drivers/gpu/drm/nouveau/nouveau_dp.c - linux - Git at Google

 /*
  * Copyright 2009 Red Hat Inc.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
  * to deal in the Software without restriction, including without limitation
  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  * and/or sell copies of the Software, and to permit persons to whom the
  * Software is furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  * OTHER DEALINGS IN THE SOFTWARE.
  *
  * Authors: Ben Skeggs
  */

 #include <drm/display/drm_dp_helper.h>

 #include "nouveau_drv.h"
 #include "nouveau_connector.h"
 #include "nouveau_encoder.h"
 #include "nouveau_crtc.h"

 #include <nvif/if0011.h>

 MODULE_PARM_DESC(mst, "Enable DisplayPort multi-stream (default: enabled)");
 static int nouveau_mst = 1;
 module_param_named(mst, nouveau_mst, int, 0400);

 static bool
 nouveau_dp_has_sink_count(struct drm_connector *connector,
 			  struct nouveau_encoder *outp)
 {
 	return drm_dp_read_sink_count_cap(connector, outp->dp.dpcd, &outp->dp.desc);
 }

 static enum drm_connector_status
 nouveau_dp_probe_dpcd(struct nouveau_connector *nv_connector,
 		      struct nouveau_encoder *outp)
 {
 	struct drm_connector *connector = &nv_connector->base;
 	struct drm_dp_aux *aux = &nv_connector->aux;
 	struct nv50_mstm *mstm = NULL;
 	enum drm_connector_status status = connector_status_disconnected;
 	int ret;
 	u8 *dpcd = outp->dp.dpcd;

 	ret = drm_dp_read_dpcd_caps(aux, dpcd);
 	if (ret < 0)
 		goto out;

 	ret = drm_dp_read_desc(aux, &outp->dp.desc, drm_dp_is_branch(dpcd));
 	if (ret < 0)
 		goto out;

 	if (nouveau_mst) {
 		mstm = outp->dp.mstm;
 		if (mstm)
 			mstm->can_mst = drm_dp_read_mst_cap(aux, dpcd);
 	}

 	if (nouveau_dp_has_sink_count(connector, outp)) {
 		ret = drm_dp_read_sink_count(aux);
 		if (ret < 0)
 			goto out;

 		outp->dp.sink_count = ret;

 		/*
 		 * Dongle connected, but no display. Don't bother reading
 		 * downstream port info
 		 */
 		if (!outp->dp.sink_count)
 			return connector_status_disconnected;
 	}

 	ret = drm_dp_read_downstream_info(aux, dpcd,
 					  outp->dp.downstream_ports);
 	if (ret < 0)
 		goto out;

 	status = connector_status_connected;
 out:
 	if (status != connector_status_connected) {
 		/* Clear any cached info */
 		outp->dp.sink_count = 0;
 	}
 	return status;
 }

 int
 nouveau_dp_detect(struct nouveau_connector *nv_connector,
 		  struct nouveau_encoder *nv_encoder)
 {
 	struct drm_device *dev = nv_encoder->base.base.dev;
 	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct drm_connector *connector = &nv_connector->base;
 	struct nv50_mstm *mstm = nv_encoder->dp.mstm;
 	enum drm_connector_status status;
 	u8 *dpcd = nv_encoder->dp.dpcd;
 	int ret = NOUVEAU_DP_NONE, hpd;

 	/* If we've already read the DPCD on an eDP device, we don't need to
 	 * reread it as it won't change
 	 */
 	if (connector->connector_type == DRM_MODE_CONNECTOR_eDP &&
 	    dpcd[DP_DPCD_REV] != 0)
 		return NOUVEAU_DP_SST;

 	mutex_lock(&nv_encoder->dp.hpd_irq_lock);
 	if (mstm) {
 		/* If we're not ready to handle MST state changes yet, just
 		 * report the last status of the connector. We'll reprobe it
 		 * once we've resumed.
 		 */
 		if (mstm->suspended) {
 			if (mstm->is_mst)
 				ret = NOUVEAU_DP_MST;
 			else if (connector->status ==
 				 connector_status_connected)
 				ret = NOUVEAU_DP_SST;

 			goto out;
 		}
 	}

 	/* Check status of HPD pin before attempting an AUX transaction that
 	 * would result in a number of (futile) retries on a connector which
 	 * has no display plugged.
 	 *
 	 * TODO: look into checking this before probing I2C to detect DVI/HDMI
 	 */
 	hpd = nvif_conn_hpd_status(&nv_connector->conn);
 	if (hpd == NVIF_CONN_HPD_STATUS_NOT_PRESENT) {
 		nvif_outp_dp_aux_pwr(&nv_encoder->outp, false);
 		goto out;
 	}
 	nvif_outp_dp_aux_pwr(&nv_encoder->outp, true);

 	status = nouveau_dp_probe_dpcd(nv_connector, nv_encoder);
 	if (status == connector_status_disconnected) {
 		nvif_outp_dp_aux_pwr(&nv_encoder->outp, false);
 		goto out;
 	}

 	/* If we're in MST mode, we're done here */
 	if (mstm && mstm->can_mst && mstm->is_mst) {
 		ret = NOUVEAU_DP_MST;
 		goto out;
 	}

 	nv_encoder->dp.link_bw = 27000 * dpcd[DP_MAX_LINK_RATE];
 	nv_encoder->dp.link_nr =
 		dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;

 	if (connector->connector_type == DRM_MODE_CONNECTOR_eDP && dpcd[DP_DPCD_REV] >= 0x13) {
 		struct drm_dp_aux *aux = &nv_connector->aux;
 		int ret, i;
 		u8 sink_rates[16];

 		ret = drm_dp_dpcd_read(aux, DP_SUPPORTED_LINK_RATES, sink_rates, sizeof(sink_rates));
 		if (ret == sizeof(sink_rates)) {
 			for (i = 0; i < ARRAY_SIZE(sink_rates); i += 2) {
 				int val = ((sink_rates[i + 1] << 8) | sink_rates[i]) * 200 / 10;
 				if (val && (i == 0 || val > nv_encoder->dp.link_bw))
 					nv_encoder->dp.link_bw = val;
 			}
 		}
 	}

 	NV_DEBUG(drm, "display: %dx%d dpcd 0x%02x\n",
 		 nv_encoder->dp.link_nr, nv_encoder->dp.link_bw,
 		 dpcd[DP_DPCD_REV]);
 	NV_DEBUG(drm, "encoder: %dx%d\n",
 		 nv_encoder->dcb->dpconf.link_nr,
 		 nv_encoder->dcb->dpconf.link_bw);

 	if (nv_encoder->dcb->dpconf.link_nr < nv_encoder->dp.link_nr)
 		nv_encoder->dp.link_nr = nv_encoder->dcb->dpconf.link_nr;
 	if (nv_encoder->dcb->dpconf.link_bw < nv_encoder->dp.link_bw)
 		nv_encoder->dp.link_bw = nv_encoder->dcb->dpconf.link_bw;

 	NV_DEBUG(drm, "maximum: %dx%d\n",
 		 nv_encoder->dp.link_nr, nv_encoder->dp.link_bw);

 	if (mstm && mstm->can_mst) {
 		ret = nv50_mstm_detect(nv_encoder);
 		if (ret == 1) {
 			ret = NOUVEAU_DP_MST;
 			goto out;
 		} else if (ret != 0) {
 			nvif_outp_dp_aux_pwr(&nv_encoder->outp, false);
 			goto out;
 		}
 	}
 	ret = NOUVEAU_DP_SST;

 out:
 	if (mstm && !mstm->suspended && ret != NOUVEAU_DP_MST)
 		nv50_mstm_remove(mstm);

 	mutex_unlock(&nv_encoder->dp.hpd_irq_lock);
 	return ret;
 }

 bool
 nouveau_dp_link_check(struct nouveau_connector *nv_connector)
 {
 	struct nouveau_encoder *nv_encoder = find_encoder(&nv_connector->base, DCB_OUTPUT_DP);

 	if (!nv_encoder || nv_encoder->outp.or.id < 0)
 		return true;

 	return nvif_outp_dp_retrain(&nv_encoder->outp) == 0;
 }

 void
 nouveau_dp_irq(struct work_struct *work)
 {
 	struct nouveau_connector *nv_connector =
 		container_of(work, typeof(*nv_connector), irq_work);
 	struct drm_connector *connector = &nv_connector->base;
 	struct nouveau_encoder *outp = find_encoder(connector, DCB_OUTPUT_DP);
 	struct nouveau_drm *drm = nouveau_drm(outp->base.base.dev);
 	struct nv50_mstm *mstm;
 	u64 hpd = 0;
 	int ret;

 	if (!outp)
 		return;

 	mstm = outp->dp.mstm;
 	NV_DEBUG(drm, "service %s\n", connector->name);

 	mutex_lock(&outp->dp.hpd_irq_lock);

 	if (mstm && mstm->is_mst) {
 		if (!nv50_mstm_service(drm, nv_connector, mstm))
 			hpd |= NVIF_CONN_EVENT_V0_UNPLUG;
 	} else {
 		drm_dp_cec_irq(&nv_connector->aux);

 		if (nouveau_dp_has_sink_count(connector, outp)) {
 			ret = drm_dp_read_sink_count(&nv_connector->aux);
 			if (ret != outp->dp.sink_count)
 				hpd |= NVIF_CONN_EVENT_V0_PLUG;
 			if (ret >= 0)
 				outp->dp.sink_count = ret;
 		}
 	}

 	mutex_unlock(&outp->dp.hpd_irq_lock);

 	nouveau_connector_hpd(nv_connector, NVIF_CONN_EVENT_V0_IRQ | hpd);
 }

 /* TODO:
  * - Validate against the DP caps advertised by the GPU (we don't check these
  *   yet)
  */
 enum drm_mode_status
 nv50_dp_mode_valid(struct drm_connector *connector,
 		   struct nouveau_encoder *outp,
 		   const struct drm_display_mode *mode,
 		   unsigned *out_clock)
 {
 	const unsigned int min_clock = 25000;
 	unsigned int max_rate, mode_rate, ds_max_dotclock, clock = mode->clock;
 	/* Check with the minmum bpc always, so we can advertise better modes.
 	 * In particlar not doing this causes modes to be dropped on HDR
 	 * displays as we might check with a bpc of 16 even.
 	 */
 	const u8 bpp = 6 * 3;

 	if (mode->flags & DRM_MODE_FLAG_INTERLACE && !outp->caps.dp_interlace)
 		return MODE_NO_INTERLACE;

 	if ((mode->flags & DRM_MODE_FLAG_3D_MASK) == DRM_MODE_FLAG_3D_FRAME_PACKING)
 		clock *= 2;

 	max_rate = outp->dp.link_nr * outp->dp.link_bw;
 	mode_rate = DIV_ROUND_UP(clock * bpp, 8);
 	if (mode_rate > max_rate)
 		return MODE_CLOCK_HIGH;

 	ds_max_dotclock = drm_dp_downstream_max_dotclock(outp->dp.dpcd, outp->dp.downstream_ports);
 	if (ds_max_dotclock && clock > ds_max_dotclock)
 		return MODE_CLOCK_HIGH;

 	if (clock < min_clock)
 		return MODE_CLOCK_LOW;

 	if (out_clock)
 		*out_clock = clock;

 	return MODE_OK;
 }
	/*
	* Copyright 2009 Red Hat Inc.
	*
	* Permission is hereby granted, free of charge, to any person obtaining a
	* copy of this software and associated documentation files (the "Software"),
	* to deal in the Software without restriction, including without limitation
	* the rights to use, copy, modify, merge, publish, distribute, sublicense,
	* and/or sell copies of the Software, and to permit persons to whom the
	* Software is furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
	* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
	* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
	* OTHER DEALINGS IN THE SOFTWARE.
	*
	* Authors: Ben Skeggs
	*/

	#include <drm/display/drm_dp_helper.h>

	#include "nouveau_drv.h"
	#include "nouveau_connector.h"
	#include "nouveau_encoder.h"
	#include "nouveau_crtc.h"

	#include <nvif/if0011.h>

	MODULE_PARM_DESC(mst, "Enable DisplayPort multi-stream (default: enabled)");
	static int nouveau_mst = 1;
	module_param_named(mst, nouveau_mst, int, 0400);

	static bool
	nouveau_dp_has_sink_count(struct drm_connector *connector,
	struct nouveau_encoder *outp)
	{
	return drm_dp_read_sink_count_cap(connector, outp->dp.dpcd, &outp->dp.desc);
	}

	static enum drm_connector_status
	nouveau_dp_probe_dpcd(struct nouveau_connector *nv_connector,
	struct nouveau_encoder *outp)
	{
	struct drm_connector *connector = &nv_connector->base;
	struct drm_dp_aux *aux = &nv_connector->aux;
	struct nv50_mstm *mstm = NULL;
	enum drm_connector_status status = connector_status_disconnected;
	int ret;
	u8 *dpcd = outp->dp.dpcd;

	ret = drm_dp_read_dpcd_caps(aux, dpcd);
	if (ret < 0)
	goto out;

	ret = drm_dp_read_desc(aux, &outp->dp.desc, drm_dp_is_branch(dpcd));
	if (ret < 0)
	goto out;

	if (nouveau_mst) {
	mstm = outp->dp.mstm;
	if (mstm)
	mstm->can_mst = drm_dp_read_mst_cap(aux, dpcd);
	}

	if (nouveau_dp_has_sink_count(connector, outp)) {
	ret = drm_dp_read_sink_count(aux);
	if (ret < 0)
	goto out;

	outp->dp.sink_count = ret;

	/*
	* Dongle connected, but no display. Don't bother reading
	* downstream port info
	*/
	if (!outp->dp.sink_count)
	return connector_status_disconnected;
	}

	ret = drm_dp_read_downstream_info(aux, dpcd,
	outp->dp.downstream_ports);
	if (ret < 0)
	goto out;

	status = connector_status_connected;
	out:
	if (status != connector_status_connected) {
	/* Clear any cached info */
	outp->dp.sink_count = 0;
	}
	return status;
	}

	int
	nouveau_dp_detect(struct nouveau_connector *nv_connector,
	struct nouveau_encoder *nv_encoder)
	{
	struct drm_device *dev = nv_encoder->base.base.dev;
	struct nouveau_drm *drm = nouveau_drm(dev);
	struct drm_connector *connector = &nv_connector->base;
	struct nv50_mstm *mstm = nv_encoder->dp.mstm;
	enum drm_connector_status status;
	u8 *dpcd = nv_encoder->dp.dpcd;
	int ret = NOUVEAU_DP_NONE, hpd;

	/* If we've already read the DPCD on an eDP device, we don't need to
	* reread it as it won't change
	*/
	if (connector->connector_type == DRM_MODE_CONNECTOR_eDP &&
	dpcd[DP_DPCD_REV] != 0)
	return NOUVEAU_DP_SST;

	mutex_lock(&nv_encoder->dp.hpd_irq_lock);
	if (mstm) {
	/* If we're not ready to handle MST state changes yet, just
	* report the last status of the connector. We'll reprobe it
	* once we've resumed.
	*/
	if (mstm->suspended) {
	if (mstm->is_mst)
	ret = NOUVEAU_DP_MST;
	else if (connector->status ==
	connector_status_connected)
	ret = NOUVEAU_DP_SST;

	goto out;
	}
	}

	/* Check status of HPD pin before attempting an AUX transaction that
	* would result in a number of (futile) retries on a connector which
	* has no display plugged.
	*
	* TODO: look into checking this before probing I2C to detect DVI/HDMI
	*/
	hpd = nvif_conn_hpd_status(&nv_connector->conn);
	if (hpd == NVIF_CONN_HPD_STATUS_NOT_PRESENT) {
	nvif_outp_dp_aux_pwr(&nv_encoder->outp, false);
	goto out;
	}
	nvif_outp_dp_aux_pwr(&nv_encoder->outp, true);

	status = nouveau_dp_probe_dpcd(nv_connector, nv_encoder);
	if (status == connector_status_disconnected) {
	nvif_outp_dp_aux_pwr(&nv_encoder->outp, false);
	goto out;
	}

	/* If we're in MST mode, we're done here */
	if (mstm && mstm->can_mst && mstm->is_mst) {
	ret = NOUVEAU_DP_MST;
	goto out;
	}

	nv_encoder->dp.link_bw = 27000 * dpcd[DP_MAX_LINK_RATE];
	nv_encoder->dp.link_nr =
	dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;

	if (connector->connector_type == DRM_MODE_CONNECTOR_eDP && dpcd[DP_DPCD_REV] >= 0x13) {
	struct drm_dp_aux *aux = &nv_connector->aux;
	int ret, i;
	u8 sink_rates[16];

	ret = drm_dp_dpcd_read(aux, DP_SUPPORTED_LINK_RATES, sink_rates, sizeof(sink_rates));
	if (ret == sizeof(sink_rates)) {
	for (i = 0; i < ARRAY_SIZE(sink_rates); i += 2) {
	int val = ((sink_rates[i + 1] << 8) \| sink_rates[i]) * 200 / 10;
	if (val && (i == 0 \|\| val > nv_encoder->dp.link_bw))
	nv_encoder->dp.link_bw = val;
	}
	}
	}

	NV_DEBUG(drm, "display: %dx%d dpcd 0x%02x\n",
	nv_encoder->dp.link_nr, nv_encoder->dp.link_bw,
	dpcd[DP_DPCD_REV]);
	NV_DEBUG(drm, "encoder: %dx%d\n",
	nv_encoder->dcb->dpconf.link_nr,
	nv_encoder->dcb->dpconf.link_bw);

	if (nv_encoder->dcb->dpconf.link_nr < nv_encoder->dp.link_nr)
	nv_encoder->dp.link_nr = nv_encoder->dcb->dpconf.link_nr;
	if (nv_encoder->dcb->dpconf.link_bw < nv_encoder->dp.link_bw)
	nv_encoder->dp.link_bw = nv_encoder->dcb->dpconf.link_bw;

	NV_DEBUG(drm, "maximum: %dx%d\n",
	nv_encoder->dp.link_nr, nv_encoder->dp.link_bw);

	if (mstm && mstm->can_mst) {
	ret = nv50_mstm_detect(nv_encoder);
	if (ret == 1) {
	ret = NOUVEAU_DP_MST;
	goto out;
	} else if (ret != 0) {
	nvif_outp_dp_aux_pwr(&nv_encoder->outp, false);
	goto out;
	}
	}
	ret = NOUVEAU_DP_SST;

	out:
	if (mstm && !mstm->suspended && ret != NOUVEAU_DP_MST)
	nv50_mstm_remove(mstm);

	mutex_unlock(&nv_encoder->dp.hpd_irq_lock);
	return ret;
	}

	bool
	nouveau_dp_link_check(struct nouveau_connector *nv_connector)
	{
	struct nouveau_encoder *nv_encoder = find_encoder(&nv_connector->base, DCB_OUTPUT_DP);

	if (!nv_encoder \|\| nv_encoder->outp.or.id < 0)
	return true;

	return nvif_outp_dp_retrain(&nv_encoder->outp) == 0;
	}

	void
	nouveau_dp_irq(struct work_struct *work)
	{
	struct nouveau_connector *nv_connector =
	container_of(work, typeof(*nv_connector), irq_work);
	struct drm_connector *connector = &nv_connector->base;
	struct nouveau_encoder *outp = find_encoder(connector, DCB_OUTPUT_DP);
	struct nouveau_drm *drm = nouveau_drm(outp->base.base.dev);
	struct nv50_mstm *mstm;
	u64 hpd = 0;
	int ret;

	if (!outp)
	return;

	mstm = outp->dp.mstm;
	NV_DEBUG(drm, "service %s\n", connector->name);

	mutex_lock(&outp->dp.hpd_irq_lock);

	if (mstm && mstm->is_mst) {
	if (!nv50_mstm_service(drm, nv_connector, mstm))
	hpd \|= NVIF_CONN_EVENT_V0_UNPLUG;
	} else {
	drm_dp_cec_irq(&nv_connector->aux);

	if (nouveau_dp_has_sink_count(connector, outp)) {
	ret = drm_dp_read_sink_count(&nv_connector->aux);
	if (ret != outp->dp.sink_count)
	hpd \|= NVIF_CONN_EVENT_V0_PLUG;
	if (ret >= 0)
	outp->dp.sink_count = ret;
	}
	}

	mutex_unlock(&outp->dp.hpd_irq_lock);

	nouveau_connector_hpd(nv_connector, NVIF_CONN_EVENT_V0_IRQ \| hpd);
	}

	/* TODO:
	* - Validate against the DP caps advertised by the GPU (we don't check these
	* yet)
	*/
	enum drm_mode_status
	nv50_dp_mode_valid(struct drm_connector *connector,
	struct nouveau_encoder *outp,
	const struct drm_display_mode *mode,
	unsigned *out_clock)
	{
	const unsigned int min_clock = 25000;
	unsigned int max_rate, mode_rate, ds_max_dotclock, clock = mode->clock;
	/* Check with the minmum bpc always, so we can advertise better modes.
	* In particlar not doing this causes modes to be dropped on HDR
	* displays as we might check with a bpc of 16 even.
	*/
	const u8 bpp = 6 * 3;

	if (mode->flags & DRM_MODE_FLAG_INTERLACE && !outp->caps.dp_interlace)
	return MODE_NO_INTERLACE;

	if ((mode->flags & DRM_MODE_FLAG_3D_MASK) == DRM_MODE_FLAG_3D_FRAME_PACKING)
	clock *= 2;

	max_rate = outp->dp.link_nr * outp->dp.link_bw;
	mode_rate = DIV_ROUND_UP(clock * bpp, 8);
	if (mode_rate > max_rate)
	return MODE_CLOCK_HIGH;

	ds_max_dotclock = drm_dp_downstream_max_dotclock(outp->dp.dpcd, outp->dp.downstream_ports);
	if (ds_max_dotclock && clock > ds_max_dotclock)
	return MODE_CLOCK_HIGH;

	if (clock < min_clock)
	return MODE_CLOCK_LOW;

	if (out_clock)
	*out_clock = clock;

	return MODE_OK;
	}