1Kernel driver lm70 2================== 3 4Supported chips: 5 * National Semiconductor LM70 6 Datasheet: http://www.national.com/pf/LM/LM70.html 7 * Texas Instruments TMP121/TMP123 8 Information: http://focus.ti.com/docs/prod/folders/print/tmp121.html 9 10Author: 11 Kaiwan N Billimoria <kaiwan@designergraphix.com> 12 13Description 14----------- 15 16This driver implements support for the National Semiconductor LM70 17temperature sensor. 18 19The LM70 temperature sensor chip supports a single temperature sensor. 20It communicates with a host processor (or microcontroller) via an 21SPI/Microwire Bus interface. 22 23Communication with the LM70 is simple: when the temperature is to be sensed, 24the driver accesses the LM70 using SPI communication: 16 SCLK cycles 25comprise the MOSI/MISO loop. At the end of the transfer, the 11-bit 2's 26complement digital temperature (sent via the SIO line), is available in the 27driver for interpretation. This driver makes use of the kernel's in-core 28SPI support. 29 30As a real (in-tree) example of this "SPI protocol driver" interfacing 31with a "SPI master controller driver", see drivers/spi/spi_lm70llp.c 32and its associated documentation. 33 34The TMP121/TMP123 are very similar; main differences are 4 wire SPI inter- 35face (read only) and 13-bit temperature data (0.0625 degrees celsius reso- 36lution). 37 38Thanks to 39--------- 40Jean Delvare <khali@linux-fr.org> for mentoring the hwmon-side driver 41development. 42