[U-Boot] [PATCH v2 1/7] riscv: Add a SYSCON driver for Andestech's PLIC

Andes
2019-03-25T07:35:14Z

The Platform-Level Interrupt Controller(PLIC)
block holds memory-mapped claim and pending registers
associated with software interrupt. It is required
for handling IPI.

Signed-off-by: Rick Chen <rick@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>
---
arch/riscv/Kconfig | 9 +++
arch/riscv/include/asm/global_data.h | 3 +
arch/riscv/include/asm/syscon.h | 2 +-
arch/riscv/lib/Makefile | 1 +
arch/riscv/lib/andes_plic.c | 111 +++++++++++++++++++++++++++++++++++
5 files changed, 125 insertions(+), 1 deletion(-)
create mode 100644 arch/riscv/lib/andes_plic.c

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 3a4470d..511768b 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -109,6 +109,15 @@ config SIFIVE_CLINT
The SiFive CLINT block holds memory-mapped control and status registers
associated with software and timer interrupts.

+config ANDES_PLIC
+ bool
+ depends on RISCV_MMODE
+ select REGMAP
+ select SYSCON
+ help
+ The Andes PLIC block holds memory-mapped claim and pending registers
+ associated with software interrupt.
+
config RISCV_RDTIME
bool
default y if RISCV_SMODE
diff --git a/arch/riscv/include/asm/global_data.h b/arch/riscv/include/asm/global_data.h
index 80e3165..b867910 100644
--- a/arch/riscv/include/asm/global_data.h
+++ b/arch/riscv/include/asm/global_data.h
@@ -18,6 +18,9 @@ struct arch_global_data {
#ifdef CONFIG_SIFIVE_CLINT
void __iomem *clint; /* clint base address */
#endif
+#ifdef CONFIG_ANDES_PLIC
+ void __iomem *plic; /* plic base address */
+#endif
#ifdef CONFIG_SMP
struct ipi_data ipi[CONFIG_NR_CPUS];
#endif
diff --git a/arch/riscv/include/asm/syscon.h b/arch/riscv/include/asm/syscon.h
index d311ee6..c1b4b86 100644
--- a/arch/riscv/include/asm/syscon.h
+++ b/arch/riscv/include/asm/syscon.h
@@ -9,11 +9,11 @@
/*
* 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) */
+ RISCV_SYSCON_PLIC, /* Platform Level Interrupt Controller (PLIC) */
};

#endif /* _ASM_SYSCON_H */
diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile
index 35dbf64..1bf554b 100644
--- a/arch/riscv/lib/Makefile
+++ b/arch/riscv/lib/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_CMD_GO) += boot.o
obj-y += cache.o
obj-$(CONFIG_RISCV_RDTIME) += rdtime.o
obj-$(CONFIG_SIFIVE_CLINT) += sifive_clint.o
+obj-$(CONFIG_ANDES_PLIC) += andes_plic.o
obj-y += interrupts.o
obj-y += reset.o
obj-$(CONFIG_SBI_IPI) += sbi_ipi.o
diff --git a/arch/riscv/lib/andes_plic.c b/arch/riscv/lib/andes_plic.c
new file mode 100644
index 0000000..abf8a73
--- /dev/null
+++ b/arch/riscv/lib/andes_plic.c
@@ -0,0 +1,111 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019, Rick Chen <rick@andestech.com>
+ *
+ * U-Boot syscon driver for Andes's Platform Level Interrupt Controller (PLIC).
+ * The PLIC block holds memory-mapped claim and pending registers
+ * associated with software interrupt.
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm/device-internal.h>
+#include <dm/lists.h>
+#include <dm/uclass-internal.h>
+#include <regmap.h>
+#include <syscon.h>
+#include <asm/io.h>
+#include <asm/syscon.h>
+#include <cpu.h>
+
+/* pending register */
+#define PENDING_REG(base, hart) ((ulong)(base) + 0x1000 + (hart) * 8)
+/* enable register */
+#define ENABLE_REG(base, hart) ((ulong)(base) + 0x2000 + (hart) * 0x80)
+/* claim register */
+#define CLAIM_REG(base, hart) ((ulong)(base) + 0x200004 + (hart) * 0x1000)
+
+#define ENABLE_HART_IPI (0x80808080)
+#define SEND_IPI_TO_HART(hart) (0x80>>hart)
+
+DECLARE_GLOBAL_DATA_PTR;
+int init_plic(void);
+
+#define PLIC_BASE_GET(void) \
+ do { \
+ long *ret; \
+ \
+ if (!gd->arch.plic) { \
+ ret = syscon_get_first_range(RISCV_SYSCON_PLIC); \
+ if (IS_ERR(ret)) \
+ return PTR_ERR(ret); \
+ gd->arch.plic = ret; \
+ init_plic(); \
+ } \
+ } while (0)
+
+int plic_init(int harts)
+{
+ int i;
+ int en = ENABLE_HART_IPI;
+
+ PLIC_BASE_GET();
+ for (i = 0; i < harts ;i++)
+ {
+ en = en >> i;
+ writel(en, (void __iomem *)ENABLE_REG(gd->arch.plic, i));
+ }
+
+ return 0;
+}
+
+int init_plic(void)
+{
+ struct udevice *dev;
+ int ret;
+
+ ret = uclass_find_first_device(UCLASS_CPU, &dev);
+ if (ret)
+ return ret;
+
+ if (ret == 0 && dev != NULL) {
+ ret = cpu_get_count(dev);
+ plic_init(ret);
+ return 0;
+ }
+
+ return -ENODEV;
+}
+
+int riscv_send_ipi(int hart)
+{
+ PLIC_BASE_GET();
+
+ writel(SEND_IPI_TO_HART(hart), (void __iomem *)PENDING_REG(gd->arch.plic, gd->arch.boot_hart));
+
+ return 0;
+}
+
+int riscv_clear_ipi(int hart)
+{
+ u32 source_id;
+
+ PLIC_BASE_GET();
+
+ source_id = readl((void __iomem *)CLAIM_REG(gd->arch.plic, hart));
+ writel(source_id, (void __iomem *)CLAIM_REG(gd->arch.plic, hart));
+
+ return 0;
+}
+
+static const struct udevice_id andes_plic_ids[] = {
+ { .compatible = "riscv,plic1", .data = RISCV_SYSCON_PLIC },
+ { }
+};
+
+U_BOOT_DRIVER(nds_plic) = {
+ .name = "andes_plic",
+ .id = UCLASS_SYSCON,
+ .of_match = andes_plic_ids,
+ .flags = DM_FLAG_PRE_RELOC,
+};
--
2.7.4