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");