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authorSeungwon Jeon <tgih.jun@samsung.com>2011-10-14 14:03:21 +0900
committerChris Ball <cjb@laptop.org>2011-10-26 16:32:28 -0400
commit881d1c25f765938a95def5afe39486ce39f9fc96 (patch)
tree694d5ea1b3fba2c28cc110123f2ca50b4408f309 /drivers/mmc/core/mmc.c
parent71fe3eb0d006861bdae57e93975b6ae3d9b55e99 (diff)
mmc: core: Add cache control for eMMC4.5 device
This patch adds cache feature of eMMC4.5 Spec. If device supports cache capability, host can utilize some specific operations. Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com> Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'drivers/mmc/core/mmc.c')
-rw-r--r--drivers/mmc/core/mmc.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 79390151920..de5900aa81c 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -470,6 +470,12 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
} else
card->ext_csd.generic_cmd6_time = 0;
+ card->ext_csd.cache_size =
+ ext_csd[EXT_CSD_CACHE_SIZE + 0] << 0 |
+ ext_csd[EXT_CSD_CACHE_SIZE + 1] << 8 |
+ ext_csd[EXT_CSD_CACHE_SIZE + 2] << 16 |
+ ext_csd[EXT_CSD_CACHE_SIZE + 3] << 24;
+
out:
return err;
}
@@ -1020,6 +1026,23 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
}
}
+ /*
+ * If cache size is higher than 0, this indicates
+ * the existence of cache and it can be turned on.
+ */
+ if ((host->caps2 & MMC_CAP2_CACHE_CTRL) &&
+ card->ext_csd.cache_size > 0) {
+ err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+ EXT_CSD_CACHE_CTRL, 1, 0);
+ if (err && err != -EBADMSG)
+ goto free_card;
+
+ /*
+ * Only if no error, cache is turned on successfully.
+ */
+ card->ext_csd.cache_ctrl = err ? 0 : 1;
+ }
+
if (!oldcard)
host->card = card;