drivers/char/drm/mga_irq.c

   1 /* mga_irq.c -- IRQ handling for radeon -*- linux-c -*-
   2  *
   3  * Copyright (C) The Weather Channel, Inc.  2002.  All Rights Reserved.
   4  *
   5  * The Weather Channel (TM) funded Tungsten Graphics to develop the
   6  * initial release of the Radeon 8500 driver under the XFree86 license.
   7  * This notice must be preserved.
   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  * PRECISION INSIGHT 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 OTHER
  26  * DEALINGS IN THE SOFTWARE.
  27  *
  28  * Authors:
  29  *    Keith Whitwell <keith@tungstengraphics.com>
  30  *    Eric Anholt <anholt@FreeBSD.org>
  31  */
  32
  33 #include "drmP.h"
  34 #include "drm.h"
  35 #include "mga_drm.h"
  36 #include "mga_drv.h"
  37
  38 u32 mga_get_vblank_counter(struct drm_device *dev, int crtc)
  39 {
  40         const drm_mga_private_t *const dev_priv =
  41                 (drm_mga_private_t *) dev->dev_private;
  42
  43         if (crtc != 0) {
  44                 return 0;
  45         }
  46
  47
  48         return atomic_read(&dev_priv->vbl_received);
  49 }
  50
  51
  52 irqreturn_t mga_driver_irq_handler(DRM_IRQ_ARGS)
  53 {
  54         struct drm_device *dev = (struct drm_device *) arg;
  55         drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
  56         int status;
  57         int handled = 0;
  58
  59         status = MGA_READ(MGA_STATUS);
  60
  61         /* VBLANK interrupt */
  62         if (status & MGA_VLINEPEN) {
  63                 MGA_WRITE(MGA_ICLEAR, MGA_VLINEICLR);
  64                 atomic_inc(&dev_priv->vbl_received);
  65                 drm_handle_vblank(dev, 0);
  66                 handled = 1;
  67         }
  68
  69         /* SOFTRAP interrupt */
  70         if (status & MGA_SOFTRAPEN) {
  71                 const u32 prim_start = MGA_READ(MGA_PRIMADDRESS);
  72                 const u32 prim_end = MGA_READ(MGA_PRIMEND);
  73
  74                 MGA_WRITE(MGA_ICLEAR, MGA_SOFTRAPICLR);
  75
  76                 /* In addition to clearing the interrupt-pending bit, we
  77                  * have to write to MGA_PRIMEND to re-start the DMA operation.
  78                  */
  79                 if ((prim_start & ~0x03) != (prim_end & ~0x03)) {
  80                         MGA_WRITE(MGA_PRIMEND, prim_end);
  81                 }
  82
  83                 atomic_inc(&dev_priv->last_fence_retired);
  84                 DRM_WAKEUP(&dev_priv->fence_queue);
  85                 handled = 1;
  86         }
  87
  88         if (handled) {
  89                 return IRQ_HANDLED;
  90         }
  91         return IRQ_NONE;
  92 }
  93
  94 int mga_enable_vblank(struct drm_device *dev, int crtc)
  95 {
  96         drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
  97
  98         if (crtc != 0) {
  99                 DRM_ERROR("tried to enable vblank on non-existent crtc %d\n",
 100                           crtc);
 101                 return 0;
 102         }
 103
 104         MGA_WRITE(MGA_IEN, MGA_VLINEIEN | MGA_SOFTRAPEN);
 105         return 0;
 106 }
 107
 108
 109 void mga_disable_vblank(struct drm_device *dev, int crtc)
 110 {
 111         if (crtc != 0) {
 112                 DRM_ERROR("tried to disable vblank on non-existent crtc %d\n",
 113                           crtc);
 114         }
 115
 116         /* Do *NOT* disable the vertical refresh interrupt.  MGA doesn't have
 117          * a nice hardware counter that tracks the number of refreshes when
 118          * the interrupt is disabled, and the kernel doesn't know the refresh
 119          * rate to calculate an estimate.
 120          */
 121         /* MGA_WRITE(MGA_IEN, MGA_VLINEIEN | MGA_SOFTRAPEN); */
 122 }
 123
 124 int mga_driver_fence_wait(struct drm_device * dev, unsigned int *sequence)
 125 {
 126         drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
 127         unsigned int cur_fence;
 128         int ret = 0;
 129
 130         /* Assume that the user has missed the current sequence number
 131          * by about a day rather than she wants to wait for years
 132          * using fences.
 133          */
 134         DRM_WAIT_ON(ret, dev_priv->fence_queue, 3 * DRM_HZ,
 135                     (((cur_fence = atomic_read(&dev_priv->last_fence_retired))
 136                       - *sequence) <= (1 << 23)));
 137
 138         *sequence = cur_fence;
 139
 140         return ret;
 141 }
 142
 143 void mga_driver_irq_preinstall(struct drm_device * dev)
 144 {
 145         drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
 146
 147         /* Disable *all* interrupts */
 148         MGA_WRITE(MGA_IEN, 0);
 149         /* Clear bits if they're already high */
 150         MGA_WRITE(MGA_ICLEAR, ~0);
 151 }
 152
 153 int mga_driver_irq_postinstall(struct drm_device * dev)
 154 {
 155         drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
 156         int ret;
 157
 158         ret = drm_vblank_init(dev, 1);
 159         if (ret)
 160                 return ret;
 161
 162         DRM_INIT_WAITQUEUE(&dev_priv->fence_queue);
 163
 164         /* Turn on soft trap interrupt.  Vertical blank interrupts are enabled
 165          * in mga_enable_vblank.
 166          */
 167         MGA_WRITE(MGA_IEN, MGA_SOFTRAPEN);
 168         return 0;
 169 }
 170
 171 void mga_driver_irq_uninstall(struct drm_device * dev)
 172 {
 173         drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
 174         if (!dev_priv)
 175                 return;
 176
 177         /* Disable *all* interrupts */
 178         MGA_WRITE(MGA_IEN, 0);
 179
 180         dev->irq_enabled = 0;
 181 }