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authorMarkus Franke <franm@hrz.tu-chemnitz.de>2012-05-26 00:45:12 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-06-13 16:47:10 -0700
commitfbf7f7b4e2ae40f790828c86d31beff2d49e9ac8 (patch)
tree101a1272b8f1ebdf948945ade2aa7cff1b9a7311 /Documentation/w1
parenta59d6293e5372d7c35212932e083e2a541151eff (diff)
downloadlinux-fbf7f7b4e2ae40f790828c86d31beff2d49e9ac8.tar.gz
w1: Add 1-wire slave device driver for DS28E04-100
Signed-off-by: Markus Franke <franm@hrz.tu-chemnitz.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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+Kernel driver w1_ds28e04
+========================
+
+Supported chips:
+ * Maxim DS28E04-100 4096-Bit Addressable 1-Wire EEPROM with PIO
+
+supported family codes:
+ W1_FAMILY_DS28E04 0x1C
+
+Author: Markus Franke, <franke.m@sebakmt.com> <franm@hrz.tu-chemnitz.de>
+
+Description
+-----------
+
+Support is provided through the sysfs files "eeprom" and "pio". CRC checking
+during memory accesses can optionally be enabled/disabled via the device
+attribute "crccheck". The strong pull-up can optionally be enabled/disabled
+via the module parameter "w1_strong_pullup".
+
+Memory Access
+
+ A read operation on the "eeprom" file reads the given amount of bytes
+ from the EEPROM of the DS28E04.
+
+ A write operation on the "eeprom" file writes the given byte sequence
+ to the EEPROM of the DS28E04. If CRC checking mode is enabled only
+ fully alligned blocks of 32 bytes with valid CRC16 values (in bytes 30
+ and 31) are allowed to be written.
+
+PIO Access
+
+ The 2 PIOs of the DS28E04-100 are accessible via the "pio" sysfs file.
+
+ The current status of the PIO's is returned as an 8 bit value. Bit 0/1
+ represent the state of PIO_0/PIO_1. Bits 2..7 do not care. The PIO's are
+ driven low-active, i.e. the driver delivers/expects low-active values.