xref: /openbmc/linux/drivers/gpu/drm/vkms/vkms_crtc.c (revision 8a2fe6c0)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * This program is free software; you can redistribute it and/or modify
4  * it under the terms of the GNU General Public License as published by
5  * the Free Software Foundation; either version 2 of the License, or
6  * (at your option) any later version.
7  */
8 
9 #include "vkms_drv.h"
10 #include <drm/drm_atomic_helper.h>
11 #include <drm/drm_probe_helper.h>
12 
13 static void _vblank_handle(struct vkms_output *output)
14 {
15 	struct drm_crtc *crtc = &output->crtc;
16 	struct vkms_crtc_state *state = to_vkms_crtc_state(crtc->state);
17 	bool ret;
18 
19 	spin_lock(&output->lock);
20 	ret = drm_crtc_handle_vblank(crtc);
21 	if (!ret)
22 		DRM_ERROR("vkms failure on handling vblank");
23 
24 	if (state && output->crc_enabled) {
25 		u64 frame = drm_crtc_accurate_vblank_count(crtc);
26 
27 		/* update frame_start only if a queued vkms_crc_work_handle()
28 		 * has read the data
29 		 */
30 		spin_lock(&output->state_lock);
31 		if (!state->frame_start)
32 			state->frame_start = frame;
33 		spin_unlock(&output->state_lock);
34 
35 		ret = queue_work(output->crc_workq, &state->crc_work);
36 		if (!ret)
37 			DRM_WARN("failed to queue vkms_crc_work_handle");
38 	}
39 
40 	spin_unlock(&output->lock);
41 }
42 
43 static enum hrtimer_restart vkms_vblank_simulate(struct hrtimer *timer)
44 {
45 	struct vkms_output *output = container_of(timer, struct vkms_output,
46 						  vblank_hrtimer);
47 	int ret_overrun;
48 
49 	_vblank_handle(output);
50 
51 	ret_overrun = hrtimer_forward_now(&output->vblank_hrtimer,
52 					  output->period_ns);
53 
54 	return HRTIMER_RESTART;
55 }
56 
57 static int vkms_enable_vblank(struct drm_crtc *crtc)
58 {
59 	struct drm_device *dev = crtc->dev;
60 	unsigned int pipe = drm_crtc_index(crtc);
61 	struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
62 	struct vkms_output *out = drm_crtc_to_vkms_output(crtc);
63 
64 	drm_calc_timestamping_constants(crtc, &crtc->mode);
65 
66 	hrtimer_init(&out->vblank_hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
67 	out->vblank_hrtimer.function = &vkms_vblank_simulate;
68 	out->period_ns = ktime_set(0, vblank->framedur_ns);
69 	hrtimer_start(&out->vblank_hrtimer, out->period_ns, HRTIMER_MODE_REL);
70 
71 	return 0;
72 }
73 
74 static void vkms_disable_vblank(struct drm_crtc *crtc)
75 {
76 	struct vkms_output *out = drm_crtc_to_vkms_output(crtc);
77 
78 	hrtimer_cancel(&out->vblank_hrtimer);
79 }
80 
81 bool vkms_get_vblank_timestamp(struct drm_device *dev, unsigned int pipe,
82 			       int *max_error, ktime_t *vblank_time,
83 			       bool in_vblank_irq)
84 {
85 	struct vkms_device *vkmsdev = drm_device_to_vkms_device(dev);
86 	struct vkms_output *output = &vkmsdev->output;
87 
88 	*vblank_time = output->vblank_hrtimer.node.expires;
89 
90 	return true;
91 }
92 
93 static void vkms_atomic_crtc_reset(struct drm_crtc *crtc)
94 {
95 	struct vkms_crtc_state *vkms_state = NULL;
96 
97 	if (crtc->state) {
98 		vkms_state = to_vkms_crtc_state(crtc->state);
99 		__drm_atomic_helper_crtc_destroy_state(crtc->state);
100 		kfree(vkms_state);
101 		crtc->state = NULL;
102 	}
103 
104 	vkms_state = kzalloc(sizeof(*vkms_state), GFP_KERNEL);
105 	if (!vkms_state)
106 		return;
107 	INIT_WORK(&vkms_state->crc_work, vkms_crc_work_handle);
108 
109 	crtc->state = &vkms_state->base;
110 	crtc->state->crtc = crtc;
111 }
112 
113 static struct drm_crtc_state *
114 vkms_atomic_crtc_duplicate_state(struct drm_crtc *crtc)
115 {
116 	struct vkms_crtc_state *vkms_state;
117 
118 	if (WARN_ON(!crtc->state))
119 		return NULL;
120 
121 	vkms_state = kzalloc(sizeof(*vkms_state), GFP_KERNEL);
122 	if (!vkms_state)
123 		return NULL;
124 
125 	__drm_atomic_helper_crtc_duplicate_state(crtc, &vkms_state->base);
126 
127 	INIT_WORK(&vkms_state->crc_work, vkms_crc_work_handle);
128 
129 	return &vkms_state->base;
130 }
131 
132 static void vkms_atomic_crtc_destroy_state(struct drm_crtc *crtc,
133 					   struct drm_crtc_state *state)
134 {
135 	struct vkms_crtc_state *vkms_state = to_vkms_crtc_state(state);
136 
137 	__drm_atomic_helper_crtc_destroy_state(state);
138 
139 	if (vkms_state) {
140 		flush_work(&vkms_state->crc_work);
141 		kfree(vkms_state);
142 	}
143 }
144 
145 static const struct drm_crtc_funcs vkms_crtc_funcs = {
146 	.set_config             = drm_atomic_helper_set_config,
147 	.destroy                = drm_crtc_cleanup,
148 	.page_flip              = drm_atomic_helper_page_flip,
149 	.reset                  = vkms_atomic_crtc_reset,
150 	.atomic_duplicate_state = vkms_atomic_crtc_duplicate_state,
151 	.atomic_destroy_state   = vkms_atomic_crtc_destroy_state,
152 	.enable_vblank		= vkms_enable_vblank,
153 	.disable_vblank		= vkms_disable_vblank,
154 	.set_crc_source		= vkms_set_crc_source,
155 	.verify_crc_source	= vkms_verify_crc_source,
156 };
157 
158 static void vkms_crtc_atomic_enable(struct drm_crtc *crtc,
159 				    struct drm_crtc_state *old_state)
160 {
161 	drm_crtc_vblank_on(crtc);
162 }
163 
164 static void vkms_crtc_atomic_disable(struct drm_crtc *crtc,
165 				     struct drm_crtc_state *old_state)
166 {
167 	drm_crtc_vblank_off(crtc);
168 }
169 
170 static void vkms_crtc_atomic_begin(struct drm_crtc *crtc,
171 				   struct drm_crtc_state *old_crtc_state)
172 {
173 	struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
174 
175 	/* This lock is held across the atomic commit to block vblank timer
176 	 * from scheduling vkms_crc_work_handle until the crc_data is updated
177 	 */
178 	spin_lock_irq(&vkms_output->lock);
179 }
180 
181 static void vkms_crtc_atomic_flush(struct drm_crtc *crtc,
182 				   struct drm_crtc_state *old_crtc_state)
183 {
184 	struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
185 	unsigned long flags;
186 
187 	if (crtc->state->event) {
188 		spin_lock_irqsave(&crtc->dev->event_lock, flags);
189 
190 		if (drm_crtc_vblank_get(crtc) != 0)
191 			drm_crtc_send_vblank_event(crtc, crtc->state->event);
192 		else
193 			drm_crtc_arm_vblank_event(crtc, crtc->state->event);
194 
195 		spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
196 
197 		crtc->state->event = NULL;
198 	}
199 
200 	spin_unlock_irq(&vkms_output->lock);
201 }
202 
203 static const struct drm_crtc_helper_funcs vkms_crtc_helper_funcs = {
204 	.atomic_begin	= vkms_crtc_atomic_begin,
205 	.atomic_flush	= vkms_crtc_atomic_flush,
206 	.atomic_enable	= vkms_crtc_atomic_enable,
207 	.atomic_disable	= vkms_crtc_atomic_disable,
208 };
209 
210 int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
211 		   struct drm_plane *primary, struct drm_plane *cursor)
212 {
213 	struct vkms_output *vkms_out = drm_crtc_to_vkms_output(crtc);
214 	int ret;
215 
216 	ret = drm_crtc_init_with_planes(dev, crtc, primary, cursor,
217 					&vkms_crtc_funcs, NULL);
218 	if (ret) {
219 		DRM_ERROR("Failed to init CRTC\n");
220 		return ret;
221 	}
222 
223 	drm_crtc_helper_add(crtc, &vkms_crtc_helper_funcs);
224 
225 	spin_lock_init(&vkms_out->lock);
226 	spin_lock_init(&vkms_out->state_lock);
227 
228 	vkms_out->crc_workq = alloc_ordered_workqueue("vkms_crc_workq", 0);
229 
230 	return ret;
231 }
232