LXR linux/drivers/gpu/drm/mga/mga

   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
  38u32 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
  50irqreturn_t mga_driver_irq_handler(DRM_IRQ_ARGS)
  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                DRM_WAKEUP(&dev_priv->fence_queue);
  83                handled = 1;
  84        }
  85
  86        if (handled)
  87                return IRQ_HANDLED;
  88        return IRQ_NONE;
  89}
  90
  91int 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
 106void 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
 121int 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 * DRM_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
 140void 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
 150int 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        DRM_INIT_WAITQUEUE(&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
 163void 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 = 0;
 173}
 174