--- /dev/null
+/*
+ * Gadget Driver for Android ADB
+ *
+ * Copyright (C) 2008 Google, Inc.
+ * Author: Mike Lockwood <lockwood@android.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/poll.h>
+#include <linux/delay.h>
+#include <linux/wait.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/miscdevice.h>
+
+#define ADB_BULK_BUFFER_SIZE 4096
+
+/* number of tx requests to allocate */
+#define TX_REQ_MAX 4
+
+static const char adb_shortname[] = "android_adb";
+
+struct adb_dev {
+ struct usb_function function;
+ struct usb_composite_dev *cdev;
+ spinlock_t lock;
+
+ struct usb_ep *ep_in;
+ struct usb_ep *ep_out;
+
+ int online;
+ int error;
+
+ atomic_t read_excl;
+ atomic_t write_excl;
+ atomic_t open_excl;
+
+ struct list_head tx_idle;
+
+ wait_queue_head_t read_wq;
+ wait_queue_head_t write_wq;
+ struct usb_request *rx_req;
+ int rx_done;
+};
+
+static struct usb_interface_descriptor adb_interface_desc = {
+ .bLength = USB_DT_INTERFACE_SIZE,
+ .bDescriptorType = USB_DT_INTERFACE,
+ .bInterfaceNumber = 0,
+ .bNumEndpoints = 2,
+ .bInterfaceClass = 0xFF,
+ .bInterfaceSubClass = 0x42,
+ .bInterfaceProtocol = 1,
+};
+
+static struct usb_endpoint_descriptor adb_highspeed_in_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+ .bEndpointAddress = USB_DIR_IN,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = __constant_cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor adb_highspeed_out_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+ .bEndpointAddress = USB_DIR_OUT,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = __constant_cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor adb_fullspeed_in_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+ .bEndpointAddress = USB_DIR_IN,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_endpoint_descriptor adb_fullspeed_out_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+ .bEndpointAddress = USB_DIR_OUT,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_descriptor_header *fs_adb_descs[] = {
+ (struct usb_descriptor_header *) &adb_interface_desc,
+ (struct usb_descriptor_header *) &adb_fullspeed_in_desc,
+ (struct usb_descriptor_header *) &adb_fullspeed_out_desc,
+ NULL,
+};
+
+static struct usb_descriptor_header *hs_adb_descs[] = {
+ (struct usb_descriptor_header *) &adb_interface_desc,
+ (struct usb_descriptor_header *) &adb_highspeed_in_desc,
+ (struct usb_descriptor_header *) &adb_highspeed_out_desc,
+ NULL,
+};
+
+
+/* temporary variable used between adb_open() and adb_gadget_bind() */
+static struct adb_dev *_adb_dev;
+
+static inline struct adb_dev *func_to_adb(struct usb_function *f)
+{
+ return container_of(f, struct adb_dev, function);
+}
+
+
+static struct usb_request *adb_request_new(struct usb_ep *ep, int buffer_size)
+{
+ struct usb_request *req = usb_ep_alloc_request(ep, GFP_KERNEL);
+ if (!req)
+ return NULL;
+
+ /* now allocate buffers for the requests */
+ req->buf = kmalloc(buffer_size, GFP_KERNEL);
+ if (!req->buf) {
+ usb_ep_free_request(ep, req);
+ return NULL;
+ }
+
+ return req;
+}
+
+static void adb_request_free(struct usb_request *req, struct usb_ep *ep)
+{
+ if (req) {
+ kfree(req->buf);
+ usb_ep_free_request(ep, req);
+ }
+}
+
+static inline int adb_lock(atomic_t *excl)
+{
+ if (atomic_inc_return(excl) == 1) {
+ return 0;
+ } else {
+ atomic_dec(excl);
+ return -1;
+ }
+}
+
+static inline void adb_unlock(atomic_t *excl)
+{
+ atomic_dec(excl);
+}
+
+/* add a request to the tail of a list */
+void adb_req_put(struct adb_dev *dev, struct list_head *head,
+ struct usb_request *req)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev->lock, flags);
+ list_add_tail(&req->list, head);
+ spin_unlock_irqrestore(&dev->lock, flags);
+}
+
+/* remove a request from the head of a list */
+struct usb_request *adb_req_get(struct adb_dev *dev, struct list_head *head)
+{
+ unsigned long flags;
+ struct usb_request *req;
+
+ spin_lock_irqsave(&dev->lock, flags);
+ if (list_empty(head)) {
+ req = 0;
+ } else {
+ req = list_first_entry(head, struct usb_request, list);
+ list_del(&req->list);
+ }
+ spin_unlock_irqrestore(&dev->lock, flags);
+ return req;
+}
+
+static void adb_complete_in(struct usb_ep *ep, struct usb_request *req)
+{
+ struct adb_dev *dev = _adb_dev;
+
+ if (req->status != 0)
+ dev->error = 1;
+
+ adb_req_put(dev, &dev->tx_idle, req);
+
+ wake_up(&dev->write_wq);
+}
+
+static void adb_complete_out(struct usb_ep *ep, struct usb_request *req)
+{
+ struct adb_dev *dev = _adb_dev;
+
+ dev->rx_done = 1;
+ if (req->status != 0)
+ dev->error = 1;
+
+ wake_up(&dev->read_wq);
+}
+
+static int adb_create_bulk_endpoints(struct adb_dev *dev,
+ struct usb_endpoint_descriptor *in_desc,
+ struct usb_endpoint_descriptor *out_desc)
+{
+ struct usb_composite_dev *cdev = dev->cdev;
+ struct usb_request *req;
+ struct usb_ep *ep;
+ int i;
+
+ DBG(cdev, "create_bulk_endpoints dev: %p\n", dev);
+
+ ep = usb_ep_autoconfig(cdev->gadget, in_desc);
+ if (!ep) {
+ DBG(cdev, "usb_ep_autoconfig for ep_in failed\n");
+ return -ENODEV;
+ }
+ DBG(cdev, "usb_ep_autoconfig for ep_in got %s\n", ep->name);
+ ep->driver_data = dev; /* claim the endpoint */
+ dev->ep_in = ep;
+
+ ep = usb_ep_autoconfig(cdev->gadget, out_desc);
+ if (!ep) {
+ DBG(cdev, "usb_ep_autoconfig for ep_out failed\n");
+ return -ENODEV;
+ }
+ DBG(cdev, "usb_ep_autoconfig for adb ep_out got %s\n", ep->name);
+ ep->driver_data = dev; /* claim the endpoint */
+ dev->ep_out = ep;
+
+ /* now allocate requests for our endpoints */
+ req = adb_request_new(dev->ep_out, ADB_BULK_BUFFER_SIZE);
+ if (!req)
+ goto fail;
+ req->complete = adb_complete_out;
+ dev->rx_req = req;
+
+ for (i = 0; i < TX_REQ_MAX; i++) {
+ req = adb_request_new(dev->ep_in, ADB_BULK_BUFFER_SIZE);
+ if (!req)
+ goto fail;
+ req->complete = adb_complete_in;
+ adb_req_put(dev, &dev->tx_idle, req);
+ }
+
+ return 0;
+
+fail:
+ printk(KERN_ERR "adb_bind() could not allocate requests\n");
+ return -1;
+}
+
+static ssize_t adb_read(struct file *fp, char __user *buf,
+ size_t count, loff_t *pos)
+{
+ struct adb_dev *dev = fp->private_data;
+ struct usb_request *req;
+ int r = count, xfer;
+ int ret;
+
+ pr_debug("adb_read(%d)\n", count);
+ if (!_adb_dev)
+ return -ENODEV;
+
+ if (count > ADB_BULK_BUFFER_SIZE)
+ return -EINVAL;
+
+ if (adb_lock(&dev->read_excl))
+ return -EBUSY;
+
+ /* we will block until we're online */
+ while (!(dev->online || dev->error)) {
+ pr_debug("adb_read: waiting for online state\n");
+ ret = wait_event_interruptible(dev->read_wq,
+ (dev->online || dev->error));
+ if (ret < 0) {
+ adb_unlock(&dev->read_excl);
+ return ret;
+ }
+ }
+ if (dev->error) {
+ r = -EIO;
+ goto done;
+ }
+
+requeue_req:
+ /* queue a request */
+ req = dev->rx_req;
+ req->length = count;
+ dev->rx_done = 0;
+ ret = usb_ep_queue(dev->ep_out, req, GFP_ATOMIC);
+ if (ret < 0) {
+ pr_debug("adb_read: failed to queue req %p (%d)\n", req, ret);
+ r = -EIO;
+ dev->error = 1;
+ goto done;
+ } else {
+ pr_debug("rx %p queue\n", req);
+ }
+
+ /* wait for a request to complete */
+ ret = wait_event_interruptible(dev->read_wq, dev->rx_done);
+ if (ret < 0) {
+ dev->error = 1;
+ r = ret;
+ usb_ep_dequeue(dev->ep_out, req);
+ goto done;
+ }
+ if (!dev->error) {
+ /* If we got a 0-len packet, throw it back and try again. */
+ if (req->actual == 0)
+ goto requeue_req;
+
+ pr_debug("rx %p %d\n", req, req->actual);
+ xfer = (req->actual < count) ? req->actual : count;
+ if (copy_to_user(buf, req->buf, xfer))
+ r = -EFAULT;
+
+ } else
+ r = -EIO;
+
+done:
+ adb_unlock(&dev->read_excl);
+ pr_debug("adb_read returning %d\n", r);
+ return r;
+}
+
+static ssize_t adb_write(struct file *fp, const char __user *buf,
+ size_t count, loff_t *pos)
+{
+ struct adb_dev *dev = fp->private_data;
+ struct usb_request *req = 0;
+ int r = count, xfer;
+ int ret;
+
+ if (!_adb_dev)
+ return -ENODEV;
+ pr_debug("adb_write(%d)\n", count);
+
+ if (adb_lock(&dev->write_excl))
+ return -EBUSY;
+
+ while (count > 0) {
+ if (dev->error) {
+ pr_debug("adb_write dev->error\n");
+ r = -EIO;
+ break;
+ }
+
+ /* get an idle tx request to use */
+ req = 0;
+ ret = wait_event_interruptible(dev->write_wq,
+ (req = adb_req_get(dev, &dev->tx_idle)) || dev->error);
+
+ if (ret < 0) {
+ r = ret;
+ break;
+ }
+
+ if (req != 0) {
+ if (count > ADB_BULK_BUFFER_SIZE)
+ xfer = ADB_BULK_BUFFER_SIZE;
+ else
+ xfer = count;
+ if (copy_from_user(req->buf, buf, xfer)) {
+ r = -EFAULT;
+ break;
+ }
+
+ req->length = xfer;
+ ret = usb_ep_queue(dev->ep_in, req, GFP_ATOMIC);
+ if (ret < 0) {
+ pr_debug("adb_write: xfer error %d\n", ret);
+ dev->error = 1;
+ r = -EIO;
+ break;
+ }
+
+ buf += xfer;
+ count -= xfer;
+
+ /* zero this so we don't try to free it on error exit */
+ req = 0;
+ }
+ }
+
+ if (req)
+ adb_req_put(dev, &dev->tx_idle, req);
+
+ adb_unlock(&dev->write_excl);
+ pr_debug("adb_write returning %d\n", r);
+ return r;
+}
+
+static int adb_open(struct inode *ip, struct file *fp)
+{
+ printk(KERN_INFO "adb_open\n");
+ if (!_adb_dev)
+ return -ENODEV;
+
+ if (adb_lock(&_adb_dev->open_excl))
+ return -EBUSY;
+
+ fp->private_data = _adb_dev;
+
+ /* clear the error latch */
+ _adb_dev->error = 0;
+
+ return 0;
+}
+
+static int adb_release(struct inode *ip, struct file *fp)
+{
+ printk(KERN_INFO "adb_release\n");
+ adb_unlock(&_adb_dev->open_excl);
+ return 0;
+}
+
+/* file operations for ADB device /dev/android_adb */
+static const struct file_operations adb_fops = {
+ .owner = THIS_MODULE,
+ .read = adb_read,
+ .write = adb_write,
+ .open = adb_open,
+ .release = adb_release,
+};
+
+static struct miscdevice adb_device = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = adb_shortname,
+ .fops = &adb_fops,
+};
+
+
+
+
+static int
+adb_function_bind(struct usb_configuration *c, struct usb_function *f)
+{
+ struct usb_composite_dev *cdev = c->cdev;
+ struct adb_dev *dev = func_to_adb(f);
+ int id;
+ int ret;
+
+ dev->cdev = cdev;
+ DBG(cdev, "adb_function_bind dev: %p\n", dev);
+
+ /* allocate interface ID(s) */
+ id = usb_interface_id(c, f);
+ if (id < 0)
+ return id;
+ adb_interface_desc.bInterfaceNumber = id;
+
+ /* allocate endpoints */
+ ret = adb_create_bulk_endpoints(dev, &adb_fullspeed_in_desc,
+ &adb_fullspeed_out_desc);
+ if (ret)
+ return ret;
+
+ /* support high speed hardware */
+ if (gadget_is_dualspeed(c->cdev->gadget)) {
+ adb_highspeed_in_desc.bEndpointAddress =
+ adb_fullspeed_in_desc.bEndpointAddress;
+ adb_highspeed_out_desc.bEndpointAddress =
+ adb_fullspeed_out_desc.bEndpointAddress;
+ }
+
+ DBG(cdev, "%s speed %s: IN/%s, OUT/%s\n",
+ gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
+ f->name, dev->ep_in->name, dev->ep_out->name);
+ return 0;
+}
+
+static void
+adb_function_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+ struct adb_dev *dev = func_to_adb(f);
+ struct usb_request *req;
+
+
+ dev->online = 0;
+ dev->error = 1;
+
+ wake_up(&dev->read_wq);
+
+ adb_request_free(dev->rx_req, dev->ep_out);
+ while ((req = adb_req_get(dev, &dev->tx_idle)))
+ adb_request_free(req, dev->ep_in);
+}
+
+static int adb_function_set_alt(struct usb_function *f,
+ unsigned intf, unsigned alt)
+{
+ struct adb_dev *dev = func_to_adb(f);
+ struct usb_composite_dev *cdev = f->config->cdev;
+ int ret;
+
+ DBG(cdev, "adb_function_set_alt intf: %d alt: %d\n", intf, alt);
+
+ ret = config_ep_by_speed(cdev->gadget, f, dev->ep_in);
+ if (ret)
+ return ret;
+
+ ret = usb_ep_enable(dev->ep_in);
+ if (ret)
+ return ret;
+
+ ret = config_ep_by_speed(cdev->gadget, f, dev->ep_out);
+ if (ret)
+ return ret;
+
+ ret = usb_ep_enable(dev->ep_out);
+ if (ret) {
+ usb_ep_disable(dev->ep_in);
+ return ret;
+ }
+ dev->online = 1;
+
+ /* readers may be blocked waiting for us to go online */
+ wake_up(&dev->read_wq);
+ return 0;
+}
+
+static void adb_function_disable(struct usb_function *f)
+{
+ struct adb_dev *dev = func_to_adb(f);
+ struct usb_composite_dev *cdev = dev->cdev;
+
+ DBG(cdev, "adb_function_disable cdev %p\n", cdev);
+ dev->online = 0;
+ dev->error = 1;
+ usb_ep_disable(dev->ep_in);
+ usb_ep_disable(dev->ep_out);
+
+ /* readers may be blocked waiting for us to go online */
+ wake_up(&dev->read_wq);
+
+ VDBG(cdev, "%s disabled\n", dev->function.name);
+}
+
+static int adb_bind_config(struct usb_configuration *c)
+{
+ struct adb_dev *dev = _adb_dev;
+
+ printk(KERN_INFO "adb_bind_config\n");
+
+ dev->cdev = c->cdev;
+ dev->function.name = "adb";
+ dev->function.descriptors = fs_adb_descs;
+ dev->function.hs_descriptors = hs_adb_descs;
+ dev->function.bind = adb_function_bind;
+ dev->function.unbind = adb_function_unbind;
+ dev->function.set_alt = adb_function_set_alt;
+ dev->function.disable = adb_function_disable;
+
+ return usb_add_function(c, &dev->function);
+}
+
+static int adb_setup(void)
+{
+ struct adb_dev *dev;
+ int ret;
+
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ return -ENOMEM;
+
+ spin_lock_init(&dev->lock);
+
+ init_waitqueue_head(&dev->read_wq);
+ init_waitqueue_head(&dev->write_wq);
+
+ atomic_set(&dev->open_excl, 0);
+ atomic_set(&dev->read_excl, 0);
+ atomic_set(&dev->write_excl, 0);
+
+ INIT_LIST_HEAD(&dev->tx_idle);
+
+ _adb_dev = dev;
+
+ ret = misc_register(&adb_device);
+ if (ret)
+ goto err;
+
+ return 0;
+
+err:
+ kfree(dev);
+ printk(KERN_ERR "adb gadget driver failed to initialize\n");
+ return ret;
+}
+
+static void adb_cleanup(void)
+{
+ misc_deregister(&adb_device);
+
+ kfree(_adb_dev);
+ _adb_dev = NULL;
+}