atmel_spi: support zero length transfer
authorAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Mon, 28 Apr 2008 09:14:19 +0000 (02:14 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Mon, 28 Apr 2008 15:58:31 +0000 (08:58 -0700)
commit06719814780da741e7acf587367a86c3965c03a2
treea6d8aabc4b3068c3679630f318a1706044c195b1
parentb687d2a8f8d46921ac5e80bf77967688afce68e2
atmel_spi: support zero length transfer

A spi transfer with zero length is not invalid.  For example, such
transfer (len == 0 && delay_usecs != 0) can be used to achieve delay
before first CLK edge after chipselect assertion.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/spi/atmel_spi.c