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-rw-r--r--share/man/man4/gpio.438
1 files changed, 20 insertions, 18 deletions
diff --git a/share/man/man4/gpio.4 b/share/man/man4/gpio.4
index 1d2eadcb525..bf99bd0bc3f 100644
--- a/share/man/man4/gpio.4
+++ b/share/man/man4/gpio.4
@@ -1,4 +1,4 @@
-.\" $OpenBSD: gpio.4,v 1.1 2004/06/03 18:41:29 grange Exp $
+.\" $OpenBSD: gpio.4,v 1.2 2004/06/03 23:53:57 jmc Exp $
.\"
.\" Copyright (c) 2004 Alexander Yurchenko <grange@openbsd.org>
.\"
@@ -36,19 +36,19 @@ controller and provides a uniform programming interface to its pins.
.Pp
Each
.Tn GPIO
-controller with attached
+controller with an attached
.Nm
-device has associated device file under the
+device has an associated device file under the
.Pa /dev
-directory, e.g.
+directory, e.g.\&
.Pa /dev/gpio0 .
Access from userland is performed through
.Xr ioctl 2
calls on these devices.
.Sh IOCTL INTERFACE
-The following structures and constants are defined in
-.Aq Pa sys/gpio.h
-header file.
+The following structures and constants are defined in the
+.Aq Pa sys/gpio.h
+header file:
.Pp
.Bl -tag -width XXXX -compact
.It Dv GPIOINFO (struct gpio_info)
@@ -64,7 +64,7 @@ struct gpio_info {
.Ed
.Pp
.It Dv GPIOPINREAD (struct gpio_pin_op)
-Returns input pin value in the
+Returns the input pin value in the
.Fa gpio_pin_op
structure:
.Bd -literal
@@ -79,22 +79,22 @@ The
field must be set before calling.
.Pp
.It Dv GPIOPINWRITE (struct gpio_pin_op)
-Writes output value to the pin.
-Value set in the
+Writes the output value to the pin.
+The value set in the
.Fa gp_value
field must be either
.Dv GPIO_PIN_LOW
(logical 0) or
.Dv GPIO_PIN_HIGH
(logical 1).
-On return
+On return, the
.Fa gp_value
-field contains old pin state.
+field contains the old pin state.
.Pp
.It Dv GPIOPINTOGGLE (struct gpio_pin_op)
-Toggles pin output value, i.e. changes it to the opposite.
+Toggles the pin output value, i.e. changes it to the opposite.
.Fa gp_value
-field is ignored and on return contains old pin state.
+field is ignored and on return contains the old pin state.
.Pp
.It Dv GPIOPINCTL (struct gpio_pin_ctl)
Changes pin configuration flags with the new ones provided in the
@@ -108,6 +108,7 @@ struct gpio_pin_ctl {
};
.Ed
.Pp
+The
.Fa gp_flags
field is a combination of the following flags:
.Pp
@@ -131,11 +132,11 @@ internal pull-up enabled
Note that the
.Tn GPIO
controller
-may not support all these flags.
+may not support all of these flags.
On return the
.Fa gp_caps
field contains flags that are supported.
-If no flags specified pin configuration stays unchanged.
+If no flags are specified, the pin configuration stays unchanged.
.El
.Sh FILES
.Bl -tag -width "/dev/gpiou" -compact
@@ -143,11 +144,12 @@ If no flags specified pin configuration stays unchanged.
GPIO device unit
.Ar u
file.
+.El
.Sh SEE ALSO
.Xr ioctl 2 ,
.Xr gscpcib 4 ,
-.Xr nsclpcsio 4
-.Xr gpioctl 8 ,
+.Xr nsclpcsio 4 ,
+.Xr gpioctl 8
.Sh HISTORY
The
.Nm