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 #include <drm/drm_irq.h> 55 #include <drm/drmP.h> 56 57 #include <linux/interrupt.h> /* For task queue support */ 58 59 #include <linux/vgaarb.h> 60 #include <linux/export.h> 61 62 #include "drm_internal.h" 63 64 /** 65 * DOC: irq helpers 66 * 67 * The DRM core provides very simple support helpers to enable IRQ handling on a 68 * device through the drm_irq_install() and drm_irq_uninstall() functions. This 69 * only supports devices with a single interrupt on the main device stored in 70 * &drm_device.dev and set as the device paramter in drm_dev_alloc(). 71 * 72 * These IRQ helpers are strictly optional. Drivers which roll their own only 73 * need to set &drm_device.irq_enabled to signal the DRM core that vblank 74 * interrupts are working. Since these helpers don't automatically clean up the 75 * requested interrupt like e.g. devm_request_irq() they're not really 76 * recommended. 77 */ 78 79 /** 80 * drm_irq_install - install IRQ handler 81 * @dev: DRM device 82 * @irq: IRQ number to install the handler for 83 * 84 * Initializes the IRQ related data. Installs the handler, calling the driver 85 * &drm_driver.irq_preinstall and &drm_driver.irq_postinstall functions before 86 * and after the installation. 87 * 88 * This is the simplified helper interface provided for drivers with no special 89 * needs. Drivers which need to install interrupt handlers for multiple 90 * interrupts must instead set &drm_device.irq_enabled to signal the DRM core 91 * that vblank interrupts are available. 92 * 93 * @irq must match the interrupt number that would be passed to request_irq(), 94 * if called directly instead of using this helper function. 95 * 96 * &drm_driver.irq_handler is called to handle the registered interrupt. 97 * 98 * Returns: 99 * Zero on success or a negative error code on failure. 100 */ 101 int drm_irq_install(struct drm_device *dev, int irq) 102 { 103 int ret; 104 unsigned long sh_flags = 0; 105 106 if (irq == 0) 107 return -EINVAL; 108 109 /* Driver must have been initialized */ 110 if (!dev->dev_private) 111 return -EINVAL; 112 113 if (dev->irq_enabled) 114 return -EBUSY; 115 dev->irq_enabled = true; 116 117 DRM_DEBUG("irq=%d\n", irq); 118 119 /* Before installing handler */ 120 if (dev->driver->irq_preinstall) 121 dev->driver->irq_preinstall(dev); 122 123 /* PCI devices require shared interrupts. */ 124 if (dev->pdev) 125 sh_flags = IRQF_SHARED; 126 127 ret = request_irq(irq, dev->driver->irq_handler, 128 sh_flags, dev->driver->name, dev); 129 130 if (ret < 0) { 131 dev->irq_enabled = false; 132 return ret; 133 } 134 135 /* After installing handler */ 136 if (dev->driver->irq_postinstall) 137 ret = dev->driver->irq_postinstall(dev); 138 139 if (ret < 0) { 140 dev->irq_enabled = false; 141 if (drm_core_check_feature(dev, DRIVER_LEGACY)) 142 vga_client_register(dev->pdev, NULL, NULL, NULL); 143 free_irq(irq, dev); 144 } else { 145 dev->irq = irq; 146 } 147 148 return ret; 149 } 150 EXPORT_SYMBOL(drm_irq_install); 151 152 /** 153 * drm_irq_uninstall - uninstall the IRQ handler 154 * @dev: DRM device 155 * 156 * Calls the driver's &drm_driver.irq_uninstall function and unregisters the IRQ 157 * handler. This should only be called by drivers which used drm_irq_install() 158 * to set up their interrupt handler. Other drivers must only reset 159 * &drm_device.irq_enabled to false. 160 * 161 * Note that for kernel modesetting drivers it is a bug if this function fails. 162 * The sanity checks are only to catch buggy user modesetting drivers which call 163 * the same function through an ioctl. 164 * 165 * Returns: 166 * Zero on success or a negative error code on failure. 167 */ 168 int drm_irq_uninstall(struct drm_device *dev) 169 { 170 unsigned long irqflags; 171 bool irq_enabled; 172 int i; 173 174 irq_enabled = dev->irq_enabled; 175 dev->irq_enabled = false; 176 177 /* 178 * Wake up any waiters so they don't hang. This is just to paper over 179 * issues for UMS drivers which aren't in full control of their 180 * vblank/irq handling. KMS drivers must ensure that vblanks are all 181 * disabled when uninstalling the irq handler. 182 */ 183 if (dev->num_crtcs) { 184 spin_lock_irqsave(&dev->vbl_lock, irqflags); 185 for (i = 0; i < dev->num_crtcs; i++) { 186 struct drm_vblank_crtc *vblank = &dev->vblank[i]; 187 188 if (!vblank->enabled) 189 continue; 190 191 WARN_ON(drm_core_check_feature(dev, DRIVER_MODESET)); 192 193 drm_vblank_disable_and_save(dev, i); 194 wake_up(&vblank->queue); 195 } 196 spin_unlock_irqrestore(&dev->vbl_lock, irqflags); 197 } 198 199 if (!irq_enabled) 200 return -EINVAL; 201 202 DRM_DEBUG("irq=%d\n", dev->irq); 203 204 if (drm_core_check_feature(dev, DRIVER_LEGACY)) 205 vga_client_register(dev->pdev, NULL, NULL, NULL); 206 207 if (dev->driver->irq_uninstall) 208 dev->driver->irq_uninstall(dev); 209 210 free_irq(dev->irq, dev); 211 212 return 0; 213 } 214 EXPORT_SYMBOL(drm_irq_uninstall); 215 216 #if IS_ENABLED(CONFIG_DRM_LEGACY) 217 int drm_legacy_irq_control(struct drm_device *dev, void *data, 218 struct drm_file *file_priv) 219 { 220 struct drm_control *ctl = data; 221 int ret = 0, irq; 222 223 /* if we haven't irq we fallback for compatibility reasons - 224 * this used to be a separate function in drm_dma.h 225 */ 226 227 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ)) 228 return 0; 229 if (!drm_core_check_feature(dev, DRIVER_LEGACY)) 230 return 0; 231 /* UMS was only ever supported on pci devices. */ 232 if (WARN_ON(!dev->pdev)) 233 return -EINVAL; 234 235 switch (ctl->func) { 236 case DRM_INST_HANDLER: 237 irq = dev->pdev->irq; 238 239 if (dev->if_version < DRM_IF_VERSION(1, 2) && 240 ctl->irq != irq) 241 return -EINVAL; 242 mutex_lock(&dev->struct_mutex); 243 ret = drm_irq_install(dev, irq); 244 mutex_unlock(&dev->struct_mutex); 245 246 return ret; 247 case DRM_UNINST_HANDLER: 248 mutex_lock(&dev->struct_mutex); 249 ret = drm_irq_uninstall(dev); 250 mutex_unlock(&dev->struct_mutex); 251 252 return ret; 253 default: 254 return -EINVAL; 255 } 256 } 257 #endif 258