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diff --git a/Documentation/i2c/chips/max6875 b/Documentation/i2c/chips/max6875 new file mode 100644 index 0000000..b020028 --- /dev/null +++ b/Documentation/i2c/chips/max6875 @@ -0,0 +1,66 @@ +Kernel driver max6875 +===================== + +Supported chips: + * Maxim MAX6874, MAX6875 + Prefix: 'max6875' + Addresses scanned: 0x50, 0x52 + Datasheet: + http://pdfserv.maxim-ic.com/en/ds/MAX6874-MAX6875.pdf + +Author: Ben Gardner <bgardner@wabtec.com> + + +Module Parameters +----------------- + +* allow_write int + Set to non-zero to enable write permission: + *0: Read only + 1: Read and write + + +Description +----------- + +The Maxim MAX6875 is an EEPROM-programmable power-supply sequencer/supervisor. +It provides timed outputs that can be used as a watchdog, if properly wired. +It also provides 512 bytes of user EEPROM. + +At reset, the MAX6875 reads the configuration EEPROM into its configuration +registers. The chip then begins to operate according to the values in the +registers. + +The Maxim MAX6874 is a similar, mostly compatible device, with more intputs +and outputs: + + vin gpi vout +MAX6874 6 4 8 +MAX6875 4 3 5 + +MAX6874 chips can have four different addresses (as opposed to only two for +the MAX6875). The additional addresses (0x54 and 0x56) are not probed by +this driver by default, but the probe module parameter can be used if +needed. + +See the datasheet for details on how to program the EEPROM. + + +Sysfs entries +------------- + +eeprom_user - 512 bytes of user-defined EEPROM space. Only writable if + allow_write was set and register 0x43 is 0. + +eeprom_config - 70 bytes of config EEPROM. Note that changes will not get + loaded into register space until a power cycle or device reset. + +reg_config - 70 bytes of register space. Any changes take affect immediately. + + +General Remarks +--------------- + +A typical application will require that the EEPROMs be programmed once and +never altered afterwards. + |