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
13static 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 */
29int 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
44void 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
52void notifier_hangup_irq(struct hvc_struct *hp, int irq)
53{
54 notifier_del_irq(hp, irq);
55}
56