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