drivers/gpu/drm/mga/mga_irq.c

   1 /* mga_irq.c -- IRQ handling for radeon -*- linux-c -*-
   2  */
   3 /*
   4  * Copyright (C) The Weather Channel, Inc.  2002.  All Rights Reserved.
   5  *
   6  * The Weather Channel (TM) funded Tungsten Graphics to develop the
   7  * initial release of the Radeon 8500 driver under the XFree86 license.
   8  * This notice must be preserved.
   9  *
  10  * Permission is hereby granted, free of charge, to any person obtaining a
  11  * copy of this software and associated documentation files (the "Software"),
  12  * to deal in the Software without restriction, including without limitation
  13  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  14  * and/or sell copies of the Software, and to permit persons to whom the
  15  * Software is furnished to do so, subject to the following conditions:
  16  *
  17  * The above copyright notice and this permission notice (including the next
  18  * paragraph) shall be included in all copies or substantial portions of the
  19  * Software.
  20  *
  21  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  22  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  23  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  24  * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  25  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  26  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  27  * DEALINGS IN THE SOFTWARE.
  28  *
  29  * Authors:
  30  *    Keith Whitwell <keith@tungstengraphics.com>
  31  *    Eric Anholt <anholt@FreeBSD.org>
  32  */
  33
  34 #include "drmP.h"
  35 #include "drm.h"
  36 #include "mga_drm.h"
  37 #include "mga_drv.h"
  38
  39 u32 mga_get_vblank_counter(struct drm_device *dev, int crtc)
  40 {
  41         const drm_mga_private_t *const dev_priv =
  42                 (drm_mga_private_t *) dev->dev_private;
  43
  44         if (crtc != 0)
  45                 return 0;
  46
  47         return atomic_read(&dev_priv->vbl_received);
  48 }
  49
  50
  51 irqreturn_t mga_driver_irq_handler(DRM_IRQ_ARGS)
  52 {
  53         struct drm_device *dev = (struct drm_device *) arg;
  54         drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
  55         int status;
  56         int handled = 0;
  57
  58         status = MGA_READ(MGA_STATUS);
  59
  60         /* VBLANK interrupt */
  61         if (status & MGA_VLINEPEN) {
  62                 MGA_WRITE(MGA_ICLEAR, MGA_VLINEICLR);
  63                 atomic_inc(&dev_priv->vbl_received);
  64                 drm_handle_vblank(dev, 0);
  65                 handled = 1;
  66         }
  67
  68         /* SOFTRAP interrupt */
  69         if (status & MGA_SOFTRAPEN) {
  70                 const u32 prim_start = MGA_READ(MGA_PRIMADDRESS);
  71                 const u32 prim_end = MGA_READ(MGA_PRIMEND);
  72
  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         return IRQ_NONE;
  91 }
  92
  93 int mga_enable_vblank(struct drm_device *dev, int crtc)
  94 {
  95         drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
  96
  97         if (crtc != 0) {
  98                 DRM_ERROR("tried to enable vblank on non-existent crtc %d\n",
  99                           crtc);
 100                 return 0;
 101         }
 102
 103         MGA_WRITE(MGA_IEN, MGA_VLINEIEN | MGA_SOFTRAPEN);
 104         return 0;
 105 }
 106
 107
 108 void mga_disable_vblank(struct drm_device *dev, int crtc)
 109 {
 110         if (crtc != 0) {
 111                 DRM_ERROR("tried to disable vblank on non-existent crtc %d\n",
 112                           crtc);
 113         }
 114
 115         /* Do *NOT* disable the vertical refresh interrupt.  MGA doesn't have
 116          * a nice hardware counter that tracks the number of refreshes when
 117          * the interrupt is disabled, and the kernel doesn't know the refresh
 118          * rate to calculate an estimate.
 119          */
 120         /* MGA_WRITE(MGA_IEN, MGA_VLINEIEN | MGA_SOFTRAPEN); */
 121 }
 122
 123 int mga_driver_fence_wait(struct drm_device * dev, unsigned int *sequence)
 124 {
 125         drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
 126         unsigned int cur_fence;
 127         int ret = 0;
 128
 129         /* Assume that the user has missed the current sequence number
 130          * by about a day rather than she wants to wait for years
 131          * using fences.
 132          */
 133         DRM_WAIT_ON(ret, dev_priv->fence_queue, 3 * DRM_HZ,
 134                     (((cur_fence = atomic_read(&dev_priv->last_fence_retired))
 135                       - *sequence) <= (1 << 23)));
 136
 137         *sequence = cur_fence;
 138
 139         return ret;
 140 }
 141
 142 void mga_driver_irq_preinstall(struct drm_device * dev)
 143 {
 144         drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
 145
 146         /* Disable *all* interrupts */
 147         MGA_WRITE(MGA_IEN, 0);
 148         /* Clear bits if they're already high */
 149         MGA_WRITE(MGA_ICLEAR, ~0);
 150 }
 151
 152 int mga_driver_irq_postinstall(struct drm_device *dev)
 153 {
 154         drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
 155
 156         DRM_INIT_WAITQUEUE(&dev_priv->fence_queue);
 157
 158         /* Turn on soft trap interrupt.  Vertical blank interrupts are enabled
 159          * in mga_enable_vblank.
 160          */
 161         MGA_WRITE(MGA_IEN, MGA_SOFTRAPEN);
 162         return 0;
 163 }
 164
 165 void mga_driver_irq_uninstall(struct drm_device * dev)
 166 {
 167         drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
 168         if (!dev_priv)
 169                 return;
 170
 171         /* Disable *all* interrupts */
 172         MGA_WRITE(MGA_IEN, 0);
 173
 174         dev->irq_enabled = 0;
 175 }