mmc: add ability to save power by powering off cards

Power can be saved by powering off cards that are not in use.  This is
similar to suspend / resume except it is under the control of the driver,
and does not require any power management support.  It can only be used
when the driver can monitor whether the card is removed, otherwise it is
unsafe.  This is possible because, unlike suspend, the driver still
receives card detect and / or cover switch interrupts.

Signed-off-by: Adrian Hunter <[email protected]>
Acked-by: Matt Fleming <[email protected]>
Cc: Ian Molton <[email protected]>
Cc: "Roberto A. Foglietta" <[email protected]>
Cc: Jarkko Lavinen <[email protected]>
Cc: Denis Karpov <[email protected]>
Cc: Pierre Ossman <[email protected]>
Cc: Philip Langdale <[email protected]>
Cc: "Madhusudhan" <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions