drivers/gpu/drm/nouveau/nouveau_dp.c

   1 /*
   2  * Copyright 2009 Red Hat Inc.
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
  18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  20  * OTHER DEALINGS IN THE SOFTWARE.
  21  *
  22  * Authors: Ben Skeggs
  23  */
  24
  25 #include <drm/drm_dp_helper.h>
  26
  27 #include "nouveau_drv.h"
  28 #include "nouveau_connector.h"
  29 #include "nouveau_encoder.h"
  30 #include "nouveau_crtc.h"
  31
  32 #include <nvif/class.h>
  33 #include <nvif/cl5070.h>
  34
  35 MODULE_PARM_DESC(mst, "Enable DisplayPort multi-stream (default: enabled)");
  36 static int nouveau_mst = 1;
  37 module_param_named(mst, nouveau_mst, int, 0400);
  38
  39 static bool
  40 nouveau_dp_has_sink_count(struct drm_connector *connector,
  41                           struct nouveau_encoder *outp)
  42 {
  43         return drm_dp_read_sink_count_cap(connector, outp->dp.dpcd, &outp->dp.desc);
  44 }
  45
  46 static enum drm_connector_status
  47 nouveau_dp_probe_dpcd(struct nouveau_connector *nv_connector,
  48                       struct nouveau_encoder *outp)
  49 {
  50         struct drm_connector *connector = &nv_connector->base;
  51         struct drm_dp_aux *aux = &nv_connector->aux;
  52         struct nv50_mstm *mstm = NULL;
  53         enum drm_connector_status status = connector_status_disconnected;
  54         int ret;
  55         u8 *dpcd = outp->dp.dpcd;
  56
  57         ret = drm_dp_read_dpcd_caps(aux, dpcd);
  58         if (ret < 0)
  59                 goto out;
  60
  61         ret = drm_dp_read_desc(aux, &outp->dp.desc, drm_dp_is_branch(dpcd));
  62         if (ret < 0)
  63                 goto out;
  64
  65         if (nouveau_mst) {
  66                 mstm = outp->dp.mstm;
  67                 if (mstm)
  68                         mstm->can_mst = drm_dp_read_mst_cap(aux, dpcd);
  69         }
  70
  71         if (nouveau_dp_has_sink_count(connector, outp)) {
  72                 ret = drm_dp_read_sink_count(aux);
  73                 if (ret < 0)
  74                         goto out;
  75
  76                 outp->dp.sink_count = ret;
  77
  78                 /*
  79                  * Dongle connected, but no display. Don't bother reading
  80                  * downstream port info
  81                  */
  82                 if (!outp->dp.sink_count)
  83                         return connector_status_disconnected;
  84         }
  85
  86         ret = drm_dp_read_downstream_info(aux, dpcd,
  87                                           outp->dp.downstream_ports);
  88         if (ret < 0)
  89                 goto out;
  90
  91         status = connector_status_connected;
  92 out:
  93         if (status != connector_status_connected) {
  94                 /* Clear any cached info */
  95                 outp->dp.sink_count = 0;
  96         }
  97         return status;
  98 }
  99
 100 int
 101 nouveau_dp_detect(struct nouveau_connector *nv_connector,
 102                   struct nouveau_encoder *nv_encoder)
 103 {
 104         struct drm_device *dev = nv_encoder->base.base.dev;
 105         struct nouveau_drm *drm = nouveau_drm(dev);
 106         struct drm_connector *connector = &nv_connector->base;
 107         struct nv50_mstm *mstm = nv_encoder->dp.mstm;
 108         enum drm_connector_status status;
 109         u8 *dpcd = nv_encoder->dp.dpcd;
 110         int ret = NOUVEAU_DP_NONE;
 111
 112         /* If we've already read the DPCD on an eDP device, we don't need to
 113          * reread it as it won't change
 114          */
 115         if (connector->connector_type == DRM_MODE_CONNECTOR_eDP &&
 116             dpcd[DP_DPCD_REV] != 0)
 117                 return NOUVEAU_DP_SST;
 118
 119         mutex_lock(&nv_encoder->dp.hpd_irq_lock);
 120         if (mstm) {
 121                 /* If we're not ready to handle MST state changes yet, just
 122                  * report the last status of the connector. We'll reprobe it
 123                  * once we've resumed.
 124                  */
 125                 if (mstm->suspended) {
 126                         if (mstm->is_mst)
 127                                 ret = NOUVEAU_DP_MST;
 128                         else if (connector->status ==
 129                                  connector_status_connected)
 130                                 ret = NOUVEAU_DP_SST;
 131
 132                         goto out;
 133                 }
 134         }
 135
 136         status = nouveau_dp_probe_dpcd(nv_connector, nv_encoder);
 137         if (status == connector_status_disconnected)
 138                 goto out;
 139
 140         /* If we're in MST mode, we're done here */
 141         if (mstm && mstm->can_mst && mstm->is_mst) {
 142                 ret = NOUVEAU_DP_MST;
 143                 goto out;
 144         }
 145
 146         nv_encoder->dp.link_bw = 27000 * dpcd[DP_MAX_LINK_RATE];
 147         nv_encoder->dp.link_nr =
 148                 dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;
 149
 150         NV_DEBUG(drm, "display: %dx%d dpcd 0x%02x\n",
 151                  nv_encoder->dp.link_nr, nv_encoder->dp.link_bw,
 152                  dpcd[DP_DPCD_REV]);
 153         NV_DEBUG(drm, "encoder: %dx%d\n",
 154                  nv_encoder->dcb->dpconf.link_nr,
 155                  nv_encoder->dcb->dpconf.link_bw);
 156
 157         if (nv_encoder->dcb->dpconf.link_nr < nv_encoder->dp.link_nr)
 158                 nv_encoder->dp.link_nr = nv_encoder->dcb->dpconf.link_nr;
 159         if (nv_encoder->dcb->dpconf.link_bw < nv_encoder->dp.link_bw)
 160                 nv_encoder->dp.link_bw = nv_encoder->dcb->dpconf.link_bw;
 161
 162         NV_DEBUG(drm, "maximum: %dx%d\n",
 163                  nv_encoder->dp.link_nr, nv_encoder->dp.link_bw);
 164
 165         if (mstm && mstm->can_mst) {
 166                 ret = nv50_mstm_detect(nv_encoder);
 167                 if (ret == 1) {
 168                         ret = NOUVEAU_DP_MST;
 169                         goto out;
 170                 } else if (ret != 0) {
 171                         goto out;
 172                 }
 173         }
 174         ret = NOUVEAU_DP_SST;
 175
 176 out:
 177         if (mstm && !mstm->suspended && ret != NOUVEAU_DP_MST)
 178                 nv50_mstm_remove(mstm);
 179
 180         mutex_unlock(&nv_encoder->dp.hpd_irq_lock);
 181         return ret;
 182 }
 183
 184 void nouveau_dp_irq(struct nouveau_drm *drm,
 185                     struct nouveau_connector *nv_connector)
 186 {
 187         struct drm_connector *connector = &nv_connector->base;
 188         struct nouveau_encoder *outp = find_encoder(connector, DCB_OUTPUT_DP);
 189         struct nv50_mstm *mstm;
 190         int ret;
 191         bool send_hpd = false;
 192
 193         if (!outp)
 194                 return;
 195
 196         mstm = outp->dp.mstm;
 197         NV_DEBUG(drm, "service %s\n", connector->name);
 198
 199         mutex_lock(&outp->dp.hpd_irq_lock);
 200
 201         if (mstm && mstm->is_mst) {
 202                 if (!nv50_mstm_service(drm, nv_connector, mstm))
 203                         send_hpd = true;
 204         } else {
 205                 drm_dp_cec_irq(&nv_connector->aux);
 206
 207                 if (nouveau_dp_has_sink_count(connector, outp)) {
 208                         ret = drm_dp_read_sink_count(&nv_connector->aux);
 209                         if (ret != outp->dp.sink_count)
 210                                 send_hpd = true;
 211                         if (ret >= 0)
 212                                 outp->dp.sink_count = ret;
 213                 }
 214         }
 215
 216         mutex_unlock(&outp->dp.hpd_irq_lock);
 217
 218         if (send_hpd)
 219                 nouveau_connector_hpd(connector);
 220 }
 221
 222 /* TODO:
 223  * - Use the minimum possible BPC here, once we add support for the max bpc
 224  *   property.
 225  * - Validate against the DP caps advertised by the GPU (we don't check these
 226  *   yet)
 227  */
 228 enum drm_mode_status
 229 nv50_dp_mode_valid(struct drm_connector *connector,
 230                    struct nouveau_encoder *outp,
 231                    const struct drm_display_mode *mode,
 232                    unsigned *out_clock)
 233 {
 234         const unsigned min_clock = 25000;
 235         unsigned max_clock, ds_clock, clock;
 236         enum drm_mode_status ret;
 237
 238         if (mode->flags & DRM_MODE_FLAG_INTERLACE && !outp->caps.dp_interlace)
 239                 return MODE_NO_INTERLACE;
 240
 241         max_clock = outp->dp.link_nr * outp->dp.link_bw;
 242         ds_clock = drm_dp_downstream_max_dotclock(outp->dp.dpcd,
 243                                                   outp->dp.downstream_ports);
 244         if (ds_clock)
 245                 max_clock = min(max_clock, ds_clock);
 246
 247         clock = mode->clock * (connector->display_info.bpc * 3) / 10;
 248         ret = nouveau_conn_mode_clock_valid(mode, min_clock, max_clock,
 249                                             &clock);
 250         if (out_clock)
 251                 *out_clock = clock;
 252         return ret;
 253 }