mmc-utils: Add AUTO_EN support in the BKOPS_EN

This patch adds support to enable auto(AUTO_EN) and
manual(MANUAL_EN) in BKOPS_EN register. Auto bkops
can only be used on eMMC 5.0 or newer.
Signed-off-by: Lars Pedersen <lapeddk@gmail.com>
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Link: https://lore.kernel.org/r/20191111110051.16490-1-lapeddk@gmail.com

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

mmc.c

@@ -131,9 +131,12 @@ static struct Command commands[] = {
 	  "<boot_bus_width> must be \"x1|x4|x8\"",
 	  NULL
 	},
-	{ do_write_bkops_en, -1,
-	  "bkops enable", "<device>\n"
-		"Enable the eMMC BKOPS feature on <device>.\nNOTE!  This is a one-time programmable (unreversible) change.",
+	{ do_write_bkops_en, -2,
+	  "bkops_en", "<auto|manual> <device>\n"
+		"Enable the eMMC BKOPS feature on <device>.\n"
+		"The auto (AUTO_EN) setting is only supported on eMMC 5.0 or newer.\n"
+		"Setting auto won't have any effect if manual is set.\n"
+		"NOTE!  Setting manual (MANUAL_EN) is one-time programmable (unreversible) change.",
 	  NULL
 	},
 	{ do_hwreset_en, -1,

mmc.h

@@ -128,9 +128,10 @@
 #define EN_REL_WR	(1<<2)
 
 /*
- * BKOPS_EN field definition
+ * BKOPS_EN field definitions
  */
-#define BKOPS_ENABLE	(1<<0)
+#define BKOPS_MAN_ENABLE	(1<<0)
+#define BKOPS_AUTO_ENABLE	(1<<1)
 
 /*
  * EXT_CSD field definitions

mmc_cmds.c

@@ -792,13 +792,15 @@ int do_write_bkops_en(int nargs, char **argv)
 	__u8 ext_csd[512], value = 0;
 	int fd, ret;
 	char *device;
+	char *en_type;
 
-	if (nargs != 2) {
-	       fprintf(stderr, "Usage: mmc bkops enable </path/to/mmcblkX>\n");
-	       exit(1);
+	if (nargs != 3) {
+		fprintf(stderr, "Usage: mmc bkops_en <auto|manual> </path/to/mmcblkX>\n");
+		exit(1);
 	}
 
-	device = argv[1];
+	en_type = argv[1];
+	device = argv[2];
 
 	fd = open(device, O_RDWR);
 	if (fd < 0) {
@@ -812,12 +814,19 @@ int do_write_bkops_en(int nargs, char **argv)
 		exit(1);
 	}
 
-	if (!(ext_csd[EXT_CSD_BKOPS_SUPPORT] & 0x1)) {
-		fprintf(stderr, "%s doesn't support BKOPS\n", device);
+	if (strcmp(en_type, "auto") == 0) {
+		if (ext_csd[EXT_CSD_REV] < EXT_CSD_REV_V5_0) {
+			fprintf(stderr, "%s doesn't support AUTO_EN in the BKOPS_EN register\n", device);
+			exit(1);
+		}
+		ret = write_extcsd_value(fd, EXT_CSD_BKOPS_EN, BKOPS_AUTO_ENABLE);
+	} else if (strcmp(en_type, "manual") == 0) {
+		ret = write_extcsd_value(fd, EXT_CSD_BKOPS_EN, BKOPS_MAN_ENABLE);
+	} else {
+		fprintf(stderr, "%s invalid mode for BKOPS_EN requested: %s. Valid options: auto or manual\n", en_type, device);
 		exit(1);
 	}
 
-	ret = write_extcsd_value(fd, EXT_CSD_BKOPS_EN, BKOPS_ENABLE);
 	if (ret) {
 		fprintf(stderr, "Could not write 0x%02x to EXT_CSD[%d] in %s\n",
 			value, EXT_CSD_BKOPS_EN, device);