HID: i2c-hid: disable runtime PM operations on hantick touchpad

[mirror_ubuntu-bionic-kernel.git] / drivers / hid / hidraw.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) 2007-2014 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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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/slab.h>
#include <linux/hid.h>
#include <linux/mutex.h>
#include <linux/sched/signal.h>
#include <linux/string.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;
        DECLARE_WAITQUEUE(wait, current);

        mutex_lock(&list->read_mutex);

        while (ret == 0) {
                if (list->head == list->tail) {
                        add_wait_queue(&list->hidraw->wait, &wait);
                        set_current_state(TASK_INTERRUPTIBLE);

                        while (list->head == list->tail) {
                                if (signal_pending(current)) {
                                        ret = -ERESTARTSYS;
                                        break;
                                }
                                if (!list->hidraw->exist) {
                                        ret = -EIO;
                                        break;
                                }
                                if (file->f_flags & O_NONBLOCK) {
                                        ret = -EAGAIN;
                                        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;

                len = list->buffer[list->tail].len > count ?
                        count : list->buffer[list->tail].len;

                if (list->buffer[list->tail].value) {
                        if (copy_to_user(buffer, list->buffer[list->tail].value, len)) {
                                ret = -EFAULT;
                                goto out;
                        }
                        ret = len;
                }

                kfree(list->buffer[list->tail].value);
                list->buffer[list->tail].value = NULL;
                list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1);
        }
out:
        mutex_unlock(&list->read_mutex);
        return ret;
}

/*
 * The first byte of the report buffer is expected to be a report number.
 *
 * This function is to be called with the minors_lock mutex held.
 */
static ssize_t hidraw_send_report(struct file *file, const char __user *buffer, size_t count, unsigned char report_type)
{
        unsigned int minor = iminor(file_inode(file));
        struct hid_device *dev;
        __u8 *buf;
        int ret = 0;

        if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
                ret = -ENODEV;
                goto out;
        }

        dev = hidraw_table[minor]->hid;

        if (count > HID_MAX_BUFFER_SIZE) {
                hid_warn(dev, "pid %d passed too large report\n",
                         task_pid_nr(current));
                ret = -EINVAL;
                goto out;
        }

        if (count < 2) {
                hid_warn(dev, "pid %d passed too short report\n",
                         task_pid_nr(current));
                ret = -EINVAL;
                goto out;
        }

        buf = memdup_user(buffer, count);
        if (IS_ERR(buf)) {
                ret = PTR_ERR(buf);
                goto out;
        }

        if ((report_type == HID_OUTPUT_REPORT) &&
            !(dev->quirks & HID_QUIRK_NO_OUTPUT_REPORTS_ON_INTR_EP)) {
                ret = hid_hw_output_report(dev, buf, count);
                /*
                 * compatibility with old implementation of USB-HID and I2C-HID:
                 * if the device does not support receiving output reports,
                 * on an interrupt endpoint, fallback to SET_REPORT HID command.
                 */
                if (ret != -ENOSYS)
                        goto out_free;
        }

        ret = hid_hw_raw_request(dev, buf[0], buf, count, report_type,
                                HID_REQ_SET_REPORT);

out_free:
        kfree(buf);
out:
        return ret;
}

static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
{
        ssize_t ret;
        mutex_lock(&minors_lock);
        ret = hidraw_send_report(file, buffer, count, HID_OUTPUT_REPORT);
        mutex_unlock(&minors_lock);
        return ret;
}


/*
 * This function performs a Get_Report transfer over the control endpoint
 * per section 7.2.1 of the HID specification, version 1.1.  The first byte
 * of buffer is the report number to request, or 0x0 if the defice does not
 * use numbered reports. The report_type parameter can be HID_FEATURE_REPORT
 * or HID_INPUT_REPORT.
 *
 * This function is to be called with the minors_lock mutex held.
 */
static ssize_t hidraw_get_report(struct file *file, char __user *buffer, size_t count, unsigned char report_type)
{
        unsigned int minor = iminor(file_inode(file));
        struct hid_device *dev;
        __u8 *buf;
        int ret = 0, len;
        unsigned char report_number;

        if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
                ret = -ENODEV;
                goto out;
        }

        dev = hidraw_table[minor]->hid;

        if (!dev->ll_driver->raw_request) {
                ret = -ENODEV;
                goto out;
        }

        if (count > HID_MAX_BUFFER_SIZE) {
                printk(KERN_WARNING "hidraw: pid %d passed too large report\n",
                                task_pid_nr(current));
                ret = -EINVAL;
                goto out;
        }

        if (count < 2) {
                printk(KERN_WARNING "hidraw: pid %d passed too short report\n",
                                task_pid_nr(current));
                ret = -EINVAL;
                goto out;
        }

        buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
        if (!buf) {
                ret = -ENOMEM;
                goto out;
        }

        /*
         * Read the first byte from the user. This is the report number,
         * which is passed to hid_hw_raw_request().
         */
        if (copy_from_user(&report_number, buffer, 1)) {
                ret = -EFAULT;
                goto out_free;
        }

        ret = hid_hw_raw_request(dev, report_number, buf, count, report_type,
                                 HID_REQ_GET_REPORT);

        if (ret < 0)
                goto out_free;

        len = (ret < count) ? ret : count;

        if (copy_to_user(buffer, buf, len)) {
                ret = -EFAULT;
                goto out_free;
        }

        ret = len;

out_free:
        kfree(buf);
out:
        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;
        unsigned long flags;
        int err = 0;

        if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) {
                err = -ENOMEM;
                goto out;
        }

        mutex_lock(&minors_lock);
        if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
                err = -ENODEV;
                goto out_unlock;
        }

        dev = hidraw_table[minor];
        if (!dev->open++) {
                err = hid_hw_power(dev->hid, PM_HINT_FULLON);
                if (err < 0) {
                        dev->open--;
                        goto out_unlock;
                }

                err = hid_hw_open(dev->hid);
                if (err < 0) {
                        hid_hw_power(dev->hid, PM_HINT_NORMAL);
                        dev->open--;
                        goto out_unlock;
                }
        }

        list->hidraw = hidraw_table[minor];
        mutex_init(&list->read_mutex);
        spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags);
        list_add_tail(&list->node, &hidraw_table[minor]->list);
        spin_unlock_irqrestore(&hidraw_table[minor]->list_lock, flags);
        file->private_data = list;
out_unlock:
        mutex_unlock(&minors_lock);
out:
        if (err < 0)
                kfree(list);
        return err;

}

static int hidraw_fasync(int fd, struct file *file, int on)
{
        struct hidraw_list *list = file->private_data;

        return fasync_helper(fd, file, on, &list->fasync);
}

static void drop_ref(struct hidraw *hidraw, int exists_bit)
{
        if (exists_bit) {
                hidraw->exist = 0;
                if (hidraw->open) {
                        hid_hw_close(hidraw->hid);
                        wake_up_interruptible(&hidraw->wait);
                }
                device_destroy(hidraw_class,
                               MKDEV(hidraw_major, hidraw->minor));
        } else {
                --hidraw->open;
        }
        if (!hidraw->open) {
                if (!hidraw->exist) {
                        hidraw_table[hidraw->minor] = NULL;
                        kfree(hidraw);
                } else {
                        /* close device for last reader */
                        hid_hw_close(hidraw->hid);
                        hid_hw_power(hidraw->hid, PM_HINT_NORMAL);
                }
        }
}

static int hidraw_release(struct inode * inode, struct file * file)
{
        unsigned int minor = iminor(inode);
        struct hidraw_list *list = file->private_data;
        unsigned long flags;

        mutex_lock(&minors_lock);

        spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags);
        list_del(&list->node);
        spin_unlock_irqrestore(&hidraw_table[minor]->list_lock, flags);
        kfree(list);

        drop_ref(hidraw_table[minor], 0);

        mutex_unlock(&minors_lock);
        return 0;
}

static long hidraw_ioctl(struct file *file, unsigned int cmd,
                                                        unsigned long arg)
{
        struct inode *inode = file_inode(file);
        unsigned int minor = iminor(inode);
        long ret = 0;
        struct hidraw *dev;
        void __user *user_arg = (void __user*) arg;

        mutex_lock(&minors_lock);
        dev = hidraw_table[minor];
        if (!dev) {
                ret = -ENODEV;
                goto out;
        }

        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') {
                                        ret = -EINVAL;
                                        break;
                                }

                                if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSFEATURE(0))) {
                                        int len = _IOC_SIZE(cmd);
                                        ret = hidraw_send_report(file, user_arg, len, HID_FEATURE_REPORT);
                                        break;
                                }
                                if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGFEATURE(0))) {
                                        int len = _IOC_SIZE(cmd);
                                        ret = hidraw_get_report(file, user_arg, len, HID_FEATURE_REPORT);
                                        break;
                                }

                                /* Begin Read-only ioctls. */
                                if (_IOC_DIR(cmd) != _IOC_READ) {
                                        ret = -EINVAL;
                                        break;
                                }

                                if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) {
                                        int 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 = 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;
        }
out:
        mutex_unlock(&minors_lock);
        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,
        .fasync =       hidraw_fasync,
#ifdef CONFIG_COMPAT
        .compat_ioctl   = hidraw_ioctl,
#endif
        .llseek =       noop_llseek,
};

int hidraw_report_event(struct hid_device *hid, u8 *data, int len)
{
        struct hidraw *dev = hid->hidraw;
        struct hidraw_list *list;
        int ret = 0;
        unsigned long flags;

        spin_lock_irqsave(&dev->list_lock, flags);
        list_for_each_entry(list, &dev->list, node) {
                int new_head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);

                if (new_head == list->tail)
                        continue;

                if (!(list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC))) {
                        ret = -ENOMEM;
                        break;
                }
                list->buffer[list->head].len = len;
                list->head = new_head;
                kill_fasync(&list->fasync, SIGIO, POLL_IN);
        }
        spin_unlock_irqrestore(&dev->list_lock, flags);

        wake_up_interruptible(&dev->wait);
        return ret;
}
EXPORT_SYMBOL_GPL(hidraw_report_event);

int hidraw_connect(struct hid_device *hid)
{
        int minor, result;
        struct hidraw *dev;

        /* we accept any HID device, all 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;
        }

        init_waitqueue_head(&dev->wait);
        spin_lock_init(&dev->list_lock);
        INIT_LIST_HEAD(&dev->list);

        dev->hid = hid;
        dev->minor = minor;

        dev->exist = 1;
        hid->hidraw = dev;

        mutex_unlock(&minors_lock);
out:
        return result;

}
EXPORT_SYMBOL_GPL(hidraw_connect);

void hidraw_disconnect(struct hid_device *hid)
{
        struct hidraw *hidraw = hid->hidraw;

        mutex_lock(&minors_lock);

        drop_ref(hidraw, 1);

        mutex_unlock(&minors_lock);
}
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");
        if (result < 0) {
                pr_warn("can't get major number\n");
                goto out;
        }

        hidraw_major = MAJOR(dev_id);

        hidraw_class = class_create(THIS_MODULE, "hidraw");
        if (IS_ERR(hidraw_class)) {
                result = PTR_ERR(hidraw_class);
                goto error_cdev;
        }

        cdev_init(&hidraw_cdev, &hidraw_ops);
        result = cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
        if (result < 0)
                goto error_class;

        printk(KERN_INFO "hidraw: raw HID events driver (C) Jiri Kosina\n");
out:
        return result;

error_class:
        class_destroy(hidraw_class);
error_cdev:
        unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
        goto out;
}

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);

}