--- /dev/null
+/*
+ * lm75.c - Part of lm_sensors, Linux kernel modules for hardware
+ * monitoring
+ * Copyright (c) 1998, 1999 Frodo Looijaard <frodol@dds.nl>
+ *
+ * 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/of.h>
+#include <linux/thermal.h>
+#include "lm75.h"
+
+
+/*
+ * This driver handles the LM75 and compatible digital temperature sensors.
+ */
+
+enum lm75_type { /* keep sorted in alphabetical order */
+ adt75,
+ ds1775,
+ ds75,
+ ds7505,
+ g751,
+ lm75,
+ lm75a,
+ lm75b,
+ max6625,
+ max6626,
+ mcp980x,
+ stds75,
+ tcn75,
+ tmp100,
+ tmp101,
+ tmp105,
+ tmp112,
+ tmp175,
+ tmp275,
+ tmp75,
+};
+
+/* Addresses scanned */
+static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
+ 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
+
+
+/* The LM75 registers */
+#define LM75_REG_CONF 0x01
+static const u8 LM75_REG_TEMP[3] = {
+ 0x00, /* input */
+ 0x03, /* max */
+ 0x02, /* hyst */
+};
+
+/* Each client has this additional data */
+struct lm75_data {
+ struct i2c_client *client;
+ struct device *hwmon_dev;
+ struct thermal_zone_device *tz;
+ struct mutex update_lock;
+ u8 orig_conf;
+ u8 resolution; /* In bits, between 9 and 12 */
+ u8 resolution_limits;
+ char valid; /* !=0 if registers are valid */
+ unsigned long last_updated; /* In jiffies */
+ unsigned long sample_time; /* In jiffies */
+ s16 temp[3]; /* Register values,
+ 0 = input
+ 1 = max
+ 2 = hyst */
+};
+
+static int lm75_read_value(struct i2c_client *client, u8 reg);
+static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value);
+static struct lm75_data *lm75_update_device(struct device *dev);
+
+
+/*-----------------------------------------------------------------------*/
+
+static inline long lm75_reg_to_mc(s16 temp, u8 resolution)
+{
+ return ((temp >> (16 - resolution)) * 1000) >> (resolution - 8);
+}
+
+/* sysfs attributes for hwmon */
+
+static int lm75_read_temp(void *dev, long *temp)
+{
+ struct lm75_data *data = lm75_update_device(dev);
+
+ if (IS_ERR(data))
+ return PTR_ERR(data);
+
+ *temp = lm75_reg_to_mc(data->temp[0], data->resolution);
+
+ return 0;
+}
+
+static ssize_t show_temp(struct device *dev, struct device_attribute *da,
+ char *buf)
+{
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+ struct lm75_data *data = lm75_update_device(dev);
+
+ if (IS_ERR(data))
+ return PTR_ERR(data);
+
+ return sprintf(buf, "%ld\n", lm75_reg_to_mc(data->temp[attr->index],
+ data->resolution));
+}
+
+static ssize_t set_temp(struct device *dev, struct device_attribute *da,
+ const char *buf, size_t count)
+{
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+ struct lm75_data *data = dev_get_drvdata(dev);
+ struct i2c_client *client = data->client;
+ int nr = attr->index;
+ long temp;
+ int error;
+ u8 resolution;
+
+ error = kstrtol(buf, 10, &temp);
+ if (error)
+ return error;
+
+ /*
+ * Resolution of limit registers is assumed to be the same as the
+ * temperature input register resolution unless given explicitly.
+ */
+ if (attr->index && data->resolution_limits)
+ resolution = data->resolution_limits;
+ else
+ resolution = data->resolution;
+
+ mutex_lock(&data->update_lock);
+ temp = clamp_val(temp, LM75_TEMP_MIN, LM75_TEMP_MAX);
+ data->temp[nr] = DIV_ROUND_CLOSEST(temp << (resolution - 8),
+ 1000) << (16 - resolution);
+ lm75_write_value(client, LM75_REG_TEMP[nr], data->temp[nr]);
+ mutex_unlock(&data->update_lock);
+ return count;
+}
+
+static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
+ show_temp, set_temp, 1);
+static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
+ show_temp, set_temp, 2);
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
+
+static struct attribute *lm75_attrs[] = {
+ &sensor_dev_attr_temp1_input.dev_attr.attr,
+ &sensor_dev_attr_temp1_max.dev_attr.attr,
+ &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
+
+ NULL
+};
+ATTRIBUTE_GROUPS(lm75);
+
+static const struct thermal_zone_of_device_ops lm75_of_thermal_ops = {
+ .get_temp = lm75_read_temp,
+};
+
+/*-----------------------------------------------------------------------*/
+
+/* device probe and removal */
+
+static int
+lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
+{
+ struct device *dev = &client->dev;
+ struct lm75_data *data;
+ int status;
+ u8 set_mask, clr_mask;
+ int new;
+ enum lm75_type kind = id->driver_data;
+
+ if (!i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
+ return -EIO;
+
+ data = devm_kzalloc(dev, sizeof(struct lm75_data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->client = client;
+ i2c_set_clientdata(client, data);
+ mutex_init(&data->update_lock);
+
+ /* Set to LM75 resolution (9 bits, 1/2 degree C) and range.
+ * Then tweak to be more precise when appropriate.
+ */
+ set_mask = 0;
+ clr_mask = LM75_SHUTDOWN; /* continuous conversions */
+
+ switch (kind) {
+ case adt75:
+ clr_mask |= 1 << 5; /* not one-shot mode */
+ data->resolution = 12;
+ data->sample_time = HZ / 8;
+ break;
+ case ds1775:
+ case ds75:
+ case stds75:
+ clr_mask |= 3 << 5;
+ set_mask |= 2 << 5; /* 11-bit mode */
+ data->resolution = 11;
+ data->sample_time = HZ;
+ break;
+ case ds7505:
+ set_mask |= 3 << 5; /* 12-bit mode */
+ data->resolution = 12;
+ data->sample_time = HZ / 4;
+ break;
+ case g751:
+ case lm75:
+ case lm75a:
+ data->resolution = 9;
+ data->sample_time = HZ / 2;
+ break;
+ case lm75b:
+ data->resolution = 11;
+ data->sample_time = HZ / 4;
+ break;
+ case max6625:
+ data->resolution = 9;
+ data->sample_time = HZ / 4;
+ break;
+ case max6626:
+ data->resolution = 12;
+ data->resolution_limits = 9;
+ data->sample_time = HZ / 4;
+ break;
+ case tcn75:
+ data->resolution = 9;
+ data->sample_time = HZ / 8;
+ break;
+ case mcp980x:
+ data->resolution_limits = 9;
+ /* fall through */
+ case tmp100:
+ case tmp101:
+ set_mask |= 3 << 5; /* 12-bit mode */
+ data->resolution = 12;
+ data->sample_time = HZ;
+ clr_mask |= 1 << 7; /* not one-shot mode */
+ break;
+ case tmp112:
+ set_mask |= 3 << 5; /* 12-bit mode */
+ clr_mask |= 1 << 7; /* not one-shot mode */
+ data->resolution = 12;
+ data->sample_time = HZ / 4;
+ break;
+ case tmp105:
+ case tmp175:
+ case tmp275:
+ case tmp75:
+ set_mask |= 3 << 5; /* 12-bit mode */
+ clr_mask |= 1 << 7; /* not one-shot mode */
+ data->resolution = 12;
+ data->sample_time = HZ / 2;
+ break;
+ }
+
+ /* configure as specified */
+ status = lm75_read_value(client, LM75_REG_CONF);
+ if (status < 0) {
+ dev_dbg(dev, "Can't read config? %d\n", status);
+ return status;
+ }
+ data->orig_conf = status;
+ new = status & ~clr_mask;
+ new |= set_mask;
+ if (status != new)
+ lm75_write_value(client, LM75_REG_CONF, new);
+ dev_dbg(dev, "Config %02x\n", new);
+
+ data->hwmon_dev = hwmon_device_register_with_groups(dev, client->name,
+ data, lm75_groups);
+ if (IS_ERR(data->hwmon_dev))
+ return PTR_ERR(data->hwmon_dev);
+
+ data->tz = thermal_zone_of_sensor_register(data->hwmon_dev, 0,
+ data->hwmon_dev,
+ &lm75_of_thermal_ops);
+ if (IS_ERR(data->tz))
+ data->tz = NULL;
+
+ dev_info(dev, "%s: sensor '%s'\n",
+ dev_name(data->hwmon_dev), client->name);
+
+ return 0;
+}
+
+static int lm75_remove(struct i2c_client *client)
+{
+ struct lm75_data *data = i2c_get_clientdata(client);
+
+ thermal_zone_of_sensor_unregister(data->hwmon_dev, data->tz);
+ hwmon_device_unregister(data->hwmon_dev);
+ lm75_write_value(client, LM75_REG_CONF, data->orig_conf);
+ return 0;
+}
+
+static const struct i2c_device_id lm75_ids[] = {
+ { "adt75", adt75, },
+ { "ds1775", ds1775, },
+ { "ds75", ds75, },
+ { "ds7505", ds7505, },
+ { "g751", g751, },
+ { "lm75", lm75, },
+ { "lm75a", lm75a, },
+ { "lm75b", lm75b, },
+ { "max6625", max6625, },
+ { "max6626", max6626, },
+ { "mcp980x", mcp980x, },
+ { "stds75", stds75, },
+ { "tcn75", tcn75, },
+ { "tmp100", tmp100, },
+ { "tmp101", tmp101, },
+ { "tmp105", tmp105, },
+ { "tmp112", tmp112, },
+ { "tmp175", tmp175, },
+ { "tmp275", tmp275, },
+ { "tmp75", tmp75, },
+ { /* LIST END */ }
+};
+MODULE_DEVICE_TABLE(i2c, lm75_ids);
+
+#define LM75A_ID 0xA1
+
+/* Return 0 if detection is successful, -ENODEV otherwise */
+static int lm75_detect(struct i2c_client *new_client,
+ struct i2c_board_info *info)
+{
+ struct i2c_adapter *adapter = new_client->adapter;
+ int i;
+ int conf, hyst, os;
+ bool is_lm75a = 0;
+
+ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
+ I2C_FUNC_SMBUS_WORD_DATA))
+ return -ENODEV;
+
+ /*
+ * Now, we do the remaining detection. There is no identification-
+ * dedicated register so we have to rely on several tricks:
+ * unused bits, registers cycling over 8-address boundaries,
+ * addresses 0x04-0x07 returning the last read value.
+ * The cycling+unused addresses combination is not tested,
+ * since it would significantly slow the detection down and would
+ * hardly add any value.
+ *
+ * The National Semiconductor LM75A is different than earlier
+ * LM75s. It has an ID byte of 0xaX (where X is the chip
+ * revision, with 1 being the only revision in existence) in
+ * register 7, and unused registers return 0xff rather than the
+ * last read value.
+ *
+ * Note that this function only detects the original National
+ * Semiconductor LM75 and the LM75A. Clones from other vendors
+ * aren't detected, on purpose, because they are typically never
+ * found on PC hardware. They are found on embedded designs where
+ * they can be instantiated explicitly so detection is not needed.
+ * The absence of identification registers on all these clones
+ * would make their exhaustive detection very difficult and weak,
+ * and odds are that the driver would bind to unsupported devices.
+ */
+
+ /* Unused bits */
+ conf = i2c_smbus_read_byte_data(new_client, 1);
+ if (conf & 0xe0)
+ return -ENODEV;
+
+ /* First check for LM75A */
+ if (i2c_smbus_read_byte_data(new_client, 7) == LM75A_ID) {
+ /* LM75A returns 0xff on unused registers so
+ just to be sure we check for that too. */
+ if (i2c_smbus_read_byte_data(new_client, 4) != 0xff
+ || i2c_smbus_read_byte_data(new_client, 5) != 0xff
+ || i2c_smbus_read_byte_data(new_client, 6) != 0xff)
+ return -ENODEV;
+ is_lm75a = 1;
+ hyst = i2c_smbus_read_byte_data(new_client, 2);
+ os = i2c_smbus_read_byte_data(new_client, 3);
+ } else { /* Traditional style LM75 detection */
+ /* Unused addresses */
+ hyst = i2c_smbus_read_byte_data(new_client, 2);
+ if (i2c_smbus_read_byte_data(new_client, 4) != hyst
+ || i2c_smbus_read_byte_data(new_client, 5) != hyst
+ || i2c_smbus_read_byte_data(new_client, 6) != hyst
+ || i2c_smbus_read_byte_data(new_client, 7) != hyst)
+ return -ENODEV;
+ os = i2c_smbus_read_byte_data(new_client, 3);
+ if (i2c_smbus_read_byte_data(new_client, 4) != os
+ || i2c_smbus_read_byte_data(new_client, 5) != os
+ || i2c_smbus_read_byte_data(new_client, 6) != os
+ || i2c_smbus_read_byte_data(new_client, 7) != os)
+ return -ENODEV;
+ }
+ /*
+ * It is very unlikely that this is a LM75 if both
+ * hysteresis and temperature limit registers are 0.
+ */
+ if (hyst == 0 && os == 0)
+ return -ENODEV;
+
+ /* Addresses cycling */
+ for (i = 8; i <= 248; i += 40) {
+ if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
+ || i2c_smbus_read_byte_data(new_client, i + 2) != hyst
+ || i2c_smbus_read_byte_data(new_client, i + 3) != os)
+ return -ENODEV;
+ if (is_lm75a && i2c_smbus_read_byte_data(new_client, i + 7)
+ != LM75A_ID)
+ return -ENODEV;
+ }
+
+ strlcpy(info->type, is_lm75a ? "lm75a" : "lm75", I2C_NAME_SIZE);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int lm75_suspend(struct device *dev)
+{
+ int status;
+ struct i2c_client *client = to_i2c_client(dev);
+ status = lm75_read_value(client, LM75_REG_CONF);
+ if (status < 0) {
+ dev_dbg(&client->dev, "Can't read config? %d\n", status);
+ return status;
+ }
+ status = status | LM75_SHUTDOWN;
+ lm75_write_value(client, LM75_REG_CONF, status);
+ return 0;
+}
+
+static int lm75_resume(struct device *dev)
+{
+ int status;
+ struct i2c_client *client = to_i2c_client(dev);
+ status = lm75_read_value(client, LM75_REG_CONF);
+ if (status < 0) {
+ dev_dbg(&client->dev, "Can't read config? %d\n", status);
+ return status;
+ }
+ status = status & ~LM75_SHUTDOWN;
+ lm75_write_value(client, LM75_REG_CONF, status);
+ return 0;
+}
+
+static const struct dev_pm_ops lm75_dev_pm_ops = {
+ .suspend = lm75_suspend,
+ .resume = lm75_resume,
+};
+#define LM75_DEV_PM_OPS (&lm75_dev_pm_ops)
+#else
+#define LM75_DEV_PM_OPS NULL
+#endif /* CONFIG_PM */
+
+static struct i2c_driver lm75_driver = {
+ .class = I2C_CLASS_HWMON,
+ .driver = {
+ .name = "lm75",
+ .pm = LM75_DEV_PM_OPS,
+ },
+ .probe = lm75_probe,
+ .remove = lm75_remove,
+ .id_table = lm75_ids,
+ .detect = lm75_detect,
+ .address_list = normal_i2c,
+};
+
+/*-----------------------------------------------------------------------*/
+
+/* register access */
+
+/*
+ * All registers are word-sized, except for the configuration register.
+ * LM75 uses a high-byte first convention, which is exactly opposite to
+ * the SMBus standard.
+ */
+static int lm75_read_value(struct i2c_client *client, u8 reg)
+{
+ if (reg == LM75_REG_CONF)
+ return i2c_smbus_read_byte_data(client, reg);
+ else
+ return i2c_smbus_read_word_swapped(client, reg);
+}
+
+static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value)
+{
+ if (reg == LM75_REG_CONF)
+ return i2c_smbus_write_byte_data(client, reg, value);
+ else
+ return i2c_smbus_write_word_swapped(client, reg, value);
+}
+
+static struct lm75_data *lm75_update_device(struct device *dev)
+{
+ struct lm75_data *data = dev_get_drvdata(dev);
+ struct i2c_client *client = data->client;
+ struct lm75_data *ret = data;
+
+ mutex_lock(&data->update_lock);
+
+ if (time_after(jiffies, data->last_updated + data->sample_time)
+ || !data->valid) {
+ int i;
+ dev_dbg(&client->dev, "Starting lm75 update\n");
+
+ for (i = 0; i < ARRAY_SIZE(data->temp); i++) {
+ int status;
+
+ status = lm75_read_value(client, LM75_REG_TEMP[i]);
+ if (unlikely(status < 0)) {
+ dev_dbg(dev,
+ "LM75: Failed to read value: reg %d, error %d\n",
+ LM75_REG_TEMP[i], status);
+ ret = ERR_PTR(status);
+ data->valid = 0;
+ goto abort;
+ }
+ data->temp[i] = status;
+ }
+ data->last_updated = jiffies;
+ data->valid = 1;
+ }
+
+abort:
+ mutex_unlock(&data->update_lock);
+ return ret;
+}
+
+module_i2c_driver(lm75_driver);
+
+MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
+MODULE_DESCRIPTION("LM75 driver");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff