| /* |
| * lm90.c - Part of lm_sensors, Linux kernel modules for hardware |
| * monitoring |
| * Copyright (C) 2003-2004 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 differenciate 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 differenciate 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/config.h> |
| #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> |
| |
| /* |
| * 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 Celcius. |
| * For remote temperatures and limits, it uses signed 11-bit values with |
| * LSB = 0.125 degree Celcius, 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 temp_input1, temp_low1, temp_high1; /* local */ |
| s16 temp_input2, temp_low2, temp_high2; /* remote, combined */ |
| s8 temp_crit1, temp_crit2; |
| u8 temp_hyst; |
| u8 alarms; /* bitvector */ |
| }; |
| |
| /* |
| * Sysfs stuff |
| */ |
| |
| #define show_temp(value, converter) \ |
| static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \ |
| { \ |
| struct lm90_data *data = lm90_update_device(dev); \ |
| return sprintf(buf, "%d\n", converter(data->value)); \ |
| } |
| show_temp(temp_input1, TEMP1_FROM_REG); |
| show_temp(temp_input2, TEMP2_FROM_REG); |
| show_temp(temp_low1, TEMP1_FROM_REG); |
| show_temp(temp_low2, TEMP2_FROM_REG); |
| show_temp(temp_high1, TEMP1_FROM_REG); |
| show_temp(temp_high2, TEMP2_FROM_REG); |
| show_temp(temp_crit1, TEMP1_FROM_REG); |
| show_temp(temp_crit2, TEMP1_FROM_REG); |
| |
| #define set_temp1(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 lm90_data *data = i2c_get_clientdata(client); \ |
| long val = simple_strtol(buf, NULL, 10); \ |
| \ |
| down(&data->update_lock); \ |
| if (data->kind == adt7461) \ |
| data->value = TEMP1_TO_REG_ADT7461(val); \ |
| else \ |
| data->value = TEMP1_TO_REG(val); \ |
| i2c_smbus_write_byte_data(client, reg, data->value); \ |
| up(&data->update_lock); \ |
| return count; \ |
| } |
| #define set_temp2(value, regh, regl) \ |
| 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 lm90_data *data = i2c_get_clientdata(client); \ |
| long val = simple_strtol(buf, NULL, 10); \ |
| \ |
| down(&data->update_lock); \ |
| if (data->kind == adt7461) \ |
| data->value = TEMP2_TO_REG_ADT7461(val); \ |
| else \ |
| data->value = TEMP2_TO_REG(val); \ |
| i2c_smbus_write_byte_data(client, regh, data->value >> 8); \ |
| i2c_smbus_write_byte_data(client, regl, data->value & 0xff); \ |
| up(&data->update_lock); \ |
| return count; \ |
| } |
| set_temp1(temp_low1, LM90_REG_W_LOCAL_LOW); |
| set_temp2(temp_low2, LM90_REG_W_REMOTE_LOWH, LM90_REG_W_REMOTE_LOWL); |
| set_temp1(temp_high1, LM90_REG_W_LOCAL_HIGH); |
| set_temp2(temp_high2, LM90_REG_W_REMOTE_HIGHH, LM90_REG_W_REMOTE_HIGHL); |
| set_temp1(temp_crit1, LM90_REG_W_LOCAL_CRIT); |
| set_temp1(temp_crit2, LM90_REG_W_REMOTE_CRIT); |
| |
| #define show_temp_hyst(value, basereg) \ |
| static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \ |
| { \ |
| struct lm90_data *data = lm90_update_device(dev); \ |
| return sprintf(buf, "%d\n", TEMP1_FROM_REG(data->basereg) \ |
| - TEMP1_FROM_REG(data->temp_hyst)); \ |
| } |
| show_temp_hyst(temp_hyst1, temp_crit1); |
| show_temp_hyst(temp_hyst2, temp_crit2); |
| |
| static ssize_t set_temp_hyst1(struct device *dev, struct device_attribute *attr, 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->temp_crit1) - 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 *attr, char *buf) |
| { |
| struct lm90_data *data = lm90_update_device(dev); |
| return sprintf(buf, "%d\n", data->alarms); |
| } |
| |
| static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input1, NULL); |
| static DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_input2, NULL); |
| static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp_low1, |
| set_temp_low1); |
| static DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp_low2, |
| set_temp_low2); |
| static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_high1, |
| set_temp_high1); |
| static DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp_high2, |
| set_temp_high2); |
| static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp_crit1, |
| set_temp_crit1); |
| static DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp_crit2, |
| set_temp_crit2); |
| static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temp_hyst1, |
| set_temp_hyst1); |
| static DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_temp_hyst2, NULL); |
| 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, &dev_attr_temp1_input); |
| device_create_file(&new_client->dev, &dev_attr_temp2_input); |
| device_create_file(&new_client->dev, &dev_attr_temp1_min); |
| device_create_file(&new_client->dev, &dev_attr_temp2_min); |
| device_create_file(&new_client->dev, &dev_attr_temp1_max); |
| device_create_file(&new_client->dev, &dev_attr_temp2_max); |
| device_create_file(&new_client->dev, &dev_attr_temp1_crit); |
| device_create_file(&new_client->dev, &dev_attr_temp2_crit); |
| device_create_file(&new_client->dev, &dev_attr_temp1_crit_hyst); |
| device_create_file(&new_client->dev, &dev_attr_temp2_crit_hyst); |
| 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->temp_input1 = i2c_smbus_read_byte_data(client, |
| LM90_REG_R_LOCAL_TEMP); |
| data->temp_high1 = i2c_smbus_read_byte_data(client, |
| LM90_REG_R_LOCAL_HIGH); |
| data->temp_low1 = i2c_smbus_read_byte_data(client, |
| LM90_REG_R_LOCAL_LOW); |
| data->temp_crit1 = i2c_smbus_read_byte_data(client, |
| LM90_REG_R_LOCAL_CRIT); |
| data->temp_crit2 = 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->temp_input2 = 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->temp_input2 = 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->temp_input2 |= (newh << 8); |
| |
| data->temp_high2 = (i2c_smbus_read_byte_data(client, |
| LM90_REG_R_REMOTE_HIGHH) << 8) + |
| i2c_smbus_read_byte_data(client, |
| LM90_REG_R_REMOTE_HIGHL); |
| data->temp_low2 = (i2c_smbus_read_byte_data(client, |
| LM90_REG_R_REMOTE_LOWH) << 8) + |
| i2c_smbus_read_byte_data(client, |
| LM90_REG_R_REMOTE_LOWL); |
| 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); |