--- /dev/null
+/* Texas Instruments TMP108 SMBus temperature sensor driver
+ *
+ * Copyright (C) 2016 John Muir <john@jmuir.com>
+ *
+ * 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 <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 u32 tmp108_chip_config[] = {
+ HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL,
+ 0
+};
+
+static const struct hwmon_channel_info tmp108_chip = {
+ .type = hwmon_chip,
+ .config = tmp108_chip_config,
+};
+
+static u32 tmp108_temp_config[] = {
+ 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,
+ 0
+};
+
+static const struct hwmon_channel_info tmp108_temp = {
+ .type = hwmon_temp,
+ .config = tmp108_temp_config,
+};
+
+static const struct hwmon_channel_info *tmp108_info[] = {
+ &tmp108_chip,
+ &tmp108_temp,
+ 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_rw = true,
+};
+
+static int tmp108_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ 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 __maybe_unused 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 __maybe_unused 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 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 = &tmp108_dev_pm_ops,
+ .of_match_table = of_match_ptr(tmp108_of_ids),
+ },
+ .probe = tmp108_probe,
+ .id_table = tmp108_i2c_ids,
+};
+
+module_i2c_driver(tmp108_driver);
+
+MODULE_AUTHOR("John Muir <john@jmuir.com>");
+MODULE_DESCRIPTION("Texas Instruments TMP108 temperature sensor driver");
+MODULE_LICENSE("GPL");
projects / linux-beck.git / commitdiff