mmc: core: Put eMMC in Sleep mode before suspend

Put MMC to sleep if it supports SLEEP/AWAKE (CMD5) in the mmc suspend
so that Vcc (NAND core) can be cut to minimize power consumption.
eMMC put into SLEEP can respond to CMD0 or H/W reset or CMD5.
Current implemention on resume from suspend relies on CMD0 in
mmc_init_card to get out of SLEEP mode.

Signed-off-by: Balaji T K <balajitk@ti.com>
Acked-by: Venkatraman S <svenkatr@ti.com>
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
This commit is contained in:
Balaji T K 2011-09-08 22:08:39 +05:30 committed by Chris Ball
parent 6fe47179a0
commit c3805467aa

View file

@ -553,6 +553,7 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
* need to tell some cards to go back to the idle
* state. We wait 1ms to give cards time to
* respond.
* mmc_go_idle is needed for eMMC that are asleep
*/
mmc_go_idle(host);
@ -900,16 +901,20 @@ static void mmc_detect(struct mmc_host *host)
*/
static int mmc_suspend(struct mmc_host *host)
{
int err = 0;
BUG_ON(!host);
BUG_ON(!host->card);
mmc_claim_host(host);
if (!mmc_host_is_spi(host))
if (mmc_card_can_sleep(host))
err = mmc_card_sleep(host);
else if (!mmc_host_is_spi(host))
mmc_deselect_cards(host);
host->card->state &= ~MMC_STATE_HIGHSPEED;
mmc_release_host(host);
return 0;
return err;
}
/*