summaryrefslogtreecommitdiffstats
path: root/drivers/hwmon/tmp102.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/hwmon/tmp102.c')
-rw-r--r--drivers/hwmon/tmp102.c312
1 files changed, 312 insertions, 0 deletions
diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c
new file mode 100644
index 000000000..2bf496a62
--- /dev/null
+++ b/drivers/hwmon/tmp102.c
@@ -0,0 +1,312 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Texas Instruments TMP102 SMBus temperature sensor driver
+ *
+ * Copyright (C) 2010 Steven King <sfking@fdwdc.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/device.h>
+#include <linux/jiffies.h>
+#include <linux/regmap.h>
+#include <linux/of.h>
+
+#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, &regval);
+ 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 0444;
+ case hwmon_temp_max_hyst:
+ case hwmon_temp_max:
+ return 0644;
+ default:
+ return 0;
+ }
+}
+
+static const struct hwmon_channel_info *tmp102_info[] = {
+ HWMON_CHANNEL_INFO(chip,
+ HWMON_C_REGISTER_TZ),
+ HWMON_CHANNEL_INFO(temp,
+ HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST),
+ 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_read = true,
+ .use_single_write = true,
+};
+
+static int tmp102_probe(struct i2c_client *client)
+{
+ 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, &regval);
+ 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;
+ }
+
+ /*
+ * Mark that we are not ready with data until the first
+ * conversion is complete
+ */
+ tmp102->ready_time = jiffies + 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;
+}
+
+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;
+}
+
+static DEFINE_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 __maybe_unused 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 = pm_sleep_ptr(&tmp102_dev_pm_ops),
+ .probe_new = tmp102_probe,
+ .id_table = tmp102_id,
+};
+
+module_i2c_driver(tmp102_driver);
+
+MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
+MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver");
+MODULE_LICENSE("GPL");