/* i915_irq.c -- IRQ support for the I915 -*- linux-c -*-
 */
/*
 * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
 * 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, sub license, 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 NON-INFRINGEMENT.
 * IN NO EVENT SHALL 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.
 *
 */

#include "drmP.h"
#include "drm.h"
#include "i915_drm.h"
#include "i915_drv.h"

#define USER_INT_FLAG (1<<1)
#define VSYNC_PIPEB_FLAG (1<<5)
#define VSYNC_PIPEA_FLAG (1<<7)

#define MAX_NOPID ((u32)~0)

irqreturn_t i915_driver_irq_handler(DRM_IRQ_ARGS)
{
	drm_device_t *dev = (drm_device_t *) arg;
	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
	u16 temp;

	temp = I915_READ16(I915REG_INT_IDENTITY_R);

	temp &= (USER_INT_FLAG | VSYNC_PIPEA_FLAG | VSYNC_PIPEB_FLAG);

	DRM_DEBUG("%s flag=%08x\n", __FUNCTION__, temp);

	if (temp == 0)
		return IRQ_NONE;

	I915_WRITE16(I915REG_INT_IDENTITY_R, temp);

	dev_priv->sarea_priv->last_dispatch = READ_BREADCRUMB(dev_priv);

	if (temp & USER_INT_FLAG)
		DRM_WAKEUP(&dev_priv->irq_queue);

	if (temp & (VSYNC_PIPEA_FLAG | VSYNC_PIPEB_FLAG)) {
		atomic_inc(&dev->vbl_received);
		DRM_WAKEUP(&dev->vbl_queue);
		drm_vbl_send_signals(dev);
	}

	return IRQ_HANDLED;
}

static int i915_emit_irq(drm_device_t * dev)
{
	drm_i915_private_t *dev_priv = dev->dev_private;
	RING_LOCALS;

	i915_kernel_lost_context(dev);

	DRM_DEBUG("%s\n", __FUNCTION__);

	dev_priv->sarea_priv->last_enqueue = ++dev_priv->counter;

	if (dev_priv->counter > 0x7FFFFFFFUL)
		dev_priv->sarea_priv->last_enqueue = dev_priv->counter = 1;

	BEGIN_LP_RING(6);
	OUT_RING(CMD_STORE_DWORD_IDX);
	OUT_RING(20);
	OUT_RING(dev_priv->counter);
	OUT_RING(0);
	OUT_RING(0);
	OUT_RING(GFX_OP_USER_INTERRUPT);
	ADVANCE_LP_RING();
	
	return dev_priv->counter;
}

static int i915_wait_irq(drm_device_t * dev, int irq_nr)
{
	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
	int ret = 0;

	DRM_DEBUG("%s irq_nr=%d breadcrumb=%d\n", __FUNCTION__, irq_nr,
		  READ_BREADCRUMB(dev_priv));

	if (READ_BREADCRUMB(dev_priv) >= irq_nr)
		return 0;

	dev_priv->sarea_priv->perf_boxes |= I915_BOX_WAIT;

	DRM_WAIT_ON(ret, dev_priv->irq_queue, 3 * DRM_HZ,
		    READ_BREADCRUMB(dev_priv) >= irq_nr);

	if (ret == DRM_ERR(EBUSY)) {
		DRM_ERROR("%s: EBUSY -- rec: %d emitted: %d\n",
			  __FUNCTION__,
			  READ_BREADCRUMB(dev_priv), (int)dev_priv->counter);
	}

	dev_priv->sarea_priv->last_dispatch = READ_BREADCRUMB(dev_priv);
	return ret;
}

int i915_driver_vblank_wait(drm_device_t *dev, unsigned int *sequence)
{
	drm_i915_private_t *dev_priv = dev->dev_private;
	unsigned int cur_vblank;
	int ret = 0;

	if (!dev_priv) {
		DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
		return DRM_ERR(EINVAL);
	}

	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;
}


/* Needs the lock as it touches the ring.
 */
int i915_irq_emit(DRM_IOCTL_ARGS)
{
	DRM_DEVICE;
	drm_i915_private_t *dev_priv = dev->dev_private;
	drm_i915_irq_emit_t emit;
	int result;

	LOCK_TEST_WITH_RETURN(dev, filp);

	if (!dev_priv) {
		DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
		return DRM_ERR(EINVAL);
	}

	DRM_COPY_FROM_USER_IOCTL(emit, (drm_i915_irq_emit_t __user *) data,
				 sizeof(emit));

	result = i915_emit_irq(dev);

	if (DRM_COPY_TO_USER(emit.irq_seq, &result, sizeof(int))) {
		DRM_ERROR("copy_to_user\n");
		return DRM_ERR(EFAULT);
	}

	return 0;
}

/* Doesn't need the hardware lock.
 */
int i915_irq_wait(DRM_IOCTL_ARGS)
{
	DRM_DEVICE;
	drm_i915_private_t *dev_priv = dev->dev_private;
	drm_i915_irq_wait_t irqwait;

	if (!dev_priv) {
		DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
		return DRM_ERR(EINVAL);
	}

	DRM_COPY_FROM_USER_IOCTL(irqwait, (drm_i915_irq_wait_t __user *) data,
				 sizeof(irqwait));

	return i915_wait_irq(dev, irqwait.irq_seq);
}

static int i915_enable_interrupt (drm_device_t *dev)
{
	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
	u16 flag;

	flag = 0;
	if (dev_priv->vblank_pipe & DRM_I915_VBLANK_PIPE_A)
		flag |= VSYNC_PIPEA_FLAG;
	if (dev_priv->vblank_pipe & DRM_I915_VBLANK_PIPE_B)
		flag |= VSYNC_PIPEB_FLAG;
	if (dev_priv->vblank_pipe & ~(DRM_I915_VBLANK_PIPE_A|DRM_I915_VBLANK_PIPE_B)) {
		DRM_ERROR("%s called with invalid pipe 0x%x\n",
			  __FUNCTION__, dev_priv->vblank_pipe);
		return DRM_ERR(EINVAL);
	}
	I915_WRITE16(I915REG_INT_ENABLE_R, USER_INT_FLAG | flag);
	return 0;
}

/* Set the vblank monitor pipe
 */
int i915_vblank_pipe_set(DRM_IOCTL_ARGS)
{
	DRM_DEVICE;
	drm_i915_private_t *dev_priv = dev->dev_private;
	drm_i915_vblank_pipe_t pipe;

	if (!dev_priv) {
		DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
		return DRM_ERR(EINVAL);
	}

	DRM_COPY_FROM_USER_IOCTL(pipe, (drm_i915_vblank_pipe_t __user *) data,
				 sizeof(pipe));

	dev_priv->vblank_pipe = pipe.pipe;
	return i915_enable_interrupt (dev);
}

int i915_vblank_pipe_get(DRM_IOCTL_ARGS)
{
	DRM_DEVICE;
	drm_i915_private_t *dev_priv = dev->dev_private;
	drm_i915_vblank_pipe_t pipe;
	u16 flag;

	if (!dev_priv) {
		DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
		return DRM_ERR(EINVAL);
	}

	flag = I915_READ(I915REG_INT_ENABLE_R);
	pipe.pipe = 0;
	if (flag & VSYNC_PIPEA_FLAG)
		pipe.pipe |= DRM_I915_VBLANK_PIPE_A;
	if (flag & VSYNC_PIPEB_FLAG)
		pipe.pipe |= DRM_I915_VBLANK_PIPE_B;
	DRM_COPY_TO_USER_IOCTL((drm_i915_vblank_pipe_t __user *) data, pipe,
				 sizeof(pipe));
	return 0;
}

/* drm_dma.h hooks
*/
void i915_driver_irq_preinstall(drm_device_t * dev)
{
	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;

	I915_WRITE16(I915REG_HWSTAM, 0xfffe);
	I915_WRITE16(I915REG_INT_MASK_R, 0x0);
	I915_WRITE16(I915REG_INT_ENABLE_R, 0x0);
}

void i915_driver_irq_postinstall(drm_device_t * dev)
{
	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;

	i915_enable_interrupt(dev);
	DRM_INIT_WAITQUEUE(&dev_priv->irq_queue);
}

void i915_driver_irq_uninstall(drm_device_t * dev)
{
	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
	u16 temp;

	if (!dev_priv)
		return;

	I915_WRITE16(I915REG_HWSTAM, 0xffff);
	I915_WRITE16(I915REG_INT_MASK_R, 0xffff);
	I915_WRITE16(I915REG_INT_ENABLE_R, 0x0);

	temp = I915_READ16(I915REG_INT_IDENTITY_R);
	I915_WRITE16(I915REG_INT_IDENTITY_R, temp);
}