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Wolfram Sang 3a9ddaf4dc i2c: only check scl functions when using generic recovery
A custom recovery function doesn't need these pointers to be populated
because it may work differently internally.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Peter Griffin <peter.griffin@linaro.org>
2016-05-13 12:37:03 +02:00
Peter Rosin 6ef91fcca8 i2c: mux: relax locking of the top i2c adapter during mux-locked muxing
With a i2c topology like the following

                       GPIO ---|  ------ BAT1
                        |      v /
   I2C  -----+----------+---- MUX
             |                   \
           EEPROM                 ------ BAT2

there is a locking problem with the GPIO controller since it is a client
on the same i2c bus that it muxes. Transfers to the mux clients (e.g. BAT1)
will lock the whole i2c bus prior to attempting to switch the mux to the
correct i2c segment. In the above case, the GPIO device is an I/O expander
with an i2c interface, and since the GPIO subsystem knows nothing (and
rightfully so) about the lockless needs of the i2c mux code, this results
in a deadlock when the GPIO driver issues i2c transfers to modify the
mux.

So, observing that while it is needed to have the i2c bus locked during the
actual MUX update in order to avoid random garbage on the slave side, it
is not strictly a must to have it locked over the whole sequence of a full
select-transfer-deselect mux client operation. The mux itself needs to be
locked, so transfers to clients behind the mux are serialized, and the mux
needs to be stable during all i2c traffic (otherwise individual mux slave
segments might see garbage, or worse).

Introduce this new locking concept as "mux-locked" muxes, and call the
pre-existing mux locking scheme "parent-locked".

Modify the i2c mux locking so that muxes that are "mux-locked" locks only
the muxes on the parent adapter instead of the whole i2c bus when there is
a transfer to the slave side of the mux. This lock serializes transfers to
the slave side of the muxes on the parent adapter.

Add code to i2c-mux-gpio and i2c-mux-pinctrl that checks if all involved
gpio/pinctrl devices have a parent that is an i2c adapter in the same
adapter tree that is muxed, and request a "mux-locked mux" if that is the
case.

Modify the select-transfer-deselect code for "mux-locked" muxes so
that each of the select-transfer-deselect ops locks the mux parent
adapter individually.

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-05-04 22:39:17 +02:00
Peter Rosin fa96f0cb9b i2c: muxes always lock the parent adapter
Instead of checking for i2c parent adapters for every lock/unlock, simply
override the locking for muxes to always lock/unlock the parent adapter
directly.

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-05-04 22:28:31 +02:00
Peter Rosin 8320f495cf i2c: allow adapter drivers to override the adapter locking
Add i2c_lock_bus() and i2c_unlock_bus(), which call the new lock_bus and
unlock_bus ops in the adapter. These funcs/ops take an additional flags
argument that indicates for what purpose the adapter is locked.

There are two flags, I2C_LOCK_ROOT_ADAPTER and I2C_LOCK_SEGMENT, but they
are both implemented the same. For now. Locking the root adapter means
that the whole bus is locked, locking the segment means that only the
current bus segment is locked (i.e. i2c traffic on the parent side of
a mux is still allowed even if the child side of the mux is locked).

Also support a trylock_bus op (but no function to call it, as it is not
expected to be needed outside of the i2c core).

Implement i2c_lock_adapter/i2c_unlock_adapter in terms of the new locking
scheme (i.e. lock with the I2C_LOCK_ROOT_ADAPTER flag).

Locking the root adapter and locking the segment is the same thing for
all root adapters (e.g. in the normal case of a simple topology with no
i2c muxes). The two locking variants are also the same for traditional
muxes (aka parent-locked muxes). These muxes traverse the tree, locking
each level as they go until they reach the root. This patch is preparatory
for a later patch in the series introducing mux-locked muxes, which behave
differently depending on the requested locking. Since all current users
are using i2c_lock_adapter, which is a wrapper for I2C_LOCK_ROOT_ADAPTER,
we only need to annotate the calls that will not need to lock the root
adapter for mux-locked muxes. I.e. the instances that needs to use
I2C_LOCK_SEGMENT instead of i2c_lock_adapter/I2C_LOCK_ROOT_ADAPTER. Those
instances are in the i2c_transfer and i2c_smbus_xfer functions, so that
mux-locked muxes can single out normal i2c accesses to its slave side
and adjust the locking for those accesses.

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-05-04 22:28:31 +02:00
Linus Walleij 04f59143b5 i2c: let I2C masters ignore their children for PM
When using a certain I2C device with runtime PM enabled on
a certain I2C bus adaper the following happens:

struct amba_device *foo
   \
   struct i2c_adapter *bar
      \
      struct i2c_client *baz

The AMBA device foo has its device PM struct set to ignore
children with pm_suspend_ignore_children(&foo->dev, true).
This makes runtime PM work just fine locally in the driver:
the fact that devices on the bus are suspended or resumed
individually does not affect its operation, and the hardware
does not power up unless transferring messages.

However this child ignorance property is not inherited into
the struct i2c_adapter *bar.

On system suspend things will work fine.

On system resume the following annoying phenomenon occurs:

- In the pm_runtime_force_resume() path of
  struct i2c_client *baz, pm_runtime_set_active(&baz->dev); is
  eventually called.

- This becomes __pm_runtime_set_status(&baz->dev, RPM_ACTIVE);

- __pm_runtime_set_status() detects that RPM state is changed,
  and checks whether the parent is:
  not active (RPM_ACTIVE) and not ignoring its children
  If this happens it concludes something is wrong, because
  a parent that is not ignoring its children must be active
  before any children activate.

- Since the struct i2c_adapter *bar does not ignore
  its children, the PM core thinks that it must indeed go
  online before its children, the check bails out with
  -EBUSY, i.e. the i2c_client *baz thinks it can't work
  because it's parent is not online, and it respects its
  parent.

- In the driver the .resume() callback returns -EBUSY from
  the runtime_force_resume() call as per above. This leaves
  the device in a suspended state, leading to bad behaviour
  later when the device is used. The following debug
  print is made with an extra printg patch but illustrates
  the problem:

[   17.040832] bh1780 2-0029: parent (i2c-2) is not active
               parent->power.ignore_children = 0
[   17.040832] bh1780 2-0029: pm_runtime_force_resume:
               pm_runtime_set_active() failed (-16)
[   17.040863] dpm_run_callback():
               pm_runtime_force_resume+0x0/0x88 returns -16
[   17.040863] PM: Device 2-0029 failed to resume: error -16

Fix this by letting all struct i2c_adapter:s ignore their
children: i2c children have no business doing keeping
their parents awake: they are completely autonomous
devices that just use their parent to talk, a usecase
which must be power managed in the host on a per-message
basis.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-04-12 23:07:28 +02:00
Wolfram Sang 041edda875 i2c: core: use new 8 bit address helper function
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-04-11 18:54:59 +02:00
Wolfram Sang 8dcf32175b i2c: prevent endless uevent loop with CONFIG_I2C_DEBUG_CORE
Jan reported this:

===
After enabling CONFIG_I2C_DEBUG_CORE my system was broken
(no network, console login not possible). System log was
flooded with the this message:

 ...
[  608.052077] rtc-ds1307 0-0068: uevent
[  608.052500] rtc-ds1307 0-0068: uevent
[  608.052925] rtc-ds1307 0-0068: uevent
 ...

The culprit is the dev_dbg printk in the i2c uevent handler.
If this is activated (for instance by CONFIG_I2C_DEBUG_CORE)
it results in an endless loop with systemd-journald.

This happens if user-space scans the system log and reads the uevent
file to get information about a newly created device, which seems fair
use to me. Unfortunately reading the "uevent" file uses the same
function that runs for creating the uevent for a new device,
generating the next syslog entry.

Ideally user-space would implement a recursion detection and
after reading the same device file for the 1000th time call it a
day, but nevertheless I think we should avoid this problem by
removing the debug print completely or using another print variant.

The same problem seems to be reported here:
https://bugs.freedesktop.org/show_bug.cgi?id=76886
===

His patch converted the message to pr_debug, but I think the debug can
simply go. We have other means to see code paths these days. This
enables us to clean up the function some more while we are here.

Reported-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Tested-by: Jan Glauber <jglauber@cavium.com>
2016-03-30 14:20:33 +02:00
Wolfram Sang b980a26d02 i2c: immediately mark ourselves as registered
Mark the i2c bus as registered right after the the bus_register call,
not at the end of init. Otherwise, we can't register our own dummy
driver.

Reported-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Fixes: 95026658c4 ("i2c: do not use internal data from driver core")
2016-03-14 18:17:25 +01:00
Sudip Mukherjee 95026658c4 i2c: do not use internal data from driver core
The variable p is a data structure which is used by the driver core
internally and it is not expected that busses will be directly accessing
these driver core internal only data.

Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[wsa: removed the unlikely()]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-03-12 16:58:11 +01:00
Wolfram Sang 53feedf891 i2c: i2c-core: sort includes
I request this for drivers, so the core should adhere to sorted includes as
well.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-02-20 23:33:38 +01:00
Wolfram Sang 9f924169c0 i2c: always enable RuntimePM for the adapter device
The adapter device is a logical device. Because of that, it already uses
pm_runtime_no_callbacks() in the core. To ensure proper propagation from
the children (i2c devices) to the parent of the adapter (the HW device),
make sure RuntimePM is enabled in any case.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-01-10 09:27:06 +01:00
Wolfram Sang 54177ccfbe i2c: make i2c_parse_fw_timings() always visible
This function used to be DT only, so it lived inside a CONFIG_OF block.
Now it uses device attributes and must be moved outside of it. No
further code changes, only one whitespace improvement.

Reported-by: Jim Davis <jim.epost@gmail.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-12-17 20:36:39 +01:00
Wolfram Sang e1dba01ca6 i2c: add generic routine to parse DT for timing information
Inspired from the i2c-rk3x driver (thanks guys!) but refactored and
extended. See built-in docs for further information.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-12-14 10:51:07 +01:00
Grygorii Strashko c18fba2306 i2c: fix wakeup irq parsing
This patch fixes obvious copy-past error in wake up irq parsing
code which leads to the fact that dev_pm_set_wake_irq() will
be called with wrong IRQ number when "wakeup" IRQ is not
defined in DT.

Fixes: 3fffd12839 ("i2c: allow specifying separate wakeup interrupt in device tree")
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: <stable@vger.kernel.org> # v4.3
2015-11-20 16:19:08 +01:00
Linus Torvalds d55fc37856 Merge branch 'i2c/for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:

 - New drivers: UniPhier (with and without FIFO)

 - some drivers got some bigger rework: ismt, designware, img-scb (rcar
   had to be reverted because issues were showing up just lately)

 - ACPI: reworked the device scanning and added support for muxes

... and quite a lot of driver bugfixes and cleanups this time.  All
files touched outside of the i2c realm have proper acks.

* 'i2c/for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (70 commits)
  i2c: rcar: Revert the latest refactoring series
  i2c: pnx: remove superfluous assignment
  MAINTAINERS: i2c: drop i2c-pnx maintainer
  MAINTAINERS: i2c: mark also subdirectories as maintained
  i2c: cadence: enable driver for ARM64
  i2c: i801: Document Intel DNV and Broxton
  i2c: at91: manage unexpected RXRDY flag when starting a transfer
  i2c: pnx: Use setup_timer instead of open coding it
  i2c: add ACPI support for I2C mux ports
  acpi: add acpi_preset_companion() stub
  i2c: pxa: Add support for pxa910/988 & new configuration features
  i2c: au1550: Convert to devm_kzalloc and devm_ioremap_resource
  i2c-dev: Fix I2C_SLAVE ioctl comment
  i2c-dev: Fix typo in ioctl name reference
  i2c: sirf: tune the divider to make i2c bus freq more accurate
  i2c: imx: Use -ENXIO as error in the NACK case
  i2c: i801: Add support for Intel Broxton
  i2c: i801: Add support for Intel DNV
  i2c: mediatek: add i2c resume support
  i2c: imx: implement bus recovery
  ...
2015-11-10 11:58:25 -08:00
Dustin Byford 8eb5c87a92 i2c: add ACPI support for I2C mux ports
Although I2C mux devices are easily enumerated using ACPI (_HID/_CID or
device property compatible string match), enumerating I2C client devices
connected through an I2C mux needs a little extra work.

This change implements a method for describing an I2C device hierarchy that
includes mux devices by using an ACPI Device() for each mux channel along
with an _ADR to set the channel number for the device.  See
Documentation/acpi/i2c-muxes.txt for a simple example.

To make this work the ismt, i801, and designware pci/platform devs now
share an ACPI companion with their I2C adapter dev similar to how it's done
in OF.  This is done on the assumption that power management functions will
not be called directly on the I2C dev that is sharing the ACPI node.

Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Dustin Byford <dustin@cumulusnetworks.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-10-25 15:49:46 +01:00
Mika Westerberg 166c2ba398 i2c / ACPI: Rework I2C device scanning
The way we currently scan I2C devices behind an I2C host controller does not
work in cases where the I2C device in question is not declared directly below
the host controller ACPI node.

This is perfectly legal according the ACPI 6.0 specification and some existing
systems are doing this.

To be able to enumerate all devices which are connected to a certain I2C host
controller we need to rework the current I2C scanning routine a bit. Instead of
scanning directly below the host controller we scan the whole ACPI namespace
for present devices with valid I2cSerialBus() connection pointing to the host
controller in question.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Dustin Byford <dustin@cumulusnetworks.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-10-20 16:51:14 +02:00
Kieran Bingham 74cedd3052 i2c: return probe deferred status on dev_pm_domain_attach
A change of return status was introduced in commit 3fffd12839
("i2c: allow specifying separate wakeup interrupt in device tree")

The commit prevents the defer status being passed up the call stack
appropriately when dev_pm_domain_attach returns -EPROBE_DEFER.

Catch the PROBE_DEFER and clear up the IRQ wakeup status

Signed-off-by: Kieran Bingham <kieranbingham@gmail.com>
Fixes: 3fffd12839 ("i2c: allow specifying separate wakeup interrupt in device tree")
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-10-15 13:35:32 +02:00
Dmitry Torokhov 3fffd12839 i2c: allow specifying separate wakeup interrupt in device tree
Instead of having each i2c driver individually parse device tree data in
case it or platform supports separate wakeup interrupt, and handle
enabling and disabling wakeup interrupts in their power management
routines, let's have i2c core do that for us.

Platforms wishing to specify separate wakeup interrupt for the device
should use named interrupt syntax in their DTSes:

	interrupt-parent = <&intc1>;
	interrupts = <5 0>, <6 0>;
	interrupt-names = "irq", "wakeup";

This patch is inspired by work done by Vignesh R <vigneshr@ti.com> for
pixcir_i2c_ts driver.

Note that the original code tried to preserve any existing wakeup
settings from userspace but was not quite right in that regard:
it would preserve wakeup flag set by userspace upon driver rebinding;
but it would re-arm the wakeup flag if it was disabled by userspace.

We think that resetting the flag upon re-binding the driver is proper
behavior as the driver is responsible for setting up and handling
wakeups.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Tested-by: Vignesh R <vigneshr@ti.com>
[wsa: updated the commit message]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-26 18:47:58 +02:00
Irina Tirdea 01eef96e37 i2c: core: Add support for best effort block read emulation
There are devices that need to handle block transactions
regardless of the capabilities exported by the adapter.
For performance reasons, they need to use i2c read blocks
if available, otherwise emulate the block transaction with word
or byte transactions.

Add support for a helper function that would read a data block
using the best transfer available: I2C_FUNC_SMBUS_READ_I2C_BLOCK,
I2C_FUNC_SMBUS_READ_WORD_DATA or I2C_FUNC_SMBUS_READ_BYTE_DATA.

Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-24 14:05:19 +02:00
Wolfram Sang c6909d6f6f i2c: slave: print warning if slave flag not set
Address collisions will be rare, but we should let the user know that
slaves have their own address space nonetheless.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-24 14:05:16 +02:00
Wolfram Sang cfa0327b0d i2c: support 10 bit and slave addresses in sysfs 'new_device'
We now have seperate address spaces for 10 bit and we-are-slave clients.
Update the sysfs device instantiation method to support these types by
accepting the address offsets that are assigned to the extra address
spaces. Update the documentation, too.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-24 14:05:15 +02:00
Wolfram Sang 9bccc70a12 i2c: take address space into account when checking for used addresses
It is not enough to compare the plain address value, we also need to
check the flags enabling a different address space. E.g. it is valid to
have address 0x50 as a 7-bit address and 0x050 as 10-bit address on the
same bus. Same for addresses when we are the slave.

Tested-by: Andrey Danin <danindrey@mail.ru>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-24 14:05:14 +02:00
Wolfram Sang b4e2f6ac12 i2c: apply DT flags when probing
Check for slave and 10-bit flags when probing and mark the client when
found. Improve the address validity check, too

Tested-by: Andrey Danin <danindrey@mail.ru>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-24 14:05:14 +02:00
Wolfram Sang c4019b7040 i2c: make address check indpendent from client struct
We want to use this function with struct boardinfo soon, so let's just
pass the parameters really needed. We also extend the type of addr, so
more types can be input. Remove a superfluous dangling comment while
here.

Tested-by: Andrey Danin <danindrey@mail.ru>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-24 14:05:13 +02:00
Wolfram Sang 66be6056eb i2c: rename address check functions
The current naming is based on the arguments of the functions and not on
what they do. Even I as the maintainer find this confusing, so let's
rename them to something more descriptive.

Tested-by: Andrey Danin <danindrey@mail.ru>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-24 14:05:12 +02:00
Wolfram Sang da899f55b3 i2c: apply address offset for slaves, too
We want a separate address range for being an I2C slave. Add an offset
of 0x1000, so it can be combined with ten bit addresses as well. Add a
separate function to create the address value, we will need it later in
other places.

Tested-by: Andrey Danin <danindrey@mail.ru>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-24 14:05:11 +02:00
Vladimir Zapolskiy 48e9743dd6 i2c: core: add and export of_get_i2c_adapter_by_node() interface
of_find_i2c_adapter_by_node() call requires quite often missing
put_device(), and i2c_put_adapter() releases a device locked by
i2c_get_adapter() only. In general module_put(adapter->owner) and
put_device(dev) are not interchangeable.

This is a common error reproduction scenario as a result of the
misusage described above (for clearness this is run on iMX6 platform
with HDMI and I2C bus drivers compiled as kernel modules):

    root@mx6q:~# lsmod | grep i2c
    i2c_imx                10213  0
    root@mx6q:~# lsmod | grep dw_hdmi_imx
    dw_hdmi_imx             3631  0
    dw_hdmi                11846  1 dw_hdmi_imx
    imxdrm                  8674  3 dw_hdmi_imx,imx_ipuv3_crtc,imx_ldb
    drm_kms_helper        113765  5 dw_hdmi,imxdrm,imx_ipuv3_crtc,imx_ldb
    root@mx6q:~# rmmod dw_hdmi_imx
    root@mx6q:~# lsmod | grep i2c
    i2c_imx                10213  -1

                                 ^^^^^

    root@mx6q:~# rmmod i2c_imx
    rmmod: ERROR: Module i2c_imx is in use

To fix existing users of these interfaces and to avoid any further
confusion and misusage in future, add one more interface
of_get_i2c_adapter_by_node(), it is similar to i2c_get_adapter() in
sense that an I2C bus device driver found and locked by user can be
correctly unlocked by i2c_put_adapter().

Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-10 08:37:36 +02:00
Vladimir Zapolskiy 611e12ea0f i2c: core: manage i2c bus device refcount in i2c_[get|put]_adapter
In addition to module_get()/module_put() add get_device()/put_device()
calls into i2c_get_adapter()/i2c_put_adapter() exported
interfaces. This is done to lock I2C bus device, if it is in use by a
client.

Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-10 08:37:35 +02:00
Vladimir Zapolskiy e331146973 i2c: fix leaked device refcount on of_find_i2c_* error path
If of_find_i2c_device_by_node() or of_find_i2c_adapter_by_node() find
a device by node, but its type does not match, a reference to that
device is still held. This change fixes the problem.

Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-01 12:11:58 +02:00
Jan Luebbe 8b06260836 i2c: core: only use set_scl for bus recovery after calling prepare_recovery
Using set_scl may be ineffective before calling the driver specific
prepare_recovery callback, which might change into a test mode. So
instead of setting SCL in i2c_generic_scl_recovery, move it to
i2c_generic_recovery (after the optional prepare_recovery).

Signed-off-by: Jan Luebbe <jlu@pengutronix.de>
Acked-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Tested-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-07-31 13:32:31 +02:00
Pantelis Antoniou 4f001fd301 i2c: Mark instantiated device nodes with OF_POPULATE
Mark (and unmark) device nodes with the POPULATE flag as appropriate.
This is required to avoid multi probing when using I2C and device
overlays containing a mux.
This patch is also more careful with the release of the adapter device
which caused a deadlock with muxes, and does not break the build
on !OF since the node flag accessors are not defined then.

Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-07-09 22:25:54 +02:00
Linus Torvalds 24867481b8 Merge branch 'i2c/for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
 "Highlights:

   - new drivers for Mediatek I2C, APM X-Gene, Broadcom Settop
   - major updates to at91, davinci
   - bugfixes to the mux infrastructure when dealing with the new quirk
     mechanism
   - more users for the bus recovery feature
   - further improvements to the slave framework

  Plus the usual bunch of smaller driver and core improvements and
  fixes.

  There is one patch removing old code from an ARM platform.  This has
  been acked by the sh_mobile maintainer Simon Horman"

* 'i2c/for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (48 commits)
  i2c: busses: i2c-bcm2835: limits cdiv to allowed values
  i2c: sh_mobile: use proper type for timeout
  i2c: sh_mobile: use adapter default for timeout
  i2c: rcar: use proper type for timeout
  i2c: rcar: use adapter default for timeout
  i2c: designware: Make sure the device is suspended before disabling runtime PM
  i2c: tegra: apply size limit quirk
  i2c: tegra: don't advertise SMBUS_QUICK
  i2c: octeon: remove unused signal handling
  i2c: davinci: Optimize SCL generation
  i2c: mux: pca954x: Use __i2c_transfer because of quirks
  i2c: mux: Use __i2c_transfer() instead of calling parent's master_xfer()
  i2c: use parent adapter quirks in mux
  i2c: bcm2835: clear reserved bits in S-Register
  ARM: shmobile: r8a7740: remove I2C errata handling
  i2c: sh_mobile: add errata workaround
  i2c: at91: fix code checker warnings
  i2c: busses: xgene-slimpro: fix incorrect __init declation for probe
  i2c: davinci: Avoid sending to own address
  i2c: davinci: Refactor i2c_davinci_wait_bus_not_busy()
  ...
2015-06-25 18:42:39 -07:00
Jarkko Nikula 7ef85f5fdd i2c: core: Reduce stack size of acpi_i2c_space_handler()
sizeof(struct i2c_client) is 1088 bytes on a CONFIG_X86_64=y build and
produces following warning when CONFIG_FRAME_WARN is set to 1024:

drivers/i2c/i2c-core.c: In function ‘acpi_i2c_space_handler’:
drivers/i2c/i2c-core.c:367:1: warning: the frame size of 1152 bytes is
larger than 1024 bytes [-Wframe-larger-than=]

This is not critical given that kernel stack is 16 kB on x86_64 but lets
reduce the stack usage by allocating the struct i2c_client from the heap.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-06-03 00:28:40 +09:00
Shailendra Verma 95cc1e3d76 i2c: core: fix typo in comment
Signed-off-by: Shailendra Verma <shailendra.capricorn@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-06-01 08:41:13 +09:00
Wolfram Sang 4c1344f105 i2c: check for proper length of the reg property
int is vague, let's simply use the type of the variable in question.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-06-01 08:22:51 +09:00
Wolfram Sang 0c7cab96ec i2c: slave: add error messages to slave core
Inform users what went wrong from the core, so drivers don't have to do
it.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-06-01 08:22:50 +09:00
Mika Westerberg 845c877009 i2c / ACPI: Assign IRQ for devices that have GpioInt automatically
Following what DT already does. If the device does not have ACPI Interrupt
resource but instead it has one or more GpioInt resources listed below it,
we take the first GpioInt resource, convert it to suitable Linux IRQ number
and pass it to the driver instead.

This makes drivers simpler because the don't need to care about GPIOs at
all if only thing they need is interrupt.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-13 10:24:35 +02:00
Mika Westerberg dab472eb93 i2c / ACPI: Use 0 to indicate that device does not have interrupt assigned
This is the convention used in most parts of the kernel including DT
counterpart of I2C slave enumeration. To make things consistent do the same
for ACPI I2C slave enumeration path as well.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-13 10:23:22 +02:00
Charles Keepax 6ada5c1e1b i2c: Mark adapter devices with pm_runtime_no_callbacks
Commit 523c5b8964 ("i2c: Remove support for legacy PM") removed the PM
ops from the bus type, which causes the pm operations on the s3c2410
adapter device to fail (-ENOSUPP in rpm_callback). The adapter device
doesn't get bound to a driver and as such can't have its own pm_runtime
callbacks. Previously this was fine as the bus callbacks would have been
used, but now this can cause devices which use PM runtime and are
attached over I2C to fail to resume.

This commit fixes this issue by marking all adapter devices with
pm_runtime_no_callbacks, since they can't have any.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: Beata Michalska <b.michalska@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Fixes: 523c5b8964
Cc: stable@kernel.org
2015-04-23 19:35:31 +02:00
Mark Brown c1c21f4e60 i2c: core: Export bus recovery functions
Current -next fails to link an ARM allmodconfig because drivers that use
the core recovery functions can be built as modules but those functions
are not exported:

ERROR: "i2c_generic_gpio_recovery" [drivers/i2c/busses/i2c-davinci.ko] undefined!
ERROR: "i2c_generic_scl_recovery" [drivers/i2c/busses/i2c-davinci.ko] undefined!
ERROR: "i2c_recover_bus" [drivers/i2c/busses/i2c-davinci.ko] undefined!

Add exports to fix this.

Fixes: 5f9296ba21 (i2c: Add bus recovery infrastructure)
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-04-15 21:02:07 +02:00
Linus Torvalds 2481bc7528 Power management and ACPI updates for v4.1-rc1
- Generic PM domains support update including new PM domain
    callbacks to handle device initialization better (Russell King,
    Rafael J Wysocki, Kevin Hilman).
 
  - Unified device properties API update including a new mechanism
    for accessing data provided by platform initialization code
    (Rafael J Wysocki, Adrian Hunter).
 
  - ARM cpuidle update including ARM32/ARM64 handling consolidation
    (Daniel Lezcano).
 
  - intel_idle update including support for the Silvermont Core in
    the Baytrail SOC and for the Airmont Core in the Cherrytrail and
    Braswell SOCs (Len Brown, Mathias Krause).
 
  - New cpufreq driver for Hisilicon ACPU (Leo Yan).
 
  - intel_pstate update including support for the Knights Landing
    chip (Dasaratharaman Chandramouli, Kristen Carlson Accardi).
 
  - QorIQ cpufreq driver update (Tang Yuantian, Arnd Bergmann).
 
  - powernv cpufreq driver update (Shilpasri G Bhat).
 
  - devfreq update including Tegra support changes (Tomeu Vizoso,
    MyungJoo Ham, Chanwoo Choi).
 
  - powercap RAPL (Running-Average Power Limit) driver update
    including support for Intel Broadwell server chips (Jacob Pan,
    Mathias Krause).
 
  - ACPI device enumeration update related to the handling of the
    special PRP0001 device ID allowing DT-style 'compatible' property
    to be used for ACPI device identification (Rafael J Wysocki).
 
  - ACPI EC driver update including limited _DEP support (Lan Tianyu,
    Lv Zheng).
 
  - ACPI backlight driver update including a new mechanism to allow
    native backlight handling to be forced on non-Windows 8 systems
    and a new quirk for Lenovo Ideapad Z570 (Aaron Lu, Hans de Goede).
 
  - New Windows Vista compatibility quirk for Sony VGN-SR19XN (Chen Yu).
 
  - Assorted ACPI fixes and cleanups (Aaron Lu, Martin Kepplinger,
    Masanari Iida, Mika Westerberg, Nan Li, Rafael J Wysocki).
 
  - Fixes related to suspend-to-idle for the iTCO watchdog driver and
    the ACPI core system suspend/resume code (Rafael J Wysocki, Chen Yu).
 
  - PM tracing support for the suspend phase of system suspend/resume
    transitions (Zhonghui Fu).
 
  - Configurable delay for the system suspend/resume testing facility
    (Brian Norris).
 
  - PNP subsystem cleanups (Peter Huewe, Rafael J Wysocki).
 
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Merge tag 'pm+acpi-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI updates from Rafael Wysocki:
 "These are mostly fixes and cleanups all over, although there are a few
  items that sort of fall into the new feature category.

  First off, we have new callbacks for PM domains that should help us to
  handle some issues related to device initialization in a better way.

  There also is some consolidation in the unified device properties API
  area allowing us to use that inferface for accessing data coming from
  platform initialization code in addition to firmware-provided data.

  We have some new device/CPU IDs in a few drivers, support for new
  chips and a new cpufreq driver too.

  Specifics:

   - Generic PM domains support update including new PM domain callbacks
     to handle device initialization better (Russell King, Rafael J
     Wysocki, Kevin Hilman)

   - Unified device properties API update including a new mechanism for
     accessing data provided by platform initialization code (Rafael J
     Wysocki, Adrian Hunter)

   - ARM cpuidle update including ARM32/ARM64 handling consolidation
     (Daniel Lezcano)

   - intel_idle update including support for the Silvermont Core in the
     Baytrail SOC and for the Airmont Core in the Cherrytrail and
     Braswell SOCs (Len Brown, Mathias Krause)

   - New cpufreq driver for Hisilicon ACPU (Leo Yan)

   - intel_pstate update including support for the Knights Landing chip
     (Dasaratharaman Chandramouli, Kristen Carlson Accardi)

   - QorIQ cpufreq driver update (Tang Yuantian, Arnd Bergmann)

   - powernv cpufreq driver update (Shilpasri G Bhat)

   - devfreq update including Tegra support changes (Tomeu Vizoso,
     MyungJoo Ham, Chanwoo Choi)

   - powercap RAPL (Running-Average Power Limit) driver update including
     support for Intel Broadwell server chips (Jacob Pan, Mathias Krause)

   - ACPI device enumeration update related to the handling of the
     special PRP0001 device ID allowing DT-style 'compatible' property
     to be used for ACPI device identification (Rafael J Wysocki)

   - ACPI EC driver update including limited _DEP support (Lan Tianyu,
     Lv Zheng)

   - ACPI backlight driver update including a new mechanism to allow
     native backlight handling to be forced on non-Windows 8 systems and
     a new quirk for Lenovo Ideapad Z570 (Aaron Lu, Hans de Goede)

   - New Windows Vista compatibility quirk for Sony VGN-SR19XN (Chen Yu)

   - Assorted ACPI fixes and cleanups (Aaron Lu, Martin Kepplinger,
     Masanari Iida, Mika Westerberg, Nan Li, Rafael J Wysocki)

   - Fixes related to suspend-to-idle for the iTCO watchdog driver and
     the ACPI core system suspend/resume code (Rafael J Wysocki, Chen Yu)

   - PM tracing support for the suspend phase of system suspend/resume
     transitions (Zhonghui Fu)

   - Configurable delay for the system suspend/resume testing facility
     (Brian Norris)

   - PNP subsystem cleanups (Peter Huewe, Rafael J Wysocki)"

* tag 'pm+acpi-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (74 commits)
  ACPI / scan: Fix NULL pointer dereference in acpi_companion_match()
  ACPI / scan: Rework modalias creation when "compatible" is present
  intel_idle: mark cpu id array as __initconst
  powercap / RAPL: mark rapl_ids array as __initconst
  powercap / RAPL: add ID for Broadwell server
  intel_pstate: Knights Landing support
  intel_pstate: remove MSR test
  cpufreq: fix qoriq uniprocessor build
  ACPI / scan: Take the PRP0001 position in the list of IDs into account
  ACPI / scan: Simplify acpi_match_device()
  ACPI / scan: Generalize of_compatible matching
  device property: Introduce firmware node type for platform data
  device property: Make it possible to use secondary firmware nodes
  PM / watchdog: iTCO: stop watchdog during system suspend
  cpufreq: hisilicon: add acpu driver
  ACPI / EC: Call acpi_walk_dep_device_list() after installing EC opregion handler
  cpufreq: powernv: Report cpu frequency throttling
  intel_idle: Add support for the Airmont Core in the Cherrytrail and Braswell SOCs
  intel_idle: Update support for Silvermont Core in Baytrail SOC
  PM / devfreq: tegra: Register governor on module init
  ...
2015-04-14 20:21:54 -07:00
Linus Torvalds c3a416a669 Merge branch 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
 "Most notable:

   - introducing the i2c_quirk infrastructure.  Now, flaws of I2C
     controllers can be described and the core will check if the flaws
     collide with the messages to be sent

   - wait_for_completion return type cleanup series

   - new drivers for Digicolor, Netlogic XLP, Ingenic JZ4780

   - updates to the I2C slave framework which include API changes.  Its
     only user was updated, too.  Documentation was finally added

   - changed dynamic bus numbering for the DT case.  This could change
     bus numbers for users.  However, it fixes a collision where dynamic
     and static busses request the same id.

   - driver bugfixes, cleanups"

* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (52 commits)
  i2c: xlp9xx: Driver for Netlogic XLP9XX/5XX I2C controller
  of: Add vendor prefix 'netlogic'
  i2c: davinci: use ICPFUNC to toggle I2C as gpio for bus recovery
  i2c: davinci: use bus recovery infrastructure
  i2c: change input parameter to i2c_adapter for prepare/unprepare_recovery
  i2c: i2c-mux-gpio: remove error messages for probe deferrals
  i2c: jz4780: Add i2c bus controller driver for Ingenic JZ4780
  i2c: dln2: set the device tree node of the adapter
  i2c: davinci: fixup wait_for_completion_timeout handling
  i2c: mpc: Fix ISR return value
  i2c: slave-eeprom: add more info when to increase the pointer
  i2c: slave: add documentation for i2c-slave-eeprom
  Documentation: i2c: describe the new slave mode
  i2c: slave: rework the slave API
  i2c: add support for the Digicolor I2C controller
  i2c: busses with dynamic ids should start after fixed ids for DT
  of: base: add function to get highest id of an alias stem
  i2c: designware: Suppress error message if platform_get_irq() < 0
  i2c: mpc: assign the correct prescaler from SVR
  i2c: img-scb: fixup of wait_for_completion_timeout return handling
  ...
2015-04-14 18:10:45 -07:00
Grygorii Strashko 2b2190a375 i2c: change input parameter to i2c_adapter for prepare/unprepare_recovery
This patch changes type of input parameter for
prepare/unprepare_recovery() callbacks from struct i2c_bus_recovery_info
* to struct i2c_adapter *. This allows to simplify implementation of
these callbacks and avoid type conversations from i2c_bus_recovery_info
to i2c_adapter. The i2c_bus_recovery_info can be simply retrieved from
struct i2c_adapter which contains pointer on it. There are no users
currently, so this is safe to do.

Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-04-10 17:54:31 +02:00
Wolfram Sang 03bde7c31a i2c: busses with dynamic ids should start after fixed ids for DT
Make sure dynamic ids do not interfere with fixed ones and let them
start after the highest fixed id. This patch might cause different
bus-numbers than before for dynamic ids, however it fixes a bug. Assume:

- fixed id0 defers probe
- fixed id1 succeeds and registers a muxed bus with dynamic id
- muxed bus gets id0
- fixed id0 wants to probe again, but its fixed id is gone now
- fixed id0 probe fails

With this patch, the fixed ids are always reserved in the DT case.
For legacy board init, we already have a mechanism like this in
i2c_register_board_info().

Reported-by: Bob Feretich <bob.feretich@rafresearch.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-03-18 13:42:14 +01:00
Rafael J. Wysocki ce793486e2 driver core / ACPI: Represent ACPI companions using fwnode_handle
Now that we have struct fwnode_handle, we can use that to point to
ACPI companions from struct device objects instead of pointing to
struct acpi_device directly.

There are two benefits from that.  First, the somewhat ugly and
hackish struct acpi_dev_node can be dropped and, second, the same
struct fwnode_handle pointer can be used in the future to point
to other (non-ACPI) firmware device node types.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Grant Likely <grant.likely@linaro.org>
2015-03-16 23:49:03 +01:00
Wolfram Sang b7f6258402 i2c: add quirk checks to core
Let the core do the checks if HW quirks prevent a transfer. Saves code
from drivers and adds consistency.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Ray Jui <rjui@broadcom.com>
Tested-by: Ivan T. Ivanov <iivanov@mm-sol.com>
Tested-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com>
Tested-By: Ludovic Desroches <ludovic.desroches@atmel.com>
2015-03-13 15:10:44 +01:00
Jakub Kicinski a494457270 Revert "i2c: core: Dispose OF IRQ mapping at client removal time"
This reverts commit e4df3a0b62
("i2c: core: Dispose OF IRQ mapping at client removal time")

Calling irq_dispose_mapping() will destroy the mapping and disassociate
the IRQ from the IRQ chip to which it belongs. Keeping it is OK, because
existent mappings are reused properly.

Also, this commit breaks drivers using devm* for IRQ management on
OF-based systems because devm* cleanup happens in device code, after
bus's remove() method returns.

Signed-off-by: Jakub Kicinski <kubakici@wp.pl>
Reported-by: Sébastien Szymanski <sebastien.szymanski@armadeus.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
[wsa: updated the commit message with findings fromt the other bug report]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
Fixes: e4df3a0b62
2015-03-12 10:23:05 +01:00
Linus Torvalds 295324556c Merge branch 'i2c/for-3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
 "Summary:

   - legacy PM code removed from the core, there were no users anymore
     (thanks to Lars-Peter Clausen)

   - new driver for Broadcom iProc

   - bigger driver updates for designware, rk3x, cadence, ocores

   - a bunch of smaller updates and bugfixes"

* 'i2c/for-3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (31 commits)
  i2c: ocores: rework clk code to handle NULL cookie
  i2c: designware-baytrail: another fixup for proper Kconfig dependencies
  i2c: fix reference to functionality constants definition
  i2c: iproc: Add Broadcom iProc I2C Driver
  i2c: designware-pci: update Intel copyright line
  i2c: ocores: add common clock support
  i2c: hix5hd2: add COMPILE_TEST
  i2c: clarify comments about the dev_released completion
  i2c: ocores: fix clock-frequency binding usage
  i2c: tegra: Maintain CPU endianness
  i2c: designware-baytrail: use proper Kconfig dependencies
  i2c: designware: Do not calculate SCL timing parameters needlessly
  i2c: do not try to load modules for of-registered devices
  i2c: designware: Add Intel Baytrail PMIC I2C bus support
  i2c: designware: Add i2c bus locking support
  of: i2c: Add i2c-mux-idle-disconnect DT property to PCA954x mux driver
  i2c: designware: use {readl|writel}_relaxed instead of readl/writel
  i2c: designware-pci: no need to provide clk_khz
  i2c: designware-pci: remove Moorestown support
  i2c: imx: whitespace and checkpatch cleanup
  ...
2015-02-21 12:41:50 -08:00
Wolfram Sang 26680ee279 i2c: clarify comments about the dev_released completion
There was quite some confusion why this completion is there and if it is
still necessary. Sadly, it is. However, let's improve the comments and
share what we rediscovered.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-02-05 22:29:21 +01:00