projects / linux-block.git / blame
| Commit | Line | Data |
|---|---|---|
| e1eb4906 GR |
1 | Kernel driver lm95234 |
| 2 | ===================== | |
| 3 | ||
| 4 | Supported chips: | |
| b32570a4 | 5 | |
| dfcd4c53 | 6 | * National Semiconductor / Texas Instruments LM95233 |
| b32570a4 | 7 | |
| dfcd4c53 | 8 | Addresses scanned: I2C 0x18, 0x2a, 0x2b |
| b32570a4 | 9 | |
| dfcd4c53 | 10 | Datasheet: Publicly available at the Texas Instruments website |
| b32570a4 | 11 | |
| fdf41645 | 12 | https://www.ti.com/product/lm95233 |
| b32570a4 | 13 | |
| e1eb4906 | 14 | * National Semiconductor / Texas Instruments LM95234 |
| b32570a4 | 15 | |
| e1eb4906 | 16 | Addresses scanned: I2C 0x18, 0x4d, 0x4e |
| b32570a4 | 17 | |
| e1eb4906 | 18 | Datasheet: Publicly available at the Texas Instruments website |
| e1eb4906 | 19 | |
| fdf41645 | 20 | https://www.ti.com/product/lm95234 |
| e1eb4906 GR |
21 | |
| 22 | Author: Guenter Roeck <linux@roeck-us.net> | |
| 23 | ||
| 24 | Description | |
| 25 | ----------- | |
| 26 | ||
| dfcd4c53 GR |
27 | LM95233 and LM95234 are 11-bit digital temperature sensors with a 2-wire |
| 28 | System Management Bus (SMBus) interface and TrueTherm technology | |
| 29 | that can very accurately monitor the temperature of two (LM95233) | |
| 30 | or four (LM95234) remote diodes as well as its own temperature. | |
| 31 | The remote diodes can be external devices such as microprocessors, | |
| 32 | graphics processors or diode-connected 2N3904s. The chip's TruTherm | |
| e1eb4906 GR |
33 | beta compensation technology allows sensing of 90 nm or 65 nm process |
| 34 | thermal diodes accurately. | |
| 35 | ||
| 36 | All temperature values are given in millidegrees Celsius. Temperature | |
| 37 | is provided within a range of -127 to +255 degrees (+127.875 degrees for | |
| 38 | the internal sensor). Resolution depends on temperature input and range. | |
| 39 | ||
| 40 | Each sensor has its own maximum limit, but the hysteresis is common to all | |
| 41 | channels. The hysteresis is configurable with the tem1_max_hyst attribute and | |
| 42 | affects the hysteresis on all channels. The first two external sensors also | |
| 43 | have a critical limit. | |
| 44 | ||
| 45 | The lm95234 driver can change its update interval to a fixed set of values. | |
| 46 | It will round up to the next selectable interval. See the datasheet for exact | |
| 47 | values. Reading sensor values more often will do no harm, but will return | |
| 48 | 'old' values. |