xref: /openbmc/linux/drivers/gpu/drm/vkms/vkms_crtc.c (revision 22d55f02)
1 // SPDX-License-Identifier: GPL-2.0+
2 
3 #include "vkms_drv.h"
4 #include <drm/drm_atomic_helper.h>
5 #include <drm/drm_probe_helper.h>
6 
7 static enum hrtimer_restart vkms_vblank_simulate(struct hrtimer *timer)
8 {
9 	struct vkms_output *output = container_of(timer, struct vkms_output,
10 						  vblank_hrtimer);
11 	struct drm_crtc *crtc = &output->crtc;
12 	struct vkms_crtc_state *state = to_vkms_crtc_state(crtc->state);
13 	u64 ret_overrun;
14 	bool ret;
15 
16 	spin_lock(&output->lock);
17 
18 	ret = drm_crtc_handle_vblank(crtc);
19 	if (!ret)
20 		DRM_ERROR("vkms failure on handling vblank");
21 
22 	if (state && output->crc_enabled) {
23 		u64 frame = drm_crtc_accurate_vblank_count(crtc);
24 
25 		/* update frame_start only if a queued vkms_crc_work_handle()
26 		 * has read the data
27 		 */
28 		spin_lock(&output->state_lock);
29 		if (!state->frame_start)
30 			state->frame_start = frame;
31 		spin_unlock(&output->state_lock);
32 
33 		ret = queue_work(output->crc_workq, &state->crc_work);
34 		if (!ret)
35 			DRM_WARN("failed to queue vkms_crc_work_handle");
36 	}
37 
38 	ret_overrun = hrtimer_forward_now(&output->vblank_hrtimer,
39 					  output->period_ns);
40 	WARN_ON(ret_overrun != 1);
41 
42 	spin_unlock(&output->lock);
43 
44 	return HRTIMER_RESTART;
45 }
46 
47 static int vkms_enable_vblank(struct drm_crtc *crtc)
48 {
49 	struct drm_device *dev = crtc->dev;
50 	unsigned int pipe = drm_crtc_index(crtc);
51 	struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
52 	struct vkms_output *out = drm_crtc_to_vkms_output(crtc);
53 
54 	drm_calc_timestamping_constants(crtc, &crtc->mode);
55 
56 	hrtimer_init(&out->vblank_hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
57 	out->vblank_hrtimer.function = &vkms_vblank_simulate;
58 	out->period_ns = ktime_set(0, vblank->framedur_ns);
59 	hrtimer_start(&out->vblank_hrtimer, out->period_ns, HRTIMER_MODE_REL);
60 
61 	return 0;
62 }
63 
64 static void vkms_disable_vblank(struct drm_crtc *crtc)
65 {
66 	struct vkms_output *out = drm_crtc_to_vkms_output(crtc);
67 
68 	hrtimer_cancel(&out->vblank_hrtimer);
69 }
70 
71 bool vkms_get_vblank_timestamp(struct drm_device *dev, unsigned int pipe,
72 			       int *max_error, ktime_t *vblank_time,
73 			       bool in_vblank_irq)
74 {
75 	struct vkms_device *vkmsdev = drm_device_to_vkms_device(dev);
76 	struct vkms_output *output = &vkmsdev->output;
77 
78 	*vblank_time = output->vblank_hrtimer.node.expires;
79 
80 	if (!in_vblank_irq)
81 		*vblank_time -= output->period_ns;
82 
83 	return true;
84 }
85 
86 static void vkms_atomic_crtc_reset(struct drm_crtc *crtc)
87 {
88 	struct vkms_crtc_state *vkms_state = NULL;
89 
90 	if (crtc->state) {
91 		vkms_state = to_vkms_crtc_state(crtc->state);
92 		__drm_atomic_helper_crtc_destroy_state(crtc->state);
93 		kfree(vkms_state);
94 		crtc->state = NULL;
95 	}
96 
97 	vkms_state = kzalloc(sizeof(*vkms_state), GFP_KERNEL);
98 	if (!vkms_state)
99 		return;
100 	INIT_WORK(&vkms_state->crc_work, vkms_crc_work_handle);
101 
102 	crtc->state = &vkms_state->base;
103 	crtc->state->crtc = crtc;
104 }
105 
106 static struct drm_crtc_state *
107 vkms_atomic_crtc_duplicate_state(struct drm_crtc *crtc)
108 {
109 	struct vkms_crtc_state *vkms_state;
110 
111 	if (WARN_ON(!crtc->state))
112 		return NULL;
113 
114 	vkms_state = kzalloc(sizeof(*vkms_state), GFP_KERNEL);
115 	if (!vkms_state)
116 		return NULL;
117 
118 	__drm_atomic_helper_crtc_duplicate_state(crtc, &vkms_state->base);
119 
120 	INIT_WORK(&vkms_state->crc_work, vkms_crc_work_handle);
121 
122 	return &vkms_state->base;
123 }
124 
125 static void vkms_atomic_crtc_destroy_state(struct drm_crtc *crtc,
126 					   struct drm_crtc_state *state)
127 {
128 	struct vkms_crtc_state *vkms_state = to_vkms_crtc_state(state);
129 
130 	__drm_atomic_helper_crtc_destroy_state(state);
131 
132 	if (vkms_state) {
133 		flush_work(&vkms_state->crc_work);
134 		kfree(vkms_state);
135 	}
136 }
137 
138 static const struct drm_crtc_funcs vkms_crtc_funcs = {
139 	.set_config             = drm_atomic_helper_set_config,
140 	.destroy                = drm_crtc_cleanup,
141 	.page_flip              = drm_atomic_helper_page_flip,
142 	.reset                  = vkms_atomic_crtc_reset,
143 	.atomic_duplicate_state = vkms_atomic_crtc_duplicate_state,
144 	.atomic_destroy_state   = vkms_atomic_crtc_destroy_state,
145 	.enable_vblank		= vkms_enable_vblank,
146 	.disable_vblank		= vkms_disable_vblank,
147 	.set_crc_source		= vkms_set_crc_source,
148 	.verify_crc_source	= vkms_verify_crc_source,
149 };
150 
151 static void vkms_crtc_atomic_enable(struct drm_crtc *crtc,
152 				    struct drm_crtc_state *old_state)
153 {
154 	drm_crtc_vblank_on(crtc);
155 }
156 
157 static void vkms_crtc_atomic_disable(struct drm_crtc *crtc,
158 				     struct drm_crtc_state *old_state)
159 {
160 	drm_crtc_vblank_off(crtc);
161 }
162 
163 static void vkms_crtc_atomic_begin(struct drm_crtc *crtc,
164 				   struct drm_crtc_state *old_crtc_state)
165 {
166 	struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
167 
168 	/* This lock is held across the atomic commit to block vblank timer
169 	 * from scheduling vkms_crc_work_handle until the crc_data is updated
170 	 */
171 	spin_lock_irq(&vkms_output->lock);
172 }
173 
174 static void vkms_crtc_atomic_flush(struct drm_crtc *crtc,
175 				   struct drm_crtc_state *old_crtc_state)
176 {
177 	struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
178 	unsigned long flags;
179 
180 	if (crtc->state->event) {
181 		spin_lock_irqsave(&crtc->dev->event_lock, flags);
182 
183 		if (drm_crtc_vblank_get(crtc) != 0)
184 			drm_crtc_send_vblank_event(crtc, crtc->state->event);
185 		else
186 			drm_crtc_arm_vblank_event(crtc, crtc->state->event);
187 
188 		spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
189 
190 		crtc->state->event = NULL;
191 	}
192 
193 	spin_unlock_irq(&vkms_output->lock);
194 }
195 
196 static const struct drm_crtc_helper_funcs vkms_crtc_helper_funcs = {
197 	.atomic_begin	= vkms_crtc_atomic_begin,
198 	.atomic_flush	= vkms_crtc_atomic_flush,
199 	.atomic_enable	= vkms_crtc_atomic_enable,
200 	.atomic_disable	= vkms_crtc_atomic_disable,
201 };
202 
203 int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
204 		   struct drm_plane *primary, struct drm_plane *cursor)
205 {
206 	struct vkms_output *vkms_out = drm_crtc_to_vkms_output(crtc);
207 	int ret;
208 
209 	ret = drm_crtc_init_with_planes(dev, crtc, primary, cursor,
210 					&vkms_crtc_funcs, NULL);
211 	if (ret) {
212 		DRM_ERROR("Failed to init CRTC\n");
213 		return ret;
214 	}
215 
216 	drm_crtc_helper_add(crtc, &vkms_crtc_helper_funcs);
217 
218 	spin_lock_init(&vkms_out->lock);
219 	spin_lock_init(&vkms_out->state_lock);
220 
221 	vkms_out->crc_workq = alloc_ordered_workqueue("vkms_crc_workq", 0);
222 	if (!vkms_out->crc_workq)
223 		return -ENOMEM;
224 
225 	return ret;
226 }
227