drivers/hwmon/scpi-hwmon.c - kernel/msm-4.9 - Gitiles

 /*
  * System Control and Power Interface(SCPI) based hwmon sensor driver
  *
  * Copyright (C) 2015 ARM Ltd.
  * Punit Agrawal <punit.agrawal@arm.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  * kind, whether express or implied; without even the implied warranty
  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  */

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

 struct sensor_data {
 	struct scpi_sensor_info info;
 	struct device_attribute dev_attr_input;
 	struct device_attribute dev_attr_label;
 	char input[20];
 	char label[20];
 };

 struct scpi_thermal_zone {
 	struct list_head list;
 	int sensor_id;
 	struct scpi_sensors *scpi_sensors;
 	struct thermal_zone_device *tzd;
 };

 struct scpi_sensors {
 	struct scpi_ops *scpi_ops;
 	struct sensor_data *data;
 	struct list_head thermal_zones;
 	struct attribute **attrs;
 	struct attribute_group group;
 	const struct attribute_group *groups[2];
 };

 static int scpi_read_temp(void *dev, int *temp)
 {
 	struct scpi_thermal_zone *zone = dev;
 	struct scpi_sensors *scpi_sensors = zone->scpi_sensors;
 	struct scpi_ops *scpi_ops = scpi_sensors->scpi_ops;
 	struct sensor_data *sensor = &scpi_sensors->data[zone->sensor_id];
 	u32 value;
 	int ret;

 	ret = scpi_ops->sensor_get_value(sensor->info.sensor_id, &value);
 	if (ret)
 		return ret;

 	*temp = value;
 	return 0;
 }

 /* hwmon callback functions */
 static ssize_t
 scpi_show_sensor(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	struct scpi_sensors *scpi_sensors = dev_get_drvdata(dev);
 	struct scpi_ops *scpi_ops = scpi_sensors->scpi_ops;
 	struct sensor_data *sensor;
 	u32 value;
 	int ret;

 	sensor = container_of(attr, struct sensor_data, dev_attr_input);

 	ret = scpi_ops->sensor_get_value(sensor->info.sensor_id, &value);
 	if (ret)
 		return ret;

 	return sprintf(buf, "%u\n", value);
 }

 static ssize_t
 scpi_show_label(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	struct sensor_data *sensor;

 	sensor = container_of(attr, struct sensor_data, dev_attr_label);

 	return sprintf(buf, "%s\n", sensor->info.name);
 }

 static void
 unregister_thermal_zones(struct platform_device *pdev,
 			 struct scpi_sensors *scpi_sensors)
 {
 	struct list_head *pos;

 	list_for_each(pos, &scpi_sensors->thermal_zones) {
 		struct scpi_thermal_zone *zone;

 		zone = list_entry(pos, struct scpi_thermal_zone, list);
 		thermal_zone_of_sensor_unregister(&pdev->dev, zone->tzd);
 	}
 }

 static struct thermal_zone_of_device_ops scpi_sensor_ops = {
 	.get_temp = scpi_read_temp,
 };

 static int scpi_hwmon_probe(struct platform_device *pdev)
 {
 	u16 nr_sensors, i;
 	int num_temp = 0, num_volt = 0, num_current = 0, num_power = 0;
 	struct scpi_ops *scpi_ops;
 	struct device *hwdev, *dev = &pdev->dev;
 	struct scpi_sensors *scpi_sensors;
 	int ret, idx;

 	scpi_ops = get_scpi_ops();
 	if (!scpi_ops)
 		return -EPROBE_DEFER;

 	ret = scpi_ops->sensor_get_capability(&nr_sensors);
 	if (ret)
 		return ret;

 	if (!nr_sensors)
 		return -ENODEV;

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

 	scpi_sensors->data = devm_kcalloc(dev, nr_sensors,
 				   sizeof(*scpi_sensors->data), GFP_KERNEL);
 	if (!scpi_sensors->data)
 		return -ENOMEM;

 	scpi_sensors->attrs = devm_kcalloc(dev, (nr_sensors * 2) + 1,
 				   sizeof(*scpi_sensors->attrs), GFP_KERNEL);
 	if (!scpi_sensors->attrs)
 		return -ENOMEM;

 	scpi_sensors->scpi_ops = scpi_ops;

 	for (i = 0, idx = 0; i < nr_sensors; i++) {
 		struct sensor_data *sensor = &scpi_sensors->data[idx];

 		ret = scpi_ops->sensor_get_info(i, &sensor->info);
 		if (ret)
 			return ret;

 		switch (sensor->info.class) {
 		case TEMPERATURE:
 			snprintf(sensor->input, sizeof(sensor->input),
 				 "temp%d_input", num_temp + 1);
 			snprintf(sensor->label, sizeof(sensor->input),
 				 "temp%d_label", num_temp + 1);
 			num_temp++;
 			break;
 		case VOLTAGE:
 			snprintf(sensor->input, sizeof(sensor->input),
 				 "in%d_input", num_volt);
 			snprintf(sensor->label, sizeof(sensor->input),
 				 "in%d_label", num_volt);
 			num_volt++;
 			break;
 		case CURRENT:
 			snprintf(sensor->input, sizeof(sensor->input),
 				 "curr%d_input", num_current + 1);
 			snprintf(sensor->label, sizeof(sensor->input),
 				 "curr%d_label", num_current + 1);
 			num_current++;
 			break;
 		case POWER:
 			snprintf(sensor->input, sizeof(sensor->input),
 				 "power%d_input", num_power + 1);
 			snprintf(sensor->label, sizeof(sensor->input),
 				 "power%d_label", num_power + 1);
 			num_power++;
 			break;
 		default:
 			continue;
 		}

 		sensor->dev_attr_input.attr.mode = S_IRUGO;
 		sensor->dev_attr_input.show = scpi_show_sensor;
 		sensor->dev_attr_input.attr.name = sensor->input;

 		sensor->dev_attr_label.attr.mode = S_IRUGO;
 		sensor->dev_attr_label.show = scpi_show_label;
 		sensor->dev_attr_label.attr.name = sensor->label;

 		scpi_sensors->attrs[idx << 1] = &sensor->dev_attr_input.attr;
 		scpi_sensors->attrs[(idx << 1) + 1] = &sensor->dev_attr_label.attr;

 		sysfs_attr_init(scpi_sensors->attrs[idx << 1]);
 		sysfs_attr_init(scpi_sensors->attrs[(idx << 1) + 1]);
 		idx++;
 	}

 	scpi_sensors->group.attrs = scpi_sensors->attrs;
 	scpi_sensors->groups[0] = &scpi_sensors->group;

 	platform_set_drvdata(pdev, scpi_sensors);

 	hwdev = devm_hwmon_device_register_with_groups(dev,
 			"scpi_sensors", scpi_sensors, scpi_sensors->groups);

 	if (IS_ERR(hwdev))
 		return PTR_ERR(hwdev);

 	/*
 	 * Register the temperature sensors with the thermal framework
 	 * to allow their usage in setting up the thermal zones from
 	 * device tree.
 	 *
 	 * NOTE: Not all temperature sensors maybe used for thermal
 	 * control
 	 */
 	INIT_LIST_HEAD(&scpi_sensors->thermal_zones);
 	for (i = 0; i < nr_sensors; i++) {
 		struct sensor_data *sensor = &scpi_sensors->data[i];
 		struct scpi_thermal_zone *zone;

 		if (sensor->info.class != TEMPERATURE)
 			continue;

 		zone = devm_kzalloc(dev, sizeof(*zone), GFP_KERNEL);
 		if (!zone) {
 			ret = -ENOMEM;
 			goto unregister_tzd;
 		}

 		zone->sensor_id = i;
 		zone->scpi_sensors = scpi_sensors;
 		zone->tzd = thermal_zone_of_sensor_register(dev,
 				sensor->info.sensor_id, zone, &scpi_sensor_ops);
 		/*
 		 * The call to thermal_zone_of_sensor_register returns
 		 * an error for sensors that are not associated with
 		 * any thermal zones or if the thermal subsystem is
 		 * not configured.
 		 */
 		if (IS_ERR(zone->tzd)) {
 			devm_kfree(dev, zone);
 			continue;
 		}
 		list_add(&zone->list, &scpi_sensors->thermal_zones);
 	}

 	return 0;

 unregister_tzd:
 	unregister_thermal_zones(pdev, scpi_sensors);
 	return ret;
 }

 static int scpi_hwmon_remove(struct platform_device *pdev)
 {
 	struct scpi_sensors *scpi_sensors = platform_get_drvdata(pdev);

 	unregister_thermal_zones(pdev, scpi_sensors);

 	return 0;
 }

 static const struct of_device_id scpi_of_match[] = {
 	{.compatible = "arm,scpi-sensors"},
 	{},
 };

 static struct platform_driver scpi_hwmon_platdrv = {
 	.driver = {
 		.name	= "scpi-hwmon",
 		.owner	= THIS_MODULE,
 		.of_match_table = scpi_of_match,
 	},
 	.probe		= scpi_hwmon_probe,
 	.remove		= scpi_hwmon_remove,
 };
 module_platform_driver(scpi_hwmon_platdrv);

 MODULE_AUTHOR("Punit Agrawal <punit.agrawal@arm.com>");
 MODULE_DESCRIPTION("ARM SCPI HWMON interface driver");
 MODULE_LICENSE("GPL v2");
	/*
	* System Control and Power Interface(SCPI) based hwmon sensor driver
	*
	* Copyright (C) 2015 ARM Ltd.
	* Punit Agrawal <punit.agrawal@arm.com>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	* This program is distributed "as is" WITHOUT ANY WARRANTY of any
	* kind, whether express or implied; without even the implied warranty
	* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*/

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

	struct sensor_data {
	struct scpi_sensor_info info;
	struct device_attribute dev_attr_input;
	struct device_attribute dev_attr_label;
	char input[20];
	char label[20];
	};

	struct scpi_thermal_zone {
	struct list_head list;
	int sensor_id;
	struct scpi_sensors *scpi_sensors;
	struct thermal_zone_device *tzd;
	};

	struct scpi_sensors {
	struct scpi_ops *scpi_ops;
	struct sensor_data *data;
	struct list_head thermal_zones;
	struct attribute **attrs;
	struct attribute_group group;
	const struct attribute_group *groups[2];
	};

	static int scpi_read_temp(void dev, int temp)
	{
	struct scpi_thermal_zone *zone = dev;
	struct scpi_sensors *scpi_sensors = zone->scpi_sensors;
	struct scpi_ops *scpi_ops = scpi_sensors->scpi_ops;
	struct sensor_data *sensor = &scpi_sensors->data[zone->sensor_id];
	u32 value;
	int ret;

	ret = scpi_ops->sensor_get_value(sensor->info.sensor_id, &value);
	if (ret)
	return ret;

	*temp = value;
	return 0;
	}

	/* hwmon callback functions */
	static ssize_t
	scpi_show_sensor(struct device dev, struct device_attribute attr, char *buf)
	{
	struct scpi_sensors *scpi_sensors = dev_get_drvdata(dev);
	struct scpi_ops *scpi_ops = scpi_sensors->scpi_ops;
	struct sensor_data *sensor;
	u32 value;
	int ret;

	sensor = container_of(attr, struct sensor_data, dev_attr_input);

	ret = scpi_ops->sensor_get_value(sensor->info.sensor_id, &value);
	if (ret)
	return ret;

	return sprintf(buf, "%u\n", value);
	}

	static ssize_t
	scpi_show_label(struct device dev, struct device_attribute attr, char *buf)
	{
	struct sensor_data *sensor;

	sensor = container_of(attr, struct sensor_data, dev_attr_label);

	return sprintf(buf, "%s\n", sensor->info.name);
	}

	static void
	unregister_thermal_zones(struct platform_device *pdev,
	struct scpi_sensors *scpi_sensors)
	{
	struct list_head *pos;

	list_for_each(pos, &scpi_sensors->thermal_zones) {
	struct scpi_thermal_zone *zone;

	zone = list_entry(pos, struct scpi_thermal_zone, list);
	thermal_zone_of_sensor_unregister(&pdev->dev, zone->tzd);
	}
	}

	static struct thermal_zone_of_device_ops scpi_sensor_ops = {
	.get_temp = scpi_read_temp,
	};

	static int scpi_hwmon_probe(struct platform_device *pdev)
	{
	u16 nr_sensors, i;
	int num_temp = 0, num_volt = 0, num_current = 0, num_power = 0;
	struct scpi_ops *scpi_ops;
	struct device hwdev, dev = &pdev->dev;
	struct scpi_sensors *scpi_sensors;
	int ret, idx;

	scpi_ops = get_scpi_ops();
	if (!scpi_ops)
	return -EPROBE_DEFER;

	ret = scpi_ops->sensor_get_capability(&nr_sensors);
	if (ret)
	return ret;

	if (!nr_sensors)
	return -ENODEV;

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

	scpi_sensors->data = devm_kcalloc(dev, nr_sensors,
	sizeof(*scpi_sensors->data), GFP_KERNEL);
	if (!scpi_sensors->data)
	return -ENOMEM;

	scpi_sensors->attrs = devm_kcalloc(dev, (nr_sensors * 2) + 1,
	sizeof(*scpi_sensors->attrs), GFP_KERNEL);
	if (!scpi_sensors->attrs)
	return -ENOMEM;

	scpi_sensors->scpi_ops = scpi_ops;

	for (i = 0, idx = 0; i < nr_sensors; i++) {
	struct sensor_data *sensor = &scpi_sensors->data[idx];

	ret = scpi_ops->sensor_get_info(i, &sensor->info);
	if (ret)
	return ret;

	switch (sensor->info.class) {
	case TEMPERATURE:
	snprintf(sensor->input, sizeof(sensor->input),
	"temp%d_input", num_temp + 1);
	snprintf(sensor->label, sizeof(sensor->input),
	"temp%d_label", num_temp + 1);
	num_temp++;
	break;
	case VOLTAGE:
	snprintf(sensor->input, sizeof(sensor->input),
	"in%d_input", num_volt);
	snprintf(sensor->label, sizeof(sensor->input),
	"in%d_label", num_volt);
	num_volt++;
	break;
	case CURRENT:
	snprintf(sensor->input, sizeof(sensor->input),
	"curr%d_input", num_current + 1);
	snprintf(sensor->label, sizeof(sensor->input),
	"curr%d_label", num_current + 1);
	num_current++;
	break;
	case POWER:
	snprintf(sensor->input, sizeof(sensor->input),
	"power%d_input", num_power + 1);
	snprintf(sensor->label, sizeof(sensor->input),
	"power%d_label", num_power + 1);
	num_power++;
	break;
	default:
	continue;
	}

	sensor->dev_attr_input.attr.mode = S_IRUGO;
	sensor->dev_attr_input.show = scpi_show_sensor;
	sensor->dev_attr_input.attr.name = sensor->input;

	sensor->dev_attr_label.attr.mode = S_IRUGO;
	sensor->dev_attr_label.show = scpi_show_label;
	sensor->dev_attr_label.attr.name = sensor->label;

	scpi_sensors->attrs[idx << 1] = &sensor->dev_attr_input.attr;
	scpi_sensors->attrs[(idx << 1) + 1] = &sensor->dev_attr_label.attr;

	sysfs_attr_init(scpi_sensors->attrs[idx << 1]);
	sysfs_attr_init(scpi_sensors->attrs[(idx << 1) + 1]);
	idx++;
	}

	scpi_sensors->group.attrs = scpi_sensors->attrs;
	scpi_sensors->groups[0] = &scpi_sensors->group;

	platform_set_drvdata(pdev, scpi_sensors);

	hwdev = devm_hwmon_device_register_with_groups(dev,
	"scpi_sensors", scpi_sensors, scpi_sensors->groups);

	if (IS_ERR(hwdev))
	return PTR_ERR(hwdev);

	/*
	* Register the temperature sensors with the thermal framework
	* to allow their usage in setting up the thermal zones from
	* device tree.
	*
	* NOTE: Not all temperature sensors maybe used for thermal
	* control
	*/
	INIT_LIST_HEAD(&scpi_sensors->thermal_zones);
	for (i = 0; i < nr_sensors; i++) {
	struct sensor_data *sensor = &scpi_sensors->data[i];
	struct scpi_thermal_zone *zone;

	if (sensor->info.class != TEMPERATURE)
	continue;

	zone = devm_kzalloc(dev, sizeof(*zone), GFP_KERNEL);
	if (!zone) {
	ret = -ENOMEM;
	goto unregister_tzd;
	}

	zone->sensor_id = i;
	zone->scpi_sensors = scpi_sensors;
	zone->tzd = thermal_zone_of_sensor_register(dev,
	sensor->info.sensor_id, zone, &scpi_sensor_ops);
	/*
	* The call to thermal_zone_of_sensor_register returns
	* an error for sensors that are not associated with
	* any thermal zones or if the thermal subsystem is
	* not configured.
	*/
	if (IS_ERR(zone->tzd)) {
	devm_kfree(dev, zone);
	continue;
	}
	list_add(&zone->list, &scpi_sensors->thermal_zones);
	}

	return 0;

	unregister_tzd:
	unregister_thermal_zones(pdev, scpi_sensors);
	return ret;
	}

	static int scpi_hwmon_remove(struct platform_device *pdev)
	{
	struct scpi_sensors *scpi_sensors = platform_get_drvdata(pdev);

	unregister_thermal_zones(pdev, scpi_sensors);

	return 0;
	}

	static const struct of_device_id scpi_of_match[] = {
	{.compatible = "arm,scpi-sensors"},
	{},
	};

	static struct platform_driver scpi_hwmon_platdrv = {
	.driver = {
	.name = "scpi-hwmon",
	.owner = THIS_MODULE,
	.of_match_table = scpi_of_match,
	},
	.probe = scpi_hwmon_probe,
	.remove = scpi_hwmon_remove,
	};
	module_platform_driver(scpi_hwmon_platdrv);

	MODULE_AUTHOR("Punit Agrawal <punit.agrawal@arm.com>");
	MODULE_DESCRIPTION("ARM SCPI HWMON interface driver");
	MODULE_LICENSE("GPL v2");