riscv: Add a SYSCON driver for Andestech's PLMT
The platform-Level Machine Timer (PLMT) block
holds memory-mapped mtime register associated
with timer tick.
This driver implements the riscv_get_time() which
is required by the generic RISC-V timer driver.
Signed-off-by: Rick Chen <rick@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile
index 1bf554b..1c332db 100644
--- a/arch/riscv/lib/Makefile
+++ b/arch/riscv/lib/Makefile
@@ -12,6 +12,7 @@
obj-$(CONFIG_RISCV_RDTIME) += rdtime.o
obj-$(CONFIG_SIFIVE_CLINT) += sifive_clint.o
obj-$(CONFIG_ANDES_PLIC) += andes_plic.o
+obj-$(CONFIG_ANDES_PLMT) += andes_plmt.o
obj-y += interrupts.o
obj-y += reset.o
obj-$(CONFIG_SBI_IPI) += sbi_ipi.o
diff --git a/arch/riscv/lib/andes_plmt.c b/arch/riscv/lib/andes_plmt.c
new file mode 100644
index 0000000..84f4607
--- /dev/null
+++ b/arch/riscv/lib/andes_plmt.c
@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019, Rick Chen <rick@andestech.com>
+ *
+ * U-Boot syscon driver for Andes's Platform Level Machine Timer (PLMT).
+ * The PLMT block holds memory-mapped mtime register
+ * associated with timer tick.
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <regmap.h>
+#include <syscon.h>
+#include <asm/io.h>
+#include <asm/syscon.h>
+
+/* mtime register */
+#define MTIME_REG(base) ((ulong)(base))
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define PLMT_BASE_GET(void) \
+ do { \
+ long *ret; \
+ \
+ if (!gd->arch.plmt) { \
+ ret = syscon_get_first_range(RISCV_SYSCON_PLMT); \
+ if (IS_ERR(ret)) \
+ return PTR_ERR(ret); \
+ gd->arch.plmt = ret; \
+ } \
+ } while (0)
+
+int riscv_get_time(u64 *time)
+{
+ PLMT_BASE_GET();
+
+ *time = readq((void __iomem *)MTIME_REG(gd->arch.plmt));
+
+ return 0;
+}
+
+static const struct udevice_id andes_plmt_ids[] = {
+ { .compatible = "riscv,plmt0", .data = RISCV_SYSCON_PLMT },
+ { }
+};
+
+U_BOOT_DRIVER(andes_plmt) = {
+ .name = "andes_plmt",
+ .id = UCLASS_SYSCON,
+ .of_match = andes_plmt_ids,
+ .flags = DM_FLAG_PRE_RELOC,
+};