xref: /linux/drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.c (revision ae22a94997b8a03dcb3c922857c203246711f9d4)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2017 The Linux Foundation. All rights reserved.
4  */
5 
6 #include "mdp5_kms.h"
7 
8 /*
9  * As of now, there are only 2 combinations possible for source split:
10  *
11  * Left | Right
12  * -----|------
13  *  LM0 | LM1
14  *  LM2 | LM5
15  *
16  */
17 static int lm_right_pair[] = { 1, -1, 5, -1, -1, -1 };
18 
19 static int get_right_pair_idx(struct mdp5_kms *mdp5_kms, int lm)
20 {
21 	int i;
22 	int pair_lm;
23 
24 	pair_lm = lm_right_pair[lm];
25 	if (pair_lm < 0)
26 		return -EINVAL;
27 
28 	for (i = 0; i < mdp5_kms->num_hwmixers; i++) {
29 		struct mdp5_hw_mixer *mixer = mdp5_kms->hwmixers[i];
30 
31 		if (mixer->lm == pair_lm)
32 			return mixer->idx;
33 	}
34 
35 	return -1;
36 }
37 
38 int mdp5_mixer_assign(struct drm_atomic_state *s, struct drm_crtc *crtc,
39 		      uint32_t caps, struct mdp5_hw_mixer **mixer,
40 		      struct mdp5_hw_mixer **r_mixer)
41 {
42 	struct msm_drm_private *priv = s->dev->dev_private;
43 	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms));
44 	struct mdp5_global_state *global_state = mdp5_get_global_state(s);
45 	struct mdp5_hw_mixer_state *new_state;
46 	int i;
47 
48 	if (IS_ERR(global_state))
49 		return PTR_ERR(global_state);
50 
51 	new_state = &global_state->hwmixer;
52 
53 	for (i = 0; i < mdp5_kms->num_hwmixers; i++) {
54 		struct mdp5_hw_mixer *cur = mdp5_kms->hwmixers[i];
55 
56 		/*
57 		 * skip if already in-use by a different CRTC. If there is a
58 		 * mixer already assigned to this CRTC, it means this call is
59 		 * a request to get an additional right mixer. Assume that the
60 		 * existing mixer is the 'left' one, and try to see if we can
61 		 * get its corresponding 'right' pair.
62 		 */
63 		if (new_state->hwmixer_to_crtc[cur->idx] &&
64 		    new_state->hwmixer_to_crtc[cur->idx] != crtc)
65 			continue;
66 
67 		/* skip if doesn't support some required caps: */
68 		if (caps & ~cur->caps)
69 			continue;
70 
71 		if (r_mixer) {
72 			int pair_idx;
73 
74 			pair_idx = get_right_pair_idx(mdp5_kms, cur->lm);
75 			if (pair_idx < 0)
76 				return -EINVAL;
77 
78 			if (new_state->hwmixer_to_crtc[pair_idx])
79 				continue;
80 
81 			*r_mixer = mdp5_kms->hwmixers[pair_idx];
82 		}
83 
84 		/*
85 		 * prefer a pair-able LM over an unpairable one. We can
86 		 * switch the CRTC from Normal mode to Source Split mode
87 		 * without requiring a full modeset if we had already
88 		 * assigned this CRTC a pair-able LM.
89 		 *
90 		 * TODO: There will be assignment sequences which would
91 		 * result in the CRTC requiring a full modeset, even
92 		 * if we have the LM resources to prevent it. For a platform
93 		 * with a few displays, we don't run out of pair-able LMs
94 		 * so easily. For now, ignore the possibility of requiring
95 		 * a full modeset.
96 		 */
97 		if (!(*mixer) || cur->caps & MDP_LM_CAP_PAIR)
98 			*mixer = cur;
99 	}
100 
101 	if (!(*mixer))
102 		return -ENOMEM;
103 
104 	if (r_mixer && !(*r_mixer))
105 		return -ENOMEM;
106 
107 	DBG("assigning Layer Mixer %d to crtc %s", (*mixer)->lm, crtc->name);
108 
109 	new_state->hwmixer_to_crtc[(*mixer)->idx] = crtc;
110 	if (r_mixer) {
111 		DBG("assigning Right Layer Mixer %d to crtc %s", (*r_mixer)->lm,
112 		    crtc->name);
113 		new_state->hwmixer_to_crtc[(*r_mixer)->idx] = crtc;
114 	}
115 
116 	return 0;
117 }
118 
119 int mdp5_mixer_release(struct drm_atomic_state *s, struct mdp5_hw_mixer *mixer)
120 {
121 	struct mdp5_global_state *global_state = mdp5_get_global_state(s);
122 	struct mdp5_hw_mixer_state *new_state;
123 
124 	if (!mixer)
125 		return 0;
126 
127 	if (IS_ERR(global_state))
128 		return PTR_ERR(global_state);
129 
130 	new_state = &global_state->hwmixer;
131 
132 	if (WARN_ON(!new_state->hwmixer_to_crtc[mixer->idx]))
133 		return -EINVAL;
134 
135 	DBG("%s: release from crtc %s", mixer->name,
136 	    new_state->hwmixer_to_crtc[mixer->idx]->name);
137 
138 	new_state->hwmixer_to_crtc[mixer->idx] = NULL;
139 
140 	return 0;
141 }
142 
143 static const char * const mixer_names[] = {
144 	"LM0", "LM1", "LM2", "LM3", "LM4", "LM5",
145 };
146 
147 struct mdp5_hw_mixer *mdp5_mixer_init(struct drm_device *dev,
148 				      const struct mdp5_lm_instance *lm)
149 {
150 	struct mdp5_hw_mixer *mixer;
151 
152 	mixer = devm_kzalloc(dev->dev, sizeof(*mixer), GFP_KERNEL);
153 	if (!mixer)
154 		return ERR_PTR(-ENOMEM);
155 
156 	mixer->name = mixer_names[lm->id];
157 	mixer->lm = lm->id;
158 	mixer->caps = lm->caps;
159 	mixer->pp = lm->pp;
160 	mixer->dspp = lm->dspp;
161 	mixer->flush_mask = mdp_ctl_flush_mask_lm(lm->id);
162 
163 	return mixer;
164 }
165