/*
 * drm_irq.c IRQ and vblank support
 *
 * \author Rickard E. (Rik) Faith <faith@valinux.com>
 * \author Gareth Hughes <gareth@valinux.com>
 *
 * 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
 * VA LINUX SYSTEMS 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.
 */

/*
 * Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
 *
 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
 * 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
 * VA LINUX SYSTEMS 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 <linux/export.h>
#include <linux/interrupt.h>	/* For task queue support */
#include <linux/pci.h>
#include <linux/vgaarb.h>

#include <drm/drm.h>
#include <drm/drm_device.h>
#include <drm/drm_drv.h>
#include <drm/drm_legacy.h>
#include <drm/drm_print.h>
#include <drm/drm_vblank.h>

#include "drm_internal.h"

#if IS_ENABLED(CONFIG_DRM_LEGACY)
static int drm_legacy_irq_install(struct drm_device *dev, int irq)
{
	int ret;
	unsigned long sh_flags = 0;

	if (irq == 0)
		return -EINVAL;

	if (dev->irq_enabled)
		return -EBUSY;
	dev->irq_enabled = true;

	DRM_DEBUG("irq=%d\n", irq);

	/* Before installing handler */
	if (dev->driver->irq_preinstall)
		dev->driver->irq_preinstall(dev);

	/* PCI devices require shared interrupts. */
	if (dev_is_pci(dev->dev))
		sh_flags = IRQF_SHARED;

	ret = request_irq(irq, dev->driver->irq_handler,
			  sh_flags, dev->driver->name, dev);

	if (ret < 0) {
		dev->irq_enabled = false;
		return ret;
	}

	/* After installing handler */
	if (dev->driver->irq_postinstall)
		ret = dev->driver->irq_postinstall(dev);

	if (ret < 0) {
		dev->irq_enabled = false;
		if (drm_core_check_feature(dev, DRIVER_LEGACY))
			vga_client_unregister(to_pci_dev(dev->dev));
		free_irq(irq, dev);
	} else {
		dev->irq = irq;
	}

	return ret;
}

int drm_legacy_irq_uninstall(struct drm_device *dev)
{
	unsigned long irqflags;
	bool irq_enabled;
	int i;

	irq_enabled = dev->irq_enabled;
	dev->irq_enabled = false;

	/*
	 * Wake up any waiters so they don't hang. This is just to paper over
	 * issues for UMS drivers which aren't in full control of their
	 * vblank/irq handling. KMS drivers must ensure that vblanks are all
	 * disabled when uninstalling the irq handler.
	 */
	if (drm_dev_has_vblank(dev)) {
		spin_lock_irqsave(&dev->vbl_lock, irqflags);
		for (i = 0; i < dev->num_crtcs; i++) {
			struct drm_vblank_crtc *vblank = &dev->vblank[i];

			if (!vblank->enabled)
				continue;

			WARN_ON(drm_core_check_feature(dev, DRIVER_MODESET));

			drm_vblank_disable_and_save(dev, i);
			wake_up(&vblank->queue);
		}
		spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
	}

	if (!irq_enabled)
		return -EINVAL;

	DRM_DEBUG("irq=%d\n", dev->irq);

	if (drm_core_check_feature(dev, DRIVER_LEGACY))
		vga_client_unregister(to_pci_dev(dev->dev));

	if (dev->driver->irq_uninstall)
		dev->driver->irq_uninstall(dev);

	free_irq(dev->irq, dev);

	return 0;
}
EXPORT_SYMBOL(drm_legacy_irq_uninstall);

int drm_legacy_irq_control(struct drm_device *dev, void *data,
			   struct drm_file *file_priv)
{
	struct drm_control *ctl = data;
	int ret = 0, irq;
	struct pci_dev *pdev;

	/* if we haven't irq we fallback for compatibility reasons -
	 * this used to be a separate function in drm_dma.h
	 */

	if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
		return 0;
	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
		return 0;
	/* UMS was only ever supported on pci devices. */
	if (WARN_ON(!dev_is_pci(dev->dev)))
		return -EINVAL;

	switch (ctl->func) {
	case DRM_INST_HANDLER:
		pdev = to_pci_dev(dev->dev);
		irq = pdev->irq;

		if (dev->if_version < DRM_IF_VERSION(1, 2) &&
		    ctl->irq != irq)
			return -EINVAL;
		mutex_lock(&dev->struct_mutex);
		ret = drm_legacy_irq_install(dev, irq);
		mutex_unlock(&dev->struct_mutex);

		return ret;
	case DRM_UNINST_HANDLER:
		mutex_lock(&dev->struct_mutex);
		ret = drm_legacy_irq_uninstall(dev);
		mutex_unlock(&dev->struct_mutex);

		return ret;
	default:
		return -EINVAL;
	}
}
#endif