On Fri, Feb 18, 2022 at 04:03:59PM -0800, Zev Weiss wrote:
> The various PMBus status bits don't all map perfectly to the more
> limited set of REGULATOR_ERROR_* flags, but there's a reasonable
> number where they correspond well enough.
>
> Signed-off-by: Zev Weiss <zev@xxxxxxxxxxxxxxxxx>
Applied to hwmon-next.
Thanks,
Guenter
> ---
>
> Changes since v1 [0]:
> - split patch out of power-efuse driver series
> - simplified pmbus_get_status() call
> - added comment explaining PB_STATUS_{IOUT_OC,VOUT_OV} checks
> - added fallback PB_STATUS_TEMPERATURE check mapping it to
> REGULATOR_ERROR_OVER_TEMP_WARN
>
> [0] https://lore.kernel.org/openbmc/20220217104444.7695-2-zev@xxxxxxxxxxxxxxxxx/
>
> drivers/hwmon/pmbus/pmbus_core.c | 109 +++++++++++++++++++++++++++++++
> 1 file changed, 109 insertions(+)
>
> diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
> index 776ee2237be2..6f05c271bdf8 100644
> --- a/drivers/hwmon/pmbus/pmbus_core.c
> +++ b/drivers/hwmon/pmbus/pmbus_core.c
> @@ -2417,10 +2417,119 @@ static int pmbus_regulator_disable(struct regulator_dev *rdev)
> return _pmbus_regulator_on_off(rdev, 0);
> }
>
> +/* A PMBus status flag and the corresponding REGULATOR_ERROR_* flag */
> +struct pmbus_regulator_status_assoc {
> + int pflag, rflag;
> +};
> +
> +/* PMBus->regulator bit mappings for a PMBus status register */
> +struct pmbus_regulator_status_category {
> + int func;
> + int reg;
> + const struct pmbus_regulator_status_assoc *bits; /* zero-terminated */
> +};
> +
> +static const struct pmbus_regulator_status_category pmbus_regulator_flag_map[] = {
> + {
> + .func = PMBUS_HAVE_STATUS_VOUT,
> + .reg = PMBUS_STATUS_VOUT,
> + .bits = (const struct pmbus_regulator_status_assoc[]) {
> + { PB_VOLTAGE_UV_WARNING, REGULATOR_ERROR_UNDER_VOLTAGE_WARN },
> + { PB_VOLTAGE_UV_FAULT, REGULATOR_ERROR_UNDER_VOLTAGE },
> + { PB_VOLTAGE_OV_WARNING, REGULATOR_ERROR_OVER_VOLTAGE_WARN },
> + { PB_VOLTAGE_OV_FAULT, REGULATOR_ERROR_REGULATION_OUT },
> + { },
> + },
> + }, {
> + .func = PMBUS_HAVE_STATUS_IOUT,
> + .reg = PMBUS_STATUS_IOUT,
> + .bits = (const struct pmbus_regulator_status_assoc[]) {
> + { PB_IOUT_OC_WARNING, REGULATOR_ERROR_OVER_CURRENT_WARN },
> + { PB_IOUT_OC_FAULT, REGULATOR_ERROR_OVER_CURRENT },
> + { PB_IOUT_OC_LV_FAULT, REGULATOR_ERROR_OVER_CURRENT },
> + { },
> + },
> + }, {
> + .func = PMBUS_HAVE_STATUS_TEMP,
> + .reg = PMBUS_STATUS_TEMPERATURE,
> + .bits = (const struct pmbus_regulator_status_assoc[]) {
> + { PB_TEMP_OT_WARNING, REGULATOR_ERROR_OVER_TEMP_WARN },
> + { PB_TEMP_OT_FAULT, REGULATOR_ERROR_OVER_TEMP },
> + { },
> + },
> + },
> +};
> +
> +static int pmbus_regulator_get_error_flags(struct regulator_dev *rdev, unsigned int *flags)
> +{
> + int i, status;
> + const struct pmbus_regulator_status_category *cat;
> + const struct pmbus_regulator_status_assoc *bit;
> + struct device *dev = rdev_get_dev(rdev);
> + struct i2c_client *client = to_i2c_client(dev->parent);
> + struct pmbus_data *data = i2c_get_clientdata(client);
> + u8 page = rdev_get_id(rdev);
> + int func = data->info->func[page];
> +
> + *flags = 0;
> +
> + for (i = 0; i < ARRAY_SIZE(pmbus_regulator_flag_map); i++) {
> + cat = &pmbus_regulator_flag_map[i];
> + if (!(func & cat->func))
> + continue;
> +
> + status = pmbus_read_byte_data(client, page, cat->reg);
> + if (status < 0)
> + return status;
> +
> + for (bit = cat->bits; bit->pflag; bit++) {
> + if (status & bit->pflag)
> + *flags |= bit->rflag;
> + }
> + }
> +
> + /*
> + * Map what bits of STATUS_{WORD,BYTE} we can to REGULATOR_ERROR_*
> + * bits. Some of the other bits are tempting (especially for cases
> + * where we don't have the relevant PMBUS_HAVE_STATUS_*
> + * functionality), but there's an unfortunate ambiguity in that
> + * they're defined as indicating a fault *or* a warning, so we can't
> + * easily determine whether to report REGULATOR_ERROR_<foo> or
> + * REGULATOR_ERROR_<foo>_WARN.
> + */
> + status = pmbus_get_status(client, page, PMBUS_STATUS_WORD);
> + if (status < 0)
> + return status;
> +
> + if (pmbus_regulator_is_enabled(rdev) && (status & PB_STATUS_OFF))
> + *flags |= REGULATOR_ERROR_FAIL;
> +
> + /*
> + * Unlike most other status bits, PB_STATUS_{IOUT_OC,VOUT_OV} are
> + * defined strictly as fault indicators (not warnings).
> + */
> + if (status & PB_STATUS_IOUT_OC)
> + *flags |= REGULATOR_ERROR_OVER_CURRENT;
> + if (status & PB_STATUS_VOUT_OV)
> + *flags |= REGULATOR_ERROR_REGULATION_OUT;
> +
> + /*
> + * If we haven't discovered any thermal faults or warnings via
> + * PMBUS_STATUS_TEMPERATURE, map PB_STATUS_TEMPERATURE to a warning as
> + * a (conservative) best-effort interpretation.
> + */
> + if (!(*flags & (REGULATOR_ERROR_OVER_TEMP | REGULATOR_ERROR_OVER_TEMP_WARN))
> + && (status & PB_STATUS_TEMPERATURE))
> + *flags |= REGULATOR_ERROR_OVER_TEMP_WARN;
> +
> + return 0;
> +}
> +
> const struct regulator_ops pmbus_regulator_ops = {
> .enable = pmbus_regulator_enable,
> .disable = pmbus_regulator_disable,
> .is_enabled = pmbus_regulator_is_enabled,
> + .get_error_flags = pmbus_regulator_get_error_flags,
> };
> EXPORT_SYMBOL_NS_GPL(pmbus_regulator_ops, PMBUS);
>
