diff options
Diffstat (limited to 'kernel/drivers/usb/gadget/function/f_hid.c')
| -rw-r--r-- | kernel/drivers/usb/gadget/function/f_hid.c | 1014 |
1 files changed, 1014 insertions, 0 deletions
diff --git a/kernel/drivers/usb/gadget/function/f_hid.c b/kernel/drivers/usb/gadget/function/f_hid.c new file mode 100644 index 000000000..f7f35a36c --- /dev/null +++ b/kernel/drivers/usb/gadget/function/f_hid.c @@ -0,0 +1,1014 @@ +/* + * f_hid.c -- USB HID function driver + * + * Copyright (C) 2010 Fabien Chouteau <fabien.chouteau@barco.com> + * + * 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. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/hid.h> +#include <linux/idr.h> +#include <linux/cdev.h> +#include <linux/mutex.h> +#include <linux/poll.h> +#include <linux/uaccess.h> +#include <linux/wait.h> +#include <linux/sched.h> +#include <linux/usb/g_hid.h> + +#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 short report_desc_length; + char *report_desc; + unsigned short report_length; + + /* recv report */ + struct list_head completed_out_req; + spinlock_t spinlock; + wait_queue_head_t read_queue; + unsigned int qlen; + + /* 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_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 */ +}; + +/* 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->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->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); + } + + /* pick the first one */ + list = list_first_entry(&hidg->completed_out_req, + struct f_hidg_req_list, list); + req = list->req; + count = min_t(unsigned int, count, req->actual - list->pos); + spin_unlock_irqrestore(&hidg->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) { + spin_lock_irqsave(&hidg->spinlock, flags); + list_del(&list->list); + kfree(list); + spin_unlock_irqrestore(&hidg->spinlock, flags); + + req->length = hidg->report_length; + ret = usb_ep_queue(hidg->out_ep, req, GFP_KERNEL); + if (ret < 0) + return ret; + } + + 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 = 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 = 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 inline struct usb_request *hidg_alloc_ep_req(struct usb_ep *ep, + unsigned length) +{ + return alloc_ep_req(ep, length, 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 f_hidg_req_list *req_list; + unsigned long flags; + + req_list = kzalloc(sizeof(*req_list), GFP_ATOMIC); + if (!req_list) + return; + + req_list->req = req; + + spin_lock_irqsave(&hidg->spinlock, flags); + list_add_tail(&req_list->list, &hidg->completed_out_req); + spin_unlock_irqrestore(&hidg->spinlock, flags); + + wake_up(&hidg->read_queue); +} + +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"); + goto stall; + 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"); + 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; + + usb_ep_disable(hidg->in_ep); + hidg->in_ep->driver_data = NULL; + + usb_ep_disable(hidg->out_ep); + hidg->out_ep->driver_data = NULL; + + list_for_each_entry_safe(list, next, &hidg->completed_out_req, list) { + list_del(&list->list); + kfree(list); + } +} + +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); + int i, 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); + + 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; + } + + + if (hidg->out_ep != NULL) { + /* restart endpoint */ + if (hidg->out_ep->driver_data != NULL) + 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 fail; + } + status = usb_ep_enable(hidg->out_ep); + if (status < 0) { + ERROR(cdev, "Enable IN endpoint FAILED!\n"); + goto fail; + } + 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); + } else { + usb_ep_disable(hidg->out_ep); + hidg->out_ep->driver_data = NULL; + status = -ENOMEM; + goto fail; + } + } + } + +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; + ep->driver_data = c->cdev; /* claim */ + hidg->in_ep = ep; + + ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_out_ep_desc); + if (!ep) + goto fail; + ep->driver_data = c->cdev; /* claim */ + hidg->out_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_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; + + status = usb_assign_descriptors(f, hidg_fs_descriptors, + hidg_hs_descriptors, NULL); + if (status) + goto fail; + + mutex_init(&hidg->lock); + spin_lock_init(&hidg->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) { + kfree(hidg->req->buf); + if (hidg->in_ep != NULL) + usb_ep_free_request(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); + + 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); +} + +CONFIGFS_ATTR_STRUCT(f_hid_opts); +CONFIGFS_ATTR_OPS(f_hid_opts); + +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, + .show_attribute = f_hid_opts_attr_show, + .store_attribute = f_hid_opts_attr_store, +}; + +#define F_HID_OPT(name, prec, limit) \ +static ssize_t f_hid_opts_##name##_show(struct f_hid_opts *opts, char *page)\ +{ \ + 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 f_hid_opts *opts, \ + const char *page, size_t len) \ +{ \ + 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; \ +} \ + \ +static struct f_hid_opts_attribute f_hid_opts_##name = \ + __CONFIGFS_ATTR(name, S_IRUGO | S_IWUSR, f_hid_opts_##name##_show,\ + f_hid_opts_##name##_store) + +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 f_hid_opts *opts, char *page) +{ + 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 f_hid_opts *opts, + const char *page, size_t len) +{ + 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; +} + +static struct f_hid_opts_attribute f_hid_opts_report_desc = + __CONFIGFS_ATTR(report_desc, S_IRUGO | S_IWUSR, + f_hid_opts_report_desc_show, + f_hid_opts_report_desc_store); + +static struct configfs_attribute *hid_attrs[] = { + &f_hid_opts_subclass.attr, + &f_hid_opts_protocol.attr, + &f_hid_opts_report_length.attr, + &f_hid_opts_report_desc.attr, + NULL, +}; + +static 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 (idr_is_empty(&hidg_ida.idr)) + 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 (idr_is_empty(&hidg_ida.idr)) { + 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 (idr_is_empty(&hidg_ida.idr)) + 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); + + /* disable/free request and end point */ + usb_ep_disable(hidg->in_ep); + kfree(hidg->req->buf); + usb_ep_free_request(hidg->in_ep, hidg->req); + + usb_free_all_descriptors(f); +} + +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); + } + } + + 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; +} |