1 files changed, 41 insertions, 2 deletions
diff --git a/share/man/man4/gpio.4 b/share/man/man4/gpio.4
index 0e2c8cdb1423..da95c39f8e98 100644
--- a/share/man/man4/gpio.4
+++ b/share/man/man4/gpio.4
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd November 5, 2013
+.Dd June 27, 2019
 .Dt GPIO 4
 .Os
 .Sh NAME
@@ -103,12 +103,50 @@ 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.pin_list"
+.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.
+Only pins with numbers from 0 to 31 can be specified using this hint.
+.It Va hint.driver.unit.pin_list
+This is a list of pin numbers of pins on the
+.Nm gpiobus
+that are connected to the device.
+The pins will be allocated to the specified driver instance.
+This is a more user friendly alternative to the
+.Ar pins
+hint.
+Additionally, this hint allows specifying pin numbers greater than 31.
+The numbers can be decimal or hexadecimal with 0x prefix.
+Any non-digit character can be used as a separator.
+For example, it can be a comma, a slash or a space.
+The separator can be followed by any number of space characters.
+.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 +171,7 @@ 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