drivers/misc/phantom.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *  Copyright (C) 2005-2007 Jiri Slaby <jirislaby@gmail.com>
  *
  *  You need a userspace library to cooperate with this driver. It (and other
  *  info) may be obtained here:
  *  http://www.fi.muni.cz/~xslaby/phantom.html
  *  or alternatively, you might use OpenHaptics provided by Sensable.
  */

 #include <linux/compat.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/device.h>
 #include <linux/pci.h>
 #include <linux/fs.h>
 #include <linux/poll.h>
 #include <linux/interrupt.h>
 #include <linux/cdev.h>
 #include <linux/slab.h>
 #include <linux/phantom.h>
 #include <linux/sched.h>
 #include <linux/mutex.h>

 #include <linux/atomic.h>
 #include <asm/io.h>

 #define PHANTOM_VERSION		"n0.9.8"

 #define PHANTOM_MAX_MINORS	8

 #define PHN_IRQCTL		0x4c    /* irq control in caddr space */

 #define PHB_RUNNING		1
 #define PHB_NOT_OH		2

 static DEFINE_MUTEX(phantom_mutex);
 static struct class *phantom_class;
 static int phantom_major;

 struct phantom_device {
 	unsigned int opened;
 	void __iomem *caddr;
 	u32 __iomem *iaddr;
 	u32 __iomem *oaddr;
 	unsigned long status;
 	atomic_t counter;

 	wait_queue_head_t wait;
 	struct cdev cdev;

 	struct mutex open_lock;
 	spinlock_t regs_lock;

 	/* used in NOT_OH mode */
 	struct phm_regs oregs;
 	u32 ctl_reg;
 };

 static unsigned char phantom_devices[PHANTOM_MAX_MINORS];

 static int phantom_status(struct phantom_device *dev, unsigned long newstat)
 {
 	pr_debug("phantom_status %lx %lx\n", dev->status, newstat);

 	if (!(dev->status & PHB_RUNNING) && (newstat & PHB_RUNNING)) {
 		atomic_set(&dev->counter, 0);
 		iowrite32(PHN_CTL_IRQ, dev->iaddr + PHN_CONTROL);
 		iowrite32(0x43, dev->caddr + PHN_IRQCTL);
 		ioread32(dev->caddr + PHN_IRQCTL); /* PCI posting */
 	} else if ((dev->status & PHB_RUNNING) && !(newstat & PHB_RUNNING)) {
 		iowrite32(0, dev->caddr + PHN_IRQCTL);
 		ioread32(dev->caddr + PHN_IRQCTL); /* PCI posting */
 	}

 	dev->status = newstat;

 	return 0;
 }

 /*
  * File ops
  */

 static long phantom_ioctl(struct file *file, unsigned int cmd,
 		unsigned long arg)
 {
 	struct phantom_device *dev = file->private_data;
 	struct phm_regs rs;
 	struct phm_reg r;
 	void __user *argp = (void __user *)arg;
 	unsigned long flags;
 	unsigned int i;

 	switch (cmd) {
 	case PHN_SETREG:
 	case PHN_SET_REG:
 		if (copy_from_user(&r, argp, sizeof(r)))
 			return -EFAULT;

 		if (r.reg > 7)
 			return -EINVAL;

 		spin_lock_irqsave(&dev->regs_lock, flags);
 		if (r.reg == PHN_CONTROL && (r.value & PHN_CTL_IRQ) &&
 				phantom_status(dev, dev->status | PHB_RUNNING)){
 			spin_unlock_irqrestore(&dev->regs_lock, flags);
 			return -ENODEV;
 		}

 		pr_debug("phantom: writing %x to %u\n", r.value, r.reg);

 		/* preserve amp bit (don't allow to change it when in NOT_OH) */
 		if (r.reg == PHN_CONTROL && (dev->status & PHB_NOT_OH)) {
 			r.value &= ~PHN_CTL_AMP;
 			r.value |= dev->ctl_reg & PHN_CTL_AMP;
 			dev->ctl_reg = r.value;
 		}

 		iowrite32(r.value, dev->iaddr + r.reg);
 		ioread32(dev->iaddr); /* PCI posting */

 		if (r.reg == PHN_CONTROL && !(r.value & PHN_CTL_IRQ))
 			phantom_status(dev, dev->status & ~PHB_RUNNING);
 		spin_unlock_irqrestore(&dev->regs_lock, flags);
 		break;
 	case PHN_SETREGS:
 	case PHN_SET_REGS:
 		if (copy_from_user(&rs, argp, sizeof(rs)))
 			return -EFAULT;

 		pr_debug("phantom: SRS %u regs %x\n", rs.count, rs.mask);
 		spin_lock_irqsave(&dev->regs_lock, flags);
 		if (dev->status & PHB_NOT_OH)
 			memcpy(&dev->oregs, &rs, sizeof(rs));
 		else {
 			u32 m = min(rs.count, 8U);
 			for (i = 0; i < m; i++)
 				if (rs.mask & BIT(i))
 					iowrite32(rs.values[i], dev->oaddr + i);
 			ioread32(dev->iaddr); /* PCI posting */
 		}
 		spin_unlock_irqrestore(&dev->regs_lock, flags);
 		break;
 	case PHN_GETREG:
 	case PHN_GET_REG:
 		if (copy_from_user(&r, argp, sizeof(r)))
 			return -EFAULT;

 		if (r.reg > 7)
 			return -EINVAL;

 		r.value = ioread32(dev->iaddr + r.reg);

 		if (copy_to_user(argp, &r, sizeof(r)))
 			return -EFAULT;
 		break;
 	case PHN_GETREGS:
 	case PHN_GET_REGS: {
 		u32 m;

 		if (copy_from_user(&rs, argp, sizeof(rs)))
 			return -EFAULT;

 		m = min(rs.count, 8U);

 		pr_debug("phantom: GRS %u regs %x\n", rs.count, rs.mask);
 		spin_lock_irqsave(&dev->regs_lock, flags);
 		for (i = 0; i < m; i++)
 			if (rs.mask & BIT(i))
 				rs.values[i] = ioread32(dev->iaddr + i);
 		atomic_set(&dev->counter, 0);
 		spin_unlock_irqrestore(&dev->regs_lock, flags);

 		if (copy_to_user(argp, &rs, sizeof(rs)))
 			return -EFAULT;
 		break;
 	} case PHN_NOT_OH:
 		spin_lock_irqsave(&dev->regs_lock, flags);
 		if (dev->status & PHB_RUNNING) {
 			printk(KERN_ERR "phantom: you need to set NOT_OH "
 					"before you start the device!\n");
 			spin_unlock_irqrestore(&dev->regs_lock, flags);
 			return -EINVAL;
 		}
 		dev->status |= PHB_NOT_OH;
 		spin_unlock_irqrestore(&dev->regs_lock, flags);
 		break;
 	default:
 		return -ENOTTY;
 	}

 	return 0;
 }

 #ifdef CONFIG_COMPAT
 static long phantom_compat_ioctl(struct file *filp, unsigned int cmd,
 		unsigned long arg)
 {
 	if (_IOC_NR(cmd) <= 3 && _IOC_SIZE(cmd) == sizeof(compat_uptr_t)) {
 		cmd &= ~(_IOC_SIZEMASK << _IOC_SIZESHIFT);
 		cmd |= sizeof(void *) << _IOC_SIZESHIFT;
 	}
 	return phantom_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
 }
 #else
 #define phantom_compat_ioctl NULL
 #endif

 static int phantom_open(struct inode *inode, struct file *file)
 {
 	struct phantom_device *dev = container_of(inode->i_cdev,
 			struct phantom_device, cdev);

 	mutex_lock(&phantom_mutex);
 	nonseekable_open(inode, file);

 	if (mutex_lock_interruptible(&dev->open_lock)) {
 		mutex_unlock(&phantom_mutex);
 		return -ERESTARTSYS;
 	}

 	if (dev->opened) {
 		mutex_unlock(&dev->open_lock);
 		mutex_unlock(&phantom_mutex);
 		return -EINVAL;
 	}

 	WARN_ON(dev->status & PHB_NOT_OH);

 	file->private_data = dev;

 	atomic_set(&dev->counter, 0);
 	dev->opened++;
 	mutex_unlock(&dev->open_lock);
 	mutex_unlock(&phantom_mutex);
 	return 0;
 }

 static int phantom_release(struct inode *inode, struct file *file)
 {
 	struct phantom_device *dev = file->private_data;

 	mutex_lock(&dev->open_lock);

 	dev->opened = 0;
 	phantom_status(dev, dev->status & ~PHB_RUNNING);
 	dev->status &= ~PHB_NOT_OH;

 	mutex_unlock(&dev->open_lock);

 	return 0;
 }

 static __poll_t phantom_poll(struct file *file, poll_table *wait)
 {
 	struct phantom_device *dev = file->private_data;
 	__poll_t mask = 0;

 	pr_debug("phantom_poll: %d\n", atomic_read(&dev->counter));
 	poll_wait(file, &dev->wait, wait);

 	if (!(dev->status & PHB_RUNNING))
 		mask = EPOLLERR;
 	else if (atomic_read(&dev->counter))
 		mask = EPOLLIN | EPOLLRDNORM;

 	pr_debug("phantom_poll end: %x/%d\n", mask, atomic_read(&dev->counter));

 	return mask;
 }

 static const struct file_operations phantom_file_ops = {
 	.open = phantom_open,
 	.release = phantom_release,
 	.unlocked_ioctl = phantom_ioctl,
 	.compat_ioctl = phantom_compat_ioctl,
 	.poll = phantom_poll,
 	.llseek = no_llseek,
 };

 static irqreturn_t phantom_isr(int irq, void *data)
 {
 	struct phantom_device *dev = data;
 	unsigned int i;
 	u32 ctl;

 	spin_lock(&dev->regs_lock);
 	ctl = ioread32(dev->iaddr + PHN_CONTROL);
 	if (!(ctl & PHN_CTL_IRQ)) {
 		spin_unlock(&dev->regs_lock);
 		return IRQ_NONE;
 	}

 	iowrite32(0, dev->iaddr);
 	iowrite32(0xc0, dev->iaddr);

 	if (dev->status & PHB_NOT_OH) {
 		struct phm_regs *r = &dev->oregs;
 		u32 m = min(r->count, 8U);

 		for (i = 0; i < m; i++)
 			if (r->mask & BIT(i))
 				iowrite32(r->values[i], dev->oaddr + i);

 		dev->ctl_reg ^= PHN_CTL_AMP;
 		iowrite32(dev->ctl_reg, dev->iaddr + PHN_CONTROL);
 	}
 	spin_unlock(&dev->regs_lock);

 	ioread32(dev->iaddr); /* PCI posting */

 	atomic_inc(&dev->counter);
 	wake_up_interruptible(&dev->wait);

 	return IRQ_HANDLED;
 }

 /*
  * Init and deinit driver
  */

 static unsigned int phantom_get_free(void)
 {
 	unsigned int i;

 	for (i = 0; i < PHANTOM_MAX_MINORS; i++)
 		if (phantom_devices[i] == 0)
 			break;

 	return i;
 }

 static int phantom_probe(struct pci_dev *pdev,
 	const struct pci_device_id *pci_id)
 {
 	struct phantom_device *pht;
 	unsigned int minor;
 	int retval;

 	retval = pci_enable_device(pdev);
 	if (retval) {
 		dev_err(&pdev->dev, "pci_enable_device failed!\n");
 		goto err;
 	}

 	minor = phantom_get_free();
 	if (minor == PHANTOM_MAX_MINORS) {
 		dev_err(&pdev->dev, "too many devices found!\n");
 		retval = -EIO;
 		goto err_dis;
 	}

 	phantom_devices[minor] = 1;

 	retval = pci_request_regions(pdev, "phantom");
 	if (retval) {
 		dev_err(&pdev->dev, "pci_request_regions failed!\n");
 		goto err_null;
 	}

 	retval = -ENOMEM;
 	pht = kzalloc(sizeof(*pht), GFP_KERNEL);
 	if (pht == NULL) {
 		dev_err(&pdev->dev, "unable to allocate device\n");
 		goto err_reg;
 	}

 	pht->caddr = pci_iomap(pdev, 0, 0);
 	if (pht->caddr == NULL) {
 		dev_err(&pdev->dev, "can't remap conf space\n");
 		goto err_fr;
 	}
 	pht->iaddr = pci_iomap(pdev, 2, 0);
 	if (pht->iaddr == NULL) {
 		dev_err(&pdev->dev, "can't remap input space\n");
 		goto err_unmc;
 	}
 	pht->oaddr = pci_iomap(pdev, 3, 0);
 	if (pht->oaddr == NULL) {
 		dev_err(&pdev->dev, "can't remap output space\n");
 		goto err_unmi;
 	}

 	mutex_init(&pht->open_lock);
 	spin_lock_init(&pht->regs_lock);
 	init_waitqueue_head(&pht->wait);
 	cdev_init(&pht->cdev, &phantom_file_ops);
 	pht->cdev.owner = THIS_MODULE;

 	iowrite32(0, pht->caddr + PHN_IRQCTL);
 	ioread32(pht->caddr + PHN_IRQCTL); /* PCI posting */
 	retval = request_irq(pdev->irq, phantom_isr,
 			IRQF_SHARED, "phantom", pht);
 	if (retval) {
 		dev_err(&pdev->dev, "can't establish ISR\n");
 		goto err_unmo;
 	}

 	retval = cdev_add(&pht->cdev, MKDEV(phantom_major, minor), 1);
 	if (retval) {
 		dev_err(&pdev->dev, "chardev registration failed\n");
 		goto err_irq;
 	}

 	if (IS_ERR(device_create(phantom_class, &pdev->dev,
 				 MKDEV(phantom_major, minor), NULL,
 				 "phantom%u", minor)))
 		dev_err(&pdev->dev, "can't create device\n");

 	pci_set_drvdata(pdev, pht);

 	return 0;
 err_irq:
 	free_irq(pdev->irq, pht);
 err_unmo:
 	pci_iounmap(pdev, pht->oaddr);
 err_unmi:
 	pci_iounmap(pdev, pht->iaddr);
 err_unmc:
 	pci_iounmap(pdev, pht->caddr);
 err_fr:
 	kfree(pht);
 err_reg:
 	pci_release_regions(pdev);
 err_null:
 	phantom_devices[minor] = 0;
 err_dis:
 	pci_disable_device(pdev);
 err:
 	return retval;
 }

 static void phantom_remove(struct pci_dev *pdev)
 {
 	struct phantom_device *pht = pci_get_drvdata(pdev);
 	unsigned int minor = MINOR(pht->cdev.dev);

 	device_destroy(phantom_class, MKDEV(phantom_major, minor));

 	cdev_del(&pht->cdev);

 	iowrite32(0, pht->caddr + PHN_IRQCTL);
 	ioread32(pht->caddr + PHN_IRQCTL); /* PCI posting */
 	free_irq(pdev->irq, pht);

 	pci_iounmap(pdev, pht->oaddr);
 	pci_iounmap(pdev, pht->iaddr);
 	pci_iounmap(pdev, pht->caddr);

 	kfree(pht);

 	pci_release_regions(pdev);

 	phantom_devices[minor] = 0;

 	pci_disable_device(pdev);
 }

 static int __maybe_unused phantom_suspend(struct device *dev_d)
 {
 	struct phantom_device *dev = dev_get_drvdata(dev_d);

 	iowrite32(0, dev->caddr + PHN_IRQCTL);
 	ioread32(dev->caddr + PHN_IRQCTL); /* PCI posting */

 	synchronize_irq(to_pci_dev(dev_d)->irq);

 	return 0;
 }

 static int __maybe_unused phantom_resume(struct device *dev_d)
 {
 	struct phantom_device *dev = dev_get_drvdata(dev_d);

 	iowrite32(0, dev->caddr + PHN_IRQCTL);

 	return 0;
 }

 static struct pci_device_id phantom_pci_tbl[] = {
 	{ .vendor = PCI_VENDOR_ID_PLX, .device = PCI_DEVICE_ID_PLX_9050,
 	  .subvendor = PCI_VENDOR_ID_PLX, .subdevice = PCI_DEVICE_ID_PLX_9050,
 	  .class = PCI_CLASS_BRIDGE_OTHER << 8, .class_mask = 0xffff00 },
 	{ 0, }
 };
 MODULE_DEVICE_TABLE(pci, phantom_pci_tbl);

 static SIMPLE_DEV_PM_OPS(phantom_pm_ops, phantom_suspend, phantom_resume);

 static struct pci_driver phantom_pci_driver = {
 	.name = "phantom",
 	.id_table = phantom_pci_tbl,
 	.probe = phantom_probe,
 	.remove = phantom_remove,
 	.driver.pm = &phantom_pm_ops,
 };

 static CLASS_ATTR_STRING(version, 0444, PHANTOM_VERSION);

 static int __init phantom_init(void)
 {
 	int retval;
 	dev_t dev;

 	phantom_class = class_create("phantom");
 	if (IS_ERR(phantom_class)) {
 		retval = PTR_ERR(phantom_class);
 		printk(KERN_ERR "phantom: can't register phantom class\n");
 		goto err;
 	}
 	retval = class_create_file(phantom_class, &class_attr_version.attr);
 	if (retval) {
 		printk(KERN_ERR "phantom: can't create sysfs version file\n");
 		goto err_class;
 	}

 	retval = alloc_chrdev_region(&dev, 0, PHANTOM_MAX_MINORS, "phantom");
 	if (retval) {
 		printk(KERN_ERR "phantom: can't register character device\n");
 		goto err_attr;
 	}
 	phantom_major = MAJOR(dev);

 	retval = pci_register_driver(&phantom_pci_driver);
 	if (retval) {
 		printk(KERN_ERR "phantom: can't register pci driver\n");
 		goto err_unchr;
 	}

 	printk(KERN_INFO "Phantom Linux Driver, version " PHANTOM_VERSION ", "
 			"init OK\n");

 	return 0;
 err_unchr:
 	unregister_chrdev_region(dev, PHANTOM_MAX_MINORS);
 err_attr:
 	class_remove_file(phantom_class, &class_attr_version.attr);
 err_class:
 	class_destroy(phantom_class);
 err:
 	return retval;
 }

 static void __exit phantom_exit(void)
 {
 	pci_unregister_driver(&phantom_pci_driver);

 	unregister_chrdev_region(MKDEV(phantom_major, 0), PHANTOM_MAX_MINORS);

 	class_remove_file(phantom_class, &class_attr_version.attr);
 	class_destroy(phantom_class);

 	pr_debug("phantom: module successfully removed\n");
 }

 module_init(phantom_init);
 module_exit(phantom_exit);

 MODULE_AUTHOR("Jiri Slaby <jirislaby@gmail.com>");
 MODULE_DESCRIPTION("Sensable Phantom driver (PCI devices)");
 MODULE_LICENSE("GPL");
 MODULE_VERSION(PHANTOM_VERSION);
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Copyright (C) 2005-2007 Jiri Slaby <jirislaby@gmail.com>
	*
	* You need a userspace library to cooperate with this driver. It (and other
	* info) may be obtained here:
	* http://www.fi.muni.cz/~xslaby/phantom.html
	* or alternatively, you might use OpenHaptics provided by Sensable.
	*/

	#include <linux/compat.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/device.h>
	#include <linux/pci.h>
	#include <linux/fs.h>
	#include <linux/poll.h>
	#include <linux/interrupt.h>
	#include <linux/cdev.h>
	#include <linux/slab.h>
	#include <linux/phantom.h>
	#include <linux/sched.h>
	#include <linux/mutex.h>

	#include <linux/atomic.h>
	#include <asm/io.h>

	#define PHANTOM_VERSION "n0.9.8"

	#define PHANTOM_MAX_MINORS 8

	#define PHN_IRQCTL 0x4c /* irq control in caddr space */

	#define PHB_RUNNING 1
	#define PHB_NOT_OH 2

	static DEFINE_MUTEX(phantom_mutex);
	static struct class *phantom_class;
	static int phantom_major;

	struct phantom_device {
	unsigned int opened;
	void __iomem *caddr;
	u32 __iomem *iaddr;
	u32 __iomem *oaddr;
	unsigned long status;
	atomic_t counter;

	wait_queue_head_t wait;
	struct cdev cdev;

	struct mutex open_lock;
	spinlock_t regs_lock;

	/* used in NOT_OH mode */
	struct phm_regs oregs;
	u32 ctl_reg;
	};

	static unsigned char phantom_devices[PHANTOM_MAX_MINORS];

	static int phantom_status(struct phantom_device *dev, unsigned long newstat)
	{
	pr_debug("phantom_status %lx %lx\n", dev->status, newstat);

	if (!(dev->status & PHB_RUNNING) && (newstat & PHB_RUNNING)) {
	atomic_set(&dev->counter, 0);
	iowrite32(PHN_CTL_IRQ, dev->iaddr + PHN_CONTROL);
	iowrite32(0x43, dev->caddr + PHN_IRQCTL);
	ioread32(dev->caddr + PHN_IRQCTL); /* PCI posting */
	} else if ((dev->status & PHB_RUNNING) && !(newstat & PHB_RUNNING)) {
	iowrite32(0, dev->caddr + PHN_IRQCTL);
	ioread32(dev->caddr + PHN_IRQCTL); /* PCI posting */
	}

	dev->status = newstat;

	return 0;
	}

	/*
	* File ops
	*/

	static long phantom_ioctl(struct file *file, unsigned int cmd,
	unsigned long arg)
	{
	struct phantom_device *dev = file->private_data;
	struct phm_regs rs;
	struct phm_reg r;
	void __user argp = (void __user )arg;
	unsigned long flags;
	unsigned int i;

	switch (cmd) {
	case PHN_SETREG:
	case PHN_SET_REG:
	if (copy_from_user(&r, argp, sizeof(r)))
	return -EFAULT;

	if (r.reg > 7)
	return -EINVAL;

	spin_lock_irqsave(&dev->regs_lock, flags);
	if (r.reg == PHN_CONTROL && (r.value & PHN_CTL_IRQ) &&
	phantom_status(dev, dev->status \| PHB_RUNNING)){
	spin_unlock_irqrestore(&dev->regs_lock, flags);
	return -ENODEV;
	}

	pr_debug("phantom: writing %x to %u\n", r.value, r.reg);

	/* preserve amp bit (don't allow to change it when in NOT_OH) */
	if (r.reg == PHN_CONTROL && (dev->status & PHB_NOT_OH)) {
	r.value &= ~PHN_CTL_AMP;
	r.value \|= dev->ctl_reg & PHN_CTL_AMP;
	dev->ctl_reg = r.value;
	}

	iowrite32(r.value, dev->iaddr + r.reg);
	ioread32(dev->iaddr); /* PCI posting */

	if (r.reg == PHN_CONTROL && !(r.value & PHN_CTL_IRQ))
	phantom_status(dev, dev->status & ~PHB_RUNNING);
	spin_unlock_irqrestore(&dev->regs_lock, flags);
	break;
	case PHN_SETREGS:
	case PHN_SET_REGS:
	if (copy_from_user(&rs, argp, sizeof(rs)))
	return -EFAULT;

	pr_debug("phantom: SRS %u regs %x\n", rs.count, rs.mask);
	spin_lock_irqsave(&dev->regs_lock, flags);
	if (dev->status & PHB_NOT_OH)
	memcpy(&dev->oregs, &rs, sizeof(rs));
	else {
	u32 m = min(rs.count, 8U);
	for (i = 0; i < m; i++)
	if (rs.mask & BIT(i))
	iowrite32(rs.values[i], dev->oaddr + i);
	ioread32(dev->iaddr); /* PCI posting */
	}
	spin_unlock_irqrestore(&dev->regs_lock, flags);
	break;
	case PHN_GETREG:
	case PHN_GET_REG:
	if (copy_from_user(&r, argp, sizeof(r)))
	return -EFAULT;

	if (r.reg > 7)
	return -EINVAL;

	r.value = ioread32(dev->iaddr + r.reg);

	if (copy_to_user(argp, &r, sizeof(r)))
	return -EFAULT;
	break;
	case PHN_GETREGS:
	case PHN_GET_REGS: {
	u32 m;

	if (copy_from_user(&rs, argp, sizeof(rs)))
	return -EFAULT;

	m = min(rs.count, 8U);

	pr_debug("phantom: GRS %u regs %x\n", rs.count, rs.mask);
	spin_lock_irqsave(&dev->regs_lock, flags);
	for (i = 0; i < m; i++)
	if (rs.mask & BIT(i))
	rs.values[i] = ioread32(dev->iaddr + i);
	atomic_set(&dev->counter, 0);
	spin_unlock_irqrestore(&dev->regs_lock, flags);

	if (copy_to_user(argp, &rs, sizeof(rs)))
	return -EFAULT;
	break;
	} case PHN_NOT_OH:
	spin_lock_irqsave(&dev->regs_lock, flags);
	if (dev->status & PHB_RUNNING) {
	printk(KERN_ERR "phantom: you need to set NOT_OH "
	"before you start the device!\n");
	spin_unlock_irqrestore(&dev->regs_lock, flags);
	return -EINVAL;
	}
	dev->status \|= PHB_NOT_OH;
	spin_unlock_irqrestore(&dev->regs_lock, flags);
	break;
	default:
	return -ENOTTY;
	}

	return 0;
	}

	#ifdef CONFIG_COMPAT
	static long phantom_compat_ioctl(struct file *filp, unsigned int cmd,
	unsigned long arg)
	{
	if (_IOC_NR(cmd) <= 3 && _IOC_SIZE(cmd) == sizeof(compat_uptr_t)) {
	cmd &= ~(_IOC_SIZEMASK << _IOC_SIZESHIFT);
	cmd \|= sizeof(void *) << _IOC_SIZESHIFT;
	}
	return phantom_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
	}
	#else
	#define phantom_compat_ioctl NULL
	#endif

	static int phantom_open(struct inode inode, struct file file)
	{
	struct phantom_device *dev = container_of(inode->i_cdev,
	struct phantom_device, cdev);

	mutex_lock(&phantom_mutex);
	nonseekable_open(inode, file);

	if (mutex_lock_interruptible(&dev->open_lock)) {
	mutex_unlock(&phantom_mutex);
	return -ERESTARTSYS;
	}

	if (dev->opened) {
	mutex_unlock(&dev->open_lock);
	mutex_unlock(&phantom_mutex);
	return -EINVAL;
	}

	WARN_ON(dev->status & PHB_NOT_OH);

	file->private_data = dev;

	atomic_set(&dev->counter, 0);
	dev->opened++;
	mutex_unlock(&dev->open_lock);
	mutex_unlock(&phantom_mutex);
	return 0;
	}

	static int phantom_release(struct inode inode, struct file file)
	{
	struct phantom_device *dev = file->private_data;

	mutex_lock(&dev->open_lock);

	dev->opened = 0;
	phantom_status(dev, dev->status & ~PHB_RUNNING);
	dev->status &= ~PHB_NOT_OH;

	mutex_unlock(&dev->open_lock);

	return 0;
	}

	static __poll_t phantom_poll(struct file file, poll_table wait)
	{
	struct phantom_device *dev = file->private_data;
	__poll_t mask = 0;

	pr_debug("phantom_poll: %d\n", atomic_read(&dev->counter));
	poll_wait(file, &dev->wait, wait);

	if (!(dev->status & PHB_RUNNING))
	mask = EPOLLERR;
	else if (atomic_read(&dev->counter))
	mask = EPOLLIN \| EPOLLRDNORM;

	pr_debug("phantom_poll end: %x/%d\n", mask, atomic_read(&dev->counter));

	return mask;
	}

	static const struct file_operations phantom_file_ops = {
	.open = phantom_open,
	.release = phantom_release,
	.unlocked_ioctl = phantom_ioctl,
	.compat_ioctl = phantom_compat_ioctl,
	.poll = phantom_poll,
	.llseek = no_llseek,
	};

	static irqreturn_t phantom_isr(int irq, void *data)
	{
	struct phantom_device *dev = data;
	unsigned int i;
	u32 ctl;

	spin_lock(&dev->regs_lock);
	ctl = ioread32(dev->iaddr + PHN_CONTROL);
	if (!(ctl & PHN_CTL_IRQ)) {
	spin_unlock(&dev->regs_lock);
	return IRQ_NONE;
	}

	iowrite32(0, dev->iaddr);
	iowrite32(0xc0, dev->iaddr);

	if (dev->status & PHB_NOT_OH) {
	struct phm_regs *r = &dev->oregs;
	u32 m = min(r->count, 8U);

	for (i = 0; i < m; i++)
	if (r->mask & BIT(i))
	iowrite32(r->values[i], dev->oaddr + i);

	dev->ctl_reg ^= PHN_CTL_AMP;
	iowrite32(dev->ctl_reg, dev->iaddr + PHN_CONTROL);
	}
	spin_unlock(&dev->regs_lock);

	ioread32(dev->iaddr); /* PCI posting */

	atomic_inc(&dev->counter);
	wake_up_interruptible(&dev->wait);

	return IRQ_HANDLED;
	}

	/*
	* Init and deinit driver
	*/

	static unsigned int phantom_get_free(void)
	{
	unsigned int i;

	for (i = 0; i < PHANTOM_MAX_MINORS; i++)
	if (phantom_devices[i] == 0)
	break;

	return i;
	}

	static int phantom_probe(struct pci_dev *pdev,
	const struct pci_device_id *pci_id)
	{
	struct phantom_device *pht;
	unsigned int minor;
	int retval;

	retval = pci_enable_device(pdev);
	if (retval) {
	dev_err(&pdev->dev, "pci_enable_device failed!\n");
	goto err;
	}

	minor = phantom_get_free();
	if (minor == PHANTOM_MAX_MINORS) {
	dev_err(&pdev->dev, "too many devices found!\n");
	retval = -EIO;
	goto err_dis;
	}

	phantom_devices[minor] = 1;

	retval = pci_request_regions(pdev, "phantom");
	if (retval) {
	dev_err(&pdev->dev, "pci_request_regions failed!\n");
	goto err_null;
	}

	retval = -ENOMEM;
	pht = kzalloc(sizeof(*pht), GFP_KERNEL);
	if (pht == NULL) {
	dev_err(&pdev->dev, "unable to allocate device\n");
	goto err_reg;
	}

	pht->caddr = pci_iomap(pdev, 0, 0);
	if (pht->caddr == NULL) {
	dev_err(&pdev->dev, "can't remap conf space\n");
	goto err_fr;
	}
	pht->iaddr = pci_iomap(pdev, 2, 0);
	if (pht->iaddr == NULL) {
	dev_err(&pdev->dev, "can't remap input space\n");
	goto err_unmc;
	}
	pht->oaddr = pci_iomap(pdev, 3, 0);
	if (pht->oaddr == NULL) {
	dev_err(&pdev->dev, "can't remap output space\n");
	goto err_unmi;
	}

	mutex_init(&pht->open_lock);
	spin_lock_init(&pht->regs_lock);
	init_waitqueue_head(&pht->wait);
	cdev_init(&pht->cdev, &phantom_file_ops);
	pht->cdev.owner = THIS_MODULE;

	iowrite32(0, pht->caddr + PHN_IRQCTL);
	ioread32(pht->caddr + PHN_IRQCTL); /* PCI posting */
	retval = request_irq(pdev->irq, phantom_isr,
	IRQF_SHARED, "phantom", pht);
	if (retval) {
	dev_err(&pdev->dev, "can't establish ISR\n");
	goto err_unmo;
	}

	retval = cdev_add(&pht->cdev, MKDEV(phantom_major, minor), 1);
	if (retval) {
	dev_err(&pdev->dev, "chardev registration failed\n");
	goto err_irq;
	}

	if (IS_ERR(device_create(phantom_class, &pdev->dev,
	MKDEV(phantom_major, minor), NULL,
	"phantom%u", minor)))
	dev_err(&pdev->dev, "can't create device\n");

	pci_set_drvdata(pdev, pht);

	return 0;
	err_irq:
	free_irq(pdev->irq, pht);
	err_unmo:
	pci_iounmap(pdev, pht->oaddr);
	err_unmi:
	pci_iounmap(pdev, pht->iaddr);
	err_unmc:
	pci_iounmap(pdev, pht->caddr);
	err_fr:
	kfree(pht);
	err_reg:
	pci_release_regions(pdev);
	err_null:
	phantom_devices[minor] = 0;
	err_dis:
	pci_disable_device(pdev);
	err:
	return retval;
	}

	static void phantom_remove(struct pci_dev *pdev)
	{
	struct phantom_device *pht = pci_get_drvdata(pdev);
	unsigned int minor = MINOR(pht->cdev.dev);

	device_destroy(phantom_class, MKDEV(phantom_major, minor));

	cdev_del(&pht->cdev);

	iowrite32(0, pht->caddr + PHN_IRQCTL);
	ioread32(pht->caddr + PHN_IRQCTL); /* PCI posting */
	free_irq(pdev->irq, pht);

	pci_iounmap(pdev, pht->oaddr);
	pci_iounmap(pdev, pht->iaddr);
	pci_iounmap(pdev, pht->caddr);

	kfree(pht);

	pci_release_regions(pdev);

	phantom_devices[minor] = 0;

	pci_disable_device(pdev);
	}

	static int __maybe_unused phantom_suspend(struct device *dev_d)
	{
	struct phantom_device *dev = dev_get_drvdata(dev_d);

	iowrite32(0, dev->caddr + PHN_IRQCTL);
	ioread32(dev->caddr + PHN_IRQCTL); /* PCI posting */

	synchronize_irq(to_pci_dev(dev_d)->irq);

	return 0;
	}

	static int __maybe_unused phantom_resume(struct device *dev_d)
	{
	struct phantom_device *dev = dev_get_drvdata(dev_d);

	iowrite32(0, dev->caddr + PHN_IRQCTL);

	return 0;
	}

	static struct pci_device_id phantom_pci_tbl[] = {
	{ .vendor = PCI_VENDOR_ID_PLX, .device = PCI_DEVICE_ID_PLX_9050,
	.subvendor = PCI_VENDOR_ID_PLX, .subdevice = PCI_DEVICE_ID_PLX_9050,
	.class = PCI_CLASS_BRIDGE_OTHER << 8, .class_mask = 0xffff00 },
	{ 0, }
	};
	MODULE_DEVICE_TABLE(pci, phantom_pci_tbl);

	static SIMPLE_DEV_PM_OPS(phantom_pm_ops, phantom_suspend, phantom_resume);

	static struct pci_driver phantom_pci_driver = {
	.name = "phantom",
	.id_table = phantom_pci_tbl,
	.probe = phantom_probe,
	.remove = phantom_remove,
	.driver.pm = &phantom_pm_ops,
	};

	static CLASS_ATTR_STRING(version, 0444, PHANTOM_VERSION);

	static int __init phantom_init(void)
	{
	int retval;
	dev_t dev;

	phantom_class = class_create("phantom");
	if (IS_ERR(phantom_class)) {
	retval = PTR_ERR(phantom_class);
	printk(KERN_ERR "phantom: can't register phantom class\n");
	goto err;
	}
	retval = class_create_file(phantom_class, &class_attr_version.attr);
	if (retval) {
	printk(KERN_ERR "phantom: can't create sysfs version file\n");
	goto err_class;
	}

	retval = alloc_chrdev_region(&dev, 0, PHANTOM_MAX_MINORS, "phantom");
	if (retval) {
	printk(KERN_ERR "phantom: can't register character device\n");
	goto err_attr;
	}
	phantom_major = MAJOR(dev);

	retval = pci_register_driver(&phantom_pci_driver);
	if (retval) {
	printk(KERN_ERR "phantom: can't register pci driver\n");
	goto err_unchr;
	}

	printk(KERN_INFO "Phantom Linux Driver, version " PHANTOM_VERSION ", "
	"init OK\n");

	return 0;
	err_unchr:
	unregister_chrdev_region(dev, PHANTOM_MAX_MINORS);
	err_attr:
	class_remove_file(phantom_class, &class_attr_version.attr);
	err_class:
	class_destroy(phantom_class);
	err:
	return retval;
	}

	static void __exit phantom_exit(void)
	{
	pci_unregister_driver(&phantom_pci_driver);

	unregister_chrdev_region(MKDEV(phantom_major, 0), PHANTOM_MAX_MINORS);

	class_remove_file(phantom_class, &class_attr_version.attr);
	class_destroy(phantom_class);

	pr_debug("phantom: module successfully removed\n");
	}

	module_init(phantom_init);
	module_exit(phantom_exit);

	MODULE_AUTHOR("Jiri Slaby <jirislaby@gmail.com>");
	MODULE_DESCRIPTION("Sensable Phantom driver (PCI devices)");
	MODULE_LICENSE("GPL");
	MODULE_VERSION(PHANTOM_VERSION);