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232 lines
5.4 KiB
232 lines
5.4 KiB
// 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 <[email protected]> |
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* Copyright (C) 2014 Pali Rohár <[email protected]> |
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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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