// SPDX-License-Identifier: GPL-2.0+ /* * f_hid.c -- USB HID function driver * * Copyright (C) 2010 Fabien Chouteau */ #include #include #include #include #include #include #include #include #include #include #include #include "u_f.h" #include "u_hid.h" #define HIDG_MINORS 4 static int major, minors; static struct class *hidg_class; static DEFINE_IDA(hidg_ida); static DEFINE_MUTEX(hidg_ida_lock); /* protects access to hidg_ida */ /*-------------------------------------------------------------------------*/ /* HID gadget struct */ struct f_hidg_req_list { struct usb_request *req; unsigned int pos; struct list_head list; }; struct f_hidg { /* configuration */ unsigned char bInterfaceSubClass; unsigned char bInterfaceProtocol; unsigned char protocol; unsigned short report_desc_length; char *report_desc; unsigned short report_length; /* recv report */ struct list_head completed_out_req; spinlock_t read_spinlock; wait_queue_head_t read_queue; unsigned int qlen; /* send report */ spinlock_t write_spinlock; 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_ep *out_ep; }; 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 = 2, .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 */ }; /* Super-Speed Support */ static struct usb_endpoint_descriptor hidg_ss_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_ss_ep_comp_descriptor hidg_ss_in_comp_desc = { .bLength = sizeof(hidg_ss_in_comp_desc), .bDescriptorType = USB_DT_SS_ENDPOINT_COMP, /* .bMaxBurst = 0, */ /* .bmAttributes = 0, */ /* .wBytesPerInterval = DYNAMIC */ }; static struct usb_endpoint_descriptor hidg_ss_out_ep_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bEndpointAddress = USB_DIR_OUT, .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_ss_ep_comp_descriptor hidg_ss_out_comp_desc = { .bLength = sizeof(hidg_ss_out_comp_desc), .bDescriptorType = USB_DT_SS_ENDPOINT_COMP, /* .bMaxBurst = 0, */ /* .bmAttributes = 0, */ /* .wBytesPerInterval = DYNAMIC */ }; static struct usb_descriptor_header *hidg_ss_descriptors[] = { (struct usb_descriptor_header *)&hidg_interface_desc, (struct usb_descriptor_header *)&hidg_desc, (struct usb_descriptor_header *)&hidg_ss_in_ep_desc, (struct usb_descriptor_header *)&hidg_ss_in_comp_desc, (struct usb_descriptor_header *)&hidg_ss_out_ep_desc, (struct usb_descriptor_header *)&hidg_ss_out_comp_desc, NULL, }; /* 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_endpoint_descriptor hidg_hs_out_ep_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bEndpointAddress = USB_DIR_OUT, .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, (struct usb_descriptor_header *)&hidg_hs_out_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_endpoint_descriptor hidg_fs_out_ep_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bEndpointAddress = USB_DIR_OUT, .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, (struct usb_descriptor_header *)&hidg_fs_out_ep_desc, NULL, }; /*-------------------------------------------------------------------------*/ /* 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, }; /*-------------------------------------------------------------------------*/ /* Char Device */ static ssize_t f_hidg_read(struct file *file, char __user *buffer, size_t count, loff_t *ptr) { struct f_hidg *hidg = file->private_data; struct f_hidg_req_list *list; struct usb_request *req; unsigned long flags; int ret; if (!count) return 0; if (!access_ok(VERIFY_WRITE, buffer, count)) return -EFAULT; spin_lock_irqsave(&hidg->read_spinlock, flags); #define READ_COND (!list_empty(&hidg->completed_out_req)) /* wait for at least one buffer to complete */ while (!READ_COND) { spin_unlock_irqrestore(&hidg->read_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->read_spinlock, flags); } /* pick the first one */ list = list_first_entry(&hidg->completed_out_req, struct f_hidg_req_list, list); /* * Remove this from list to protect it from beign free() * while host disables our function */ list_del(&list->list); req = list->req; count = min_t(unsigned int, count, req->actual - list->pos); spin_unlock_irqrestore(&hidg->read_spinlock, flags); /* copy to user outside spinlock */ count -= copy_to_user(buffer, req->buf + list->pos, count); list->pos += count; /* * if this request is completely handled and transfered to * userspace, remove its entry from the list and requeue it * again. Otherwise, we will revisit it again upon the next * call, taking into account its current read position. */ if (list->pos == req->actual) { kfree(list); req->length = hidg->report_length; ret = usb_ep_queue(hidg->out_ep, req, GFP_KERNEL); if (ret < 0) { free_ep_req(hidg->out_ep, req); return ret; } } else { spin_lock_irqsave(&hidg->read_spinlock, flags); list_add(&list->list, &hidg->completed_out_req); spin_unlock_irqrestore(&hidg->read_spinlock, flags); wake_up(&hidg->read_queue); } 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; unsigned long flags; if (req->status != 0) { ERROR(hidg->func.config->cdev, "End Point Request ERROR: %d\n", req->status); } spin_lock_irqsave(&hidg->write_spinlock, flags); hidg->write_pending = 0; spin_unlock_irqrestore(&hidg->write_spinlock, flags); 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 = file->private_data; struct usb_request *req; unsigned long flags; ssize_t status = -ENOMEM; if (!access_ok(VERIFY_READ, buffer, count)) return -EFAULT; spin_lock_irqsave(&hidg->write_spinlock, flags); #define WRITE_COND (!hidg->write_pending) try_again: /* write queue */ while (!WRITE_COND) { spin_unlock_irqrestore(&hidg->write_spinlock, flags); if (file->f_flags & O_NONBLOCK) return -EAGAIN; if (wait_event_interruptible_exclusive( hidg->write_queue, WRITE_COND)) return -ERESTARTSYS; spin_lock_irqsave(&hidg->write_spinlock, flags); } hidg->write_pending = 1; req = hidg->req; count = min_t(unsigned, count, hidg->report_length); spin_unlock_irqrestore(&hidg->write_spinlock, flags); status = copy_from_user(req->buf, buffer, count); if (status != 0) { ERROR(hidg->func.config->cdev, "copy_from_user error\n"); status = -EINVAL; goto release_write_pending; } spin_lock_irqsave(&hidg->write_spinlock, flags); /* when our function has been disabled by host */ if (!hidg->req) { free_ep_req(hidg->in_ep, req); /* * TODO * Should we fail with error here? */ goto try_again; } req->status = 0; req->zero = 0; req->length = count; req->complete = f_hidg_req_complete; req->context = hidg; spin_unlock_irqrestore(&hidg->write_spinlock, flags); status = usb_ep_queue(hidg->in_ep, req, GFP_ATOMIC); if (status < 0) { ERROR(hidg->func.config->cdev, "usb_ep_queue error on int endpoint %zd\n", status); goto release_write_pending; } else { status = count; } return status; release_write_pending: spin_lock_irqsave(&hidg->write_spinlock, flags); hidg->write_pending = 0; spin_unlock_irqrestore(&hidg->write_spinlock, flags); wake_up(&hidg->write_queue); return status; } static __poll_t f_hidg_poll(struct file *file, poll_table *wait) { struct f_hidg *hidg = file->private_data; __poll_t ret = 0; poll_wait(file, &hidg->read_queue, wait); poll_wait(file, &hidg->write_queue, wait); if (WRITE_COND) ret |= EPOLLOUT | EPOLLWRNORM; if (READ_COND) ret |= EPOLLIN | EPOLLRDNORM; 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 inline struct usb_request *hidg_alloc_ep_req(struct usb_ep *ep, unsigned length) { return alloc_ep_req(ep, length); } static void hidg_set_report_complete(struct usb_ep *ep, struct usb_request *req) { struct f_hidg *hidg = (struct f_hidg *) req->context; struct usb_composite_dev *cdev = hidg->func.config->cdev; struct f_hidg_req_list *req_list; unsigned long flags; switch (req->status) { case 0: req_list = kzalloc(sizeof(*req_list), GFP_ATOMIC); if (!req_list) { ERROR(cdev, "Unable to allocate mem for req_list\n"); goto free_req; } req_list->req = req; spin_lock_irqsave(&hidg->read_spinlock, flags); list_add_tail(&req_list->list, &hidg->completed_out_req); spin_unlock_irqrestore(&hidg->read_spinlock, flags); wake_up(&hidg->read_queue); break; default: ERROR(cdev, "Set report failed %d\n", req->status); /* FALLTHROUGH */ case -ECONNABORTED: /* hardware forced ep reset */ case -ECONNRESET: /* request dequeued */ case -ESHUTDOWN: /* disconnect from host */ free_req: free_ep_req(ep, req); 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, "%s crtl_request : bRequestType:0x%x bRequest:0x%x Value:0x%x\n", __func__, 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"); length = min_t(unsigned int, length, 1); ((u8 *) req->buf)[0] = hidg->protocol; goto respond; break; case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8 | HID_REQ_SET_REPORT): VDBG(cdev, "set_report | wLength=%d\n", ctrl->wLength); goto stall; break; case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8 | HID_REQ_SET_PROTOCOL): VDBG(cdev, "set_protocol\n"); if (value > HID_REPORT_PROTOCOL) goto stall; length = 0; /* * We assume that programs implementing the Boot protocol * are also compatible with the Report Protocol */ if (hidg->bInterfaceSubClass == USB_INTERFACE_SUBCLASS_BOOT) { hidg->protocol = value; goto respond; } goto stall; break; case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8 | USB_REQ_GET_DESCRIPTOR): switch (value >> 8) { case HID_DT_HID: { struct hid_descriptor hidg_desc_copy = hidg_desc; VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n"); hidg_desc_copy.desc[0].bDescriptorType = HID_DT_REPORT; hidg_desc_copy.desc[0].wDescriptorLength = cpu_to_le16(hidg->report_desc_length); length = min_t(unsigned short, length, hidg_desc_copy.bLength); memcpy(req->buf, &hidg_desc_copy, length); goto respond; break; } 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 descriptor 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); struct f_hidg_req_list *list, *next; unsigned long flags; usb_ep_disable(hidg->in_ep); usb_ep_disable(hidg->out_ep); spin_lock_irqsave(&hidg->read_spinlock, flags); list_for_each_entry_safe(list, next, &hidg->completed_out_req, list) { free_ep_req(hidg->out_ep, list->req); list_del(&list->list); kfree(list); } spin_unlock_irqrestore(&hidg->read_spinlock, flags); spin_lock_irqsave(&hidg->write_spinlock, flags); if (!hidg->write_pending) { free_ep_req(hidg->in_ep, hidg->req); hidg->write_pending = 1; } hidg->req = NULL; spin_unlock_irqrestore(&hidg->write_spinlock, flags); } 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); struct usb_request *req_in = NULL; unsigned long flags; int i, status = 0; VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt); if (hidg->in_ep != NULL) { /* restart endpoint */ usb_ep_disable(hidg->in_ep); status = config_ep_by_speed(f->config->cdev->gadget, f, hidg->in_ep); if (status) { ERROR(cdev, "config_ep_by_speed FAILED!\n"); goto fail; } status = usb_ep_enable(hidg->in_ep); if (status < 0) { ERROR(cdev, "Enable IN endpoint FAILED!\n"); goto fail; } hidg->in_ep->driver_data = hidg; req_in = hidg_alloc_ep_req(hidg->in_ep, hidg->report_length); if (!req_in) { status = -ENOMEM; goto disable_ep_in; } } if (hidg->out_ep != NULL) { /* restart endpoint */ usb_ep_disable(hidg->out_ep); status = config_ep_by_speed(f->config->cdev->gadget, f, hidg->out_ep); if (status) { ERROR(cdev, "config_ep_by_speed FAILED!\n"); goto free_req_in; } status = usb_ep_enable(hidg->out_ep); if (status < 0) { ERROR(cdev, "Enable OUT endpoint FAILED!\n"); goto free_req_in; } hidg->out_ep->driver_data = hidg; /* * allocate a bunch of read buffers and queue them all at once. */ for (i = 0; i < hidg->qlen && status == 0; i++) { struct usb_request *req = hidg_alloc_ep_req(hidg->out_ep, hidg->report_length); if (req) { req->complete = hidg_set_report_complete; req->context = hidg; status = usb_ep_queue(hidg->out_ep, req, GFP_ATOMIC); if (status) { ERROR(cdev, "%s queue req --> %d\n", hidg->out_ep->name, status); free_ep_req(hidg->out_ep, req); } } else { status = -ENOMEM; goto disable_out_ep; } } } if (hidg->in_ep != NULL) { spin_lock_irqsave(&hidg->write_spinlock, flags); hidg->req = req_in; hidg->write_pending = 0; spin_unlock_irqrestore(&hidg->write_spinlock, flags); wake_up(&hidg->write_queue); } return 0; disable_out_ep: usb_ep_disable(hidg->out_ep); free_req_in: if (req_in) free_ep_req(hidg->in_ep, req_in); disable_ep_in: if (hidg->in_ep) usb_ep_disable(hidg->in_ep); fail: return status; } static 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, .llseek = noop_llseek, }; static int hidg_bind(struct usb_configuration *c, struct usb_function *f) { struct usb_ep *ep; struct f_hidg *hidg = func_to_hidg(f); struct usb_string *us; struct device *device; int status; dev_t dev; /* maybe allocate device-global string IDs, and patch descriptors */ us = usb_gstrings_attach(c->cdev, ct_func_strings, ARRAY_SIZE(ct_func_string_defs)); if (IS_ERR(us)) return PTR_ERR(us); hidg_interface_desc.iInterface = us[CT_FUNC_HID_IDX].id; /* 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; hidg->in_ep = ep; ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_out_ep_desc); if (!ep) goto fail; hidg->out_ep = ep; /* set descriptor dynamic values */ hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass; hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol; hidg->protocol = HID_REPORT_PROTOCOL; hidg_ss_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length); hidg_ss_in_comp_desc.wBytesPerInterval = cpu_to_le16(hidg->report_length); 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_ss_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length); hidg_ss_out_comp_desc.wBytesPerInterval = cpu_to_le16(hidg->report_length); hidg_hs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length); hidg_fs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length); /* * We can use hidg_desc struct here but we should not relay * that its content won't change after returning from this function. */ hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT; hidg_desc.desc[0].wDescriptorLength = cpu_to_le16(hidg->report_desc_length); hidg_hs_in_ep_desc.bEndpointAddress = hidg_fs_in_ep_desc.bEndpointAddress; hidg_hs_out_ep_desc.bEndpointAddress = hidg_fs_out_ep_desc.bEndpointAddress; hidg_ss_in_ep_desc.bEndpointAddress = hidg_fs_in_ep_desc.bEndpointAddress; hidg_ss_out_ep_desc.bEndpointAddress = hidg_fs_out_ep_desc.bEndpointAddress; status = usb_assign_descriptors(f, hidg_fs_descriptors, hidg_hs_descriptors, hidg_ss_descriptors, NULL); if (status) goto fail; spin_lock_init(&hidg->write_spinlock); hidg->write_pending = 1; hidg->req = NULL; spin_lock_init(&hidg->read_spinlock); init_waitqueue_head(&hidg->write_queue); init_waitqueue_head(&hidg->read_queue); INIT_LIST_HEAD(&hidg->completed_out_req); /* 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_free_descs; device = device_create(hidg_class, NULL, dev, NULL, "%s%d", "hidg", hidg->minor); if (IS_ERR(device)) { status = PTR_ERR(device); goto del; } return 0; del: cdev_del(&hidg->cdev); fail_free_descs: usb_free_all_descriptors(f); fail: ERROR(f->config->cdev, "hidg_bind FAILED\n"); if (hidg->req != NULL) free_ep_req(hidg->in_ep, hidg->req); return status; } static inline int hidg_get_minor(void) { int ret; ret = ida_simple_get(&hidg_ida, 0, 0, GFP_KERNEL); if (ret >= HIDG_MINORS) { ida_simple_remove(&hidg_ida, ret); ret = -ENODEV; } return ret; } static inline struct f_hid_opts *to_f_hid_opts(struct config_item *item) { return container_of(to_config_group(item), struct f_hid_opts, func_inst.group); } static void hid_attr_release(struct config_item *item) { struct f_hid_opts *opts = to_f_hid_opts(item); usb_put_function_instance(&opts->func_inst); } static struct configfs_item_operations hidg_item_ops = { .release = hid_attr_release, }; #define F_HID_OPT(name, prec, limit) \ static ssize_t f_hid_opts_##name##_show(struct config_item *item, char *page)\ { \ struct f_hid_opts *opts = to_f_hid_opts(item); \ int result; \ \ mutex_lock(&opts->lock); \ result = sprintf(page, "%d\n", opts->name); \ mutex_unlock(&opts->lock); \ \ return result; \ } \ \ static ssize_t f_hid_opts_##name##_store(struct config_item *item, \ const char *page, size_t len) \ { \ struct f_hid_opts *opts = to_f_hid_opts(item); \ int ret; \ u##prec num; \ \ mutex_lock(&opts->lock); \ if (opts->refcnt) { \ ret = -EBUSY; \ goto end; \ } \ \ ret = kstrtou##prec(page, 0, &num); \ if (ret) \ goto end; \ \ if (num > limit) { \ ret = -EINVAL; \ goto end; \ } \ opts->name = num; \ ret = len; \ \ end: \ mutex_unlock(&opts->lock); \ return ret; \ } \ \ CONFIGFS_ATTR(f_hid_opts_, name) F_HID_OPT(subclass, 8, 255); F_HID_OPT(protocol, 8, 255); F_HID_OPT(report_length, 16, 65535); static ssize_t f_hid_opts_report_desc_show(struct config_item *item, char *page) { struct f_hid_opts *opts = to_f_hid_opts(item); int result; mutex_lock(&opts->lock); result = opts->report_desc_length; memcpy(page, opts->report_desc, opts->report_desc_length); mutex_unlock(&opts->lock); return result; } static ssize_t f_hid_opts_report_desc_store(struct config_item *item, const char *page, size_t len) { struct f_hid_opts *opts = to_f_hid_opts(item); int ret = -EBUSY; char *d; mutex_lock(&opts->lock); if (opts->refcnt) goto end; if (len > PAGE_SIZE) { ret = -ENOSPC; goto end; } d = kmemdup(page, len, GFP_KERNEL); if (!d) { ret = -ENOMEM; goto end; } kfree(opts->report_desc); opts->report_desc = d; opts->report_desc_length = len; opts->report_desc_alloc = true; ret = len; end: mutex_unlock(&opts->lock); return ret; } CONFIGFS_ATTR(f_hid_opts_, report_desc); static ssize_t f_hid_opts_dev_show(struct config_item *item, char *page) { struct f_hid_opts *opts = to_f_hid_opts(item); return sprintf(page, "%d:%d\n", major, opts->minor); } CONFIGFS_ATTR_RO(f_hid_opts_, dev); static struct configfs_attribute *hid_attrs[] = { &f_hid_opts_attr_subclass, &f_hid_opts_attr_protocol, &f_hid_opts_attr_report_length, &f_hid_opts_attr_report_desc, &f_hid_opts_attr_dev, NULL, }; static const struct config_item_type hid_func_type = { .ct_item_ops = &hidg_item_ops, .ct_attrs = hid_attrs, .ct_owner = THIS_MODULE, }; static inline void hidg_put_minor(int minor) { ida_simple_remove(&hidg_ida, minor); } static void hidg_free_inst(struct usb_function_instance *f) { struct f_hid_opts *opts; opts = container_of(f, struct f_hid_opts, func_inst); mutex_lock(&hidg_ida_lock); hidg_put_minor(opts->minor); if (ida_is_empty(&hidg_ida)) ghid_cleanup(); mutex_unlock(&hidg_ida_lock); if (opts->report_desc_alloc) kfree(opts->report_desc); kfree(opts); } static struct usb_function_instance *hidg_alloc_inst(void) { struct f_hid_opts *opts; struct usb_function_instance *ret; int status = 0; opts = kzalloc(sizeof(*opts), GFP_KERNEL); if (!opts) return ERR_PTR(-ENOMEM); mutex_init(&opts->lock); opts->func_inst.free_func_inst = hidg_free_inst; ret = &opts->func_inst; mutex_lock(&hidg_ida_lock); if (ida_is_empty(&hidg_ida)) { status = ghid_setup(NULL, HIDG_MINORS); if (status) { ret = ERR_PTR(status); kfree(opts); goto unlock; } } opts->minor = hidg_get_minor(); if (opts->minor < 0) { ret = ERR_PTR(opts->minor); kfree(opts); if (ida_is_empty(&hidg_ida)) ghid_cleanup(); goto unlock; } config_group_init_type_name(&opts->func_inst.group, "", &hid_func_type); unlock: mutex_unlock(&hidg_ida_lock); return ret; } static void hidg_free(struct usb_function *f) { struct f_hidg *hidg; struct f_hid_opts *opts; hidg = func_to_hidg(f); opts = container_of(f->fi, struct f_hid_opts, func_inst); kfree(hidg->report_desc); kfree(hidg); mutex_lock(&opts->lock); --opts->refcnt; mutex_unlock(&opts->lock); } 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); usb_free_all_descriptors(f); } static struct hidg_func_descriptor hid_data = { .subclass = 0, /* No subclass */ .protocol = 0, /* Mouse Protocol */ .report_length = 4, .report_desc_length = 7, .report_desc = { 0x05, 0x01, /* USAGE_PAGE (Generic Desktop) */ 0x09, 0x00, /* USAGE (None) */ 0xa1, 0x01, /* COLLECTION (Application) */ 0xc0 /* END_COLLECTION */ } }; static struct usb_function *hidg_alloc(struct usb_function_instance *fi) { struct f_hidg *hidg; struct f_hid_opts *opts; /* allocate and initialize one new instance */ hidg = kzalloc(sizeof(*hidg), GFP_KERNEL); if (!hidg) return ERR_PTR(-ENOMEM); opts = container_of(fi, struct f_hid_opts, func_inst); mutex_lock(&opts->lock); ++opts->refcnt; hidg->minor = opts->minor; hidg->bInterfaceSubClass = opts->subclass; hidg->bInterfaceProtocol = opts->protocol; hidg->report_length = opts->report_length; hidg->report_desc_length = opts->report_desc_length; if (opts->report_desc) { hidg->report_desc = kmemdup(opts->report_desc, opts->report_desc_length, GFP_KERNEL); if (!hidg->report_desc) { kfree(hidg); mutex_unlock(&opts->lock); return ERR_PTR(-ENOMEM); } } /* HACK, replace content, duplicate code from above */ hidg->bInterfaceSubClass = hid_data.subclass; hidg->bInterfaceProtocol = hid_data.protocol; hidg->report_length = hid_data.report_length; hidg->report_desc_length = hid_data.report_desc_length; hidg->report_desc = kmemdup(hid_data.report_desc, hid_data.report_desc_length, GFP_KERNEL); if (!hidg->report_desc) { kfree(hidg); mutex_unlock(&opts->lock); return ERR_PTR(-ENOMEM); } mutex_unlock(&opts->lock); hidg->func.name = "hid"; 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; hidg->func.free_func = hidg_free; /* this could me made configurable at some point */ hidg->qlen = 4; return &hidg->func; } DECLARE_USB_FUNCTION_INIT(hid, hidg_alloc_inst, hidg_alloc); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Fabien Chouteau"); int ghid_setup(struct usb_gadget *g, int count) { int status; dev_t dev; hidg_class = class_create(THIS_MODULE, "hidg"); if (IS_ERR(hidg_class)) { status = PTR_ERR(hidg_class); hidg_class = NULL; return status; } status = alloc_chrdev_region(&dev, 0, count, "hidg"); if (status) { class_destroy(hidg_class); hidg_class = NULL; return status; } major = MAJOR(dev); minors = count; return 0; } void ghid_cleanup(void) { if (major) { unregister_chrdev_region(MKDEV(major, 0), minors); major = minors = 0; } class_destroy(hidg_class); hidg_class = NULL; }