--- /dev/null
+/*
+ * cdc-wdm.c
+ *
+ * This driver supports USB CDC WCM Device Management.
+ *
+ * Copyright (c) 2007-2008 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/slab.h>
+#include <linux/module.h>
+#include <linux/smp_lock.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>
+
+/*
+ * Version Information
+ */
+#define DRIVER_VERSION "v0.02"
+#define DRIVER_AUTHOR "Oliver Neukum"
+
+static 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
+ },
+ { }
+};
+
+#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_MAX 16
+
+
+static DEFINE_MUTEX(wdm_mutex);
+
+/* --- 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;
+ u16 bMaxPacketSize0;
+ __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;
+ int werr;
+ int rerr;
+};
+
+static struct usb_driver wdm_driver;
+
+/* --- callbacks --- */
+static void wdm_out_callback(struct urb *urb)
+{
+ struct wdm_device *desc;
+ desc = urb->context;
+ spin_lock(&desc->iuspin);
+ desc->werr = urb->status;
+ spin_unlock(&desc->iuspin);
+ clear_bit(WDM_IN_USE, &desc->flags);
+ kfree(desc->outbuf);
+ wake_up(&desc->wait);
+}
+
+static void wdm_in_callback(struct urb *urb)
+{
+ struct wdm_device *desc = urb->context;
+ int status = urb->status;
+
+ spin_lock(&desc->iuspin);
+
+ if (status) {
+ switch (status) {
+ case -ENOENT:
+ dev_dbg(&desc->intf->dev,
+ "nonzero urb status received: -ENOENT");
+ break;
+ case -ECONNRESET:
+ dev_dbg(&desc->intf->dev,
+ "nonzero urb status received: -ECONNRESET");
+ break;
+ case -ESHUTDOWN:
+ dev_dbg(&desc->intf->dev,
+ "nonzero urb status received: -ESHUTDOWN");
+ break;
+ case -EPIPE:
+ err("nonzero urb status received: -EPIPE");
+ break;
+ default:
+ err("Unexpected error %d", status);
+ break;
+ }
+ }
+
+ desc->rerr = status;
+ desc->reslength = urb->actual_length;
+ memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
+ desc->length += desc->reslength;
+ wake_up(&desc->wait);
+
+ set_bit(WDM_READ, &desc->flags);
+ spin_unlock(&desc->iuspin);
+}
+
+static void wdm_int_callback(struct urb *urb)
+{
+ int rv = 0;
+ int status = urb->status;
+ struct wdm_device *desc;
+ struct usb_ctrlrequest *req;
+ struct usb_cdc_notification *dr;
+
+ desc = urb->context;
+ req = desc->irq;
+ 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);
+ err("Stall on int endpoint");
+ goto sw; /* halt is cleared in work */
+ default:
+ err("nonzero urb status received: %d", status);
+ break;
+ }
+ }
+
+ if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
+ err("wdm_int_callback - %d bytes", 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",
+ dr->wIndex, dr->wLength);
+ break;
+
+ case USB_CDC_NOTIFY_NETWORK_CONNECTION:
+
+ dev_dbg(&desc->intf->dev,
+ "NOTIFY_NETWORK_CONNECTION %s network",
+ dr->wValue ? "connected to" : "disconnected from");
+ goto exit;
+ default:
+ clear_bit(WDM_POLL_RUNNING, &desc->flags);
+ err("unknown notification %d received: index %d len %d",
+ dr->bNotificationType, dr->wIndex, dr->wLength);
+ goto exit;
+ }
+
+ req->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
+ req->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
+ req->wValue = 0;
+ req->wIndex = desc->inum;
+ req->wLength = cpu_to_le16(desc->bMaxPacketSize0);
+
+ usb_fill_control_urb(
+ desc->response,
+ interface_to_usbdev(desc->intf),
+ /* using common endpoint 0 */
+ usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
+ (unsigned char *)req,
+ desc->inbuf,
+ desc->bMaxPacketSize0,
+ wdm_in_callback,
+ desc
+ );
+ desc->response->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+ spin_lock(&desc->iuspin);
+ clear_bit(WDM_READ, &desc->flags);
+ if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
+ rv = usb_submit_urb(desc->response, GFP_ATOMIC);
+ dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
+ __func__, rv);
+ }
+ spin_unlock(&desc->iuspin);
+ if (rv < 0) {
+ if (rv == -EPERM)
+ return;
+ if (rv == -ENOMEM) {
+sw:
+ rv = schedule_work(&desc->rxwork);
+ if (rv)
+ err("Cannot schedule work");
+ }
+ }
+exit:
+ rv = usb_submit_urb(urb, GFP_ATOMIC);
+ if (rv)
+ err("%s - usb_submit_urb failed with result %d",
+ __func__, rv);
+
+}
+
+static void kill_urbs(struct wdm_device *desc)
+{
+ 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)
+{
+ usb_buffer_free(interface_to_usbdev(desc->intf),
+ desc->wMaxPacketSize,
+ desc->sbuf,
+ desc->validity->transfer_dma);
+ usb_buffer_free(interface_to_usbdev(desc->intf),
+ desc->wMaxPacketSize,
+ desc->inbuf,
+ desc->response->transfer_dma);
+ 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 -EIO;
+
+ r = mutex_lock_interruptible(&desc->wlock); /* concurrent writes */
+ rv = -ERESTARTSYS;
+ if (r)
+ goto outnl;
+
+ r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
+ &desc->flags));
+ if (r < 0)
+ goto out;
+
+ if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
+ rv = -ENODEV;
+ goto out;
+ }
+
+ desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
+ if (!buf) {
+ rv = -ENOMEM;
+ goto out;
+ }
+
+ r = copy_from_user(buf, buffer, count);
+ if (r > 0) {
+ kfree(buf);
+ rv = -EFAULT;
+ goto out;
+ }
+
+ 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;
+ req->wLength = cpu_to_le16(count);
+ set_bit(WDM_IN_USE, &desc->flags);
+
+ rv = usb_submit_urb(desc->command, GFP_KERNEL);
+ if (rv < 0) {
+ kfree(buf);
+ clear_bit(WDM_IN_USE, &desc->flags);
+ } else {
+ dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
+ req->wIndex);
+ }
+out:
+ mutex_unlock(&desc->wlock);
+outnl:
+ return rv < 0 ? rv : count;
+}
+
+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;
+
+ if (desc->length == 0) {
+ desc->read = 0;
+retry:
+ i++;
+ rv = wait_event_interruptible(desc->wait,
+ test_bit(WDM_READ, &desc->flags));
+
+ if (rv < 0) {
+ rv = -ERESTARTSYS;
+ goto err;
+ }
+
+ spin_lock_irq(&desc->iuspin);
+
+ if (desc->rerr) { /* read completed, error happened */
+ int t = desc->rerr;
+ desc->rerr = 0;
+ spin_unlock_irq(&desc->iuspin);
+ err("reading had resulted in %d", t);
+ rv = -EIO;
+ 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 */
+ spin_unlock_irq(&desc->iuspin);
+ goto retry;
+ }
+ clear_bit(WDM_READ, &desc->flags);
+ spin_unlock_irq(&desc->iuspin);
+ }
+
+ cntr = count > desc->length ? desc->length : count;
+ rv = copy_to_user(buffer, desc->ubuf, cntr);
+ if (rv > 0) {
+ rv = -EFAULT;
+ goto err;
+ }
+
+ for (i = 0; i < desc->length - cntr; i++)
+ desc->ubuf[i] = desc->ubuf[i + cntr];
+
+ desc->length -= cntr;
+ rv = cntr;
+
+err:
+ mutex_unlock(&desc->rlock);
+ if (rv < 0)
+ err("wdm_read: exit error");
+ return rv;
+}
+
+static int wdm_flush(struct file *file, fl_owner_t id)
+{
+ struct wdm_device *desc = file->private_data;
+
+ wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
+ if (desc->werr < 0)
+ err("Error in flush path: %d", desc->werr);
+
+ return desc->werr;
+}
+
+static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
+{
+ struct wdm_device *desc = file->private_data;
+ unsigned long flags;
+ unsigned int mask = 0;
+
+ spin_lock_irqsave(&desc->iuspin, flags);
+ if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
+ mask = POLLERR;
+ spin_unlock_irqrestore(&desc->iuspin, flags);
+ goto desc_out;
+ }
+ if (test_bit(WDM_READ, &desc->flags))
+ mask = POLLIN | POLLRDNORM;
+ if (desc->rerr || desc->werr)
+ mask |= POLLERR;
+ if (!test_bit(WDM_IN_USE, &desc->flags))
+ mask |= POLLOUT | POLLWRNORM;
+ 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);
+ intf = usb_find_interface(&wdm_driver, minor);
+ if (!intf)
+ goto out;
+
+ desc = usb_get_intfdata(intf);
+ if (test_bit(WDM_DISCONNECTING, &desc->flags))
+ goto out;
+
+ desc->count++;
+ file->private_data = desc;
+
+ rv = usb_submit_urb(desc->validity, GFP_KERNEL);
+
+ if (rv < 0) {
+ desc->count--;
+ err("Error submitting int urb - %d", rv);
+ goto out;
+ }
+ rv = 0;
+
+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);
+ desc->count--;
+ if (!desc->count) {
+ dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
+ kill_urbs(desc);
+ }
+ mutex_unlock(&wdm_mutex);
+ return 0;
+}
+
+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
+};
+
+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;
+
+ spin_lock_irqsave(&desc->iuspin, flags);
+ if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
+ spin_unlock_irqrestore(&desc->iuspin, flags);
+ } else {
+ spin_unlock_irqrestore(&desc->iuspin, flags);
+ rv = usb_submit_urb(desc->response, GFP_KERNEL);
+ if (rv < 0 && rv != -EPERM) {
+ spin_lock_irqsave(&desc->iuspin, flags);
+ if (!test_bit(WDM_DISCONNECTING, &desc->flags))
+ schedule_work(&desc->rxwork);
+ spin_unlock_irqrestore(&desc->iuspin, flags);
+ }
+ }
+}
+
+/* --- hotplug --- */
+
+static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
+{
+ int rv = -EINVAL;
+ struct usb_device *udev = interface_to_usbdev(intf);
+ struct wdm_device *desc;
+ struct usb_host_interface *iface;
+ struct usb_endpoint_descriptor *ep;
+ struct usb_cdc_dmm_desc *dmhd;
+ u8 *buffer = intf->altsetting->extra;
+ int buflen = intf->altsetting->extralen;
+ u16 maxcom = 0;
+
+ if (!buffer)
+ goto out;
+
+ while (buflen > 0) {
+ if (buffer [1] != USB_DT_CS_INTERFACE) {
+ err("skipping garbage");
+ goto next_desc;
+ }
+
+ switch (buffer [2]) {
+ case USB_CDC_HEADER_TYPE:
+ break;
+ case USB_CDC_DMM_TYPE:
+ dmhd = (struct usb_cdc_dmm_desc *)buffer;
+ maxcom = le16_to_cpu(dmhd->wMaxCommand);
+ dev_dbg(&intf->dev,
+ "Finding maximum buffer length: %d", maxcom);
+ break;
+ default:
+ err("Ignoring extra header, type %d, length %d",
+ buffer[2], buffer[0]);
+ break;
+ }
+next_desc:
+ buflen -= buffer[0];
+ buffer += buffer[0];
+ }
+
+ rv = -ENOMEM;
+ desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
+ if (!desc)
+ goto out;
+ mutex_init(&desc->wlock);
+ mutex_init(&desc->rlock);
+ spin_lock_init(&desc->iuspin);
+ init_waitqueue_head(&desc->wait);
+ desc->wMaxCommand = maxcom;
+ desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
+ desc->intf = intf;
+ INIT_WORK(&desc->rxwork, wdm_rxwork);
+
+ iface = &intf->altsetting[0];
+ ep = &iface->endpoint[0].desc;
+ if (!usb_endpoint_is_int_in(ep)) {
+ rv = -EINVAL;
+ goto err;
+ }
+
+ desc->wMaxPacketSize = ep->wMaxPacketSize;
+ desc->bMaxPacketSize0 = cpu_to_le16(udev->descriptor.bMaxPacketSize0);
+
+ 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 = usb_buffer_alloc(interface_to_usbdev(intf),
+ desc->wMaxPacketSize,
+ GFP_KERNEL,
+ &desc->validity->transfer_dma);
+ if (!desc->sbuf)
+ goto err;
+
+ desc->inbuf = usb_buffer_alloc(interface_to_usbdev(intf),
+ desc->bMaxPacketSize0,
+ GFP_KERNEL,
+ &desc->response->transfer_dma);
+ if (!desc->inbuf)
+ goto err2;
+
+ 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->validity->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+
+ usb_set_intfdata(intf, desc);
+ rv = usb_register_dev(intf, &wdm_class);
+ dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n",
+ intf->minor - WDM_MINOR_BASE);
+ if (rv < 0)
+ goto err;
+out:
+ return rv;
+err2:
+ usb_buffer_free(interface_to_usbdev(desc->intf),
+ desc->wMaxPacketSize,
+ desc->sbuf,
+ desc->validity->transfer_dma);
+err:
+ free_urbs(desc);
+ kfree(desc->ubuf);
+ kfree(desc->orq);
+ kfree(desc->irq);
+ kfree(desc);
+ return rv;
+}
+
+static void wdm_disconnect(struct usb_interface *intf)
+{
+ struct wdm_device *desc;
+ unsigned long flags;
+
+ usb_deregister_dev(intf, &wdm_class);
+ mutex_lock(&wdm_mutex);
+ desc = usb_get_intfdata(intf);
+
+ /* 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);
+ clear_bit(WDM_IN_USE, &desc->flags);
+ spin_unlock_irqrestore(&desc->iuspin, flags);
+ cancel_work_sync(&desc->rxwork);
+ kill_urbs(desc);
+ wake_up_all(&desc->wait);
+ if (!desc->count)
+ cleanup(desc);
+ mutex_unlock(&wdm_mutex);
+}
+
+static struct usb_driver wdm_driver = {
+ .name = "cdc_wdm",
+ .probe = wdm_probe,
+ .disconnect = wdm_disconnect,
+ .id_table = wdm_ids,
+};
+
+/* --- low level module stuff --- */
+
+static int __init wdm_init(void)
+{
+ int rv;
+
+ rv = usb_register(&wdm_driver);
+
+ return rv;
+}
+
+static void __exit wdm_exit(void)
+{
+ usb_deregister(&wdm_driver);
+}
+
+module_init(wdm_init);
+module_exit(wdm_exit);
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION("USB Abstract Control Model driver for "
+ "USB WCM Device Management");
+MODULE_LICENSE("GPL");
projects / GitHub / exynos8895 / android_kernel_samsung_universal8895.git / commitdiff