Commit e0f0307a authored by Zev Weiss's avatar Zev Weiss Committed by Guenter Roeck
Browse files

hwmon: (pmbus) Add get_error_flags support to regulator ops 



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: default avatarZev Weiss <zev@bewilderbeest.net>
Link: https://lore.kernel.org/r/20220219000359.19985-1-zev@bewilderbeest.net


[groeck: Added missing locking]
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent 034dadfb

drivers/hwmon/pmbus/pmbus_core.c

+114 −0
Original line number Diff line number Diff line
@@ -2432,10 +2432,124 @@ 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;



	mutex_lock(&data->update_lock);



	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) {

			mutex_unlock(&data->update_lock);

			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);

	mutex_unlock(&data->update_lock);

	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);