drivers/tty/hvc/hvc_irq.c

   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, IRQF_DISABLED,
  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 }