| Steve Hardy | 5812f92 | 2008-01-22 23:00:02 +0000 | [diff] [blame] | 1 | Kernel driver ads7828 |
| 2 | ===================== |
| 3 | |
| 4 | Supported chips: |
| Mauro Carvalho Chehab | b04f2f7 | 2019-04-17 06:46:28 -0300 | [diff] [blame] | 5 | |
| Steve Hardy | 5812f92 | 2008-01-22 23:00:02 +0000 | [diff] [blame] | 6 | * Texas Instruments/Burr-Brown ADS7828 |
| Mauro Carvalho Chehab | b04f2f7 | 2019-04-17 06:46:28 -0300 | [diff] [blame] | 7 | |
| Steve Hardy | 5812f92 | 2008-01-22 23:00:02 +0000 | [diff] [blame] | 8 | Prefix: 'ads7828' |
| Mauro Carvalho Chehab | b04f2f7 | 2019-04-17 06:46:28 -0300 | [diff] [blame] | 9 | |
| Vivien Didelot | 46d7846 | 2012-10-03 16:54:07 -0400 | [diff] [blame] | 10 | Datasheet: Publicly available at the Texas Instruments website: |
| Mauro Carvalho Chehab | b04f2f7 | 2019-04-17 06:46:28 -0300 | [diff] [blame] | 11 | |
| 12 | http://focus.ti.com/lit/ds/symlink/ads7828.pdf |
| Steve Hardy | 5812f92 | 2008-01-22 23:00:02 +0000 | [diff] [blame] | 13 | |
| Guillaume Roguez | 0962e0f | 2012-10-03 16:54:08 -0400 | [diff] [blame] | 14 | * Texas Instruments ADS7830 |
| Mauro Carvalho Chehab | b04f2f7 | 2019-04-17 06:46:28 -0300 | [diff] [blame] | 15 | |
| Guillaume Roguez | 0962e0f | 2012-10-03 16:54:08 -0400 | [diff] [blame] | 16 | Prefix: 'ads7830' |
| Mauro Carvalho Chehab | b04f2f7 | 2019-04-17 06:46:28 -0300 | [diff] [blame] | 17 | |
| Guillaume Roguez | 0962e0f | 2012-10-03 16:54:08 -0400 | [diff] [blame] | 18 | Datasheet: Publicly available at the Texas Instruments website: |
| Mauro Carvalho Chehab | b04f2f7 | 2019-04-17 06:46:28 -0300 | [diff] [blame] | 19 | |
| 20 | http://focus.ti.com/lit/ds/symlink/ads7830.pdf |
| Guillaume Roguez | 0962e0f | 2012-10-03 16:54:08 -0400 | [diff] [blame] | 21 | |
| Steve Hardy | 5812f92 | 2008-01-22 23:00:02 +0000 | [diff] [blame] | 22 | Authors: |
| Mauro Carvalho Chehab | b04f2f7 | 2019-04-17 06:46:28 -0300 | [diff] [blame] | 23 | - Steve Hardy <shardy@redhat.com> |
| 24 | - Vivien Didelot <vivien.didelot@savoirfairelinux.com> |
| 25 | - Guillaume Roguez <guillaume.roguez@savoirfairelinux.com> |
| Steve Hardy | 5812f92 | 2008-01-22 23:00:02 +0000 | [diff] [blame] | 26 | |
| Vivien Didelot | 46d7846 | 2012-10-03 16:54:07 -0400 | [diff] [blame] | 27 | Platform data |
| 28 | ------------- |
| Steve Hardy | 5812f92 | 2008-01-22 23:00:02 +0000 | [diff] [blame] | 29 | |
| Vivien Didelot | 46d7846 | 2012-10-03 16:54:07 -0400 | [diff] [blame] | 30 | The ads7828 driver accepts an optional ads7828_platform_data structure (defined |
| 31 | in include/linux/platform_data/ads7828.h). The structure fields are: |
| 32 | |
| 33 | * diff_input: (bool) Differential operation |
| Mauro Carvalho Chehab | b04f2f7 | 2019-04-17 06:46:28 -0300 | [diff] [blame] | 34 | set to true for differential mode, false for default single ended mode. |
| Vivien Didelot | 46d7846 | 2012-10-03 16:54:07 -0400 | [diff] [blame] | 35 | |
| 36 | * ext_vref: (bool) External reference |
| Mauro Carvalho Chehab | b04f2f7 | 2019-04-17 06:46:28 -0300 | [diff] [blame] | 37 | set to true if it operates with an external reference, false for default |
| 38 | internal reference. |
| Vivien Didelot | 46d7846 | 2012-10-03 16:54:07 -0400 | [diff] [blame] | 39 | |
| 40 | * vref_mv: (unsigned int) Voltage reference |
| Mauro Carvalho Chehab | b04f2f7 | 2019-04-17 06:46:28 -0300 | [diff] [blame] | 41 | if using an external reference, set this to the reference voltage in mV, |
| 42 | otherwise it will default to the internal value (2500mV). This value will be |
| 43 | bounded with limits accepted by the chip, described in the datasheet. |
| Vivien Didelot | 46d7846 | 2012-10-03 16:54:07 -0400 | [diff] [blame] | 44 | |
| 45 | If no structure is provided, the configuration defaults to single ended |
| 46 | operation and internal voltage reference (2.5V). |
| Steve Hardy | 5812f92 | 2008-01-22 23:00:02 +0000 | [diff] [blame] | 47 | |
| 48 | Description |
| 49 | ----------- |
| 50 | |
| Guillaume Roguez | 0962e0f | 2012-10-03 16:54:08 -0400 | [diff] [blame] | 51 | This driver implements support for the Texas Instruments ADS7828 and ADS7830. |
| Steve Hardy | 5812f92 | 2008-01-22 23:00:02 +0000 | [diff] [blame] | 52 | |
| Guillaume Roguez | 0962e0f | 2012-10-03 16:54:08 -0400 | [diff] [blame] | 53 | The ADS7828 device is a 12-bit 8-channel A/D converter, while the ADS7830 does |
| 54 | 8-bit sampling. |
| Steve Hardy | 5812f92 | 2008-01-22 23:00:02 +0000 | [diff] [blame] | 55 | |
| 56 | It can operate in single ended mode (8 +ve inputs) or in differential mode, |
| 57 | where 4 differential pairs can be measured. |
| 58 | |
| 59 | The chip also has the facility to use an external voltage reference. This |
| 60 | may be required if your hardware supplies the ADS7828 from a 5V supply, see |
| 61 | the datasheet for more details. |
| Vivien Didelot | 46d7846 | 2012-10-03 16:54:07 -0400 | [diff] [blame] | 62 | |
| 63 | There is no reliable way to identify this chip, so the driver will not scan |
| 64 | some addresses to try to auto-detect it. That means that you will have to |
| 65 | statically declare the device in the platform support code. |