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Diffstat (limited to 'static/netbsd/man9/ddc.9')
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diff --git a/static/netbsd/man9/ddc.9 b/static/netbsd/man9/ddc.9 new file mode 100644 index 00000000..f1c02071 --- /dev/null +++ b/static/netbsd/man9/ddc.9 @@ -0,0 +1,110 @@ +.\" $NetBSD: ddc.9,v 1.8 2017/07/03 21:28:48 wiz Exp $ +.\" +.\" Copyright 2006 Itronix Inc. +.\" All rights reserved. +.\" +.\" Written by Garrett D'Amore for Itronix Inc. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. The name of Intronix Inc. may not be used to endorse +.\" or promote products derived from this software without specific prior +.\" written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY INTRONIX INC. ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED +.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR +.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL ITRONIX INC. BE LIABLE FOR ANY +.\" DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR +.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF +.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN +.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) +.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +.\" POSSIBILITY OF SUCH DAMAGE. +.\" +.Dd May 11, 2006 +.Dt DDC 9 +.Os +.Sh NAME +.Nm ddc +.Nd VESA Display Data Channel V2 +.Sh SYNOPSIS +.In dev/i2c/ddcvar.h +.Ft int +.Fo ddc_read_edid +.Fa "i2c_tag_t tag" +.Fa "uint8_t *dest" +.Fa "size_t len" +.Fc +.Sh DESCRIPTION +The +.Fn ddc_read_edid +reads a VESA Extended Display Identification Data block (EDID) via +VESA Display Data Channel (DDCv2). +DDCv2 is a protocol for data exchange between display devices (such +as monitors and flat panels) and host machines using an I2C bus. +.Pp +The +.Fa tag +argument is a machine-dependent tag used to specify the I2C +bus on which the DDCv2 device is located. +The +.Fa dest +argument is a pointer to a buffer where the EDID data will be stored. +The +.Fa len +argument is the amount of data to read into the buffer. +(The buffer must be large enough.) +Typically, this value will be 128, which is the size of a normal +EDID data block. +.Pp +Normally the EDID data block will be post-processed with the +.Fn edid_parse +function. +.Sh RETURN VALUES +The +.Fn ddc_read_edid +function returns zero on success, and non-zero otherwise. +.Sh ENVIRONMENT +The +.Fn ddc_read_edid +function is part of the +.Xr ddc 4 +driver, and is only included in the kernel if that driver is also included. +.Sh EXAMPLES +The following code uses +.Fn ddc_read_edid +to retrieve and print information about a monitor: +.Pp +.Bd -literal -compact + struct edid_info info; + i2c_tag_t tag; + char buffer[128]; + + ... + /* initialize i2c tag... */ + ... + if ((ddc_read_edid(tag, buffer, 128) == 0) && + (edid_parse(buffer, &info) == 0)) + edid_print(info); + ... +.Ed +.Pp +Note that this must be called before the PCI bus is attached during +autoconfiguration. +.Sh SEE ALSO +.Xr ddc 4 , +.Xr edid 9 , +.Xr iic 9 +.Sh HISTORY +DDCv2 support was added in +.Nx 4.0 . +.Sh AUTHORS +.An Garrett D'Amore Aq Mt gdamore@NetBSD.org |