[PATCH v2 06/12] lib: utils/reset: Add Andes fdt reset driver support

Anup Patel anup at brainfault.org
Tue Oct 11 09:35:10 PDT 2022


On Mon, Oct 3, 2022 at 5:23 PM Yu Chien Peter Lin
<peterlin at andestech.com> wrote:
>
> Add ATCWDT200 as reset device of ae350 platform, this driver requires
> SMU to program the reset vector registers before triggering WDT software
> restart signal.
>
> dts example:
>
>   smu at f0100000 {
>     compatible = "andestech,atcsmu";
>     reg = <0x00000000 0xf0100000 0x00000000 0x00001000>;
>   };
>
>   wdt: wdt at f0500000 {
>     compatible = "andestech,atcwdt200";
>     reg = <0x00000000 0xf0500000 0x00000000 0x00001000>;
>     interrupts = <3 4>;
>     interrupt-parent = <&plic0>;
>     clock-frequency = <15000000>;
>   };
>
> Signed-off-by: Yu Chien Peter Lin <peterlin at andestech.com>
> Reviewed-by: Leo Yu-Chi Liang <ycliang at andestech.com>

Looks good to me.

Reviewed-by: Anup Patel <anup at brainfault.org>

Regards,
Anup

> ---
>  lib/utils/reset/Kconfig               |   4 +
>  lib/utils/reset/fdt_reset_atcwdt200.c | 122 ++++++++++++++++++++++++++
>  lib/utils/reset/objects.mk            |   3 +
>  platform/andes/ae350/Kconfig          |   2 +
>  platform/andes/ae350/platform.c       |   3 +
>  5 files changed, 134 insertions(+)
>  create mode 100644 lib/utils/reset/fdt_reset_atcwdt200.c
>
> diff --git a/lib/utils/reset/Kconfig b/lib/utils/reset/Kconfig
> index 2e83ff6..0e0c2c1 100644
> --- a/lib/utils/reset/Kconfig
> +++ b/lib/utils/reset/Kconfig
> @@ -9,6 +9,10 @@ config FDT_RESET
>
>  if FDT_RESET
>
> +config FDT_RESET_ATCWDT200
> +       bool "Andes WDT FDT reset driver"
> +       default n
> +
>  config FDT_RESET_GPIO
>         bool "GPIO FDT reset driver"
>         depends on FDT_GPIO
> diff --git a/lib/utils/reset/fdt_reset_atcwdt200.c b/lib/utils/reset/fdt_reset_atcwdt200.c
> new file mode 100644
> index 0000000..91acc9f
> --- /dev/null
> +++ b/lib/utils/reset/fdt_reset_atcwdt200.c
> @@ -0,0 +1,122 @@
> +/*
> + * SPDX-License-Identifier: BSD-2-Clause
> + *
> + * Copyright (c) 2022 Andes Technology Corporation
> + *
> + * Authors:
> + *   Yu Chien Peter Lin <peterlin at andestech.com>
> + */
> +
> +#include <libfdt.h>
> +#include <sbi/riscv_io.h>
> +#include <sbi/sbi_ecall_interface.h>
> +#include <sbi/sbi_error.h>
> +#include <sbi/sbi_hart.h>
> +#include <sbi/sbi_platform.h>
> +#include <sbi/sbi_system.h>
> +#include <sbi_utils/fdt/fdt_helper.h>
> +#include <sbi_utils/reset/fdt_reset.h>
> +
> +#define ATCWDT200_WP_NUM 0x5aa5
> +#define WREN_REG 0x18
> +#define CTRL_REG 0x10
> +#define RST_TIME_OFF 8
> +#define RST_TIME_MSK (0x3 << RST_TIME_OFF)
> +#define RST_CLK_128 (0 << RST_TIME_OFF)
> +#define RST_CLK_256 (1 << RST_TIME_OFF)
> +#define RST_CLK_512 (2 << RST_TIME_OFF)
> +#define RST_CLK_1024 (3 << RST_TIME_OFF)
> +#define INT_TIME_OFF 4
> +#define INT_TIME_MSK (0xf << INT_TIME_OFF)
> +#define INT_CLK_64 (0 << INT_TIME_OFF)
> +#define INT_CLK_256 (1 << INT_TIME_OFF)
> +#define INT_CLK_1024 (2 << INT_TIME_OFF)
> +#define INT_CLK_2048 (3 << INT_TIME_OFF)
> +#define INT_CLK_4096 (4 << INT_TIME_OFF)
> +#define INT_CLK_8192 (5 << INT_TIME_OFF)
> +#define INT_CLK_16384 (6 << INT_TIME_OFF)
> +#define INT_CLK_32768 (7 << INT_TIME_OFF)
> +#define RST_EN (1 << 3)
> +#define INT_EN (1 << 2)
> +#define CLK_PCLK (1 << 1)
> +#define WDT_EN (1 << 0)
> +
> +#define FLASH_BASE 0x80000000ULL
> +#define SMU_RESET_VEC_LO_OFF 0x50
> +#define SMU_RESET_VEC_HI_OFF 0x60
> +#define SMU_HARTn_RESET_VEC_LO(n) (SMU_RESET_VEC_LO_OFF + (n * 0x4))
> +#define SMU_HARTn_RESET_VEC_HI(n) (SMU_RESET_VEC_HI_OFF + (n * 0x4))
> +
> +static volatile char *wdt_addr;
> +static volatile char *smu_addr;
> +
> +static int ae350_system_reset_check(u32 type, u32 reason)
> +{
> +       switch (type) {
> +       case SBI_SRST_RESET_TYPE_COLD_REBOOT:
> +               return 1;
> +       case SBI_SRST_RESET_TYPE_SHUTDOWN:
> +       case SBI_SRST_RESET_TYPE_WARM_REBOOT:
> +       default:
> +               return 0;
> +       }
> +}
> +
> +static void ae350_system_reset(u32 type, u32 reason)
> +{
> +       const struct sbi_platform *plat = sbi_platform_thishart_ptr();
> +
> +       for (int i = 0; i < sbi_platform_hart_count(plat); i++) {
> +               writel(FLASH_BASE, smu_addr + SMU_HARTn_RESET_VEC_LO(i));
> +               writel(FLASH_BASE >> 32, smu_addr + SMU_HARTn_RESET_VEC_HI(i));
> +       }
> +
> +       /* Program WDT control register  */
> +       writew(ATCWDT200_WP_NUM, wdt_addr + WREN_REG);
> +       writel(INT_CLK_32768 | INT_EN | RST_CLK_128 | RST_EN | WDT_EN,
> +              wdt_addr + CTRL_REG);
> +
> +       sbi_hart_hang();
> +}
> +
> +static struct sbi_system_reset_device atcwdt200_reset = {
> +       .name               = "atcwdt200",
> +       .system_reset_check = ae350_system_reset_check,
> +       .system_reset       = ae350_system_reset,
> +};
> +
> +static int atcwdt200_reset_init(void *fdt, int nodeoff,
> +                               const struct fdt_match *match)
> +{
> +       uint64_t reg_addr;
> +       int rc;
> +
> +       rc = fdt_get_node_addr_size(fdt, nodeoff, 0, &reg_addr, NULL);
> +       if (rc < 0 || !reg_addr)
> +               return SBI_ENODEV;
> +
> +       wdt_addr = (volatile char *)(unsigned long)reg_addr;
> +
> +       /*
> +        * The reset device requires smu to program the reset
> +        * vector for each hart.
> +        */
> +       if (fdt_parse_compat_addr(fdt, &reg_addr, "andestech,atcsmu"))
> +               return SBI_ENODEV;
> +
> +       smu_addr = (volatile char *)(unsigned long)reg_addr;
> +
> +       sbi_system_reset_add_device(&atcwdt200_reset);
> +
> +       return 0;
> +}
> +
> +static const struct fdt_match atcwdt200_reset_match[] = {
> +       { .compatible = "andestech,atcwdt200" },
> +       {},
> +};
> +
> +struct fdt_reset fdt_reset_atcwdt200 = {
> +       .match_table = atcwdt200_reset_match,
> +       .init        = atcwdt200_reset_init,
> +};
> diff --git a/lib/utils/reset/objects.mk b/lib/utils/reset/objects.mk
> index 8a50dd0..c9f851c 100644
> --- a/lib/utils/reset/objects.mk
> +++ b/lib/utils/reset/objects.mk
> @@ -10,6 +10,9 @@
>  libsbiutils-objs-$(CONFIG_FDT_RESET) += reset/fdt_reset.o
>  libsbiutils-objs-$(CONFIG_FDT_RESET) += reset/fdt_reset_drivers.o
>
> +carray-fdt_reset_drivers-$(CONFIG_FDT_RESET_ATCWDT200) += fdt_reset_atcwdt200
> +libsbiutils-objs-$(CONFIG_FDT_RESET_ATCWDT200) += reset/fdt_reset_atcwdt200.o
> +
>  carray-fdt_reset_drivers-$(CONFIG_FDT_RESET_GPIO) += fdt_poweroff_gpio
>  carray-fdt_reset_drivers-$(CONFIG_FDT_RESET_GPIO) += fdt_reset_gpio
>  libsbiutils-objs-$(CONFIG_FDT_RESET_GPIO) += reset/fdt_reset_gpio.o
> diff --git a/platform/andes/ae350/Kconfig b/platform/andes/ae350/Kconfig
> index f6f50eb..8486f08 100644
> --- a/platform/andes/ae350/Kconfig
> +++ b/platform/andes/ae350/Kconfig
> @@ -8,6 +8,8 @@ config PLATFORM_ANDES_AE350
>         select FDT_SERIAL_UART8250
>         select FDT_TIMER
>         select FDT_TIMER_PLMT
> +       select FDT_RESET
> +       select FDT_RESET_ATCWDT200
>         default y
>
>  if PLATFORM_ANDES_AE350
> diff --git a/platform/andes/ae350/platform.c b/platform/andes/ae350/platform.c
> index 79736c0..c6a8eeb 100644
> --- a/platform/andes/ae350/platform.c
> +++ b/platform/andes/ae350/platform.c
> @@ -18,6 +18,7 @@
>  #include <sbi_utils/fdt/fdt_helper.h>
>  #include <sbi_utils/fdt/fdt_fixup.h>
>  #include <sbi_utils/irqchip/plic.h>
> +#include <sbi_utils/reset/fdt_reset.h>
>  #include <sbi_utils/serial/fdt_serial.h>
>  #include <sbi_utils/timer/fdt_timer.h>
>  #include "platform.h"
> @@ -37,6 +38,8 @@ static int ae350_final_init(bool cold_boot)
>         if (!cold_boot)
>                 return 0;
>
> +       fdt_reset_init();
> +
>         fdt = fdt_get_address();
>         fdt_fixups(fdt);
>
> --
> 2.34.1
>
>
> --
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