[PATCH] drivers: mmc: support secure erase.

[dennis]

According to the JEDEC Standard, eMMC v4.4 cards can supoort secure erase.
the first bit in ext_csd[EXT_CSD_SEC_FEATURE_SUPPORT] - EXT_CSD_SEC_ER_EN
is used to check if secure erase supoort by the device.

Signed-off-by: dennis <dennislaplacian1 at gmail.com>
---
 drivers/mmc/Kconfig     |  8 ++++++++
 drivers/mmc/mmc.c       |  4 ++++
 drivers/mmc/mmc_write.c | 16 +++++++++++++---
 include/mmc.h           |  5 ++++-
 4 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index 14d7913986..6105cbe960 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -18,6 +18,14 @@ config MMC_WRITE
 	help
 	  Enable write access to MMC and SD Cards
 
+config MMC_SECURE_ERASE
+	bool "Enable secure erase for eMMC"
+	depends on MMC_WRITE
+	default n
+	help
+	  This option replace the default erase with secure erase in eMMC v4.4
+	  and above cards.
+
 config MMC_BROKEN_CD
 	bool "Poll for broken card detection case"
 	help
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index a6394bcf30..56b17070e7 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -2272,6 +2272,10 @@ static int mmc_startup_v4(struct mmc *mmc)
 		if ((capacity >> 20) > 2 * 1024)
 			mmc->capacity_user = capacity;
 	}
+#if CONFIG_IS_ENABLED(MMC_SECURE_ERASE)
+	if (mmc->version >= MMC_VERSION_4_4 && IS_MMC(mmc))
+		mmc->sec_feature_support = ext_csd[EXT_CSD_SEC_FEATURE_SUPPORT];
+#endif
 
 	if (mmc->version >= MMC_VERSION_4_5)
 		mmc->gen_cmd6_time = ext_csd[EXT_CSD_GENERIC_CMD6_TIME];
diff --git a/drivers/mmc/mmc_write.c b/drivers/mmc/mmc_write.c
index 6a4453ca02..0b720ccf7e 100644
--- a/drivers/mmc/mmc_write.c
+++ b/drivers/mmc/mmc_write.c
@@ -15,7 +15,7 @@
 #include <linux/math64.h>
 #include "mmc_private.h"
 
-static ulong mmc_erase_t(struct mmc *mmc, ulong start, lbaint_t blkcnt)
+static ulong mmc_erase_t(struct mmc *mmc, ulong start, lbaint_t blkcnt, uint arg)
 {
 	struct mmc_cmd cmd;
 	ulong end;
@@ -52,7 +52,7 @@ static ulong mmc_erase_t(struct mmc *mmc, ulong start, lbaint_t blkcnt)
 		goto err_out;
 
 	cmd.cmdidx = MMC_CMD_ERASE;
-	cmd.cmdarg = MMC_ERASE_ARG;
+	cmd.cmdarg = arg;
 	cmd.resp_type = MMC_RSP_R1b;
 
 	err = mmc_send_cmd(mmc, &cmd, NULL);
@@ -81,6 +81,7 @@ ulong mmc_berase(struct blk_desc *block_dev, lbaint_t start, lbaint_t blkcnt)
 	struct mmc *mmc = find_mmc_device(dev_num);
 	lbaint_t blk = 0, blk_r = 0;
 	int timeout_ms = 1000;
+	uint arg = MMC_ERASE_ARG;
 
 	if (!mmc)
 		return -1;
@@ -105,6 +106,15 @@ ulong mmc_berase(struct blk_desc *block_dev, lbaint_t start, lbaint_t blkcnt)
 		       ((start + blkcnt + mmc->erase_grp_size)
 		       & ~(mmc->erase_grp_size - 1)) - 1);
 
+#if CONFIG_IS_ENABLED(MMC_SECURE_ERASE)
+	if (!(mmc->sec_feature_support & EXT_CSD_SEC_ER_EN)) {
+		printf("secure erase not supported on device\n"
+		       "perform insecure erase\n");
+	} else {
+		arg = MMC_SECURE_ERASE_ARG;
+	}
+#endif
+
 	while (blk < blkcnt) {
 		if (IS_SD(mmc) && mmc->ssr.au) {
 			blk_r = ((blkcnt - blk) > mmc->ssr.au) ?
@@ -113,7 +123,7 @@ ulong mmc_berase(struct blk_desc *block_dev, lbaint_t start, lbaint_t blkcnt)
 			blk_r = ((blkcnt - blk) > mmc->erase_grp_size) ?
 				mmc->erase_grp_size : (blkcnt - blk);
 		}
-		err = mmc_erase_t(mmc, start + blk, blk_r);
+		err = mmc_erase_t(mmc, start + blk, blk_r, arg);
 		if (err)
 			break;
 
diff --git a/include/mmc.h b/include/mmc.h
index 1d377e0281..bfdc712bdd 100644
--- a/include/mmc.h
+++ b/include/mmc.h
@@ -80,7 +80,6 @@ struct bd_info;
 #define MMC_MODE_1BIT		BIT(28)
 #define MMC_MODE_SPI		BIT(27)
 
-
 #define SD_DATA_4BIT	0x00040000
 
 #define IS_SD(x)	((x)->version & SD_VERSION_SD)
@@ -240,6 +239,7 @@ static inline bool mmc_is_tuning_cmd(uint cmdidx)
 #define EXT_CSD_HC_WP_GRP_SIZE		221	/* RO */
 #define EXT_CSD_HC_ERASE_GRP_SIZE	224	/* RO */
 #define EXT_CSD_BOOT_MULT		226	/* RO */
+#define EXT_CSD_SEC_FEATURE_SUPPORT 231 /* RO */
 #define EXT_CSD_GENERIC_CMD6_TIME       248     /* RO */
 #define EXT_CSD_BKOPS_SUPPORT		502	/* RO */
 
@@ -247,6 +247,8 @@ static inline bool mmc_is_tuning_cmd(uint cmdidx)
  * EXT_CSD field definitions
  */
 
+#define EXT_CSD_SEC_ER_EN   BIT(0)
+
 #define EXT_CSD_CMD_SET_NORMAL		(1 << 0)
 #define EXT_CSD_CMD_SET_SECURE		(1 << 1)
 #define EXT_CSD_CMD_SET_CPSECURE	(1 << 2)
@@ -690,6 +692,7 @@ struct mmc {
 	uint tran_speed;
 	uint legacy_speed; /* speed for the legacy mode provided by the card */
 	uint read_bl_len;
+	u8 sec_feature_support;
 #if CONFIG_IS_ENABLED(MMC_WRITE)
 	uint write_bl_len;
 	uint erase_grp_size;	/* in 512-byte sectors */
-- 
2.17.1