- 根目录:
- drivers
- usb
- gadget
- f_adb.c
/*
* 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.
*
*/
/* #define DEBUG */
/* #define VERBOSE_DEBUG */
#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>
#include <linux/usb/android_composite.h>
#define BULK_BUFFER_SIZE 4096
/* number of tx requests to allocate */
#define TX_REQ_MAX 4
static const char 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 atomic_t adb_enable_excl;
static inline struct adb_dev *func_to_dev(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 _lock(atomic_t *excl)
{
if (atomic_inc_return(excl) == 1) {
return 0;
} else {
atomic_dec(excl);
return -1;
}
}
static inline void _unlock(atomic_t *excl)
{
atomic_dec(excl);
}
/* add a request to the tail of a list */
void 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 *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;
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 __init 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, 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, BULK_BUFFER_SIZE);
if (!req)
goto fail;
req->complete = adb_complete_in;
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_composite_dev *cdev = dev->cdev;
struct usb_request *req;
int r = count, xfer;
int ret;
DBG(cdev, "adb_read(%d)\n", count);
if (count > BULK_BUFFER_SIZE)
return -EINVAL;
if (_lock(&dev->read_excl))
return -EBUSY;
/* we will block until we're online */
while (!(dev->online || dev->error)) {
DBG(cdev, "adb_read: waiting for online state\n");
ret = wait_event_interruptible(dev->read_wq,
(dev->online || dev->error));
if (ret < 0) {
_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) {
DBG(cdev, "adb_read: failed to queue req %p (%d)\n", req, ret);
r = -EIO;
dev->error = 1;
goto done;
} else {
DBG(cdev, "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;
DBG(cdev, "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:
_unlock(&dev->read_excl);
DBG(cdev, "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_composite_dev *cdev = dev->cdev;
struct usb_request *req = 0;
int r = count, xfer;
int ret;
DBG(cdev, "adb_write(%d)\n", count);
if (_lock(&dev->write_excl))
return -EBUSY;
while (count > 0) {
if (dev->error) {
DBG(cdev, "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 = req_get(dev, &dev->tx_idle)) || dev->error));
if (ret < 0) {
r = ret;
break;
}
if (req != 0) {
if (count > BULK_BUFFER_SIZE)
xfer = 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) {
DBG(cdev, "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)
req_put(dev, &dev->tx_idle, req);
_unlock(&dev->write_excl);
DBG(cdev, "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 (_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");
_unlock(&_adb_dev->open_excl);
return 0;
}
/* file operations for ADB device /dev/android_adb */
static 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 = shortname,
.fops = &adb_fops,
};
static int adb_enable_open(struct inode *ip, struct file *fp)
{
if (atomic_inc_return(&adb_enable_excl) != 1) {
atomic_dec(&adb_enable_excl);
return -EBUSY;
}
printk(KERN_INFO "enabling adb\n");
android_enable_function(&_adb_dev->function, 1);
return 0;
}
static int adb_enable_release(struct inode *ip, struct file *fp)
{
printk(KERN_INFO "disabling adb\n");
android_enable_function(&_adb_dev->function, 0);
atomic_dec(&adb_enable_excl);
return 0;
}
static const struct file_operations adb_enable_fops = {
.owner = THIS_MODULE,
.open = adb_enable_open,
.release = adb_enable_release,
};
static struct miscdevice adb_enable_device = {
.minor = MISC_DYNAMIC_MINOR,
.name = "android_adb_enable",
.fops = &adb_enable_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_dev(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 = 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_dev(f);
struct usb_request *req;
spin_lock_irq(&dev->lock);
adb_request_free(dev->rx_req, dev->ep_out);
while ((req = req_get(dev, &dev->tx_idle)))
adb_request_free(req, dev->ep_in);
dev->online = 0;
dev->error = 1;
spin_unlock_irq(&dev->lock);
misc_deregister(&adb_device);
misc_deregister(&adb_enable_device);
kfree(_adb_dev);
_adb_dev = NULL;
}
static int adb_function_set_alt(struct usb_function *f,
unsigned intf, unsigned alt)
{
struct adb_dev *dev = func_to_dev(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 = usb_ep_enable(dev->ep_in,
ep_choose(cdev->gadget,
&adb_highspeed_in_desc,
&adb_fullspeed_in_desc));
if (ret)
return ret;
ret = usb_ep_enable(dev->ep_out,
ep_choose(cdev->gadget,
&adb_highspeed_out_desc,
&adb_fullspeed_out_desc));
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_dev(f);
struct usb_composite_dev *cdev = dev->cdev;
DBG(cdev, "adb_function_disable\n");
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;
int ret;
printk(KERN_INFO "adb_bind_config\n");
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);
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;
/* start disabled */
dev->function.disabled = 1;
/* _adb_dev must be set before calling usb_gadget_register_driver */
_adb_dev = dev;
ret = misc_register(&adb_device);
if (ret)
goto err1;
ret = misc_register(&adb_enable_device);
if (ret)
goto err2;
ret = usb_add_function(c, &dev->function);
if (ret)
goto err3;
return 0;
err3:
misc_deregister(&adb_enable_device);
err2:
misc_deregister(&adb_device);
err1:
kfree(dev);
printk(KERN_ERR "adb gadget driver failed to initialize\n");
return ret;
}
static struct android_usb_function adb_function = {
.name = "adb",
.bind_config = adb_bind_config,
};
static int __init init(void)
{
printk(KERN_INFO "f_adb init\n");
android_register_function(&adb_function);
return 0;
}
module_init(init);