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 * National Semiconductor LM71 10 Datasheet: http://www.ti.com/product/LM71 11 * National Semiconductor LM74 12 Datasheet: http://www.ti.com/product/LM74 13 14Author: 15 Kaiwan N Billimoria <kaiwan@designergraphix.com> 16 17Description 18----------- 19 20This driver implements support for the National Semiconductor LM70 21temperature sensor. 22 23The LM70 temperature sensor chip supports a single temperature sensor. 24It communicates with a host processor (or microcontroller) via an 25SPI/Microwire Bus interface. 26 27Communication with the LM70 is simple: when the temperature is to be sensed, 28the driver accesses the LM70 using SPI communication: 16 SCLK cycles 29comprise the MOSI/MISO loop. At the end of the transfer, the 11-bit 2's 30complement digital temperature (sent via the SIO line), is available in the 31driver for interpretation. This driver makes use of the kernel's in-core 32SPI support. 33 34As a real (in-tree) example of this "SPI protocol driver" interfacing 35with a "SPI master controller driver", see drivers/spi/spi_lm70llp.c 36and its associated documentation. 37 38The LM74 and TMP121/TMP123 are very similar; main difference is 13-bit 39temperature data (0.0625 degrees celsius resolution). 40 41The LM71 is also very similar; main difference is 14-bit temperature 42data (0.03125 degrees celsius resolution). 43 44Thanks to 45--------- 46Jean Delvare <jdelvare@suse.de> for mentoring the hwmon-side driver 47development. 48