Baikal-T1 System Controller is equipped with a dedicated I2C Controller
which functionality is based on the DW APB I2C IP-core, the only
difference in a way it' registers are accessed. There are three access
register provided in the System Controller registers map, which indirectly
address the normal DW APB I2C registers space. So in order to have the
Baikal-T1 System I2C Controller supported by the common DW APB I2C driver
we created a dedicated Dw I2C controller model quirk, which retrieves the
syscon regmap from the parental dt node and creates a new regmap based on
it.
Signed-off-by: NSerge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

This is a preparation patch before adding a quirk with custom registers
map creation required for the Baikal-T1 System I2C support.
Signed-off-by: NSerge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

Some platforms might need to activate the driver quirks at a very early
probe stage. For instance, Baikal-T1 System I2C doesn't need to map the
registers space as ones belong to the system controller. Instead it will
request the syscon regmap from the parental DT node. In order to be able
to do so let's retrieve the model flags right after the DW I2C private
data is created. While at it replace the or-assignment with just
assignment operator since or-ing is redundant at this stage.
Signed-off-by: NSerge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

A PM workaround activated by the flag MODEL_CHERRYTRAIL has been removed
since commit 9cbeeca0 ("i2c: designware: Remove Cherry Trail PMIC I2C
bus pm_disabled workaround"), but the flag most likely by mistake has been
left in the Dw I2C drivers. Let's remove it. Since MODEL_MSCC_OCELOT is
the only model-flag left, redefine it to be 0x100 so setting a very first
bit in the MODEL_MASK bits range.
Signed-off-by: NSerge Semin <Sergey.Semin@baikalelectronics.ru>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

For possible code reuse in the future, move ACPI parts into common module.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

In order to export array supported speed for wider use, move it
to a header along with i2c_dw_validate_speed() helper moved to
a common code.

No functional changes intended.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

As a preparatory patch to support slave mode for PCI enumerated devices rename
i2c_dw_probe() to i2c_dw_probe_master() and split common i2c_dw_probe() as
inline helper.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

Move configuration routines to respective modules, i.e. master and slave.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

Use devm_platform_ioremap_resource() instead of
platform_get_resource() + devm_ioremap_resource().
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

Rename DPM_FLAG_LEAVE_SUSPENDED to DPM_FLAG_MAY_SKIP_RESUME which
matches its purpose more closely.

No functional impact.
Suggested-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de> # for I2C
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>

We already set DPM_FLAG_SMART_PREPARE, so we completely skip all
callbacks (other then prepare) where possible, quoting from
dw_i2c_plat_prepare():

        /*
         * If the ACPI companion device object is present for this device, it
         * may be accessed during suspend and resume of other devices via I2C
         * operation regions, so tell the PM core and middle layers to avoid
         * skipping system suspend/resume callbacks for it in that case.
         */
        return !has_acpi_companion(dev);

Also setting the DPM_FLAG_SMART_SUSPEND will cause acpi_subsys_suspend()
to leave the controller runtime-suspended even if dw_i2c_plat_prepare()
returned 0.

Leaving the controller runtime-suspended normally, when the I2C controller
is suspended during the suspend_late phase, is not an issue because
the pm_runtime_get_sync() done by i2c_dw_xfer() will (runtime-)resume it.

But for dw I2C controllers on Bay- and Cherry-Trail devices acpi_lpss.c
leaves the controller alive until the suspend_noirq phase, because it may
be used by the _PS3 ACPI methods of PCI devices and PCI devices are left
powered on until the suspend_noirq phase.

Between the suspend_late and resume_early phases runtime-pm is disabled.
So for any ACPI I2C OPRegion accesses done after the suspend_late phase,
the pm_runtime_get_sync() done by i2c_dw_xfer() is a no-op and the
controller is left runtime-suspended.

i2c_dw_xfer() has a check to catch this condition (rather then waiting
for the I2C transfer to timeout because the controller is suspended).
acpi_subsys_suspend() leaving the controller runtime-suspended in
combination with an ACPI I2C OPRegion access done after the suspend_late
phase triggers this check, leading to the following error being logged
on a Bay Trail based Lenovo Thinkpad 8 tablet:

[   93.275882] i2c_designware 80860F41:00: Transfer while suspended
[   93.275993] WARNING: CPU: 0 PID: 412 at drivers/i2c/busses/i2c-designware-master.c:429 i2c_dw_xfer+0x239/0x280
...
[   93.276252] Workqueue: kacpi_notify acpi_os_execute_deferred
[   93.276267] RIP: 0010:i2c_dw_xfer+0x239/0x280
...
[   93.276340] Call Trace:
[   93.276366]  __i2c_transfer+0x121/0x520
[   93.276379]  i2c_transfer+0x4c/0x100
[   93.276392]  i2c_acpi_space_handler+0x219/0x510
[   93.276408]  ? up+0x40/0x60
[   93.276419]  ? i2c_acpi_notify+0x130/0x130
[   93.276433]  acpi_ev_address_space_dispatch+0x1e1/0x252
...

So since on BYT and CHT platforms we want ACPI I2c OPRegion accesses
to work until the suspend_noirq phase, we need the controller to be
runtime-resumed during the suspend phase if it is runtime-suspended
suspended at that time. This means that we must not set the
DPM_FLAG_SMART_SUSPEND on these platforms.

On BYT and CHT we already have a special ACCESS_NO_IRQ_SUSPEND flag
to make sure the controller stays functional until the suspend_noirq
phase. This commit makes the driver not set the DPM_FLAG_SMART_SUSPEND
flag when that flag is set.

Cc: stable@vger.kernel.org
Fixes: b30f2f65 ("i2c: designware: Set IRQF_NO_SUSPEND flag for all BYT and CHT controllers")
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Since we have generic definitions for bus frequencies, let's use them.
Reviewed-by: NNicolas Saenz Julienne <nsaenzjulienne@suse.de>
Acked-by: NRobert Richter <rrichter@marvell.com>
Reviewed-by: NThor Thayer <thor.thayer@linux.intel.com>
Acked-by: NElie Morisse <syniurge@gmail.com>
Acked-by: NNehal Shah <nehal-bakulchandra.shah@amd.com>
Reviewed-by: NBrendan Higgins <brendanhiggins@google.com>
Acked-by: NScott Branden <scott.branden@broadcom.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: NBaruch Siach <baruch@tkos.co.il>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Acked-by: NOleksij Rempel <o.rempel@pengutronix.de>
Acked-by: NVladimir Zapolskiy <vz@mleia.com>
Acked-by: NGregory CLEMENT <gregory.clement@bootlin.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: NChris Brandt <chris.brandt@renesas.com>
Reviewed-by: NBaolin Wang <baolin.wang7@gmail.com>
Reviewed-by: NPierre-Yves MORDRET <pierre-yves.mordret@st.com>
Acked-by: NPatrice Chotard <patrice.chotard@st.com>
Acked-by: NArd Biesheuvel <ardb@kernel.org>
Reviewed-by: NDmitry Osipenko <digetx@gmail.com>
Acked-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The problem with detecting the FIFO depth in the platform driver
is that in order to implement this we have to access the controller
IC_COMP_PARAM_1 register. Currently it's done before the
i2c_dw_set_reg_access() method execution, which is errors prone since
the method determines the registers endianness and access mode and we
can't use dw_readl/dw_writel accessors before this information is
retrieved. We also can't move the i2c_dw_set_reg_access() function
invocation to after the master/slave probe functions call (when endianness
and access mode are determined), since the FIFO depth information is used
by them for initializations. So in order to fix the problem we have no
choice but to move the FIFO size detection methods to the common code and
call it at the probe stage.
Signed-off-by: NSerge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: NAlexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Add ACPI HID HISI02A3 for Hisilicon Hip08 Lite, which has different
clock frequency from Hip08 for I2C controller.
Tested-by: NSheng Feng <fengsheng5@huawei.com>
Signed-off-by: NHanjun Guo <guohanjun@huawei.com>
Acked-by: NNikula <jarkko.nikula@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The commit bb475230 ("reset: make optional functions really optional")
brought a missed part of the support for an optional reset handlers.

Since that we don't need to have special error handling in the driver.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The commit c62ebb3d ("i2c: designware: Add support for an interface clock")
introduced an optional clock while missed correct error handling.
assert reset line back if error happen at ->probe().

Fixes: c62ebb3d ("i2c: designware: Add support for an interface clock")
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The Synopsys I2C Controller has an interface clock, but most SoCs hide
this away. However, on some SoCs you need to explicitly enable the
interface clock in order to access the registers. Therefore, add
support for an optional interface clock.
Signed-off-by: NPhil Edworthy <phil.edworthy@renesas.com>
Signed-off-by: NGareth Williams <gareth.williams.jx@renesas.com>
Acked-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Before this commit the i2c-designware-platdrv assumes that if the pdev
has an apci-companion it should use a dynamic adapter-nr and it sets
adapter->nr to -1, otherwise it will use pdev->id as adapter->nr.

There are 3 ways how platform_device-s to which i2c-designware-platdrv
will bind can be instantiated:

1) Through of / devicetree
2) Through ACPI enumeration
3) Explicitly instantiated through platform_device_create + add

1) In case of devicetree-instantiation the drivers/of code always sets
pdev->id to PLATFORM_DEVID_NONE, which is -1 so in this case both paths
to set adapter->nr end up doing the same thing.

2) In case of ACPI instantiation the device will always have an
ACPI-companion, so we are already using dynamic adapter-nrs.

3) There are 2 places manually instantiating a designware_i2c platform_dev:
drivers/mfd/intel_quark_i2c_gpio.c
drivers/mfd/intel-lpss.c

In the intel_quark_i2c_gpio.c case pdev->id is always 0, so switching to
dynamic adapter-nrs here could lead to the bus-number no longer being
stable, but the quark X1000 only has 1 i2c-controller, which will also
be assigned bus-number 0 when using dynamic adapter-nrs.

In the intel-lpss.c case intel_lpss_probe() is called from either
intel-lpss-acpi.c in which case there always is an ACPI-companion, or
from intel-lpss-pci.c. In most cases devices handled by intel-lpss-pci.c
also have an ACPI-companion, so we use a dynamic adapter-nr. But in some
cases the ACPI-companion is missing and we would use pdev->id (allocated
from intel_lpss_devid_ida). Devices which use the intel-lpss-pci.c code
typically have many i2c busses, so using pdev->id in this case may lead
to a bus-number conflict, triggering a WARN(id < 0, "couldn't get idr")
in i2c-core-base.c causing an oops an the adapter registration to fail.
So in this case using non dynamic adapter-nrs is actually undesirable.

One machine on which this oops was triggering is the Apollo Lake based
Acer TravelMate Spin B118.

TL;DR: Switching to always using dynamic adapter-numbers does not make
any difference in most cases and in the one case where it does make a
difference the behavior change is desirable because the old behavior
caused an oops.

BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1687065Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Acked-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

i2c-designware-platdrv assumes that if the pdev has an apci-companion
it should use a dynamic adapter-nr and otherwise it will use pdev->id
as adapter-nr.

Before this commit the setting of the adapter.nr was somewhat convoluted,
in the acpi_companion case it was set from dw_i2c_acpi_configure, in the
non acpi_companion case it was set from dw_i2c_set_fifo_size based on
tx_fifo_depth not being set yet indicating that dw_i2c_acpi_configure was
not executed.

This cleans this up, directly setting the adapter-nr from
dw_i2c_plat_probe for both cases.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

On most Intel Bay- and Cherry-Trail systems the PMIC is connected over I2C
and the PMIC is accessed through various means by the _PS0 and _PS3 ACPI
methods (power on / off methods) of various devices.

This leads to suspend/resume ordering problems where a device may be
resumed and get its _PS0 method executed before the I2C controller is
resumed. On Cherry Trail this leads to errors like these:

     i2c_designware 808622C1:06: controller timed out
     ACPI Error: AE_ERROR, Returned by Handler for [UserDefinedRegion]
     ACPI Error: Method parse/execution failed \_SB.P18W._ON, AE_ERROR
     video LNXVIDEO:00: Failed to change power state to D0

But on Bay Trail this caused I2C reads to seem to succeed, but they end
up returning wrong data, which ends up getting written back by the typical
read-modify-write cycle done to turn on various power-resources.

Debugging the problems caused by this silent data corruption is quite
nasty. This commit adds a check which disallows i2c_dw_xfer() calls to
happen until the controller's resume method has completed.

Which turns the silent data corruption into getting these errors in
dmesg instead:

    i2c_designware 80860F41:04: Error i2c_dw_xfer call while suspended
    ACPI Error: AE_ERROR, Returned by Handler for [UserDefinedRegion]
    ACPI Error: Method parse/execution failed \_SB.PCI0.GFX0._PS0, AE_ERROR

Which is much better.

Note the above errors are an example of issues which this patch will
help to debug, the actual fix requires fixing the suspend order and
this has been fixed by a different commit.

Note the setting / clearing of the suspended flag in the suspend / resume
methods is NOT protected by i2c_lock_bus(). This is intentional as these
methods get called from i2c_dw_xfer() (through pm_runtime_get/put) a nd
i2c_dw_xfer() is called with the i2c_bus_lock held, so otherwise we would
deadlock. This means that there is a theoretical race between a non runtime
suspend and the suspended check in i2c_dw_xfer(), this is not a problem
since normally we should not hit the race and this check is primarily a
debugging tool so hitting the check if there are suspend/resume ordering
problems does not need to be 100% reliable.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Now that most of the special Bay- / Cherry-Trail bus lock handling has
been moved to the iosf_mbi code we can simplify the remaining code a bit.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: NWolfram Sang <wsa@the-dreams.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

On some Cherry Trail systems the GPU ACPI fwnode has power-resources which
point to the PMIC, which is connected over a LPSS I2C controller. The GPU
is a PCI device and PCI devices are powered-on at the resume_noirq resume
phase.

Since the GPU power-resources need the I2C controller, recent acpi_lpss.c
changes now also power-up the LPSS I2C controllers on BYT and CHT devices
in the resume_noirq resume phase. But during this phase the IRQ of the
controller is disabled leading to these errors:

 i2c_designware 808622C1:06: controller timed out
 ACPI Error: AE_ERROR, Returned by Handler for [UserDefinedRegion]
 ACPI Error: Method parse/execution failed \_SB.P18W._ON, AE_ERROR
 video LNXVIDEO:00: Failed to change power state to D0

This commit makes the i2c-designware controller set the IRQF_NO_SUSPEND
flag when requesting the interrupt on BYT and CHT devices, so that the IRQ
is left enabled during the noirq phase, fixing this.
Tested-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Commit a3d411fb ("i2c: designware: Disable pm for PMIC i2c-bus even if
there is no _SEM method"), always set the pm_disabled flag on the I2C7
controller, even if its bus was not shared with the PUNIT.

This was a workaround for various suspend/resume issues, after the
following 2 commits this workaround is no longer necessary:

Commit 54152772 ("PM: i2c-designware-platdrv: Suspend/resume at the
                     late/early stages")
Commit e6ce0ce3 ("ACPI / LPSS: Add device link for CHT SD card
                     dependency on I2C")

Therefor this commit removes this workaround.

After this commit the pm_disabled flag is only used to indicate that the
bus is shared with the PUNIT and after other recent changes we no longer
call dev_pm_syscore_device(dev, true), so we are no longer actually
disabling (non-runtime) pm, so this commit also renames the flag to
shared_with_punit to better reflect what it is for.
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The Microsemi Ocelot I2C controller is a designware IP. It also has a
second set of registers to allow tweaking SDA hold time and spike
filtering.
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
[wsa: made one function static]
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Move the #ifdef CONFIG_OF section to the top of the file, after the ACPI
section so functions defined there can be used in dw_i2c_plat_probe.
Tested-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Switch to device_get_match_data in probe to match the device specific data
instead of using the acpi specific function.
Suggested-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

On Bay Trail and Cherry Trail devices we set the pm_disabled flag for I2C
busses which the OS shares with the PUNIT as these need special handling.
Until now we called dev_pm_syscore_device(dev, true) for I2C controllers
with this flag set to keep these I2C controllers always on.

After commit 12864ff8 ("ACPI / LPSS: Avoid PM quirks on suspend and
resume from hibernation"), this no longer works. This commit modifies
lpss_iosf_exit_d3_state() to only run if lpss_iosf_enter_d3_state() has ran
before it, so that it does not run on a resume from hibernate (or from S3).

On these systems the conditions for lpss_iosf_enter_d3_state() to run
never become true, so lpss_iosf_exit_d3_state() never gets called and
the 2 LPSS DMA controllers never get forced into D0 mode, instead they
are left in their default automatic power-on when needed mode.

The not forcing of D0 mode for the DMA controllers enables these systems
to properly enter S0ix modes, which is a good thing.

But after entering S0ix modes the I2C controller connected to the PMIC
no longer works, leading to e.g. broken battery monitoring.

The _PS3 method for this I2C controller looks like this:

            Method (_PS3, 0, NotSerialized)  // _PS3: Power State 3
            {
                If ((((PMID == 0x04) || (PMID == 0x05)) || (PMID == 0x06)))
                {
                    Return (Zero)
                }

                PSAT |= 0x03
                Local0 = PSAT /* \_SB_.I2C5.PSAT */
            }

Where PMID = 0x05, so we enter the Return (Zero) path on these systems.

So even if we were to not call dev_pm_syscore_device(dev, true) the
I2C controller will be left in D0 rather then be switched to D3.

Yet on other Bay and Cherry Trail devices S0ix is not entered unless *all*
I2C controllers are in D3 mode. This combined with the I2C controller no
longer working now that we reach S0ix states on these systems leads to me
believing that the PUNIT itself puts the I2C controller in D3 when all
other conditions for entering S0ix states are true.

Since now the I2C controller is put in D3 over a suspend/resume we must
re-initialize it afterwards and that does indeed fix it no longer working.

This commit implements this fix by:

1) Making the suspend_late callback a no-op if pm_disabled is set and
making the resume_early callback skip the clock re-enable (since it now was
not disabled) while still doing the necessary I2C controller re-init.

2) Removing the dev_pm_syscore_device(dev, true) call, so that the suspend
and resume callbacks are actually called. Normally this would cause the
ACPI pm code to call _PS3 putting the I2C controller in D3, wreaking havoc
since it is shared with the PUNIT, but in this special case the _PS3 method
is a no-op so we can safely allow a "fake" suspend / resume.

Fixes: 12864ff8 ("ACPI / LPSS: Avoid PM quirks on suspend and resume ...")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=200861
Cc: 4.15+ <stable@vger.kernel.org> # 4.15+
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Replace short statement in comment with proper SPDX license tag.

Note, for i2c-desingware-slave.c the identifier is chosen
in accordance with MODULE_LICENSE() macro since it is visible to user.
Another point to this choice is that the header seems to be copy'n'paste
from the other file of this very driver.
Acked-by: NLuis Oliveira <Luis.Oliveira@synopsys.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Instead of using custom variables and parser, convert the driver to use
the ones provided by I2C core.

No functional change intended.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Tested-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Optimize the power management in i2c-designware-platdrv by making it
set the DPM_FLAG_SMART_SUSPEND and DPM_FLAG_LEAVE_SUSPENDED which
allows some code to be dropped from its PM callbacks.

First, setting DPM_FLAG_SMART_SUSPEND causes the intel-lpss driver
to avoid resuming i2c-designware-platdrv devices in its ->prepare
callback, so they can stay in runtime suspend after that point even
if the direct-complete feature is not used for them.

It also causes the ACPI PM domain and the PM core to avoid invoking
"late" and "noirq" suspend callbacks for these devices if they are
in runtime suspend at the beginning of the "late" phase of device
suspend during system suspend.  That guarantees dw_i2c_plat_suspend()
to be called for a device only if it is not in runtime suspend.

Moreover, it causes the device's runtime PM status to be set to
"active" after calling dw_i2c_plat_resume() for it, so the
driver doesn't need internal flags to avoid invoking either
dw_i2c_plat_suspend() or dw_i2c_plat_resume() twice in a row.

Second, setting DPM_FLAG_LEAVE_SUSPENDED enables the optimization
allowing the device to stay suspended after system resume under
suitable conditions, so again the driver doesn't need to take
care of that by itself.

Accordingly, the internal "suspended" and "skip_resume" flags
used by the driver are not necessary any more, so drop them and
simplify the driver's PM callbacks.

Additionally, notice that dw_i2c_plat_complete() only needs to
schedule runtime PM resume for the device if platform firmware
has been involved in resuming the system, so make it call
pm_resume_via_firmware() to check that.  Also make it check the
runtime PM status of the device instead of its direct_complete
flag which also works if the device remained suspended due to
the DPM_FLAG_LEAVE_SUSPENDED driver flag.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: NWolfram Sang <wsa@the-dreams.de>
Tested-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>

Modify i2c-designware-platdrv to set DPM_FLAG_SMART_PREPARE for its
devices and return 0 from the system suspend ->prepare callback
if the device has an ACPI companion object in order to tell the PM
core and middle layers to avoid skipping system suspend/resume
callbacks for the device in that case (which may be problematic,
because the device may be accessed during suspend and resume of
other devices via I2C operation regions then).

Also the pm_runtime_suspended() check in dw_i2c_plat_prepare()
is not necessary any more, because the core does it when setting
power.direct_complete for the device, so drop it.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: NWolfram Sang <wsa@the-dreams.de>
Tested-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>

For consistency with the rest of the file rename function and parameter to
be consistent with the reset of the common file.
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NPhil Reid <preid@electromag.com.au>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Move the i2c_dw_plat_prepare_clk funciton to common file in preparation
for its use also by the master driver.
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NPhil Reid <preid@electromag.com.au>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

According to data sheet SCL timing parameters and DW_IC_CON SPEED mode
bits are not used when operating in slave mode.
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: NLuis Oliveira <lolivei@synopsys.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Don't populate const array supported_speeds on the stack, instead
make it static.  Makes the object code smaller by 150 bytes:

Before:
   text	   data	    bss	    dec	    hex	filename
   8474	   1440	      0	   9914	   26ba	i2c-designware-platdrv.o

After:
   text	   data	    bss	    dec	    hex	filename
   8324	   1440	      0	   9764	   2624	i2c-designware-platdrv.o

(gcc version 7.2.0 x86_64)
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

As reported by Rajat Jain, there are problems when ACPI operation
region handlers or similar, called at the ->resume_early() time, for
I2C client devices try to access an I2C controller that has already
been suspended at that point.  To avoid that, move the suspend/resume
of i2c-designware-platdrv to the late/early stages, respectively.

While at it, avoid resuming the device from runtime suspend in the
driver's ->suspend callback which isn't particularly nice.  [A better
approach would be to make the driver track the PM state of the device
so that it doesn't need to resume it in ->suspend, so implement it.]

First, drop dw_i2c_plat_suspend() added by commit a23318fe (i2c:
designware: Fix system suspend) and rename dw_i2c_plat_runtime_suspend()
back to dw_i2c_plat_suspend().

Second, point the driver's ->late_suspend and ->early_resume
callbacks, rather than its ->suspend and ->resume callbacks,
to dw_i2c_plat_suspend() and dw_i2c_plat_resume(), respectively,
so that they are not executed in parallel with each other, for
example if runtime resume of the device takes place during system
suspend.

Finally, add "suspended" and "skip_resume" flags to struct dw_i2c_dev
and make dw_i2c_plat_suspend() and dw_i2c_plat_resume() use them to
avoid suspending or resuming the device twice in a row and to avoid
resuming a previously runtime-suspended device during system resume.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: NJohannes Stezenbach <js@sig21.net>
Tested-by: NRajat Jain <rajatja@google.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The power management handling in dw_i2c_plat_probe() is somewhat
messy and it is rather hard to figure out the code intention for
the case when pm_disabled is set.  In that case, the driver doesn't
enable runtime PM at all, but in addition to that it calls
pm_runtime_forbid() as though it wasn't sure if runtime PM might
be enabled for the device later by someone else.

Although that concern doesn't seem to be actually valid, the
device is clearly still expected to be PM-capable even in the
pm_disabled set case, so a better approach would be to enable
runtime PM for it unconditionally and prevent it from being
runtime-suspended by using pm_runtime_get_noresume().

Make the driver do that.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The Lenovo Miix2 8 DSDT contains an i2c clk / bus speed of 1700000 Hz
for one if its devices, which is not supported.

This is the second DSDT to show up with an unsupported clk in a short
time, remove the hardcoded fix for DSDTs with a 1 MiHz clock and simply
always round down the clk to the nearest supported value.

Reported-by: russianneuromancer@ya.ru
Fixes: 682c6c21 ("i2c: designware: Some broken DSTDs use 1MiHz ...")
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Code sets bit DW_IC_CON_SPEED_FAST (0x4) always when configuring the slave
mode. This results incorrect register value DW_IC_CON_SPEED_HIGH (0x6)
when OR'ed together with DW_IC_CON_SPEED_STD (0x2).

Remove this and let the code set the speed mode bits according to clock
frequency or default to fast mode.
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The commit 8503ff16 ("i2c: designware: Avoid unnecessary resuming
during system suspend"), may suggest to the PM core to try out the so
called direct_complete path for system sleep. In this path, the PM core
treats a runtime suspended device as it's already in a proper low power
state for system sleep, which makes it skip calling the system sleep
callbacks for the device, except for the ->prepare() and the ->complete()
callbacks.

However, the PM core may unset the direct_complete flag for a parent
device, in case its child device are being system suspended before. In this
scenario, the PM core invokes the system sleep callbacks, no matter if the
device is runtime suspended or not.

Particularly in cases of an existing i2c slave device, the above path is
triggered, which breaks the assumption that the i2c device is always
runtime resumed whenever the dw_i2c_plat_suspend() is being called.

More precisely, dw_i2c_plat_suspend() calls clk_core_disable() and
clk_core_unprepare(), for an already disabled/unprepared clock, leading to
a splat in the log about clocks calls being wrongly balanced and breaking
system sleep.

To still allow the direct_complete path in cases when it's possible, but
also to keep the fix simple, let's runtime resume the i2c device in the
->suspend() callback, before continuing to put the device into low power
state.

Note, in cases when the i2c device is attached to the ACPI PM domain, this
problem doesn't occur, because ACPI's ->suspend() callback, assigned to
acpi_subsys_suspend(), already calls pm_runtime_resume() for the device.

It should also be noted that this change does not fix commit 8503ff16
("i2c: designware: Avoid unnecessary resuming during system suspend").
Because for the non-ACPI case, the system sleep support was already broken
prior that point.

Cc: <stable@vger.kernel.org> # v4.4+
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: NJohn Stultz <john.stultz@linaro.org>
Tested-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>