rio500.c

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/* -*- linux-c -*- */

/* 
 * Driver for USB Rio 500
 *
 * Cesar Miquel ([email protected])
 * 
 * based on hp_scanner.c by David E. Nelson ([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.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Based upon mouse.c (Brad Keryan) and printer.c (Michael Gee).
 *
 * Changelog:
 * 30/05/2003  replaced lock/unlock kernel with up/down
 *             Daniele Bellucci  [email protected]
 * */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/mutex.h>
#include <linux/errno.h>
#include <linux/random.h>
#include <linux/poll.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/usb.h>
#include <linux/wait.h>

#include "rio500_usb.h"

/*
 * Version Information
 */
#define DRIVER_VERSION "v1.1"
#define DRIVER_AUTHOR "Cesar Miquel <[email protected]>"
#define DRIVER_DESC "USB Rio 500 driver"

#define RIO_MINOR   64

/* stall/wait timeout for rio */
#define NAK_TIMEOUT (HZ)

#define IBUF_SIZE 0x1000

/* Size of the rio buffer */
#define OBUF_SIZE 0x10000

struct rio_usb_data {
        struct usb_device *rio_dev;     /* init: probe_rio */
        unsigned int ifnum;             /* Interface number of the USB device */
        int isopen;                     /* nz if open */
        int present;                    /* Device is present on the bus */
        char *obuf, *ibuf;              /* transfer buffers */
        char bulk_in_ep, bulk_out_ep;   /* Endpoint assignments */
        wait_queue_head_t wait_q;       /* for timeouts */
    struct mutex lock;          /* general race avoidance */
};

static DEFINE_MUTEX(rio500_mutex);
static struct rio_usb_data rio_instance;

static int open_rio(struct inode *inode, struct file *file)
{
    struct rio_usb_data *rio = &rio_instance;

    /* against disconnect() */
    mutex_lock(&rio500_mutex);
    mutex_lock(&(rio->lock));

    if (rio->isopen || !rio->present) {
        mutex_unlock(&(rio->lock));
        mutex_unlock(&rio500_mutex);
        return -EBUSY;
    }
    rio->isopen = 1;

    init_waitqueue_head(&rio->wait_q);

    mutex_unlock(&(rio->lock));

    dev_info(&rio->rio_dev->dev, "Rio opened.\n");
    mutex_unlock(&rio500_mutex);

    return 0;
}

static int close_rio(struct inode *inode, struct file *file)
{
    struct rio_usb_data *rio = &rio_instance;

    rio->isopen = 0;

    dev_info(&rio->rio_dev->dev, "Rio closed.\n");
    return 0;
}

static long ioctl_rio(struct file *file, unsigned int cmd, unsigned long arg)
{
    struct RioCommand rio_cmd;
    struct rio_usb_data *rio = &rio_instance;
    void __user *data;
    unsigned char *buffer;
    int result, requesttype;
    int retries;
    int retval=0;

    mutex_lock(&(rio->lock));
        /* Sanity check to make sure rio is connected, powered, etc */
        if (rio->present == 0 || rio->rio_dev == NULL) {
        retval = -ENODEV;
        goto err_out;
    }

    switch (cmd) {
    case RIO_RECV_COMMAND:
        data = (void __user *) arg;
        if (data == NULL)
            break;
        if (copy_from_user(&rio_cmd, data, sizeof(struct RioCommand))) {
            retval = -EFAULT;
            goto err_out;
        }
        if (rio_cmd.length < 0 || rio_cmd.length > PAGE_SIZE) {
            retval = -EINVAL;
            goto err_out;
        }
        buffer = (unsigned char *) __get_free_page(GFP_KERNEL);
        if (buffer == NULL) {
            retval = -ENOMEM;
            goto err_out;
        }
        if (copy_from_user(buffer, rio_cmd.buffer, rio_cmd.length)) {
            retval = -EFAULT;
            free_page((unsigned long) buffer);
            goto err_out;
        }

        requesttype = rio_cmd.requesttype | USB_DIR_IN |
            USB_TYPE_VENDOR | USB_RECIP_DEVICE;
        dev_dbg(&rio->rio_dev->dev,
            "sending command:reqtype=%0x req=%0x value=%0x index=%0x len=%0x\n",
            requesttype, rio_cmd.request, rio_cmd.value,
            rio_cmd.index, rio_cmd.length);
        /* Send rio control message */
        retries = 3;
        while (retries) {
            result = usb_control_msg(rio->rio_dev,
                         usb_rcvctrlpipe(rio-> rio_dev, 0),
                         rio_cmd.request,
                         requesttype,
                         rio_cmd.value,
                         rio_cmd.index, buffer,
                         rio_cmd.length,
                         jiffies_to_msecs(rio_cmd.timeout));
            if (result == -ETIMEDOUT)
                retries--;
            else if (result < 0) {
                dev_err(&rio->rio_dev->dev,
                    "Error executing ioctrl. code = %d\n",
                    result);
                retries = 0;
            } else {
                dev_dbg(&rio->rio_dev->dev,
                    "Executed ioctl. Result = %d (data=%02x)\n",
                    result, buffer[0]);
                if (copy_to_user(rio_cmd.buffer, buffer,
                         rio_cmd.length)) {
                    free_page((unsigned long) buffer);
                    retval = -EFAULT;
                    goto err_out;
                }
                retries = 0;
            }

            /* rio_cmd.buffer contains a raw stream of single byte
               data which has been returned from rio.  Data is
               interpreted at application level.  For data that
               will be cast to data types longer than 1 byte, data
               will be little_endian and will potentially need to
               be swapped at the app level */

        }
        free_page((unsigned long) buffer);
        break;

    case RIO_SEND_COMMAND:
        data = (void __user *) arg;
        if (data == NULL)
            break;
        if (copy_from_user(&rio_cmd, data, sizeof(struct RioCommand))) {
            retval = -EFAULT;
            goto err_out;
        }
        if (rio_cmd.length < 0 || rio_cmd.length > PAGE_SIZE) {
            retval = -EINVAL;
            goto err_out;
        }
        buffer = (unsigned char *) __get_free_page(GFP_KERNEL);
        if (buffer == NULL) {
            retval = -ENOMEM;
            goto err_out;
        }
        if (copy_from_user(buffer, rio_cmd.buffer, rio_cmd.length)) {
            free_page((unsigned long)buffer);
            retval = -EFAULT;
            goto err_out;
        }

        requesttype = rio_cmd.requesttype | USB_DIR_OUT |
            USB_TYPE_VENDOR | USB_RECIP_DEVICE;
        dev_dbg(&rio->rio_dev->dev,
            "sending command: reqtype=%0x req=%0x value=%0x index=%0x len=%0x\n",
            requesttype, rio_cmd.request, rio_cmd.value,
            rio_cmd.index, rio_cmd.length);
        /* Send rio control message */
        retries = 3;
        while (retries) {
            result = usb_control_msg(rio->rio_dev,
                         usb_sndctrlpipe(rio-> rio_dev, 0),
                         rio_cmd.request,
                         requesttype,
                         rio_cmd.value,
                         rio_cmd.index, buffer,
                         rio_cmd.length,
                         jiffies_to_msecs(rio_cmd.timeout));
            if (result == -ETIMEDOUT)
                retries--;
            else if (result < 0) {
                dev_err(&rio->rio_dev->dev,
                    "Error executing ioctrl. code = %d\n",
                    result);
                retries = 0;
            } else {
                dev_dbg(&rio->rio_dev->dev,
                    "Executed ioctl. Result = %d\n", result);
                retries = 0;

            }

        }
        free_page((unsigned long) buffer);
        break;

    default:
        retval = -ENOTTY;
        break;
    }


err_out:
    mutex_unlock(&(rio->lock));
    return retval;
}

static ssize_t
write_rio(struct file *file, const char __user *buffer,
      size_t count, loff_t * ppos)
{
    DEFINE_WAIT(wait);
    struct rio_usb_data *rio = &rio_instance;

    unsigned long copy_size;
    unsigned long bytes_written = 0;
    unsigned int partial;

    int result = 0;
    int maxretry;
    int errn = 0;
    int intr;

    intr = mutex_lock_interruptible(&(rio->lock));
    if (intr)
        return -EINTR;
        /* Sanity check to make sure rio is connected, powered, etc */
        if (rio->present == 0 || rio->rio_dev == NULL) {
        mutex_unlock(&(rio->lock));
        return -ENODEV;
    }



    do {
        unsigned long thistime;
        char *obuf = rio->obuf;

        thistime = copy_size =
            (count >= OBUF_SIZE) ? OBUF_SIZE : count;
        if (copy_from_user(rio->obuf, buffer, copy_size)) {
            errn = -EFAULT;
            goto error;
        }
        maxretry = 5;
        while (thistime) {
            if (!rio->rio_dev) {
                errn = -ENODEV;
                goto error;
            }
            if (signal_pending(current)) {
                mutex_unlock(&(rio->lock));
                return bytes_written ? bytes_written : -EINTR;
            }

            result = usb_bulk_msg(rio->rio_dev,
                     usb_sndbulkpipe(rio->rio_dev, 2),
                     obuf, thistime, &partial, 5000);

            dev_dbg(&rio->rio_dev->dev,
                "write stats: result:%d thistime:%lu partial:%u\n",
                result, thistime, partial);

            if (result == -ETIMEDOUT) { /* NAK - so hold for a while */
                if (!maxretry--) {
                    errn = -ETIME;
                    goto error;
                }
                prepare_to_wait(&rio->wait_q, &wait, TASK_INTERRUPTIBLE);
                schedule_timeout(NAK_TIMEOUT);
                finish_wait(&rio->wait_q, &wait);
                continue;
            } else if (!result && partial) {
                obuf += partial;
                thistime -= partial;
            } else
                break;
        }
        if (result) {
            dev_err(&rio->rio_dev->dev, "Write Whoops - %x\n",
                result);
            errn = -EIO;
            goto error;
        }
        bytes_written += copy_size;
        count -= copy_size;
        buffer += copy_size;
    } while (count > 0);

    mutex_unlock(&(rio->lock));

    return bytes_written ? bytes_written : -EIO;

error:
    mutex_unlock(&(rio->lock));
    return errn;
}

static ssize_t
read_rio(struct file *file, char __user *buffer, size_t count, loff_t * ppos)
{
    DEFINE_WAIT(wait);
    struct rio_usb_data *rio = &rio_instance;
    ssize_t read_count;
    unsigned int partial;
    int this_read;
    int result;
    int maxretry = 10;
    char *ibuf;
    int intr;

    intr = mutex_lock_interruptible(&(rio->lock));
    if (intr)
        return -EINTR;
    /* Sanity check to make sure rio is connected, powered, etc */
        if (rio->present == 0 || rio->rio_dev == NULL) {
        mutex_unlock(&(rio->lock));
        return -ENODEV;
    }

    ibuf = rio->ibuf;

    read_count = 0;


    while (count > 0) {
        if (signal_pending(current)) {
            mutex_unlock(&(rio->lock));
            return read_count ? read_count : -EINTR;
        }
        if (!rio->rio_dev) {
            mutex_unlock(&(rio->lock));
            return -ENODEV;
        }
        this_read = (count >= IBUF_SIZE) ? IBUF_SIZE : count;

        result = usb_bulk_msg(rio->rio_dev,
                      usb_rcvbulkpipe(rio->rio_dev, 1),
                      ibuf, this_read, &partial,
                      8000);

        dev_dbg(&rio->rio_dev->dev,
            "read stats: result:%d this_read:%u partial:%u\n",
            result, this_read, partial);

        if (partial) {
            count = this_read = partial;
        } else if (result == -ETIMEDOUT || result == 15) {  /* FIXME: 15 ??? */
            if (!maxretry--) {
                mutex_unlock(&(rio->lock));
                dev_err(&rio->rio_dev->dev,
                    "read_rio: maxretry timeout\n");
                return -ETIME;
            }
            prepare_to_wait(&rio->wait_q, &wait, TASK_INTERRUPTIBLE);
            schedule_timeout(NAK_TIMEOUT);
            finish_wait(&rio->wait_q, &wait);
            continue;
        } else if (result != -EREMOTEIO) {
            mutex_unlock(&(rio->lock));
            dev_err(&rio->rio_dev->dev,
                "Read Whoops - result:%u partial:%u this_read:%u\n",
                result, partial, this_read);
            return -EIO;
        } else {
            mutex_unlock(&(rio->lock));
            return (0);
        }

        if (this_read) {
            if (copy_to_user(buffer, ibuf, this_read)) {
                mutex_unlock(&(rio->lock));
                return -EFAULT;
            }
            count -= this_read;
            read_count += this_read;
            buffer += this_read;
        }
    }
    mutex_unlock(&(rio->lock));
    return read_count;
}

static const struct file_operations usb_rio_fops = {
    .owner =    THIS_MODULE,
    .read =     read_rio,
    .write =    write_rio,
    .unlocked_ioctl = ioctl_rio,
    .open =     open_rio,
    .release =  close_rio,
    .llseek =   noop_llseek,
};

static struct usb_class_driver usb_rio_class = {
    .name =     "rio500%d",
    .fops =     &usb_rio_fops,
    .minor_base =   RIO_MINOR,
};

static int probe_rio(struct usb_interface *intf,
             const struct usb_device_id *id)
{
    struct usb_device *dev = interface_to_usbdev(intf);
    struct rio_usb_data *rio = &rio_instance;
    int retval;

    dev_info(&intf->dev, "USB Rio found at address %d\n", dev->devnum);

    retval = usb_register_dev(intf, &usb_rio_class);
    if (retval) {
        dev_err(&dev->dev,
            "Not able to get a minor for this device.\n");
        return -ENOMEM;
    }

    rio->rio_dev = dev;

    if (!(rio->obuf = kmalloc(OBUF_SIZE, GFP_KERNEL))) {
        dev_err(&dev->dev,
            "probe_rio: Not enough memory for the output buffer\n");
        usb_deregister_dev(intf, &usb_rio_class);
        return -ENOMEM;
    }
    dev_dbg(&intf->dev, "obuf address:%p\n", rio->obuf);

    if (!(rio->ibuf = kmalloc(IBUF_SIZE, GFP_KERNEL))) {
        dev_err(&dev->dev,
            "probe_rio: Not enough memory for the input buffer\n");
        usb_deregister_dev(intf, &usb_rio_class);
        kfree(rio->obuf);
        return -ENOMEM;
    }
    dev_dbg(&intf->dev, "ibuf address:%p\n", rio->ibuf);

    mutex_init(&(rio->lock));

    usb_set_intfdata (intf, rio);
    rio->present = 1;

    return 0;
}

static void disconnect_rio(struct usb_interface *intf)
{
    struct rio_usb_data *rio = usb_get_intfdata (intf);

    usb_set_intfdata (intf, NULL);
    mutex_lock(&rio500_mutex);
    if (rio) {
        usb_deregister_dev(intf, &usb_rio_class);

        mutex_lock(&(rio->lock));
        if (rio->isopen) {
            rio->isopen = 0;
            /* better let it finish - the release will do whats needed */
            rio->rio_dev = NULL;
            mutex_unlock(&(rio->lock));
            mutex_unlock(&rio500_mutex);
            return;
        }
        kfree(rio->ibuf);
        kfree(rio->obuf);

        dev_info(&intf->dev, "USB Rio disconnected.\n");

        rio->present = 0;
        mutex_unlock(&(rio->lock));
    }
    mutex_unlock(&rio500_mutex);
}

static const struct usb_device_id rio_table[] = {
    { USB_DEVICE(0x0841, 1) },      /* Rio 500 */
    { }                 /* Terminating entry */
};

MODULE_DEVICE_TABLE (usb, rio_table);

static struct usb_driver rio_driver = {
    .name =     "rio500",
    .probe =    probe_rio,
    .disconnect =   disconnect_rio,
    .id_table = rio_table,
};

module_usb_driver(rio_driver);

MODULE_AUTHOR( DRIVER_AUTHOR );
MODULE_DESCRIPTION( DRIVER_DESC );
MODULE_LICENSE("GPL");