// SPDX-License-Identifier: GPL-2.0+
/*
* adutux - driver for ADU devices from Ontrak Control Systems
* This is an experimental driver. Use at your own risk.
* This driver is not supported by Ontrak Control Systems.
*
* Copyright (c) 2003 John Homppi (SCO, leave this notice here)
*
* derived from the Lego USB Tower driver 0.56:
* Copyright (c) 2003 David Glance <[email protected]>
* 2001 Juergen Stuber <[email protected]>
* that was derived from USB Skeleton driver - 0.5
* Copyright (c) 2001 Greg Kroah-Hartman ([email protected])
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/sched/signal.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/mutex.h>
#include <linux/uaccess.h>
#define DRIVER_AUTHOR "John Homppi"
#define DRIVER_DESC "adutux (see www.ontrak.net)"
/* Define these values to match your device */
#define ADU_VENDOR_ID 0x0a07
#define ADU_PRODUCT_ID 0x0064
/* table of devices that work with this driver */
static const struct usb_device_id device_table[] = {
{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID) }, /* ADU100 */
{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+20) }, /* ADU120 */
{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+30) }, /* ADU130 */
{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+100) }, /* ADU200 */
{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+108) }, /* ADU208 */
{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+118) }, /* ADU218 */
{ } /* Terminating entry */
};
MODULE_DEVICE_TABLE(usb, device_table);
#ifdef CONFIG_USB_DYNAMIC_MINORS
#define ADU_MINOR_BASE 0
#else
#define ADU_MINOR_BASE 67
#endif
/* we can have up to this number of device plugged in at once */
#define MAX_DEVICES 16
#define COMMAND_TIMEOUT (2*HZ)
/*
* The locking scheme is a vanilla 3-lock:
* adu_device.buflock: A spinlock, covers what IRQs touch.
* adutux_mutex: A Static lock to cover open_count. It would also cover
* any globals, but we don't have them in 2.6.
* adu_device.mtx: A mutex to hold across sleepers like copy_from_user.
* It covers all of adu_device, except the open_count
* and what .buflock covers.
*/
/* Structure to hold all of our device specific stuff */
struct adu_device {
struct mutex mtx;
struct usb_device *udev; /* save off the usb device pointer */
struct usb_interface *interface;
unsigned int minor; /* the starting minor number for this device */
char serial_number[8];
int open_count; /* number of times this port has been opened */
unsigned long disconnected:1;
char *read_buffer_primary;
int read_buffer_length;
char *read_buffer_secondary;
int secondary_head;
int secondary_tail;
spinlock_t buflock;
wait_queue_head_t read_wait;
wait_queue_head_t write_wait;
char *interrupt_in_buffer;
struct usb_endpoint_descriptor *interrupt_in_endpoint;
struct urb *interrupt_in_urb;
int read_urb_finished;
char *interrupt_out_buffer;
struct usb_endpoint_descriptor *interrupt_out_endpoint;
struct urb *interrupt_out_urb;
int out_urb_finished;
};
static DEFINE_MUTEX(adutux_mutex);
static struct usb_driver adu_driver;
static inline void adu_debug_data(struct device *dev, const char *function,
int size, const unsigned char *data)
{
dev_dbg(dev, "%s - length = %d, data = %*ph\n",
function, size, size, data);
}
/*
* adu_abort_transfers
* aborts transfers and frees associated data structures
*/
static void adu_abort_transfers(struct adu_device *dev)
{
unsigned long flags;
if (dev->disconnected)
return;
/* shutdown transfer */
/* XXX Anchor these instead */
spin_lock_irqsave(&dev->buflock, flags);
if (!dev->read_urb_finished) {
spin_unlock_irqrestore(&dev->buflock, flags);
usb_kill_urb(dev->interrupt_in_urb);
} else
spin_unlock_irqrestore(&dev->buflock, flags);
spin_lock_irqsave(&dev->buflock, flags);
if (!dev->out_urb_finished) {
spin_unlock_irqrestore(&dev->buflock, flags);
wait_event_timeout(dev->write_wait, dev->out_urb_finished,
COMMAND_TIMEOUT);
usb_kill_urb(dev->interrupt_out_urb);
} else
spin_unlock_irqrestore(&dev->buflock, flags);
}
static void adu_delete(struct adu_device *dev)
{
/* free data structures */
usb_free_urb(dev->interrupt_in_urb);
usb_free_urb(dev->interrupt_out_urb);
kfree(dev->read_buffer_primary);
kfree(dev->read_buffer_secondary);
kfree(dev->interrupt_in_buffer);
kfree(dev->interrupt_out_buffer);
usb_put_dev(dev->udev);
kfree(dev);
}
static void adu_interrupt_in_callback(struct urb *urb)
{
struct adu_device *dev = urb->context;
int status = urb->status;
unsigned long flags;
adu_debug_data(&dev->udev->dev, __func__,
urb->actual_length, urb->transfer_buffer);
spin_lock_irqsave(&dev->buflock, flags);
if (status != 0) {
if ((status != -ENOENT) && (status != -ECONNRESET) &&
(status != -ESHUTDOWN)) {
dev_dbg(&dev->udev->dev,
"%s : nonzero status received: %d\n",
__func__, status);
}
goto exit;
}
if (urb->actual_length > 0 && dev->interrupt_in_buffer[0] != 0x00) {
if (dev->read_buffer_length <
(4 * usb_endpoint_maxp(dev->interrupt_in_endpoint)) -
(urb->actual_length)) {
memcpy (dev->read_buffer_primary +
dev->read_buffer_length,
dev->interrupt_in_buffer, urb->actual_length);
dev->read_buffer_length += urb->actual_length;
dev_dbg(&dev->udev->dev, "%s reading %d\n", __func__,
urb->actual_length);
} else {
dev_dbg(&dev->udev->dev, "%s : read_buffer overflow\n",
__func__);
}
}
exit:
dev->read_urb_finished = 1;
spin_unlock_irqrestore(&dev->buflock, flags);
/* always wake up so we recover from errors */
wake_up_interruptible(&dev->read_wait);
}
static void adu_interrupt_out_callback(struct urb *urb)
{
struct adu_device *dev = urb->context;
int status = urb->status;
unsigned long flags;
adu_debug_data(&dev->udev->dev, __func__,
urb->actual_length, urb->transfer_buffer);
if (status != 0) {
if ((status != -ENOENT) &&
(status != -ESHUTDOWN) &&
(status != -ECONNRESET)) {
dev_dbg(&dev->udev->dev,
"%s :nonzero status received: %d\n", __func__,
status);
}
return;
}
spin_lock_irqsave(&dev->buflock, flags);
dev->out_urb_finished = 1;
wake_up(&dev->write_wait);
spin_unlock_irqrestore(&dev->buflock, flags);
}
static int adu_open(struct inode *inode, struct file *file)
{
struct adu_device *dev = NULL;
struct usb_interface *interface;
int subminor;
int retval;
subminor = iminor(inode);
retval = mutex_lock_interruptible(&adutux_mutex);
if (retval)
goto exit_no_lock;
interface = usb_find_interface(&adu_driver, subminor);
if (!interface) {
pr_err("%s - error, can't find device for minor %d\n",
__func__, subminor);
retval = -ENODEV;
goto exit_no_device;
}
dev = usb_get_intfdata(interface);
if (!dev) {
retval = -ENODEV;
goto exit_no_device;
}
/* check that nobody else is using the device */
if (dev->open_count) {
retval = -EBUSY;
goto exit_no_device;
}
++dev->open_count;
dev_dbg(&dev->udev->dev, "%s: open count %d\n", __func__,
dev->open_count);
/* save device in the file's private structure */
file->private_data = dev;
/* initialize in direction */
dev->read_buffer_length = 0;
/* fixup first read by having urb waiting for it */
usb_fill_int_urb(dev->interrupt_in_urb, dev->udev,
usb_rcvintpipe(dev->udev,
dev->interrupt_in_endpoint->bEndpointAddress),
dev->interrupt_in_buffer,
usb_endpoint_maxp(dev->interrupt_in_endpoint),
adu_interrupt_in_callback, dev,
dev->interrupt_in_endpoint->bInterval);
dev->read_urb_finished = 0;
if (usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL))
dev->read_urb_finished = 1;
/* we ignore failure */
/* end of fixup for first read */
/* initialize out direction */
dev->out_urb_finished = 1;
retval = 0;
exit_no_device:
mutex_unlock(&adutux_mutex);
exit_no_lock:
return retval;
}
static void adu_release_internal(struct adu_device *dev)
{
/* decrement our usage count for the device */
--dev->open_count;
dev_dbg(&dev->udev->dev, "%s : open count %d\n", __func__,
dev->open_count);
if (dev->open_count <= 0) {
adu_abort_transfers(dev);
dev->open_count = 0;
}
}
static int adu_release(struct inode *inode, struct file *file)
{
struct adu_device *dev;
int retval = 0;
if (file == NULL) {
retval = -ENODEV;
goto exit;
}
dev = file->private_data;
if (dev == NULL) {
retval = -ENODEV;
goto exit;
}
mutex_lock(&adutux_mutex); /* not interruptible */
if (dev->open_count <= 0) {
dev_dbg(&dev->udev->dev, "%s : device not opened\n", __func__);
retval = -ENODEV;
goto unlock;
}
adu_release_internal(dev);
if (dev->disconnected) {
/* the device was unplugged before the file was released */
if (!dev->open_count) /* ... and we're the last user */
adu_delete(dev);
}
unlock:
mutex_unlock(&adutux_mutex);
exit:
return retval;
}
static ssize_t adu_read(struct file *file, __user char *buffer, size_t count,
loff_t *ppos)
{
struct adu_device *dev;
size_t bytes_read = 0;
size_t bytes_to_read = count;
int retval = 0;
int timeout = 0;
int should_submit = 0;
unsigned long flags;
DECLARE_WAITQUEUE(wait, current);
dev = file->private_data;
if (mutex_lock_interruptible(&dev->mtx))
return -ERESTARTSYS;
/* verify that the device wasn't unplugged */
if (dev->disconnected) {
retval = -ENODEV;
pr_err("No device or device unplugged %d\n", retval);
goto exit;
}
/* verify that some data was requested */
if (count == 0) {
dev_dbg(&dev->udev->dev, "%s : read request of 0 bytes\n",
__func__);
goto exit;
}
timeout = COMMAND_TIMEOUT;
dev_dbg(&dev->udev->dev, "%s : about to start looping\n", __func__);
while (bytes_to_read) {
size_t data_in_secondary = dev->secondary_tail - dev->secondary_head;
dev_dbg(&dev->udev->dev,
"%s : while, data_in_secondary=%zu, status=%d\n",
__func__, data_in_secondary,
dev->interrupt_in_urb->status);
if (data_in_secondary) {
/* drain secondary buffer */
size_t amount = min(bytes_to_read, data_in_secondary);
if (copy_to_user(buffer, dev->read_buffer_secondary+dev->secondary_head, amount)) {
retval = -EFAULT;
goto exit;
}
dev->secondary_head += amount;
bytes_read += amount;
bytes_to_read -= amount;
} else {
/* we check the primary buffer */
spin_lock_irqsave (&dev->buflock, flags);
if (dev->read_buffer_length) {
/* we secure access to the primary */
dev_dbg(&dev->udev->dev,
"%s : swap, read_buffer_length = %d\n",
__func__, dev->read_buffer_length);
swap(dev->read_buffer_primary, dev->read_buffer_secondary);
dev->secondary_head = 0;
dev->secondary_tail = dev->read_buffer_length;
dev->read_buffer_length = 0;
spin_unlock_irqrestore(&dev->buflock, flags);
/* we have a free buffer so use it */
should_submit = 1;
} else {
/* even the primary was empty - we may need to do IO */
if (!dev->read_urb_finished) {
/* somebody is doing IO */
spin_unlock_irqrestore(&dev->buflock, flags);
dev_dbg(&dev->udev->dev,
"%s : submitted already\n",
__func__);
} else {
/* we must initiate input */
dev_dbg(&dev->udev->dev,
"%s : initiate input\n",
__func__);
dev->read_urb_finished = 0;
spin_unlock_irqrestore(&dev->buflock, flags);
usb_fill_int_urb(dev->interrupt_in_urb, dev->udev,
usb_rcvintpipe(dev->udev,
dev->interrupt_in_endpoint->bEndpointAddress),
dev->interrupt_in_buffer,
usb_endpoint_maxp(dev->interrupt_in_endpoint),
adu_interrupt_in_callback,
dev,
dev->interrupt_in_endpoint->bInterval);
retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
if (retval) {
dev->read_urb_finished = 1;
if (retval == -ENOMEM) {
retval = bytes_read ? bytes_read : -ENOMEM;
}
dev_dbg(&dev->udev->dev,
"%s : submit failed\n",
__func__);
goto exit;
}
}
/* we wait for I/O to complete */
set_current_state(TASK_INTERRUPTIBLE);
add_wait_queue(&dev->read_wait, &wait);
spin_lock_irqsave(&dev->buflock, flags);
if (!dev->read_urb_finished) {
spin_unlock_irqrestore(&dev->buflock, flags);
timeout = schedule_timeout(COMMAND_TIMEOUT);
} else {
spin_unlock_irqrestore(&dev->buflock, flags);
set_current_state(TASK_RUNNING);
}
remove_wait_queue(&dev->read_wait, &wait);
if (timeout <= 0) {
dev_dbg(&dev->udev->dev,
"%s : timeout\n", __func__);
retval = bytes_read ? bytes_read : -ETIMEDOUT;
goto exit;
}
if (signal_pending(current)) {
dev_dbg(&dev->udev->dev,
"%s : signal pending\n",
__func__);
retval = bytes_read ? bytes_read : -EINTR;
goto exit;
}
}
}
}
retval = bytes_read;
/* if the primary buffer is empty then use it */
spin_lock_irqsave(&dev->buflock, flags);
if (should_submit && dev->read_urb_finished) {
dev->read_urb_finished = 0;
spin_unlock_irqrestore(&dev->buflock, flags);
usb_fill_int_urb(dev->interrupt_in_urb, dev->udev,
usb_rcvintpipe(dev->udev,
dev->interrupt_in_endpoint->bEndpointAddress),
dev->interrupt_in_buffer,
usb_endpoint_maxp(dev->interrupt_in_endpoint),
adu_interrupt_in_callback,
dev,
dev->interrupt_in_endpoint->bInterval);
if (usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL) != 0)
dev->read_urb_finished = 1;
/* we ignore failure */
} else {
spin_unlock_irqrestore(&dev->buflock, flags);
}
exit:
/* unlock the device */
mutex_unlock(&dev->mtx);
return retval;
}
static ssize_t adu_write(struct file *file, const __user char *buffer,
size_t count, loff_t *ppos)
{
DECLARE_WAITQUEUE(waita, current);
struct adu_device *dev;
size_t bytes_written = 0;
size_t bytes_to_write;
size_t buffer_size;
unsigned long flags;
int retval;
dev = file->private_data;
retval = mutex_lock_interruptible(&dev->mtx);
if (retval)
goto exit_nolock;
/* verify that the device wasn't unplugged */
if (dev->disconnected) {
retval = -ENODEV;
pr_err("No device or device unplugged %d\n", retval);
goto exit;
}
/* verify that we actually have some data to write */
if (count == 0) {
dev_dbg(&dev->udev->dev, "%s : write request of 0 bytes\n",
__func__);
goto exit;
}
while (count > 0) {
add_wait_queue(&dev->write_wait, &waita);
set_current_state(TASK_INTERRUPTIBLE);
spin_lock_irqsave(&dev->buflock, flags);
if (!dev->out_urb_finished) {
spin_unlock_irqrestore(&dev->buflock, flags);
mutex_unlock(&dev->mtx);
if (signal_pending(current)) {
dev_dbg(&dev->udev->dev, "%s : interrupted\n",
__func__);
set_current_state(TASK_RUNNING);
retval = -EINTR;
goto exit_onqueue;
}
if (schedule_timeout(COMMAND_TIMEOUT) == 0) {
dev_dbg(&dev->udev->dev,
"%s - command timed out.\n", __func__);
retval = -ETIMEDOUT;
goto exit_onqueue;
}
remove_wait_queue(&dev->write_wait, &waita);
retval = mutex_lock_interruptible(&dev->mtx);
if (retval) {
retval = bytes_written ? bytes_written : retval;
goto exit_nolock;
}
dev_dbg(&dev->udev->dev,
"%s : in progress, count = %zd\n",
__func__, count);
} else {
spin_unlock_irqrestore(&dev->buflock, flags);
set_current_state(TASK_RUNNING);
remove_wait_queue(&dev->write_wait, &waita);
dev_dbg(&dev->udev->dev, "%s : sending, count = %zd\n",
__func__, count);
/* write the data into interrupt_out_buffer from userspace */
buffer_size = usb_endpoint_maxp(dev->interrupt_out_endpoint);
bytes_to_write = count > buffer_size ? buffer_size : count;
dev_dbg(&dev->udev->dev,
"%s : buffer_size = %zd, count = %zd, bytes_to_write = %zd\n",
__func__, buffer_size, count, bytes_to_write);
if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write) != 0) {
retval = -EFAULT;
goto exit;
}
/* send off the urb */
usb_fill_int_urb(
dev->interrupt_out_urb,
dev->udev,
usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
dev->interrupt_out_buffer,
bytes_to_write,
adu_interrupt_out_callback,
dev,
dev->interrupt_out_endpoint->bInterval);
dev->interrupt_out_urb->actual_length = bytes_to_write;
dev->out_urb_finished = 0;
retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
if (retval < 0) {
dev->out_urb_finished = 1;
dev_err(&dev->udev->dev, "Couldn't submit "
"interrupt_out_urb %d\n", retval);
goto exit;
}
buffer += bytes_to_write;
count -= bytes_to_write;
bytes_written += bytes_to_write;
}
}
mutex_unlock(&dev->mtx);
return bytes_written;
exit:
mutex_unlock(&dev->mtx);
exit_nolock:
return retval;
exit_onqueue:
remove_wait_queue(&dev->write_wait, &waita);
return retval;
}
/* file operations needed when we register this driver */
static const struct file_operations adu_fops = {
.owner = THIS_MODULE,
.read = adu_read,
.write = adu_write,
.open = adu_open,
.release = adu_release,
.llseek = noop_llseek,
};
/*
* usb class driver info in order to get a minor number from the usb core,
* and to have the device registered with devfs and the driver core
*/
static struct usb_class_driver adu_class = {
.name = "usb/adutux%d",
.fops = &adu_fops,
.minor_base = ADU_MINOR_BASE,
};
/*
* adu_probe
*
* Called by the usb core when a new device is connected that it thinks
* this driver might be interested in.
*/
static int adu_probe(struct usb_interface *interface,
const struct usb_device_id *id)
{
struct usb_device *udev = interface_to_usbdev(interface);
struct adu_device *dev = NULL;
int retval = -ENOMEM;
int in_end_size;
int out_end_size;
int res;
/* allocate memory for our device state and initialize it */
dev = kzalloc(sizeof(struct adu_device), GFP_KERNEL);
if (!dev)
return -ENOMEM;
mutex_init(&dev->mtx);
spin_lock_init(&dev->buflock);
dev->udev = usb_get_dev(udev);
init_waitqueue_head(&dev->read_wait);
init_waitqueue_head(&dev->write_wait);
res = usb_find_common_endpoints_reverse(interface->cur_altsetting,
NULL, NULL,
&dev->interrupt_in_endpoint,
&dev->interrupt_out_endpoint);
if (res) {
dev_err(&interface->dev, "interrupt endpoints not found\n");
retval = res;
goto error;
}
in_end_size = usb_endpoint_maxp(dev->interrupt_in_endpoint);
out_end_size = usb_endpoint_maxp(dev->interrupt_out_endpoint);
dev->read_buffer_primary = kmalloc((4 * in_end_size), GFP_KERNEL);
if (!dev->read_buffer_primary)
goto error;
/* debug code prime the buffer */
memset(dev->read_buffer_primary, 'a', in_end_size);
memset(dev->read_buffer_primary + in_end_size, 'b', in_end_size);
memset(dev->read_buffer_primary + (2 * in_end_size), 'c', in_end_size);
memset(dev->read_buffer_primary + (3 * in_end_size), 'd', in_end_size);
dev->read_buffer_secondary = kmalloc((4 * in_end_size), GFP_KERNEL);
if (!dev->read_buffer_secondary)
goto error;
/* debug code prime the buffer */
memset(dev->read_buffer_secondary, 'e', in_end_size);
memset(dev->read_buffer_secondary + in_end_size, 'f', in_end_size);
memset(dev->read_buffer_secondary + (2 * in_end_size), 'g', in_end_size);
memset(dev->read_buffer_secondary + (3 * in_end_size), 'h', in_end_size);
dev->interrupt_in_buffer = kmalloc(in_end_size, GFP_KERNEL);
if (!dev->interrupt_in_buffer)
goto error;
/* debug code prime the buffer */
memset(dev->interrupt_in_buffer, 'i', in_end_size);
dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
if (!dev->interrupt_in_urb)
goto error;
dev->interrupt_out_buffer = kmalloc(out_end_size, GFP_KERNEL);
if (!dev->interrupt_out_buffer)
goto error;
dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
if (!dev->interrupt_out_urb)
goto error;
if (!usb_string(udev, udev->descriptor.iSerialNumber, dev->serial_number,
sizeof(dev->serial_number))) {
dev_err(&interface->dev, "Could not retrieve serial number\n");
retval = -EIO;
goto error;
}
dev_dbg(&interface->dev, "serial_number=%s", dev->serial_number);
/* we can register the device now, as it is ready */
usb_set_intfdata(interface, dev);
retval = usb_register_dev(interface, &adu_class);
if (retval) {
/* something prevented us from registering this driver */
dev_err(&interface->dev, "Not able to get a minor for this device.\n");
usb_set_intfdata(interface, NULL);
goto error;
}
dev->minor = interface->minor;
/* let the user know what node this device is now attached to */
dev_info(&interface->dev, "ADU%d %s now attached to /dev/usb/adutux%d\n",
le16_to_cpu(udev->descriptor.idProduct), dev->serial_number,
(dev->minor - ADU_MINOR_BASE));
return 0;
error:
adu_delete(dev);
return retval;
}
/*
* adu_disconnect
*
* Called by the usb core when the device is removed from the system.
*/
static void adu_disconnect(struct usb_interface *interface)
{
struct adu_device *dev;
dev = usb_get_intfdata(interface);
usb_deregister_dev(interface, &adu_class);
usb_poison_urb(dev->interrupt_in_urb);
usb_poison_urb(dev->interrupt_out_urb);
mutex_lock(&adutux_mutex);
usb_set_intfdata(interface, NULL);
mutex_lock(&dev->mtx); /* not interruptible */
dev->disconnected = 1;
mutex_unlock(&dev->mtx);
/* if the device is not opened, then we clean up right now */
if (!dev->open_count)
adu_delete(dev);
mutex_unlock(&adutux_mutex);
}
/* usb specific object needed to register this driver with the usb subsystem */
static struct usb_driver adu_driver = {
.name = "adutux",
.probe = adu_probe,
.disconnect = adu_disconnect,
.id_table = device_table,
};
module_usb_driver(adu_driver);
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
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