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Commit 4ff6471c authored by Pierre Ossman's avatar Pierre Ossman
Browse files

sdio: enable wide bus mode 



Enable 4-bit data bus mode, according to host and card
capabilities.

Signed-off-by: default avatarPierre Ossman <drzeus@drzeus.cx>
parent 6db5020e

drivers/mmc/core/sdio.c

+33 −0
Original line number Diff line number Diff line
@@ -138,6 +138,32 @@ static int sdio_read_cccr(struct mmc_card *card) 
	return ret;

}



static int sdio_enable_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;



	ctrl |= SDIO_BUS_WIDTH_4BIT;



	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_4);



	return 0;

}



/*

 * Host is being removed. Free up the current card.

 */
@@ -299,6 +325,13 @@ int mmc_attach_sdio(struct mmc_host *host, u32 ocr) 
	 */

	mmc_set_clock(host, card->cis.max_dtr);



	/*

	 * Switch to wider bus (if supported).

	 */

	err = sdio_enable_wide(card);

	if (err)

		goto remove;



	/*

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

	 */