Commit graph

74 commits

Author SHA1 Message Date
Jean Delvare
eefcd75e72 i2c: Documentation update
Make the documentation on how to write and port i2c drivers more in
line with the current state of things:
* i2c-isa is deprecated and soon gone, so stop advertising it.
* Drop many sensors-specific references. Most of them were outdated
  anyway.
* Update the example code to reflect the recent and not-so-recent
  API and coding style preference changes.
* Simplify the example init and cleanup functions.

This should make things less complex to understand for newcomers.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-01 23:26:35 +02:00
Jean Delvare
b3e820968a i2c: Make i2c_del_driver a void function
Make i2c_del_driver a void function, like all other driver removal
functions. It always returned 0 even when errors occured, and nobody
ever actually checked the return value anyway. And we cannot fail
a module removal anyway.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-01 23:26:32 +02:00
Jean Delvare
ce9e0794c2 i2c: Document i2c_new_device()
Document the new i2c_new_device(), i2c_new_probed_device() and
i2c_unregister_device() functions.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-01 23:26:32 +02:00
David Brownell
4298cfc3eb i2c: i2c probe() and remove() documented
Update Documentation/i2c to match previous patches updating probe()
and remove() logic.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-01 23:26:31 +02:00
Jean Delvare
f75803de6a i2c-nforce2: Add support for the MCP61 and MCP65
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Hans-Frieder Vogt <hfvogt@gmx.net>
2007-05-01 23:26:29 +02:00
Jonathan McDowell
55249cf750 i2c-parport: Add support for One For All remote JP1 interface
This simple patch adds support to i2c-parport for the One For All remote
JP1 parallel port interfaces which can be found detailed at:

http://www.hifi-remote.com/jp1/hardware.shtml

These allow access to the internal configuration EEPROM on various
remote controls and there are a variety of Windows tools that make use
of this hardware. I have tested this patch with the "simple" parallel
port device and a One For All URC-7562 and confirmed that the data read
using the eeprom i2c driver matches that returned by the Windows "IR"
JP1 tool.

Signed-off-by: Jonathan McDowell <noodles@earth.li>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-02-13 22:09:02 +01:00
Jean Delvare
ab6a6ed271 i2c-viapro: Add support for the VIA CX700 south bridge
We do not have any documentation for the CX700, but it was reported
to work fine. Thanks to Claas Langbehn for testing.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-02-13 22:09:02 +01:00
David Brownell
f37dd80ac2 i2c: Add driver suspend/resume/shutdown support
Driver model updates for the I2C core:

 - Add new suspend(), resume(), and shutdown() methods.  Use them in the
   standard driver model style; document them.

 - Minor doc updates to highlight zero-initialized fields in drivers, and
   the driver model accessors for "clientdata".

If any i2c drivers were previously using the old suspend/resume calls
in "struct driver", they were getting warning messages ... and will
now no longer work.  Other than that, this patch changes no behaviors;
and it lets I2C drivers use conventional PM and shutdown support.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-02-13 22:09:00 +01:00
Jean Delvare
099ab118b6 i2c-i801: Document the SMBus unhiding quirk
This is a frequently asked question so it deserves a paragraph in
the driver documentation.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-02-13 22:09:00 +01:00
Mike Frysinger
3f9a4790a3 i2c: Fix typo in SMBus Write Word Data description
Write data, don't read it.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-02-13 22:08:59 +01:00
Jean Delvare
4e6697fcc1 i2c-piix4: Add support for the ATI SB600
Add support for the ATI SB600 SMBus controller.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-02-13 22:08:59 +01:00
Jason Gaston
a980a99ae5 i2c: i2c-i801 documentation update
Add the Intel ICH9/ICH8/ESB2 SMBus Controller text to
i2c-i801 documentation.

Signed-off-by: Jason Gaston <jason.d.gaston@intel.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2006-12-10 21:21:31 +01:00
Hans-Frieder Vogt
ad04d5c387 i2c: Cleanups to the i2c-nforce2 bus driver
Summary of changes:

- fixes:
   o legacy I/O region size is 64 bytes, not 8 bytes
- general cleanup:
   o removed code for the unsupported I2C block data, block data,
      proc call and block proc call transfer modes
   o removed detail warnings about unsupported modes that are
     covered in a general warning (unsupported transaction...)
     anyway
   o removed necessity of a definition of struct i2c_adapter
   o moved definition of struct i2c_algorithm, making forward
     declarations of nforce2_access and nforce2_func unnecessary
- minor changes:
   o in the description mention the nForce 5xx chipsets
   o changes my e-mail address in MODULE_AUTHOR

Theses cleanups shrink the driver binary size from 4.0 kB to 2.7 kB
on i386.

Signed-off-by: Hans-Frieder Vogt <hfvogt@gmx.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2006-12-10 21:21:29 +01:00
Jean Delvare
26f95c4ae2 i2c: Fix documentation typos
Fix typos in i2c bus drivers documentation.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2006-12-10 21:21:28 +01:00
Rudolf Marek
c243353a90 i2c-viapro: Add support for the VT8237A and VT8251
i2c-viapro: Add support for the VT8237A and VT8251

Documentation update included. Compile tested.

Signed-off-by: Rudolf Marek <r.marek@sh.cvut.cz>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-26 15:38:52 -07:00
Jean Delvare
7a8d29cec7 i2c-stub: Chip address as a module parameter
i2c-stub: Chip address as a module parameter

Add a mandatory chip_addr parameter to i2c-stub. This parameter
defines to which chip address the driver will respond, instead of
reponding to all addresses as before. The idea is to prevent the
users from loading i2c-stub at random and being then confused by
the results of sensors-detect or other user-space tools.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-26 15:38:51 -07:00
Jean Delvare
5d925fecac [PATCH] i2c: New mailing list
We have a new mailing list dedicated to linux i2c:
http://lists.lm-sensors.org/mailman/listinfo/i2c

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-07-12 15:43:07 -07:00
Jean Delvare
d8db8f9856 [PATCH] i2c-i801: Remove force_addr parameter
i2c-i801: Remove force_addr parameter

Remove the force_addr module parameter. It doesn't appear to ever
have been needed, and PCI resources shouldn't be arbitrarily
changed anyway.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-22 11:10:35 -07:00
Jean Delvare
62aaa288ab [PATCH] scx200_acb: Documentation update
Documentation update for the scx200_acb driver. Hopefully this will
help future users.

References:

[lm-sensors] Support of i2c-nscacb (April, May 2005)
  http://lists.lm-sensors.org/pipermail/lm-sensors/2005-April/011756.html
  http://lists.lm-sensors.org/pipermail/lm-sensors/2005-May/012043.html

[lm-sensors] making a geode i2c slave driver (April 2006)
  http://lists.lm-sensors.org/pipermail/lm-sensors/2006-April/015998.html

Kernel bug #6445
  http://bugzilla.kernel.org/show_bug.cgi?id=6445

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-22 11:10:35 -07:00
Peter Korsgaard
18f98b1e31 [PATCH] i2c: New bus driver for the OpenCores I2C controller
The following patch adds support for the OpenCores I2C controller IP
core (See http://www.opencores.org/projects.cgi/web/i2c/overview).

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-22 11:10:33 -07:00
Jean Delvare
5c7ae65899 [PATCH] I2C: i2c-nforce2: Add support for the nForce4 MCP51 and MCP55
Add support for the new nForce4 MCP51 (also known as nForce 410 or
430) and nForce4 MCP55 to the i2c-nforce2 driver. Some code changes
were required because the base I/O address registers have changed in
these versions. Standard BARs are now being used, while the original
nForce2 chips used non-standard ones.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-22 11:10:33 -07:00
Jean Delvare
f9ba6c04ef [PATCH] I2C: i2c-piix4: Document the IBM problem more clearly
Properly document on which systems the i2c-piix4 SMBus driver will
refuse to load. Hopefully this will make it clearer for users, which
were often wondering why their destop or server systems were detected
as laptops.

Closes bug #6429.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-22 11:10:32 -07:00
Jean Delvare
7aadb8f943 [PATCH] I2C: i2c-piix4: Fix typo in documentation
Fix i2c-piix4 documentation typo.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-22 11:10:32 -07:00
Rudolf Marek
54aaa1ca10 [PATCH] I2C: i2c-piix4: Remove the fix_hstcfg parameter
This patch removes the fix_hstcfg option from the driver and related
SMBus Interrupt Select register magic because now we know what are
valid values for this register. This patch updates the documentation
and adds new IRQ mode check so we are sure not to miss any new
"unusual" value.

The PCI quirk for users of fix_hstcfg was not developed because the
chipset lacks of subsystem ID registers and DMI is stated "To be
filled". Impact to existing systems is minimal because the problem
showed up on motherboards like 10 years back. On the other hand users
of newer Serverworks and HT1000 systems won't be misleaded by the
message suggesting to try the fix_hstcfg any more.

Signed-off-by: Rudolf Marek <r.marek@sh.cvut.cz>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-22 11:10:32 -07:00
Rudolf Marek
02e0c5d5c2 [PATCH] i2c-piix4: Add ATI IXP200/300/400 support
This patch adds the ATI IXP southbridges support to i2c-piix4,
as it turned out those chips are compatible with it.

Signed-off-by: Rudolf Marek <r.marek@sh.cvut.cz>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-22 11:10:32 -07:00
Mark M. Hoffman
e97b81ddbb [PATCH] i2c-parport: Make type parameter mandatory
This patch forces the user to specify what type of adapter is present when
loading i2c-parport or i2c-parport-light.  If none is specified, the driver
init simply fails - instead of assuming adapter type 0.

This alleviates the sometimes lengthy boot time delays which can be caused
by accidentally building one of these into a kernel along with several i2c
slave drivers that have lengthy probe routines (e.g. hwmon drivers).

Kconfig and documentation updated accordingly.

Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-04-14 11:18:34 -07:00
Martin Devera
5f7ea3c58c [PATCH] I2C: i2c-piix4: Add Broadcom HT-1000 support
Add Broadcom HT-1000 south bridge's PCI ID to i2c-piix driver. Note
that at least on Supermicro H8SSL it uses non-standard SMBHSTCFG = 3
and standard values like 0 or 9 causes hangup.

Signed-off-by: Martin Devera <devik@cdi.cz>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-03-23 14:21:55 -08:00
Ben Gardner
a417bbd33b [PATCH] i2c: scx200_acb minimal documentation update
scx200_acb: Minimal documentation update

Signed-off-by: Ben Gardner <bgardner@wabtec.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-03-23 14:21:50 -08:00
Rudolf Marek
806ba64090 [PATCH] i2c: Rename i2c-sis96x documentation file
This patch just renames the documentation file to correct file name.
i2c-sis69x -> i2c-sis96x.

Signed-off-by: Rudolf Marek <r.marek@sh.cvut.cz>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-02-06 12:02:14 -08:00
Jean Delvare
7c72ccf09b [PATCH] i2c: i2c-nforce2 add nforce4 MCP-04 device ID
One more supported PCI ID for the i2c-nforce2 driver.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-05 22:16:27 -08:00
Jean Delvare
fb687d73fa [PATCH] i2c: update i2c_driver.command documentation
Document i2c_driver.command as being deprecated, and don't suggest an
empty implementation of this callback as it doesn't make any sense.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-05 22:16:26 -08:00
Jean Delvare
d82c0bf88f [PATCH] i2c: Documentation update
Update the i2c documentation to reflect the recent change to
i2c_add_driver.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-05 22:16:25 -08:00
Jean Delvare
d45d204f0c [PATCH] i2c: Drop i2c_driver.{owner,name}, 11 of 11
Document the drop of the owner and name fields of the i2c_driver
structure.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
CC: Laurent Riffard <laurent.riffard@free.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-05 22:16:24 -08:00
Jean Delvare
92b4294612 [PATCH] i2c: Chip driver porting guide update
Update Documentation/i2c/porting-clients. Many recent changes to the i2c
and hwmon subsystems were never reported there.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-05 22:16:22 -08:00
Jean Delvare
cf02df7702 [PATCH] i2c: Rework client usage count, 3 of 3
Do not limit the usage count of i2c clients to 1. In other words,
change the client usage count behavior from the old I2C_CLIENT_ALLOW_USE
to the old I2C_CLIENT_ALLOW_MULTIPLE_USE. The rationale is that no
driver actually needs the limiting behavior, and the unlimiting
behavior is slightly easier to implement.

Update the documentation to reflect this change.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-05 22:16:22 -08:00
Jean Delvare
8a9947552d [PATCH] i2c: Drop i2c_driver.flags, 2 of 3
Just about every i2c chip driver sets the I2C_DF_NOTIFY flag, so we
can simply make it the default and drop the flag. If any driver really
doesn't want to be notified when i2c adapters are added, that driver
can simply omit to set .attach_adapter. This approach is also more
robust as it prevents accidental NULL pointer dereferences.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-05 22:16:21 -08:00
Peter Korsgaard
1d26f455eb [PATCH] i2c: Add support for Barco LPT->DVI to i2c-parport
The following patch adds support for the Barco LPT->DVI I2C adapter to
the i2c-parport driver.

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-05 22:16:21 -08:00
Jean Delvare
8750197f0e [PATCH] i2c-viapro: Some adjustments
The big i2c-viapro SMBus driver update which went into 2.6.14-git1
introduced a few minor issues. Nothing critical, but I would like a
few adjustments to be merged in to fix the following problems:

* VIA should not be spelled Via.
* Frodo Looijaard and Philip Edelbrock did not write the i2c-viapro
  driver.
* When debugging is disabled, half of messages would be logged.
* Drop an unneeded masking.
* Some port reads can be avoided now that the transaction size is
  passed as a parameter to vt596_transaction().
* SMBus Receive Byte transactions are used for probing too (for
  EEPROMs), so hide errors on these too.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-11-07 21:46:38 -08:00
Jean Delvare
a852daa00a [PATCH] i2c: writing-client doc update complement
My latest update to the writing-clients i2c documentation file was
incomplete, here's the complement.

Large parts of this file are still way out-of-date, but at least now
the memory allocation and freeing instructions are consistent.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-11-07 21:46:37 -08:00
Jeff Garzik
d61780c0d3 [PATCH] remove some more check_region stuff
Removed some more references to check_region().

I checked these changes into the 'checkreg' branch of
rsync://rsync.kernel.org/pub/scm/linux/kernel/git/jgarzik/misc-2.6.git

The only valid references remaining are in:
drivers/scsi/advansys.c
drivers/scsi/BusLogic.c
drivers/cdrom/sbpcd.c
sound/oss/pss.c

  Remove last vestiges of ide_check_region()
  drivers/char/specialix: trim trailing whitespace
  drivers/char/specialix: eliminate use of check_region()
  Remove outdated and unused references to check_region()
  [sound oss] remove check_region() usage from cs4232, wavfront
  [netdrvr eepro] trim trailing whitespace
  [netdrvr eepro] remove check_region() usage

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30 17:37:18 -08:00
Jean Delvare
142078f6f0 [PATCH] i2c: i2c-i810 documentation update
Update the documented list of devices supported by the i2c-i810
driver.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-10-28 14:02:13 -07:00
Jean Delvare
2445eb62e9 [PATCH] i2c: Documentation update
Update the i2c documentation: kzalloc should be used instead of
kmalloc.

I also fixed a couple other things nearby in writing-clients, as several
past changes had never been reported there.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-10-28 14:02:12 -07:00
Alessandro Zummo
4d4e5ce864 [PATCH] i2c: New Xicor X1205 RTC driver
New driver for the Xicor X1205 RTC chip.

Signed-off-by: Alessandro Zummo <alessandro.zummo@towertech.it>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-10-28 14:02:12 -07:00
Jean Delvare
7865e24935 [PATCH] i2c: Documentation fixes
i2c documentation fixes.

>From Hideki Iwamoto:
* i2c_smbus_read_i2c_block_data is not deleted in 2.6.10. It still
  exists.
* The name which can be set to i2c_driver is up to 31 characters.

>From Jean Delvare:
* Reword the paragraph about i2c_driver.name, to reflect the "new"
  naming policy.
* Delete the out-of-date note about now gone inc_use and dec_use
  fields.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-10-28 14:02:09 -07:00
Jean Delvare
aaf7f14776 [PATCH] i2c-viapro: Update supported devices list
Make it clearer which chips are supported by the i2c-viapro driver,
and which support I2C block transactions.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

 Documentation/i2c/busses/i2c-viapro |   12 ++++++------
 drivers/i2c/busses/i2c-viapro.c     |   22 +++++++++++++---------
 2 files changed, 19 insertions(+), 15 deletions(-)
2005-10-28 14:02:08 -07:00
Jean Delvare
f118301416 [PATCH] i2c-viapro: Implement I2C Block transactions
Implement the I2C block transactions on VIA chips which support them:
VT82C686B, VT8233, VT8233A, VT8235 and VT8237R. This speeds up EEPROM
accesses by a factor 10 or so.

I would like to thank Antonino A. Daplas, Hinko Kocevar, Salah Coronya
and Andreas Henriksson for their help in testing this new feature.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

 Documentation/i2c/busses/i2c-viapro |    7 +++++-
 drivers/i2c/busses/i2c-viapro.c     |   39 +++++++++++++++++++++++++++++++++---
 2 files changed, 42 insertions(+), 4 deletions(-)
2005-10-28 14:02:08 -07:00
Jean Delvare
5f49ef8e8c [PATCH] i2c-viapro: Coding style fixes
Before I go on cleaning up and improving the i2c-viapro driver, let's
fix all the coding style issues: mostly trailing white space, and
spaces used where tabs should be.

Signed-off-by: Jean Delvare <khali@linux-fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

 Documentation/i2c/busses/i2c-viapro |   12 ++---
 drivers/i2c/busses/i2c-viapro.c     |   76 ++++++++++++++++++------------------
 2 files changed, 43 insertions(+), 45 deletions(-)
2005-10-28 14:02:07 -07:00
Hideki Iwamoto
d057c96cab [PATCH] i2c: Fix I2C_FUNC_PROTOCOL_MANGLING documentation
Fix the description of I2C_FUNC_PROTOCOL_MANGLING.

From: Hideki Iwamoto <h-iwamoto@kit.hi-ho.ne.jp>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

 Documentation/i2c/functionality |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)
2005-10-28 14:02:07 -07:00
Jean Delvare
4c9337da37 [PATCH] I2C: Centralize 24RF08 corruption prevention
The 24RF08 corruption would better be prevented at i2c-core level than
at chip driver level, for several reasons:
* The second quick write should happen as soon as possible after the
  first one, so as to limit the risk that another command is issued on
  the bus inbetween, causing the corruption.
* As a matter of fact, the protection code at driver level was reworked
  at least three times already, which proves how hard it is to get it
  right there, while it's straightforward at i2c-core level.
* It's easy to add a new driver that would need the protection, and
  forget to add it. This did happen already.
* As additional probing addresses can be passed to most i2c chip drivers
  as module parameters, virtually every i2c chip driver would need the
  protection if we want to be really safe.
* Why duplicate code when we can easily avoid it?

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-09-05 09:14:25 -07:00
Jean Delvare
a89ba0bc02 [PATCH] I2C: Rewrite i2c_probe
i2c_probe was quite complex and slow, so I rewrote it in a more
efficient and hopefully clearer way.

Note that this slightly changes the way the module parameters are
handled. This shouldn't change anything for the most common cases
though.

For one thing, the function now respects the order of the parameters
for address probing. It used to always do lower addresses first. The
new approach gives the user more control.

For another, ignore addresses don't overrule probe addresses anymore.
This could have been restored the way it was at the cost of a few more
lines of code, but I don't think it's worth it. Both lists are given
as module parameters, so a user would be quite silly to specify the
same addresses in both lists. The normal addresses list is the only
one that isn't controlled by a module parameter, thus is the only one
the user may reasonably want to remove an address from.

Another significant change is the fact that i2c_probe() will no more
stop when a detection function returns -ENODEV. Just because a driver
found a chip it doesn't support isn't a valid reason to stop all
probings for this one driver. This closes the long standing lm_sensors
ticket #1807.

  http://www2.lm-sensors.nu/~lm78/readticket.cgi?ticket=1807

I updated the documentation accordingly.

In terms of algorithmic complexity, the new code is way better. If
I is the ignore address count, P the probe address count, N the
normal address count and F the force address count, the old code
was doing 128 * (F + I + P + N) iterations max, while the new code
does F + P + ((I+1) * N) iterations max. For the most common case
where F, I and P are empty, this is down from 128 * N to N.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-09-05 09:14:25 -07:00