.. SPDX-License-Identifier: GPL-2.0-or-later

Kernel driver fs1603
====================

Supported chips:

  * TDK FS1603

    Prefix: 'fs1603'

    Datasheet: Publicly available at the TDK website

  * TDK FS1604

    Prefix: 'fs1604'

    Datasheet: Publicly available at the TDK website

  * TDK FS1606, FS1606-0600, FS1606-2500

    Prefixes: 'fs1606', 'fs1606_0600', 'fs1606_2500'

    Datasheet: Publicly available at the TDK website

  * TDK FS1006-3300, FS1006-5000

    Prefixes: 'fs1006_3300', 'fs1006_5000'

    Datasheet: Publicly available at the TDK website

Author:

  * Kevin Jia <kjia@nexthop.ai>

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

The TDK FS160x and FS1006 are uPOL DC-DC converters with an integrated
inductor. They report input voltage, output voltage, output current and
temperature over a proprietary I2C register map. They are not PMBus devices,
and their register numbers collide with PMBus command codes, so a PMBus driver
must not be bound to them.

The model is not auto-detected. It must be declared through the I2C device
name or the devicetree compatible. The FS1606-2500 preset uses the voltage
scaling of the FS1603, FS1604 and FS1006 rather than that of the base FS1606,
and the FS1606-0600 applies a gain correction to the output current, so
neither can be declared as an FS1606.

The driver is read-only. On boards that use a feedback divider to reach a
higher rail voltage, the output voltage is still reported for the rail, and the
over-voltage threshold is scaled to the rail by the divider ratio, measured at
probe from the output voltage and the feedback pin. TDK notes that current
reporting does not apply in that configuration.

Sysfs attributes
----------------

=================== == ========================================================
in0_input           RO Input voltage in millivolts.
in0_label           RO "vin"
in1_input           RO Output voltage in millivolts.
in1_label           RO "vout"
in1_crit            RO Output over-voltage protection threshold in millivolts:
                       the OV_Threshold percentage of the VOUT_SET target,
                       scaled to the rail on boards with a feedback divider.
in1_alarm           RO Output over-voltage status.
curr1_input         RO Output current in milliamperes.
curr1_alarm         RO Over-current status.
temp1_input         RO Temperature in millidegrees Celsius.
temp1_crit          RO Over-temperature protection threshold in millidegrees
                       Celsius.
temp1_alarm         RO Over-temperature status.
=================== == ========================================================