Commit 07fb7627 authored by Mårten Lindahl's avatar Mårten Lindahl Committed by Guenter Roeck
Browse files

hwmon: (pmbus) Introduce and use cached vout margins 



When setting a new voltage the voltage boundaries are read every time to
check that the new voltage is within the proper range. Checking these
voltage boundaries consists of reading one of PMBUS_MFR_VOUT_MIN/
PMBUS_VOUT_MARGIN_LOW registers and then PMBUS_MFR_VOUT_MAX/
PMBUS_VOUT_MARGIN_HIGH together with writing the PMBUS_CLEAR_FAULTS
register.

Since these boundaries are never being changed, it can be cached and
thus saving unnecessary smbus transmissions.

Signed-off-by: default avatarMårten Lindahl <marten.lindahl@axis.com>
Link: https://lore.kernel.org/r/20220614093856.3470672-2-marten.lindahl@axis.com


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent b674bcb1

drivers/hwmon/pmbus/pmbus_core.c

+61 −17
Original line number Diff line number Diff line
@@ -104,6 +104,9 @@ struct pmbus_data { 


	s16 currpage;	/* current page, -1 for unknown/unset */

	s16 currphase;	/* current phase, 0xff for all, -1 for unknown/unset */



	int vout_low[PMBUS_PAGES];	/* voltage low margin */

	int vout_high[PMBUS_PAGES];	/* voltage high margin */

};



struct pmbus_debugfs_entry {
@@ -2848,6 +2851,58 @@ static int pmbus_regulator_get_error_flags(struct regulator_dev *rdev, unsigned 
	return 0;

}



static int pmbus_regulator_get_low_margin(struct i2c_client *client, int page)

{

	struct pmbus_data *data = i2c_get_clientdata(client);

	struct pmbus_sensor s = {

		.page = page,

		.class = PSC_VOLTAGE_OUT,

		.convert = true,

		.data = -1,

	};



	if (!data->vout_low[page]) {

		if (pmbus_check_word_register(client, page, PMBUS_MFR_VOUT_MIN))

			s.data = _pmbus_read_word_data(client, page, 0xff,

						       PMBUS_MFR_VOUT_MIN);

		if (s.data < 0) {

			s.data = _pmbus_read_word_data(client, page, 0xff,

						       PMBUS_VOUT_MARGIN_LOW);

			if (s.data < 0)

				return s.data;

		}

		data->vout_low[page] = pmbus_reg2data(data, &s);

	}



	return data->vout_low[page];

}



static int pmbus_regulator_get_high_margin(struct i2c_client *client, int page)

{

	struct pmbus_data *data = i2c_get_clientdata(client);

	struct pmbus_sensor s = {

		.page = page,

		.class = PSC_VOLTAGE_OUT,

		.convert = true,

		.data = -1,

	};



	if (!data->vout_high[page]) {

		if (pmbus_check_word_register(client, page, PMBUS_MFR_VOUT_MAX))

			s.data = _pmbus_read_word_data(client, page, 0xff,

						       PMBUS_MFR_VOUT_MAX);

		if (s.data < 0) {

			s.data = _pmbus_read_word_data(client, page, 0xff,

						       PMBUS_VOUT_MARGIN_HIGH);

			if (s.data < 0)

				return s.data;

		}

		data->vout_high[page] = pmbus_reg2data(data, &s);

	}



	return data->vout_high[page];

}



static int pmbus_regulator_get_voltage(struct regulator_dev *rdev)

{

	struct device *dev = rdev_get_dev(rdev);
@@ -2883,24 +2938,13 @@ static int pmbus_regulator_set_voltage(struct regulator_dev *rdev, int min_uv, 


	*selector = 0;



	if (pmbus_check_word_register(client, s.page, PMBUS_MFR_VOUT_MIN))

		s.data = _pmbus_read_word_data(client, s.page, 0xff, PMBUS_MFR_VOUT_MIN);

	if (s.data < 0) {

		s.data = _pmbus_read_word_data(client, s.page, 0xff, PMBUS_VOUT_MARGIN_LOW);

		if (s.data < 0)

			return s.data;

	}

	low = pmbus_reg2data(data, &s);

	low = pmbus_regulator_get_low_margin(client, s.page);

	if (low < 0)

		return low;



	s.data = -1;

	if (pmbus_check_word_register(client, s.page, PMBUS_MFR_VOUT_MAX))

		s.data = _pmbus_read_word_data(client, s.page, 0xff, PMBUS_MFR_VOUT_MAX);

	if (s.data < 0) {

		s.data = _pmbus_read_word_data(client, s.page, 0xff, PMBUS_VOUT_MARGIN_HIGH);

		if (s.data < 0)

			return s.data;

	}

	high = pmbus_reg2data(data, &s);

	high = pmbus_regulator_get_high_margin(client, s.page);

	if (high < 0)

		return high;



	/* Make sure we are within margins */

	if (low > val)