xref: /openbmc/linux/drivers/tty/hvc/hvc_irq.c (revision 9cfc5c90)
1 /*
2  * Copyright IBM Corp. 2001,2008
3  *
4  * This file contains the IRQ specific code for hvc_console
5  *
6  */
7 
8 #include <linux/interrupt.h>
9 
10 #include "hvc_console.h"
11 
12 static irqreturn_t hvc_handle_interrupt(int irq, void *dev_instance)
13 {
14 	/* if hvc_poll request a repoll, then kick the hvcd thread */
15 	if (hvc_poll(dev_instance))
16 		hvc_kick();
17 	return IRQ_HANDLED;
18 }
19 
20 /*
21  * For IRQ based systems these callbacks can be used
22  */
23 int notifier_add_irq(struct hvc_struct *hp, int irq)
24 {
25 	int rc;
26 
27 	if (!irq) {
28 		hp->irq_requested = 0;
29 		return 0;
30 	}
31 	rc = request_irq(irq, hvc_handle_interrupt, 0,
32 			   "hvc_console", hp);
33 	if (!rc)
34 		hp->irq_requested = 1;
35 	return rc;
36 }
37 
38 void notifier_del_irq(struct hvc_struct *hp, int irq)
39 {
40 	if (!hp->irq_requested)
41 		return;
42 	free_irq(irq, hp);
43 	hp->irq_requested = 0;
44 }
45 
46 void notifier_hangup_irq(struct hvc_struct *hp, int irq)
47 {
48 	notifier_del_irq(hp, irq);
49 }
50