[RFC] [PATCH] TMP105 : Driver support for the temperature sensor

[Datta, Shubhrajyoti]

Adds the driver support for the TMP105 temperature sensor device. The interface is I2C.The driver supports the read of the temperature values.

Signed-off-by: Shubhrajyoti D <shubhrajyoti@xxxxxx>
---
 drivers/hwmon/Kconfig  |   10 ++
 drivers/hwmon/Makefile |    1 +
 drivers/hwmon/tmp105.c |  326 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 337 insertions(+), 0 deletions(-)
 create mode 100644 drivers/hwmon/tmp105.c

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 68cf877..a4a5352 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1076,6 +1076,16 @@ config SENSORS_MC13783_ADC
         help
           Support for the A/D converter on MC13783 PMIC.
 
+config SENSORS_TMP105
+	tristate "Texas Instruments TMP421 and compatible"
+	depends on I2C
+	help
+	  If you say yes here you get support for Texas Instruments TMP105
+	  temperature sensor chips.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called tmp105.
+
 if ACPI
 
 comment "ACPI drivers"
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 4bc215c..2c4e7a5 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -99,6 +99,7 @@ obj-$(CONFIG_SENSORS_W83L785TS)	+= w83l785ts.o
 obj-$(CONFIG_SENSORS_W83L786NG)	+= w83l786ng.o
 obj-$(CONFIG_SENSORS_WM831X)	+= wm831x-hwmon.o
 obj-$(CONFIG_SENSORS_WM8350)	+= wm8350-hwmon.o
+obj-$(CONFIG_SENSORS_TMP105)    += tmp105.o
 
 ifeq ($(CONFIG_HWMON_DEBUG_CHIP),y)
 EXTRA_CFLAGS += -DDEBUG
diff --git a/drivers/hwmon/tmp105.c b/drivers/hwmon/tmp105.c
new file mode 100644
index 0000000..8765b11
--- /dev/null
+++ b/drivers/hwmon/tmp105.c
@@ -0,0 +1,326 @@
+/*
+ * tmp105.c
+ *
+ * TMP105 temperature sensor driver
+ *
+ * Copyright (C) 2010 Texas Instruments
+ *
+ * Author: Shubhrajyoti Datta <a0393217@xxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+*/
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+
+/* Registers */
+#define		TMP105_TEMP_REG		0x00
+#define		TMP105_CONF_REG		0x01
+#define		TMP105_TLOW_REG		0x02
+#define		TMP105_THIGH_REG	0x03
+
+/* Configuration register parameters */
+#define		TMP105_CONF_SD		0x01
+#define		TMP105_CONF_TM		0x02
+#define		TMP105_CONF_POL		0x04
+#define		TMP105_CONF_F0		0x08
+#define		TMP105_CONF_F1		0x10
+#define		TMP105_CONF_R0		0x20
+#define		TMP105_CONF_R1		0x40
+#define		TMP105_CONF_OS		0x80
+
+#define 	TMP105_I2C_ADDRESS	0x48
+
+#define         MAX_TEMP		128
+#define         MIN_TEMP		-55
+
+/* Each client has this additional data */
+struct tmp105_data {
+	struct i2c_client *client;
+	/* mutex for sysfs operations */
+	struct mutex lock;
+	struct device *hwmon_dev;
+	s16 temp[3];
+	unsigned long last_updated;
+	u8 configuration_setting;
+};
+
+static const u8 tmp105_reg[] = {
+	TMP105_TEMP_REG,
+	TMP105_TLOW_REG,
+	TMP105_THIGH_REG,
+};
+
+static void tmp105_init_client(struct i2c_client *client);
+
+static signed long tmp105_reg_to_mC(s16 val)
+{
+	signed long temp_mC;
+	if (val  & 0x800)
+		val = val - 0x1000 ;
+	 temp_mC = (val * 64000) / 1024;
+	 return temp_mC;
+}
+
+static u16 tmp105_C_to_reg(signed long val)
+{
+	val =  (val * 1024) / 64000;
+	if (val < 0)
+		val = val + 0x1000;
+	return (u16)val;
+}
+
+static s16 *tmp105_update_device(struct i2c_client *client,
+						int  index)
+{
+	struct tmp105_data *data = i2c_get_clientdata(client);
+	u8 tmp[2];
+
+	mutex_lock(&data->lock);
+
+	if (time_after(jiffies, data->last_updated +  HZ/4)) {
+		i2c_smbus_read_i2c_block_data(client,
+						tmp105_reg[index], 2, tmp);
+		data->temp[index] = ((tmp[0] << 4) | ((tmp[1] & 0xF0) >> 4));
+		printk(KERN_INFO "Raw temperature: %u\n", data->temp[index]);
+		data->last_updated = jiffies;
+	}
+
+	mutex_unlock(&data->lock);
+	return data->temp[index] ;
+}
+
+static ssize_t show_temp_value(struct device *dev,
+			       struct device_attribute *devattr, char *buf)
+{
+	struct sensor_device_attribute *sda = to_sensor_dev_attr(devattr);
+	struct i2c_client *client = to_i2c_client(dev);
+	s16 temperature = tmp105_update_device(client , sda->index);
+	signed long temp_in_mC;
+
+	temp_in_mC = tmp105_reg_to_mC(temperature);
+
+	return sprintf(buf, "%d\n", temp_in_mC);
+}
+
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_value, NULL , 0);
+
+static ssize_t tmp105_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 i2c_client *client = to_i2c_client(dev);
+	struct tmp105_data *tmp105 = i2c_get_clientdata(client);
+	signed long val;
+	int status = 0;
+	u16 temp;
+
+	if ((strict_strtol(buf, 10, &val) < 0))
+		return -EINVAL;
+
+	SENSORS_LIMIT(val , MIN_TEMP , MAX_TEMP);
+
+	mutex_lock(&tmp105->lock);
+
+	temp = tmp105_C_to_reg(val);
+	temp = ((temp & 0xFF0) >> 4) | ((temp & 0xF)<<12);
+
+	status = i2c_smbus_write_word_data(client, tmp105_reg[sda->index],
+			temp);
+
+	tmp105->temp[sda->index] = temp;
+	mutex_unlock(&tmp105->lock);
+	return status ? : count;
+}
+
+static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp_value,
+	tmp105_set_temp, 1);
+static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_value,
+	tmp105_set_temp, 2);
+
+/* sysfs call */
+static ssize_t set_configuration(struct device *dev,
+				struct device_attribute *attr,
+				const char *buf, size_t count)
+{
+	s32 status;
+	struct i2c_client *client = to_i2c_client(dev);
+	struct tmp105_data *data = i2c_get_clientdata(client);
+	data->configuration_setting = simple_strtoul(buf, NULL, 10);
+	/* I2C write to the configuration register */
+	status = i2c_smbus_write_byte_data(client, TMP105_CONF_REG,
+			data->configuration_setting);
+	return count;
+}
+
+static ssize_t show_configuration(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct tmp105_data *data = i2c_get_clientdata(client);
+	u8 tmp;
+	i2c_smbus_read_i2c_block_data(client, TMP105_CONF_REG, 1, &tmp);
+	data->configuration_setting = tmp;
+	return sprintf(buf, "%u\n", data->configuration_setting);
+}
+static DEVICE_ATTR(configuration, S_IWUSR | S_IRUGO, show_configuration,
+		set_configuration);
+
+
+static struct attribute *tmp105_attributes[] = {
+	&dev_attr_configuration.attr,
+	&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
+};
+
+static const struct attribute_group tmp105_attr_group = {
+	.attrs = tmp105_attributes,
+};
+
+static int tmp105_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	struct tmp105_data *tmp105_data;
+	int err;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+		dev_dbg(&client->dev, "adapter doesn't support I2C\n");
+		return -ENODEV;
+	}
+
+	tmp105_data = kzalloc(sizeof(struct tmp105_data), GFP_KERNEL);
+	if (!tmp105_data) {
+		err = -ENOMEM;
+		goto exit;
+	}
+	tmp105_data->client = client;
+
+	i2c_set_clientdata(client, tmp105_data);
+	mutex_init(&tmp105_data->lock);
+
+	/* Initialize the TMP105 chip */
+	tmp105_init_client(client);
+
+	/* Register sysfs hooks */
+	err = sysfs_create_group(&client->dev.kobj, &tmp105_attr_group);
+	if (err)
+		goto exit_free;
+	tmp105_data->hwmon_dev = hwmon_device_register(&client->dev);
+	if (IS_ERR(tmp105_data->hwmon_dev)) {
+		err = PTR_ERR(tmp105_data->hwmon_dev);
+		tmp105_data->hwmon_dev = NULL;
+		goto exit_remove;
+	}
+	return 0;
+
+exit_remove:
+	sysfs_remove_group(&client->dev.kobj, &tmp105_attr_group);
+exit_free:
+	i2c_set_clientdata(client, NULL);
+	kfree(tmp105_data);
+exit:
+	return err;
+}
+
+static int tmp105_remove(struct i2c_client *client)
+{
+	struct tmp105_data *tmp105 = i2c_get_clientdata(client);
+	hwmon_device_unregister(tmp105->hwmon_dev);
+
+	sysfs_remove_group(&client->dev.kobj, &tmp105_attr_group);
+	i2c_set_clientdata(client, NULL);
+	kfree(tmp105);
+	return 0;
+}
+
+/* Called when we have found a new TMP105. */
+static void tmp105_init_client(struct i2c_client *client)
+{
+	struct tmp105_data *data = i2c_get_clientdata(client);
+	data->last_updated = jiffies - HZ;
+	mutex_init(&data->lock);
+}
+
+static const struct i2c_device_id tmp105_id[] = {
+	{ "tmp105", 0 },
+	{ }
+};
+
+#ifdef CONFIG_PM
+static int tmp105_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	u8 config_reg;
+	i2c_smbus_read_i2c_block_data(client, TMP105_CONF_REG, 1, &config_reg);
+	config_reg = config_reg | TMP102_CONF_SD;
+	i2c_smbus_write_byte_data(client, TMP105_CONF_REG, TMP102_CONF_SD);
+	return 0;
+}
+
+static int tmp105_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	i2c_smbus_read_i2c_block_data(client, TMP105_CONF_REG, 1, &config_reg);
+	config_reg = config_reg & ~TMP102_CONF_SD;
+	i2c_smbus_write_byte_data(client, TMP105_CONF_REG, TMP102_CONF_SD);
+}
+
+static struct dev_pm_ops tmp105_dev_pm_ops = {
+	.suspend = tmp105_suspend,
+	.resume = tmp105_resume,
+};
+
+#define TMP105_DEV_PM_OPS (&tmp105_dev_pm_ops)
+#else
+#define TMP105_DEV_PM_OPS NULL
+#endif /* CONFIG_PM */
+
+
+static struct i2c_driver tmp105_driver = {
+	.driver = {
+		.name	= "tmp105",
+		.owner = THIS_MODULE,
+		.pm = TMP105_DEV_PM_OPS,
+	},
+	.probe		= tmp105_probe,
+	.remove		= tmp105_remove,
+	.id_table	= tmp105_id,
+	.class = I2C_CLASS_HWMON,
+};
+
+static int __init tmp105_init(void)
+{
+	return i2c_add_driver(&tmp105_driver);
+}
+
+static void __exit tmp105_exit(void)
+{
+	i2c_del_driver(&tmp105_driver);
+}
+
+MODULE_DESCRIPTION("TMP105 driver");
+MODULE_LICENSE("GPL");
+
+module_init(tmp105_init);
+module_exit(tmp105_exit);
+
-- 
1.5.4.7

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