aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation/hwmon/ads7828
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/hwmon/ads7828')
-rw-r--r--Documentation/hwmon/ads782846
1 files changed, 34 insertions, 12 deletions
diff --git a/Documentation/hwmon/ads7828 b/Documentation/hwmon/ads7828
index 2bbebe6f771..f6e263e0f60 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.