089bd86632
Here is a proposed documentation update for the new max6875 i2c chip driver. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
66 lines
1.8 KiB
Text
66 lines
1.8 KiB
Text
Kernel driver max6875
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=====================
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Supported chips:
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* Maxim MAX6874, MAX6875
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Prefix: 'max6875'
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Addresses scanned: 0x50, 0x52
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Datasheet:
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http://pdfserv.maxim-ic.com/en/ds/MAX6874-MAX6875.pdf
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Author: Ben Gardner <bgardner@wabtec.com>
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Module Parameters
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-----------------
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* allow_write int
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Set to non-zero to enable write permission:
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*0: Read only
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1: Read and write
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Description
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-----------
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The Maxim MAX6875 is an EEPROM-programmable power-supply sequencer/supervisor.
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It provides timed outputs that can be used as a watchdog, if properly wired.
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It also provides 512 bytes of user EEPROM.
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At reset, the MAX6875 reads the configuration EEPROM into its configuration
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registers. The chip then begins to operate according to the values in the
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registers.
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The Maxim MAX6874 is a similar, mostly compatible device, with more intputs
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and outputs:
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vin gpi vout
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MAX6874 6 4 8
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MAX6875 4 3 5
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MAX6874 chips can have four different addresses (as opposed to only two for
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the MAX6875). The additional addresses (0x54 and 0x56) are not probed by
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this driver by default, but the probe module parameter can be used if
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needed.
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See the datasheet for details on how to program the EEPROM.
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Sysfs entries
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-------------
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eeprom_user - 512 bytes of user-defined EEPROM space. Only writable if
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allow_write was set and register 0x43 is 0.
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eeprom_config - 70 bytes of config EEPROM. Note that changes will not get
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loaded into register space until a power cycle or device reset.
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reg_config - 70 bytes of register space. Any changes take affect immediately.
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General Remarks
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---------------
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A typical application will require that the EEPROMs be programmed once and
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never altered afterwards.
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