Commit Graph

263 Commits

Author SHA1 Message Date
Wolfram Sang 976cf2056c i2c: slave: docs: be more precise about the prerequsites
There was some confusion what was needed to utilize the slave support,
so let's be more precise about this. Add an introductory paragraph to
the development section while we are here.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-06-01 08:07:19 +09:00
Wolfram Sang d0c892f59c i2c: slave: add documentation for i2c-slave-eeprom
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-03-27 16:53:39 +01:00
Wolfram Sang 7c60375083 Documentation: i2c: describe the new slave mode
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-03-27 16:53:39 +01:00
Baruch Siach 8421d4fe8e i2c: fix reference to functionality constants definition
Since commit 607ca46e97 ('UAPI: (Scripted) Disintegrate include/linux') the
list of functionality constants moved to include/uapi/linux/i2c.h. Update the
reference accordingly.

Fixes: 607ca46e97 ('UAPI: (Scripted) Disintegrate include/linux')
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-02-19 16:57:48 +01:00
Lars-Peter Clausen 5f835cef77 Documentation: i2c: Use PM ops instead of legacy suspend/resume
New drivers should use PM ops instead of the legacy suspend/resume
callbacks. Update the I2C device driver guides to reflect this.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-12-04 19:09:03 +01:00
Devin Ryles 3eee1799ae i2c: i801: Add DeviceIDs for SunrisePoint LP
Signed-off-by: Devin Ryles <devin.ryles@intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-11-12 17:19:13 +01:00
james.d.ralston@intel.com 3e27a8445c i2c: i801: Add Device IDs for Intel Sunrise Point PCH
This patch adds the I2C/SMBus Device IDs for the Intel Sunrise Point PCH.

Signed-off-by: James Ralston <james.d.ralston@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-10-16 09:16:22 +02:00
Jose Manuel Alarcon Roldan 257d6ef4aa Documentation: i2c: rename variable "register" to "reg"
The example code provided with the i2c device interface documentation
won't compile since it uses the reserved word "register" to name a
variable.

The compiler fails with this error message:

 error: expected identifier or '(' before '=' token
   __u8 register = 0x20; /* Device register to access */
                 ^

Rename the variable "register" to simply "reg" in the example code.

Another couple of typos has been fixed as well.
[Change "! =" to "!=".]

Signed-off-by: Jose Alarcon Roldan <jose.alarcon.roldan@gmail.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-09-07 15:21:13 -07:00
Jean Delvare b299de8391 i2c: i801: Add device ID for Intel Wildcat Point PCH
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-07-17 19:56:23 +02:00
Jean Delvare 2408c17fce i2c: stub: Add support for banked register ranges
Some chips implement banked register ranges. This allows implementing
more registers than the limited 8-bit address space originally allows.
In order to access a register on these chips, you must first select
the proper bank. Add support for this mechanism to the i2c-stub driver
so that such chips can be emulated. All the bank settings are passed
as module parameters.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-07-17 19:56:15 +02:00
Guenter Roeck 6f16b75a41 i2c: stub: Add support for SMBus block commands
SMBus block commands are different to I2C block commands since
the returned data is not normally accessible with byte or word
commands on other command offsets. Add linked list of 'block'
commands to support those commands.

Access mechanism is quite simple: Block commands must be written
before they can be read. Subsequent writes can be partial. Block
read commands always return the number of bytes associated with
the longest previous write.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-07-17 19:11:35 +02:00
Wolfram Sang 9f02fba84b Documentation: i2c: improve section about flags mangling the protocol
Sort the entries alphabetically. Make the introductory paragraph more
precise. Skip useless 'Flag' introduction from the entries. Remove
trailing white spaces from the file. Add missing I2C_M_STOP entry.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-04-06 13:53:48 +02:00
Geert Uytterhoeven 6808b00252 i2c: Spelling s/than/that/
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-03-12 08:15:41 +01:00
Chew, Kean ho 1b31e9b76e i2c: i801: enable Intel BayTrail SMBUS
Add Device ID of Intel BayTrail SMBus Controller.

Signed-off-by: Chew, Kean ho <kean.ho.chew@intel.com>
Signed-off-by: Chew, Chiau Ee <chiau.ee.chew@intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-03-09 21:40:25 +01:00
Wolfram Sang fde1e418ab Documentation: i2c: mention ACPI method for instantiating devices
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Guenter Roeck <linux@roeck-us.net>
2014-02-15 19:46:34 +01:00
Wolfram Sang aeca0fe62a Documentation: i2c: describe devicetree method for instantiating devices
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-02-15 19:46:29 +01:00
Linus Torvalds f7a6ad9fa2 Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull more i2c updates from Wolfram Sang:
 "Mostly bugfixes, small but wanted cleanups, and Paul's init.h removal
  applied"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: rcar: fix NACK error code
  i2c: update i2c_algorithm documentation
  i2c: rcar: use devm_clk_get to ensure clock is properly ref-counted
  i2c: rcar: do not print error if device nacks transfer
  i2c: rely on driver core when sanitizing devices
  i2c: delete non-required instances of include <linux/init.h>
  i2c: acorn: is tristate and should use module.h
  i2c: piix4: Standardize log messages
  i2c: piix4: Use different message for AMD Auxiliary SMBus Controller
  i2c: piix4: Add support for AMD ML and CZ SMBus changes
2014-01-29 19:56:20 -08:00
Linus Torvalds 9076e0cae7 Merge branch 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging
Pull hwmon updates from Jean Delvare:
 "This include it87 driver improvements, and a tree-wide change of my
  e-mail address"

* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
  Update Jean Delvare's e-mail address
  hwmon: (it87) Print proper names for the IT8771E and IT8772E
  hwmon: (it87) Add support for the ITE IT8603E
2014-01-29 18:56:27 -08:00
Jean Delvare 7c81c60f37 Update Jean Delvare's e-mail address
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2014-01-29 20:40:08 +01:00
Shane Huang 032f708bc4 i2c: piix4: Add support for AMD ML and CZ SMBus changes
The locations of SMBus register base address and enablement bit are changed
from AMD ML, which need this patch to be supported.

Signed-off-by: Shane Huang <shane.huang@amd.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@vger.kernel.org
2014-01-24 17:48:51 +01:00
Helia Correia ce5a111a1b Documentation: i2c: Remove obsolete example
Documentation/i2c/fault-codes illustrates EINVAL error code
as follows:

"One example would be a driver trying an SMBus Block Write
with block size outside the range of 1-32 bytes."

However, the actual implementation of i2c subsystem truncates
data length to be 32 bytes.
Hence this example cannot happen anymore, and since it's obsolete,
let's simply remove it from Documentation/i2c/fault-codes.

Signed-off-by: Helia Correia <helia.correia@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-01-09 23:02:46 +01:00
James Ralston afc6592412 i2c: i801: Add Device IDs for Intel Wildcat Point-LP PCH
This patch adds the SMBus Device IDs for the Intel Wildcat Point-LP PCH.

Signed-off-by: James Ralston <james.d.ralston@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-11-14 18:38:04 +01:00
Linus Torvalds 2e515bf096 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree from Jiri Kosina:
 "The usual trivial updates all over the tree -- mostly typo fixes and
  documentation updates"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (52 commits)
  doc: Documentation/cputopology.txt fix typo
  treewide: Convert retrun typos to return
  Fix comment typo for init_cma_reserved_pageblock
  Documentation/trace: Correcting and extending tracepoint documentation
  mm/hotplug: fix a typo in Documentation/memory-hotplug.txt
  power: Documentation: Update s2ram link
  doc: fix a typo in Documentation/00-INDEX
  Documentation/printk-formats.txt: No casts needed for u64/s64
  doc: Fix typo "is is" in Documentations
  treewide: Fix printks with 0x%#
  zram: doc fixes
  Documentation/kmemcheck: update kmemcheck documentation
  doc: documentation/hwspinlock.txt fix typo
  PM / Hibernate: add section for resume options
  doc: filesystems : Fix typo in Documentations/filesystems
  scsi/megaraid fixed several typos in comments
  ppc: init_32: Fix error typo "CONFIG_START_KERNEL"
  treewide: Add __GFP_NOWARN to k.alloc calls with v.alloc fallbacks
  page_isolation: Fix a comment typo in test_pages_isolated()
  doc: fix a typo about irq affinity
  ...
2013-09-06 09:36:28 -07:00
Sachin Kamat 42fa278d70 Documentation: i2c: Fix example in instantiating-devices
__initdata should be placed between the variable name and equal
sign for the variable to be placed in the intended section.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-08-19 19:50:32 +02:00
Rudolf Marek a94dd00f2e i2c: piix4: Add support for secondary SMBus on AMD SB800 and AMD FCH chipsets
Add support for the secondary SMBus controller on the AMD SB800 and AMD FCH
chipsets.

Signed-off-by: Rudolf Marek <r.marek@assembler.cz>
Tested-by: Paul Menzel <paulepanter@users.sourceforge.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-08-15 15:17:31 +02:00
Masanari Iida c9f3f2d8b3 doc: Fix typo in doucmentations
Correct typo (double words) in documentations.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-07-25 12:34:15 +02:00
Linus Torvalds 98f486f18d Merge branch 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
 - new drivers: Kontron PLD, Wondermedia VT
 - mv64xxx driver gained sun4i support and a bigger cleanup
 - duplicate driver 'intel-mid' removed
 - added generic device tree binding for sda holding time (and
   designware driver already uses it)
 - we tried to allow driver probing with only device tree and no i2c
   ids, but I had to revert it because of side effects.  Needs some
   rethinking.
 - driver bugfixes, cleanups...

* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (34 commits)
  i2c-designware: use div_u64 to fix link
  i2c: Kontron PLD i2c bus driver
  i2c: iop3xxx: fix build failure after waitqueue changes
  i2c-designware: make SDA hold time configurable
  i2c: mv64xxx: Set bus frequency to 100kHz if clock-frequency is not provided
  i2c: imx: allow autoloading on dt ids
  i2c: mv64xxx: Fix transfer error code
  i2c: i801: SMBus patch for Intel Coleto Creek DeviceIDs
  i2c: omap: correct usage of the interrupt enable register
  i2c-pxa: prepare clock before use
  Revert "i2c: core: make it possible to match a pure device tree driver"
  i2c: nomadik: allocate adapter number dynamically
  i2c: nomadik: support elder Nomadiks
  i2c: mv64xxx: Add Allwinner sun4i compatible
  i2c: mv64xxx: make the registers offset configurable
  i2c: mv64xxx: Add macros to access parts of registers
  i2c: vt8500: Add support for I2C bus on Wondermedia SoCs
  i2c: designware: fix race between subsequent xfers
  i2c: bfin-twi: Read and write the FIFO in loop
  i2c: core: make it possible to match a pure device tree driver
  ...
2013-07-04 14:02:09 -07:00
Seth Heasley f39901c1be i2c: i801: SMBus patch for Intel Coleto Creek DeviceIDs
This patch adds the i801 SMBus Controller DeviceIDs for the Intel Coleto Creek PCH.

Signed-off-by: Seth Heasley <seth.heasley@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-06-20 21:32:27 +02:00
Shane Huang b996ac90f5 i2c-piix4: Add AMD CZ SMBus device ID
To add AMD CZ SMBus controller device ID.

[bhelgaas: drop pci_ids.h update]
Signed-off-by: Shane Huang <shane.huang@amd.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Cc: stable@vger.kernel.org
2013-06-03 13:02:45 -06:00
Guenter Roeck b104153e36 i2c: Fix my e-mail address in drivers and documentation
My old e-mail address is no longer working.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-03-22 11:18:34 +01:00
James Ralston a3fc0ff00a i2c: i801: Add Device IDs for Intel Wellsburg PCH
This patch adds the SMBus Device IDs for the Intel Wellsburg PCH

Signed-off-by: James Ralston <james.d.ralston@intel.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>
2013-02-15 20:46:01 +01:00
Amaury Decrême 974d6a3797 i2c: sis630: Add SIS964 support
Signed-off-by: Amaury Decrême <amaury.decreme@gmail.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>
2013-02-11 15:59:38 +01:00
Neil Horman 13f35ac14c i2c: Adding support for Intel iSMT SMBus 2.0 host controller
The iSMT (Intel SMBus Message Transport) supports multi-master I2C/SMBus,
as well as IPMI.  It's operation is DMA-based and utilizes descriptors to
initiate transactions on the bus.

The iSMT hardware can act as both a master and a target, although this
driver only supports being a master.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Bill Brown <bill.e.brown@intel.com>
Tested-by: Seth Heasley <seth.heasley@intel.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>
2013-02-10 19:55:25 +01:00
Seth Heasley c2db409cbc i2c: i801: SMBus patch for Intel Avoton DeviceIDs
This patch adds the PCU SMBus DeviceID for the Intel Avoton SOC.

Signed-off-by: Seth Heasley <seth.heasley@intel.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2013-02-08 20:06:29 +01:00
Tushar Behera c811093320 i2c: core: Remove definition of i2c_smbus_process_call
i2c_smbus_process_call has no users in the kernel, so this can be
removed. Documentation for the same has been updated accordingly.

Fixes following sparse warning.
drivers/i2c/i2c-core.c:1871:5: warning: symbol 'i2c_smbus_process_call'
was not declared. Should it be static?

[wsa: updated the documentation]

Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2013-01-28 05:26:41 +01:00
Greg Kroah-Hartman 63a29f744f Documentation: remove __dev* attributes.
CONFIG_HOTPLUG is going away as an option.  As a result, the __dev*
markings need to be removed.

This change removes the use of __devinit, __devexit_p, __devinitdata,
__devinitconst, and __devexit from the kernel documentation.

Based on patches originally written by Bill Pemberton, but redone by me
in order to handle some of the coding style issues better, by hand.

Cc: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-03 15:57:16 -08:00
Jean Delvare a1681781da i2c: Mention functionality flags in SMBus protocol documentation
While the mapping between I2C adapter functionality flags and
i2c_smbus_*() helper functions is rather obvious, let's still document
it for clarity.

Also drop the reference to 2 command byte I2C block reads, there is no
support for that in the kernel at the moment.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-12-16 21:11:55 +01:00
Jean Delvare 600a711cfe i2c-mux-gpio: Update documentation
* Document the possibility to pass relative GPIO pin numbers.
* Document what platform device IDs to use, so that they do not
  collide.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Peter Korsgaard <peter.korsgaard@barco.com>
2012-10-05 22:23:54 +02:00
Jean Delvare 01d56a6aa1 i2c-viapro: Add VIA VX900 device ID
The SMBus controller in the VIA VX900 appears to be compatible with
the VIA VX855, so just add the device ID.

This closes kernel bug #43096.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-10-05 22:23:53 +02:00
James Ralston 4a8f1ddde9 i2c-i801: Add Device IDs for Intel Lynx Point-LP PCH
Add the SMBus Device IDs for the Intel Lynx Point-LP PCH.

Signed-off-by: James Ralston <james.d.ralston@intel.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-09-10 10:14:02 +02:00
Daniel Kurtz 636752bcb5 i2c-i801: Enable IRQ for SMBus transactions
Add a new 'feature' to i2c-i801 to enable using PCI interrupts.
When the feature is enabled, then an isr is installed for the device's
PCI IRQ.

An I2C/SMBus transaction is always terminated by one of the following
interrupt sources: FAILED, BUS_ERR, DEV_ERR, or on success: INTR.

When the isr fires for one of these cases, it sets the ->status variable
and wakes up the waitq.  The waitq then saves off the status code, and
clears ->status (in preparation for some future transaction).
The SMBus controller generates an INTR irq at the end of each
transaction where INTREN was set in the HST_CNT register.

No locking is needed around accesses to priv->status since all writes to
it are serialized: it is only ever set once in the isr at the end of a
transaction, and cleared while no interrupts can occur.  In addition, the
I2C adapter lock guarantees that entire I2C transactions for a single
adapter are always serialized.

For this patch, the INTREN bit is set only for SMBus block, byte and word
transactions, but not for I2C reads or writes.  The use of the DS
(BYTE_DONE) interrupt with byte-by-byte I2C transactions is implemented in
a subsequent patch.

The interrupt feature has only been enabled for COUGARPOINT hardware.
In addition, it is disabled if SMBus is using the SMI# interrupt.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24 14:13:58 +02:00
Jean Delvare 9cd3f2e849 i2c/writing-clients: Mention module_i2c_driver()
Based on a previous patch from Peter Meerwald.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Peter Meerwald <p.meerwald@bct-electronic.com>
2012-07-24 14:13:57 +02:00
Andrew Armenia 2a2f7404a1 i2c-piix4: Support AMD auxiliary SMBus controller
Some AMD chipsets, such as the SP5100, have an auxiliary SMBus
controller with a second set of registers. This patch adds
support for this auxiliary controller.

Tested on ASUS KCMA-D8 motherboard.

Signed-off-by: Andrew Armenia <andrew@asquaredlabs.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24 14:13:57 +02:00
Mark Brown 14674e7011 i2c: Split I2C_M_NOSTART support out of I2C_FUNC_PROTOCOL_MANGLING
Since there are uses for I2C_M_NOSTART which are much more sensible and
standard than most of the protocol mangling functionality (the main one
being gather writes to devices where something like a register address
needs to be inserted before a block of data) create a new I2C_FUNC_NOSTART
for this feature and update all the users to use it.

Also strengthen the disrecommendation of the protocol mangling while we're
at it.

In the case of regmap-i2c we remove the requirement for mangling as
I2C_M_NOSTART is the only mangling feature which is being used.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-05-30 10:55:34 +02:00
Jean Delvare e7065e20d9 i2c: Rename last mux driver to standard pattern
Update the MAINTAINERS entry and all other references accordingly.

Based on an original patch by Wolfram Sang.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Peter Korsgaard <peter.korsgaard@barco.com>

[wsa: fixed merge conflict due to rework in i2c_add_mux_adapter()]

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-05-12 14:28:18 +02:00
Lucas De Marchi 970e248649 Documentation: remove references to /etc/modprobe.conf
Usage of /etc/modprobe.conf file was deprecated by module-init-tools and
is no longer parsed by new kmod tool. References to this file are
replaced in Documentation, comments and Kconfig according to the
context.

There are also some references to the old /etc/modules.conf from 2.4
kernels that are being removed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-30 16:03:15 -07:00
Seth Heasley 062737fb6d i2c-i801: Add device IDs for Intel Lynx Point
Add the SMBus controller device IDs for the Intel Lynx Point PCH.

Signed-off-by: Seth Heasley <seth.heasley@intel.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-03-26 21:47:19 +02:00
Roland Stigge 286431048b USB: ohci-nxp: Rename symbols from pnx4008 to nxp
Since this driver is compatible with several NXP devices, the driver was renamed
accordingly. This patch also changes the respective symbol names.

Signed-off-by: Roland Stigge <stigge@antcom.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-13 14:27:28 -07:00
Jean Delvare cbb4451404 i2c: Fix device name for 10-bit slave address
10-bit addresses overlap with traditional 7-bit addresses, leading in
device name collisions. Add an arbitrary offset to 10-bit addresses to
prevent this collision. The offset was chosen so that the address is
still easily recognizable.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
2011-11-23 11:33:07 +01:00
Jonathan Cameron 06a67848c6 i2c: Functions for byte-swapped smbus_write/read_word_data
Reimplemented at least 17 times discounting error mangling cases
where it could be used.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-10-30 13:47:25 +01:00
Seth Heasley 6e2a851e71 i2c-i801: SMBus patch for Intel Panther Point DeviceIDs
This patch adds the SMBus controller DeviceID for the Intel Panther Point PCH.

Signed-off-by: Seth Heasley <seth.heasley@intel.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-05-24 20:58:49 +02:00
Vikram Narayanan 3116c86033 i2c/writing-clients: Fix foo_driver.id_table
The i2c_device_id structure variable's name is not used in the
i2c_driver structure.

Signed-off-by: Vikram Narayanan <vikram186@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-05-24 20:58:48 +02:00
Lucas De Marchi 25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Linus Torvalds 75ea6358bc Merge branch 'for-linus/2639/i2c-2' of git://git.fluff.org/bjdooks/linux
* 'for-linus/2639/i2c-2' of git://git.fluff.org/bjdooks/linux:
  i2c-pxa2xx: Don't clear isr bits too early
  i2c-pxa2xx: Fix register offsets
  i2c-pxa2xx: pass of_node from platform driver to adapter and publish
  i2c-pxa2xx: check timeout correctly
  i2c-pxa2xx: add support for shared IRQ handler
  i2c-pxa2xx: Add PCI support for PXA I2C controller
  ARM: pxa2xx: reorganize I2C files
  i2c-pxa2xx: use dynamic register layout
  i2c-mxs: set controller to pio queue mode after reset
  i2c-eg20t: support new device OKI SEMICONDUCTOR ML7213 IOH
  i2c/busses: Add support for Diolan U2C-12 USB-I2C adapter
2011-03-22 10:05:27 -07:00
Seth Heasley 662cda8abb i2c-i801: SMBus patch for Intel DH89xxCC DeviceIDs
Add the SMBus Controller DeviceIDs for the Intel DH89xxCC PCH.

Signed-off-by: Seth Heasley <seth.heasley@intel.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-03-20 14:50:53 +01:00
Jean Delvare ed065e26b8 i2c: Minor fixes to upgrading-clients document
* Typical legacy drivers implemented method .detach_client, not
  .detach_adapter.
* Drop all references to __devexit, as i2c drivers shouldn't use it.

Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-03-20 14:50:52 +01:00
Roman Fietze 6ced9e6b39 i2c: Fix typo in instantiating-devices document
The struct i2c_board_info member holding the name is "type", not
"name".

Signed-off-by: Roman Fietze <roman.fietze@telemotive.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: stable@kernel.org
2011-03-20 14:50:52 +01:00
Guenter Roeck 335d7c58fc i2c/busses: Add support for Diolan U2C-12 USB-I2C adapter
This patch adds support for the Diolan U2C-12 USB-I2C adapter.
It also updates MAINTAINERS to list the author as maintainer.

Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2011-01-27 00:39:30 +00:00
Peter Korsgaard 92ed1a76ca i2c: Add generic I2C multiplexer using GPIO API
Add an i2c mux driver providing access to i2c bus segments using a
hardware MUX sitting on a master bus and controlled through gpio pins.

E.G. something like:

  ----------              ----------  Bus segment 1   - - - - -
 |          | SCL/SDA    |          |-------------- |           |
 |          |------------|          |
 |          |            |          | Bus segment 2 |           |
 |  Linux   | GPIO 1..N  |   MUX    |---------------   Devices
 |          |------------|          |               |           |
 |          |            |          | Bus segment M
 |          |            |          |---------------|           |
  ----------              ----------                  - - - - -

SCL/SDA of the master I2C bus is multiplexed to bus segment 1..M
according to the settings of the GPIO pins 1..N.

Signed-off-by: Peter Korsgaard <peter.korsgaard@barco.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-01-10 22:11:23 +01:00
David Woodhouse 55fee8d7f7 i2c-i801: Add PCI idents for Patsburg 'IDF' SMBus controllers
These are the extra 'Integrated Device Function' SMBus controllers found
on the Patsburg chipset. Mention the absence of slave mode support.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-10-31 21:07:00 +01:00
Seth Heasley e30d9859cf i2c-i801: Add Intel Patsburg device ID
Add support for the Intel Patsburg PCH SMBus Controller.

Signed-off-by: Seth Heasley <seth.heasley@intel.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-10-31 21:06:59 +01:00
Jean Delvare 9a94241afc i2c: Add support for custom probe function
The probe method used by i2c_new_probed_device() may not be suitable
for all cases. Let the caller provide its own, optional probe
function.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2010-08-11 18:20:56 +02:00
Justin P. Mattock 0ea6e61122 Documentation: update broken web addresses.
Below you will find an updated version from the original series bunching all patches into one big patch
updating broken web addresses that are located in Documentation/*
Some of the addresses date as far far back as 1995 etc... so searching became a bit difficult,
the best way to deal with these is to use web.archive.org to locate these addresses that are outdated.
Now there are also some addresses pointing to .spec files some are located, but some(after searching
on the companies site)where still no where to be found. In this case I just changed the address
to the company site this way the users can contact the company and they can locate them for the users.

Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
Signed-off-by: Thomas Weber <weber@corscience.de>
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Cc: Paulo Marques <pmarques@grupopie.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Michael Neuling <mikey@neuling.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-08-04 15:21:40 +02:00
Andrea Gelmini 89140f4157 Documentation/i2c: Checkpatch cleanup
Remove all trailing whitespace in Documentation/i2c.

Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-06-03 11:33:50 +02:00
Jean Delvare adff687d8c i2c-i801: Let the user disable selected driver features
Let the user disable selected features normally supported by the
device. This makes it possible to work around possible driver or
hardware bugs if the feature in question doesn't work as intended
for whatever reason.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Felix Rubinstein <felixru@gmail.com>
2010-05-21 18:40:54 +02:00
Wolfram Sang e4a7b9b04d i2c-core: Erase pointer to clientdata on removal
After discovering that a lot of i2c-drivers leave the pointer to their
clientdata dangling, it was decided to let the core handle this issue.
It is assumed that the core may access the private data after remove()
as there are no guarantees for the lifetime of such pointers anyhow (see
thread starting at http://lkml.org/lkml/2010/3/21/68)

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-05-04 11:09:27 +02:00
Zhangfei Gao 0c43ea544c i2c: Document the message size limit
i2c_master_send & i2c_master_recv do not support more than 64 kb
transfer, since msg.len is u16.

Signed-off-by: Zhangfei Gao <zgao6@marvell.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-03-02 12:23:49 +01:00
Jean Delvare 927ab2f807 i2c-parport-light: Add SMBus alert support
Add support for the SMBus alert mechanism to the i2c-parport-light
driver. The ADM1032 evaluation board at least is properly wired for
this.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Trent Piepho <tpiepho@freescale.com>
2010-03-02 12:23:45 +01:00
Jean Delvare 3585925448 i2c-parport: Add SMBus alert support
Add support for the SMBus alert mechanism to the i2c-parport driver.
The ADM1032 evaluation board at least is properly wired for this.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Trent Piepho <tpiepho@freescale.com>
2010-03-02 12:23:44 +01:00
Jean Delvare b5527a7766 i2c: Add SMBus alert support
SMBus alert support. The SMBus alert protocol allows several SMBus
slave devices to share a single interrupt pin on the SMBus master,
while still allowing the master to know which slave triggered the
interrupt.

This is based on preliminary work by David Brownell. The key
difference between David's implementation and mine is that his was
part of i2c-core, while mine is split into a separate, standalone
module named i2c-smbus. The i2c-smbus module is meant to include
support for all SMBus extensions to the I2C protocol in the future.

The benefit of this approach is a zero cost for I2C bus segments which
do not need SMBus alert support. Where David's implementation
increased the size of struct i2c_adapter by 7% (40 bytes on i386),
mine doesn't touch it. Where David's implementation added over 150
lines of code to i2c-core (+10%), mine doesn't touch it. The only
change that touches all the users of the i2c subsystem is a new
callback in struct i2c_driver (common to both implementations.) I seem
to remember Trent was worried about the footprint of David'd
implementation, hopefully mine addresses the issue.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Trent Piepho <tpiepho@freescale.com>
2010-03-02 12:23:42 +01:00
Seth Heasley 393764340b i2c-i801: Add Intel Cougar Point device IDs
Add the Intel Cougar Point (PCH) SMBus controller device IDs.

Signed-off-by: Seth Heasley <seth.heasley@intel.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-03-02 12:23:39 +01:00
Jean Delvare c3813d6af1 i2c: Get rid of struct i2c_client_address_data
Struct i2c_client_address_data only contains one field at this point,
which makes its usefulness questionable. Get rid of it and pass simple
address lists around instead.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Wolfram Sang <w.sang@pengutronix.de>
2009-12-14 21:17:25 +01:00
Jean Delvare 6471b68982 i2c-stub: Documentation update
There is nothing sensors-specific to i2c-stub.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-12-06 17:06:30 +01:00
Jean Delvare 38f41f282f i2c-stub: Allow user to disable some commands
Add a module parameter to override the functionality bitfield. This
lets the user disable some commands. This can be used to force a chip
driver to take different code paths.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-12-06 17:06:29 +01:00
Jean Delvare 4710317891 i2c-stub: Implement I2C block support
This is required to test some drivers, for example at24.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-12-06 17:06:28 +01:00
Jean Delvare c7b25a9e96 i2c: Drop probe, ignore and force module parameters
The legacy probe and force module parameters are obsolete now, the
same can be achieved using the new_device sysfs interface, which is
both more flexible and cheaper (it is implemented by i2c-core rather
than replicated in every driver module.)

The legacy ignore module parameters can be dropped as well. Ignoring
can be done by instantiating a "dummy" device at the problematic
address.

This is the first step of a huge cleanup to i2c-core's i2c_detect
function, i2c.h's I2C_CLIENT_INSMOD* macros, and all drivers that made
use of them.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-12-06 17:06:24 +01:00
Jean Delvare a0c11cdd6a i2c-voodoo3: Delete
Superseded by tdfxfb. I2C/DDC support used to live in a separate
driver but this caused driver conflicts.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Krzysztof Helt <krzysztof.h1@wp.pl>
2009-12-06 17:06:21 +01:00
Crane Cai 3806e94b01 i2c-piix4: Modify code name SB900 to Hudson-2
Change SB900 to its formal code name Hudson-2.

Signed-off-by: Crane Cai <crane.cai@amd.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-11-07 13:10:46 +01:00
Jean Delvare 03f1805ad0 i2c: Minor documentation update
The sysfs path to i2c adapters has changed recently, update the
documentation to reflect that change.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-10-04 22:53:45 +02:00
Jean Delvare f546c65cd5 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>
2009-10-04 22:53:40 +02:00
Crane Cai 76b3e28fa7 i2c-piix4: Add AMD SB900 SMBus device ID
Add new SMBus device ID for AMD SB900.

Signed-off-by: Crane Cai <crane.cai@amd.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-09-18 22:45:50 +02:00
Wolfram Sang e7c5c49ecd i2c/chips: Remove deprecated pcf8574 driver
The pcf8574 driver in drivers/i2c/chips which just exports its register to
sysfs is superseded by drivers/gpio/pcf857x.c which properly uses the gpiolib.
As this driver has been deprecated for more than a year, finally remove it.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-09-18 22:45:49 +02:00
Wolfram Sang 732d481127 i2c/chips: Remove deprecated pca9539 driver
The pca9539 driver in drivers/i2c/chips which just exports its registers to
sysfs is superseded by drivers/gpio/pca953x.c which properly uses the gpiolib.
As this driver has been deprecated for more than a year, finally remove it.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Ben Gardner <gardner.ben@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-09-18 22:45:48 +02:00
Wolfram Sang 8f67eeb0b4 i2c/chips: Remove deprecated pcf8575 driver
The pcf8575 driver in drivers/i2c/chips which just exports its register to
sysfs is superseded by drivers/gpio/pcf857x.c which properly uses the gpiolib.
As this driver has been deprecated for more than a year, finally remove it.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Bart Van Assche <bart.vanassche@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-09-18 22:45:48 +02:00
Jean Delvare 99cd8e2587 i2c: Add a sysfs interface to instantiate devices
Add a sysfs interface to instantiate and delete I2C devices. This is
primarily a replacement of the force_* module parameters implemented
by some i2c drivers. These module parameters were implemented
internally by the I2C_CLIENT_INSMOD* macros, which don't scale well.

This can also be used when developing a driver on a self-soldered
board which doesn't yet have proper I2C device declaration at the
platform level, and presumably for various debugging situations.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <dbrownell@users.sourceforge.net>
2009-06-19 16:58:20 +02:00
Jean Delvare 729d6dd571 i2c: Get rid of the legacy binding model
We converted all the legacy i2c drivers so we can finally get rid of
the legacy binding model. Hooray!

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <dbrownell@users.sourceforge.net>
2009-06-19 16:58:18 +02:00
Harald Welte a231591f04 i2c-viapro: Add new PCI device ID for VX855
The south bridge of the VIA VX855 chipset has a different PCI Device ID
so i2c-viapro.c needs to be updated with this.

Signed-off-by: Harald Welte <HaraldWelte@viatech.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-06-15 18:01:49 +02:00
Richard Röjfors dd14be4c27 i2c-ocores: Can add I2C devices to the bus
There is sometimes a need for the ocores driver to add devices to the
bus when installed.

i2c_register_board_info can not always be used, because the I2C devices
 are not known at an early state, they could for instance be connected
 on a I2C bus on a PCI device which has the Open Cores IP.

i2c_new_device can not be used in all cases either since the resulting
bus nummer might be unknown.

The solution is the pass a list of I2C devices in the platform data to
the Open Cores driver. This is useful for MFD drivers.

Signed-off-by: Richard Röjfors <richard.rojfors.ext@mocean-labs.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2009-06-13 10:39:28 +01:00
Jean Delvare fb4504fe84 Move the pcf8591 driver to hwmon
Directory drivers/i2c/chips is going away, so drivers there must find
new homes. For the pcf8591 driver, the best choice seems to be the
hwmon subsystem. While the Philips PCF8591 device isn't a typical
hardware monitoring chip, its DAC interface is compatible with the
hwmon one, so it fits somewhat.

If a better subsystem is ever created for ADC/DAC chips, the driver
could be moved there.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Aurelien Jarno <aurelien@aurel32.net>
2009-03-30 21:46:43 +02:00
Flavio Leitner 506a8b6c27 i2c-piix4: Add support for the Broadcom HT1100 chipset
Add support for the Broadcom HT1100 LD chipset (SMBus function.)

Signed-off-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-03-28 21:34:46 +01:00
Jean Delvare d2dd14ac18 i2c-nforce2: Add support for MCP67, MCP73, MCP78S and MCP79
The MCP78S and MCP79 appear to be compatible with the previous nForce
chips as far as the SMBus controller is concerned. The MCP67 and MCP73
were not tested yet but I'd be very surprised if they weren't
compatible too.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Oleg Ryjkov <olegr@olegr.ca>
Cc: Malcolm Lalkaka <mlalkaka@gmail.com>
Cc: Zbigniew Luszpinski <zbiggy@o2.pl>
2009-03-28 21:34:41 +01:00
Jean Delvare 764c16918f i2c: Document the different ways to instantiate i2c devices
On popular demand, here comes some documentation about how to
instantiate i2c devices in the new (standard) i2c device driver
binding model.

I have also clarified how the class bitfield lets driver authors
control which buses are probed in the auto-detect case, and warned
more loudly against the abuse of this method.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Michael Lawnick <nospam_lawnick@gmx.de>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
2009-03-28 21:34:40 +01:00
Jean Delvare 846557d3ce i2c: The i2c mailing list is moving
Replace all references to the old i2c mailing list.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-30 15:55:47 +01:00
Jean Delvare 0e47858da4 i2c: Update and clean up writing-clients document
* Strip trailing white space.
* Remove out-of-date or irrelevant parts.
* Insist on the fact that command is deprecated.
* Fix spelling mistakes and typos.
* Reformat code examples and function prototypes to comply with the
  kernel coding style.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-22 20:21:32 +02:00
Jean Delvare e313353dd4 i2c: Delete legacy model documentation
The legacy i2c binding model is deprecated and will be removed soon,
so we no longer need to document it.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-22 20:21:31 +02:00
Jean Delvare 7d1d8999b4 i2c: Constify i2c_get_clientdata's parameter
i2c_get_clientdata doesn't change the i2c_client it is passed as a
parameter, so it can be constified. Same for i2c_get_adapdata.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-22 20:21:31 +02:00
Jean Delvare d955cafb5c i2c: Delete outdated client porting guide
The document describing how to port i2c chip drivers from Linux 2.4 to
Linux 2.6 is outdated. As I suspect that most drivers that had to be
ported have already been by now, I do not want to spend time updating
it. Let's just delete it instead.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-22 20:21:30 +02:00
Seth Heasley c429a247f5 i2c-i801: Add support for Intel Ibex Peak
Adds the Intel Ibex Peak (PCH) SMBus Controller Device IDs.

Signed-off-by: Seth Heasley <seth.heasley@intel.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-22 20:21:29 +02:00
Prakash Mortha 596c88f460 i2c: Restore i2c_smbus_process_call function
Restore the i2c_smbus_process_call() as one driver (for the
Micronas MAP5401) will need it soon.

[JD: Update documentation accordingly.]

Signed-off-by: Prakash Mortha <pmortha@escient.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-14 17:30:06 +02:00
Jean Delvare 7c15fd1249 i2c: Document the implementation details of the /dev interface
I wrote this explanation to answer a question on the i2c mailing list,
and thought it would be good to have in the kernel documentation.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-14 17:30:05 +02:00