mirror of
https://github.com/cirosantilli/linux-kernel-module-cheat.git
synced 2026-01-25 19:21:35 +01:00
62 lines
1.2 KiB
C
62 lines
1.2 KiB
C
/*
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TODO: get handler running multiple times on some existing interrupt from /proc/interrupts.
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*/
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#include <asm/uaccess.h> /* copy_from_user, copy_to_user */
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#include <linux/fs.h>
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#include <linux/interrupt.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#define NAME "lkmc_character_device"
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MODULE_LICENSE("GPL");
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static int major;
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static int irq = 0;
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module_param_named(i, irq, int, S_IRUSR);
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MODULE_PARM_DESC(i, "irq line number");
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/**
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* Return value from kernel docs:*
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*
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* enum irqreturn
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* @IRQ_NON interrupt was not from this device or was not handled
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* @IRQ_HANDLED interrupt was handled by this device
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* @IRQ_WAKE_THREAD handler requests to wake the handler thread
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*/
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static irqreturn_t handler(int irq, void *v)
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{
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pr_info("handler irq = %d\n", irq);
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return IRQ_HANDLED;
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}
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static const struct file_operations fops;
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static int myinit(void)
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{
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int ret;
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major = register_chrdev(0, NAME, &fops);
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for (int i = 0; i < 128; ++i) {
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ret = request_irq(
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i,
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handler,
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IRQF_SHARED,
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"myirqhandler0",
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&major
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);
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pr_info("request_irq irq = %d ret = %d\n", i, ret);
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}
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return 0;
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}
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static void myexit(void)
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{
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free_irq(irq, NULL);
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unregister_chrdev(major, NAME);
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}
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module_init(myinit)
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module_exit(myexit)
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