/*
* 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/of_device.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 {
unsigned int scale;
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 {
int sensor_id;
struct scpi_sensors *scpi_sensors;
};
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 const u32 gxbb_scpi_scale[] = {
[TEMPERATURE] = 1, /* (celsius) */
[VOLTAGE] = 1000, /* (millivolts) */
[CURRENT] = 1000, /* (milliamperes) */
[POWER] = 1000000, /* (microwatts) */
[ENERGY] = 1000000, /* (microjoules) */
};
static const u32 scpi_scale[] = {
[TEMPERATURE] = 1000, /* (millicelsius) */
[VOLTAGE] = 1000, /* (millivolts) */
[CURRENT] = 1000, /* (milliamperes) */
[POWER] = 1000000, /* (microwatts) */
[ENERGY] = 1000000, /* (microjoules) */
};
static void scpi_scale_reading(u64 *value, struct sensor_data *sensor)
{
if (scpi_scale[sensor->info.class] != sensor->scale) {
*value *= scpi_scale[sensor->info.class];
do_div(*value, sensor->scale);
}
}
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];
u64 value;
int ret;
ret = scpi_ops->sensor_get_value(sensor->info.sensor_id, &value);
if (ret)
return ret;
scpi_scale_reading(&value, sensor);
*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;
u64 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;
scpi_scale_reading(&value, sensor);
return sprintf(buf, "%llu\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 const struct thermal_zone_of_device_ops scpi_sensor_ops = {
.get_temp = scpi_read_temp,
};
static const struct of_device_id scpi_of_match[] = {
{.compatible = "arm,scpi-sensors", .data = &scpi_scale},
{.compatible = "amlogic,meson-gxbb-scpi-sensors", .data = &gxbb_scpi_scale},
{},
};
MODULE_DEVICE_TABLE(of, scpi_of_match);
static int scpi_hwmon_probe(struct platform_device *pdev)
{
u16 nr_sensors, i;
const u32 *scale;
int num_temp = 0, num_volt = 0, num_current = 0, num_power = 0;
int num_energy = 0;
struct scpi_ops *scpi_ops;
struct device *hwdev, *dev = &pdev->dev;
struct scpi_sensors *scpi_sensors;
const struct of_device_id *of_id;
int idx, ret;
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;
of_id = of_match_device(scpi_of_match, &pdev->dev);
if (!of_id) {
dev_err(&pdev->dev, "Unable to initialize scpi-hwmon data\n");
return -ENODEV;
}
scale = of_id->data;
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;
case ENERGY:
snprintf(sensor->input, sizeof(sensor->input),
"energy%d_input", num_energy + 1);
snprintf(sensor->label, sizeof(sensor->input),
"energy%d_label", num_energy + 1);
num_energy++;
break;
default:
continue;
}
sensor->scale = scale[sensor->info.class];
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 thermal_zone_device *z;
struct scpi_thermal_zone *zone;
if (sensor->info.class != TEMPERATURE)
continue;
zone = devm_kzalloc(dev, sizeof(*zone), GFP_KERNEL);
if (!zone)
return -ENOMEM;
zone->sensor_id = i;
zone->scpi_sensors = scpi_sensors;
z = devm_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(z)) {
devm_kfree(dev, zone);
continue;
}
}
return 0;
}
static struct platform_driver scpi_hwmon_platdrv = {
.driver = {
.name = "scpi-hwmon",
.of_match_table = scpi_of_match,
},
.probe = scpi_hwmon_probe,
};
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");
