linux/Documentation/misc-devices/eeprom
<<
e="v3e="v3e=//spa6.3e=/spa6 class="lxr_search">e="ve="v3e="v3e="v3typ Searche="v3e=//spa6.3"v3< e=/input typ e"v3< < <1//a>Kernel driver eeprom < <2//a>==================== < <3//a>e< <4//a>Supported chips:e< <5//a> * Any EEPROM chip in>the designated address rangee< <6//a> 3< <7//a> 3< <8//a> 3< <9//a> 3<<<<<<<<<<<<< > a> 3<<<<<<<<<<<<< 11> a> 3<<<<<<<<<<<<< 12> a> 3<<<<<<<<<<<<< 13> a> 3<<<<<<<<<<<<< 14> a> 3<<<<<<<<<<<<< 15> a> 3<<<<<<<<<<<<< 16> a> 3<<<<<<<<<<<<< 17> a> 3<<<<<<<<<<<<< 18//a>e< 19//a> 3<<<<< 2 > a> 3<<<<<24C01<<<<<1K<<<<<<<<<<<<0x50 (shadows at<0x51 - 0x57) < 21> a> 3<<<<<24C01A<<<<1K<<<<<<<<<<<<0x50 - 0x57 (Typical device on DIMMs) < 22> a> 3<<<<<24C02<<<<<2K<<<<<<<<<<<<0x50 - 0x57 < 23> a> 3<<<<<24C04<<<<<4K<<<<<<<<<<<<0x50,<0x52,<0x54,<0x56 < 24> a> 3<<<<<<<<<<<<<<<<<<<<<<<<<<<<<(addiv2.6al data at<0x51,<0x53,<0x55, 0x57) < 25> a> 3<<<<<24C08<<<<<8K<<<<<<<<<<<<0x50,<0x54<(addiv2.6al data at<0x51,<0x52,e< 26> a> 3<<<<<<<<<<<<<<<<<<<<<<<<<<<<<0x53,<0x55, 0x56, 0x57) < 27> a> 3<<<<<24C16<<<<16K<<<<<<<<<<<<0x50 (addiv2.6al data at<0x51 - 0x57) < 28> a> 3<<<<< 29//a>e< 3 > a> 3<<<<< 31> a> 3<<<<< 32> a> 3<<<<< 33> a> 3<<<<< 34> a> 3<<<<< 35> a> 3<<<<< 36//a>e< 37//a>e< 38> a>Authors:e< 39//a> 3<<<<< 4 > a> 3<<<<< 41> a> 3<<<<< 42> a> 3<<<<< 43> a> 3<<<<< 44//a>e< 45> a>Descri v2.6e< 46//a>-----------e< 47//a>e< 48> a>This is a simple EEPROM module meant to enable reading>the first 256 bytes < 49//a>of an EEPROM (on a SDRAM DIMM for example). However, it will access seriale< 5 > a>EEPROMs on any I2C adapter. The supported devices are generically callede< 51> a>24Cxx,the numbering>for thesee< 52> a>industry-standard devices may vary by manufacturer.e< 53//a>e< 54> a>This module was a programming>exercise to get used to the new projecte< 55> a>organizav2.6 laid out by Frodo, but it should be at< 56//a>effective>for decoding>the contents of EEPROMs on DIMMs.e< 57//a>e< 58> a>DIMMS will typically contain a 24C01A< 59> a>The other devices will not be found on a DIMM because they respond to moree< 6 > a>than one address.e< 61//a>e< 62> a>DDC Monitors may contain any device. Often a 24C01, which responds to all 8e< 63//a>addresses, is found.e< 64//a>e< 65> a>Recentan EEPROM at<0x57. We couldn't get thee< 66//a>specificav2.6, so it is guess workcomplete.e< 67//a>e< 68> a>The Microchip 24AA52/24LCS52,an addiv2.6ale< 69> a>software write protect register at<0x30 - 0x37 (0x20< 7 > a>locav2.6). The chip responds to "write quick" detect2.6 at this address bute< 71//a>does not respond to byte reads. If this register is present, the lower 128e< 72> a>bytes of the memory array are not write protected. Any byte data write toe< 73> a>this address will write protect the memory array permanently,< 74//a>device will no longer respond at the 0x30-37 address. The eeprom drivere< 75//a>does not support>this register.e< 76//a>e< 77//a>Lacking>funcv2.6ality:e< 78//a>e< 79> a>* Full support>for larger devices (24C04,<24C08,<24C16). These are note< 8 > a>typically found on a PC. These devices will appear as separate devices ate< 81//a>multiple addresses.e< 82//a>e< 83> a>* Support>for really large devices (24C32,<24C64,<24C128,<24C256, 24C512).e< 84> a>These devices require two-byte address fields and are not supported.e< 85//a>e< 86> a>* Enable Writing. Again, no technical reason why not, but making>it easye< 87//a>to change>the contents of the EEPROMs (on DIMMs anyway) also makes it easye< 88//a>to disable the DIMMs (potentially preventing>the computer from booting) < 89> a>until>the s are restored somehow.e< 90//a>e< 91//a>Use:e< 92//a>e< 93> a>After inserting>the module (and any other required SMBus/i2c modules), youe< 94> a>should have>some EEPROM directories in /sys/bus/i2c/devices/* of nam s suche< 95//a>as "0-0050". Inside each of these is a series of files, the eeprom filee< 96> a>contains the binary data from EEPROM.e< 97//a> The origi6al LXR software by the LXR community//a>,>this experimental vers2.6 by lxr@linux.no//a>. //div.3/div class="subfooter"> lxr.linux.no kindly hosted by Redpill Linpro AS//a>,>provider of Linux consulting>and operav2.6s services since 1995. //div.3 //body.3//html.3