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linux-next/drivers/hwmon/scmi-hwmon.c
Sudeep Holla b017b2791c hwmon: (scmi-hwmon) Match scmi device by both name and protocol id
The scmi bus now has support to match the driver with devices not only
based on their protocol id but also based on their device name if one is
available. This was added to cater the need to support multiple devices
and drivers for the same protocol.

Let us add the name "hwmon" to scmi_device_id table in the driver so
that in matches only with device with the same name and protocol id
SCMI_PROTOCOL_SENSOR. This is just for sake of completion and must
not be used to add IIO support in parallel. Instead, if IIO support is
added ever in future, we need to drop this hwmon driver entirely and
use the iio->hwmon bridge to access the sensors as hwmon devices if
needed.

Cc: linux-hwmon@vger.kernel.org
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2019-12-24 11:37:35 +00:00

277 lines
6.0 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* System Control and Management Interface(SCMI) based hwmon sensor driver
*
* Copyright (C) 2018 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>
struct scmi_sensors {
const struct scmi_handle *handle;
const struct scmi_sensor_info **info[hwmon_max];
};
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)
{
s8 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(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long *val)
{
int ret;
u64 value;
const struct scmi_sensor_info *sensor;
struct scmi_sensors *scmi_sensors = dev_get_drvdata(dev);
const struct scmi_handle *h = scmi_sensors->handle;
sensor = *(scmi_sensors->info[type] + channel);
ret = h->sensor_ops->reading_get(h, sensor->id, &value);
if (ret)
return ret;
ret = scmi_hwmon_scale(sensor, &value);
if (!ret)
*val = value;
return ret;
}
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_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_chip] = HWMON_C_REGISTER_TZ,
[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_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;
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;
if (!handle || !handle->sensor_ops)
return -ENODEV;
nr_sensors = handle->sensor_ops->count_get(handle);
if (!nr_sensors)
return -EIO;
scmi_sensors = devm_kzalloc(dev, sizeof(*scmi_sensors), GFP_KERNEL);
if (!scmi_sensors)
return -ENOMEM;
scmi_sensors->handle = handle;
for (i = 0; i < nr_sensors; i++) {
sensor = handle->sensor_ops->info_get(handle, 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[hwmon_chip]++, nr_types++;
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 = handle->sensor_ops->info_get(handle, 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);
return PTR_ERR_OR_ZERO(hwdev);
}
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");