xref: /openbmc/linux/drivers/gpu/drm/omapdrm/omap_irq.c (revision 4ae555a5)
1 /*
2  * drivers/gpu/drm/omapdrm/omap_irq.c
3  *
4  * Copyright (C) 2012 Texas Instruments
5  * Author: Rob Clark <rob.clark@linaro.org>
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms of the GNU General Public License version 2 as published by
9  * the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14  * more details.
15  *
16  * You should have received a copy of the GNU General Public License along with
17  * this program.  If not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "omap_drv.h"
21 
22 static DEFINE_SPINLOCK(list_lock);
23 
24 static void omap_irq_error_handler(struct omap_drm_irq *irq,
25 		uint32_t irqstatus)
26 {
27 	DRM_ERROR("errors: %08x\n", irqstatus);
28 }
29 
30 /* call with list_lock and dispc runtime held */
31 static void omap_irq_update(struct drm_device *dev)
32 {
33 	struct omap_drm_private *priv = dev->dev_private;
34 	struct omap_drm_irq *irq;
35 	uint32_t irqmask = priv->vblank_mask;
36 
37 	assert_spin_locked(&list_lock);
38 
39 	list_for_each_entry(irq, &priv->irq_list, node)
40 		irqmask |= irq->irqmask;
41 
42 	DBG("irqmask=%08x", irqmask);
43 
44 	dispc_write_irqenable(irqmask);
45 	dispc_read_irqenable();        /* flush posted write */
46 }
47 
48 void __omap_irq_register(struct drm_device *dev, struct omap_drm_irq *irq)
49 {
50 	struct omap_drm_private *priv = dev->dev_private;
51 	unsigned long flags;
52 
53 	spin_lock_irqsave(&list_lock, flags);
54 
55 	if (!WARN_ON(irq->registered)) {
56 		irq->registered = true;
57 		list_add(&irq->node, &priv->irq_list);
58 		omap_irq_update(dev);
59 	}
60 
61 	spin_unlock_irqrestore(&list_lock, flags);
62 }
63 
64 void omap_irq_register(struct drm_device *dev, struct omap_drm_irq *irq)
65 {
66 	dispc_runtime_get();
67 
68 	__omap_irq_register(dev, irq);
69 
70 	dispc_runtime_put();
71 }
72 
73 void __omap_irq_unregister(struct drm_device *dev, struct omap_drm_irq *irq)
74 {
75 	unsigned long flags;
76 
77 	spin_lock_irqsave(&list_lock, flags);
78 
79 	if (!WARN_ON(!irq->registered)) {
80 		irq->registered = false;
81 		list_del(&irq->node);
82 		omap_irq_update(dev);
83 	}
84 
85 	spin_unlock_irqrestore(&list_lock, flags);
86 }
87 
88 void omap_irq_unregister(struct drm_device *dev, struct omap_drm_irq *irq)
89 {
90 	dispc_runtime_get();
91 
92 	__omap_irq_unregister(dev, irq);
93 
94 	dispc_runtime_put();
95 }
96 
97 struct omap_irq_wait {
98 	struct omap_drm_irq irq;
99 	int count;
100 };
101 
102 static DECLARE_WAIT_QUEUE_HEAD(wait_event);
103 
104 static void wait_irq(struct omap_drm_irq *irq, uint32_t irqstatus)
105 {
106 	struct omap_irq_wait *wait =
107 			container_of(irq, struct omap_irq_wait, irq);
108 	wait->count--;
109 	wake_up_all(&wait_event);
110 }
111 
112 struct omap_irq_wait * omap_irq_wait_init(struct drm_device *dev,
113 		uint32_t irqmask, int count)
114 {
115 	struct omap_irq_wait *wait = kzalloc(sizeof(*wait), GFP_KERNEL);
116 	wait->irq.irq = wait_irq;
117 	wait->irq.irqmask = irqmask;
118 	wait->count = count;
119 	omap_irq_register(dev, &wait->irq);
120 	return wait;
121 }
122 
123 int omap_irq_wait(struct drm_device *dev, struct omap_irq_wait *wait,
124 		unsigned long timeout)
125 {
126 	int ret = wait_event_timeout(wait_event, (wait->count <= 0), timeout);
127 	omap_irq_unregister(dev, &wait->irq);
128 	kfree(wait);
129 	if (ret == 0)
130 		return -1;
131 	return 0;
132 }
133 
134 /**
135  * enable_vblank - enable vblank interrupt events
136  * @dev: DRM device
137  * @crtc: which irq to enable
138  *
139  * Enable vblank interrupts for @crtc.  If the device doesn't have
140  * a hardware vblank counter, this routine should be a no-op, since
141  * interrupts will have to stay on to keep the count accurate.
142  *
143  * RETURNS
144  * Zero on success, appropriate errno if the given @crtc's vblank
145  * interrupt cannot be enabled.
146  */
147 int omap_irq_enable_vblank(struct drm_device *dev, int crtc_id)
148 {
149 	struct omap_drm_private *priv = dev->dev_private;
150 	struct drm_crtc *crtc = priv->crtcs[crtc_id];
151 	unsigned long flags;
152 
153 	DBG("dev=%p, crtc=%d", dev, crtc_id);
154 
155 	dispc_runtime_get();
156 	spin_lock_irqsave(&list_lock, flags);
157 	priv->vblank_mask |= pipe2vbl(crtc);
158 	omap_irq_update(dev);
159 	spin_unlock_irqrestore(&list_lock, flags);
160 	dispc_runtime_put();
161 
162 	return 0;
163 }
164 
165 /**
166  * disable_vblank - disable vblank interrupt events
167  * @dev: DRM device
168  * @crtc: which irq to enable
169  *
170  * Disable vblank interrupts for @crtc.  If the device doesn't have
171  * a hardware vblank counter, this routine should be a no-op, since
172  * interrupts will have to stay on to keep the count accurate.
173  */
174 void omap_irq_disable_vblank(struct drm_device *dev, int crtc_id)
175 {
176 	struct omap_drm_private *priv = dev->dev_private;
177 	struct drm_crtc *crtc = priv->crtcs[crtc_id];
178 	unsigned long flags;
179 
180 	DBG("dev=%p, crtc=%d", dev, crtc_id);
181 
182 	dispc_runtime_get();
183 	spin_lock_irqsave(&list_lock, flags);
184 	priv->vblank_mask &= ~pipe2vbl(crtc);
185 	omap_irq_update(dev);
186 	spin_unlock_irqrestore(&list_lock, flags);
187 	dispc_runtime_put();
188 }
189 
190 irqreturn_t omap_irq_handler(int irq, void *arg)
191 {
192 	struct drm_device *dev = (struct drm_device *) arg;
193 	struct omap_drm_private *priv = dev->dev_private;
194 	struct omap_drm_irq *handler, *n;
195 	unsigned long flags;
196 	unsigned int id;
197 	u32 irqstatus;
198 
199 	irqstatus = dispc_read_irqstatus();
200 	dispc_clear_irqstatus(irqstatus);
201 	dispc_read_irqstatus();        /* flush posted write */
202 
203 	VERB("irqs: %08x", irqstatus);
204 
205 	for (id = 0; id < priv->num_crtcs; id++) {
206 		struct drm_crtc *crtc = priv->crtcs[id];
207 
208 		if (irqstatus & pipe2vbl(crtc))
209 			drm_handle_vblank(dev, id);
210 	}
211 
212 	spin_lock_irqsave(&list_lock, flags);
213 	list_for_each_entry_safe(handler, n, &priv->irq_list, node) {
214 		if (handler->irqmask & irqstatus) {
215 			spin_unlock_irqrestore(&list_lock, flags);
216 			handler->irq(handler, handler->irqmask & irqstatus);
217 			spin_lock_irqsave(&list_lock, flags);
218 		}
219 	}
220 	spin_unlock_irqrestore(&list_lock, flags);
221 
222 	return IRQ_HANDLED;
223 }
224 
225 void omap_irq_preinstall(struct drm_device *dev)
226 {
227 	DBG("dev=%p", dev);
228 	dispc_runtime_get();
229 	dispc_clear_irqstatus(0xffffffff);
230 	dispc_runtime_put();
231 }
232 
233 int omap_irq_postinstall(struct drm_device *dev)
234 {
235 	struct omap_drm_private *priv = dev->dev_private;
236 	struct omap_drm_irq *error_handler = &priv->error_handler;
237 
238 	DBG("dev=%p", dev);
239 
240 	INIT_LIST_HEAD(&priv->irq_list);
241 
242 	error_handler->irq = omap_irq_error_handler;
243 	error_handler->irqmask = DISPC_IRQ_OCP_ERR;
244 
245 	/* for now ignore DISPC_IRQ_SYNC_LOST_DIGIT.. really I think
246 	 * we just need to ignore it while enabling tv-out
247 	 */
248 	error_handler->irqmask &= ~DISPC_IRQ_SYNC_LOST_DIGIT;
249 
250 	omap_irq_register(dev, error_handler);
251 
252 	return 0;
253 }
254 
255 void omap_irq_uninstall(struct drm_device *dev)
256 {
257 	DBG("dev=%p", dev);
258 	// TODO prolly need to call drm_irq_uninstall() somewhere too
259 }
260 
261 /*
262  * We need a special version, instead of just using drm_irq_install(),
263  * because we need to register the irq via omapdss.  Once omapdss and
264  * omapdrm are merged together we can assign the dispc hwmod data to
265  * ourselves and drop these and just use drm_irq_{install,uninstall}()
266  */
267 
268 int omap_drm_irq_install(struct drm_device *dev)
269 {
270 	int ret;
271 
272 	mutex_lock(&dev->struct_mutex);
273 
274 	if (dev->irq_enabled) {
275 		mutex_unlock(&dev->struct_mutex);
276 		return -EBUSY;
277 	}
278 	dev->irq_enabled = true;
279 	mutex_unlock(&dev->struct_mutex);
280 
281 	/* Before installing handler */
282 	if (dev->driver->irq_preinstall)
283 		dev->driver->irq_preinstall(dev);
284 
285 	ret = dispc_request_irq(dev->driver->irq_handler, dev);
286 
287 	if (ret < 0) {
288 		mutex_lock(&dev->struct_mutex);
289 		dev->irq_enabled = false;
290 		mutex_unlock(&dev->struct_mutex);
291 		return ret;
292 	}
293 
294 	/* After installing handler */
295 	if (dev->driver->irq_postinstall)
296 		ret = dev->driver->irq_postinstall(dev);
297 
298 	if (ret < 0) {
299 		mutex_lock(&dev->struct_mutex);
300 		dev->irq_enabled = false;
301 		mutex_unlock(&dev->struct_mutex);
302 		dispc_free_irq(dev);
303 	}
304 
305 	return ret;
306 }
307 
308 int omap_drm_irq_uninstall(struct drm_device *dev)
309 {
310 	unsigned long irqflags;
311 	bool irq_enabled;
312 	int i;
313 
314 	mutex_lock(&dev->struct_mutex);
315 	irq_enabled = dev->irq_enabled;
316 	dev->irq_enabled = false;
317 	mutex_unlock(&dev->struct_mutex);
318 
319 	/*
320 	 * Wake up any waiters so they don't hang.
321 	 */
322 	if (dev->num_crtcs) {
323 		spin_lock_irqsave(&dev->vbl_lock, irqflags);
324 		for (i = 0; i < dev->num_crtcs; i++) {
325 			wake_up(&dev->vblank[i].queue);
326 			dev->vblank[i].enabled = false;
327 			dev->vblank[i].last =
328 				dev->driver->get_vblank_counter(dev, i);
329 		}
330 		spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
331 	}
332 
333 	if (!irq_enabled)
334 		return -EINVAL;
335 
336 	if (dev->driver->irq_uninstall)
337 		dev->driver->irq_uninstall(dev);
338 
339 	dispc_free_irq(dev);
340 
341 	return 0;
342 }
343