phantom.c

Go to the documentation of this file.

/*
 *  Copyright (C) 2005-2007 Jiri Slaby <[email protected]>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  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 unsigned int phantom_poll(struct file *file, poll_table *wait)
{
    struct phantom_device *dev = file->private_data;
    unsigned int mask = 0;

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

    if (!(dev->status & PHB_RUNNING))
        mask = POLLERR;
    else if (atomic_read(&dev->counter))
        mask = POLLIN | POLLRDNORM;

    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 __devinit 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 __devinit 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 | IRQF_DISABLED, "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 __devexit 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);
}

#ifdef CONFIG_PM
static int phantom_suspend(struct pci_dev *pdev, pm_message_t state)
{
    struct phantom_device *dev = pci_get_drvdata(pdev);

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

    synchronize_irq(pdev->irq);

    return 0;
}

static int phantom_resume(struct pci_dev *pdev)
{
    struct phantom_device *dev = pci_get_drvdata(pdev);

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

    return 0;
}
#else
#define phantom_suspend NULL
#define phantom_resume  NULL
#endif

static struct pci_device_id phantom_pci_tbl[] __devinitdata = {
    { .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 struct pci_driver phantom_pci_driver = {
    .name = "phantom",
    .id_table = phantom_pci_tbl,
    .probe = phantom_probe,
    .remove = __devexit_p(phantom_remove),
    .suspend = phantom_suspend,
    .resume = phantom_resume
};

static CLASS_ATTR_STRING(version, 0444, PHANTOM_VERSION);

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

    phantom_class = class_create(THIS_MODULE, "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 <[email protected]>");
MODULE_DESCRIPTION("Sensable Phantom driver (PCI devices)");
MODULE_LICENSE("GPL");
MODULE_VERSION(PHANTOM_VERSION);