xref: /linux/drivers/gpu/drm/nouveau/nouveau_dp.c (revision 3932b9ca55b0be314a36d3e84faff3e823c081f5)
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_drm.h"
29 #include "nouveau_connector.h"
30 #include "nouveau_encoder.h"
31 #include "nouveau_crtc.h"
32 
33 static void
34 nouveau_dp_probe_oui(struct drm_device *dev, struct nouveau_i2c_port *auxch,
35 		     u8 *dpcd)
36 {
37 	struct nouveau_drm *drm = nouveau_drm(dev);
38 	u8 buf[3];
39 
40 	if (!(dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_OUI_SUPPORT))
41 		return;
42 
43 	if (!nv_rdaux(auxch, DP_SINK_OUI, buf, 3))
44 		NV_DEBUG(drm, "Sink OUI: %02hx%02hx%02hx\n",
45 			     buf[0], buf[1], buf[2]);
46 
47 	if (!nv_rdaux(auxch, DP_BRANCH_OUI, buf, 3))
48 		NV_DEBUG(drm, "Branch OUI: %02hx%02hx%02hx\n",
49 			     buf[0], buf[1], buf[2]);
50 
51 }
52 
53 int
54 nouveau_dp_detect(struct nouveau_encoder *nv_encoder)
55 {
56 	struct drm_device *dev = nv_encoder->base.base.dev;
57 	struct nouveau_drm *drm = nouveau_drm(dev);
58 	struct nouveau_i2c_port *auxch;
59 	u8 *dpcd = nv_encoder->dp.dpcd;
60 	int ret;
61 
62 	auxch = nv_encoder->i2c;
63 	if (!auxch)
64 		return -ENODEV;
65 
66 	ret = nv_rdaux(auxch, DP_DPCD_REV, dpcd, 8);
67 	if (ret)
68 		return ret;
69 
70 	nv_encoder->dp.link_bw = 27000 * dpcd[1];
71 	nv_encoder->dp.link_nr = dpcd[2] & DP_MAX_LANE_COUNT_MASK;
72 
73 	NV_DEBUG(drm, "display: %dx%d dpcd 0x%02x\n",
74 		     nv_encoder->dp.link_nr, nv_encoder->dp.link_bw, dpcd[0]);
75 	NV_DEBUG(drm, "encoder: %dx%d\n",
76 		     nv_encoder->dcb->dpconf.link_nr,
77 		     nv_encoder->dcb->dpconf.link_bw);
78 
79 	if (nv_encoder->dcb->dpconf.link_nr < nv_encoder->dp.link_nr)
80 		nv_encoder->dp.link_nr = nv_encoder->dcb->dpconf.link_nr;
81 	if (nv_encoder->dcb->dpconf.link_bw < nv_encoder->dp.link_bw)
82 		nv_encoder->dp.link_bw = nv_encoder->dcb->dpconf.link_bw;
83 
84 	NV_DEBUG(drm, "maximum: %dx%d\n",
85 		     nv_encoder->dp.link_nr, nv_encoder->dp.link_bw);
86 
87 	nouveau_dp_probe_oui(dev, auxch, dpcd);
88 	return 0;
89 }
90