blob: 6827169c82d4dca174883c35b07d343a0d3edc14 [file] [log] [blame]
/*
* 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"},
{},
};
MODULE_DEVICE_TABLE(of, scpi_of_match);
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");