128 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			128 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * (C) Copyright IBM Corp. 2004
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 * tape_class.c
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 *
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 * Tape class device support
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 *
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 * Author: Stefan Bader <shbader@de.ibm.com>
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 * Based on simple class device code by Greg K-H
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 */
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#include "tape_class.h"
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MODULE_AUTHOR("Stefan Bader <shbader@de.ibm.com>");
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MODULE_DESCRIPTION(
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	"(C) Copyright IBM Corp. 2004   All Rights Reserved.\n"
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	"tape_class.c"
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);
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MODULE_LICENSE("GPL");
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static struct class *tape_class;
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/*
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 * Register a tape device and return a pointer to the cdev structure.
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 *
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 * device
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 *	The pointer to the struct device of the physical (base) device.
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 * drivername
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 *	The pointer to the drivers name for it's character devices.
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 * dev
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 *	The intended major/minor number. The major number may be 0 to
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 *	get a dynamic major number.
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 * fops
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 *	The pointer to the drivers file operations for the tape device.
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 * devname
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 *	The pointer to the name of the character device.
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 */
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struct tape_class_device *register_tape_dev(
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	struct device *		device,
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	dev_t			dev,
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	const struct file_operations *fops,
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	char *			device_name,
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	char *			mode_name)
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{
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	struct tape_class_device *	tcd;
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	int		rc;
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	char *		s;
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	tcd = kzalloc(sizeof(struct tape_class_device), GFP_KERNEL);
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	if (!tcd)
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		return ERR_PTR(-ENOMEM);
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	strncpy(tcd->device_name, device_name, TAPECLASS_NAME_LEN);
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	for (s = strchr(tcd->device_name, '/'); s; s = strchr(s, '/'))
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		*s = '!';
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	strncpy(tcd->mode_name, mode_name, TAPECLASS_NAME_LEN);
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	for (s = strchr(tcd->mode_name, '/'); s; s = strchr(s, '/'))
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		*s = '!';
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	tcd->char_device = cdev_alloc();
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	if (!tcd->char_device) {
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		rc = -ENOMEM;
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		goto fail_with_tcd;
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	}
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	tcd->char_device->owner = fops->owner;
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	tcd->char_device->ops   = fops;
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	tcd->char_device->dev   = dev;
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	rc = cdev_add(tcd->char_device, tcd->char_device->dev, 1);
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	if (rc)
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		goto fail_with_cdev;
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	tcd->class_device = device_create(tape_class, device,
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					  tcd->char_device->dev, NULL,
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					  "%s", tcd->device_name);
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	rc = IS_ERR(tcd->class_device) ? PTR_ERR(tcd->class_device) : 0;
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	if (rc)
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		goto fail_with_cdev;
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	rc = sysfs_create_link(
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		&device->kobj,
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		&tcd->class_device->kobj,
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		tcd->mode_name
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	);
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	if (rc)
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		goto fail_with_class_device;
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	return tcd;
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fail_with_class_device:
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	device_destroy(tape_class, tcd->char_device->dev);
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fail_with_cdev:
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	cdev_del(tcd->char_device);
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fail_with_tcd:
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	kfree(tcd);
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	return ERR_PTR(rc);
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}
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EXPORT_SYMBOL(register_tape_dev);
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void unregister_tape_dev(struct device *device, struct tape_class_device *tcd)
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{
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	if (tcd != NULL && !IS_ERR(tcd)) {
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		sysfs_remove_link(&device->kobj, tcd->mode_name);
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		device_destroy(tape_class, tcd->char_device->dev);
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		cdev_del(tcd->char_device);
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		kfree(tcd);
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	}
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}
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EXPORT_SYMBOL(unregister_tape_dev);
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static int __init tape_init(void)
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{
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	tape_class = class_create(THIS_MODULE, "tape390");
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	return 0;
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}
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static void __exit tape_exit(void)
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{
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	class_destroy(tape_class);
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	tape_class = NULL;
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}
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postcore_initcall(tape_init);
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module_exit(tape_exit);
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