diff options
Diffstat (limited to 'drivers/usb/gadget/f_adb.c')
-rw-r--r-- | drivers/usb/gadget/f_adb.c | 685 |
1 files changed, 685 insertions, 0 deletions
diff --git a/drivers/usb/gadget/f_adb.c b/drivers/usb/gadget/f_adb.c new file mode 100644 index 000000000000..8cead67c3060 --- /dev/null +++ b/drivers/usb/gadget/f_adb.c @@ -0,0 +1,685 @@ +/* + * 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/types.h> +#include <linux/device.h> +#include <linux/miscdevice.h> +#include <linux/wakelock.h> + +#include <linux/usb/ch9.h> +#include <linux/usb/composite.h> +#include <linux/usb/gadget.h> + +#include "f_adb.h" + +#define ADB_BULK_BUFFER_SIZE 4096 + +/* number of rx and tx requests to allocate */ +#define RX_REQ_MAX 4 +#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; + struct list_head rx_idle; + struct list_head rx_done; + + wait_queue_head_t read_wq; + wait_queue_head_t write_wq; + + /* the request we're currently reading from */ + struct usb_request *read_req; + unsigned char *read_buf; + unsigned read_count; + + struct wake_lock wake_lock; +}; + +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, +}; + +/* used when adb function is disabled */ +static struct usb_descriptor_header *null_adb_descs[] = { + NULL, +}; + + +/* temporary variable used between adb_open() and adb_gadget_bind() */ +static struct adb_dev *_adb_dev; + +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; + + if (req->status != 0) { + dev->error = 1; + req_put(dev, &dev->rx_idle, req); + } else { + req_put(dev, &dev->rx_done, req); + } + + 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); + 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); + dev->ep_out = ep; + + /* now allocate requests for our endpoints */ + for (i = 0; i < RX_REQ_MAX; i++) { + req = adb_request_new(dev->ep_out, ADB_BULK_BUFFER_SIZE); + if (!req) + goto fail; + req->complete = adb_complete_out; + req_put(dev, &dev->rx_idle, 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; + 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 (_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; + } + } + + while (count > 0) { + if (dev->error) { + DBG(cdev, "adb_read dev->error\n"); + r = -EIO; + break; + } + + /* if we have idle read requests, get them queued */ + while ((req = req_get(dev, &dev->rx_idle))) { +requeue_req: + req->length = ADB_BULK_BUFFER_SIZE; + ret = usb_ep_queue(dev->ep_out, req, GFP_ATOMIC); + + if (ret < 0) { + r = -EIO; + dev->error = 1; + req_put(dev, &dev->rx_idle, req); + goto fail; + } else { + DBG(cdev, "rx %p queue\n", req); + } + } + + /* if we have data pending, give it to userspace */ + if (dev->read_count > 0) { + if (dev->read_count < count) + xfer = dev->read_count; + else + xfer = count; + + if (copy_to_user(buf, dev->read_buf, xfer)) { + r = -EFAULT; + break; + } + dev->read_buf += xfer; + dev->read_count -= xfer; + buf += xfer; + count -= xfer; + + /* if we've emptied the buffer, release the request */ + if (dev->read_count == 0) { + req_put(dev, &dev->rx_idle, dev->read_req); + dev->read_req = 0; + } + continue; + } + + /* wait for a request to complete */ + req = 0; + ret = wait_event_interruptible(dev->read_wq, + ((req = req_get(dev, &dev->rx_done)) || dev->error)); + if (req != 0) { + /* if we got a 0-len one we need to put it back into + ** service. if we made it the current read req we'd + ** be stuck forever + */ + if (req->actual == 0) + goto requeue_req; + + dev->read_req = req; + dev->read_count = req->actual; + dev->read_buf = req->buf; + DBG(cdev, "rx %p %d\n", req, req->actual); + } + + if (ret < 0) { + r = ret; + break; + } + } + +fail: + _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 > 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) { + 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 __init +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); + + while ((req = req_get(dev, &dev->rx_idle))) + adb_request_free(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); + 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; + + wake_lock(&dev->wake_lock); + /* 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 void adb_function_suspend(struct usb_function *f) +{ + struct adb_dev *dev = func_to_dev(f); + struct usb_composite_dev *cdev = dev->cdev; + wake_unlock(&dev->wake_lock); + DBG(cdev, "adb function suspend\n"); +} + +int __init adb_function_add(struct usb_composite_dev *cdev, + struct usb_configuration *c) +{ + struct adb_dev *dev; + int ret; + + printk(KERN_INFO "adb_function_add\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->rx_idle); + INIT_LIST_HEAD(&dev->rx_done); + INIT_LIST_HEAD(&dev->tx_idle); + + wake_lock_init(&dev->wake_lock, WAKE_LOCK_SUSPEND, + "usb_adb"); + + dev->cdev = cdev; + dev->function.name = "adb"; + dev->function.descriptors = null_adb_descs; + dev->function.hs_descriptors = null_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; + dev->function.suspend = adb_function_suspend; + + /* _adb_dev must be set before calling usb_gadget_register_driver */ + _adb_dev = dev; + + ret = misc_register(&adb_device); + if (ret) + goto err1; + ret = usb_add_function(c, &dev->function); + if (ret) + goto err2; + + return 0; + +err2: + misc_deregister(&adb_device); +err1: + wake_lock_destroy(&dev->wake_lock); + kfree(dev); + printk(KERN_ERR "adb gadget driver failed to initialize\n"); + return ret; +} + +void adb_function_enable(int enable) +{ + struct adb_dev *dev = _adb_dev; + + if (dev) { + DBG(dev->cdev, "adb_function_enable(%s)\n", + enable ? "true" : "false"); + + if (enable) { + dev->function.descriptors = fs_adb_descs; + dev->function.hs_descriptors = hs_adb_descs; + } else { + dev->function.descriptors = null_adb_descs; + dev->function.hs_descriptors = null_adb_descs; + } + } +} + |