1*4882a593SmuzhiyunKernel driver ads7828 2*4882a593Smuzhiyun===================== 3*4882a593Smuzhiyun 4*4882a593SmuzhiyunSupported chips: 5*4882a593Smuzhiyun 6*4882a593Smuzhiyun * Texas Instruments/Burr-Brown ADS7828 7*4882a593Smuzhiyun 8*4882a593Smuzhiyun Prefix: 'ads7828' 9*4882a593Smuzhiyun 10*4882a593Smuzhiyun Datasheet: Publicly available at the Texas Instruments website: 11*4882a593Smuzhiyun 12*4882a593Smuzhiyun http://focus.ti.com/lit/ds/symlink/ads7828.pdf 13*4882a593Smuzhiyun 14*4882a593Smuzhiyun * Texas Instruments ADS7830 15*4882a593Smuzhiyun 16*4882a593Smuzhiyun Prefix: 'ads7830' 17*4882a593Smuzhiyun 18*4882a593Smuzhiyun Datasheet: Publicly available at the Texas Instruments website: 19*4882a593Smuzhiyun 20*4882a593Smuzhiyun http://focus.ti.com/lit/ds/symlink/ads7830.pdf 21*4882a593Smuzhiyun 22*4882a593SmuzhiyunAuthors: 23*4882a593Smuzhiyun - Steve Hardy <shardy@redhat.com> 24*4882a593Smuzhiyun - Vivien Didelot <vivien.didelot@savoirfairelinux.com> 25*4882a593Smuzhiyun - Guillaume Roguez <guillaume.roguez@savoirfairelinux.com> 26*4882a593Smuzhiyun 27*4882a593SmuzhiyunPlatform data 28*4882a593Smuzhiyun------------- 29*4882a593Smuzhiyun 30*4882a593SmuzhiyunThe ads7828 driver accepts an optional ads7828_platform_data structure (defined 31*4882a593Smuzhiyunin include/linux/platform_data/ads7828.h). The structure fields are: 32*4882a593Smuzhiyun 33*4882a593Smuzhiyun* diff_input: (bool) Differential operation 34*4882a593Smuzhiyun set to true for differential mode, false for default single ended mode. 35*4882a593Smuzhiyun 36*4882a593Smuzhiyun* ext_vref: (bool) External reference 37*4882a593Smuzhiyun set to true if it operates with an external reference, false for default 38*4882a593Smuzhiyun internal reference. 39*4882a593Smuzhiyun 40*4882a593Smuzhiyun* vref_mv: (unsigned int) Voltage reference 41*4882a593Smuzhiyun if using an external reference, set this to the reference voltage in mV, 42*4882a593Smuzhiyun otherwise it will default to the internal value (2500mV). This value will be 43*4882a593Smuzhiyun bounded with limits accepted by the chip, described in the datasheet. 44*4882a593Smuzhiyun 45*4882a593Smuzhiyun If no structure is provided, the configuration defaults to single ended 46*4882a593Smuzhiyun operation and internal voltage reference (2.5V). 47*4882a593Smuzhiyun 48*4882a593SmuzhiyunDescription 49*4882a593Smuzhiyun----------- 50*4882a593Smuzhiyun 51*4882a593SmuzhiyunThis driver implements support for the Texas Instruments ADS7828 and ADS7830. 52*4882a593Smuzhiyun 53*4882a593SmuzhiyunThe ADS7828 device is a 12-bit 8-channel A/D converter, while the ADS7830 does 54*4882a593Smuzhiyun8-bit sampling. 55*4882a593Smuzhiyun 56*4882a593SmuzhiyunIt can operate in single ended mode (8 +ve inputs) or in differential mode, 57*4882a593Smuzhiyunwhere 4 differential pairs can be measured. 58*4882a593Smuzhiyun 59*4882a593SmuzhiyunThe chip also has the facility to use an external voltage reference. This 60*4882a593Smuzhiyunmay be required if your hardware supplies the ADS7828 from a 5V supply, see 61*4882a593Smuzhiyunthe datasheet for more details. 62*4882a593Smuzhiyun 63*4882a593SmuzhiyunThere is no reliable way to identify this chip, so the driver will not scan 64*4882a593Smuzhiyunsome addresses to try to auto-detect it. That means that you will have to 65*4882a593Smuzhiyunstatically declare the device in the platform support code. 66