| Alexander Stein | fffd80c | 2011-06-28 15:11:23 +0000 | [diff] [blame] | 1 | Kernel driver lm95245 |
| 2 | ================== |
| 3 | |
| 4 | Supported chips: |
| Guenter Roeck | 162a8df | 2014-04-22 08:48:57 -0700 | [diff] [blame] | 5 | * TI LM95235 |
| 6 | Addresses scanned: I2C 0x18, 0x29, 0x4c |
| 7 | Datasheet: Publicly available at the TI website |
| 8 | http://www.ti.com/lit/ds/symlink/lm95235.pdf |
| 9 | * TI / National Semiconductor LM95245 |
| Alexander Stein | fffd80c | 2011-06-28 15:11:23 +0000 | [diff] [blame] | 10 | Addresses scanned: I2C 0x18, 0x19, 0x29, 0x4c, 0x4d |
| Guenter Roeck | 162a8df | 2014-04-22 08:48:57 -0700 | [diff] [blame] | 11 | Datasheet: Publicly available at the TI website |
| 12 | http://www.ti.com/lit/ds/symlink/lm95245.pdf |
| Alexander Stein | fffd80c | 2011-06-28 15:11:23 +0000 | [diff] [blame] | 13 | |
| 14 | |
| 15 | Author: Alexander Stein <alexander.stein@systec-electronic.com> |
| 16 | |
| 17 | Description |
| 18 | ----------- |
| 19 | |
| Guenter Roeck | 162a8df | 2014-04-22 08:48:57 -0700 | [diff] [blame] | 20 | LM95235 and LM95245 are 11-bit digital temperature sensors with a 2-wire System |
| Alexander Stein | fffd80c | 2011-06-28 15:11:23 +0000 | [diff] [blame] | 21 | Management Bus (SMBus) interface and TruTherm technology that can monitor |
| 22 | the temperature of a remote diode as well as its own temperature. |
| Guenter Roeck | 162a8df | 2014-04-22 08:48:57 -0700 | [diff] [blame] | 23 | The chips can be used to very accurately monitor the temperature of |
| Alexander Stein | fffd80c | 2011-06-28 15:11:23 +0000 | [diff] [blame] | 24 | external devices such as microprocessors. |
| 25 | |
| 26 | All temperature values are given in millidegrees Celsius. Local temperature |
| 27 | is given within a range of -127 to +127.875 degrees. Remote temperatures are |
| 28 | given within a range of -127 to +255 degrees. Resolution depends on |
| 29 | temperature input and range. |
| 30 | |
| Guenter Roeck | a41a892 | 2014-02-22 08:17:34 -0800 | [diff] [blame] | 31 | Each sensor has its own critical limit. Additionally, there is a relative |
| 32 | hysteresis value common to both critical limits. To make life easier to |
| 33 | user-space applications, two absolute values are exported, one for each |
| 34 | channel, but these values are of course linked. Only the local hysteresis |
| 35 | can be set from user-space, and the same delta applies to the remote |
| 36 | hysteresis. |
| Alexander Stein | fffd80c | 2011-06-28 15:11:23 +0000 | [diff] [blame] | 37 | |
| 38 | The lm95245 driver can change its update interval to a fixed set of values. |
| 39 | It will round up to the next selectable interval. See the datasheet for exact |
| 40 | values. Reading sensor values more often will do no harm, but will return |
| 41 | 'old' values. |