diff options
| author | Daniel Drake | 2010-03-05 13:43:34 -0800 |
|---|---|---|
| committer | Linus Torvalds | 2010-03-06 11:26:37 -0800 |
| commit | 6b5eda369ac3772dad416ef96d86064204d74770 (patch) | |
| tree | cf137f4f28c62d8e8d1683590048b75830c1e9a2 /drivers/mmc | |
| parent | 40216842dca4fa485cb1aa5eb231149a4a57cc85 (diff) | |
sdio: put active devices into 1-bit mode during suspend
And bring them back to 4-bit mode during resume.
Signed-off-by: Daniel Drake <dsd@laptop.org>
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/mmc')
| -rw-r--r-- | drivers/mmc/core/sdio.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c index 5840de106b69..2dd4cfe7ca17 100644 --- a/drivers/mmc/core/sdio.c +++ b/drivers/mmc/core/sdio.c @@ -188,6 +188,40 @@ static int sdio_disable_cd(struct mmc_card *card) } /* + * 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. */ static int sdio_enable_hs(struct mmc_card *card) @@ -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); |