[U-Boot] [PATCH v3 08/25] riscv: Add a SYSCON driver for SiFive's Core Local Interruptor
Bin Meng
bmeng.cn at gmail.com
Tue Dec 11 09:34:44 UTC 2018
This adds 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.
This driver implements the riscv_get_time() API as required by
the generic RISC-V timer driver, as well as some other APIs that
are needed for handling IPI.
Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
---
Changes in v3:
- check return value of syscon_get_first_range()
Changes in v2:
- rename the driver name to sifive_clint
- save the clint base address to arch specific global data to support
pre-relocation stage
- remove the probe routine
- add riscv_clear_ipi() API
arch/riscv/Kconfig | 9 ++++
arch/riscv/include/asm/global_data.h | 3 ++
arch/riscv/include/asm/syscon.h | 19 ++++++++
arch/riscv/lib/Makefile | 1 +
arch/riscv/lib/sifive_clint.c | 84 ++++++++++++++++++++++++++++++++++++
5 files changed, 116 insertions(+)
create mode 100644 arch/riscv/include/asm/syscon.h
create mode 100644 arch/riscv/lib/sifive_clint.c
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 55c60e4..f513f52 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -95,4 +95,13 @@ config 32BIT
config 64BIT
bool
+config SIFIVE_CLINT
+ bool
+ depends on RISCV_MMODE
+ select REGMAP
+ select SYSCON
+ help
+ The SiFive CLINT block holds memory-mapped control and status registers
+ associated with software and timer interrupts.
+
endmenu
diff --git a/arch/riscv/include/asm/global_data.h b/arch/riscv/include/asm/global_data.h
index 4d5d623..46fcfab 100644
--- a/arch/riscv/include/asm/global_data.h
+++ b/arch/riscv/include/asm/global_data.h
@@ -12,6 +12,9 @@
/* Architecture-specific global data */
struct arch_global_data {
+#ifdef CONFIG_SIFIVE_CLINT
+ void __iomem *clint; /* clint base address */
+#endif
};
#include <asm-generic/global_data.h>
diff --git a/arch/riscv/include/asm/syscon.h b/arch/riscv/include/asm/syscon.h
new file mode 100644
index 0000000..d311ee6
--- /dev/null
+++ b/arch/riscv/include/asm/syscon.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2018, Bin Meng <bmeng.cn at gmail.com>
+ */
+
+#ifndef _ASM_SYSCON_H
+#define _ASM_SYSCON_H
+
+/*
+ * System controllers in a RISC-V system
+ *
+ * So far only SiFive's Core Local Interruptor (CLINT) is defined.
+ */
+enum {
+ RISCV_NONE,
+ RISCV_SYSCON_CLINT, /* Core Local Interruptor (CLINT) */
+};
+
+#endif /* _ASM_SYSCON_H */
diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile
index b58db89..b13c876 100644
--- a/arch/riscv/lib/Makefile
+++ b/arch/riscv/lib/Makefile
@@ -9,6 +9,7 @@
obj-$(CONFIG_CMD_BOOTM) += bootm.o
obj-$(CONFIG_CMD_GO) += boot.o
obj-y += cache.o
+obj-$(CONFIG_SIFIVE_CLINT) += sifive_clint.o
obj-y += interrupts.o
obj-y += reset.o
obj-y += setjmp.o
diff --git a/arch/riscv/lib/sifive_clint.c b/arch/riscv/lib/sifive_clint.c
new file mode 100644
index 0000000..d24e0d5
--- /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 at 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,
+};
--
2.7.4
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