linux/io.h: add generic ioremap()/iounmap() defines

For most of architectures in U-Boot, virtual address is straight
mapped to physical address.  So, it makes sense to have generic
defines of ioremap and friends in <linux/io.h>.

All of them are just empty and will disappear at compile time, but
they will be helpful to implement drivers which are counterparts of
Linux ones.

I notice MIPS already has its own implementation, so I added a
Kconfig symbol CONFIG_HAVE_ARCH_IOREMAP which MIPS (and maybe
Sandbox as well) can select.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/include/linux/io.h b/include/linux/io.h
index 1b36a22..a104b7e 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -5,6 +5,22 @@
 #ifndef _LINUX_IO_H
 #define _LINUX_IO_H
 
+#include <linux/compiler.h>
+#include <linux/types.h>
 #include <asm/io.h>
 
+#ifndef CONFIG_HAVE_ARCH_IOREMAP
+static inline void __iomem *ioremap(resource_size_t offset,
+				    resource_size_t size)
+{
+	return (void __iomem *)(unsigned long)offset;
+}
+
+static inline void iounmap(void __iomem *addr)
+{
+}
+
+#define devm_ioremap(dev, offset, size)		ioremap(offset, size)
+#endif
+
 #endif /* _LINUX_IO_H */