linux-toradex.git/include/linux/i2c.h, branch v2.6.15.1

[PATCH] fix missing includes

2005-10-31T01:37:32+00:00

I recently picked up my older work to remove unnecessary #includes of
sched.h, starting from a patch by Dave Jones to not include sched.h
from module.h. This reduces the number of indirect includes of sched.h
by ~300. Another ~400 pointless direct includes can be removed after
this disentangling (patch to follow later).
However, quite a few indirect includes need to be fixed up for this.

In order to feed the patches through -mm with as little disturbance as
possible, I've split out the fixes I accumulated up to now (complete for
i386 and x86_64, more archs to follow later) and post them before the real
patch.  This way this large part of the patch is kept simple with only
adding #includes, and all hunks are independent of each other.  So if any
hunk rejects or gets in the way of other patches, just drop it.  My scripts
will pick it up again in the next round.

Signed-off-by: Tim Schmielau 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] I2C: add i2c module alias for i2c drivers to use

2005-10-28T21:02:15+00:00

This is the start of adding hotplug-like support for i2c devices.

Signed-off-by: Greg Kroah-Hartman

[PATCH] i2c: SMBus PEC support rewrite, 3 of 3

2005-10-28T21:02:14+00:00

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 
Signed-off-by: Greg Kroah-Hartman

[PATCH] i2c: SMBus PEC support rewrite, 2 of 3

2005-10-28T21:02:14+00:00

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 
Signed-off-by: Greg Kroah-Hartman

[PATCH] i2c: SMBus PEC support rewrite, 1 of 3

2005-10-28T21:02:13+00:00

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 
Signed-off-by: Greg Kroah-Hartman

[PATCH] i2c: Drop I2C_SMBUS_I2C_BLOCK_MAX

2005-10-28T21:02:10+00:00

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 
Signed-off-by: Greg Kroah-Hartman

[PATCH] i2c: Drop out-of-date, colliding ioctl definitions

2005-10-28T21:02:09+00:00

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 
Signed-off-by: Greg Kroah-Hartman

[PATCH] i2c: Fix misplaced i2c.h comment

2005-10-28T21:02:09+00:00

Fix a misplaced comment in i2c.h. Spotted by Hideki Iwamoto.

Signed-off-by: Jean Delvare 
Signed-off-by: Greg Kroah-Hartman

[PATCH] i2c: Drop useless CVS revision IDs

2005-10-28T21:02:09+00:00

CVS revision IDs are totally useless and irrelevant by now.

Signed-off-by: Jean Delvare 
Signed-off-by: Greg Kroah-Hartman

[PATCH] i2c: Fix union i2c_smbus_data definition

2005-10-28T21:02:07+00:00

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 
Signed-off-by: Jean Delvare 
Signed-off-by: Greg Kroah-Hartman 

 include/linux/i2c.h |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)