drivers/gpu/drm/drm_irq.c

   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 int drm_legacy_irq_control(struct drm_device *dev, void *data,
 217                            struct drm_file *file_priv)
 218 {
 219         struct drm_control *ctl = data;
 220         int ret = 0, irq;
 221
 222         /* if we haven't irq we fallback for compatibility reasons -
 223          * this used to be a separate function in drm_dma.h
 224          */
 225
 226         if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
 227                 return 0;
 228         if (!drm_core_check_feature(dev, DRIVER_LEGACY))
 229                 return 0;
 230         /* UMS was only ever supported on pci devices. */
 231         if (WARN_ON(!dev->pdev))
 232                 return -EINVAL;
 233
 234         switch (ctl->func) {
 235         case DRM_INST_HANDLER:
 236                 irq = dev->pdev->irq;
 237
 238                 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
 239                     ctl->irq != irq)
 240                         return -EINVAL;
 241                 mutex_lock(&dev->struct_mutex);
 242                 ret = drm_irq_install(dev, irq);
 243                 mutex_unlock(&dev->struct_mutex);
 244
 245                 return ret;
 246         case DRM_UNINST_HANDLER:
 247                 mutex_lock(&dev->struct_mutex);
 248                 ret = drm_irq_uninstall(dev);
 249                 mutex_unlock(&dev->struct_mutex);
 250
 251                 return ret;
 252         default:
 253                 return -EINVAL;
 254         }
 255 }