1Kernel driver lm70 2================== 3 4Supported chips: 5 6 * National Semiconductor LM70 7 8 Datasheet: http://www.national.com/pf/LM/LM70.html 9 10 * Texas Instruments TMP121/TMP123 11 12 Information: http://focus.ti.com/docs/prod/folders/print/tmp121.html 13 14 * Texas Instruments TMP122/TMP124 15 16 Information: http://www.ti.com/product/tmp122 17 18 * National Semiconductor LM71 19 20 Datasheet: http://www.ti.com/product/LM71 21 22 * National Semiconductor LM74 23 24 Datasheet: http://www.ti.com/product/LM74 25 26 27Author: 28 Kaiwan N Billimoria <kaiwan@designergraphix.com> 29 30Description 31----------- 32 33This driver implements support for the National Semiconductor LM70 34temperature sensor. 35 36The LM70 temperature sensor chip supports a single temperature sensor. 37It communicates with a host processor (or microcontroller) via an 38SPI/Microwire Bus interface. 39 40Communication with the LM70 is simple: when the temperature is to be sensed, 41the driver accesses the LM70 using SPI communication: 16 SCLK cycles 42comprise the MOSI/MISO loop. At the end of the transfer, the 11-bit 2's 43complement digital temperature (sent via the SIO line), is available in the 44driver for interpretation. This driver makes use of the kernel's in-core 45SPI support. 46 47As a real (in-tree) example of this "SPI protocol driver" interfacing 48with a "SPI master controller driver", see drivers/spi/spi_lm70llp.c 49and its associated documentation. 50 51The LM74 and TMP121/TMP122/TMP123/TMP124 are very similar; main difference is 5213-bit temperature data (0.0625 degrees celsius resolution). 53 54The TMP122/TMP124 also feature configurable temperature thresholds. 55 56The LM71 is also very similar; main difference is 14-bit temperature 57data (0.03125 degrees celsius resolution). 58 59Thanks to 60--------- 61Jean Delvare <jdelvare@suse.de> for mentoring the hwmon-side driver 62development. 63