I2C of helpers used to live in of_i2c.c but experience (from SPI) shows
that it is much cleaner to have this in the core. This also removes a
circular dependency between the helpers and the core, and so we can
finally register child nodes in the core instead of doing this manually
in each driver. So, fix the drivers and documentation, too.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

According to I2C specification the NACK should be handled as folowing:
"When SDA remains HIGH during this ninth clock pulse, this is defined as the Not
Acknowledge signal. The master can then gene rate either a STOP condition to
abort the transfer, or a repeated START condition to start a new transfer."
[http://www.nxp.com/documents/user_manual/UM10204.pdf]

The same is recomened by TI I2C wiki:
 http://processors.wiki.ti.com/index.php/I2C_Tips

Currently, the OMAP I2C driver interrupts I2C trunsfer in case of NACK, but
It queries Stop condition OMAP_I2C_CON_REG.STP=1 only if NACK has been received
during the last message transmitting/recieving.
This may lead to stuck Bus in "Bus Busy" until I2C IP reset (idle/enable).

Hence, fix it by querying Stop condition (STP) always when NACK is received.
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Acked-by: NHein Tibosch <hein_tibosch@yahoo.es>
Acked-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Since commit ab78029e (drivers/pinctrl: grab default handles from device core),
we can rely on device core for setting the default pins. Compile tested only.

Acked-by: Linus Walleij <linus.walleij@linaro.org> (personally at LCE13)
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

We've been lucky not to have any interrupts fire during the suspend
path, otherwise we would have unpredictable behaviour in the kernel.

Based on the logic of the kernel code interrupts from i2c should be
prohibited during suspend. Kernel writes 0 to the I2C_IE register in
the omap_i2c_runtime_suspend() function. In the other side kernel
writes saved interrupt flags to the I2C_IE register in
omap_i2c_runtime_resume() function. I.e. interrupts should be disabled
during suspend.

This works for chips with version1 registers scheme. Interrupts are
disabled during suspend. For chips with version2 scheme registers
writting 0 to the I2C_IE register does nothing (because now the
I2C_IRQENABLE_SET register is located at this address). This register
is used to enable interrupts. For disabling interrupts
I2C_IRQENABLE_CLR register should be used.

Because the registers I2C_IRQENABLE_SET and I2C_IE have the same
addresses, the interrupt enabling procedure is unchanged.

I've checked that interrupts in the i2c controller are still enabled
after writting 0 to the I2C_IRQENABLE_SET register. With this patch
interrupts are disabled in the omap_i2c_runtime_suspend() function.

Patch is based on:
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tag: v3.10-rc2

Verified on OMAP4430.
Signed-off-by: NOleksandr Dmytryshyn <oleksandr.dmytryshyn@ti.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

devm_ioremap_resource does sanity checks on the given resource. No need to
duplicate this in the driver.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

There is simply no reason to be manually setting the private driver
data to NULL in the remove/fail to probe cases.  This is just extra
cruft code that can be removed.

A few notes:
* Nothing relies on drvdata being set to NULL.
* The __device_release_driver() function eventually calls
  dev_set_drvdata(dev, NULL) anyway, so there's no need to do it
  twice.
* I verified that there were no cases where xxx_get_drvdata() was
  being called in these drivers and checking for / relying on the NULL
  return value.

This could be cleaned up kernel-wide but for now just take the baby
step and remove from the i2c subsystem.
Reported-by: NWolfram Sang <wsa@the-dreams.de>
Reported-by: NStephen Warren <swarren@wwwdotorg.org>
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Reviewed-by: NJean Delvare <khali@linux-fr.org>
Acked-by: NPeter Korsgaard <jacmet@sunsite.dk>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NMarek Vasut <marex@denx.de>
Signed-off-by: NWolfram Sang <wolfram@the-dreams.de>

Convert all uses of devm_request_and_ioremap() to the newly introduced
devm_ioremap_resource() which provides more consistent error handling.

devm_ioremap_resource() provides its own error messages so all explicit
error messages can be removed from the failure code paths.
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>
Acked-by: NWolfram Sang <w.sang@pengutronix.de>
Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 0bdfe0cb (i2c: omap: sanitize
exit path) changed the interrupt handler to exit early and complete
the transfer after the draining IRQ is handled. As a result, the ARDY
may not be cleared properly, and it may cause all future I2C transfers
to timeout with "timeout waiting for bus ready". This is reproducible
at least with N900 when twl4030_gpio makes a long write (> FIFO size)
during the probe (http://marc.info/?l=linux-omap&m=135818882610432&w=2).

The fix is to continue until we get ARDY interrupt that completes the
transfer. Tested with 3.8-rc4 + N900: 20 boots in a row without errors;
without the patch the problem triggers after few reboots.
Signed-off-by: NAaro Koskinen <aaro.koskinen@iki.fi>
Acked-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

The errata handling function acks wrong interrupt in case of "Arbitration
lost". Fix it.

Discovered during code review, the real impact of the bug is unknown.
Signed-off-by: NAaro Koskinen <aaro.koskinen@iki.fi>
Reviewed-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

CONFIG_HOTPLUG is going away as an option.  As result the __dev*
markings will be going away.

Remove use of __devinit, __devexit_p, __devinitdata, __devinitconst,
and __devexit.
Signed-off-by: NBill Pemberton <wfp5p@virginia.edu>
Acked-by: Peter Korsgaard <peter.korsgaard@barco.com> (for ocores and mux-gpio)
Acked-by: Havard Skinnemoen <hskinnemoen@gmail.com> (for i2c-gpio)
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> (for puf3)
Acked-by: Barry Song <baohua.song@csr.com> (for sirf)
Reviewed-by: NJean Delvare <khali@linux-fr.org>
[wsa: Fixed "foo* bar" flaws while we are here]
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

The OMAP_I2C_FLAG_RESET_REGS_POSTIDLE is not used anymore
in the i2c driver. Remove the flag.
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Reviewed-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Currently we just queue the transfer and release the
qos constraints, however we do not wait for the transfer
to complete to release the constraint. Move the remove
constraint after the bus busy as we are sure that the
transfers are completed by then.
Acked-by: NJean Pihet <j-pihet@ti.com>
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Acked-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NWolfram Sang <wolfram@the-dreams.de>

Currently after the reset the sysc is written with hardcoded values.
The patch reads the sysc register and writes back the same value
after reset.

- Some unnecessary rev checks can be optimised.
- Also due to whatever reason the hwmod flags are changed
we will not reset the values.
- In some of the cases the minor values of the 2430 register
is different(0x37) in that case the autoidle setting may be missed.
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Currently the restore is done based on the flag
OMAP_I2C_FLAG_RESET_REGS_POSTIDLE.

This helps the following
- The driver is always capable of restoring regardless
of the off mode support being there or not.

- While testing omap2430 it is found that in case of certain
error paths (timeout) a reset is done. However the restore
never happens as it is dependent on the POSTIDLE flag.
The other option would be to call a restore in the reset
case. As there are only a few registers to be restored
the penalty in the idle case should not be much.
Reviewed-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Implement reset as a separate function.
This will enable us to make sure that we don't do the
calculation again on every transfer.
Also at probe the reset is not added as the hwmod is doing that
for us.
Reviewed-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

re-factor omap_i2c_init() so that we can re-use it for resume.
While at it also remove the bufstate variable as we write it
in omap_i2c_resize_fifo for every transfer.
Reviewed-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

The commit [i2c: omap: use revision check for OMAP_I2C_FLAG_APPLY_ERRATA_I207]
uses the revision id instead of the flag. So the flag can be safely removed.
Reviewed-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

The dtrev is used only for the comments. Remove the same and use
the scheme instead to know if it is version2.
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Reviewed-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

The errata i207 is enabled for 2430 and 3xxx. Use the revision check
to enable the erratum instead.
Reviewed-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

The revision register on OMAP4 is a 16-bit lo and a 16-bit
hi. Currently the driver reads only the lower 8-bits.
Fix the same by preventing the truncating of the rev register
for OMAP4.

Also use the scheme bit ie bit-14 of the hi register to know if it
is OMAP_I2C_IP_VERSION_2.

On platforms previous to OMAP4 the offset 0x04 is IE register whose
bit-14 reset value is 0, the code uses the same to its advantage.

Also since the omap_i2c_read_reg uses reg_map_ip_* a raw_readw is done
to fetch the revision register.

The dev->regs is populated after reading the rev_hi. A NULL check
has been added in the resume handler to prevent the access before
the setting of the regs.
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Reviewed-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Some GPIO expanders need some early pin control muxing. Due to
legacy boards sometimes the driver uses subsys_initcall instead of
module_init. This patch takes advantage of defer probe feature
and pin control in order to wait until pin control probing before
GPIO driver probing. It has been tested on OMAP5 board with TCA6424
driver.
Signed-off-by: NSebastien Guiriec <s-guiriec@ti.com>
Acked-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Reviewed-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

if we allow compiler reorder our writes, we could
fall into a situation where dev->buf_len is reset
for no apparent reason.

This bug was found with a simple script which would
transfer data to an i2c client from 1 to 1024 bytes
(a simple for loop), when we got to transfer sizes
bigger than the fifo size, dev->buf_len was reset
to zero before we had an oportunity to handle XDR
Interrupt. Because dev->buf_len was zero, we entered
omap_i2c_transmit_data() to transfer zero bytes,
which would mean we would just silently exit
omap_i2c_transmit_data() without actually writing
anything to DATA register. That would cause XDR
IRQ to trigger forever and we would never transfer
the remaining bytes.

After adding the memory barrier, we also drop resetting
dev->buf_len to zero in omap_i2c_xfer_msg() because
both omap_i2c_transmit_data() and omap_i2c_receive_data()
will act until dev->buf_len reaches zero, rendering the
other write in omap_i2c_xfer_msg() redundant.

This patch has been tested with pandaboard for a few
iterations of the script mentioned above.
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

if we allow compiler reorder our writes, we could
fall into a situation where dev->buf_len is reset
for no apparent reason.

This bug was found with a simple script which would
transfer data to an i2c client from 1 to 1024 bytes
(a simple for loop), when we got to transfer sizes
bigger than the fifo size, dev->buf_len was reset
to zero before we had an oportunity to handle XDR
Interrupt. Because dev->buf_len was zero, we entered
omap_i2c_transmit_data() to transfer zero bytes,
which would mean we would just silently exit
omap_i2c_transmit_data() without actually writing
anything to DATA register. That would cause XDR
IRQ to trigger forever and we would never transfer
the remaining bytes.

After adding the memory barrier, we also drop resetting
dev->buf_len to zero in omap_i2c_xfer_msg() because
both omap_i2c_transmit_data() and omap_i2c_receive_data()
will act until dev->buf_len reaches zero, rendering the
other write in omap_i2c_xfer_msg() redundant.

This patch has been tested with pandaboard for a few
iterations of the script mentioned above.
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

This reverts commit 3db11fef
(ARM: OMAP: convert I2C driver to PM QoS for MPU latency constraints).
This commit causes I2C timeouts to appear on several OMAP3430/3530-based
boards:

  http://marc.info/?l=linux-arm-kernel&m=135071372426971&w=2
  http://marc.info/?l=linux-arm-kernel&m=135067558415214&w=2
  http://marc.info/?l=linux-arm-kernel&m=135216013608196&w=2

and appears to have been sent for merging before one of its prerequisites
was merged:

  http://marc.info/?l=linux-arm-kernel&m=135219411617621&w=2Signed-off-by: NPaul Walmsley <paul@pwsan.com>
Acked-by: NJean Pihet <j-pihet@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

This reverts commit 3db11fef
(ARM: OMAP: convert I2C driver to PM QoS for MPU latency constraints).
This commit causes I2C timeouts to appear on several OMAP3430/3530-based
boards:

  http://marc.info/?l=linux-arm-kernel&m=135071372426971&w=2
  http://marc.info/?l=linux-arm-kernel&m=135067558415214&w=2
  http://marc.info/?l=linux-arm-kernel&m=135216013608196&w=2

and appears to have been sent for merging before one of its prerequisites
was merged:

  http://marc.info/?l=linux-arm-kernel&m=135219411617621&w=2Signed-off-by: NPaul Walmsley <paul@pwsan.com>
Acked-by: NJean Pihet <j-pihet@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Convert the driver from the outdated omap_pm_set_max_mpu_wakeup_lat
API to the new PM QoS API.
Since the constraint is on the MPU subsystem, use the PM_QOS_CPU_DMA_LATENCY
class of PM QoS. The resulting MPU constraints are used by cpuidle to
decide the next power state of the MPU subsystem.

The I2C device latency timing is derived from the FIFO size and the
clock speed and so is applicable to all OMAP SoCs.
Signed-off-by: NJean Pihet <j-pihet@ti.com>
Acked-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Acked-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

When booting using a device tree, the adapter number is dynamically
assigned after the log message is sent.
This patch modifies the log message to get a correct adapter id.
Signed-off-by: NFlorian Vaussard <florian.vaussard@epfl.ch>
Tested-by: NBenoit Cousson <b-cousson@ti.com>
Acked-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

move the goto out label one line down, so that
it can be used when stat is read as zero. All
other exits, can be done with a break statement.

While at that, also break out as soon as we
complete draining IRQ, since at that time
we know we transferred everything there was
to be transferred.
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

this helps us reduce unnecessary pm transitions
in case we have another i2c message starting soon.
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

before starting any messages we call pm_runtime_get_sync()
which will make sure that by the time we program a transfer
and our IRQ handler gets called, we're not suspended
anymore.
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

for OMAP2, we can easily switch over to threaded
IRQs on the I2C driver. This will allow us to
spend less time in hardirq context.
Signed-off-by: NFelipe Balbi <balbi@ti.com>
[Trivial formating changes]
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Currently omap_i2c_ack_stat doesn't use the stat variable.
After the read of the I2C_STAT_REG it is not used.
Remove the redundant read of the status register.
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

we can ack stat and complete the command from
the errata handling itself.
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

This patch will try to avoid the usage of
draining feature by reconfiguring the FIFO
the start condition of each message based
on the message's size.

By doing that, we will be better utilizing
the FIFO when doing big transfers.

While at that also drop the now unneeded
check for dev->buf_len as we always know
the amount of data to be transmitted.
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

instead of having multiple return points, use
a goto statement to make that clearer.
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

Always return IRQ_HANDLED otherwise we could get our IRQ line disabled due
to many spurious IRQs.
Signed-off-by: NFelipe Balbi <balbi@ti.com>
[Trivial changes to commitlogs]
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

omap_i2c_dev is allocated with kzalloc(),
so we need not initialize b_hw to zero.
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

that way we can ignore TX IRQs while in receiver
mode and ignore RX IRQs while in transmitter mode.
Signed-off-by: NFelipe Balbi <balbi@ti.com>
[Remove unnecessary braces]
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>