drivers/gpu/drm/via/via_irq.c - kernel/prism - Git at Google

 /* via_irq.c
  *
  * Copyright 2004 BEAM Ltd.
  * Copyright 2002 Tungsten Graphics, Inc.
  * Copyright 2005 Thomas Hellstrom.
  * All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
  * to deal in the Software without restriction, including without limitation
  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  * and/or sell copies of the Software, and to permit persons to whom the
  * Software is furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice (including the next
  * paragraph) shall be included in all copies or substantial portions of the
  * Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  * BEAM LTD, TUNGSTEN GRAPHICS  AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
  * DAMAGES OR
  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  * DEALINGS IN THE SOFTWARE.
  *
  * Authors:
  *    Terry Barnaby <terry1@beam.ltd.uk>
  *    Keith Whitwell <keith@tungstengraphics.com>
  *    Thomas Hellstrom <unichrome@shipmail.org>
  *
  * This code provides standard DRM access to the Via Unichrome / Pro Vertical blank
  * interrupt, as well as an infrastructure to handle other interrupts of the chip.
  * The refresh rate is also calculated for video playback sync purposes.
  */

 #include "drmP.h"
 #include "drm.h"
 #include "via_drm.h"
 #include "via_drv.h"

 #define VIA_REG_INTERRUPT       0x200

 /* VIA_REG_INTERRUPT */
 #define VIA_IRQ_GLOBAL	  (1 << 31)
 #define VIA_IRQ_VBLANK_ENABLE   (1 << 19)
 #define VIA_IRQ_VBLANK_PENDING  (1 << 3)
 #define VIA_IRQ_HQV0_ENABLE     (1 << 11)
 #define VIA_IRQ_HQV1_ENABLE     (1 << 25)
 #define VIA_IRQ_HQV0_PENDING    (1 << 9)
 #define VIA_IRQ_HQV1_PENDING    (1 << 10)
 #define VIA_IRQ_DMA0_DD_ENABLE  (1 << 20)
 #define VIA_IRQ_DMA0_TD_ENABLE  (1 << 21)
 #define VIA_IRQ_DMA1_DD_ENABLE  (1 << 22)
 #define VIA_IRQ_DMA1_TD_ENABLE  (1 << 23)
 #define VIA_IRQ_DMA0_DD_PENDING (1 << 4)
 #define VIA_IRQ_DMA0_TD_PENDING (1 << 5)
 #define VIA_IRQ_DMA1_DD_PENDING (1 << 6)
 #define VIA_IRQ_DMA1_TD_PENDING (1 << 7)


 /*
  * Device-specific IRQs go here. This type might need to be extended with
  * the register if there are multiple IRQ control registers.
  * Currently we activate the HQV interrupts of  Unichrome Pro group A.
  */

 static maskarray_t via_pro_group_a_irqs[] = {
 	{VIA_IRQ_HQV0_ENABLE, VIA_IRQ_HQV0_PENDING, 0x000003D0, 0x00008010,
 	 0x00000000 },
 	{VIA_IRQ_HQV1_ENABLE, VIA_IRQ_HQV1_PENDING, 0x000013D0, 0x00008010,
 	 0x00000000 },
 	{VIA_IRQ_DMA0_TD_ENABLE, VIA_IRQ_DMA0_TD_PENDING, VIA_PCI_DMA_CSR0,
 	 VIA_DMA_CSR_TA | VIA_DMA_CSR_TD, 0x00000008},
 	{VIA_IRQ_DMA1_TD_ENABLE, VIA_IRQ_DMA1_TD_PENDING, VIA_PCI_DMA_CSR1,
 	 VIA_DMA_CSR_TA | VIA_DMA_CSR_TD, 0x00000008},
 };
 static int via_num_pro_group_a = ARRAY_SIZE(via_pro_group_a_irqs);
 static int via_irqmap_pro_group_a[] = {0, 1, -1, 2, -1, 3};

 static maskarray_t via_unichrome_irqs[] = {
 	{VIA_IRQ_DMA0_TD_ENABLE, VIA_IRQ_DMA0_TD_PENDING, VIA_PCI_DMA_CSR0,
 	 VIA_DMA_CSR_TA | VIA_DMA_CSR_TD, 0x00000008},
 	{VIA_IRQ_DMA1_TD_ENABLE, VIA_IRQ_DMA1_TD_PENDING, VIA_PCI_DMA_CSR1,
 	 VIA_DMA_CSR_TA | VIA_DMA_CSR_TD, 0x00000008}
 };
 static int via_num_unichrome = ARRAY_SIZE(via_unichrome_irqs);
 static int via_irqmap_unichrome[] = {-1, -1, -1, 0, -1, 1};


 static unsigned time_diff(struct timeval *now, struct timeval *then)
 {
 	return (now->tv_usec >= then->tv_usec) ?
 		now->tv_usec - then->tv_usec :
 		1000000 - (then->tv_usec - now->tv_usec);
 }

 u32 via_get_vblank_counter(struct drm_device *dev, int crtc)
 {
 	drm_via_private_t *dev_priv = dev->dev_private;
 	if (crtc != 0)
 		return 0;

 	return atomic_read(&dev_priv->vbl_received);
 }

 irqreturn_t via_driver_irq_handler(DRM_IRQ_ARGS)
 {
 	struct drm_device *dev = (struct drm_device *) arg;
 	drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
 	u32 status;
 	int handled = 0;
 	struct timeval cur_vblank;
 	drm_via_irq_t *cur_irq = dev_priv->via_irqs;
 	int i;

 	status = VIA_READ(VIA_REG_INTERRUPT);
 	if (status & VIA_IRQ_VBLANK_PENDING) {
 		atomic_inc(&dev_priv->vbl_received);
 		if (!(atomic_read(&dev_priv->vbl_received) & 0x0F)) {
 			do_gettimeofday(&cur_vblank);
 			if (dev_priv->last_vblank_valid) {
 				dev_priv->usec_per_vblank =
 					time_diff(&cur_vblank,
 						  &dev_priv->last_vblank) >> 4;
 			}
 			dev_priv->last_vblank = cur_vblank;
 			dev_priv->last_vblank_valid = 1;
 		}
 		if (!(atomic_read(&dev_priv->vbl_received) & 0xFF)) {
 			DRM_DEBUG("US per vblank is: %u\n",
 				  dev_priv->usec_per_vblank);
 		}
 		drm_handle_vblank(dev, 0);
 		handled = 1;
 	}

 	for (i = 0; i < dev_priv->num_irqs; ++i) {
 		if (status & cur_irq->pending_mask) {
 			atomic_inc(&cur_irq->irq_received);
 			DRM_WAKEUP(&cur_irq->irq_queue);
 			handled = 1;
 			if (dev_priv->irq_map[drm_via_irq_dma0_td] == i) {
 				via_dmablit_handler(dev, 0, 1);
 			} else if (dev_priv->irq_map[drm_via_irq_dma1_td] == i) {
 				via_dmablit_handler(dev, 1, 1);
 			}
 		}
 		cur_irq++;
 	}

 	/* Acknowlege interrupts */
 	VIA_WRITE(VIA_REG_INTERRUPT, status);


 	if (handled)
 		return IRQ_HANDLED;
 	else
 		return IRQ_NONE;
 }

 static __inline__ void viadrv_acknowledge_irqs(drm_via_private_t * dev_priv)
 {
 	u32 status;

 	if (dev_priv) {
 		/* Acknowlege interrupts */
 		status = VIA_READ(VIA_REG_INTERRUPT);
 		VIA_WRITE(VIA_REG_INTERRUPT, status |
 			  dev_priv->irq_pending_mask);
 	}
 }

 int via_enable_vblank(struct drm_device *dev, int crtc)
 {
 	drm_via_private_t *dev_priv = dev->dev_private;
 	u32 status;

 	if (crtc != 0) {
 		DRM_ERROR("%s:  bad crtc %d\n", __func__, crtc);
 		return -EINVAL;
 	}

 	status = VIA_READ(VIA_REG_INTERRUPT);
 	VIA_WRITE(VIA_REG_INTERRUPT, status | VIA_IRQ_VBLANK_ENABLE);

 	VIA_WRITE8(0x83d4, 0x11);
 	VIA_WRITE8(0x83d5, VIA_READ8(0x83d5) | 0x30);

 	return 0;
 }

 void via_disable_vblank(struct drm_device *dev, int crtc)
 {
 	drm_via_private_t *dev_priv = dev->dev_private;
 	u32 status;

 	status = VIA_READ(VIA_REG_INTERRUPT);
 	VIA_WRITE(VIA_REG_INTERRUPT, status & ~VIA_IRQ_VBLANK_ENABLE);

 	VIA_WRITE8(0x83d4, 0x11);
 	VIA_WRITE8(0x83d5, VIA_READ8(0x83d5) & ~0x30);

 	if (crtc != 0)
 		DRM_ERROR("%s:  bad crtc %d\n", __func__, crtc);
 }

 static int
 via_driver_irq_wait(struct drm_device * dev, unsigned int irq, int force_sequence,
 		    unsigned int *sequence)
 {
 	drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
 	unsigned int cur_irq_sequence;
 	drm_via_irq_t *cur_irq;
 	int ret = 0;
 	maskarray_t *masks;
 	int real_irq;

 	DRM_DEBUG("\n");

 	if (!dev_priv) {
 		DRM_ERROR("called with no initialization\n");
 		return -EINVAL;
 	}

 	if (irq >= drm_via_irq_num) {
 		DRM_ERROR("Trying to wait on unknown irq %d\n", irq);
 		return -EINVAL;
 	}

 	real_irq = dev_priv->irq_map[irq];

 	if (real_irq < 0) {
 		DRM_ERROR("Video IRQ %d not available on this hardware.\n",
 			  irq);
 		return -EINVAL;
 	}

 	masks = dev_priv->irq_masks;
 	cur_irq = dev_priv->via_irqs + real_irq;

 	if (masks[real_irq][2] && !force_sequence) {
 		DRM_WAIT_ON(ret, cur_irq->irq_queue, 3 * DRM_HZ,
 			    ((VIA_READ(masks[irq][2]) & masks[irq][3]) ==
 			     masks[irq][4]));
 		cur_irq_sequence = atomic_read(&cur_irq->irq_received);
 	} else {
 		DRM_WAIT_ON(ret, cur_irq->irq_queue, 3 * DRM_HZ,
 			    (((cur_irq_sequence =
 			       atomic_read(&cur_irq->irq_received)) -
 			      *sequence) <= (1 << 23)));
 	}
 	*sequence = cur_irq_sequence;
 	return ret;
 }


 /*
  * drm_dma.h hooks
  */

 void via_driver_irq_preinstall(struct drm_device * dev)
 {
 	drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
 	u32 status;
 	drm_via_irq_t *cur_irq;
 	int i;

 	DRM_DEBUG("dev_priv: %p\n", dev_priv);
 	if (dev_priv) {
 		cur_irq = dev_priv->via_irqs;

 		dev_priv->irq_enable_mask = VIA_IRQ_VBLANK_ENABLE;
 		dev_priv->irq_pending_mask = VIA_IRQ_VBLANK_PENDING;

 		if (dev_priv->chipset == VIA_PRO_GROUP_A ||
 		    dev_priv->chipset == VIA_DX9_0) {
 			dev_priv->irq_masks = via_pro_group_a_irqs;
 			dev_priv->num_irqs = via_num_pro_group_a;
 			dev_priv->irq_map = via_irqmap_pro_group_a;
 		} else {
 			dev_priv->irq_masks = via_unichrome_irqs;
 			dev_priv->num_irqs = via_num_unichrome;
 			dev_priv->irq_map = via_irqmap_unichrome;
 		}

 		for (i = 0; i < dev_priv->num_irqs; ++i) {
 			atomic_set(&cur_irq->irq_received, 0);
 			cur_irq->enable_mask = dev_priv->irq_masks[i][0];
 			cur_irq->pending_mask = dev_priv->irq_masks[i][1];
 			DRM_INIT_WAITQUEUE(&cur_irq->irq_queue);
 			dev_priv->irq_enable_mask |= cur_irq->enable_mask;
 			dev_priv->irq_pending_mask |= cur_irq->pending_mask;
 			cur_irq++;

 			DRM_DEBUG("Initializing IRQ %d\n", i);
 		}

 		dev_priv->last_vblank_valid = 0;

 		/* Clear VSync interrupt regs */
 		status = VIA_READ(VIA_REG_INTERRUPT);
 		VIA_WRITE(VIA_REG_INTERRUPT, status &
 			  ~(dev_priv->irq_enable_mask));

 		/* Clear bits if they're already high */
 		viadrv_acknowledge_irqs(dev_priv);
 	}
 }

 int via_driver_irq_postinstall(struct drm_device *dev)
 {
 	drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
 	u32 status;

 	DRM_DEBUG("via_driver_irq_postinstall\n");
 	if (!dev_priv)
 		return -EINVAL;

 	status = VIA_READ(VIA_REG_INTERRUPT);
 	VIA_WRITE(VIA_REG_INTERRUPT, status | VIA_IRQ_GLOBAL
 		  | dev_priv->irq_enable_mask);

 	/* Some magic, oh for some data sheets ! */
 	VIA_WRITE8(0x83d4, 0x11);
 	VIA_WRITE8(0x83d5, VIA_READ8(0x83d5) | 0x30);

 	return 0;
 }

 void via_driver_irq_uninstall(struct drm_device * dev)
 {
 	drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
 	u32 status;

 	DRM_DEBUG("\n");
 	if (dev_priv) {

 		/* Some more magic, oh for some data sheets ! */

 		VIA_WRITE8(0x83d4, 0x11);
 		VIA_WRITE8(0x83d5, VIA_READ8(0x83d5) & ~0x30);

 		status = VIA_READ(VIA_REG_INTERRUPT);
 		VIA_WRITE(VIA_REG_INTERRUPT, status &
 			  ~(VIA_IRQ_VBLANK_ENABLE | dev_priv->irq_enable_mask));
 	}
 }

 int via_wait_irq(struct drm_device *dev, void *data, struct drm_file *file_priv)
 {
 	drm_via_irqwait_t *irqwait = data;
 	struct timeval now;
 	int ret = 0;
 	drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
 	drm_via_irq_t *cur_irq = dev_priv->via_irqs;
 	int force_sequence;

 	if (irqwait->request.irq >= dev_priv->num_irqs) {
 		DRM_ERROR("Trying to wait on unknown irq %d\n",
 			  irqwait->request.irq);
 		return -EINVAL;
 	}

 	cur_irq += irqwait->request.irq;

 	switch (irqwait->request.type & ~VIA_IRQ_FLAGS_MASK) {
 	case VIA_IRQ_RELATIVE:
 		irqwait->request.sequence +=
 			atomic_read(&cur_irq->irq_received);
 		irqwait->request.type &= ~_DRM_VBLANK_RELATIVE;
 	case VIA_IRQ_ABSOLUTE:
 		break;
 	default:
 		return -EINVAL;
 	}

 	if (irqwait->request.type & VIA_IRQ_SIGNAL) {
 		DRM_ERROR("Signals on Via IRQs not implemented yet.\n");
 		return -EINVAL;
 	}

 	force_sequence = (irqwait->request.type & VIA_IRQ_FORCE_SEQUENCE);

 	ret = via_driver_irq_wait(dev, irqwait->request.irq, force_sequence,
 				  &irqwait->request.sequence);
 	do_gettimeofday(&now);
 	irqwait->reply.tval_sec = now.tv_sec;
 	irqwait->reply.tval_usec = now.tv_usec;

 	return ret;
 }
	/* via_irq.c
	*
	* Copyright 2004 BEAM Ltd.
	* Copyright 2002 Tungsten Graphics, Inc.
	* Copyright 2005 Thomas Hellstrom.
	* All Rights Reserved.
	*
	* Permission is hereby granted, free of charge, to any person obtaining a
	* copy of this software and associated documentation files (the "Software"),
	* to deal in the Software without restriction, including without limitation
	* the rights to use, copy, modify, merge, publish, distribute, sublicense,
	* and/or sell copies of the Software, and to permit persons to whom the
	* Software is furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice (including the next
	* paragraph) shall be included in all copies or substantial portions of the
	* Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	* BEAM LTD, TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
	* DAMAGES OR
	* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
	* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
	* DEALINGS IN THE SOFTWARE.
	*
	* Authors:
	* Terry Barnaby <terry1@beam.ltd.uk>
	* Keith Whitwell <keith@tungstengraphics.com>
	* Thomas Hellstrom <unichrome@shipmail.org>
	*
	* This code provides standard DRM access to the Via Unichrome / Pro Vertical blank
	* interrupt, as well as an infrastructure to handle other interrupts of the chip.
	* The refresh rate is also calculated for video playback sync purposes.
	*/

	#include "drmP.h"
	#include "drm.h"
	#include "via_drm.h"
	#include "via_drv.h"

	#define VIA_REG_INTERRUPT 0x200

	/* VIA_REG_INTERRUPT */
	#define VIA_IRQ_GLOBAL (1 << 31)
	#define VIA_IRQ_VBLANK_ENABLE (1 << 19)
	#define VIA_IRQ_VBLANK_PENDING (1 << 3)
	#define VIA_IRQ_HQV0_ENABLE (1 << 11)
	#define VIA_IRQ_HQV1_ENABLE (1 << 25)
	#define VIA_IRQ_HQV0_PENDING (1 << 9)
	#define VIA_IRQ_HQV1_PENDING (1 << 10)
	#define VIA_IRQ_DMA0_DD_ENABLE (1 << 20)
	#define VIA_IRQ_DMA0_TD_ENABLE (1 << 21)
	#define VIA_IRQ_DMA1_DD_ENABLE (1 << 22)
	#define VIA_IRQ_DMA1_TD_ENABLE (1 << 23)
	#define VIA_IRQ_DMA0_DD_PENDING (1 << 4)
	#define VIA_IRQ_DMA0_TD_PENDING (1 << 5)
	#define VIA_IRQ_DMA1_DD_PENDING (1 << 6)
	#define VIA_IRQ_DMA1_TD_PENDING (1 << 7)


	/*
	* Device-specific IRQs go here. This type might need to be extended with
	* the register if there are multiple IRQ control registers.
	* Currently we activate the HQV interrupts of Unichrome Pro group A.
	*/

	static maskarray_t via_pro_group_a_irqs[] = {
	{VIA_IRQ_HQV0_ENABLE, VIA_IRQ_HQV0_PENDING, 0x000003D0, 0x00008010,
	0x00000000 },
	{VIA_IRQ_HQV1_ENABLE, VIA_IRQ_HQV1_PENDING, 0x000013D0, 0x00008010,
	0x00000000 },
	{VIA_IRQ_DMA0_TD_ENABLE, VIA_IRQ_DMA0_TD_PENDING, VIA_PCI_DMA_CSR0,
	VIA_DMA_CSR_TA \| VIA_DMA_CSR_TD, 0x00000008},
	{VIA_IRQ_DMA1_TD_ENABLE, VIA_IRQ_DMA1_TD_PENDING, VIA_PCI_DMA_CSR1,
	VIA_DMA_CSR_TA \| VIA_DMA_CSR_TD, 0x00000008},
	};
	static int via_num_pro_group_a = ARRAY_SIZE(via_pro_group_a_irqs);
	static int via_irqmap_pro_group_a[] = {0, 1, -1, 2, -1, 3};

	static maskarray_t via_unichrome_irqs[] = {
	{VIA_IRQ_DMA0_TD_ENABLE, VIA_IRQ_DMA0_TD_PENDING, VIA_PCI_DMA_CSR0,
	VIA_DMA_CSR_TA \| VIA_DMA_CSR_TD, 0x00000008},
	{VIA_IRQ_DMA1_TD_ENABLE, VIA_IRQ_DMA1_TD_PENDING, VIA_PCI_DMA_CSR1,
	VIA_DMA_CSR_TA \| VIA_DMA_CSR_TD, 0x00000008}
	};
	static int via_num_unichrome = ARRAY_SIZE(via_unichrome_irqs);
	static int via_irqmap_unichrome[] = {-1, -1, -1, 0, -1, 1};


	static unsigned time_diff(struct timeval now, struct timeval then)
	{
	return (now->tv_usec >= then->tv_usec) ?
	now->tv_usec - then->tv_usec :
	1000000 - (then->tv_usec - now->tv_usec);
	}

	u32 via_get_vblank_counter(struct drm_device *dev, int crtc)
	{
	drm_via_private_t *dev_priv = dev->dev_private;
	if (crtc != 0)
	return 0;

	return atomic_read(&dev_priv->vbl_received);
	}

	irqreturn_t via_driver_irq_handler(DRM_IRQ_ARGS)
	{
	struct drm_device dev = (struct drm_device ) arg;
	drm_via_private_t dev_priv = (drm_via_private_t ) dev->dev_private;
	u32 status;
	int handled = 0;
	struct timeval cur_vblank;
	drm_via_irq_t *cur_irq = dev_priv->via_irqs;
	int i;

	status = VIA_READ(VIA_REG_INTERRUPT);
	if (status & VIA_IRQ_VBLANK_PENDING) {
	atomic_inc(&dev_priv->vbl_received);
	if (!(atomic_read(&dev_priv->vbl_received) & 0x0F)) {
	do_gettimeofday(&cur_vblank);
	if (dev_priv->last_vblank_valid) {
	dev_priv->usec_per_vblank =
	time_diff(&cur_vblank,
	&dev_priv->last_vblank) >> 4;
	}
	dev_priv->last_vblank = cur_vblank;
	dev_priv->last_vblank_valid = 1;
	}
	if (!(atomic_read(&dev_priv->vbl_received) & 0xFF)) {
	DRM_DEBUG("US per vblank is: %u\n",
	dev_priv->usec_per_vblank);
	}
	drm_handle_vblank(dev, 0);
	handled = 1;
	}

	for (i = 0; i < dev_priv->num_irqs; ++i) {
	if (status & cur_irq->pending_mask) {
	atomic_inc(&cur_irq->irq_received);
	DRM_WAKEUP(&cur_irq->irq_queue);
	handled = 1;
	if (dev_priv->irq_map[drm_via_irq_dma0_td] == i) {
	via_dmablit_handler(dev, 0, 1);
	} else if (dev_priv->irq_map[drm_via_irq_dma1_td] == i) {
	via_dmablit_handler(dev, 1, 1);
	}
	}
	cur_irq++;
	}

	/* Acknowlege interrupts */
	VIA_WRITE(VIA_REG_INTERRUPT, status);


	if (handled)
	return IRQ_HANDLED;
	else
	return IRQ_NONE;
	}

	static __inline__ void viadrv_acknowledge_irqs(drm_via_private_t * dev_priv)
	{
	u32 status;

	if (dev_priv) {
	/* Acknowlege interrupts */
	status = VIA_READ(VIA_REG_INTERRUPT);
	VIA_WRITE(VIA_REG_INTERRUPT, status \|
	dev_priv->irq_pending_mask);
	}
	}

	int via_enable_vblank(struct drm_device *dev, int crtc)
	{
	drm_via_private_t *dev_priv = dev->dev_private;
	u32 status;

	if (crtc != 0) {
	DRM_ERROR("%s: bad crtc %d\n", __func__, crtc);
	return -EINVAL;
	}

	status = VIA_READ(VIA_REG_INTERRUPT);
	VIA_WRITE(VIA_REG_INTERRUPT, status \| VIA_IRQ_VBLANK_ENABLE);

	VIA_WRITE8(0x83d4, 0x11);
	VIA_WRITE8(0x83d5, VIA_READ8(0x83d5) \| 0x30);

	return 0;
	}

	void via_disable_vblank(struct drm_device *dev, int crtc)
	{
	drm_via_private_t *dev_priv = dev->dev_private;
	u32 status;

	status = VIA_READ(VIA_REG_INTERRUPT);
	VIA_WRITE(VIA_REG_INTERRUPT, status & ~VIA_IRQ_VBLANK_ENABLE);

	VIA_WRITE8(0x83d4, 0x11);
	VIA_WRITE8(0x83d5, VIA_READ8(0x83d5) & ~0x30);

	if (crtc != 0)
	DRM_ERROR("%s: bad crtc %d\n", __func__, crtc);
	}

	static int
	via_driver_irq_wait(struct drm_device * dev, unsigned int irq, int force_sequence,
	unsigned int *sequence)
	{
	drm_via_private_t dev_priv = (drm_via_private_t ) dev->dev_private;
	unsigned int cur_irq_sequence;
	drm_via_irq_t *cur_irq;
	int ret = 0;
	maskarray_t *masks;
	int real_irq;

	DRM_DEBUG("\n");

	if (!dev_priv) {
	DRM_ERROR("called with no initialization\n");
	return -EINVAL;
	}

	if (irq >= drm_via_irq_num) {
	DRM_ERROR("Trying to wait on unknown irq %d\n", irq);
	return -EINVAL;
	}

	real_irq = dev_priv->irq_map[irq];

	if (real_irq < 0) {
	DRM_ERROR("Video IRQ %d not available on this hardware.\n",
	irq);
	return -EINVAL;
	}

	masks = dev_priv->irq_masks;
	cur_irq = dev_priv->via_irqs + real_irq;

	if (masks[real_irq][2] && !force_sequence) {
	DRM_WAIT_ON(ret, cur_irq->irq_queue, 3 * DRM_HZ,
	((VIA_READ(masks[irq][2]) & masks[irq][3]) ==
	masks[irq][4]));
	cur_irq_sequence = atomic_read(&cur_irq->irq_received);
	} else {
	DRM_WAIT_ON(ret, cur_irq->irq_queue, 3 * DRM_HZ,
	(((cur_irq_sequence =
	atomic_read(&cur_irq->irq_received)) -
	*sequence) <= (1 << 23)));
	}
	*sequence = cur_irq_sequence;
	return ret;
	}


	/*
	* drm_dma.h hooks
	*/

	void via_driver_irq_preinstall(struct drm_device * dev)
	{
	drm_via_private_t dev_priv = (drm_via_private_t ) dev->dev_private;
	u32 status;
	drm_via_irq_t *cur_irq;
	int i;

	DRM_DEBUG("dev_priv: %p\n", dev_priv);
	if (dev_priv) {
	cur_irq = dev_priv->via_irqs;

	dev_priv->irq_enable_mask = VIA_IRQ_VBLANK_ENABLE;
	dev_priv->irq_pending_mask = VIA_IRQ_VBLANK_PENDING;

	if (dev_priv->chipset == VIA_PRO_GROUP_A \|\|
	dev_priv->chipset == VIA_DX9_0) {
	dev_priv->irq_masks = via_pro_group_a_irqs;
	dev_priv->num_irqs = via_num_pro_group_a;
	dev_priv->irq_map = via_irqmap_pro_group_a;
	} else {
	dev_priv->irq_masks = via_unichrome_irqs;
	dev_priv->num_irqs = via_num_unichrome;
	dev_priv->irq_map = via_irqmap_unichrome;
	}

	for (i = 0; i < dev_priv->num_irqs; ++i) {
	atomic_set(&cur_irq->irq_received, 0);
	cur_irq->enable_mask = dev_priv->irq_masks[i][0];
	cur_irq->pending_mask = dev_priv->irq_masks[i][1];
	DRM_INIT_WAITQUEUE(&cur_irq->irq_queue);
	dev_priv->irq_enable_mask \|= cur_irq->enable_mask;
	dev_priv->irq_pending_mask \|= cur_irq->pending_mask;
	cur_irq++;

	DRM_DEBUG("Initializing IRQ %d\n", i);
	}

	dev_priv->last_vblank_valid = 0;

	/* Clear VSync interrupt regs */
	status = VIA_READ(VIA_REG_INTERRUPT);
	VIA_WRITE(VIA_REG_INTERRUPT, status &
	~(dev_priv->irq_enable_mask));

	/* Clear bits if they're already high */
	viadrv_acknowledge_irqs(dev_priv);
	}
	}

	int via_driver_irq_postinstall(struct drm_device *dev)
	{
	drm_via_private_t dev_priv = (drm_via_private_t ) dev->dev_private;
	u32 status;

	DRM_DEBUG("via_driver_irq_postinstall\n");
	if (!dev_priv)
	return -EINVAL;

	status = VIA_READ(VIA_REG_INTERRUPT);
	VIA_WRITE(VIA_REG_INTERRUPT, status \| VIA_IRQ_GLOBAL
	\| dev_priv->irq_enable_mask);

	/* Some magic, oh for some data sheets ! */
	VIA_WRITE8(0x83d4, 0x11);
	VIA_WRITE8(0x83d5, VIA_READ8(0x83d5) \| 0x30);

	return 0;
	}

	void via_driver_irq_uninstall(struct drm_device * dev)
	{
	drm_via_private_t dev_priv = (drm_via_private_t ) dev->dev_private;
	u32 status;

	DRM_DEBUG("\n");
	if (dev_priv) {

	/* Some more magic, oh for some data sheets ! */

	VIA_WRITE8(0x83d4, 0x11);
	VIA_WRITE8(0x83d5, VIA_READ8(0x83d5) & ~0x30);

	status = VIA_READ(VIA_REG_INTERRUPT);
	VIA_WRITE(VIA_REG_INTERRUPT, status &
	~(VIA_IRQ_VBLANK_ENABLE \| dev_priv->irq_enable_mask));
	}
	}

	int via_wait_irq(struct drm_device dev, void data, struct drm_file *file_priv)
	{
	drm_via_irqwait_t *irqwait = data;
	struct timeval now;
	int ret = 0;
	drm_via_private_t dev_priv = (drm_via_private_t ) dev->dev_private;
	drm_via_irq_t *cur_irq = dev_priv->via_irqs;
	int force_sequence;

	if (irqwait->request.irq >= dev_priv->num_irqs) {
	DRM_ERROR("Trying to wait on unknown irq %d\n",
	irqwait->request.irq);
	return -EINVAL;
	}

	cur_irq += irqwait->request.irq;

	switch (irqwait->request.type & ~VIA_IRQ_FLAGS_MASK) {
	case VIA_IRQ_RELATIVE:
	irqwait->request.sequence +=
	atomic_read(&cur_irq->irq_received);
	irqwait->request.type &= ~_DRM_VBLANK_RELATIVE;
	case VIA_IRQ_ABSOLUTE:
	break;
	default:
	return -EINVAL;
	}

	if (irqwait->request.type & VIA_IRQ_SIGNAL) {
	DRM_ERROR("Signals on Via IRQs not implemented yet.\n");
	return -EINVAL;
	}

	force_sequence = (irqwait->request.type & VIA_IRQ_FORCE_SEQUENCE);

	ret = via_driver_irq_wait(dev, irqwait->request.irq, force_sequence,
	&irqwait->request.sequence);
	do_gettimeofday(&now);
	irqwait->reply.tval_sec = now.tv_sec;
	irqwait->reply.tval_usec = now.tv_usec;

	return ret;
	}