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![Pali Rohár](/assets/img/avatar_default.png)
For security reasons I stopped using gmail account and kernel address is now up-to-date alias to my personal address. People periodically send me emails to address which they found in source code of drivers, so this change reflects state where people can contact me. [ Added .mailmap entry as per Joe Perches - Linus ] Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Joe Perches <joe@perches.com> Link: http://lkml.kernel.org/r/20200307104237.8199-1-pali@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
232 lines
5.4 KiB
C
232 lines
5.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* dell-smo8800.c - Dell Latitude ACPI SMO88XX freefall sensor driver
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*
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* Copyright (C) 2012 Sonal Santan <sonal.santan@gmail.com>
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* Copyright (C) 2014 Pali Rohár <pali@kernel.org>
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*
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* This is loosely based on lis3lv02d driver.
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*/
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#define DRIVER_NAME "smo8800"
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/acpi.h>
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#include <linux/interrupt.h>
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#include <linux/miscdevice.h>
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#include <linux/uaccess.h>
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#include <linux/fs.h>
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struct smo8800_device {
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u32 irq; /* acpi device irq */
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atomic_t counter; /* count after last read */
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struct miscdevice miscdev; /* for /dev/freefall */
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unsigned long misc_opened; /* whether the device is open */
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wait_queue_head_t misc_wait; /* Wait queue for the misc dev */
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struct device *dev; /* acpi device */
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};
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static irqreturn_t smo8800_interrupt_quick(int irq, void *data)
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{
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struct smo8800_device *smo8800 = data;
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atomic_inc(&smo8800->counter);
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wake_up_interruptible(&smo8800->misc_wait);
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return IRQ_WAKE_THREAD;
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}
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static irqreturn_t smo8800_interrupt_thread(int irq, void *data)
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{
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struct smo8800_device *smo8800 = data;
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dev_info(smo8800->dev, "detected free fall\n");
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return IRQ_HANDLED;
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}
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static acpi_status smo8800_get_resource(struct acpi_resource *resource,
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void *context)
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{
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struct acpi_resource_extended_irq *irq;
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if (resource->type != ACPI_RESOURCE_TYPE_EXTENDED_IRQ)
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return AE_OK;
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irq = &resource->data.extended_irq;
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if (!irq || !irq->interrupt_count)
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return AE_OK;
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*((u32 *)context) = irq->interrupts[0];
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return AE_CTRL_TERMINATE;
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}
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static u32 smo8800_get_irq(struct acpi_device *device)
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{
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u32 irq = 0;
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acpi_status status;
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status = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
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smo8800_get_resource, &irq);
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if (ACPI_FAILURE(status)) {
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dev_err(&device->dev, "acpi_walk_resources failed\n");
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return 0;
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}
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return irq;
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}
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static ssize_t smo8800_misc_read(struct file *file, char __user *buf,
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size_t count, loff_t *pos)
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{
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struct smo8800_device *smo8800 = container_of(file->private_data,
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struct smo8800_device, miscdev);
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u32 data = 0;
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unsigned char byte_data;
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ssize_t retval = 1;
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if (count < 1)
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return -EINVAL;
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atomic_set(&smo8800->counter, 0);
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retval = wait_event_interruptible(smo8800->misc_wait,
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(data = atomic_xchg(&smo8800->counter, 0)));
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if (retval)
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return retval;
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retval = 1;
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if (data < 255)
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byte_data = data;
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else
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byte_data = 255;
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if (put_user(byte_data, buf))
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retval = -EFAULT;
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return retval;
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}
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static int smo8800_misc_open(struct inode *inode, struct file *file)
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{
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struct smo8800_device *smo8800 = container_of(file->private_data,
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struct smo8800_device, miscdev);
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if (test_and_set_bit(0, &smo8800->misc_opened))
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return -EBUSY; /* already open */
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atomic_set(&smo8800->counter, 0);
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return 0;
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}
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static int smo8800_misc_release(struct inode *inode, struct file *file)
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{
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struct smo8800_device *smo8800 = container_of(file->private_data,
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struct smo8800_device, miscdev);
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clear_bit(0, &smo8800->misc_opened); /* release the device */
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return 0;
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}
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static const struct file_operations smo8800_misc_fops = {
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.owner = THIS_MODULE,
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.read = smo8800_misc_read,
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.open = smo8800_misc_open,
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.release = smo8800_misc_release,
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};
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static int smo8800_add(struct acpi_device *device)
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{
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int err;
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struct smo8800_device *smo8800;
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smo8800 = devm_kzalloc(&device->dev, sizeof(*smo8800), GFP_KERNEL);
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if (!smo8800) {
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dev_err(&device->dev, "failed to allocate device data\n");
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return -ENOMEM;
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}
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smo8800->dev = &device->dev;
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smo8800->miscdev.minor = MISC_DYNAMIC_MINOR;
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smo8800->miscdev.name = "freefall";
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smo8800->miscdev.fops = &smo8800_misc_fops;
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init_waitqueue_head(&smo8800->misc_wait);
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err = misc_register(&smo8800->miscdev);
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if (err) {
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dev_err(&device->dev, "failed to register misc dev: %d\n", err);
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return err;
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}
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device->driver_data = smo8800;
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smo8800->irq = smo8800_get_irq(device);
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if (!smo8800->irq) {
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dev_err(&device->dev, "failed to obtain IRQ\n");
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err = -EINVAL;
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goto error;
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}
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err = request_threaded_irq(smo8800->irq, smo8800_interrupt_quick,
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smo8800_interrupt_thread,
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IRQF_TRIGGER_RISING | IRQF_ONESHOT,
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DRIVER_NAME, smo8800);
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if (err) {
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dev_err(&device->dev,
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"failed to request thread for IRQ %d: %d\n",
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smo8800->irq, err);
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goto error;
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}
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dev_dbg(&device->dev, "device /dev/freefall registered with IRQ %d\n",
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smo8800->irq);
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return 0;
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error:
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misc_deregister(&smo8800->miscdev);
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return err;
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}
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static int smo8800_remove(struct acpi_device *device)
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{
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struct smo8800_device *smo8800 = device->driver_data;
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free_irq(smo8800->irq, smo8800);
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misc_deregister(&smo8800->miscdev);
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dev_dbg(&device->dev, "device /dev/freefall unregistered\n");
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return 0;
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}
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/* NOTE: Keep this list in sync with drivers/i2c/busses/i2c-i801.c */
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static const struct acpi_device_id smo8800_ids[] = {
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{ "SMO8800", 0 },
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{ "SMO8801", 0 },
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{ "SMO8810", 0 },
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{ "SMO8811", 0 },
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{ "SMO8820", 0 },
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{ "SMO8821", 0 },
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{ "SMO8830", 0 },
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{ "SMO8831", 0 },
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{ "", 0 },
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};
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MODULE_DEVICE_TABLE(acpi, smo8800_ids);
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static struct acpi_driver smo8800_driver = {
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.name = DRIVER_NAME,
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.class = "Latitude",
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.ids = smo8800_ids,
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.ops = {
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.add = smo8800_add,
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.remove = smo8800_remove,
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},
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.owner = THIS_MODULE,
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};
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module_acpi_driver(smo8800_driver);
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MODULE_DESCRIPTION("Dell Latitude freefall driver (ACPI SMO88XX)");
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Sonal Santan, Pali Rohár");
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