.. SPDX-License-Identifier: GPL-2.0

Kernel driver vt7505
====================

Supported chips:

  * Analog Devices MAX16545

    Prefix: 'max16545'

    Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/max16545b-max16545c.pdf

  * Analog Devices MAX16550

    Prefix: 'max16550'

    Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/max16550.pdf

  * Volterra VT7505

    Prefix: 'vt7505'

    Datasheet: Not publicly available; register-compatible with the MAX16545.

Author: Georgi Vlaev <gvlaev@juniper.net>

Description
-----------

This driver supports hardware monitoring for the Analog Devices MAX16545 and
MAX16550, and the Volterra VT7505 PMBus controllers.

The devices report input and output voltage, input and output current,
input power, and temperature. All values use the PMBus direct data format.
Peak (maximum) values for input voltage, output voltage, output current,
input power and temperature are exposed and can be reset. Writing to any
``*_reset_history`` attribute clears all of the device's peak values.

The reported current and power values depend on the resistance of the
external current-report resistor connected between the ILOAD pin and
ground. This resistance can be provided via the ``adi,rload-ohms``
device tree property; a default of 4750 ohms is used when it is absent.

Sysfs entries
-------------

The limit and alarm attributes are created by the PMBus core for the limit
registers that the device implements. See
Documentation/hwmon/sysfs-interface.rst for the meaning of each attribute.

======================= ========================================================
in1_label               "vin"
in1_input               Measured input voltage.
in1_min                 Input undervoltage warning limit.
in1_min_alarm           Input undervoltage warning alarm.
in1_lcrit               Input undervoltage fault limit.
in1_lcrit_alarm         Input undervoltage fault alarm.
in1_highest             Historical maximum input voltage.
in1_reset_history       Write to reset all peak values.
in2_label               "vout1"
in2_input               Measured output voltage.
in2_min                 Output undervoltage warning limit.
in2_min_alarm           Output undervoltage warning alarm.
in2_highest             Historical maximum output voltage.
in2_reset_history       Write to reset all peak values.
curr1_label             "iin"
curr1_input             Measured input current.
curr1_alarm             Input current alarm.
curr2_label             "iout1"
curr2_input             Measured output current.
curr2_max               Output overcurrent warning limit.
curr2_max_alarm         Output overcurrent warning alarm.
curr2_highest           Historical maximum output current.
curr2_reset_history     Write to reset all peak values.
power1_label            "pin"
power1_input            Measured input power.
power1_max              Input overpower warning limit.
power1_alarm            Input overpower warning alarm.
power1_input_highest    Historical maximum input power.
power1_reset_history    Write to reset all peak values.
temp1_input             Measured temperature.
temp1_max               Overtemperature warning limit.
temp1_max_alarm         Overtemperature warning alarm.
temp1_crit              Overtemperature fault limit.
temp1_crit_alarm        Overtemperature fault alarm.
temp1_highest           Historical maximum temperature.
temp1_reset_history     Write to reset all peak values.
======================= ========================================================