drivers/fsi: Add device read/write/peek API

This change introduces the fsi device API: simple read, write and peek
accessors for the devices' address spaces.

Includes contributions from Christopher Bostic
<cbostic@linux.vnet.ibm.com> and Edward A. James <eajames@us.ibm.com>.

Signed-off-by: Edward A. James <eajames@us.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/fsi.h b/include/linux/fsi.h
index efa55ba..66bce48 100644
--- a/include/linux/fsi.h
+++ b/include/linux/fsi.h
@@ -27,6 +27,12 @@ struct fsi_device {
 	uint32_t		size;
 };
 
+extern int fsi_device_read(struct fsi_device *dev, uint32_t addr,
+		void *val, size_t size);
+extern int fsi_device_write(struct fsi_device *dev, uint32_t addr,
+		const void *val, size_t size);
+extern int fsi_device_peek(struct fsi_device *dev, void *val);
+
 struct fsi_device_id {
 	u8	engine_type;
 	u8	version;
@@ -40,7 +46,6 @@ struct fsi_device_id {
 #define FSI_DEVICE_VERSIONED(t, v) \
 	.engine_type = (t), .version = (v),
 
-
 struct fsi_driver {
 	struct device_driver		drv;
 	const struct fsi_device_id	*id_table;