usb: gadget: adb: Add ADB function
authorBenoit Goby <benoit@android.com>
Mon, 19 Dec 2011 22:38:41 +0000 (14:38 -0800)
committerJohn Stultz <john.stultz@linaro.org>
Tue, 16 Feb 2016 21:51:52 +0000 (13:51 -0800)
Android Debug Bridge (adb) is a command line tool that lets
users communicate with a Android-powered device. It is used
mainly to debug applications and tranfer files. f_adb implements
the transport layer between the ADB Server (on the host) and the
ADBD daemon (on the device).

Change-Id: Ib11672fa3439dcb3a6588774b132b5a85e03e8ba
Signed-off-by: Mike Lockwood <lockwood@android.com>
drivers/usb/gadget/f_adb.c [new file with mode: 0644]

diff --git a/drivers/usb/gadget/f_adb.c b/drivers/usb/gadget/f_adb.c
new file mode 100644 (file)
index 0000000..5415353
--- /dev/null
@@ -0,0 +1,611 @@
+/*
+ * 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;
+}