The new SMBus PEC implementation doesn't support PEC emulation on
non-PEC non-I2C SMBus masters, so we can drop all related code.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This is my rewrite of the SMBus PEC support. The original
implementation was known to have bugs (credits go to Hideki Iwamoto
for reporting many of them recently), and was incomplete due to a
conceptual limitation.
The rewrite affects only software PEC. Hardware PEC needs very little
code and is mostly untouched.
Technically, both implementations differ in that the original one
was emulating PEC in software by modifying the contents of an
i2c_smbus_data union (changing the transaction to a different type),
while the new one works one level lower, on i2c_msg structures (working
on message contents). Due to the definition of the i2c_smbus_data union,
not all SMBus transactions could be handled (at least not without
changing the definition of this union, which would break user-space
compatibility), and those which could had to be implemented
individually. At the opposite, adding PEC to an i2c_msg structure
can be done on any SMBus transaction with common code.
Advantages of the new implementation:
* It's about twice as small (from ~136 lines before to ~70 now, only
counting i2c-core, including blank and comment lines). The memory
used by i2c-core is down by ~640 bytes (~3.5%).
* Easier to validate, less tricky code. The code being common to all
transactions by design, the risk that a bug can stay uncovered is
lower.
* All SMBus transactions have PEC support in I2C emulation mode
(providing the non-PEC transaction is also implemented). Transactions
which have no emulation code right now will get PEC support for free
when they finally get implemented.
* Allows for code simplifications in header files and bus drivers
(patch follows).
Drawbacks (I guess there had to be at least one):
* PEC emulation for non-PEC capable non-I2C SMBus masters was dropped.
It was based on SMBus tricks and doesn't quite fit in the new design.
I don't think it's really a problem, as the benefit was certainly
not worth the additional complexity, but it's only fair that I at
least mention it.
Lastly, let's note that the new implementation does slightly affect
compatibility (both in kernel and user-space), but doesn't actually
break it. Some defines will be dropped, but the code can always be
changed in a way that will work with both the old and the new
implementations. It shouldn't be a problem as there doesn't seem to be
many users of SMBus PEC to date anyway.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Discard I2C_FUNC_SMBUS_*_PEC defines. i2c clients are not supposed to
check for PEC support of i2c bus drivers on individual SMBus
transactions, and i2c bus drivers are not supposed to advertise them.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Drop I2C_SMBUS_I2C_BLOCK_MAX, use I2C_SMBUS_BLOCK_MAX instead.
I2C_SMBUS_I2C_BLOCK_MAX has always been defined to the same value as
I2C_SMBUS_BLOCK_MAX, and this will never change: setting it to a lower
value would make no sense, setting it to a higher value would break
i2c_smbus_data compatibility. There is no point in changing
i2c_smbus_data to support larger block transactions in SMBus mode, as
no SMBus hardware supports more than 32 byte blocks. Thus, for larger
transactions, direct I2C transfers are the way to go.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Delete 2 out-of-date, colliding ioctl defines. I2C_UDELAY and
I2C_MDELAY are supposed to be used by i2c-algo-bit, but actually
aren't (and I suspect never were). Moreover, their values are the same
as I2C_FUNCS and I2C_SLAVE_FORCE, respectively, which *are* widely
used.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix a misplaced comment in i2c.h. Spotted by Hideki Iwamoto.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
CVS revision IDs are totally useless and irrelevant by now.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The i2c_smbus_data union block member has a comment stating that an
extra byte is required for SMBus Block Process Call transactions. This
has been true for three weeks around June 2002, but no more since, so
it is about time that we drop this comment and fix the definition.
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>
include/linux/i2c.h | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
Kill an unused member of the i2c_adapter structure. This additionally
fixes a potential bug, because <linux/i2c.h> doesn't include
<linux/config.h>, so different files including <linux/i2c.h> could see a
different definition of the i2c_adapter structure, depending on them
including <linux/config.h> (or other header files themselves including
<linux/config.h>) before <linux/i2c.h>, or not.
Credits go to Jörn Engel for pointing me to the problem.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Drop the I2C_ACK_TEST ioctl, which was commented out. It never really
existed (not after 1999 anyway), and there is no such thing as a ack
test on I2C/SMBus anyway.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
I2C_DEVNAME and i2c_clientname were introduced in 2.5.68 [1] to help
media/video driver authors who wanted their code to be compatible with
both Linux 2.4 and 2.6. The cause of the incompatibility has gone since
[2], so I think we can get rid of them, as they tend to make the code
harder to read and longer to preprocess/compile for no more benefit.
I'd hope nobody seriously attempts to keep media/video driver compatible
across Linux trees anymore, BTW.
[1] http://marc.theaimsgroup.com/?l=linux-kernel&m=104930186524598&w=2
[2] http://www.linuxhq.com/kernel/v2.6/0-test3/include/linux/i2c.h
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Delete an outdated comment about i2c_algorithm.id being computed
from algo->id.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There are no more users of i2c_algorithm.id, so we can finally drop
this structure member.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The name member of the i2c_algorithm is never used, although all
drivers conscientiously fill it. We can drop it completely, this
structure doesn't need to have a name.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The only thing left in i2c-sensor.h are module parameter definition
macros. It's only an extension of what i2c.h offers, and this extension
is not sensors-specific. As a matter of fact, a few non-sensors drivers
use them. So we better merge them in i2c.h, and get rid of i2c-sensor.h
altogether.
Signed-off-by: Jean Delvare <khali@linux-fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add support for kind-forced addresses to i2c_probe, like i2c_detect
has for (essentially) hardware monitoring drivers.
Note that this change will slightly increase the size of the drivers
using I2C_CLIENT_INSMOD, with no immediate benefit. This is a
requirement if we want to merge i2c_probe and i2c_detect though, and
seems a reasonable price to pay in comparison with the previous
cleanups which saved much more than that (such as the i2c-isa cleanup
or the i2c address ranges removal.)
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We could inline i2c_adapter_id, as it is really, really short. Doing
so saves a few bytes both in i2c-core and in the drivers using this
function.
before after diff
drivers/hwmon/adm1026.ko 41344 41305 -39
drivers/hwmon/asb100.ko 27325 27246 -79
drivers/hwmon/gl518sm.ko 20824 20785 -39
drivers/hwmon/it87.ko 26419 26380 -39
drivers/hwmon/lm78.ko 21424 21385 -39
drivers/hwmon/lm85.ko 41034 40939 -95
drivers/hwmon/w83781d.ko 39561 39514 -47
drivers/hwmon/w83792d.ko 32979 32932 -47
drivers/i2c/i2c-core.ko 24708 24531 -177
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Move the definitions of i2c_is_isa_client and i2c_is_isa_adapter from
i2c.h to i2c-isa.h. Only hybrid drivers still need them.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Kill normal_isa in header files, documentation and all chip drivers, as
it is no more used.
normal_i2c could be renamed to normal, but I decided not to do so at the
moment, so as to limit the number of changes. This might be done later
as part of the i2c_probe/i2c_detect merge.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Temporarily export a few structures and functions from i2c-core, because we
will soon need them in i2c-isa.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Move the inline function kobj_to_i2c_client() from max6875.c to i2c.h.
Signed-off-by: Ben Gardner <bgardner@wabtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Some months ago, you killed the address ranges mechanism from all
sensors i2c chip drivers (both the module parameters and the in-code
address lists). I think it was a very good move, as the ranges can
easily be replaced by individual addresses, and this allowed for
significant cleanups in the i2c core (let alone the impressive size
shrink for all these drivers).
Unfortunately you did not do the same for non-sensors i2c chip drivers.
These need the address ranges even less, so we could get rid of the
ranges here as well for another significant i2c core cleanup. Here comes
a patch which does just that. Since the process is exactly the same as
what you did for the other drivers set already, I did not split this one
in parts.
A documentation update is included.
The change saves 308 bytes in the i2c core, and an average 1382 bytes
for chip drivers which use I2C_CLIENT_INSMOD, 126 bytes for those which
do not.
This change is required if we want to merge the sensors and non-sensors
i2c code (and we want to do this).
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Index: gregkh-2.6/Documentation/i2c/writing-clients
===================================================================
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
