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 * Texas Instruments TMP122/TMP124 10 Information: http://www.ti.com/product/tmp122 11 * National Semiconductor LM71 12 Datasheet: http://www.ti.com/product/LM71 13 * National Semiconductor LM74 14 Datasheet: http://www.ti.com/product/LM74 15 16Author: 17 Kaiwan N Billimoria <kaiwan@designergraphix.com> 18 19Description 20----------- 21 22This driver implements support for the National Semiconductor LM70 23temperature sensor. 24 25The LM70 temperature sensor chip supports a single temperature sensor. 26It communicates with a host processor (or microcontroller) via an 27SPI/Microwire Bus interface. 28 29Communication with the LM70 is simple: when the temperature is to be sensed, 30the driver accesses the LM70 using SPI communication: 16 SCLK cycles 31comprise the MOSI/MISO loop. At the end of the transfer, the 11-bit 2's 32complement digital temperature (sent via the SIO line), is available in the 33driver for interpretation. This driver makes use of the kernel's in-core 34SPI support. 35 36As a real (in-tree) example of this "SPI protocol driver" interfacing 37with a "SPI master controller driver", see drivers/spi/spi_lm70llp.c 38and its associated documentation. 39 40The LM74 and TMP121/TMP122/TMP123/TMP124 are very similar; main difference is 4113-bit temperature data (0.0625 degrees celsius resolution). 42 43The TMP122/TMP124 also feature configurable temperature thresholds. 44 45The LM71 is also very similar; main difference is 14-bit temperature 46data (0.03125 degrees celsius resolution). 47 48Thanks to 49--------- 50Jean Delvare <jdelvare@suse.de> for mentoring the hwmon-side driver 51development. 52