sdio: add CD disable support (006ebd5d) · Commits · 戴 / test

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:

Ohad Ben-Cohen <ohad@wizery.com> Acked-by:

Matt 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:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

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 {

Admin message