sysreset: psci: support system reset in a generic way with PSCI
If the system is running PSCI firmware, the System Reset function
(func ID: 0x80000009) is supposed to be handled by PSCI, that is,
the SoC/board specific reset implementation should be moved to PSCI.
U-Boot should call the PSCI service according to the arm-smccc
manner.
The arm-smccc is supported on ARMv7 or later. Especially, ARMv8
generation SoCs are likely to run ARM Trusted Firmware BL31. In
this case, U-Boot is a non-secure world boot loader, so it should
not be able to reset the system directly.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/drivers/sysreset/Kconfig b/drivers/sysreset/Kconfig
index 05a37b9..9664630 100644
--- a/drivers/sysreset/Kconfig
+++ b/drivers/sysreset/Kconfig
@@ -13,4 +13,14 @@
to effect a reset. The uclass will try all available drivers when
reset_walk() is called.
+if SYSRESET
+
+config SYSRESET_PSCI
+ bool "Enable support for PSCI System Reset"
+ depends on ARM_PSCI_FW
+ help
+ Enable PSCI SYSTEM_RESET function call. To use this, PSCI firmware
+ must be running on your system.
+
+endif
endmenu
diff --git a/drivers/sysreset/Makefile b/drivers/sysreset/Makefile
index 49b8bb6..7bb8406 100644
--- a/drivers/sysreset/Makefile
+++ b/drivers/sysreset/Makefile
@@ -5,6 +5,7 @@
#
obj-$(CONFIG_SYSRESET) += sysreset-uclass.o
+obj-$(CONFIG_SYSRESET_PSCI) += sysreset_psci.o
ifndef CONFIG_SPL_BUILD
obj-$(CONFIG_ROCKCHIP_RK3036) += sysreset_rk3036.o
diff --git a/drivers/sysreset/sysreset_psci.c b/drivers/sysreset/sysreset_psci.c
new file mode 100644
index 0000000..a4911b7
--- /dev/null
+++ b/drivers/sysreset/sysreset_psci.c
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2017 Masahiro Yamada <yamada.masahiro@socionext.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <dm/device.h>
+#include <sysreset.h>
+#include <linux/errno.h>
+#include <linux/psci.h>
+
+static int psci_sysreset_request(struct udevice *dev, enum sysreset_t type)
+{
+ unsigned long function_id;
+
+ switch (type) {
+ case SYSRESET_WARM:
+ case SYSRESET_COLD:
+ function_id = PSCI_0_2_FN_SYSTEM_RESET;
+ break;
+ case SYSRESET_POWER:
+ function_id = PSCI_0_2_FN_SYSTEM_OFF;
+ break;
+ default:
+ return -ENOSYS;
+ }
+
+ invoke_psci_fn(function_id, 0, 0, 0);
+
+ return -EINPROGRESS;
+}
+
+static struct sysreset_ops psci_sysreset_ops = {
+ .request = psci_sysreset_request,
+};
+
+U_BOOT_DRIVER(psci_sysreset) = {
+ .name = "psci-sysreset",
+ .id = UCLASS_SYSRESET,
+ .ops = &psci_sysreset_ops,
+};