LXR linux/drivers/tty/hvc/hvc

   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