// SPDX-License-Identifier: GPL-2.0
/*
* Lochnagar hardware monitoring features
*
* Copyright (c) 2016-2019 Cirrus Logic, Inc. and
* Cirrus Logic International Semiconductor Ltd.
*
* Author: Lucas Tanure <[email protected]>
*/
#include <linux/delay.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/math64.h>
#include <linux/mfd/lochnagar.h>
#include <linux/mfd/lochnagar2_regs.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#define LN2_MAX_NSAMPLE 1023
#define LN2_SAMPLE_US 1670
#define LN2_CURR_UNITS 1000
#define LN2_VOLT_UNITS 1000
#define LN2_TEMP_UNITS 1000
#define LN2_PWR_UNITS 1000000
static const char * const lochnagar_chan_names[] = {
"DBVDD1",
"1V8 DSP",
"1V8 CDC",
"VDDCORE DSP",
"AVDD 1V8",
"SYSVDD",
"VDDCORE CDC",
"MICVDD",
};
struct lochnagar_hwmon {
struct regmap *regmap;
long power_nsamples[ARRAY_SIZE(lochnagar_chan_names)];
/* Lock to ensure only a single sensor is read at a time */
struct mutex sensor_lock;
};
enum lochnagar_measure_mode {
LN2_CURR = 0,
LN2_VOLT,
LN2_TEMP,
};
/**
* float_to_long - Convert ieee754 reading from hardware to an integer
*
* @data: Value read from the hardware
* @precision: Units to multiply up to eg. 1000 = milli, 1000000 = micro
*
* Return: Converted integer reading
*
* Depending on the measurement type the hardware returns an ieee754
* floating point value in either volts, amps or celsius. This function
* will convert that into an integer in a smaller unit such as micro-amps
* or milli-celsius. The hardware does not return NaN, so consideration of
* that is not required.
*/
static long float_to_long(u32 data, u32 precision)
{
u64 man = data & 0x007FFFFF;
int exp = ((data & 0x7F800000) >> 23) - 127 - 23;
bool negative = data & 0x80000000;
long result;
man = (man + (1 << 23)) * precision;
if (fls64(man) + exp > (int)sizeof(long) * 8 - 1)
result = LONG_MAX;
else if (exp < 0)
result = (man + (1ull << (-exp - 1))) >> -exp;
else
result = man << exp;
return negative ? -result : result;
}
static int do_measurement(struct regmap *regmap, int chan,
enum lochnagar_measure_mode mode, int nsamples)
{
unsigned int val;
int ret;
chan = 1 << (chan + LOCHNAGAR2_IMON_MEASURED_CHANNELS_SHIFT);
ret = regmap_write(regmap, LOCHNAGAR2_IMON_CTRL1,
LOCHNAGAR2_IMON_ENA_MASK | chan | mode);
if (ret < 0)
return ret;
ret = regmap_write(regmap, LOCHNAGAR2_IMON_CTRL2, nsamples);
if (ret < 0)
return ret;
ret = regmap_write(regmap, LOCHNAGAR2_IMON_CTRL3,
LOCHNAGAR2_IMON_CONFIGURE_MASK);
if (ret < 0)
return ret;
ret = regmap_read_poll_timeout(regmap, LOCHNAGAR2_IMON_CTRL3, val,
val & LOCHNAGAR2_IMON_DONE_MASK,
1000, 10000);
if (ret < 0)
return ret;
ret = regmap_write(regmap, LOCHNAGAR2_IMON_CTRL3,
LOCHNAGAR2_IMON_MEASURE_MASK);
if (ret < 0)
return ret;
/*
* Actual measurement time is ~1.67mS per sample, approximate this
* with a 1.5mS per sample msleep and then poll for success up to
* ~0.17mS * 1023 (LN2_MAX_NSAMPLES). Normally for smaller values
* of nsamples the poll will complete on the first loop due to
* other latency in the system.
*/
msleep((nsamples * 3) / 2);
ret = regmap_read_poll_timeout(regmap, LOCHNAGAR2_IMON_CTRL3, val,
val & LOCHNAGAR2_IMON_DONE_MASK,
5000, 200000);
if (ret < 0)
return ret;
return regmap_write(regmap, LOCHNAGAR2_IMON_CTRL3, 0);
}
static int request_data(struct regmap *regmap, int chan, u32 *data)
{
unsigned int val;
int ret;
ret = regmap_write(regmap, LOCHNAGAR2_IMON_CTRL4,
LOCHNAGAR2_IMON_DATA_REQ_MASK |
chan << LOCHNAGAR2_IMON_CH_SEL_SHIFT);
if (ret < 0)
return ret;
ret = regmap_read_poll_timeout(regmap, LOCHNAGAR2_IMON_CTRL4, val,
val & LOCHNAGAR2_IMON_DATA_RDY_MASK,
1000, 10000);
if (ret < 0)
return ret;
ret = regmap_read(regmap, LOCHNAGAR2_IMON_DATA1, &val);
if (ret < 0)
return ret;
*data = val << 16;
ret = regmap_read(regmap, LOCHNAGAR2_IMON_DATA2, &val);
if (ret < 0)
return ret;
*data |= val;
return regmap_write(regmap, LOCHNAGAR2_IMON_CTRL4, 0);
}
static int read_sensor(struct device *dev, int chan,
enum lochnagar_measure_mode mode, int nsamples,
unsigned int precision, long *val)
{
struct lochnagar_hwmon *priv = dev_get_drvdata(dev);
struct regmap *regmap = priv->regmap;
u32 data;
int ret;
mutex_lock(&priv->sensor_lock);
ret = do_measurement(regmap, chan, mode, nsamples);
if (ret < 0) {
dev_err(dev, "Failed to perform measurement: %d\n", ret);
goto error;
}
ret = request_data(regmap, chan, &data);
if (ret < 0) {
dev_err(dev, "Failed to read measurement: %d\n", ret);
goto error;
}
*val = float_to_long(data, precision);
error:
mutex_unlock(&priv->sensor_lock);
return ret;
}
static int read_power(struct device *dev, int chan, long *val)
{
struct lochnagar_hwmon *priv = dev_get_drvdata(dev);
int nsamples = priv->power_nsamples[chan];
u64 power;
int ret;
if (!strcmp("SYSVDD", lochnagar_chan_names[chan])) {
power = 5 * LN2_PWR_UNITS;
} else {
ret = read_sensor(dev, chan, LN2_VOLT, 1, LN2_PWR_UNITS, val);
if (ret < 0)
return ret;
power = abs(*val);
}
ret = read_sensor(dev, chan, LN2_CURR, nsamples, LN2_PWR_UNITS, val);
if (ret < 0)
return ret;
power *= abs(*val);
power = DIV_ROUND_CLOSEST_ULL(power, LN2_PWR_UNITS);
if (power > LONG_MAX)
*val = LONG_MAX;
else
*val = power;
return 0;
}
static umode_t lochnagar_is_visible(const void *drvdata,
enum hwmon_sensor_types type,
u32 attr, int chan)
{
switch (type) {
case hwmon_in:
if (!strcmp("SYSVDD", lochnagar_chan_names[chan]))
return 0;
break;
case hwmon_power:
if (attr == hwmon_power_average_interval)
return 0644;
break;
default:
break;
}
return 0444;
}
static int lochnagar_read(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int chan, long *val)
{
struct lochnagar_hwmon *priv = dev_get_drvdata(dev);
int interval;
switch (type) {
case hwmon_in:
return read_sensor(dev, chan, LN2_VOLT, 1, LN2_VOLT_UNITS, val);
case hwmon_curr:
return read_sensor(dev, chan, LN2_CURR, 1, LN2_CURR_UNITS, val);
case hwmon_temp:
return read_sensor(dev, chan, LN2_TEMP, 1, LN2_TEMP_UNITS, val);
case hwmon_power:
switch (attr) {
case hwmon_power_average:
return read_power(dev, chan, val);
case hwmon_power_average_interval:
interval = priv->power_nsamples[chan] * LN2_SAMPLE_US;
*val = DIV_ROUND_CLOSEST(interval, 1000);
return 0;
default:
return -EOPNOTSUPP;
}
default:
return -EOPNOTSUPP;
}
}
static int lochnagar_read_string(struct device *dev,
enum hwmon_sensor_types type, u32 attr,
int chan, const char **str)
{
switch (type) {
case hwmon_in:
case hwmon_curr:
case hwmon_power:
*str = lochnagar_chan_names[chan];
return 0;
default:
return -EOPNOTSUPP;
}
}
static int lochnagar_write(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int chan, long val)
{
struct lochnagar_hwmon *priv = dev_get_drvdata(dev);
if (type != hwmon_power || attr != hwmon_power_average_interval)
return -EOPNOTSUPP;
val = clamp_t(long, val, 1, (LN2_MAX_NSAMPLE * LN2_SAMPLE_US) / 1000);
val = DIV_ROUND_CLOSEST(val * 1000, LN2_SAMPLE_US);
priv->power_nsamples[chan] = val;
return 0;
}
static const struct hwmon_ops lochnagar_ops = {
.is_visible = lochnagar_is_visible,
.read = lochnagar_read,
.read_string = lochnagar_read_string,
.write = lochnagar_write,
};
static const struct hwmon_channel_info * const lochnagar_info[] = {
HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
HWMON_CHANNEL_INFO(in, HWMON_I_INPUT | HWMON_I_LABEL,
HWMON_I_INPUT | HWMON_I_LABEL,
HWMON_I_INPUT | HWMON_I_LABEL,
HWMON_I_INPUT | HWMON_I_LABEL,
HWMON_I_INPUT | HWMON_I_LABEL,
HWMON_I_INPUT | HWMON_I_LABEL,
HWMON_I_INPUT | HWMON_I_LABEL,
HWMON_I_INPUT | HWMON_I_LABEL),
HWMON_CHANNEL_INFO(curr, HWMON_C_INPUT | HWMON_C_LABEL,
HWMON_C_INPUT | HWMON_C_LABEL,
HWMON_C_INPUT | HWMON_C_LABEL,
HWMON_C_INPUT | HWMON_C_LABEL,
HWMON_C_INPUT | HWMON_C_LABEL,
HWMON_C_INPUT | HWMON_C_LABEL,
HWMON_C_INPUT | HWMON_C_LABEL,
HWMON_C_INPUT | HWMON_C_LABEL),
HWMON_CHANNEL_INFO(power, HWMON_P_AVERAGE | HWMON_P_AVERAGE_INTERVAL |
HWMON_P_LABEL,
HWMON_P_AVERAGE | HWMON_P_AVERAGE_INTERVAL |
HWMON_P_LABEL,
HWMON_P_AVERAGE | HWMON_P_AVERAGE_INTERVAL |
HWMON_P_LABEL,
HWMON_P_AVERAGE | HWMON_P_AVERAGE_INTERVAL |
HWMON_P_LABEL,
HWMON_P_AVERAGE | HWMON_P_AVERAGE_INTERVAL |
HWMON_P_LABEL,
HWMON_P_AVERAGE | HWMON_P_AVERAGE_INTERVAL |
HWMON_P_LABEL,
HWMON_P_AVERAGE | HWMON_P_AVERAGE_INTERVAL |
HWMON_P_LABEL,
HWMON_P_AVERAGE | HWMON_P_AVERAGE_INTERVAL |
HWMON_P_LABEL),
NULL
};
static const struct hwmon_chip_info lochnagar_chip_info = {
.ops = &lochnagar_ops,
.info = lochnagar_info,
};
static const struct of_device_id lochnagar_of_match[] = {
{ .compatible = "cirrus,lochnagar2-hwmon" },
{}
};
MODULE_DEVICE_TABLE(of, lochnagar_of_match);
static int lochnagar_hwmon_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device *hwmon_dev;
struct lochnagar_hwmon *priv;
int i;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
mutex_init(&priv->sensor_lock);
priv->regmap = dev_get_regmap(dev->parent, NULL);
if (!priv->regmap) {
dev_err(dev, "No register map found\n");
return -EINVAL;
}
for (i = 0; i < ARRAY_SIZE(priv->power_nsamples); i++)
priv->power_nsamples[i] = 96;
hwmon_dev = devm_hwmon_device_register_with_info(dev, "Lochnagar", priv,
&lochnagar_chip_info,
NULL);
return PTR_ERR_OR_ZERO(hwmon_dev);
}
static struct platform_driver lochnagar_hwmon_driver = {
.driver = {
.name = "lochnagar-hwmon",
.of_match_table = lochnagar_of_match,
},
.probe = lochnagar_hwmon_probe,
};
module_platform_driver(lochnagar_hwmon_driver);
MODULE_AUTHOR("Lucas Tanure <[email protected]>");
MODULE_DESCRIPTION("Lochnagar hardware monitoring features");
MODULE_LICENSE("GPL");
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