Put ADT7461 into extended temperature range mode, which will change the range of readings from 0..127 to -64..191 degC. Adjust the register conversion functions accordingly. This also eliminates the need to check the compatibility mode bit during probing since we always force extended mode now. Signed-off-by: Nate Case <ncase at xes-inc.com> --- drivers/hwmon/lm90.c | 76 ++++++++++++++++++++++++++++++++++++------------- 1 files changed, 56 insertions(+), 20 deletions(-) diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c index 5f2db18..5a1fc2d 100644 --- a/drivers/hwmon/lm90.c +++ b/drivers/hwmon/lm90.c @@ -51,12 +51,11 @@ * The MAX6680 and MAX6681 only differ in the pinout so they can be * treated identically. * - * 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: + * This driver also supports the ADT7461 chip from Analog Devices. + * The chip is placed into "extended mode" to support a range of + * -64..191 degC. It is mostly compatible with LM90 except for this + * data format difference in extended mode. Complete datasheet can be + * obtained from Analog's website at: * http://www.analog.com/en/prod/0,2877,ADT7461,00.html * * Since the LM90 was the first chipset supported by this driver, most @@ -242,22 +241,32 @@ static s16 temp2_to_reg(int val) } /* - * 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. + * ADT7461 versions of the above for "extended mode" operation + * which follows the same data format as LM90, but with an offset + * of 64 and unsigned integers. The range is restricted to -64..191 degC. */ +static int temp1_from_reg_adt7461(s8 val) +{ + return ((u8) val - 64) * 1000; +} + +static int temp2_from_reg_adt7461(s16 val) +{ + return ((u16) val - 0x4000) / 32 * 125; +} + static s8 temp1_to_reg_adt7461(int val) { - return val <= 0 ? 0 : - val >= 127000 ? 127 : - (val + 500) / 1000; + return val <= -64000 ? 0 : + val >= 191000 ? (s8) 0xff : + (s8) ((val + 500) / 1000 + 64); } static s16 temp2_to_reg_adt7461(int val) { - return val <= 0 ? 0 : - val >= 127750 ? 0x7FC0 : - (val + 125) / 250 * 64; + return val <= -64000 ? 0 : + val >= 191750 ? (s16) 0xffc0 : + (s16) ((val + 125) / 250 * 64 + 0x4000); } /* @@ -269,7 +278,14 @@ static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr, { 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])); + int temp; + + if (data->kind == adt7461) + temp = temp1_from_reg_adt7461(data->temp8[attr->index]); + else + temp = temp1_from_reg(data->temp8[attr->index]); + + return sprintf(buf, "%d\n", temp); } static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr, @@ -303,7 +319,14 @@ static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr, { 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])); + int temp; + + if (data->kind == adt7461) + temp = temp2_from_reg_adt7461(data->temp11[attr->index]); + else + temp = temp2_from_reg(data->temp11[attr->index]); + + return sprintf(buf, "%d\n", temp); } static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr, @@ -342,8 +365,14 @@ static ssize_t show_temphyst(struct device *dev, struct device_attribute *devatt { 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)); + int temp; + + if (data->kind == adt7461) + temp = temp1_from_reg_adt7461(data->temp8[attr->index]); + else + temp = temp1_from_reg(data->temp8[attr->index]); + + return sprintf(buf, "%d\n", temp - temp1_from_reg(data->temp_hyst)); } static ssize_t set_temphyst(struct device *dev, struct device_attribute *dummy, @@ -600,7 +629,6 @@ static int lm90_detect(struct i2c_adapter *adapter, int address, int kind) kind = adm1032; } else if (chip_id == 0x51 /* ADT7461 */ - && (reg_config1 & 0x1F) == 0x00 /* check compat mode */ && reg_convrate <= 0x0A) { kind = adt7461; } @@ -733,6 +761,14 @@ static void lm90_init_client(struct i2c_client *client) config |= 0x18; } + /* + * Put ADT7461 into extended temperature range mode, which will + * change the range of readings from 0..127 to -64..191 degC. + * This also affects the format of the limit registers. + */ + if (data->kind == adt7461) + config |= 0x04; + config &= 0xBF; /* run */ if (config != config_orig) /* Only write if changed */ i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1, config); -- 1.5.4.4
