[RFC PATCH 4/4] power: reset: Implement a PSCI SYSTEM_RESET2 reboot-mode driver
From: Elliot Berman
Date: Mon Jul 24 2023 - 18:32:15 EST
PSCI implements a restart notifier for architectural defined resets.
The SYSTEM_RESET2 allows vendor firmware to define additional reset
types which could be mapped to the reboot reason.
Implement a driver to wire the reboot-mode framework to make vendor
SYSTEM_RESET2 calls on reboot.
Signed-off-by: Elliot Berman <quic_eberman@xxxxxxxxxxx>
---
MAINTAINERS | 1 +
drivers/firmware/psci/psci.c | 9 +++++
drivers/power/reset/Kconfig | 9 +++++
drivers/power/reset/Makefile | 1 +
drivers/power/reset/psci-vendor-reset.c | 49 +++++++++++++++++++++++++
include/linux/psci.h | 2 +
6 files changed, 71 insertions(+)
create mode 100644 drivers/power/reset/psci-vendor-reset.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 2da4c5f1917b..214b14c1da63 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16984,6 +16984,7 @@ L: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx (moderated for non-subscribers)
S: Maintained
F: Documentation/devicetree/bindings/power/reset/arm,psci-vendor-reset.yaml
F: drivers/firmware/psci/
+F: drivers/power/reset/psci-vendor-reset.c
F: include/linux/psci.h
F: include/uapi/linux/psci.h
diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
index d9629ff87861..6db73f9d2304 100644
--- a/drivers/firmware/psci/psci.c
+++ b/drivers/firmware/psci/psci.c
@@ -328,6 +328,15 @@ static struct notifier_block psci_sys_reset_nb = {
.priority = 129,
};
+void psci_vendor_sys_reset2(u32 reset_type, u32 cookie)
+{
+ if (psci_system_reset2_supported)
+ invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2),
+ reset_type | BIT_ULL(31),
+ cookie, 0);
+}
+EXPORT_SYMBOL_GPL(psci_vendor_sys_reset2);
+
static void psci_sys_poweroff(void)
{
invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index fff07b2bd77b..1474b9d51089 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -311,4 +311,13 @@ config POWER_MLXBF
help
This driver supports reset or low power mode handling for Mellanox BlueField.
+config POWER_RESET_PSCI_VENDOR_RESET
+ tristate "PSCI Vendor SYSTEM_RESET2 driver"
+ depends on ARM64 || ARM || COMPILE_TEST
+ select ARM_PSCI_FW
+ select REBOOT_MODE
+ help
+ Say y/m here to enable driver to use Vendor SYSTEM_RESET2 types on
+ chips which have firmware implementing custom SYSTEM_RESET2 types.
+
endif
diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index d763e6735ee3..d09243966b74 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -37,3 +37,4 @@ obj-$(CONFIG_SYSCON_REBOOT_MODE) += syscon-reboot-mode.o
obj-$(CONFIG_POWER_RESET_SC27XX) += sc27xx-poweroff.o
obj-$(CONFIG_NVMEM_REBOOT_MODE) += nvmem-reboot-mode.o
obj-$(CONFIG_POWER_MLXBF) += pwr-mlxbf.o
+obj-$(CONFIG_POWER_RESET_PSCI_VENDOR_RESET) += psci-vendor-reset.o
diff --git a/drivers/power/reset/psci-vendor-reset.c b/drivers/power/reset/psci-vendor-reset.c
new file mode 100644
index 000000000000..95d027225185
--- /dev/null
+++ b/drivers/power/reset/psci-vendor-reset.c
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/**
+ * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/reboot-mode.h>
+#include <linux/psci.h>
+
+static int psci_vendor_system_reset2(struct reboot_mode_driver *reboot, unsigned int magic)
+{
+ psci_vendor_sys_reset2(magic, 0);
+
+ return NOTIFY_DONE;
+}
+
+static int psci_vendor_reset_probe(struct platform_device *pdev)
+{
+ struct reboot_mode_driver *reboot;
+
+ reboot = devm_kzalloc(&pdev->dev, sizeof(*reboot), GFP_KERNEL);
+ if (!reboot)
+ return -ENOMEM;
+
+ reboot->write = psci_vendor_system_reset2;
+
+ return devm_reboot_mode_register(&pdev->dev, reboot);
+}
+
+static const struct of_device_id psci_vendor_reset_id_table[] = {
+ { .compatible = "arm,psci-vendor-reset" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, psci_vendor_reset_id_table);
+
+static struct platform_driver psci_vendor_reset_driver = {
+ .probe = psci_vendor_reset_probe,
+ .driver = {
+ .name = "psci-vendor-reset",
+ .of_match_table = of_match_ptr(psci_vendor_reset_id_table),
+ },
+};
+module_platform_driver(psci_vendor_reset_driver);
+
+MODULE_DESCRIPTION("PSCI Vendor SYSTEM_RESET2 Driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/psci.h b/include/linux/psci.h
index 4ca0060a3fc4..0c652c12e0a8 100644
--- a/include/linux/psci.h
+++ b/include/linux/psci.h
@@ -21,6 +21,8 @@ bool psci_power_state_is_valid(u32 state);
int psci_set_osi_mode(bool enable);
bool psci_has_osi_support(void);
+void psci_vendor_sys_reset2(u32 reset_type, u32 cookie);
+
struct psci_operations {
u32 (*get_version)(void);
int (*cpu_suspend)(u32 state, unsigned long entry_point);
--
2.41.0