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kernel-ark/drivers/usb/input/hiddev.c
David Howells 7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers 
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00

843 lines
20 KiB
C
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/*
* Copyright (c) 2001 Paul Stewart
* Copyright (c) 2001 Vojtech Pavlik
*
* HID char devices, giving access to raw HID device events.
*
*/
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Should you need to contact me, the author, you can do so either by
* e-mail - mail your message to Paul Stewart <stewart@wetlogic.net>
*/
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/smp_lock.h>
#include <linux/input.h>
#include <linux/usb.h>
#include "hid.h"
#include <linux/hiddev.h>
#ifdef CONFIG_USB_DYNAMIC_MINORS
#define HIDDEV_MINOR_BASE 0
#define HIDDEV_MINORS 256
#else
#define HIDDEV_MINOR_BASE 96
#define HIDDEV_MINORS 16
#endif
#define HIDDEV_BUFFER_SIZE 64
struct hiddev {
int exist;
int open;
wait_queue_head_t wait;
struct hid_device *hid;
struct list_head list;
};
struct hiddev_list {
struct hiddev_usage_ref buffer[HIDDEV_BUFFER_SIZE];
int head;
int tail;
unsigned flags;
struct fasync_struct *fasync;
struct hiddev *hiddev;
struct list_head node;
};
static struct hiddev *hiddev_table[HIDDEV_MINORS];
/*
* Find a report, given the report's type and ID. The ID can be specified
* indirectly by REPORT_ID_FIRST (which returns the first report of the given
* type) or by (REPORT_ID_NEXT | old_id), which returns the next report of the
* given type which follows old_id.
*/
static struct hid_report *
hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
{
unsigned int flags = rinfo->report_id & ~HID_REPORT_ID_MASK;
unsigned int rid = rinfo->report_id & HID_REPORT_ID_MASK;
struct hid_report_enum *report_enum;
struct hid_report *report;
struct list_head *list;
if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
rinfo->report_type > HID_REPORT_TYPE_MAX)
return NULL;
report_enum = hid->report_enum +
(rinfo->report_type - HID_REPORT_TYPE_MIN);
switch (flags) {
case 0: /* Nothing to do -- report_id is already set correctly */
break;
case HID_REPORT_ID_FIRST:
if (list_empty(&report_enum->report_list))
return NULL;
list = report_enum->report_list.next;
report = list_entry(list, struct hid_report, list);
rinfo->report_id = report->id;
break;
case HID_REPORT_ID_NEXT:
report = report_enum->report_id_hash[rid];
if (!report)
return NULL;
list = report->list.next;
if (list == &report_enum->report_list)
return NULL;
report = list_entry(list, struct hid_report, list);
rinfo->report_id = report->id;
break;
default:
return NULL;
}
return report_enum->report_id_hash[rinfo->report_id];
}
/*
* Perform an exhaustive search of the report table for a usage, given its
* type and usage id.
*/
static struct hid_field *
hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
{
int i, j;
struct hid_report *report;
struct hid_report_enum *report_enum;
struct hid_field *field;
if (uref->report_type < HID_REPORT_TYPE_MIN ||
uref->report_type > HID_REPORT_TYPE_MAX)
return NULL;
report_enum = hid->report_enum +
(uref->report_type - HID_REPORT_TYPE_MIN);
list_for_each_entry(report, &report_enum->report_list, list) {
for (i = 0; i < report->maxfield; i++) {
field = report->field[i];
for (j = 0; j < field->maxusage; j++) {
if (field->usage[j].hid == uref->usage_code) {
uref->report_id = report->id;
uref->field_index = i;
uref->usage_index = j;
return field;
}
}
}
}
return NULL;
}
static void hiddev_send_event(struct hid_device *hid,
struct hiddev_usage_ref *uref)
{
struct hiddev *hiddev = hid->hiddev;
struct hiddev_list *list;
list_for_each_entry(list, &hiddev->list, node) {
if (uref->field_index != HID_FIELD_INDEX_NONE ||
(list->flags & HIDDEV_FLAG_REPORT) != 0) {
list->buffer[list->head] = *uref;
list->head = (list->head + 1) &
(HIDDEV_BUFFER_SIZE - 1);
kill_fasync(&list->fasync, SIGIO, POLL_IN);
}
}
wake_up_interruptible(&hiddev->wait);
}
/*
* This is where hid.c calls into hiddev to pass an event that occurred over
* the interrupt pipe
*/
void hiddev_hid_event(struct hid_device *hid, struct hid_field *field,
struct hid_usage *usage, __s32 value)
{
unsigned type = field->report_type;
struct hiddev_usage_ref uref;
uref.report_type =
(type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
uref.report_id = field->report->id;
uref.field_index = field->index;
uref.usage_index = (usage - field->usage);
uref.usage_code = usage->hid;
uref.value = value;
hiddev_send_event(hid, &uref);
}
void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
{
unsigned type = report->type;
struct hiddev_usage_ref uref;
memset(&uref, 0, sizeof(uref));
uref.report_type =
(type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
uref.report_id = report->id;
uref.field_index = HID_FIELD_INDEX_NONE;
hiddev_send_event(hid, &uref);
}
/*
* fasync file op
*/
static int hiddev_fasync(int fd, struct file *file, int on)
{
int retval;
struct hiddev_list *list = file->private_data;
retval = fasync_helper(fd, file, on, &list->fasync);
return retval < 0 ? retval : 0;
}
/*
* release file op
*/
static int hiddev_release(struct inode * inode, struct file * file)
{
struct hiddev_list *list = file->private_data;
hiddev_fasync(-1, file, 0);
list_del(&list->node);
if (!--list->hiddev->open) {
if (list->hiddev->exist)
hid_close(list->hiddev->hid);
else
kfree(list->hiddev);
}
kfree(list);
return 0;
}
/*
* open file op
*/
static int hiddev_open(struct inode *inode, struct file *file)
{
struct hiddev_list *list;
int i = iminor(inode) - HIDDEV_MINOR_BASE;
if (i >= HIDDEV_MINORS || !hiddev_table[i])
return -ENODEV;
if (!(list = kzalloc(sizeof(struct hiddev_list), GFP_KERNEL)))
return -ENOMEM;
list->hiddev = hiddev_table[i];
list_add_tail(&list->node, &hiddev_table[i]->list);
file->private_data = list;
if (!list->hiddev->open++)
if (list->hiddev->exist)
hid_open(hiddev_table[i]->hid);
return 0;
}
/*
* "write" file op
*/
static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
{
return -EINVAL;
}
/*
* "read" file op
*/
static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
{
DECLARE_WAITQUEUE(wait, current);
struct hiddev_list *list = file->private_data;
int event_size;
int retval = 0;
event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
if (count < event_size)
return 0;
while (retval == 0) {
if (list->head == list->tail) {
add_wait_queue(&list->hiddev->wait, &wait);
set_current_state(TASK_INTERRUPTIBLE);
while (list->head == list->tail) {
if (file->f_flags & O_NONBLOCK) {
retval = -EAGAIN;
break;
}
if (signal_pending(current)) {
retval = -ERESTARTSYS;
break;
}
if (!list->hiddev->exist) {
retval = -EIO;
break;
}
schedule();
set_current_state(TASK_INTERRUPTIBLE);
}
set_current_state(TASK_RUNNING);
remove_wait_queue(&list->hiddev->wait, &wait);
}
if (retval)
return retval;
while (list->head != list->tail &&
retval + event_size <= count) {
if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
if (list->buffer[list->tail].field_index !=
HID_FIELD_INDEX_NONE) {
struct hiddev_event event;
event.hid = list->buffer[list->tail].usage_code;
event.value = list->buffer[list->tail].value;
if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event)))
return -EFAULT;
retval += sizeof(struct hiddev_event);
}
} else {
if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
(list->flags & HIDDEV_FLAG_REPORT) != 0) {
if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref)))
return -EFAULT;
retval += sizeof(struct hiddev_usage_ref);
}
}
list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
}
}
return retval;
}
/*
* "poll" file op
* No kernel lock - fine
*/
static unsigned int hiddev_poll(struct file *file, poll_table *wait)
{
struct hiddev_list *list = file->private_data;
poll_wait(file, &list->hiddev->wait, wait);
if (list->head != list->tail)
return POLLIN | POLLRDNORM;
if (!list->hiddev->exist)
return POLLERR | POLLHUP;
return 0;
}
/*
* "ioctl" file op
*/
static int hiddev_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
struct hiddev_list *list = file->private_data;
struct hiddev *hiddev = list->hiddev;
struct hid_device *hid = hiddev->hid;
struct usb_device *dev = hid->dev;
struct hiddev_collection_info cinfo;
struct hiddev_report_info rinfo;
struct hiddev_field_info finfo;
struct hiddev_usage_ref_multi *uref_multi = NULL;
struct hiddev_usage_ref *uref;
struct hiddev_devinfo dinfo;
struct hid_report *report;
struct hid_field *field;
void __user *user_arg = (void __user *)arg;
int i;
if (!hiddev->exist)
return -EIO;
switch (cmd) {
case HIDIOCGVERSION:
return put_user(HID_VERSION, (int __user *)arg);
case HIDIOCAPPLICATION:
if (arg < 0 || arg >= hid->maxapplication)
return -EINVAL;
for (i = 0; i < hid->maxcollection; i++)
if (hid->collection[i].type ==
HID_COLLECTION_APPLICATION && arg-- == 0)
break;
if (i == hid->maxcollection)
return -EINVAL;
return hid->collection[i].usage;
case HIDIOCGDEVINFO:
dinfo.bustype = BUS_USB;
dinfo.busnum = dev->bus->busnum;
dinfo.devnum = dev->devnum;
dinfo.ifnum = hid->ifnum;
dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
dinfo.num_applications = hid->maxapplication;
if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
return -EFAULT;
return 0;
case HIDIOCGFLAG:
if (put_user(list->flags, (int __user *)arg))
return -EFAULT;
return 0;
case HIDIOCSFLAG:
{
int newflags;
if (get_user(newflags, (int __user *)arg))
return -EFAULT;
if ((newflags & ~HIDDEV_FLAGS) != 0 ||
((newflags & HIDDEV_FLAG_REPORT) != 0 &&
(newflags & HIDDEV_FLAG_UREF) == 0))
return -EINVAL;
list->flags = newflags;
return 0;
}
case HIDIOCGSTRING:
{
int idx, len;
char *buf;
if (get_user(idx, (int __user *)arg))
return -EFAULT;
if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
return -ENOMEM;
if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
kfree(buf);
return -EINVAL;
}
if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
kfree(buf);
return -EFAULT;
}
kfree(buf);
return len;
}
case HIDIOCINITREPORT:
hid_init_reports(hid);
return 0;
case HIDIOCGREPORT:
if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
return -EFAULT;
if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
return -EINVAL;
if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
return -EINVAL;
hid_submit_report(hid, report, USB_DIR_IN);
hid_wait_io(hid);
return 0;
case HIDIOCSREPORT:
if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
return -EFAULT;
if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
return -EINVAL;
if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
return -EINVAL;
hid_submit_report(hid, report, USB_DIR_OUT);
hid_wait_io(hid);
return 0;
case HIDIOCGREPORTINFO:
if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
return -EFAULT;
if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
return -EINVAL;
rinfo.num_fields = report->maxfield;
if (copy_to_user(user_arg, &rinfo, sizeof(rinfo)))
return -EFAULT;
return 0;
case HIDIOCGFIELDINFO:
if (copy_from_user(&finfo, user_arg, sizeof(finfo)))
return -EFAULT;
rinfo.report_type = finfo.report_type;
rinfo.report_id = finfo.report_id;
if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
return -EINVAL;
if (finfo.field_index >= report->maxfield)
return -EINVAL;
field = report->field[finfo.field_index];
memset(&finfo, 0, sizeof(finfo));
finfo.report_type = rinfo.report_type;
finfo.report_id = rinfo.report_id;
finfo.field_index = field->report_count - 1;
finfo.maxusage = field->maxusage;
finfo.flags = field->flags;
finfo.physical = field->physical;
finfo.logical = field->logical;
finfo.application = field->application;
finfo.logical_minimum = field->logical_minimum;
finfo.logical_maximum = field->logical_maximum;
finfo.physical_minimum = field->physical_minimum;
finfo.physical_maximum = field->physical_maximum;
finfo.unit_exponent = field->unit_exponent;
finfo.unit = field->unit;
if (copy_to_user(user_arg, &finfo, sizeof(finfo)))
return -EFAULT;
return 0;
case HIDIOCGUCODE:
uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
if (!uref_multi)
return -ENOMEM;
uref = &uref_multi->uref;
if (copy_from_user(uref, user_arg, sizeof(*uref)))
goto fault;
rinfo.report_type = uref->report_type;
rinfo.report_id = uref->report_id;
if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
goto inval;
if (uref->field_index >= report->maxfield)
goto inval;
field = report->field[uref->field_index];
if (uref->usage_index >= field->maxusage)
goto inval;
uref->usage_code = field->usage[uref->usage_index].hid;
if (copy_to_user(user_arg, uref, sizeof(*uref)))
goto fault;
kfree(uref_multi);
return 0;
case HIDIOCGUSAGE:
case HIDIOCSUSAGE:
case HIDIOCGUSAGES:
case HIDIOCSUSAGES:
case HIDIOCGCOLLECTIONINDEX:
uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
if (!uref_multi)
return -ENOMEM;
uref = &uref_multi->uref;
if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
if (copy_from_user(uref_multi, user_arg,
sizeof(*uref_multi)))
goto fault;
} else {
if (copy_from_user(uref, user_arg, sizeof(*uref)))
goto fault;
}
if (cmd != HIDIOCGUSAGE &&
cmd != HIDIOCGUSAGES &&
uref->report_type == HID_REPORT_TYPE_INPUT)
goto inval;
if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
field = hiddev_lookup_usage(hid, uref);
if (field == NULL)
goto inval;
} else {
rinfo.report_type = uref->report_type;
rinfo.report_id = uref->report_id;
if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
goto inval;
if (uref->field_index >= report->maxfield)
goto inval;
field = report->field[uref->field_index];
if (cmd == HIDIOCGCOLLECTIONINDEX) {
if (uref->usage_index >= field->maxusage)
goto inval;
} else if (uref->usage_index >= field->report_count)
goto inval;
else if ((cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) &&
(uref_multi->num_values > HID_MAX_MULTI_USAGES ||
uref->usage_index + uref_multi->num_values > field->report_count))
goto inval;
}
switch (cmd) {
case HIDIOCGUSAGE:
uref->value = field->value[uref->usage_index];
if (copy_to_user(user_arg, uref, sizeof(*uref)))
goto fault;
goto goodreturn;
case HIDIOCSUSAGE:
field->value[uref->usage_index] = uref->value;
goto goodreturn;
case HIDIOCGCOLLECTIONINDEX:
kfree(uref_multi);
return field->usage[uref->usage_index].collection_index;
case HIDIOCGUSAGES:
for (i = 0; i < uref_multi->num_values; i++)
uref_multi->values[i] =
field->value[uref->usage_index + i];
if (copy_to_user(user_arg, uref_multi,
sizeof(*uref_multi)))
goto fault;
goto goodreturn;
case HIDIOCSUSAGES:
for (i = 0; i < uref_multi->num_values; i++)
field->value[uref->usage_index + i] =
uref_multi->values[i];
goto goodreturn;
}
goodreturn:
kfree(uref_multi);
return 0;
fault:
kfree(uref_multi);
return -EFAULT;
inval:
kfree(uref_multi);
return -EINVAL;
case HIDIOCGCOLLECTIONINFO:
if (copy_from_user(&cinfo, user_arg, sizeof(cinfo)))
return -EFAULT;
if (cinfo.index >= hid->maxcollection)
return -EINVAL;
cinfo.type = hid->collection[cinfo.index].type;
cinfo.usage = hid->collection[cinfo.index].usage;
cinfo.level = hid->collection[cinfo.index].level;
if (copy_to_user(user_arg, &cinfo, sizeof(cinfo)))
return -EFAULT;
return 0;
default:
if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
return -EINVAL;
if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
int len;
if (!hid->name)
return 0;
len = strlen(hid->name) + 1;
if (len > _IOC_SIZE(cmd))
len = _IOC_SIZE(cmd);
return copy_to_user(user_arg, hid->name, len) ?
-EFAULT : len;
}
if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
int len;
if (!hid->phys)
return 0;
len = strlen(hid->phys) + 1;
if (len > _IOC_SIZE(cmd))
len = _IOC_SIZE(cmd);
return copy_to_user(user_arg, hid->phys, len) ?
-EFAULT : len;
}
}
return -EINVAL;
}
static const struct file_operations hiddev_fops = {
.owner = THIS_MODULE,
.read = hiddev_read,
.write = hiddev_write,
.poll = hiddev_poll,
.open = hiddev_open,
.release = hiddev_release,
.ioctl = hiddev_ioctl,
.fasync = hiddev_fasync,
};
static struct usb_class_driver hiddev_class = {
.name = "hiddev%d",
.fops = &hiddev_fops,
.minor_base = HIDDEV_MINOR_BASE,
};
/*
* This is where hid.c calls us to connect a hid device to the hiddev driver
*/
int hiddev_connect(struct hid_device *hid)
{
struct hiddev *hiddev;
int i;
int retval;
for (i = 0; i < hid->maxcollection; i++)
if (hid->collection[i].type ==
HID_COLLECTION_APPLICATION &&
!IS_INPUT_APPLICATION(hid->collection[i].usage))
break;
if (i == hid->maxcollection && (hid->quirks & HID_QUIRK_HIDDEV) == 0)
return -1;
if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
return -1;
retval = usb_register_dev(hid->intf, &hiddev_class);
if (retval) {
err("Not able to get a minor for this device.");
kfree(hiddev);
return -1;
}
init_waitqueue_head(&hiddev->wait);
INIT_LIST_HEAD(&hiddev->list);
hiddev->hid = hid;
hiddev->exist = 1;
hid->minor = hid->intf->minor;
hid->hiddev = hiddev;
hiddev_table[hid->intf->minor - HIDDEV_MINOR_BASE] = hiddev;
return 0;
}
/*
* This is where hid.c calls us to disconnect a hiddev device from the
* corresponding hid device (usually because the usb device has disconnected)
*/
static struct usb_class_driver hiddev_class;
void hiddev_disconnect(struct hid_device *hid)
{
struct hiddev *hiddev = hid->hiddev;
hiddev->exist = 0;
hiddev_table[hiddev->hid->minor - HIDDEV_MINOR_BASE] = NULL;
usb_deregister_dev(hiddev->hid->intf, &hiddev_class);
if (hiddev->open) {
hid_close(hiddev->hid);
wake_up_interruptible(&hiddev->wait);
} else {
kfree(hiddev);
}
}
/* Currently this driver is a USB driver. It's not a conventional one in
* the sense that it doesn't probe at the USB level. Instead it waits to
* be connected by HID through the hiddev_connect / hiddev_disconnect
* routines. The reason to register as a USB device is to gain part of the
* minor number space from the USB major.
*
* In theory, should the HID code be generalized to more than one physical
* medium (say, IEEE 1384), this driver will probably need to register its
* own major number, and in doing so, no longer need to register with USB.
* At that point the probe routine and hiddev_driver struct below will no
* longer be useful.
*/
/* We never attach in this manner, and rely on HID to connect us. This
* is why there is no disconnect routine defined in the usb_driver either.
*/
static int hiddev_usbd_probe(struct usb_interface *intf,
const struct usb_device_id *hiddev_info)
{
return -ENODEV;
}
static /* const */ struct usb_driver hiddev_driver = {
.name = "hiddev",
.probe = hiddev_usbd_probe,
};
int __init hiddev_init(void)
{
return usb_register(&hiddev_driver);
}
void hiddev_exit(void)
{
usb_deregister(&hiddev_driver);
}
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