mmc: Resolve BKOPS compatability issue

This patch is coming to fix compatibility issue of BKOPS_EN  field of EXT_CSD.
In eMMC-5.1, BKOPS_EN was changed, and now it has two operational bits:
Bit 0 - MANUAL_EN
Bit 1 - AUTO_EN
In previous eMMC revisions, only Bit 0 was supported.

Signed-off-by: Alexey Skidanov <alexey.skidanov@sandisk.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/core/core.c

@@ -275,7 +275,7 @@ void mmc_start_bkops(struct mmc_card *card, bool from_exception)
 
 	BUG_ON(!card);
 
-	if (!card->ext_csd.bkops_en || mmc_card_doing_bkops(card))
+	if (!card->ext_csd.man_bkops_en || mmc_card_doing_bkops(card))
 		return;
 
 	err = mmc_read_bkops_status(card);

drivers/mmc/core/mmc.c

@@ -483,11 +483,13 @@ static int mmc_decode_ext_csd(struct mmc_card *card, u8 *ext_csd)
 		/* check whether the eMMC card supports BKOPS */
 		if (ext_csd[EXT_CSD_BKOPS_SUPPORT] & 0x1) {
 			card->ext_csd.bkops = 1;
-			card->ext_csd.bkops_en = ext_csd[EXT_CSD_BKOPS_EN];
+			card->ext_csd.man_bkops_en =
+					(ext_csd[EXT_CSD_BKOPS_EN] &
+						EXT_CSD_MANUAL_BKOPS_MASK);
 			card->ext_csd.raw_bkops_status =
 				ext_csd[EXT_CSD_BKOPS_STATUS];
-			if (!card->ext_csd.bkops_en)
-				pr_info("%s: BKOPS_EN bit is not set\n",
+			if (!card->ext_csd.man_bkops_en)
+				pr_info("%s: MAN_BKOPS_EN bit is not set\n",
 					mmc_hostname(card->host));
 		}
 

include/linux/mmc/card.h

@@ -83,7 +83,7 @@ struct mmc_ext_csd {
 	bool			hpi;			/* HPI support bit */
 	unsigned int		hpi_cmd;		/* cmd used as HPI */
 	bool			bkops;		/* background support bit */
-	bool			bkops_en;	/* background enable bit */
+	bool			man_bkops_en;	/* manual bkops enable bit */
 	unsigned int            data_sector_size;       /* 512 bytes or 4KB */
 	unsigned int            data_tag_unit_size;     /* DATA TAG UNIT size */
 	unsigned int		boot_ro_lock;		/* ro lock support */

include/linux/mmc/mmc.h

@@ -427,6 +427,11 @@ struct _mmc_csd {
  */
 #define EXT_CSD_BKOPS_LEVEL_2		0x2
 
+/*
+ * BKOPS modes
+ */
+#define EXT_CSD_MANUAL_BKOPS_MASK	0x01
+
 /*
  * MMC_SWITCH access modes
  */