1 files changed, 55 insertions, 0 deletions
diff --git a/arch/x86/kernel/i8237.c b/arch/x86/kernel/i8237.c
new file mode 100644
index 000000000..8eeaa81de
--- /dev/null
+++ b/arch/x86/kernel/i8237.c
@@ -0,0 +1,55 @@
+/*
+ * 8237A DMA controller suspend functions.
+ *
+ * Written by Pierre Ossman, 2005.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ */
+
+#include <linux/init.h>
+#include <linux/syscore_ops.h>
+
+#include <asm/dma.h>
+
+/*
+ * This module just handles suspend/resume issues with the
+ * 8237A DMA controller (used for ISA and LPC).
+ * Allocation is handled in kernel/dma.c and normal usage is
+ * in asm/dma.h.
+ */
+
+static void i8237A_resume(void)
+{
+	unsigned long flags;
+	int i;
+
+	flags = claim_dma_lock();
+
+	dma_outb(0, DMA1_RESET_REG);
+	dma_outb(0, DMA2_RESET_REG);
+
+	for (i = 0; i < 8; i++) {
+		set_dma_addr(i, 0x000000);
+		/* DMA count is a bit weird so this is not 0 */
+		set_dma_count(i, 1);
+	}
+
+	/* Enable cascade DMA or channel 0-3 won't work */
+	enable_dma(4);
+
+	release_dma_lock(flags);
+}
+
+static struct syscore_ops i8237_syscore_ops = {
+	.resume		= i8237A_resume,
+};
+
+static int __init i8237A_init_ops(void)
+{
+	register_syscore_ops(&i8237_syscore_ops);
+	return 0;
+}
+device_initcall(i8237A_init_ops);