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Commit 006ebd5d authored by Ohad Ben-Cohen's avatar Ohad Ben-Cohen Committed by Linus Torvalds
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sdio: add CD disable support 



Add support to disconnect the pull-up resistor on CD/DAT[3] (pin 1)
of the card. This may be desired on certain setups of boards,
controllers and embedded sdio devices which do not need the card's
pull-up. As a result, card detection is disabled and power is saved.

[akpm@linux-foundation.org: simplify sdio_disable_cd() a bit]
Signed-off-by: default avatarOhad Ben-Cohen <ohad@wizery.com>
Acked-by: default avatarMatt Fleming <matt@console-pimps.org>
Cc: Ian Molton <ian@mnementh.co.uk>
Cc: "Roberto A. Foglietta" <roberto.foglietta@gmail.com>
Cc: Philip Langdale <philipl@overt.org>
Cc: Pierre Ossman <pierre@ossman.eu>
Cc: David Vrabel <david.vrabel@csr.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 653f41b5

drivers/mmc/core/sdio.c

+30 −0
Original line number Diff line number Diff line
@@ -164,6 +164,29 @@ static int sdio_enable_wide(struct mmc_card *card) 
	return 0;

}



/*

 * If desired, disconnect the pull-up resistor on CD/DAT[3] (pin 1)

 * of the card. This may be required on certain setups of boards,

 * controllers and embedded sdio device which do not need the card's

 * pull-up. As a result, card detection is disabled and power is saved.

 */

static int sdio_disable_cd(struct mmc_card *card)

{

	int ret;

	u8 ctrl;



	if (!card->cccr.disable_cd)

		return 0;



	ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_IF, 0, &ctrl);

	if (ret)

		return ret;



	ctrl |= SDIO_BUS_CD_DISABLE;



	return mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_IF, ctrl, NULL);

}



/*

 * Test if the card supports high-speed mode and, if so, switch to it.

 */
@@ -384,6 +407,13 @@ int mmc_attach_sdio(struct mmc_host *host, u32 ocr) 
	if (err)

		goto remove;



	/*

	 * If needed, disconnect card detection pull-up resistor.

	 */

	err = sdio_disable_cd(card);

	if (err)

		goto remove;



	/*

	 * Initialize (but don't add) all present functions.

	 */

include/linux/mmc/card.h

+2 −1
Original line number Diff line number Diff line
@@ -64,7 +64,8 @@ struct sdio_cccr { 
				low_speed:1,

				wide_bus:1,

				high_power:1,

				high_speed:1;

				high_speed:1,

				disable_cd:1;

};



struct sdio_cis {