mdp5_mixer.c

  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 */
 17static int lm_right_pair[] = { 1, -1, 5, -1, -1, -1 };
 18
 19static 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
 38int 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
119int 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
143static const char * const mixer_names[] = {
144	"LM0", "LM1", "LM2", "LM3", "LM4", "LM5",
145};
146
147struct 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}