// SPDX-License-Identifier: GPL-2.0+
/*
* f_hid.c -- USB HID function driver
*
* Copyright (C) 2010 Fabien Chouteau <[email protected]>
*/
#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/workqueue.h>
#include <linux/usb/func_utils.h>
#include <linux/usb/g_hid.h>
#include <uapi/linux/usb/g_hid.h>
#include "u_hid.h"
#define HIDG_MINORS 4
/*
* Most operating systems seem to allow for 5000ms timeout, we will allow
* userspace half that time to respond before we return an empty report.
*/
#define GET_REPORT_TIMEOUT_MS 2500
static int major, minors;
static const struct class hidg_class = {
.name = "hidg",
};
static DEFINE_IDA(hidg_ida);
static DEFINE_MUTEX(hidg_ida_lock); /* protects access to hidg_ida */
struct report_entry {
struct usb_hidg_report report_data;
struct list_head node;
};
/*-------------------------------------------------------------------------*/
/* 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 char idle;
unsigned short report_desc_length;
char *report_desc;
unsigned short report_length;
/*
* use_out_ep - if true, the OUT Endpoint (interrupt out method)
* will be used to receive reports from the host
* using functions with the "intout" suffix.
* Otherwise, the OUT Endpoint will not be configured
* and the SETUP/SET_REPORT method ("ssreport" suffix)
* will be used to receive reports.
*/
bool use_out_ep;
/* recv report */
spinlock_t read_spinlock;
wait_queue_head_t read_queue;
/* recv report - interrupt out only (use_out_ep == 1) */
struct list_head completed_out_req;
unsigned int qlen;
/* recv report - setup set_report only (use_out_ep == 0) */
char *set_report_buf;
unsigned int set_report_length;
/* send report */
spinlock_t write_spinlock;
bool write_pending;
wait_queue_head_t write_queue;
struct usb_request *req;
/* get report */
struct usb_request *get_req;
struct usb_hidg_report get_report;
bool get_report_returned;
int get_report_req_report_id;
int get_report_req_report_length;
spinlock_t get_report_spinlock;
wait_queue_head_t get_queue; /* Waiting for userspace response */
wait_queue_head_t get_id_queue; /* Get ID came in */
struct work_struct work;
struct workqueue_struct *workqueue;
struct list_head report_list;
struct device dev;
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 void hidg_release(struct device *dev)
{
struct f_hidg *hidg = container_of(dev, struct f_hidg, dev);
kfree(hidg->report_desc);
kfree(hidg->set_report_buf);
kfree(hidg);
}
/*-------------------------------------------------------------------------*/
/* Static descriptors */
static struct usb_interface_descriptor hidg_interface_desc = {
.bLength = sizeof hidg_interface_desc,
.bDescriptorType = USB_DT_INTERFACE,
/* .bInterfaceNumber = DYNAMIC */
.bAlternateSetting = 0,
/* .bNumEndpoints = DYNAMIC (depends on use_out_ep) */
.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 = cpu_to_le16(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_intout[] = {
(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,
};
static struct usb_descriptor_header *hidg_ss_descriptors_ssreport[] = {
(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,
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_intout[] = {
(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,
};
static struct usb_descriptor_header *hidg_hs_descriptors_ssreport[] = {
(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_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_intout[] = {
(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,
};
static struct usb_descriptor_header *hidg_fs_descriptors_ssreport[] = {
(struct usb_descriptor_header *)&hidg_interface_desc,
(struct usb_descriptor_header *)&hidg_desc,
(struct usb_descriptor_header *)&hidg_fs_in_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_intout_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;
spin_lock_irqsave(&hidg->read_spinlock, flags);
#define READ_COND_INTOUT (!list_empty(&hidg->completed_out_req))
/* wait for at least one buffer to complete */
while (!READ_COND_INTOUT) {
spin_unlock_irqrestore(&hidg->read_spinlock, flags);
if (file->f_flags & O_NONBLOCK)
return -EAGAIN;
if (wait_event_interruptible(hidg->read_queue, READ_COND_INTOUT))
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;
}
#define READ_COND_SSREPORT (hidg->set_report_buf != NULL)
static ssize_t f_hidg_ssreport_read(struct file *file, char __user *buffer,
size_t count, loff_t *ptr)
{
struct f_hidg *hidg = file->private_data;
char *tmp_buf = NULL;
unsigned long flags;
if (!count)
return 0;
spin_lock_irqsave(&hidg->read_spinlock, flags);
while (!READ_COND_SSREPORT) {
spin_unlock_irqrestore(&hidg->read_spinlock, flags);
if (file->f_flags & O_NONBLOCK)
return -EAGAIN;
if (wait_event_interruptible(hidg->read_queue, READ_COND_SSREPORT))
return -ERESTARTSYS;
spin_lock_irqsave(&hidg->read_spinlock, flags);
}
count = min_t(unsigned int, count, hidg->set_report_length);
tmp_buf = hidg->set_report_buf;
hidg->set_report_buf = NULL;
spin_unlock_irqrestore(&hidg->read_spinlock, flags);
if (tmp_buf != NULL) {
count -= copy_to_user(buffer, tmp_buf, count);
kfree(tmp_buf);
} else {
count = -ENOMEM;
}
wake_up(&hidg->read_queue);
return count;
}
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;
if (hidg->use_out_ep)
return f_hidg_intout_read(file, buffer, count, ptr);
else
return f_hidg_ssreport_read(file, buffer, count, ptr);
}
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;
spin_lock_irqsave(&hidg->write_spinlock, flags);
if (!hidg->req) {
spin_unlock_irqrestore(&hidg->write_spinlock, flags);
return -ESHUTDOWN;
}
#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);
if (!req) {
ERROR(hidg->func.config->cdev, "hidg->req is NULL\n");
status = -ESHUTDOWN;
goto release_write_pending;
}
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);
if (!hidg->in_ep->enabled) {
ERROR(hidg->func.config->cdev, "in_ep is disabled\n");
status = -ESHUTDOWN;
goto release_write_pending;
}
status = usb_ep_queue(hidg->in_ep, req, GFP_ATOMIC);
if (status < 0)
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 struct report_entry *f_hidg_search_for_report(struct f_hidg *hidg, u8 report_id)
{
struct list_head *ptr;
struct report_entry *entry;
list_for_each(ptr, &hidg->report_list) {
entry = list_entry(ptr, struct report_entry, node);
if (entry->report_data.report_id == report_id)
return entry;
}
return NULL;
}
static void get_report_workqueue_handler(struct work_struct *work)
{
struct f_hidg *hidg = container_of(work, struct f_hidg, work);
struct usb_composite_dev *cdev = hidg->func.config->cdev;
struct usb_request *req;
struct report_entry *ptr;
unsigned long flags;
int status = 0;
spin_lock_irqsave(&hidg->get_report_spinlock, flags);
req = hidg->get_req;
if (!req) {
spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
return;
}
req->zero = 0;
req->length = min_t(unsigned int, min_t(unsigned int, hidg->get_report_req_report_length,
hidg->report_length),
MAX_REPORT_LENGTH);
/* Check if there is a response available for immediate response */
ptr = f_hidg_search_for_report(hidg, hidg->get_report_req_report_id);
if (ptr && !ptr->report_data.userspace_req) {
/* Report exists in list and it is to be used for immediate response */
req->buf = ptr->report_data.data;
status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
hidg->get_report_returned = true;
spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
} else {
/*
* Report does not exist in list or should not be immediately sent
* i.e. give userspace time to respond
*/
hidg->get_report_returned = false;
spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
wake_up(&hidg->get_id_queue);
#define GET_REPORT_COND (!hidg->get_report_returned)
/* Wait until userspace has responded or timeout */
status = wait_event_interruptible_timeout(hidg->get_queue, !GET_REPORT_COND,
msecs_to_jiffies(GET_REPORT_TIMEOUT_MS));
spin_lock_irqsave(&hidg->get_report_spinlock, flags);
req = hidg->get_req;
if (!req) {
spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
return;
}
if (status == 0 && !hidg->get_report_returned) {
/* GET_REPORT request was not serviced by userspace within timeout period */
VDBG(cdev, "get_report : userspace timeout.\n");
hidg->get_report_returned = true;
}
/* Search again for report ID in list and respond to GET_REPORT request */
ptr = f_hidg_search_for_report(hidg, hidg->get_report_req_report_id);
if (ptr) {
/*
* Either get an updated response just serviced by userspace
* or send the latest response in the list
*/
req->buf = ptr->report_data.data;
} else {
/* If there are no prevoiusly sent reports send empty report */
req->buf = hidg->get_report.data;
memset(req->buf, 0x0, req->length);
}
status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
}
if (status < 0)
VDBG(cdev, "usb_ep_queue error on ep0 responding to GET_REPORT\n");
}
static int f_hidg_get_report_id(struct file *file, __u8 __user *buffer)
{
struct f_hidg *hidg = file->private_data;
int ret = 0;
ret = put_user(hidg->get_report_req_report_id, buffer);
return ret;
}
static int f_hidg_get_report(struct file *file, struct usb_hidg_report __user *buffer)
{
struct f_hidg *hidg = file->private_data;
struct usb_composite_dev *cdev = hidg->func.config->cdev;
unsigned long flags;
struct report_entry *entry;
struct report_entry *ptr;
__u8 report_id;
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
if (!entry)
return -ENOMEM;
if (copy_from_user(&entry->report_data, buffer,
sizeof(struct usb_hidg_report))) {
ERROR(cdev, "copy_from_user error\n");
kfree(entry);
return -EINVAL;
}
report_id = entry->report_data.report_id;
spin_lock_irqsave(&hidg->get_report_spinlock, flags);
ptr = f_hidg_search_for_report(hidg, report_id);
if (ptr) {
/* Report already exists in list - update it */
if (copy_from_user(&ptr->report_data, buffer,
sizeof(struct usb_hidg_report))) {
spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
ERROR(cdev, "copy_from_user error\n");
kfree(entry);
return -EINVAL;
}
kfree(entry);
} else {
/* Report does not exist in list - add it */
list_add_tail(&entry->node, &hidg->report_list);
}
/* If there is no response pending then do nothing further */
if (hidg->get_report_returned) {
spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
return 0;
}
/* If this userspace response serves the current pending report */
if (hidg->get_report_req_report_id == report_id) {
hidg->get_report_returned = true;
wake_up(&hidg->get_queue);
}
spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
return 0;
}
static long f_hidg_ioctl(struct file *file, unsigned int code, unsigned long arg)
{
switch (code) {
case GADGET_HID_READ_GET_REPORT_ID:
return f_hidg_get_report_id(file, (__u8 __user *)arg);
case GADGET_HID_WRITE_GET_REPORT:
return f_hidg_get_report(file, (struct usb_hidg_report __user *)arg);
default:
return -ENOTTY;
}
}
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);
poll_wait(file, &hidg->get_queue, wait);
poll_wait(file, &hidg->get_id_queue, wait);
if (WRITE_COND)
ret |= EPOLLOUT | EPOLLWRNORM;
if (hidg->use_out_ep) {
if (READ_COND_INTOUT)
ret |= EPOLLIN | EPOLLRDNORM;
} else {
if (READ_COND_SSREPORT)
ret |= EPOLLIN | EPOLLRDNORM;
}
if (GET_REPORT_COND)
ret |= EPOLLPRI;
return ret;
}
#undef WRITE_COND
#undef READ_COND_SSREPORT
#undef READ_COND_INTOUT
#undef GET_REPORT_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_intout_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 void hidg_ssreport_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;
char *new_buf = NULL;
unsigned long flags;
if (req->status != 0 || req->buf == NULL || req->actual == 0) {
ERROR(cdev,
"%s FAILED: status=%d, buf=%p, actual=%d\n",
__func__, req->status, req->buf, req->actual);
return;
}
spin_lock_irqsave(&hidg->read_spinlock, flags);
new_buf = krealloc(hidg->set_report_buf, req->actual, GFP_ATOMIC);
if (new_buf == NULL) {
spin_unlock_irqrestore(&hidg->read_spinlock, flags);
return;
}
hidg->set_report_buf = new_buf;
hidg->set_report_length = req->actual;
memcpy(hidg->set_report_buf, req->buf, req->actual);
spin_unlock_irqrestore(&hidg->read_spinlock, flags);
wake_up(&hidg->read_queue);
}
static void hidg_get_report_complete(struct usb_ep *ep, struct usb_request *req)
{
}
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;
unsigned long flags;
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 | wLength=%d\n", ctrl->wLength);
/*
* Update GET_REPORT ID so that an ioctl can be used to determine what
* GET_REPORT the request was actually for.
*/
spin_lock_irqsave(&hidg->get_report_spinlock, flags);
hidg->get_report_req_report_id = value & 0xff;
hidg->get_report_req_report_length = length;
spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
queue_work(hidg->workqueue, &hidg->work);
return status;
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_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
| HID_REQ_GET_IDLE):
VDBG(cdev, "get_idle\n");
length = min_t(unsigned int, length, 1);
((u8 *) req->buf)[0] = hidg->idle;
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);
if (hidg->use_out_ep)
goto stall;
req->complete = hidg_ssreport_complete;
req->context = hidg;
goto respond;
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_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
| HID_REQ_SET_IDLE):
VDBG(cdev, "set_idle\n");
length = 0;
hidg->idle = value >> 8;
goto respond;
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);
if (hidg->out_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->get_report_spinlock, flags);
if (!hidg->get_report_returned) {
usb_ep_free_request(f->config->cdev->gadget->ep0, hidg->get_req);
hidg->get_req = NULL;
hidg->get_report_returned = true;
}
spin_unlock_irqrestore(&hidg->get_report_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->use_out_ep && 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_intout_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:
if (hidg->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;
}
#ifdef CONFIG_COMPAT
static long f_hidg_compat_ioctl(struct file *file, unsigned int code,
unsigned long value)
{
return f_hidg_ioctl(file, code, value);
}
#endif
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,
.unlocked_ioctl = f_hidg_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = f_hidg_compat_ioctl,
#endif
.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;
int status;
hidg->get_req = usb_ep_alloc_request(c->cdev->gadget->ep0, GFP_ATOMIC);
if (!hidg->get_req)
return -ENOMEM;
hidg->get_req->zero = 0;
hidg->get_req->complete = hidg_get_report_complete;
hidg->get_req->context = hidg;
hidg->get_report_returned = true;
/* 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;
hidg->out_ep = NULL;
if (hidg->use_out_ep) {
ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_out_ep_desc);
if (!ep)
goto fail;
hidg->out_ep = ep;
}
/* used only if use_out_ep == 1 */
hidg->set_report_buf = NULL;
/* set descriptor dynamic values */
hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
hidg_interface_desc.bNumEndpoints = hidg->use_out_ep ? 2 : 1;
hidg->protocol = HID_REPORT_PROTOCOL;
hidg->idle = 1;
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;
if (hidg->use_out_ep)
status = usb_assign_descriptors(f,
hidg_fs_descriptors_intout,
hidg_hs_descriptors_intout,
hidg_ss_descriptors_intout,
hidg_ss_descriptors_intout);
else
status = usb_assign_descriptors(f,
hidg_fs_descriptors_ssreport,
hidg_hs_descriptors_ssreport,
hidg_ss_descriptors_ssreport,
hidg_ss_descriptors_ssreport);
if (status)
goto fail;
spin_lock_init(&hidg->write_spinlock);
hidg->write_pending = 1;
hidg->req = NULL;
spin_lock_init(&hidg->read_spinlock);
spin_lock_init(&hidg->get_report_spinlock);
init_waitqueue_head(&hidg->write_queue);
init_waitqueue_head(&hidg->read_queue);
init_waitqueue_head(&hidg->get_queue);
init_waitqueue_head(&hidg->get_id_queue);
INIT_LIST_HEAD(&hidg->completed_out_req);
INIT_LIST_HEAD(&hidg->report_list);
INIT_WORK(&hidg->work, get_report_workqueue_handler);
hidg->workqueue = alloc_workqueue("report_work",
WQ_FREEZABLE |
WQ_MEM_RECLAIM,
1);
if (!hidg->workqueue) {
status = -ENOMEM;
goto fail;
}
/* create char device */
cdev_init(&hidg->cdev, &f_hidg_fops);
status = cdev_device_add(&hidg->cdev, &hidg->dev);
if (status)
goto fail_free_descs;
return 0;
fail_free_descs:
destroy_workqueue(hidg->workqueue);
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);
usb_ep_free_request(c->cdev->gadget->ep0, hidg->get_req);
hidg->get_req = NULL;
return status;
}
static inline int hidg_get_minor(void)
{
int ret;
ret = ida_alloc(&hidg_ida, GFP_KERNEL);
if (ret >= HIDG_MINORS) {
ida_free(&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(no_out_endpoint, 8, 1);
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_no_out_endpoint,
&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_free(&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);
put_device(&hidg->dev);
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);
cdev_device_del(&hidg->cdev, &hidg->dev);
destroy_workqueue(hidg->workqueue);
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;
int ret;
/* 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);
device_initialize(&hidg->dev);
hidg->dev.release = hidg_release;
hidg->dev.class = &hidg_class;
hidg->dev.devt = MKDEV(major, opts->minor);
ret = dev_set_name(&hidg->dev, "hidg%d", opts->minor);
if (ret)
goto err_unlock;
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) {
ret = -ENOMEM;
goto err_put_device;
}
}
hidg->use_out_ep = !opts->no_out_endpoint;
++opts->refcnt;
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 be made configurable at some point */
hidg->qlen = 4;
return &hidg->func;
err_put_device:
put_device(&hidg->dev);
err_unlock:
mutex_unlock(&opts->lock);
return ERR_PTR(ret);
}
DECLARE_USB_FUNCTION_INIT(hid, hidg_alloc_inst, hidg_alloc);
MODULE_DESCRIPTION("USB HID function driver");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Fabien Chouteau");
int ghid_setup(struct usb_gadget *g, int count)
{
int status;
dev_t dev;
status = class_register(&hidg_class);
if (status)
return status;
status = alloc_chrdev_region(&dev, 0, count, "hidg");
if (status) {
class_unregister(&hidg_class);
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_unregister(&hidg_class);
}
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