1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright IBM Corp. 2001,2008
4 *
5 * This file contains the IRQ specific code for hvc_console
6 *
7 */
8
9 #include <linux/interrupt.h>
10
11 #include "hvc_console.h"
12
hvc_handle_interrupt(int irq,void * dev_instance)13 static irqreturn_t hvc_handle_interrupt(int irq, void *dev_instance)
14 {
15 /* if hvc_poll request a repoll, then kick the hvcd thread */
16 if (hvc_poll(dev_instance))
17 hvc_kick();
18
19 /*
20 * We're safe to always return IRQ_HANDLED as the hvcd thread will
21 * iterate through each hvc_struct.
22 */
23 return IRQ_HANDLED;
24 }
25
26 /*
27 * For IRQ based systems these callbacks can be used
28 */
notifier_add_irq(struct hvc_struct * hp,int irq)29 int notifier_add_irq(struct hvc_struct *hp, int irq)
30 {
31 int rc;
32
33 if (!irq) {
34 hp->irq_requested = 0;
35 return 0;
36 }
37 rc = request_irq(irq, hvc_handle_interrupt, hp->flags,
38 "hvc_console", hp);
39 if (!rc)
40 hp->irq_requested = 1;
41 return rc;
42 }
43
notifier_del_irq(struct hvc_struct * hp,int irq)44 void notifier_del_irq(struct hvc_struct *hp, int irq)
45 {
46 if (!hp->irq_requested)
47 return;
48 free_irq(irq, hp);
49 hp->irq_requested = 0;
50 }
51
notifier_hangup_irq(struct hvc_struct * hp,int irq)52 void notifier_hangup_irq(struct hvc_struct *hp, int irq)
53 {
54 notifier_del_irq(hp, irq);
55 }
56