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