[PATCH v3 6/6] platform: sifive_fu740: add platform reset driver

Alexandre Ghiti alexandre.ghiti at canonical.com
Tue Nov 9 23:41:58 PST 2021


On Tue, Nov 9, 2021 at 1:41 PM Nikita Shubin <nikita.shubin at maquefel.me> wrote:
>
> From: Nikita Shubin <n.shubin at yadro.com>
>
> da9063 PMIC can be used to reset/shutdown the
> Sifive Unmatched board.
>
> shutdown is done simply by writing SHUTDOWN bit to
> DA9063_REG_CONTROL_F register.
>
> reset via setting WAKEUP bit in DA9063_REG_CONTROL_F
> register followed by masking POWER and POWER1 domains
> and setting STANDBY bit in DA9063_REG_CONTROL_A,
> originally discovered by Alexandre Ghiti on linux-riscv
> maillists.
>
> Signed-off-by: Nikita Shubin <n.shubin at yadro.com>
> ---
> v2->v3:
> - moved to platform code
> - dropped unused defines
> - dropped configure
> - dropped separate dts binding
> - changed priority to hardcoded
> ---
>  platform/generic/fdt_reset_da9063.c | 186 ++++++++++++++++++++++++++++
>  platform/generic/objects.mk         |   1 +
>  platform/generic/sifive_fu740.c     |  22 ++++
>  3 files changed, 209 insertions(+)
>  create mode 100644 platform/generic/fdt_reset_da9063.c
>
> diff --git a/platform/generic/fdt_reset_da9063.c b/platform/generic/fdt_reset_da9063.c
> new file mode 100644
> index 0000000..1fe20e2
> --- /dev/null
> +++ b/platform/generic/fdt_reset_da9063.c
> @@ -0,0 +1,186 @@
> +/*
> + * SPDX-License-Identifier: BSD-2-Clause
> + *
> + * Copyright (c) 2021 YADRO
> + *
> + * Authors:
> + *   Nikita Shubin <nshubin at yadro.com>
> + */
> +
> +#include <libfdt.h>
> +#include <sbi/sbi_error.h>
> +#include <sbi/sbi_console.h>
> +#include <sbi/sbi_ecall_interface.h>
> +#include <sbi/sbi_hart.h>
> +#include <sbi/sbi_system.h>
> +#include <sbi_utils/fdt/fdt_helper.h>
> +#include <sbi_utils/i2c/fdt_i2c.h>
> +#include <sbi_utils/reset/fdt_reset.h>
> +
> +#define DA9063_REG_PAGE_CON            0x00
> +#define DA9063_REG_CONTROL_A           0x0e
> +#define DA9063_REG_CONTROL_F           0x13
> +#define DA9063_REG_DEVICE_ID           0x81
> +
> +#define DA9063_CONTROL_A_M_POWER1_EN   (1 << 6)
> +#define DA9063_CONTROL_A_M_POWER_EN    (1 << 5)
> +#define DA9063_CONTROL_A_STANDBY       (1 << 3)
> +
> +#define DA9063_CONTROL_F_WAKEUP                (1 << 2)
> +#define DA9063_CONTROL_F_SHUTDOWN      (1 << 1)
> +
> +#define PMIC_CHIP_ID_DA9063            0x61
> +
> +static struct {
> +       struct i2c_adapter *adapter;
> +       uint32_t reg;
> +} da9063;
> +
> +static int da9063_system_reset_check(u32 type, u32 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 inline int da9063_sanity_check(struct i2c_adapter *adap, uint32_t reg)
> +{
> +       uint8_t val;
> +       int rc = i2c_adapter_reg_write(adap, reg, DA9063_REG_PAGE_CON, 0x02);
> +
> +       if (rc)
> +               return rc;
> +
> +       /* check set page*/
> +       rc = i2c_adapter_reg_read(adap, reg, 0x0, &val);
> +       if (rc)
> +               return rc;
> +
> +       if (val != 0x02)
> +               return SBI_ENODEV;
> +
> +       /* read and check device id */
> +       rc = i2c_adapter_reg_read(adap, reg, DA9063_REG_DEVICE_ID, &val);
> +       if (rc)
> +               return rc;
> +
> +       if (val != PMIC_CHIP_ID_DA9063)
> +               return SBI_ENODEV;
> +
> +       return 0;
> +}
> +
> +static inline int da9063_shutdown(struct i2c_adapter *adap, uint32_t reg)
> +{
> +       int rc = i2c_adapter_reg_write(adap, da9063.reg, DA9063_REG_PAGE_CON, 0x00);
> +
> +       if (rc)
> +               return rc;
> +
> +       return i2c_adapter_reg_write(adap, da9063.reg,
> +                               DA9063_REG_CONTROL_F, DA9063_CONTROL_F_SHUTDOWN);
> +}
> +
> +static inline int da9063_reset(struct i2c_adapter *adap, uint32_t reg)
> +{
> +       int rc = i2c_adapter_reg_write(adap, da9063.reg, DA9063_REG_PAGE_CON, 0x00);
> +
> +       if (rc)
> +               return rc;
> +
> +       rc = i2c_adapter_reg_write(adap, da9063.reg,
> +                             DA9063_REG_CONTROL_F, DA9063_CONTROL_F_WAKEUP);
> +       if (rc)
> +               return rc;
> +
> +       return i2c_adapter_reg_write(adap, da9063.reg,
> +                               DA9063_REG_CONTROL_A,
> +                               DA9063_CONTROL_A_M_POWER1_EN |
> +                               DA9063_CONTROL_A_M_POWER_EN |
> +                               DA9063_CONTROL_A_STANDBY);
> +}
> +
> +static void da9063_system_reset(u32 type, u32 reason)
> +{
> +       struct i2c_adapter *adap = da9063.adapter;
> +       uint32_t reg = da9063.reg;
> +       int rc;
> +
> +       if (adap) {
> +               /* sanity check */
> +               rc = da9063_sanity_check(adap, reg);
> +               if (rc) {
> +                       sbi_printf("%s: chip is not da9063 PMIC\n", __func__);
> +                       goto skip_reset;
> +               }
> +
> +               switch (type) {
> +               case SBI_SRST_RESET_TYPE_SHUTDOWN:
> +                       da9063_shutdown(adap, reg);
> +                       break;
> +               case SBI_SRST_RESET_TYPE_COLD_REBOOT:
> +               case SBI_SRST_RESET_TYPE_WARM_REBOOT:
> +                       da9063_reset(adap, reg);
> +                       break;
> +               }
> +
> +               while
> +                       (1);
> +skip_reset:
> +       }
> +
> +       sbi_hart_hang();
> +}
> +
> +static struct sbi_system_reset_device da9063_reset_i2c = {
> +       .name = "da9063-reset",
> +       .system_reset_check = da9063_system_reset_check,
> +       .system_reset = da9063_system_reset
> +};
> +
> +static int da9063_reset_init(void *fdt, int nodeoff,
> +                          const struct fdt_match *match)
> +{
> +       int rc, i2c_bus;
> +       struct i2c_adapter *adapter;
> +       uint64_t addr;
> +
> +       /* we are dlg,da9063 node */
> +       rc = fdt_get_node_addr_size(fdt, nodeoff, 0, &addr, NULL);
> +       if (rc)
> +               return rc;
> +
> +       da9063.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, &adapter);
> +       if (rc)
> +               return rc;
> +
> +       da9063.adapter = adapter;
> +
> +       sbi_system_reset_add_device(&da9063_reset_i2c);
> +
> +       return 0;
> +}
> +
> +static const struct fdt_match da9063_reset_match[] = {
> +       { .compatible = "dlg,da9063", .data = (void *)TRUE },
> +       { },
> +};
> +
> +struct fdt_reset fdt_reset_da9063 = {
> +       .match_table = da9063_reset_match,
> +       .init = da9063_reset_init,
> +};
> diff --git a/platform/generic/objects.mk b/platform/generic/objects.mk
> index cb15a18..596b4c9 100644
> --- a/platform/generic/objects.mk
> +++ b/platform/generic/objects.mk
> @@ -10,3 +10,4 @@
>  platform-objs-y += platform.o
>  platform-objs-y += sifive_fu540.o
>  platform-objs-y += sifive_fu740.o
> +platform-objs-y += fdt_reset_da9063.o
> diff --git a/platform/generic/sifive_fu740.c b/platform/generic/sifive_fu740.c
> index c8325d3..f489f40 100644
> --- a/platform/generic/sifive_fu740.c
> +++ b/platform/generic/sifive_fu740.c
> @@ -8,8 +8,14 @@
>   */
>
>  #include <platform_override.h>
> +#include <sbi/sbi_error.h>
> +#include <sbi/sbi_system.h>
> +#include <sbi/sbi_console.h>
>  #include <sbi_utils/fdt/fdt_helper.h>
>  #include <sbi_utils/fdt/fdt_fixup.h>
> +#include <sbi_utils/reset/fdt_reset.h>
> +
> +extern struct fdt_reset fdt_reset_da9063;
>
>  static u64 sifive_fu740_tlbr_flush_limit(const struct fdt_match *match)
>  {
> @@ -23,6 +29,21 @@ static u64 sifive_fu740_tlbr_flush_limit(const struct fdt_match *match)
>         return 0;
>  }
>
> +static int sifive_fu740_final_init(bool cold_boot, const struct fdt_match *)
> +{
> +       int rc;
> +       void *fdt = fdt_get_address();
> +
> +       if (cold_boot) {
> +               rc = fdt_reset_driver_init(fdt, &fdt_reset_da9063);
> +               if (rc)
> +                       sbi_printf("%s: failed to find da9063 for reset\n",
> +                                  __func__);
> +       }
> +
> +       return 0;
> +}
> +
>  static const struct fdt_match sifive_fu740_match[] = {
>         { .compatible = "sifive,fu740" },
>         { .compatible = "sifive,fu740-c000" },
> @@ -33,4 +54,5 @@ static const struct fdt_match sifive_fu740_match[] = {
>  const struct platform_override sifive_fu740 = {
>         .match_table = sifive_fu740_match,
>         .tlbr_flush_limit = sifive_fu740_tlbr_flush_limit,
> +       .final_init = sifive_fu740_final_init,
>  };
> --
> 2.31.1
>

We'll see in the long term if this type of reset is problematic or
not, and we'll still have the alarm as an alternative solution, so you
can add:

Reviewed-by: Alexandre Ghiti <alexandre.ghiti at canonical.com>
Tested-by: Alexandre Ghiti <alexandre.ghiti at canonical.com>

Thanks,

Alex



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