| 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. |
| |