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
  18         /*
  19          * We're safe to always return IRQ_HANDLED as the hvcd thread will
  20          * iterate through each hvc_struct.
  21          */
  22         return IRQ_HANDLED;
  23 }
  24
  25 /*
  26  * For IRQ based systems these callbacks can be used
  27  */
  28 int notifier_add_irq(struct hvc_struct *hp, int irq)
  29 {
  30         int rc;
  31
  32         if (!irq) {
  33                 hp->irq_requested = 0;
  34                 return 0;
  35         }
  36         rc = request_irq(irq, hvc_handle_interrupt, hp->flags,
  37                         "hvc_console", hp);
  38         if (!rc)
  39                 hp->irq_requested = 1;
  40         return rc;
  41 }
  42
  43 void notifier_del_irq(struct hvc_struct *hp, int irq)
  44 {
  45         if (!hp->irq_requested)
  46                 return;
  47         free_irq(irq, hp);
  48         hp->irq_requested = 0;
  49 }
  50
  51 void notifier_hangup_irq(struct hvc_struct *hp, int irq)
  52 {
  53         notifier_del_irq(hp, irq);
  54 }