blob: 55f5b804d06924cd28cbaa8d6cd56cc1675c104f [file] [log] [blame]
/*
* 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;
atomic_t online;
atomic_t 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;
bool notify_close;
bool close_notified;
};
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_superspeed_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(1024),
};
static struct usb_ss_ep_comp_descriptor adb_superspeed_in_comp_desc = {
.bLength = sizeof adb_superspeed_in_comp_desc,
.bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
/* the following 2 values can be tweaked if necessary */
/* .bMaxBurst = 0, */
/* .bmAttributes = 0, */
};
static struct usb_endpoint_descriptor adb_superspeed_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(1024),
};
static struct usb_ss_ep_comp_descriptor adb_superspeed_out_comp_desc = {
.bLength = sizeof adb_superspeed_out_comp_desc,
.bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
/* the following 2 values can be tweaked if necessary */
/* .bMaxBurst = 0, */
/* .bmAttributes = 0, */
};
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,
};
static struct usb_descriptor_header *ss_adb_descs[] = {
(struct usb_descriptor_header *) &adb_interface_desc,
(struct usb_descriptor_header *) &adb_superspeed_in_desc,
(struct usb_descriptor_header *) &adb_superspeed_in_comp_desc,
(struct usb_descriptor_header *) &adb_superspeed_out_desc,
(struct usb_descriptor_header *) &adb_superspeed_out_comp_desc,
NULL,
};
static void adb_ready_callback(void);
static void adb_closed_callback(void);
/* 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)
atomic_set(&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 && req->status != -ECONNRESET)
atomic_set(&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 (!(atomic_read(&dev->online) || atomic_read(&dev->error))) {
pr_debug("adb_read: waiting for online state\n");
ret = wait_event_interruptible(dev->read_wq,
(atomic_read(&dev->online) ||
atomic_read(&dev->error)));
if (ret < 0) {
adb_unlock(&dev->read_excl);
return ret;
}
}
if (atomic_read(&dev->error)) {
r = -EIO;
goto done;
}
requeue_req:
/* queue a request */
req = dev->rx_req;
req->length = ADB_BULK_BUFFER_SIZE;
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;
atomic_set(&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 ||
atomic_read(&dev->error));
if (ret < 0) {
if (ret != -ERESTARTSYS)
atomic_set(&dev->error, 1);
r = ret;
usb_ep_dequeue(dev->ep_out, req);
goto done;
}
if (!atomic_read(&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:
if (atomic_read(&dev->error))
wake_up(&dev->write_wq);
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 (atomic_read(&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)) ||
atomic_read(&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);
atomic_set(&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);
if (atomic_read(&dev->error))
wake_up(&dev->read_wq);
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)
{
static DEFINE_RATELIMIT_STATE(rl, 10*HZ, 1);
if (__ratelimit(&rl))
pr_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 */
atomic_set(&_adb_dev->error, 0);
if (_adb_dev->close_notified) {
_adb_dev->close_notified = false;
adb_ready_callback();
}
_adb_dev->notify_close = true;
return 0;
}
static int adb_release(struct inode *ip, struct file *fp)
{
static DEFINE_RATELIMIT_STATE(rl, 10*HZ, 1);
if (__ratelimit(&rl))
pr_info("adb_release\n");
/*
* ADB daemon closes the device file after I/O error. The
* I/O error happen when Rx requests are flushed during
* cable disconnect or bus reset in configured state. Disabling
* USB configuration and pull-up during these scenarios are
* undesired. We want to force bus reset only for certain
* commands like "adb root" and "adb usb".
*/
if (_adb_dev->notify_close) {
adb_closed_callback();
_adb_dev->close_notified = true;
}
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;
}
/* support super speed hardware */
if (gadget_is_superspeed(c->cdev->gadget)) {
adb_superspeed_in_desc.bEndpointAddress =
adb_fullspeed_in_desc.bEndpointAddress;
adb_superspeed_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;
atomic_set(&dev->online, 0);
atomic_set(&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) {
dev->ep_in->desc = NULL;
ERROR(cdev, "config_ep_by_speed failes for ep %s, result %d\n",
dev->ep_in->name, ret);
return ret;
}
ret = usb_ep_enable(dev->ep_in);
if (ret) {
ERROR(cdev, "failed to enable ep %s, result %d\n",
dev->ep_in->name, ret);
return ret;
}
ret = config_ep_by_speed(cdev->gadget, f, dev->ep_out);
if (ret) {
dev->ep_out->desc = NULL;
ERROR(cdev, "config_ep_by_speed failes for ep %s, result %d\n",
dev->ep_out->name, ret);
usb_ep_disable(dev->ep_in);
return ret;
}
ret = usb_ep_enable(dev->ep_out);
if (ret) {
ERROR(cdev, "failed to enable ep %s, result %d\n",
dev->ep_out->name, ret);
usb_ep_disable(dev->ep_in);
return ret;
}
atomic_set(&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);
/*
* Bus reset happened or cable disconnected. No
* need to disable the configuration now. We will
* set noify_close to true when device file is re-opened.
*/
dev->notify_close = false;
atomic_set(&dev->online, 0);
atomic_set(&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;
pr_debug("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;
if (gadget_is_superspeed(c->cdev->gadget))
dev->function.ss_descriptors = ss_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);
/* config is disabled by default if adb is present. */
dev->close_notified = true;
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;
}