6b13f685e
 김민수
BSP 최초 추가
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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
* National Semiconductor LM71
Datasheet: http://www.ti.com/product/LM71
* National Semiconductor LM74
Datasheet: http://www.ti.com/product/LM74
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 LM74 and TMP121/TMP123 are very similar; main difference is 13-bit
temperature data (0.0625 degrees celsius resolution).
The LM71 is also very similar; main difference is 14-bit temperature
data (0.03125 degrees celsius resolution).
Thanks to
---------
Jean Delvare <jdelvare@suse.de> for mentoring the hwmon-side driver
development.
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