc->direction_input = ltc4283_gpio_direction_input; + gc->direction_output = ltc4283_gpio_direction_output; + gc->get = ltc4283_gpio_get_value; + gc->set = ltc4283_gpio_set_value; + gc->init_valid_mask = ltc4283_init_valid_mask; + gc->can_sleep = true; + + gc->base = -1; + gc->ngpio = LTC4283_PINS_MAX; + gc->label = adev->name; + gc->owner = THIS_MODULE; + + return devm_gpiochip_add_data(dev, &st->gpio_chip, st); +} + +static const struct auxiliary_device_id ltc4283_aux_id_table[] = { + { "ltc4283.gpio" }, + { } +}; +MODULE_DEVICE_TABLE(auxiliary, ltc4283_aux_id_table); + +static struct auxiliary_driver ltc4283_gpio_driver = { + .probe = ltc4283_gpio_probe, + .id_table = ltc4283_aux_id_table, +}; +module_auxiliary_driver(ltc4283_gpio_driver); + +MODULE_AUTHOR("Nuno Sá <nuno.sa@analog.com>"); +MODULE_DESCRIPTION("GPIO LTC4283 Driver"); +MODULE_LICENSE("GPL"); -- 2.53.0 ^ permalink raw reply related [flat|nested] 8+ messages in thread
end of thread, other threads:[~2026-03-11 10:31 UTC | newest] Thread overview: 8+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2026-03-03 17:00 [PATCH v6 0/3] hwmon: Add support for the LTC4283 Hot Swap Controller Nuno Sá via B4 Relay 2026-03-03 17:00 ` [PATCH v6 1/3] dt-bindings: hwmon: Document the LTC4283 " Nuno Sá via B4 Relay 2026-03-03 17:00 ` [PATCH v6 2/3] hwmon: ltc4283: Add support for " Nuno Sá via B4 Relay 2026-03-04 11:05 ` kernel test robot 2026-03-04 12:20 ` Nuno Sá 2026-03-06 17:41 ` Guenter Roeck 2026-03-11 10:32 ` Nuno Sá 2026-03-03 17:00 ` [PATCH v6 3/3] gpio: gpio-ltc4283: " Nuno Sá via B4 Relay
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