| 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 | |
| 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 TMP121/TMP123 are very similar; main differences are 4 wire SPI inter- | |
| face (read only) and 13-bit temperature data (0.0625 degrees celsius reso- | |
| lution). | |
| Thanks to | |
| --------- | |
| Jean Delvare <khali@linux-fr.org> for mentoring the hwmon-side driver | |
| development. |