diff options
Diffstat (limited to 'drivers/usb/gadget/f_accessory.c')
| -rw-r--r-- | drivers/usb/gadget/f_accessory.c | 792 |
1 files changed, 792 insertions, 0 deletions
diff --git a/drivers/usb/gadget/f_accessory.c b/drivers/usb/gadget/f_accessory.c new file mode 100644 index 000000000000..05e65e5cd704 --- /dev/null +++ b/drivers/usb/gadget/f_accessory.c @@ -0,0 +1,792 @@ +/* + * Gadget Function Driver for Android USB accessories + * + * Copyright (C) 2011 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/kthread.h> +#include <linux/freezer.h> + +#include <linux/types.h> +#include <linux/file.h> +#include <linux/device.h> +#include <linux/miscdevice.h> + +#include <linux/usb.h> +#include <linux/usb/ch9.h> +#include <linux/usb/f_accessory.h> + +#define BULK_BUFFER_SIZE 16384 +#define ACC_STRING_SIZE 256 + +#define PROTOCOL_VERSION 1 + +/* String IDs */ +#define INTERFACE_STRING_INDEX 0 + +/* number of tx and rx requests to allocate */ +#define TX_REQ_MAX 4 +#define RX_REQ_MAX 2 + +struct acc_dev { + struct usb_function function; + struct usb_composite_dev *cdev; + spinlock_t lock; + + struct usb_ep *ep_in; + struct usb_ep *ep_out; + + /* set to 1 when we connect */ + int online:1; + /* Set to 1 when we disconnect. + * Not cleared until our file is closed. + */ + int disconnected:1; + + /* strings sent by the host */ + char manufacturer[ACC_STRING_SIZE]; + char model[ACC_STRING_SIZE]; + char description[ACC_STRING_SIZE]; + char version[ACC_STRING_SIZE]; + char uri[ACC_STRING_SIZE]; + char serial[ACC_STRING_SIZE]; + + /* for acc_complete_set_string */ + int string_index; + + /* set to 1 if we have a pending start request */ + int start_requested; + + /* synchronize access to our device file */ + 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[RX_REQ_MAX]; + int rx_done; + struct delayed_work work; +}; + +static struct usb_interface_descriptor acc_interface_desc = { + .bLength = USB_DT_INTERFACE_SIZE, + .bDescriptorType = USB_DT_INTERFACE, + .bInterfaceNumber = 0, + .bNumEndpoints = 2, + .bInterfaceClass = USB_CLASS_VENDOR_SPEC, + .bInterfaceSubClass = USB_SUBCLASS_VENDOR_SPEC, + .bInterfaceProtocol = 0, +}; + +static struct usb_endpoint_descriptor acc_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 acc_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 acc_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 acc_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_acc_descs[] = { + (struct usb_descriptor_header *) &acc_interface_desc, + (struct usb_descriptor_header *) &acc_fullspeed_in_desc, + (struct usb_descriptor_header *) &acc_fullspeed_out_desc, + NULL, +}; + +static struct usb_descriptor_header *hs_acc_descs[] = { + (struct usb_descriptor_header *) &acc_interface_desc, + (struct usb_descriptor_header *) &acc_highspeed_in_desc, + (struct usb_descriptor_header *) &acc_highspeed_out_desc, + NULL, +}; + +static struct usb_string acc_string_defs[] = { + [INTERFACE_STRING_INDEX].s = "Android Accessory Interface", + { }, /* end of list */ +}; + +static struct usb_gadget_strings acc_string_table = { + .language = 0x0409, /* en-US */ + .strings = acc_string_defs, +}; + +static struct usb_gadget_strings *acc_strings[] = { + &acc_string_table, + NULL, +}; + +/* temporary variable used between acc_open() and acc_gadget_bind() */ +static struct acc_dev *_acc_dev; + +static inline struct acc_dev *func_to_dev(struct usb_function *f) +{ + return container_of(f, struct acc_dev, function); +} + +static struct usb_request *acc_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 acc_request_free(struct usb_request *req, struct usb_ep *ep) +{ + if (req) { + kfree(req->buf); + usb_ep_free_request(ep, req); + } +} + +/* add a request to the tail of a list */ +static void req_put(struct acc_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 */ +static struct usb_request *req_get(struct acc_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 acc_set_disconnected(struct acc_dev *dev) +{ + dev->online = 0; + dev->disconnected = 1; +} + +static void acc_complete_in(struct usb_ep *ep, struct usb_request *req) +{ + struct acc_dev *dev = _acc_dev; + + if (req->status != 0) + acc_set_disconnected(dev); + + req_put(dev, &dev->tx_idle, req); + + wake_up(&dev->write_wq); +} + +static void acc_complete_out(struct usb_ep *ep, struct usb_request *req) +{ + struct acc_dev *dev = _acc_dev; + + dev->rx_done = 1; + if (req->status != 0) + acc_set_disconnected(dev); + + wake_up(&dev->read_wq); +} + +static void acc_complete_set_string(struct usb_ep *ep, struct usb_request *req) +{ + struct acc_dev *dev = ep->driver_data; + char *string_dest = NULL; + int length = req->actual; + + if (req->status != 0) { + pr_err("acc_complete_set_string, err %d\n", req->status); + return; + } + + switch (dev->string_index) { + case ACCESSORY_STRING_MANUFACTURER: + string_dest = dev->manufacturer; + break; + case ACCESSORY_STRING_MODEL: + string_dest = dev->model; + break; + case ACCESSORY_STRING_DESCRIPTION: + string_dest = dev->description; + break; + case ACCESSORY_STRING_VERSION: + string_dest = dev->version; + break; + case ACCESSORY_STRING_URI: + string_dest = dev->uri; + break; + case ACCESSORY_STRING_SERIAL: + string_dest = dev->serial; + break; + } + if (string_dest) { + unsigned long flags; + + if (length >= ACC_STRING_SIZE) + length = ACC_STRING_SIZE - 1; + + spin_lock_irqsave(&dev->lock, flags); + memcpy(string_dest, req->buf, length); + /* ensure zero termination */ + string_dest[length] = 0; + spin_unlock_irqrestore(&dev->lock, flags); + } else { + pr_err("unknown accessory string index %d\n", + dev->string_index); + } +} + +static int __init create_bulk_endpoints(struct acc_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 ep_out got %s\n", ep->name); + ep->driver_data = dev; /* claim the endpoint */ + dev->ep_out = 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 ep_out got %s\n", ep->name); + ep->driver_data = dev; /* claim the endpoint */ + dev->ep_out = ep; + + /* now allocate requests for our endpoints */ + for (i = 0; i < TX_REQ_MAX; i++) { + req = acc_request_new(dev->ep_in, BULK_BUFFER_SIZE); + if (!req) + goto fail; + req->complete = acc_complete_in; + req_put(dev, &dev->tx_idle, req); + } + for (i = 0; i < RX_REQ_MAX; i++) { + req = acc_request_new(dev->ep_out, BULK_BUFFER_SIZE); + if (!req) + goto fail; + req->complete = acc_complete_out; + dev->rx_req[i] = req; + } + + return 0; + +fail: + printk(KERN_ERR "acc_bind() could not allocate requests\n"); + while ((req = req_get(dev, &dev->tx_idle))) + acc_request_free(req, dev->ep_in); + for (i = 0; i < RX_REQ_MAX; i++) + acc_request_free(dev->rx_req[i], dev->ep_out); + return -1; +} + +static ssize_t acc_read(struct file *fp, char __user *buf, + size_t count, loff_t *pos) +{ + struct acc_dev *dev = fp->private_data; + struct usb_request *req; + int r = count, xfer; + int ret = 0; + + pr_debug("acc_read(%d)\n", count); + + if (dev->disconnected) + return -ENODEV; + + if (count > BULK_BUFFER_SIZE) + count = BULK_BUFFER_SIZE; + + /* we will block until we're online */ + pr_debug("acc_read: waiting for online\n"); + ret = wait_event_interruptible(dev->read_wq, dev->online); + if (ret < 0) { + r = ret; + goto done; + } + +requeue_req: + /* queue a request */ + req = dev->rx_req[0]; + req->length = count; + dev->rx_done = 0; + ret = usb_ep_queue(dev->ep_out, req, GFP_KERNEL); + if (ret < 0) { + r = -EIO; + 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) { + r = ret; + usb_ep_dequeue(dev->ep_out, req); + goto done; + } + if (dev->online) { + /* 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; + r = xfer; + if (copy_to_user(buf, req->buf, xfer)) + r = -EFAULT; + } else + r = -EIO; + +done: + pr_debug("acc_read returning %d\n", r); + return r; +} + +static ssize_t acc_write(struct file *fp, const char __user *buf, + size_t count, loff_t *pos) +{ + struct acc_dev *dev = fp->private_data; + struct usb_request *req = 0; + int r = count, xfer; + int ret; + + pr_debug("acc_write(%d)\n", count); + + if (!dev->online || dev->disconnected) + return -ENODEV; + + while (count > 0) { + if (!dev->online) { + pr_debug("acc_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->online)); + if (!req) { + r = ret; + break; + } + + 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_KERNEL); + if (ret < 0) { + pr_debug("acc_write: xfer error %d\n", ret); + 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); + + pr_debug("acc_write returning %d\n", r); + return r; +} + +static long acc_ioctl(struct file *fp, unsigned code, unsigned long value) +{ + struct acc_dev *dev = fp->private_data; + char *src = NULL; + int ret; + + switch (code) { + case ACCESSORY_GET_STRING_MANUFACTURER: + src = dev->manufacturer; + break; + case ACCESSORY_GET_STRING_MODEL: + src = dev->model; + break; + case ACCESSORY_GET_STRING_DESCRIPTION: + src = dev->description; + break; + case ACCESSORY_GET_STRING_VERSION: + src = dev->version; + break; + case ACCESSORY_GET_STRING_URI: + src = dev->uri; + break; + case ACCESSORY_GET_STRING_SERIAL: + src = dev->serial; + break; + case ACCESSORY_IS_START_REQUESTED: + return dev->start_requested; + } + if (!src) + return -EINVAL; + + ret = strlen(src) + 1; + if (copy_to_user((void __user *)value, src, ret)) + ret = -EFAULT; + return ret; +} + +static int acc_open(struct inode *ip, struct file *fp) +{ + printk(KERN_INFO "acc_open\n"); + if (atomic_xchg(&_acc_dev->open_excl, 1)) + return -EBUSY; + + _acc_dev->disconnected = 0; + fp->private_data = _acc_dev; + return 0; +} + +static int acc_release(struct inode *ip, struct file *fp) +{ + printk(KERN_INFO "acc_release\n"); + + WARN_ON(!atomic_xchg(&_acc_dev->open_excl, 0)); + _acc_dev->disconnected = 0; + return 0; +} + +/* file operations for /dev/acc_usb */ +static const struct file_operations acc_fops = { + .owner = THIS_MODULE, + .read = acc_read, + .write = acc_write, + .unlocked_ioctl = acc_ioctl, + .open = acc_open, + .release = acc_release, +}; + +static struct miscdevice acc_device = { + .minor = MISC_DYNAMIC_MINOR, + .name = "usb_accessory", + .fops = &acc_fops, +}; + + +static int acc_ctrlrequest(struct usb_composite_dev *cdev, + const struct usb_ctrlrequest *ctrl) +{ + struct acc_dev *dev = _acc_dev; + int value = -EOPNOTSUPP; + u8 b_requestType = ctrl->bRequestType; + u8 b_request = ctrl->bRequest; + u16 w_index = le16_to_cpu(ctrl->wIndex); + u16 w_value = le16_to_cpu(ctrl->wValue); + u16 w_length = le16_to_cpu(ctrl->wLength); + +/* + printk(KERN_INFO "acc_ctrlrequest " + "%02x.%02x v%04x i%04x l%u\n", + b_requestType, b_request, + w_value, w_index, w_length); +*/ + + if (b_requestType == (USB_DIR_OUT | USB_TYPE_VENDOR)) { + if (b_request == ACCESSORY_START) { + dev->start_requested = 1; + schedule_delayed_work( + &dev->work, msecs_to_jiffies(10)); + value = 0; + } else if (b_request == ACCESSORY_SEND_STRING) { + dev->string_index = w_index; + cdev->gadget->ep0->driver_data = dev; + cdev->req->complete = acc_complete_set_string; + value = w_length; + } + } else if (b_requestType == (USB_DIR_IN | USB_TYPE_VENDOR)) { + if (b_request == ACCESSORY_GET_PROTOCOL) { + *((u16 *)cdev->req->buf) = PROTOCOL_VERSION; + value = sizeof(u16); + + /* clear any strings left over from a previous session */ + memset(dev->manufacturer, 0, sizeof(dev->manufacturer)); + memset(dev->model, 0, sizeof(dev->model)); + memset(dev->description, 0, sizeof(dev->description)); + memset(dev->version, 0, sizeof(dev->version)); + memset(dev->uri, 0, sizeof(dev->uri)); + memset(dev->serial, 0, sizeof(dev->serial)); + dev->start_requested = 0; + } + } + + if (value >= 0) { + cdev->req->zero = 0; + cdev->req->length = value; + value = usb_ep_queue(cdev->gadget->ep0, cdev->req, GFP_ATOMIC); + if (value < 0) + ERROR(cdev, "%s setup response queue error\n", + __func__); + } + + if (value == -EOPNOTSUPP) + VDBG(cdev, + "unknown class-specific control req " + "%02x.%02x v%04x i%04x l%u\n", + ctrl->bRequestType, ctrl->bRequest, + w_value, w_index, w_length); + return value; +} + +static int +acc_function_bind(struct usb_configuration *c, struct usb_function *f) +{ + struct usb_composite_dev *cdev = c->cdev; + struct acc_dev *dev = func_to_dev(f); + int id; + int ret; + + DBG(cdev, "acc_function_bind dev: %p\n", dev); + + dev->start_requested = 0; + + /* allocate interface ID(s) */ + id = usb_interface_id(c, f); + if (id < 0) + return id; + acc_interface_desc.bInterfaceNumber = id; + + /* allocate endpoints */ + ret = create_bulk_endpoints(dev, &acc_fullspeed_in_desc, + &acc_fullspeed_out_desc); + if (ret) + return ret; + + /* support high speed hardware */ + if (gadget_is_dualspeed(c->cdev->gadget)) { + acc_highspeed_in_desc.bEndpointAddress = + acc_fullspeed_in_desc.bEndpointAddress; + acc_highspeed_out_desc.bEndpointAddress = + acc_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 +acc_function_unbind(struct usb_configuration *c, struct usb_function *f) +{ + struct acc_dev *dev = func_to_dev(f); + struct usb_request *req; + int i; + + while ((req = req_get(dev, &dev->tx_idle))) + acc_request_free(req, dev->ep_in); + for (i = 0; i < RX_REQ_MAX; i++) + acc_request_free(dev->rx_req[i], dev->ep_out); +} + +static void acc_work(struct work_struct *data) +{ + char *envp[2] = { "ACCESSORY=START", NULL }; + kobject_uevent_env(&acc_device.this_device->kobj, KOBJ_CHANGE, envp); +} + +static int acc_function_set_alt(struct usb_function *f, + unsigned intf, unsigned alt) +{ + struct acc_dev *dev = func_to_dev(f); + struct usb_composite_dev *cdev = f->config->cdev; + int ret; + + DBG(cdev, "acc_function_set_alt intf: %d alt: %d\n", intf, alt); + ret = usb_ep_enable(dev->ep_in, + ep_choose(cdev->gadget, + &acc_highspeed_in_desc, + &acc_fullspeed_in_desc)); + if (ret) + return ret; + ret = usb_ep_enable(dev->ep_out, + ep_choose(cdev->gadget, + &acc_highspeed_out_desc, + &acc_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 acc_function_disable(struct usb_function *f) +{ + struct acc_dev *dev = func_to_dev(f); + struct usb_composite_dev *cdev = dev->cdev; + + DBG(cdev, "acc_function_disable\n"); + acc_set_disconnected(dev); + 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 acc_bind_config(struct usb_configuration *c) +{ + struct acc_dev *dev = _acc_dev; + int ret; + + printk(KERN_INFO "acc_bind_config\n"); + + /* allocate a string ID for our interface */ + if (acc_string_defs[INTERFACE_STRING_INDEX].id == 0) { + ret = usb_string_id(c->cdev); + if (ret < 0) + return ret; + acc_string_defs[INTERFACE_STRING_INDEX].id = ret; + acc_interface_desc.iInterface = ret; + } + + dev->cdev = c->cdev; + dev->function.name = "accessory"; + dev->function.strings = acc_strings, + dev->function.descriptors = fs_acc_descs; + dev->function.hs_descriptors = hs_acc_descs; + dev->function.bind = acc_function_bind; + dev->function.unbind = acc_function_unbind; + dev->function.set_alt = acc_function_set_alt; + dev->function.disable = acc_function_disable; + + return usb_add_function(c, &dev->function); +} + +static int acc_setup(void) +{ + struct acc_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); + INIT_LIST_HEAD(&dev->tx_idle); + INIT_DELAYED_WORK(&dev->work, acc_work); + + /* _acc_dev must be set before calling usb_gadget_register_driver */ + _acc_dev = dev; + + ret = misc_register(&acc_device); + if (ret) + goto err; + + return 0; + +err: + kfree(dev); + printk(KERN_ERR "USB accessory gadget driver failed to initialize\n"); + return ret; +} + +static void acc_cleanup(void) +{ + misc_deregister(&acc_device); + kfree(_acc_dev); + _acc_dev = NULL; +} |