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}