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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
Jean Delvare
Jiri Kosina
Uwe Kleine-König
Enrik Berkhan
Dave Airlie
Wolfram Sang
Marco Aurelio da Costa
Frank Seidel
Roel Kluin
David Miller
Eric Brower
David Brownell