| Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 1 | Kernel driver lm70 |
| 2 | ================== |
| 3 | |
| Manuel Lauss | c8ac32e | 2009-01-07 16:37:34 +0100 | [diff] [blame] | 4 | Supported chips: |
| Mauro Carvalho Chehab | b04f2f7 | 2019-04-17 06:46:28 -0300 | [diff] [blame] | 5 | |
| Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 6 | * National Semiconductor LM70 |
| Mauro Carvalho Chehab | b04f2f7 | 2019-04-17 06:46:28 -0300 | [diff] [blame] | 7 | |
| Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 8 | Datasheet: http://www.national.com/pf/LM/LM70.html |
| Mauro Carvalho Chehab | b04f2f7 | 2019-04-17 06:46:28 -0300 | [diff] [blame] | 9 | |
| Manuel Lauss | c8ac32e | 2009-01-07 16:37:34 +0100 | [diff] [blame] | 10 | * Texas Instruments TMP121/TMP123 |
| Mauro Carvalho Chehab | b04f2f7 | 2019-04-17 06:46:28 -0300 | [diff] [blame] | 11 | |
| Manuel Lauss | c8ac32e | 2009-01-07 16:37:34 +0100 | [diff] [blame] | 12 | Information: http://focus.ti.com/docs/prod/folders/print/tmp121.html |
| Mauro Carvalho Chehab | b04f2f7 | 2019-04-17 06:46:28 -0300 | [diff] [blame] | 13 | |
| Florian Fainelli | 68f0c8c | 2017-01-21 11:20:10 -0800 | [diff] [blame] | 14 | * Texas Instruments TMP122/TMP124 |
| Mauro Carvalho Chehab | b04f2f7 | 2019-04-17 06:46:28 -0300 | [diff] [blame] | 15 | |
| Alexander A. Klimov | ad736c1 | 2020-07-19 19:55:12 +0200 | [diff] [blame] | 16 | Information: https://www.ti.com/product/tmp122 |
| Mauro Carvalho Chehab | b04f2f7 | 2019-04-17 06:46:28 -0300 | [diff] [blame] | 17 | |
| Christophe Leroy | a86e94d | 2012-09-05 11:49:14 +0200 | [diff] [blame] | 18 | * National Semiconductor LM71 |
| Mauro Carvalho Chehab | b04f2f7 | 2019-04-17 06:46:28 -0300 | [diff] [blame] | 19 | |
| Alexander A. Klimov | ad736c1 | 2020-07-19 19:55:12 +0200 | [diff] [blame] | 20 | Datasheet: https://www.ti.com/product/LM71 |
| Mauro Carvalho Chehab | b04f2f7 | 2019-04-17 06:46:28 -0300 | [diff] [blame] | 21 | |
| Christophe Leroy | a86e94d | 2012-09-05 11:49:14 +0200 | [diff] [blame] | 22 | * National Semiconductor LM74 |
| Mauro Carvalho Chehab | b04f2f7 | 2019-04-17 06:46:28 -0300 | [diff] [blame] | 23 | |
| Alexander A. Klimov | ad736c1 | 2020-07-19 19:55:12 +0200 | [diff] [blame] | 24 | Datasheet: https://www.ti.com/product/LM74 |
| Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 25 | |
| Mauro Carvalho Chehab | b04f2f7 | 2019-04-17 06:46:28 -0300 | [diff] [blame] | 26 | |
| Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 27 | Author: |
| Mauro Carvalho Chehab | b04f2f7 | 2019-04-17 06:46:28 -0300 | [diff] [blame] | 28 | Kaiwan N Billimoria <kaiwan@designergraphix.com> |
| Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 29 | |
| 30 | Description |
| 31 | ----------- |
| 32 | |
| 33 | This driver implements support for the National Semiconductor LM70 |
| 34 | temperature sensor. |
| 35 | |
| 36 | The LM70 temperature sensor chip supports a single temperature sensor. |
| 37 | It communicates with a host processor (or microcontroller) via an |
| 38 | SPI/Microwire Bus interface. |
| 39 | |
| 40 | Communication with the LM70 is simple: when the temperature is to be sensed, |
| 41 | the driver accesses the LM70 using SPI communication: 16 SCLK cycles |
| 42 | comprise the MOSI/MISO loop. At the end of the transfer, the 11-bit 2's |
| 43 | complement digital temperature (sent via the SIO line), is available in the |
| 44 | driver for interpretation. This driver makes use of the kernel's in-core |
| 45 | SPI support. |
| 46 | |
| Kaiwan N Billimoria | 2b73005 | 2009-01-07 16:37:34 +0100 | [diff] [blame] | 47 | As a real (in-tree) example of this "SPI protocol driver" interfacing |
| 48 | with a "SPI master controller driver", see drivers/spi/spi_lm70llp.c |
| 49 | and its associated documentation. |
| 50 | |
| Florian Fainelli | 68f0c8c | 2017-01-21 11:20:10 -0800 | [diff] [blame] | 51 | The LM74 and TMP121/TMP122/TMP123/TMP124 are very similar; main difference is |
| 52 | 13-bit temperature data (0.0625 degrees celsius resolution). |
| 53 | |
| 54 | The TMP122/TMP124 also feature configurable temperature thresholds. |
| Christophe Leroy | a86e94d | 2012-09-05 11:49:14 +0200 | [diff] [blame] | 55 | |
| 56 | The LM71 is also very similar; main difference is 14-bit temperature |
| 57 | data (0.03125 degrees celsius resolution). |
| Manuel Lauss | c8ac32e | 2009-01-07 16:37:34 +0100 | [diff] [blame] | 58 | |
| Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 59 | Thanks to |
| 60 | --------- |
| Jean Delvare | 7c81c60f | 2014-01-29 20:40:08 +0100 | [diff] [blame] | 61 | Jean Delvare <jdelvare@suse.de> for mentoring the hwmon-side driver |
| Kaiwan N Billimoria | e1a8e91 | 2006-06-12 22:00:05 +0200 | [diff] [blame] | 62 | development. |