hwmon: Driver for TI TMP103 temperature sensor

Driver for the TI TMP103.

The TI TMP103 is similar to the TMP102. It differs from the TMP102
by having only 8 bit registers.

Signed-off-by: Heiko Schocher <[e-mail]>
[[e-mail]: Select REGMAP_I2C in Kconfig]
Signed-off-by: Guenter Roeck <[e-mail]>

Documentation/devicetree/bindings/i2c/trivial-devices.txt

···
 taos,tsl2550		Ambient Light Sensor with SMBUS/Two Wire Serial Interface
 ti,tsc2003		I2C Touch-Screen Controller
 ti,tmp102		Low Power Digital Temperature Sensor with SMBUS/Two Wire Serial Interface
+ti,tmp103		Low Power Digital Temperature Sensor with SMBUS/Two Wire Serial Interface
 ti,tmp275		Digital Temperature Sensor
 winbond,wpct301		i2c trusted platform module (TPM)

Documentation/hwmon/tmp103

···
+Kernel driver tmp103
+====================
+
+Supported chips:
+  * Texas Instruments TMP103
+    Prefix: 'tmp103'
+    Addresses scanned: none
+    Product info and datasheet: http://www.ti.com/product/tmp103
+
+Author:
+	Heiko Schocher <[e-mail]>
+
+Description
+-----------
+
+The TMP103 is a digital output temperature sensor in a four-ball
+wafer chip-scale package (WCSP). The TMP103 is capable of reading
+temperatures to a resolution of 1°C. The TMP103 is specified for
+operation over a temperature range of –40°C to +125°C.
+
+Resolution: 8 Bits
+Accuracy: ±1°C Typ (–10°C to +100°C)
+
+The driver provides the common sysfs-interface for temperatures (see
+Documentation/hwmon/sysfs-interface under Temperatures).
+
+Please refer how to instantiate this driver:
+Documentation/i2c/instantiating-devices

drivers/hwmon/Kconfig

···
 	  This driver can also be built as a module.  If so, the module
 	  will be called tmp102.
 
+config SENSORS_TMP103
+	tristate "Texas Instruments TMP103"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  If you say yes here you get support for Texas Instruments TMP103
+	  sensor chips.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called tmp103.
+
 config SENSORS_TMP401
 	tristate "Texas Instruments TMP401 and compatibles"
 	depends on I2C

drivers/hwmon/Makefile

···
 obj-$(CONFIG_SENSORS_AMC6821)	+= amc6821.o
 obj-$(CONFIG_SENSORS_THMC50)	+= thmc50.o
 obj-$(CONFIG_SENSORS_TMP102)	+= tmp102.o
+obj-$(CONFIG_SENSORS_TMP103)	+= tmp103.o
 obj-$(CONFIG_SENSORS_TMP401)	+= tmp401.o
 obj-$(CONFIG_SENSORS_TMP421)	+= tmp421.o
 obj-$(CONFIG_SENSORS_TWL4030_MADC)+= twl4030-madc-hwmon.o

drivers/hwmon/tmp103.c

···
+/*
+ * Texas Instruments TMP103 SMBus temperature sensor driver
+ * Copyright (C) 2014 Heiko Schocher <[e-mail]>
+ *
+ * Based on:
+ * Texas Instruments TMP102 SMBus temperature sensor driver
+ *
+ * Copyright (C) 2010 Steven King <[e-mail]>
+ *
+ * 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/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>
+
+#define TMP103_TEMP_REG		0x00
+#define TMP103_CONF_REG		0x01
+#define TMP103_TLOW_REG		0x02
+#define TMP103_THIGH_REG	0x03
+
+#define TMP103_CONF_M0		0x01
+#define TMP103_CONF_M1		0x02
+#define TMP103_CONF_LC		0x04
+#define TMP103_CONF_FL		0x08
+#define TMP103_CONF_FH		0x10
+#define TMP103_CONF_CR0		0x20
+#define TMP103_CONF_CR1		0x40
+#define TMP103_CONF_ID		0x80
+#define TMP103_CONF_SD		(TMP103_CONF_M1)
+#define TMP103_CONF_SD_MASK	(TMP103_CONF_M0 | TMP103_CONF_M1)
+
+#define TMP103_CONFIG		(TMP103_CONF_CR1 | TMP103_CONF_M1)
+#define TMP103_CONFIG_MASK	(TMP103_CONF_CR0 | TMP103_CONF_CR1 | \
+				 TMP103_CONF_M0 | TMP103_CONF_M1)
+
+static inline int tmp103_reg_to_mc(s8 val)
+{
+	return val * 1000;
+}
+
+static inline u8 tmp103_mc_to_reg(int val)
+{
+	return DIV_ROUND_CLOSEST(val, 1000);
+}
+
+static ssize_t tmp103_show_temp(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
+	struct regmap *regmap = dev_get_drvdata(dev);
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(regmap, sda->index, &regval);
+	if (ret < 0)
+		return ret;
+
+	return sprintf(buf, "%d\n", tmp103_reg_to_mc(regval));
+}
+
+static ssize_t tmp103_set_temp(struct device *dev,
+			       struct device_attribute *attr,
+			       const char *buf, size_t count)
+{
+	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
+	struct regmap *regmap = dev_get_drvdata(dev);
+	long val;
+	int ret;
+
+	if (kstrtol(buf, 10, &val) < 0)
+		return -EINVAL;
+
+	val = clamp_val(val, -55000, 127000);
+	ret = regmap_write(regmap, sda->index, tmp103_mc_to_reg(val));
+	return ret ? ret : count;
+}
+
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp103_show_temp, NULL ,
+			  TMP103_TEMP_REG);
+
+static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, tmp103_show_temp,
+			  tmp103_set_temp, TMP103_TLOW_REG);
+
+static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp103_show_temp,
+			  tmp103_set_temp, TMP103_THIGH_REG);
+
+static struct attribute *tmp103_attrs[] = {
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	&sensor_dev_attr_temp1_min.dev_attr.attr,
+	&sensor_dev_attr_temp1_max.dev_attr.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(tmp103);
+
+static bool tmp103_regmap_is_volatile(struct device *dev, unsigned int reg)
+{
+	return reg == TMP103_TEMP_REG;
+}
+
+static struct regmap_config tmp103_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = TMP103_THIGH_REG,
+	.volatile_reg = tmp103_regmap_is_volatile,
+};
+
+static int tmp103_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	struct device *hwmon_dev;
+	struct regmap *regmap;
+	int ret;
+
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_BYTE_DATA)) {
+		dev_err(&client->dev,
+			"adapter doesn't support SMBus byte transactions\n");
+		return -ENODEV;
+	}
+
+	regmap = devm_regmap_init_i2c(client, &tmp103_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(dev, "failed to allocate register map\n");
+		return PTR_ERR(regmap);
+	}
+
+	ret = regmap_update_bits(regmap, TMP103_CONF_REG, TMP103_CONFIG_MASK,
+				 TMP103_CONFIG);
+	if (ret < 0) {
+		dev_err(&client->dev, "error writing config register\n");
+		return ret;
+	}
+
+	hwmon_dev = hwmon_device_register_with_groups(dev, client->name,
+						      regmap, tmp103_groups);
+	return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+#ifdef CONFIG_PM
+static int tmp103_suspend(struct device *dev)
+{
+	struct regmap *regmap = dev_get_drvdata(dev);
+
+	return regmap_update_bits(regmap, TMP103_CONF_REG,
+				  TMP103_CONF_SD_MASK, 0);
+}
+
+static int tmp103_resume(struct device *dev)
+{
+	struct regmap *regmap = dev_get_drvdata(dev);
+
+	return regmap_update_bits(regmap, TMP103_CONF_REG,
+				  TMP103_CONF_SD_MASK, TMP103_CONF_SD);
+}
+
+static const struct dev_pm_ops tmp103_dev_pm_ops = {
+	.suspend	= tmp103_suspend,
+	.resume		= tmp103_resume,
+};
+
+#define TMP103_DEV_PM_OPS (&tmp103_dev_pm_ops)
+#else
+#define	TMP103_DEV_PM_OPS NULL
+#endif /* CONFIG_PM */
+
+static const struct i2c_device_id tmp103_id[] = {
+	{ "tmp103", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, tmp103_id);
+
+static struct i2c_driver tmp103_driver = {
+	.driver = {
+		.name	= "tmp103",
+		.pm	= TMP103_DEV_PM_OPS,
+	},
+	.probe		= tmp103_probe,
+	.id_table	= tmp103_id,
+};
+
+module_i2c_driver(tmp103_driver);
+
+MODULE_AUTHOR("Heiko Schocher <[e-mail]>");
+MODULE_DESCRIPTION("Texas Instruments TMP103 temperature sensor driver");
+MODULE_LICENSE("GPL");