From: Kevin Hilman <khilman@deeprootsystems.com>
Date: Thu, 2 Apr 2009 23:56:56 +0000 (-0700)
Subject: memory_accessor: new interface for reading/writing persistent memory
X-Git-Tag: v2.6.30-rc1~391
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=06c421ee0d5af95c8c6749ca0ba620cd5010707f;p=platform%2Fupstream%2Fkernel-adaptation-pc.git

memory_accessor: new interface for reading/writing persistent memory

Add an interface by which other kernel code can read/write persistent
memory such as I2C or SPI EEPROMs, or devices which provide NVRAM.  Use
cases include storage of board-specific configuration data like Ethernet
addresses and sensor calibrations.

Original idea, review and improvement suggestions by David Brownell.

Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/include/linux/memory.h b/include/linux/memory.h
index 3fdc108..42767d1 100644
--- a/include/linux/memory.h
+++ b/include/linux/memory.h
@@ -99,4 +99,15 @@ enum mem_add_context { BOOT, HOTPLUG };
 #define hotplug_memory_notifier(fn, pri) do { } while (0)
 #endif
 
+/*
+ * 'struct memory_accessor' is a generic interface to provide
+ * in-kernel access to persistent memory such as i2c or SPI EEPROMs
+ */
+struct memory_accessor {
+	ssize_t (*read)(struct memory_accessor *, char *buf, off_t offset,
+			size_t count);
+	ssize_t (*write)(struct memory_accessor *, const char *buf,
+			 off_t offset, size_t count);
+};
+
 #endif /* _LINUX_MEMORY_H_ */