drivers/hwmon/scmi-hwmon.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * System Control and Management Interface(SCMI) based hwmon sensor driver
  *
  * Copyright (C) 2018-2021 ARM Ltd.
  * Sudeep Holla <sudeep.holla@arm.com>
  */

 #include <linux/hwmon.h>
 #include <linux/module.h>
 #include <linux/scmi_protocol.h>
 #include <linux/slab.h>
 #include <linux/sysfs.h>
 #include <linux/thermal.h>

 static const struct scmi_sensor_proto_ops *sensor_ops;

 struct scmi_sensors {
 	const struct scmi_protocol_handle *ph;
 	const struct scmi_sensor_info **info[hwmon_max];
 };

 struct scmi_thermal_sensor {
 	const struct scmi_protocol_handle *ph;
 	const struct scmi_sensor_info *info;
 };

 static inline u64 __pow10(u8 x)
 {
 	u64 r = 1;

 	while (x--)
 		r *= 10;

 	return r;
 }

 static int scmi_hwmon_scale(const struct scmi_sensor_info *sensor, u64 *value)
 {
 	int scale = sensor->scale;
 	u64 f;

 	switch (sensor->type) {
 	case TEMPERATURE_C:
 	case VOLTAGE:
 	case CURRENT:
 		scale += 3;
 		break;
 	case POWER:
 	case ENERGY:
 		scale += 6;
 		break;
 	default:
 		break;
 	}

 	if (scale == 0)
 		return 0;

 	if (abs(scale) > 19)
 		return -E2BIG;

 	f = __pow10(abs(scale));
 	if (scale > 0)
 		*value *= f;
 	else
 		*value = div64_u64(*value, f);

 	return 0;
 }

 static int scmi_hwmon_read_scaled_value(const struct scmi_protocol_handle *ph,
 					const struct scmi_sensor_info *sensor,
 					long *val)
 {
 	int ret;
 	u64 value;

 	ret = sensor_ops->reading_get(ph, sensor->id, &value);
 	if (ret)
 		return ret;

 	ret = scmi_hwmon_scale(sensor, &value);
 	if (!ret)
 		*val = value;

 	return ret;
 }

 static int scmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
 			   u32 attr, int channel, long *val)
 {
 	const struct scmi_sensor_info *sensor;
 	struct scmi_sensors *scmi_sensors = dev_get_drvdata(dev);

 	sensor = *(scmi_sensors->info[type] + channel);

 	return scmi_hwmon_read_scaled_value(scmi_sensors->ph, sensor, val);
 }

 static int
 scmi_hwmon_read_string(struct device *dev, enum hwmon_sensor_types type,
 		       u32 attr, int channel, const char **str)
 {
 	const struct scmi_sensor_info *sensor;
 	struct scmi_sensors *scmi_sensors = dev_get_drvdata(dev);

 	sensor = *(scmi_sensors->info[type] + channel);
 	*str = sensor->name;

 	return 0;
 }

 static umode_t
 scmi_hwmon_is_visible(const void *drvdata, enum hwmon_sensor_types type,
 		      u32 attr, int channel)
 {
 	const struct scmi_sensor_info *sensor;
 	const struct scmi_sensors *scmi_sensors = drvdata;

 	sensor = *(scmi_sensors->info[type] + channel);
 	if (sensor)
 		return 0444;

 	return 0;
 }

 static const struct hwmon_ops scmi_hwmon_ops = {
 	.is_visible = scmi_hwmon_is_visible,
 	.read = scmi_hwmon_read,
 	.read_string = scmi_hwmon_read_string,
 };

 static struct hwmon_chip_info scmi_chip_info = {
 	.ops = &scmi_hwmon_ops,
 	.info = NULL,
 };

 static int scmi_hwmon_thermal_get_temp(struct thermal_zone_device *tz,
 				       int *temp)
 {
 	int ret;
 	long value;
 	struct scmi_thermal_sensor *th_sensor = thermal_zone_device_priv(tz);

 	ret = scmi_hwmon_read_scaled_value(th_sensor->ph, th_sensor->info,
 					   &value);
 	if (!ret)
 		*temp = value;

 	return ret;
 }

 static const struct thermal_zone_device_ops scmi_hwmon_thermal_ops = {
 	.get_temp = scmi_hwmon_thermal_get_temp,
 };

 static int scmi_hwmon_add_chan_info(struct hwmon_channel_info *scmi_hwmon_chan,
 				    struct device *dev, int num,
 				    enum hwmon_sensor_types type, u32 config)
 {
 	int i;
 	u32 *cfg = devm_kcalloc(dev, num + 1, sizeof(*cfg), GFP_KERNEL);

 	if (!cfg)
 		return -ENOMEM;

 	scmi_hwmon_chan->type = type;
 	scmi_hwmon_chan->config = cfg;
 	for (i = 0; i < num; i++, cfg++)
 		*cfg = config;

 	return 0;
 }

 static enum hwmon_sensor_types scmi_types[] = {
 	[TEMPERATURE_C] = hwmon_temp,
 	[VOLTAGE] = hwmon_in,
 	[CURRENT] = hwmon_curr,
 	[POWER] = hwmon_power,
 	[ENERGY] = hwmon_energy,
 };

 static u32 hwmon_attributes[hwmon_max] = {
 	[hwmon_temp] = HWMON_T_INPUT | HWMON_T_LABEL,
 	[hwmon_in] = HWMON_I_INPUT | HWMON_I_LABEL,
 	[hwmon_curr] = HWMON_C_INPUT | HWMON_C_LABEL,
 	[hwmon_power] = HWMON_P_INPUT | HWMON_P_LABEL,
 	[hwmon_energy] = HWMON_E_INPUT | HWMON_E_LABEL,
 };

 static int scmi_thermal_sensor_register(struct device *dev,
 					const struct scmi_protocol_handle *ph,
 					const struct scmi_sensor_info *sensor)
 {
 	struct scmi_thermal_sensor *th_sensor;
 	struct thermal_zone_device *tzd;

 	th_sensor = devm_kzalloc(dev, sizeof(*th_sensor), GFP_KERNEL);
 	if (!th_sensor)
 		return -ENOMEM;

 	th_sensor->ph = ph;
 	th_sensor->info = sensor;

 	/*
 	 * Try to register a temperature sensor with the Thermal Framework:
 	 * skip sensors not defined as part of any thermal zone (-ENODEV) but
 	 * report any other errors related to misconfigured zones/sensors.
 	 */
 	tzd = devm_thermal_of_zone_register(dev, th_sensor->info->id, th_sensor,
 					    &scmi_hwmon_thermal_ops);
 	if (IS_ERR(tzd)) {
 		devm_kfree(dev, th_sensor);

 		if (PTR_ERR(tzd) != -ENODEV)
 			return PTR_ERR(tzd);

 		dev_dbg(dev, "Sensor '%s' not attached to any thermal zone.\n",
 			sensor->name);
 	} else {
 		dev_dbg(dev, "Sensor '%s' attached to thermal zone ID:%d\n",
 			sensor->name, thermal_zone_device_id(tzd));
 	}

 	return 0;
 }

 static int scmi_hwmon_probe(struct scmi_device *sdev)
 {
 	int i, idx;
 	u16 nr_sensors;
 	enum hwmon_sensor_types type;
 	struct scmi_sensors *scmi_sensors;
 	const struct scmi_sensor_info *sensor;
 	int nr_count[hwmon_max] = {0}, nr_types = 0, nr_count_temp = 0;
 	const struct hwmon_chip_info *chip_info;
 	struct device *hwdev, *dev = &sdev->dev;
 	struct hwmon_channel_info *scmi_hwmon_chan;
 	const struct hwmon_channel_info **ptr_scmi_ci;
 	const struct scmi_handle *handle = sdev->handle;
 	struct scmi_protocol_handle *ph;

 	if (!handle)
 		return -ENODEV;

 	sensor_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_SENSOR, &ph);
 	if (IS_ERR(sensor_ops))
 		return PTR_ERR(sensor_ops);

 	nr_sensors = sensor_ops->count_get(ph);
 	if (!nr_sensors)
 		return -EIO;

 	scmi_sensors = devm_kzalloc(dev, sizeof(*scmi_sensors), GFP_KERNEL);
 	if (!scmi_sensors)
 		return -ENOMEM;

 	scmi_sensors->ph = ph;

 	for (i = 0; i < nr_sensors; i++) {
 		sensor = sensor_ops->info_get(ph, i);
 		if (!sensor)
 			return -EINVAL;

 		switch (sensor->type) {
 		case TEMPERATURE_C:
 		case VOLTAGE:
 		case CURRENT:
 		case POWER:
 		case ENERGY:
 			type = scmi_types[sensor->type];
 			if (!nr_count[type])
 				nr_types++;
 			nr_count[type]++;
 			break;
 		}
 	}

 	if (nr_count[hwmon_temp])
 		nr_count_temp = nr_count[hwmon_temp];

 	scmi_hwmon_chan = devm_kcalloc(dev, nr_types, sizeof(*scmi_hwmon_chan),
 				       GFP_KERNEL);
 	if (!scmi_hwmon_chan)
 		return -ENOMEM;

 	ptr_scmi_ci = devm_kcalloc(dev, nr_types + 1, sizeof(*ptr_scmi_ci),
 				   GFP_KERNEL);
 	if (!ptr_scmi_ci)
 		return -ENOMEM;

 	scmi_chip_info.info = ptr_scmi_ci;
 	chip_info = &scmi_chip_info;

 	for (type = 0; type < hwmon_max; type++) {
 		if (!nr_count[type])
 			continue;

 		scmi_hwmon_add_chan_info(scmi_hwmon_chan, dev, nr_count[type],
 					 type, hwmon_attributes[type]);
 		*ptr_scmi_ci++ = scmi_hwmon_chan++;

 		scmi_sensors->info[type] =
 			devm_kcalloc(dev, nr_count[type],
 				     sizeof(*scmi_sensors->info), GFP_KERNEL);
 		if (!scmi_sensors->info[type])
 			return -ENOMEM;
 	}

 	for (i = nr_sensors - 1; i >= 0 ; i--) {
 		sensor = sensor_ops->info_get(ph, i);
 		if (!sensor)
 			continue;

 		switch (sensor->type) {
 		case TEMPERATURE_C:
 		case VOLTAGE:
 		case CURRENT:
 		case POWER:
 		case ENERGY:
 			type = scmi_types[sensor->type];
 			idx = --nr_count[type];
 			*(scmi_sensors->info[type] + idx) = sensor;
 			break;
 		}
 	}

 	hwdev = devm_hwmon_device_register_with_info(dev, "scmi_sensors",
 						     scmi_sensors, chip_info,
 						     NULL);
 	if (IS_ERR(hwdev))
 		return PTR_ERR(hwdev);

 	for (i = 0; i < nr_count_temp; i++) {
 		int ret;

 		sensor = *(scmi_sensors->info[hwmon_temp] + i);
 		if (!sensor)
 			continue;

 		/*
 		 * Warn on any misconfiguration related to thermal zones but
 		 * bail out of probing only on memory errors.
 		 */
 		ret = scmi_thermal_sensor_register(dev, ph, sensor);
 		if (ret) {
 			if (ret == -ENOMEM)
 				return ret;
 			dev_warn(dev,
 				 "Thermal zone misconfigured for %s. err=%d\n",
 				 sensor->name, ret);
 		}
 	}

 	return 0;
 }

 static const struct scmi_device_id scmi_id_table[] = {
 	{ SCMI_PROTOCOL_SENSOR, "hwmon" },
 	{ },
 };
 MODULE_DEVICE_TABLE(scmi, scmi_id_table);

 static struct scmi_driver scmi_hwmon_drv = {
 	.name		= "scmi-hwmon",
 	.probe		= scmi_hwmon_probe,
 	.id_table	= scmi_id_table,
 };
 module_scmi_driver(scmi_hwmon_drv);

 MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
 MODULE_DESCRIPTION("ARM SCMI HWMON interface driver");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0
	/*
	* System Control and Management Interface(SCMI) based hwmon sensor driver
	*
	* Copyright (C) 2018-2021 ARM Ltd.
	* Sudeep Holla <sudeep.holla@arm.com>
	*/

	#include <linux/hwmon.h>
	#include <linux/module.h>
	#include <linux/scmi_protocol.h>
	#include <linux/slab.h>
	#include <linux/sysfs.h>
	#include <linux/thermal.h>

	static const struct scmi_sensor_proto_ops *sensor_ops;

	struct scmi_sensors {
	const struct scmi_protocol_handle *ph;
	const struct scmi_sensor_info **info[hwmon_max];
	};

	struct scmi_thermal_sensor {
	const struct scmi_protocol_handle *ph;
	const struct scmi_sensor_info *info;
	};

	static inline u64 __pow10(u8 x)
	{
	u64 r = 1;

	while (x--)
	r *= 10;

	return r;
	}

	static int scmi_hwmon_scale(const struct scmi_sensor_info sensor, u64 value)
	{
	int scale = sensor->scale;
	u64 f;

	switch (sensor->type) {
	case TEMPERATURE_C:
	case VOLTAGE:
	case CURRENT:
	scale += 3;
	break;
	case POWER:
	case ENERGY:
	scale += 6;
	break;
	default:
	break;
	}

	if (scale == 0)
	return 0;

	if (abs(scale) > 19)
	return -E2BIG;

	f = __pow10(abs(scale));
	if (scale > 0)
	value = f;
	else
	value = div64_u64(value, f);

	return 0;
	}

	static int scmi_hwmon_read_scaled_value(const struct scmi_protocol_handle *ph,
	const struct scmi_sensor_info *sensor,
	long *val)
	{
	int ret;
	u64 value;

	ret = sensor_ops->reading_get(ph, sensor->id, &value);
	if (ret)
	return ret;

	ret = scmi_hwmon_scale(sensor, &value);
	if (!ret)
	*val = value;

	return ret;
	}

	static int scmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
	u32 attr, int channel, long *val)
	{
	const struct scmi_sensor_info *sensor;
	struct scmi_sensors *scmi_sensors = dev_get_drvdata(dev);

	sensor = *(scmi_sensors->info[type] + channel);

	return scmi_hwmon_read_scaled_value(scmi_sensors->ph, sensor, val);
	}

	static int
	scmi_hwmon_read_string(struct device *dev, enum hwmon_sensor_types type,
	u32 attr, int channel, const char **str)
	{
	const struct scmi_sensor_info *sensor;
	struct scmi_sensors *scmi_sensors = dev_get_drvdata(dev);

	sensor = *(scmi_sensors->info[type] + channel);
	*str = sensor->name;

	return 0;
	}

	static umode_t
	scmi_hwmon_is_visible(const void *drvdata, enum hwmon_sensor_types type,
	u32 attr, int channel)
	{
	const struct scmi_sensor_info *sensor;
	const struct scmi_sensors *scmi_sensors = drvdata;

	sensor = *(scmi_sensors->info[type] + channel);
	if (sensor)
	return 0444;

	return 0;
	}

	static const struct hwmon_ops scmi_hwmon_ops = {
	.is_visible = scmi_hwmon_is_visible,
	.read = scmi_hwmon_read,
	.read_string = scmi_hwmon_read_string,
	};

	static struct hwmon_chip_info scmi_chip_info = {
	.ops = &scmi_hwmon_ops,
	.info = NULL,
	};

	static int scmi_hwmon_thermal_get_temp(struct thermal_zone_device *tz,
	int *temp)
	{
	int ret;
	long value;
	struct scmi_thermal_sensor *th_sensor = thermal_zone_device_priv(tz);

	ret = scmi_hwmon_read_scaled_value(th_sensor->ph, th_sensor->info,
	&value);
	if (!ret)
	*temp = value;

	return ret;
	}

	static const struct thermal_zone_device_ops scmi_hwmon_thermal_ops = {
	.get_temp = scmi_hwmon_thermal_get_temp,
	};

	static int scmi_hwmon_add_chan_info(struct hwmon_channel_info *scmi_hwmon_chan,
	struct device *dev, int num,
	enum hwmon_sensor_types type, u32 config)
	{
	int i;
	u32 cfg = devm_kcalloc(dev, num + 1, sizeof(cfg), GFP_KERNEL);

	if (!cfg)
	return -ENOMEM;

	scmi_hwmon_chan->type = type;
	scmi_hwmon_chan->config = cfg;
	for (i = 0; i < num; i++, cfg++)
	*cfg = config;

	return 0;
	}

	static enum hwmon_sensor_types scmi_types[] = {
	[TEMPERATURE_C] = hwmon_temp,
	[VOLTAGE] = hwmon_in,
	[CURRENT] = hwmon_curr,
	[POWER] = hwmon_power,
	[ENERGY] = hwmon_energy,
	};

	static u32 hwmon_attributes[hwmon_max] = {
	[hwmon_temp] = HWMON_T_INPUT \| HWMON_T_LABEL,
	[hwmon_in] = HWMON_I_INPUT \| HWMON_I_LABEL,
	[hwmon_curr] = HWMON_C_INPUT \| HWMON_C_LABEL,
	[hwmon_power] = HWMON_P_INPUT \| HWMON_P_LABEL,
	[hwmon_energy] = HWMON_E_INPUT \| HWMON_E_LABEL,
	};

	static int scmi_thermal_sensor_register(struct device *dev,
	const struct scmi_protocol_handle *ph,
	const struct scmi_sensor_info *sensor)
	{
	struct scmi_thermal_sensor *th_sensor;
	struct thermal_zone_device *tzd;

	th_sensor = devm_kzalloc(dev, sizeof(*th_sensor), GFP_KERNEL);
	if (!th_sensor)
	return -ENOMEM;

	th_sensor->ph = ph;
	th_sensor->info = sensor;

	/*
	* Try to register a temperature sensor with the Thermal Framework:
	* skip sensors not defined as part of any thermal zone (-ENODEV) but
	* report any other errors related to misconfigured zones/sensors.
	*/
	tzd = devm_thermal_of_zone_register(dev, th_sensor->info->id, th_sensor,
	&scmi_hwmon_thermal_ops);
	if (IS_ERR(tzd)) {
	devm_kfree(dev, th_sensor);

	if (PTR_ERR(tzd) != -ENODEV)
	return PTR_ERR(tzd);

	dev_dbg(dev, "Sensor '%s' not attached to any thermal zone.\n",
	sensor->name);
	} else {
	dev_dbg(dev, "Sensor '%s' attached to thermal zone ID:%d\n",
	sensor->name, thermal_zone_device_id(tzd));
	}

	return 0;
	}

	static int scmi_hwmon_probe(struct scmi_device *sdev)
	{
	int i, idx;
	u16 nr_sensors;
	enum hwmon_sensor_types type;
	struct scmi_sensors *scmi_sensors;
	const struct scmi_sensor_info *sensor;
	int nr_count[hwmon_max] = {0}, nr_types = 0, nr_count_temp = 0;
	const struct hwmon_chip_info *chip_info;
	struct device hwdev, dev = &sdev->dev;
	struct hwmon_channel_info *scmi_hwmon_chan;
	const struct hwmon_channel_info **ptr_scmi_ci;
	const struct scmi_handle *handle = sdev->handle;
	struct scmi_protocol_handle *ph;

	if (!handle)
	return -ENODEV;

	sensor_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_SENSOR, &ph);
	if (IS_ERR(sensor_ops))
	return PTR_ERR(sensor_ops);

	nr_sensors = sensor_ops->count_get(ph);
	if (!nr_sensors)
	return -EIO;

	scmi_sensors = devm_kzalloc(dev, sizeof(*scmi_sensors), GFP_KERNEL);
	if (!scmi_sensors)
	return -ENOMEM;

	scmi_sensors->ph = ph;

	for (i = 0; i < nr_sensors; i++) {
	sensor = sensor_ops->info_get(ph, i);
	if (!sensor)
	return -EINVAL;

	switch (sensor->type) {
	case TEMPERATURE_C:
	case VOLTAGE:
	case CURRENT:
	case POWER:
	case ENERGY:
	type = scmi_types[sensor->type];
	if (!nr_count[type])
	nr_types++;
	nr_count[type]++;
	break;
	}
	}

	if (nr_count[hwmon_temp])
	nr_count_temp = nr_count[hwmon_temp];

	scmi_hwmon_chan = devm_kcalloc(dev, nr_types, sizeof(*scmi_hwmon_chan),
	GFP_KERNEL);
	if (!scmi_hwmon_chan)
	return -ENOMEM;

	ptr_scmi_ci = devm_kcalloc(dev, nr_types + 1, sizeof(*ptr_scmi_ci),
	GFP_KERNEL);
	if (!ptr_scmi_ci)
	return -ENOMEM;

	scmi_chip_info.info = ptr_scmi_ci;
	chip_info = &scmi_chip_info;

	for (type = 0; type < hwmon_max; type++) {
	if (!nr_count[type])
	continue;

	scmi_hwmon_add_chan_info(scmi_hwmon_chan, dev, nr_count[type],
	type, hwmon_attributes[type]);
	*ptr_scmi_ci++ = scmi_hwmon_chan++;

	scmi_sensors->info[type] =
	devm_kcalloc(dev, nr_count[type],
	sizeof(*scmi_sensors->info), GFP_KERNEL);
	if (!scmi_sensors->info[type])
	return -ENOMEM;
	}

	for (i = nr_sensors - 1; i >= 0 ; i--) {
	sensor = sensor_ops->info_get(ph, i);
	if (!sensor)
	continue;

	switch (sensor->type) {
	case TEMPERATURE_C:
	case VOLTAGE:
	case CURRENT:
	case POWER:
	case ENERGY:
	type = scmi_types[sensor->type];
	idx = --nr_count[type];
	*(scmi_sensors->info[type] + idx) = sensor;
	break;
	}
	}

	hwdev = devm_hwmon_device_register_with_info(dev, "scmi_sensors",
	scmi_sensors, chip_info,
	NULL);
	if (IS_ERR(hwdev))
	return PTR_ERR(hwdev);

	for (i = 0; i < nr_count_temp; i++) {
	int ret;

	sensor = *(scmi_sensors->info[hwmon_temp] + i);
	if (!sensor)
	continue;

	/*
	* Warn on any misconfiguration related to thermal zones but
	* bail out of probing only on memory errors.
	*/
	ret = scmi_thermal_sensor_register(dev, ph, sensor);
	if (ret) {
	if (ret == -ENOMEM)
	return ret;
	dev_warn(dev,
	"Thermal zone misconfigured for %s. err=%d\n",
	sensor->name, ret);
	}
	}

	return 0;
	}

	static const struct scmi_device_id scmi_id_table[] = {
	{ SCMI_PROTOCOL_SENSOR, "hwmon" },
	{ },
	};
	MODULE_DEVICE_TABLE(scmi, scmi_id_table);

	static struct scmi_driver scmi_hwmon_drv = {
	.name = "scmi-hwmon",
	.probe = scmi_hwmon_probe,
	.id_table = scmi_id_table,
	};
	module_scmi_driver(scmi_hwmon_drv);

	MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
	MODULE_DESCRIPTION("ARM SCMI HWMON interface driver");
	MODULE_LICENSE("GPL v2");