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 if (dev->irq_enabled) 115 return -EBUSY; 116 dev->irq_enabled = true; 117 118 DRM_DEBUG("irq=%d\n", irq); 119 120 /* Before installing handler */ 121 if (dev->driver->irq_preinstall) 122 dev->driver->irq_preinstall(dev); 123 124 /* PCI devices require shared interrupts. */ 125 if (dev->pdev) 126 sh_flags = IRQF_SHARED; 127 128 ret = request_irq(irq, dev->driver->irq_handler, 129 sh_flags, dev->driver->name, dev); 130 131 if (ret < 0) { 132 dev->irq_enabled = false; 133 return ret; 134 } 135 136 /* After installing handler */ 137 if (dev->driver->irq_postinstall) 138 ret = dev->driver->irq_postinstall(dev); 139 140 if (ret < 0) { 141 dev->irq_enabled = false; 142 if (drm_core_check_feature(dev, DRIVER_LEGACY)) 143 vga_client_register(dev->pdev, NULL, NULL, NULL); 144 free_irq(irq, dev); 145 } else { 146 dev->irq = irq; 147 } 148 149 return ret; 150 } 151 EXPORT_SYMBOL(drm_irq_install); 152 153 /** 154 * drm_irq_uninstall - uninstall the IRQ handler 155 * @dev: DRM device 156 * 157 * Calls the driver's &drm_driver.irq_uninstall function and unregisters the IRQ 158 * handler. This should only be called by drivers which used drm_irq_install() 159 * to set up their interrupt handler. Other drivers must only reset 160 * &drm_device.irq_enabled to false. 161 * 162 * Note that for kernel modesetting drivers it is a bug if this function fails. 163 * The sanity checks are only to catch buggy user modesetting drivers which call 164 * the same function through an ioctl. 165 * 166 * Returns: 167 * Zero on success or a negative error code on failure. 168 */ 169 int drm_irq_uninstall(struct drm_device *dev) 170 { 171 unsigned long irqflags; 172 bool irq_enabled; 173 int i; 174 175 irq_enabled = dev->irq_enabled; 176 dev->irq_enabled = false; 177 178 /* 179 * Wake up any waiters so they don't hang. This is just to paper over 180 * issues for UMS drivers which aren't in full control of their 181 * vblank/irq handling. KMS drivers must ensure that vblanks are all 182 * disabled when uninstalling the irq handler. 183 */ 184 if (drm_dev_has_vblank(dev)) { 185 spin_lock_irqsave(&dev->vbl_lock, irqflags); 186 for (i = 0; i < dev->num_crtcs; i++) { 187 struct drm_vblank_crtc *vblank = &dev->vblank[i]; 188 189 if (!vblank->enabled) 190 continue; 191 192 WARN_ON(drm_core_check_feature(dev, DRIVER_MODESET)); 193 194 drm_vblank_disable_and_save(dev, i); 195 wake_up(&vblank->queue); 196 } 197 spin_unlock_irqrestore(&dev->vbl_lock, irqflags); 198 } 199 200 if (!irq_enabled) 201 return -EINVAL; 202 203 DRM_DEBUG("irq=%d\n", dev->irq); 204 205 if (drm_core_check_feature(dev, DRIVER_LEGACY)) 206 vga_client_register(dev->pdev, NULL, NULL, NULL); 207 208 if (dev->driver->irq_uninstall) 209 dev->driver->irq_uninstall(dev); 210 211 free_irq(dev->irq, dev); 212 213 return 0; 214 } 215 EXPORT_SYMBOL(drm_irq_uninstall); 216 217 #if IS_ENABLED(CONFIG_DRM_LEGACY) 218 int drm_legacy_irq_control(struct drm_device *dev, void *data, 219 struct drm_file *file_priv) 220 { 221 struct drm_control *ctl = data; 222 int ret = 0, irq; 223 224 /* if we haven't irq we fallback for compatibility reasons - 225 * this used to be a separate function in drm_dma.h 226 */ 227 228 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ)) 229 return 0; 230 if (!drm_core_check_feature(dev, DRIVER_LEGACY)) 231 return 0; 232 /* UMS was only ever supported on pci devices. */ 233 if (WARN_ON(!dev->pdev)) 234 return -EINVAL; 235 236 switch (ctl->func) { 237 case DRM_INST_HANDLER: 238 irq = dev->pdev->irq; 239 240 if (dev->if_version < DRM_IF_VERSION(1, 2) && 241 ctl->irq != irq) 242 return -EINVAL; 243 mutex_lock(&dev->struct_mutex); 244 ret = drm_irq_install(dev, irq); 245 mutex_unlock(&dev->struct_mutex); 246 247 return ret; 248 case DRM_UNINST_HANDLER: 249 mutex_lock(&dev->struct_mutex); 250 ret = drm_irq_uninstall(dev); 251 mutex_unlock(&dev->struct_mutex); 252 253 return ret; 254 default: 255 return -EINVAL; 256 } 257 } 258 #endif 259