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_dpcd_read(aux, DP_DPCD_REV, dpcd, DP_RECEIVER_CAP_SIZE);
  58         if (ret == DP_RECEIVER_CAP_SIZE && dpcd[DP_DPCD_REV]) {
  59                 ret = drm_dp_read_desc(aux, &outp->dp.desc,
  60                                        drm_dp_is_branch(dpcd));
  61                 if (ret < 0)
  62                         goto out;
  63         } else {
  64                 goto out;
  65         }
  66
  67         if (nouveau_mst) {
  68                 mstm = outp->dp.mstm;
  69                 if (mstm)
  70                         mstm->can_mst = drm_dp_read_mst_cap(aux, dpcd);
  71         }
  72
  73         if (nouveau_dp_has_sink_count(connector, outp)) {
  74                 ret = drm_dp_read_sink_count(aux);
  75                 if (ret < 0)
  76                         goto out;
  77
  78                 outp->dp.sink_count = ret;
  79
  80                 /*
  81                  * Dongle connected, but no display. Don't bother reading
  82                  * downstream port info
  83                  */
  84                 if (!outp->dp.sink_count)
  85                         return connector_status_disconnected;
  86         }
  87
  88         ret = drm_dp_read_downstream_info(aux, dpcd,
  89                                           outp->dp.downstream_ports);
  90         if (ret < 0)
  91                 goto out;
  92
  93         status = connector_status_connected;
  94 out:
  95         if (status != connector_status_connected) {
  96                 /* Clear any cached info */
  97                 outp->dp.sink_count = 0;
  98         }
  99         return status;
 100 }
 101
 102 int
 103 nouveau_dp_detect(struct nouveau_connector *nv_connector,
 104                   struct nouveau_encoder *nv_encoder)
 105 {
 106         struct drm_device *dev = nv_encoder->base.base.dev;
 107         struct nouveau_drm *drm = nouveau_drm(dev);
 108         struct drm_connector *connector = &nv_connector->base;
 109         struct nv50_mstm *mstm = nv_encoder->dp.mstm;
 110         enum drm_connector_status status;
 111         u8 *dpcd = nv_encoder->dp.dpcd;
 112         int ret = NOUVEAU_DP_NONE;
 113
 114         /* If we've already read the DPCD on an eDP device, we don't need to
 115          * reread it as it won't change
 116          */
 117         if (connector->connector_type == DRM_MODE_CONNECTOR_eDP &&
 118             dpcd[DP_DPCD_REV] != 0)
 119                 return NOUVEAU_DP_SST;
 120
 121         mutex_lock(&nv_encoder->dp.hpd_irq_lock);
 122         if (mstm) {
 123                 /* If we're not ready to handle MST state changes yet, just
 124                  * report the last status of the connector. We'll reprobe it
 125                  * once we've resumed.
 126                  */
 127                 if (mstm->suspended) {
 128                         if (mstm->is_mst)
 129                                 ret = NOUVEAU_DP_MST;
 130                         else if (connector->status ==
 131                                  connector_status_connected)
 132                                 ret = NOUVEAU_DP_SST;
 133
 134                         goto out;
 135                 }
 136         }
 137
 138         status = nouveau_dp_probe_dpcd(nv_connector, nv_encoder);
 139         if (status == connector_status_disconnected)
 140                 goto out;
 141
 142         /* If we're in MST mode, we're done here */
 143         if (mstm && mstm->can_mst && mstm->is_mst) {
 144                 ret = NOUVEAU_DP_MST;
 145                 goto out;
 146         }
 147
 148         nv_encoder->dp.link_bw = 27000 * dpcd[DP_MAX_LINK_RATE];
 149         nv_encoder->dp.link_nr =
 150                 dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;
 151
 152         NV_DEBUG(drm, "display: %dx%d dpcd 0x%02x\n",
 153                  nv_encoder->dp.link_nr, nv_encoder->dp.link_bw,
 154                  dpcd[DP_DPCD_REV]);
 155         NV_DEBUG(drm, "encoder: %dx%d\n",
 156                  nv_encoder->dcb->dpconf.link_nr,
 157                  nv_encoder->dcb->dpconf.link_bw);
 158
 159         if (nv_encoder->dcb->dpconf.link_nr < nv_encoder->dp.link_nr)
 160                 nv_encoder->dp.link_nr = nv_encoder->dcb->dpconf.link_nr;
 161         if (nv_encoder->dcb->dpconf.link_bw < nv_encoder->dp.link_bw)
 162                 nv_encoder->dp.link_bw = nv_encoder->dcb->dpconf.link_bw;
 163
 164         NV_DEBUG(drm, "maximum: %dx%d\n",
 165                  nv_encoder->dp.link_nr, nv_encoder->dp.link_bw);
 166
 167         if (mstm && mstm->can_mst) {
 168                 ret = nv50_mstm_detect(nv_encoder);
 169                 if (ret == 1) {
 170                         ret = NOUVEAU_DP_MST;
 171                         goto out;
 172                 } else if (ret != 0) {
 173                         goto out;
 174                 }
 175         }
 176         ret = NOUVEAU_DP_SST;
 177
 178 out:
 179         if (mstm && !mstm->suspended && ret != NOUVEAU_DP_MST)
 180                 nv50_mstm_remove(mstm);
 181
 182         mutex_unlock(&nv_encoder->dp.hpd_irq_lock);
 183         return ret;
 184 }
 185
 186 void nouveau_dp_irq(struct nouveau_drm *drm,
 187                     struct nouveau_connector *nv_connector)
 188 {
 189         struct drm_connector *connector = &nv_connector->base;
 190         struct nouveau_encoder *outp = find_encoder(connector, DCB_OUTPUT_DP);
 191         struct nv50_mstm *mstm;
 192         int ret;
 193         bool send_hpd = false;
 194
 195         if (!outp)
 196                 return;
 197
 198         mstm = outp->dp.mstm;
 199         NV_DEBUG(drm, "service %s\n", connector->name);
 200
 201         mutex_lock(&outp->dp.hpd_irq_lock);
 202
 203         if (mstm && mstm->is_mst) {
 204                 if (!nv50_mstm_service(drm, nv_connector, mstm))
 205                         send_hpd = true;
 206         } else {
 207                 drm_dp_cec_irq(&nv_connector->aux);
 208
 209                 if (nouveau_dp_has_sink_count(connector, outp)) {
 210                         ret = drm_dp_read_sink_count(&nv_connector->aux);
 211                         if (ret != outp->dp.sink_count)
 212                                 send_hpd = true;
 213                         if (ret >= 0)
 214                                 outp->dp.sink_count = ret;
 215                 }
 216         }
 217
 218         mutex_unlock(&outp->dp.hpd_irq_lock);
 219
 220         if (send_hpd)
 221                 nouveau_connector_hpd(connector);
 222 }
 223
 224 /* TODO:
 225  * - Use the minimum possible BPC here, once we add support for the max bpc
 226  *   property.
 227  * - Validate against the DP caps advertised by the GPU (we don't check these
 228  *   yet)
 229  */
 230 enum drm_mode_status
 231 nv50_dp_mode_valid(struct drm_connector *connector,
 232                    struct nouveau_encoder *outp,
 233                    const struct drm_display_mode *mode,
 234                    unsigned *out_clock)
 235 {
 236         const unsigned min_clock = 25000;
 237         unsigned max_clock, ds_clock, clock;
 238         enum drm_mode_status ret;
 239
 240         if (mode->flags & DRM_MODE_FLAG_INTERLACE && !outp->caps.dp_interlace)
 241                 return MODE_NO_INTERLACE;
 242
 243         max_clock = outp->dp.link_nr * outp->dp.link_bw;
 244         ds_clock = drm_dp_downstream_max_clock(outp->dp.dpcd,
 245                                                outp->dp.downstream_ports);
 246         if (ds_clock)
 247                 max_clock = min(max_clock, ds_clock);
 248
 249         clock = mode->clock * (connector->display_info.bpc * 3) / 10;
 250         ret = nouveau_conn_mode_clock_valid(mode, min_clock, max_clock,
 251                                             &clock);
 252         if (out_clock)
 253                 *out_clock = clock;
 254         return ret;
 255 }