asm-generic: add legacy I/O header files

The dma.h, hw_irq.h, serial.h and timex.h files originally
described PC-style i8237, i8259A, i8250, i8253 and i8255 chips
as well as the VGA style text mode graphics.

Modern architectures live happily without these specific
interfaces, but a few definitions from these headers keep
getting used in common code.

The new generic headers are what most architectures use
anyway nowadays, just implementing the minimal definitions.

Signed-off-by: Remis Lima Baima <remis.developer@googlemail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/asm-generic/hw_irq.h b/include/asm-generic/hw_irq.h
new file mode 100644
index 000000000000..89036d7b40e0
--- /dev/null
+++ b/include/asm-generic/hw_irq.h
@@ -0,0 +1,9 @@
+#ifndef __ASM_GENERIC_HW_IRQ_H
+#define __ASM_GENERIC_HW_IRQ_H
+/*
+ * hw_irq.h has internal declarations for the low-level interrupt
+ * controller, like the original i8259A.
+ * In general, this is not needed for new architectures.
+ */
+
+#endif /* __ASM_GENERIC_HW_IRQ_H */