xref: /netbsd-src/sys/external/bsd/drm2/dist/drm/nouveau/nouveau_dp.c (revision 41ec02673d281bbb3d38e6c78504ce6e30c228c1)
1 /*	$NetBSD: nouveau_dp.c,v 1.4 2021/12/18 23:45:32 riastradh Exp $	*/
2 
3 /*
4  * Copyright 2009 Red Hat Inc.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the "Software"),
8  * to deal in the Software without restriction, including without limitation
9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10  * and/or sell copies of the Software, and to permit persons to whom the
11  * Software is furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22  * OTHER DEALINGS IN THE SOFTWARE.
23  *
24  * Authors: Ben Skeggs
25  */
26 
27 #include <sys/cdefs.h>
28 __KERNEL_RCSID(0, "$NetBSD: nouveau_dp.c,v 1.4 2021/12/18 23:45:32 riastradh Exp $");
29 
30 #include <drm/drm_dp_helper.h>
31 
32 #include "nouveau_drv.h"
33 #include "nouveau_connector.h"
34 #include "nouveau_encoder.h"
35 #include "nouveau_crtc.h"
36 
37 #include <nvif/class.h>
38 #include <nvif/cl5070.h>
39 
40 MODULE_PARM_DESC(mst, "Enable DisplayPort multi-stream (default: enabled)");
41 static int nouveau_mst = 1;
42 module_param_named(mst, nouveau_mst, int, 0400);
43 
44 static void
nouveau_dp_probe_oui(struct drm_device * dev,struct nvkm_i2c_aux * aux,u8 * dpcd)45 nouveau_dp_probe_oui(struct drm_device *dev, struct nvkm_i2c_aux *aux, u8 *dpcd)
46 {
47 	struct nouveau_drm *drm = nouveau_drm(dev);
48 	u8 buf[3];
49 
50 	if (!(dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_OUI_SUPPORT))
51 		return;
52 
53 	if (!nvkm_rdaux(aux, DP_SINK_OUI, buf, 3))
54 		NV_DEBUG(drm, "Sink OUI: %02"PRIx8"%02"PRIx8"%02"PRIx8"\n",
55 			     buf[0], buf[1], buf[2]);
56 
57 	if (!nvkm_rdaux(aux, DP_BRANCH_OUI, buf, 3))
58 		NV_DEBUG(drm, "Branch OUI: %02"PRIx8"%02"PRIx8"%02"PRIx8"\n",
59 			     buf[0], buf[1], buf[2]);
60 
61 }
62 
63 int
nouveau_dp_detect(struct nouveau_encoder * nv_encoder)64 nouveau_dp_detect(struct nouveau_encoder *nv_encoder)
65 {
66 	struct drm_device *dev = nv_encoder->base.base.dev;
67 	struct nouveau_drm *drm = nouveau_drm(dev);
68 	struct nvkm_i2c_aux *aux;
69 	u8 dpcd[8];
70 	int ret;
71 
72 	aux = nv_encoder->aux;
73 	if (!aux)
74 		return -ENODEV;
75 
76 	ret = nvkm_rdaux(aux, DP_DPCD_REV, dpcd, sizeof(dpcd));
77 	if (ret)
78 		return ret;
79 
80 	nv_encoder->dp.link_bw = 27000 * dpcd[1];
81 	nv_encoder->dp.link_nr = dpcd[2] & DP_MAX_LANE_COUNT_MASK;
82 
83 	NV_DEBUG(drm, "display: %dx%d dpcd 0x%02x\n",
84 		     nv_encoder->dp.link_nr, nv_encoder->dp.link_bw, dpcd[0]);
85 	NV_DEBUG(drm, "encoder: %dx%d\n",
86 		     nv_encoder->dcb->dpconf.link_nr,
87 		     nv_encoder->dcb->dpconf.link_bw);
88 
89 	if (nv_encoder->dcb->dpconf.link_nr < nv_encoder->dp.link_nr)
90 		nv_encoder->dp.link_nr = nv_encoder->dcb->dpconf.link_nr;
91 	if (nv_encoder->dcb->dpconf.link_bw < nv_encoder->dp.link_bw)
92 		nv_encoder->dp.link_bw = nv_encoder->dcb->dpconf.link_bw;
93 
94 	NV_DEBUG(drm, "maximum: %dx%d\n",
95 		     nv_encoder->dp.link_nr, nv_encoder->dp.link_bw);
96 
97 	nouveau_dp_probe_oui(dev, aux, dpcd);
98 
99 	ret = nv50_mstm_detect(nv_encoder->dp.mstm, dpcd, nouveau_mst);
100 	if (ret == 1)
101 		return NOUVEAU_DP_MST;
102 	if (ret == 0)
103 		return NOUVEAU_DP_SST;
104 	return ret;
105 }
106