62 lines
2.1 KiB
C
62 lines
2.1 KiB
C
// SPDX-FileCopyrightText: 2024 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
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// SPDX-License-Identifier: GPL-3.0-only
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#include "jfjoch_drv.h"
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#include <linux/module.h>
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#include <linux/spinlock.h>
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static int device_index = 0;
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int jfjoch_register_misc_dev(struct pci_dev *pdev) {
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int err;
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struct jfjoch_drvdata *drvdata = pci_get_drvdata(pdev);
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drvdata->file_write_open_count = 0;
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spin_lock_init(&drvdata->file_write_open_count_spinlock);
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snprintf( drvdata->name, 255, "jfjoch%d", device_index++);
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drvdata->miscdev.parent = &pdev->dev;
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drvdata->miscdev.mode = 0664;
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drvdata->miscdev.minor = MISC_DYNAMIC_MINOR;
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drvdata->miscdev.fops = &jfjoch_cdev_fileops;
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drvdata->miscdev.name = drvdata->name;
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err = misc_register(&drvdata->miscdev);
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if (err)
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pr_notice("Misc device registration failed\n");
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return err;
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}
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void jfjoch_unregister_misc_dev(struct pci_dev *pdev) {
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struct jfjoch_drvdata *drvdata = pci_get_drvdata(pdev);
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misc_deregister(&drvdata->miscdev);
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}
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int jfjoch_cdev_open(struct inode *inode, struct file *file) {
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struct jfjoch_drvdata *drvdata = container_of(file->private_data, struct jfjoch_drvdata, miscdev);
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bool ok = true;
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if (file->f_mode & FMODE_WRITE) {
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unsigned long flags;
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spin_lock_irqsave(&drvdata->file_write_open_count_spinlock, flags);
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ok = (drvdata->file_write_open_count == 0);
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drvdata->file_write_open_count = 1;
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spin_unlock_irqrestore(&drvdata->file_write_open_count_spinlock, flags);
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}
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if (!ok)
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return -EBUSY;
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return 0;
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}
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int jfjoch_cdev_release(struct inode *inode, struct file *file) {
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struct jfjoch_drvdata *drvdata = container_of(file->private_data, struct jfjoch_drvdata, miscdev);
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if (file->f_mode & FMODE_WRITE) {
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unsigned long flags;
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jfjoch_cancel(drvdata);
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spin_lock_irqsave(&drvdata->file_write_open_count_spinlock, flags);
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drvdata->file_write_open_count = 0;
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spin_unlock_irqrestore(&drvdata->file_write_open_count_spinlock, flags);
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}
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return 0;
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}
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