0001 Kernel driver lm70
0002 ==================
0003
0004 Supported chips:
0005
0006 * National Semiconductor LM70
0007
0008 Datasheet: http://www.national.com/pf/LM/LM70.html
0009
0010 * Texas Instruments TMP121/TMP123
0011
0012 Information: http://focus.ti.com/docs/prod/folders/print/tmp121.html
0013
0014 * Texas Instruments TMP122/TMP124
0015
0016 Information: https://www.ti.com/product/tmp122
0017
0018 * Texas Instruments TMP125
0019
0020 Information: https://www.ti.com/product/tmp125
0021
0022 * National Semiconductor LM71
0023
0024 Datasheet: https://www.ti.com/product/LM71
0025
0026 * National Semiconductor LM74
0027
0028 Datasheet: https://www.ti.com/product/LM74
0029
0030
0031 Author:
0032 Kaiwan N Billimoria <kaiwan@designergraphix.com>
0033
0034 Description
0035 -----------
0036
0037 This driver implements support for the National Semiconductor LM70
0038 temperature sensor.
0039
0040 The LM70 temperature sensor chip supports a single temperature sensor.
0041 It communicates with a host processor (or microcontroller) via an
0042 SPI/Microwire Bus interface.
0043
0044 Communication with the LM70 is simple: when the temperature is to be sensed,
0045 the driver accesses the LM70 using SPI communication: 16 SCLK cycles
0046 comprise the MOSI/MISO loop. At the end of the transfer, the 11-bit 2's
0047 complement digital temperature (sent via the SIO line), is available in the
0048 driver for interpretation. This driver makes use of the kernel's in-core
0049 SPI support.
0050
0051 As a real (in-tree) example of this "SPI protocol driver" interfacing
0052 with a "SPI master controller driver", see drivers/spi/spi_lm70llp.c
0053 and its associated documentation.
0054
0055 The LM74 and TMP121/TMP122/TMP123/TMP124 are very similar; main difference is
0056 13-bit temperature data (0.0625 degrees celsius resolution).
0057
0058 The TMP122/TMP124 also feature configurable temperature thresholds.
0059
0060 The TMP125 is less accurate and provides 10-bit temperature data
0061 with 0.25 degrees Celsius resolution.
0062
0063 The LM71 is also very similar; main difference is 14-bit temperature
0064 data (0.03125 degrees celsius resolution).
0065
0066 Thanks to
0067 ---------
0068 Jean Delvare <jdelvare@suse.de> for mentoring the hwmon-side driver
0069 development.
