// SPDX-License-Identifier: GPL-2.0
/*
* System Control and Management Interface(SCMI) based hwmon sensor driver
*
* Copyright (C) 2018-2021 ARM Ltd.
* Sudeep Holla <[email protected]>
*/
#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 <[email protected]>");
MODULE_DESCRIPTION("ARM SCMI HWMON interface driver");
MODULE_LICENSE("GPL v2");
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