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Diffstat (limited to 'kernel/Documentation/hwmon/lm70')
| -rw-r--r-- | kernel/Documentation/hwmon/lm70 | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/kernel/Documentation/hwmon/lm70 b/kernel/Documentation/hwmon/lm70 new file mode 100644 index 000000000..1bb2db440 --- /dev/null +++ b/kernel/Documentation/hwmon/lm70 @@ -0,0 +1,47 @@ +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. |