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Commit 068345f4 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'i2c-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6 

* 'i2c-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6: (26 commits)
  i2c-rpx: Remove
  i2c-mpc: work around missing-9th-clock-pulse bug
  i2c: New PMC MSP71xx TWI bus driver
  i2c-savage4: Delete many unused defines
  i2c/tsl2550: Speed up initialization
  i2c: New bus driver for the TAOS evaluation modules
  i2c-i801: Use the internal 32-byte buffer on ICH4+
  i2c-i801: Various cleanups
  i2c: Add support for the TSL2550
  i2c-pxa: Support new-style I2C drivers
  i2c-gpio: Make some internal functions static
  i2c-gpio: Add support for new-style clients
  i2c-iop3xx: Switch to static adapter numbering
  i2c-sis5595: Resolve resource conflict with sis5595
  matroxfb: Clean-up i2c header inclusions
  i2c-nforce2: Add support for SMBus block transactions
  i2c-mpc: Use i2c_add_numbered_adapter
  i2c-mv64xxx: Use i2c_add_numbered_adapter
  i2c-piix4: Add support for the ATI SB700
  i2c: New DS1682 chip driver
  ...
parents c3973682 0a85e9a2

Documentation/DocBook/kernel-api.tmpl

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@@ -643,6 +643,60 @@ X!Idrivers/video/console/fonts.c 
!Edrivers/spi/spi.c

  </chapter>



  <chapter id="i2c">

     <title>I<superscript>2</superscript>C and SMBus Subsystem</title>



     <para>

	I<superscript>2</superscript>C (or without fancy typography, "I2C")

	is an acronym for the "Inter-IC" bus, a simple bus protocol which is

	widely used where low data rate communications suffice.

	Since it's also a licensed trademark, some vendors use another

	name (such as "Two-Wire Interface", TWI) for the same bus.

	I2C only needs two signals (SCL for clock, SDA for data), conserving

	board real estate and minimizing signal quality issues.

	Most I2C devices use seven bit addresses, and bus speeds of up

	to 400 kHz; there's a high speed extension (3.4 MHz) that's not yet

	found wide use.

	I2C is a multi-master bus; open drain signaling is used to

	arbitrate between masters, as well as to handshake and to

	synchronize clocks from slower clients.

     </para>



     <para>

	The Linux I2C programming interfaces support only the master

	side of bus interactions, not the slave side.

	The programming interface is structured around two kinds of driver,

	and two kinds of device.

	An I2C "Adapter Driver" abstracts the controller hardware; it binds

	to a physical device (perhaps a PCI device or platform_device) and

	exposes a <structname>struct i2c_adapter</structname> representing

	each I2C bus segment it manages.

	On each I2C bus segment will be I2C devices represented by a

	<structname>struct i2c_client</structname>.  Those devices will

	be bound to a <structname>struct i2c_driver</structname>,

	which should follow the standard Linux driver model.

	(At this writing, a legacy model is more widely used.)

	There are functions to perform various I2C protocol operations; at

	this writing all such functions are usable only from task context.

     </para>



     <para>

	The System Management Bus (SMBus) is a sibling protocol.  Most SMBus

	systems are also I2C conformant.  The electrical constraints are

	tighter for SMBus, and it standardizes particular protocol messages

	and idioms.  Controllers that support I2C can also support most

	SMBus operations, but SMBus controllers don't support all the protocol

	options that an I2C controller will.

	There are functions to perform various SMBus protocol operations,

	either using I2C primitives or by issuing SMBus commands to

	i2c_adapter devices which don't support those I2C operations.

     </para>



!Iinclude/linux/i2c.h

!Fdrivers/i2c/i2c-boardinfo.c i2c_register_board_info

!Edrivers/i2c/i2c-core.c

  </chapter>



  <chapter id="splice">

      <title>splice API</title>

  <para>)
@@ -654,4 +708,5 @@ X!Idrivers/video/console/fonts.c 
!Ffs/splice.c

  </chapter>





</book>

Documentation/feature-removal-schedule.txt

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@@ -330,3 +330,10 @@ Who: Tejun Heo <htejun@gmail.com> 


---------------------------



What:	Legacy RTC drivers (under drivers/i2c/chips)

When:	November 2007

Why:	Obsolete. We have a RTC subsystem with better drivers.

Who:	Jean Delvare <khali@linux-fr.org>



---------------------------

Documentation/i2c/busses/i2c-i801

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@@ -5,8 +5,8 @@ Supported adapters: 
    '810' and '810E' chipsets)

  * Intel 82801BA (ICH2 - part of the '815E' chipset)

  * Intel 82801CA/CAM (ICH3)

  * Intel 82801DB (ICH4) (HW PEC supported, 32 byte buffer not supported)

  * Intel 82801EB/ER (ICH5) (HW PEC supported, 32 byte buffer not supported)

  * Intel 82801DB (ICH4) (HW PEC supported)

  * Intel 82801EB/ER (ICH5) (HW PEC supported)

  * Intel 6300ESB

  * Intel 82801FB/FR/FW/FRW (ICH6)

  * Intel 82801G (ICH7)

Documentation/i2c/busses/i2c-piix4

+1 −1
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@@ -6,7 +6,7 @@ Supported adapters: 
    Datasheet: Publicly available at the Intel website

  * ServerWorks OSB4, CSB5, CSB6 and HT-1000 southbridges

    Datasheet: Only available via NDA from ServerWorks

  * ATI IXP200, IXP300, IXP400 and SB600 southbridges

  * ATI IXP200, IXP300, IXP400, SB600 and SB700 southbridges

    Datasheet: Not publicly available

  * Standard Microsystems (SMSC) SLC90E66 (Victory66) southbridge

    Datasheet: Publicly available at the SMSC website http://www.smsc.com

Documentation/i2c/busses/i2c-taos-evm

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Kernel driver i2c-taos-evm



Author: Jean Delvare <khali@linux-fr.org>



This is a driver for the evaluation modules for TAOS I2C/SMBus chips.

The modules include an SMBus master with limited capabilities, which can

be controlled over the serial port. Virtually all evaluation modules

are supported, but a few lines of code need to be added for each new

module to instantiate the right I2C chip on the bus. Obviously, a driver

for the chip in question is also needed.



Currently supported devices are:



* TAOS TSL2550 EVM



For addtional information on TAOS products, please see

  http://www.taosinc.com/





Using this driver

-----------------



In order to use this driver, you'll need the serport driver, and the

inputattach tool, which is part of the input-utils package. The following

commands will tell the kernel that you have a TAOS EVM on the first

serial port:



# modprobe serport

# inputattach --taos-evm /dev/ttyS0





Technical details

-----------------



Only 4 SMBus transaction types are supported by the TAOS evaluation

modules:

* Receive Byte

* Send Byte

* Read Byte

* Write Byte



The communication protocol is text-based and pretty simple. It is

described in a PDF document on the CD which comes with the evaluation

module. The communication is rather slow, because the serial port has

to operate at 1200 bps. However, I don't think this is a big concern in

practice, as these modules are meant for evaluation and testing only.