1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2017-2020, The Linux Foundation. All rights reserved.
4 */
5
6#include <drm/drm_atomic_helper.h>
7#include <drm/drm_atomic.h>
8#include <drm/drm_bridge.h>
9#include <drm/drm_bridge_connector.h>
10#include <drm/drm_crtc.h>
11
12#include "msm_drv.h"
13#include "msm_kms.h"
14#include "dp_drm.h"
15
16/**
17 * dp_bridge_detect - callback to determine if connector is connected
18 * @bridge: Pointer to drm bridge structure
19 * Returns: Bridge's 'is connected' status
20 */
21static enum drm_connector_status dp_bridge_detect(struct drm_bridge *bridge)
22{
23	struct msm_dp *dp;
24
25	dp = to_dp_bridge(bridge)->dp_display;
26
27	drm_dbg_dp(dp->drm_dev, "link_ready = %s\n",
28		(dp->link_ready) ? "true" : "false");
29
30	return (dp->link_ready) ? connector_status_connected :
31					connector_status_disconnected;
32}
33
34static int dp_bridge_atomic_check(struct drm_bridge *bridge,
35			    struct drm_bridge_state *bridge_state,
36			    struct drm_crtc_state *crtc_state,
37			    struct drm_connector_state *conn_state)
38{
39	struct msm_dp *dp;
40
41	dp = to_dp_bridge(bridge)->dp_display;
42
43	drm_dbg_dp(dp->drm_dev, "link_ready = %s\n",
44		(dp->link_ready) ? "true" : "false");
45
46	/*
47	 * There is no protection in the DRM framework to check if the display
48	 * pipeline has been already disabled before trying to disable it again.
49	 * Hence if the sink is unplugged, the pipeline gets disabled, but the
50	 * crtc->active is still true. Any attempt to set the mode or manually
51	 * disable this encoder will result in the crash.
52	 *
53	 * TODO: add support for telling the DRM subsystem that the pipeline is
54	 * disabled by the hardware and thus all access to it should be forbidden.
55	 * After that this piece of code can be removed.
56	 */
57	if (bridge->ops & DRM_BRIDGE_OP_HPD)
58		return (dp->link_ready) ? 0 : -ENOTCONN;
59
60	return 0;
61}
62
63
64/**
65 * dp_bridge_get_modes - callback to add drm modes via drm_mode_probed_add()
66 * @bridge: Poiner to drm bridge
67 * @connector: Pointer to drm connector structure
68 * Returns: Number of modes added
69 */
70static int dp_bridge_get_modes(struct drm_bridge *bridge, struct drm_connector *connector)
71{
72	int rc = 0;
73	struct msm_dp *dp;
74
75	if (!connector)
76		return 0;
77
78	dp = to_dp_bridge(bridge)->dp_display;
79
80	/* pluggable case assumes EDID is read when HPD */
81	if (dp->link_ready) {
82		rc = dp_display_get_modes(dp);
83		if (rc <= 0) {
84			DRM_ERROR("failed to get DP sink modes, rc=%d\n", rc);
85			return rc;
86		}
87	} else {
88		drm_dbg_dp(connector->dev, "No sink connected\n");
89	}
90	return rc;
91}
92
93static void dp_bridge_debugfs_init(struct drm_bridge *bridge, struct dentry *root)
94{
95	struct msm_dp *dp = to_dp_bridge(bridge)->dp_display;
96
97	dp_display_debugfs_init(dp, root, false);
98}
99
100static const struct drm_bridge_funcs dp_bridge_ops = {
101	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
102	.atomic_destroy_state   = drm_atomic_helper_bridge_destroy_state,
103	.atomic_reset           = drm_atomic_helper_bridge_reset,
104	.atomic_enable          = dp_bridge_atomic_enable,
105	.atomic_disable         = dp_bridge_atomic_disable,
106	.atomic_post_disable    = dp_bridge_atomic_post_disable,
107	.mode_set     = dp_bridge_mode_set,
108	.mode_valid   = dp_bridge_mode_valid,
109	.get_modes    = dp_bridge_get_modes,
110	.detect       = dp_bridge_detect,
111	.atomic_check = dp_bridge_atomic_check,
112	.hpd_enable   = dp_bridge_hpd_enable,
113	.hpd_disable  = dp_bridge_hpd_disable,
114	.hpd_notify   = dp_bridge_hpd_notify,
115	.debugfs_init = dp_bridge_debugfs_init,
116};
117
118static int edp_bridge_atomic_check(struct drm_bridge *drm_bridge,
119				   struct drm_bridge_state *bridge_state,
120				   struct drm_crtc_state *crtc_state,
121				   struct drm_connector_state *conn_state)
122{
123	struct msm_dp *dp = to_dp_bridge(drm_bridge)->dp_display;
124
125	if (WARN_ON(!conn_state))
126		return -ENODEV;
127
128	conn_state->self_refresh_aware = dp->psr_supported;
129
130	if (!conn_state->crtc || !crtc_state)
131		return 0;
132
133	if (crtc_state->self_refresh_active && !dp->psr_supported)
134		return -EINVAL;
135
136	return 0;
137}
138
139static void edp_bridge_atomic_enable(struct drm_bridge *drm_bridge,
140				     struct drm_bridge_state *old_bridge_state)
141{
142	struct drm_atomic_state *atomic_state = old_bridge_state->base.state;
143	struct drm_crtc *crtc;
144	struct drm_crtc_state *old_crtc_state;
145	struct msm_dp_bridge *dp_bridge = to_dp_bridge(drm_bridge);
146	struct msm_dp *dp = dp_bridge->dp_display;
147
148	/*
149	 * Check the old state of the crtc to determine if the panel
150	 * was put into psr state previously by the edp_bridge_atomic_disable.
151	 * If the panel is in psr, just exit psr state and skip the full
152	 * bridge enable sequence.
153	 */
154	crtc = drm_atomic_get_new_crtc_for_encoder(atomic_state,
155						   drm_bridge->encoder);
156	if (!crtc)
157		return;
158
159	old_crtc_state = drm_atomic_get_old_crtc_state(atomic_state, crtc);
160
161	if (old_crtc_state && old_crtc_state->self_refresh_active) {
162		dp_display_set_psr(dp, false);
163		return;
164	}
165
166	dp_bridge_atomic_enable(drm_bridge, old_bridge_state);
167}
168
169static void edp_bridge_atomic_disable(struct drm_bridge *drm_bridge,
170				      struct drm_bridge_state *old_bridge_state)
171{
172	struct drm_atomic_state *atomic_state = old_bridge_state->base.state;
173	struct drm_crtc *crtc;
174	struct drm_crtc_state *new_crtc_state = NULL, *old_crtc_state = NULL;
175	struct msm_dp_bridge *dp_bridge = to_dp_bridge(drm_bridge);
176	struct msm_dp *dp = dp_bridge->dp_display;
177
178	crtc = drm_atomic_get_old_crtc_for_encoder(atomic_state,
179						   drm_bridge->encoder);
180	if (!crtc)
181		goto out;
182
183	new_crtc_state = drm_atomic_get_new_crtc_state(atomic_state, crtc);
184	if (!new_crtc_state)
185		goto out;
186
187	old_crtc_state = drm_atomic_get_old_crtc_state(atomic_state, crtc);
188	if (!old_crtc_state)
189		goto out;
190
191	/*
192	 * Set self refresh mode if current crtc state is active.
193	 *
194	 * If old crtc state is active, then this is a display disable
195	 * call while the sink is in psr state. So, exit psr here.
196	 * The eDP controller will be disabled in the
197	 * edp_bridge_atomic_post_disable function.
198	 *
199	 * We observed sink is stuck in self refresh if psr exit is skipped
200	 * when display disable occurs while the sink is in psr state.
201	 */
202	if (new_crtc_state->self_refresh_active) {
203		dp_display_set_psr(dp, true);
204		return;
205	} else if (old_crtc_state->self_refresh_active) {
206		dp_display_set_psr(dp, false);
207		return;
208	}
209
210out:
211	dp_bridge_atomic_disable(drm_bridge, old_bridge_state);
212}
213
214static void edp_bridge_atomic_post_disable(struct drm_bridge *drm_bridge,
215				struct drm_bridge_state *old_bridge_state)
216{
217	struct drm_atomic_state *atomic_state = old_bridge_state->base.state;
218	struct drm_crtc *crtc;
219	struct drm_crtc_state *new_crtc_state = NULL;
220
221	crtc = drm_atomic_get_old_crtc_for_encoder(atomic_state,
222						   drm_bridge->encoder);
223	if (!crtc)
224		return;
225
226	new_crtc_state = drm_atomic_get_new_crtc_state(atomic_state, crtc);
227	if (!new_crtc_state)
228		return;
229
230	/*
231	 * Self refresh mode is already set in edp_bridge_atomic_disable.
232	 */
233	if (new_crtc_state->self_refresh_active)
234		return;
235
236	dp_bridge_atomic_post_disable(drm_bridge, old_bridge_state);
237}
238
239/**
240 * edp_bridge_mode_valid - callback to determine if specified mode is valid
241 * @bridge: Pointer to drm bridge structure
242 * @info: display info
243 * @mode: Pointer to drm mode structure
244 * Returns: Validity status for specified mode
245 */
246static enum drm_mode_status edp_bridge_mode_valid(struct drm_bridge *bridge,
247					  const struct drm_display_info *info,
248					  const struct drm_display_mode *mode)
249{
250	struct msm_dp *dp;
251	int mode_pclk_khz = mode->clock;
252
253	dp = to_dp_bridge(bridge)->dp_display;
254
255	if (!dp || !mode_pclk_khz || !dp->connector) {
256		DRM_ERROR("invalid params\n");
257		return -EINVAL;
258	}
259
260	if (mode->clock > DP_MAX_PIXEL_CLK_KHZ)
261		return MODE_CLOCK_HIGH;
262
263	/*
264	 * The eDP controller currently does not have a reliable way of
265	 * enabling panel power to read sink capabilities. So, we rely
266	 * on the panel driver to populate only supported modes for now.
267	 */
268	return MODE_OK;
269}
270
271static void edp_bridge_debugfs_init(struct drm_bridge *bridge, struct dentry *root)
272{
273	struct msm_dp *dp = to_dp_bridge(bridge)->dp_display;
274
275	dp_display_debugfs_init(dp, root, true);
276}
277
278static const struct drm_bridge_funcs edp_bridge_ops = {
279	.atomic_enable = edp_bridge_atomic_enable,
280	.atomic_disable = edp_bridge_atomic_disable,
281	.atomic_post_disable = edp_bridge_atomic_post_disable,
282	.mode_set = dp_bridge_mode_set,
283	.mode_valid = edp_bridge_mode_valid,
284	.atomic_reset = drm_atomic_helper_bridge_reset,
285	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
286	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
287	.atomic_check = edp_bridge_atomic_check,
288	.debugfs_init = edp_bridge_debugfs_init,
289};
290
291int dp_bridge_init(struct msm_dp *dp_display, struct drm_device *dev,
292			struct drm_encoder *encoder)
293{
294	int rc;
295	struct msm_dp_bridge *dp_bridge;
296	struct drm_bridge *bridge;
297
298	dp_bridge = devm_kzalloc(dev->dev, sizeof(*dp_bridge), GFP_KERNEL);
299	if (!dp_bridge)
300		return -ENOMEM;
301
302	dp_bridge->dp_display = dp_display;
303
304	bridge = &dp_bridge->bridge;
305	bridge->funcs = dp_display->is_edp ? &edp_bridge_ops : &dp_bridge_ops;
306	bridge->type = dp_display->connector_type;
307
308	/*
309	 * Many ops only make sense for DP. Why?
310	 * - Detect/HPD are used by DRM to know if a display is _physically_
311	 *   there, not whether the display is powered on / finished initting.
312	 *   On eDP we assume the display is always there because you can't
313	 *   know until power is applied. If we don't implement the ops DRM will
314	 *   assume our display is always there.
315	 * - Currently eDP mode reading is driven by the panel driver. This
316	 *   allows the panel driver to properly power itself on to read the
317	 *   modes.
318	 */
319	if (!dp_display->is_edp) {
320		bridge->ops =
321			DRM_BRIDGE_OP_DETECT |
322			DRM_BRIDGE_OP_HPD |
323			DRM_BRIDGE_OP_MODES;
324	}
325
326	rc = devm_drm_bridge_add(dev->dev, bridge);
327	if (rc) {
328		DRM_ERROR("failed to add bridge, rc=%d\n", rc);
329
330		return rc;
331	}
332
333	rc = drm_bridge_attach(encoder, bridge, NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
334	if (rc) {
335		DRM_ERROR("failed to attach bridge, rc=%d\n", rc);
336
337		return rc;
338	}
339
340	if (dp_display->next_bridge) {
341		rc = drm_bridge_attach(encoder,
342					dp_display->next_bridge, bridge,
343					DRM_BRIDGE_ATTACH_NO_CONNECTOR);
344		if (rc < 0) {
345			DRM_ERROR("failed to attach panel bridge: %d\n", rc);
346			return rc;
347		}
348	}
349
350	dp_display->bridge = bridge;
351
352	return 0;
353}
354
355/* connector initialization */
356struct drm_connector *dp_drm_connector_init(struct msm_dp *dp_display, struct drm_encoder *encoder,
357					    bool yuv_supported)
358{
359	struct drm_connector *connector = NULL;
360
361	connector = drm_bridge_connector_init(dp_display->drm_dev, encoder);
362	if (IS_ERR(connector))
363		return connector;
364
365	if (!dp_display->is_edp)
366		drm_connector_attach_dp_subconnector_property(connector);
367
368	if (yuv_supported)
369		connector->ycbcr_420_allowed = true;
370
371	drm_connector_attach_encoder(connector, encoder);
372
373	return connector;
374}
375