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
36 u32 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
48 irqreturn_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
89 int 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
104 void 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
119 void 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
136 void 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
146 int 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
159 void 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 }