From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- drivers/usb/misc/ldusb.c | 794 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 794 insertions(+) create mode 100644 drivers/usb/misc/ldusb.c (limited to 'drivers/usb/misc/ldusb.c') diff --git a/drivers/usb/misc/ldusb.c b/drivers/usb/misc/ldusb.c new file mode 100644 index 000000000..71132a15e --- /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 + * + * Derived from Lego USB Tower driver + * Copyright (C) 2003 David Glance + * 2001-2004 Juergen Stuber + */ + +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +/* 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 "); +MODULE_DESCRIPTION("LD USB Driver"); +MODULE_LICENSE("GPL"); + +/* 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 kref kref; + struct mutex mutex; /* locks this structure */ + struct usb_interface *intf; /* save off the usb interface pointer */ + unsigned long disconnected:1; + + 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; + usb_kill_urb(dev->interrupt_in_urb); + } + if (dev->interrupt_out_busy) + usb_kill_urb(dev->interrupt_out_urb); +} + +/* + * ld_usb_delete + */ +static void ld_usb_delete(struct kref *kref) +{ + struct ld_usb *dev = container_of(kref, struct ld_usb, kref); + + /* 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) { + 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; + + stream_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; + } + + kref_get(&dev->kref); + + /* 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; + } + + mutex_lock(&dev->mutex); + + if (dev->disconnected) + goto unlock_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); + kref_put(&dev->kref, ld_usb_delete); +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->disconnected) + 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->disconnected) { + 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); + while (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; + + spin_lock_irq(&dev->rbsl); + } + 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)); + if (*actual_buffer > dev->interrupt_in_endpoint_size) { + retval = -EIO; + goto unlock_exit; + } + bytes_to_read = min(count, *actual_buffer); + if (bytes_to_read < *actual_buffer) + dev_warn(&dev->intf->dev, "Read buffer overflow, %zu 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; + } + retval = bytes_to_read; + + spin_lock_irq(&dev->rbsl); + dev->ring_tail = (dev->ring_tail + 1) % ring_buffer_size; + + 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->disconnected) { + 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, %zu bytes dropped\n", + count - bytes_to_write); + dev_dbg(&dev->intf->dev, "%s: count = %zu, bytes_to_write = %zu\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); + 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, +}; + +/* + * 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_obj(*dev); + if (!dev) + goto exit; + + kref_init(&dev->kref); + 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 = kcalloc(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 = max_t(int, min_interrupt_in_interval, + dev->interrupt_in_endpoint->bInterval); + if (dev->interrupt_out_endpoint) + dev->interrupt_out_interval = max_t(int, 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: + kref_put(&dev->kref, ld_usb_delete); + + 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); + + usb_poison_urb(dev->interrupt_in_urb); + usb_poison_urb(dev->interrupt_out_urb); + + mutex_lock(&dev->mutex); + + dev->disconnected = 1; + + if (dev->open_count) { + /* wake up pollers */ + wake_up_interruptible_all(&dev->read_wait); + wake_up_interruptible_all(&dev->write_wait); + } + + mutex_unlock(&dev->mutex); + + kref_put(&dev->kref, ld_usb_delete); + + 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); + -- cgit v1.3.1