'\" t .\" Title: drm_dp_dpcd_write .\" Author: .\" Generator: DocBook XSL Stylesheets v1.78.1 .\" Date: May 2018 .\" Manual: DRM Core .\" Source: Kernel Hackers Manual 3.16.56 .\" Language: English .\" .TH "DRM_DP_DPCD_WRITE" "9" "May 2018" "Kernel Hackers Manual 3\&.16\&" "DRM Core" .\" ----------------------------------------------------------------- .\" * Define some portability stuff .\" ----------------------------------------------------------------- .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .\" http://bugs.debian.org/507673 .\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" ----------------------------------------------------------------- .\" * set default formatting .\" ----------------------------------------------------------------- .\" disable hyphenation .nh .\" disable justification (adjust text to left margin only) .ad l .\" ----------------------------------------------------------------- .\" * MAIN CONTENT STARTS HERE * .\" ----------------------------------------------------------------- .SH "NAME" drm_dp_dpcd_write \- write a series of bytes to the DPCD .SH "SYNOPSIS" .HP \w'ssize_t\ drm_dp_dpcd_write('u .BI "ssize_t drm_dp_dpcd_write(struct\ drm_dp_aux\ *\ " "aux" ", unsigned\ int\ " "offset" ", void\ *\ " "buffer" ", size_t\ " "size" ");" .SH "ARGUMENTS" .PP \fIaux\fR .RS 4 DisplayPort AUX channel .RE .PP \fIoffset\fR .RS 4 address of the (first) register to write .RE .PP \fIbuffer\fR .RS 4 buffer containing the values to write .RE .PP \fIsize\fR .RS 4 number of bytes in \fIbuffer\fR .RE .SH "DESCRIPTION" .PP Returns the number of bytes transferred on success, or a negative error code on failure\&. \-EIO is returned if the request was NAKed by the sink or if the retry count was exceeded\&. If not all bytes were transferred, this function returns \-EPROTO\&. Errors from the underlying AUX channel transfer function, with the exception of \-EBUSY (which causes the transaction to be retried), are propagated to the caller\&. .SH "AUTHORS" .PP \fBJesse Barnes\fR <\&jesse.barnes@intel.com\&> .br Intel Corporation, .RS 4 Initial version .RE .PP \fBLaurent Pinchart\fR <\&laurent.pinchart@ideasonboard.com\&> .br Ideas on board SPRL, .RS 4 Driver internals .RE .PP \fBDaniel Vetter\fR <\&daniel.vetter@ffwll.ch\&> .br Intel Corporation, .RS 4 Contributions all over the place .RE .SH "COPYRIGHT" .br