| .. 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 Sรก <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_reset_history Clears Under and Overvoltage fault logs. |
| 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. |
| ============================== ========================================================== |
