Commit Graph

76 Commits

Author SHA1 Message Date
Jeffrey (Sheng-Hui) Chu
cc6bcf7d2e i2c-algo-bit: Generate correct i2c address sequence for 10-bit target
The wrong bits were put on the wire, fix that.

This fixes kernel bug #42562.

Signed-off-by: Sheng-Hui J. Chu <jeffchu@broadcom.com>
Cc: stable@kernel.org
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-11-23 11:33:07 +01:00
Jean Delvare
4403988afc i2c-algo-pca: Return standard fault codes
Adjust i2c-algo-pca to return fault codes compliant with
Documentation/i2c/fault-codes, rather than the undocumented and
vague -EREMOTEIO.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Wolfram Sang <w.sang@pengutronix.de>
2011-10-30 13:47:25 +01:00
Jean Delvare
abc01b2718 i2c-algo-bit: Return standard fault codes
Adjust i2c-algo-bit to return fault codes compliant with
Documentation/i2c/fault-codes, rather than the undocumented and
vague -EREMOTEIO.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-10-30 13:47:25 +01:00
Jean Delvare
f6beb67d8e i2c-algo-bit: Be verbose on bus testing failure
If bus testing fails due to the bus being seen as busy, it might be
helpful for developers to know which line is unexpectedly low.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Alex Deucher <alexdeucher@gmail.com>
2011-10-30 13:47:25 +01:00
Jean Delvare
1bddab7f7d i2c-algo-bit: Let user test buses without failing
Always failing to register I2C buses when the line testing fails is a
little harsh. While such a failure is definitely a bug in the driver
that exposes the affected I2C bus, things may still work fine if the
missing initialization steps are done later, before the I2C bus is
used. So it seems a better debugging tool to just report the test
failure by default. I introduce bit_test=2 if anyone really misses the
original behavior of bit_test=1.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Alex Deucher <alexdeucher@gmail.com>
2011-10-30 13:47:25 +01:00
Alex Deucher
d3b3e15da1 i2c-algo-bit: Call pre/post_xfer for bit_test
Apparently some distros set i2c-algo-bit.bit_test to 1 by
default.  In some cases this causes i2c_bit_add_bus
to fail and prevents the i2c bus from being added.  In the
radeon case, we fail to add the ddc i2c buses which prevents
the driver from being able to detect attached monitors.
The i2c bus works fine even if bit_test fails.  This is likely
due to gpio switching that is required and handled in the
pre/post_xfer hooks, so call the pre/post_xfer hooks in the
bit test as well.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=36221

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: stable@kernel.org [.38 down to .34]
2011-04-17 10:20:19 +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
Jean Delvare
af5a60baae i2c-algo-bit: Complain about masters which can't read SCL
The I2C specification explicitly describes both SDA and SCL as
bidirectional lines. An I2C master with a read-only SCL is thus not
compliant. If a slow slave stretches the clock, errors will happen,
so the bus can't be considered as reliable.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-01-10 22:11:23 +01:00
Jean Delvare
f451171c5a i2c-algo-bit: Refactor adapter registration
Use a function pointer to decide whether to call i2c_add_adapter or
i2c_add_numbered_adapter. This makes the code more compact than the
current strategy of having the common code in a separate function.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-01-10 22:11:23 +01:00
Arnaud Lacombe
c38bd4ffc7 i2c/algos: convert Kconfig to use the menu's `visible' keyword
Signed-off-by: Arnaud Lacombe <lacombar@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2010-11-22 11:27:35 -02:00
Arnaud Lacombe
dfc518dd6b Revert "i2c: Fix Kconfig dependencies"
This reverts commit 0a57274ea0.

Signed-off-by: Arnaud Lacombe <lacombar@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2010-11-22 11:27:33 -02:00
matt mooney
ef9d9b8fb6 i2c: Change to new flag variable
Replace EXTRA_CFLAGS with ccflags-y.

Signed-off-by: matt mooney <mfm@muteddisk.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-10-24 18:16:58 +02:00
Jean Delvare
0a57274ea0 i2c: Fix Kconfig dependencies
drivers/i2c/algos/Kconfig makes all the algorithms dependent on
!I2C_HELPER_AUTO, which triggers a Kconfig warning about broken
dependencies when some driver selects one of the algorithms. Ideally
we would make only the prompts dependent on !I2C_HELPER_AUTO, however
Kconfig doesn't currently support that. So we have to redefine the
symbols separately for the I2C_HELPER_AUTO=y case.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Michal Marek <mmarek@suse.cz>
2010-10-24 18:16:57 +02:00
Farid Hammane
2086ca482f i2c-algo-pca: Fix coding style issues
Fix up some coding style issues. i2c-algo-pca.c has been built
successfully after applying this patch and the binary object is
still exactly the same. Other issues found by checkpatch.pl were
voluntarily not fixed, either to keep readability, or because of
false positive errors.

Signed-off-by: Farid Hammane <farid.hammane@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-05-21 18:41:00 +02:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Jean Delvare
0a9c147513 i2c-algo-bit: Add pre- and post-xfer hooks
Drivers might have to do random things before and/or after I2C
transfers. Add hooks to the i2c-algo-bit implementation to let them do
so.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Alex Deucher <alexdeucher@gmail.com>
2010-03-13 20:56:56 +01:00
Jiri Kosina
318ae2edc3 Merge branch 'for-next' into for-linus
Conflicts:
	Documentation/filesystems/proc.txt
	arch/arm/mach-u300/include/mach/debug-macro.S
	drivers/net/qlge/qlge_ethtool.c
	drivers/net/qlge/qlge_main.c
	drivers/net/typhoon.c
2010-03-08 16:55:37 +01:00
Jean Delvare
eec74a257f i2c-algo-pca: Drop duplicate variable
Thanks to -Wshadow.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
2010-03-02 12:23:47 +01:00
Uwe Kleine-König
7d9b48ea81 fix typo "definetly" -> "definitely" in comment
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-02-05 12:22:42 +01:00
Enrik Berkhan
2196d1cf4a i2c-algo-pca: Let PCA9564 recover from unacked data byte (state 0x30)
Currently, the i2c-algo-pca driver does nothing if the chip enters state
0x30 (Data byte in I2CDAT has been transmitted; NOT ACK has been
received).  Thus, the i2c bus connected to the controller gets stuck
afterwards.

I have seen this kind of error on a custom board in certain load
situations most probably caused by interference or noise.

A possible reaction is to let the controller generate a STOP condition.
This is documented in the PCA9564 data sheet (2006-09-01) and the same
is done for other NACK states as well.

Further, state 0x38 isn't handled completely, either. Try to do another
START in this case like the data sheet says. As this couldn't be tested,
I've added a comment to try to reset the chip if the START doesn't help
as suggested by Wolfram Sang.

Signed-off-by: Enrik Berkhan <Enrik.Berkhan@ge.com>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-05-05 08:39:25 +02:00
Dave Airlie
0cdba07bb2 i2c-algo-bit: Fix timeout test
When fetching DDC using i2c algo bit, we were often seeing timeouts
before getting valid EDID on a retry. The VESA spec states 2ms is the
DDC timeout, so when this translates into 1 jiffie and we are close
to the end of the time period, it could return with a timeout less than
2ms.

Change this code to use time_after instead of time_after_eq.

Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-05-05 08:39:24 +02:00
Jean Delvare
c454dee21d i2c-algo-pca: Fix use of uninitialized variable in debug message
A recent change broke debugging of pca_xfer(), fix it.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
2009-04-13 17:02:13 +02:00
Jean Delvare
abe213d7f6 i2c: Delete unused i2c-algo-sgi helper module
The i2c-algo-sgi code was merged into the vino driver, so we can
delete it now.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-04-06 18:12:25 +02:00
Wolfram Sang
2378bc09b9 i2c-algo-pca: Use timeout for checking the state machine
We now timeout also if the state machine does not change within the
given time. For that, the driver-specific completion-functions are
extended to return true or false depending on the timeout. This then
gets checked in the algorithm.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-03-28 21:34:45 +01:00
Wolfram Sang
8e99ada8de i2c-algo-pca: Rework waiting for a free bus
Waiting for a free bus now accepts the timeout value in jiffies and does
proper checking using time_before.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-03-28 21:34:45 +01:00
Marco Aurelio da Costa
eff9ec95ef i2c-algo-pca: Add PCA9665 support
Add support for the PCA9665 I2C controller.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-03-28 21:34:44 +01:00
Frank Seidel
bac3e7c2aa i2c: Adapt debug macros for KERN_* constants
According to kerneljanitors todo list all printk calls (beginning
a new line) should have an according KERN_* constant.
Those are the changes to the debug macros in the i2c subsystem
to meet this requirement. Also changing no-debug statements
to raw printks again.

Signed-off-by: Frank Seidel <frank@f-seidel.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Wolfram Sang <w.sang@pengutronix.de>
2009-03-28 21:34:44 +01:00
Jean Delvare
8fcfef6e65 i2c: Set a default timeout value for all adapters
Setting a default timeout value on a per-algo basis doesn't make any
sense. Move the default value setting to i2c-core. Individual adapter
drivers can specify a different (non-zero) value if they wish.

Also express the timeout value in a way which results in the same
duration regarless of the value of HZ.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
2009-03-28 21:34:43 +01:00
Frank Seidel
154d22b04a i2c: Add missing KERN_* constants to printks
According to kerneljanitors todo list all printk calls (beginning
a new line) should have an according KERN_* constant.
Those are the missing pieces here for the i2c subsystem.

Signed-off-by: Frank Seidel <frank@f-seidel.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-03-28 21:34:42 +01:00
Roel Kluin
94d78e180c i2c-algo-pcf: Handle timeout correctly
With a postfix decrement these timeouts reach -1 rather than 0, but after the
loop it is tested whether they have become 0.

As pointed out by Jean Delvare, the msg_num should be tested before the timeout.
With the current order, you could exit with a timeout error while all the
messages were successfully transferred.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Eric Brower <ebrower@gmail.com>
2009-03-28 21:34:42 +01:00
Roel Kluin
0c168ceb9e i2c-algo-pcf: Style cleanups
cleanup whitespace, fix comments and remove the unused STUB_I2C.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Eric Brower <ebrower@gmail.com>
2009-03-28 21:34:42 +01:00
David Miller
a672b4c1b2 i2c-algo-pcf: Fix typo in debugging log message
Fix typo in debugging log message.

deteted --> detected

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-22 20:21:30 +02:00
David Miller
30091404af i2c-algo-pcf: Add adapter hooks around xfer begin and end
Some I2C bus implementations need to synchronize with external
entities, such as system firmware, which might also be programming the
same I2C bus.

In order to facilitate this add ->xfer_begin() and ->xfer_end() hooks
which are invoked around pcf_xfer().

[JD: Make these hooks optional.]

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-22 20:21:30 +02:00
David Miller
08e5338d11 i2c-algo-pcf: Pass adapter data into ->waitforpin() method
Pass adapter data into ->waitforpin() method.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-22 20:21:29 +02:00
Jean Delvare
8d24f8dcb7 i2c: Let users select algorithm drivers manually again
In kernel 2.6.26, the ability to select I2C algorithm drivers manually
was removed, as all in-kernel drivers do that automatically. However
there were some complaints that it was a problem for out-of-tree I2C
bus drivers. In order to address these complaints, let's allow manual
selection of these drivers again, but still hide them by default for
better general user experience.

This closes bug #11140:
http://bugzilla.kernel.org/show_bug.cgi?id=11140

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-08-10 22:56:15 +02:00
Eric Brower
0573d11b2b i2c-algo-pcf: Multi-master lost-arbitration improvement
Improve lost-arbitration handling of PCF8584.  This is necessary for
support of a currently out-of-kernel driver for Sun Microsystems E250
environmental management; perhaps others.

Signed-off-by: Eric Brower <ebrower@gmail.com>
Acked-by: Dan Smolik <marvin@mydatex.cz>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-07-14 22:38:31 +02:00
Wolfram Sang
c80ebe7987 i2c-pca-algo: Fix error code
Give a more concrete error code, when the bus is not idle.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-07-14 22:38:26 +02:00
David Brownell
97140342e6 i2c: Bus drivers return -Errno not -1
Tighten error paths used by various i2c adapters (mostly x86) so
they return real fault/errno codes instead of a "-1" (which is
most often interpreted as "-EPERM").  Build tested, with eyeball
review.

One minor initial goal is to have adapters consistently return
the code "-ENXIO" when addressing a device doesn't get an ACK
response, at least in the probe paths where they are already
good at stifling related logspam.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-07-14 22:38:25 +02:00
Wolfram Sang
c01b083105 i2c-algo-pca: Extend for future drivers
The separation between algorithm and adapter was unsharp at places. This was
partly hidden by the fact, that the ISA-driver allowed just one instance and
had all private data in static variables. This patch makes neccessary
preparations to add a platform driver on top of the algorithm, while still
supporting ISA. Note: Due to lack of hardware, the ISA-driver could not be
tested except that it builds.

Concerning the core struct i2c_algo_pca_data:

- A private data field was added, all hardware dependant data may go here.
  Similar to other algorithms, now a pointer to this data is passed to the
  adapter's functions. In order to make as less changes as possible to the
  ISA-driver, it leaves the private data empty and still only uses its static
  variables.

- A "reset_chip" function pointer was added; such a functionality must come
  from the adapter, not the algorithm.

- use a variable "i2c_clock" instead of a function pointer "get_clock",
  allowing for write access to a default in case a wrong value was supplied.

In the algorithm-file:

- move "i2c-pca-algo.h" into "linux/i2c-algo-pca.h"
- now using per_instance timeout values (i2c_adap->timeout)
- error messages specify the device, not only the driver name
- restructure initialization to easily support "i2c_add_numbered_adapter"
- drop "retries" and "own" (i2c address) as they were unused

(The state-machine for I2C-communication was not touched.)

In the ISA-driver:

- adapt to new algorithm

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-04-22 22:16:46 +02:00
Wolfram Sang
3d4382913f i2c-algo-pca: Remove trailing whitespaces and unnecessary UTF
Remove trailing whitespaces to make further patches more readable.  Also remove
an unnecessary UTF-char for simplicity ("us" for microseconds is fine enough).

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-04-22 22:16:46 +02:00
Jean Delvare
3845de25c5 i2c: Remove the algorithm drivers from the config menu
The algorithm drivers are helper drivers that are selected automatically
as needed. There's no point in listing them in the config menu, it can
only confuse users and waste their time.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-04-22 22:16:46 +02:00
Jean Delvare
6408a8338c i2c-algo-pcf: Delete broken 10-bit address support
The 10-bit address support in i2c-algo-pcf is so heavily broken that
it can't have ever been used. Nobody ever complained, so I'll take it
that nobody needs it. Let's just delete it.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-01-27 18:14:46 +01:00
David Brownell
bf3e2d1d9b i2c-algo-bit: Fix NAK/ARB comments
Update comments and logging on return path for byte writes.  NAK is
an error, to be reported or optionally ignored.  Timeouts are always
errors.  Lost arbitration is not currently handled, so don't even list
it as an option in the error message.

Don't return bogus EFAULT code for inappropriate NAK; EIO is better,
there is no bad userspace address in question.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-01-27 18:14:46 +01:00
David Brownell
cf978ab284 i2c-algo-bit: Whitespace fixes (+ NAK/ARB comments)
Fix *LOTS* of whitespace goofs and checkpatch.pl warnings, strangely
parenthesized ternary expressions, and other CodingStyle glitches.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-01-27 18:14:46 +01:00
Jan Engelhardt
96de0e252c Convert files to UTF-8 and some cleanups
* Convert files to UTF-8.

  * Also correct some people's names
    (one example is Eißfeldt, which was found in a source file.
    Given that the author used an ß at all in a source file
    indicates that the real name has in fact a 'ß' and not an 'ss',
    which is commonly used as a substitute for 'ß' when limited to
    7bit.)

  * Correct town names (Goettingen -> Göttingen)

  * Update Eberhard Mönkeberg's address (http://lkml.org/lkml/2007/1/8/313)

Signed-off-by: Jan Engelhardt <jengelh@gmx.de>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
2007-10-19 23:21:04 +02:00
David Brownell
939bc4943d i2c-algo-bit: Read block data bugfix
This fixes a bug in the way i2c-algo-bit handles I2C_M_RECV_LEN,
used to implement i2c_smbus_read_block_data().  Previously, in the
absence of PEC (rarely used!) it would NAK the "length" byte:

	S addr Rd [A] [length] NA

That prevents the subsequent data bytes from being read:

	S addr Rd [A] [length] { A [data] }* NA

The primary fix just reorders two code blocks, so the length used
in the "should I NAK now?" check incorporates the data which it
just read from the slave device.

However, that move also highlighted other fault handling glitches.
This fixes those by abstracting the RX path ack/nak logic, so it
can be used in more than one location.  Also, a few CodingStyle
issues were also resolved.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-09-09 22:29:14 +02:00
Jean Delvare
0a85e9a271 i2c-rpx: Remove
This driver has been broken forever. It depends on i2c-algo-8xx which
has never been in the mainline kernel.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-07-12 14:12:32 +02:00
Jan Engelhardt
16538e6b32 Use menuconfig objects - I2C
Allow the whole I2C menu to be disabled at once without diving into
the submenus for deselecting all options (should the user desire so).

Signed-off-by: Jan Engelhardt <jengelh@gmx.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-01 23:26:34 +02:00
Jean Delvare
494dbb64dc i2c-algo-bit: Improve debugging
Improve the debugging features of the i2c-algo-bit driver:
* Make it possible to compile the driver without debugging support
  at all, making it much smaller.
* Use dev_dbg() for debugging messages where possible, and dev_err()
  for error messages.
* Remove redundant debugging messages.

These changes allowed for minor code cleanups, which are included
as well.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-01 23:26:33 +02:00
Jean Delvare
424ed67c7d i2c-algo-bit: Implement a 50/50 SCL duty cycle
The original i2c-algo-bit implementation uses a 33/66 SCL duty cycle
when bits are being written on the bus. While the I2C specification
doesn't forbid it, this prevents us from driving the I2C bus to its
max speed, limiting us to 66 kbps max on standard I2C busses.

Implementing a 50/50 duty cycle instead lets us max out the bandwidth
up to the theoretical max of 100 kbps on standard I2C busses. This is
particularly important when large amounts of data need to be transfered
over the bus, as is the case with some TV adapters when the firmware is
being uploaded.

In fact this change even allows, at least in theory, fast-mode I2C
support at 125, 166 and 250 kbps. There's no way to reach the
theoretical max of 400 kbps with this implementation. But I don't
think we want to put efforts in that direction anyway: software-driven
I2C is very CPU-intensive and bad for latency.

Other timing changes:
* Don't set SDA high explicitly on error, we're going to issue a stop
  condition before we leave anyway.
* If an error occurs when sending the slave address, yield the CPU
  before retrying, and remove the additional delay after the new start
  condition.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-01 23:26:33 +02:00