[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>

Author: David Brownell

drivers/spi/Kconfig

@@ -135,6 +135,16 @@ config SPI_S3C24XX_GPIO
 comment "SPI Protocol Masters"
 	depends on SPI_MASTER
 
+config SPI_AT25
+	tristate "SPI EEPROMs from most vendors"
+	depends on SPI_MASTER && SYSFS
+	help
+	  Enable this driver to get read/write support to most SPI EEPROMs,
+	  after you configure the board init code to know about each eeprom
+	  on your target board.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called at25.
 
 #
 # Add new SPI protocol masters in alphabetical order above this line

drivers/spi/Makefile

@@ -22,6 +22,7 @@ obj-$(CONFIG_SPI_S3C24XX)		+= spi_s3c24xx.o
 # 	... add above this line ...
 
 # SPI protocol drivers (device/link on bus)
+obj-$(CONFIG_SPI_AT25)		+= at25.o
 # 	... add above this line ...
 
 # SPI slave controller drivers (upstream link)