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                 atomic_inc(&dev_priv->last_fence_retired);
  83                 DRM_WAKEUP(&dev_priv->fence_queue);
  84                 handled = 1;
  85         }
  86
  87         if (handled)
  88                 return IRQ_HANDLED;
  89         return IRQ_NONE;
  90 }
  91
  92 int mga_enable_vblank(struct drm_device *dev, int crtc)
  93 {
  94         drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
  95
  96         if (crtc != 0) {
  97                 DRM_ERROR("tried to enable vblank on non-existent crtc %d\n",
  98                           crtc);
  99                 return 0;
 100         }
 101
 102         MGA_WRITE(MGA_IEN, MGA_VLINEIEN | MGA_SOFTRAPEN);
 103         return 0;
 104 }
 105
 106
 107 void mga_disable_vblank(struct drm_device *dev, int crtc)
 108 {
 109         if (crtc != 0) {
 110                 DRM_ERROR("tried to disable vblank on non-existent crtc %d\n",
 111                           crtc);
 112         }
 113
 114         /* Do *NOT* disable the vertical refresh interrupt.  MGA doesn't have
 115          * a nice hardware counter that tracks the number of refreshes when
 116          * the interrupt is disabled, and the kernel doesn't know the refresh
 117          * rate to calculate an estimate.
 118          */
 119         /* MGA_WRITE(MGA_IEN, MGA_VLINEIEN | MGA_SOFTRAPEN); */
 120 }
 121
 122 int mga_driver_fence_wait(struct drm_device *dev, unsigned int *sequence)
 123 {
 124         drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
 125         unsigned int cur_fence;
 126         int ret = 0;
 127
 128         /* Assume that the user has missed the current sequence number
 129          * by about a day rather than she wants to wait for years
 130          * using fences.
 131          */
 132         DRM_WAIT_ON(ret, dev_priv->fence_queue, 3 * DRM_HZ,
 133                     (((cur_fence = atomic_read(&dev_priv->last_fence_retired))
 134                       - *sequence) <= (1 << 23)));
 135
 136         *sequence = cur_fence;
 137
 138         return ret;
 139 }
 140
 141 void mga_driver_irq_preinstall(struct drm_device *dev)
 142 {
 143         drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
 144
 145         /* Disable *all* interrupts */
 146         MGA_WRITE(MGA_IEN, 0);
 147         /* Clear bits if they're already high */
 148         MGA_WRITE(MGA_ICLEAR, ~0);
 149 }
 150
 151 int mga_driver_irq_postinstall(struct drm_device *dev)
 152 {
 153         drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
 154
 155         DRM_INIT_WAITQUEUE(&dev_priv->fence_queue);
 156
 157         /* Turn on soft trap interrupt.  Vertical blank interrupts are enabled
 158          * in mga_enable_vblank.
 159          */
 160         MGA_WRITE(MGA_IEN, MGA_SOFTRAPEN);
 161         return 0;
 162 }
 163
 164 void mga_driver_irq_uninstall(struct drm_device *dev)
 165 {
 166         drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
 167         if (!dev_priv)
 168                 return;
 169
 170         /* Disable *all* interrupts */
 171         MGA_WRITE(MGA_IEN, 0);
 172
 173         dev->irq_enabled = 0;
 174 }