| Steve Hardy | 5812f92 | 2008-01-22 23:00:02 +0000 | [diff] [blame] | 1 | Kernel driver ads7828 |
| 2 | ===================== |
| 3 | |
| 4 | Supported chips: |
| 5 | * Texas Instruments/Burr-Brown ADS7828 |
| 6 | Prefix: 'ads7828' |
| Vivien Didelot | 46d7846 | 2012-10-03 16:54:07 -0400 | [diff] [blame] | 7 | Datasheet: Publicly available at the Texas Instruments website: |
| Steve Hardy | 5812f92 | 2008-01-22 23:00:02 +0000 | [diff] [blame] | 8 | http://focus.ti.com/lit/ds/symlink/ads7828.pdf |
| 9 | |
| Guillaume Roguez | 0962e0f | 2012-10-03 16:54:08 -0400 | [diff] [blame] | 10 | * Texas Instruments ADS7830 |
| 11 | Prefix: 'ads7830' |
| 12 | Datasheet: Publicly available at the Texas Instruments website: |
| 13 | http://focus.ti.com/lit/ds/symlink/ads7830.pdf |
| 14 | |
| Steve Hardy | 5812f92 | 2008-01-22 23:00:02 +0000 | [diff] [blame] | 15 | Authors: |
| Steven Hardy | 5d84291 | 2011-01-12 21:55:08 +0100 | [diff] [blame] | 16 | Steve Hardy <shardy@redhat.com> |
| Vivien Didelot | 46d7846 | 2012-10-03 16:54:07 -0400 | [diff] [blame] | 17 | Vivien Didelot <vivien.didelot@savoirfairelinux.com> |
| Guillaume Roguez | 0962e0f | 2012-10-03 16:54:08 -0400 | [diff] [blame] | 18 | Guillaume Roguez <guillaume.roguez@savoirfairelinux.com> |
| Steve Hardy | 5812f92 | 2008-01-22 23:00:02 +0000 | [diff] [blame] | 19 | |
| Vivien Didelot | 46d7846 | 2012-10-03 16:54:07 -0400 | [diff] [blame] | 20 | Platform data |
| 21 | ------------- |
| Steve Hardy | 5812f92 | 2008-01-22 23:00:02 +0000 | [diff] [blame] | 22 | |
| Vivien Didelot | 46d7846 | 2012-10-03 16:54:07 -0400 | [diff] [blame] | 23 | The ads7828 driver accepts an optional ads7828_platform_data structure (defined |
| 24 | in include/linux/platform_data/ads7828.h). The structure fields are: |
| 25 | |
| 26 | * diff_input: (bool) Differential operation |
| 27 | set to true for differential mode, false for default single ended mode. |
| 28 | |
| 29 | * ext_vref: (bool) External reference |
| 30 | set to true if it operates with an external reference, false for default |
| 31 | internal reference. |
| 32 | |
| 33 | * vref_mv: (unsigned int) Voltage reference |
| 34 | if using an external reference, set this to the reference voltage in mV, |
| 35 | otherwise it will default to the internal value (2500mV). This value will be |
| 36 | bounded with limits accepted by the chip, described in the datasheet. |
| 37 | |
| 38 | If no structure is provided, the configuration defaults to single ended |
| 39 | operation and internal voltage reference (2.5V). |
| Steve Hardy | 5812f92 | 2008-01-22 23:00:02 +0000 | [diff] [blame] | 40 | |
| 41 | Description |
| 42 | ----------- |
| 43 | |
| Guillaume Roguez | 0962e0f | 2012-10-03 16:54:08 -0400 | [diff] [blame] | 44 | This driver implements support for the Texas Instruments ADS7828 and ADS7830. |
| Steve Hardy | 5812f92 | 2008-01-22 23:00:02 +0000 | [diff] [blame] | 45 | |
| Guillaume Roguez | 0962e0f | 2012-10-03 16:54:08 -0400 | [diff] [blame] | 46 | The ADS7828 device is a 12-bit 8-channel A/D converter, while the ADS7830 does |
| 47 | 8-bit sampling. |
| Steve Hardy | 5812f92 | 2008-01-22 23:00:02 +0000 | [diff] [blame] | 48 | |
| 49 | It can operate in single ended mode (8 +ve inputs) or in differential mode, |
| 50 | where 4 differential pairs can be measured. |
| 51 | |
| 52 | The chip also has the facility to use an external voltage reference. This |
| 53 | may be required if your hardware supplies the ADS7828 from a 5V supply, see |
| 54 | the datasheet for more details. |
| Vivien Didelot | 46d7846 | 2012-10-03 16:54:07 -0400 | [diff] [blame] | 55 | |
| 56 | There is no reliable way to identify this chip, so the driver will not scan |
| 57 | some addresses to try to auto-detect it. That means that you will have to |
| 58 | statically declare the device in the platform support code. |