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_irq.h>
64 #include <drm/drm_print.h>
65 #include <drm/drm_vblank.h>
66
67 #include "drm_internal.h"
68
69 /**
70 * DOC: irq helpers
71 *
72 * The DRM core provides very simple support helpers to enable IRQ handling on a
73 * device through the drm_irq_install() and drm_irq_uninstall() functions. This
74 * only supports devices with a single interrupt on the main device stored in
75 * &drm_device.dev and set as the device paramter in drm_dev_alloc().
76 *
77 * These IRQ helpers are strictly optional. Drivers which roll their own only
78 * need to set &drm_device.irq_enabled to signal the DRM core that vblank
79 * interrupts are working. Since these helpers don't automatically clean up the
80 * requested interrupt like e.g. devm_request_irq() they're not really
81 * recommended.
82 */
83
84 /**
85 * drm_irq_install - install IRQ handler
86 * @dev: DRM device
87 * @irq: IRQ number to install the handler for
88 *
89 * Initializes the IRQ related data. Installs the handler, calling the driver
90 * &drm_driver.irq_preinstall and &drm_driver.irq_postinstall functions before
91 * and after the installation.
92 *
93 * This is the simplified helper interface provided for drivers with no special
94 * needs. Drivers which need to install interrupt handlers for multiple
95 * interrupts must instead set &drm_device.irq_enabled to signal the DRM core
96 * that vblank interrupts are available.
97 *
98 * @irq must match the interrupt number that would be passed to request_irq(),
99 * if called directly instead of using this helper function.
100 *
101 * &drm_driver.irq_handler is called to handle the registered interrupt.
102 *
103 * Returns:
104 * Zero on success or a negative error code on failure.
105 */
106 int drm_irq_install(struct drm_device *dev, int irq)
107 {
108 int ret;
109 unsigned long sh_flags = 0;
110
111 if (irq == 0)
112 return -EINVAL;
113
114 /* Driver must have been initialized */
115 if (!dev->dev_private)
116 return -EINVAL;
117
118 if (dev->irq_enabled)
119 return -EBUSY;
120 dev->irq_enabled = true;
121
122 DRM_DEBUG("irq=%d\n", irq);
123
124 /* Before installing handler */
125 if (dev->driver->irq_preinstall)
126 dev->driver->irq_preinstall(dev);
127
128 /* PCI devices require shared interrupts. */
129 if (dev->pdev)
130 sh_flags = IRQF_SHARED;
131
132 ret = request_irq(irq, dev->driver->irq_handler,
133 sh_flags, dev->driver->name, dev);
134
135 if (ret < 0) {
136 dev->irq_enabled = false;
137 return ret;
138 }
139
140 /* After installing handler */
141 if (dev->driver->irq_postinstall)
142 ret = dev->driver->irq_postinstall(dev);
143
144 if (ret < 0) {
145 dev->irq_enabled = false;
146 if (drm_core_check_feature(dev, DRIVER_LEGACY))
147 vga_client_register(dev->pdev, NULL, NULL, NULL);
148 free_irq(irq, dev);
149 } else {
150 dev->irq = irq;
151 }
152
153 return ret;
154 }
155 EXPORT_SYMBOL(drm_irq_install);
156
157 /**
158 * drm_irq_uninstall - uninstall the IRQ handler
159 * @dev: DRM device
160 *
161 * Calls the driver's &drm_driver.irq_uninstall function and unregisters the IRQ
162 * handler. This should only be called by drivers which used drm_irq_install()
163 * to set up their interrupt handler. Other drivers must only reset
164 * &drm_device.irq_enabled to false.
165 *
166 * Note that for kernel modesetting drivers it is a bug if this function fails.
167 * The sanity checks are only to catch buggy user modesetting drivers which call
168 * the same function through an ioctl.
169 *
170 * Returns:
171 * Zero on success or a negative error code on failure.
172 */
173 int drm_irq_uninstall(struct drm_device *dev)
174 {
175 unsigned long irqflags;
176 bool irq_enabled;
177 int i;
178
179 irq_enabled = dev->irq_enabled;
180 dev->irq_enabled = false;
181
182 /*
183 * Wake up any waiters so they don't hang. This is just to paper over
184 * issues for UMS drivers which aren't in full control of their
185 * vblank/irq handling. KMS drivers must ensure that vblanks are all
186 * disabled when uninstalling the irq handler.
187 */
188 if (dev->num_crtcs) {
189 spin_lock_irqsave(&dev->vbl_lock, irqflags);
190 for (i = 0; i < dev->num_crtcs; i++) {
191 struct drm_vblank_crtc *vblank = &dev->vblank[i];
192
193 if (!vblank->enabled)
194 continue;
195
196 WARN_ON(drm_core_check_feature(dev, DRIVER_MODESET));
197
198 drm_vblank_disable_and_save(dev, i);
199 wake_up(&vblank->queue);
200 }
201 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
202 }
203
204 if (!irq_enabled)
205 return -EINVAL;
206
207 DRM_DEBUG("irq=%d\n", dev->irq);
208
209 if (drm_core_check_feature(dev, DRIVER_LEGACY))
210 vga_client_register(dev->pdev, NULL, NULL, NULL);
211
212 if (dev->driver->irq_uninstall)
213 dev->driver->irq_uninstall(dev);
214
215 free_irq(dev->irq, dev);
216
217 return 0;
218 }
219 EXPORT_SYMBOL(drm_irq_uninstall);
220
221 #if IS_ENABLED(CONFIG_DRM_LEGACY)
222 int drm_legacy_irq_control(struct drm_device *dev, void *data,
223 struct drm_file *file_priv)
224 {
225 struct drm_control *ctl = data;
226 int ret = 0, irq;
227
228 /* if we haven't irq we fallback for compatibility reasons -
229 * this used to be a separate function in drm_dma.h
230 */
231
232 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
233 return 0;
234 if (!drm_core_check_feature(dev, DRIVER_LEGACY))
235 return 0;
236 /* UMS was only ever supported on pci devices. */
237 if (WARN_ON(!dev->pdev))
238 return -EINVAL;
239
240 switch (ctl->func) {
241 case DRM_INST_HANDLER:
242 irq = dev->pdev->irq;
243
244 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
245 ctl->irq != irq)
246 return -EINVAL;
247 mutex_lock(&dev->struct_mutex);
248 ret = drm_irq_install(dev, irq);
249 mutex_unlock(&dev->struct_mutex);
250
251 return ret;
252 case DRM_UNINST_HANDLER:
253 mutex_lock(&dev->struct_mutex);
254 ret = drm_irq_uninstall(dev);
255 mutex_unlock(&dev->struct_mutex);
256
257 return ret;
258 default:
259 return -EINVAL;
260 }
261 }
262 #endif