Read a series of bytes from the dpcd
ssize_t drm_dp_dpcd_read(struct drm_dp_aux * aux, unsigned int offset, void * buffer, size_t size);
aux
DisplayPort AUX channel
offset
address of the (first) register to read
buffer
buffer to store the register values
size
number of bytes in buffer
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.
Jesse Barnes <[email protected]>
Intel Corporation,
Initial version
Laurent Pinchart <[email protected]>
Ideas on board SPRL,
Driver internals
Daniel Vetter <[email protected]>
Intel Corporation,
Contributions all over the place