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/display/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/if0011.h>
33 
34 MODULE_PARM_DESC(mst, "Enable DisplayPort multi-stream (default: enabled)");
35 static int nouveau_mst = 1;
36 module_param_named(mst, nouveau_mst, int, 0400);
37 
38 static bool
39 nouveau_dp_has_sink_count(struct drm_connector *connector,
40 			  struct nouveau_encoder *outp)
41 {
42 	return drm_dp_read_sink_count_cap(connector, outp->dp.dpcd, &outp->dp.desc);
43 }
44 
45 static enum drm_connector_status
46 nouveau_dp_probe_dpcd(struct nouveau_connector *nv_connector,
47 		      struct nouveau_encoder *outp)
48 {
49 	struct drm_connector *connector = &nv_connector->base;
50 	struct drm_dp_aux *aux = &nv_connector->aux;
51 	struct nv50_mstm *mstm = NULL;
52 	enum drm_connector_status status = connector_status_disconnected;
53 	int ret;
54 	u8 *dpcd = outp->dp.dpcd;
55 
56 	ret = drm_dp_read_dpcd_caps(aux, dpcd);
57 	if (ret < 0)
58 		goto out;
59 
60 	ret = drm_dp_read_desc(aux, &outp->dp.desc, drm_dp_is_branch(dpcd));
61 	if (ret < 0)
62 		goto out;
63 
64 	if (nouveau_mst) {
65 		mstm = outp->dp.mstm;
66 		if (mstm)
67 			mstm->can_mst = drm_dp_read_mst_cap(aux, dpcd);
68 	}
69 
70 	if (nouveau_dp_has_sink_count(connector, outp)) {
71 		ret = drm_dp_read_sink_count(aux);
72 		if (ret < 0)
73 			goto out;
74 
75 		outp->dp.sink_count = ret;
76 
77 		/*
78 		 * Dongle connected, but no display. Don't bother reading
79 		 * downstream port info
80 		 */
81 		if (!outp->dp.sink_count)
82 			return connector_status_disconnected;
83 	}
84 
85 	ret = drm_dp_read_downstream_info(aux, dpcd,
86 					  outp->dp.downstream_ports);
87 	if (ret < 0)
88 		goto out;
89 
90 	status = connector_status_connected;
91 out:
92 	if (status != connector_status_connected) {
93 		/* Clear any cached info */
94 		outp->dp.sink_count = 0;
95 	}
96 	return status;
97 }
98 
99 int
100 nouveau_dp_detect(struct nouveau_connector *nv_connector,
101 		  struct nouveau_encoder *nv_encoder)
102 {
103 	struct drm_device *dev = nv_encoder->base.base.dev;
104 	struct nouveau_drm *drm = nouveau_drm(dev);
105 	struct drm_connector *connector = &nv_connector->base;
106 	struct nv50_mstm *mstm = nv_encoder->dp.mstm;
107 	enum drm_connector_status status;
108 	u8 *dpcd = nv_encoder->dp.dpcd;
109 	int ret = NOUVEAU_DP_NONE, hpd;
110 
111 	/* If we've already read the DPCD on an eDP device, we don't need to
112 	 * reread it as it won't change
113 	 */
114 	if (connector->connector_type == DRM_MODE_CONNECTOR_eDP &&
115 	    dpcd[DP_DPCD_REV] != 0)
116 		return NOUVEAU_DP_SST;
117 
118 	mutex_lock(&nv_encoder->dp.hpd_irq_lock);
119 	if (mstm) {
120 		/* If we're not ready to handle MST state changes yet, just
121 		 * report the last status of the connector. We'll reprobe it
122 		 * once we've resumed.
123 		 */
124 		if (mstm->suspended) {
125 			if (mstm->is_mst)
126 				ret = NOUVEAU_DP_MST;
127 			else if (connector->status ==
128 				 connector_status_connected)
129 				ret = NOUVEAU_DP_SST;
130 
131 			goto out;
132 		}
133 	}
134 
135 	/* Check status of HPD pin before attempting an AUX transaction that
136 	 * would result in a number of (futile) retries on a connector which
137 	 * has no display plugged.
138 	 *
139 	 * TODO: look into checking this before probing I2C to detect DVI/HDMI
140 	 */
141 	hpd = nvif_conn_hpd_status(&nv_connector->conn);
142 	if (hpd == NVIF_CONN_HPD_STATUS_NOT_PRESENT) {
143 		nvif_outp_dp_aux_pwr(&nv_encoder->outp, false);
144 		goto out;
145 	}
146 	nvif_outp_dp_aux_pwr(&nv_encoder->outp, true);
147 
148 	status = nouveau_dp_probe_dpcd(nv_connector, nv_encoder);
149 	if (status == connector_status_disconnected) {
150 		nvif_outp_dp_aux_pwr(&nv_encoder->outp, false);
151 		goto out;
152 	}
153 
154 	/* If we're in MST mode, we're done here */
155 	if (mstm && mstm->can_mst && mstm->is_mst) {
156 		ret = NOUVEAU_DP_MST;
157 		goto out;
158 	}
159 
160 	nv_encoder->dp.link_bw = 27000 * dpcd[DP_MAX_LINK_RATE];
161 	nv_encoder->dp.link_nr =
162 		dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;
163 
164 	if (connector->connector_type == DRM_MODE_CONNECTOR_eDP && dpcd[DP_DPCD_REV] >= 0x13) {
165 		struct drm_dp_aux *aux = &nv_connector->aux;
166 		int ret, i;
167 		u8 sink_rates[16];
168 
169 		ret = drm_dp_dpcd_read(aux, DP_SUPPORTED_LINK_RATES, sink_rates, sizeof(sink_rates));
170 		if (ret == sizeof(sink_rates)) {
171 			for (i = 0; i < ARRAY_SIZE(sink_rates); i += 2) {
172 				int val = ((sink_rates[i + 1] << 8) | sink_rates[i]) * 200 / 10;
173 				if (val && (i == 0 || val > nv_encoder->dp.link_bw))
174 					nv_encoder->dp.link_bw = val;
175 			}
176 		}
177 	}
178 
179 	NV_DEBUG(drm, "display: %dx%d dpcd 0x%02x\n",
180 		 nv_encoder->dp.link_nr, nv_encoder->dp.link_bw,
181 		 dpcd[DP_DPCD_REV]);
182 	NV_DEBUG(drm, "encoder: %dx%d\n",
183 		 nv_encoder->dcb->dpconf.link_nr,
184 		 nv_encoder->dcb->dpconf.link_bw);
185 
186 	if (nv_encoder->dcb->dpconf.link_nr < nv_encoder->dp.link_nr)
187 		nv_encoder->dp.link_nr = nv_encoder->dcb->dpconf.link_nr;
188 	if (nv_encoder->dcb->dpconf.link_bw < nv_encoder->dp.link_bw)
189 		nv_encoder->dp.link_bw = nv_encoder->dcb->dpconf.link_bw;
190 
191 	NV_DEBUG(drm, "maximum: %dx%d\n",
192 		 nv_encoder->dp.link_nr, nv_encoder->dp.link_bw);
193 
194 	if (mstm && mstm->can_mst) {
195 		ret = nv50_mstm_detect(nv_encoder);
196 		if (ret == 1) {
197 			ret = NOUVEAU_DP_MST;
198 			goto out;
199 		} else if (ret != 0) {
200 			nvif_outp_dp_aux_pwr(&nv_encoder->outp, false);
201 			goto out;
202 		}
203 	}
204 	ret = NOUVEAU_DP_SST;
205 
206 out:
207 	if (mstm && !mstm->suspended && ret != NOUVEAU_DP_MST)
208 		nv50_mstm_remove(mstm);
209 
210 	mutex_unlock(&nv_encoder->dp.hpd_irq_lock);
211 	return ret;
212 }
213 
214 bool
215 nouveau_dp_link_check(struct nouveau_connector *nv_connector)
216 {
217 	struct nouveau_encoder *nv_encoder = find_encoder(&nv_connector->base, DCB_OUTPUT_DP);
218 
219 	if (!nv_encoder || nv_encoder->outp.or.id < 0)
220 		return true;
221 
222 	return nvif_outp_dp_retrain(&nv_encoder->outp) == 0;
223 }
224 
225 void
226 nouveau_dp_irq(struct work_struct *work)
227 {
228 	struct nouveau_connector *nv_connector =
229 		container_of(work, typeof(*nv_connector), irq_work);
230 	struct drm_connector *connector = &nv_connector->base;
231 	struct nouveau_encoder *outp = find_encoder(connector, DCB_OUTPUT_DP);
232 	struct nouveau_drm *drm = nouveau_drm(outp->base.base.dev);
233 	struct nv50_mstm *mstm;
234 	u64 hpd = 0;
235 	int ret;
236 
237 	if (!outp)
238 		return;
239 
240 	mstm = outp->dp.mstm;
241 	NV_DEBUG(drm, "service %s\n", connector->name);
242 
243 	mutex_lock(&outp->dp.hpd_irq_lock);
244 
245 	if (mstm && mstm->is_mst) {
246 		if (!nv50_mstm_service(drm, nv_connector, mstm))
247 			hpd |= NVIF_CONN_EVENT_V0_UNPLUG;
248 	} else {
249 		drm_dp_cec_irq(&nv_connector->aux);
250 
251 		if (nouveau_dp_has_sink_count(connector, outp)) {
252 			ret = drm_dp_read_sink_count(&nv_connector->aux);
253 			if (ret != outp->dp.sink_count)
254 				hpd |= NVIF_CONN_EVENT_V0_PLUG;
255 			if (ret >= 0)
256 				outp->dp.sink_count = ret;
257 		}
258 	}
259 
260 	mutex_unlock(&outp->dp.hpd_irq_lock);
261 
262 	nouveau_connector_hpd(nv_connector, NVIF_CONN_EVENT_V0_IRQ | hpd);
263 }
264 
265 /* TODO:
266  * - Validate against the DP caps advertised by the GPU (we don't check these
267  *   yet)
268  */
269 enum drm_mode_status
270 nv50_dp_mode_valid(struct drm_connector *connector,
271 		   struct nouveau_encoder *outp,
272 		   const struct drm_display_mode *mode,
273 		   unsigned *out_clock)
274 {
275 	const unsigned int min_clock = 25000;
276 	unsigned int max_rate, mode_rate, ds_max_dotclock, clock = mode->clock;
277 	/* Check with the minmum bpc always, so we can advertise better modes.
278 	 * In particlar not doing this causes modes to be dropped on HDR
279 	 * displays as we might check with a bpc of 16 even.
280 	 */
281 	const u8 bpp = 6 * 3;
282 
283 	if (mode->flags & DRM_MODE_FLAG_INTERLACE && !outp->caps.dp_interlace)
284 		return MODE_NO_INTERLACE;
285 
286 	if ((mode->flags & DRM_MODE_FLAG_3D_MASK) == DRM_MODE_FLAG_3D_FRAME_PACKING)
287 		clock *= 2;
288 
289 	max_rate = outp->dp.link_nr * outp->dp.link_bw;
290 	mode_rate = DIV_ROUND_UP(clock * bpp, 8);
291 	if (mode_rate > max_rate)
292 		return MODE_CLOCK_HIGH;
293 
294 	ds_max_dotclock = drm_dp_downstream_max_dotclock(outp->dp.dpcd, outp->dp.downstream_ports);
295 	if (ds_max_dotclock && clock > ds_max_dotclock)
296 		return MODE_CLOCK_HIGH;
297 
298 	if (clock < min_clock)
299 		return MODE_CLOCK_LOW;
300 
301 	if (out_clock)
302 		*out_clock = clock;
303 
304 	return MODE_OK;
305 }
306