mirror of
https://github.com/torvalds/linux.git
synced 2024-11-23 20:51:44 +00:00
0962e0f1a5
The ADS7830 device is almost the same as the ADS7828, except that it does 8-bit sampling, instead of 12-bit. This patch extends the ads7828 driver to support this chip. Signed-off-by: Guillaume Roguez <guillaume.roguez@savoirfairelinux.com> Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
59 lines
2.1 KiB
Plaintext
59 lines
2.1 KiB
Plaintext
Kernel driver ads7828
|
|
=====================
|
|
|
|
Supported chips:
|
|
* Texas Instruments/Burr-Brown ADS7828
|
|
Prefix: 'ads7828'
|
|
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:
|
|
|
|
* diff_input: (bool) Differential operation
|
|
set to true for differential mode, false for default single ended mode.
|
|
|
|
* 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 and ADS7830.
|
|
|
|
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.
|
|
|
|
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.
|