[PATCH] spi: mtd dataflash driver

This is a conversion of the AT91rm9200 DataFlash MTD driver to use the
lightweight SPI framework, and no longer be AT91-specific.  It compiles
down to less than 3KBytes on ARM.

The driver allows board-specific init code to provide platform_data with
the relevant MTD partitioning information, and hotplugs.

This version has been lightly tested.  Its parent at91_dataflash driver has
been pretty well banged on, although kernel.org JFFS2 dataflash support was
acting broken the last time I tried it.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/mtd/devices/Kconfig

@@ -47,6 +47,14 @@ config MTD_MS02NV
 	  accelerator.  Say Y here if you have a DECstation 5000/2x0 or a
 	  DECsystem 5900 equipped with such a module.
 
+config MTD_DATAFLASH
+	tristate "Support for AT45xxx DataFlash"
+	depends on MTD && SPI_MASTER && EXPERIMENTAL
+	help
+	  This enables access to AT45xxx DataFlash chips, using SPI.
+	  Sometimes DataFlash chips are packaged inside MMC-format
+	  cards; at this writing, the MMC stack won't handle those.
+
 config MTD_SLRAM
 	tristate "Uncached system RAM"
 	depends on MTD

drivers/mtd/devices/Makefile

@@ -23,3 +23,4 @@ obj-$(CONFIG_MTD_MTDRAM)	+= mtdram.o
 obj-$(CONFIG_MTD_LART)		+= lart.o
 obj-$(CONFIG_MTD_BLKMTD)	+= blkmtd.o
 obj-$(CONFIG_MTD_BLOCK2MTD)	+= block2mtd.o
+obj-$(CONFIG_MTD_DATAFLASH)	+= mtd_dataflash.o

include/linux/spi/flash.h

+#ifndef LINUX_SPI_FLASH_H
+#define LINUX_SPI_FLASH_H
+
+struct mtd_partition;
+
+/**
+ * struct flash_platform_data: board-specific flash data
+ * @name: optional flash device name (eg, as used with mtdparts=)
+ * @parts: optional array of mtd_partitions for static partitioning
+ * @nr_parts: number of mtd_partitions for static partitoning
+ *
+ * Board init code (in arch/.../mach-xxx/board-yyy.c files) can
+ * provide information about SPI flash parts (such as DataFlash) to
+ * help set up the device and its appropriate default partitioning.
+ *
+ * Note that for DataFlash, sizes for pages, blocks, and sectors are
+ * rarely powers of two; and partitions should be sector-aligned.
+ */
+struct flash_platform_data {
+	char		*name;
+	struct mtd_partition *parts;
+	unsigned int	nr_parts;
+
+	/* we'll likely add more ... use JEDEC IDs, etc */
+};
+
+#endif