1 /* $NetBSD: mga_irq.c,v 1.3 2021/12/18 23:45:32 riastradh Exp $ */
2
3 /* mga_irq.c -- IRQ handling for radeon -*- linux-c -*-
4 */
5 /*
6 * Copyright (C) The Weather Channel, Inc. 2002. All Rights Reserved.
7 *
8 * The Weather Channel (TM) funded Tungsten Graphics to develop the
9 * initial release of the Radeon 8500 driver under the XFree86 license.
10 * This notice must be preserved.
11 *
12 * Permission is hereby granted, free of charge, to any person obtaining a
13 * copy of this software and associated documentation files (the "Software"),
14 * to deal in the Software without restriction, including without limitation
15 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
16 * and/or sell copies of the Software, and to permit persons to whom the
17 * Software is furnished to do so, subject to the following conditions:
18 *
19 * The above copyright notice and this permission notice (including the next
20 * paragraph) shall be included in all copies or substantial portions of the
21 * Software.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
24 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
25 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
26 * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
27 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
28 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
29 * DEALINGS IN THE SOFTWARE.
30 *
31 * Authors:
32 * Keith Whitwell <keith@tungstengraphics.com>
33 * Eric Anholt <anholt@FreeBSD.org>
34 */
35
36 #include <sys/cdefs.h>
37 __KERNEL_RCSID(0, "$NetBSD: mga_irq.c,v 1.3 2021/12/18 23:45:32 riastradh Exp $");
38
39 #include "mga_drv.h"
40
mga_get_vblank_counter(struct drm_device * dev,unsigned int pipe)41 u32 mga_get_vblank_counter(struct drm_device *dev, unsigned int pipe)
42 {
43 const drm_mga_private_t *const dev_priv =
44 (drm_mga_private_t *) dev->dev_private;
45
46 if (pipe != 0)
47 return 0;
48
49 return atomic_read(&dev_priv->vbl_received);
50 }
51
52
mga_driver_irq_handler(int irq,void * arg)53 irqreturn_t mga_driver_irq_handler(int irq, void *arg)
54 {
55 struct drm_device *dev = (struct drm_device *) arg;
56 drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
57 int status;
58 int handled = 0;
59
60 status = MGA_READ(MGA_STATUS);
61
62 /* VBLANK interrupt */
63 if (status & MGA_VLINEPEN) {
64 MGA_WRITE(MGA_ICLEAR, MGA_VLINEICLR);
65 atomic_inc(&dev_priv->vbl_received);
66 drm_handle_vblank(dev, 0);
67 handled = 1;
68 }
69
70 /* SOFTRAP interrupt */
71 if (status & MGA_SOFTRAPEN) {
72 const u32 prim_start = MGA_READ(MGA_PRIMADDRESS);
73 const u32 prim_end = MGA_READ(MGA_PRIMEND);
74
75
76 MGA_WRITE(MGA_ICLEAR, MGA_SOFTRAPICLR);
77
78 /* In addition to clearing the interrupt-pending bit, we
79 * have to write to MGA_PRIMEND to re-start the DMA operation.
80 */
81 if ((prim_start & ~0x03) != (prim_end & ~0x03))
82 MGA_WRITE(MGA_PRIMEND, prim_end);
83
84 atomic_inc(&dev_priv->last_fence_retired);
85 wake_up(&dev_priv->fence_queue);
86 handled = 1;
87 }
88
89 if (handled)
90 return IRQ_HANDLED;
91 return IRQ_NONE;
92 }
93
mga_enable_vblank(struct drm_device * dev,unsigned int pipe)94 int mga_enable_vblank(struct drm_device *dev, unsigned int pipe)
95 {
96 drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
97
98 if (pipe != 0) {
99 DRM_ERROR("tried to enable vblank on non-existent crtc %u\n",
100 pipe);
101 return 0;
102 }
103
104 MGA_WRITE(MGA_IEN, MGA_VLINEIEN | MGA_SOFTRAPEN);
105 return 0;
106 }
107
108
mga_disable_vblank(struct drm_device * dev,unsigned int pipe)109 void mga_disable_vblank(struct drm_device *dev, unsigned int pipe)
110 {
111 if (pipe != 0) {
112 DRM_ERROR("tried to disable vblank on non-existent crtc %u\n",
113 pipe);
114 }
115
116 /* Do *NOT* disable the vertical refresh interrupt. MGA doesn't have
117 * a nice hardware counter that tracks the number of refreshes when
118 * the interrupt is disabled, and the kernel doesn't know the refresh
119 * rate to calculate an estimate.
120 */
121 /* MGA_WRITE(MGA_IEN, MGA_VLINEIEN | MGA_SOFTRAPEN); */
122 }
123
mga_driver_fence_wait(struct drm_device * dev,unsigned int * sequence)124 void mga_driver_fence_wait(struct drm_device *dev, unsigned int *sequence)
125 {
126 drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
127 unsigned int cur_fence;
128
129 /* Assume that the user has missed the current sequence number
130 * by about a day rather than she wants to wait for years
131 * using fences.
132 */
133 wait_event_timeout(dev_priv->fence_queue,
134 (((cur_fence = atomic_read(&dev_priv->last_fence_retired))
135 - *sequence) <= (1 << 23)),
136 msecs_to_jiffies(3000));
137
138 *sequence = cur_fence;
139 }
140
mga_driver_irq_preinstall(struct drm_device * dev)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
mga_driver_irq_postinstall(struct drm_device * dev)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 init_waitqueue_head(&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
mga_driver_irq_uninstall(struct drm_device * dev)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 = false;
174 }
175