[PATCH 2/2] lib: utils/reset: Add Metanoia MT5824 system reset driver

[Benoît Monin]

Add a driver for the system reset function found in Metanoia MT5824 SoC
and enable it in the generic platform configuration.

Originally-by: Jun Chang <jun.chang at metanoia-comm.com>
Signed-off-by: Benoît Monin <benoit.monin at bootlin.com>
---
 lib/utils/reset/Kconfig              |  4 ++
 lib/utils/reset/fdt_reset_metanoia.c | 72 ++++++++++++++++++++++++++++++++++++
 lib/utils/reset/objects.mk           |  3 ++
 platform/generic/configs/defconfig   |  1 +
 4 files changed, 80 insertions(+)

diff --git a/lib/utils/reset/Kconfig b/lib/utils/reset/Kconfig
index b2ac120e..8988548c 100644
--- a/lib/utils/reset/Kconfig
+++ b/lib/utils/reset/Kconfig
@@ -29,6 +29,10 @@ config FDT_RESET_LITEX
 	depends on FDT_GPIO
 	default n
 
+config FDT_RESET_METANOIA
+	bool "Metanoia FDT reset driver"
+	default n
+
 config FDT_RESET_RPMI
 	bool "RPMI FDT reset driver"
 	depends on FDT_MAILBOX && RPMI_MAILBOX
diff --git a/lib/utils/reset/fdt_reset_metanoia.c b/lib/utils/reset/fdt_reset_metanoia.c
new file mode 100644
index 00000000..8a71e107
--- /dev/null
+++ b/lib/utils/reset/fdt_reset_metanoia.c
@@ -0,0 +1,72 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2026 Metanoia Communications Inc.
+ *
+ */
+
+#include <sbi/riscv_io.h>
+#include <sbi/sbi_platform.h>
+#include <sbi/sbi_system.h>
+#include <sbi_utils/fdt/fdt_helper.h>
+#include <sbi_utils/fdt/fdt_driver.h>
+
+#define SWRSTREQ_CTRL_REG_OFFSET 0x00
+#define SWRSTREQ_REG_OFFSET 0x04
+
+struct reset_metanoia_data {
+	u8 *reg_base;
+};
+
+static struct reset_metanoia_data reset_data;
+
+static int metanoia_system_reset_check(u32 type, u32 reason)
+{
+	switch (type) {
+	case SBI_SRST_RESET_TYPE_WARM_REBOOT:
+	case SBI_SRST_RESET_TYPE_COLD_REBOOT:
+		return 1;
+	case SBI_SRST_RESET_TYPE_SHUTDOWN:
+	default:
+		return 0;
+	}
+}
+
+static void metanoia_system_reset(u32 type, u32 reason)
+{
+	writew(0x1, reset_data.reg_base + SWRSTREQ_CTRL_REG_OFFSET);
+	writew(0x1, reset_data.reg_base + SWRSTREQ_REG_OFFSET);
+}
+
+static struct sbi_system_reset_device metanoia_reset = {
+	.name		    = "metanoia mt5824 reset",
+	.system_reset_check = metanoia_system_reset_check,
+	.system_reset	    = metanoia_system_reset,
+};
+
+static int metanoia_reset_init(const void *fdt, int nodeoff,
+			       const struct fdt_match *match)
+{
+	u64 reg_addr;
+	int rc;
+
+	rc = fdt_get_node_addr_size(fdt, nodeoff, 0, &reg_addr, NULL);
+	if (rc < 0 || !reg_addr)
+		return SBI_ENODEV;
+
+	reset_data.reg_base = (u8 *)reg_addr;
+
+	sbi_system_reset_add_device(&metanoia_reset);
+
+	return 0;
+}
+
+static const struct fdt_match metanoia_reset_match[] = {
+	{ .compatible = "metanoia,mt5824-reboot" },
+	{ /* sentinel */ }
+};
+
+const struct fdt_driver fdt_reset_metanoia = {
+	.match_table = metanoia_reset_match,
+	.init	     = metanoia_reset_init,
+};
diff --git a/lib/utils/reset/objects.mk b/lib/utils/reset/objects.mk
index 38b4e306..a9b6edad 100644
--- a/lib/utils/reset/objects.mk
+++ b/lib/utils/reset/objects.mk
@@ -20,6 +20,9 @@ libsbiutils-objs-$(CONFIG_FDT_RESET_HTIF) += reset/fdt_reset_htif.o
 carray-fdt_early_drivers-$(CONFIG_FDT_RESET_LITEX) += fdt_reset_litex
 libsbiutils-objs-$(CONFIG_FDT_RESET_LITEX) += reset/fdt_reset_litex.o
 
+carray-fdt_early_drivers-$(CONFIG_FDT_RESET_METANOIA) += fdt_reset_metanoia
+libsbiutils-objs-$(CONFIG_FDT_RESET_METANOIA) += reset/fdt_reset_metanoia.o
+
 carray-fdt_early_drivers-$(CONFIG_FDT_RESET_SG2042_HWMON_MCU) += fdt_reset_sg2042_mcu
 libsbiutils-objs-$(CONFIG_FDT_RESET_SG2042_HWMON_MCU) += reset/fdt_reset_sg2042_hwmon_mcu.o
 
diff --git a/platform/generic/configs/defconfig b/platform/generic/configs/defconfig
index 1ae436e4..9e67122a 100644
--- a/platform/generic/configs/defconfig
+++ b/platform/generic/configs/defconfig
@@ -52,6 +52,7 @@ CONFIG_FDT_RESET_ATCWDT200=y
 CONFIG_FDT_RESET_GPIO=y
 CONFIG_FDT_RESET_LITEX=y
 CONFIG_FDT_RESET_HTIF=y
+CONFIG_FDT_RESET_METANOIA=y
 CONFIG_FDT_RESET_RPMI=y
 CONFIG_FDT_RESET_SG2042_HWMON_MCU=y
 CONFIG_FDT_RESET_SPACEMIT_P1=y

-- 
2.54.0