[PATCH] SPI eeprom driver

This is adds a simple SPI EEPROM driver, providing access to the EEPROM
through sysfs much like the I2C "eeprom" driver ...  except this driver
supports write access, and multiple EEPROM sizes.

From: "Tuppa, Walter" <walter.tuppa@siemens.com>

Since I have EEPROMs on SPI with different address sizing, I made some
changes to your at25.c to support them.  Works perfectly.  (Also includes a
small bugfix for the "what size address" test.)

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Walter Tuppa <walter.tuppa@siemens.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 22 insertions, 0 deletions

diff --git a/include/linux/spi/eeprom.h b/include/linux/spi/eeprom.h
new file mode 100644
index 000000000000..1085212c446e
--- /dev/null
+++ b/include/linux/spi/eeprom.h
@@ -0,0 +1,22 @@
+#ifndef __LINUX_SPI_EEPROM_H
+#define __LINUX_SPI_EEPROM_H
+
+/*
+ * Put one of these structures in platform_data for SPI EEPROMS handled
+ * by the "at25" driver.  On SPI, most EEPROMS understand the same core
+ * command set.  If you need to support EEPROMs that don't yet fit, add
+ * flags to support those protocol options.  These values all come from
+ * the chip datasheets.
+ */
+struct spi_eeprom {
+        u32             byte_len;
+        char            name[10];
+        u16             page_size;              /* for writes */
+        u16             flags;
+#define EE_ADDR1        0x0001                  /*  8 bit addrs */
+#define EE_ADDR2        0x0002                  /* 16 bit addrs */
+#define EE_ADDR3        0x0004                  /* 24 bit addrs */
+#define EE_READONLY     0x0008                  /* disallow writes */
+};
+
+#endif /* __LINUX_SPI_EEPROM_H */