diff mbox

[v5,1/4] enable HW reset cap for supported eMMC card

Message ID 20101209122426.GB13236@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Chuanxiao.Dong Dec. 9, 2010, 12:24 p.m. UTC
None
diff mbox

Patch

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 76bb621..1d138b3 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -310,6 +310,10 @@  static int mmc_read_ext_csd(struct mmc_card *card)
 			ext_csd[EXT_CSD_SEC_FEATURE_SUPPORT];
 		card->ext_csd.trim_timeout = 300 *
 			ext_csd[EXT_CSD_TRIM_MULT];
+		/*
+		 * check Hardware reset cap
+		 */
+		card->ext_csd.rst = ext_csd[EXT_CSD_RST];
 	}
 
 	if (ext_csd[EXT_CSD_ERASED_MEM_CONT])
@@ -484,6 +488,31 @@  static int mmc_init_card(struct mmc_host *host, u32 ocr,
 	}
 
 	/*
+	 * eMMC4.4 version card has HW reset capability.
+	 * Enable this feature here:
+	 * RST_N_FUNCTION register is W/R, one time programmable
+	 * or readable.
+	 * So need to enable this register only once after power on
+	 */
+	if (card->csd.mmca_vsn >= CSD_SPEC_VER_4 &&
+			card->ext_csd.rev >= 5 &&
+			card->ext_csd.rst == 0) {
+		err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+				EXT_CSD_RST, 1);
+
+		if (err && err != -EBADMSG)
+			goto free_card;
+
+		if (err) {
+			printk(KERN_WARNING "%s: switch to rst enable "
+				   "failed %d\n",
+				   mmc_hostname(card->host), err);
+			err = 0;
+		} else
+			card->ext_csd.rst = 1;
+	}
+
+	/*
 	 * Activate high speed (if supported)
 	 */
 	if ((card->ext_csd.hs_max_dtr != 0) &&
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 8ce0827..ebee676 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -54,6 +54,7 @@  struct mmc_ext_csd {
 	unsigned int		sec_trim_mult;	/* Secure trim multiplier  */
 	unsigned int		sec_erase_mult;	/* Secure erase multiplier */
 	unsigned int		trim_timeout;		/* In milliseconds */
+	unsigned int		rst; /* hardware reset enable bit */
 };
 
 struct sd_scr {
diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index 956fbd8..b7ab0da 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -251,6 +251,7 @@  struct _mmc_csd {
  * EXT_CSD fields
  */
 
+#define EXT_CSD_RST		162	/* onetime programmable R/W */
 #define EXT_CSD_ERASE_GROUP_DEF		175	/* R/W */
 #define EXT_CSD_ERASED_MEM_CONT		181	/* RO */
 #define EXT_CSD_BUS_WIDTH		183	/* R/W */