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sdio: enable wide bus mode

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

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This commit is contained in:
Pierre Ossman 2007-07-30 18:23:53 +02:00
parent 6db5020e73
commit 4ff6471c02
1 changed files with 33 additions and 0 deletions
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33
drivers/mmc/core/sdio.c
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@ -138,6 +138,32 @@ out:
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.
*/