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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * ds1621.c - Part of lm_sensors, Linux kernel modules for hardware4 * monitoring5 * Christian W. Zuckschwerdt <zany@triq.net> 2000-11-236 * based on lm75.c by Frodo Looijaard <frodol@dds.nl>7 * Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with8 * the help of Jean Delvare <jdelvare@suse.de>9 *10 * The DS1621 device is a digital temperature/thermometer with 9-bit11 * resolution, a thermal alarm output (Tout), and user-defined minimum12 * and maximum temperature thresholds (TH and TL).13 *14 * The DS1625, DS1631, DS1721, and DS1731 are pin compatible with the DS162115 * and similar in operation, with slight variations as noted in the device16 * datasheets (please refer to www.maximintegrated.com for specific17 * device information).18 *19 * Since the DS1621 was the first chipset supported by this driver,20 * most comments will refer to this chipset, but are actually general21 * and concern all supported chipsets, unless mentioned otherwise.22 */23 24#include <linux/module.h>25#include <linux/init.h>26#include <linux/slab.h>27#include <linux/jiffies.h>28#include <linux/i2c.h>29#include <linux/hwmon.h>30#include <linux/hwmon-sysfs.h>31#include <linux/err.h>32#include <linux/mutex.h>33#include <linux/sysfs.h>34#include <linux/kernel.h>35 36/* Supported devices */37enum chips { ds1621, ds1625, ds1631, ds1721, ds1731 };38 39/* Insmod parameters */40static int polarity = -1;41module_param(polarity, int, 0);42MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low");43 44/*45 * The Configuration/Status register46 *47 * - DS1621:48 * 7 6 5 4 3 2 1 049 * |Done|THF |TLF |NVB | X | X |POL |1SHOT|50 *51 * - DS1625:52 * 7 6 5 4 3 2 1 053 * |Done|THF |TLF |NVB | 1 | 0 |POL |1SHOT|54 *55 * - DS1631, DS1731:56 * 7 6 5 4 3 2 1 057 * |Done|THF |TLF |NVB | R1 | R0 |POL |1SHOT|58 *59 * - DS1721:60 * 7 6 5 4 3 2 1 061 * |Done| X | X | U | R1 | R0 |POL |1SHOT|62 *63 * Where:64 * - 'X' is Reserved65 * - 'U' is Undefined66 */67#define DS1621_REG_CONFIG_NVB 0x1068#define DS1621_REG_CONFIG_RESOL 0x0C69#define DS1621_REG_CONFIG_POLARITY 0x0270#define DS1621_REG_CONFIG_1SHOT 0x0171#define DS1621_REG_CONFIG_DONE 0x8072 73#define DS1621_REG_CONFIG_RESOL_SHIFT 274 75/* ds1721 conversion rates: {C/LSB, time(ms), resolution bit setting} */76static const unsigned short ds1721_convrates[] = {77 94, /* 9-bits (0.5, 93.75, RES[0..1] = 0 */78 188, /* 10-bits (0.25, 187.5, RES[0..1] = 1 */79 375, /* 11-bits (0.125, 375, RES[0..1] = 2 */80 750, /* 12-bits (0.0625, 750, RES[0..1] = 3 */81};82 83#define DS1621_CONVERSION_MAX 75084#define DS1625_CONVERSION_MAX 50085 86#define DS1621_TEMP_MAX 12500087#define DS1621_TEMP_MIN (-55000)88 89/* The DS1621 temperature registers */90static const u8 DS1621_REG_TEMP[3] = {91 0xAA, /* input, word, RO */92 0xA2, /* min, word, RW */93 0xA1, /* max, word, RW */94};95#define DS1621_REG_CONF 0xAC /* byte, RW */96#define DS1621_COM_START 0xEE /* no data */97#define DS1721_COM_START 0x51 /* no data */98#define DS1621_COM_STOP 0x22 /* no data */99 100/* The DS1621 configuration register */101#define DS1621_ALARM_TEMP_HIGH 0x40102#define DS1621_ALARM_TEMP_LOW 0x20103 104/* Conversions */105#define ALARMS_FROM_REG(val) ((val) & \106 (DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW))107 108/* Each client has this additional data */109struct ds1621_data {110 struct i2c_client *client;111 struct mutex update_lock;112 bool valid; /* true if following fields are valid */113 unsigned long last_updated; /* In jiffies */114 enum chips kind; /* device type */115 116 u16 temp[3]; /* Register values, word */117 u8 conf; /* Register encoding, combined */118 u8 zbits; /* Resolution encoded as number of119 * zero bits */120 u16 update_interval; /* Conversion rate in milliseconds */121};122 123static inline int DS1621_TEMP_FROM_REG(u16 reg)124{125 return DIV_ROUND_CLOSEST(((s16)reg / 16) * 625, 10);126}127 128/*129 * TEMP: 0.001C/bit (-55C to +125C)130 * REG:131 * - 1621, 1625: 0.5C/bit, 7 zero-bits132 * - 1631, 1721, 1731: 0.0625C/bit, 4 zero-bits133 */134static inline u16 DS1621_TEMP_TO_REG(long temp, u8 zbits)135{136 temp = clamp_val(temp, DS1621_TEMP_MIN, DS1621_TEMP_MAX);137 temp = DIV_ROUND_CLOSEST(temp * (1 << (8 - zbits)), 1000) << zbits;138 return temp;139}140 141static void ds1621_init_client(struct ds1621_data *data,142 struct i2c_client *client)143{144 u8 conf, new_conf, sreg, resol;145 146 new_conf = conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);147 /* switch to continuous conversion mode */148 new_conf &= ~DS1621_REG_CONFIG_1SHOT;149 150 /* setup output polarity */151 if (polarity == 0)152 new_conf &= ~DS1621_REG_CONFIG_POLARITY;153 else if (polarity == 1)154 new_conf |= DS1621_REG_CONFIG_POLARITY;155 156 if (conf != new_conf)157 i2c_smbus_write_byte_data(client, DS1621_REG_CONF, new_conf);158 159 switch (data->kind) {160 case ds1625:161 data->update_interval = DS1625_CONVERSION_MAX;162 data->zbits = 7;163 sreg = DS1621_COM_START;164 break;165 case ds1631:166 case ds1721:167 case ds1731:168 resol = (new_conf & DS1621_REG_CONFIG_RESOL) >>169 DS1621_REG_CONFIG_RESOL_SHIFT;170 data->update_interval = ds1721_convrates[resol];171 data->zbits = 7 - resol;172 sreg = DS1721_COM_START;173 break;174 default:175 data->update_interval = DS1621_CONVERSION_MAX;176 data->zbits = 7;177 sreg = DS1621_COM_START;178 break;179 }180 181 /* start conversion */182 i2c_smbus_write_byte(client, sreg);183}184 185static struct ds1621_data *ds1621_update_client(struct device *dev)186{187 struct ds1621_data *data = dev_get_drvdata(dev);188 struct i2c_client *client = data->client;189 u8 new_conf;190 191 mutex_lock(&data->update_lock);192 193 if (time_after(jiffies, data->last_updated + data->update_interval) ||194 !data->valid) {195 int i;196 197 dev_dbg(&client->dev, "Starting ds1621 update\n");198 199 data->conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);200 201 for (i = 0; i < ARRAY_SIZE(data->temp); i++)202 data->temp[i] = i2c_smbus_read_word_swapped(client,203 DS1621_REG_TEMP[i]);204 205 /* reset alarms if necessary */206 new_conf = data->conf;207 if (data->temp[0] > data->temp[1]) /* input > min */208 new_conf &= ~DS1621_ALARM_TEMP_LOW;209 if (data->temp[0] < data->temp[2]) /* input < max */210 new_conf &= ~DS1621_ALARM_TEMP_HIGH;211 if (data->conf != new_conf)212 i2c_smbus_write_byte_data(client, DS1621_REG_CONF,213 new_conf);214 215 data->last_updated = jiffies;216 data->valid = true;217 }218 219 mutex_unlock(&data->update_lock);220 221 return data;222}223 224static ssize_t temp_show(struct device *dev, struct device_attribute *da,225 char *buf)226{227 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);228 struct ds1621_data *data = ds1621_update_client(dev);229 return sprintf(buf, "%d\n",230 DS1621_TEMP_FROM_REG(data->temp[attr->index]));231}232 233static ssize_t temp_store(struct device *dev, struct device_attribute *da,234 const char *buf, size_t count)235{236 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);237 struct ds1621_data *data = dev_get_drvdata(dev);238 long val;239 int err;240 241 err = kstrtol(buf, 10, &val);242 if (err)243 return err;244 245 mutex_lock(&data->update_lock);246 data->temp[attr->index] = DS1621_TEMP_TO_REG(val, data->zbits);247 i2c_smbus_write_word_swapped(data->client, DS1621_REG_TEMP[attr->index],248 data->temp[attr->index]);249 mutex_unlock(&data->update_lock);250 return count;251}252 253static ssize_t alarms_show(struct device *dev, struct device_attribute *da,254 char *buf)255{256 struct ds1621_data *data = ds1621_update_client(dev);257 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf));258}259 260static ssize_t alarm_show(struct device *dev, struct device_attribute *da,261 char *buf)262{263 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);264 struct ds1621_data *data = ds1621_update_client(dev);265 return sprintf(buf, "%d\n", !!(data->conf & attr->index));266}267 268static ssize_t update_interval_show(struct device *dev,269 struct device_attribute *da, char *buf)270{271 struct ds1621_data *data = dev_get_drvdata(dev);272 return sysfs_emit(buf, "%hu\n", data->update_interval);273}274 275static ssize_t update_interval_store(struct device *dev,276 struct device_attribute *da,277 const char *buf, size_t count)278{279 struct ds1621_data *data = dev_get_drvdata(dev);280 struct i2c_client *client = data->client;281 unsigned long convrate;282 s32 err;283 int resol = 0;284 285 err = kstrtoul(buf, 10, &convrate);286 if (err)287 return err;288 289 /* Convert rate into resolution bits */290 while (resol < (ARRAY_SIZE(ds1721_convrates) - 1) &&291 convrate > ds1721_convrates[resol])292 resol++;293 294 mutex_lock(&data->update_lock);295 data->conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);296 data->conf &= ~DS1621_REG_CONFIG_RESOL;297 data->conf |= (resol << DS1621_REG_CONFIG_RESOL_SHIFT);298 i2c_smbus_write_byte_data(client, DS1621_REG_CONF, data->conf);299 data->update_interval = ds1721_convrates[resol];300 data->zbits = 7 - resol;301 mutex_unlock(&data->update_lock);302 303 return count;304}305 306static DEVICE_ATTR_RO(alarms);307static DEVICE_ATTR_RW(update_interval);308 309static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0);310static SENSOR_DEVICE_ATTR_RW(temp1_min, temp, 1);311static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, 2);312static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, alarm, DS1621_ALARM_TEMP_LOW);313static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, DS1621_ALARM_TEMP_HIGH);314 315static struct attribute *ds1621_attributes[] = {316 &sensor_dev_attr_temp1_input.dev_attr.attr,317 &sensor_dev_attr_temp1_min.dev_attr.attr,318 &sensor_dev_attr_temp1_max.dev_attr.attr,319 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,320 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,321 &dev_attr_alarms.attr,322 &dev_attr_update_interval.attr,323 NULL324};325 326static umode_t ds1621_attribute_visible(struct kobject *kobj,327 struct attribute *attr, int index)328{329 struct device *dev = kobj_to_dev(kobj);330 struct ds1621_data *data = dev_get_drvdata(dev);331 332 if (attr == &dev_attr_update_interval.attr)333 if (data->kind == ds1621 || data->kind == ds1625)334 /* shhh, we're hiding update_interval */335 return 0;336 return attr->mode;337}338 339static const struct attribute_group ds1621_group = {340 .attrs = ds1621_attributes,341 .is_visible = ds1621_attribute_visible342};343__ATTRIBUTE_GROUPS(ds1621);344 345static int ds1621_probe(struct i2c_client *client)346{347 struct ds1621_data *data;348 struct device *hwmon_dev;349 350 data = devm_kzalloc(&client->dev, sizeof(struct ds1621_data),351 GFP_KERNEL);352 if (!data)353 return -ENOMEM;354 355 mutex_init(&data->update_lock);356 357 data->kind = (uintptr_t)i2c_get_match_data(client);358 data->client = client;359 360 /* Initialize the DS1621 chip */361 ds1621_init_client(data, client);362 363 hwmon_dev = devm_hwmon_device_register_with_groups(&client->dev,364 client->name, data,365 ds1621_groups);366 return PTR_ERR_OR_ZERO(hwmon_dev);367}368 369static const struct i2c_device_id ds1621_id[] = {370 { "ds1621", ds1621 },371 { "ds1625", ds1625 },372 { "ds1631", ds1631 },373 { "ds1721", ds1721 },374 { "ds1731", ds1731 },375 { }376};377MODULE_DEVICE_TABLE(i2c, ds1621_id);378 379/* This is the driver that will be inserted */380static struct i2c_driver ds1621_driver = {381 .driver = {382 .name = "ds1621",383 },384 .probe = ds1621_probe,385 .id_table = ds1621_id,386};387 388module_i2c_driver(ds1621_driver);389 390MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>");391MODULE_DESCRIPTION("DS1621 driver");392MODULE_LICENSE("GPL");393