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 void
40 nouveau_dp_probe_oui(struct drm_device *dev, struct nvkm_i2c_aux *aux, u8 *dpcd)
41 {
42 	struct nouveau_drm *drm = nouveau_drm(dev);
43 	u8 buf[3];
44 
45 	if (!(dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_OUI_SUPPORT))
46 		return;
47 
48 	if (!nvkm_rdaux(aux, DP_SINK_OUI, buf, 3))
49 		NV_DEBUG(drm, "Sink OUI: %02hx%02hx%02hx\n",
50 			     buf[0], buf[1], buf[2]);
51 
52 	if (!nvkm_rdaux(aux, DP_BRANCH_OUI, buf, 3))
53 		NV_DEBUG(drm, "Branch OUI: %02hx%02hx%02hx\n",
54 			     buf[0], buf[1], buf[2]);
55 
56 }
57 
58 int
59 nouveau_dp_detect(struct nouveau_encoder *nv_encoder)
60 {
61 	struct drm_device *dev = nv_encoder->base.base.dev;
62 	struct nouveau_drm *drm = nouveau_drm(dev);
63 	struct nvkm_i2c_aux *aux;
64 	u8 dpcd[8];
65 	int ret;
66 
67 	aux = nv_encoder->aux;
68 	if (!aux)
69 		return -ENODEV;
70 
71 	ret = nvkm_rdaux(aux, DP_DPCD_REV, dpcd, sizeof(dpcd));
72 	if (ret)
73 		return ret;
74 
75 	nv_encoder->dp.link_bw = 27000 * dpcd[1];
76 	nv_encoder->dp.link_nr = dpcd[2] & DP_MAX_LANE_COUNT_MASK;
77 
78 	NV_DEBUG(drm, "display: %dx%d dpcd 0x%02x\n",
79 		     nv_encoder->dp.link_nr, nv_encoder->dp.link_bw, dpcd[0]);
80 	NV_DEBUG(drm, "encoder: %dx%d\n",
81 		     nv_encoder->dcb->dpconf.link_nr,
82 		     nv_encoder->dcb->dpconf.link_bw);
83 
84 	if (nv_encoder->dcb->dpconf.link_nr < nv_encoder->dp.link_nr)
85 		nv_encoder->dp.link_nr = nv_encoder->dcb->dpconf.link_nr;
86 	if (nv_encoder->dcb->dpconf.link_bw < nv_encoder->dp.link_bw)
87 		nv_encoder->dp.link_bw = nv_encoder->dcb->dpconf.link_bw;
88 
89 	NV_DEBUG(drm, "maximum: %dx%d\n",
90 		     nv_encoder->dp.link_nr, nv_encoder->dp.link_bw);
91 
92 	nouveau_dp_probe_oui(dev, aux, dpcd);
93 
94 	ret = nv50_mstm_detect(nv_encoder->dp.mstm, dpcd, nouveau_mst);
95 	if (ret == 1)
96 		return NOUVEAU_DP_MST;
97 	if (ret == 0)
98 		return NOUVEAU_DP_SST;
99 	return ret;
100 }
101 
102 /* TODO:
103  * - Use the minimum possible BPC here, once we add support for the max bpc
104  *   property.
105  * - Validate the mode against downstream port caps (see
106  *   drm_dp_downstream_max_clock())
107  * - Validate against the DP caps advertised by the GPU (we don't check these
108  *   yet)
109  */
110 enum drm_mode_status
111 nv50_dp_mode_valid(struct drm_connector *connector,
112 		   struct nouveau_encoder *outp,
113 		   const struct drm_display_mode *mode,
114 		   unsigned *out_clock)
115 {
116 	const unsigned min_clock = 25000;
117 	unsigned max_clock, clock;
118 	enum drm_mode_status ret;
119 
120 	if (mode->flags & DRM_MODE_FLAG_INTERLACE && !outp->caps.dp_interlace)
121 		return MODE_NO_INTERLACE;
122 
123 	max_clock = outp->dp.link_nr * outp->dp.link_bw;
124 	clock = mode->clock * (connector->display_info.bpc * 3) / 10;
125 
126 	ret = nouveau_conn_mode_clock_valid(mode, min_clock, max_clock,
127 					    &clock);
128 	if (out_clock)
129 		*out_clock = clock;
130 	return ret;
131 }
132