[PATCH 03/12] power: reset: Add TI-SCI reboot driver

From: Andrew Davis
Date: Wed Jan 31 2024 - 17:20:29 EST


This reboot driver calls into firmware using TI-SCI to reboot the system.
We register the handler with low priority as we want PSCI to remain the
main way these devices are rebooted. This driver acts as a fallback if
PSCI is not able to reboot the system.

Signed-off-by: Andrew Davis <afd@xxxxxx>
---
MAINTAINERS | 1 +
drivers/power/reset/Kconfig | 7 ++++
drivers/power/reset/Makefile | 1 +
drivers/power/reset/ti-sci-reboot.c | 63 +++++++++++++++++++++++++++++
4 files changed, 72 insertions(+)
create mode 100644 drivers/power/reset/ti-sci-reboot.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 45983bb174fe4..ee67ea497fc56 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -21758,6 +21758,7 @@ F: drivers/clk/keystone/sci-clk.c
F: drivers/firmware/ti_sci*
F: drivers/irqchip/irq-ti-sci-inta.c
F: drivers/irqchip/irq-ti-sci-intr.c
+F: drivers/power/reset/ti-sci-reboot.c
F: drivers/reset/reset-ti-sci.c
F: drivers/soc/ti/ti_sci_inta_msi.c
F: drivers/pmdomain/ti/ti_sci_pm_domains.c
diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index fece990af4a75..d3e91e54cae24 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -205,6 +205,13 @@ config POWER_RESET_ST
help
Reset support for STMicroelectronics boards.

+config POWER_RESET_TI_SCI
+ tristate "TI System Control Interface (TI-SCI) reboot driver"
+ depends on TI_SCI_PROTOCOL
+ help
+ This enables the reboot driver support over TI System Control
+ Interface available on some TI's SoCs.
+
config POWER_RESET_TPS65086
bool "TPS65086 restart driver"
depends on MFD_TPS65086
diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index a95d1bd275d18..881ca58a43b9c 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -23,6 +23,7 @@ obj-$(CONFIG_POWER_RESET_QNAP) += qnap-poweroff.o
obj-$(CONFIG_POWER_RESET_REGULATOR) += regulator-poweroff.o
obj-$(CONFIG_POWER_RESET_RESTART) += restart-poweroff.o
obj-$(CONFIG_POWER_RESET_ST) += st-poweroff.o
+obj-$(CONFIG_POWER_RESET_TI_SCI) += ti-sci-reboot.o
obj-$(CONFIG_POWER_RESET_TPS65086) += tps65086-restart.o
obj-$(CONFIG_POWER_RESET_VERSATILE) += arm-versatile-reboot.o
obj-$(CONFIG_POWER_RESET_VEXPRESS) += vexpress-poweroff.o
diff --git a/drivers/power/reset/ti-sci-reboot.c b/drivers/power/reset/ti-sci-reboot.c
new file mode 100644
index 0000000000000..400bd5d740f8b
--- /dev/null
+++ b/drivers/power/reset/ti-sci-reboot.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Texas Instrument's System Control Interface (TI-SCI) reboot driver
+ *
+ * Copyright (C) 2024 Texas Instruments Incorporated - https://www.ti.com/
+ * Andrew Davis <afd@xxxxxx>
+ */
+
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+
+#include <linux/soc/ti/ti_sci_protocol.h>
+
+static int ti_sci_reboot_handler(struct sys_off_data *data)
+{
+ const struct ti_sci_handle *sci = data->cb_data;
+ const struct ti_sci_core_ops *core_ops = &sci->ops.core_ops;
+
+ core_ops->reboot_device(sci);
+
+ return NOTIFY_DONE;
+}
+
+static int ti_sci_reboot_probe(struct platform_device *pdev)
+{
+ const struct ti_sci_handle *sci;
+ int err;
+
+ sci = devm_ti_sci_get_handle(&pdev->dev);
+ if (IS_ERR(sci))
+ return PTR_ERR(sci);
+
+ err = devm_register_sys_off_handler(&pdev->dev,
+ SYS_OFF_MODE_RESTART,
+ SYS_OFF_PRIO_LOW,
+ ti_sci_reboot_handler,
+ (void *)sci);
+ if (err)
+ return dev_err_probe(&pdev->dev, err, "Cannot register restart handler\n");
+
+ return 0;
+}
+
+static const struct of_device_id ti_sci_reboot_of_match[] = {
+ { .compatible = "ti,sci-reboot", },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, ti_sci_reboot_of_match);
+
+static struct platform_driver ti_sci_reboot_driver = {
+ .probe = ti_sci_reboot_probe,
+ .driver = {
+ .name = "ti-sci-reboot",
+ .of_match_table = ti_sci_reboot_of_match,
+ },
+};
+module_platform_driver(ti_sci_reboot_driver);
+
+MODULE_AUTHOR("Andrew Davis <afd@xxxxxx>");
+MODULE_DESCRIPTION("TI System Control Interface (TI SCI) Reboot driver");
+MODULE_LICENSE("GPL");
--
2.39.2