1Kernel driver ads7828 2===================== 3 4Supported chips: 5 6 * Texas Instruments/Burr-Brown ADS7828 7 8 Prefix: 'ads7828' 9 10 Datasheet: Publicly available at the Texas Instruments website: 11 12 http://focus.ti.com/lit/ds/symlink/ads7828.pdf 13 14 * Texas Instruments ADS7830 15 16 Prefix: 'ads7830' 17 18 Datasheet: Publicly available at the Texas Instruments website: 19 20 http://focus.ti.com/lit/ds/symlink/ads7830.pdf 21 22Authors: 23 - Steve Hardy <shardy@redhat.com> 24 - Vivien Didelot <vivien.didelot@savoirfairelinux.com> 25 - Guillaume Roguez <guillaume.roguez@savoirfairelinux.com> 26 27Platform data 28------------- 29 30The ads7828 driver accepts an optional ads7828_platform_data structure (defined 31in include/linux/platform_data/ads7828.h). The structure fields are: 32 33* diff_input: (bool) Differential operation 34 set to true for differential mode, false for default single ended mode. 35 36* ext_vref: (bool) External reference 37 set to true if it operates with an external reference, false for default 38 internal reference. 39 40* vref_mv: (unsigned int) Voltage reference 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. 44 45 If no structure is provided, the configuration defaults to single ended 46 operation and internal voltage reference (2.5V). 47 48Description 49----------- 50 51This driver implements support for the Texas Instruments ADS7828 and ADS7830. 52 53The ADS7828 device is a 12-bit 8-channel A/D converter, while the ADS7830 does 548-bit sampling. 55 56It can operate in single ended mode (8 +ve inputs) or in differential mode, 57where 4 differential pairs can be measured. 58 59The chip also has the facility to use an external voltage reference. This 60may be required if your hardware supplies the ADS7828 from a 5V supply, see 61the datasheet for more details. 62 63There is no reliable way to identify this chip, so the driver will not scan 64some addresses to try to auto-detect it. That means that you will have to 65statically declare the device in the platform support code. 66