xref: /openbmc/linux/drivers/gpu/drm/omapdrm/omap_irq.c (revision eb3fcf00)
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 	spin_lock_irqsave(&list_lock, flags);
156 	priv->vblank_mask |= pipe2vbl(crtc);
157 	omap_irq_update(dev);
158 	spin_unlock_irqrestore(&list_lock, flags);
159 
160 	return 0;
161 }
162 
163 /**
164  * disable_vblank - disable vblank interrupt events
165  * @dev: DRM device
166  * @crtc: which irq to enable
167  *
168  * Disable vblank interrupts for @crtc.  If the device doesn't have
169  * a hardware vblank counter, this routine should be a no-op, since
170  * interrupts will have to stay on to keep the count accurate.
171  */
172 void omap_irq_disable_vblank(struct drm_device *dev, int crtc_id)
173 {
174 	struct omap_drm_private *priv = dev->dev_private;
175 	struct drm_crtc *crtc = priv->crtcs[crtc_id];
176 	unsigned long flags;
177 
178 	DBG("dev=%p, crtc=%d", dev, crtc_id);
179 
180 	spin_lock_irqsave(&list_lock, flags);
181 	priv->vblank_mask &= ~pipe2vbl(crtc);
182 	omap_irq_update(dev);
183 	spin_unlock_irqrestore(&list_lock, flags);
184 }
185 
186 static irqreturn_t omap_irq_handler(int irq, void *arg)
187 {
188 	struct drm_device *dev = (struct drm_device *) arg;
189 	struct omap_drm_private *priv = dev->dev_private;
190 	struct omap_drm_irq *handler, *n;
191 	unsigned long flags;
192 	unsigned int id;
193 	u32 irqstatus;
194 
195 	irqstatus = dispc_read_irqstatus();
196 	dispc_clear_irqstatus(irqstatus);
197 	dispc_read_irqstatus();        /* flush posted write */
198 
199 	VERB("irqs: %08x", irqstatus);
200 
201 	for (id = 0; id < priv->num_crtcs; id++) {
202 		struct drm_crtc *crtc = priv->crtcs[id];
203 
204 		if (irqstatus & pipe2vbl(crtc))
205 			drm_handle_vblank(dev, id);
206 	}
207 
208 	spin_lock_irqsave(&list_lock, flags);
209 	list_for_each_entry_safe(handler, n, &priv->irq_list, node) {
210 		if (handler->irqmask & irqstatus) {
211 			spin_unlock_irqrestore(&list_lock, flags);
212 			handler->irq(handler, handler->irqmask & irqstatus);
213 			spin_lock_irqsave(&list_lock, flags);
214 		}
215 	}
216 	spin_unlock_irqrestore(&list_lock, flags);
217 
218 	return IRQ_HANDLED;
219 }
220 
221 /*
222  * We need a special version, instead of just using drm_irq_install(),
223  * because we need to register the irq via omapdss.  Once omapdss and
224  * omapdrm are merged together we can assign the dispc hwmod data to
225  * ourselves and drop these and just use drm_irq_{install,uninstall}()
226  */
227 
228 int omap_drm_irq_install(struct drm_device *dev)
229 {
230 	struct omap_drm_private *priv = dev->dev_private;
231 	struct omap_drm_irq *error_handler = &priv->error_handler;
232 	int ret;
233 
234 	INIT_LIST_HEAD(&priv->irq_list);
235 
236 	dispc_runtime_get();
237 	dispc_clear_irqstatus(0xffffffff);
238 	dispc_runtime_put();
239 
240 	ret = dispc_request_irq(omap_irq_handler, dev);
241 	if (ret < 0)
242 		return ret;
243 
244 	error_handler->irq = omap_irq_error_handler;
245 	error_handler->irqmask = DISPC_IRQ_OCP_ERR;
246 
247 	/* for now ignore DISPC_IRQ_SYNC_LOST_DIGIT.. really I think
248 	 * we just need to ignore it while enabling tv-out
249 	 */
250 	error_handler->irqmask &= ~DISPC_IRQ_SYNC_LOST_DIGIT;
251 
252 	omap_irq_register(dev, error_handler);
253 
254 	dev->irq_enabled = true;
255 
256 	return 0;
257 }
258 
259 void omap_drm_irq_uninstall(struct drm_device *dev)
260 {
261 	unsigned long irqflags;
262 	int i;
263 
264 	if (!dev->irq_enabled)
265 		return;
266 
267 	dev->irq_enabled = false;
268 
269 	/* Wake up any waiters so they don't hang. */
270 	if (dev->num_crtcs) {
271 		spin_lock_irqsave(&dev->vbl_lock, irqflags);
272 		for (i = 0; i < dev->num_crtcs; i++) {
273 			wake_up(&dev->vblank[i].queue);
274 			dev->vblank[i].enabled = false;
275 			dev->vblank[i].last =
276 				dev->driver->get_vblank_counter(dev, i);
277 		}
278 		spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
279 	}
280 
281 	dispc_free_irq(dev);
282 }
283