diff options
Diffstat (limited to 'drivers/usb/misc/legousbtower.c')
| -rw-r--r-- | drivers/usb/misc/legousbtower.c | 967 |
1 files changed, 967 insertions, 0 deletions
diff --git a/drivers/usb/misc/legousbtower.c b/drivers/usb/misc/legousbtower.c new file mode 100644 index 000000000..23061f152 --- /dev/null +++ b/drivers/usb/misc/legousbtower.c @@ -0,0 +1,967 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * LEGO USB Tower driver + * + * Copyright (C) 2003 David Glance <davidgsf@sourceforge.net> + * 2001-2004 Juergen Stuber <starblue@users.sourceforge.net> + * + * derived from USB Skeleton driver - 0.5 + * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com) + * + * History: + * + * 2001-10-13 - 0.1 js + * - first version + * 2001-11-03 - 0.2 js + * - simplified buffering, one-shot URBs for writing + * 2001-11-10 - 0.3 js + * - removed IOCTL (setting power/mode is more complicated, postponed) + * 2001-11-28 - 0.4 js + * - added vendor commands for mode of operation and power level in open + * 2001-12-04 - 0.5 js + * - set IR mode by default (by oversight 0.4 set VLL mode) + * 2002-01-11 - 0.5? pcchan + * - make read buffer reusable and work around bytes_to_write issue between + * uhci and legusbtower + * 2002-09-23 - 0.52 david (david@csse.uwa.edu.au) + * - imported into lejos project + * - changed wake_up to wake_up_interruptible + * - changed to use lego0 rather than tower0 + * - changed dbg() to use __func__ rather than deprecated __func__ + * 2003-01-12 - 0.53 david (david@csse.uwa.edu.au) + * - changed read and write to write everything or + * timeout (from a patch by Chris Riesen and Brett Thaeler driver) + * - added ioctl functionality to set timeouts + * 2003-07-18 - 0.54 davidgsf (david@csse.uwa.edu.au) + * - initial import into LegoUSB project + * - merge of existing LegoUSB.c driver + * 2003-07-18 - 0.56 davidgsf (david@csse.uwa.edu.au) + * - port to 2.6 style driver + * 2004-02-29 - 0.6 Juergen Stuber <starblue@users.sourceforge.net> + * - fix locking + * - unlink read URBs which are no longer needed + * - allow increased buffer size, eliminates need for timeout on write + * - have read URB running continuously + * - added poll + * - forbid seeking + * - added nonblocking I/O + * - changed back __func__ to __func__ + * - read and log tower firmware version + * - reset tower on probe, avoids failure of first write + * 2004-03-09 - 0.7 Juergen Stuber <starblue@users.sourceforge.net> + * - timeout read now only after inactivity, shorten default accordingly + * 2004-03-11 - 0.8 Juergen Stuber <starblue@users.sourceforge.net> + * - log major, minor instead of possibly confusing device filename + * - whitespace cleanup + * 2004-03-12 - 0.9 Juergen Stuber <starblue@users.sourceforge.net> + * - normalize whitespace in debug messages + * - take care about endianness in control message responses + * 2004-03-13 - 0.91 Juergen Stuber <starblue@users.sourceforge.net> + * - make default intervals longer to accommodate current EHCI driver + * 2004-03-19 - 0.92 Juergen Stuber <starblue@users.sourceforge.net> + * - replaced atomic_t by memory barriers + * 2004-04-21 - 0.93 Juergen Stuber <starblue@users.sourceforge.net> + * - wait for completion of write urb in release (needed for remotecontrol) + * - corrected poll for write direction (missing negation) + * 2004-04-22 - 0.94 Juergen Stuber <starblue@users.sourceforge.net> + * - make device locking interruptible + * 2004-04-30 - 0.95 Juergen Stuber <starblue@users.sourceforge.net> + * - check for valid udev on resubmitting and unlinking urbs + * 2004-08-03 - 0.96 Juergen Stuber <starblue@users.sourceforge.net> + * - move reset into open to clean out spurious data + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/completion.h> +#include <linux/mutex.h> +#include <linux/uaccess.h> +#include <linux/usb.h> +#include <linux/poll.h> + + +#define DRIVER_AUTHOR "Juergen Stuber <starblue@sourceforge.net>" +#define DRIVER_DESC "LEGO USB Tower Driver" + + +/* The defaults are chosen to work with the latest versions of leJOS and NQC. + */ + +/* Some legacy software likes to receive packets in one piece. + * In this case read_buffer_size should exceed the maximal packet length + * (417 for datalog uploads), and packet_timeout should be set. + */ +static int read_buffer_size = 480; +module_param(read_buffer_size, int, 0); +MODULE_PARM_DESC(read_buffer_size, "Read buffer size"); + +/* Some legacy software likes to send packets in one piece. + * In this case write_buffer_size should exceed the maximal packet length + * (417 for firmware and program downloads). + * A problem with long writes is that the following read may time out + * if the software is not prepared to wait long enough. + */ +static int write_buffer_size = 480; +module_param(write_buffer_size, int, 0); +MODULE_PARM_DESC(write_buffer_size, "Write buffer size"); + +/* Some legacy software expects reads to contain whole LASM packets. + * To achieve this, characters which arrive before a packet timeout + * occurs will be returned in a single read operation. + * A problem with long reads is that the software may time out + * if it is not prepared to wait long enough. + * The packet timeout should be greater than the time between the + * reception of subsequent characters, which should arrive about + * every 5ms for the standard 2400 baud. + * Set it to 0 to disable. + */ +static int packet_timeout = 50; +module_param(packet_timeout, int, 0); +MODULE_PARM_DESC(packet_timeout, "Packet timeout in ms"); + +/* Some legacy software expects blocking reads to time out. + * Timeout occurs after the specified time of read and write inactivity. + * Set it to 0 to disable. + */ +static int read_timeout = 200; +module_param(read_timeout, int, 0); +MODULE_PARM_DESC(read_timeout, "Read timeout in ms"); + +/* As of kernel version 2.6.4 ehci-hcd uses an + * "only one interrupt transfer per frame" shortcut + * to simplify the scheduling of periodic transfers. + * This conflicts with our standard 1ms intervals for in and out URBs. + * We use default intervals of 2ms for in and 8ms for out transfers, + * which is fast enough for 2400 baud and allows a small additional load. + * Increase the interval to allow more devices that do interrupt transfers, + * or set to 0 to use the standard interval from the endpoint descriptors. + */ +static int interrupt_in_interval = 2; +module_param(interrupt_in_interval, int, 0); +MODULE_PARM_DESC(interrupt_in_interval, "Interrupt in interval in ms"); + +static int interrupt_out_interval = 8; +module_param(interrupt_out_interval, int, 0); +MODULE_PARM_DESC(interrupt_out_interval, "Interrupt out interval in ms"); + +/* Define these values to match your device */ +#define LEGO_USB_TOWER_VENDOR_ID 0x0694 +#define LEGO_USB_TOWER_PRODUCT_ID 0x0001 + +/* Vendor requests */ +#define LEGO_USB_TOWER_REQUEST_RESET 0x04 +#define LEGO_USB_TOWER_REQUEST_GET_VERSION 0xFD + +struct tower_reset_reply { + __le16 size; /* little-endian */ + __u8 err_code; + __u8 spare; +} __attribute__ ((packed)); + +struct tower_get_version_reply { + __le16 size; /* little-endian */ + __u8 err_code; + __u8 spare; + __u8 major; + __u8 minor; + __le16 build_no; /* little-endian */ +} __attribute__ ((packed)); + + +/* table of devices that work with this driver */ +static const struct usb_device_id tower_table[] = { + { USB_DEVICE(LEGO_USB_TOWER_VENDOR_ID, LEGO_USB_TOWER_PRODUCT_ID) }, + { } /* Terminating entry */ +}; + +MODULE_DEVICE_TABLE (usb, tower_table); + +#define LEGO_USB_TOWER_MINOR_BASE 160 + + +/* Structure to hold all of our device specific stuff */ +struct lego_usb_tower { + struct mutex lock; /* locks this structure */ + struct usb_device* udev; /* save off the usb device pointer */ + unsigned char minor; /* the starting minor number for this device */ + + int open_count; /* number of times this port has been opened */ + unsigned long disconnected:1; + + char* read_buffer; + size_t read_buffer_length; /* this much came in */ + size_t read_packet_length; /* this much will be returned on read */ + spinlock_t read_buffer_lock; + int packet_timeout_jiffies; + unsigned long read_last_arrival; + + 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 interrupt_in_interval; + int interrupt_in_running; + int interrupt_in_done; + + char* interrupt_out_buffer; + struct usb_endpoint_descriptor* interrupt_out_endpoint; + struct urb* interrupt_out_urb; + int interrupt_out_interval; + int interrupt_out_busy; + +}; + + +/* local function prototypes */ +static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos); +static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos); +static inline void tower_delete (struct lego_usb_tower *dev); +static int tower_open (struct inode *inode, struct file *file); +static int tower_release (struct inode *inode, struct file *file); +static __poll_t tower_poll (struct file *file, poll_table *wait); +static loff_t tower_llseek (struct file *file, loff_t off, int whence); + +static void tower_abort_transfers (struct lego_usb_tower *dev); +static void tower_check_for_read_packet (struct lego_usb_tower *dev); +static void tower_interrupt_in_callback (struct urb *urb); +static void tower_interrupt_out_callback (struct urb *urb); + +static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id); +static void tower_disconnect (struct usb_interface *interface); + + +/* file operations needed when we register this driver */ +static const struct file_operations tower_fops = { + .owner = THIS_MODULE, + .read = tower_read, + .write = tower_write, + .open = tower_open, + .release = tower_release, + .poll = tower_poll, + .llseek = tower_llseek, +}; + +static char *legousbtower_devnode(struct device *dev, umode_t *mode) +{ + return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev)); +} + +/* + * usb class driver info in order to get a minor number from the usb core, + * and to have the device registered with the driver core + */ +static struct usb_class_driver tower_class = { + .name = "legousbtower%d", + .devnode = legousbtower_devnode, + .fops = &tower_fops, + .minor_base = LEGO_USB_TOWER_MINOR_BASE, +}; + + +/* usb specific object needed to register this driver with the usb subsystem */ +static struct usb_driver tower_driver = { + .name = "legousbtower", + .probe = tower_probe, + .disconnect = tower_disconnect, + .id_table = tower_table, +}; + + +/** + * lego_usb_tower_debug_data + */ +static inline void lego_usb_tower_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); +} + + +/** + * tower_delete + */ +static inline void tower_delete (struct lego_usb_tower *dev) +{ + /* free data structures */ + usb_free_urb(dev->interrupt_in_urb); + usb_free_urb(dev->interrupt_out_urb); + kfree (dev->read_buffer); + kfree (dev->interrupt_in_buffer); + kfree (dev->interrupt_out_buffer); + usb_put_dev(dev->udev); + kfree (dev); +} + + +/** + * tower_open + */ +static int tower_open (struct inode *inode, struct file *file) +{ + struct lego_usb_tower *dev = NULL; + int subminor; + int retval = 0; + struct usb_interface *interface; + struct tower_reset_reply *reset_reply; + int result; + + reset_reply = kmalloc(sizeof(*reset_reply), GFP_KERNEL); + + if (!reset_reply) { + retval = -ENOMEM; + goto exit; + } + + nonseekable_open(inode, file); + subminor = iminor(inode); + + interface = usb_find_interface (&tower_driver, subminor); + + if (!interface) { + pr_err("error, can't find device for minor %d\n", subminor); + retval = -ENODEV; + goto exit; + } + + dev = usb_get_intfdata(interface); + if (!dev) { + retval = -ENODEV; + goto exit; + } + + /* lock this device */ + if (mutex_lock_interruptible(&dev->lock)) { + retval = -ERESTARTSYS; + goto exit; + } + + + /* allow opening only once */ + if (dev->open_count) { + retval = -EBUSY; + goto unlock_exit; + } + + /* reset the tower */ + result = usb_control_msg (dev->udev, + usb_rcvctrlpipe(dev->udev, 0), + LEGO_USB_TOWER_REQUEST_RESET, + USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, + 0, + 0, + reset_reply, + sizeof(*reset_reply), + 1000); + if (result < 0) { + dev_err(&dev->udev->dev, + "LEGO USB Tower reset control request failed\n"); + retval = result; + goto unlock_exit; + } + + /* initialize in direction */ + dev->read_buffer_length = 0; + dev->read_packet_length = 0; + 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), + tower_interrupt_in_callback, + dev, + dev->interrupt_in_interval); + + dev->interrupt_in_running = 1; + dev->interrupt_in_done = 0; + mb(); + + retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL); + if (retval) { + dev_err(&dev->udev->dev, + "Couldn't submit interrupt_in_urb %d\n", retval); + dev->interrupt_in_running = 0; + goto unlock_exit; + } + + /* save device in the file's private structure */ + file->private_data = dev; + + dev->open_count = 1; + +unlock_exit: + mutex_unlock(&dev->lock); + +exit: + kfree(reset_reply); + return retval; +} + +/** + * tower_release + */ +static int tower_release (struct inode *inode, struct file *file) +{ + struct lego_usb_tower *dev; + int retval = 0; + + dev = file->private_data; + + if (dev == NULL) { + retval = -ENODEV; + goto exit; + } + + mutex_lock(&dev->lock); + + if (dev->open_count != 1) { + dev_dbg(&dev->udev->dev, "%s: device not opened exactly once\n", + __func__); + retval = -ENODEV; + goto unlock_exit; + } + + if (dev->disconnected) { + /* the device was unplugged before the file was released */ + + /* unlock here as tower_delete frees dev */ + mutex_unlock(&dev->lock); + tower_delete (dev); + goto exit; + } + + /* wait until write transfer is finished */ + if (dev->interrupt_out_busy) { + wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ); + } + tower_abort_transfers (dev); + dev->open_count = 0; + +unlock_exit: + mutex_unlock(&dev->lock); +exit: + return retval; +} + + +/** + * tower_abort_transfers + * aborts transfers and frees associated data structures + */ +static void tower_abort_transfers (struct lego_usb_tower *dev) +{ + if (dev == NULL) + return; + + /* shutdown transfer */ + if (dev->interrupt_in_running) { + dev->interrupt_in_running = 0; + mb(); + usb_kill_urb(dev->interrupt_in_urb); + } + if (dev->interrupt_out_busy) + usb_kill_urb(dev->interrupt_out_urb); +} + + +/** + * tower_check_for_read_packet + * + * To get correct semantics for signals and non-blocking I/O + * with packetizing we pretend not to see any data in the read buffer + * until it has been there unchanged for at least + * dev->packet_timeout_jiffies, or until the buffer is full. + */ +static void tower_check_for_read_packet (struct lego_usb_tower *dev) +{ + spin_lock_irq (&dev->read_buffer_lock); + if (!packet_timeout + || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies) + || dev->read_buffer_length == read_buffer_size) { + dev->read_packet_length = dev->read_buffer_length; + } + dev->interrupt_in_done = 0; + spin_unlock_irq (&dev->read_buffer_lock); +} + + +/** + * tower_poll + */ +static __poll_t tower_poll (struct file *file, poll_table *wait) +{ + struct lego_usb_tower *dev; + __poll_t mask = 0; + + dev = file->private_data; + + if (dev->disconnected) + return EPOLLERR | EPOLLHUP; + + poll_wait(file, &dev->read_wait, wait); + poll_wait(file, &dev->write_wait, wait); + + tower_check_for_read_packet(dev); + if (dev->read_packet_length > 0) { + mask |= EPOLLIN | EPOLLRDNORM; + } + if (!dev->interrupt_out_busy) { + mask |= EPOLLOUT | EPOLLWRNORM; + } + + return mask; +} + + +/** + * tower_llseek + */ +static loff_t tower_llseek (struct file *file, loff_t off, int whence) +{ + return -ESPIPE; /* unseekable */ +} + + +/** + * tower_read + */ +static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos) +{ + struct lego_usb_tower *dev; + size_t bytes_to_read; + int i; + int retval = 0; + unsigned long timeout = 0; + + dev = file->private_data; + + /* lock this object */ + if (mutex_lock_interruptible(&dev->lock)) { + retval = -ERESTARTSYS; + goto exit; + } + + /* verify that the device wasn't unplugged */ + if (dev->disconnected) { + retval = -ENODEV; + pr_err("No device or device unplugged %d\n", retval); + goto unlock_exit; + } + + /* verify that we actually have some data to read */ + if (count == 0) { + dev_dbg(&dev->udev->dev, "read request of 0 bytes\n"); + goto unlock_exit; + } + + if (read_timeout) { + timeout = jiffies + msecs_to_jiffies(read_timeout); + } + + /* wait for data */ + tower_check_for_read_packet (dev); + while (dev->read_packet_length == 0) { + if (file->f_flags & O_NONBLOCK) { + retval = -EAGAIN; + goto unlock_exit; + } + retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies); + if (retval < 0) { + goto unlock_exit; + } + + /* reset read timeout during read or write activity */ + if (read_timeout + && (dev->read_buffer_length || dev->interrupt_out_busy)) { + timeout = jiffies + msecs_to_jiffies(read_timeout); + } + /* check for read timeout */ + if (read_timeout && time_after (jiffies, timeout)) { + retval = -ETIMEDOUT; + goto unlock_exit; + } + tower_check_for_read_packet (dev); + } + + /* copy the data from read_buffer into userspace */ + bytes_to_read = min(count, dev->read_packet_length); + + if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) { + retval = -EFAULT; + goto unlock_exit; + } + + spin_lock_irq (&dev->read_buffer_lock); + dev->read_buffer_length -= bytes_to_read; + dev->read_packet_length -= bytes_to_read; + for (i=0; i<dev->read_buffer_length; i++) { + dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read]; + } + spin_unlock_irq (&dev->read_buffer_lock); + + retval = bytes_to_read; + +unlock_exit: + /* unlock the device */ + mutex_unlock(&dev->lock); + +exit: + return retval; +} + + +/** + * tower_write + */ +static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) +{ + struct lego_usb_tower *dev; + size_t bytes_to_write; + int retval = 0; + + dev = file->private_data; + + /* lock this object */ + if (mutex_lock_interruptible(&dev->lock)) { + retval = -ERESTARTSYS; + goto exit; + } + + /* verify that the device wasn't unplugged */ + if (dev->disconnected) { + retval = -ENODEV; + pr_err("No device or device unplugged %d\n", retval); + goto unlock_exit; + } + + /* verify that we actually have some data to write */ + if (count == 0) { + dev_dbg(&dev->udev->dev, "write request of 0 bytes\n"); + goto unlock_exit; + } + + /* wait until previous transfer is finished */ + while (dev->interrupt_out_busy) { + if (file->f_flags & O_NONBLOCK) { + retval = -EAGAIN; + goto unlock_exit; + } + retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy); + if (retval) { + goto unlock_exit; + } + } + + /* write the data into interrupt_out_buffer from userspace */ + bytes_to_write = min_t(int, count, write_buffer_size); + dev_dbg(&dev->udev->dev, "%s: count = %zd, bytes_to_write = %zd\n", + __func__, count, bytes_to_write); + + if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) { + retval = -EFAULT; + goto unlock_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, + tower_interrupt_out_callback, + dev, + dev->interrupt_out_interval); + + dev->interrupt_out_busy = 1; + wmb(); + + retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL); + if (retval) { + dev->interrupt_out_busy = 0; + dev_err(&dev->udev->dev, + "Couldn't submit interrupt_out_urb %d\n", retval); + goto unlock_exit; + } + retval = bytes_to_write; + +unlock_exit: + /* unlock the device */ + mutex_unlock(&dev->lock); + +exit: + return retval; +} + + +/** + * tower_interrupt_in_callback + */ +static void tower_interrupt_in_callback (struct urb *urb) +{ + struct lego_usb_tower *dev = urb->context; + int status = urb->status; + int retval; + unsigned long flags; + + lego_usb_tower_debug_data(&dev->udev->dev, __func__, + urb->actual_length, urb->transfer_buffer); + + if (status) { + if (status == -ENOENT || + status == -ECONNRESET || + status == -ESHUTDOWN) { + goto exit; + } else { + dev_dbg(&dev->udev->dev, + "%s: nonzero status received: %d\n", __func__, + status); + goto resubmit; /* maybe we can recover */ + } + } + + if (urb->actual_length > 0) { + spin_lock_irqsave(&dev->read_buffer_lock, flags); + if (dev->read_buffer_length + urb->actual_length < read_buffer_size) { + memcpy (dev->read_buffer + dev->read_buffer_length, + dev->interrupt_in_buffer, + urb->actual_length); + dev->read_buffer_length += urb->actual_length; + dev->read_last_arrival = jiffies; + dev_dbg(&dev->udev->dev, "%s: received %d bytes\n", + __func__, urb->actual_length); + } else { + pr_warn("read_buffer overflow, %d bytes dropped\n", + urb->actual_length); + } + spin_unlock_irqrestore(&dev->read_buffer_lock, flags); + } + +resubmit: + /* resubmit if we're still running */ + if (dev->interrupt_in_running) { + retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC); + if (retval) + dev_err(&dev->udev->dev, + "%s: usb_submit_urb failed (%d)\n", + __func__, retval); + } + +exit: + dev->interrupt_in_done = 1; + wake_up_interruptible (&dev->read_wait); +} + + +/** + * tower_interrupt_out_callback + */ +static void tower_interrupt_out_callback (struct urb *urb) +{ + struct lego_usb_tower *dev = urb->context; + int status = urb->status; + + lego_usb_tower_debug_data(&dev->udev->dev, __func__, + urb->actual_length, urb->transfer_buffer); + + /* sync/async unlink faults aren't errors */ + if (status && !(status == -ENOENT || + status == -ECONNRESET || + status == -ESHUTDOWN)) { + dev_dbg(&dev->udev->dev, + "%s: nonzero write bulk status received: %d\n", __func__, + status); + } + + dev->interrupt_out_busy = 0; + wake_up_interruptible(&dev->write_wait); +} + + +/** + * tower_probe + * + * Called by the usb core when a new device is connected that it thinks + * this driver might be interested in. + */ +static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id) +{ + struct device *idev = &interface->dev; + struct usb_device *udev = interface_to_usbdev(interface); + struct lego_usb_tower *dev = NULL; + struct tower_get_version_reply *get_version_reply = NULL; + int retval = -ENOMEM; + int result; + + /* allocate memory for our device state and initialize it */ + + dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL); + + if (!dev) + goto exit; + + mutex_init(&dev->lock); + + dev->udev = usb_get_dev(udev); + dev->open_count = 0; + dev->disconnected = 0; + + dev->read_buffer = NULL; + dev->read_buffer_length = 0; + dev->read_packet_length = 0; + spin_lock_init (&dev->read_buffer_lock); + dev->packet_timeout_jiffies = msecs_to_jiffies(packet_timeout); + dev->read_last_arrival = jiffies; + + init_waitqueue_head (&dev->read_wait); + init_waitqueue_head (&dev->write_wait); + + dev->interrupt_in_buffer = NULL; + dev->interrupt_in_endpoint = NULL; + dev->interrupt_in_urb = NULL; + dev->interrupt_in_running = 0; + dev->interrupt_in_done = 0; + + dev->interrupt_out_buffer = NULL; + dev->interrupt_out_endpoint = NULL; + dev->interrupt_out_urb = NULL; + dev->interrupt_out_busy = 0; + + result = usb_find_common_endpoints_reverse(interface->cur_altsetting, + NULL, NULL, + &dev->interrupt_in_endpoint, + &dev->interrupt_out_endpoint); + if (result) { + dev_err(idev, "interrupt endpoints not found\n"); + retval = result; + goto error; + } + + dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL); + if (!dev->read_buffer) + goto error; + dev->interrupt_in_buffer = kmalloc (usb_endpoint_maxp(dev->interrupt_in_endpoint), GFP_KERNEL); + if (!dev->interrupt_in_buffer) + goto error; + dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL); + if (!dev->interrupt_in_urb) + goto error; + dev->interrupt_out_buffer = kmalloc (write_buffer_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; + dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval; + dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval; + + get_version_reply = kmalloc(sizeof(*get_version_reply), GFP_KERNEL); + + if (!get_version_reply) { + retval = -ENOMEM; + goto error; + } + + /* get the firmware version and log it */ + result = usb_control_msg (udev, + usb_rcvctrlpipe(udev, 0), + LEGO_USB_TOWER_REQUEST_GET_VERSION, + USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, + 0, + 0, + get_version_reply, + sizeof(*get_version_reply), + 1000); + if (result != sizeof(*get_version_reply)) { + if (result >= 0) + result = -EIO; + dev_err(idev, "get version request failed: %d\n", result); + retval = result; + goto error; + } + dev_info(&interface->dev, + "LEGO USB Tower firmware version is %d.%d build %d\n", + get_version_reply->major, + get_version_reply->minor, + le16_to_cpu(get_version_reply->build_no)); + + /* we can register the device now, as it is ready */ + usb_set_intfdata (interface, dev); + + retval = usb_register_dev (interface, &tower_class); + + if (retval) { + /* something prevented us from registering this driver */ + dev_err(idev, "Not able to get a minor for this device.\n"); + goto error; + } + dev->minor = interface->minor; + + /* let the user know what node this device is now attached to */ + dev_info(&interface->dev, "LEGO USB Tower #%d now attached to major " + "%d minor %d\n", (dev->minor - LEGO_USB_TOWER_MINOR_BASE), + USB_MAJOR, dev->minor); + +exit: + kfree(get_version_reply); + return retval; + +error: + kfree(get_version_reply); + tower_delete(dev); + return retval; +} + + +/** + * tower_disconnect + * + * Called by the usb core when the device is removed from the system. + */ +static void tower_disconnect (struct usb_interface *interface) +{ + struct lego_usb_tower *dev; + int minor; + + dev = usb_get_intfdata (interface); + + minor = dev->minor; + + /* give back our minor and prevent further open() */ + usb_deregister_dev (interface, &tower_class); + + /* stop I/O */ + usb_poison_urb(dev->interrupt_in_urb); + usb_poison_urb(dev->interrupt_out_urb); + + mutex_lock(&dev->lock); + + /* if the device is not opened, then we clean up right now */ + if (!dev->open_count) { + mutex_unlock(&dev->lock); + tower_delete (dev); + } else { + dev->disconnected = 1; + /* wake up pollers */ + wake_up_interruptible_all(&dev->read_wait); + wake_up_interruptible_all(&dev->write_wait); + mutex_unlock(&dev->lock); + } + + dev_info(&interface->dev, "LEGO USB Tower #%d now disconnected\n", + (minor - LEGO_USB_TOWER_MINOR_BASE)); +} + +module_usb_driver(tower_driver); + +MODULE_AUTHOR(DRIVER_AUTHOR); +MODULE_DESCRIPTION(DRIVER_DESC); +#ifdef MODULE_LICENSE +MODULE_LICENSE("GPL"); +#endif |