sdio: set the functions' block size

Before a driver is probed, set the function's block size to the default so the
driver is sure the block size is something sensible and it needn't explicitly
set it.

The default block size is the largest that's supported by both the card and
the host, with a maximum of 512 to ensure aribitrarily sized transfer use the
optimal (least) number of commands.

See http://lkml.org/lkml/2007/8/7/150 for reasons for the block size choice.

Signed-off-by: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
diff --git a/include/linux/mmc/sdio_func.h b/include/linux/mmc/sdio_func.h
index af813ff..f057579 100644
--- a/include/linux/mmc/sdio_func.h
+++ b/include/linux/mmc/sdio_func.h
@@ -43,7 +43,8 @@
 	unsigned short		vendor;		/* vendor id */
 	unsigned short		device;		/* device id */
 
-	unsigned short		blksize;	/* maximum block size */
+	unsigned		max_blksize;	/* maximum block size */
+	unsigned		cur_blksize;	/* current block size */
 
 	unsigned int		state;		/* function state */
 #define SDIO_STATE_PRESENT	(1<<0)		/* present in sysfs */
@@ -111,6 +112,8 @@
 extern int sdio_enable_func(struct sdio_func *func);
 extern int sdio_disable_func(struct sdio_func *func);
 
+extern int sdio_set_block_size(struct sdio_func *func, unsigned blksz);
+
 extern int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler);
 extern int sdio_release_irq(struct sdio_func *func);