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authorJean Delvare <khali@linux-fr.org>2005-07-02 18:20:26 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2005-07-11 14:42:50 -0700
commit8d5d45fb14680326f833295f2316a4ec5e357220 (patch)
tree3b29dbdea18dfecf33b18219c6c374316d99b88b /drivers/hwmon/lm90.c
parentad2f931dcb41bcfae38cc77d78b7821dfef83cf2 (diff)
downloadop-kernel-dev-8d5d45fb14680326f833295f2316a4ec5e357220.zip
op-kernel-dev-8d5d45fb14680326f833295f2316a4ec5e357220.tar.gz
[PATCH] I2C: Move hwmon drivers (2/3)
Part 2: Move the driver files themselves. Note that the patch "adds trailing whitespace", because it does move the files as-is, and some files happen to have trailing whitespace. From: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/hwmon/lm90.c')
-rw-r--r--drivers/hwmon/lm90.c655
1 files changed, 655 insertions, 0 deletions
diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
new file mode 100644
index 0000000..a67dcad
--- /dev/null
+++ b/drivers/hwmon/lm90.c
@@ -0,0 +1,655 @@
+/*
+ * lm90.c - Part of lm_sensors, Linux kernel modules for hardware
+ * monitoring
+ * Copyright (C) 2003-2005 Jean Delvare <khali@linux-fr.org>
+ *
+ * Based on the lm83 driver. The LM90 is a sensor chip made by National
+ * Semiconductor. It reports up to two temperatures (its own plus up to
+ * one external one) with a 0.125 deg resolution (1 deg for local
+ * temperature) and a 3-4 deg accuracy. Complete datasheet can be
+ * obtained from National's website at:
+ * http://www.national.com/pf/LM/LM90.html
+ *
+ * This driver also supports the LM89 and LM99, two other sensor chips
+ * made by National Semiconductor. Both have an increased remote
+ * temperature measurement accuracy (1 degree), and the LM99
+ * additionally shifts remote temperatures (measured and limits) by 16
+ * degrees, which allows for higher temperatures measurement. The
+ * driver doesn't handle it since it can be done easily in user-space.
+ * Complete datasheets can be obtained from National's website at:
+ * http://www.national.com/pf/LM/LM89.html
+ * http://www.national.com/pf/LM/LM99.html
+ * Note that there is no way to differentiate between both chips.
+ *
+ * This driver also supports the LM86, another sensor chip made by
+ * National Semiconductor. It is exactly similar to the LM90 except it
+ * has a higher accuracy.
+ * Complete datasheet can be obtained from National's website at:
+ * http://www.national.com/pf/LM/LM86.html
+ *
+ * This driver also supports the ADM1032, a sensor chip made by Analog
+ * Devices. That chip is similar to the LM90, with a few differences
+ * that are not handled by this driver. Complete datasheet can be
+ * obtained from Analog's website at:
+ * http://products.analog.com/products/info.asp?product=ADM1032
+ * Among others, it has a higher accuracy than the LM90, much like the
+ * LM86 does.
+ *
+ * This driver also supports the MAX6657, MAX6658 and MAX6659 sensor
+ * chips made by Maxim. These chips are similar to the LM86. Complete
+ * datasheet can be obtained at Maxim's website at:
+ * http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2578
+ * Note that there is no easy way to differentiate between the three
+ * variants. The extra address and features of the MAX6659 are not
+ * supported by this driver.
+ *
+ * This driver also supports the ADT7461 chip from Analog Devices but
+ * only in its "compatability mode". If an ADT7461 chip is found but
+ * is configured in non-compatible mode (where its temperature
+ * register values are decoded differently) it is ignored by this
+ * driver. Complete datasheet can be obtained from Analog's website
+ * at:
+ * http://products.analog.com/products/info.asp?product=ADT7461
+ *
+ * Since the LM90 was the first chipset supported by this driver, most
+ * comments will refer to this chipset, but are actually general and
+ * concern all supported chipsets, unless mentioned otherwise.
+ *
+ * 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/i2c-sensor.h>
+#include <linux/hwmon-sysfs.h>
+
+/*
+ * Addresses to scan
+ * Address is fully defined internally and cannot be changed except for
+ * MAX6659.
+ * LM86, LM89, LM90, LM99, ADM1032, MAX6657 and MAX6658 have address 0x4c.
+ * LM89-1, and LM99-1 have address 0x4d.
+ * MAX6659 can have address 0x4c, 0x4d or 0x4e (unsupported).
+ * ADT7461 always has address 0x4c.
+ */
+
+static unsigned short normal_i2c[] = { 0x4c, 0x4d, I2C_CLIENT_END };
+static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END };
+
+/*
+ * Insmod parameters
+ */
+
+SENSORS_INSMOD_6(lm90, adm1032, lm99, lm86, max6657, adt7461);
+
+/*
+ * The LM90 registers
+ */
+
+#define LM90_REG_R_MAN_ID 0xFE
+#define LM90_REG_R_CHIP_ID 0xFF
+#define LM90_REG_R_CONFIG1 0x03
+#define LM90_REG_W_CONFIG1 0x09
+#define LM90_REG_R_CONFIG2 0xBF
+#define LM90_REG_W_CONFIG2 0xBF
+#define LM90_REG_R_CONVRATE 0x04
+#define LM90_REG_W_CONVRATE 0x0A
+#define LM90_REG_R_STATUS 0x02
+#define LM90_REG_R_LOCAL_TEMP 0x00
+#define LM90_REG_R_LOCAL_HIGH 0x05
+#define LM90_REG_W_LOCAL_HIGH 0x0B
+#define LM90_REG_R_LOCAL_LOW 0x06
+#define LM90_REG_W_LOCAL_LOW 0x0C
+#define LM90_REG_R_LOCAL_CRIT 0x20
+#define LM90_REG_W_LOCAL_CRIT 0x20
+#define LM90_REG_R_REMOTE_TEMPH 0x01
+#define LM90_REG_R_REMOTE_TEMPL 0x10
+#define LM90_REG_R_REMOTE_OFFSH 0x11
+#define LM90_REG_W_REMOTE_OFFSH 0x11
+#define LM90_REG_R_REMOTE_OFFSL 0x12
+#define LM90_REG_W_REMOTE_OFFSL 0x12
+#define LM90_REG_R_REMOTE_HIGHH 0x07
+#define LM90_REG_W_REMOTE_HIGHH 0x0D
+#define LM90_REG_R_REMOTE_HIGHL 0x13
+#define LM90_REG_W_REMOTE_HIGHL 0x13
+#define LM90_REG_R_REMOTE_LOWH 0x08
+#define LM90_REG_W_REMOTE_LOWH 0x0E
+#define LM90_REG_R_REMOTE_LOWL 0x14
+#define LM90_REG_W_REMOTE_LOWL 0x14
+#define LM90_REG_R_REMOTE_CRIT 0x19
+#define LM90_REG_W_REMOTE_CRIT 0x19
+#define LM90_REG_R_TCRIT_HYST 0x21
+#define LM90_REG_W_TCRIT_HYST 0x21
+
+/*
+ * Conversions and various macros
+ * For local temperatures and limits, critical limits and the hysteresis
+ * value, the LM90 uses signed 8-bit values with LSB = 1 degree Celsius.
+ * For remote temperatures and limits, it uses signed 11-bit values with
+ * LSB = 0.125 degree Celsius, left-justified in 16-bit registers.
+ */
+
+#define TEMP1_FROM_REG(val) ((val) * 1000)
+#define TEMP1_TO_REG(val) ((val) <= -128000 ? -128 : \
+ (val) >= 127000 ? 127 : \
+ (val) < 0 ? ((val) - 500) / 1000 : \
+ ((val) + 500) / 1000)
+#define TEMP2_FROM_REG(val) ((val) / 32 * 125)
+#define TEMP2_TO_REG(val) ((val) <= -128000 ? 0x8000 : \
+ (val) >= 127875 ? 0x7FE0 : \
+ (val) < 0 ? ((val) - 62) / 125 * 32 : \
+ ((val) + 62) / 125 * 32)
+#define HYST_TO_REG(val) ((val) <= 0 ? 0 : (val) >= 30500 ? 31 : \
+ ((val) + 500) / 1000)
+
+/*
+ * ADT7461 is almost identical to LM90 except that attempts to write
+ * values that are outside the range 0 < temp < 127 are treated as
+ * the boundary value.
+ */
+
+#define TEMP1_TO_REG_ADT7461(val) ((val) <= 0 ? 0 : \
+ (val) >= 127000 ? 127 : \
+ ((val) + 500) / 1000)
+#define TEMP2_TO_REG_ADT7461(val) ((val) <= 0 ? 0 : \
+ (val) >= 127750 ? 0x7FC0 : \
+ ((val) + 125) / 250 * 64)
+
+/*
+ * Functions declaration
+ */
+
+static int lm90_attach_adapter(struct i2c_adapter *adapter);
+static int lm90_detect(struct i2c_adapter *adapter, int address,
+ int kind);
+static void lm90_init_client(struct i2c_client *client);
+static int lm90_detach_client(struct i2c_client *client);
+static struct lm90_data *lm90_update_device(struct device *dev);
+
+/*
+ * Driver data (common to all clients)
+ */
+
+static struct i2c_driver lm90_driver = {
+ .owner = THIS_MODULE,
+ .name = "lm90",
+ .id = I2C_DRIVERID_LM90,
+ .flags = I2C_DF_NOTIFY,
+ .attach_adapter = lm90_attach_adapter,
+ .detach_client = lm90_detach_client,
+};
+
+/*
+ * Client data (each client gets its own)
+ */
+
+struct lm90_data {
+ struct i2c_client client;
+ struct semaphore update_lock;
+ char valid; /* zero until following fields are valid */
+ unsigned long last_updated; /* in jiffies */
+ int kind;
+
+ /* registers values */
+ s8 temp8[5]; /* 0: local input
+ 1: local low limit
+ 2: local high limit
+ 3: local critical limit
+ 4: remote critical limit */
+ s16 temp11[3]; /* 0: remote input
+ 1: remote low limit
+ 2: remote high limit */
+ u8 temp_hyst;
+ u8 alarms; /* bitvector */
+};
+
+/*
+ * Sysfs stuff
+ */
+
+static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr,
+ char *buf)
+{
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+ struct lm90_data *data = lm90_update_device(dev);
+ return sprintf(buf, "%d\n", TEMP1_FROM_REG(data->temp8[attr->index]));
+}
+
+static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr,
+ const char *buf, size_t count)
+{
+ static const u8 reg[4] = {
+ LM90_REG_W_LOCAL_LOW,
+ LM90_REG_W_LOCAL_HIGH,
+ LM90_REG_W_LOCAL_CRIT,
+ LM90_REG_W_REMOTE_CRIT,
+ };
+
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+ struct i2c_client *client = to_i2c_client(dev);
+ struct lm90_data *data = i2c_get_clientdata(client);
+ long val = simple_strtol(buf, NULL, 10);
+ int nr = attr->index;
+
+ down(&data->update_lock);
+ if (data->kind == adt7461)
+ data->temp8[nr] = TEMP1_TO_REG_ADT7461(val);
+ else
+ data->temp8[nr] = TEMP1_TO_REG(val);
+ i2c_smbus_write_byte_data(client, reg[nr - 1], data->temp8[nr]);
+ up(&data->update_lock);
+ return count;
+}
+
+static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr,
+ char *buf)
+{
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+ struct lm90_data *data = lm90_update_device(dev);
+ return sprintf(buf, "%d\n", TEMP2_FROM_REG(data->temp11[attr->index]));
+}
+
+static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
+ const char *buf, size_t count)
+{
+ static const u8 reg[4] = {
+ LM90_REG_W_REMOTE_LOWH,
+ LM90_REG_W_REMOTE_LOWL,
+ LM90_REG_W_REMOTE_HIGHH,
+ LM90_REG_W_REMOTE_HIGHL,
+ };
+
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+ struct i2c_client *client = to_i2c_client(dev);
+ struct lm90_data *data = i2c_get_clientdata(client);
+ long val = simple_strtol(buf, NULL, 10);
+ int nr = attr->index;
+
+ down(&data->update_lock);
+ if (data->kind == adt7461)
+ data->temp11[nr] = TEMP2_TO_REG_ADT7461(val);
+ else
+ data->temp11[nr] = TEMP2_TO_REG(val);
+ i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2],
+ data->temp11[nr] >> 8);
+ i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2 + 1],
+ data->temp11[nr] & 0xff);
+ up(&data->update_lock);
+ return count;
+}
+
+static ssize_t show_temphyst(struct device *dev, struct device_attribute *devattr,
+ char *buf)
+{
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+ struct lm90_data *data = lm90_update_device(dev);
+ return sprintf(buf, "%d\n", TEMP1_FROM_REG(data->temp8[attr->index])
+ - TEMP1_FROM_REG(data->temp_hyst));
+}
+
+static ssize_t set_temphyst(struct device *dev, struct device_attribute *dummy,
+ const char *buf, size_t count)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct lm90_data *data = i2c_get_clientdata(client);
+ long val = simple_strtol(buf, NULL, 10);
+ long hyst;
+
+ down(&data->update_lock);
+ hyst = TEMP1_FROM_REG(data->temp8[3]) - val;
+ i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST,
+ HYST_TO_REG(hyst));
+ up(&data->update_lock);
+ return count;
+}
+
+static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
+ char *buf)
+{
+ struct lm90_data *data = lm90_update_device(dev);
+ return sprintf(buf, "%d\n", data->alarms);
+}
+
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp8, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp11, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp8,
+ set_temp8, 1);
+static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp11,
+ set_temp11, 1);
+static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp8,
+ set_temp8, 2);
+static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp11,
+ set_temp11, 2);
+static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp8,
+ set_temp8, 3);
+static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp8,
+ set_temp8, 4);
+static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temphyst,
+ set_temphyst, 3);
+static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_temphyst, NULL, 4);
+static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
+
+/*
+ * Real code
+ */
+
+static int lm90_attach_adapter(struct i2c_adapter *adapter)
+{
+ if (!(adapter->class & I2C_CLASS_HWMON))
+ return 0;
+ return i2c_detect(adapter, &addr_data, lm90_detect);
+}
+
+/*
+ * The following function does more than just detection. If detection
+ * succeeds, it also registers the new chip.
+ */
+static int lm90_detect(struct i2c_adapter *adapter, int address, int kind)
+{
+ struct i2c_client *new_client;
+ struct lm90_data *data;
+ int err = 0;
+ const char *name = "";
+
+ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+ goto exit;
+
+ if (!(data = kmalloc(sizeof(struct lm90_data), GFP_KERNEL))) {
+ err = -ENOMEM;
+ goto exit;
+ }
+ memset(data, 0, sizeof(struct lm90_data));
+
+ /* The common I2C client data is placed right before the
+ LM90-specific data. */
+ new_client = &data->client;
+ i2c_set_clientdata(new_client, data);
+ new_client->addr = address;
+ new_client->adapter = adapter;
+ new_client->driver = &lm90_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.
+ */
+
+ /* Default to an LM90 if forced */
+ if (kind == 0)
+ kind = lm90;
+
+ if (kind < 0) { /* detection and identification */
+ u8 man_id, chip_id, reg_config1, reg_convrate;
+
+ man_id = i2c_smbus_read_byte_data(new_client,
+ LM90_REG_R_MAN_ID);
+ chip_id = i2c_smbus_read_byte_data(new_client,
+ LM90_REG_R_CHIP_ID);
+ reg_config1 = i2c_smbus_read_byte_data(new_client,
+ LM90_REG_R_CONFIG1);
+ reg_convrate = i2c_smbus_read_byte_data(new_client,
+ LM90_REG_R_CONVRATE);
+
+ if (man_id == 0x01) { /* National Semiconductor */
+ u8 reg_config2;
+
+ reg_config2 = i2c_smbus_read_byte_data(new_client,
+ LM90_REG_R_CONFIG2);
+
+ if ((reg_config1 & 0x2A) == 0x00
+ && (reg_config2 & 0xF8) == 0x00
+ && reg_convrate <= 0x09) {
+ if (address == 0x4C
+ && (chip_id & 0xF0) == 0x20) { /* LM90 */
+ kind = lm90;
+ } else
+ if ((chip_id & 0xF0) == 0x30) { /* LM89/LM99 */
+ kind = lm99;
+ } else
+ if (address == 0x4C
+ && (chip_id & 0xF0) == 0x10) { /* LM86 */
+ kind = lm86;
+ }
+ }
+ } else
+ if (man_id == 0x41) { /* Analog Devices */
+ if (address == 0x4C
+ && (chip_id & 0xF0) == 0x40 /* ADM1032 */
+ && (reg_config1 & 0x3F) == 0x00
+ && reg_convrate <= 0x0A) {
+ kind = adm1032;
+ } else
+ if (address == 0x4c
+ && chip_id == 0x51 /* ADT7461 */
+ && (reg_config1 & 0x1F) == 0x00 /* check compat mode */
+ && reg_convrate <= 0x0A) {
+ kind = adt7461;
+ }
+ } else
+ if (man_id == 0x4D) { /* Maxim */
+ /*
+ * The Maxim variants do NOT have a chip_id register.
+ * Reading from that address will return the last read
+ * value, which in our case is those of the man_id
+ * register. Likewise, the config1 register seems to
+ * lack a low nibble, so the value will be those of the
+ * previous read, so in our case those of the man_id
+ * register.
+ */
+ if (chip_id == man_id
+ && (reg_config1 & 0x1F) == (man_id & 0x0F)
+ && reg_convrate <= 0x09) {
+ kind = max6657;
+ }
+ }
+
+ if (kind <= 0) { /* identification failed */
+ dev_info(&adapter->dev,
+ "Unsupported chip (man_id=0x%02X, "
+ "chip_id=0x%02X).\n", man_id, chip_id);
+ goto exit_free;
+ }
+ }
+
+ if (kind == lm90) {
+ name = "lm90";
+ } else if (kind == adm1032) {
+ name = "adm1032";
+ } else if (kind == lm99) {
+ name = "lm99";
+ } else if (kind == lm86) {
+ name = "lm86";
+ } else if (kind == max6657) {
+ name = "max6657";
+ } else if (kind == adt7461) {
+ name = "adt7461";
+ }
+
+ /* We can fill in the remaining client fields */
+ strlcpy(new_client->name, name, I2C_NAME_SIZE);
+ data->valid = 0;
+ data->kind = kind;
+ init_MUTEX(&data->update_lock);
+
+ /* Tell the I2C layer a new client has arrived */
+ if ((err = i2c_attach_client(new_client)))
+ goto exit_free;
+
+ /* Initialize the LM90 chip */
+ lm90_init_client(new_client);
+
+ /* Register sysfs hooks */
+ device_create_file(&new_client->dev,
+ &sensor_dev_attr_temp1_input.dev_attr);
+ device_create_file(&new_client->dev,
+ &sensor_dev_attr_temp2_input.dev_attr);
+ device_create_file(&new_client->dev,
+ &sensor_dev_attr_temp1_min.dev_attr);
+ device_create_file(&new_client->dev,
+ &sensor_dev_attr_temp2_min.dev_attr);
+ device_create_file(&new_client->dev,
+ &sensor_dev_attr_temp1_max.dev_attr);
+ device_create_file(&new_client->dev,
+ &sensor_dev_attr_temp2_max.dev_attr);
+ device_create_file(&new_client->dev,
+ &sensor_dev_attr_temp1_crit.dev_attr);
+ device_create_file(&new_client->dev,
+ &sensor_dev_attr_temp2_crit.dev_attr);
+ device_create_file(&new_client->dev,
+ &sensor_dev_attr_temp1_crit_hyst.dev_attr);
+ device_create_file(&new_client->dev,
+ &sensor_dev_attr_temp2_crit_hyst.dev_attr);
+ device_create_file(&new_client->dev, &dev_attr_alarms);
+
+ return 0;
+
+exit_free:
+ kfree(data);
+exit:
+ return err;
+}
+
+static void lm90_init_client(struct i2c_client *client)
+{
+ u8 config;
+
+ /*
+ * Start the conversions.
+ */
+ i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE,
+ 5); /* 2 Hz */
+ config = i2c_smbus_read_byte_data(client, LM90_REG_R_CONFIG1);
+ if (config & 0x40)
+ i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
+ config & 0xBF); /* run */
+}
+
+static int lm90_detach_client(struct i2c_client *client)
+{
+ int err;
+
+ if ((err = i2c_detach_client(client))) {
+ dev_err(&client->dev, "Client deregistration failed, "
+ "client not detached.\n");
+ return err;
+ }
+
+ kfree(i2c_get_clientdata(client));
+ return 0;
+}
+
+static struct lm90_data *lm90_update_device(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct lm90_data *data = i2c_get_clientdata(client);
+
+ down(&data->update_lock);
+
+ if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
+ u8 oldh, newh;
+
+ dev_dbg(&client->dev, "Updating lm90 data.\n");
+ data->temp8[0] = i2c_smbus_read_byte_data(client,
+ LM90_REG_R_LOCAL_TEMP);
+ data->temp8[1] = i2c_smbus_read_byte_data(client,
+ LM90_REG_R_LOCAL_LOW);
+ data->temp8[2] = i2c_smbus_read_byte_data(client,
+ LM90_REG_R_LOCAL_HIGH);
+ data->temp8[3] = i2c_smbus_read_byte_data(client,
+ LM90_REG_R_LOCAL_CRIT);
+ data->temp8[4] = i2c_smbus_read_byte_data(client,
+ LM90_REG_R_REMOTE_CRIT);
+ data->temp_hyst = i2c_smbus_read_byte_data(client,
+ LM90_REG_R_TCRIT_HYST);
+
+ /*
+ * There is a trick here. We have to read two registers to
+ * have the remote sensor temperature, but we have to beware
+ * a conversion could occur inbetween the readings. The
+ * datasheet says we should either use the one-shot
+ * conversion register, which we don't want to do (disables
+ * hardware monitoring) or monitor the busy bit, which is
+ * impossible (we can't read the values and monitor that bit
+ * at the exact same time). So the solution used here is to
+ * read the high byte once, then the low byte, then the high
+ * byte again. If the new high byte matches the old one,
+ * then we have a valid reading. Else we have to read the low
+ * byte again, and now we believe we have a correct reading.
+ */
+ oldh = i2c_smbus_read_byte_data(client,
+ LM90_REG_R_REMOTE_TEMPH);
+ data->temp11[0] = i2c_smbus_read_byte_data(client,
+ LM90_REG_R_REMOTE_TEMPL);
+ newh = i2c_smbus_read_byte_data(client,
+ LM90_REG_R_REMOTE_TEMPH);
+ if (newh != oldh) {
+ data->temp11[0] = i2c_smbus_read_byte_data(client,
+ LM90_REG_R_REMOTE_TEMPL);
+#ifdef DEBUG
+ oldh = i2c_smbus_read_byte_data(client,
+ LM90_REG_R_REMOTE_TEMPH);
+ /* oldh is actually newer */
+ if (newh != oldh)
+ dev_warn(&client->dev, "Remote temperature may be "
+ "wrong.\n");
+#endif
+ }
+ data->temp11[0] |= (newh << 8);
+
+ data->temp11[1] = (i2c_smbus_read_byte_data(client,
+ LM90_REG_R_REMOTE_LOWH) << 8) +
+ i2c_smbus_read_byte_data(client,
+ LM90_REG_R_REMOTE_LOWL);
+ data->temp11[2] = (i2c_smbus_read_byte_data(client,
+ LM90_REG_R_REMOTE_HIGHH) << 8) +
+ i2c_smbus_read_byte_data(client,
+ LM90_REG_R_REMOTE_HIGHL);
+ data->alarms = i2c_smbus_read_byte_data(client,
+ LM90_REG_R_STATUS);
+
+ data->last_updated = jiffies;
+ data->valid = 1;
+ }
+
+ up(&data->update_lock);
+
+ return data;
+}
+
+static int __init sensors_lm90_init(void)
+{
+ return i2c_add_driver(&lm90_driver);
+}
+
+static void __exit sensors_lm90_exit(void)
+{
+ i2c_del_driver(&lm90_driver);
+}
+
+MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
+MODULE_DESCRIPTION("LM90/ADM1032 driver");
+MODULE_LICENSE("GPL");
+
+module_init(sensors_lm90_init);
+module_exit(sensors_lm90_exit);
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