1 /*
2  * Copyright (C) 2017 The Linux Foundation. All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms of the GNU General Public License version 2 as published by
6  * the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * You should have received a copy of the GNU General Public License along with
14  * this program.  If not, see <http://www.gnu.org/licenses/>.
15  */
16 
17 #include "mdp5_kms.h"
18 
19 /*
20  * As of now, there are only 2 combinations possible for source split:
21  *
22  * Left | Right
23  * -----|------
24  *  LM0 | LM1
25  *  LM2 | LM5
26  *
27  */
28 static int lm_right_pair[] = { 1, -1, 5, -1, -1, -1 };
29 
30 static int get_right_pair_idx(struct mdp5_kms *mdp5_kms, int lm)
31 {
32 	int i;
33 	int pair_lm;
34 
35 	pair_lm = lm_right_pair[lm];
36 	if (pair_lm < 0)
37 		return -EINVAL;
38 
39 	for (i = 0; i < mdp5_kms->num_hwmixers; i++) {
40 		struct mdp5_hw_mixer *mixer = mdp5_kms->hwmixers[i];
41 
42 		if (mixer->lm == pair_lm)
43 			return mixer->idx;
44 	}
45 
46 	return -1;
47 }
48 
49 int mdp5_mixer_assign(struct drm_atomic_state *s, struct drm_crtc *crtc,
50 		      uint32_t caps, struct mdp5_hw_mixer **mixer,
51 		      struct mdp5_hw_mixer **r_mixer)
52 {
53 	struct msm_drm_private *priv = s->dev->dev_private;
54 	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms));
55 	struct mdp5_global_state *global_state = mdp5_get_global_state(s);
56 	struct mdp5_hw_mixer_state *new_state;
57 	int i;
58 
59 	if (IS_ERR(global_state))
60 		return PTR_ERR(global_state);
61 
62 	new_state = &global_state->hwmixer;
63 
64 	for (i = 0; i < mdp5_kms->num_hwmixers; i++) {
65 		struct mdp5_hw_mixer *cur = mdp5_kms->hwmixers[i];
66 
67 		/*
68 		 * skip if already in-use by a different CRTC. If there is a
69 		 * mixer already assigned to this CRTC, it means this call is
70 		 * a request to get an additional right mixer. Assume that the
71 		 * existing mixer is the 'left' one, and try to see if we can
72 		 * get its corresponding 'right' pair.
73 		 */
74 		if (new_state->hwmixer_to_crtc[cur->idx] &&
75 		    new_state->hwmixer_to_crtc[cur->idx] != crtc)
76 			continue;
77 
78 		/* skip if doesn't support some required caps: */
79 		if (caps & ~cur->caps)
80 			continue;
81 
82 		if (r_mixer) {
83 			int pair_idx;
84 
85 			pair_idx = get_right_pair_idx(mdp5_kms, cur->lm);
86 			if (pair_idx < 0)
87 				return -EINVAL;
88 
89 			if (new_state->hwmixer_to_crtc[pair_idx])
90 				continue;
91 
92 			*r_mixer = mdp5_kms->hwmixers[pair_idx];
93 		}
94 
95 		/*
96 		 * prefer a pair-able LM over an unpairable one. We can
97 		 * switch the CRTC from Normal mode to Source Split mode
98 		 * without requiring a full modeset if we had already
99 		 * assigned this CRTC a pair-able LM.
100 		 *
101 		 * TODO: There will be assignment sequences which would
102 		 * result in the CRTC requiring a full modeset, even
103 		 * if we have the LM resources to prevent it. For a platform
104 		 * with a few displays, we don't run out of pair-able LMs
105 		 * so easily. For now, ignore the possibility of requiring
106 		 * a full modeset.
107 		 */
108 		if (!(*mixer) || cur->caps & MDP_LM_CAP_PAIR)
109 			*mixer = cur;
110 	}
111 
112 	if (!(*mixer))
113 		return -ENOMEM;
114 
115 	if (r_mixer && !(*r_mixer))
116 		return -ENOMEM;
117 
118 	DBG("assigning Layer Mixer %d to crtc %s", (*mixer)->lm, crtc->name);
119 
120 	new_state->hwmixer_to_crtc[(*mixer)->idx] = crtc;
121 	if (r_mixer) {
122 		DBG("assigning Right Layer Mixer %d to crtc %s", (*r_mixer)->lm,
123 		    crtc->name);
124 		new_state->hwmixer_to_crtc[(*r_mixer)->idx] = crtc;
125 	}
126 
127 	return 0;
128 }
129 
130 void mdp5_mixer_release(struct drm_atomic_state *s, struct mdp5_hw_mixer *mixer)
131 {
132 	struct mdp5_global_state *global_state = mdp5_get_global_state(s);
133 	struct mdp5_hw_mixer_state *new_state = &global_state->hwmixer;
134 
135 	if (!mixer)
136 		return;
137 
138 	if (WARN_ON(!new_state->hwmixer_to_crtc[mixer->idx]))
139 		return;
140 
141 	DBG("%s: release from crtc %s", mixer->name,
142 	    new_state->hwmixer_to_crtc[mixer->idx]->name);
143 
144 	new_state->hwmixer_to_crtc[mixer->idx] = NULL;
145 }
146 
147 void mdp5_mixer_destroy(struct mdp5_hw_mixer *mixer)
148 {
149 	kfree(mixer);
150 }
151 
152 static const char * const mixer_names[] = {
153 	"LM0", "LM1", "LM2", "LM3", "LM4", "LM5",
154 };
155 
156 struct mdp5_hw_mixer *mdp5_mixer_init(const struct mdp5_lm_instance *lm)
157 {
158 	struct mdp5_hw_mixer *mixer;
159 
160 	mixer = kzalloc(sizeof(*mixer), GFP_KERNEL);
161 	if (!mixer)
162 		return ERR_PTR(-ENOMEM);
163 
164 	mixer->name = mixer_names[lm->id];
165 	mixer->lm = lm->id;
166 	mixer->caps = lm->caps;
167 	mixer->pp = lm->pp;
168 	mixer->dspp = lm->dspp;
169 	mixer->flush_mask = mdp_ctl_flush_mask_lm(lm->id);
170 
171 	return mixer;
172 }
173