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- // SPDX-License-Identifier: GPL-2.0-or-later
- /* Texas Instruments TMP108 SMBus temperature sensor driver
- *
- * Copyright (C) 2016 John Muir <[email protected]>
- */
- #include <linux/delay.h>
- #include <linux/device.h>
- #include <linux/err.h>
- #include <linux/hwmon.h>
- #include <linux/hwmon-sysfs.h>
- #include <linux/module.h>
- #include <linux/mutex.h>
- #include <linux/of.h>
- #include <linux/i2c.h>
- #include <linux/init.h>
- #include <linux/jiffies.h>
- #include <linux/regmap.h>
- #include <linux/slab.h>
- #define DRIVER_NAME "tmp108"
- #define TMP108_REG_TEMP 0x00
- #define TMP108_REG_CONF 0x01
- #define TMP108_REG_TLOW 0x02
- #define TMP108_REG_THIGH 0x03
- #define TMP108_TEMP_MIN_MC -50000 /* Minimum millicelcius. */
- #define TMP108_TEMP_MAX_MC 127937 /* Maximum millicelcius. */
- /* Configuration register bits.
- * Note: these bit definitions are byte swapped.
- */
- #define TMP108_CONF_M0 0x0100 /* Sensor mode. */
- #define TMP108_CONF_M1 0x0200
- #define TMP108_CONF_TM 0x0400 /* Thermostat mode. */
- #define TMP108_CONF_FL 0x0800 /* Watchdog flag - TLOW */
- #define TMP108_CONF_FH 0x1000 /* Watchdog flag - THIGH */
- #define TMP108_CONF_CR0 0x2000 /* Conversion rate. */
- #define TMP108_CONF_CR1 0x4000
- #define TMP108_CONF_ID 0x8000
- #define TMP108_CONF_HYS0 0x0010 /* Hysteresis. */
- #define TMP108_CONF_HYS1 0x0020
- #define TMP108_CONF_POL 0x0080 /* Polarity of alert. */
- /* Defaults set by the hardware upon reset. */
- #define TMP108_CONF_DEFAULTS (TMP108_CONF_CR0 | TMP108_CONF_TM |\
- TMP108_CONF_HYS0 | TMP108_CONF_M1)
- /* These bits are read-only. */
- #define TMP108_CONF_READ_ONLY (TMP108_CONF_FL | TMP108_CONF_FH |\
- TMP108_CONF_ID)
- #define TMP108_CONF_MODE_MASK (TMP108_CONF_M0|TMP108_CONF_M1)
- #define TMP108_MODE_SHUTDOWN 0x0000
- #define TMP108_MODE_ONE_SHOT TMP108_CONF_M0
- #define TMP108_MODE_CONTINUOUS TMP108_CONF_M1 /* Default */
- /* When M1 is set, M0 is ignored. */
- #define TMP108_CONF_CONVRATE_MASK (TMP108_CONF_CR0|TMP108_CONF_CR1)
- #define TMP108_CONVRATE_0P25HZ 0x0000
- #define TMP108_CONVRATE_1HZ TMP108_CONF_CR0 /* Default */
- #define TMP108_CONVRATE_4HZ TMP108_CONF_CR1
- #define TMP108_CONVRATE_16HZ (TMP108_CONF_CR0|TMP108_CONF_CR1)
- #define TMP108_CONF_HYSTERESIS_MASK (TMP108_CONF_HYS0|TMP108_CONF_HYS1)
- #define TMP108_HYSTERESIS_0C 0x0000
- #define TMP108_HYSTERESIS_1C TMP108_CONF_HYS0 /* Default */
- #define TMP108_HYSTERESIS_2C TMP108_CONF_HYS1
- #define TMP108_HYSTERESIS_4C (TMP108_CONF_HYS0|TMP108_CONF_HYS1)
- #define TMP108_CONVERSION_TIME_MS 30 /* in milli-seconds */
- struct tmp108 {
- struct regmap *regmap;
- u16 orig_config;
- unsigned long ready_time;
- };
- /* convert 12-bit TMP108 register value to milliCelsius */
- static inline int tmp108_temp_reg_to_mC(s16 val)
- {
- return (val & ~0x0f) * 1000 / 256;
- }
- /* convert milliCelsius to left adjusted 12-bit TMP108 register value */
- static inline u16 tmp108_mC_to_temp_reg(int val)
- {
- return (val * 256) / 1000;
- }
- static int tmp108_read(struct device *dev, enum hwmon_sensor_types type,
- u32 attr, int channel, long *temp)
- {
- struct tmp108 *tmp108 = dev_get_drvdata(dev);
- unsigned int regval;
- int err, hyst;
- if (type == hwmon_chip) {
- if (attr == hwmon_chip_update_interval) {
- err = regmap_read(tmp108->regmap, TMP108_REG_CONF,
- ®val);
- if (err < 0)
- return err;
- switch (regval & TMP108_CONF_CONVRATE_MASK) {
- case TMP108_CONVRATE_0P25HZ:
- default:
- *temp = 4000;
- break;
- case TMP108_CONVRATE_1HZ:
- *temp = 1000;
- break;
- case TMP108_CONVRATE_4HZ:
- *temp = 250;
- break;
- case TMP108_CONVRATE_16HZ:
- *temp = 63;
- break;
- }
- return 0;
- }
- return -EOPNOTSUPP;
- }
- switch (attr) {
- case hwmon_temp_input:
- /* Is it too early to return a conversion ? */
- if (time_before(jiffies, tmp108->ready_time)) {
- dev_dbg(dev, "%s: Conversion not ready yet..\n",
- __func__);
- return -EAGAIN;
- }
- err = regmap_read(tmp108->regmap, TMP108_REG_TEMP, ®val);
- if (err < 0)
- return err;
- *temp = tmp108_temp_reg_to_mC(regval);
- break;
- case hwmon_temp_min:
- case hwmon_temp_max:
- err = regmap_read(tmp108->regmap, attr == hwmon_temp_min ?
- TMP108_REG_TLOW : TMP108_REG_THIGH, ®val);
- if (err < 0)
- return err;
- *temp = tmp108_temp_reg_to_mC(regval);
- break;
- case hwmon_temp_min_alarm:
- case hwmon_temp_max_alarm:
- err = regmap_read(tmp108->regmap, TMP108_REG_CONF, ®val);
- if (err < 0)
- return err;
- *temp = !!(regval & (attr == hwmon_temp_min_alarm ?
- TMP108_CONF_FL : TMP108_CONF_FH));
- break;
- case hwmon_temp_min_hyst:
- case hwmon_temp_max_hyst:
- err = regmap_read(tmp108->regmap, TMP108_REG_CONF, ®val);
- if (err < 0)
- return err;
- switch (regval & TMP108_CONF_HYSTERESIS_MASK) {
- case TMP108_HYSTERESIS_0C:
- default:
- hyst = 0;
- break;
- case TMP108_HYSTERESIS_1C:
- hyst = 1000;
- break;
- case TMP108_HYSTERESIS_2C:
- hyst = 2000;
- break;
- case TMP108_HYSTERESIS_4C:
- hyst = 4000;
- break;
- }
- err = regmap_read(tmp108->regmap, attr == hwmon_temp_min_hyst ?
- TMP108_REG_TLOW : TMP108_REG_THIGH, ®val);
- if (err < 0)
- return err;
- *temp = tmp108_temp_reg_to_mC(regval);
- if (attr == hwmon_temp_min_hyst)
- *temp += hyst;
- else
- *temp -= hyst;
- break;
- default:
- return -EOPNOTSUPP;
- }
- return 0;
- }
- static int tmp108_write(struct device *dev, enum hwmon_sensor_types type,
- u32 attr, int channel, long temp)
- {
- struct tmp108 *tmp108 = dev_get_drvdata(dev);
- u32 regval, mask;
- int err;
- if (type == hwmon_chip) {
- if (attr == hwmon_chip_update_interval) {
- if (temp < 156)
- mask = TMP108_CONVRATE_16HZ;
- else if (temp < 625)
- mask = TMP108_CONVRATE_4HZ;
- else if (temp < 2500)
- mask = TMP108_CONVRATE_1HZ;
- else
- mask = TMP108_CONVRATE_0P25HZ;
- return regmap_update_bits(tmp108->regmap,
- TMP108_REG_CONF,
- TMP108_CONF_CONVRATE_MASK,
- mask);
- }
- return -EOPNOTSUPP;
- }
- switch (attr) {
- case hwmon_temp_min:
- case hwmon_temp_max:
- temp = clamp_val(temp, TMP108_TEMP_MIN_MC, TMP108_TEMP_MAX_MC);
- return regmap_write(tmp108->regmap,
- attr == hwmon_temp_min ?
- TMP108_REG_TLOW : TMP108_REG_THIGH,
- tmp108_mC_to_temp_reg(temp));
- case hwmon_temp_min_hyst:
- case hwmon_temp_max_hyst:
- temp = clamp_val(temp, TMP108_TEMP_MIN_MC, TMP108_TEMP_MAX_MC);
- err = regmap_read(tmp108->regmap,
- attr == hwmon_temp_min_hyst ?
- TMP108_REG_TLOW : TMP108_REG_THIGH,
- ®val);
- if (err < 0)
- return err;
- if (attr == hwmon_temp_min_hyst)
- temp -= tmp108_temp_reg_to_mC(regval);
- else
- temp = tmp108_temp_reg_to_mC(regval) - temp;
- if (temp < 500)
- mask = TMP108_HYSTERESIS_0C;
- else if (temp < 1500)
- mask = TMP108_HYSTERESIS_1C;
- else if (temp < 3000)
- mask = TMP108_HYSTERESIS_2C;
- else
- mask = TMP108_HYSTERESIS_4C;
- return regmap_update_bits(tmp108->regmap, TMP108_REG_CONF,
- TMP108_CONF_HYSTERESIS_MASK, mask);
- default:
- return -EOPNOTSUPP;
- }
- }
- static umode_t tmp108_is_visible(const void *data, enum hwmon_sensor_types type,
- u32 attr, int channel)
- {
- if (type == hwmon_chip && attr == hwmon_chip_update_interval)
- return 0644;
- if (type != hwmon_temp)
- return 0;
- switch (attr) {
- case hwmon_temp_input:
- case hwmon_temp_min_alarm:
- case hwmon_temp_max_alarm:
- return 0444;
- case hwmon_temp_min:
- case hwmon_temp_max:
- case hwmon_temp_min_hyst:
- case hwmon_temp_max_hyst:
- return 0644;
- default:
- return 0;
- }
- }
- static const struct hwmon_channel_info *tmp108_info[] = {
- HWMON_CHANNEL_INFO(chip,
- HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL),
- HWMON_CHANNEL_INFO(temp,
- HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
- HWMON_T_MIN_HYST | HWMON_T_MAX_HYST |
- HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM),
- NULL
- };
- static const struct hwmon_ops tmp108_hwmon_ops = {
- .is_visible = tmp108_is_visible,
- .read = tmp108_read,
- .write = tmp108_write,
- };
- static const struct hwmon_chip_info tmp108_chip_info = {
- .ops = &tmp108_hwmon_ops,
- .info = tmp108_info,
- };
- static void tmp108_restore_config(void *data)
- {
- struct tmp108 *tmp108 = data;
- regmap_write(tmp108->regmap, TMP108_REG_CONF, tmp108->orig_config);
- }
- static bool tmp108_is_writeable_reg(struct device *dev, unsigned int reg)
- {
- return reg != TMP108_REG_TEMP;
- }
- static bool tmp108_is_volatile_reg(struct device *dev, unsigned int reg)
- {
- /* Configuration register must be volatile to enable FL and FH. */
- return reg == TMP108_REG_TEMP || reg == TMP108_REG_CONF;
- }
- static const struct regmap_config tmp108_regmap_config = {
- .reg_bits = 8,
- .val_bits = 16,
- .max_register = TMP108_REG_THIGH,
- .writeable_reg = tmp108_is_writeable_reg,
- .volatile_reg = tmp108_is_volatile_reg,
- .val_format_endian = REGMAP_ENDIAN_BIG,
- .cache_type = REGCACHE_RBTREE,
- .use_single_read = true,
- .use_single_write = true,
- };
- static int tmp108_probe(struct i2c_client *client)
- {
- struct device *dev = &client->dev;
- struct device *hwmon_dev;
- struct tmp108 *tmp108;
- int err;
- u32 config;
- if (!i2c_check_functionality(client->adapter,
- I2C_FUNC_SMBUS_WORD_DATA)) {
- dev_err(dev,
- "adapter doesn't support SMBus word transactions\n");
- return -ENODEV;
- }
- tmp108 = devm_kzalloc(dev, sizeof(*tmp108), GFP_KERNEL);
- if (!tmp108)
- return -ENOMEM;
- dev_set_drvdata(dev, tmp108);
- tmp108->regmap = devm_regmap_init_i2c(client, &tmp108_regmap_config);
- if (IS_ERR(tmp108->regmap)) {
- err = PTR_ERR(tmp108->regmap);
- dev_err(dev, "regmap init failed: %d", err);
- return err;
- }
- err = regmap_read(tmp108->regmap, TMP108_REG_CONF, &config);
- if (err < 0) {
- dev_err(dev, "error reading config register: %d", err);
- return err;
- }
- tmp108->orig_config = config;
- /* Only continuous mode is supported. */
- config &= ~TMP108_CONF_MODE_MASK;
- config |= TMP108_MODE_CONTINUOUS;
- /* Only comparator mode is supported. */
- config &= ~TMP108_CONF_TM;
- err = regmap_write(tmp108->regmap, TMP108_REG_CONF, config);
- if (err < 0) {
- dev_err(dev, "error writing config register: %d", err);
- return err;
- }
- tmp108->ready_time = jiffies;
- if ((tmp108->orig_config & TMP108_CONF_MODE_MASK) ==
- TMP108_MODE_SHUTDOWN)
- tmp108->ready_time +=
- msecs_to_jiffies(TMP108_CONVERSION_TIME_MS);
- err = devm_add_action_or_reset(dev, tmp108_restore_config, tmp108);
- if (err) {
- dev_err(dev, "add action or reset failed: %d", err);
- return err;
- }
- hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
- tmp108,
- &tmp108_chip_info,
- NULL);
- return PTR_ERR_OR_ZERO(hwmon_dev);
- }
- static int tmp108_suspend(struct device *dev)
- {
- struct tmp108 *tmp108 = dev_get_drvdata(dev);
- return regmap_update_bits(tmp108->regmap, TMP108_REG_CONF,
- TMP108_CONF_MODE_MASK, TMP108_MODE_SHUTDOWN);
- }
- static int tmp108_resume(struct device *dev)
- {
- struct tmp108 *tmp108 = dev_get_drvdata(dev);
- int err;
- err = regmap_update_bits(tmp108->regmap, TMP108_REG_CONF,
- TMP108_CONF_MODE_MASK, TMP108_MODE_CONTINUOUS);
- tmp108->ready_time = jiffies +
- msecs_to_jiffies(TMP108_CONVERSION_TIME_MS);
- return err;
- }
- static DEFINE_SIMPLE_DEV_PM_OPS(tmp108_dev_pm_ops, tmp108_suspend, tmp108_resume);
- static const struct i2c_device_id tmp108_i2c_ids[] = {
- { "tmp108", 0 },
- { }
- };
- MODULE_DEVICE_TABLE(i2c, tmp108_i2c_ids);
- #ifdef CONFIG_OF
- static const struct of_device_id tmp108_of_ids[] = {
- { .compatible = "ti,tmp108", },
- {}
- };
- MODULE_DEVICE_TABLE(of, tmp108_of_ids);
- #endif
- static struct i2c_driver tmp108_driver = {
- .driver = {
- .name = DRIVER_NAME,
- .pm = pm_sleep_ptr(&tmp108_dev_pm_ops),
- .of_match_table = of_match_ptr(tmp108_of_ids),
- },
- .probe_new = tmp108_probe,
- .id_table = tmp108_i2c_ids,
- };
- module_i2c_driver(tmp108_driver);
- MODULE_AUTHOR("John Muir <[email protected]>");
- MODULE_DESCRIPTION("Texas Instruments TMP108 temperature sensor driver");
- MODULE_LICENSE("GPL");
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