linux/drivers/hid/hidraw.c
Oliver Neukum 0361a28d3f HID: autosuspend support for USB HID
This uses the USB busy mechanism for aggessive autosuspend of USB
HID devices. It autosuspends all opened devices supporting remote wakeup
after a timeout unless

- output is being done to the device
- a key is being held down (remote wakeup isn't triggered upon key release)
- LED(s) are lit
- hiddev is opened

As in the current driver closed devices will be autosuspended even if they
don't support remote wakeup.

The patch is quite large because output to devices is done in hard interrupt
context meaning a lot a queuing and locking had to be touched. The LED stuff
has been solved by means of a simple counter. Additions to the generic HID code
could be avoided. In addition it now covers hidraw. It contains an embryonic
version of an API to let the generic HID code tell the lower levels which
capabilities with respect to power management are needed.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-03-25 17:57:57 +01:00

460 lines
10 KiB
C

/*
* HID raw devices, giving access to raw HID events.
*
* In comparison to hiddev, this device does not process the
* hid events at all (no parsing, no lookups). This lets applications
* to work on raw hid events as they want to, and avoids a need to
* use a transport-specific userspace libhid/libusb libraries.
*
* Copyright (c) 2007 Jiri Kosina
*/
/*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* 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.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/cdev.h>
#include <linux/poll.h>
#include <linux/device.h>
#include <linux/major.h>
#include <linux/hid.h>
#include <linux/mutex.h>
#include <linux/smp_lock.h>
#include <linux/hidraw.h>
static int hidraw_major;
static struct cdev hidraw_cdev;
static struct class *hidraw_class;
static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES];
static DEFINE_MUTEX(minors_lock);
static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
{
struct hidraw_list *list = file->private_data;
int ret = 0, len;
char *report;
DECLARE_WAITQUEUE(wait, current);
while (ret == 0) {
mutex_lock(&list->read_mutex);
if (list->head == list->tail) {
add_wait_queue(&list->hidraw->wait, &wait);
set_current_state(TASK_INTERRUPTIBLE);
while (list->head == list->tail) {
if (file->f_flags & O_NONBLOCK) {
ret = -EAGAIN;
break;
}
if (signal_pending(current)) {
ret = -ERESTARTSYS;
break;
}
if (!list->hidraw->exist) {
ret = -EIO;
break;
}
/* allow O_NONBLOCK to work well from other threads */
mutex_unlock(&list->read_mutex);
schedule();
mutex_lock(&list->read_mutex);
set_current_state(TASK_INTERRUPTIBLE);
}
set_current_state(TASK_RUNNING);
remove_wait_queue(&list->hidraw->wait, &wait);
}
if (ret)
goto out;
report = list->buffer[list->tail].value;
len = list->buffer[list->tail].len > count ?
count : list->buffer[list->tail].len;
if (copy_to_user(buffer, list->buffer[list->tail].value, len)) {
ret = -EFAULT;
goto out;
}
ret += len;
kfree(list->buffer[list->tail].value);
list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1);
}
out:
mutex_unlock(&list->read_mutex);
return ret;
}
/* the first byte is expected to be a report number */
static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
{
unsigned int minor = iminor(file->f_path.dentry->d_inode);
/* FIXME: What stops hidraw_table going NULL */
struct hid_device *dev = hidraw_table[minor]->hid;
__u8 *buf;
int ret = 0;
if (!dev->hid_output_raw_report)
return -ENODEV;
if (count > HID_MAX_BUFFER_SIZE) {
printk(KERN_WARNING "hidraw: pid %d passed too large report\n",
task_pid_nr(current));
return -EINVAL;
}
if (count < 2) {
printk(KERN_WARNING "hidraw: pid %d passed too short report\n",
task_pid_nr(current));
return -EINVAL;
}
buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
if (!buf)
return -ENOMEM;
if (copy_from_user(buf, buffer, count)) {
ret = -EFAULT;
goto out;
}
ret = dev->hid_output_raw_report(dev, buf, count);
out:
kfree(buf);
return ret;
}
static unsigned int hidraw_poll(struct file *file, poll_table *wait)
{
struct hidraw_list *list = file->private_data;
poll_wait(file, &list->hidraw->wait, wait);
if (list->head != list->tail)
return POLLIN | POLLRDNORM;
if (!list->hidraw->exist)
return POLLERR | POLLHUP;
return 0;
}
static int hidraw_open(struct inode *inode, struct file *file)
{
unsigned int minor = iminor(inode);
struct hidraw *dev;
struct hidraw_list *list;
int err = 0;
if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) {
err = -ENOMEM;
goto out;
}
lock_kernel();
mutex_lock(&minors_lock);
if (!hidraw_table[minor]) {
printk(KERN_EMERG "hidraw device with minor %d doesn't exist\n",
minor);
kfree(list);
err = -ENODEV;
goto out_unlock;
}
list->hidraw = hidraw_table[minor];
mutex_init(&list->read_mutex);
list_add_tail(&list->node, &hidraw_table[minor]->list);
file->private_data = list;
dev = hidraw_table[minor];
if (!dev->open++) {
if (dev->hid->ll_driver->power) {
err = dev->hid->ll_driver->power(dev->hid, PM_HINT_FULLON);
if (err < 0)
goto out_unlock;
}
err = dev->hid->ll_driver->open(dev->hid);
if (err < 0) {
if (dev->hid->ll_driver->power)
dev->hid->ll_driver->power(dev->hid, PM_HINT_NORMAL);
dev->open--;
}
}
out_unlock:
mutex_unlock(&minors_lock);
unlock_kernel();
out:
return err;
}
static int hidraw_release(struct inode * inode, struct file * file)
{
unsigned int minor = iminor(inode);
struct hidraw *dev;
struct hidraw_list *list = file->private_data;
if (!hidraw_table[minor]) {
printk(KERN_EMERG "hidraw device with minor %d doesn't exist\n",
minor);
return -ENODEV;
}
list_del(&list->node);
dev = hidraw_table[minor];
if (!--dev->open) {
if (list->hidraw->exist) {
if (dev->hid->ll_driver->power)
dev->hid->ll_driver->power(dev->hid, PM_HINT_NORMAL);
dev->hid->ll_driver->close(dev->hid);
} else {
kfree(list->hidraw);
}
}
kfree(list);
return 0;
}
static long hidraw_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct inode *inode = file->f_path.dentry->d_inode;
unsigned int minor = iminor(inode);
long ret = 0;
/* FIXME: What stops hidraw_table going NULL */
struct hidraw *dev = hidraw_table[minor];
void __user *user_arg = (void __user*) arg;
lock_kernel();
switch (cmd) {
case HIDIOCGRDESCSIZE:
if (put_user(dev->hid->rsize, (int __user *)arg))
ret = -EFAULT;
break;
case HIDIOCGRDESC:
{
__u32 len;
if (get_user(len, (int __user *)arg))
ret = -EFAULT;
else if (len > HID_MAX_DESCRIPTOR_SIZE - 1)
ret = -EINVAL;
else if (copy_to_user(user_arg + offsetof(
struct hidraw_report_descriptor,
value[0]),
dev->hid->rdesc,
min(dev->hid->rsize, len)))
ret = -EFAULT;
break;
}
case HIDIOCGRAWINFO:
{
struct hidraw_devinfo dinfo;
dinfo.bustype = dev->hid->bus;
dinfo.vendor = dev->hid->vendor;
dinfo.product = dev->hid->product;
if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
ret = -EFAULT;
break;
}
default:
{
struct hid_device *hid = dev->hid;
if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ) {
ret = -EINVAL;
break;
}
if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) {
int len;
if (!hid->name)
return 0;
len = strlen(hid->name) + 1;
if (len > _IOC_SIZE(cmd))
len = _IOC_SIZE(cmd);
ret = copy_to_user(user_arg, hid->name, len) ?
-EFAULT : len;
break;
}
if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWPHYS(0))) {
int len;
if (!hid->phys)
return 0;
len = strlen(hid->phys) + 1;
if (len > _IOC_SIZE(cmd))
len = _IOC_SIZE(cmd);
ret = copy_to_user(user_arg, hid->phys, len) ?
-EFAULT : len;
break;
}
}
ret = -ENOTTY;
}
unlock_kernel();
return ret;
}
static const struct file_operations hidraw_ops = {
.owner = THIS_MODULE,
.read = hidraw_read,
.write = hidraw_write,
.poll = hidraw_poll,
.open = hidraw_open,
.release = hidraw_release,
.unlocked_ioctl = hidraw_ioctl,
};
void hidraw_report_event(struct hid_device *hid, u8 *data, int len)
{
struct hidraw *dev = hid->hidraw;
struct hidraw_list *list;
list_for_each_entry(list, &dev->list, node) {
list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC);
list->buffer[list->head].len = len;
list->head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);
kill_fasync(&list->fasync, SIGIO, POLL_IN);
}
wake_up_interruptible(&dev->wait);
}
EXPORT_SYMBOL_GPL(hidraw_report_event);
int hidraw_connect(struct hid_device *hid)
{
int minor, result;
struct hidraw *dev;
/* TODO currently we accept any HID device. This should later
* probably be fixed to accept only those devices which provide
* non-input applications
*/
dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL);
if (!dev)
return -ENOMEM;
result = -EINVAL;
mutex_lock(&minors_lock);
for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) {
if (hidraw_table[minor])
continue;
hidraw_table[minor] = dev;
result = 0;
break;
}
if (result) {
mutex_unlock(&minors_lock);
kfree(dev);
goto out;
}
dev->dev = device_create(hidraw_class, &hid->dev, MKDEV(hidraw_major, minor),
NULL, "%s%d", "hidraw", minor);
if (IS_ERR(dev->dev)) {
hidraw_table[minor] = NULL;
mutex_unlock(&minors_lock);
result = PTR_ERR(dev->dev);
kfree(dev);
goto out;
}
mutex_unlock(&minors_lock);
init_waitqueue_head(&dev->wait);
INIT_LIST_HEAD(&dev->list);
dev->hid = hid;
dev->minor = minor;
dev->exist = 1;
hid->hidraw = dev;
out:
return result;
}
EXPORT_SYMBOL_GPL(hidraw_connect);
void hidraw_disconnect(struct hid_device *hid)
{
struct hidraw *hidraw = hid->hidraw;
hidraw->exist = 0;
mutex_lock(&minors_lock);
hidraw_table[hidraw->minor] = NULL;
mutex_unlock(&minors_lock);
device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor));
if (hidraw->open) {
hid->ll_driver->close(hid);
wake_up_interruptible(&hidraw->wait);
} else {
kfree(hidraw);
}
}
EXPORT_SYMBOL_GPL(hidraw_disconnect);
int __init hidraw_init(void)
{
int result;
dev_t dev_id;
result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR,
HIDRAW_MAX_DEVICES, "hidraw");
hidraw_major = MAJOR(dev_id);
if (result < 0) {
printk(KERN_WARNING "hidraw: can't get major number\n");
result = 0;
goto out;
}
hidraw_class = class_create(THIS_MODULE, "hidraw");
if (IS_ERR(hidraw_class)) {
result = PTR_ERR(hidraw_class);
unregister_chrdev(hidraw_major, "hidraw");
goto out;
}
cdev_init(&hidraw_cdev, &hidraw_ops);
cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
out:
return result;
}
void hidraw_exit(void)
{
dev_t dev_id = MKDEV(hidraw_major, 0);
cdev_del(&hidraw_cdev);
class_destroy(hidraw_class);
unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
}