stm32mp1: add command poweroff

Activate the command poweroff by default for STM32MP1:
- with PCSI from TF-A for trusted boot
- with PMIC sysreset request for basic boot (SYSRESET_POWER)

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 33628b8..28d4d35 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1403,6 +1403,7 @@
 	select SYSRESET
 	select SYS_THUMB_BUILD
 	imply CMD_DM
+	imply CMD_POWEROFF
 	imply ENV_VARS_UBOOT_RUNTIME_CONFIG
 	help
 	  Support for STM32MP SoC family developed by STMicroelectronics,
diff --git a/arch/arm/mach-stm32mp/Makefile b/arch/arm/mach-stm32mp/Makefile
index f59ced5..1493914 100644
--- a/arch/arm/mach-stm32mp/Makefile
+++ b/arch/arm/mach-stm32mp/Makefile
@@ -11,6 +11,9 @@
 obj-y += spl.o
 else
 obj-y += bsec.o
+ifndef CONFIG_STM32MP1_TRUSTED
+obj-$(CONFIG_SYSRESET) += cmd_poweroff.o
+endif
 endif
 obj-$(CONFIG_ARMV7_PSCI) += psci.o
 obj-$(CONFIG_$(SPL_)DM_REGULATOR) += pwr_regulator.o
diff --git a/arch/arm/mach-stm32mp/cmd_poweroff.c b/arch/arm/mach-stm32mp/cmd_poweroff.c
new file mode 100644
index 0000000..f54dd1d
--- /dev/null
+++ b/arch/arm/mach-stm32mp/cmd_poweroff.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
+/*
+ * Copyright (C) 2019, STMicroelectronics - All Rights Reserved
+ */
+
+#include <common.h>
+#include <command.h>
+#include <sysreset.h>
+
+int do_poweroff(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	int ret;
+
+	puts("poweroff ...\n");
+	mdelay(100);
+
+	ret = sysreset_walk(SYSRESET_POWER);
+
+	if (ret == -EINPROGRESS)
+		mdelay(1000);
+
+	/*NOTREACHED when power off*/
+	return CMD_RET_FAILURE;
+}