1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2011 Texas Instruments Incorporated - https://www.ti.com/
4  * Author: Rob Clark <rob.clark@linaro.org>
5  */
6 
7 #include <drm/drm_vblank.h>
8 
9 #include "omap_drv.h"
10 
11 struct omap_irq_wait {
12 	struct list_head node;
13 	wait_queue_head_t wq;
14 	u32 irqmask;
15 	int count;
16 };
17 
18 /* call with wait_lock and dispc runtime held */
omap_irq_update(struct drm_device * dev)19 static void omap_irq_update(struct drm_device *dev)
20 {
21 	struct omap_drm_private *priv = dev->dev_private;
22 	struct omap_irq_wait *wait;
23 	u32 irqmask = priv->irq_mask;
24 
25 	assert_spin_locked(&priv->wait_lock);
26 
27 	list_for_each_entry(wait, &priv->wait_list, node)
28 		irqmask |= wait->irqmask;
29 
30 	DBG("irqmask=%08x", irqmask);
31 
32 	dispc_write_irqenable(priv->dispc, irqmask);
33 }
34 
omap_irq_wait_handler(struct omap_irq_wait * wait)35 static void omap_irq_wait_handler(struct omap_irq_wait *wait)
36 {
37 	wait->count--;
38 	wake_up(&wait->wq);
39 }
40 
omap_irq_wait_init(struct drm_device * dev,u32 irqmask,int count)41 struct omap_irq_wait * omap_irq_wait_init(struct drm_device *dev,
42 		u32 irqmask, int count)
43 {
44 	struct omap_drm_private *priv = dev->dev_private;
45 	struct omap_irq_wait *wait = kzalloc(sizeof(*wait), GFP_KERNEL);
46 	unsigned long flags;
47 
48 	init_waitqueue_head(&wait->wq);
49 	wait->irqmask = irqmask;
50 	wait->count = count;
51 
52 	spin_lock_irqsave(&priv->wait_lock, flags);
53 	list_add(&wait->node, &priv->wait_list);
54 	omap_irq_update(dev);
55 	spin_unlock_irqrestore(&priv->wait_lock, flags);
56 
57 	return wait;
58 }
59 
omap_irq_wait(struct drm_device * dev,struct omap_irq_wait * wait,unsigned long timeout)60 int omap_irq_wait(struct drm_device *dev, struct omap_irq_wait *wait,
61 		unsigned long timeout)
62 {
63 	struct omap_drm_private *priv = dev->dev_private;
64 	unsigned long flags;
65 	int ret;
66 
67 	ret = wait_event_timeout(wait->wq, (wait->count <= 0), timeout);
68 
69 	spin_lock_irqsave(&priv->wait_lock, flags);
70 	list_del(&wait->node);
71 	omap_irq_update(dev);
72 	spin_unlock_irqrestore(&priv->wait_lock, flags);
73 
74 	kfree(wait);
75 
76 	return ret == 0 ? -1 : 0;
77 }
78 
omap_irq_enable_framedone(struct drm_crtc * crtc,bool enable)79 int omap_irq_enable_framedone(struct drm_crtc *crtc, bool enable)
80 {
81 	struct drm_device *dev = crtc->dev;
82 	struct omap_drm_private *priv = dev->dev_private;
83 	unsigned long flags;
84 	enum omap_channel channel = omap_crtc_channel(crtc);
85 	int framedone_irq =
86 		dispc_mgr_get_framedone_irq(priv->dispc, channel);
87 
88 	DBG("dev=%p, crtc=%u, enable=%d", dev, channel, enable);
89 
90 	spin_lock_irqsave(&priv->wait_lock, flags);
91 	if (enable)
92 		priv->irq_mask |= framedone_irq;
93 	else
94 		priv->irq_mask &= ~framedone_irq;
95 	omap_irq_update(dev);
96 	spin_unlock_irqrestore(&priv->wait_lock, flags);
97 
98 	return 0;
99 }
100 
101 /**
102  * enable_vblank - enable vblank interrupt events
103  * @crtc: DRM CRTC
104  *
105  * Enable vblank interrupts for @crtc.  If the device doesn't have
106  * a hardware vblank counter, this routine should be a no-op, since
107  * interrupts will have to stay on to keep the count accurate.
108  *
109  * RETURNS
110  * Zero on success, appropriate errno if the given @crtc's vblank
111  * interrupt cannot be enabled.
112  */
omap_irq_enable_vblank(struct drm_crtc * crtc)113 int omap_irq_enable_vblank(struct drm_crtc *crtc)
114 {
115 	struct drm_device *dev = crtc->dev;
116 	struct omap_drm_private *priv = dev->dev_private;
117 	unsigned long flags;
118 	enum omap_channel channel = omap_crtc_channel(crtc);
119 
120 	DBG("dev=%p, crtc=%u", dev, channel);
121 
122 	spin_lock_irqsave(&priv->wait_lock, flags);
123 	priv->irq_mask |= dispc_mgr_get_vsync_irq(priv->dispc,
124 							     channel);
125 	omap_irq_update(dev);
126 	spin_unlock_irqrestore(&priv->wait_lock, flags);
127 
128 	return 0;
129 }
130 
131 /**
132  * disable_vblank - disable vblank interrupt events
133  * @crtc: DRM CRTC
134  *
135  * Disable vblank interrupts for @crtc.  If the device doesn't have
136  * a hardware vblank counter, this routine should be a no-op, since
137  * interrupts will have to stay on to keep the count accurate.
138  */
omap_irq_disable_vblank(struct drm_crtc * crtc)139 void omap_irq_disable_vblank(struct drm_crtc *crtc)
140 {
141 	struct drm_device *dev = crtc->dev;
142 	struct omap_drm_private *priv = dev->dev_private;
143 	unsigned long flags;
144 	enum omap_channel channel = omap_crtc_channel(crtc);
145 
146 	DBG("dev=%p, crtc=%u", dev, channel);
147 
148 	spin_lock_irqsave(&priv->wait_lock, flags);
149 	priv->irq_mask &= ~dispc_mgr_get_vsync_irq(priv->dispc,
150 							      channel);
151 	omap_irq_update(dev);
152 	spin_unlock_irqrestore(&priv->wait_lock, flags);
153 }
154 
omap_irq_fifo_underflow(struct omap_drm_private * priv,u32 irqstatus)155 static void omap_irq_fifo_underflow(struct omap_drm_private *priv,
156 				    u32 irqstatus)
157 {
158 	static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
159 				      DEFAULT_RATELIMIT_BURST);
160 	static const struct {
161 		const char *name;
162 		u32 mask;
163 	} sources[] = {
164 		{ "gfx", DISPC_IRQ_GFX_FIFO_UNDERFLOW },
165 		{ "vid1", DISPC_IRQ_VID1_FIFO_UNDERFLOW },
166 		{ "vid2", DISPC_IRQ_VID2_FIFO_UNDERFLOW },
167 		{ "vid3", DISPC_IRQ_VID3_FIFO_UNDERFLOW },
168 	};
169 
170 	const u32 mask = DISPC_IRQ_GFX_FIFO_UNDERFLOW
171 		       | DISPC_IRQ_VID1_FIFO_UNDERFLOW
172 		       | DISPC_IRQ_VID2_FIFO_UNDERFLOW
173 		       | DISPC_IRQ_VID3_FIFO_UNDERFLOW;
174 	unsigned int i;
175 
176 	spin_lock(&priv->wait_lock);
177 	irqstatus &= priv->irq_mask & mask;
178 	spin_unlock(&priv->wait_lock);
179 
180 	if (!irqstatus)
181 		return;
182 
183 	if (!__ratelimit(&_rs))
184 		return;
185 
186 	DRM_ERROR("FIFO underflow on ");
187 
188 	for (i = 0; i < ARRAY_SIZE(sources); ++i) {
189 		if (sources[i].mask & irqstatus)
190 			pr_cont("%s ", sources[i].name);
191 	}
192 
193 	pr_cont("(0x%08x)\n", irqstatus);
194 }
195 
omap_irq_ocp_error_handler(struct drm_device * dev,u32 irqstatus)196 static void omap_irq_ocp_error_handler(struct drm_device *dev,
197 	u32 irqstatus)
198 {
199 	if (!(irqstatus & DISPC_IRQ_OCP_ERR))
200 		return;
201 
202 	dev_err_ratelimited(dev->dev, "OCP error\n");
203 }
204 
omap_irq_handler(int irq,void * arg)205 static irqreturn_t omap_irq_handler(int irq, void *arg)
206 {
207 	struct drm_device *dev = (struct drm_device *) arg;
208 	struct omap_drm_private *priv = dev->dev_private;
209 	struct omap_irq_wait *wait, *n;
210 	unsigned long flags;
211 	unsigned int id;
212 	u32 irqstatus;
213 
214 	irqstatus = dispc_read_irqstatus(priv->dispc);
215 	dispc_clear_irqstatus(priv->dispc, irqstatus);
216 	dispc_read_irqstatus(priv->dispc);	/* flush posted write */
217 
218 	VERB("irqs: %08x", irqstatus);
219 
220 	for (id = 0; id < priv->num_pipes; id++) {
221 		struct drm_crtc *crtc = priv->pipes[id].crtc;
222 		enum omap_channel channel = omap_crtc_channel(crtc);
223 
224 		if (irqstatus & dispc_mgr_get_vsync_irq(priv->dispc, channel)) {
225 			drm_handle_vblank(dev, id);
226 			omap_crtc_vblank_irq(crtc);
227 		}
228 
229 		if (irqstatus & dispc_mgr_get_sync_lost_irq(priv->dispc, channel))
230 			omap_crtc_error_irq(crtc, irqstatus);
231 
232 		if (irqstatus & dispc_mgr_get_framedone_irq(priv->dispc, channel))
233 			omap_crtc_framedone_irq(crtc, irqstatus);
234 	}
235 
236 	omap_irq_ocp_error_handler(dev, irqstatus);
237 	omap_irq_fifo_underflow(priv, irqstatus);
238 
239 	spin_lock_irqsave(&priv->wait_lock, flags);
240 	list_for_each_entry_safe(wait, n, &priv->wait_list, node) {
241 		if (wait->irqmask & irqstatus)
242 			omap_irq_wait_handler(wait);
243 	}
244 	spin_unlock_irqrestore(&priv->wait_lock, flags);
245 
246 	return IRQ_HANDLED;
247 }
248 
249 static const u32 omap_underflow_irqs[] = {
250 	[OMAP_DSS_GFX] = DISPC_IRQ_GFX_FIFO_UNDERFLOW,
251 	[OMAP_DSS_VIDEO1] = DISPC_IRQ_VID1_FIFO_UNDERFLOW,
252 	[OMAP_DSS_VIDEO2] = DISPC_IRQ_VID2_FIFO_UNDERFLOW,
253 	[OMAP_DSS_VIDEO3] = DISPC_IRQ_VID3_FIFO_UNDERFLOW,
254 };
255 
omap_drm_irq_install(struct drm_device * dev)256 int omap_drm_irq_install(struct drm_device *dev)
257 {
258 	struct omap_drm_private *priv = dev->dev_private;
259 	unsigned int num_mgrs = dispc_get_num_mgrs(priv->dispc);
260 	unsigned int max_planes;
261 	unsigned int i;
262 	int ret;
263 
264 	spin_lock_init(&priv->wait_lock);
265 	INIT_LIST_HEAD(&priv->wait_list);
266 
267 	priv->irq_mask = DISPC_IRQ_OCP_ERR;
268 
269 	max_planes = min(ARRAY_SIZE(priv->planes),
270 			 ARRAY_SIZE(omap_underflow_irqs));
271 	for (i = 0; i < max_planes; ++i) {
272 		if (priv->planes[i])
273 			priv->irq_mask |= omap_underflow_irqs[i];
274 	}
275 
276 	for (i = 0; i < num_mgrs; ++i)
277 		priv->irq_mask |= dispc_mgr_get_sync_lost_irq(priv->dispc, i);
278 
279 	dispc_runtime_get(priv->dispc);
280 	dispc_clear_irqstatus(priv->dispc, 0xffffffff);
281 	dispc_runtime_put(priv->dispc);
282 
283 	ret = dispc_request_irq(priv->dispc, omap_irq_handler, dev);
284 	if (ret < 0)
285 		return ret;
286 
287 	priv->irq_enabled = true;
288 
289 	return 0;
290 }
291 
omap_drm_irq_uninstall(struct drm_device * dev)292 void omap_drm_irq_uninstall(struct drm_device *dev)
293 {
294 	struct omap_drm_private *priv = dev->dev_private;
295 
296 	if (!priv->irq_enabled)
297 		return;
298 
299 	priv->irq_enabled = false;
300 
301 	dispc_free_irq(priv->dispc, dev);
302 }
303