/* Texas Instruments TMP102 SMBus temperature sensor driver * * Copyright (C) 2010 Steven King * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #define DRIVER_NAME "tmp102" #define TMP102_TEMP_REG 0x00 #define TMP102_CONF_REG 0x01 /* note: these bit definitions are byte swapped */ #define TMP102_CONF_SD 0x0100 #define TMP102_CONF_TM 0x0200 #define TMP102_CONF_POL 0x0400 #define TMP102_CONF_F0 0x0800 #define TMP102_CONF_F1 0x1000 #define TMP102_CONF_R0 0x2000 #define TMP102_CONF_R1 0x4000 #define TMP102_CONF_OS 0x8000 #define TMP102_CONF_EM 0x0010 #define TMP102_CONF_AL 0x0020 #define TMP102_CONF_CR0 0x0040 #define TMP102_CONF_CR1 0x0080 #define TMP102_TLOW_REG 0x02 #define TMP102_THIGH_REG 0x03 #define TMP102_CONFREG_MASK (TMP102_CONF_SD | TMP102_CONF_TM | \ TMP102_CONF_POL | TMP102_CONF_F0 | \ TMP102_CONF_F1 | TMP102_CONF_OS | \ TMP102_CONF_EM | TMP102_CONF_AL | \ TMP102_CONF_CR0 | TMP102_CONF_CR1) #define TMP102_CONFIG_CLEAR (TMP102_CONF_SD | TMP102_CONF_OS | \ TMP102_CONF_CR0) #define TMP102_CONFIG_SET (TMP102_CONF_TM | TMP102_CONF_EM | \ TMP102_CONF_CR1) #define CONVERSION_TIME_MS 35 /* in milli-seconds */ struct tmp102 { struct regmap *regmap; u16 config_orig; unsigned long ready_time; }; /* convert left adjusted 13-bit TMP102 register value to milliCelsius */ static inline int tmp102_reg_to_mC(s16 val) { return ((val & ~0x01) * 1000) / 128; } /* convert milliCelsius to left adjusted 13-bit TMP102 register value */ static inline u16 tmp102_mC_to_reg(int val) { return (val * 128) / 1000; } static int tmp102_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long *temp) { struct tmp102 *tmp102 = dev_get_drvdata(dev); unsigned int regval; int err, reg; switch (attr) { case hwmon_temp_input: /* Is it too early to return a conversion ? */ if (time_before(jiffies, tmp102->ready_time)) { dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__); return -EAGAIN; } reg = TMP102_TEMP_REG; break; case hwmon_temp_max_hyst: reg = TMP102_TLOW_REG; break; case hwmon_temp_max: reg = TMP102_THIGH_REG; break; default: return -EOPNOTSUPP; } err = regmap_read(tmp102->regmap, reg, ®val); if (err < 0) return err; *temp = tmp102_reg_to_mC(regval); return 0; } static int tmp102_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long temp) { struct tmp102 *tmp102 = dev_get_drvdata(dev); int reg; switch (attr) { case hwmon_temp_max_hyst: reg = TMP102_TLOW_REG; break; case hwmon_temp_max: reg = TMP102_THIGH_REG; break; default: return -EOPNOTSUPP; } temp = clamp_val(temp, -256000, 255000); return regmap_write(tmp102->regmap, reg, tmp102_mC_to_reg(temp)); } static umode_t tmp102_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr, int channel) { if (type != hwmon_temp) return 0; switch (attr) { case hwmon_temp_input: return S_IRUGO; case hwmon_temp_max_hyst: case hwmon_temp_max: return S_IRUGO | S_IWUSR; default: return 0; } } static u32 tmp102_chip_config[] = { HWMON_C_REGISTER_TZ, 0 }; static const struct hwmon_channel_info tmp102_chip = { .type = hwmon_chip, .config = tmp102_chip_config, }; static u32 tmp102_temp_config[] = { HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST, 0 }; static const struct hwmon_channel_info tmp102_temp = { .type = hwmon_temp, .config = tmp102_temp_config, }; static const struct hwmon_channel_info *tmp102_info[] = { &tmp102_chip, &tmp102_temp, NULL }; static const struct hwmon_ops tmp102_hwmon_ops = { .is_visible = tmp102_is_visible, .read = tmp102_read, .write = tmp102_write, }; static const struct hwmon_chip_info tmp102_chip_info = { .ops = &tmp102_hwmon_ops, .info = tmp102_info, }; static void tmp102_restore_config(void *data) { struct tmp102 *tmp102 = data; regmap_write(tmp102->regmap, TMP102_CONF_REG, tmp102->config_orig); } static bool tmp102_is_writeable_reg(struct device *dev, unsigned int reg) { return reg != TMP102_TEMP_REG; } static bool tmp102_is_volatile_reg(struct device *dev, unsigned int reg) { return reg == TMP102_TEMP_REG; } static const struct regmap_config tmp102_regmap_config = { .reg_bits = 8, .val_bits = 16, .max_register = TMP102_THIGH_REG, .writeable_reg = tmp102_is_writeable_reg, .volatile_reg = tmp102_is_volatile_reg, .val_format_endian = REGMAP_ENDIAN_BIG, .cache_type = REGCACHE_RBTREE, .use_single_rw = true, }; static int tmp102_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct device *dev = &client->dev; struct device *hwmon_dev; struct tmp102 *tmp102; unsigned int regval; int err; if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA)) { dev_err(dev, "adapter doesn't support SMBus word transactions\n"); return -ENODEV; } tmp102 = devm_kzalloc(dev, sizeof(*tmp102), GFP_KERNEL); if (!tmp102) return -ENOMEM; i2c_set_clientdata(client, tmp102); tmp102->regmap = devm_regmap_init_i2c(client, &tmp102_regmap_config); if (IS_ERR(tmp102->regmap)) return PTR_ERR(tmp102->regmap); err = regmap_read(tmp102->regmap, TMP102_CONF_REG, ®val); if (err < 0) { dev_err(dev, "error reading config register\n"); return err; } if ((regval & ~TMP102_CONFREG_MASK) != (TMP102_CONF_R0 | TMP102_CONF_R1)) { dev_err(dev, "unexpected config register value\n"); return -ENODEV; } tmp102->config_orig = regval; err = devm_add_action_or_reset(dev, tmp102_restore_config, tmp102); if (err) return err; regval &= ~TMP102_CONFIG_CLEAR; regval |= TMP102_CONFIG_SET; err = regmap_write(tmp102->regmap, TMP102_CONF_REG, regval); if (err < 0) { dev_err(dev, "error writing config register\n"); return err; } tmp102->ready_time = jiffies; if (tmp102->config_orig & TMP102_CONF_SD) { /* * Mark that we are not ready with data until the first * conversion is complete */ tmp102->ready_time += msecs_to_jiffies(CONVERSION_TIME_MS); } hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, tmp102, &tmp102_chip_info, NULL); if (IS_ERR(hwmon_dev)) { dev_dbg(dev, "unable to register hwmon device\n"); return PTR_ERR(hwmon_dev); } dev_info(dev, "initialized\n"); return 0; } #ifdef CONFIG_PM_SLEEP static int tmp102_suspend(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); struct tmp102 *tmp102 = i2c_get_clientdata(client); return regmap_update_bits(tmp102->regmap, TMP102_CONF_REG, TMP102_CONF_SD, TMP102_CONF_SD); } static int tmp102_resume(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); struct tmp102 *tmp102 = i2c_get_clientdata(client); int err; err = regmap_update_bits(tmp102->regmap, TMP102_CONF_REG, TMP102_CONF_SD, 0); tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS); return err; } #endif /* CONFIG_PM */ static SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops, tmp102_suspend, tmp102_resume); static const struct i2c_device_id tmp102_id[] = { { "tmp102", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, tmp102_id); static const struct of_device_id tmp102_of_match[] = { { .compatible = "ti,tmp102" }, { }, }; MODULE_DEVICE_TABLE(of, tmp102_of_match); static struct i2c_driver tmp102_driver = { .driver.name = DRIVER_NAME, .driver.of_match_table = of_match_ptr(tmp102_of_match), .driver.pm = &tmp102_dev_pm_ops, .probe = tmp102_probe, .id_table = tmp102_id, }; module_i2c_driver(tmp102_driver); MODULE_AUTHOR("Steven King "); MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver"); MODULE_LICENSE("GPL");