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path: root/drivers/tty/hvc/hvc_irq.c
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Diffstat (limited to 'drivers/tty/hvc/hvc_irq.c')
-rw-r--r--drivers/tty/hvc/hvc_irq.c55
1 files changed, 55 insertions, 0 deletions
diff --git a/drivers/tty/hvc/hvc_irq.c b/drivers/tty/hvc/hvc_irq.c
new file mode 100644
index 0000000000..4b255dfef2
--- /dev/null
+++ b/drivers/tty/hvc/hvc_irq.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright IBM Corp. 2001,2008
+ *
+ * This file contains the IRQ specific code for hvc_console
+ *
+ */
+
+#include <linux/interrupt.h>
+
+#include "hvc_console.h"
+
+static irqreturn_t hvc_handle_interrupt(int irq, void *dev_instance)
+{
+ /* if hvc_poll request a repoll, then kick the hvcd thread */
+ if (hvc_poll(dev_instance))
+ hvc_kick();
+
+ /*
+ * We're safe to always return IRQ_HANDLED as the hvcd thread will
+ * iterate through each hvc_struct.
+ */
+ return IRQ_HANDLED;
+}
+
+/*
+ * For IRQ based systems these callbacks can be used
+ */
+int notifier_add_irq(struct hvc_struct *hp, int irq)
+{
+ int rc;
+
+ if (!irq) {
+ hp->irq_requested = 0;
+ return 0;
+ }
+ rc = request_irq(irq, hvc_handle_interrupt, hp->flags,
+ "hvc_console", hp);
+ if (!rc)
+ hp->irq_requested = 1;
+ return rc;
+}
+
+void notifier_del_irq(struct hvc_struct *hp, int irq)
+{
+ if (!hp->irq_requested)
+ return;
+ free_irq(irq, hp);
+ hp->irq_requested = 0;
+}
+
+void notifier_hangup_irq(struct hvc_struct *hp, int irq)
+{
+ notifier_del_irq(hp, irq);
+}