diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/usb/class/cdc-wdm.c | 1371 |
1 files changed, 1371 insertions, 0 deletions
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c new file mode 100644 index 000000000..1f0951be1 --- /dev/null +++ b/drivers/usb/class/cdc-wdm.c @@ -0,0 +1,1371 @@ +// 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/skbuff.h> +#include <linux/usb.h> +#include <linux/usb/cdc.h> +#include <linux/wwan.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_WWAN_IN_USE 11 + +#define WDM_MAX 16 + +/* we cannot wait forever at flush() */ +#define WDM_FLUSH_TIMEOUT (30 * HZ) + +/* 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); + + enum wwan_port_type wwanp_type; + struct wwan_port *wwanp; +}; + +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_all(&desc->wait); +} + +static void wdm_wwan_rx(struct wdm_device *desc, int length); + +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; + } + } + + if (test_bit(WDM_WWAN_IN_USE, &desc->flags)) { + wdm_wwan_rx(desc, length); + goto out; + } + + /* + * 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); + } +out: + 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 poison_urbs(struct wdm_device *desc) +{ + /* the order here is essential */ + usb_poison_urb(desc->command); + usb_poison_urb(desc->validity); + usb_poison_urb(desc->response); +} + +static void unpoison_urbs(struct wdm_device *desc) +{ + /* + * the order here is not essential + * it is symmetrical just to be nice + */ + usb_unpoison_urb(desc->response); + usb_unpoison_urb(desc->validity); + usb_unpoison_urb(desc->command); +} + +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 (test_bit(WDM_DISCONNECTING, &desc->flags)) + r = -ENODEV; + + 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); + wake_up_all(&desc->wait); /* for wdm_wait_for_response() */ + 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; + + if (test_bit(WDM_DISCONNECTING, &desc->flags)) { + rv = -ENODEV; + goto out; + } + if (test_bit(WDM_RESETTING, &desc->flags)) { + rv = -EIO; + 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) { + if (!test_bit(WDM_DISCONNECTING, &desc->flags)) + 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_wait_for_response(struct file *file, long timeout) +{ + struct wdm_device *desc = file->private_data; + long rv; /* Use long here because (int) MAX_SCHEDULE_TIMEOUT < 0. */ + + /* + * Needs both flags. We cannot do with one because resetting it would + * cause a race with write() yet we need to signal a disconnect. + */ + rv = wait_event_interruptible_timeout(desc->wait, + !test_bit(WDM_IN_USE, &desc->flags) || + test_bit(WDM_DISCONNECTING, &desc->flags), + timeout); + + /* + * To report the correct error. This is best effort. + * We are inevitably racing with the hardware. + */ + if (test_bit(WDM_DISCONNECTING, &desc->flags)) + return -ENODEV; + if (!rv) + return -EIO; + if (rv < 0) + return -EINTR; + + spin_lock_irq(&desc->iuspin); + rv = desc->werr; + desc->werr = 0; + spin_unlock_irq(&desc->iuspin); + + return usb_translate_errors(rv); + +} + +/* + * You need to send a signal when you react to malicious or defective hardware. + * Also, don't abort when fsync() returned -EINVAL, for older kernels which do + * not implement wdm_flush() will return -EINVAL. + */ +static int wdm_fsync(struct file *file, loff_t start, loff_t end, int datasync) +{ + return wdm_wait_for_response(file, MAX_SCHEDULE_TIMEOUT); +} + +/* + * Same with wdm_fsync(), except it uses finite timeout in order to react to + * malicious or defective hardware which ceased communication after close() was + * implicitly called due to process termination. + */ +static int wdm_flush(struct file *file, fl_owner_t id) +{ + return wdm_wait_for_response(file, WDM_FLUSH_TIMEOUT); +} + +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; + + if (test_bit(WDM_WWAN_IN_USE, &desc->flags)) { + rv = -EBUSY; + goto out; + } + + 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"); + poison_urbs(desc); + spin_lock_irq(&desc->iuspin); + desc->resp_count = 0; + clear_bit(WDM_RESPONDING, &desc->flags); + spin_unlock_irq(&desc->iuspin); + desc->manage_power(desc->intf, 0); + unpoison_urbs(desc); + } 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, + .fsync = wdm_fsync, + .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, +}; + +/* --- WWAN framework integration --- */ +#ifdef CONFIG_WWAN +static int wdm_wwan_port_start(struct wwan_port *port) +{ + struct wdm_device *desc = wwan_port_get_drvdata(port); + + /* The interface is both exposed via the WWAN framework and as a + * legacy usbmisc chardev. If chardev is already open, just fail + * to prevent concurrent usage. Otherwise, switch to WWAN mode. + */ + mutex_lock(&wdm_mutex); + if (desc->count) { + mutex_unlock(&wdm_mutex); + return -EBUSY; + } + set_bit(WDM_WWAN_IN_USE, &desc->flags); + mutex_unlock(&wdm_mutex); + + desc->manage_power(desc->intf, 1); + + /* tx is allowed */ + wwan_port_txon(port); + + /* Start getting events */ + return usb_submit_urb(desc->validity, GFP_KERNEL); +} + +static void wdm_wwan_port_stop(struct wwan_port *port) +{ + struct wdm_device *desc = wwan_port_get_drvdata(port); + + /* Stop all transfers and disable WWAN mode */ + poison_urbs(desc); + desc->manage_power(desc->intf, 0); + clear_bit(WDM_READ, &desc->flags); + clear_bit(WDM_WWAN_IN_USE, &desc->flags); + unpoison_urbs(desc); +} + +static void wdm_wwan_port_tx_complete(struct urb *urb) +{ + struct sk_buff *skb = urb->context; + struct wdm_device *desc = skb_shinfo(skb)->destructor_arg; + + usb_autopm_put_interface(desc->intf); + wwan_port_txon(desc->wwanp); + kfree_skb(skb); +} + +static int wdm_wwan_port_tx(struct wwan_port *port, struct sk_buff *skb) +{ + struct wdm_device *desc = wwan_port_get_drvdata(port); + struct usb_interface *intf = desc->intf; + struct usb_ctrlrequest *req = desc->orq; + int rv; + + rv = usb_autopm_get_interface(intf); + if (rv) + return rv; + + usb_fill_control_urb( + desc->command, + interface_to_usbdev(intf), + usb_sndctrlpipe(interface_to_usbdev(intf), 0), + (unsigned char *)req, + skb->data, + skb->len, + wdm_wwan_port_tx_complete, + skb + ); + + 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; + req->wLength = cpu_to_le16(skb->len); + + skb_shinfo(skb)->destructor_arg = desc; + + rv = usb_submit_urb(desc->command, GFP_KERNEL); + if (rv) + usb_autopm_put_interface(intf); + else /* One transfer at a time, stop TX until URB completion */ + wwan_port_txoff(port); + + return rv; +} + +static const struct wwan_port_ops wdm_wwan_port_ops = { + .start = wdm_wwan_port_start, + .stop = wdm_wwan_port_stop, + .tx = wdm_wwan_port_tx, +}; + +static void wdm_wwan_init(struct wdm_device *desc) +{ + struct usb_interface *intf = desc->intf; + struct wwan_port *port; + + /* Only register to WWAN core if protocol/type is known */ + if (desc->wwanp_type == WWAN_PORT_UNKNOWN) { + dev_info(&intf->dev, "Unknown control protocol\n"); + return; + } + + port = wwan_create_port(&intf->dev, desc->wwanp_type, &wdm_wwan_port_ops, desc); + if (IS_ERR(port)) { + dev_err(&intf->dev, "%s: Unable to create WWAN port\n", + dev_name(intf->usb_dev)); + return; + } + + desc->wwanp = port; +} + +static void wdm_wwan_deinit(struct wdm_device *desc) +{ + if (!desc->wwanp) + return; + + wwan_remove_port(desc->wwanp); + desc->wwanp = NULL; +} + +static void wdm_wwan_rx(struct wdm_device *desc, int length) +{ + struct wwan_port *port = desc->wwanp; + struct sk_buff *skb; + + /* Forward data to WWAN port */ + skb = alloc_skb(length, GFP_ATOMIC); + if (!skb) + return; + + skb_put_data(skb, desc->inbuf, length); + wwan_port_rx(port, skb); + + /* inbuf has been copied, it is safe to check for outstanding data */ + schedule_work(&desc->service_outs_intr); +} +#else /* CONFIG_WWAN */ +static void wdm_wwan_init(struct wdm_device *desc) {} +static void wdm_wwan_deinit(struct wdm_device *desc) {} +static void wdm_wwan_rx(struct wdm_device *desc, int length) {} +#endif /* CONFIG_WWAN */ + +/* --- 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, enum wwan_port_type type, + 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; + desc->wwanp_type = type; + INIT_WORK(&desc->rxwork, wdm_rxwork); + INIT_WORK(&desc->service_outs_intr, service_interrupt_work); + + if (!usb_endpoint_is_int_in(ep)) { + rv = -EINVAL; + 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)); + + wdm_wwan_init(desc); + +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, WWAN_PORT_UNKNOWN, &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 + * @type: Type/protocol of the transported data (MBIM, QMI...) + * @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, enum wwan_port_type type, + int (*manage_power)(struct usb_interface *, int)) +{ + int rv; + + rv = wdm_create(intf, ep, bufsize, type, 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); + + wdm_wwan_deinit(desc); + + /* 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); + poison_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 */ + poison_urbs(desc); + cancel_work_sync(&desc->rxwork); + cancel_work_sync(&desc->service_outs_intr); + unpoison_urbs(desc); + } + 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); + poison_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; + + unpoison_urbs(desc); + 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"); |