| Kernel driver lm70 |
| ================== |
| |
| Supported chips: |
| |
| * National Semiconductor LM70 |
| |
| Datasheet: http://www.national.com/pf/LM/LM70.html |
| |
| * Texas Instruments TMP121/TMP123 |
| |
| Information: http://focus.ti.com/docs/prod/folders/print/tmp121.html |
| |
| * Texas Instruments TMP122/TMP124 |
| |
| Information: http://www.ti.com/product/tmp122 |
| |
| * National Semiconductor LM71 |
| |
| Datasheet: http://www.ti.com/product/LM71 |
| |
| * National Semiconductor LM74 |
| |
| Datasheet: http://www.ti.com/product/LM74 |
| |
| |
| Author: |
| Kaiwan N Billimoria <kaiwan@designergraphix.com> |
| |
| Description |
| ----------- |
| |
| This driver implements support for the National Semiconductor LM70 |
| temperature sensor. |
| |
| The LM70 temperature sensor chip supports a single temperature sensor. |
| It communicates with a host processor (or microcontroller) via an |
| SPI/Microwire Bus interface. |
| |
| Communication with the LM70 is simple: when the temperature is to be sensed, |
| the driver accesses the LM70 using SPI communication: 16 SCLK cycles |
| comprise the MOSI/MISO loop. At the end of the transfer, the 11-bit 2's |
| complement digital temperature (sent via the SIO line), is available in the |
| driver for interpretation. This driver makes use of the kernel's in-core |
| SPI support. |
| |
| As a real (in-tree) example of this "SPI protocol driver" interfacing |
| with a "SPI master controller driver", see drivers/spi/spi_lm70llp.c |
| and its associated documentation. |
| |
| The LM74 and TMP121/TMP122/TMP123/TMP124 are very similar; main difference is |
| 13-bit temperature data (0.0625 degrees celsius resolution). |
| |
| The TMP122/TMP124 also feature configurable temperature thresholds. |
| |
| The LM71 is also very similar; main difference is 14-bit temperature |
| data (0.03125 degrees celsius resolution). |
| |
| Thanks to |
| --------- |
| Jean Delvare <jdelvare@suse.de> for mentoring the hwmon-side driver |
| development. |
