View source for Subsystem History

= History of the i2c subsystem =

This document lists the important changes that happened to the i2c subsystem over time. Device driver changes are purposely not listed. Changes are listed from newest to oldest.

{| class="wikitable"
|-
! Kernel version
! Changes
|-
| 3.6
|
* An unlocked flavor of function <code>i2c_transfer</code> was exported ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commit;h=b37d2a3a75cb0e72e18c29336cb2095b63dabfc8 commit]).
* SCCB support was added ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commit;h=d47726c52122d64253ae56e0fafdb7d0b954e97c 1/2], [http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commit;h=72fc2c7f78b0c365454e60ad33b0e74aea43e3ab 2/2]).
|-
| 3.5
|
* Helper function <code>i2c_verify_adapter</code> was added ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commit;h=643dd09eb27b40ced671564edbe2640935fe37c2 commit]).
* Support for <code>I2C_M_RECV_LEN</code> was added to i2c-dev ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commit;h=838bfa6049fb84dc66c9c9bbeb3a968ec987fd3d commit]).
* <code>I2C_M_NOSTART</code> support was split out of <code>I2C_FUNC_PROTOCOL_MANGLING</code> ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commit;h=14674e70119ea01549ce593d8901a797f8a90f74 commit]).
|-
| 3.3
|
* The <code>module_i2c_driver</code> helper macro was added ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commit;h=7c92784a546d2945b6d6973a30f7134be78eb7a4 commit]).
|-
| 3.2
|
* Functions for byte-swapped SMBus Read/Write Word were added ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commit;h=06a67848c6681a73e621e47c056490d51a07289f commit]).
* Device name for 10-bit slave address was fixed ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commit;h=cbb44514048a250647c6c6b3df27ff62cb71f7d5 commit]).
|-
| 3.1
|
* Function <code>i2c_add_numbered_adapter</code> was allowed to assign a bus id ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commit;h=488bf314bf219c66922305a1a320950efa86662f commit]).
|-
| 2.6.39
|
* Header file <linux/i2c-id.h> was deleted ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=0c31f8e5720e1191b4cf46a9b5374fe6b857c53c commit]) and <code>i2c_adapter.id</code> was dropped ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=c185a9420bd1c645252249018e6887a968d3e1de commit]).
* The <code>i2c_for_each_dev</code> iterator was made available to drivers ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=7ae31482a8376fb0df3a0c5ff0677a92820c06b7 commit]).
* <code>i2c_driver.attach_adapter</code> and <code>i2c_driver.detach_adapter</code> were deprecated ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=9ea3e941d161f41f920462c50e9b651cc00eccc7 1/2], [http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=fe6fc25857d293546bd400432cdb77866c797c9b 2/2]).
|-
| 2.6.37
|
* Function <code>i2c_parent_is_i2c_adapter</code> was changed to return the parent adapter ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=97cc4d49cfcda1c2dad89c00b62a25b628ce2115 commit]).
* The <code>I2C_CLASS_TV_ANALOG</code> and <code>I2C_CLASS_TV_DIGITAL</code> flags were dropped ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=cbf4bd380a9caa72118525eabe7b82c6a3c8da78 commit]).
|-
| 2.6.36
|
* Support for custom probe functions was added ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=9a94241afcc9a481691a9c29b7460217925b59b8 1/2], [http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=d44f19d586b6113fb5db10e1a36457f0db3b01aa 2/2]).
* Support for multiplexed I2C bus topologies was added ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=0826374bff57411d239f2fcb15da3c35af0a93cd commit]).
|-
| 2.6.35
|
* User-space device lists are now handled per adapter ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=6629dcff19470a894ce294d0adb9cbab94ee1fb9 commit]).
* The same I2C device presence detection logic is used everywhere ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=63e4e80218803ff506b3ea4f2349b17916a35730 1/2], [http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=3a89db5f30576654bf1b0036af9b50ed5ab1b6c5 2/2]).
|-
| 2.6.34
|
* Support for SMBus alert was added ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=b5527a7766f0505dc72efe3cefe5e9dea826f611 commit]).
* Directory drivers/i2c/chips was emptied and deleted ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=6a9bcced518b98a7e52b9e8e96af228b171e0498 commit]).<br />Configuration option I2C_DEBUG_CHIP was dropped ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=e77482d735efa2606c1f2afeebd53e1119d0e5c6 commit]).
* Pre- and post-transfer hooks were added to i2c-algo-bit ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=0a9c14751377a1407f5e35791e13651d2fc7801c commit]).
|-
| 2.6.33
|
* Probe, ignore and force module parameters were dropped ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=c7b25a9e96dc89954ae8d8f473f56fae62030f84 commit]).<br />Structure <code>i2c_client_address_data</code> was dropped ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=c3813d6af177fab19e322f3114b1f64fbcf08d71 commit]).<br />The "kind" parameter of detect driver callbacks was dropped ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=310ec79210d754afe51e2e4a983e846b60179abd commit]).
* The <code>I2C_CLIENT_INSMOD_*</code> macros were dropped ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=1f86df49ddfd0067cce941187d57b2fd2f749a9e 1/2], [http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=e5e9f44c246fbafe723e579e9fe887677beb40e4 2/2]).<br />The <code>I2C_CLIENT_MODULE_PARM</code> macro was dropped ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=7f508118b1c1f9856a1c899a2bd4867a962b0225 commit]).
* Adapter locking moved to real-time mutex ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=194684e596af4bdaebb424166d94a8aa528edfda commit]).
|-
| 2.6.32
| 
* I2C bus segments (i2c_adapter) were converted from class devices to bus devices ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=51298d1257b9f0a356ad66650c9fe2ca5bfa5ae3 1/2], [http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=4f8cf8240a0c8b232c2ae22e019a4ba1d5f19ccd 2/2]).
|-
| 2.6.31
|
* Support for instantiating I2C devices from user-space (using sysfs) was added ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=99cd8e25875a109455b709b5a41d4891b8d8e58e commit]).
|-
| 2.6.25
|
* Migration to the standard device driver binding model was finalized ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=bdc511f438f6ca40307e06edda00331e6ac0f813 1/4], [http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=87c6c22945e5d68eb96dd1e5cb26185253cd5b9d 2/4], [http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=026526f5afcd421dce110f53e4c4e2b9e78753c2 3/4], [http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=9b766b814d6a5f31ca1e9da1ebc08164b9352941 4/4]).
|-
| 2.6.22
|
* Migration to the standard device driver binding model was initiated ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=7b4fbc50fabb810523be522fe7ec5cc40f85c7a1 1/5], [http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=a1d9e6e49f4b473a6945a6b553f5070e8c793e0a 2/5], [http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=9c1600eda42e52796f49b36cf15b9debcfd09bea 3/5], [http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=6e13e641841833cc2aa5baefe89bb04bc388801b 4/5], [http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=12b5053ac58709c7d475888bc18d1f61958afc4e 5/5]).
|-
| 2.6.21
|
* Driver suspend/resume/shutdown support was added ([http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=f37dd80ac2a67e4e4e921f99d34a1ceeb2488abb commit]).
|}