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1// SPDX-License-Identifier: GPL-2.0-or-later2/* Texas Instruments TMP102 SMBus temperature sensor driver3 *4 * Copyright (C) 2010 Steven King <sfking@fdwdc.com>5 */6 7#include <linux/delay.h>8#include <linux/module.h>9#include <linux/init.h>10#include <linux/slab.h>11#include <linux/i2c.h>12#include <linux/hwmon.h>13#include <linux/hwmon-sysfs.h>14#include <linux/err.h>15#include <linux/mutex.h>16#include <linux/device.h>17#include <linux/jiffies.h>18#include <linux/regmap.h>19#include <linux/of.h>20 21#define DRIVER_NAME "tmp102"22 23#define TMP102_TEMP_REG 0x0024#define TMP102_CONF_REG 0x0125/* note: these bit definitions are byte swapped */26#define TMP102_CONF_SD 0x010027#define TMP102_CONF_TM 0x020028#define TMP102_CONF_POL 0x040029#define TMP102_CONF_F0 0x080030#define TMP102_CONF_F1 0x100031#define TMP102_CONF_R0 0x200032#define TMP102_CONF_R1 0x400033#define TMP102_CONF_OS 0x800034#define TMP102_CONF_EM 0x001035#define TMP102_CONF_AL 0x002036#define TMP102_CONF_CR0 0x004037#define TMP102_CONF_CR1 0x008038#define TMP102_TLOW_REG 0x0239#define TMP102_THIGH_REG 0x0340 41#define TMP102_CONFREG_MASK (TMP102_CONF_SD | TMP102_CONF_TM | \42 TMP102_CONF_POL | TMP102_CONF_F0 | \43 TMP102_CONF_F1 | TMP102_CONF_OS | \44 TMP102_CONF_EM | TMP102_CONF_AL | \45 TMP102_CONF_CR0 | TMP102_CONF_CR1)46 47#define TMP102_CONFIG_CLEAR (TMP102_CONF_SD | TMP102_CONF_OS | \48 TMP102_CONF_CR0)49#define TMP102_CONFIG_SET (TMP102_CONF_TM | TMP102_CONF_EM | \50 TMP102_CONF_CR1)51 52#define CONVERSION_TIME_MS 35 /* in milli-seconds */53 54struct tmp102 {55 struct regmap *regmap;56 u16 config_orig;57 unsigned long ready_time;58};59 60/* convert left adjusted 13-bit TMP102 register value to milliCelsius */61static inline int tmp102_reg_to_mC(s16 val)62{63 return ((val & ~0x01) * 1000) / 128;64}65 66/* convert milliCelsius to left adjusted 13-bit TMP102 register value */67static inline u16 tmp102_mC_to_reg(int val)68{69 return (val * 128) / 1000;70}71 72static int tmp102_read(struct device *dev, enum hwmon_sensor_types type,73 u32 attr, int channel, long *temp)74{75 struct tmp102 *tmp102 = dev_get_drvdata(dev);76 unsigned int regval;77 int err, reg;78 79 switch (attr) {80 case hwmon_temp_input:81 /* Is it too early to return a conversion ? */82 if (time_before(jiffies, tmp102->ready_time)) {83 dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__);84 return -EAGAIN;85 }86 reg = TMP102_TEMP_REG;87 break;88 case hwmon_temp_max_hyst:89 reg = TMP102_TLOW_REG;90 break;91 case hwmon_temp_max:92 reg = TMP102_THIGH_REG;93 break;94 default:95 return -EOPNOTSUPP;96 }97 98 err = regmap_read(tmp102->regmap, reg, ®val);99 if (err < 0)100 return err;101 *temp = tmp102_reg_to_mC(regval);102 103 return 0;104}105 106static int tmp102_write(struct device *dev, enum hwmon_sensor_types type,107 u32 attr, int channel, long temp)108{109 struct tmp102 *tmp102 = dev_get_drvdata(dev);110 int reg;111 112 switch (attr) {113 case hwmon_temp_max_hyst:114 reg = TMP102_TLOW_REG;115 break;116 case hwmon_temp_max:117 reg = TMP102_THIGH_REG;118 break;119 default:120 return -EOPNOTSUPP;121 }122 123 temp = clamp_val(temp, -256000, 255000);124 return regmap_write(tmp102->regmap, reg, tmp102_mC_to_reg(temp));125}126 127static umode_t tmp102_is_visible(const void *data, enum hwmon_sensor_types type,128 u32 attr, int channel)129{130 if (type != hwmon_temp)131 return 0;132 133 switch (attr) {134 case hwmon_temp_input:135 return 0444;136 case hwmon_temp_max_hyst:137 case hwmon_temp_max:138 return 0644;139 default:140 return 0;141 }142}143 144static const struct hwmon_channel_info * const tmp102_info[] = {145 HWMON_CHANNEL_INFO(chip,146 HWMON_C_REGISTER_TZ),147 HWMON_CHANNEL_INFO(temp,148 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST),149 NULL150};151 152static const struct hwmon_ops tmp102_hwmon_ops = {153 .is_visible = tmp102_is_visible,154 .read = tmp102_read,155 .write = tmp102_write,156};157 158static const struct hwmon_chip_info tmp102_chip_info = {159 .ops = &tmp102_hwmon_ops,160 .info = tmp102_info,161};162 163static void tmp102_restore_config(void *data)164{165 struct tmp102 *tmp102 = data;166 167 regmap_write(tmp102->regmap, TMP102_CONF_REG, tmp102->config_orig);168}169 170static bool tmp102_is_writeable_reg(struct device *dev, unsigned int reg)171{172 return reg != TMP102_TEMP_REG;173}174 175static bool tmp102_is_volatile_reg(struct device *dev, unsigned int reg)176{177 return reg == TMP102_TEMP_REG;178}179 180static const struct regmap_config tmp102_regmap_config = {181 .reg_bits = 8,182 .val_bits = 16,183 .max_register = TMP102_THIGH_REG,184 .writeable_reg = tmp102_is_writeable_reg,185 .volatile_reg = tmp102_is_volatile_reg,186 .val_format_endian = REGMAP_ENDIAN_BIG,187 .cache_type = REGCACHE_MAPLE,188 .use_single_read = true,189 .use_single_write = true,190};191 192static int tmp102_probe(struct i2c_client *client)193{194 struct device *dev = &client->dev;195 struct device *hwmon_dev;196 struct tmp102 *tmp102;197 unsigned int regval;198 int err;199 200 if (!i2c_check_functionality(client->adapter,201 I2C_FUNC_SMBUS_WORD_DATA)) {202 dev_err(dev,203 "adapter doesn't support SMBus word transactions\n");204 return -ENODEV;205 }206 207 tmp102 = devm_kzalloc(dev, sizeof(*tmp102), GFP_KERNEL);208 if (!tmp102)209 return -ENOMEM;210 211 i2c_set_clientdata(client, tmp102);212 213 tmp102->regmap = devm_regmap_init_i2c(client, &tmp102_regmap_config);214 if (IS_ERR(tmp102->regmap))215 return PTR_ERR(tmp102->regmap);216 217 err = regmap_read(tmp102->regmap, TMP102_CONF_REG, ®val);218 if (err < 0) {219 dev_err(dev, "error reading config register\n");220 return err;221 }222 223 if ((regval & ~TMP102_CONFREG_MASK) !=224 (TMP102_CONF_R0 | TMP102_CONF_R1)) {225 dev_err(dev, "unexpected config register value\n");226 return -ENODEV;227 }228 229 tmp102->config_orig = regval;230 231 err = devm_add_action_or_reset(dev, tmp102_restore_config, tmp102);232 if (err)233 return err;234 235 regval &= ~TMP102_CONFIG_CLEAR;236 regval |= TMP102_CONFIG_SET;237 238 err = regmap_write(tmp102->regmap, TMP102_CONF_REG, regval);239 if (err < 0) {240 dev_err(dev, "error writing config register\n");241 return err;242 }243 244 /*245 * Mark that we are not ready with data until the first246 * conversion is complete247 */248 tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS);249 250 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,251 tmp102,252 &tmp102_chip_info,253 NULL);254 if (IS_ERR(hwmon_dev)) {255 dev_dbg(dev, "unable to register hwmon device\n");256 return PTR_ERR(hwmon_dev);257 }258 dev_info(dev, "initialized\n");259 260 return 0;261}262 263static int tmp102_suspend(struct device *dev)264{265 struct i2c_client *client = to_i2c_client(dev);266 struct tmp102 *tmp102 = i2c_get_clientdata(client);267 268 return regmap_update_bits(tmp102->regmap, TMP102_CONF_REG,269 TMP102_CONF_SD, TMP102_CONF_SD);270}271 272static int tmp102_resume(struct device *dev)273{274 struct i2c_client *client = to_i2c_client(dev);275 struct tmp102 *tmp102 = i2c_get_clientdata(client);276 int err;277 278 err = regmap_update_bits(tmp102->regmap, TMP102_CONF_REG,279 TMP102_CONF_SD, 0);280 281 tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS);282 283 return err;284}285 286static DEFINE_SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops, tmp102_suspend, tmp102_resume);287 288static const struct i2c_device_id tmp102_id[] = {289 { "tmp102" },290 { }291};292MODULE_DEVICE_TABLE(i2c, tmp102_id);293 294static const struct of_device_id __maybe_unused tmp102_of_match[] = {295 { .compatible = "ti,tmp102" },296 { },297};298MODULE_DEVICE_TABLE(of, tmp102_of_match);299 300static struct i2c_driver tmp102_driver = {301 .driver.name = DRIVER_NAME,302 .driver.of_match_table = of_match_ptr(tmp102_of_match),303 .driver.pm = pm_sleep_ptr(&tmp102_dev_pm_ops),304 .probe = tmp102_probe,305 .id_table = tmp102_id,306};307 308module_i2c_driver(tmp102_driver);309 310MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");311MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver");312MODULE_LICENSE("GPL");313