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irq kind of works!

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Ciro Santilli
2017-06-15 11:40:20 +01:00
parent 5a4e0ed50b
commit 4eae56e36f
1 changed files with 43 additions and 14 deletions
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57
kernel_module/irq.c
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@@ -1,44 +1,73 @@
/* /*
TODO: get handler running multiple times on some existing interrupt from /proc/interrupts. TODO: get handler running multiple times on some existing interrupt from /proc/interrupts.
Inside QEMU, try:
watch -n 1 cat /proc/interrupts
Then see how clicking the mouse and keyboard affect the interrupts. This will point you to:
- 1: keyboard
- 12: mouse click and drags
Likely this uses some old and simple serial interface that QEMU implements:
USB mouses and keyboards are not that nice.
*/ */
#include <asm/uaccess.h> /* copy_from_user, copy_to_user */
#include <linux/fs.h>
#include <linux/interrupt.h> #include <linux/interrupt.h>
#include <linux/jiffies.h>
#include <linux/kernel.h> #include <linux/kernel.h>
#include <linux/module.h> #include <linux/module.h>
#define NAME "lkmc_character_device"
MODULE_LICENSE("GPL"); MODULE_LICENSE("GPL");
static int major;
static int irq = 0;
module_param_named(i, irq, int, S_IRUSR);
MODULE_PARM_DESC(i, "irq line number");
/** /**
* Return value from kernel docs:* * Return value from kernel docs:*
* *
* enum irqreturn * enum irqreturn
* @IRQ_NON interrupt was not from this device or was not handled * @IRQ_NONE interrupt was not from this device or was not handled
* @IRQ_HANDLED interrupt was handled by this device * @IRQ_HANDLED interrupt was handled by this device
* @IRQ_WAKE_THREAD handler requests to wake the handler thread * @IRQ_WAKE_THREAD handler requests to wake the handler thread
*/ */
static irqreturn_t handler(int i, void *v) static irqreturn_t handler(int irq, void *dev)
{ {
pr_info("handler %llu\n", (unsigned long long)jiffies); pr_info("handler irq = %d dev = %d\n", irq, *(int *)dev);
return IRQ_HANDLED; return IRQ_HANDLED;
} }
static const struct file_operations fops;
static int myinit(void) static int myinit(void)
{ {
irqreturn_t r; int ret;
r = request_irq(
1, major = register_chrdev(0, NAME, &fops);
handler, for (int i = 0; i < 128; ++i) {
IRQF_SHARED, ret = request_irq(
"myirqhandler0", i,
0 handler,
); /* Requires an associated device. */
pr_info("request_irq %llu\n", (unsigned long long)r); IRQF_SHARED,
"myirqhandler0",
&major
);
pr_info("request_irq irq = %d ret = %d\n", i, ret);
}
return 0; return 0;
} }
static void myexit(void) static void myexit(void)
{ {
free_irq(irq, NULL);
unregister_chrdev(major, NAME);
} }
module_init(myinit) module_init(myinit)