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 "mga_drv.h"
  35
  36u32 mga_get_vblank_counter(struct drm_device *dev, unsigned int pipe)
  37{
  38        const drm_mga_private_t *const dev_priv =
  39                (drm_mga_private_t *) dev->dev_private;
  40
  41        if (pipe != 0)
  42                return 0;
  43
  44        return atomic_read(&dev_priv->vbl_received);
  45}
  46
  47
  48irqreturn_t mga_driver_irq_handler(int irq, void *arg)
  49{
  50        struct drm_device *dev = (struct drm_device *) arg;
  51        drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
  52        int status;
  53        int handled = 0;
  54
  55        status = MGA_READ(MGA_STATUS);
  56
  57        /* VBLANK interrupt */
  58        if (status & MGA_VLINEPEN) {
  59                MGA_WRITE(MGA_ICLEAR, MGA_VLINEICLR);
  60                atomic_inc(&dev_priv->vbl_received);
  61                drm_handle_vblank(dev, 0);
  62                handled = 1;
  63        }
  64
  65        /* SOFTRAP interrupt */
  66        if (status & MGA_SOFTRAPEN) {
  67                const u32 prim_start = MGA_READ(MGA_PRIMADDRESS);
  68                const u32 prim_end = MGA_READ(MGA_PRIMEND);
  69
  70
  71                MGA_WRITE(MGA_ICLEAR, MGA_SOFTRAPICLR);
  72
  73                /* In addition to clearing the interrupt-pending bit, we
  74                 * have to write to MGA_PRIMEND to re-start the DMA operation.
  75                 */
  76                if ((prim_start & ~0x03) != (prim_end & ~0x03))
  77                        MGA_WRITE(MGA_PRIMEND, prim_end);
  78
  79                atomic_inc(&dev_priv->last_fence_retired);
  80                wake_up(&dev_priv->fence_queue);
  81                handled = 1;
  82        }
  83
  84        if (handled)
  85                return IRQ_HANDLED;
  86        return IRQ_NONE;
  87}
  88
  89int mga_enable_vblank(struct drm_device *dev, unsigned int pipe)
  90{
  91        drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
  92
  93        if (pipe != 0) {
  94                DRM_ERROR("tried to enable vblank on non-existent crtc %u\n",
  95                          pipe);
  96                return 0;
  97        }
  98
  99        MGA_WRITE(MGA_IEN, MGA_VLINEIEN | MGA_SOFTRAPEN);
 100        return 0;
 101}
 102
 103
 104void mga_disable_vblank(struct drm_device *dev, unsigned int pipe)
 105{
 106        if (pipe != 0) {
 107                DRM_ERROR("tried to disable vblank on non-existent crtc %u\n",
 108                          pipe);
 109        }
 110
 111        /* Do *NOT* disable the vertical refresh interrupt.  MGA doesn't have
 112         * a nice hardware counter that tracks the number of refreshes when
 113         * the interrupt is disabled, and the kernel doesn't know the refresh
 114         * rate to calculate an estimate.
 115         */
 116        /* MGA_WRITE(MGA_IEN, MGA_VLINEIEN | MGA_SOFTRAPEN); */
 117}
 118
 119void mga_driver_fence_wait(struct drm_device *dev, unsigned int *sequence)
 120{
 121        drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
 122        unsigned int cur_fence;
 123
 124        /* Assume that the user has missed the current sequence number
 125         * by about a day rather than she wants to wait for years
 126         * using fences.
 127         */
 128        wait_event_timeout(dev_priv->fence_queue,
 129                    (((cur_fence = atomic_read(&dev_priv->last_fence_retired))
 130                      - *sequence) <= (1 << 23)),
 131                    msecs_to_jiffies(3000));
 132
 133        *sequence = cur_fence;
 134}
 135
 136void mga_driver_irq_preinstall(struct drm_device *dev)
 137{
 138        drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
 139
 140        /* Disable *all* interrupts */
 141        MGA_WRITE(MGA_IEN, 0);
 142        /* Clear bits if they're already high */
 143        MGA_WRITE(MGA_ICLEAR, ~0);
 144}
 145
 146int mga_driver_irq_postinstall(struct drm_device *dev)
 147{
 148        drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
 149
 150        init_waitqueue_head(&dev_priv->fence_queue);
 151
 152        /* Turn on soft trap interrupt.  Vertical blank interrupts are enabled
 153         * in mga_enable_vblank.
 154         */
 155        MGA_WRITE(MGA_IEN, MGA_SOFTRAPEN);
 156        return 0;
 157}
 158
 159void mga_driver_irq_uninstall(struct drm_device *dev)
 160{
 161        drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
 162        if (!dev_priv)
 163                return;
 164
 165        /* Disable *all* interrupts */
 166        MGA_WRITE(MGA_IEN, 0);
 167
 168        dev->irq_enabled = false;
 169}
 170