[ACPI] save/restore ELCR on suspend/resume (David Shaohua Li)

http://bugzilla.kernel.org/show_bug.cgi?id=2643

arch/i386/kernel/i8259.c

@@ -238,14 +238,39 @@ void mask_and_ack_8259A(unsigned int irq)
 	}
 }
 
+static char irq_trigger[2];
+/**
+ * ELCR registers (0x4d0, 0x4d1) control edge/level of IRQ
+ */
+static void restore_ELCR(char *trigger)
+{
+	outb(trigger[0], 0x4d0);
+	outb(trigger[1], 0x4d1);
+}
+
+static void save_ELCR(char *trigger)
+{
+	/* IRQ 0,1,2,8,13 are marked as reserved */
+	trigger[0] = inb(0x4d0) & 0xF8;
+	trigger[1] = inb(0x4d1) & 0xDE;
+}
+
 static int i8259A_resume(struct sys_device *dev)
 {
 	init_8259A(0);
+	restore_ELCR(irq_trigger);
+	return 0;
+}
+
+static int i8259A_suspend(struct sys_device *dev, u32 state)
+{
+	save_ELCR(irq_trigger);
 	return 0;
 }
 
 static struct sysdev_class i8259_sysdev_class = {
 	set_kset_name("i8259"),
+	.suspend = i8259A_suspend,
 	.resume = i8259A_resume,
 };
 

arch/x86_64/kernel/i8259.c

@@ -318,7 +318,7 @@ void mask_and_ack_8259A(unsigned int irq)
 	}
 }
 
-void __init init_8259A(int auto_eoi)
+void init_8259A(int auto_eoi)
 {
 	unsigned long flags;
 
@@ -361,6 +361,57 @@ void __init init_8259A(int auto_eoi)
 	spin_unlock_irqrestore(&i8259A_lock, flags);
 }
 
+static char irq_trigger[2];
+/**
+ * ELCR registers (0x4d0, 0x4d1) control edge/level of IRQ
+ */
+static void restore_ELCR(char *trigger)
+{
+	outb(trigger[0], 0x4d0);
+	outb(trigger[1], 0x4d1);
+}
+
+static void save_ELCR(char *trigger)
+{
+	/* IRQ 0,1,2,8,13 are marked as reserved */
+	trigger[0] = inb(0x4d0) & 0xF8;
+	trigger[1] = inb(0x4d1) & 0xDE;
+}
+
+static int i8259A_resume(struct sys_device *dev)
+{
+	init_8259A(0);
+	restore_ELCR(irq_trigger);
+	return 0;
+}
+
+static int i8259A_suspend(struct sys_device *dev, u32 state)
+{
+	save_ELCR(irq_trigger);
+	return 0;
+}
+
+static struct sysdev_class i8259_sysdev_class = {
+	set_kset_name("i8259"),
+	.suspend = i8259A_suspend,
+	.resume = i8259A_resume,
+};
+
+static struct sys_device device_i8259A = {
+	.id	= 0,
+	.cls	= &i8259_sysdev_class,
+};
+
+static int __init i8259A_init_sysfs(void)
+{
+	int error = sysdev_class_register(&i8259_sysdev_class);
+	if (!error)
+		error = sysdev_register(&device_i8259A);
+	return error;
+}
+
+device_initcall(i8259A_init_sysfs);
+
 /*
  * IRQ2 is cascade interrupt to second interrupt controller
  */