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author | Jean Delvare <khali@linux-fr.org> | 2009-10-04 22:53:40 +0200 |
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committer | Jean Delvare <khali@linux-fr.org> | 2009-10-04 22:53:40 +0200 |
commit | f546c65cd59275c7b95eba4f9b3ab83b38a5e9cb (patch) | |
tree | e8957c44efeb5f331272d092cab974679fa896c8 /Documentation/i2c/chips/max6875 | |
parent | 8a0382f6fceaf0c6479e582e1054f36333ea3d24 (diff) | |
download | kernel_samsung_smdk4412-f546c65cd59275c7b95eba4f9b3ab83b38a5e9cb.tar.gz kernel_samsung_smdk4412-f546c65cd59275c7b95eba4f9b3ab83b38a5e9cb.tar.bz2 kernel_samsung_smdk4412-f546c65cd59275c7b95eba4f9b3ab83b38a5e9cb.zip |
i2c: Move misc devices documentation
Some times ago the eeprom and max6875 drivers moved to
drivers/misc/eeprom, but their documentation did not follow. It's
finally time to get rid of Documentation/i2c/chips.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Ben Gardner <gardner.ben@gmail.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Diffstat (limited to 'Documentation/i2c/chips/max6875')
-rw-r--r-- | Documentation/i2c/chips/max6875 | 108 |
1 files changed, 0 insertions, 108 deletions
diff --git a/Documentation/i2c/chips/max6875 b/Documentation/i2c/chips/max6875 deleted file mode 100644 index 10ca43cd1a7..00000000000 --- a/Documentation/i2c/chips/max6875 +++ /dev/null @@ -1,108 +0,0 @@ -Kernel driver max6875 -===================== - -Supported chips: - * Maxim MAX6874, MAX6875 - Prefix: 'max6875' - Addresses scanned: None (see below) - Datasheet: - http://pdfserv.maxim-ic.com/en/ds/MAX6874-MAX6875.pdf - -Author: Ben Gardner <bgardner@wabtec.com> - - -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 - -See the datasheet for more information. - - -Sysfs entries -------------- - -eeprom - 512 bytes of user-defined EEPROM space. - - -General Remarks ---------------- - -Valid addresses for the MAX6875 are 0x50 and 0x52. -Valid addresses for the MAX6874 are 0x50, 0x52, 0x54 and 0x56. -The driver does not probe any address, so you must force the address. - -Example: -$ modprobe max6875 force=0,0x50 - -The MAX6874/MAX6875 ignores address bit 0, so this driver attaches to multiple -addresses. For example, for address 0x50, it also reserves 0x51. -The even-address instance is called 'max6875', the odd one is 'dummy'. - - -Programming the chip using i2c-dev ----------------------------------- - -Use the i2c-dev interface to access and program the chips. -Reads and writes are performed differently depending on the address range. - -The configuration registers are at addresses 0x00 - 0x45. -Use i2c_smbus_write_byte_data() to write a register and -i2c_smbus_read_byte_data() to read a register. -The command is the register number. - -Examples: -To write a 1 to register 0x45: - i2c_smbus_write_byte_data(fd, 0x45, 1); - -To read register 0x45: - value = i2c_smbus_read_byte_data(fd, 0x45); - - -The configuration EEPROM is at addresses 0x8000 - 0x8045. -The user EEPROM is at addresses 0x8100 - 0x82ff. - -Use i2c_smbus_write_word_data() to write a byte to EEPROM. - -The command is the upper byte of the address: 0x80, 0x81, or 0x82. -The data word is the lower part of the address or'd with data << 8. - cmd = address >> 8; - val = (address & 0xff) | (data << 8); - -Example: -To write 0x5a to address 0x8003: - i2c_smbus_write_word_data(fd, 0x80, 0x5a03); - - -Reading data from the EEPROM is a little more complicated. -Use i2c_smbus_write_byte_data() to set the read address and then -i2c_smbus_read_byte() or i2c_smbus_read_i2c_block_data() to read the data. - -Example: -To read data starting at offset 0x8100, first set the address: - i2c_smbus_write_byte_data(fd, 0x81, 0x00); - -And then read the data - value = i2c_smbus_read_byte(fd); - - or - - count = i2c_smbus_read_i2c_block_data(fd, 0x84, 16, buffer); - -The block read should read 16 bytes. -0x84 is the block read command. - -See the datasheet for more details. - |