Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 6b5eda36 authored by Daniel Drake's avatar Daniel Drake Committed by Linus Torvalds
Browse files

sdio: put active devices into 1-bit mode during suspend 



And bring them back to 4-bit mode during resume.

Signed-off-by: default avatarDaniel Drake <dsd@laptop.org>
Signed-off-by: default avatarNicolas Pitre <nico@marvell.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 40216842

drivers/mmc/core/sdio.c

+43 −0
Original line number Diff line number Diff line
@@ -187,6 +187,40 @@ static int sdio_disable_cd(struct mmc_card *card) 
	return mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_IF, ctrl, NULL);

}



/*

 * Devices that remain active during a system suspend are

 * put back into 1-bit mode.

 */

static int sdio_disable_wide(struct mmc_card *card)

{

	int ret;

	u8 ctrl;



	if (!(card->host->caps & MMC_CAP_4_BIT_DATA))

		return 0;



	if (card->cccr.low_speed && !card->cccr.wide_bus)

		return 0;



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

	if (ret)

		return ret;



	if (!(ctrl & SDIO_BUS_WIDTH_4BIT))

		return 0;



	ctrl &= ~SDIO_BUS_WIDTH_4BIT;

	ctrl |= SDIO_BUS_ASYNC_INT;



	ret = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_IF, ctrl, NULL);

	if (ret)

		return ret;



	mmc_set_bus_width(card->host, MMC_BUS_WIDTH_1);



	return 0;

}



/*

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

 */
@@ -427,6 +461,12 @@ static int mmc_sdio_suspend(struct mmc_host *host) 
		}

	}



	if (!err && host->pm_flags & MMC_PM_KEEP_POWER) {

		mmc_claim_host(host);

		sdio_disable_wide(host->card);

		mmc_release_host(host);

	}



	return err;

}
@@ -441,6 +481,9 @@ static int mmc_sdio_resume(struct mmc_host *host) 
	mmc_claim_host(host);

	err = mmc_sdio_init_card(host, host->ocr, host->card,

				 (host->pm_flags & MMC_PM_KEEP_POWER));

	if (!err)

		/* We may have switched to 1-bit mode during suspend. */

		err = sdio_enable_wide(host->card);

	if (!err && host->sdio_irqs)

		mmc_signal_sdio_irq(host);

	mmc_release_host(host);

include/linux/mmc/sdio.h

+2 −0
Original line number Diff line number Diff line
@@ -95,6 +95,8 @@ 
#define  SDIO_BUS_WIDTH_1BIT	0x00

#define  SDIO_BUS_WIDTH_4BIT	0x02



#define  SDIO_BUS_ASYNC_INT	0x20



#define  SDIO_BUS_CD_DISABLE     0x80	/* disable pull-up on DAT3 (pin 1) */



#define SDIO_CCCR_CAPS		0x08