| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * cdc-wdm.c |
| * |
| * This driver supports USB CDC WCM Device Management. |
| * |
| * Copyright (c) 2007-2009 Oliver Neukum |
| * |
| * Some code taken from cdc-acm.c |
| * |
| * Released under the GPLv2. |
| * |
| * Many thanks to Carl Nordbeck |
| */ |
| #include <linux/kernel.h> |
| #include <linux/errno.h> |
| #include <linux/ioctl.h> |
| #include <linux/slab.h> |
| #include <linux/module.h> |
| #include <linux/mutex.h> |
| #include <linux/uaccess.h> |
| #include <linux/bitops.h> |
| #include <linux/poll.h> |
| #include <linux/usb.h> |
| #include <linux/usb/cdc.h> |
| #include <asm/byteorder.h> |
| #include <asm/unaligned.h> |
| #include <linux/usb/cdc-wdm.h> |
| |
| #define DRIVER_AUTHOR "Oliver Neukum" |
| #define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management" |
| |
| static const struct usb_device_id wdm_ids[] = { |
| { |
| .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS | |
| USB_DEVICE_ID_MATCH_INT_SUBCLASS, |
| .bInterfaceClass = USB_CLASS_COMM, |
| .bInterfaceSubClass = USB_CDC_SUBCLASS_DMM |
| }, |
| { } |
| }; |
| |
| MODULE_DEVICE_TABLE (usb, wdm_ids); |
| |
| #define WDM_MINOR_BASE 176 |
| |
| |
| #define WDM_IN_USE 1 |
| #define WDM_DISCONNECTING 2 |
| #define WDM_RESULT 3 |
| #define WDM_READ 4 |
| #define WDM_INT_STALL 5 |
| #define WDM_POLL_RUNNING 6 |
| #define WDM_RESPONDING 7 |
| #define WDM_SUSPENDING 8 |
| #define WDM_RESETTING 9 |
| #define WDM_OVERFLOW 10 |
| |
| #define WDM_MAX 16 |
| |
| /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */ |
| #define WDM_DEFAULT_BUFSIZE 256 |
| |
| static DEFINE_MUTEX(wdm_mutex); |
| static DEFINE_SPINLOCK(wdm_device_list_lock); |
| static LIST_HEAD(wdm_device_list); |
| |
| /* --- method tables --- */ |
| |
| struct wdm_device { |
| u8 *inbuf; /* buffer for response */ |
| u8 *outbuf; /* buffer for command */ |
| u8 *sbuf; /* buffer for status */ |
| u8 *ubuf; /* buffer for copy to user space */ |
| |
| struct urb *command; |
| struct urb *response; |
| struct urb *validity; |
| struct usb_interface *intf; |
| struct usb_ctrlrequest *orq; |
| struct usb_ctrlrequest *irq; |
| spinlock_t iuspin; |
| |
| unsigned long flags; |
| u16 bufsize; |
| u16 wMaxCommand; |
| u16 wMaxPacketSize; |
| __le16 inum; |
| int reslength; |
| int length; |
| int read; |
| int count; |
| dma_addr_t shandle; |
| dma_addr_t ihandle; |
| struct mutex wlock; |
| struct mutex rlock; |
| wait_queue_head_t wait; |
| struct work_struct rxwork; |
| struct work_struct service_outs_intr; |
| int werr; |
| int rerr; |
| int resp_count; |
| |
| struct list_head device_list; |
| int (*manage_power)(struct usb_interface *, int); |
| }; |
| |
| static struct usb_driver wdm_driver; |
| |
| /* return intfdata if we own the interface, else look up intf in the list */ |
| static struct wdm_device *wdm_find_device(struct usb_interface *intf) |
| { |
| struct wdm_device *desc; |
| |
| spin_lock(&wdm_device_list_lock); |
| list_for_each_entry(desc, &wdm_device_list, device_list) |
| if (desc->intf == intf) |
| goto found; |
| desc = NULL; |
| found: |
| spin_unlock(&wdm_device_list_lock); |
| |
| return desc; |
| } |
| |
| static struct wdm_device *wdm_find_device_by_minor(int minor) |
| { |
| struct wdm_device *desc; |
| |
| spin_lock(&wdm_device_list_lock); |
| list_for_each_entry(desc, &wdm_device_list, device_list) |
| if (desc->intf->minor == minor) |
| goto found; |
| desc = NULL; |
| found: |
| spin_unlock(&wdm_device_list_lock); |
| |
| return desc; |
| } |
| |
| /* --- callbacks --- */ |
| static void wdm_out_callback(struct urb *urb) |
| { |
| struct wdm_device *desc; |
| unsigned long flags; |
| |
| desc = urb->context; |
| spin_lock_irqsave(&desc->iuspin, flags); |
| desc->werr = urb->status; |
| spin_unlock_irqrestore(&desc->iuspin, flags); |
| kfree(desc->outbuf); |
| desc->outbuf = NULL; |
| clear_bit(WDM_IN_USE, &desc->flags); |
| wake_up(&desc->wait); |
| } |
| |
| static void wdm_in_callback(struct urb *urb) |
| { |
| unsigned long flags; |
| struct wdm_device *desc = urb->context; |
| int status = urb->status; |
| int length = urb->actual_length; |
| |
| spin_lock_irqsave(&desc->iuspin, flags); |
| clear_bit(WDM_RESPONDING, &desc->flags); |
| |
| if (status) { |
| switch (status) { |
| case -ENOENT: |
| dev_dbg(&desc->intf->dev, |
| "nonzero urb status received: -ENOENT\n"); |
| goto skip_error; |
| case -ECONNRESET: |
| dev_dbg(&desc->intf->dev, |
| "nonzero urb status received: -ECONNRESET\n"); |
| goto skip_error; |
| case -ESHUTDOWN: |
| dev_dbg(&desc->intf->dev, |
| "nonzero urb status received: -ESHUTDOWN\n"); |
| goto skip_error; |
| case -EPIPE: |
| dev_err(&desc->intf->dev, |
| "nonzero urb status received: -EPIPE\n"); |
| break; |
| default: |
| dev_err(&desc->intf->dev, |
| "Unexpected error %d\n", status); |
| break; |
| } |
| } |
| |
| /* |
| * only set a new error if there is no previous error. |
| * Errors are only cleared during read/open |
| * Avoid propagating -EPIPE (stall) to userspace since it is |
| * better handled as an empty read |
| */ |
| if (desc->rerr == 0 && status != -EPIPE) |
| desc->rerr = status; |
| |
| if (length + desc->length > desc->wMaxCommand) { |
| /* The buffer would overflow */ |
| set_bit(WDM_OVERFLOW, &desc->flags); |
| } else { |
| /* we may already be in overflow */ |
| if (!test_bit(WDM_OVERFLOW, &desc->flags)) { |
| memmove(desc->ubuf + desc->length, desc->inbuf, length); |
| desc->length += length; |
| desc->reslength = length; |
| } |
| } |
| skip_error: |
| |
| if (desc->rerr) { |
| /* |
| * Since there was an error, userspace may decide to not read |
| * any data after poll'ing. |
| * We should respond to further attempts from the device to send |
| * data, so that we can get unstuck. |
| */ |
| schedule_work(&desc->service_outs_intr); |
| } else { |
| set_bit(WDM_READ, &desc->flags); |
| wake_up(&desc->wait); |
| } |
| spin_unlock_irqrestore(&desc->iuspin, flags); |
| } |
| |
| static void wdm_int_callback(struct urb *urb) |
| { |
| unsigned long flags; |
| int rv = 0; |
| int responding; |
| int status = urb->status; |
| struct wdm_device *desc; |
| struct usb_cdc_notification *dr; |
| |
| desc = urb->context; |
| dr = (struct usb_cdc_notification *)desc->sbuf; |
| |
| if (status) { |
| switch (status) { |
| case -ESHUTDOWN: |
| case -ENOENT: |
| case -ECONNRESET: |
| return; /* unplug */ |
| case -EPIPE: |
| set_bit(WDM_INT_STALL, &desc->flags); |
| dev_err(&desc->intf->dev, "Stall on int endpoint\n"); |
| goto sw; /* halt is cleared in work */ |
| default: |
| dev_err(&desc->intf->dev, |
| "nonzero urb status received: %d\n", status); |
| break; |
| } |
| } |
| |
| if (urb->actual_length < sizeof(struct usb_cdc_notification)) { |
| dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n", |
| urb->actual_length); |
| goto exit; |
| } |
| |
| switch (dr->bNotificationType) { |
| case USB_CDC_NOTIFY_RESPONSE_AVAILABLE: |
| dev_dbg(&desc->intf->dev, |
| "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d\n", |
| le16_to_cpu(dr->wIndex), le16_to_cpu(dr->wLength)); |
| break; |
| |
| case USB_CDC_NOTIFY_NETWORK_CONNECTION: |
| |
| dev_dbg(&desc->intf->dev, |
| "NOTIFY_NETWORK_CONNECTION %s network\n", |
| dr->wValue ? "connected to" : "disconnected from"); |
| goto exit; |
| case USB_CDC_NOTIFY_SPEED_CHANGE: |
| dev_dbg(&desc->intf->dev, "SPEED_CHANGE received (len %u)\n", |
| urb->actual_length); |
| goto exit; |
| default: |
| clear_bit(WDM_POLL_RUNNING, &desc->flags); |
| dev_err(&desc->intf->dev, |
| "unknown notification %d received: index %d len %d\n", |
| dr->bNotificationType, |
| le16_to_cpu(dr->wIndex), |
| le16_to_cpu(dr->wLength)); |
| goto exit; |
| } |
| |
| spin_lock_irqsave(&desc->iuspin, flags); |
| responding = test_and_set_bit(WDM_RESPONDING, &desc->flags); |
| if (!desc->resp_count++ && !responding |
| && !test_bit(WDM_DISCONNECTING, &desc->flags) |
| && !test_bit(WDM_SUSPENDING, &desc->flags)) { |
| rv = usb_submit_urb(desc->response, GFP_ATOMIC); |
| dev_dbg(&desc->intf->dev, "submit response URB %d\n", rv); |
| } |
| spin_unlock_irqrestore(&desc->iuspin, flags); |
| if (rv < 0) { |
| clear_bit(WDM_RESPONDING, &desc->flags); |
| if (rv == -EPERM) |
| return; |
| if (rv == -ENOMEM) { |
| sw: |
| rv = schedule_work(&desc->rxwork); |
| if (rv) |
| dev_err(&desc->intf->dev, |
| "Cannot schedule work\n"); |
| } |
| } |
| exit: |
| rv = usb_submit_urb(urb, GFP_ATOMIC); |
| if (rv) |
| dev_err(&desc->intf->dev, |
| "%s - usb_submit_urb failed with result %d\n", |
| __func__, rv); |
| |
| } |
| |
| static void kill_urbs(struct wdm_device *desc) |
| { |
| /* the order here is essential */ |
| usb_kill_urb(desc->command); |
| usb_kill_urb(desc->validity); |
| usb_kill_urb(desc->response); |
| } |
| |
| static void free_urbs(struct wdm_device *desc) |
| { |
| usb_free_urb(desc->validity); |
| usb_free_urb(desc->response); |
| usb_free_urb(desc->command); |
| } |
| |
| static void cleanup(struct wdm_device *desc) |
| { |
| kfree(desc->sbuf); |
| kfree(desc->inbuf); |
| kfree(desc->orq); |
| kfree(desc->irq); |
| kfree(desc->ubuf); |
| free_urbs(desc); |
| kfree(desc); |
| } |
| |
| static ssize_t wdm_write |
| (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) |
| { |
| u8 *buf; |
| int rv = -EMSGSIZE, r, we; |
| struct wdm_device *desc = file->private_data; |
| struct usb_ctrlrequest *req; |
| |
| if (count > desc->wMaxCommand) |
| count = desc->wMaxCommand; |
| |
| spin_lock_irq(&desc->iuspin); |
| we = desc->werr; |
| desc->werr = 0; |
| spin_unlock_irq(&desc->iuspin); |
| if (we < 0) |
| return usb_translate_errors(we); |
| |
| buf = memdup_user(buffer, count); |
| if (IS_ERR(buf)) |
| return PTR_ERR(buf); |
| |
| /* concurrent writes and disconnect */ |
| r = mutex_lock_interruptible(&desc->wlock); |
| rv = -ERESTARTSYS; |
| if (r) |
| goto out_free_mem; |
| |
| if (test_bit(WDM_DISCONNECTING, &desc->flags)) { |
| rv = -ENODEV; |
| goto out_free_mem_lock; |
| } |
| |
| r = usb_autopm_get_interface(desc->intf); |
| if (r < 0) { |
| rv = usb_translate_errors(r); |
| goto out_free_mem_lock; |
| } |
| |
| if (!(file->f_flags & O_NONBLOCK)) |
| r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE, |
| &desc->flags)); |
| else |
| if (test_bit(WDM_IN_USE, &desc->flags)) |
| r = -EAGAIN; |
| |
| if (test_bit(WDM_RESETTING, &desc->flags)) |
| r = -EIO; |
| |
| if (r < 0) { |
| rv = r; |
| goto out_free_mem_pm; |
| } |
| |
| req = desc->orq; |
| usb_fill_control_urb( |
| desc->command, |
| interface_to_usbdev(desc->intf), |
| /* using common endpoint 0 */ |
| usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0), |
| (unsigned char *)req, |
| buf, |
| count, |
| wdm_out_callback, |
| desc |
| ); |
| |
| req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS | |
| USB_RECIP_INTERFACE); |
| req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND; |
| req->wValue = 0; |
| req->wIndex = desc->inum; /* already converted */ |
| req->wLength = cpu_to_le16(count); |
| set_bit(WDM_IN_USE, &desc->flags); |
| desc->outbuf = buf; |
| |
| rv = usb_submit_urb(desc->command, GFP_KERNEL); |
| if (rv < 0) { |
| desc->outbuf = NULL; |
| clear_bit(WDM_IN_USE, &desc->flags); |
| dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv); |
| rv = usb_translate_errors(rv); |
| goto out_free_mem_pm; |
| } else { |
| dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d\n", |
| le16_to_cpu(req->wIndex)); |
| } |
| |
| usb_autopm_put_interface(desc->intf); |
| mutex_unlock(&desc->wlock); |
| return count; |
| |
| out_free_mem_pm: |
| usb_autopm_put_interface(desc->intf); |
| out_free_mem_lock: |
| mutex_unlock(&desc->wlock); |
| out_free_mem: |
| kfree(buf); |
| return rv; |
| } |
| |
| /* |
| * Submit the read urb if resp_count is non-zero. |
| * |
| * Called with desc->iuspin locked |
| */ |
| static int service_outstanding_interrupt(struct wdm_device *desc) |
| { |
| int rv = 0; |
| |
| /* submit read urb only if the device is waiting for it */ |
| if (!desc->resp_count || !--desc->resp_count) |
| goto out; |
| |
| set_bit(WDM_RESPONDING, &desc->flags); |
| spin_unlock_irq(&desc->iuspin); |
| rv = usb_submit_urb(desc->response, GFP_KERNEL); |
| spin_lock_irq(&desc->iuspin); |
| if (rv) { |
| dev_err(&desc->intf->dev, |
| "usb_submit_urb failed with result %d\n", rv); |
| |
| /* make sure the next notification trigger a submit */ |
| clear_bit(WDM_RESPONDING, &desc->flags); |
| desc->resp_count = 0; |
| } |
| out: |
| return rv; |
| } |
| |
| static ssize_t wdm_read |
| (struct file *file, char __user *buffer, size_t count, loff_t *ppos) |
| { |
| int rv, cntr; |
| int i = 0; |
| struct wdm_device *desc = file->private_data; |
| |
| |
| rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */ |
| if (rv < 0) |
| return -ERESTARTSYS; |
| |
| cntr = READ_ONCE(desc->length); |
| if (cntr == 0) { |
| desc->read = 0; |
| retry: |
| if (test_bit(WDM_DISCONNECTING, &desc->flags)) { |
| rv = -ENODEV; |
| goto err; |
| } |
| if (test_bit(WDM_OVERFLOW, &desc->flags)) { |
| clear_bit(WDM_OVERFLOW, &desc->flags); |
| rv = -ENOBUFS; |
| goto err; |
| } |
| i++; |
| if (file->f_flags & O_NONBLOCK) { |
| if (!test_bit(WDM_READ, &desc->flags)) { |
| rv = -EAGAIN; |
| goto err; |
| } |
| rv = 0; |
| } else { |
| rv = wait_event_interruptible(desc->wait, |
| test_bit(WDM_READ, &desc->flags)); |
| } |
| |
| /* may have happened while we slept */ |
| if (test_bit(WDM_DISCONNECTING, &desc->flags)) { |
| rv = -ENODEV; |
| goto err; |
| } |
| if (test_bit(WDM_RESETTING, &desc->flags)) { |
| rv = -EIO; |
| goto err; |
| } |
| usb_mark_last_busy(interface_to_usbdev(desc->intf)); |
| if (rv < 0) { |
| rv = -ERESTARTSYS; |
| goto err; |
| } |
| |
| spin_lock_irq(&desc->iuspin); |
| |
| if (desc->rerr) { /* read completed, error happened */ |
| rv = usb_translate_errors(desc->rerr); |
| desc->rerr = 0; |
| spin_unlock_irq(&desc->iuspin); |
| goto err; |
| } |
| /* |
| * recheck whether we've lost the race |
| * against the completion handler |
| */ |
| if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */ |
| spin_unlock_irq(&desc->iuspin); |
| goto retry; |
| } |
| |
| if (!desc->reslength) { /* zero length read */ |
| dev_dbg(&desc->intf->dev, "zero length - clearing WDM_READ\n"); |
| clear_bit(WDM_READ, &desc->flags); |
| rv = service_outstanding_interrupt(desc); |
| spin_unlock_irq(&desc->iuspin); |
| if (rv < 0) |
| goto err; |
| goto retry; |
| } |
| cntr = desc->length; |
| spin_unlock_irq(&desc->iuspin); |
| } |
| |
| if (cntr > count) |
| cntr = count; |
| rv = copy_to_user(buffer, desc->ubuf, cntr); |
| if (rv > 0) { |
| rv = -EFAULT; |
| goto err; |
| } |
| |
| spin_lock_irq(&desc->iuspin); |
| |
| for (i = 0; i < desc->length - cntr; i++) |
| desc->ubuf[i] = desc->ubuf[i + cntr]; |
| |
| desc->length -= cntr; |
| /* in case we had outstanding data */ |
| if (!desc->length) { |
| clear_bit(WDM_READ, &desc->flags); |
| service_outstanding_interrupt(desc); |
| } |
| spin_unlock_irq(&desc->iuspin); |
| rv = cntr; |
| |
| err: |
| mutex_unlock(&desc->rlock); |
| return rv; |
| } |
| |
| static int wdm_flush(struct file *file, fl_owner_t id) |
| { |
| struct wdm_device *desc = file->private_data; |
| |
| wait_event(desc->wait, |
| /* |
| * needs both flags. We cannot do with one |
| * because resetting it would cause a race |
| * with write() yet we need to signal |
| * a disconnect |
| */ |
| !test_bit(WDM_IN_USE, &desc->flags) || |
| test_bit(WDM_DISCONNECTING, &desc->flags)); |
| |
| /* cannot dereference desc->intf if WDM_DISCONNECTING */ |
| if (test_bit(WDM_DISCONNECTING, &desc->flags)) |
| return -ENODEV; |
| if (desc->werr < 0) |
| dev_err(&desc->intf->dev, "Error in flush path: %d\n", |
| desc->werr); |
| |
| return usb_translate_errors(desc->werr); |
| } |
| |
| static __poll_t wdm_poll(struct file *file, struct poll_table_struct *wait) |
| { |
| struct wdm_device *desc = file->private_data; |
| unsigned long flags; |
| __poll_t mask = 0; |
| |
| spin_lock_irqsave(&desc->iuspin, flags); |
| if (test_bit(WDM_DISCONNECTING, &desc->flags)) { |
| mask = EPOLLHUP | EPOLLERR; |
| spin_unlock_irqrestore(&desc->iuspin, flags); |
| goto desc_out; |
| } |
| if (test_bit(WDM_READ, &desc->flags)) |
| mask = EPOLLIN | EPOLLRDNORM; |
| if (desc->rerr || desc->werr) |
| mask |= EPOLLERR; |
| if (!test_bit(WDM_IN_USE, &desc->flags)) |
| mask |= EPOLLOUT | EPOLLWRNORM; |
| spin_unlock_irqrestore(&desc->iuspin, flags); |
| |
| poll_wait(file, &desc->wait, wait); |
| |
| desc_out: |
| return mask; |
| } |
| |
| static int wdm_open(struct inode *inode, struct file *file) |
| { |
| int minor = iminor(inode); |
| int rv = -ENODEV; |
| struct usb_interface *intf; |
| struct wdm_device *desc; |
| |
| mutex_lock(&wdm_mutex); |
| desc = wdm_find_device_by_minor(minor); |
| if (!desc) |
| goto out; |
| |
| intf = desc->intf; |
| if (test_bit(WDM_DISCONNECTING, &desc->flags)) |
| goto out; |
| file->private_data = desc; |
| |
| rv = usb_autopm_get_interface(desc->intf); |
| if (rv < 0) { |
| dev_err(&desc->intf->dev, "Error autopm - %d\n", rv); |
| goto out; |
| } |
| |
| /* using write lock to protect desc->count */ |
| mutex_lock(&desc->wlock); |
| if (!desc->count++) { |
| desc->werr = 0; |
| desc->rerr = 0; |
| rv = usb_submit_urb(desc->validity, GFP_KERNEL); |
| if (rv < 0) { |
| desc->count--; |
| dev_err(&desc->intf->dev, |
| "Error submitting int urb - %d\n", rv); |
| rv = usb_translate_errors(rv); |
| } |
| } else { |
| rv = 0; |
| } |
| mutex_unlock(&desc->wlock); |
| if (desc->count == 1) |
| desc->manage_power(intf, 1); |
| usb_autopm_put_interface(desc->intf); |
| out: |
| mutex_unlock(&wdm_mutex); |
| return rv; |
| } |
| |
| static int wdm_release(struct inode *inode, struct file *file) |
| { |
| struct wdm_device *desc = file->private_data; |
| |
| mutex_lock(&wdm_mutex); |
| |
| /* using write lock to protect desc->count */ |
| mutex_lock(&desc->wlock); |
| desc->count--; |
| mutex_unlock(&desc->wlock); |
| |
| if (!desc->count) { |
| if (!test_bit(WDM_DISCONNECTING, &desc->flags)) { |
| dev_dbg(&desc->intf->dev, "wdm_release: cleanup\n"); |
| kill_urbs(desc); |
| spin_lock_irq(&desc->iuspin); |
| desc->resp_count = 0; |
| spin_unlock_irq(&desc->iuspin); |
| desc->manage_power(desc->intf, 0); |
| } else { |
| /* must avoid dev_printk here as desc->intf is invalid */ |
| pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__); |
| cleanup(desc); |
| } |
| } |
| mutex_unlock(&wdm_mutex); |
| return 0; |
| } |
| |
| static long wdm_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
| { |
| struct wdm_device *desc = file->private_data; |
| int rv = 0; |
| |
| switch (cmd) { |
| case IOCTL_WDM_MAX_COMMAND: |
| if (copy_to_user((void __user *)arg, &desc->wMaxCommand, sizeof(desc->wMaxCommand))) |
| rv = -EFAULT; |
| break; |
| default: |
| rv = -ENOTTY; |
| } |
| return rv; |
| } |
| |
| static const struct file_operations wdm_fops = { |
| .owner = THIS_MODULE, |
| .read = wdm_read, |
| .write = wdm_write, |
| .open = wdm_open, |
| .flush = wdm_flush, |
| .release = wdm_release, |
| .poll = wdm_poll, |
| .unlocked_ioctl = wdm_ioctl, |
| .compat_ioctl = compat_ptr_ioctl, |
| .llseek = noop_llseek, |
| }; |
| |
| static struct usb_class_driver wdm_class = { |
| .name = "cdc-wdm%d", |
| .fops = &wdm_fops, |
| .minor_base = WDM_MINOR_BASE, |
| }; |
| |
| /* --- error handling --- */ |
| static void wdm_rxwork(struct work_struct *work) |
| { |
| struct wdm_device *desc = container_of(work, struct wdm_device, rxwork); |
| unsigned long flags; |
| int rv = 0; |
| int responding; |
| |
| spin_lock_irqsave(&desc->iuspin, flags); |
| if (test_bit(WDM_DISCONNECTING, &desc->flags)) { |
| spin_unlock_irqrestore(&desc->iuspin, flags); |
| } else { |
| responding = test_and_set_bit(WDM_RESPONDING, &desc->flags); |
| spin_unlock_irqrestore(&desc->iuspin, flags); |
| if (!responding) |
| rv = usb_submit_urb(desc->response, GFP_KERNEL); |
| if (rv < 0 && rv != -EPERM) { |
| spin_lock_irqsave(&desc->iuspin, flags); |
| clear_bit(WDM_RESPONDING, &desc->flags); |
| if (!test_bit(WDM_DISCONNECTING, &desc->flags)) |
| schedule_work(&desc->rxwork); |
| spin_unlock_irqrestore(&desc->iuspin, flags); |
| } |
| } |
| } |
| |
| static void service_interrupt_work(struct work_struct *work) |
| { |
| struct wdm_device *desc; |
| |
| desc = container_of(work, struct wdm_device, service_outs_intr); |
| |
| spin_lock_irq(&desc->iuspin); |
| service_outstanding_interrupt(desc); |
| if (!desc->resp_count) { |
| set_bit(WDM_READ, &desc->flags); |
| wake_up(&desc->wait); |
| } |
| spin_unlock_irq(&desc->iuspin); |
| } |
| |
| /* --- hotplug --- */ |
| |
| static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep, |
| u16 bufsize, int (*manage_power)(struct usb_interface *, int)) |
| { |
| int rv = -ENOMEM; |
| struct wdm_device *desc; |
| |
| desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL); |
| if (!desc) |
| goto out; |
| INIT_LIST_HEAD(&desc->device_list); |
| mutex_init(&desc->rlock); |
| mutex_init(&desc->wlock); |
| spin_lock_init(&desc->iuspin); |
| init_waitqueue_head(&desc->wait); |
| desc->wMaxCommand = bufsize; |
| /* this will be expanded and needed in hardware endianness */ |
| desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber); |
| desc->intf = intf; |
| INIT_WORK(&desc->rxwork, wdm_rxwork); |
| INIT_WORK(&desc->service_outs_intr, service_interrupt_work); |
| |
| rv = -EINVAL; |
| if (!usb_endpoint_is_int_in(ep)) |
| goto err; |
| |
| desc->wMaxPacketSize = usb_endpoint_maxp(ep); |
| |
| desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL); |
| if (!desc->orq) |
| goto err; |
| desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL); |
| if (!desc->irq) |
| goto err; |
| |
| desc->validity = usb_alloc_urb(0, GFP_KERNEL); |
| if (!desc->validity) |
| goto err; |
| |
| desc->response = usb_alloc_urb(0, GFP_KERNEL); |
| if (!desc->response) |
| goto err; |
| |
| desc->command = usb_alloc_urb(0, GFP_KERNEL); |
| if (!desc->command) |
| goto err; |
| |
| desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL); |
| if (!desc->ubuf) |
| goto err; |
| |
| desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL); |
| if (!desc->sbuf) |
| goto err; |
| |
| desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL); |
| if (!desc->inbuf) |
| goto err; |
| |
| usb_fill_int_urb( |
| desc->validity, |
| interface_to_usbdev(intf), |
| usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress), |
| desc->sbuf, |
| desc->wMaxPacketSize, |
| wdm_int_callback, |
| desc, |
| ep->bInterval |
| ); |
| |
| desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE); |
| desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE; |
| desc->irq->wValue = 0; |
| desc->irq->wIndex = desc->inum; /* already converted */ |
| desc->irq->wLength = cpu_to_le16(desc->wMaxCommand); |
| |
| usb_fill_control_urb( |
| desc->response, |
| interface_to_usbdev(intf), |
| /* using common endpoint 0 */ |
| usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0), |
| (unsigned char *)desc->irq, |
| desc->inbuf, |
| desc->wMaxCommand, |
| wdm_in_callback, |
| desc |
| ); |
| |
| desc->manage_power = manage_power; |
| |
| spin_lock(&wdm_device_list_lock); |
| list_add(&desc->device_list, &wdm_device_list); |
| spin_unlock(&wdm_device_list_lock); |
| |
| rv = usb_register_dev(intf, &wdm_class); |
| if (rv < 0) |
| goto err; |
| else |
| dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev)); |
| out: |
| return rv; |
| err: |
| spin_lock(&wdm_device_list_lock); |
| list_del(&desc->device_list); |
| spin_unlock(&wdm_device_list_lock); |
| cleanup(desc); |
| return rv; |
| } |
| |
| static int wdm_manage_power(struct usb_interface *intf, int on) |
| { |
| /* need autopm_get/put here to ensure the usbcore sees the new value */ |
| int rv = usb_autopm_get_interface(intf); |
| |
| intf->needs_remote_wakeup = on; |
| if (!rv) |
| usb_autopm_put_interface(intf); |
| return 0; |
| } |
| |
| static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id) |
| { |
| int rv = -EINVAL; |
| struct usb_host_interface *iface; |
| struct usb_endpoint_descriptor *ep; |
| struct usb_cdc_parsed_header hdr; |
| u8 *buffer = intf->altsetting->extra; |
| int buflen = intf->altsetting->extralen; |
| u16 maxcom = WDM_DEFAULT_BUFSIZE; |
| |
| if (!buffer) |
| goto err; |
| |
| cdc_parse_cdc_header(&hdr, intf, buffer, buflen); |
| |
| if (hdr.usb_cdc_dmm_desc) |
| maxcom = le16_to_cpu(hdr.usb_cdc_dmm_desc->wMaxCommand); |
| |
| iface = intf->cur_altsetting; |
| if (iface->desc.bNumEndpoints != 1) |
| goto err; |
| ep = &iface->endpoint[0].desc; |
| |
| rv = wdm_create(intf, ep, maxcom, &wdm_manage_power); |
| |
| err: |
| return rv; |
| } |
| |
| /** |
| * usb_cdc_wdm_register - register a WDM subdriver |
| * @intf: usb interface the subdriver will associate with |
| * @ep: interrupt endpoint to monitor for notifications |
| * @bufsize: maximum message size to support for read/write |
| * @manage_power: call-back invoked during open and release to |
| * manage the device's power |
| * Create WDM usb class character device and associate it with intf |
| * without binding, allowing another driver to manage the interface. |
| * |
| * The subdriver will manage the given interrupt endpoint exclusively |
| * and will issue control requests referring to the given intf. It |
| * will otherwise avoid interferring, and in particular not do |
| * usb_set_intfdata/usb_get_intfdata on intf. |
| * |
| * The return value is a pointer to the subdriver's struct usb_driver. |
| * The registering driver is responsible for calling this subdriver's |
| * disconnect, suspend, resume, pre_reset and post_reset methods from |
| * its own. |
| */ |
| struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf, |
| struct usb_endpoint_descriptor *ep, |
| int bufsize, |
| int (*manage_power)(struct usb_interface *, int)) |
| { |
| int rv; |
| |
| rv = wdm_create(intf, ep, bufsize, manage_power); |
| if (rv < 0) |
| goto err; |
| |
| return &wdm_driver; |
| err: |
| return ERR_PTR(rv); |
| } |
| EXPORT_SYMBOL(usb_cdc_wdm_register); |
| |
| static void wdm_disconnect(struct usb_interface *intf) |
| { |
| struct wdm_device *desc; |
| unsigned long flags; |
| |
| usb_deregister_dev(intf, &wdm_class); |
| desc = wdm_find_device(intf); |
| mutex_lock(&wdm_mutex); |
| |
| /* the spinlock makes sure no new urbs are generated in the callbacks */ |
| spin_lock_irqsave(&desc->iuspin, flags); |
| set_bit(WDM_DISCONNECTING, &desc->flags); |
| set_bit(WDM_READ, &desc->flags); |
| spin_unlock_irqrestore(&desc->iuspin, flags); |
| wake_up_all(&desc->wait); |
| mutex_lock(&desc->rlock); |
| mutex_lock(&desc->wlock); |
| kill_urbs(desc); |
| cancel_work_sync(&desc->rxwork); |
| cancel_work_sync(&desc->service_outs_intr); |
| mutex_unlock(&desc->wlock); |
| mutex_unlock(&desc->rlock); |
| |
| /* the desc->intf pointer used as list key is now invalid */ |
| spin_lock(&wdm_device_list_lock); |
| list_del(&desc->device_list); |
| spin_unlock(&wdm_device_list_lock); |
| |
| if (!desc->count) |
| cleanup(desc); |
| else |
| dev_dbg(&intf->dev, "%d open files - postponing cleanup\n", desc->count); |
| mutex_unlock(&wdm_mutex); |
| } |
| |
| #ifdef CONFIG_PM |
| static int wdm_suspend(struct usb_interface *intf, pm_message_t message) |
| { |
| struct wdm_device *desc = wdm_find_device(intf); |
| int rv = 0; |
| |
| dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor); |
| |
| /* if this is an autosuspend the caller does the locking */ |
| if (!PMSG_IS_AUTO(message)) { |
| mutex_lock(&desc->rlock); |
| mutex_lock(&desc->wlock); |
| } |
| spin_lock_irq(&desc->iuspin); |
| |
| if (PMSG_IS_AUTO(message) && |
| (test_bit(WDM_IN_USE, &desc->flags) |
| || test_bit(WDM_RESPONDING, &desc->flags))) { |
| spin_unlock_irq(&desc->iuspin); |
| rv = -EBUSY; |
| } else { |
| |
| set_bit(WDM_SUSPENDING, &desc->flags); |
| spin_unlock_irq(&desc->iuspin); |
| /* callback submits work - order is essential */ |
| kill_urbs(desc); |
| cancel_work_sync(&desc->rxwork); |
| cancel_work_sync(&desc->service_outs_intr); |
| } |
| if (!PMSG_IS_AUTO(message)) { |
| mutex_unlock(&desc->wlock); |
| mutex_unlock(&desc->rlock); |
| } |
| |
| return rv; |
| } |
| #endif |
| |
| static int recover_from_urb_loss(struct wdm_device *desc) |
| { |
| int rv = 0; |
| |
| if (desc->count) { |
| rv = usb_submit_urb(desc->validity, GFP_NOIO); |
| if (rv < 0) |
| dev_err(&desc->intf->dev, |
| "Error resume submitting int urb - %d\n", rv); |
| } |
| return rv; |
| } |
| |
| #ifdef CONFIG_PM |
| static int wdm_resume(struct usb_interface *intf) |
| { |
| struct wdm_device *desc = wdm_find_device(intf); |
| int rv; |
| |
| dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor); |
| |
| clear_bit(WDM_SUSPENDING, &desc->flags); |
| rv = recover_from_urb_loss(desc); |
| |
| return rv; |
| } |
| #endif |
| |
| static int wdm_pre_reset(struct usb_interface *intf) |
| { |
| struct wdm_device *desc = wdm_find_device(intf); |
| |
| /* |
| * we notify everybody using poll of |
| * an exceptional situation |
| * must be done before recovery lest a spontaneous |
| * message from the device is lost |
| */ |
| spin_lock_irq(&desc->iuspin); |
| set_bit(WDM_RESETTING, &desc->flags); /* inform read/write */ |
| set_bit(WDM_READ, &desc->flags); /* unblock read */ |
| clear_bit(WDM_IN_USE, &desc->flags); /* unblock write */ |
| desc->rerr = -EINTR; |
| spin_unlock_irq(&desc->iuspin); |
| wake_up_all(&desc->wait); |
| mutex_lock(&desc->rlock); |
| mutex_lock(&desc->wlock); |
| kill_urbs(desc); |
| cancel_work_sync(&desc->rxwork); |
| cancel_work_sync(&desc->service_outs_intr); |
| return 0; |
| } |
| |
| static int wdm_post_reset(struct usb_interface *intf) |
| { |
| struct wdm_device *desc = wdm_find_device(intf); |
| int rv; |
| |
| clear_bit(WDM_OVERFLOW, &desc->flags); |
| clear_bit(WDM_RESETTING, &desc->flags); |
| rv = recover_from_urb_loss(desc); |
| mutex_unlock(&desc->wlock); |
| mutex_unlock(&desc->rlock); |
| return rv; |
| } |
| |
| static struct usb_driver wdm_driver = { |
| .name = "cdc_wdm", |
| .probe = wdm_probe, |
| .disconnect = wdm_disconnect, |
| #ifdef CONFIG_PM |
| .suspend = wdm_suspend, |
| .resume = wdm_resume, |
| .reset_resume = wdm_resume, |
| #endif |
| .pre_reset = wdm_pre_reset, |
| .post_reset = wdm_post_reset, |
| .id_table = wdm_ids, |
| .supports_autosuspend = 1, |
| .disable_hub_initiated_lpm = 1, |
| }; |
| |
| module_usb_driver(wdm_driver); |
| |
| MODULE_AUTHOR(DRIVER_AUTHOR); |
| MODULE_DESCRIPTION(DRIVER_DESC); |
| MODULE_LICENSE("GPL"); |