xref: /openbmc/linux/drivers/gpu/drm/drm_irq.c (revision 48cc39c3)
1 /*
2  * drm_irq.c IRQ and vblank support
3  *
4  * \author Rickard E. (Rik) Faith <faith@valinux.com>
5  * \author Gareth Hughes <gareth@valinux.com>
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a
8  * copy of this software and associated documentation files (the "Software"),
9  * to deal in the Software without restriction, including without limitation
10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11  * and/or sell copies of the Software, and to permit persons to whom the
12  * Software is furnished to do so, subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice (including the next
15  * paragraph) shall be included in all copies or substantial portions of the
16  * Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
21  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
22  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
23  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
24  * OTHER DEALINGS IN THE SOFTWARE.
25  */
26 
27 /*
28  * Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
29  *
30  * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
31  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
32  * All Rights Reserved.
33  *
34  * Permission is hereby granted, free of charge, to any person obtaining a
35  * copy of this software and associated documentation files (the "Software"),
36  * to deal in the Software without restriction, including without limitation
37  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
38  * and/or sell copies of the Software, and to permit persons to whom the
39  * Software is furnished to do so, subject to the following conditions:
40  *
41  * The above copyright notice and this permission notice (including the next
42  * paragraph) shall be included in all copies or substantial portions of the
43  * Software.
44  *
45  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
46  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
47  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
48  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
49  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
50  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
51  * OTHER DEALINGS IN THE SOFTWARE.
52  */
53 
54 
55 #include <linux/export.h>
56 #include <linux/interrupt.h>	/* For task queue support */
57 #include <linux/pci.h>
58 #include <linux/vgaarb.h>
59 
60 #include <drm/drm.h>
61 #include <drm/drm_device.h>
62 #include <drm/drm_drv.h>
63 #include <drm/drm_legacy.h>
64 #include <drm/drm_print.h>
65 #include <drm/drm_vblank.h>
66 
67 #include "drm_internal.h"
68 
69 #if IS_ENABLED(CONFIG_DRM_LEGACY)
70 static int drm_legacy_irq_install(struct drm_device *dev, int irq)
71 {
72 	int ret;
73 	unsigned long sh_flags = 0;
74 
75 	if (irq == 0)
76 		return -EINVAL;
77 
78 	if (dev->irq_enabled)
79 		return -EBUSY;
80 	dev->irq_enabled = true;
81 
82 	DRM_DEBUG("irq=%d\n", irq);
83 
84 	/* Before installing handler */
85 	if (dev->driver->irq_preinstall)
86 		dev->driver->irq_preinstall(dev);
87 
88 	/* PCI devices require shared interrupts. */
89 	if (dev_is_pci(dev->dev))
90 		sh_flags = IRQF_SHARED;
91 
92 	ret = request_irq(irq, dev->driver->irq_handler,
93 			  sh_flags, dev->driver->name, dev);
94 
95 	if (ret < 0) {
96 		dev->irq_enabled = false;
97 		return ret;
98 	}
99 
100 	/* After installing handler */
101 	if (dev->driver->irq_postinstall)
102 		ret = dev->driver->irq_postinstall(dev);
103 
104 	if (ret < 0) {
105 		dev->irq_enabled = false;
106 		if (drm_core_check_feature(dev, DRIVER_LEGACY))
107 			vga_client_unregister(to_pci_dev(dev->dev));
108 		free_irq(irq, dev);
109 	} else {
110 		dev->irq = irq;
111 	}
112 
113 	return ret;
114 }
115 
116 int drm_legacy_irq_uninstall(struct drm_device *dev)
117 {
118 	unsigned long irqflags;
119 	bool irq_enabled;
120 	int i;
121 
122 	irq_enabled = dev->irq_enabled;
123 	dev->irq_enabled = false;
124 
125 	/*
126 	 * Wake up any waiters so they don't hang. This is just to paper over
127 	 * issues for UMS drivers which aren't in full control of their
128 	 * vblank/irq handling. KMS drivers must ensure that vblanks are all
129 	 * disabled when uninstalling the irq handler.
130 	 */
131 	if (drm_dev_has_vblank(dev)) {
132 		spin_lock_irqsave(&dev->vbl_lock, irqflags);
133 		for (i = 0; i < dev->num_crtcs; i++) {
134 			struct drm_vblank_crtc *vblank = &dev->vblank[i];
135 
136 			if (!vblank->enabled)
137 				continue;
138 
139 			WARN_ON(drm_core_check_feature(dev, DRIVER_MODESET));
140 
141 			drm_vblank_disable_and_save(dev, i);
142 			wake_up(&vblank->queue);
143 		}
144 		spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
145 	}
146 
147 	if (!irq_enabled)
148 		return -EINVAL;
149 
150 	DRM_DEBUG("irq=%d\n", dev->irq);
151 
152 	if (drm_core_check_feature(dev, DRIVER_LEGACY))
153 		vga_client_unregister(to_pci_dev(dev->dev));
154 
155 	if (dev->driver->irq_uninstall)
156 		dev->driver->irq_uninstall(dev);
157 
158 	free_irq(dev->irq, dev);
159 
160 	return 0;
161 }
162 EXPORT_SYMBOL(drm_legacy_irq_uninstall);
163 
164 int drm_legacy_irq_control(struct drm_device *dev, void *data,
165 			   struct drm_file *file_priv)
166 {
167 	struct drm_control *ctl = data;
168 	int ret = 0, irq;
169 	struct pci_dev *pdev;
170 
171 	/* if we haven't irq we fallback for compatibility reasons -
172 	 * this used to be a separate function in drm_dma.h
173 	 */
174 
175 	if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
176 		return 0;
177 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
178 		return 0;
179 	/* UMS was only ever supported on pci devices. */
180 	if (WARN_ON(!dev_is_pci(dev->dev)))
181 		return -EINVAL;
182 
183 	switch (ctl->func) {
184 	case DRM_INST_HANDLER:
185 		pdev = to_pci_dev(dev->dev);
186 		irq = pdev->irq;
187 
188 		if (dev->if_version < DRM_IF_VERSION(1, 2) &&
189 		    ctl->irq != irq)
190 			return -EINVAL;
191 		mutex_lock(&dev->struct_mutex);
192 		ret = drm_legacy_irq_install(dev, irq);
193 		mutex_unlock(&dev->struct_mutex);
194 
195 		return ret;
196 	case DRM_UNINST_HANDLER:
197 		mutex_lock(&dev->struct_mutex);
198 		ret = drm_legacy_irq_uninstall(dev);
199 		mutex_unlock(&dev->struct_mutex);
200 
201 		return ret;
202 	default:
203 		return -EINVAL;
204 	}
205 }
206 #endif
207