hwmon: LM95241 driver

An hwmon driver for the National Semiconductor LM95241 triple temperature
sensors chip

Signed-off-by: Davide Rizzo <elpa-rizzo@gmail.com>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: "Mark M. Hoffman" <mhoffman@lightlink.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 537 insertions, 0 deletions

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 51ff9b3..8a91c99 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -582,6 +582,15 @@ config SENSORS_LTC4245
 	  This driver can also be built as a module. If so, the module will
 	  be called ltc4245.
 
+config SENSORS_LM95241
+	tristate "National Semiconductor LM95241 sensor chip"
+	depends on I2C
+	help
+	  If you say yes here you get support for LM95241 sensor chip.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called lm95241.
+
 config SENSORS_MAX1111
 	tristate "Maxim MAX1111 Multichannel, Serial 8-bit ADC chip"
 	depends on SPI_MASTER
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index e332d62..81c8882 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -64,6 +64,7 @@ obj-$(CONFIG_SENSORS_LM87)	+= lm87.o
 obj-$(CONFIG_SENSORS_LM90)	+= lm90.o
 obj-$(CONFIG_SENSORS_LM92)	+= lm92.o
 obj-$(CONFIG_SENSORS_LM93)	+= lm93.o
+obj-$(CONFIG_SENSORS_LM95241)	+= lm95241.o
 obj-$(CONFIG_SENSORS_LTC4245)	+= ltc4245.o
 obj-$(CONFIG_SENSORS_MAX1111)	+= max1111.o
 obj-$(CONFIG_SENSORS_MAX1619)	+= max1619.o
diff --git a/drivers/hwmon/lm95241.c b/drivers/hwmon/lm95241.c
new file mode 100644
index 0000000..091d95f
--- /dev/null
+++ b/drivers/hwmon/lm95241.c
@@ -0,0 +1,527 @@
+/*
+ * lm95241.c - Part of lm_sensors, Linux kernel modules for hardware
+ *             monitoring
+ * Copyright (C) 2008 Davide Rizzo <elpa-rizzo@gmail.com>
+ *
+ * Based on the max1619 driver. The LM95241 is a sensor chip made by National
+ *   Semiconductors.
+ * It reports up to three temperatures (its own plus up to
+ * two external ones). Complete datasheet can be
+ * obtained from National's website at:
+ *   http://www.national.com/ds.cgi/LM/LM95241.pdf
+ *
+ * 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.
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/jiffies.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/sysfs.h>
+
+static const unsigned short normal_i2c[] = {
+	0x19, 0x2a, 0x2b, I2C_CLIENT_END};
+
+/* Insmod parameters */
+I2C_CLIENT_INSMOD_1(lm95241);
+
+/* LM95241 registers */
+#define LM95241_REG_R_MAN_ID		0xFE
+#define LM95241_REG_R_CHIP_ID		0xFF
+#define LM95241_REG_R_STATUS		0x02
+#define LM95241_REG_RW_CONFIG		0x03
+#define LM95241_REG_RW_REM_FILTER	0x06
+#define LM95241_REG_RW_TRUTHERM		0x07
+#define LM95241_REG_W_ONE_SHOT  	0x0F
+#define LM95241_REG_R_LOCAL_TEMPH	0x10
+#define LM95241_REG_R_REMOTE1_TEMPH	0x11
+#define LM95241_REG_R_REMOTE2_TEMPH	0x12
+#define LM95241_REG_R_LOCAL_TEMPL	0x20
+#define LM95241_REG_R_REMOTE1_TEMPL	0x21
+#define LM95241_REG_R_REMOTE2_TEMPL	0x22
+#define LM95241_REG_RW_REMOTE_MODEL	0x30
+
+/* LM95241 specific bitfields */
+#define CFG_STOP 0x40
+#define CFG_CR0076 0x00
+#define CFG_CR0182 0x10
+#define CFG_CR1000 0x20
+#define CFG_CR2700 0x30
+#define R1MS_SHIFT 0
+#define R2MS_SHIFT 2
+#define R1MS_MASK (0x01 << (R1MS_SHIFT))
+#define R2MS_MASK (0x01 << (R2MS_SHIFT))
+#define R1DF_SHIFT 1
+#define R2DF_SHIFT 2
+#define R1DF_MASK (0x01 << (R1DF_SHIFT))
+#define R2DF_MASK (0x01 << (R2DF_SHIFT))
+#define R1FE_MASK 0x01
+#define R2FE_MASK 0x05
+#define TT1_SHIFT 0
+#define TT2_SHIFT 4
+#define TT_OFF 0
+#define TT_ON 1
+#define TT_MASK 7
+#define MANUFACTURER_ID 0x01
+#define DEFAULT_REVISION 0xA4
+
+/* Conversions and various macros */
+#define TEMP_FROM_REG(val_h, val_l) (((val_h) & 0x80 ? (val_h) - 0x100 : \
+    (val_h)) * 1000 + (val_l) * 1000 / 256)
+
+/* Functions declaration */
+static int lm95241_attach_adapter(struct i2c_adapter *adapter);
+static int lm95241_detect(struct i2c_adapter *adapter, int address,
+			  int kind);
+static void lm95241_init_client(struct i2c_client *client);
+static int lm95241_detach_client(struct i2c_client *client);
+static struct lm95241_data *lm95241_update_device(struct device *dev);
+
+/* Driver data (common to all clients) */
+static struct i2c_driver lm95241_driver = {
+	.driver = {
+		.name   = "lm95241",
+	},
+	.attach_adapter = lm95241_attach_adapter,
+	.detach_client  = lm95241_detach_client,
+};
+
+/* Client data (each client gets its own) */
+struct lm95241_data {
+	struct i2c_client client;
+	struct device *hwmon_dev;
+	struct mutex update_lock;
+	unsigned long last_updated, rate; /* in jiffies */
+	char valid; /* zero until following fields are valid */
+	/* registers values */
+	u8 local_h, local_l; /* local */
+	u8 remote1_h, remote1_l; /* remote1 */
+	u8 remote2_h, remote2_l; /* remote2 */
+	u8 config, model, trutherm;
+};
+
+/* Sysfs stuff */
+#define show_temp(value) \
+static ssize_t show_##value(struct device *dev, \
+    struct device_attribute *attr, char *buf) \
+{ \
+	struct lm95241_data *data = lm95241_update_device(dev); \
+	snprintf(buf, PAGE_SIZE - 1, "%d\n", \
+		TEMP_FROM_REG(data->value##_h, data->value##_l)); \
+	return strlen(buf); \
+}
+show_temp(local);
+show_temp(remote1);
+show_temp(remote2);
+
+static ssize_t show_rate(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct lm95241_data *data = lm95241_update_device(dev);
+
+	snprintf(buf, PAGE_SIZE - 1, "%lu\n", 1000 * data->rate / HZ);
+	return strlen(buf);
+}
+
+static ssize_t set_rate(struct device *dev, struct device_attribute *attr,
+			const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct lm95241_data *data = i2c_get_clientdata(client);
+
+	strict_strtol(buf, 10, &data->rate);
+	data->rate = data->rate * HZ / 1000;
+
+	return count;
+}
+
+#define show_type(flag) \
+static ssize_t show_type##flag(struct device *dev, \
+				   struct device_attribute *attr, char *buf) \
+{ \
+	struct i2c_client *client = to_i2c_client(dev); \
+	struct lm95241_data *data = i2c_get_clientdata(client); \
+\
+	snprintf(buf, PAGE_SIZE - 1, \
+		data->model & R##flag##MS_MASK ? "1\n" : "2\n"); \
+	return strlen(buf); \
+}
+show_type(1);
+show_type(2);
+
+#define show_min(flag) \
+static ssize_t show_min##flag(struct device *dev, \
+    struct device_attribute *attr, char *buf) \
+{ \
+	struct i2c_client *client = to_i2c_client(dev); \
+	struct lm95241_data *data = i2c_get_clientdata(client); \
+\
+	snprintf(buf, PAGE_SIZE - 1, \
+		data->config & R##flag##DF_MASK ?	\
+		"-127000\n" : "0\n"); \
+	return strlen(buf); \
+}
+show_min(1);
+show_min(2);
+
+#define show_max(flag) \
+static ssize_t show_max##flag(struct device *dev, \
+    struct device_attribute *attr, char *buf) \
+{ \
+	struct i2c_client *client = to_i2c_client(dev); \
+	struct lm95241_data *data = i2c_get_clientdata(client); \
+\
+	snprintf(buf, PAGE_SIZE - 1, \
+		data->config & R##flag##DF_MASK ? \
+		"127000\n" : "255000\n"); \
+	return strlen(buf); \
+}
+show_max(1);
+show_max(2);
+
+#define set_type(flag) \
+static ssize_t set_type##flag(struct device *dev, \
+				  struct device_attribute *attr, \
+				  const char *buf, size_t count) \
+{ \
+	struct i2c_client *client = to_i2c_client(dev); \
+	struct lm95241_data *data = i2c_get_clientdata(client); \
+\
+	long val; \
+	strict_strtol(buf, 10, &val); \
+\
+	if ((val == 1) || (val == 2)) { \
+\
+		mutex_lock(&data->update_lock); \
+\
+		data->trutherm &= ~(TT_MASK << TT##flag##_SHIFT); \
+		if (val == 1) { \
+			data->model |= R##flag##MS_MASK; \
+			data->trutherm |= (TT_ON << TT##flag##_SHIFT); \
+		} \
+		else { \
+			data->model &= ~R##flag##MS_MASK; \
+			data->trutherm |= (TT_OFF << TT##flag##_SHIFT); \
+		} \
+\
+		data->valid = 0; \
+\
+		i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL, \
+					  data->model); \
+		i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM, \
+					  data->trutherm); \
+\
+		mutex_unlock(&data->update_lock); \
+\
+	} \
+	return count; \
+}
+set_type(1);
+set_type(2);
+
+#define set_min(flag) \
+static ssize_t set_min##flag(struct device *dev, \
+	struct device_attribute *devattr, const char *buf, size_t count) \
+{ \
+	struct i2c_client *client = to_i2c_client(dev); \
+	struct lm95241_data *data = i2c_get_clientdata(client); \
+\
+	long val; \
+	strict_strtol(buf, 10, &val); \
+\
+	mutex_lock(&data->update_lock); \
+\
+	if (val < 0) \
+		data->config |= R##flag##DF_MASK; \
+	else \
+		data->config &= ~R##flag##DF_MASK; \
+\
+	data->valid = 0; \
+\
+	i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, \
+		data->config); \
+\
+	mutex_unlock(&data->update_lock); \
+\
+	return count; \
+}
+set_min(1);
+set_min(2);
+
+#define set_max(flag) \
+static ssize_t set_max##flag(struct device *dev, \
+	struct device_attribute *devattr, const char *buf, size_t count) \
+{ \
+	struct i2c_client *client = to_i2c_client(dev); \
+	struct lm95241_data *data = i2c_get_clientdata(client); \
+\
+	long val; \
+	strict_strtol(buf, 10, &val); \
+\
+	mutex_lock(&data->update_lock); \
+\
+	if (val <= 127000) \
+		data->config |= R##flag##DF_MASK; \
+	else \
+		data->config &= ~R##flag##DF_MASK; \
+\
+	data->valid = 0; \
+\
+	i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, \
+		data->config); \
+\
+	mutex_unlock(&data->update_lock); \
+\
+	return count; \
+}
+set_max(1);
+set_max(2);
+
+static DEVICE_ATTR(temp1_input, S_IRUGO, show_local, NULL);
+static DEVICE_ATTR(temp2_input, S_IRUGO, show_remote1, NULL);
+static DEVICE_ATTR(temp3_input, S_IRUGO, show_remote2, NULL);
+static DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type1, set_type1);
+static DEVICE_ATTR(temp3_type, S_IWUSR | S_IRUGO, show_type2, set_type2);
+static DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_min1, set_min1);
+static DEVICE_ATTR(temp3_min, S_IWUSR | S_IRUGO, show_min2, set_min2);
+static DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_max1, set_max1);
+static DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_max2, set_max2);
+static DEVICE_ATTR(rate, S_IWUSR | S_IRUGO, show_rate, set_rate);
+
+static struct attribute *lm95241_attributes[] = {
+	&dev_attr_temp1_input.attr,
+	&dev_attr_temp2_input.attr,
+	&dev_attr_temp3_input.attr,
+	&dev_attr_temp2_type.attr,
+	&dev_attr_temp3_type.attr,
+	&dev_attr_temp2_min.attr,
+	&dev_attr_temp3_min.attr,
+	&dev_attr_temp2_max.attr,
+	&dev_attr_temp3_max.attr,
+	&dev_attr_rate.attr,
+	NULL
+};
+
+static const struct attribute_group lm95241_group = {
+	.attrs = lm95241_attributes,
+};
+
+/* Init/exit code */
+static int lm95241_attach_adapter(struct i2c_adapter *adapter)
+{
+	if (!(adapter->class & I2C_CLASS_HWMON))
+		return 0;
+	return i2c_probe(adapter, &addr_data, lm95241_detect);
+}
+
+/*
+ * The following function does more than just detection. If detection
+ * succeeds, it also registers the new chip.
+ */
+static int lm95241_detect(struct i2c_adapter *adapter, int address, int kind)
+{
+	struct i2c_client *new_client;
+	struct lm95241_data *data;
+	int err = 0;
+	const char *name = "";
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+		goto exit;
+
+	data = kzalloc(sizeof(struct lm95241_data), GFP_KERNEL);
+	if (!data) {
+		err = -ENOMEM;
+		goto exit;
+	}
+
+	/* The common I2C client data is placed right before the
+	   LM95241-specific data. */
+	new_client = &data->client;
+	i2c_set_clientdata(new_client, data);
+	new_client->addr = address;
+	new_client->adapter = adapter;
+	new_client->driver = &lm95241_driver;
+	new_client->flags = 0;
+
+	/*
+	 * Now we do the remaining detection. A negative kind means that
+	 * the driver was loaded with no force parameter (default), so we
+	 * must both detect and identify the chip. A zero kind means that
+	 * the driver was loaded with the force parameter, the detection
+	 * step shall be skipped. A positive kind means that the driver
+	 * was loaded with the force parameter and a given kind of chip is
+	 * requested, so both the detection and the identification steps
+	 * are skipped.
+	 */
+	if (kind < 0) {	/* detection */
+		if ((i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID)
+		     != MANUFACTURER_ID)
+		|| (i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID)
+		    < DEFAULT_REVISION)) {
+			dev_dbg(&adapter->dev,
+				"LM95241 detection failed at 0x%02x.\n",
+				address);
+			goto exit_free;
+		}
+	}
+
+	if (kind <= 0) { /* identification */
+		if ((i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID)
+		     == MANUFACTURER_ID)
+		&& (i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID)
+		    >= DEFAULT_REVISION)) {
+
+			kind = lm95241;
+
+			if (kind <= 0) { /* identification failed */
+				dev_info(&adapter->dev, "Unsupported chip\n");
+				goto exit_free;
+			}
+		}
+	}
+
+	if (kind == lm95241)
+		name = "lm95241";
+
+	/* We can fill in the remaining client fields */
+	strlcpy(new_client->name, name, I2C_NAME_SIZE);
+	data->valid = 0;
+	mutex_init(&data->update_lock);
+
+	/* Tell the I2C layer a new client has arrived */
+	err = i2c_attach_client(new_client);
+	if (err)
+		goto exit_free;
+
+	/* Initialize the LM95241 chip */
+	lm95241_init_client(new_client);
+
+	/* Register sysfs hooks */
+	err = sysfs_create_group(&new_client->dev.kobj, &lm95241_group);
+	if (err)
+		goto exit_detach;
+
+	data->hwmon_dev = hwmon_device_register(&new_client->dev);
+	if (IS_ERR(data->hwmon_dev)) {
+		err = PTR_ERR(data->hwmon_dev);
+		goto exit_remove_files;
+	}
+
+	return 0;
+
+exit_remove_files:
+	sysfs_remove_group(&new_client->dev.kobj, &lm95241_group);
+exit_detach:
+	i2c_detach_client(new_client);
+exit_free:
+	kfree(data);
+exit:
+	return err;
+}
+
+static void lm95241_init_client(struct i2c_client *client)
+{
+	struct lm95241_data *data = i2c_get_clientdata(client);
+
+	data->rate = HZ;    /* 1 sec default */
+	data->valid = 0;
+	data->config = CFG_CR0076;
+	data->model = 0;
+	data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT);
+
+	i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG,
+				  data->config);
+	i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER,
+				  R1FE_MASK | R2FE_MASK);
+	i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
+				  data->trutherm);
+	i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
+				  data->model);
+}
+
+static int lm95241_detach_client(struct i2c_client *client)
+{
+	struct lm95241_data *data = i2c_get_clientdata(client);
+	int err;
+
+	hwmon_device_unregister(data->hwmon_dev);
+	sysfs_remove_group(&client->dev.kobj, &lm95241_group);
+
+	err = i2c_detach_client(client);
+	if (err)
+		return err;
+
+	kfree(data);
+	return 0;
+}
+
+static struct lm95241_data *lm95241_update_device(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct lm95241_data *data = i2c_get_clientdata(client);
+
+	mutex_lock(&data->update_lock);
+
+	if (time_after(jiffies, data->last_updated + data->rate) ||
+	    !data->valid) {
+		dev_dbg(&client->dev, "Updating lm95241 data.\n");
+		data->local_h =
+			i2c_smbus_read_byte_data(client,
+						 LM95241_REG_R_LOCAL_TEMPH);
+		data->local_l =
+			i2c_smbus_read_byte_data(client,
+						 LM95241_REG_R_LOCAL_TEMPL);
+		data->remote1_h =
+			i2c_smbus_read_byte_data(client,
+						 LM95241_REG_R_REMOTE1_TEMPH);
+		data->remote1_l =
+			i2c_smbus_read_byte_data(client,
+						 LM95241_REG_R_REMOTE1_TEMPL);
+		data->remote2_h =
+			i2c_smbus_read_byte_data(client,
+						 LM95241_REG_R_REMOTE2_TEMPH);
+		data->remote2_l =
+			i2c_smbus_read_byte_data(client,
+						 LM95241_REG_R_REMOTE2_TEMPL);
+		data->last_updated = jiffies;
+		data->valid = 1;
+	}
+
+	mutex_unlock(&data->update_lock);
+
+	return data;
+}
+
+static int __init sensors_lm95241_init(void)
+{
+	return i2c_add_driver(&lm95241_driver);
+}
+
+static void __exit sensors_lm95241_exit(void)
+{
+	i2c_del_driver(&lm95241_driver);
+}
+
+MODULE_AUTHOR("Davide Rizzo <elpa-rizzo@gmail.com>");
+MODULE_DESCRIPTION("LM95241 sensor driver");
+MODULE_LICENSE("GPL");
+
+module_init(sensors_lm95241_init);
+module_exit(sensors_lm95241_exit);