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
34MODULE_PARM_DESC(mst, "Enable DisplayPort multi-stream (default: enabled)");
35static int nouveau_mst = 1;
36module_param_named(mst, nouveau_mst, int, 0400);
37
38static bool
39nouveau_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
45static enum drm_connector_status
46nouveau_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;
91out:
92	if (status != connector_status_connected) {
93		/* Clear any cached info */
94		outp->dp.sink_count = 0;
95	}
96	return status;
97}
98
99int
100nouveau_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
206out:
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
214bool
215nouveau_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
225void
226nouveau_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 */
269enum drm_mode_status
270nv50_dp_mode_valid(struct nouveau_encoder *outp,
271		   const struct drm_display_mode *mode,
272		   unsigned *out_clock)
273{
274	const unsigned int min_clock = 25000;
275	unsigned int max_rate, mode_rate, ds_max_dotclock, clock = mode->clock;
276	/* Check with the minmum bpc always, so we can advertise better modes.
277	 * In particlar not doing this causes modes to be dropped on HDR
278	 * displays as we might check with a bpc of 16 even.
279	 */
280	const u8 bpp = 6 * 3;
281
282	if (mode->flags & DRM_MODE_FLAG_INTERLACE && !outp->caps.dp_interlace)
283		return MODE_NO_INTERLACE;
284
285	if ((mode->flags & DRM_MODE_FLAG_3D_MASK) == DRM_MODE_FLAG_3D_FRAME_PACKING)
286		clock *= 2;
287
288	max_rate = outp->dp.link_nr * outp->dp.link_bw;
289	mode_rate = DIV_ROUND_UP(clock * bpp, 8);
290	if (mode_rate > max_rate)
291		return MODE_CLOCK_HIGH;
292
293	ds_max_dotclock = drm_dp_downstream_max_dotclock(outp->dp.dpcd, outp->dp.downstream_ports);
294	if (ds_max_dotclock && clock > ds_max_dotclock)
295		return MODE_CLOCK_HIGH;
296
297	if (clock < min_clock)
298		return MODE_CLOCK_LOW;
299
300	if (out_clock)
301		*out_clock = clock;
302
303	return MODE_OK;
304}
305