[Buildroot] [PATCH 1/1] uboot: zynqmp: Support loading a PMU config

[Brandon Maier <brandon.maier@rockwellcollins.com>]

Before now, U-Boot SPL could only load the Platform Management Unit
(PMU) by patching the board-specific pm_cfg_obj.c file into the generic
PMU firmware, but that then requires generating a new PMU firmware for
every board configuration. To fix that, Luca Ceresoli added support to
U-Boot to load the pm_cfg_obj[1].

Like the PMU firmware, we need a way to pass the PMU cfg to U-Boot
during build. U-Boot only accepts the binary format of the cfg, so we
must convert the source file with the tool provided with U-Boot.

[1] https://lucaceresoli.net/zynqmp-uboot-spl-pmufw-cfg-load/

Signed-off-by: Brandon Maier <brandon.maier@rockwellcollins.com>
---
 boot/uboot/Config.in | 22 ++++++++++++++++++++++
 boot/uboot/uboot.mk  | 17 +++++++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/boot/uboot/Config.in b/boot/uboot/Config.in
index 8cce9b1bae..5fa3b5942e 100644
--- a/boot/uboot/Config.in
+++ b/boot/uboot/Config.in
@@ -458,6 +458,28 @@ config BR2_TARGET_UBOOT_ZYNQMP_PMUFW
 
 	  This feature requires U-Boot >= 2018.07.
 
+config BR2_TARGET_UBOOT_ZYNQMP_PM_CFG
+	string "PMU configuration location"
+	depends on BR2_TARGET_UBOOT_BUILD_SYSTEM_KCONFIG
+	help
+	  Location of a PMU configuration file.
+
+	  If not empty, Buildroot will convert the PMU configuration
+	  file into a loadable blob and pass it to U-Boot. The blob gets
+	  embedded into the U-Boot SPL and is used to configure the PMU
+	  during board initialization.
+
+	  Unlike the PMU firmware, the PMU configuration file is unique
+	  to each board configuration. A PMU configuration file can be
+	  generated by building your Xilinx SDK BSP. It can be found in
+	  the BSP source, for example at
+	  > ./psu_cortexa53_0/libsrc/xilpm_v2_4/src/pm_cfg_obj.c
+
+	  Leave this option empty if your PMU firmware has a hard-coded
+	  configuration object or you are loading it by any other means.
+
+	  This feature requires U-Boot >= v2019.10.
+
 config BR2_TARGET_UBOOT_ZYNQMP_PSU_INIT_FILE
 	string "Custom psu_init_gpl file"
 	depends on BR2_TARGET_UBOOT_BUILD_SYSTEM_KCONFIG
diff --git a/boot/uboot/uboot.mk b/boot/uboot/uboot.mk
index 71689207e3..67d153189d 100644
--- a/boot/uboot/uboot.mk
+++ b/boot/uboot/uboot.mk
@@ -293,6 +293,11 @@ define UBOOT_BUILD_CMDS
 	$(if $(UBOOT_CUSTOM_DTS_PATH),
 		cp -f $(UBOOT_CUSTOM_DTS_PATH) $(@D)/arch/$(UBOOT_ARCH)/dts/
 	)
+	$(if $(UBOOT_ZYNQMP_PM_CFG_PATH),
+		$(UBOOT_DIR)/tools/zynqmp_pm_cfg_obj_convert.py \
+			"$(UBOOT_ZYNQMP_PM_CFG_PATH)" \
+			"$(UBOOT_ZYNQMP_PM_CFG_BIN)"
+	)
 	$(TARGET_CONFIGURE_OPTS) \
 		$(BR2_MAKE) -C $(@D) $(UBOOT_MAKE_OPTS) \
 		$(UBOOT_MAKE_TARGET)
@@ -360,6 +365,17 @@ define UBOOT_ZYNQMP_KCONFIG_PMUFW
 	$(call KCONFIG_SET_OPT,CONFIG_PMUFW_INIT_FILE,"$(UBOOT_ZYNQMP_PMUFW_PATH)")
 endef
 
+UBOOT_ZYNQMP_PM_CFG = $(call qstrip,$(BR2_TARGET_UBOOT_ZYNQMP_PM_CFG))
+UBOOT_ZYNQMP_PM_CFG_PATH = $(shell readlink -f $(UBOOT_ZYNQMP_PM_CFG))
+
+ifneq ($(UBOOT_ZYNQMP_PM_CFG_PATH),)
+UBOOT_ZYNQMP_PM_CFG_BIN = $(UBOOT_DIR)/pm_cfg_obj.bin
+define UBOOT_ZYNQMP_KCONFIG_PM_CFG
+	$(call KCONFIG_SET_OPT,CONFIG_ZYNQMP_SPL_PM_CFG_OBJ_FILE,"$(UBOOT_ZYNQMP_PM_CFG_BIN)", \
+		$(@D)/.config)
+endef
+endif
+
 UBOOT_ZYNQMP_PSU_INIT = $(call qstrip,$(BR2_TARGET_UBOOT_ZYNQMP_PSU_INIT_FILE))
 UBOOT_ZYNQMP_PSU_INIT_PATH = $(shell readlink -f $(UBOOT_ZYNQMP_PSU_INIT))
 
@@ -422,6 +438,7 @@ endif
 
 define UBOOT_KCONFIG_FIXUP_CMDS
 	$(UBOOT_ZYNQMP_KCONFIG_PMUFW)
+	$(UBOOT_ZYNQMP_KCONFIG_PM_CFG)
 	$(UBOOT_ZYNQMP_KCONFIG_PSU_INIT)
 endef
 
-- 
2.25.1