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/drmP.h>
  26 #include <drm/drm_dp_helper.h>
  27
  28 #include "nouveau_drv.h"
  29 #include "nouveau_connector.h"
  30 #include "nouveau_encoder.h"
  31 #include "nouveau_crtc.h"
  32
  33 #include <nvif/class.h>
  34 #include <nvif/cl5070.h>
  35
  36 MODULE_PARM_DESC(mst, "Enable DisplayPort multi-stream (default: enabled)");
  37 static int nouveau_mst = 1;
  38 module_param_named(mst, nouveau_mst, int, 0400);
  39
  40 static void
  41 nouveau_dp_probe_oui(struct drm_device *dev, struct nvkm_i2c_aux *aux, u8 *dpcd)
  42 {
  43         struct nouveau_drm *drm = nouveau_drm(dev);
  44         u8 buf[3];
  45
  46         if (!(dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_OUI_SUPPORT))
  47                 return;
  48
  49         if (!nvkm_rdaux(aux, DP_SINK_OUI, buf, 3))
  50                 NV_DEBUG(drm, "Sink OUI: %02hx%02hx%02hx\n",
  51                              buf[0], buf[1], buf[2]);
  52
  53         if (!nvkm_rdaux(aux, DP_BRANCH_OUI, buf, 3))
  54                 NV_DEBUG(drm, "Branch OUI: %02hx%02hx%02hx\n",
  55                              buf[0], buf[1], buf[2]);
  56
  57 }
  58
  59 int
  60 nouveau_dp_detect(struct nouveau_encoder *nv_encoder)
  61 {
  62         struct drm_device *dev = nv_encoder->base.base.dev;
  63         struct nouveau_drm *drm = nouveau_drm(dev);
  64         struct nvkm_i2c_aux *aux;
  65         u8 dpcd[8];
  66         int ret;
  67
  68         aux = nv_encoder->aux;
  69         if (!aux)
  70                 return -ENODEV;
  71
  72         ret = nvkm_rdaux(aux, DP_DPCD_REV, dpcd, sizeof(dpcd));
  73         if (ret)
  74                 return ret;
  75
  76         nv_encoder->dp.link_bw = 27000 * dpcd[1];
  77         nv_encoder->dp.link_nr = dpcd[2] & DP_MAX_LANE_COUNT_MASK;
  78
  79         NV_DEBUG(drm, "display: %dx%d dpcd 0x%02x\n",
  80                      nv_encoder->dp.link_nr, nv_encoder->dp.link_bw, dpcd[0]);
  81         NV_DEBUG(drm, "encoder: %dx%d\n",
  82                      nv_encoder->dcb->dpconf.link_nr,
  83                      nv_encoder->dcb->dpconf.link_bw);
  84
  85         if (nv_encoder->dcb->dpconf.link_nr < nv_encoder->dp.link_nr)
  86                 nv_encoder->dp.link_nr = nv_encoder->dcb->dpconf.link_nr;
  87         if (nv_encoder->dcb->dpconf.link_bw < nv_encoder->dp.link_bw)
  88                 nv_encoder->dp.link_bw = nv_encoder->dcb->dpconf.link_bw;
  89
  90         NV_DEBUG(drm, "maximum: %dx%d\n",
  91                      nv_encoder->dp.link_nr, nv_encoder->dp.link_bw);
  92
  93         nouveau_dp_probe_oui(dev, aux, dpcd);
  94
  95         ret = nv50_mstm_detect(nv_encoder->dp.mstm, dpcd, nouveau_mst);
  96         if (ret == 1)
  97                 return NOUVEAU_DP_MST;
  98         if (ret == 0)
  99                 return NOUVEAU_DP_SST;
 100         return ret;
 101 }