From 59c94acee91870f20e4522f95432442529e5708a Mon Sep 17 00:00:00 2001
From: Andriy Gapon <avg@FreeBSD.org>
Date: Wed, 26 Jun 2019 07:38:31 +0000
Subject: [PATCH] gpio.4: document device hints common to all devices on
 gpiobus

"at" keyword is documented in device.hints(5) for all buses, but it does
hurt to add another reference to it.
"pins" keyword is specific to gpiobus.
At least these two hints should be configured for any gpiobus device on
a hints based system.

MFC after:	10 days
---
 share/man/man4/gpio.4 | 29 +++++++++++++++++++++++++++--
 1 file changed, 27 insertions(+), 2 deletions(-)

diff --git a/share/man/man4/gpio.4 b/share/man/man4/gpio.4
index 0e2c8cdb1423..b1eb1ef8a5bc 100644
--- a/share/man/man4/gpio.4
+++ b/share/man/man4/gpio.4
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd November 5, 2013
+.Dd June 26, 2019
 .Dt GPIO 4
 .Os
 .Sh NAME
@@ -103,12 +103,36 @@ passed to the kernel, being either statically compiled in, or by a variety
 of ways where the boot loader (or Open Firmware enabled system) passes the
 DTS blob to the kernel at boot.
 .Pp
+On a
+.Xr device.hints 5
+based system these hints can be used to configure drivers for devices
+attached to
+.Nm
+pins:
+.Bl -tag -width ".Va hint.driver.unit.pins"
+.It Va hint.driver.unit.at
+The
+.Nm gpiobus
+where the device is attached.
+For example,
+.Qq gpiobus0 .
+.Ar driver
+and
+.Ar unit
+are the driver name and the unit number for the device driver.
+.It Va hint.driver.unit.pins
+This is a bitmask of the pins on the
+.Nm gpiobus
+that are connected to the device.
+The pins will be allocated to the specified driver instance.
+.El
+.Pp
 The following
 .Xr device.hints 5
 are only provided by the
 .Cd ar71xx_gpio
 driver:
-.Bl -tag -width ".Va hint.gpioiic.%d.atXXX"
+.Bl -tag -width ".Va hint.gpio.function_clear"
 .It Va hint.gpio.%d.pinmask
 This is a bitmask of pins on the GPIO board that we would like to expose
 for use to the host operating system.
@@ -133,6 +157,7 @@ of some device in a system.
 .Xr gpioiic 4 ,
 .Xr gpioled 4 ,
 .Xr iicbus 4 ,
+.Xr device.hints 5 ,
 .Xr gpioctl 8
 .Sh HISTORY
 The