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 <drm/drmP.h>
  35 #include <drm/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         return atomic_read(&dev_priv->vbl_received);
  47 }
  48
  49
  50 irqreturn_t mga_driver_irq_handler(int irq, void *arg)
  51 {
  52         struct drm_device *dev = (struct drm_device *) arg;
  53         drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
  54         int status;
  55         int handled = 0;
  56
  57         status = MGA_READ(MGA_STATUS);
  58
  59         /* VBLANK interrupt */
  60         if (status & MGA_VLINEPEN) {
  61                 MGA_WRITE(MGA_ICLEAR, MGA_VLINEICLR);
  62                 atomic_inc(&dev_priv->vbl_received);
  63                 drm_handle_vblank(dev, 0);
  64                 handled = 1;
  65         }
  66
  67         /* SOFTRAP interrupt */
  68         if (status & MGA_SOFTRAPEN) {
  69                 const u32 prim_start = MGA_READ(MGA_PRIMADDRESS);
  70                 const u32 prim_end = MGA_READ(MGA_PRIMEND);
  71
  72
  73                 MGA_WRITE(MGA_ICLEAR, MGA_SOFTRAPICLR);
  74
  75                 /* In addition to clearing the interrupt-pending bit, we
  76                  * have to write to MGA_PRIMEND to re-start the DMA operation.
  77                  */
  78                 if ((prim_start & ~0x03) != (prim_end & ~0x03))
  79                         MGA_WRITE(MGA_PRIMEND, prim_end);
  80
  81                 atomic_inc(&dev_priv->last_fence_retired);
  82                 wake_up(&dev_priv->fence_queue);
  83                 handled = 1;
  84         }
  85
  86         if (handled)
  87                 return IRQ_HANDLED;
  88         return IRQ_NONE;
  89 }
  90
  91 int mga_enable_vblank(struct drm_device *dev, int crtc)
  92 {
  93         drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
  94
  95         if (crtc != 0) {
  96                 DRM_ERROR("tried to enable vblank on non-existent crtc %d\n",
  97                           crtc);
  98                 return 0;
  99         }
 100
 101         MGA_WRITE(MGA_IEN, MGA_VLINEIEN | MGA_SOFTRAPEN);
 102         return 0;
 103 }
 104
 105
 106 void mga_disable_vblank(struct drm_device *dev, int crtc)
 107 {
 108         if (crtc != 0) {
 109                 DRM_ERROR("tried to disable vblank on non-existent crtc %d\n",
 110                           crtc);
 111         }
 112
 113         /* Do *NOT* disable the vertical refresh interrupt.  MGA doesn't have
 114          * a nice hardware counter that tracks the number of refreshes when
 115          * the interrupt is disabled, and the kernel doesn't know the refresh
 116          * rate to calculate an estimate.
 117          */
 118         /* MGA_WRITE(MGA_IEN, MGA_VLINEIEN | MGA_SOFTRAPEN); */
 119 }
 120
 121 int mga_driver_fence_wait(struct drm_device *dev, unsigned int *sequence)
 122 {
 123         drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
 124         unsigned int cur_fence;
 125         int ret = 0;
 126
 127         /* Assume that the user has missed the current sequence number
 128          * by about a day rather than she wants to wait for years
 129          * using fences.
 130          */
 131         DRM_WAIT_ON(ret, dev_priv->fence_queue, 3 * HZ,
 132                     (((cur_fence = atomic_read(&dev_priv->last_fence_retired))
 133                       - *sequence) <= (1 << 23)));
 134
 135         *sequence = cur_fence;
 136
 137         return ret;
 138 }
 139
 140 void mga_driver_irq_preinstall(struct drm_device *dev)
 141 {
 142         drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
 143
 144         /* Disable *all* interrupts */
 145         MGA_WRITE(MGA_IEN, 0);
 146         /* Clear bits if they're already high */
 147         MGA_WRITE(MGA_ICLEAR, ~0);
 148 }
 149
 150 int mga_driver_irq_postinstall(struct drm_device *dev)
 151 {
 152         drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
 153
 154         init_waitqueue_head(&dev_priv->fence_queue);
 155
 156         /* Turn on soft trap interrupt.  Vertical blank interrupts are enabled
 157          * in mga_enable_vblank.
 158          */
 159         MGA_WRITE(MGA_IEN, MGA_SOFTRAPEN);
 160         return 0;
 161 }
 162
 163 void mga_driver_irq_uninstall(struct drm_device *dev)
 164 {
 165         drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
 166         if (!dev_priv)
 167                 return;
 168
 169         /* Disable *all* interrupts */
 170         MGA_WRITE(MGA_IEN, 0);
 171
 172         dev->irq_enabled = false;
 173 }