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 2bbebe6f771f..f6e263e0f607 100644
--- a/Documentation/hwmon/ads7828
+++ b/Documentation/hwmon/ads7828
@@ -4,29 +4,47 @@ Kernel driver ads7828
4Supported chips: 4Supported chips:
5 * Texas Instruments/Burr-Brown ADS7828 5 * Texas Instruments/Burr-Brown ADS7828
6 Prefix: 'ads7828' 6 Prefix: 'ads7828'
7 Addresses scanned: I2C 0x48, 0x49, 0x4a, 0x4b 7 Datasheet: Publicly available at the Texas Instruments website:
8 Datasheet: Publicly available at the Texas Instruments website :
9 http://focus.ti.com/lit/ds/symlink/ads7828.pdf 8 http://focus.ti.com/lit/ds/symlink/ads7828.pdf
10 9
10 * Texas Instruments ADS7830
11 Prefix: 'ads7830'
12 Datasheet: Publicly available at the Texas Instruments website:
13 http://focus.ti.com/lit/ds/symlink/ads7830.pdf
14
11Authors: 15Authors:
12 Steve Hardy <shardy@redhat.com> 16 Steve Hardy <shardy@redhat.com>
17 Vivien Didelot <vivien.didelot@savoirfairelinux.com>
18 Guillaume Roguez <guillaume.roguez@savoirfairelinux.com>
19
20Platform data
21-------------
22
23The ads7828 driver accepts an optional ads7828_platform_data structure (defined
24in include/linux/platform_data/ads7828.h). The structure fields are:
13 25
14Module Parameters 26* diff_input: (bool) Differential operation
15----------------- 27 set to true for differential mode, false for default single ended mode.
16 28
17* se_input: bool (default Y) 29* ext_vref: (bool) External reference
18 Single ended operation - set to N for differential mode 30 set to true if it operates with an external reference, false for default
19* int_vref: bool (default Y) 31 internal reference.
20 Operate with the internal 2.5V reference - set to N for external reference 32
21* vref_mv: int (default 2500) 33* vref_mv: (unsigned int) Voltage reference
22 If using an external reference, set this to the reference voltage in mV 34 if using an external reference, set this to the reference voltage in mV,
35 otherwise it will default to the internal value (2500mV). This value will be
36 bounded with limits accepted by the chip, described in the datasheet.
37
38 If no structure is provided, the configuration defaults to single ended
39 operation and internal voltage reference (2.5V).
23 40
24Description 41Description
25----------- 42-----------
26 43
27This driver implements support for the Texas Instruments ADS7828. 44This driver implements support for the Texas Instruments ADS7828 and ADS7830.
28 45
29This device is a 12-bit 8-channel A-D converter. 46The ADS7828 device is a 12-bit 8-channel A/D converter, while the ADS7830 does
478-bit sampling.
30 48
31It can operate in single ended mode (8 +ve inputs) or in differential mode, 49It can operate in single ended mode (8 +ve inputs) or in differential mode,
32where 4 differential pairs can be measured. 50where 4 differential pairs can be measured.
@@ -34,3 +52,7 @@ where 4 differential pairs can be measured.
34The chip also has the facility to use an external voltage reference. This 52The chip also has the facility to use an external voltage reference. This
35may be required if your hardware supplies the ADS7828 from a 5V supply, see 53may be required if your hardware supplies the ADS7828 from a 5V supply, see
36the datasheet for more details. 54the datasheet for more details.
55
56There is no reliable way to identify this chip, so the driver will not scan
57some addresses to try to auto-detect it. That means that you will have to
58statically declare the device in the platform support code.