arm: Add PSCI shutdown function

Using PSCI you can not only reset the system, you can also shut it down!
This patch exposes a function to do exactly that to whatever code wants
to make use of it.

Signed-off-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Simon Glass <sjg@chromium.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/arch/arm/cpu/armv8/fwcall.c b/arch/arm/cpu/armv8/fwcall.c
index 6bb68f2ed3..b3ef7c0f73 100644
--- a/arch/arm/cpu/armv8/fwcall.c
+++ b/arch/arm/cpu/armv8/fwcall.c
@@ -97,3 +97,18 @@ void __noreturn psci_system_reset(void)
 	while (1)
 		;
 }
+
+void __noreturn psci_system_off(void)
+{
+	struct pt_regs regs;
+
+	regs.regs[0] = ARM_PSCI_0_2_FN_SYSTEM_OFF;
+
+	if (use_smc_for_psci)
+		smc_call(&regs);
+	else
+		hvc_call(&regs);
+
+	while (1)
+		;
+}