Commit 2f221a5e authored by David Francis's avatar David Francis Committed by Alex Deucher
Browse files

drm/dp_mst: Add MST support to DP DPCD R/W functions 



Instead of having drm_dp_dpcd_read/write and
drm_dp_mst_dpcd_read/write as entry points into the
aux code, have drm_dp_dpcd_read/write handle both.

This means that DRM drivers can make MST DPCD read/writes.

v2: Fix spacing
v3: Dump dpcd access on MST read/writes
v4: Fix calling wrong function on DPCD write
v5: delete deprecated include of drmP.h

Reviewed-by: default avatarLyude Paul <lyude@redhat.com>
Reviewed-by: default avatarHarry Wentland <harry.wentland@amd.com>
Signed-off-by: default avatarDavid Francis <David.Francis@amd.com>
Signed-off-by: default avatarMikita Lipski <mikita.lipski@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent a3c2b0ff

drivers/gpu/drm/drm_dp_aux_dev.c

+2 −10
Original line number Diff line number Diff line
@@ -163,10 +163,6 @@ static ssize_t auxdev_read_iter(struct kiocb *iocb, struct iov_iter *to) 
			break;

		}



		if (aux_dev->aux->is_remote)

			res = drm_dp_mst_dpcd_read(aux_dev->aux, pos, buf,

						   todo);

		else

		res = drm_dp_dpcd_read(aux_dev->aux, pos, buf, todo);



		if (res <= 0)
@@ -215,10 +211,6 @@ static ssize_t auxdev_write_iter(struct kiocb *iocb, struct iov_iter *from) 
			break;

		}



		if (aux_dev->aux->is_remote)

			res = drm_dp_mst_dpcd_write(aux_dev->aux, pos, buf,

						    todo);

		else

		res = drm_dp_dpcd_write(aux_dev->aux, pos, buf, todo);



		if (res <= 0)

drivers/gpu/drm/drm_dp_helper.c

+20 −10
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ 
#include <drm/drm_dp_helper.h>

#include <drm/drm_print.h>

#include <drm/drm_vblank.h>

#include <drm/drm_dp_mst_helper.h>



#include "drm_crtc_helper_internal.h"
@@ -266,7 +267,7 @@ unlock: 


/**

 * drm_dp_dpcd_read() - read a series of bytes from the DPCD

 * @aux: DisplayPort AUX channel

 * @aux: DisplayPort AUX channel (SST or MST)

 * @offset: address of the (first) register to read

 * @buffer: buffer to store the register values

 * @size: number of bytes in @buffer
@@ -295,13 +296,18 @@ ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset, 
	 * We just have to do it before any DPCD access and hope that the

	 * monitor doesn't power down exactly after the throw away read.

	 */

	ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, DP_DPCD_REV, buffer,

				 1);

	if (!aux->is_remote) {

		ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, DP_DPCD_REV,

					 buffer, 1);

		if (ret != 1)

			goto out;

	}



	ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, offset, buffer,

				 size);

	if (aux->is_remote)

		ret = drm_dp_mst_dpcd_read(aux, offset, buffer, size);

	else

		ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, offset,

					 buffer, size);



out:

	drm_dp_dump_access(aux, DP_AUX_NATIVE_READ, offset, buffer, ret);
@@ -311,7 +317,7 @@ EXPORT_SYMBOL(drm_dp_dpcd_read); 


/**

 * drm_dp_dpcd_write() - write a series of bytes to the DPCD

 * @aux: DisplayPort AUX channel

 * @aux: DisplayPort AUX channel (SST or MST)

 * @offset: address of the (first) register to write

 * @buffer: buffer containing the values to write

 * @size: number of bytes in @buffer
@@ -328,8 +334,12 @@ ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset, 
{

	int ret;



	ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_WRITE, offset, buffer,

				 size);

	if (aux->is_remote)

		ret = drm_dp_mst_dpcd_write(aux, offset, buffer, size);

	else

		ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_WRITE, offset,

					 buffer, size);



	drm_dp_dump_access(aux, DP_AUX_NATIVE_WRITE, offset, buffer, ret);

	return ret;

}

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