mmc-utils: Add disable partition boot to 'mmc bootpart enable'

Modified 'bootpart enable' function to disable partition boot
by setting the <partition> parameter to 0.
Signed-off-by: Markus Schuetterle <markus.schuetterle@intel.com>
Signed-off-by: Chris Ball <chris@printf.net>

man/mmc.1

@@ -52,6 +52,7 @@ Print the response to STATUS_SEND (CMD13).
 .TP
 .BR "bootpart enable <boot_partition> <send_ack> <device>"
 Enable the boot partition for the <device>.
+Disable the boot partition for the <device> with <boot_partition> set to 0.
 To receive acknowledgment of boot from the card set <send_ack>
 to 1, else set it to 0.
 .TP

mmc.c

@@ -95,7 +95,7 @@ static struct Command commands[] = {
 	},
 	{ do_write_boot_en, -3,
 	  "bootpart enable", "<boot_partition> " "<send_ack> " "<device>\n"
-		"Enable the boot partition for the <device>.\nTo receive acknowledgment of boot from the card set <send_ack>\nto 1, else set it to 0.",
+		"Enable the boot partition for the <device>.\nDisable the boot partition for the <device> if <boot_partition> is set to 0.\nTo receive acknowledgment of boot from the card set <send_ack>\nto 1, else set it to 0.",
 	  NULL
 	},
 	{ do_boot_bus_conditions_set, -4,

mmc.h

@@ -150,6 +150,7 @@
 #define EXT_CSD_HW_RESET_EN		(0x01)
 #define EXT_CSD_HW_RESET_DIS		(0x02)
 #define EXT_CSD_PART_CONFIG_ACC_MASK	  (0x7)
+#define EXT_CSD_PART_CONFIG_ACC_NONE	  (0x0)
 #define EXT_CSD_PART_CONFIG_ACC_BOOT0	  (0x1)
 #define EXT_CSD_PART_CONFIG_ACC_BOOT1	  (0x2)
 #define EXT_CSD_PART_CONFIG_ACC_USER_AREA (0x7)

mmc_cmds.c

@@ -275,6 +275,9 @@ int do_write_boot_en(int nargs, char **argv)
 	value = ext_csd[EXT_CSD_PART_CONFIG];
 
 	switch (boot_area) {
+	case EXT_CSD_PART_CONFIG_ACC_NONE:
+		value &= ~(7 << 3);
+		break;
 	case EXT_CSD_PART_CONFIG_ACC_BOOT0:
 		value |= (1 << 3);
 		value &= ~(3 << 4);