diff mbox

[v2,1/1] mmc: implemented eMMC4.4 enhanced area feature

Message ID 20110113125727.GA20452@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Chuanxiao.Dong Jan. 13, 2011, 12:57 p.m. UTC
None
diff mbox

Patch

diff --git a/Documentation/ABI/testing/sysfs-devices-mmc b/Documentation/ABI/testing/sysfs-devices-mmc
new file mode 100644
index 0000000..f0fb053
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-devices-mmc
@@ -0,0 +1,19 @@ 
+What:		/sys/devices/.../mmc_host/mmcX/mmcX:XXXX/enhanced_area_offset
+Date:		January 2011
+Contact:	Chuanxiao Dong <chuanxiao.dong@intel.com>
+Description:
+		Enhanced area is a new feature defined in eMMC4.4 standard.
+		eMMC4.4 or later card can support such feature. This kind of area
+		can help to improve the card performance. If the feature is enabled,
+		this attribute will indicate the start address of enhanced data
+		area. If not, this attribute will be 0. Unit Byte.
+
+What:		/sys/devices/.../mmc_host/mmcX/mmcX:XXXX/enhanced_area_size
+Date:		January 2011
+Contact:	Chuanxiao Dong <chuanxiao.dong@intel.com>
+Description:
+		Enhanced area is a new feature defined in eMMC4.4 standard.
+		eMMC4.4 or later card can support such feature. This kind of area
+		can help to improve the card performance. If the feature is enabled,
+		this attribute will indicate the size of enhanced data area. If not,
+		this attribute will be 0. Unit KBytes.
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 16006ef..c8b5b3b 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -302,6 +302,41 @@  static int mmc_read_ext_csd(struct mmc_card *card)
 	}
 
 	if (card->ext_csd.rev >= 4) {
+		/*
+		 * Enhanced area feature support
+		 * check whether eMMC card is enabled enhanced area,
+		 * if so, export enhanced area offset and size to
+		 * user by adding sysfs interface
+		 */
+		if ((ext_csd[EXT_CSD_PARTITION_SUPPORT] & 0x2) &&
+				(ext_csd[EXT_CSD_PARTITION_ATTRIBUTE] & 0x1)) {
+			u8 hc_erase_grp_sz =
+				ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE];
+			u8 hc_wp_grp_sz =
+				ext_csd[EXT_CSD_HC_WP_GRP_SIZE];
+			/*
+			 * set a flag to identify whether the enhanced
+			 * user data are enabled
+			 */
+			card->ext_csd.enhanced_area_en = 1;
+			/*
+			 * caculate the enhanced data area offset, unit B
+			 */
+			card->ext_csd.enhanced_area_offset =
+				(ext_csd[139] << 24) + (ext_csd[138] << 16) +
+				(ext_csd[137] << 8) + ext_csd[136];
+			if (mmc_card_blockaddr(card))
+				card->ext_csd.enhanced_area_offset <<= 9;
+			/*
+			 * caculate the enhanced data area size, unit KB
+			 */
+			card->ext_csd.enhanced_area_size =
+				(ext_csd[142] << 16) + (ext_csd[141] << 8) +
+				ext_csd[140];
+			card->ext_csd.enhanced_area_size *=
+				(size_t)(hc_erase_grp_sz * hc_wp_grp_sz);
+			card->ext_csd.enhanced_area_size <<= 9;
+		}
 		card->ext_csd.sec_trim_mult =
 			ext_csd[EXT_CSD_SEC_TRIM_MULT];
 		card->ext_csd.sec_erase_mult =
@@ -336,6 +371,9 @@  MMC_DEV_ATTR(manfid, "0x%06x\n", card->cid.manfid);
 MMC_DEV_ATTR(name, "%s\n", card->cid.prod_name);
 MMC_DEV_ATTR(oemid, "0x%04x\n", card->cid.oemid);
 MMC_DEV_ATTR(serial, "0x%08x\n", card->cid.serial);
+MMC_DEV_ATTR(enhanced_area_offset, "0x%llxB\n",
+		card->ext_csd.enhanced_area_offset);
+MMC_DEV_ATTR(enhanced_area_size, "0x%xKB\n", card->ext_csd.enhanced_area_size);
 
 static struct attribute *mmc_std_attrs[] = {
 	&dev_attr_cid.attr,
@@ -349,6 +387,8 @@  static struct attribute *mmc_std_attrs[] = {
 	&dev_attr_name.attr,
 	&dev_attr_oemid.attr,
 	&dev_attr_serial.attr,
+	&dev_attr_enhanced_area_offset.attr,
+	&dev_attr_enhanced_area_size.attr,
 	NULL,
 };
 
@@ -484,6 +524,39 @@  static int mmc_init_card(struct mmc_host *host, u32 ocr,
 	}
 
 	/*
+	 * If enhanced_area_en is TRUE, host need to enable
+	 * ERASE_GRP_DEF bit.
+	 * ERASE_GRP_DEF bit will be lost everytime
+	 * after a reset or power off.
+	 */
+	if (card->ext_csd.enhanced_area_en) {
+		err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+				EXT_CSD_ERASE_GROUP_DEF, 1);
+
+		if (err && err != -EBADMSG)
+			goto free_card;
+
+		if (err) {
+			err = 0;
+			/*
+			 * Just disable enhanced area off & sz
+			 * will try to enable ERASE_GROUP_DEF
+			 * during next time reinit
+			 */
+			card->ext_csd.enhanced_area_offset = 0;
+			card->ext_csd.enhanced_area_size = 0;
+		} else {
+			card->ext_csd.erase_group_def = 1;
+			/*
+			 * enable ERASE_GRP_DEF successfully.
+			 * This will affect the erase size, so
+			 * here need to reset erase size
+			 */
+			mmc_set_erase_size(card);
+		}
+	}
+
+	/*
 	 * 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..cc9a07e 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -54,6 +54,9 @@  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 */
+	bool		enhanced_area_en; /* enhanced area enable bit */
+	loff_t		enhanced_area_offset; /* enhanced area addr */
+	size_t		enhanced_area_size; /* enhanced area size */
 };
 
 struct sd_scr {
diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index 612301f..c50ede6 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -253,6 +253,8 @@  struct _mmc_csd {
  * EXT_CSD fields
  */
 
+#define EXT_CSD_PARTITION_ATTRIBUTE 156	/* R/W */
+#define EXT_CSD_PARTITION_SUPPORT	160	/* RO */
 #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 */
@@ -262,6 +264,7 @@  struct _mmc_csd {
 #define EXT_CSD_CARD_TYPE		196	/* RO */
 #define EXT_CSD_SEC_CNT			212	/* RO, 4 bytes */
 #define EXT_CSD_S_A_TIMEOUT		217	/* RO */
+#define EXT_CSD_HC_WP_GRP_SIZE		221	/* RO */
 #define EXT_CSD_ERASE_TIMEOUT_MULT	223	/* RO */
 #define EXT_CSD_HC_ERASE_GRP_SIZE	224	/* RO */
 #define EXT_CSD_SEC_TRIM_MULT		229	/* RO */