v4.19.13 snapshot.
diff --git a/drivers/usb/misc/ldusb.c b/drivers/usb/misc/ldusb.c
new file mode 100644
index 0000000..006762b
--- /dev/null
+++ b/drivers/usb/misc/ldusb.c
@@ -0,0 +1,794 @@
+// SPDX-License-Identifier: GPL-2.0+
+/**
+ * Generic USB driver for report based interrupt in/out devices
+ * like LD Didactic's USB devices. LD Didactic's USB devices are
+ * HID devices which do not use HID report definitons (they use
+ * raw interrupt in and our reports only for communication).
+ *
+ * This driver uses a ring buffer for time critical reading of
+ * interrupt in reports and provides read and write methods for
+ * raw interrupt reports (similar to the Windows HID driver).
+ * Devices based on the book USB COMPLETE by Jan Axelson may need
+ * such a compatibility to the Windows HID driver.
+ *
+ * Copyright (C) 2005 Michael Hund <mhund@ld-didactic.de>
+ *
+ * Derived from Lego USB Tower driver
+ * Copyright (C) 2003 David Glance <advidgsf@sourceforge.net>
+ * 2001-2004 Juergen Stuber <starblue@users.sourceforge.net>
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+
+#include <linux/uaccess.h>
+#include <linux/input.h>
+#include <linux/usb.h>
+#include <linux/poll.h>
+
+/* Define these values to match your devices */
+#define USB_VENDOR_ID_LD 0x0f11 /* USB Vendor ID of LD Didactic GmbH */
+#define USB_DEVICE_ID_LD_CASSY 0x1000 /* USB Product ID of CASSY-S modules with 8 bytes endpoint size */
+#define USB_DEVICE_ID_LD_CASSY2 0x1001 /* USB Product ID of CASSY-S modules with 64 bytes endpoint size */
+#define USB_DEVICE_ID_LD_POCKETCASSY 0x1010 /* USB Product ID of Pocket-CASSY */
+#define USB_DEVICE_ID_LD_POCKETCASSY2 0x1011 /* USB Product ID of Pocket-CASSY 2 (reserved) */
+#define USB_DEVICE_ID_LD_MOBILECASSY 0x1020 /* USB Product ID of Mobile-CASSY */
+#define USB_DEVICE_ID_LD_MOBILECASSY2 0x1021 /* USB Product ID of Mobile-CASSY 2 (reserved) */
+#define USB_DEVICE_ID_LD_MICROCASSYVOLTAGE 0x1031 /* USB Product ID of Micro-CASSY Voltage */
+#define USB_DEVICE_ID_LD_MICROCASSYCURRENT 0x1032 /* USB Product ID of Micro-CASSY Current */
+#define USB_DEVICE_ID_LD_MICROCASSYTIME 0x1033 /* USB Product ID of Micro-CASSY Time (reserved) */
+#define USB_DEVICE_ID_LD_MICROCASSYTEMPERATURE 0x1035 /* USB Product ID of Micro-CASSY Temperature */
+#define USB_DEVICE_ID_LD_MICROCASSYPH 0x1038 /* USB Product ID of Micro-CASSY pH */
+#define USB_DEVICE_ID_LD_POWERANALYSERCASSY 0x1040 /* USB Product ID of Power Analyser CASSY */
+#define USB_DEVICE_ID_LD_CONVERTERCONTROLLERCASSY 0x1042 /* USB Product ID of Converter Controller CASSY */
+#define USB_DEVICE_ID_LD_MACHINETESTCASSY 0x1043 /* USB Product ID of Machine Test CASSY */
+#define USB_DEVICE_ID_LD_JWM 0x1080 /* USB Product ID of Joule and Wattmeter */
+#define USB_DEVICE_ID_LD_DMMP 0x1081 /* USB Product ID of Digital Multimeter P (reserved) */
+#define USB_DEVICE_ID_LD_UMIP 0x1090 /* USB Product ID of UMI P */
+#define USB_DEVICE_ID_LD_UMIC 0x10A0 /* USB Product ID of UMI C */
+#define USB_DEVICE_ID_LD_UMIB 0x10B0 /* USB Product ID of UMI B */
+#define USB_DEVICE_ID_LD_XRAY 0x1100 /* USB Product ID of X-Ray Apparatus 55481 */
+#define USB_DEVICE_ID_LD_XRAY2 0x1101 /* USB Product ID of X-Ray Apparatus 554800 */
+#define USB_DEVICE_ID_LD_XRAYCT 0x1110 /* USB Product ID of X-Ray Apparatus CT 554821*/
+#define USB_DEVICE_ID_LD_VIDEOCOM 0x1200 /* USB Product ID of VideoCom */
+#define USB_DEVICE_ID_LD_MOTOR 0x1210 /* USB Product ID of Motor (reserved) */
+#define USB_DEVICE_ID_LD_COM3LAB 0x2000 /* USB Product ID of COM3LAB */
+#define USB_DEVICE_ID_LD_TELEPORT 0x2010 /* USB Product ID of Terminal Adapter */
+#define USB_DEVICE_ID_LD_NETWORKANALYSER 0x2020 /* USB Product ID of Network Analyser */
+#define USB_DEVICE_ID_LD_POWERCONTROL 0x2030 /* USB Product ID of Converter Control Unit */
+#define USB_DEVICE_ID_LD_MACHINETEST 0x2040 /* USB Product ID of Machine Test System */
+#define USB_DEVICE_ID_LD_MOSTANALYSER 0x2050 /* USB Product ID of MOST Protocol Analyser */
+#define USB_DEVICE_ID_LD_MOSTANALYSER2 0x2051 /* USB Product ID of MOST Protocol Analyser 2 */
+#define USB_DEVICE_ID_LD_ABSESP 0x2060 /* USB Product ID of ABS ESP */
+#define USB_DEVICE_ID_LD_AUTODATABUS 0x2070 /* USB Product ID of Automotive Data Buses */
+#define USB_DEVICE_ID_LD_MCT 0x2080 /* USB Product ID of Microcontroller technique */
+#define USB_DEVICE_ID_LD_HYBRID 0x2090 /* USB Product ID of Automotive Hybrid */
+#define USB_DEVICE_ID_LD_HEATCONTROL 0x20A0 /* USB Product ID of Heat control */
+
+#ifdef CONFIG_USB_DYNAMIC_MINORS
+#define USB_LD_MINOR_BASE 0
+#else
+#define USB_LD_MINOR_BASE 176
+#endif
+
+/* table of devices that work with this driver */
+static const struct usb_device_id ld_usb_table[] = {
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CASSY) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CASSY2) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POCKETCASSY) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POCKETCASSY2) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOBILECASSY) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOBILECASSY2) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYVOLTAGE) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYCURRENT) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYTIME) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYTEMPERATURE) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYPH) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POWERANALYSERCASSY) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CONVERTERCONTROLLERCASSY) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MACHINETESTCASSY) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_JWM) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_DMMP) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIP) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIC) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIB) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY2) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_VIDEOCOM) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOTOR) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_COM3LAB) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_TELEPORT) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_NETWORKANALYSER) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POWERCONTROL) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MACHINETEST) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOSTANALYSER) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOSTANALYSER2) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_ABSESP) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_AUTODATABUS) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MCT) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_HYBRID) },
+ { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_HEATCONTROL) },
+ { } /* Terminating entry */
+};
+MODULE_DEVICE_TABLE(usb, ld_usb_table);
+MODULE_AUTHOR("Michael Hund <mhund@ld-didactic.de>");
+MODULE_DESCRIPTION("LD USB Driver");
+MODULE_LICENSE("GPL");
+MODULE_SUPPORTED_DEVICE("LD USB Devices");
+
+/* All interrupt in transfers are collected in a ring buffer to
+ * avoid racing conditions and get better performance of the driver.
+ */
+static int ring_buffer_size = 128;
+module_param(ring_buffer_size, int, 0000);
+MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size in reports");
+
+/* The write_buffer can contain more than one interrupt out transfer.
+ */
+static int write_buffer_size = 10;
+module_param(write_buffer_size, int, 0000);
+MODULE_PARM_DESC(write_buffer_size, "Write buffer size in reports");
+
+/* 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 2ms for out transfers,
+ * which should be fast enough.
+ * Increase the interval to allow more devices that do interrupt transfers,
+ * or set to 1 to use the standard interval from the endpoint descriptors.
+ */
+static int min_interrupt_in_interval = 2;
+module_param(min_interrupt_in_interval, int, 0000);
+MODULE_PARM_DESC(min_interrupt_in_interval, "Minimum interrupt in interval in ms");
+
+static int min_interrupt_out_interval = 2;
+module_param(min_interrupt_out_interval, int, 0000);
+MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in ms");
+
+/* Structure to hold all of our device specific stuff */
+struct ld_usb {
+ struct mutex mutex; /* locks this structure */
+ struct usb_interface *intf; /* save off the usb interface pointer */
+
+ int open_count; /* number of times this port has been opened */
+
+ char *ring_buffer;
+ unsigned int ring_head;
+ unsigned int ring_tail;
+
+ 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;
+ size_t interrupt_in_endpoint_size;
+ int interrupt_in_running;
+ int interrupt_in_done;
+ int buffer_overflow;
+ spinlock_t rbsl;
+
+ char *interrupt_out_buffer;
+ struct usb_endpoint_descriptor *interrupt_out_endpoint;
+ struct urb *interrupt_out_urb;
+ int interrupt_out_interval;
+ size_t interrupt_out_endpoint_size;
+ int interrupt_out_busy;
+};
+
+static struct usb_driver ld_usb_driver;
+
+/**
+ * ld_usb_abort_transfers
+ * aborts transfers and frees associated data structures
+ */
+static void ld_usb_abort_transfers(struct ld_usb *dev)
+{
+ /* shutdown transfer */
+ if (dev->interrupt_in_running) {
+ dev->interrupt_in_running = 0;
+ if (dev->intf)
+ usb_kill_urb(dev->interrupt_in_urb);
+ }
+ if (dev->interrupt_out_busy)
+ if (dev->intf)
+ usb_kill_urb(dev->interrupt_out_urb);
+}
+
+/**
+ * ld_usb_delete
+ */
+static void ld_usb_delete(struct ld_usb *dev)
+{
+ ld_usb_abort_transfers(dev);
+
+ /* free data structures */
+ usb_free_urb(dev->interrupt_in_urb);
+ usb_free_urb(dev->interrupt_out_urb);
+ kfree(dev->ring_buffer);
+ kfree(dev->interrupt_in_buffer);
+ kfree(dev->interrupt_out_buffer);
+ kfree(dev);
+}
+
+/**
+ * ld_usb_interrupt_in_callback
+ */
+static void ld_usb_interrupt_in_callback(struct urb *urb)
+{
+ struct ld_usb *dev = urb->context;
+ size_t *actual_buffer;
+ unsigned int next_ring_head;
+ int status = urb->status;
+ unsigned long flags;
+ int retval;
+
+ if (status) {
+ if (status == -ENOENT ||
+ status == -ECONNRESET ||
+ status == -ESHUTDOWN) {
+ goto exit;
+ } else {
+ dev_dbg(&dev->intf->dev,
+ "%s: nonzero status received: %d\n", __func__,
+ status);
+ spin_lock_irqsave(&dev->rbsl, flags);
+ goto resubmit; /* maybe we can recover */
+ }
+ }
+
+ spin_lock_irqsave(&dev->rbsl, flags);
+ if (urb->actual_length > 0) {
+ next_ring_head = (dev->ring_head+1) % ring_buffer_size;
+ if (next_ring_head != dev->ring_tail) {
+ actual_buffer = (size_t *)(dev->ring_buffer + dev->ring_head * (sizeof(size_t)+dev->interrupt_in_endpoint_size));
+ /* actual_buffer gets urb->actual_length + interrupt_in_buffer */
+ *actual_buffer = urb->actual_length;
+ memcpy(actual_buffer+1, dev->interrupt_in_buffer, urb->actual_length);
+ dev->ring_head = next_ring_head;
+ dev_dbg(&dev->intf->dev, "%s: received %d bytes\n",
+ __func__, urb->actual_length);
+ } else {
+ dev_warn(&dev->intf->dev,
+ "Ring buffer overflow, %d bytes dropped\n",
+ urb->actual_length);
+ dev->buffer_overflow = 1;
+ }
+ }
+
+resubmit:
+ /* resubmit if we're still running */
+ if (dev->interrupt_in_running && !dev->buffer_overflow && dev->intf) {
+ retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
+ if (retval) {
+ dev_err(&dev->intf->dev,
+ "usb_submit_urb failed (%d)\n", retval);
+ dev->buffer_overflow = 1;
+ }
+ }
+ spin_unlock_irqrestore(&dev->rbsl, flags);
+exit:
+ dev->interrupt_in_done = 1;
+ wake_up_interruptible(&dev->read_wait);
+}
+
+/**
+ * ld_usb_interrupt_out_callback
+ */
+static void ld_usb_interrupt_out_callback(struct urb *urb)
+{
+ struct ld_usb *dev = urb->context;
+ int status = urb->status;
+
+ /* sync/async unlink faults aren't errors */
+ if (status && !(status == -ENOENT ||
+ status == -ECONNRESET ||
+ status == -ESHUTDOWN))
+ dev_dbg(&dev->intf->dev,
+ "%s - nonzero write interrupt status received: %d\n",
+ __func__, status);
+
+ dev->interrupt_out_busy = 0;
+ wake_up_interruptible(&dev->write_wait);
+}
+
+/**
+ * ld_usb_open
+ */
+static int ld_usb_open(struct inode *inode, struct file *file)
+{
+ struct ld_usb *dev;
+ int subminor;
+ int retval;
+ struct usb_interface *interface;
+
+ nonseekable_open(inode, file);
+ subminor = iminor(inode);
+
+ interface = usb_find_interface(&ld_usb_driver, subminor);
+
+ if (!interface) {
+ printk(KERN_ERR "%s - error, can't find device for minor %d\n",
+ __func__, subminor);
+ return -ENODEV;
+ }
+
+ dev = usb_get_intfdata(interface);
+
+ if (!dev)
+ return -ENODEV;
+
+ /* lock this device */
+ if (mutex_lock_interruptible(&dev->mutex))
+ return -ERESTARTSYS;
+
+ /* allow opening only once */
+ if (dev->open_count) {
+ retval = -EBUSY;
+ goto unlock_exit;
+ }
+ dev->open_count = 1;
+
+ /* initialize in direction */
+ dev->ring_head = 0;
+ dev->ring_tail = 0;
+ dev->buffer_overflow = 0;
+ usb_fill_int_urb(dev->interrupt_in_urb,
+ interface_to_usbdev(interface),
+ usb_rcvintpipe(interface_to_usbdev(interface),
+ dev->interrupt_in_endpoint->bEndpointAddress),
+ dev->interrupt_in_buffer,
+ dev->interrupt_in_endpoint_size,
+ ld_usb_interrupt_in_callback,
+ dev,
+ dev->interrupt_in_interval);
+
+ dev->interrupt_in_running = 1;
+ dev->interrupt_in_done = 0;
+
+ retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
+ if (retval) {
+ dev_err(&interface->dev, "Couldn't submit interrupt_in_urb %d\n", retval);
+ dev->interrupt_in_running = 0;
+ dev->open_count = 0;
+ goto unlock_exit;
+ }
+
+ /* save device in the file's private structure */
+ file->private_data = dev;
+
+unlock_exit:
+ mutex_unlock(&dev->mutex);
+
+ return retval;
+}
+
+/**
+ * ld_usb_release
+ */
+static int ld_usb_release(struct inode *inode, struct file *file)
+{
+ struct ld_usb *dev;
+ int retval = 0;
+
+ dev = file->private_data;
+
+ if (dev == NULL) {
+ retval = -ENODEV;
+ goto exit;
+ }
+
+ if (mutex_lock_interruptible(&dev->mutex)) {
+ retval = -ERESTARTSYS;
+ goto exit;
+ }
+
+ if (dev->open_count != 1) {
+ retval = -ENODEV;
+ goto unlock_exit;
+ }
+ if (dev->intf == NULL) {
+ /* the device was unplugged before the file was released */
+ mutex_unlock(&dev->mutex);
+ /* unlock here as ld_usb_delete frees dev */
+ ld_usb_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);
+ ld_usb_abort_transfers(dev);
+ dev->open_count = 0;
+
+unlock_exit:
+ mutex_unlock(&dev->mutex);
+
+exit:
+ return retval;
+}
+
+/**
+ * ld_usb_poll
+ */
+static __poll_t ld_usb_poll(struct file *file, poll_table *wait)
+{
+ struct ld_usb *dev;
+ __poll_t mask = 0;
+
+ dev = file->private_data;
+
+ if (!dev->intf)
+ return EPOLLERR | EPOLLHUP;
+
+ poll_wait(file, &dev->read_wait, wait);
+ poll_wait(file, &dev->write_wait, wait);
+
+ if (dev->ring_head != dev->ring_tail)
+ mask |= EPOLLIN | EPOLLRDNORM;
+ if (!dev->interrupt_out_busy)
+ mask |= EPOLLOUT | EPOLLWRNORM;
+
+ return mask;
+}
+
+/**
+ * ld_usb_read
+ */
+static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count,
+ loff_t *ppos)
+{
+ struct ld_usb *dev;
+ size_t *actual_buffer;
+ size_t bytes_to_read;
+ int retval = 0;
+ int rv;
+
+ dev = file->private_data;
+
+ /* verify that we actually have some data to read */
+ if (count == 0)
+ goto exit;
+
+ /* lock this object */
+ if (mutex_lock_interruptible(&dev->mutex)) {
+ retval = -ERESTARTSYS;
+ goto exit;
+ }
+
+ /* verify that the device wasn't unplugged */
+ if (dev->intf == NULL) {
+ retval = -ENODEV;
+ printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval);
+ goto unlock_exit;
+ }
+
+ /* wait for data */
+ spin_lock_irq(&dev->rbsl);
+ if (dev->ring_head == dev->ring_tail) {
+ dev->interrupt_in_done = 0;
+ spin_unlock_irq(&dev->rbsl);
+ if (file->f_flags & O_NONBLOCK) {
+ retval = -EAGAIN;
+ goto unlock_exit;
+ }
+ retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done);
+ if (retval < 0)
+ goto unlock_exit;
+ } else {
+ spin_unlock_irq(&dev->rbsl);
+ }
+
+ /* actual_buffer contains actual_length + interrupt_in_buffer */
+ actual_buffer = (size_t *)(dev->ring_buffer + dev->ring_tail * (sizeof(size_t)+dev->interrupt_in_endpoint_size));
+ bytes_to_read = min(count, *actual_buffer);
+ if (bytes_to_read < *actual_buffer)
+ dev_warn(&dev->intf->dev, "Read buffer overflow, %zd bytes dropped\n",
+ *actual_buffer-bytes_to_read);
+
+ /* copy one interrupt_in_buffer from ring_buffer into userspace */
+ if (copy_to_user(buffer, actual_buffer+1, bytes_to_read)) {
+ retval = -EFAULT;
+ goto unlock_exit;
+ }
+ dev->ring_tail = (dev->ring_tail+1) % ring_buffer_size;
+
+ retval = bytes_to_read;
+
+ spin_lock_irq(&dev->rbsl);
+ if (dev->buffer_overflow) {
+ dev->buffer_overflow = 0;
+ spin_unlock_irq(&dev->rbsl);
+ rv = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
+ if (rv < 0)
+ dev->buffer_overflow = 1;
+ } else {
+ spin_unlock_irq(&dev->rbsl);
+ }
+
+unlock_exit:
+ /* unlock the device */
+ mutex_unlock(&dev->mutex);
+
+exit:
+ return retval;
+}
+
+/**
+ * ld_usb_write
+ */
+static ssize_t ld_usb_write(struct file *file, const char __user *buffer,
+ size_t count, loff_t *ppos)
+{
+ struct ld_usb *dev;
+ size_t bytes_to_write;
+ int retval = 0;
+
+ dev = file->private_data;
+
+ /* verify that we actually have some data to write */
+ if (count == 0)
+ goto exit;
+
+ /* lock this object */
+ if (mutex_lock_interruptible(&dev->mutex)) {
+ retval = -ERESTARTSYS;
+ goto exit;
+ }
+
+ /* verify that the device wasn't unplugged */
+ if (dev->intf == NULL) {
+ retval = -ENODEV;
+ printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval);
+ goto unlock_exit;
+ }
+
+ /* wait until previous transfer is finished */
+ if (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 < 0) {
+ goto unlock_exit;
+ }
+ }
+
+ /* write the data into interrupt_out_buffer from userspace */
+ bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size);
+ if (bytes_to_write < count)
+ dev_warn(&dev->intf->dev, "Write buffer overflow, %zd bytes dropped\n", count-bytes_to_write);
+ dev_dbg(&dev->intf->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;
+ }
+
+ if (dev->interrupt_out_endpoint == NULL) {
+ /* try HID_REQ_SET_REPORT=9 on control_endpoint instead of interrupt_out_endpoint */
+ retval = usb_control_msg(interface_to_usbdev(dev->intf),
+ usb_sndctrlpipe(interface_to_usbdev(dev->intf), 0),
+ 9,
+ USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
+ 1 << 8, 0,
+ dev->interrupt_out_buffer,
+ bytes_to_write,
+ USB_CTRL_SET_TIMEOUT * HZ);
+ if (retval < 0)
+ dev_err(&dev->intf->dev,
+ "Couldn't submit HID_REQ_SET_REPORT %d\n",
+ retval);
+ goto unlock_exit;
+ }
+
+ /* send off the urb */
+ usb_fill_int_urb(dev->interrupt_out_urb,
+ interface_to_usbdev(dev->intf),
+ usb_sndintpipe(interface_to_usbdev(dev->intf),
+ dev->interrupt_out_endpoint->bEndpointAddress),
+ dev->interrupt_out_buffer,
+ bytes_to_write,
+ ld_usb_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->intf->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->mutex);
+
+exit:
+ return retval;
+}
+
+/* file operations needed when we register this driver */
+static const struct file_operations ld_usb_fops = {
+ .owner = THIS_MODULE,
+ .read = ld_usb_read,
+ .write = ld_usb_write,
+ .open = ld_usb_open,
+ .release = ld_usb_release,
+ .poll = ld_usb_poll,
+ .llseek = no_llseek,
+};
+
+/*
+ * 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 ld_usb_class = {
+ .name = "ldusb%d",
+ .fops = &ld_usb_fops,
+ .minor_base = USB_LD_MINOR_BASE,
+};
+
+/**
+ * ld_usb_probe
+ *
+ * Called by the usb core when a new device is connected that it thinks
+ * this driver might be interested in.
+ */
+static int ld_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
+{
+ struct usb_device *udev = interface_to_usbdev(intf);
+ struct ld_usb *dev = NULL;
+ struct usb_host_interface *iface_desc;
+ char *buffer;
+ int retval = -ENOMEM;
+ int res;
+
+ /* allocate memory for our device state and initialize it */
+
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ goto exit;
+ mutex_init(&dev->mutex);
+ spin_lock_init(&dev->rbsl);
+ dev->intf = intf;
+ init_waitqueue_head(&dev->read_wait);
+ init_waitqueue_head(&dev->write_wait);
+
+ /* workaround for early firmware versions on fast computers */
+ if ((le16_to_cpu(udev->descriptor.idVendor) == USB_VENDOR_ID_LD) &&
+ ((le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_CASSY) ||
+ (le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_COM3LAB)) &&
+ (le16_to_cpu(udev->descriptor.bcdDevice) <= 0x103)) {
+ buffer = kmalloc(256, GFP_KERNEL);
+ if (!buffer)
+ goto error;
+ /* usb_string makes SETUP+STALL to leave always ControlReadLoop */
+ usb_string(udev, 255, buffer, 256);
+ kfree(buffer);
+ }
+
+ iface_desc = intf->cur_altsetting;
+
+ res = usb_find_last_int_in_endpoint(iface_desc,
+ &dev->interrupt_in_endpoint);
+ if (res) {
+ dev_err(&intf->dev, "Interrupt in endpoint not found\n");
+ retval = res;
+ goto error;
+ }
+
+ res = usb_find_last_int_out_endpoint(iface_desc,
+ &dev->interrupt_out_endpoint);
+ if (res)
+ dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n");
+
+ dev->interrupt_in_endpoint_size = usb_endpoint_maxp(dev->interrupt_in_endpoint);
+ dev->ring_buffer =
+ kmalloc_array(ring_buffer_size,
+ sizeof(size_t) + dev->interrupt_in_endpoint_size,
+ GFP_KERNEL);
+ if (!dev->ring_buffer)
+ goto error;
+ dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, 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_endpoint_size = dev->interrupt_out_endpoint ? usb_endpoint_maxp(dev->interrupt_out_endpoint) :
+ udev->descriptor.bMaxPacketSize0;
+ dev->interrupt_out_buffer =
+ kmalloc_array(write_buffer_size,
+ dev->interrupt_out_endpoint_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 = min_interrupt_in_interval > dev->interrupt_in_endpoint->bInterval ? min_interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
+ if (dev->interrupt_out_endpoint)
+ dev->interrupt_out_interval = min_interrupt_out_interval > dev->interrupt_out_endpoint->bInterval ? min_interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
+
+ /* we can register the device now, as it is ready */
+ usb_set_intfdata(intf, dev);
+
+ retval = usb_register_dev(intf, &ld_usb_class);
+ if (retval) {
+ /* something prevented us from registering this driver */
+ dev_err(&intf->dev, "Not able to get a minor for this device.\n");
+ usb_set_intfdata(intf, NULL);
+ goto error;
+ }
+
+ /* let the user know what node this device is now attached to */
+ dev_info(&intf->dev, "LD USB Device #%d now attached to major %d minor %d\n",
+ (intf->minor - USB_LD_MINOR_BASE), USB_MAJOR, intf->minor);
+
+exit:
+ return retval;
+
+error:
+ ld_usb_delete(dev);
+
+ return retval;
+}
+
+/**
+ * ld_usb_disconnect
+ *
+ * Called by the usb core when the device is removed from the system.
+ */
+static void ld_usb_disconnect(struct usb_interface *intf)
+{
+ struct ld_usb *dev;
+ int minor;
+
+ dev = usb_get_intfdata(intf);
+ usb_set_intfdata(intf, NULL);
+
+ minor = intf->minor;
+
+ /* give back our minor */
+ usb_deregister_dev(intf, &ld_usb_class);
+
+ mutex_lock(&dev->mutex);
+
+ /* if the device is not opened, then we clean up right now */
+ if (!dev->open_count) {
+ mutex_unlock(&dev->mutex);
+ ld_usb_delete(dev);
+ } else {
+ dev->intf = NULL;
+ /* wake up pollers */
+ wake_up_interruptible_all(&dev->read_wait);
+ wake_up_interruptible_all(&dev->write_wait);
+ mutex_unlock(&dev->mutex);
+ }
+
+ dev_info(&intf->dev, "LD USB Device #%d now disconnected\n",
+ (minor - USB_LD_MINOR_BASE));
+}
+
+/* usb specific object needed to register this driver with the usb subsystem */
+static struct usb_driver ld_usb_driver = {
+ .name = "ldusb",
+ .probe = ld_usb_probe,
+ .disconnect = ld_usb_disconnect,
+ .id_table = ld_usb_table,
+};
+
+module_usb_driver(ld_usb_driver);
+