dm: MIGRATION: Add migration plan for DM_MMC

Given that at this point the MMC subsystem itself has been migrated
along with a number of subsystem drivers, formalize a deadline for
migration.

Reviewed-by: Simon Glass <sjg@chromium.org>
Cc: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>

Makefile

@@ -919,6 +919,16 @@ ifeq ($(CONFIG_DM_I2C_COMPAT)$(CONFIG_SANDBOX),y)
 	@echo "(possibly in a subsequent patch in your series)"
 	@echo "before sending patches to the mailing list."
 	@echo "===================================================="
+endif
+ifeq ($(CONFIG_MMC),y)
+ifneq ($(CONFIG_DM_MMC)$(CONFIG_OF_CONTROL)$(CONFIG_BLK),yyy)
+	@echo "===================== WARNING ======================"
+	@echo "This board does not use CONFIG_DM_MMC. Please update"
+	@echo "the board to use CONFIG_DM_MMC before the v2019.04 release."
+	@echo "Failure to update by the deadline may result in board removal."
+	@echo "See doc/driver-model/MIGRATION.txt for more info."
+	@echo "===================================================="
+endif
 endif
 	@# Check that this build does not use CONFIG options that we do not
 	@# know about unless they are in Kconfig. All the existing CONFIG

doc/driver-model/MIGRATION.txt

@@ -5,6 +5,15 @@ U-Boot has been migrating to a new driver model since its introduction in
 2014. This file describes the schedule for deprecation of pre-driver-model
 features.
 
+CONFIG_DM_MMC
+-------------
+
+Status: In progress
+Deadline: 2019.04
+
+The subsystem itself has been converted and maintainers should submit patches
+switching over to using CONFIG_DM_MMC and other base driver model options in
+time for inclusion in the 2019.04 rerelease.
 
 CONFIG_BLK
 ----------