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Diffstat (limited to 'kernel/Documentation/hwmon/max197')
| -rw-r--r-- | kernel/Documentation/hwmon/max197 | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/kernel/Documentation/hwmon/max197 b/kernel/Documentation/hwmon/max197 new file mode 100644 index 000000000..8d89b9009 --- /dev/null +++ b/kernel/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 |