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1// SPDX-License-Identifier: GPL-2.02/*3 * Lochnagar hardware monitoring features4 *5 * Copyright (c) 2016-2019 Cirrus Logic, Inc. and6 * Cirrus Logic International Semiconductor Ltd.7 *8 * Author: Lucas Tanure <tanureal@opensource.cirrus.com>9 */10 11#include <linux/delay.h>12#include <linux/hwmon.h>13#include <linux/hwmon-sysfs.h>14#include <linux/math64.h>15#include <linux/mfd/lochnagar.h>16#include <linux/mfd/lochnagar2_regs.h>17#include <linux/module.h>18#include <linux/of.h>19#include <linux/platform_device.h>20#include <linux/regmap.h>21 22#define LN2_MAX_NSAMPLE 102323#define LN2_SAMPLE_US 167024 25#define LN2_CURR_UNITS 100026#define LN2_VOLT_UNITS 100027#define LN2_TEMP_UNITS 100028#define LN2_PWR_UNITS 100000029 30static const char * const lochnagar_chan_names[] = {31 "DBVDD1",32 "1V8 DSP",33 "1V8 CDC",34 "VDDCORE DSP",35 "AVDD 1V8",36 "SYSVDD",37 "VDDCORE CDC",38 "MICVDD",39};40 41struct lochnagar_hwmon {42 struct regmap *regmap;43 44 long power_nsamples[ARRAY_SIZE(lochnagar_chan_names)];45 46 /* Lock to ensure only a single sensor is read at a time */47 struct mutex sensor_lock;48};49 50enum lochnagar_measure_mode {51 LN2_CURR = 0,52 LN2_VOLT,53 LN2_TEMP,54};55 56/**57 * float_to_long - Convert ieee754 reading from hardware to an integer58 *59 * @data: Value read from the hardware60 * @precision: Units to multiply up to eg. 1000 = milli, 1000000 = micro61 *62 * Return: Converted integer reading63 *64 * Depending on the measurement type the hardware returns an ieee75465 * floating point value in either volts, amps or celsius. This function66 * will convert that into an integer in a smaller unit such as micro-amps67 * or milli-celsius. The hardware does not return NaN, so consideration of68 * that is not required.69 */70static long float_to_long(u32 data, u32 precision)71{72 u64 man = data & 0x007FFFFF;73 int exp = ((data & 0x7F800000) >> 23) - 127 - 23;74 bool negative = data & 0x80000000;75 long result;76 77 man = (man + (1 << 23)) * precision;78 79 if (fls64(man) + exp > (int)sizeof(long) * 8 - 1)80 result = LONG_MAX;81 else if (exp < 0)82 result = (man + (1ull << (-exp - 1))) >> -exp;83 else84 result = man << exp;85 86 return negative ? -result : result;87}88 89static int do_measurement(struct regmap *regmap, int chan,90 enum lochnagar_measure_mode mode, int nsamples)91{92 unsigned int val;93 int ret;94 95 chan = 1 << (chan + LOCHNAGAR2_IMON_MEASURED_CHANNELS_SHIFT);96 97 ret = regmap_write(regmap, LOCHNAGAR2_IMON_CTRL1,98 LOCHNAGAR2_IMON_ENA_MASK | chan | mode);99 if (ret < 0)100 return ret;101 102 ret = regmap_write(regmap, LOCHNAGAR2_IMON_CTRL2, nsamples);103 if (ret < 0)104 return ret;105 106 ret = regmap_write(regmap, LOCHNAGAR2_IMON_CTRL3,107 LOCHNAGAR2_IMON_CONFIGURE_MASK);108 if (ret < 0)109 return ret;110 111 ret = regmap_read_poll_timeout(regmap, LOCHNAGAR2_IMON_CTRL3, val,112 val & LOCHNAGAR2_IMON_DONE_MASK,113 1000, 10000);114 if (ret < 0)115 return ret;116 117 ret = regmap_write(regmap, LOCHNAGAR2_IMON_CTRL3,118 LOCHNAGAR2_IMON_MEASURE_MASK);119 if (ret < 0)120 return ret;121 122 /*123 * Actual measurement time is ~1.67mS per sample, approximate this124 * with a 1.5mS per sample msleep and then poll for success up to125 * ~0.17mS * 1023 (LN2_MAX_NSAMPLES). Normally for smaller values126 * of nsamples the poll will complete on the first loop due to127 * other latency in the system.128 */129 msleep((nsamples * 3) / 2);130 131 ret = regmap_read_poll_timeout(regmap, LOCHNAGAR2_IMON_CTRL3, val,132 val & LOCHNAGAR2_IMON_DONE_MASK,133 5000, 200000);134 if (ret < 0)135 return ret;136 137 return regmap_write(regmap, LOCHNAGAR2_IMON_CTRL3, 0);138}139 140static int request_data(struct regmap *regmap, int chan, u32 *data)141{142 unsigned int val;143 int ret;144 145 ret = regmap_write(regmap, LOCHNAGAR2_IMON_CTRL4,146 LOCHNAGAR2_IMON_DATA_REQ_MASK |147 chan << LOCHNAGAR2_IMON_CH_SEL_SHIFT);148 if (ret < 0)149 return ret;150 151 ret = regmap_read_poll_timeout(regmap, LOCHNAGAR2_IMON_CTRL4, val,152 val & LOCHNAGAR2_IMON_DATA_RDY_MASK,153 1000, 10000);154 if (ret < 0)155 return ret;156 157 ret = regmap_read(regmap, LOCHNAGAR2_IMON_DATA1, &val);158 if (ret < 0)159 return ret;160 161 *data = val << 16;162 163 ret = regmap_read(regmap, LOCHNAGAR2_IMON_DATA2, &val);164 if (ret < 0)165 return ret;166 167 *data |= val;168 169 return regmap_write(regmap, LOCHNAGAR2_IMON_CTRL4, 0);170}171 172static int read_sensor(struct device *dev, int chan,173 enum lochnagar_measure_mode mode, int nsamples,174 unsigned int precision, long *val)175{176 struct lochnagar_hwmon *priv = dev_get_drvdata(dev);177 struct regmap *regmap = priv->regmap;178 u32 data;179 int ret;180 181 mutex_lock(&priv->sensor_lock);182 183 ret = do_measurement(regmap, chan, mode, nsamples);184 if (ret < 0) {185 dev_err(dev, "Failed to perform measurement: %d\n", ret);186 goto error;187 }188 189 ret = request_data(regmap, chan, &data);190 if (ret < 0) {191 dev_err(dev, "Failed to read measurement: %d\n", ret);192 goto error;193 }194 195 *val = float_to_long(data, precision);196 197error:198 mutex_unlock(&priv->sensor_lock);199 200 return ret;201}202 203static int read_power(struct device *dev, int chan, long *val)204{205 struct lochnagar_hwmon *priv = dev_get_drvdata(dev);206 int nsamples = priv->power_nsamples[chan];207 u64 power;208 int ret;209 210 if (!strcmp("SYSVDD", lochnagar_chan_names[chan])) {211 power = 5 * LN2_PWR_UNITS;212 } else {213 ret = read_sensor(dev, chan, LN2_VOLT, 1, LN2_PWR_UNITS, val);214 if (ret < 0)215 return ret;216 217 power = abs(*val);218 }219 220 ret = read_sensor(dev, chan, LN2_CURR, nsamples, LN2_PWR_UNITS, val);221 if (ret < 0)222 return ret;223 224 power *= abs(*val);225 power = DIV_ROUND_CLOSEST_ULL(power, LN2_PWR_UNITS);226 227 if (power > LONG_MAX)228 *val = LONG_MAX;229 else230 *val = power;231 232 return 0;233}234 235static umode_t lochnagar_is_visible(const void *drvdata,236 enum hwmon_sensor_types type,237 u32 attr, int chan)238{239 switch (type) {240 case hwmon_in:241 if (!strcmp("SYSVDD", lochnagar_chan_names[chan]))242 return 0;243 break;244 case hwmon_power:245 if (attr == hwmon_power_average_interval)246 return 0644;247 break;248 default:249 break;250 }251 252 return 0444;253}254 255static int lochnagar_read(struct device *dev, enum hwmon_sensor_types type,256 u32 attr, int chan, long *val)257{258 struct lochnagar_hwmon *priv = dev_get_drvdata(dev);259 int interval;260 261 switch (type) {262 case hwmon_in:263 return read_sensor(dev, chan, LN2_VOLT, 1, LN2_VOLT_UNITS, val);264 case hwmon_curr:265 return read_sensor(dev, chan, LN2_CURR, 1, LN2_CURR_UNITS, val);266 case hwmon_temp:267 return read_sensor(dev, chan, LN2_TEMP, 1, LN2_TEMP_UNITS, val);268 case hwmon_power:269 switch (attr) {270 case hwmon_power_average:271 return read_power(dev, chan, val);272 case hwmon_power_average_interval:273 interval = priv->power_nsamples[chan] * LN2_SAMPLE_US;274 *val = DIV_ROUND_CLOSEST(interval, 1000);275 return 0;276 default:277 return -EOPNOTSUPP;278 }279 default:280 return -EOPNOTSUPP;281 }282}283 284static int lochnagar_read_string(struct device *dev,285 enum hwmon_sensor_types type, u32 attr,286 int chan, const char **str)287{288 switch (type) {289 case hwmon_in:290 case hwmon_curr:291 case hwmon_power:292 *str = lochnagar_chan_names[chan];293 return 0;294 default:295 return -EOPNOTSUPP;296 }297}298 299static int lochnagar_write(struct device *dev, enum hwmon_sensor_types type,300 u32 attr, int chan, long val)301{302 struct lochnagar_hwmon *priv = dev_get_drvdata(dev);303 304 if (type != hwmon_power || attr != hwmon_power_average_interval)305 return -EOPNOTSUPP;306 307 val = clamp_t(long, val, 1, (LN2_MAX_NSAMPLE * LN2_SAMPLE_US) / 1000);308 val = DIV_ROUND_CLOSEST(val * 1000, LN2_SAMPLE_US);309 310 priv->power_nsamples[chan] = val;311 312 return 0;313}314 315static const struct hwmon_ops lochnagar_ops = {316 .is_visible = lochnagar_is_visible,317 .read = lochnagar_read,318 .read_string = lochnagar_read_string,319 .write = lochnagar_write,320};321 322static const struct hwmon_channel_info * const lochnagar_info[] = {323 HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),324 HWMON_CHANNEL_INFO(in, HWMON_I_INPUT | HWMON_I_LABEL,325 HWMON_I_INPUT | HWMON_I_LABEL,326 HWMON_I_INPUT | HWMON_I_LABEL,327 HWMON_I_INPUT | HWMON_I_LABEL,328 HWMON_I_INPUT | HWMON_I_LABEL,329 HWMON_I_INPUT | HWMON_I_LABEL,330 HWMON_I_INPUT | HWMON_I_LABEL,331 HWMON_I_INPUT | HWMON_I_LABEL),332 HWMON_CHANNEL_INFO(curr, HWMON_C_INPUT | HWMON_C_LABEL,333 HWMON_C_INPUT | HWMON_C_LABEL,334 HWMON_C_INPUT | HWMON_C_LABEL,335 HWMON_C_INPUT | HWMON_C_LABEL,336 HWMON_C_INPUT | HWMON_C_LABEL,337 HWMON_C_INPUT | HWMON_C_LABEL,338 HWMON_C_INPUT | HWMON_C_LABEL,339 HWMON_C_INPUT | HWMON_C_LABEL),340 HWMON_CHANNEL_INFO(power, HWMON_P_AVERAGE | HWMON_P_AVERAGE_INTERVAL |341 HWMON_P_LABEL,342 HWMON_P_AVERAGE | HWMON_P_AVERAGE_INTERVAL |343 HWMON_P_LABEL,344 HWMON_P_AVERAGE | HWMON_P_AVERAGE_INTERVAL |345 HWMON_P_LABEL,346 HWMON_P_AVERAGE | HWMON_P_AVERAGE_INTERVAL |347 HWMON_P_LABEL,348 HWMON_P_AVERAGE | HWMON_P_AVERAGE_INTERVAL |349 HWMON_P_LABEL,350 HWMON_P_AVERAGE | HWMON_P_AVERAGE_INTERVAL |351 HWMON_P_LABEL,352 HWMON_P_AVERAGE | HWMON_P_AVERAGE_INTERVAL |353 HWMON_P_LABEL,354 HWMON_P_AVERAGE | HWMON_P_AVERAGE_INTERVAL |355 HWMON_P_LABEL),356 NULL357};358 359static const struct hwmon_chip_info lochnagar_chip_info = {360 .ops = &lochnagar_ops,361 .info = lochnagar_info,362};363 364static const struct of_device_id lochnagar_of_match[] = {365 { .compatible = "cirrus,lochnagar2-hwmon" },366 {}367};368MODULE_DEVICE_TABLE(of, lochnagar_of_match);369 370static int lochnagar_hwmon_probe(struct platform_device *pdev)371{372 struct device *dev = &pdev->dev;373 struct device *hwmon_dev;374 struct lochnagar_hwmon *priv;375 int i;376 377 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);378 if (!priv)379 return -ENOMEM;380 381 mutex_init(&priv->sensor_lock);382 383 priv->regmap = dev_get_regmap(dev->parent, NULL);384 if (!priv->regmap) {385 dev_err(dev, "No register map found\n");386 return -EINVAL;387 }388 389 for (i = 0; i < ARRAY_SIZE(priv->power_nsamples); i++)390 priv->power_nsamples[i] = 96;391 392 hwmon_dev = devm_hwmon_device_register_with_info(dev, "Lochnagar", priv,393 &lochnagar_chip_info,394 NULL);395 396 return PTR_ERR_OR_ZERO(hwmon_dev);397}398 399static struct platform_driver lochnagar_hwmon_driver = {400 .driver = {401 .name = "lochnagar-hwmon",402 .of_match_table = lochnagar_of_match,403 },404 .probe = lochnagar_hwmon_probe,405};406module_platform_driver(lochnagar_hwmon_driver);407 408MODULE_AUTHOR("Lucas Tanure <tanureal@opensource.cirrus.com>");409MODULE_DESCRIPTION("Lochnagar hardware monitoring features");410MODULE_LICENSE("GPL");411