From b3bf915308ca2b50f3beec6cc824083870f0f4b5 Mon Sep 17 00:00:00 2001 From: Kyungmin Park Date: Tue, 18 Oct 2011 09:34:04 +0900 Subject: mmc: core: new discard feature support at eMMC v4.5 MMC v4.5 supports the DISCARD feature (CMD38). It's different from trim and there's no check bit. Currently it's only supported at v4.5. Signed-off-by: Kyungmin Park Signed-off-by: Jaehoon Chung Signed-off-by: Chris Ball --- drivers/mmc/core/core.c | 14 ++++++++++++++ drivers/mmc/core/mmc.c | 4 ++++ 2 files changed, 18 insertions(+) (limited to 'drivers/mmc/core') diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index d9836e5..772de2c 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -1709,10 +1709,24 @@ int mmc_can_trim(struct mmc_card *card) { if (card->ext_csd.sec_feature_support & EXT_CSD_SEC_GB_CL_EN) return 1; + if (mmc_can_discard(card)) + return 1; return 0; } EXPORT_SYMBOL(mmc_can_trim); +int mmc_can_discard(struct mmc_card *card) +{ + /* + * As there's no way to detect the discard support bit at v4.5 + * use the s/w feature support filed. + */ + if (card->ext_csd.feature_support & MMC_DISCARD_FEATURE) + return 1; + return 0; +} +EXPORT_SYMBOL(mmc_can_discard); + int mmc_can_sanitize(struct mmc_card *card) { if (card->ext_csd.sec_feature_support & EXT_CSD_SEC_SANITIZE) diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index f8ea938..5408876 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -452,6 +452,10 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd) card->ext_csd.rst_n_function = ext_csd[EXT_CSD_RST_N_FUNCTION]; } + /* eMMC v4.5 or later */ + if (card->ext_csd.rev >= 6) + card->ext_csd.feature_support |= MMC_DISCARD_FEATURE; + card->ext_csd.raw_erased_mem_count = ext_csd[EXT_CSD_ERASED_MEM_CONT]; if (ext_csd[EXT_CSD_ERASED_MEM_CONT]) card->erased_byte = 0xFF; -- cgit v1.1