platform: Add Andes AE350 initial support

This commit provides basic support for the AE350 platform.

Signed-off-by: Zong Li <zongbox@gmail.com>
Signed-off-by: Nylon Chen <nylon7@andestech.com>

10 files changed, 650 insertions, 0 deletions

diff --git a/docs/platform/andes-ae350.md b/docs/platform/andes-ae350.md
new file mode 100644
index 0000000..b979927
--- /dev/null
+++ b/docs/platform/andes-ae350.md
@@ -0,0 +1,28 @@
+Andes AE350 SoC Platform
+========================
+The AE350 AXI/AHB-based platform N25(F)/NX25(F)/D25F/A25/AX25 CPU with
+level-one memories,interrupt controller, debug module, AXI and AHB Bus
+Matrix Controller, AXI-to-AHB Bridge and a collection of fundamentalAHB/APB
+bus IP components pre-integrated together as a system design.The high-quality
+and configurable AHB/APB IPs suites a majority embedded systems,
+and the verified platform serves as a starting point to jump start SoC designs.
+
+To build platform specific library and firmwares, provide the *PLATFORM=andes/ae350* parameter to the top level make command.
+
+Platform Options
+----------------
+
+The Andes AE350 platform does not have any platform-specific options.
+
+Building Andes AE350 Platform
+-----------------------------
+
+To use Linux v5.2 should be used to build Andes AE350 OpenSBI binaries by using the compile time option FW_PAYLOAD_FDT_PATH.
+
+AE350's dts is included in https://github.com/andestech/linux/tree/ast-v3_2_0-release-public
+
+**Linux Kernel Payload**
+
+```
+make PLATFORM=andes/ae350 FW_PAYLOAD_PATH=<linux_build_directory>/arch/riscv/boot/Image FW_PAYLOAD_FDT_PATH=<ae350.dtb path>
+```
diff --git a/docs/platform/platform.md b/docs/platform/platform.md
index 49fa3e9..424efe9 100644
--- a/docs/platform/platform.md
+++ b/docs/platform/platform.md
@@ -24,6 +24,8 @@ OpenSBI currently supports the following virtual and hardware platforms:
 * **Ariane FPGA SoC**: Platform support for the Ariane FPGA SoC used on
   Genesys 2 board.
 
+* **Andes AE350 SoC**: Platform support for the Andes's SoC (AE350).
+
 The code for these supported platforms can be used as example to implement
 support for other platforms. The *platform/template* directory also provides
 template files for implementing support for a new platform. The *object.mk*,
@@ -34,3 +36,4 @@ facilitate the implementation.
 [qemu_sifive_u.md]: qemu_sifive_u.md
 [sifive_fu540.md]: sifive_fu540.md
 [ariane-fpga.md]: ariane-fpga.md
+[andes_ae350.md]: andes-ae350.md
diff --git a/platform/andes/ae350/config.mk b/platform/andes/ae350/config.mk
new file mode 100644
index 0000000..f555ef5
--- /dev/null
+++ b/platform/andes/ae350/config.mk
@@ -0,0 +1,36 @@
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+# Copyright (c) 2019 Andes Technology Corporation
+#
+# Authors:
+#   Zong Li <zong@andestech.com>
+#   Nylon Chen <nylon7@andestech.com>
+
+# Compiler flags
+platform-cppflags-y =
+platform-cflags-y =
+platform-asflags-y =
+platform-ldflags-y =
+
+# Blobs to build
+FW_TEXT_START=0x00000000
+
+FW_DYNAMIC=y
+
+FW_JUMP=y
+ifeq ($(PLATFORM_RISCV_XLEN), 32)
+  FW_JUMP_ADDR=0x400000
+else
+  FW_JUMP_ADDR=0x200000
+endif
+FW_JUMP_FDT_ADDR=0x2000000
+
+FW_PAYLOAD=y
+ifeq ($(PLATFORM_RISCV_XLEN), 32)
+  FW_PAYLOAD_OFFSET=0x400000
+else
+  FW_PAYLOAD_OFFSET=0x200000
+endif
+
+FW_PAYLOAD_FDT_ADDR=0x2000000
diff --git a/platform/andes/ae350/objects.mk b/platform/andes/ae350/objects.mk
new file mode 100644
index 0000000..4ed152e
--- /dev/null
+++ b/platform/andes/ae350/objects.mk
@@ -0,0 +1,11 @@
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+# Copyright (c) 2019 Andes Technology Corporation
+#
+# Authors:
+#   Zong Li <zong@andestech.com>
+#   Nylon Chen <nylon7@andestech.com>
+#
+
+platform-objs-y += plicsw.o plmt.o platform.o
diff --git a/platform/andes/ae350/platform.c b/platform/andes/ae350/platform.c
new file mode 100644
index 0000000..d14266d
--- /dev/null
+++ b/platform/andes/ae350/platform.c
@@ -0,0 +1,194 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2019 Andes Technology Corporation
+ *
+ * Authors:
+ *   Zong Li <zong@andestech.com>
+ *   Nylon Chen <nylon7@andestech.com>
+ */
+
+#include <sbi/riscv_encoding.h>
+#include <sbi/sbi_const.h>
+#include <sbi/sbi_hart.h>
+#include <sbi/sbi_platform.h>
+#include <sbi/sbi_console.h>
+#include <sbi_utils/serial/uart8250.h>
+#include <sbi_utils/irqchip/plic.h>
+#include "platform.h"
+#include "plmt.h"
+#include "plicsw.h"
+
+/* Platform final initialization. */
+static int ae350_final_init(bool cold_boot)
+{
+	void *fdt;
+
+	/* enable L1 cache */
+	uintptr_t mcache_ctl_val = csr_read(CSR_MCACHECTL);
+
+	if (!(mcache_ctl_val & V5_MCACHE_CTL_IC_EN))
+		mcache_ctl_val |= V5_MCACHE_CTL_IC_EN;
+	if (!(mcache_ctl_val & V5_MCACHE_CTL_DC_EN))
+		mcache_ctl_val |= V5_MCACHE_CTL_DC_EN;
+	if (!(mcache_ctl_val & V5_MCACHE_CTL_CCTL_SUEN))
+		mcache_ctl_val |= V5_MCACHE_CTL_CCTL_SUEN;
+	csr_write(CSR_MCACHECTL, mcache_ctl_val);
+
+	/* enable L2 cache */
+	uint32_t *l2c_ctl_base = (void *)AE350_L2C_ADDR + V5_L2C_CTL_OFFSET;
+	uint32_t l2c_ctl_val = *l2c_ctl_base;
+
+	if (!(l2c_ctl_val & V5_L2C_CTL_ENABLE_MASK))
+		l2c_ctl_val |= V5_L2C_CTL_ENABLE_MASK;
+	*l2c_ctl_base = l2c_ctl_val;
+
+	if (!cold_boot)
+		return 0;
+
+	fdt = sbi_scratch_thishart_arg1_ptr();
+	plic_fdt_fixup(fdt, "riscv,plic0");
+
+	return 0;
+}
+
+/* Get number of PMP regions for given HART. */
+static u32 ae350_pmp_region_count(u32 hartid)
+{
+	return 1;
+}
+
+/*
+ * Get PMP regions details (namely: protection, base address, and size) for
+ * a given HART.
+ */
+static int ae350_pmp_region_info(u32 hartid, u32 index, ulong *prot,
+				 ulong *addr, ulong *log2size)
+{
+	int ret = 0;
+
+	switch (index) {
+	case 0:
+		*prot	  = PMP_R | PMP_W | PMP_X;
+		*addr	  = 0;
+		*log2size = __riscv_xlen;
+		break;
+	default:
+		ret = -1;
+		break;
+	};
+
+	return ret;
+}
+
+/* Initialize the platform console. */
+static int ae350_console_init(void)
+{
+	return uart8250_init(AE350_UART_ADDR,
+			     AE350_UART_FREQUENCY,
+			     AE350_UART_BAUDRATE,
+			     AE350_UART_REG_SHIFT,
+			     AE350_UART_REG_WIDTH);
+}
+
+/* Initialize the platform interrupt controller for current HART. */
+static int ae350_irqchip_init(bool cold_boot)
+{
+	u32 hartid = sbi_current_hartid();
+	int ret;
+
+	if (cold_boot) {
+		ret = plic_cold_irqchip_init(AE350_PLIC_ADDR,
+					     AE350_PLIC_NUM_SOURCES,
+					     AE350_HART_COUNT);
+		if (ret)
+			return ret;
+	}
+
+	return plic_warm_irqchip_init(hartid, 2 * hartid, 2 * hartid + 1);
+}
+
+/* Initialize IPI for current HART. */
+static int ae350_ipi_init(bool cold_boot)
+{
+	int ret;
+
+	if (cold_boot) {
+		ret = plicsw_cold_ipi_init(AE350_PLICSW_ADDR,
+					   AE350_HART_COUNT);
+		if (ret)
+			return ret;
+	}
+
+	return plicsw_warm_ipi_init();
+}
+
+/* Initialize platform timer for current HART. */
+static int ae350_timer_init(bool cold_boot)
+{
+	int ret;
+
+	if (cold_boot) {
+		ret = plmt_cold_timer_init(AE350_PLMT_ADDR,
+					   AE350_HART_COUNT);
+		if (ret)
+			return ret;
+	}
+
+	return plmt_warm_timer_init();
+}
+
+/* Reboot the platform. */
+static int ae350_system_reboot(u32 type)
+{
+	/* For now nothing to do. */
+	sbi_printf("System reboot\n");
+	return 0;
+}
+
+/* Shutdown or poweroff the platform. */
+static int ae350_system_shutdown(u32 type)
+{
+	/* For now nothing to do. */
+	sbi_printf("System shutdown\n");
+	return 0;
+}
+
+/* Platform descriptor. */
+const struct sbi_platform_operations platform_ops = {
+
+	.final_init = ae350_final_init,
+
+	.pmp_region_count = ae350_pmp_region_count,
+	.pmp_region_info  = ae350_pmp_region_info,
+
+	.console_init = ae350_console_init,
+	.console_putc = uart8250_putc,
+	.console_getc = uart8250_getc,
+
+	.irqchip_init = ae350_irqchip_init,
+
+	.ipi_init     = ae350_ipi_init,
+	.ipi_send     = plicsw_ipi_send,
+	.ipi_clear    = plicsw_ipi_clear,
+
+	.timer_init	   = ae350_timer_init,
+	.timer_value	   = plmt_timer_value,
+	.timer_event_start = plmt_timer_event_start,
+	.timer_event_stop  = plmt_timer_event_stop,
+
+	.system_reboot	 = ae350_system_reboot,
+	.system_shutdown = ae350_system_shutdown
+};
+
+const struct sbi_platform platform = {
+
+	.opensbi_version = OPENSBI_VERSION,
+	.platform_version = SBI_PLATFORM_VERSION(0x0, 0x01),
+	.name = "Andes AE350",
+	.features = SBI_PLATFORM_DEFAULT_FEATURES,
+	.hart_count = AE350_HART_COUNT,
+	.hart_stack_size = AE350_HART_STACK_SIZE,
+	.disabled_hart_mask = 0,
+	.platform_ops_addr = (unsigned long)&platform_ops
+};
diff --git a/platform/andes/ae350/platform.h b/platform/andes/ae350/platform.h
new file mode 100644
index 0000000..eff2996
--- /dev/null
+++ b/platform/andes/ae350/platform.h
@@ -0,0 +1,67 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2019 Andes Technology Corporation
+ *
+ * Authors:
+ *   Zong Li <zong@andestech.com>
+ *   Nylon Chen <nylon7@andestech.com>
+ */
+
+#ifndef _AE350_PLATFORM_H_
+#define _AE350_PLATFORM_H_
+
+#define AE350_HART_COUNT		4
+#define AE350_HART_STACK_SIZE		8192
+
+#define AE350_PLIC_ADDR			0xe4000000
+#define AE350_PLIC_NUM_SOURCES		71
+
+#define AE350_PLICSW_ADDR		0xe6400000
+
+#define AE350_PLMT_ADDR			0xe6000000
+
+#define AE350_L2C_ADDR			0xe0500000
+
+#define AE350_UART_ADDR_OFFSET		0x20
+#define AE350_UART_ADDR			(0xf0300000 + AE350_UART_ADDR_OFFSET)
+#define AE350_UART_FREQUENCY		19660800
+#define AE350_UART_BAUDRATE		38400
+#define AE350_UART_REG_SHIFT		2
+#define AE350_UART_REG_WIDTH		0
+
+/* nds mcache_ctl register*/
+#define CSR_MCACHECTL			0x7ca
+
+#define V5_MCACHE_CTL_IC_EN_OFFSET      0
+#define V5_MCACHE_CTL_DC_EN_OFFSET      1
+#define V5_MCACHE_CTL_IC_ECCEN_OFFSET   2
+#define V5_MCACHE_CTL_DC_ECCEN_OFFSET   4
+#define V5_MCACHE_CTL_IC_RWECC_OFFSET   6
+#define V5_MCACHE_CTL_DC_RWECC_OFFSET   7
+#define V5_MCACHE_CTL_CCTL_SUEN_OFFSET  8
+
+#define V5_MCACHE_CTL_IC_EN     (1UL << V5_MCACHE_CTL_IC_EN_OFFSET)
+#define V5_MCACHE_CTL_DC_EN     (1UL << V5_MCACHE_CTL_DC_EN_OFFSET)
+#define V5_MCACHE_CTL_IC_RWECC  (1UL << V5_MCACHE_CTL_IC_RWECC_OFFSET)
+#define V5_MCACHE_CTL_DC_RWECC  (1UL << V5_MCACHE_CTL_DC_RWECC_OFFSET)
+#define V5_MCACHE_CTL_CCTL_SUEN (1UL << V5_MCACHE_CTL_CCTL_SUEN_OFFSET)
+
+#define V5_L2C_CTL_OFFSET           0x8
+#define V5_L2C_CTL_ENABLE_OFFSET    0
+#define V5_L2C_CTL_IPFDPT_OFFSET    3
+#define V5_L2C_CTL_DPFDPT_OFFSET    5
+#define V5_L2C_CTL_TRAMOCTL_OFFSET  8
+#define V5_L2C_CTL_TRAMICTL_OFFSET  10
+#define V5_L2C_CTL_DRAMOCTL_OFFSET  11
+#define V5_L2C_CTL_DRAMICTL_OFFSET  13
+
+#define V5_L2C_CTL_ENABLE_MASK      (1UL << V5_L2C_CTL_ENABLE_OFFSET)
+#define V5_L2C_CTL_IPFDPT_MASK      (3UL << V5_L2C_CTL_IPFDPT_OFFSET)
+#define V5_L2C_CTL_DPFDPT_MASK      (3UL << V5_L2C_CTL_DPFDPT_OFFSET)
+#define V5_L2C_CTL_TRAMOCTL_MASK    (3UL << V5_L2C_CTL_TRAMOCTL_OFFSET)
+#define V5_L2C_CTL_TRAMICTL_MASK    (1UL << V5_L2C_CTL_TRAMICTL_OFFSET)
+#define V5_L2C_CTL_DRAMOCTL_MASK    (3UL << V5_L2C_CTL_DRAMOCTL_OFFSET)
+#define V5_L2C_CTL_DRAMICTL_MASK    (1UL << V5_L2C_CTL_DRAMICTL_OFFSET)
+
+#endif /* _AE350_PLATFORM_H_ */
diff --git a/platform/andes/ae350/plicsw.c b/platform/andes/ae350/plicsw.c
new file mode 100644
index 0000000..17fe947
--- /dev/null
+++ b/platform/andes/ae350/plicsw.c
@@ -0,0 +1,145 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2019 Andes Technology Corporation
+ *
+ * Authors:
+ *   Zong Li <zong@andestech.com>
+ *   Nylon Chen <nylon7@andestech.com>
+ */
+
+#include <sbi/sbi_types.h>
+#include <sbi/sbi_hart.h>
+#include <sbi/riscv_io.h>
+#include "plicsw.h"
+#include "platform.h"
+
+static u32 plicsw_ipi_hart_count;
+static struct plicsw plicsw_dev[AE350_HART_COUNT];
+
+static inline void plicsw_claim(void)
+{
+	u32 source_hart = sbi_current_hartid();
+
+	plicsw_dev[source_hart].source_id =
+		readl(plicsw_dev[source_hart].plicsw_claim);
+}
+
+static inline void plicsw_complete(void)
+{
+	u32 source_hart = sbi_current_hartid();
+	u32 source = plicsw_dev[source_hart].source_id;
+
+	writel(source, plicsw_dev[source_hart].plicsw_claim);
+}
+
+static inline u32 plicsw_get_pending(u32 source_hart, u32 target_hart)
+{
+	return readl(plicsw_dev[source_hart].plicsw_pending)
+	       & (PLICSW_HART_MASK >> target_hart);
+}
+
+static inline void plic_sw_pending(u32 target_hart)
+{
+	/*
+	 * The pending array registers are w1s type.
+	 * IPI pending array mapping as following:
+	 *
+	 * Pending array start address: base + 0x1000
+	 * -------------------------------------
+	 * | hart 3 | hart 2 | hart 1 | hart 0 |
+	 * -------------------------------------
+	 * Each hart X can send IPI to another hart by setting the
+	 * corresponding bit in hart X own region(see the below).
+	 *
+	 * In each hart region:
+	 * -----------------------------------------------
+	 * | bit 7 | bit 6 | bit 5 | bit 4 | ... | bit 0 |
+	 * -----------------------------------------------
+	 * The bit 7 is used to send IPI to hart 0
+	 * The bit 6 is used to send IPI to hart 1
+	 * The bit 5 is used to send IPI to hart 2
+	 * The bit 4 is used to send IPI to hart 3
+	 */
+	u32 source_hart = sbi_current_hartid();
+	u32 target_offset = (PLICSW_PENDING_PER_HART - 1) - target_hart;
+	u32 per_hart_offset = PLICSW_PENDING_PER_HART * source_hart;
+	u32 val = 1 << target_offset << per_hart_offset;
+
+	writel(val, plicsw_dev[source_hart].plicsw_pending);
+}
+
+void plicsw_ipi_send(u32 target_hart)
+{
+	if (plicsw_ipi_hart_count <= target_hart)
+		return;
+
+	/* Set PLICSW IPI */
+	plic_sw_pending(target_hart);
+}
+
+void plicsw_ipi_clear(u32 target_hart)
+{
+	if (plicsw_ipi_hart_count <= target_hart)
+		return;
+
+	/* Clear CLINT IPI */
+	plicsw_claim();
+	plicsw_complete();
+}
+
+int plicsw_warm_ipi_init(void)
+{
+	u32 hartid = sbi_current_hartid();
+
+	if (!plicsw_dev[hartid].plicsw_pending
+	    && !plicsw_dev[hartid].plicsw_enable
+	    && !plicsw_dev[hartid].plicsw_claim)
+		return -1;
+
+	/* Clear PLICSW IPI */
+	plicsw_ipi_clear(hartid);
+
+	return 0;
+}
+
+int plicsw_cold_ipi_init(unsigned long base, u32 hart_count)
+{
+	/* Setup source priority */
+	uint32_t *priority = (void *)base + PLICSW_PRIORITY_BASE;
+
+	for (int i = 0; i < AE350_HART_COUNT*PLICSW_PENDING_PER_HART; i++)
+		writel(1, &priority[i]);
+
+	/* Setup target enable.*/
+	uint32_t enable_mask = PLICSW_HART_MASK;
+
+	for (int i = 0; i < AE350_HART_COUNT; i++) {
+		uint32_t *enable = (void *)base + PLICSW_ENABLE_BASE
+			+ PLICSW_ENABLE_PER_HART * i;
+		writel(enable_mask, &enable[0]);
+		enable_mask >>= 1;
+	}
+
+	/* Figure-out PLICSW IPI register address */
+	plicsw_ipi_hart_count = hart_count;
+
+	for (u32 hartid = 0; hartid < AE350_HART_COUNT; hartid++) {
+		plicsw_dev[hartid].source_id = 0;
+		plicsw_dev[hartid].plicsw_pending =
+			(void *)base
+			+ PLICSW_PENDING_BASE
+			+ ((hartid / 4) * 4);
+		plicsw_dev[hartid].plicsw_enable  =
+			(void *)base
+			+ PLICSW_ENABLE_BASE
+			+ PLICSW_ENABLE_PER_HART * hartid;
+		plicsw_dev[hartid].plicsw_claim   =
+			(void *)base
+			+ PLICSW_CONTEXT_BASE
+			+ PLICSW_CONTEXT_CLAIM
+			+ PLICSW_CONTEXT_PER_HART * hartid;
+	}
+
+	return 0;
+}
diff --git a/platform/andes/ae350/plicsw.h b/platform/andes/ae350/plicsw.h
new file mode 100644
index 0000000..8be6194
--- /dev/null
+++ b/platform/andes/ae350/plicsw.h
@@ -0,0 +1,46 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2019 Andes Technology Corporation
+ *
+ * Authors:
+ *   Zong Li <zong@andestech.com>
+ *   Nylon Chen <nylon7@andestech.com>
+ */
+
+#ifndef _AE350_PLICSW_H_
+#define _AE350_PLICSW_H_
+
+#define PLICSW_PRIORITY_BASE		0x4
+
+#define PLICSW_PENDING_BASE		0x1000
+#define PLICSW_PENDING_PER_HART		0x8
+
+#define PLICSW_ENABLE_BASE		0x2000
+#define PLICSW_ENABLE_PER_HART		0x80
+
+#define PLICSW_CONTEXT_BASE		0x200000
+#define PLICSW_CONTEXT_PER_HART		0x1000
+#define PLICSW_CONTEXT_CLAIM		0x4
+
+#define PLICSW_HART_MASK		0x80808080
+
+struct plicsw {
+	u32 source_id;
+
+	volatile uint32_t *plicsw_pending;
+	volatile uint32_t *plicsw_enable;
+	volatile uint32_t *plicsw_claim;
+};
+
+void plicsw_ipi_send(u32 target_hart);
+
+void plicsw_ipi_sync(u32 target_hart);
+
+void plicsw_ipi_clear(u32 target_hart);
+
+int plicsw_warm_ipi_init(void);
+
+int plicsw_cold_ipi_init(unsigned long base, u32 hart_count);
+
+#endif /* _AE350_PLICSW_H_ */
diff --git a/platform/andes/ae350/plmt.c b/platform/andes/ae350/plmt.c
new file mode 100644
index 0000000..db80813
--- /dev/null
+++ b/platform/andes/ae350/plmt.c
@@ -0,0 +1,97 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2019 Andes Technology Corporation
+ *
+ * Authors:
+ *   Zong Li <zong@andestech.com>
+ *   Nylon Chen <nylon7@andestech.com>
+ */
+
+#include <sbi/riscv_io.h>
+#include <sbi/sbi_hart.h>
+
+static u32 plmt_time_hart_count;
+static volatile void *plmt_time_base;
+static volatile u64 *plmt_time_val;
+static volatile u64 *plmt_time_cmp;
+
+u64 plmt_timer_value(void)
+{
+#if __riscv_xlen == 64
+	return readq_relaxed(plmt_time_val);
+#else
+	u32 lo, hi;
+
+	do {
+		hi = readl_relaxed((void *)plmt_time_val + 0x04);
+		lo = readl_relaxed(plmt_time_val);
+	} while (hi != readl_relaxed((void *)plmt_time_val + 0x04));
+
+	return ((u64)hi << 32) | (u64)lo;
+#endif
+}
+
+void plmt_timer_event_stop(void)
+{
+	u32 target_hart = sbi_current_hartid();
+
+	if (plmt_time_hart_count <= target_hart)
+		return;
+
+	/* Clear PLMT Time Compare */
+#if __riscv_xlen == 64
+	writeq_relaxed(-1ULL, &plmt_time_cmp[target_hart]);
+#else
+	writel_relaxed(-1UL, &plmt_time_cmp[target_hart]);
+	writel_relaxed(-1UL, (void *)(&plmt_time_cmp[target_hart]) + 0x04);
+#endif
+}
+
+void plmt_timer_event_start(u64 next_event)
+{
+	u32 target_hart = sbi_current_hartid();
+
+	if (plmt_time_hart_count <= target_hart)
+		return;
+
+	/* Program PLMT Time Compare */
+#if __riscv_xlen == 64
+	writeq_relaxed(next_event, &plmt_time_cmp[target_hart]);
+#else
+	u32 mask = -1UL;
+
+	writel_relaxed(next_event & mask, &plmt_time_cmp[target_hart]);
+	writel_relaxed(next_event >> 32,
+		       (void *)(&plmt_time_cmp[target_hart]) + 0x04);
+#endif
+
+}
+
+int plmt_warm_timer_init(void)
+{
+	u32 target_hart = sbi_current_hartid();
+
+	if (plmt_time_hart_count <= target_hart || !plmt_time_base)
+		return -1;
+
+	/* Clear PLMT Time Compare */
+#if __riscv_xlen == 64
+	writeq_relaxed(-1ULL, &plmt_time_cmp[target_hart]);
+#else
+	writel_relaxed(-1UL, &plmt_time_cmp[target_hart]);
+	writel_relaxed(-1UL, (void *)(&plmt_time_cmp[target_hart]) + 0x04);
+#endif
+
+	return 0;
+}
+
+int plmt_cold_timer_init(unsigned long base, u32 hart_count)
+{
+	plmt_time_hart_count = hart_count;
+	plmt_time_base	     = (void *)base;
+	plmt_time_val        = (u64 *)(plmt_time_base);
+	plmt_time_cmp        = (u64 *)(plmt_time_base + 0x8);
+
+	return 0;
+}
diff --git a/platform/andes/ae350/plmt.h b/platform/andes/ae350/plmt.h
new file mode 100644
index 0000000..129fcf8
--- /dev/null
+++ b/platform/andes/ae350/plmt.h
@@ -0,0 +1,23 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2019 Andes Technology Corporation
+ *
+ * Authors:
+ *   Zong Li <zong@andestech.com>
+ */
+
+#ifndef _AE350_PLMT_H_
+#define _AE350_PLMT_H_
+
+u64 plmt_timer_value(void);
+
+void plmt_timer_event_stop(void);
+
+void plmt_timer_event_start(u64 next_event);
+
+int plmt_warm_timer_init(void);
+
+int plmt_cold_timer_init(unsigned long base, u32 hart_count);
+
+#endif /* _AE350_PLMT_H_ */