ACPI SSCN/FMCN methods were originally added because then the platform can
provide the most accurate HCNT/LCNT values to the driver. However, this
seems not to be true for Dell Inspiron 7348 where using these causes the
touchpad to fail in boot:

  i2c_hid i2c-DLL0675:00: failed to retrieve report from device.
  i2c_designware INT3433:00: i2c_dw_handle_tx_abort: lost arbitration
  i2c_hid i2c-DLL0675:00: failed to retrieve report from device.
  i2c_designware INT3433:00: controller timed out

The values received from ACPI are (in fast mode):

  HCNT: 72
  LCNT: 160

this translates to following timings (input clock is 100MHz on Broadwell):

  tHIGH: 720 ns (spec min 600 ns)
  tLOW: 1600 ns (spec min 1300 ns)
  Bus period: 2920 ns (assuming 300 ns tf and tr)
  Bus speed: 342.5 kHz

Both tHIGH and tLOW are within the I2C specification.

The calculated values when ACPI parameters are not used are (in fast mode):

  HCNT: 87
  LCNT: 159

which translates to:

  tHIGH: 870 ns (spec min 600 ns)
  tLOW: 1590 ns (spec min 1300 ns)
  Bus period 3060 ns (assuming 300 ns tf and tr)
  Bus speed 326.8 kHz

These values are also within the I2C specification.

Since both ACPI and calculated values meet the I2C specification timing
requirements it is hard to say why the touchpad does not function properly
with the ACPI values except that the bus speed is higher in this case (but
still well below the max 400kHz).

Solve this by adding DMI quirk to the driver that disables using ACPI
parameters on this particulare machine.
Reported-by: NPavel Roskin <plroskin@gmail.com>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: NPavel Roskin <plroskin@gmail.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

The core may register clients attached to this master which may use
funtionality from the master. So, RuntimePM must be enabled before, otherwise
this will fail.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Cc: stable@kernel.org

The driver calls pm_runtime_put() right before pm_runtime_disable() in its
->remove() hook to make sure clock is gated etc. However, it turns out that
pm_runtime_put() only calls ->idle() hook without actually suspending
anything. The following pm_runtime_disable() will prevent the driver from
suspending thus leaving it "active".

It is better to suspend the device synchronously to make sure it is
actually suspended before disabling runtime PM from it.

While there, undo call to pm_runtime_use_autosuspend().
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Commit 1fc2fe20 ("i2c: designware: Add runtime PM hooks") adds
runtime pm support using the same ops for system pm and runtime pm.
When suspend to ram, the i2c host may have been runtime suspended, thus
i2c_dw_disable() hangs.

Previously, I fixed this issue by separating ops for system pm and
runtime pm, then in the system suspend/resume path, runtime pm apis are
used to ensure the device is at correct state.

But as Mika Westerberg pointed out: it sounds a bit silly to resume the
device just because you want to call i2c_dw_disable() for it before
suspending again. He then suggested an elegant solution which keeps the
device runtime suspended during system suspend with the help of
'dev->power.direct_complete'. This patch adopted this solution, and in
fact Mika provided the main code.
Signed-off-by: NJisheng Zhang <jszhang@marvell.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Now that the ACPI companions of devices are represented by pointers
to struct fwnode_handle, it is not quite efficient to check whether
or not an ACPI companion of a device is present by evaluating the
ACPI_COMPANION() macro.

For this reason, introduce a special static inline routine for that,
has_acpi_companion(), and update the code to use it where applicable.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

With -EPROBE_DEFER, this message is confusing and we hope for a
centralized printout in the future anyhow.
Signed-off-by: NAlexey Brodkin <abrodkin@synopsys.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NChristian Ruppert <christian.ruppert@alitech.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This patch implements an I2C bus sharing mechanism between the host and platform
hardware on select Intel BayTrail SoC platforms using the X-Powers AXP288 PMIC.

On these platforms access to the PMIC must be shared with platform hardware. The
hardware unit assumes full control of the I2C bus and the host must request
access through a special semaphore. Hardware control of the bus also makes it
necessary to disable runtime pm to avoid interfering with hardware transactions.
Signed-off-by: NDavid E. Box <david.e.box@linux.intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

We have a central copy of the GPL for that. Some addresses were already
outdated.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>

A platform_driver does not need to set an owner, it will be populated by the
driver core.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Add support for AMD version of the DW I2C host controller. The device is
enumerated from ACPI namespace with ACPI ID AMD0010. Because the core
driver needs an input source clock, and this is not an Intel LPSS device
where clocks are provided through drivers/acpi/acpi_lpss.c, we register the
clock ourselves if the clock rate is given in ->driver_data
Signed-off-by: NCarl Peng <carlpeng008@gmail.com>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

In order to be able to create missing clock for AMD (and in future possibly
others) we move getting clock for the device a bit later. Also make ACPI/DT
configuration in the same place depending on from where the device was
enumerated from.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

There is no way in ACPI to tell in which speed the host controller is
supposed to run, so we default to fast mode (400KHz). Since this has been
the default all the time there should be no functional changes with this
change.

This is the first step required to refactor the driver probe so that we can
supply source clock from ACPI part of the driver to the core.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Use the platform data to set the clk_freq when there is no DT configuration
available. The clk_freq in turn will determine the I2C speed mode.

In Quark, there is currently no other configuration mechanism other than
board files.
Signed-off-by: NRaymond Tan <raymond.tan@intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NHock Leong Kweh <hock.leong.kweh@intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Some legacy devices support ony I2C standard mode at 100kHz.
This patch allows to select the standard mode through the DTS
with the use of the existing clock-frequency parameter.

When clock-frequency parameter is not set, the fast mode is selected.
Only when the parameter is set at 100000, the standard mode is selected.
Signed-off-by: NRomain Baeriswyl <romainba@abilis.com>
Reviewed-by: NChristian Ruppert <christian.ruppert@abilis.com>
Acked-by: NAlan Tull <atull@opensource.altera.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This may appear as PCI or ACPI depending upon the firmware so we
have to list both. All share the same ACPI identifier but not
the same PCI identifier.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This driver has been flagged to drop class based instantiation. The removal
improves boot-up time and is unneeded for embedded controllers. Users have been
warned to switch for some time now, so we can actually do the removal. Keep the
DEPRECATED flag, so the core can inform users that the behaviour finally
changed now. After another transition period, this flag can go, too.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

It is possible that after entering runtime PM suspend the controller
context is lost due the fact that its power is removed. This happens for
example on Asus T100, an Intel Baytrail based tablet/laptop.

In order to get the controller back to functional state, we need to
implement runtime PM hooks which will re-initialize the hardware during
runtime PM resume. We can re-use the existing system suspend hooks as the
steps to resume/suspend the controller are the same.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Userspace can initiate system suspend on arbitrary times which means that
device drivers must make sure that their device gets quiesced before system
suspend is entered. Therefore disable the I2C host controller in the driver
system suspend hook.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Warn users that class based instantiation is going away soon in favour
of more robust probing and faster bootup times.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This patch allows to set independantly SCL and SDA falling times.
The tLOW period is computed by taking into account the SCL falling time.
The tHIGH period is computed by taking into account the SDA falling time.

For instance in case the margin on tLOW is considered too small, it can
be increased by increasing the SCL falling time which is by default set
at 300ns.

The same applies for tHIGH period with the help of SDA falling time.
Signed-off-by: NRomain Baeriswyl <romainba@abilis.com>
Reviewed-by: NChristian Ruppert <christian.ruppert@abilis.com>
Acked-by: NShinya Kuribayashi <skuribay@pobox.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Newer Intel PCHs with LPSS have the same Designware I2C controllers than
Haswell but the ACPI IDs differ. Add these IDs to the driver list.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Subsystems like pinctrl and gpio rightfully make use of deferred probing at
core level. Now, deferred drivers won't be retried if they don't have a .probe
function specified in the driver struct. Fix this driver to have that, so the
devices it supports won't get lost in a deferred probe.
Reported-by: NZhangfei Gao <zhangfei.gao@linaro.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Some Intel LPSS I2C devices make the SDA hold time and *CNT parameters
available via SSCN (standard mode) and FMCN (fast mode) ACPI methods.

Implement support for this so that we check whether an ACPI method exists
and if it does, fill in the SDA hold time and *CNT values to the device
private structure for core to use.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This follows what has already been done for the DeviceTree helpers. Move
the ACPI helpers from drivers/acpi/acpi_i2c.c to the I2C core and update
documentation accordingly.

This also solves a problem reported by Jerry Snitselaar that we can't build
the ACPI I2C helpers as a module.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

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>

Add CONFIG_PM_SLEEP to suspend/resume functions to fix the following
build warning when CONFIG_PM_SLEEP is not selected. This is because
sleep PM callbacks defined by SIMPLE_DEV_PM_OPS are only used when
the CONFIG_PM_SLEEP is enabled.

drivers/i2c/busses/i2c-designware-platdrv.c:211:12: warning: 'dw_i2c_suspend' defined but not used [-Wunused-function]
drivers/i2c/busses/i2c-designware-platdrv.c:221:12: warning: 'dw_i2c_resume' defined but not used [-Wunused-function]
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This fixes the following link error:

  drivers/built-in.o: In function `dw_i2c_probe':
  of_iommu.c:(.text+0x18c8f0): undefined reference to `__aeabi_uldivmod'
  make: *** [vmlinux] Error 1
Signed-off-by: NVincent Stehlé <vincent.stehle@freescale.com>
Tested-by: NKevin Hilman <khilman@linaro.org>
Reviewed-by: NChristian Ruppert <christian.ruppert@abilis.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This patch makes the SDA hold time configurable through device tree.
Signed-off-by: NChristian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: NPierrick Hascoet <pierrick.hascoet@abilis.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com> for arch/arc bits
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>

This is the same controller as on Intel Lynxpoint but the ACPI ID is
different (8086F41). Add support for this.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Driver core already takes care of refcounting, no need to do this on
driver level again.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>

Using autosuspend helps to reduce the resume latency in situations where
another I2C message is going to be started soon. For example with HID over
I2C touch panels we get several messages in a short period of time while
the touch panel is in use.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

It is not good idea to mix static and dynamic I2C adapter numbering. In
this particular case on Lynxpoint we had graphics I2C adapter which took
the first numbers preventing the designware I2C driver from using the
adapter numbers it preferred.

Since Lynxpoint support was just introduced and there is no hardware available
outside Intel we can fix this by switching to use dynamic adapter numbering
instead of static.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This makes the error handling much more simpler than open-coding everything
and in addition makes the probe function smaller and tidier.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The ACPI handle of struct i2c_adapter's dev member should not be
set, because this causes that struct i2c_adapter to be associated
with the ACPI device node corresponding to its parent as the
second "physical_device", which is incorrect (this happens during
the registration of struct i2c_adapter).  Consequently,
acpi_i2c_register_devices() should use the ACPI handle of the
parent of the struct i2c_adapter it is called for rather than the
struct i2c_adapter's ACPI handle (which should be NULL).

Make that happen and modify the i2c-designware-platdrv driver,
which currently is the only driver for ACPI-enumerated I2C
controller chips, not to set the ACPI handle for the
struct i2c_adapter it creates.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NAaron Lu <aaron.lu@intel.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-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>

Intel Lynxpoint has two I2C controllers. These controllers are enumerated
from ACPI namespace with IDs INT33C2 and INT33C3. Add support for these to
the I2C DesignWare platform driver.

This is based on the work of Dirk Brandewie.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

In order to save power the device should be put to low power states
whenever it is not being used. We implement this by enabling minimal
runtime PM support.

There isn't much to do for the device itself as it is disabled once the
last transfer is completed but subsystem/domain runtime PM hooks can save
more power by power gating the device etc.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.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>

clk_{un}prepare is mandatory for platforms using common clock framework. Since
this driver is used by SPEAr platform, which supports common clock framework,
add clk_{un}prepare() support for designware i2c.
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>