Add man page for sambat(4).

ok deraadt@

share/man/man4/sambat.4

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+.\"	$OpenBSD: sambat.4,v 1.1 2026/05/19 04:42:20 mglocker Exp $
+.\"
+.\" Copyright (c) 2026 Marcus Glocker <mglocker@openbsd.org>
+.\"
+.\" Permission to use, copy, modify, and distribute this software for any
+.\" purpose with or without fee is hereby granted, provided that the above
+.\" copyright notice and this permission notice appear in all copies.
+.\"
+.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+.\"
+.Dd $Mdocdate: May 19 2026 $
+.Dt SAMBAT 4
+.Os
+.Sh NAME
+.Nm sambat
+.Nd Samsung laptop battery monitor
+.Sh SYNOPSIS
+.Cd "sambat* at iic?"
+.Sh DESCRIPTION
+The
+.Nm
+driver provides support for the embedded controller found in Samsung
+laptops based on the Qualcomm Snapdragon X1E80100, such as the Galaxy
+Book4 Edge.
+The controller, identified as
+.Dq SAM060B
+in ACPI, is an ENE KB9058 micro controller running Samsung firmware,
+and provides battery and AC adapter status over the I2C bus using a
+vendor
+.Dq Mbox
+command protocol.
+.Pp
+Battery values are exposed through the
+.Xr sysctl 8
+sensor framework and the
+.Xr apm 8
+power management interface.
+.Sh SEE ALSO
+.Xr iic 4 ,
+.Xr intro 4 ,
+.Xr apm 8 ,
+.Xr sysctl 8
+.Sh HISTORY
+The
+.Nm
+driver first appeared in
+.Ox 8.0 .
+.Sh AUTHORS
+.An -nosplit
+The
+.Nm
+driver was written by
+.An Marcus Glocker Aq Mt mglocker@openbsd.org .
+.Sh BUGS
+The AC adapter online status is reported correctly at boot and after
+the power cable is unplugged, but does not refresh after the cable
+is plugged back in.