.\" $NetBSD: tps65217pmic.4,v 1.10 2018/06/28 22:00:50 wiz Exp $
.\"
.\" Copyright (c) 2013 The NetBSD Foundation, Inc.
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.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Radoslaw Kujawa.
.\"
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.Dd June 28, 2018
.Dt TPS65217PMIC 4
.Os
.Sh NAME
.Nm tps65217pmic
.Nd Texas Instruments TPS65217 Power Management IC driver
.Sh SYNOPSIS
.Cd "tps65217pmic0 at iic? addr 0x24"
.Sh DESCRIPTION
The
.Nm
driver provides minimal support for the TPS65217 chip and allows reporting
regulated voltages through the
.Xr envsys 4
API.
.Pp
The TPS65217 consists of low-dropout regulators (LDO) and step-down converters
with integrated switching FETs (DCDC):
.Bl -bullet -compact
.It
LDO1: 1.0V - 3.3V
.It
LDO2: 0.9V - 3.3V
.It
LDO3: 1.5V - 3.3V
.It
LDO4: 1.5V - 3.3V
.It
DCDC1: 0.9V - 1.8V
.It
DCDC2: 0.9V - 3.3V
.It
DCDC1: 0.9V - 1.5V
.El
.Sh SEE ALSO
.Xr envsys 4
.Sh HISTORY
The
.Nm
device first appeared in
.Nx 7.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was written by
.An Radoslaw Kujawa Aq Mt radoslaw.kujawa@gmail.com .
Voltage change callback for AM335x was added by
.An Manuel Bouyer .
White LED (backlight) support was added by
.An KIYOHARA Takashi .
.Sh CAVEATS
The driver can only report current voltage regulator settings.
It can not measure the real voltage, as the TPS65217 chip lacks hardware to do
that.
Some boards allow voltage measurement by connecting the power output to
external sensor, or analog input of the MPU, but this is outside of the
scope of this driver.
.Pp
Modifying voltage regulator parameters from user space was deliberately left
unimplemented, as these parameters should only be set at the firmware or
kernel level.
Setting wrong parameters may result in permanent hardware damage.
.Pp
The
.Nm
driver offers a function that can be used to change the voltage from other
kernel components (currently used by AM335x support code).
.Sh BUGS
Battery and interrupt support is not implemented.