Root/Documentation/hwmon/lm70

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

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