summaryrefslogtreecommitdiff
path: root/drivers/hwmon/lm77.c
diff options
context:
space:
mode:
authorSrikant Patnaik2015-01-11 12:28:04 +0530
committerSrikant Patnaik2015-01-11 12:28:04 +0530
commit871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch)
tree8718f573808810c2a1e8cb8fb6ac469093ca2784 /drivers/hwmon/lm77.c
parent9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff)
downloadFOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.gz
FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.bz2
FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.zip
Moved, renamed, and deleted files
The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure.
Diffstat (limited to 'drivers/hwmon/lm77.c')
-rw-r--r--drivers/hwmon/lm77.c458
1 files changed, 458 insertions, 0 deletions
diff --git a/drivers/hwmon/lm77.c b/drivers/hwmon/lm77.c
new file mode 100644
index 00000000..0fca8613
--- /dev/null
+++ b/drivers/hwmon/lm77.c
@@ -0,0 +1,458 @@
+/*
+ * lm77.c - Part of lm_sensors, Linux kernel modules for hardware
+ * monitoring
+ *
+ * Copyright (c) 2004 Andras BALI <drewie@freemail.hu>
+ *
+ * Heavily based on lm75.c by Frodo Looijaard <frodol@dds.nl>. The LM77
+ * is a temperature sensor and thermal window comparator with 0.5 deg
+ * resolution made by National Semiconductor. Complete datasheet can be
+ * obtained at their site:
+ * http://www.national.com/pf/LM/LM77.html
+ *
+ * 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>
+
+/* Addresses to scan */
+static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
+ I2C_CLIENT_END };
+
+/* The LM77 registers */
+#define LM77_REG_TEMP 0x00
+#define LM77_REG_CONF 0x01
+#define LM77_REG_TEMP_HYST 0x02
+#define LM77_REG_TEMP_CRIT 0x03
+#define LM77_REG_TEMP_MIN 0x04
+#define LM77_REG_TEMP_MAX 0x05
+
+/* Each client has this additional data */
+struct lm77_data {
+ struct device *hwmon_dev;
+ struct mutex update_lock;
+ char valid;
+ unsigned long last_updated; /* In jiffies */
+ int temp_input; /* Temperatures */
+ int temp_crit;
+ int temp_min;
+ int temp_max;
+ int temp_hyst;
+ u8 alarms;
+};
+
+static int lm77_probe(struct i2c_client *client,
+ const struct i2c_device_id *id);
+static int lm77_detect(struct i2c_client *client, struct i2c_board_info *info);
+static void lm77_init_client(struct i2c_client *client);
+static int lm77_remove(struct i2c_client *client);
+static u16 lm77_read_value(struct i2c_client *client, u8 reg);
+static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value);
+
+static struct lm77_data *lm77_update_device(struct device *dev);
+
+
+static const struct i2c_device_id lm77_id[] = {
+ { "lm77", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, lm77_id);
+
+/* This is the driver that will be inserted */
+static struct i2c_driver lm77_driver = {
+ .class = I2C_CLASS_HWMON,
+ .driver = {
+ .name = "lm77",
+ },
+ .probe = lm77_probe,
+ .remove = lm77_remove,
+ .id_table = lm77_id,
+ .detect = lm77_detect,
+ .address_list = normal_i2c,
+};
+
+/* straight from the datasheet */
+#define LM77_TEMP_MIN (-55000)
+#define LM77_TEMP_MAX 125000
+
+/*
+ * In the temperature registers, the low 3 bits are not part of the
+ * temperature values; they are the status bits.
+ */
+static inline s16 LM77_TEMP_TO_REG(int temp)
+{
+ int ntemp = SENSORS_LIMIT(temp, LM77_TEMP_MIN, LM77_TEMP_MAX);
+ return (ntemp / 500) * 8;
+}
+
+static inline int LM77_TEMP_FROM_REG(s16 reg)
+{
+ return (reg / 8) * 500;
+}
+
+/* sysfs stuff */
+
+/* read routines for temperature limits */
+#define show(value) \
+static ssize_t show_##value(struct device *dev, \
+ struct device_attribute *attr, \
+ char *buf) \
+{ \
+ struct lm77_data *data = lm77_update_device(dev); \
+ return sprintf(buf, "%d\n", data->value); \
+}
+
+show(temp_input);
+show(temp_crit);
+show(temp_min);
+show(temp_max);
+
+/* read routines for hysteresis values */
+static ssize_t show_temp_crit_hyst(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct lm77_data *data = lm77_update_device(dev);
+ return sprintf(buf, "%d\n", data->temp_crit - data->temp_hyst);
+}
+static ssize_t show_temp_min_hyst(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct lm77_data *data = lm77_update_device(dev);
+ return sprintf(buf, "%d\n", data->temp_min + data->temp_hyst);
+}
+static ssize_t show_temp_max_hyst(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct lm77_data *data = lm77_update_device(dev);
+ return sprintf(buf, "%d\n", data->temp_max - data->temp_hyst);
+}
+
+/* write routines */
+#define set(value, reg) \
+static ssize_t set_##value(struct device *dev, struct device_attribute *attr, \
+ const char *buf, size_t count) \
+{ \
+ struct i2c_client *client = to_i2c_client(dev); \
+ struct lm77_data *data = i2c_get_clientdata(client); \
+ long val; \
+ int err = kstrtol(buf, 10, &val); \
+ if (err) \
+ return err; \
+ \
+ mutex_lock(&data->update_lock); \
+ data->value = val; \
+ lm77_write_value(client, reg, LM77_TEMP_TO_REG(data->value)); \
+ mutex_unlock(&data->update_lock); \
+ return count; \
+}
+
+set(temp_min, LM77_REG_TEMP_MIN);
+set(temp_max, LM77_REG_TEMP_MAX);
+
+/*
+ * hysteresis is stored as a relative value on the chip, so it has to be
+ * converted first
+ */
+static ssize_t set_temp_crit_hyst(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct lm77_data *data = i2c_get_clientdata(client);
+ unsigned long val;
+ int err;
+
+ err = kstrtoul(buf, 10, &val);
+ if (err)
+ return err;
+
+ mutex_lock(&data->update_lock);
+ data->temp_hyst = data->temp_crit - val;
+ lm77_write_value(client, LM77_REG_TEMP_HYST,
+ LM77_TEMP_TO_REG(data->temp_hyst));
+ mutex_unlock(&data->update_lock);
+ return count;
+}
+
+/* preserve hysteresis when setting T_crit */
+static ssize_t set_temp_crit(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct lm77_data *data = i2c_get_clientdata(client);
+ int oldcrithyst;
+ unsigned long val;
+ int err;
+
+ err = kstrtoul(buf, 10, &val);
+ if (err)
+ return err;
+
+ mutex_lock(&data->update_lock);
+ oldcrithyst = data->temp_crit - data->temp_hyst;
+ data->temp_crit = val;
+ data->temp_hyst = data->temp_crit - oldcrithyst;
+ lm77_write_value(client, LM77_REG_TEMP_CRIT,
+ LM77_TEMP_TO_REG(data->temp_crit));
+ lm77_write_value(client, LM77_REG_TEMP_HYST,
+ LM77_TEMP_TO_REG(data->temp_hyst));
+ mutex_unlock(&data->update_lock);
+ return count;
+}
+
+static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ int bitnr = to_sensor_dev_attr(attr)->index;
+ struct lm77_data *data = lm77_update_device(dev);
+ return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1);
+}
+
+static DEVICE_ATTR(temp1_input, S_IRUGO,
+ show_temp_input, NULL);
+static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO,
+ show_temp_crit, set_temp_crit);
+static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
+ show_temp_min, set_temp_min);
+static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
+ show_temp_max, set_temp_max);
+
+static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO,
+ show_temp_crit_hyst, set_temp_crit_hyst);
+static DEVICE_ATTR(temp1_min_hyst, S_IRUGO,
+ show_temp_min_hyst, NULL);
+static DEVICE_ATTR(temp1_max_hyst, S_IRUGO,
+ show_temp_max_hyst, NULL);
+
+static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2);
+static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1);
+
+static struct attribute *lm77_attributes[] = {
+ &dev_attr_temp1_input.attr,
+ &dev_attr_temp1_crit.attr,
+ &dev_attr_temp1_min.attr,
+ &dev_attr_temp1_max.attr,
+ &dev_attr_temp1_crit_hyst.attr,
+ &dev_attr_temp1_min_hyst.attr,
+ &dev_attr_temp1_max_hyst.attr,
+ &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
+ &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
+ &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
+ NULL
+};
+
+static const struct attribute_group lm77_group = {
+ .attrs = lm77_attributes,
+};
+
+/* Return 0 if detection is successful, -ENODEV otherwise */
+static int lm77_detect(struct i2c_client *new_client,
+ struct i2c_board_info *info)
+{
+ struct i2c_adapter *adapter = new_client->adapter;
+ int i, cur, conf, hyst, crit, min, max;
+
+ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
+ I2C_FUNC_SMBUS_WORD_DATA))
+ return -ENODEV;
+
+ /*
+ * Here comes the remaining detection. Since the LM77 has no
+ * register dedicated to identification, we have to rely on the
+ * following tricks:
+ *
+ * 1. the high 4 bits represent the sign and thus they should
+ * always be the same
+ * 2. the high 3 bits are unused in the configuration register
+ * 3. addresses 0x06 and 0x07 return the last read value
+ * 4. registers cycling over 8-address boundaries
+ *
+ * Word-sized registers are high-byte first.
+ */
+
+ /* addresses cycling */
+ cur = i2c_smbus_read_word_data(new_client, 0);
+ conf = i2c_smbus_read_byte_data(new_client, 1);
+ hyst = i2c_smbus_read_word_data(new_client, 2);
+ crit = i2c_smbus_read_word_data(new_client, 3);
+ min = i2c_smbus_read_word_data(new_client, 4);
+ max = i2c_smbus_read_word_data(new_client, 5);
+ for (i = 8; i <= 0xff; i += 8) {
+ if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
+ || i2c_smbus_read_word_data(new_client, i + 2) != hyst
+ || i2c_smbus_read_word_data(new_client, i + 3) != crit
+ || i2c_smbus_read_word_data(new_client, i + 4) != min
+ || i2c_smbus_read_word_data(new_client, i + 5) != max)
+ return -ENODEV;
+ }
+
+ /* sign bits */
+ if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0)
+ || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0)
+ || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0)
+ || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0)
+ || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0))
+ return -ENODEV;
+
+ /* unused bits */
+ if (conf & 0xe0)
+ return -ENODEV;
+
+ /* 0x06 and 0x07 return the last read value */
+ cur = i2c_smbus_read_word_data(new_client, 0);
+ if (i2c_smbus_read_word_data(new_client, 6) != cur
+ || i2c_smbus_read_word_data(new_client, 7) != cur)
+ return -ENODEV;
+ hyst = i2c_smbus_read_word_data(new_client, 2);
+ if (i2c_smbus_read_word_data(new_client, 6) != hyst
+ || i2c_smbus_read_word_data(new_client, 7) != hyst)
+ return -ENODEV;
+ min = i2c_smbus_read_word_data(new_client, 4);
+ if (i2c_smbus_read_word_data(new_client, 6) != min
+ || i2c_smbus_read_word_data(new_client, 7) != min)
+ return -ENODEV;
+
+ strlcpy(info->type, "lm77", I2C_NAME_SIZE);
+
+ return 0;
+}
+
+static int lm77_probe(struct i2c_client *new_client,
+ const struct i2c_device_id *id)
+{
+ struct lm77_data *data;
+ int err;
+
+ data = kzalloc(sizeof(struct lm77_data), GFP_KERNEL);
+ if (!data) {
+ err = -ENOMEM;
+ goto exit;
+ }
+
+ i2c_set_clientdata(new_client, data);
+ data->valid = 0;
+ mutex_init(&data->update_lock);
+
+ /* Initialize the LM77 chip */
+ lm77_init_client(new_client);
+
+ /* Register sysfs hooks */
+ err = sysfs_create_group(&new_client->dev.kobj, &lm77_group);
+ if (err)
+ goto exit_free;
+
+ data->hwmon_dev = hwmon_device_register(&new_client->dev);
+ if (IS_ERR(data->hwmon_dev)) {
+ err = PTR_ERR(data->hwmon_dev);
+ goto exit_remove;
+ }
+
+ return 0;
+
+exit_remove:
+ sysfs_remove_group(&new_client->dev.kobj, &lm77_group);
+exit_free:
+ kfree(data);
+exit:
+ return err;
+}
+
+static int lm77_remove(struct i2c_client *client)
+{
+ struct lm77_data *data = i2c_get_clientdata(client);
+ hwmon_device_unregister(data->hwmon_dev);
+ sysfs_remove_group(&client->dev.kobj, &lm77_group);
+ kfree(data);
+ return 0;
+}
+
+/*
+ * All registers are word-sized, except for the configuration register.
+ * The LM77 uses the high-byte first convention.
+ */
+static u16 lm77_read_value(struct i2c_client *client, u8 reg)
+{
+ if (reg == LM77_REG_CONF)
+ return i2c_smbus_read_byte_data(client, reg);
+ else
+ return i2c_smbus_read_word_swapped(client, reg);
+}
+
+static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value)
+{
+ if (reg == LM77_REG_CONF)
+ return i2c_smbus_write_byte_data(client, reg, value);
+ else
+ return i2c_smbus_write_word_swapped(client, reg, value);
+}
+
+static void lm77_init_client(struct i2c_client *client)
+{
+ /* Initialize the LM77 chip - turn off shutdown mode */
+ int conf = lm77_read_value(client, LM77_REG_CONF);
+ if (conf & 1)
+ lm77_write_value(client, LM77_REG_CONF, conf & 0xfe);
+}
+
+static struct lm77_data *lm77_update_device(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct lm77_data *data = i2c_get_clientdata(client);
+
+ mutex_lock(&data->update_lock);
+
+ if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
+ || !data->valid) {
+ dev_dbg(&client->dev, "Starting lm77 update\n");
+ data->temp_input =
+ LM77_TEMP_FROM_REG(lm77_read_value(client,
+ LM77_REG_TEMP));
+ data->temp_hyst =
+ LM77_TEMP_FROM_REG(lm77_read_value(client,
+ LM77_REG_TEMP_HYST));
+ data->temp_crit =
+ LM77_TEMP_FROM_REG(lm77_read_value(client,
+ LM77_REG_TEMP_CRIT));
+ data->temp_min =
+ LM77_TEMP_FROM_REG(lm77_read_value(client,
+ LM77_REG_TEMP_MIN));
+ data->temp_max =
+ LM77_TEMP_FROM_REG(lm77_read_value(client,
+ LM77_REG_TEMP_MAX));
+ data->alarms =
+ lm77_read_value(client, LM77_REG_TEMP) & 0x0007;
+ data->last_updated = jiffies;
+ data->valid = 1;
+ }
+
+ mutex_unlock(&data->update_lock);
+
+ return data;
+}
+
+module_i2c_driver(lm77_driver);
+
+MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>");
+MODULE_DESCRIPTION("LM77 driver");
+MODULE_LICENSE("GPL");