66 строки
2.1 KiB
ReStructuredText
66 строки
2.1 KiB
ReStructuredText
Kernel driver ads7828
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=====================
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Supported chips:
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* Texas Instruments/Burr-Brown ADS7828
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Prefix: 'ads7828'
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Datasheet: Publicly available at the Texas Instruments website:
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http://focus.ti.com/lit/ds/symlink/ads7828.pdf
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* Texas Instruments ADS7830
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Prefix: 'ads7830'
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Datasheet: Publicly available at the Texas Instruments website:
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http://focus.ti.com/lit/ds/symlink/ads7830.pdf
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Authors:
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- Steve Hardy <shardy@redhat.com>
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- Vivien Didelot <vivien.didelot@savoirfairelinux.com>
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- Guillaume Roguez <guillaume.roguez@savoirfairelinux.com>
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Platform data
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-------------
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The ads7828 driver accepts an optional ads7828_platform_data structure (defined
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in include/linux/platform_data/ads7828.h). The structure fields are:
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* diff_input: (bool) Differential operation
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set to true for differential mode, false for default single ended mode.
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* ext_vref: (bool) External reference
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set to true if it operates with an external reference, false for default
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internal reference.
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* vref_mv: (unsigned int) Voltage reference
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if using an external reference, set this to the reference voltage in mV,
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otherwise it will default to the internal value (2500mV). This value will be
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bounded with limits accepted by the chip, described in the datasheet.
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If no structure is provided, the configuration defaults to single ended
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operation and internal voltage reference (2.5V).
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Description
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-----------
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This driver implements support for the Texas Instruments ADS7828 and ADS7830.
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The ADS7828 device is a 12-bit 8-channel A/D converter, while the ADS7830 does
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8-bit sampling.
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It can operate in single ended mode (8 +ve inputs) or in differential mode,
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where 4 differential pairs can be measured.
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The chip also has the facility to use an external voltage reference. This
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may be required if your hardware supplies the ADS7828 from a 5V supply, see
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the datasheet for more details.
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There is no reliable way to identify this chip, so the driver will not scan
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some addresses to try to auto-detect it. That means that you will have to
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statically declare the device in the platform support code.
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