/* mach64_irq.c -- IRQ handling for ATI Mach64 -*- linux-c -*-
 * Created: Tue Feb 25, 2003 by Leif Delgass, based on radeon_irq.c/r128_irq.c
 *
 * Copyright (C) The Weather Channel, Inc.  2002.
 * Copyright 2003 Leif Delgass
 * All Rights Reserved.
 *
 * The Weather Channel (TM) funded Tungsten Graphics to develop the
 * initial release of the Radeon 8500 driver under the XFree86 license.
 * This notice must be preserved.
 *
 * 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
 * THE COPYRIGHT OWNER(S) 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:
 *    Keith Whitwell <keith@tungstengraphics.com>
 *    Eric Anholt <anholt@FreeBSD.org>
 *    Leif Delgass <ldelgass@retinalburn.net>
 */

#include "mach64.h"
#include "drmP.h"
#include "drm.h"
#include "mach64_drm.h"
#include "mach64_drv.h"

irqreturn_t mach64_driver_irq_handler( DRM_IRQ_ARGS )
{
	drm_device_t *dev = (drm_device_t *) arg;
	drm_mach64_private_t *dev_priv = 
	   (drm_mach64_private_t *)dev->dev_private;
	int status;

	status = MACH64_READ( MACH64_CRTC_INT_CNTL );

	/* VBLANK interrupt */
	if (status & MACH64_CRTC_VBLANK_INT) {
	    /* Mask off all interrupt ack bits before setting the ack bit, since
	     * there may be other handlers outside the DRM.  
	     *
	     * NOTE: On mach64, you need to keep the enable bits set when doing
	     * the ack, despite what the docs say about not acking and enabling
	     * in a single write.
	     */
	    MACH64_WRITE( MACH64_CRTC_INT_CNTL, (status & ~MACH64_CRTC_INT_ACKS)
			  | MACH64_CRTC_VBLANK_INT );

	    atomic_inc(&dev->vbl_received);
	    DRM_WAKEUP(&dev->vbl_queue);
	    DRM(vbl_send_signals)( dev );
            return IRQ_HANDLED;
	}
	return IRQ_NONE;
}

int mach64_driver_vblank_wait(drm_device_t *dev, unsigned int *sequence)
{
	unsigned int cur_vblank;
	int ret = 0;

	/* Assume that the user has missed the current sequence number
	 * by about a day rather than she wants to wait for years
	 * using vertical blanks... 
	 */
	DRM_WAIT_ON( ret, dev->vbl_queue, 3*DRM_HZ, 
		     ( ( ( cur_vblank = atomic_read(&dev->vbl_received ) )
			 - *sequence ) <= (1<<23) ) );

	*sequence = cur_vblank;

	return ret;
}

/* drm_dma.h hooks
*/
void mach64_driver_irq_preinstall( drm_device_t *dev ) {
	drm_mach64_private_t *dev_priv =
		(drm_mach64_private_t *)dev->dev_private;

	u32 status = MACH64_READ( MACH64_CRTC_INT_CNTL );

	DRM_DEBUG("before install CRTC_INT_CTNL: 0x%08x\n", status );

 	/* Disable and clear VBLANK interrupt */
	MACH64_WRITE( MACH64_CRTC_INT_CNTL, (status & ~MACH64_CRTC_VBLANK_INT_EN) 
		      | MACH64_CRTC_VBLANK_INT );
}

void mach64_driver_irq_postinstall( drm_device_t *dev ) {
	drm_mach64_private_t *dev_priv =
		(drm_mach64_private_t *)dev->dev_private;

	/* Turn on VBLANK interrupt */
   	MACH64_WRITE( MACH64_CRTC_INT_CNTL, MACH64_READ( MACH64_CRTC_INT_CNTL )
		      | MACH64_CRTC_VBLANK_INT_EN );

	DRM_DEBUG("after install CRTC_INT_CTNL: 0x%08x\n", MACH64_READ( MACH64_CRTC_INT_CNTL ));

}

void mach64_driver_irq_uninstall( drm_device_t *dev ) {
	drm_mach64_private_t *dev_priv =
		(drm_mach64_private_t *)dev->dev_private;
	if ( !dev_priv )
		return;

	/* Disable and clear VBLANK interrupt */
	MACH64_WRITE( MACH64_CRTC_INT_CNTL, 
		      (MACH64_READ( MACH64_CRTC_INT_CNTL ) & ~MACH64_CRTC_VBLANK_INT_EN) 
		      | MACH64_CRTC_VBLANK_INT );

	DRM_DEBUG("after uninstall CRTC_INT_CTNL: 0x%08x\n", 
		  MACH64_READ( MACH64_CRTC_INT_CNTL ));
}
