diff options
| author | Vivien Didelot <vivien.didelot@savoirfairelinux.com> | 2012-08-30 21:42:57 -0400 |
|---|---|---|
| committer | Guenter Roeck <linux@roeck-us.net> | 2012-09-23 21:08:33 -0700 |
| commit | 6c1fe725fd76f4328e22c146d3a36513963a01ea (patch) | |
| tree | 23c2fabf8c2e38beac375353dde793138366a37c /Documentation/hwmon/max197 | |
| parent | 37f9648b2745fc3830f3715a601f7f94296de838 (diff) | |
hwmon: add Maxim MAX197 support
The MAX197 is an A/D converter, made by Maxim. This driver currently
supports the MAX197, and MAX199. They are both 8-Channel, Multi-Range,
5V, 12-Bit DAS with 8+4 Bus Interface and Fault Protection.
The available ranges for the MAX197 are {0,-5V} to 5V, and {0,-10V} to
10V, while they are {0,-2V} to 2V, and {0,-4V} to 4V on the MAX199.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'Documentation/hwmon/max197')
| -rw-r--r-- | Documentation/hwmon/max197 | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/Documentation/hwmon/max197 b/Documentation/hwmon/max197 new file mode 100644 index 000000000000..8d89b9009df8 --- /dev/null +++ b/Documentation/hwmon/max197 @@ -0,0 +1,60 @@ +Maxim MAX197 driver +=================== + +Author: + * Vivien Didelot <vivien.didelot@savoirfairelinux.com> + +Supported chips: + * Maxim MAX197 + Prefix: 'max197' + Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX197.pdf + + * Maxim MAX199 + Prefix: 'max199' + Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX199.pdf + +Description +----------- + +The A/D converters MAX197, and MAX199 are both 8-Channel, Multi-Range, 5V, +12-Bit DAS with 8+4 Bus Interface and Fault Protection. + +The available ranges for the MAX197 are {0,-5V} to 5V, and {0,-10V} to 10V, +while they are {0,-2V} to 2V, and {0,-4V} to 4V on the MAX199. + +Platform data +------------- + +The MAX197 platform data (defined in linux/platform_data/max197.h) should be +filled with a pointer to a conversion function, defined like: + + int convert(u8 ctrl); + +ctrl is the control byte to write to start a new conversion. +On success, the function must return the 12-bit raw value read from the chip, +or a negative error code otherwise. + +Control byte format: + +Bit Name Description +7,6 PD1,PD0 Clock and Power-Down modes +5 ACQMOD Internal or External Controlled Acquisition +4 RNG Full-scale voltage magnitude at the input +3 BIP Unipolar or Bipolar conversion mode +2,1,0 A2,A1,A0 Channel + +Sysfs interface +--------------- + +* in[0-7]_input: The conversion value for the corresponding channel. + RO + +* in[0-7]_min: The lower limit (in mV) for the corresponding channel. + For the MAX197, it will be adjusted to -10000, -5000, or 0. + For the MAX199, it will be adjusted to -4000, -2000, or 0. + RW + +* in[0-7]_max: The higher limit (in mV) for the corresponding channel. + For the MAX197, it will be adjusted to 0, 5000, or 10000. + For the MAX199, it will be adjusted to 0, 2000, or 4000. + RW |