Document the APGIOC_XXX ioctls and associated structures.

ok matthieu@

1 files changed, 103 insertions, 4 deletions

diff --git a/share/man/man4/vga.4 b/share/man/man4/vga.4
index c0c81b2a805..c0edf28a23e 100644
--- a/share/man/man4/vga.4
+++ b/share/man/man4/vga.4
@@ -1,4 +1,4 @@
-.\" $OpenBSD: vga.4,v 1.10 2005/05/04 05:05:32 jaredy Exp $
+.\" $OpenBSD: vga.4,v 1.11 2006/03/16 21:24:33 dim Exp $
 .\" $NetBSD: vga.4,v 1.2.4.1 2000/08/09 07:48:40 drochner Exp $
 .\"
 .\" Copyright (c) 1999, 2000
@@ -120,12 +120,110 @@ This is only useful with the
 screen types; a font containing the ASCII
 range of characters must be available too on this screen.
 .Pp
+.Sh AGP SUPPORT
 .Ic option PCIAGP
-enables support for the AGP GART programming through
+enables support for programming the AGP GART through
 .Xr ioctl 2 ,
-for use by
+which is used by
 .Xr Xorg 1
 on some architectures.
+.Pp
+The following
+.Xr ioctl 2
+operations can be performed on
+.Pa /dev/ttyC0 ,
+which are defined in
+.In sys/agpio.h :
+.Bl -tag -width indent
+.It Dv AGPIOC_INFO
+Returns information about the AGP subsystem.
+The result is a pointer to the following structure:
+.Bd -literal
+typedef struct _agp_info {
+	agp_version version;  /* version of driver (unused)   */
+	u_int32_t bridge_id;  /* bridge vendor/device         */
+	u_int32_t agp_mode;   /* mode info of bridge          */
+	off_t aper_base;      /* base of aperture             */
+	size_t aper_size;     /* size of aperture             */
+	size_t pg_total;      /* max pages (swap + system)    */
+	size_t pg_system;     /* max pages (system)           */
+	size_t pg_used;       /* current pages used           */
+} agp_info;
+.Ed
+.It Dv AGPIOC_ACQUIRE
+Acquire control of the AGP chipset for use by this client.
+Returns
+.Er EBUSY
+if the AGP chipset is already acquired by another client.
+.It Dv AGPIOC_RELEASE
+Release control of the AGP chipset.
+This does not unbind or free any allocated memory, which is the
+responsibility of the client to handle if necessary.
+.It Dv AGPIOC_SETUP
+Enable the AGP hardware with the relevant mode.
+This
+.Xr ioctl 2
+takes the following structure:
+.Bd -literal
+typedef struct _agp_setup {
+	u_int32_t agp_mode;   /* mode info of bridge */
+} agp_setup;
+.Ed
+.Pp
+The mode bits are defined in
+.In sys/agpio.h .
+.It Dv AGPIOC_ALLOCATE
+Allocate physical memory suitable for mapping into the AGP aperture.
+This
+.Xr ioctl 2
+takes the following structure:
+.Bd -literal
+typedef struct _agp_allocate {
+	int key;              /* tag of allocation            */
+	size_t pg_count;      /* number of pages              */
+	u_int32_t type;       /* 0 == normal, other devspec   */
+	u_int32_t physical;   /* device specific (some devices
+			       * need a phys address of the
+			       * actual page behind the gatt
+			       * table)                       */
+} agp_allocate;
+.Ed
+.Pp
+Returns a handle to the allocated memory.
+.It Dv AGPIOC_DEALLOCATE
+Free the previously allocated memory associated with the handle passed.
+.It Dv AGPIOC_BIND
+Bind the allocated memory at given offset with the AGP aperture.
+Returns
+.Er EINVAL
+if the memory is already bound or the offset is not at AGP page boundary.
+This
+.Xr ioctl 2
+takes the following structure:
+.Bd -literal
+typedef struct _agp_bind {
+	int key;         /* tag of allocation            */
+	off_t pg_start;  /* starting page to populate    */
+} agp_bind;
+.Ed
+.Pp
+The tag of allocation is the handle returned by
+.Dv AGPIOC_ALLOCATE .
+.It Dv AGPIOC_UNBIND
+Unbind memory from the AGP aperture.
+Returns
+.Er EINVAL
+if the memory is not bound.
+This
+.Xr ioctl 2
+takes the following structure:
+.Bd -literal
+typedef struct _agp_unbind {
+	int key;                /* tag of allocation         */
+	u_int32_t priority;     /* priority for paging out   */
+} agp_unbind;
+.Ed
+.El
 .Sh SEE ALSO
 .Xr intro 4 ,
 .Xr isa 4 ,
@@ -134,7 +232,8 @@ on some architectures.
 .Xr wscons 4 ,
 .Xr wsdisplay 4 ,
 .Xr wsconscfg 8 ,
-.Xr wsfontload 8
+.Xr wsfontload 8 ,
+.Xr ioctl 2
 .Sh BUGS
 Only a subset of the possible text modes is supported.
 .Pp