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>
---
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);
--
2.35.1
