3 files changed, 127 insertions, 0 deletions
diff --git a/lib/utils/suspend/Kconfig b/lib/utils/suspend/Kconfig
index 6c09d952..8d05aff6 100644
--- a/lib/utils/suspend/Kconfig
+++ b/lib/utils/suspend/Kconfig
@@ -9,6 +9,11 @@ config FDT_SUSPEND
 
 if FDT_SUSPEND
 
+config FDT_SUSPEND_ANDES_ATCSMU
+	bool "FDT Andes ATCSMU suspend driver"
+	depends on FDT_HSM_ANDES_ATCSMU && FDT_CACHE_ANDES_LLCACHE
+	default n
+
 config FDT_SUSPEND_RPMI
 	bool "FDT RPMI suspend driver"
 	depends on FDT_MAILBOX && RPMI_MAILBOX
diff --git a/lib/utils/suspend/fdt_suspend_andes_atcsmu.c b/lib/utils/suspend/fdt_suspend_andes_atcsmu.c
new file mode 100644
index 00000000..072accc0
--- /dev/null
+++ b/lib/utils/suspend/fdt_suspend_andes_atcsmu.c
@@ -0,0 +1,119 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2025 Andes Technology Corporation
+ */
+
+#include <andes/andes.h>
+#include <sbi/riscv_asm.h>
+#include <sbi/sbi_console.h>
+#include <sbi/sbi_domain.h>
+#include <sbi/sbi_error.h>
+#include <sbi/sbi_ecall_interface.h>
+#include <sbi/sbi_hart.h>
+#include <sbi/sbi_system.h>
+#include <sbi_utils/cache/fdt_cmo_helper.h>
+#include <sbi_utils/fdt/fdt_driver.h>
+#include <sbi_utils/fdt/fdt_helper.h>
+#include <sbi_utils/hsm/fdt_hsm_andes_atcsmu.h>
+
+static int check_secondary_harts_sleep(u32 hartid, bool deep_sleep)
+{
+	const struct sbi_domain *dom = &root;
+	unsigned long i;
+	u32 target;
+
+	/* Ensure the secondary harts entering the corresponding sleep state */
+	sbi_hartmask_for_each_hartindex(i, dom->possible_harts) {
+		target = sbi_hartindex_to_hartid(i);
+		if (target != hartid && !atcsmu_pcs_is_sleep(target, deep_sleep))
+			return SBI_EFAIL;
+	}
+
+	return SBI_OK;
+}
+
+static int ae350_system_suspend_check(u32 sleep_type)
+{
+	return (sleep_type == SBI_SUSP_SLEEP_TYPE_SUSPEND ||
+		sleep_type == SBI_SUSP_AE350_LIGHT_SLEEP) ? SBI_OK : SBI_EINVAL;
+}
+
+static int ae350_system_suspend(u32 sleep_type, unsigned long addr)
+{
+	u32 hartid = current_hartid();
+	int rc;
+
+	/* Prevent the core leaving the WFI mode unexpectedly */
+	csr_write(CSR_MIE, 0);
+
+	/*
+	 * Only allow the S-mode external interrupts (UART2 and RTC alarm) to
+	 * wake up the primary hart
+	 */
+	csr_set(CSR_SIE, MIP_SEIP);
+	atcsmu_set_wakeup_events(PCS_WAKEUP_RTC_ALARM_MASK | PCS_WAKEUP_UART2_MASK, hartid);
+
+	if (sleep_type == SBI_SUSP_AE350_LIGHT_SLEEP) {
+		rc = check_secondary_harts_sleep(hartid, false);
+		if (rc)
+			return rc;
+
+		atcsmu_set_command(LIGHT_SLEEP_CMD, hartid);
+	} else if (sleep_type == SBI_SUSP_SLEEP_TYPE_SUSPEND) {
+		rc = check_secondary_harts_sleep(hartid, true);
+		if (rc)
+			return rc;
+
+		atcsmu_set_command(DEEP_SLEEP_CMD, hartid);
+		rc = atcsmu_set_reset_vector((ulong)ae350_enable_coherency_warmboot, hartid);
+		if (rc)
+			return rc;
+
+		ae350_non_ret_save(sbi_scratch_thishart_ptr());
+		fdt_cmo_llc_enable(false);
+		rc = fdt_cmo_llc_flush_all();
+		if (rc)
+			return rc;
+	}
+
+	ae350_disable_coherency();
+	wfi();
+
+	/* Light sleep resumes here */
+	ae350_enable_coherency();
+
+	return SBI_OK;
+}
+
+static void ae350_system_resume(void)
+{
+	u32 hartid = current_hartid();
+	u32 sleep_type = atcsmu_get_sleep_type(hartid);
+
+	if (sleep_type == SBI_SUSP_SLEEP_TYPE_SUSPEND)
+		fdt_cmo_llc_enable(true);
+}
+
+static struct sbi_system_suspend_device suspend_andes_atcsmu = {
+	.name = "andes_atcsmu",
+	.system_suspend_check = ae350_system_suspend_check,
+	.system_suspend = ae350_system_suspend,
+	.system_resume = ae350_system_resume,
+};
+
+static int suspend_andes_atcsmu_probe(const void *fdt, int nodeoff, const struct fdt_match *match)
+{
+	sbi_system_suspend_set_device(&suspend_andes_atcsmu);
+	return 0;
+}
+
+static const struct fdt_match suspend_andes_atcsmu_match[] = {
+	{ .compatible = "andestech,atcsmu-sys" },
+	{ },
+};
+
+const struct fdt_driver fdt_suspend_andes_atcsmu = {
+	.match_table = suspend_andes_atcsmu_match,
+	.init = suspend_andes_atcsmu_probe,
+};
diff --git a/lib/utils/suspend/objects.mk b/lib/utils/suspend/objects.mk
index 1fb29b5e..fb1ad9ae 100644
--- a/lib/utils/suspend/objects.mk
+++ b/lib/utils/suspend/objects.mk
@@ -7,6 +7,9 @@
 #   Anup Patel <apatel@ventanamicro.com>
 #
 
+carray-fdt_early_drivers-$(CONFIG_FDT_SUSPEND_ANDES_ATCSMU) += fdt_suspend_andes_atcsmu
+libsbiutils-objs-$(CONFIG_FDT_SUSPEND_ANDES_ATCSMU) += suspend/fdt_suspend_andes_atcsmu.o
+
 carray-fdt_early_drivers-$(CONFIG_FDT_SUSPEND_RPMI) += fdt_suspend_rpmi
 libsbiutils-objs-$(CONFIG_FDT_SUSPEND_RPMI) += suspend/fdt_suspend_rpmi.o