drm_irq.c revision 1.1.1.4
1 /* $NetBSD: drm_irq.c,v 1.1.1.4 2021/12/18 20:11:02 riastradh Exp $ */ 2 3 /* 4 * drm_irq.c IRQ and vblank support 5 * 6 * \author Rickard E. (Rik) Faith <faith (at) valinux.com> 7 * \author Gareth Hughes <gareth (at) valinux.com> 8 * 9 * Permission is hereby granted, free of charge, to any person obtaining a 10 * copy of this software and associated documentation files (the "Software"), 11 * to deal in the Software without restriction, including without limitation 12 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 13 * and/or sell copies of the Software, and to permit persons to whom the 14 * Software is furnished to do so, subject to the following conditions: 15 * 16 * The above copyright notice and this permission notice (including the next 17 * paragraph) shall be included in all copies or substantial portions of the 18 * Software. 19 * 20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 23 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 24 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 25 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 26 * OTHER DEALINGS IN THE SOFTWARE. 27 */ 28 29 /* 30 * Created: Fri Mar 19 14:30:16 1999 by faith (at) valinux.com 31 * 32 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas. 33 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California. 34 * All Rights Reserved. 35 * 36 * Permission is hereby granted, free of charge, to any person obtaining a 37 * copy of this software and associated documentation files (the "Software"), 38 * to deal in the Software without restriction, including without limitation 39 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 40 * and/or sell copies of the Software, and to permit persons to whom the 41 * Software is furnished to do so, subject to the following conditions: 42 * 43 * The above copyright notice and this permission notice (including the next 44 * paragraph) shall be included in all copies or substantial portions of the 45 * Software. 46 * 47 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 48 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 49 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 50 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 51 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 52 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 53 * OTHER DEALINGS IN THE SOFTWARE. 54 */ 55 56 57 #include <sys/cdefs.h> 58 __KERNEL_RCSID(0, "$NetBSD: drm_irq.c,v 1.1.1.4 2021/12/18 20:11:02 riastradh Exp $"); 59 60 #include <linux/export.h> 61 #include <linux/interrupt.h> /* For task queue support */ 62 #include <linux/pci.h> 63 #include <linux/vgaarb.h> 64 65 #include <drm/drm.h> 66 #include <drm/drm_device.h> 67 #include <drm/drm_drv.h> 68 #include <drm/drm_irq.h> 69 #include <drm/drm_print.h> 70 #include <drm/drm_vblank.h> 71 72 #include "drm_internal.h" 73 74 /** 75 * DOC: irq helpers 76 * 77 * The DRM core provides very simple support helpers to enable IRQ handling on a 78 * device through the drm_irq_install() and drm_irq_uninstall() functions. This 79 * only supports devices with a single interrupt on the main device stored in 80 * &drm_device.dev and set as the device paramter in drm_dev_alloc(). 81 * 82 * These IRQ helpers are strictly optional. Drivers which roll their own only 83 * need to set &drm_device.irq_enabled to signal the DRM core that vblank 84 * interrupts are working. Since these helpers don't automatically clean up the 85 * requested interrupt like e.g. devm_request_irq() they're not really 86 * recommended. 87 */ 88 89 /** 90 * drm_irq_install - install IRQ handler 91 * @dev: DRM device 92 * @irq: IRQ number to install the handler for 93 * 94 * Initializes the IRQ related data. Installs the handler, calling the driver 95 * &drm_driver.irq_preinstall and &drm_driver.irq_postinstall functions before 96 * and after the installation. 97 * 98 * This is the simplified helper interface provided for drivers with no special 99 * needs. Drivers which need to install interrupt handlers for multiple 100 * interrupts must instead set &drm_device.irq_enabled to signal the DRM core 101 * that vblank interrupts are available. 102 * 103 * @irq must match the interrupt number that would be passed to request_irq(), 104 * if called directly instead of using this helper function. 105 * 106 * &drm_driver.irq_handler is called to handle the registered interrupt. 107 * 108 * Returns: 109 * Zero on success or a negative error code on failure. 110 */ 111 int drm_irq_install(struct drm_device *dev, int irq) 112 { 113 int ret; 114 unsigned long sh_flags = 0; 115 116 if (irq == 0) 117 return -EINVAL; 118 119 /* Driver must have been initialized */ 120 if (!dev->dev_private) 121 return -EINVAL; 122 123 if (dev->irq_enabled) 124 return -EBUSY; 125 dev->irq_enabled = true; 126 127 DRM_DEBUG("irq=%d\n", irq); 128 129 /* Before installing handler */ 130 if (dev->driver->irq_preinstall) 131 dev->driver->irq_preinstall(dev); 132 133 /* PCI devices require shared interrupts. */ 134 if (dev->pdev) 135 sh_flags = IRQF_SHARED; 136 137 ret = request_irq(irq, dev->driver->irq_handler, 138 sh_flags, dev->driver->name, dev); 139 140 if (ret < 0) { 141 dev->irq_enabled = false; 142 return ret; 143 } 144 145 /* After installing handler */ 146 if (dev->driver->irq_postinstall) 147 ret = dev->driver->irq_postinstall(dev); 148 149 if (ret < 0) { 150 dev->irq_enabled = false; 151 if (drm_core_check_feature(dev, DRIVER_LEGACY)) 152 vga_client_register(dev->pdev, NULL, NULL, NULL); 153 free_irq(irq, dev); 154 } else { 155 dev->irq = irq; 156 } 157 158 return ret; 159 } 160 EXPORT_SYMBOL(drm_irq_install); 161 162 /** 163 * drm_irq_uninstall - uninstall the IRQ handler 164 * @dev: DRM device 165 * 166 * Calls the driver's &drm_driver.irq_uninstall function and unregisters the IRQ 167 * handler. This should only be called by drivers which used drm_irq_install() 168 * to set up their interrupt handler. Other drivers must only reset 169 * &drm_device.irq_enabled to false. 170 * 171 * Note that for kernel modesetting drivers it is a bug if this function fails. 172 * The sanity checks are only to catch buggy user modesetting drivers which call 173 * the same function through an ioctl. 174 * 175 * Returns: 176 * Zero on success or a negative error code on failure. 177 */ 178 int drm_irq_uninstall(struct drm_device *dev) 179 { 180 unsigned long irqflags; 181 bool irq_enabled; 182 int i; 183 184 irq_enabled = dev->irq_enabled; 185 dev->irq_enabled = false; 186 187 /* 188 * Wake up any waiters so they don't hang. This is just to paper over 189 * issues for UMS drivers which aren't in full control of their 190 * vblank/irq handling. KMS drivers must ensure that vblanks are all 191 * disabled when uninstalling the irq handler. 192 */ 193 if (dev->num_crtcs) { 194 spin_lock_irqsave(&dev->vbl_lock, irqflags); 195 for (i = 0; i < dev->num_crtcs; i++) { 196 struct drm_vblank_crtc *vblank = &dev->vblank[i]; 197 198 if (!vblank->enabled) 199 continue; 200 201 WARN_ON(drm_core_check_feature(dev, DRIVER_MODESET)); 202 203 drm_vblank_disable_and_save(dev, i); 204 wake_up(&vblank->queue); 205 } 206 spin_unlock_irqrestore(&dev->vbl_lock, irqflags); 207 } 208 209 if (!irq_enabled) 210 return -EINVAL; 211 212 DRM_DEBUG("irq=%d\n", dev->irq); 213 214 if (drm_core_check_feature(dev, DRIVER_LEGACY)) 215 vga_client_register(dev->pdev, NULL, NULL, NULL); 216 217 if (dev->driver->irq_uninstall) 218 dev->driver->irq_uninstall(dev); 219 220 free_irq(dev->irq, dev); 221 222 return 0; 223 } 224 EXPORT_SYMBOL(drm_irq_uninstall); 225 226 #if IS_ENABLED(CONFIG_DRM_LEGACY) 227 int drm_legacy_irq_control(struct drm_device *dev, void *data, 228 struct drm_file *file_priv) 229 { 230 struct drm_control *ctl = data; 231 int ret = 0, irq; 232 233 /* if we haven't irq we fallback for compatibility reasons - 234 * this used to be a separate function in drm_dma.h 235 */ 236 237 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ)) 238 return 0; 239 if (!drm_core_check_feature(dev, DRIVER_LEGACY)) 240 return 0; 241 /* UMS was only ever supported on pci devices. */ 242 if (WARN_ON(!dev->pdev)) 243 return -EINVAL; 244 245 switch (ctl->func) { 246 case DRM_INST_HANDLER: 247 irq = dev->pdev->irq; 248 249 if (dev->if_version < DRM_IF_VERSION(1, 2) && 250 ctl->irq != irq) 251 return -EINVAL; 252 mutex_lock(&dev->struct_mutex); 253 ret = drm_irq_install(dev, irq); 254 mutex_unlock(&dev->struct_mutex); 255 256 return ret; 257 case DRM_UNINST_HANDLER: 258 mutex_lock(&dev->struct_mutex); 259 ret = drm_irq_uninstall(dev); 260 mutex_unlock(&dev->struct_mutex); 261 262 return ret; 263 default: 264 return -EINVAL; 265 } 266 } 267 #endif 268
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