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Diffstat (limited to 'arch/riscv/lib/sifive_clint.c')
-rw-r--r--arch/riscv/lib/sifive_clint.c84
1 files changed, 84 insertions, 0 deletions
diff --git a/arch/riscv/lib/sifive_clint.c b/arch/riscv/lib/sifive_clint.c
new file mode 100644
index 0000000000..d24e0d585b
--- /dev/null
+++ b/arch/riscv/lib/sifive_clint.c
@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
+ *
+ * U-Boot syscon driver for SiFive's Core Local Interruptor (CLINT).
+ * The CLINT block holds memory-mapped control and status registers
+ * associated with software and timer interrupts.
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <regmap.h>
+#include <syscon.h>
+#include <asm/io.h>
+#include <asm/syscon.h>
+
+/* MSIP registers */
+#define MSIP_REG(base, hart) ((ulong)(base) + (hart) * 4)
+/* mtime compare register */
+#define MTIMECMP_REG(base, hart) ((ulong)(base) + 0x4000 + (hart) * 8)
+/* mtime register */
+#define MTIME_REG(base) ((ulong)(base) + 0xbff8)
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define CLINT_BASE_GET(void) \
+ do { \
+ long *ret; \
+ \
+ if (!gd->arch.clint) { \
+ ret = syscon_get_first_range(RISCV_SYSCON_CLINT); \
+ if (IS_ERR(ret)) \
+ return PTR_ERR(ret); \
+ gd->arch.clint = ret; \
+ } \
+ } while (0)
+
+int riscv_get_time(u64 *time)
+{
+ CLINT_BASE_GET();
+
+ *time = readq((void __iomem *)MTIME_REG(gd->arch.clint));
+
+ return 0;
+}
+
+int riscv_set_timecmp(int hart, u64 cmp)
+{
+ CLINT_BASE_GET();
+
+ writeq(cmp, (void __iomem *)MTIMECMP_REG(gd->arch.clint, hart));
+
+ return 0;
+}
+
+int riscv_send_ipi(int hart)
+{
+ CLINT_BASE_GET();
+
+ writel(1, (void __iomem *)MSIP_REG(gd->arch.clint, hart));
+
+ return 0;
+}
+
+int riscv_clear_ipi(int hart)
+{
+ CLINT_BASE_GET();
+
+ writel(0, (void __iomem *)MSIP_REG(gd->arch.clint, hart));
+
+ return 0;
+}
+
+static const struct udevice_id sifive_clint_ids[] = {
+ { .compatible = "riscv,clint0", .data = RISCV_SYSCON_CLINT },
+ { }
+};
+
+U_BOOT_DRIVER(sifive_clint) = {
+ .name = "sifive_clint",
+ .id = UCLASS_SYSCON,
+ .of_match = sifive_clint_ids,
+ .flags = DM_FLAG_PRE_RELOC,
+};