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