xref: /openbmc/linux/drivers/gpu/drm/omapdrm/omap_irq.c (revision e2c75e76)
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 	uint32_t 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 	uint32_t 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(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 		uint32_t 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(channel);
112 	omap_irq_update(dev);
113 	spin_unlock_irqrestore(&priv->wait_lock, flags);
114 
115 	return 0;
116 }
117 
118 /**
119  * disable_vblank - disable vblank interrupt events
120  * @dev: DRM device
121  * @pipe: which irq to enable
122  *
123  * Disable vblank interrupts for @crtc.  If the device doesn't have
124  * a hardware vblank counter, this routine should be a no-op, since
125  * interrupts will have to stay on to keep the count accurate.
126  */
127 void omap_irq_disable_vblank(struct drm_crtc *crtc)
128 {
129 	struct drm_device *dev = crtc->dev;
130 	struct omap_drm_private *priv = dev->dev_private;
131 	unsigned long flags;
132 	enum omap_channel channel = omap_crtc_channel(crtc);
133 
134 	DBG("dev=%p, crtc=%u", dev, channel);
135 
136 	spin_lock_irqsave(&priv->wait_lock, flags);
137 	priv->irq_mask &= ~priv->dispc_ops->mgr_get_vsync_irq(channel);
138 	omap_irq_update(dev);
139 	spin_unlock_irqrestore(&priv->wait_lock, flags);
140 }
141 
142 static void omap_irq_fifo_underflow(struct omap_drm_private *priv,
143 				    u32 irqstatus)
144 {
145 	static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
146 				      DEFAULT_RATELIMIT_BURST);
147 	static const struct {
148 		const char *name;
149 		u32 mask;
150 	} sources[] = {
151 		{ "gfx", DISPC_IRQ_GFX_FIFO_UNDERFLOW },
152 		{ "vid1", DISPC_IRQ_VID1_FIFO_UNDERFLOW },
153 		{ "vid2", DISPC_IRQ_VID2_FIFO_UNDERFLOW },
154 		{ "vid3", DISPC_IRQ_VID3_FIFO_UNDERFLOW },
155 	};
156 
157 	const u32 mask = DISPC_IRQ_GFX_FIFO_UNDERFLOW
158 		       | DISPC_IRQ_VID1_FIFO_UNDERFLOW
159 		       | DISPC_IRQ_VID2_FIFO_UNDERFLOW
160 		       | DISPC_IRQ_VID3_FIFO_UNDERFLOW;
161 	unsigned int i;
162 
163 	spin_lock(&priv->wait_lock);
164 	irqstatus &= priv->irq_mask & mask;
165 	spin_unlock(&priv->wait_lock);
166 
167 	if (!irqstatus)
168 		return;
169 
170 	if (!__ratelimit(&_rs))
171 		return;
172 
173 	DRM_ERROR("FIFO underflow on ");
174 
175 	for (i = 0; i < ARRAY_SIZE(sources); ++i) {
176 		if (sources[i].mask & irqstatus)
177 			pr_cont("%s ", sources[i].name);
178 	}
179 
180 	pr_cont("(0x%08x)\n", irqstatus);
181 }
182 
183 static void omap_irq_ocp_error_handler(struct drm_device *dev,
184 	u32 irqstatus)
185 {
186 	if (!(irqstatus & DISPC_IRQ_OCP_ERR))
187 		return;
188 
189 	dev_err_ratelimited(dev->dev, "OCP error\n");
190 }
191 
192 static irqreturn_t omap_irq_handler(int irq, void *arg)
193 {
194 	struct drm_device *dev = (struct drm_device *) arg;
195 	struct omap_drm_private *priv = dev->dev_private;
196 	struct omap_irq_wait *wait, *n;
197 	unsigned long flags;
198 	unsigned int id;
199 	u32 irqstatus;
200 
201 	irqstatus = priv->dispc_ops->read_irqstatus();
202 	priv->dispc_ops->clear_irqstatus(irqstatus);
203 	priv->dispc_ops->read_irqstatus();        /* flush posted write */
204 
205 	VERB("irqs: %08x", irqstatus);
206 
207 	for (id = 0; id < priv->num_crtcs; id++) {
208 		struct drm_crtc *crtc = priv->crtcs[id];
209 		enum omap_channel channel = omap_crtc_channel(crtc);
210 
211 		if (irqstatus & priv->dispc_ops->mgr_get_vsync_irq(channel)) {
212 			drm_handle_vblank(dev, id);
213 			omap_crtc_vblank_irq(crtc);
214 		}
215 
216 		if (irqstatus & priv->dispc_ops->mgr_get_sync_lost_irq(channel))
217 			omap_crtc_error_irq(crtc, irqstatus);
218 	}
219 
220 	omap_irq_ocp_error_handler(dev, irqstatus);
221 	omap_irq_fifo_underflow(priv, irqstatus);
222 
223 	spin_lock_irqsave(&priv->wait_lock, flags);
224 	list_for_each_entry_safe(wait, n, &priv->wait_list, node) {
225 		if (wait->irqmask & irqstatus)
226 			omap_irq_wait_handler(wait);
227 	}
228 	spin_unlock_irqrestore(&priv->wait_lock, flags);
229 
230 	return IRQ_HANDLED;
231 }
232 
233 static const u32 omap_underflow_irqs[] = {
234 	[OMAP_DSS_GFX] = DISPC_IRQ_GFX_FIFO_UNDERFLOW,
235 	[OMAP_DSS_VIDEO1] = DISPC_IRQ_VID1_FIFO_UNDERFLOW,
236 	[OMAP_DSS_VIDEO2] = DISPC_IRQ_VID2_FIFO_UNDERFLOW,
237 	[OMAP_DSS_VIDEO3] = DISPC_IRQ_VID3_FIFO_UNDERFLOW,
238 };
239 
240 /*
241  * We need a special version, instead of just using drm_irq_install(),
242  * because we need to register the irq via omapdss.  Once omapdss and
243  * omapdrm are merged together we can assign the dispc hwmod data to
244  * ourselves and drop these and just use drm_irq_{install,uninstall}()
245  */
246 
247 int omap_drm_irq_install(struct drm_device *dev)
248 {
249 	struct omap_drm_private *priv = dev->dev_private;
250 	unsigned int num_mgrs = priv->dispc_ops->get_num_mgrs();
251 	unsigned int max_planes;
252 	unsigned int i;
253 	int ret;
254 
255 	spin_lock_init(&priv->wait_lock);
256 	INIT_LIST_HEAD(&priv->wait_list);
257 
258 	priv->irq_mask = DISPC_IRQ_OCP_ERR;
259 
260 	max_planes = min(ARRAY_SIZE(priv->planes),
261 			 ARRAY_SIZE(omap_underflow_irqs));
262 	for (i = 0; i < max_planes; ++i) {
263 		if (priv->planes[i])
264 			priv->irq_mask |= omap_underflow_irqs[i];
265 	}
266 
267 	for (i = 0; i < num_mgrs; ++i)
268 		priv->irq_mask |= priv->dispc_ops->mgr_get_sync_lost_irq(i);
269 
270 	priv->dispc_ops->runtime_get();
271 	priv->dispc_ops->clear_irqstatus(0xffffffff);
272 	priv->dispc_ops->runtime_put();
273 
274 	ret = priv->dispc_ops->request_irq(omap_irq_handler, dev);
275 	if (ret < 0)
276 		return ret;
277 
278 	dev->irq_enabled = true;
279 
280 	return 0;
281 }
282 
283 void omap_drm_irq_uninstall(struct drm_device *dev)
284 {
285 	struct omap_drm_private *priv = dev->dev_private;
286 
287 	if (!dev->irq_enabled)
288 		return;
289 
290 	dev->irq_enabled = false;
291 
292 	priv->dispc_ops->free_irq(dev);
293 }
294