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Diffstat (limited to 'Documentation/hwmon/ads7828')
| -rw-r--r-- | Documentation/hwmon/ads7828 | 46 |
1 files changed, 34 insertions, 12 deletions
diff --git a/Documentation/hwmon/ads7828 b/Documentation/hwmon/ads7828 index 2bbebe6f771f..f6e263e0f607 100644 --- a/Documentation/hwmon/ads7828 +++ b/Documentation/hwmon/ads7828 @@ -4,29 +4,47 @@ Kernel driver ads7828 Supported chips: * Texas Instruments/Burr-Brown ADS7828 Prefix: 'ads7828' - Addresses scanned: I2C 0x48, 0x49, 0x4a, 0x4b - Datasheet: Publicly available at the Texas Instruments website : + Datasheet: Publicly available at the Texas Instruments website: http://focus.ti.com/lit/ds/symlink/ads7828.pdf + * Texas Instruments ADS7830 + Prefix: 'ads7830' + Datasheet: Publicly available at the Texas Instruments website: + http://focus.ti.com/lit/ds/symlink/ads7830.pdf + Authors: Steve Hardy <shardy@redhat.com> + Vivien Didelot <vivien.didelot@savoirfairelinux.com> + Guillaume Roguez <guillaume.roguez@savoirfairelinux.com> + +Platform data +------------- + +The ads7828 driver accepts an optional ads7828_platform_data structure (defined +in include/linux/platform_data/ads7828.h). The structure fields are: -Module Parameters ------------------ +* diff_input: (bool) Differential operation + set to true for differential mode, false for default single ended mode. -* se_input: bool (default Y) - Single ended operation - set to N for differential mode -* int_vref: bool (default Y) - Operate with the internal 2.5V reference - set to N for external reference -* vref_mv: int (default 2500) - If using an external reference, set this to the reference voltage in mV +* ext_vref: (bool) External reference + set to true if it operates with an external reference, false for default + internal reference. + +* vref_mv: (unsigned int) Voltage reference + if using an external reference, set this to the reference voltage in mV, + otherwise it will default to the internal value (2500mV). This value will be + bounded with limits accepted by the chip, described in the datasheet. + + If no structure is provided, the configuration defaults to single ended + operation and internal voltage reference (2.5V). Description ----------- -This driver implements support for the Texas Instruments ADS7828. +This driver implements support for the Texas Instruments ADS7828 and ADS7830. -This device is a 12-bit 8-channel A-D converter. +The ADS7828 device is a 12-bit 8-channel A/D converter, while the ADS7830 does +8-bit sampling. It can operate in single ended mode (8 +ve inputs) or in differential mode, where 4 differential pairs can be measured. @@ -34,3 +52,7 @@ where 4 differential pairs can be measured. The chip also has the facility to use an external voltage reference. This may be required if your hardware supplies the ADS7828 from a 5V supply, see the datasheet for more details. + +There is no reliable way to identify this chip, so the driver will not scan +some addresses to try to auto-detect it. That means that you will have to +statically declare the device in the platform support code. |