xref: /openbmc/linux/drivers/gpu/drm/omapdrm/omap_irq.c (revision addee42a)
1 /*
2  * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
3  * Author: Rob Clark <rob.clark@linaro.org>
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms of the GNU General Public License version 2 as published by
7  * the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  * You should have received a copy of the GNU General Public License along with
15  * this program.  If not, see <http://www.gnu.org/licenses/>.
16  */
17 
18 #include "omap_drv.h"
19 
20 struct omap_irq_wait {
21 	struct list_head node;
22 	wait_queue_head_t wq;
23 	u32 irqmask;
24 	int count;
25 };
26 
27 /* call with wait_lock and dispc runtime held */
28 static void omap_irq_update(struct drm_device *dev)
29 {
30 	struct omap_drm_private *priv = dev->dev_private;
31 	struct omap_irq_wait *wait;
32 	u32 irqmask = priv->irq_mask;
33 
34 	assert_spin_locked(&priv->wait_lock);
35 
36 	list_for_each_entry(wait, &priv->wait_list, node)
37 		irqmask |= wait->irqmask;
38 
39 	DBG("irqmask=%08x", irqmask);
40 
41 	priv->dispc_ops->write_irqenable(priv->dispc, irqmask);
42 }
43 
44 static void omap_irq_wait_handler(struct omap_irq_wait *wait)
45 {
46 	wait->count--;
47 	wake_up(&wait->wq);
48 }
49 
50 struct omap_irq_wait * omap_irq_wait_init(struct drm_device *dev,
51 		u32 irqmask, int count)
52 {
53 	struct omap_drm_private *priv = dev->dev_private;
54 	struct omap_irq_wait *wait = kzalloc(sizeof(*wait), GFP_KERNEL);
55 	unsigned long flags;
56 
57 	init_waitqueue_head(&wait->wq);
58 	wait->irqmask = irqmask;
59 	wait->count = count;
60 
61 	spin_lock_irqsave(&priv->wait_lock, flags);
62 	list_add(&wait->node, &priv->wait_list);
63 	omap_irq_update(dev);
64 	spin_unlock_irqrestore(&priv->wait_lock, flags);
65 
66 	return wait;
67 }
68 
69 int omap_irq_wait(struct drm_device *dev, struct omap_irq_wait *wait,
70 		unsigned long timeout)
71 {
72 	struct omap_drm_private *priv = dev->dev_private;
73 	unsigned long flags;
74 	int ret;
75 
76 	ret = wait_event_timeout(wait->wq, (wait->count <= 0), timeout);
77 
78 	spin_lock_irqsave(&priv->wait_lock, flags);
79 	list_del(&wait->node);
80 	omap_irq_update(dev);
81 	spin_unlock_irqrestore(&priv->wait_lock, flags);
82 
83 	kfree(wait);
84 
85 	return ret == 0 ? -1 : 0;
86 }
87 
88 /**
89  * enable_vblank - enable vblank interrupt events
90  * @dev: DRM device
91  * @pipe: which irq to enable
92  *
93  * Enable vblank interrupts for @crtc.  If the device doesn't have
94  * a hardware vblank counter, this routine should be a no-op, since
95  * interrupts will have to stay on to keep the count accurate.
96  *
97  * RETURNS
98  * Zero on success, appropriate errno if the given @crtc's vblank
99  * interrupt cannot be enabled.
100  */
101 int omap_irq_enable_vblank(struct drm_crtc *crtc)
102 {
103 	struct drm_device *dev = crtc->dev;
104 	struct omap_drm_private *priv = dev->dev_private;
105 	unsigned long flags;
106 	enum omap_channel channel = omap_crtc_channel(crtc);
107 
108 	DBG("dev=%p, crtc=%u", dev, channel);
109 
110 	spin_lock_irqsave(&priv->wait_lock, flags);
111 	priv->irq_mask |= priv->dispc_ops->mgr_get_vsync_irq(priv->dispc,
112 							     channel);
113 	omap_irq_update(dev);
114 	spin_unlock_irqrestore(&priv->wait_lock, flags);
115 
116 	return 0;
117 }
118 
119 /**
120  * disable_vblank - disable vblank interrupt events
121  * @dev: DRM device
122  * @pipe: which irq to enable
123  *
124  * Disable vblank interrupts for @crtc.  If the device doesn't have
125  * a hardware vblank counter, this routine should be a no-op, since
126  * interrupts will have to stay on to keep the count accurate.
127  */
128 void omap_irq_disable_vblank(struct drm_crtc *crtc)
129 {
130 	struct drm_device *dev = crtc->dev;
131 	struct omap_drm_private *priv = dev->dev_private;
132 	unsigned long flags;
133 	enum omap_channel channel = omap_crtc_channel(crtc);
134 
135 	DBG("dev=%p, crtc=%u", dev, channel);
136 
137 	spin_lock_irqsave(&priv->wait_lock, flags);
138 	priv->irq_mask &= ~priv->dispc_ops->mgr_get_vsync_irq(priv->dispc,
139 							      channel);
140 	omap_irq_update(dev);
141 	spin_unlock_irqrestore(&priv->wait_lock, flags);
142 }
143 
144 static void omap_irq_fifo_underflow(struct omap_drm_private *priv,
145 				    u32 irqstatus)
146 {
147 	static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
148 				      DEFAULT_RATELIMIT_BURST);
149 	static const struct {
150 		const char *name;
151 		u32 mask;
152 	} sources[] = {
153 		{ "gfx", DISPC_IRQ_GFX_FIFO_UNDERFLOW },
154 		{ "vid1", DISPC_IRQ_VID1_FIFO_UNDERFLOW },
155 		{ "vid2", DISPC_IRQ_VID2_FIFO_UNDERFLOW },
156 		{ "vid3", DISPC_IRQ_VID3_FIFO_UNDERFLOW },
157 	};
158 
159 	const u32 mask = DISPC_IRQ_GFX_FIFO_UNDERFLOW
160 		       | DISPC_IRQ_VID1_FIFO_UNDERFLOW
161 		       | DISPC_IRQ_VID2_FIFO_UNDERFLOW
162 		       | DISPC_IRQ_VID3_FIFO_UNDERFLOW;
163 	unsigned int i;
164 
165 	spin_lock(&priv->wait_lock);
166 	irqstatus &= priv->irq_mask & mask;
167 	spin_unlock(&priv->wait_lock);
168 
169 	if (!irqstatus)
170 		return;
171 
172 	if (!__ratelimit(&_rs))
173 		return;
174 
175 	DRM_ERROR("FIFO underflow on ");
176 
177 	for (i = 0; i < ARRAY_SIZE(sources); ++i) {
178 		if (sources[i].mask & irqstatus)
179 			pr_cont("%s ", sources[i].name);
180 	}
181 
182 	pr_cont("(0x%08x)\n", irqstatus);
183 }
184 
185 static void omap_irq_ocp_error_handler(struct drm_device *dev,
186 	u32 irqstatus)
187 {
188 	if (!(irqstatus & DISPC_IRQ_OCP_ERR))
189 		return;
190 
191 	dev_err_ratelimited(dev->dev, "OCP error\n");
192 }
193 
194 static irqreturn_t omap_irq_handler(int irq, void *arg)
195 {
196 	struct drm_device *dev = (struct drm_device *) arg;
197 	struct omap_drm_private *priv = dev->dev_private;
198 	struct omap_irq_wait *wait, *n;
199 	unsigned long flags;
200 	unsigned int id;
201 	u32 irqstatus;
202 
203 	irqstatus = priv->dispc_ops->read_irqstatus(priv->dispc);
204 	priv->dispc_ops->clear_irqstatus(priv->dispc, irqstatus);
205 	priv->dispc_ops->read_irqstatus(priv->dispc);	/* flush posted write */
206 
207 	VERB("irqs: %08x", irqstatus);
208 
209 	for (id = 0; id < priv->num_crtcs; id++) {
210 		struct drm_crtc *crtc = priv->crtcs[id];
211 		enum omap_channel channel = omap_crtc_channel(crtc);
212 
213 		if (irqstatus & priv->dispc_ops->mgr_get_vsync_irq(priv->dispc, channel)) {
214 			drm_handle_vblank(dev, id);
215 			omap_crtc_vblank_irq(crtc);
216 		}
217 
218 		if (irqstatus & priv->dispc_ops->mgr_get_sync_lost_irq(priv->dispc, channel))
219 			omap_crtc_error_irq(crtc, irqstatus);
220 	}
221 
222 	omap_irq_ocp_error_handler(dev, irqstatus);
223 	omap_irq_fifo_underflow(priv, irqstatus);
224 
225 	spin_lock_irqsave(&priv->wait_lock, flags);
226 	list_for_each_entry_safe(wait, n, &priv->wait_list, node) {
227 		if (wait->irqmask & irqstatus)
228 			omap_irq_wait_handler(wait);
229 	}
230 	spin_unlock_irqrestore(&priv->wait_lock, flags);
231 
232 	return IRQ_HANDLED;
233 }
234 
235 static const u32 omap_underflow_irqs[] = {
236 	[OMAP_DSS_GFX] = DISPC_IRQ_GFX_FIFO_UNDERFLOW,
237 	[OMAP_DSS_VIDEO1] = DISPC_IRQ_VID1_FIFO_UNDERFLOW,
238 	[OMAP_DSS_VIDEO2] = DISPC_IRQ_VID2_FIFO_UNDERFLOW,
239 	[OMAP_DSS_VIDEO3] = DISPC_IRQ_VID3_FIFO_UNDERFLOW,
240 };
241 
242 /*
243  * We need a special version, instead of just using drm_irq_install(),
244  * because we need to register the irq via omapdss.  Once omapdss and
245  * omapdrm are merged together we can assign the dispc hwmod data to
246  * ourselves and drop these and just use drm_irq_{install,uninstall}()
247  */
248 
249 int omap_drm_irq_install(struct drm_device *dev)
250 {
251 	struct omap_drm_private *priv = dev->dev_private;
252 	unsigned int num_mgrs = priv->dispc_ops->get_num_mgrs(priv->dispc);
253 	unsigned int max_planes;
254 	unsigned int i;
255 	int ret;
256 
257 	spin_lock_init(&priv->wait_lock);
258 	INIT_LIST_HEAD(&priv->wait_list);
259 
260 	priv->irq_mask = DISPC_IRQ_OCP_ERR;
261 
262 	max_planes = min(ARRAY_SIZE(priv->planes),
263 			 ARRAY_SIZE(omap_underflow_irqs));
264 	for (i = 0; i < max_planes; ++i) {
265 		if (priv->planes[i])
266 			priv->irq_mask |= omap_underflow_irqs[i];
267 	}
268 
269 	for (i = 0; i < num_mgrs; ++i)
270 		priv->irq_mask |= priv->dispc_ops->mgr_get_sync_lost_irq(priv->dispc, i);
271 
272 	priv->dispc_ops->runtime_get(priv->dispc);
273 	priv->dispc_ops->clear_irqstatus(priv->dispc, 0xffffffff);
274 	priv->dispc_ops->runtime_put(priv->dispc);
275 
276 	ret = priv->dispc_ops->request_irq(priv->dispc, omap_irq_handler, dev);
277 	if (ret < 0)
278 		return ret;
279 
280 	dev->irq_enabled = true;
281 
282 	return 0;
283 }
284 
285 void omap_drm_irq_uninstall(struct drm_device *dev)
286 {
287 	struct omap_drm_private *priv = dev->dev_private;
288 
289 	if (!dev->irq_enabled)
290 		return;
291 
292 	dev->irq_enabled = false;
293 
294 	priv->dispc_ops->free_irq(priv->dispc, dev);
295 }
296