From 71adf118946957839a13aa4d1094183e05c6c094 Mon Sep 17 00:00:00 2001 From: Fabien Chouteau Date: Thu, 8 Apr 2010 09:31:15 +0200 Subject: USB: gadget: add HID gadget driver g_hid is a USB gadget driver implementing the Human Interface Device class specification. The driver handles basic HID protocol handling in the kernel, and allows userspace to read/write HID reports trough /dev/hidgX character devices. Signed-off-by: Fabien Chouteau Signed-off-by: Peter Korsgaard Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/f_hid.c | 673 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 673 insertions(+) create mode 100644 drivers/usb/gadget/f_hid.c (limited to 'drivers/usb/gadget/f_hid.c') diff --git a/drivers/usb/gadget/f_hid.c b/drivers/usb/gadget/f_hid.c new file mode 100644 index 0000000..1e00ff9 --- /dev/null +++ b/drivers/usb/gadget/f_hid.c @@ -0,0 +1,673 @@ +/* + * f_hid.c -- USB HID function driver + * + * Copyright (C) 2010 Fabien Chouteau + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static int major, minors; +static struct class *hidg_class; + +/*-------------------------------------------------------------------------*/ +/* HID gadget struct */ + +struct f_hidg { + /* configuration */ + unsigned char bInterfaceSubClass; + unsigned char bInterfaceProtocol; + unsigned short report_desc_length; + char *report_desc; + unsigned short report_length; + + /* recv report */ + char *set_report_buff; + unsigned short set_report_length; + spinlock_t spinlock; + wait_queue_head_t read_queue; + + /* send report */ + struct mutex lock; + bool write_pending; + wait_queue_head_t write_queue; + struct usb_request *req; + + int minor; + struct cdev cdev; + struct usb_function func; + struct usb_ep *in_ep; + struct usb_endpoint_descriptor *fs_in_ep_desc; + struct usb_endpoint_descriptor *hs_in_ep_desc; +}; + +static inline struct f_hidg *func_to_hidg(struct usb_function *f) +{ + return container_of(f, struct f_hidg, func); +} + +/*-------------------------------------------------------------------------*/ +/* Static descriptors */ + +static struct usb_interface_descriptor hidg_interface_desc = { + .bLength = sizeof hidg_interface_desc, + .bDescriptorType = USB_DT_INTERFACE, + /* .bInterfaceNumber = DYNAMIC */ + .bAlternateSetting = 0, + .bNumEndpoints = 1, + .bInterfaceClass = USB_CLASS_HID, + /* .bInterfaceSubClass = DYNAMIC */ + /* .bInterfaceProtocol = DYNAMIC */ + /* .iInterface = DYNAMIC */ +}; + +static struct hid_descriptor hidg_desc = { + .bLength = sizeof hidg_desc, + .bDescriptorType = HID_DT_HID, + .bcdHID = 0x0101, + .bCountryCode = 0x00, + .bNumDescriptors = 0x1, + /*.desc[0].bDescriptorType = DYNAMIC */ + /*.desc[0].wDescriptorLenght = DYNAMIC */ +}; + +/* High-Speed Support */ + +static struct usb_endpoint_descriptor hidg_hs_in_ep_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + .bEndpointAddress = USB_DIR_IN, + .bmAttributes = USB_ENDPOINT_XFER_INT, + /*.wMaxPacketSize = DYNAMIC */ + .bInterval = 4, /* FIXME: Add this field in the + * HID gadget configuration? + * (struct hidg_func_descriptor) + */ +}; + +static struct usb_descriptor_header *hidg_hs_descriptors[] = { + (struct usb_descriptor_header *)&hidg_interface_desc, + (struct usb_descriptor_header *)&hidg_desc, + (struct usb_descriptor_header *)&hidg_hs_in_ep_desc, + NULL, +}; + +/* Full-Speed Support */ + +static struct usb_endpoint_descriptor hidg_fs_in_ep_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + .bEndpointAddress = USB_DIR_IN, + .bmAttributes = USB_ENDPOINT_XFER_INT, + /*.wMaxPacketSize = DYNAMIC */ + .bInterval = 10, /* FIXME: Add this field in the + * HID gadget configuration? + * (struct hidg_func_descriptor) + */ +}; + +static struct usb_descriptor_header *hidg_fs_descriptors[] = { + (struct usb_descriptor_header *)&hidg_interface_desc, + (struct usb_descriptor_header *)&hidg_desc, + (struct usb_descriptor_header *)&hidg_fs_in_ep_desc, + NULL, +}; + +/*-------------------------------------------------------------------------*/ +/* Char Device */ + +static ssize_t f_hidg_read(struct file *file, char __user *buffer, + size_t count, loff_t *ptr) +{ + struct f_hidg *hidg = (struct f_hidg *)file->private_data; + char *tmp_buff = NULL; + unsigned long flags; + + if (!count) + return 0; + + if (!access_ok(VERIFY_WRITE, buffer, count)) + return -EFAULT; + + spin_lock_irqsave(&hidg->spinlock, flags); + +#define READ_COND (hidg->set_report_buff != NULL) + + while (!READ_COND) { + spin_unlock_irqrestore(&hidg->spinlock, flags); + if (file->f_flags & O_NONBLOCK) + return -EAGAIN; + + if (wait_event_interruptible(hidg->read_queue, READ_COND)) + return -ERESTARTSYS; + + spin_lock_irqsave(&hidg->spinlock, flags); + } + + + count = min_t(unsigned, count, hidg->set_report_length); + tmp_buff = hidg->set_report_buff; + hidg->set_report_buff = NULL; + + spin_unlock_irqrestore(&hidg->spinlock, flags); + + if (tmp_buff != NULL) { + /* copy to user outside spinlock */ + count -= copy_to_user(buffer, tmp_buff, count); + kfree(tmp_buff); + } else + count = -ENOMEM; + + return count; +} + +static void f_hidg_req_complete(struct usb_ep *ep, struct usb_request *req) +{ + struct f_hidg *hidg = (struct f_hidg *)ep->driver_data; + + if (req->status != 0) { + ERROR(hidg->func.config->cdev, + "End Point Request ERROR: %d\n", req->status); + } + + hidg->write_pending = 0; + wake_up(&hidg->write_queue); +} + +static ssize_t f_hidg_write(struct file *file, const char __user *buffer, + size_t count, loff_t *offp) +{ + struct f_hidg *hidg = (struct f_hidg *)file->private_data; + ssize_t status = -ENOMEM; + + if (!access_ok(VERIFY_READ, buffer, count)) + return -EFAULT; + + mutex_lock(&hidg->lock); + +#define WRITE_COND (!hidg->write_pending) + + /* write queue */ + while (!WRITE_COND) { + mutex_unlock(&hidg->lock); + if (file->f_flags & O_NONBLOCK) + return -EAGAIN; + + if (wait_event_interruptible_exclusive( + hidg->write_queue, WRITE_COND)) + return -ERESTARTSYS; + + mutex_lock(&hidg->lock); + } + + count = min_t(unsigned, count, hidg->report_length); + status = copy_from_user(hidg->req->buf, buffer, count); + + if (status != 0) { + ERROR(hidg->func.config->cdev, + "copy_from_user error\n"); + mutex_unlock(&hidg->lock); + return -EINVAL; + } + + hidg->req->status = 0; + hidg->req->zero = 0; + hidg->req->length = count; + hidg->req->complete = f_hidg_req_complete; + hidg->req->context = hidg; + hidg->write_pending = 1; + + status = usb_ep_queue(hidg->in_ep, hidg->req, GFP_ATOMIC); + if (status < 0) { + ERROR(hidg->func.config->cdev, + "usb_ep_queue error on int endpoint %zd\n", status); + hidg->write_pending = 0; + wake_up(&hidg->write_queue); + } else { + status = count; + } + + mutex_unlock(&hidg->lock); + + return status; +} + +static unsigned int f_hidg_poll(struct file *file, poll_table *wait) +{ + struct f_hidg *hidg = (struct f_hidg *)file->private_data; + unsigned int ret = 0; + + poll_wait(file, &hidg->read_queue, wait); + poll_wait(file, &hidg->write_queue, wait); + + if (WRITE_COND) + ret |= POLLOUT | POLLWRNORM; + + if (READ_COND) + ret |= POLLIN | POLLRDNORM; + + return ret; +} + +#undef WRITE_COND +#undef READ_COND + +static int f_hidg_release(struct inode *inode, struct file *fd) +{ + fd->private_data = NULL; + return 0; +} + +static int f_hidg_open(struct inode *inode, struct file *fd) +{ + struct f_hidg *hidg = + container_of(inode->i_cdev, struct f_hidg, cdev); + + fd->private_data = hidg; + + return 0; +} + +/*-------------------------------------------------------------------------*/ +/* usb_function */ + +static void hidg_set_report_complete(struct usb_ep *ep, struct usb_request *req) +{ + struct f_hidg *hidg = (struct f_hidg *)req->context; + + if (req->status != 0 || req->buf == NULL || req->actual == 0) { + ERROR(hidg->func.config->cdev, "%s FAILED\n", __func__); + return; + } + + spin_lock(&hidg->spinlock); + + hidg->set_report_buff = krealloc(hidg->set_report_buff, + req->actual, GFP_ATOMIC); + + if (hidg->set_report_buff == NULL) { + spin_unlock(&hidg->spinlock); + return; + } + hidg->set_report_length = req->actual; + memcpy(hidg->set_report_buff, req->buf, req->actual); + + spin_unlock(&hidg->spinlock); + + wake_up(&hidg->read_queue); + + return; +} + +static int hidg_setup(struct usb_function *f, + const struct usb_ctrlrequest *ctrl) +{ + struct f_hidg *hidg = func_to_hidg(f); + struct usb_composite_dev *cdev = f->config->cdev; + struct usb_request *req = cdev->req; + int status = 0; + __u16 value, length; + + value = __le16_to_cpu(ctrl->wValue); + length = __le16_to_cpu(ctrl->wLength); + + VDBG(cdev, "hid_setup crtl_request : bRequestType:0x%x bRequest:0x%x " + "Value:0x%x\n", ctrl->bRequestType, ctrl->bRequest, value); + + switch ((ctrl->bRequestType << 8) | ctrl->bRequest) { + case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8 + | HID_REQ_GET_REPORT): + VDBG(cdev, "get_report\n"); + + /* send an empty report */ + length = min_t(unsigned, length, hidg->report_length); + memset(req->buf, 0x0, length); + + goto respond; + break; + + case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8 + | HID_REQ_GET_PROTOCOL): + VDBG(cdev, "get_protocol\n"); + goto stall; + break; + + case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8 + | HID_REQ_SET_REPORT): + VDBG(cdev, "set_report | wLenght=%d\n", ctrl->wLength); + req->context = hidg; + req->complete = hidg_set_report_complete; + goto respond; + break; + + case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8 + | HID_REQ_SET_PROTOCOL): + VDBG(cdev, "set_protocol\n"); + goto stall; + break; + + case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8 + | USB_REQ_GET_DESCRIPTOR): + switch (value >> 8) { + case HID_DT_REPORT: + VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n"); + length = min_t(unsigned short, length, + hidg->report_desc_length); + memcpy(req->buf, hidg->report_desc, length); + goto respond; + break; + + default: + VDBG(cdev, "Unknown decriptor request 0x%x\n", + value >> 8); + goto stall; + break; + } + break; + + default: + VDBG(cdev, "Unknown request 0x%x\n", + ctrl->bRequest); + goto stall; + break; + } + +stall: + return -EOPNOTSUPP; + +respond: + req->zero = 0; + req->length = length; + status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC); + if (status < 0) + ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value); + return status; +} + +static void hidg_disable(struct usb_function *f) +{ + struct f_hidg *hidg = func_to_hidg(f); + + usb_ep_disable(hidg->in_ep); + hidg->in_ep->driver_data = NULL; + + return; +} + +static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt) +{ + struct usb_composite_dev *cdev = f->config->cdev; + struct f_hidg *hidg = func_to_hidg(f); + const struct usb_endpoint_descriptor *ep_desc; + int status = 0; + + VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt); + + if (hidg->in_ep != NULL) { + /* restart endpoint */ + if (hidg->in_ep->driver_data != NULL) + usb_ep_disable(hidg->in_ep); + + ep_desc = ep_choose(f->config->cdev->gadget, + hidg->hs_in_ep_desc, hidg->fs_in_ep_desc); + status = usb_ep_enable(hidg->in_ep, ep_desc); + if (status < 0) { + ERROR(cdev, "Enable endpoint FAILED!\n"); + goto fail; + } + hidg->in_ep->driver_data = hidg; + } +fail: + return status; +} + +const struct file_operations f_hidg_fops = { + .owner = THIS_MODULE, + .open = f_hidg_open, + .release = f_hidg_release, + .write = f_hidg_write, + .read = f_hidg_read, + .poll = f_hidg_poll, +}; + +static int __init hidg_bind(struct usb_configuration *c, struct usb_function *f) +{ + struct usb_ep *ep; + struct f_hidg *hidg = func_to_hidg(f); + int status; + dev_t dev; + + /* allocate instance-specific interface IDs, and patch descriptors */ + status = usb_interface_id(c, f); + if (status < 0) + goto fail; + hidg_interface_desc.bInterfaceNumber = status; + + + /* allocate instance-specific endpoints */ + status = -ENODEV; + ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc); + if (!ep) + goto fail; + ep->driver_data = c->cdev; /* claim */ + hidg->in_ep = ep; + + /* preallocate request and buffer */ + status = -ENOMEM; + hidg->req = usb_ep_alloc_request(hidg->in_ep, GFP_KERNEL); + if (!hidg->req) + goto fail; + + + hidg->req->buf = kmalloc(hidg->report_length, GFP_KERNEL); + if (!hidg->req->buf) + goto fail; + + /* set descriptor dynamic values */ + hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass; + hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol; + hidg_hs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length); + hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length); + hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT; + hidg_desc.desc[0].wDescriptorLength = + cpu_to_le16(hidg->report_desc_length); + + hidg->set_report_buff = NULL; + + /* copy descriptors */ + f->descriptors = usb_copy_descriptors(hidg_fs_descriptors); + if (!f->descriptors) + goto fail; + + hidg->fs_in_ep_desc = usb_find_endpoint(hidg_fs_descriptors, + f->descriptors, + &hidg_fs_in_ep_desc); + + if (gadget_is_dualspeed(c->cdev->gadget)) { + hidg_hs_in_ep_desc.bEndpointAddress = + hidg_fs_in_ep_desc.bEndpointAddress; + f->hs_descriptors = usb_copy_descriptors(hidg_hs_descriptors); + if (!f->hs_descriptors) + goto fail; + hidg->hs_in_ep_desc = usb_find_endpoint(hidg_hs_descriptors, + f->hs_descriptors, + &hidg_hs_in_ep_desc); + } else { + hidg->hs_in_ep_desc = NULL; + } + + mutex_init(&hidg->lock); + spin_lock_init(&hidg->spinlock); + init_waitqueue_head(&hidg->write_queue); + init_waitqueue_head(&hidg->read_queue); + + /* create char device */ + cdev_init(&hidg->cdev, &f_hidg_fops); + dev = MKDEV(major, hidg->minor); + status = cdev_add(&hidg->cdev, dev, 1); + if (status) + goto fail; + + device_create(hidg_class, NULL, dev, NULL, "%s%d", "hidg", hidg->minor); + + return 0; + +fail: + ERROR(f->config->cdev, "hidg_bind FAILED\n"); + if (hidg->req != NULL) { + kfree(hidg->req->buf); + if (hidg->in_ep != NULL) + usb_ep_free_request(hidg->in_ep, hidg->req); + } + + usb_free_descriptors(f->hs_descriptors); + usb_free_descriptors(f->descriptors); + + return status; +} + +static void hidg_unbind(struct usb_configuration *c, struct usb_function *f) +{ + struct f_hidg *hidg = func_to_hidg(f); + + device_destroy(hidg_class, MKDEV(major, hidg->minor)); + cdev_del(&hidg->cdev); + + /* disable/free request and end point */ + usb_ep_disable(hidg->in_ep); + usb_ep_dequeue(hidg->in_ep, hidg->req); + kfree(hidg->req->buf); + usb_ep_free_request(hidg->in_ep, hidg->req); + + /* free descriptors copies */ + usb_free_descriptors(f->hs_descriptors); + usb_free_descriptors(f->descriptors); + + kfree(hidg->report_desc); + kfree(hidg->set_report_buff); + kfree(hidg); +} + +/*-------------------------------------------------------------------------*/ +/* Strings */ + +#define CT_FUNC_HID_IDX 0 + +static struct usb_string ct_func_string_defs[] = { + [CT_FUNC_HID_IDX].s = "HID Interface", + {}, /* end of list */ +}; + +static struct usb_gadget_strings ct_func_string_table = { + .language = 0x0409, /* en-US */ + .strings = ct_func_string_defs, +}; + +static struct usb_gadget_strings *ct_func_strings[] = { + &ct_func_string_table, + NULL, +}; + +/*-------------------------------------------------------------------------*/ +/* usb_configuration */ + +int __init hidg_bind_config(struct usb_configuration *c, + struct hidg_func_descriptor *fdesc, int index) +{ + struct f_hidg *hidg; + int status; + + if (index >= minors) + return -ENOENT; + + /* maybe allocate device-global string IDs, and patch descriptors */ + if (ct_func_string_defs[CT_FUNC_HID_IDX].id == 0) { + status = usb_string_id(c->cdev); + if (status < 0) + return status; + ct_func_string_defs[CT_FUNC_HID_IDX].id = status; + hidg_interface_desc.iInterface = status; + } + + /* allocate and initialize one new instance */ + hidg = kzalloc(sizeof *hidg, GFP_KERNEL); + if (!hidg) + return -ENOMEM; + + hidg->minor = index; + hidg->bInterfaceSubClass = fdesc->subclass; + hidg->bInterfaceProtocol = fdesc->protocol; + hidg->report_length = fdesc->report_length; + hidg->report_desc_length = fdesc->report_desc_length; + hidg->report_desc = kmemdup(fdesc->report_desc, + fdesc->report_desc_length, + GFP_KERNEL); + if (!hidg->report_desc) { + kfree(hidg); + return -ENOMEM; + } + + hidg->func.name = "hid"; + hidg->func.strings = ct_func_strings; + hidg->func.bind = hidg_bind; + hidg->func.unbind = hidg_unbind; + hidg->func.set_alt = hidg_set_alt; + hidg->func.disable = hidg_disable; + hidg->func.setup = hidg_setup; + + status = usb_add_function(c, &hidg->func); + if (status) + kfree(hidg); + + return status; +} + +int __init ghid_setup(struct usb_gadget *g, int count) +{ + int status; + dev_t dev; + + hidg_class = class_create(THIS_MODULE, "hidg"); + + status = alloc_chrdev_region(&dev, 0, count, "hidg"); + if (!status) { + major = MAJOR(dev); + minors = count; + } + + return status; +} + +void ghid_cleanup(void) +{ + if (major) { + unregister_chrdev_region(MKDEV(major, 0), minors); + major = minors = 0; + } + + class_destroy(hidg_class); + hidg_class = NULL; +} -- cgit v1.1