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

Bin Meng
2019-03-29T09:20:11Z

Hi Rick,

On Mon, Mar 25, 2019 at 3:39 PM Andes <uboot@andestech.com> wrote:
>
> From: Rick Chen <rick@andestech.com>
>
> The Platform-Level Interrupt Controller(PLIC)

nits: it should have a space before (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
>

Could you please include a changelog in the future?

> 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)

nits: suggest change the name to enable_ipi(), to better refelct what
is done in the function, and it should be "static"

> +{
> + int i;
> + int en = ENABLE_HART_IPI;
> +
> + PLIC_BASE_GET();

There is no need to call PLIC_BASE_GET() here.

> + 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)

nits: it should be "static"

> +{
> + 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,
> +};
> --

Regards,
Bin