[PATCH 2/2] lib: utils/reset: add SpacemiT P1 PMIC support

[Anand Moon]

Hi Aurelien,

On Sun, 19 Apr 2026 at 20:40, Aurelien Jarno <aurelien at aurel32.net> wrote:
>
> The SpacemiT P1 is a PMIC commonly found with SpacemiT CPU like K1. Add
> a reset driver for it.
>
> Signed-off-by: Aurelien Jarno <aurelien at aurel32.net>

Tested-by: Anand Moon <linux.amoon at gmail.com>

Thanks
-Anand
> ---
>  lib/utils/reset/Kconfig                 |   4 +
>  lib/utils/reset/fdt_reset_spacemit_p1.c | 112 ++++++++++++++++++++++++
>  lib/utils/reset/objects.mk              |   3 +
>  platform/generic/configs/defconfig      |   1 +
>  4 files changed, 120 insertions(+)
>  create mode 100644 lib/utils/reset/fdt_reset_spacemit_p1.c
>
> diff --git a/lib/utils/reset/Kconfig b/lib/utils/reset/Kconfig
> index 4835921f..f98926e5 100644
> --- a/lib/utils/reset/Kconfig
> +++ b/lib/utils/reset/Kconfig
> @@ -33,6 +33,10 @@ config FDT_RESET_SG2042_HWMON_MCU
>         bool "Sophgo SG2042 hwmon MCU FDT reset driver"
>         default n
>
> +config FDT_RESET_SPACEMIT_P1
> +       bool "SpacemiT P1 reset driver"
> +       default n
> +
>  config FDT_RESET_SUNXI_WDT
>         bool "Sunxi WDT FDT reset driver"
>         default n
> diff --git a/lib/utils/reset/fdt_reset_spacemit_p1.c b/lib/utils/reset/fdt_reset_spacemit_p1.c
> new file mode 100644
> index 00000000..5312e741
> --- /dev/null
> +++ b/lib/utils/reset/fdt_reset_spacemit_p1.c
> @@ -0,0 +1,112 @@
> +/*
> + * SPDX-License-Identifier: BSD-2-Clause
> + *
> + * Copyright (c) 2026 Aurelien Jarno
> + * Authors:
> + *   Aurelien Jarno <aurelien at aurel32.net>
> + */
> +
> +#include <libfdt.h>
> +#include <platform_override.h>
> +#include <sbi/sbi_bitops.h>
> +#include <sbi/sbi_console.h>
> +#include <sbi/sbi_system.h>
> +#include <sbi_utils/fdt/fdt_driver.h>
> +#include <sbi_utils/i2c/fdt_i2c.h>
> +
> +/* SpacemiT P1 Power Control Register 2 */
> +#define PWR_CTRL2              0x7e
> +#define PWR_CTRL2_SHUTDOWN     BIT(2)  /* Shutdown request */
> +#define PWR_CTRL2_RST          BIT(1)  /* Reset request */
> +
> +static struct i2c_adapter *p1_adapter = NULL;
> +static uint32_t p1_reg = 0;
> +
> +static int p1_system_reset_check(uint32_t type, uint32_t reason)
> +{
> +       switch (type) {
> +       case SBI_SRST_RESET_TYPE_SHUTDOWN:
> +               return 1;
> +       case SBI_SRST_RESET_TYPE_COLD_REBOOT:
> +       case SBI_SRST_RESET_TYPE_WARM_REBOOT:
> +               return 255;
> +       }
> +
> +       return 0;
> +}
> +
> +static void p1_ops(uint32_t type)
> +{
> +       uint8_t byte;
> +       int rc;
> +
> +       rc = i2c_adapter_reg_read(p1_adapter, p1_reg, PWR_CTRL2, &byte);
> +       if (rc) {
> +               sbi_printf("%s: cannot read P1 Power Control Register 2\n", __func__);
> +               return;
> +       }
> +
> +       if (type == SBI_SRST_RESET_TYPE_SHUTDOWN)
> +               byte |= PWR_CTRL2_SHUTDOWN;
> +       else
> +               byte |= PWR_CTRL2_RST;
> +
> +       rc = i2c_adapter_reg_write(p1_adapter, p1_reg, PWR_CTRL2, byte);
> +       if (rc)
> +               sbi_printf("%s: cannot write P1 Power Control Register 2\n", __func__);
> +}
> +
> +static void p1_system_reset(uint32_t type, uint32_t reason)
> +{
> +       switch (type) {
> +       case SBI_SRST_RESET_TYPE_SHUTDOWN:
> +       case SBI_SRST_RESET_TYPE_COLD_REBOOT:
> +       case SBI_SRST_RESET_TYPE_WARM_REBOOT:
> +               p1_ops(type);
> +               break;
> +       }
> +}
> +
> +static struct sbi_system_reset_device p1_reset = {
> +       .name = "spacemit-p1-reset",
> +       .system_reset_check = p1_system_reset_check,
> +       .system_reset = p1_system_reset
> +};
> +
> +static int p1_reset_init(const void *fdt, int nodeoff,
> +                        const struct fdt_match *match)
> +{
> +       int rc, i2c_bus;
> +       uint64_t addr;
> +
> +       /* we are spacemit,p1 node */
> +       rc = fdt_get_node_addr_size(fdt, nodeoff, 0, &addr, NULL);
> +       if (rc)
> +               return rc;
> +
> +       p1_reg = addr;
> +
> +       /* find i2c bus parent node */
> +       i2c_bus = fdt_parent_offset(fdt, nodeoff);
> +       if (i2c_bus < 0)
> +               return i2c_bus;
> +
> +       /* i2c adapter get */
> +       rc = fdt_i2c_adapter_get(fdt, i2c_bus, &p1_adapter);
> +       if (rc)
> +               return rc;
> +
> +       sbi_system_reset_add_device(&p1_reset);
> +
> +       return 0;
> +}
> +
> +static const struct fdt_match p1_reset_match[] = {
> +       { .compatible = "spacemit,p1", .data = (void *)true },
> +       { },
> +};
> +
> +const struct fdt_driver fdt_reset_spacemit_p1 = {
> +       .match_table = p1_reset_match,
> +       .init = p1_reset_init,
> +};
> diff --git a/lib/utils/reset/objects.mk b/lib/utils/reset/objects.mk
> index ac38b49d..3c681c27 100644
> --- a/lib/utils/reset/objects.mk
> +++ b/lib/utils/reset/objects.mk
> @@ -20,6 +20,9 @@ libsbiutils-objs-$(CONFIG_FDT_RESET_HTIF) += reset/fdt_reset_htif.o
>  carray-fdt_early_drivers-$(CONFIG_FDT_RESET_SG2042_HWMON_MCU) += fdt_reset_sg2042_mcu
>  libsbiutils-objs-$(CONFIG_FDT_RESET_SG2042_HWMON_MCU) += reset/fdt_reset_sg2042_hwmon_mcu.o
>
> +carray-fdt_early_drivers-$(CONFIG_FDT_RESET_SPACEMIT_P1) += fdt_reset_spacemit_p1
> +libsbiutils-objs-$(CONFIG_FDT_RESET_SPACEMIT_P1) += reset/fdt_reset_spacemit_p1.o
> +
>  carray-fdt_early_drivers-$(CONFIG_FDT_RESET_SUNXI_WDT) += fdt_reset_sunxi_wdt
>  libsbiutils-objs-$(CONFIG_FDT_RESET_SUNXI_WDT) += reset/fdt_reset_sunxi_wdt.o
>
> diff --git a/platform/generic/configs/defconfig b/platform/generic/configs/defconfig
> index a9cb0f06..ae278856 100644
> --- a/platform/generic/configs/defconfig
> +++ b/platform/generic/configs/defconfig
> @@ -51,6 +51,7 @@ CONFIG_FDT_RESET_GPIO=y
>  CONFIG_FDT_RESET_HTIF=y
>  CONFIG_FDT_RESET_RPMI=y
>  CONFIG_FDT_RESET_SG2042_HWMON_MCU=y
> +CONFIG_FDT_RESET_SPACEMIT_P1=y
>  CONFIG_FDT_RESET_SUNXI_WDT=y
>  CONFIG_FDT_RESET_SYSCON=y
>  CONFIG_FDT_SERIAL=y
> --
> 2.53.0
>
>
> --
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